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Sample records for ammonium thiocyanate-induced dermo-epidermal

  1. Characterization of pigmented dermo-epidermal skin substitutes in a long-term in vivo assay.

    PubMed

    Böttcher-Haberzeth, Sophie; Biedermann, Thomas; Klar, Agnieszka S; Widmer, Daniel S; Neuhaus, Kathrin; Schiestl, Clemens; Meuli, Martin; Reichmann, Ernst

    2015-01-01

    In our laboratory, we have been using human pigmented dermo-epidermal skin substitutes for short-term experiments since several years. Little is known, however, about the long-term biology of such constructs after transplantation. We constructed human, melanocyte-containing dermo-epidermal skin substitutes of different (light and dark) pigmentation types and studied them in a long-term animal experiment. Developmental and maturational stages of the epidermal and dermal compartment as well as signs of homoeostasis were analysed 15 weeks after transplantation. Keratinocytes, melanocytes and fibroblasts from human skin biopsies were isolated and assembled into dermo-epidermal skin substitutes. These were transplanted onto immuno-incompetent rats and investigated 15 weeks after transplantation. Chromameter evaluation showed a consistent skin colour between 3 and 4 months after transplantation. Melanocytes resided in the epidermal basal layer in physiological numbers and melanin accumulated in keratinocytes in a supranuclear position. Skin substitutes showed a mature epidermis in a homoeostatic state and the presence of dermal components such as Fibrillin and Tropoelastin suggested advanced maturation. Overall, pigmented dermo-epidermal skin substitutes show a promising development towards achieving near-normal skin characteristics and epidermal and dermal tissue homoeostasis. In particular, melanocytes function correctly over several months whilst remaining in a physiological, epidermal position and yield a pigmentation resembling original donor skin colour.

  2. Diffuse cutaneous bullous mastocytosis with IgM deposits at dermo-epidermal junction.

    PubMed

    Slavescu, Kinga Cristina; Chiorean, Roxana; Danescu, Sorina; Bota, Madalina; Rogojan, Liliana; Baican, Adrian

    2016-03-01

    Cutaneous mastocytosis is a disease characterized by the infiltration and proliferation of mast cells in the skin. In children, the most common form of presentation is urticaria pigmentosa, while the diffuse cutaneous bullous mastocytosis is one of the rarest subtypes seen. The aim of this paper is to present a case of diffuse bullous mastocytosis with detection of IgM deposits at dermo-epidermal junction using direct immunofluorescence (DIF) microscopy. The diagnosis of diffuse bullous mastocytosis is a challenge, and DIF microscopy is necessary in order to exclude an autoimmune bullous disorder. However, IgM deposits at dermo-epidermal junction can be nonspecific, being found in a variety of skin disorders. A 6-month-old girl presented with bullous lesions and erosions on the scalp and the trunk. During hospitalization, further bullous lesions appeared, along with generalized erythrodermia. Skin biopsy revealed aspects of urticaria pigmentosa. Taking into account the clinical findings, the case was enclosed as bullous mastocytosis. Treatment included the avoidance of trigger factors, and administration of antihistamines along with a short-term course of systemic steroids. The evolution was favorable, with remission of the existing lesions and without occurrence of new ones.

  3. Tissue-engineered dermo-epidermal skin grafts prevascularized with adipose-derived cells.

    PubMed

    Klar, Agnieszka S; Güven, Sinan; Biedermann, Thomas; Luginbühl, Joachim; Böttcher-Haberzeth, Sophie; Meuli-Simmen, Claudia; Meuli, Martin; Martin, Ivan; Scherberich, Arnaud; Reichmann, Ernst

    2014-06-01

    The major problem in skin grafting is that tissue-engineered skin grafts after their transplantation are initially entirely dependent on diffusion. Since this process is slow and inefficient, nutrients, growth factors, and oxygen will insufficiently be supplied and the regenerating graft will undergo a physiological crisis, resulting in scar-like dermal structures and shrinkage. The tissue-engineering of a vascular network in human dermo-epidermal skin substitutes (DESS) is a promising approach to overcome this limitation. Here we report, for the first time, on the use of the adipose stromal vascular fraction (SVF)-derived endothelial cell population to tissue-engineer DESS containing a highly efficient capillary plexus. To develop vascular networks in vitro, we employed optimized 3D fibrin or collagen type I hydrogel systems. Upon transplantation onto immune-deficient rats, these pre-formed vascular networks anastomosed to the recipient's vasculature within only four days. As a consequence, the neo-epidermis efficiently established tissue homeostasis, the dermis underwent almost no contraction, and showed sustained epidermal coverage in vivo. Overall, the here described rapid and efficient perfusion of SVF-based skin grafts opens new perspectives for the treatment of hitherto unmet clinical needs in burn/plastic surgery and dermatology.

  4. Cross-linking of the dermo-epidermal junction of skin regenerating from keratinocyte autografts. Anchoring fibrils are a target for tissue transglutaminase.

    PubMed

    Raghunath, M; Höpfner, B; Aeschlimann, D; Lüthi, U; Meuli, M; Altermatt, S; Gobet, R; Bruckner-Tuderman, L; Steinmann, B

    1996-09-01

    Since transglutaminases create covalent gamma-glutamyl-epsilon-lysine cross-links between extracellular matrix proteins they are prime candidates for stabilizing tissue during wound healing. Therefore, we studied the temporo-spatial expression of transglutaminase activity in skin regenerating from cultured epithelial autografts in severely burned children by the specific incorporation of monodansylcadaverine into cryostat sections from skin biopsies obtained between 5 d to 17 mo after grafting. The dansyl label was subsequently immunolocalized in the epidermis, dermal connective tissue, and along the basement membrane. Incubation of cryosections of normal and regenerating skin with purified tissue transglutaminase confirmed the dermo-epidermal junction and the papillary dermis as targets for this enzyme and revealed that in regenerating skin transamidation of the basement membrane zone was completed only 4-5 mo after grafting. Immunoelectron microscopy revealed that three distinct regions on the central portion of anchoring fibrils were positive for monodansylcadaverine in normal skin which were negative during the initial phase of de novo formation of anchoring fibrils in regenerating skin. Biochemically, we identified collagen VII as potential substrate for tissue transglutaminase. Thus, tissue transglutaminase appears to play an important role not only in cross-linking of the papillary dermis but also of the dermo-epidermal junction in particular.

  5. Aging decreases collagen IV expression in vivo in the dermo-epidermal junction and in vitro in dermal fibroblasts: possible involvement of TGF-β1.

    PubMed

    Feru, Jezabel; Delobbe, Etienne; Ramont, Laurent; Brassart, Bertrand; Terryn, Christine; Dupont-Deshorgue, Aurelie; Garbar, Christian; Monboisse, Jean-Claude; Maquart, Francois-Xavier; Brassart-Pasco, Sylvie

    2016-08-01

    Collagen IV is a major component of the dermo-epidermal junction (DEJ). To study expression of collagen IV upon aging in the DEJ and dermal fibroblasts isolated from the same patients. A model of senescent fibroblasts was developed in order to identify biological compounds that might restore the level of collagen IV. Skin fragments of women (30 to 70 years old) were collected. Localisation of collagen IV expression in the DEJ was studied by immunofluorescence. Fibroblast collagen IV expression was studied by real-time PCR, ELISA, and western blotting. Premature senescence was simulated by exposing fibroblasts to subcytotoxic H2O2 concentrations. Collagen IV decreased in the DEJ and fibroblasts relative to age. TGF-β1 treatment significantly increased collagen IV gene and protein expression in fibroblasts and restored expression in the model of senescence. Addition of TGF-β1-neutralizing antibody to fibroblast cultures decreased collagen IV expression. Taken together, the results suggest that the decrease in collagen IV in the DEJ, relative to age, could be due to a decrease in collagen IV expression by senescent dermal fibroblasts and may involve TGF-β1 signalling.

  6. Evaluation of cultured human dermal- and dermo-epidermal substitutes focusing on extracellular matrix components: Comparison of protein and RNA analysis.

    PubMed

    Oostendorp, Corien; Meyer, Sarah; Sobrio, Monia; van Arendonk, Joyce; Reichmann, Ernst; Daamen, Willeke F; van Kuppevelt, Toin H

    2017-05-01

    Treatment of full-thickness skin defects with split-thickness skin grafts is generally associated with contraction and scar formation and cellular skin substitutes have been developed to improve skin regeneration. The evaluation of cultured skin substitutes is generally based on qualitative parameters focusing on histology. In this study we focused on quantitative evaluation to provide a template for comparison of human bio-engineered skin substitutes between clinical and/or research centers, and to supplement histological data. We focused on extracellular matrix proteins since these components play an important role in skin regeneration. As a model we analyzed the human dermal substitute denovoDerm and the dermo-epidermal skin substitute denovoSkin. The quantification of the extracellular matrix proteins type III collagen and laminin 5 in tissue homogenates using western blotting analysis and ELISA was not successful. The same was true for assaying lysyl oxidase, an enzyme involved in crosslinking of matrix molecules. As an alternative, gene expression levels were measured using qPCR. Various RNA isolation procedures were probed. The gene expression profile for specific dermal and epidermal genes could be measured reliably and reproducibly. Differences caused by changes in the cell culture conditions could easily be detected. The number of cells in the skin substitutes was measured using the PicoGreen dsDNA assay, which was found highly quantitative and reproducible. The (dis) advantages of assays used for quantitative evaluation of skin substitutes are discussed.

  7. Construction of three-dimensional dermo-epidermal skin equivalents using cell coating technology and their utilization as alternative skin for permeation studies and skin irritation tests.

    PubMed

    Akagi, Takami; Nagura, Mayuka; Hiura, Ayami; Kojima, Hajime; Akashi, Mitsuru

    2017-03-23

    In vitro generated human skin equivalents are generating interest as promising tools in basic research, as alternatives to animal testing and for clinical applications in regenerative medicine. For prediction of skin irritation and corrosion, three-dimensional (3D) human skin equivalents consisting of differentiated human keratinocytes have been developed and some models have been internationally accepted. However, more delicate assessments using full-thickness skin models, such as skin sensitization tests cannot be performed because of the lack of a dermis containing fibroblasts or appendages. In a previous study, we developed dermo-epidermal human skin equivalents (DESEs) using a cell coating technique, which employs cell surface coating by layer-by-layer (LbL) assembled extracellular matrix (ECM) films. The DESEs with dermis consisting of normal human dermal fibroblasts (NHDF) and epidermis consisting of human keratinocytes (KC) were easily fabricated by using this technology. In this study, the constructed DESEs were evaluated as an alternative skin for skin permeation and irritation tests. A good relationship of permeability coefficient of chemicals was observed between the DESEs and human skin data. We investigated whether the DESEs, a new in vitro skin model, are able to identify skin irritant and non-irritant substances among 20 reference chemicals. It was confirmed that the DESEs are applicable to skin irritation testing as defined in the European Centre for the Validation of Alternative Methods (ECVAM) Performance Standard (OECD Test Guideline 439). We further studied the construction of the DESEs with density-controlled blood capillary networks using human umbilical vein endothelial cells (HUVEC). The results suggest that DESEs allowing incorporation of skin appendages are more promising alternatives to animal testing, and can be applied to the design of physiologically relevant in vitro skin models.

  8. Ammonium methacrylate

    Integrated Risk Information System (IRIS)

    Ammonium methacrylate ; CASRN 16325 - 47 - 6 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 Noncarcin

  9. Ammonium sulfamate

    Integrated Risk Information System (IRIS)

    Ammonium sulfamate ; CASRN 7773 - 06 - 0 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 Noncarcinogen

  10. Ammonium acetate

    Integrated Risk Information System (IRIS)

    Ammonium acetate ; CASRN 631 - 61 - 8 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

  11. Human eccrine sweat gland cells turn into melanin-uptaking keratinocytes in dermo-epidermal skin substitutes.

    PubMed

    Böttcher-Haberzeth, Sophie; Biedermann, Thomas; Pontiggia, Luca; Braziulis, Erik; Schiestl, Clemens; Hendriks, Bart; Eichhoff, Ossia M; Widmer, Daniel S; Meuli-Simmen, Claudia; Meuli, Martin; Reichmann, Ernst

    2013-02-01

    Recently, Biedermann et al. (2010) have demonstrated that human eccrine sweat gland cells can develop a multilayered epidermis. The question still remains whether these cells can fulfill exclusive and very specific functional properties of epidermal keratinocytes, such as the incorporation of melanin, a feature absent in sweat gland cells. We added human melanocytes to eccrine sweat gland cells to let them develop into an epidermal analog in vivo. The interaction between melanocytes and sweat gland-derived keratinocytes was investigated. The following results were gained: (1) macroscopically, a pigmentation of the substitutes was seen 2-3 weeks after transplantation; (2) we confirmed the development of a multilayered, stratified epidermis with melanocytes distributed evenly throughout the basal layer; (3) melanocytic dendrites projected to suprabasal layers; and (4) melanin was observed to be integrated into former eccrine sweat gland cells. These skin substitutes were similar or equal to skin substitutes cultured from human epidermal keratinocytes. The only differences observed were a delay in pigmentation and less melanin uptake. These data suggest that eccrine sweat gland cells can form a functional epidermal melanin unit, thereby providing striking evidence that they can assume one of the most characteristic keratinocyte properties.

  12. Insensitive Ammonium Nitrate.

    DTIC Science & Technology

    is reduced by replacing the ammonium nitrate with a solid solution of potassium nitrate in form III ammonium nitrate wherein the potassium nitrate...constitutes from more than zero to less than 50 weight percent of the solid solution . (Author)

  13. Ammonium nitrate explosive systems

    DOEpatents

    Stinecipher, Mary M.; Coburn, Michael D.

    1981-01-01

    Novel explosives which comprise mixtures of ammonium nitrate and an ammonium salt of a nitroazole in desired ratios are disclosed. A preferred nitroazole is 3,5-dinitro-1,2,4-triazole. The explosive and physical properties of these explosives may readily be varied by the addition of other explosives and oxidizers. Certain of these mixtures have been found to act as ideal explosives.

  14. 70. INTERIOR VIEW OF AMMONIUM NITRATE HOUSE, LOOKING AT AMMONIUM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    70. INTERIOR VIEW OF AMMONIUM NITRATE HOUSE, LOOKING AT AMMONIUM NITRATE IN STORAGE. APRIL 18, 1919. - United States Nitrate Plant No. 2, Reservation Road, Muscle Shoals, Muscle Shoals, Colbert County, AL

  15. Glufosinate-ammonium

    Integrated Risk Information System (IRIS)

    Glufosinate - ammonium ; CASRN 77182 - 82 - 2 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 Noncarci

  16. Acute ammonium dichromate poisoning.

    PubMed

    Meert, K L; Ellis, J; Aronow, R; Perrin, E

    1994-10-01

    We report the ingestion of ammonium dichromate by a child that resulted in multiple-organ-system failure and death. Exchange transfusion and hemodialysis were ineffective in removing significant amounts of chromium or causing sustained clinical improvement. We suggest that immediate, large doses of the reducing agent ascorbic acid would allow effective reduction of hexavalent chromium with less cellular toxicity.

  17. Ammonium imidazolium dichromate.

    PubMed

    Zhu, Run-Qiang

    2012-04-01

    In the crystal structure of the title compound, (C(3)H(5)N(2))(NH(4))[Cr(2)O(7)], the anions and cations are linked through N-H⋯O hydrogen bonds, resulting in a three-dimensional structure which contains three kinds of layers parallel to (001). One layer contains imidazole cations, the other two layers the ammonium cations and dichromate anions. The dichromate anion has an eclipsed conformation with a dihedral angle of 14.65 (18)° between the mean planes of the O-P-O-P-O backbone.

  18. Hydrothermal synthesis of ammonium illite

    USGS Publications Warehouse

    Sucha, V.; Elsass, F.; Eberl, D.D.; Kuchta, L'.; Madejova, J.; Gates, W.P.; Komadel, P.

    1998-01-01

    Synthetic gel and glass of illitic composition, natural kaolinite, and mixed-layer illite-smectite were used as starting materials for hydrothermal synthesis of ammonium illite. Ammonium illite was prepared from synthetic gel by hydrothermal treatment at 300??C. The onset of crystallization began within 3 h, and well-crystallized ammonium illite appeared at 24 h. Increasing reaction time (up to four weeks) led to many illite layers per crystal. In the presence of equivalent proportions of potassium and ammonium, the gel was transformed to illite with equimolar contents of K and NH4. In contrast, synthesis using glass under the same conditions resulted in a mixture of mixed-layer ammonium illite-smectite with large expandability and discrete illite. Hydrothermal treatments of the fine fractions of natural kaolinite and illite-smectite produced ammonium illite from kaolinite but the illite-smectite remained unchanged.

  19. Toxicokinetics of ammonium perfluorohexanoate.

    PubMed

    Iwai, Hiroyuki

    2011-10-01

    Excretion patterns and rates of ammonium perfluorohexanoate (APFHx) after administration of a single and multiple (14 days) oral dose(s) at 50 mg/kg to male and female mice and rats were examined. The test substance was [(14)C]-labeled APFHx. After a single oral administration, total excretion was rapid, with mean recoveries of over 90% of the dose at 24 hours after administration, irrespective of gender or species. The major route of elimination was via the urine (means of percentage recovery between 73.0 and 90.2% of the dose), followed by the feces (means of percentage recovery between 7.0 and 15.5% of the dose). Elimination via expired air was negligible. For the multiple dose tests, multiple (13 daily doses) oral administration of APFHx was followed by a single oral administration of [(14)C]-APFHx. Excretion was rapid, with mean recoveries of over 90% of the administered dose (mean values >95% of the ultimately recovered material) at 24 hours after dosing, irrespective of gender or species. The major route of elimination was via the urine (means of percentage recovery between 77.8 and 83.4% of the dose), followed by the feces (means of percentage recovery between 9.6 and 12.9% of the dose).

  20. High performance ammonium nitrate propellant

    NASA Technical Reports Server (NTRS)

    Anderson, F. A. (Inventor)

    1979-01-01

    A high performance propellant having greatly reduced hydrogen chloride emission is presented. It is comprised of: (1) a minor amount of hydrocarbon binder (10-15%), (2) at least 85% solids including ammonium nitrate as the primary oxidizer (about 40% to 70%), (3) a significant amount (5-25%) powdered metal fuel, such as aluminum, (4) a small amount (5-25%) of ammonium perchlorate as a supplementary oxidizer, and (5) optionally a small amount (0-20%) of a nitramine.

  1. 21 CFR 184.1138 - Ammonium chloride.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... GRAS § 184.1138 Ammonium chloride. (a) Ammonium chloride (NH4Cl, CAS Reg. No. 12125-02-9) is produced by the reaction of sodium chloride and an ammonium salt in solution. The less soluble sodium salt... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ammonium chloride. 184.1138 Section 184.1138...

  2. 46 CFR 148.205 - Ammonium nitrate and ammonium nitrate fertilizers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Ammonium nitrate and ammonium nitrate fertilizers. 148... Materials § 148.205 Ammonium nitrate and ammonium nitrate fertilizers. (a) This section applies to the stowage and transportation in bulk of ammonium nitrate and the following fertilizers composed of...

  3. 46 CFR 148.205 - Ammonium nitrate and ammonium nitrate fertilizers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Ammonium nitrate and ammonium nitrate fertilizers. 148... Materials § 148.205 Ammonium nitrate and ammonium nitrate fertilizers. (a) This section applies to the stowage and transportation in bulk of ammonium nitrate and the following fertilizers composed of...

  4. 46 CFR 148.205 - Ammonium nitrate and ammonium nitrate fertilizers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Ammonium nitrate and ammonium nitrate fertilizers. 148... Materials § 148.205 Ammonium nitrate and ammonium nitrate fertilizers. (a) This section applies to the stowage and transportation in bulk of ammonium nitrate and the following fertilizers composed of...

  5. 46 CFR 148.205 - Ammonium nitrate and ammonium nitrate fertilizers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Ammonium nitrate and ammonium nitrate fertilizers. 148... Materials § 148.205 Ammonium nitrate and ammonium nitrate fertilizers. (a) This section applies to the stowage and transportation in bulk of ammonium nitrate and the following fertilizers composed of...

  6. TREATMENT OF AMMONIUM NITRATE SOLUTIONS

    DOEpatents

    Boyer, T.W.; MacHutchin, J.G.; Yaffe, L.

    1958-06-10

    The treatment of waste solutions obtained in the processing of neutron- irradiated uranium containing fission products and ammonium nitrate is described. The object of this process is to provide a method whereby the ammonium nitrate is destroyed and removed from the solution so as to permit subsequent concentration of the solution.. In accordance with the process the residual nitrate solutions are treated with an excess of alkyl acid anhydride, such as acetic anhydride. Preferably, the residual nitrate solution is added to an excess of the acetic anhydride at such a rate that external heat is not required. The result of this operation is that the ammonium nitrate and acetic anhydride react to form N/sub 2/ O and acetic acid.

  7. Benzylic Ammonium Ylide Mediated Epoxidations

    PubMed Central

    Roiser, Lukas; Robiette, Raphaël; Waser, Mario

    2016-01-01

    A high yielding synthesis of stilbene oxides using ammonium ylides has been developed. It turned out that the amine leaving group plays a crucial role as trimethylamine gives higher yields than DABCO or quinuclidine. The amine group also influences the diastereoselectivity, and detailed DFT calculations to understand the key parameters of these reactions have been carried out. PMID:27766017

  8. 21 CFR 582.7133 - Ammonium alginate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ammonium alginate. 582.7133 Section 582.7133 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Ammonium alginate. (a) Product. Ammonium alginate. (b) Conditions of use. This substance is...

  9. 21 CFR 582.1141 - Ammonium phosphate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ammonium phosphate. 582.1141 Section 582.1141 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1141 Ammonium phosphate. (a) Product. Ammonium phosphate (mono- and dibasic). (b)...

  10. 21 CFR 582.1141 - Ammonium phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Ammonium phosphate. 582.1141 Section 582.1141 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1141 Ammonium phosphate. (a) Product. Ammonium phosphate (mono- and dibasic). (b)...

  11. 21 CFR 582.1141 - Ammonium phosphate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Ammonium phosphate. 582.1141 Section 582.1141 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1141 Ammonium phosphate. (a) Product. Ammonium phosphate (mono- and dibasic). (b)...

  12. 21 CFR 582.1141 - Ammonium phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Ammonium phosphate. 582.1141 Section 582.1141 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1141 Ammonium phosphate. (a) Product. Ammonium phosphate (mono- and dibasic). (b)...

  13. 21 CFR 582.1141 - Ammonium phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Ammonium phosphate. 582.1141 Section 582.1141 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1141 Ammonium phosphate. (a) Product. Ammonium phosphate (mono- and dibasic). (b)...

  14. 21 CFR 184.1143 - Ammonium sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ammonium sulfate. 184.1143 Section 184.1143 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Specific Substances Affirmed as GRAS § 184.1143 Ammonium sulfate. (a) Ammonium sulfate ((NH4)2SO4, CAS...

  15. 21 CFR 582.1143 - Ammonium sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Ammonium sulfate. 582.1143 Section 582.1143 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1143 Ammonium sulfate. (a) Product. Ammonium sulfate. (b) Conditions of use. This...

  16. 21 CFR 582.1143 - Ammonium sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Ammonium sulfate. 582.1143 Section 582.1143 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1143 Ammonium sulfate. (a) Product. Ammonium sulfate. (b) Conditions of use. This...

  17. 21 CFR 582.1143 - Ammonium sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Ammonium sulfate. 582.1143 Section 582.1143 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1143 Ammonium sulfate. (a) Product. Ammonium sulfate. (b) Conditions of use. This...

  18. 21 CFR 184.1143 - Ammonium sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ammonium sulfate. 184.1143 Section 184.1143 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DIRECT... GRAS § 184.1143 Ammonium sulfate. (a) Ammonium sulfate ((NH4)2SO4, CAS Reg. No. 7783-20-2)...

  19. 21 CFR 184.1143 - Ammonium sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ammonium sulfate. 184.1143 Section 184.1143 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Specific Substances Affirmed as GRAS § 184.1143 Ammonium sulfate. (a) Ammonium sulfate ((NH4)2SO4, CAS...

  20. 21 CFR 184.1143 - Ammonium sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ammonium sulfate. 184.1143 Section 184.1143 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Specific Substances Affirmed as GRAS § 184.1143 Ammonium sulfate. (a) Ammonium sulfate ((NH4)2SO4, CAS...

  1. 21 CFR 582.1143 - Ammonium sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Ammonium sulfate. 582.1143 Section 582.1143 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1143 Ammonium sulfate. (a) Product. Ammonium sulfate. (b) Conditions of use. This...

  2. 21 CFR 582.1143 - Ammonium sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ammonium sulfate. 582.1143 Section 582.1143 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1143 Ammonium sulfate. (a) Product. Ammonium sulfate. (b) Conditions of use. This...

  3. 21 CFR 184.1138 - Ammonium chloride.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    .... No. 12125-02-9) is produced by the reaction of sodium chloride and an ammonium salt in solution. The less soluble sodium salt separates out at elevated temperatures, and ammonium chloride is recovered... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ammonium chloride. 184.1138 Section 184.1138...

  4. 21 CFR 184.1138 - Ammonium chloride.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    .... No. 12125-02-9) is produced by the reaction of sodium chloride and an ammonium salt in solution. The less soluble sodium salt separates out at elevated temperatures, and ammonium chloride is recovered... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ammonium chloride. 184.1138 Section 184.1138...

  5. 21 CFR 184.1138 - Ammonium chloride.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .... No. 12125-02-9) is produced by the reaction of sodium chloride and an ammonium salt in solution. The less soluble sodium salt separates out at elevated temperatures, and ammonium chloride is recovered... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ammonium chloride. 184.1138 Section 184.1138...

  6. 21 CFR 184.1138 - Ammonium chloride.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    .... No. 12125-02-9) is produced by the reaction of sodium chloride and an ammonium salt in solution. The less soluble sodium salt separates out at elevated temperatures, and ammonium chloride is recovered... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ammonium chloride. 184.1138 Section 184.1138...

  7. Extraction of urea and ammonium ion

    NASA Technical Reports Server (NTRS)

    Anselmi, R. T.; Husted, R. R.; Schulz, J. R.

    1977-01-01

    Water purification system keeps urea and ammonium ion concentration below toxic limits in recirculated water of closed loop aquatic habitat. Urea is first converted to ammonium ions and carbon dioxide by enzygmatic action. Ammonium ions are removed by ion exchange. Bioburden is controlled by filtration through 0.45 micron millipore filters.

  8. 76 FR 70366 - Ammonium Nitrate Security Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-14

    ... SECURITY Office of the Secretary 6 CFR Part 31 RIN 1601-AA52 Ammonium Nitrate Security Program AGENCY... ``Ammonium Nitrate Security Program,'' which was published in the Federal Register on August 3, 2011. The... 62311). Under the proposed Ammonium Nitrate Security Program, the DHS will regulate the sale...

  9. 76 FR 62311 - Ammonium Nitrate Security Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-07

    ...; ] DEPARTMENT OF HOMELAND SECURITY Office of the Secretary 6 CFR Part 31 RIN 1601-AA52 Ammonium Nitrate Security...), entitled ``Ammonium Nitrate Security Program,'' which was published in the Federal Register on August 3... of ammonium nitrate pursuant to section 563 of the Fiscal Year 2008 Department of Homeland...

  10. 76 FR 11273 - Ammonium Nitrate From Russia

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-01

    ... COMMISSION Ammonium Nitrate From Russia AGENCY: United States International Trade Commission. ACTION: Institution of a five-year review concerning the suspended investigation on ammonium nitrate from Russia... investigation on ammonium nitrate from Russia would be likely to lead to continuation or recurrence of...

  11. 76 FR 47238 - Ammonium Nitrate From Russia

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-04

    ... COMMISSION Ammonium Nitrate From Russia Determination On the basis of the record \\1\\ developed in the subject... order on ammonium nitrate from Russia would be likely to lead to continuation or recurrence of material... Commission are contained in USITC Publication 4249 (August 2011), entitled Ammonium Nitrate from...

  12. 21 CFR 556.375 - Maduramicin ammonium.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... residues of maduramicin ammonium in chickens as follows: (a) A tolerance for maduramicin ammonium (marker residue) in chickens is 0.38 parts per million in fat (target tissue). A tolerance refers to the... animals. (b) The safe concentrations for total maduramicin ammonium residues in uncooked edible...

  13. Phase diagram of ammonium nitrate

    NASA Astrophysics Data System (ADS)

    Dunuwille, M.; Yoo, C. S.

    2014-05-01

    Ammonium Nitrate (AN) has often subjected to uses in improvised explosive devices, due to its wide availability as a fertilizer and its capability of becoming explosive with slight additions of organic and inorganic compounds. Yet, the origin of enhanced energetic properties of impure AN (or AN mixtures) is neither chemically unique nor well understood -resulting in rather catastrophic disasters in the past1 and thereby a significant burden on safety in using ammonium nitrates even today. To remedy this situation, we have carried out an extensive study to investigate the phase stability of AN at high pressure and temperature, using diamond anvil cells and micro-Raman spectroscopy. The present results confirm the recently proposed phase IV-to-IV' transition above 17 GPa2 and provide new constraints for the melting and phase diagram of AN to 40 GPa and 400 °C.

  14. Structural study of ammonium metatungstate

    SciTech Connect

    Christian, Joel B. Whittingham, M. Stanley

    2008-08-15

    Several techniques have been used to study the structure of the Keggin-type polyoxometalate salt ammonium metatungstate (AMT)-(NH{sub 4}){sub 6}[H{sub 2}W{sub 12}O{sub 40}]*nH{sub 2}O, a potential fuel cell catalyst. The dehydrated salt is comprised of a mixture of crystallites of different unit cells in a centered eutactic cubic configuration, with an average unit cell of a{approx_equal}12.295. Varied orientations of the Keggin ions in the cubic arrangement create the differences, and orientational variation within each unit cell size represents an energy well. Progressive hydration of each crystallite leads to expansion of the lattice, with the degree of expansion depending on the locations of the water added in relation to the Keggin ion, which is influenced by cation location and hydrogen bonding. The structural hypothesis is supported by electron diffraction of single and multicrystal samples, by powder density measurements, X-ray powder diffraction studies, synchrotron powder X-ray diffraction, and a priori structural modeling studies. Based on the structure, projected active site densities are compared with nanostructured platinum catalysts for fuel cell application. - Graphical abstract: The structure of ammonium metatungstate powders are highly dependent on hydration and POM molecule rotation, with cation and hydrogen bonding forces directing a mixture of structures that have been studied with bulk and single-crystal methods. The illustration shows Monte Carlo simulated anion structural disorder for the fully dehydrated form of the title compound.

  15. Phase Diagram of Ammonium Nitrate

    NASA Astrophysics Data System (ADS)

    Dunuwille, Mihindra; Yoo, Choong-Shik

    2013-06-01

    Ammonium Nitrate (AN) has often been subjected to uses in improvised explosive devices, due to its wide availability as a fertilizer and its capability of becoming explosive with slight additions of organic and inorganic compounds. Yet, the origin of enhanced energetic properties of impure AN (or AN mixtures) is neither chemically unique nor well understood - resulting in rather catastrophic disasters in the past1 and thereby a significant burden on safety, in using ammonium nitrates even today. To remedy this situation, we have carried out an extensive study to investigate the phase stability of AN, in different chemical environments, at high pressure and temperature, using diamond anvil cells and micro-Raman spectroscopy. The present results confirm the recently proposed phase IV-to-IV' transition above 15 GPa2 and provide new constraints for the melting and phase diagram of AN to 40 GPa and 673 K. The present study has been supported by the U.S. DHS under Award Number 2008-ST-061-ED0001.

  16. 33 CFR 126.28 - Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate; general provisions. 126.28 Section 126...) WATERFRONT FACILITIES HANDLING OF DANGEROUS CARGO AT WATERFRONT FACILITIES § 126.28 Ammonium...

  17. 33 CFR 126.28 - Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate; general provisions. 126.28 Section 126...) WATERFRONT FACILITIES HANDLING OF DANGEROUS CARGO AT WATERFRONT FACILITIES § 126.28 Ammonium...

  18. 49 CFR 176.410 - Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures. 176.410 Section 176.410 Transportation Other Regulations Relating to... nitrate and ammonium nitrate mixtures. (a) This section prescribes requirements to be observed...

  19. 33 CFR 126.28 - Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate; general provisions. 126.28 Section 126...) WATERFRONT FACILITIES HANDLING OF DANGEROUS CARGO AT WATERFRONT FACILITIES § 126.28 Ammonium...

  20. 49 CFR 176.410 - Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures. 176.410 Section 176.410 Transportation Other Regulations Relating to... nitrate and ammonium nitrate mixtures. (a) This section prescribes requirements to be observed...

  1. 49 CFR 176.410 - Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures. 176.410 Section 176.410 Transportation Other Regulations Relating to... nitrate and ammonium nitrate mixtures. (a) This section prescribes requirements to be observed...

  2. 33 CFR 126.28 - Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate; general provisions. 126.28 Section 126...) WATERFRONT FACILITIES HANDLING OF DANGEROUS CARGO AT WATERFRONT FACILITIES § 126.28 Ammonium...

  3. 49 CFR 176.410 - Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures. 176.410 Section 176.410 Transportation Other Regulations Relating to... nitrate and ammonium nitrate mixtures. (a) This section prescribes requirements to be observed...

  4. 49 CFR 176.410 - Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures. 176.410 Section 176.410 Transportation Other Regulations Relating to... nitrate and ammonium nitrate mixtures. (a) This section prescribes requirements to be observed...

  5. 33 CFR 126.28 - Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate; general provisions. 126.28 Section 126...) WATERFRONT FACILITIES HANDLING OF DANGEROUS CARGO AT WATERFRONT FACILITIES § 126.28 Ammonium...

  6. Phase diagram of ammonium nitrate

    NASA Astrophysics Data System (ADS)

    Dunuwille, Mihindra; Yoo, Choong-Shik

    2013-12-01

    Ammonium Nitrate (AN) is a fertilizer, yet becomes an explosive upon a small addition of chemical impurities. The origin of enhanced chemical sensitivity in impure AN (or AN mixtures) is not well understood, posing significant safety issues in using AN even today. To remedy the situation, we have carried out an extensive study to investigate the phase stability of AN and its mixtures with hexane (ANFO-AN mixed with fuel oil) and Aluminum (Ammonal) at high pressures and temperatures, using diamond anvil cells (DAC) and micro-Raman spectroscopy. The results indicate that pure AN decomposes to N2, N2O, and H2O at the onset of the melt, whereas the mixtures, ANFO and Ammonal, decompose at substantially lower temperatures. The present results also confirm the recently proposed phase IV-IV' transition above 17 GPa and provide new constraints for the melting and phase diagram of AN to 40 GPa and 400°C.

  7. Ammonium nonanoate broadcast application over onions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ammonium nonanoate occurs in nature and is primarily formed from biodegradation of higher fatty acids. Racer (40% ammonium nonaoate) is a potential contact herbicide for weed control in organic crop production. Field research was conducted in southeast Oklahoma (Atoka County, Lane, OK) to determin...

  8. Biodegradation of rocket propellant waste, ammonium perchlorate

    NASA Technical Reports Server (NTRS)

    Naqvi, S. M. Z.; Latif, A.

    1975-01-01

    The short term effects of ammonium perchlorate on selected organisms were studied. A long term experiment was also designed to assess the changes incurred by ammonium perchlorate on the nitrogen and chloride contents of soil within a period of 3 years. In addition, an attempt was made to produce methane gas from anaerobic fermentation of the aquatic weed, Alternanthera philoxeroides.

  9. 21 CFR 184.1137 - Ammonium carbonate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...). It is prepared by the sublimation of a mixture of ammonium sulfate and calcium carbonate and occurs... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ammonium carbonate. 184.1137 Section 184.1137 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD...

  10. 21 CFR 184.1137 - Ammonium carbonate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...). It is prepared by the sublimation of a mixture of ammonium sulfate and calcium carbonate and occurs... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ammonium carbonate. 184.1137 Section 184.1137 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD...

  11. 21 CFR 184.1137 - Ammonium carbonate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... sublimation of a mixture of ammonium sulfate and calcium carbonate and occurs as a white powder or a hard... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ammonium carbonate. 184.1137 Section 184.1137 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED)...

  12. 21 CFR 184.1137 - Ammonium carbonate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...). It is prepared by the sublimation of a mixture of ammonium sulfate and calcium carbonate and occurs... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ammonium carbonate. 184.1137 Section 184.1137 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD...

  13. Dielectric relaxations in partly deuterated ammonium dichromate

    NASA Astrophysics Data System (ADS)

    Gilchrist, John le G.

    1987-12-01

    Two dielectric relaxations in partly deuterated ammonium dichromate are attributed to reorientations of mixed-isotope ammonium ions. Loss peaks were observed between 20 and 40 K and obey the Arrhenius law with activation energy 1.5 kcal/mol for the stronger relaxation. The dipole moment is of the order of 0.015 D.

  14. Evolution of Electrogenic Ammonium Transporters (AMTs)

    PubMed Central

    McDonald, Tami R.; Ward, John M.

    2016-01-01

    The ammonium transporter gene family consists of three main clades, AMT, MEP, and Rh. The evolutionary history of the AMT/MEP/Rh gene family is characterized by multiple horizontal gene transfer events, gene family expansion and contraction, and gene loss; thus the gene tree for this family of transporters is unlike the organismal tree. The genomes of angiosperms contain genes for both electrogenic and electroneutral ammonium transporters, but it is not clear how far back in the land plant lineage electrogenic ammonium transporters occur. Here, we place Marchantia polymorpha ammonium transporters in the AMT/MEP/Rh phylogeny and we show that AMTs from the liverwort M. polymorpha are electrogenic. This information suggests that electrogenic ammonium transport evolved at least as early as the divergence of bryophytes in the land plant lineage. PMID:27066024

  15. 49 CFR 176.415 - Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... nitrates, and certain ammonium nitrate fertilizers. 176.415 Section 176.415 Transportation Other... requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers. (a) Except as... Captain of the Port (COTP). (1) Ammonium nitrate UN1942, ammonium nitrate fertilizers containing more...

  16. 49 CFR 176.415 - Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... nitrates, and certain ammonium nitrate fertilizers. 176.415 Section 176.415 Transportation Other... requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers. (a) Except as... Captain of the Port (COTP). (1) Ammonium nitrate UN1942, ammonium nitrate fertilizers containing more...

  17. 49 CFR 176.415 - Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... nitrates, and certain ammonium nitrate fertilizers. 176.415 Section 176.415 Transportation Other... requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers. (a) Except as... Captain of the Port (COTP). (1) Ammonium nitrate UN1942, ammonium nitrate fertilizers containing more...

  18. 49 CFR 176.415 - Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... nitrates, and certain ammonium nitrate fertilizers. 176.415 Section 176.415 Transportation Other... requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers. (a) Except as... Captain of the Port (COTP). (1) Ammonium nitrate UN1942, ammonium nitrate fertilizers containing more...

  19. 49 CFR 176.415 - Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... nitrates, and certain ammonium nitrate fertilizers. 176.415 Section 176.415 Transportation Other... requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers. (a) Except as... Captain of the Port (COTP). (1) Ammonium nitrate UN1942, ammonium nitrate fertilizers containing more...

  20. 21 CFR 73.1298 - Ferric ammonium ferrocyanide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) Identity. (1) The color additive ferric ammonium ferrocyanide is the blue pigment obtained by oxidizing... product is filtered, washed, and dried. The pigment consists principally of ferric ammonium...

  1. 21 CFR 73.1298 - Ferric ammonium ferrocyanide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) Identity. (1) The color additive ferric ammonium ferrocyanide is the blue pigment obtained by oxidizing... product is filtered, washed, and dried. The pigment consists principally of ferric ammonium...

  2. 21 CFR 73.1298 - Ferric ammonium ferrocyanide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) Identity. (1) The color additive ferric ammonium ferrocyanide is the blue pigment obtained by oxidizing... product is filtered, washed, and dried. The pigment consists principally of ferric ammonium...

  3. 21 CFR 73.1298 - Ferric ammonium ferrocyanide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) Identity. (1) The color additive ferric ammonium ferrocyanide is the blue pigment obtained by oxidizing... product is filtered, washed, and dried. The pigment consists principally of ferric ammonium...

  4. Phase diagram of ammonium nitrate

    SciTech Connect

    Dunuwille, Mihindra; Yoo, Choong-Shik

    2013-12-07

    Ammonium Nitrate (AN) is a fertilizer, yet becomes an explosive upon a small addition of chemical impurities. The origin of enhanced chemical sensitivity in impure AN (or AN mixtures) is not well understood, posing significant safety issues in using AN even today. To remedy the situation, we have carried out an extensive study to investigate the phase stability of AN and its mixtures with hexane (ANFO–AN mixed with fuel oil) and Aluminum (Ammonal) at high pressures and temperatures, using diamond anvil cells (DAC) and micro-Raman spectroscopy. The results indicate that pure AN decomposes to N{sub 2}, N{sub 2}O, and H{sub 2}O at the onset of the melt, whereas the mixtures, ANFO and Ammonal, decompose at substantially lower temperatures. The present results also confirm the recently proposed phase IV-IV{sup ′} transition above 17 GPa and provide new constraints for the melting and phase diagram of AN to 40 GPa and 400°C.

  5. Substrate specificity of Rhbg: ammonium and methyl ammonium transport

    PubMed Central

    Abdulnour-Nakhoul, Solange M.; Boulpaep, Emile L.; Rabon, Edd; Schmidt, Eric; Hamm, L. Lee

    2010-01-01

    Rhbg is a nonerythroid membrane glycoprotein belonging to the Rh antigen family. In the kidney, Rhbg is expressed at the basolateral membrane of intercalated cells of the distal nephron and is involved in NH4+ transport. We investigated the substrate specificity of Rhbg by comparing transport of NH3/NH4+ with that of methyl amine (hydrochloride) (MA/MA+), often used to replace NH3/NH4+, in oocytes expressing Rhbg. Methyl amine (HCl) in solution exists as neutral methyl amine (MA) in equilibrium with the protonated methyl ammonium (MA+). To assess transport, we used ion-selective microelectrodes and voltage-clamp experiments to measure NH3/NH4+- and MA/MA+-induced intracellular pH (pHi) changes and whole cell currents. Our data showed that in Rhbg oocytes, NH3/NH4+ caused an inward current and decrease in pHi consistent with electrogenic NH4+ transport. These changes were significantly larger than in H2O-injected oocytes. The NH3/NH4+-induced current was not inhibited in the presence of barium or in the absence of Na+. In Rhbg oocytes, MA/MA+ caused an inward current but an increase (rather than a decrease) in pHi. MA/MA+ did not cause any changes in H2O-injected oocytes. The MA/MA+-induced current and pHi increase were saturated at higher concentrations of MA/MA+. Amiloride inhibited MA/MA+-induced current and the increase in pHi in oocytes expressing Rhbg but had no effect on control oocytes. These results indicate that MA/MA+ is transported by Rhbg but differently than NH3/NH4+. The protonated MA+ is likely a direct substrate whose transport resembles that of NH4+. Transport of electroneutral MA is also enhanced by expression of Rhbg. PMID:20592240

  6. Substrate specificity of Rhbg: ammonium and methyl ammonium transport.

    PubMed

    Nakhoul, Nazih L; Abdulnour-Nakhoul, Solange M; Boulpaep, Emile L; Rabon, Edd; Schmidt, Eric; Hamm, L Lee

    2010-09-01

    Rhbg is a nonerythroid membrane glycoprotein belonging to the Rh antigen family. In the kidney, Rhbg is expressed at the basolateral membrane of intercalated cells of the distal nephron and is involved in NH4+ transport. We investigated the substrate specificity of Rhbg by comparing transport of NH3/NH4+ with that of methyl amine (hydrochloride) (MA/MA+), often used to replace NH3/NH4+, in oocytes expressing Rhbg. Methyl amine (HCl) in solution exists as neutral methyl amine (MA) in equilibrium with the protonated methyl ammonium (MA+). To assess transport, we used ion-selective microelectrodes and voltage-clamp experiments to measure NH3/NH4+- and MA/MA+-induced intracellular pH (pH(i)) changes and whole cell currents. Our data showed that in Rhbg oocytes, NH3/NH4+ caused an inward current and decrease in pH(i) consistent with electrogenic NH4+ transport. These changes were significantly larger than in H2O-injected oocytes. The NH3/NH4+-induced current was not inhibited in the presence of barium or in the absence of Na+. In Rhbg oocytes, MA/MA+ caused an inward current but an increase (rather than a decrease) in pH(i). MA/MA+ did not cause any changes in H2O-injected oocytes. The MA/MA+-induced current and pH(i) increase were saturated at higher concentrations of MA/MA+. Amiloride inhibited MA/MA+-induced current and the increase in pH(i) in oocytes expressing Rhbg but had no effect on control oocytes. These results indicate that MA/MA+ is transported by Rhbg but differently than NH3/NH4+. The protonated MA+ is likely a direct substrate whose transport resembles that of NH4+. Transport of electroneutral MA is also enhanced by expression of Rhbg.

  7. Biodegradation of rocket propellent waste, ammonium perchlorate

    NASA Technical Reports Server (NTRS)

    Naqui, S. M. Z.

    1975-01-01

    The impact of the biodegradation rate of ammonium perchlorate on the environment was studied in terms of growth, metabolic rate, and total biomass of selected animal and plant species. Brief methodology and detailed results are presented.

  8. Toxicology of ammonium sulfate in the lung

    SciTech Connect

    Pepelko, W.E.; Mattox, J.K.; Cohen, A.L.

    1980-01-01

    Despite the relatively low toxicity of ammonium sulfate in experimental animals, it cannot be concluded that increased sulfuric acid production is harmless to human health. Many other pollutants are present in ambient air with possible synergistic effects. Sulfuric acid undoubtedly reacts to produce other sulfates in ambient air which are often much more toxic. For example zinc sulfate and zinc ammonium sulfate are much more irritating to the lung than ammonium sulfate. In order to assess with more certainty the health effects of increased sulfuric acid production, it will be necessary to determine accurately that proportion inhaled as free sulfuric acid compared with ammonium sulfate as well as the proportion and kinds of other sulfates present in the atmosphere.

  9. 76 FR 46907 - Ammonium Nitrate Security Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-03

    ... used in agricultural operations indicated that ammonium nitrate is the best choice for nitrogen... contains not less than 33 percent nitrogen by weight.'' See 6 U.S.C. 488(1)(A). DHS proposes to use...

  10. Evidence of ammonium ion-exchange properties of natural bentonite and application to ammonium detection.

    PubMed

    Zazoua, A; Kazane, I; Khedimallah, N; Dernane, C; Errachid, A; Jaffrezic-Renault, N

    2013-12-01

    Ammonium exchange with hybrid PVC-bentonite (mineral montmorillonite clay) thin film was revealed using FTIR spectroscopy, EDX, cyclic voltammetry and electrochemical impedance spectroscopy. The effect of ammonium exchange on the charge transfer resistance of PVC-bentonite hybrid thin film was attributed to a modification of the intersheet distance and hydration of bentonite crystals. The obtained impedimetric ammonium sensor shows a linear range of detection from 10(-4)M to 1M and a detection limit around 10(-6)M.

  11. Electrochemically and bioelectrochemically induced ammonium recovery.

    PubMed

    Gildemyn, Sylvia; Luther, Amanda K; Andersen, Stephen J; Desloover, Joachim; Rabaey, Korneel

    2015-01-22

    Streams such as urine and manure can contain high levels of ammonium, which could be recovered for reuse in agriculture or chemistry. The extraction of ammonium from an ammonium-rich stream is demonstrated using an electrochemical and a bioelectrochemical system. Both systems are controlled by a potentiostat to either fix the current (for the electrochemical cell) or fix the potential of the working electrode (for the bioelectrochemical cell). In the bioelectrochemical cell, electroactive bacteria catalyze the anodic reaction, whereas in the electrochemical cell the potentiostat applies a higher voltage to produce a current. The current and consequent restoration of the charge balance across the cell allow the transport of cations, such as ammonium, across a cation exchange membrane from the anolyte to the catholyte. The high pH of the catholyte leads to formation of ammonia, which can be stripped from the medium and captured in an acid solution, thus enabling the recovery of a valuable nutrient. The flux of ammonium across the membrane is characterized at different anolyte ammonium concentrations and currents for both the abiotic and biotic reactor systems. Both systems are compared based on current and removal efficiencies for ammonium, as well as the energy input required to drive ammonium transfer across the cation exchange membrane. Finally, a comparative analysis considering key aspects such as reliability, electrode cost, and rate is made. This video article and protocol provide the necessary information to conduct electrochemical and bioelectrochemical ammonia recovery experiments. The reactor setup for the two cases is explained, as well as the reactor operation. We elaborate on data analysis for both reactor types and on the advantages and disadvantages of bioelectrochemical and electrochemical systems.

  12. Electrochemically and Bioelectrochemically Induced Ammonium Recovery

    PubMed Central

    Gildemyn, Sylvia; Luther, Amanda K.; Andersen, Stephen J.; Desloover, Joachim; Rabaey, Korneel

    2015-01-01

    Streams such as urine and manure can contain high levels of ammonium, which could be recovered for reuse in agriculture or chemistry. The extraction of ammonium from an ammonium-rich stream is demonstrated using an electrochemical and a bioelectrochemical system. Both systems are controlled by a potentiostat to either fix the current (for the electrochemical cell) or fix the potential of the working electrode (for the bioelectrochemical cell). In the bioelectrochemical cell, electroactive bacteria catalyze the anodic reaction, whereas in the electrochemical cell the potentiostat applies a higher voltage to produce a current. The current and consequent restoration of the charge balance across the cell allow the transport of cations, such as ammonium, across a cation exchange membrane from the anolyte to the catholyte. The high pH of the catholyte leads to formation of ammonia, which can be stripped from the medium and captured in an acid solution, thus enabling the recovery of a valuable nutrient. The flux of ammonium across the membrane is characterized at different anolyte ammonium concentrations and currents for both the abiotic and biotic reactor systems. Both systems are compared based on current and removal efficiencies for ammonium, as well as the energy input required to drive ammonium transfer across the cation exchange membrane. Finally, a comparative analysis considering key aspects such as reliability, electrode cost, and rate is made. This video article and protocol provide the necessary information to conduct electrochemical and bioelectrochemical ammonia recovery experiments. The reactor setup for the two cases is explained, as well as the reactor operation. We elaborate on data analysis for both reactor types and on the advantages and disadvantages of bioelectrochemical and electrochemical systems. PMID:25651406

  13. 21 CFR 172.165 - Quaternary ammonium chloride combination.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Quaternary ammonium chloride combination. 172.165... § 172.165 Quaternary ammonium chloride combination. The food additive, quaternary ammonium chloride... the following compounds: n-dodecyl dimethyl benzyl ammonium chloride (CAS Reg. No. 139-07-1);...

  14. 21 CFR 172.430 - Iron ammonium citrate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Iron ammonium citrate. 172.430 Section 172.430... CONSUMPTION Anticaking Agents § 172.430 Iron ammonium citrate. Iron ammonium citrate may be safely used in... human consumption so that the level of iron ammonium citrate does not exceed 25 parts per million...

  15. 21 CFR 172.430 - Iron ammonium citrate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Iron ammonium citrate. 172.430 Section 172.430... CONSUMPTION Anticaking Agents § 172.430 Iron ammonium citrate. Iron ammonium citrate may be safely used in... human consumption so that the level of iron ammonium citrate does not exceed 25 parts per million...

  16. 21 CFR 172.430 - Iron ammonium citrate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Iron ammonium citrate. 172.430 Section 172.430... CONSUMPTION Anticaking Agents § 172.430 Iron ammonium citrate. Iron ammonium citrate may be safely used in... human consumption so that the level of iron ammonium citrate does not exceed 25 parts per million...

  17. 21 CFR 172.430 - Iron ammonium citrate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Iron ammonium citrate. 172.430 Section 172.430 Food... Anticaking Agents § 172.430 Iron ammonium citrate. Iron ammonium citrate may be safely used in food in... consumption so that the level of iron ammonium citrate does not exceed 25 parts per million (0.0025...

  18. 21 CFR 573.560 - Iron ammonium citrate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Iron ammonium citrate. 573.560 Section 573.560... Additive Listing § 573.560 Iron ammonium citrate. Iron ammonium citrate may be safely used in animal feed... consumption so that the level of iron ammonium citrate does not exceed 25 parts per million (0.0025...

  19. Transcription Factor OsDOF18 Controls Ammonium Uptake by Inducing Ammonium Transporters in Rice Roots

    PubMed Central

    Wu, Yunfei; Yang, Wenzhu; Wei, Jinhuan; Yoon, Hyeryung; An, Gynheung

    2017-01-01

    Nitrogen is one of the most important mineral elements for plant growth. We studied the functional roles of Oryza sativa DNA BINDING WITH ONE FINGER 18 (OsDOF18) in controlling ammonium uptake. The growth of null mutants of OsDOF18 was retarded in a medium containing ammonium as the sole nitrogen source. In contrast, those mutants grew normally in a medium with nitrate as the sole nitrogen source. The gene expression was induced by ammonium but not by nitrate. Uptake of ammonium was lower in osdof18 mutants than in the wild type, while that of nitrate was not affected by the mutation. This indicated that OsDOF18 is involved in regulating ammonium transport. Among the 10 ammonium transporter genes examined here, expression of OsAMT1;1, OsAMT1;3, OsAMT2;1, and OsAMT4;1 was reduced in osdof18 mutants, demonstrating that the ammonium transporter genes function downstream of OsDOF18. Genes for nitrogen assimilation were also affected in the mutants. These results provide evidence that OsDOF18 mediates ammonium transport and nitrogen distribution, which then affects nitrogen use efficiency. PMID:28292004

  20. Crystallization characteristics of ammonium uranyl carbonate (AUC) in ammonium carbonate solutions

    NASA Astrophysics Data System (ADS)

    Tae-Joon, Kim; Kyung-Chai, Jeong; Jin-Ho, Park; In-Soon, Chang; Cheong-Song, Choi

    1994-05-01

    Ammonium carbonate solutions with an excessive amount of NH 3 were produced in a commercial AUC (ammonium uranyl carbonate) conversion plant. In this study the AUC crystals, precipitated with uranyl nitrate and ammonium carbonate solutions prepared in the laboratory, were characterized to determine the feasibility of recycling ammonium carbonate solution. The AUC crystals were easily agglomerated with the increasing concentration of CO 32- and mole ratio of {NH 4+}/{CO 32-} in ammonium carbonate solution. Effects of a mixing system for the solution in the AUC crystallizer and the feed location of the solution on the agglomeration of AUC crystals were also studied along with the effects of agglomerated AUC powders on UO 2 powders. Finally, the feasibility of manufacturing UO 2 fuel with a sintered pellet density of 10.52 g/cm 3, using the AUC powders generated in this experiment, was demonstrated.

  1. Calcium sulphate in ammonium sulphate solution

    USGS Publications Warehouse

    Sullivan, E.C.

    1905-01-01

    Calcium sulphate, at 25?? C., is two-thirds as soluble in dilute (o.i mol per liter) and twice as soluble in concentrated (3 mois per liter) ammonium sulphate solution as in water. The specific electric conductivity of concentrated ammonium sulphate solutions is lessened by saturating with calcium sulphate. Assuming that dissociation of ammonium sulphate takes place into 2NH4?? and SO4" and of calcium sulphate into Ca and SO4" only, and that the conductivity is a measure of such dissociation, the solubility of calcium sulphate in dilute ammonium sulphate solutions is greater than required by the mass-law. The conductivity of the dilute mixtures may be accurately calculated by means of Arrhenius' principle of isohydric solutions. In the data obtained in these calculations, the concentration of non-dissociated calcium sulphate decreases with increasing ammonium sulphate. The work as a whole is additional evidence of the fact that we are not yet in possession of all the factors necessary for reconciling the mass-law to the behavior of electrolytes. The measurements above described were made in the chemical laboratory of the University of Michigan.

  2. On the evaporation of ammonium sulfate solution

    SciTech Connect

    Drisdell, Walter S.; Saykally, Richard J.; Cohen, Ronald C.

    2009-07-16

    Aqueous evaporation and condensation kinetics are poorly understood, and uncertainties in their rates affect predictions of cloud behavior and therefore climate. We measured the cooling rate of 3 M ammonium sulfate droplets undergoing free evaporation via Raman thermometry. Analysis of the measurements yields a value of 0.58 {+-} 0.05 for the evaporation coefficient, identical to that previously determined for pure water. These results imply that subsaturated aqueous ammonium sulfate, which is the most abundant inorganic component of atmospheric aerosol, does not affect the vapor-liquid exchange mechanism for cloud droplets, despite reducing the saturation vapor pressure of water significantly.

  3. 21 CFR 573.170 - Ammonium formate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) The additive is manufactured by the reaction of 99.5 percent ammonia gas and 99 percent formic acid in...) To assure safe use of the additive, in addition to the other information required by the Federal Food... labeled as containing ammonium formate. (d) To assure safe use of the additive, in addition to the...

  4. 21 CFR 184.1133 - Ammonium alginate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...: Category of food Maximum level of use in food (as served) (percent) Functional use Confections, frostings... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ammonium alginate. 184.1133 Section 184.1133 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD...

  5. Diamond Head Revisited with Ammonium Dichromate.

    ERIC Educational Resources Information Center

    Arrigoni, Edward

    1981-01-01

    The classroom demonstration using ammonium dichromate to simulate a volcanic eruption can be modified into a more dramatic and accurate representation of the geologic processes involved in the formation of a volcanic crater. The materials, demonstration setup, safety procedures, and applications to instruction are presented. (Author/WB)

  6. 21 CFR 184.1133 - Ammonium alginate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...-34-9) is the ammonium salt of alginic acid, a natural polyuronide constituent of certain brown algae..., § 170.3(n)(9) of this chapter 0.4 Stabilizer, thickener, § 170.3(o)(28) of this chapter. Fats and...

  7. 21 CFR 184.1133 - Ammonium alginate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...-34-9) is the ammonium salt of alginic acid, a natural polyuronide constituent of certain brown algae..., § 170.3(n)(9) of this chapter 0.4 Stabilizer, thickener, § 170.3(o)(28) of this chapter. Fats and...

  8. 21 CFR 184.1133 - Ammonium alginate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...: Category of food Maximum level of use in food (as served) (percent) Functional use Confections, frostings... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ammonium alginate. 184.1133 Section 184.1133 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD...

  9. 21 CFR 184.1135 - Ammonium bicarbonate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE... practice. The affirmation of this ingredient as generally recognized as safe (GRAS) as a direct human food... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ammonium bicarbonate. 184.1135 Section...

  10. 21 CFR 184.1139 - Ammonium hydroxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of... ingredient as generally recognized as safe (GRAS) as a direct human food ingredient is based upon the... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ammonium hydroxide. 184.1139 Section 184.1139...

  11. 21 CFR 184.1137 - Ammonium carbonate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of... ingredient as generally recognized as safe (GRAS) as a direct human food ingredient is based upon the... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ammonium carbonate. 184.1137 Section 184.1137...

  12. 21 CFR 184.1143 - Ammonium sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ammonium sulfate. 184.1143 Section 184.1143 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing...

  13. 21 CFR 573.170 - Ammonium formate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) The additive is manufactured by the reaction of 99.5 percent ammonia gas and 99 percent formic acid in...) To assure safe use of the additive, in addition to the other information required by the Federal Food... labeled as containing ammonium formate. (d) To assure safe use of the additive, in addition to the...

  14. 21 CFR 573.170 - Ammonium formate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) The additive is manufactured by the reaction of 99.5 percent ammonia gas and 99 percent formic acid in...) To assure safe use of the additive, in addition to the other information required by the Federal Food... labeled as containing ammonium formate. (d) To assure safe use of the additive, in addition to the...

  15. 21 CFR 573.170 - Ammonium formate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... is manufactured by the reaction of 99.5 percent ammonia gas and 99 percent formic acid in a... safe use of the additive, in addition to the other information required by the Federal Food, Drug, and... ammonium formate. (d) To assure safe use of the additive, in addition to the other information required...

  16. PRN 88-2: Clustering of Quaternary Ammonium Compounds

    EPA Pesticide Factsheets

    This Notice announces that EPA has clustered the Quaternary Ammonium Compounds into four groups for the purpose of testing chemicals to build a database that will support continued registration of the entire family of quaternary ammonium compounds

  17. Contribution of ammonium ions to the lethality and antimetamorphic effects of ammonium perchlorate.

    PubMed

    Goleman, Wanda L; Carr, James A

    2006-04-01

    Ammonium perchlorate (AP) is a widespread military waste product in the United States and is a potent thyroid function disruptor in all vertebrates tested thus far. To determine the relative contribution of ammonium ions to the toxicity of AP, we exposed embryonic and larval Xenopus laevis to various concentrations of sodium perchlorate (SP) or ammonium chloride (AC). Ammonium perchlorate was significantly more lethal than SP; 5-d LC50s were 83 and 2,780 mg/L, respectively. To determine whether ammonium ions contribute to the antithyroid effects of AP, we exposed embryonic and larval X. laevis to two sublethal, environmentally relevant concentrations of AP or identical concentrations of AC or SP. At the smaller concentration, only AP delayed metamorphosis and reduced hindlimb growth. Sodium perchlorate and AP, but not AC, prevented metamorphosis and reduced hindlimb growth at the greater concentration. Although AP was slightly more effective in reducing outward manifestations of thyroid disruption, both perchlorate salts, unlike AC, caused profound histopathologic changes in the thyroid. Exposure to the higher concentration of either perchlorate salt produced a feminizing effect, resulting in a skewed sex ratio. We conclude that ammonium ions contribute significantly to the toxicity of AP but not to the direct antithyroid effects of perchlorate.

  18. Electricity production coupled to ammonium in a microbial fuel cell.

    PubMed

    He, Zhen; Kan, Jinjun; Wang, Yanbing; Huang, Yuelong; Mansfeld, Florian; Nealson, Kenneth H

    2009-05-01

    The production of electricity from ammonium was examined using a rotating-cathode microbial fuel cell (MFC). The addition of ammonium chloride, ammonium sulfate, or ammonium phosphate (monobasic) resulted in electricity generation, while adding sodium chloride, nitrate, or nitrite did not cause any increase in current production. The peak current increased with increasing amount of ammonium addition up to 62.3 mM of ammonium chloride, suggesting that ammonium was involved in electricity generation either directly as the anodic fuel or indirectly as substrates for nitrifiers to produce organic compounds for heterotrophs. Adding nitrate or nitrite with ammonium increased current production compared to solely ammonium addition. Using 16S rRNA-linked molecular analyses, we found ammonium-oxidizing bacteria and denitrifying bacteria on both the anode and cathode electrodes, whereas no anammox bacteria were detected. The dominant ammonium-oxidizing bacteria were closely related to Nitrosomonas europaea. The present MFC achieved an ammonium removal efficiency of 49.2 +/- 5.9 or 69.7 +/- 3.6%, depending on hydraulic retention time, but exhibited a very low Coulombic efficiency.

  19. 21 CFR 184.1141b - Ammonium phosphate, dibasic.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ammonium phosphate, dibasic. 184.1141b Section 184... Listing of Specific Substances Affirmed as GRAS § 184.1141b Ammonium phosphate, dibasic. (a) Ammonium phosphate, dibasic ((NH4)2HPO4, CAS Reg. No. 7783-28-0) is manufactured by reacting ammonia with...

  20. 21 CFR 184.1141a - Ammonium phosphate, monobasic.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ammonium phosphate, monobasic. 184.1141a Section... SAFE Listing of Specific Substances Affirmed as GRAS § 184.1141a Ammonium phosphate, monobasic. (a) Ammonium phosphate, monobasic (NH4H2PO4, CAS Reg. No. 7722-76-1) is manufactured by reacting ammonia...

  1. 21 CFR 184.1141b - Ammonium phosphate, dibasic.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ammonium phosphate, dibasic. 184.1141b Section 184... Listing of Specific Substances Affirmed as GRAS § 184.1141b Ammonium phosphate, dibasic. (a) Ammonium phosphate, dibasic ((NH4)2HPO4, CAS Reg. No. 7783-28-0) is manufactured by reacting ammonia with...

  2. 21 CFR 184.1141b - Ammonium phosphate, dibasic.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ammonium phosphate, dibasic. 184.1141b Section 184... Listing of Specific Substances Affirmed as GRAS § 184.1141b Ammonium phosphate, dibasic. (a) Ammonium phosphate, dibasic ((NH4)2HPO4, CAS Reg. No. 7783-28-0) is manufactured by reacting ammonia with...

  3. 21 CFR 184.1141b - Ammonium phosphate, dibasic.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ammonium phosphate, dibasic. 184.1141b Section 184.1141b Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... as GRAS § 184.1141b Ammonium phosphate, dibasic. (a) Ammonium phosphate, dibasic ((NH4)2HPO4, CAS...

  4. 21 CFR 184.1141a - Ammonium phosphate, monobasic.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ammonium phosphate, monobasic. 184.1141a Section... SAFE Listing of Specific Substances Affirmed as GRAS § 184.1141a Ammonium phosphate, monobasic. (a) Ammonium phosphate, monobasic (NH4H2PO4, CAS Reg. No. 7722-76-1) is manufactured by reacting ammonia...

  5. 21 CFR 184.1141a - Ammonium phosphate, monobasic.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ammonium phosphate, monobasic. 184.1141a Section 184.1141a Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Affirmed as GRAS § 184.1141a Ammonium phosphate, monobasic. (a) Ammonium phosphate, monobasic...

  6. 21 CFR 184.1141a - Ammonium phosphate, monobasic.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ammonium phosphate, monobasic. 184.1141a Section... SAFE Listing of Specific Substances Affirmed as GRAS § 184.1141a Ammonium phosphate, monobasic. (a) Ammonium phosphate, monobasic (NH4H2PO4, CAS Reg. No. 7722-76-1) is manufactured by reacting ammonia...

  7. 21 CFR 184.1141b - Ammonium phosphate, dibasic.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ammonium phosphate, dibasic. 184.1141b Section 184... Listing of Specific Substances Affirmed as GRAS § 184.1141b Ammonium phosphate, dibasic. (a) Ammonium phosphate, dibasic ((NH4)2HPO4, CAS Reg. No. 7783-28-0) is manufactured by reacting ammonia with...

  8. 21 CFR 184.1141a - Ammonium phosphate, monobasic.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ammonium phosphate, monobasic. 184.1141a Section... SAFE Listing of Specific Substances Affirmed as GRAS § 184.1141a Ammonium phosphate, monobasic. (a) Ammonium phosphate, monobasic (NH4H2PO4, CAS Reg. No. 7722-76-1) is manufactured by reacting ammonia...

  9. 21 CFR 172.165 - Quaternary ammonium chloride combination.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Quaternary ammonium chloride combination. 172.165... HUMAN CONSUMPTION Food Preservatives § 172.165 Quaternary ammonium chloride combination. The food additive, quaternary ammonium chloride combination, may be safely used in food in accordance with...

  10. 21 CFR 172.165 - Quaternary ammonium chloride combination.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Quaternary ammonium chloride combination. 172.165... HUMAN CONSUMPTION Food Preservatives § 172.165 Quaternary ammonium chloride combination. The food additive, quaternary ammonium chloride combination, may be safely used in food in accordance with...

  11. 21 CFR 172.165 - Quaternary ammonium chloride combination.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Quaternary ammonium chloride combination. 172.165... HUMAN CONSUMPTION Food Preservatives § 172.165 Quaternary ammonium chloride combination. The food additive, quaternary ammonium chloride combination, may be safely used in food in accordance with...

  12. 21 CFR 172.165 - Quaternary ammonium chloride combination.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Quaternary ammonium chloride combination. 172.165... HUMAN CONSUMPTION Food Preservatives § 172.165 Quaternary ammonium chloride combination. The food additive, quaternary ammonium chloride combination, may be safely used in food in accordance with...

  13. 40 CFR 721.10302 - Zinc ammonium phosphate (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Zinc ammonium phosphate (generic). 721... Substances § 721.10302 Zinc ammonium phosphate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as zinc ammonium phosphate (PMN...

  14. 40 CFR 721.10302 - Zinc ammonium phosphate (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Zinc ammonium phosphate (generic). 721... Substances § 721.10302 Zinc ammonium phosphate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as zinc ammonium phosphate (PMN...

  15. 40 CFR 721.10302 - Zinc ammonium phosphate (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Zinc ammonium phosphate (generic). 721... Substances § 721.10302 Zinc ammonium phosphate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as zinc ammonium phosphate (PMN...

  16. 21 CFR 172.430 - Iron ammonium citrate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Iron ammonium citrate. 172.430 Section 172.430... ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Anticaking Agents § 172.430 Iron ammonium citrate. Iron ammonium citrate may be safely used in food in accordance with the...

  17. 40 CFR 721.10511 - Quaternary ammonium salts (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Quaternary ammonium salts (generic... Specific Chemical Substances § 721.10511 Quaternary ammonium salts (generic). (a) Chemical substance and... ammonium salts (PMNs P-07-320, P-07-321, P-07-322, P-07-323, and P-07-324) are subject to reporting...

  18. 40 CFR 721.10511 - Quaternary ammonium salts (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Quaternary ammonium salts (generic... Specific Chemical Substances § 721.10511 Quaternary ammonium salts (generic). (a) Chemical substance and... ammonium salts (PMNs P-07-320, P-07-321, P-07-322, P-07-323, and P-07-324) are subject to reporting...

  19. 40 CFR 721.10430 - Tetra alkyl ammonium salt (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Tetra alkyl ammonium salt (generic... Specific Chemical Substances § 721.10430 Tetra alkyl ammonium salt (generic). (a) Chemical substance and... ammonium salt (PMN P-97-823) is subject to reporting under this section for the significant new...

  20. 40 CFR 721.10430 - Tetra alkyl ammonium salt (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Tetra alkyl ammonium salt (generic... Specific Chemical Substances § 721.10430 Tetra alkyl ammonium salt (generic). (a) Chemical substance and... ammonium salt (PMN P-97-823) is subject to reporting under this section for the significant new...

  1. 21 CFR 582.1127 - Aluminum ammonium sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Aluminum ammonium sulfate. 582.1127 Section 582.1127 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Additives § 582.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

  2. 21 CFR 582.1127 - Aluminum ammonium sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Aluminum ammonium sulfate. 582.1127 Section 582.1127 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Additives § 582.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

  3. 21 CFR 182.1127 - Aluminum ammonium sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Aluminum ammonium sulfate. 182.1127 Section 182.1127 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate....

  4. 21 CFR 582.1127 - Aluminum ammonium sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Aluminum ammonium sulfate. 582.1127 Section 582.1127 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Additives § 582.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

  5. 21 CFR 582.1127 - Aluminum ammonium sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Aluminum ammonium sulfate. 582.1127 Section 582.1127 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Additives § 582.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

  6. 21 CFR 182.1127 - Aluminum ammonium sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Aluminum ammonium sulfate. 182.1127 Section 182.1127 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate....

  7. 21 CFR 582.1127 - Aluminum ammonium sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Aluminum ammonium sulfate. 582.1127 Section 582.1127 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Additives § 582.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

  8. 21 CFR 182.1127 - Aluminum ammonium sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Aluminum ammonium sulfate. 182.1127 Section 182...) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Multiple Purpose GRAS Food Substances § 182.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions of use. This substance is...

  9. 21 CFR 182.1127 - Aluminum ammonium sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Aluminum ammonium sulfate. 182.1127 Section 182.1127 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate....

  10. 21 CFR 182.1127 - Aluminum ammonium sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Aluminum ammonium sulfate. 182.1127 Section 182.1127 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate....

  11. 78 FR 32690 - Certain Ammonium Nitrate From Ukraine

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-31

    ... COMMISSION Certain Ammonium Nitrate From Ukraine Determination On the basis of the record \\1\\ developed in... antidumping duty order on certain ammonium nitrate from Ukraine would be likely to lead to continuation or... Publication 4396 (May 2013), entitled Certain Ammonium Nitrate from Ukraine: Investigation No....

  12. 40 CFR 721.10582 - Quaternary ammonium compound (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Quaternary ammonium compound (generic... Specific Chemical Substances § 721.10582 Quaternary ammonium compound (generic). (a) Chemical substance and... ammonium compound (PMN P-10-571) is subject to reporting under this section for the significant new...

  13. 40 CFR 721.10591 - Tertiary ammonium compound (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Tertiary ammonium compound (generic... Specific Chemical Substances § 721.10591 Tertiary ammonium compound (generic). (a) Chemical substance and... ammonium compound (PMN P-11-110) is subject to reporting under this section for the significant new...

  14. 40 CFR 721.10582 - Quaternary ammonium compound (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Quaternary ammonium compound (generic... Specific Chemical Substances § 721.10582 Quaternary ammonium compound (generic). (a) Chemical substance and... ammonium compound (PMN P-10-571) is subject to reporting under this section for the significant new...

  15. 40 CFR 721.10591 - Tertiary ammonium compound (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Tertiary ammonium compound (generic... Specific Chemical Substances § 721.10591 Tertiary ammonium compound (generic). (a) Chemical substance and... ammonium compound (PMN P-11-110) is subject to reporting under this section for the significant new...

  16. Decomposition of free chlorine with tertiary ammonium.

    PubMed

    Katano, Hajime; Uematsu, Kohei; Tatsumi, Hirosuke; Tsukatani, Toshihide

    2010-01-01

    The reaction of free chlorine with tertiary ammonium or amine compounds in aqueous solution was studied by the amperometry at a rotating Pt-disk electrode. The amperometric method can be applied to follow the concentration of free chlorine (c(Cl)) even in the presence of chloramine species. By addition of mono- and dibutylammonium to the solution containing free chlorine, the step-like decrease in c(Cl) was observed, indicating the rapid formation of the stable chloramine species. By addition of tributylammonium, the c(Cl) was decreased exponentially to nearly zero even if the free chlorine was present initially in excess. The c(Cl)-t curves can be explained by tributylammonium-species-catalyzed decomposition of free chlorine to chloride ion. The catalytic decomposition was observed also with the tertiary-ammonium-based anion-exchange resins. Furthermore, the anion-exchange resins exhibited the decomposition of not only free chlorine but also chloramines in water.

  17. Detonation Properties of Ammonium Dinitramide (ADN)

    NASA Astrophysics Data System (ADS)

    Wätterstam, A.; Östmark, H.; Helte, A.; Karlsson, S.

    1999-06-01

    Ammonium Dinitramide, ADN, has a potential as an oxidizer for underwater high explosives. Pure ADN has a large reaction-zone length and shows a strong non-ideal behaviour. The work presented here is an extension of previous work.(Sensitivity and Performance Characterization of Ammonium Dinitramide (ADN). Presented at 11th International Detonation Symposium, Snowmass, CO, 1998.) Experiments for determining the detonation velocity as a function of inverse charge radius and density, reaction-zone length and curvature, and the detonation pressure are presented. Measurements of pressure indicates that no, or weak von-Neumann spike exists, suggesting an immediate chemical decomposition. Experimental data are compared with predicted using thermochemical codes and ZND-theory.

  18. Ammonium chloride poisoning in chronic renal disease

    PubMed Central

    Levene, Donald L.; Knight, Allan

    1974-01-01

    A 58-year-old woman with a long history of renal stone disease and urinary tract infection presented to the emergency room with exhaustion and air hunger. Laboratory data confirmed profound metabolic acidosis. Unduly large quantities of bicarbonate and potassium were required for correction of the deficits. She had been taking 6 g daily of ammonium chloride as a urine-acidifying agent for a period of six months in addition to agents directed against urinary tract infection. The combination of impaired renal function and effective hydrogen ion loading resulted in profound systemic acidosis. The metabolic derangements associated with the administration of ammonium chloride and its use as a therapeutic agent are discussed. PMID:4850503

  19. Corrosion and repairs of ammonium carbamate decomposers

    SciTech Connect

    De Romero, M.F.; Galban, J.P.

    1996-05-01

    Corrosion-erosion problems occurred in the carbon steel base metal of the ammonium carbamate decomposers in an urea extraction process lined with type 316L (UNS S31603) urea grade stainless steel. The cladding was replaced by weld overlay using a semiautomatic gas metal arc welding process. The first layer was alloy 25%Cr-15%Ni-2%Mo (UNS W30923); the second layer was alloy 25%Cr-22%Ni-2%Mo (UNS W31020).

  20. PROCESS FOR THE PRODUCTION OF AMMONIUM URANIUM FLUORIDE

    DOEpatents

    Ellis, A.S.; Mooney, R.B.

    1953-08-25

    This patent relates to the preparation of ammonium uranium fluoride. The process comprises adding a water soluble fluoride to an aqueous solution of a uranous compound containing an ammonium salt, and isolating the resulting precipitate. This patent relates to the manufacture of uranium tetnafluoride from ammonium uranium fluoride, NH/sub 4/UF/sub 5/. Uranium tetrafluoride is prepared by heating the ammonium uranium fluoride to a temperature at which dissociation occurs with liberation of ammonium fluoride. Preferably the process is carried out under reduced pressure, or in a current of an inert gas.

  1. Oxidation of ammonium sulfite in aqueous solutions using ozone technology

    NASA Astrophysics Data System (ADS)

    Li, Yue; Shang, Kefeng; Lu, Na; Li, Jie; Wu, Yan

    2013-03-01

    How to deal with unstable ammonium sulfite, the byproduct of flue gas desulfuration by ammonia absorption methods, has been a difficult problem in recent years. Oxidation of ammonium sulfite in aqueous solutions using ozone produced by a surface discharge system was investigated in the paper. The oxidation efficiency of ammonium sulfite by ozone and traditional air aeration were compared, and the factors including ozone concentration, gas flow rate, initial concentration of ammonium sulfite solution and reaction temperature were discussed. The results show that the oxidation efficiency of ammonium sulfite by ozone technology reached nearly 100% under the optimum conditions, which had a significant increase compared with that by air aeration.

  2. Equation of State of Ammonium Nitrate

    NASA Astrophysics Data System (ADS)

    Robbins, David L.; Sheffield, Stephen A.; Dattelbaum, Dana M.; Velisavljevic, Nenad; Stahl, David B.

    2009-12-01

    Ammonium nitrate (AN) is a widely used fertilizer and mining explosive. AN is commonly used in ammonium nitrate-fuel oil (ANFO), which is a mixture of explosive-grade AN prills and fuel oil in a 94:6 ratio by weight. ANFO is a non-ideal explosive with measured detonation velocities around 4 km/s. The equation of state properties and known initiation behavior of neat AN are limited. We present the results of a series of gas gun-driven plate impact experiments on pressed neat ammonium nitrate at 1.72 g/cm3. No evidence of initiation was observed under shock loading to 22 GPa. High pressure x-ray diffraction experiments in diamond anvil cells provided insight into the high pressure phase behavior over the same pressure range (to 25 GPa), as well as a static isotherm at ambient temperature. From the isotherm and thermodynamic properties at ambient conditions, a preliminary unreacted equation of state (EOS) has been developed based on the Murnaghan isotherm and Helmholtz formalism [1], which compares favorably with the available experimental Hugoniot data on several densities of AN.

  3. Ammonium Ion Currents in the Squid Giant Axon

    PubMed Central

    Binstock, Leonard; Lecar, Harold

    1969-01-01

    Voltage-clamp studies on intact and internally perfused squid giant axons demonstrate that ammonium can substitute partially for either sodium or potassium. Ammonium carries the early transient current with 0.3 times the permeability of sodium and it carries the delayed current with 0.3 times the potassium permeability. The conductance changes observed in voltage clamp show approximately the same time course in ammonium solutions as in the normal physiological solutions. These ammonium ion permeabilities account for the known effects of ammonium on nerve excitability. Experiments with the drugs tetrodotoxin (TTX) and tetraethyl ammonium chloride (TEA) demonstrate that these molecules block the early and late components of the current selectively, even when both components are carried by the same ion, ammonium. PMID:5767336

  4. Polymeric Quaternary Ammonium Compounds: Versatile Antimicrobial Materials.

    PubMed

    Zubris, Deanna L; Minbiole, Kevin P C; Wuest, William M

    2017-01-01

    Polymeric Quaternary Ammonium Compounds (polyQACs) comprise a broad class of materials with applications in medical implants, food processing, and surface sanitizing, amongst many others. These polymeric substances are especially promising due to their potent antibacterial activity and limited hemolytic toxicity. In particular, many polyQACs have superior therapeutic indices and a lower likelihood of developing antibacterial resistance in comparison to their monomers, making them ideal materials for wound dressings, catheters, and other biomedical applications. This review outlines the history and development, previous successes, current state of the research, and future directions of polyQACs in society.

  5. Mild ammonium stress increases chlorophyll content in Arabidopsis thaliana.

    PubMed

    Sanchez-Zabala, Joseba; González-Murua, Carmen; Marino, Daniel

    2015-01-01

    Nitrate (NO3(-)) and ammonium (NH4(+)) are the main forms of nitrogen available in the soil for plants. Excessive NH4(+) accumulation in tissues is toxic for plants and exclusive NH4(+)-based nutrition enhances this effect. Ammonium toxicity syndrome commonly includes growth impairment, ion imbalance and chlorosis among others. In this work, we observed high intraspecific variability in chlorophyll content in 47 Arabidopsis thaliana natural accessions grown under 1 mM NH4(+) or 1 mM NO3(-) as N-source. Interestingly, chlorophyll content increased in every accession upon ammonium nutrition. Moreover, this increase was independent of ammonium tolerance capacity. Thus, chlorosis seems to be an exclusive effect of severe ammonium toxicity while mild ammonium stress induces chlorophyll accumulation.

  6. Ammonium dichromate poisoning: A rare cause of acute kidney injury.

    PubMed

    Radhakrishnan, H; Gopi, M; Arumugam, A

    2014-11-01

    Ammonium dichromate is an inorganic compound frequently used in screen and color printing. Being a strong oxidizing agent, it causes oxygen free radical injury resulting in organ failure. We report a 25-year-old female who presented with acute kidney injury after consumption of ammonium dichromate. She was managed successfully with hemodialysis and supportive measures. This case is reported to highlight the toxicity of ammonium dichromate.

  7. Reassimilation of ammonium in Lotus japonicus.

    PubMed

    Betti, Marco; García-Calderón, Margarita; Pérez-Delgado, Carmen M; Credali, Alfredo; Pal'ove-Balang, Peter; Estivill, Guillermo; Repčák, Miroslav; Vega, José M; Galván, Francisco; Márquez, Antonio J

    2014-10-01

    This review summarizes the most recent results obtained in the analysis of two important metabolic pathways involved in the release of internal sources of ammonium in the model legume Lotus japonicus: photorespiratory metabolism and asparagine breakdown mediated by aparaginase (NSE). The use of photorespiratory mutants deficient in plastidic glutamine synthetase (GS2) enabled us to investigate the transcriptomics and metabolomic changes associated with photorespiratory ammonium accumulation in this plant. The results obtained indicate the existence of a coordinate regulation of genes involved in photorespiratory metabolism. Other types of evidence illustrate the multiple interconnections existing among the photorespiratory pathway and other processes such as intermediate metabolism, nodule function, and secondary metabolism in this plant, all of which are substantially affected in GS2-deficient mutants because of the impairment of the photorespiratory cycle. Finally, the importance of asparagine metabolism in L. japonicus is highlighted because of the fact that asparagine constitutes the vast majority of the reduced nitrogen translocated between different organs of this plant. The different types of NSE enzymes and genes which are present in L. japonicus are described. There is a particular focus on the most abundant K(+)-dependent LjNSE1 isoform and how TILLING mutants were used to demonstrate by reverse genetics the importance of this particular isoform in plant growth and seed production.

  8. Ammonium nitrate: a promising rocket propellant oxidizer

    PubMed

    Oommen; Jain

    1999-06-30

    Ammonium nitrate (AN) is extensively used in the area of fertilizers and explosives. It is present as the major component in most industrial explosives. Its use as an oxidizer in the area of propellants, however, is not as extensive as in explosive compositions or gas generators. With the growing demand for environmental friendly chlorine free propellants, many attempts have been made of late to investigate oxidizers producing innocuous combustion products. AN, unlike the widely used ammonium perchlorate, produces completely ecofriendly smokeless products. Besides, it is one of the cheapest and easily available compounds. However, its use in large rocket motors is restricted due to some of its adverse characteristics like hygroscopicity, near room temperature phase transformation involving a volume change, and low burning rate (BR) and energetics. The review is an attempt to consolidate the information available on the various issues pertaining to its use as a solid propellant oxidizer. Detailed discussions on the aspects relating to phase modifications, decomposition chemistry, and BR and energetics of AN-based propellants, are presented. To make the review more comprehensive brief descriptions of the history, manufacture, safety, physical and chemical properties and various other applications of the salt are also included. Copyright 1999 Elsevier Science B.V.

  9. Safety Testing of Ammonium Nitrate Based Mixtures

    NASA Astrophysics Data System (ADS)

    Phillips, Jason; Lappo, Karmen; Phelan, James; Peterson, Nathan; Gilbert, Don

    2013-06-01

    Ammonium nitrate (AN)/ammonium nitrate based explosives have a lengthy documented history of use by adversaries in acts of terror. While historical research has been conducted on AN-based explosive mixtures, it has primarily focused on detonation performance while varying the oxygen balance between the oxidizer and fuel components. Similarly, historical safety data on these materials is often lacking in pertinent details such as specific fuel type, particle size parameters, oxidizer form, etc. A variety of AN-based fuel-oxidizer mixtures were tested for small-scale sensitivity in preparation for large-scale testing. Current efforts focus on maintaining a zero oxygen-balance (a stoichiometric ratio for active chemical participants) while varying factors such as charge geometry, oxidizer form, particle size, and inert diluent ratios. Small-scale safety testing was conducted on various mixtures and fuels. It was found that ESD sensitivity is significantly affected by particle size, while this is less so for impact and friction. Thermal testing is in progress to evaluate hazards that may be experienced during large-scale testing.

  10. Evidence for ammonium-bearing minerals in Ceres

    NASA Technical Reports Server (NTRS)

    King, T. V. V.; Clark, R. N.; Calvin, W. M.; Sherman, D. M.; Swayze, G. A.; Brown, R. H.

    1991-01-01

    Evidence for ammonium-bearing minerals was found on the surface of the largest asteroid Ceres. The presence of ammonium-bearing clays suggests that Ceres has experienced a period of alteration by substantial amounts of an ammonium-bearing fluid. The presence of the ammonium-bearing clays does not preclude Ceres maintaining a volatile inventory in the core or in a volatile-rich zone at some distance below the surface. Telescopic observations of Ceres, using the 3.0 meter NASA Infrared telescope facility prompted this reevaluation of its surface mineralogy.

  11. Antifungal activity of gemini quaternary ammonium salts.

    PubMed

    Obłąk, Ewa; Piecuch, Agata; Krasowska, Anna; Luczyński, Jacek

    2013-12-14

    A series of gemini quaternary ammonium chlorides and bromides with various alkyl chain and spacer lengths was synthesized. The most active compounds against fungi were chlorides with 10 carbon atoms within the hydrophobic chain. Among these compounds were few with no hemolytic activity at minimal inhibitory concentrations. None of the tested compounds were cytotoxic and mutagenic. Cationic gemini surfactants poorly reduced the adhesion of microorganisms to the polystyrene plate, but inhibited the filamentation of Candida albicans. One of the tested compounds eradicated C. albicans and Rodotorula mucilaginosa biofilm, what could be important in overcoming catheter-associated infections. It was also shown that gemini surfactants enhanced the sensitivity of C. albicans to azoles and polyenes, thus they might be potentially used in combined therapy against fungi.

  12. 40 CFR 721.6070 - Alkyl phosphonate ammonium salts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkyl phosphonate ammonium salts. 721... Substances § 721.6070 Alkyl phosphonate ammonium salts. (a) Chemical substances and significant new uses... salts (PMNs P-93-725 and P-93-726) are subject to reporting under this section for the significant...

  13. 40 CFR 721.6070 - Alkyl phosphonate ammonium salts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl phosphonate ammonium salts. 721... Substances § 721.6070 Alkyl phosphonate ammonium salts. (a) Chemical substances and significant new uses... salts (PMNs P-93-725 and P-93-726) are subject to reporting under this section for the significant...

  14. THE MASS ACCOMMODATION COEFFICIENT OF AMMONIUM NITRATE AEROSOL. (R823514)

    EPA Science Inventory

    The mass transfer rate of pure ammonium nitrate between the aerosol and gas phases was
    quantified experimentally by the use of the tandem differential mobility analyzer/scanning mobility
    particle sizer (TDMA/SMPS) technique. Ammonium nitrate particles 80-220 nm in diameter<...

  15. 21 CFR 73.1025 - Ferric ammonium citrate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Ferric ammonium citrate. 73.1025 Section 73.1025 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1025 Ferric ammonium citrate. (a) Identity....

  16. 21 CFR 73.1025 - Ferric ammonium citrate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Ferric ammonium citrate. 73.1025 Section 73.1025 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1025 Ferric ammonium citrate. (a) Identity....

  17. 21 CFR 73.1025 - Ferric ammonium citrate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Ferric ammonium citrate. 73.1025 Section 73.1025 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1025 Ferric ammonium citrate. (a) Identity....

  18. 21 CFR 73.1025 - Ferric ammonium citrate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Ferric ammonium citrate. 73.1025 Section 73.1025 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1025 Ferric ammonium citrate. (a) Identity....

  19. 21 CFR 73.1025 - Ferric ammonium citrate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Ferric ammonium citrate. 73.1025 Section 73.1025 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1025 Ferric ammonium citrate. (a) Identity....

  20. 40 CFR 180.473 - Glufosinate ammonium; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... measuring the sum of glufosinate ammonium, butanoic acid, 2-amino-4-(hydroxymethylphosphinyl) monoammonium...-(hydroxymethylphosphinyl)propanoic acid, expressed as 2-amino-4-(hydroxymethylphosphinyl)butanoic acid equivalents... below is to be determined by measuring the sum of glufosinate ammonium, butanoic acid,...

  1. 40 CFR 180.473 - Glufosinate ammonium; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... residues of the herbicide glufosinate-ammonium (butanoic acid, 2-amino-4-(hydroxymethylphosphinyl...-propionic acid, expressed as 2-amino-4-(hydroxymethylphosphinyl)butanoic acid equivalents, in or on the... ammonium, butanoic acid, 2-amino-4-(hydroxymethylphosphinyl)-, monoammonium salt and its metabolite,...

  2. 21 CFR 184.1140 - Ammonium citrate, dibasic.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Listing of Specific Substances Affirmed as GRAS § 184.1140 Ammonium citrate, dibasic. (a) Ammonium citrate, dibasic ((NH4)2HC6H5O7, CAS Reg. No. 3012-65-5) is the diammonium salt of citric acid. It is prepared by partially neutralizing citric acid with ammonia. (b) The ingredient must be of a purity suitable for...

  3. 21 CFR 184.1140 - Ammonium citrate, dibasic.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Listing of Specific Substances Affirmed as GRAS § 184.1140 Ammonium citrate, dibasic. (a) Ammonium citrate, dibasic ((NH4)2HC6H5O7, CAS Reg. No. 3012-65-5) is the diammonium salt of citric acid. It is prepared by partially neutralizing citric acid with ammonia. (b) The ingredient must be of a purity suitable for...

  4. 40 CFR 721.6070 - Alkyl phosphonate ammonium salts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkyl phosphonate ammonium salts. 721... Substances § 721.6070 Alkyl phosphonate ammonium salts. (a) Chemical substances and significant new uses... salts (PMNs P-93-725 and P-93-726) are subject to reporting under this section for the significant...

  5. 40 CFR 721.6070 - Alkyl phosphonate ammonium salts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkyl phosphonate ammonium salts. 721... Substances § 721.6070 Alkyl phosphonate ammonium salts. (a) Chemical substances and significant new uses... salts (PMNs P-93-725 and P-93-726) are subject to reporting under this section for the significant...

  6. 40 CFR 721.6070 - Alkyl phosphonate ammonium salts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl phosphonate ammonium salts. 721... Substances § 721.6070 Alkyl phosphonate ammonium salts. (a) Chemical substances and significant new uses... salts (PMNs P-93-725 and P-93-726) are subject to reporting under this section for the significant...

  7. Racer (Ammonium Nonanoate) weed control evaluation for onions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Racer has been labeled as a herbicide for food use and is currently under consideration as an organic herbicide for organically grown food crops. The main component (40%) of Racer is ammonium nonanoate (ammonium pelargonate), which occurs in nature and primarily formed from biodegradation of higher...

  8. 46 CFR 148.220 - Ammonium nitrate-phosphate fertilizers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Ammonium nitrate-phosphate fertilizers. 148.220 Section... § 148.220 Ammonium nitrate-phosphate fertilizers. (a) This section applies to the stowage and... nitrate and containing a maximum of 0.4 percent total added combustible material or containing a...

  9. 46 CFR 148.220 - Ammonium nitrate-phosphate fertilizers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Ammonium nitrate-phosphate fertilizers. 148.220 Section... § 148.220 Ammonium nitrate-phosphate fertilizers. (a) This section applies to the stowage and... nitrate and containing a maximum of 0.4 percent total added combustible material or containing a...

  10. 46 CFR 148.220 - Ammonium nitrate-phosphate fertilizers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Ammonium nitrate-phosphate fertilizers. 148.220 Section... § 148.220 Ammonium nitrate-phosphate fertilizers. (a) This section applies to the stowage and... nitrate and containing a maximum of 0.4 percent total added combustible material or containing a...

  11. 46 CFR 148.220 - Ammonium nitrate-phosphate fertilizers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Ammonium nitrate-phosphate fertilizers. 148.220 Section... § 148.220 Ammonium nitrate-phosphate fertilizers. (a) This section applies to the stowage and... nitrate and containing a maximum of 0.4 percent total added combustible material or containing a...

  12. 40 CFR 721.655 - Ethoxylated alkyl quaternary ammonium compound.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... compound. 721.655 Section 721.655 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.655 Ethoxylated alkyl quaternary ammonium compound. (a) Chemical... as an ethoxylated alkyl quaternary ammonium compound (PMN P-96-573) is subject to reporting...

  13. 40 CFR 721.655 - Ethoxylated alkyl quaternary ammonium compound.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... compound. 721.655 Section 721.655 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.655 Ethoxylated alkyl quaternary ammonium compound. (a) Chemical... as an ethoxylated alkyl quaternary ammonium compound (PMN P-96-573) is subject to reporting...

  14. 40 CFR 721.655 - Ethoxylated alkyl quaternary ammonium compound.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... compound. 721.655 Section 721.655 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.655 Ethoxylated alkyl quaternary ammonium compound. (a) Chemical... as an ethoxylated alkyl quaternary ammonium compound (PMN P-96-573) is subject to reporting...

  15. 40 CFR 721.655 - Ethoxylated alkyl quaternary ammonium compound.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... compound. 721.655 Section 721.655 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.655 Ethoxylated alkyl quaternary ammonium compound. (a) Chemical... as an ethoxylated alkyl quaternary ammonium compound (PMN P-96-573) is subject to reporting...

  16. 40 CFR 721.655 - Ethoxylated alkyl quaternary ammonium compound.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... compound. 721.655 Section 721.655 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.655 Ethoxylated alkyl quaternary ammonium compound. (a) Chemical... as an ethoxylated alkyl quaternary ammonium compound (PMN P-96-573) is subject to reporting...

  17. 75 FR 14082 - Ammonium Salts of Fatty Acids (C8

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-24

    ... AGENCY 40 CFR Part 180 Ammonium Salts of Fatty Acids (C 8 -C 18 Saturated); Exemption from the... fatty acids (C 8 -C 18 saturated) applied pre- and post-harvest on all raw agricultural commodities when... eliminates the need to establish a maximum permissible level for residues of ammonium salts of fatty acids...

  18. Shock wave synthesis of amino acids from solutions of ammonium formate and ammonium bicarbonate

    NASA Astrophysics Data System (ADS)

    Suzuki, Chizuka; Furukawa, Yoshihiro; Kobayashi, Takamichi; Sekine, Toshimori; Nakazawa, Hiromoto; Kakegawa, Takeshi

    2015-07-01

    The emergence of life's building blocks, such as amino acids and nucleobases, on the prebiotic Earth was a critical step for the beginning of life. Reduced species with low mass, such as ammonia, amines, or carboxylic acids, are potential precursors for these building blocks of life. These precursors may have been provided to the prebiotic ocean by carbonaceous chondrites and chemical reactions related to meteorite impacts on the early Earth. The impact of extraterrestrial objects on Earth occurred more frequently during this period than at present. Such impacts generated shock waves in the ocean, which have the potential to progress chemical reactions to form the building blocks of life from reduced species. To simulate shock-induced reactions in the prebiotic ocean, we conducted shock-recovery experiments on ammonium bicarbonate solution and ammonium formate solution at impact velocities ranging from 0.51 to 0.92 km/s. In the products from the ammonium formate solution, several amino acids (glycine, alanine, ß-alanine, and sarcosine) and aliphatic amines (methylamine, ethylamine, propylamine, and butylamine) were detected, although yields were less than 0.1 mol % of the formic acid reactant. From the ammonium bicarbonate solution, smaller amounts of glycine, methylamine, ethylamine, and propylamine were formed. The impact velocities used in this study represent minimum cases because natural meteorite impacts typically have higher velocities and longer durations. Our results therefore suggest that shock waves could have been involved in forming life's building blocks in the ocean of prebiotic Earth, and potentially in aquifers of other planets, satellites, and asteroids.

  19. Control of ammonium assimilation in Rhizobium 32H1.

    PubMed Central

    Ludwig, R A

    1978-01-01

    The symbiotic, nitrogen-fixing bacterium Rhizobium sp. 32H1 is a specialized ammonium producer during symbiosis. However, during free-living growth, Rhizobium 32H1 assimilates ammonium very poorly. Two pathways of ammonium assimilation exist in enteric bacteria. One is mediated by glutamate dehydrogenase, and the other is mediated by glutamine synthetase-glutamate synthase. The former pathway is altogether inoperative in Rhizobium 32H1; the latter pathway operates at a slow rate and is under strict negative control by ammonium itself. Rhizobium 32H1 glutamine synthetase activity is modulated by both repression-derepression and reversible adenylylation. For a biochemical process lacking an alternative pathway, such a regulatory pattern exacerbates the very process. This suggests that Rhizobium 32H1 restricts its own ammonium assimilation to maximize the contribution of fixed nitrogen to the host plant during symbiosis. PMID:27498

  20. Assimilation of ammonium and nitrate nitrogen by bean plants

    SciTech Connect

    Volk, R.J. ); Chaillou, S.; Morot-Gaudry, J.F. ); Mariotti, A. )

    1989-04-01

    Enhanced growth is often observed in plants growing on combined ammonium and nitrate nutrition. The physiological basis for such enhancement was examined by exposing non-nodulated bean (Phaseolus vulgaris L.) plants to {sup 15}N-labeled, 1.0 mM N solutions containing 0, 33, 67 or 100% of the N as ammonium, the balance being nitrate. Maximal total N uptake and biomass production were attained by plants receiving 33% ammonium. A higher proportion of incoming ammonium than nitrate was incorporated into root protein. This was accompanied by increased partitioning of plant biomass to roots. It was concluded that as a consequence of greater N metabolism in the root under mixed ammonium and nitrate nutrition, the root became a more active sink for photosynthate. Concurrently, the augmented supply of N to the shoot enhanced net photosynthesis as reflected in increased plant biomass.

  1. Hybrid organic-inorganic crystals based on ammonium dihydrogen phosphate and ammonium salicylate

    NASA Astrophysics Data System (ADS)

    Voronov, A. P.; Salo, V. I.; Puzikov, V. M.; Babenko, G. N.; Roshal, A. D.; Tkachenko, V. F.

    2011-11-01

    ADP-NH 4Sal hybrid crystals are grown from aqueous solutions. The influence of the acidity of the mixed solution on the conditions of co-crystallization of the components is studied. The spectral and scintillation characteristics are determined. Co-crystallization of ammonium salicylate (NH 4Sal) and ammonium dihydrogen phosphate (ADP, NH 4H 2PO 4) is shown to be feasible, the structure of the doping addition being defined by the solution рН. In basic and weak acidic media the hybrid crystals ADP:NH 4Sal are formed in which salicylate anions are located in the interplanar space between the {110}-type planes in the lattice of ADP. The luminescence spectra contain an emission band maximum with λ max=360 nm. In acidic solutions there are ADP:HSal crystals in which salicylic acid molecules captured by the growth macrosteps are located in the interplanar space of the prismatic {100} and pyramidal {101} growth sectors. The luminescence band undergoes bathochromic shift to λmax=400 nm. The sensitivity of ADP:NH 4Sal scintillation crystals to fast neutrons depends on the concentration of ammonium salicylate in ADP matrix. The highest neutron sensitivity is characteristic of the co-doped ADP:NH 4Sal/Tl scintillation crystals.

  2. 76 FR 49449 - Continuation of Antidumping Duty Order on Solid Fertilizer Grade Ammonium Nitrate From the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-10

    ... Nitrate From the Russian Federation AGENCY: Import Administration, International Trade Administration... duty investigation on solid fertilizer grade ammonium nitrate (``ammonium nitrate'') from the Russian... and the ITC instituted a second sunset review of the ammonium nitrate suspended investigation....

  3. 76 FR 23569 - Termination of the Suspension Agreement on Solid Fertilizer Grade Ammonium Nitrate From the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-27

    ... Nitrate From the Russian Federation and Notice of Antidumping Duty Order AGENCY: Import Administration... (``AD'') Investigation on Solid Fertilizer Grade Ammonium Nitrate from the Russian Federation (``the... determine whether imports of solid fertilizer grade ammonium nitrate (``ammonium nitrate'') from Russia...

  4. Effective ammonium removal by anaerobic oxidation in microbial fuel cells.

    PubMed

    Jadhav, Dipak A; Ghangrekar, Makarand M

    2015-01-01

    Dual-chamber microbial fuel cells (MFCs), made of clayware cylinder, were operated at different chemical oxygen demands: ammonium-nitrogen (COD:NH4+) ratio (1:1, 10:1 and 5:1) under batch mode for simultaneous removal of ammonia and organic matter from wastewater. Ammonium-N removal efficiencies of 63-32.66% were obtained for COD:NH4+ ratio of 1:10, respectively. Average COD removal efficiencies demonstrated by these MFCs were about 88%; indicating effective use of MFCs for treatment of wastewater containing organic matter and high ammonia concentration. MFCs operated with COD:NH4+ ratio of 10:1 produced highest volumetric power density of 752.88 mW/m3. The ammonium-N removal slightly increased when microbes were exposed to only ammonium as a source of electron when organic source was not supplemented. When this MFC was operated with imposed potential on cathode and without aeration in the cathode chamber, oxidation of ammonium ions at a faster rate confirmed anaerobic oxidation. During the non-turnover condition of cyclic voltammetry, MFC operated with COD:NH4+ ratio of 10:1 gave higher oxidative and reductive currents than MFC operated with COD:NH4+ ratio of 1:1 due to higher redox species. Successful application of such an anammox process for ammonium oxidation in MFCs will be useful for treatment of wastewater containing higher ammonium concentration and harvesting energy in the form of electricity.

  5. Population of Nitrifying Bacteria and Nitrification in Ammonium Saturated Clinoptilolite

    NASA Technical Reports Server (NTRS)

    McGilloway, R. L.; Weaver, R. W.; Ming, Douglas W.; Gruener, J.

    1999-01-01

    As humans begin to spend longer periods of time in space, plants will be incorporated into life support systems. Ammonium saturated clinoptilolite is one plant growth substrate but a balance between ammonium and nitrate is needed. A laboratory study was conducted to determine effects of nitrifying bacteria on ammonium concentrations and kinetics of nitrification. Columns containing clinoptilolite substrate amended with nitrifying bacteria obtained from soil enrichment were analyzed weekly for a 90 day period. The enrichment culture initially contained 1 x 10(exp 5) ammonium oxidizing bacteria and 1 x 10(exp 2) nitrite oxidizing bacteria per gram of substrate. Populations of ammonium oxidizing bacteria increased to 1 x 10(exp 6) and nitrite oxidizing bacteria increased to 1 x 10(exp 3) per gram of substrate. The nitrification rate was approximately 0.25mg NO3(-)-N/kg.hr. Experiments were also conducted to enumerate nitrifying bacteria in a clinoptilolite substrate used to grow wheat (Triticum aestivum L.). Seventy days following the initial inoculation with an unknown number of commercial nitrifying bacteria, 1 x 10(exp 5) ammonium oxidizing bacteria per gram of substrate were present. The number of nitrite oxidizing bacteria was between 1 x 10(exp 3) to 10(exp 4) per gram of substrate as measured by the most probable number method. Nitrification rates were approximately 0.20mg NO3(-)-N/kg.hr. Clinoptilolite readily exchanged sufficient concentrations of ammonium to support nitrifying bacteria and they survived well in this medium.

  6. Ammonium Hydrosulfide and Jupiter's Great Red Spot

    NASA Astrophysics Data System (ADS)

    Loeffler, M. J.; Hudson, R.; Chanover, N.; Simon, A. A.

    2014-12-01

    The color and composition of Jupiter's Great Red Spot (GRS) has been debated for more than a century. While there are numerous hypotheses for the origin of Jupiter's GRS, recent work suggests that the GRS's color could originate from multiple components (Carlson et al., 2012; Simon et al., submitted). In light of this, we have recently begun conducting in situ laboratory experiments that test whether ammonium hydrosulfide, NH4SH, or its radiation decomposition products contribute to the GRS spectrum. In this presentation, we will discuss some of our most recent results, where we have studied the stability of NH4SH samples as a function of temperature using infrared and mass spectrometry. Funding for this work has been provided by NASA's Planetary Atmospheres and Outer Planets Research programs. ReferencesCarlson, R. W., K. H. Baines, M. S. Anderson, G. Filacchione. Chromophores from photolyzed ammonia reacting with acetylene: Application to Jupiter's Great Red Spot, DPS, 44, 2012. Simon, A. A., J. Legarreta, F. Sanz-Requena, S. Perez-Hoyos, E. Garcia-Melendo, R. W. Carlson. Spectral Comparison and Stability of Red Regions on Jupiter. J. Geophys. Res. - Planets, submitted.

  7. Combustion of ammonium and hydrazine azides

    SciTech Connect

    Fogelzang, A.E.; Egorshev, V.Y.; Sinditsky, V.P.; Kolesov, B.I. )

    1992-09-01

    This paper reports that steady-state combustion of ammonium azide (AA) and hydrazne azide (HA) was studied in a window constant-pressure bomb over a pressure range of 0.1-36 MPa. HA burns three to four times faster than AA over the whole pressure range. The temperature distribution in the combustion wave of AA and HA was measured using 5-{mu}m-thick {pi}-shaped tungsten-rhenium tape thermocouples. The combustion temperature of both compounds is 240-430 K higher than the temperature calculated for the thermodynamically equilibrium composition of the combustion products due to the presence of large amounts of ammonia (0.97 and 0.87 mol per AA and HA mole, respectively). The burning surface is formed via dissociation of the salts into hydrazoic acid HN{sub 3} and the parent base. The growth of the surface temperature with pressure is determined by the dissociation enthalpy of the slats. The burning rate of these compounds is determined by heat release in the gas phase.

  8. Aerosol isotopic ammonium signatures over the remote Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Lin, C. T.; Jickells, T. D.; Baker, A. R.; Marca, A.; Johnson, M. T.

    2016-05-01

    We report aerosol ammonium 15N signatures for samples collected from research cruises on the South Atlantic and Caribbean using a new high sensitivity method. We confirm a pattern of isotopic signals from generally light (δ15N -5 to -10‰), for aerosols with very low (<2 nmol m-3) ammonium concentrations from the remote high latitude ocean, to generally heavier values (δ15N +5 to +10‰), for aerosols collected in temperate and tropical latitudes and with higher ammonium concentrations (>2 nmol m-3). We discuss whether this reflects a mixing of aerosols from two end-members (polluted continental and remote marine emissions), or isotopic fractionation during aerosol transport.

  9. Antimicrobial Polymeric Materials with Quaternary Ammonium and Phosphonium Salts

    PubMed Central

    Xue, Yan; Xiao, Huining; Zhang, Yi

    2015-01-01

    Polymeric materials containing quaternary ammonium and/or phosphonium salts have been extensively studied and applied to a variety of antimicrobial-relevant areas. With various architectures, polymeric quaternary ammonium/phosphonium salts were prepared using different approaches, exhibiting different antimicrobial activities and potential applications. This review focuses on the state of the art of antimicrobial polymers with quaternary ammonium/phosphonium salts. In particular, it discusses the structure and synthesis method, mechanisms of antimicrobial action, and the comparison of antimicrobial performance between these two kinds of polymers. PMID:25667977

  10. Nitrogen removal with the anaerobic ammonium oxidation process.

    PubMed

    Hu, Ziye; Lotti, Tommaso; van Loosdrecht, Mark; Kartal, Boran

    2013-08-01

    Anaerobic ammonium-oxidizing (anammox) bacteria convert ammonium to N2 with nitrite as the terminal electron acceptor in the absence of O2. Nitritation-anammox bioreactors provide a cost-effective and environment-friendly alternative to conventional nitrification/denitrification nitrogen removal systems. Currently, this process is only applied for ammonium removal from wastewater with high ammonium load and temperature. Nevertheless, recent results obtained with laboratory-scale bioreactors suggest new possible routes of application of the Nitritation-anammox technology including (1) municipal wastewater treatment, removal of (2) methane in combination with nitrite-reducing methane-oxidizing bacteria, (3) nitrate coupled to organic acid oxidation and (4) nitrogen oxides. The current review summarizes the state-of-the-art of the application of Nitritation-anammox systems and discusses the possibilities of utilizing these recent results for wastewater treatment.

  11. Direct esterification of ammonium salts of carboxylic acids

    DOEpatents

    Halpern, Yuval

    2003-06-24

    A non-catalytic process for producing esters, the process comprising reacting an ammonium salt of a carboxylic acid with an alcohol and removing ammonia from the reaction mixture. Selectivities for the desired ester product can exceed 95 percent.

  12. High-affinity ammonium transporters and nitrogen sensing in mycorrhizas.

    PubMed

    Javelle, Arnaud; André, Bruno; Marini, Anne Marie; Chalot, Michel

    2003-02-01

    Most terrestrial plants live in mutualistic symbiosis with root-infecting mycorrhizal fungi. This association requires a molecular dialogue between the two partners. However, the nature of the chemical signals that induce hyphal differentiation are not well characterized and the mechanisms for signal reception are still unknown. In addition to its role in ammonium scavenging, the Mep2 protein from Saccharomyces cerevisiae has been proposed to act as an ammonium sensor that is essential for pseudohyphal differentiation in response to ammonium limitation. We propose that the high-affinity ammonium transporters from mycorrhizal fungi act in a similar manner to sense the environment and induce, via as-yet-unidentified signal transduction cascades, the switch in the mode of fungal growth observed during the formation of mycorrhiza.

  13. Deliquescence behavior of organic/ammonium sulfate aerosol

    NASA Astrophysics Data System (ADS)

    Brooks, Sarah D.; Wise, Matthew E.; Cushing, Melinda; Tolbert, Margaret A.

    2002-10-01

    Recent studies have shown that tropospheric aerosols composed of internal mixtures of organics with sulfates are quite common with the organic composing up to 50% of the particle mass. The influences of the organics on the chemical and physical properties of the aerosol are not known. In this paper, we report the solubility of a series of dicarboxylic acids in saturated ammonium sulfate solution as a function of temperature. We also report the deliquescence relative humidity (DRH) of the pure dicarboxylic acids and of mixtures of dicarboxylic acids with ammonium sulfate. For the systems studied, we find that the presence of water-soluble dicarboxylic acids caused deliquescence to occur at a lower relative humidity (RH) than pure ammonium sulfate. In contrast, the less soluble dicarboxylic acids had no measurable effect on the deliquescence relative humidity of ammonium sulfate.

  14. The effect of ammonium sulfate injection on peripheral nerve.

    PubMed

    Kobayashi, J; Mackinnon, S E; Langer, J C; Hertl, M C; Hunter, D A; Tarasidis, G

    1997-08-01

    Local anesthetic drugs with prolonged nerve-block effect would have clinical application for postoperative or neuromatous pain relief. This study evaluated the possibility of peripheral nerve neurotoxicity by injection of 10 percent ammonium sulfate. Both intrafascicular and extrafascicular injection of 10 percent ammonium sulfate were tested in the rat sciatic nerve model. One percent lidocaine HCl, 5 percent phenol, and normal saline were similarly injected for comparison. Using histologic studies and motor function evaluation with walking-track analysis, 10 percent ammonium sulfate was found to be neurotoxic when it is injected intrafascicularly; however, extrafascicular injection of this drug did not cause significant nerve injury. The neurotoxicity of the 10 percent ammonium sulfate solution was intermediate between the neurotoxicity of 0.1 percent lidocaine hydrochloride and the marked neurotoxicity of 5 percent phenol solution.

  15. Chemical Advisory - Solid Ammonium Nitrate (AN) Storage, Handling and Management

    EPA Pesticide Factsheets

    Advisory contains information on recent and past accidents involving AMMONIUM NITRATE (commonly referred to as AN), on the hazards of AN, how to manage these hazards, and appropriate steps for community emergency planning and proper emergency response.

  16. 40 CFR 180.473 - Glufosinate ammonium; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 2-amino-4-(hydroxymethylphosphinyl)butanoic acid, in or on the commodity. Commodity Parts per... ammonium, 2-amino-4-(hydroxymethylphosphinyl)butanoic acid monoammonium salt, and its metabolite, 3-(hydroxymethylphosphinyl)propionic acid, calculated as the stoichiometric equivalent of...

  17. 40 CFR 180.473 - Glufosinate ammonium; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 2-amino-4-(hydroxymethylphosphinyl)butanoic acid, in or on the commodity. Commodity Parts per... ammonium, 2-amino-4-(hydroxymethylphosphinyl)butanoic acid monoammonium salt, and its metabolite, 3-(hydroxymethylphosphinyl)propionic acid, calculated as the stoichiometric equivalent of...

  18. Formation of urea and guanidine by irradiation of ammonium cyanide.

    NASA Technical Reports Server (NTRS)

    Lohrmann, R.

    1972-01-01

    Aqueous solutions of ammonium cyanide yield urea, cyanamide and guanidine when exposed to sunlight or an unfiltered 254 nm ultraviolet source. The prebiotic significance of these results is discussed.

  19. 21 CFR 73.2298 - Ferric ammonium ferrocyanide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2298 Ferric ammonium ferrocyanide. (a... ferrocyanide is safe for use in coloring externally applied cosmetics, including cosmetics applied to the...

  20. 21 CFR 73.2298 - Ferric ammonium ferrocyanide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2298 Ferric ammonium ferrocyanide. (a... ferrocyanide is safe for use in coloring externally applied cosmetics, including cosmetics applied to the...

  1. 21 CFR 73.2298 - Ferric ammonium ferrocyanide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2298 Ferric ammonium ferrocyanide. (a... ferrocyanide is safe for use in coloring externally applied cosmetics, including cosmetics applied to the...

  2. 21 CFR 73.2298 - Ferric ammonium ferrocyanide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2298 Ferric ammonium ferrocyanide. (a... ferrocyanide is safe for use in coloring externally applied cosmetics, including cosmetics applied to the...

  3. 21 CFR 73.2298 - Ferric ammonium ferrocyanide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2298 Ferric ammonium ferrocyanide. (a... ferrocyanide is safe for use in coloring externally applied cosmetics, including cosmetics applied to the...

  4. Redox potentials in ammonium nitrate solutions

    SciTech Connect

    Ngameni, E.; Ammaa, B.B.; Wandji, R.; Bessiere, J.

    1995-03-01

    The redox potentials of M{sup n+}/M (M{sup n+} = Cu{sup 2+}, Pb{sup 2+}, Sn{sup 2+}, Cd{sup 2+}, Ag{sup +}, Zn{sup 2+}, Hg{sup 2+}), M{sup n+}/M {sup (n{minus}m)+} (Fe{sup 3+}/Fe{sup 2+}, Fe(CN){sub 6}3{minus}/Fe(CN){sub 6}{sup 4{minus}}), and AgX/Ag, X{sup {minus}} (X = Cl, Br, and I) have been measured in aqueous solutions of ammonium nitrate (1--14 M). The variation of salvation of ions, characterized by the solvent transfer coefficient f{sup tr}, is calculated from the normal redox potentials of the systems. For all the cases, the potential of the ferricinium/ferrocene system (Fe{sup +}/Fc) is used as a reference of potential. It appears as a general trend that when the concentration of salt increases from 1 to 14 M, the potentials of the systems vary slightly, indicating weak interactions between these solutes and the salt. The examined ions can be classified into two groups: those that are less solvated as the concentration of NH{sub 4}NO{sub 3} increases (CU{sup 2+}, Cd{sup 2+}, Zn{sup 2+}, Cl{sup {minus}}, Br{sup {minus}}, I{sup {minus}}) and those that are more solvated, (Pb{sup 2+}, Ag{sup +}, Hg{sup 2+}, Sn{sup 2+}). The solubility constants of the AgX salts in the H{sub 2}O + NH{sub 4}NO{sub 3} mixtures are also calculated.

  5. Analytical techniques for determining bound ammonium

    SciTech Connect

    Altaner, S.P.; Krohn, M.D

    1985-01-01

    Ammonium (NH/sub 4//sup +/) has been found to substitute for alkali cations in feldspars, micas, smectites, and alunites several Hg/Au-bearing hot springs deposits and volcanogenic stratabound Pb/Zn deposits. The authors compared four analytical techniques for determining the NH/sub 4//sup +/ content in rocks from these types of deposit and in synthetic NH/sub 4//sup +/-bearing feldspars, micas, and alunites: 1) X-ray diffraction (XRD), 2) mid- and 3) near-infrared spectroscopy (MIR and NIR) and 4) ion chromatography (IC). MIR analysis of synthetic minerals indicates that 7 ..mu..m band depth depends upon mineral type but that, for a given mineral, band depth is directly proportional to NH/sub 4//sup +/ concentration. NIR reflectance spectroscopy gives a rapid qualitative determination of NH/sub 4//sup +/ and allows positive field identification of NH/sub 4//sup +/. 4) IC gives a measure of the percent of NH/sub 4//sup +/ substitution by determining NH/sub 4//sup +/, K/sup +/, and Na/sup +/ concentrations. The procedure involves sample dissolution by HCl and HF in a microwave oven followed by separation and detection by an ion chromatograph. They estimate the detection limits of these analytical techniques for NH/sub 4//sup +/ concentration to be: XRD, 10-20% NH/sub 4//sup +/; MIR, 1-5% NG/sub 4//sup +/; and IC, <1% NH/sub 4//sup +/. Determination of NH/sub 4//sup +/ abundance in rocks will help to delineate the relationship of NH/sub 4//sup +/-bearing minerals to mineralization in ore deposits and promises to be an excellent method for prospecting.

  6. The regulation of ammonium translocation in plants.

    PubMed

    Schjoerring, J K; Husted, S; Mäck, G; Mattsson, M

    2002-04-01

    Much controversy exists about whether or not NH(+)(4) is translocated in the xylem from roots to shoots. In this paper it is shown that such translocation can indeed take place, but that interference from other metabolites such as amino acids and amines may give rise to large uncertainties about the magnitude of xylem NH(+)(4) concentrations. Elimination of interference requires sample stabilization by, for instance, formic acid or methanol. Subsequent quantification of NH(+)(4) should be done by the OPA-fluorometric method at neutral pH with 2-mercaptoethanol as the reducing agent since this method is sensitive and reliable. Colorimetric methods based on the Berthelot reaction should never be used, as they are prone to give erroneous results. Significant concentrations of NH(+)(4), exceeding 1 mM, were measured in both xylem sap and leaf apoplastic solution of oilseed rape and tomato plants growing with NO(-)(3) as the sole N source. When NO(-)(3) was replaced by NH(+)(4), xylem sap NH(+)(4) concentrations increased with increasing external concentrations and with time of exposure to NH(+)(4). Up to 11% of the translocated N was constituted by NH(+)(4). Glutamine synthetase (GS) incorporates NH(+)(4) into glutamine, but root GS activity and expression were repressed when high levels of NH(+)(4) were supplied. Ammonium concentrations measured in xylem sap sampled just above the stem base were highly correlated with NH(+)(4) concentrations in apoplastic solution from the leaves. Young leaves tended to have higher apoplastic NH(+)(4) concentrations than older non-senescing leaves. The flux of NH(+)(4) (concentration multiplied by transpirational water flow) increased with temperature despite a decline in xylem NH(+)(4) concentration. Retrieval of leaf apoplastic NH(+)(4) involves both high and low affinity transporters in the plasma membrane of mesophyll cells. Current knowledge about these transporters and their regulation is discussed.

  7. Crystal structure of cyclo-hexyl-ammonium thio-cyanate.

    PubMed

    Bagabas, Abdulaziz A; Alhoshan, Sultan B; Ghabbour, Hazem A; Chidan Kumar, C S; Fun, Hoong-Kun

    2015-01-01

    In the title salt, C6H11NH3 (+)·SCN(-), the cyclo-hexyl-ammonium ring adopts a slightly distorted chair conformation. The ammonium group occupies an equatorial position to minimize 1,3 and 1,5 diaxial inter-actions. In the crystal, the components are linked by N-H⋯N and N-H⋯S hydrogen-bonding inter-actions, resulting in a three-dimensional network.

  8. Localized corrosion of stainless steels in ammonium chloride solutions

    SciTech Connect

    Forsen, O.; Aromaa, J.; Tavi, M.; Virtanen, J.

    1997-05-01

    Ammonium chloride deposition is a well-known problem in oil refining. When these deposits form in a moist environment, they are corrosive to carbon steel. When unexpected corrosion problems are faced, the material is often changed to alloys like stainless steels (SS). Electrochemical measurements were used to study the corrosion resistance of SS in ammonium chloride environments with different chloride contents and at different temperatures.

  9. Safety assessment of ammonium hectorites as used in cosmetics.

    PubMed

    Becker, Lillian C; Bergfeld, Wilma F; Belsito, Donald V; Hill, Ronald A; Klaassen, Curtis D; Liebler, Daniel C; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Andersen, F Alan

    2013-01-01

    The Cosmetic Ingredient Review Expert Panel (Panel) reviewed the safety of 4 ammonium hectorite compounds used in cosmetics: disteardimonium hectorite, dihydrogenated tallow benzylmonium hectorite, stearalkonium hectorite, and quaternium-18 hectorite. These ingredients function in cosmetics mainly as nonsurfactant suspending agents. The Panel reviewed available animal and human data and concluded that these ammonium hectorite compounds were safe as cosmetic ingredients in the practices of use and concentration as given in this safety assessment.

  10. Sorption of aromatic ionizable organic compounds to montmorillonites modified by hexadecyltrimethyl ammonium and polydiallyldimethyl ammonium.

    PubMed

    Xu, Huaizhou; Wan, Yuqiu; Li, Hui; Zheng, Shourong; Zhu, Dongqiang

    2011-01-01

    Environmental residues of aromatic ionizable organic compounds (AIOCs) have received considerable attention due to their potential human health and ecological risks. The main objective of this study was to investigate the key factors and mechanisms controlling sorption of a series of anionic and zwitterionic AIOCs (two aromatic sulfonates, 4-methyl-2,6-dinitrophenol, tetracycline, sulfamethoxazole, and tannic acid) to montmorillonites modified with hexadecyltrimethyl ammonium (HDTMA) and polydiallyldimethyl ammonium (PDADMA). Compared with naphthalene (a nonpolar and nonionic solute), all AIOCs showed stronger sorption (the sorbent-to-solution distribution coefficient was in the order of 10-10 L kg) to the two organoclays in spite of the much lower hydrophobicity, indicating the predominance of electrostatic interaction in sorption. The proposed electrostatic mechanism of the tested AIOCs was supported by the pH dependency of sorption to the two organoclays. The two organoclays manifested weaker sorption affinity but faster sorption kinetics for bulky AIOCs than commercial activated carbon, resulting from the high accessibility of sorption sites in the open, ordered clay interlayer. The findings of this study highlight the potential of using HDTMA- and PDADMA-exchanged montmorillonites as effective sorbents for AIOCs in water and wastewater treatments.

  11. Thermal Decomposition Behavior of Ammonium Perchlorate and of an Ammonium-Perchlorate-Based Composite Propellant

    NASA Technical Reports Server (NTRS)

    Behrens, R.; Minier, L.

    1998-01-01

    The thermal decomposition of ammonium perchlorate (AP) and ammonium-perchlorate-based composite propellants is studied using the simultaneous thermogravimetric modulated beam mass spectrometry (STMBMS) technique. The main objective of the present work is to evaluate whether the STMBMS can provide new data on these materials that will have sufficient detail on the reaction mechanisms and associated reaction kinetics to permit creation of a detailed model of the thermal decomposition process. Such a model is a necessary ingredient to engineering models of ignition and slow-cookoff for these AP-based composite propellants. Results show that the decomposition of pure AP is controlled by two processes. One occurs at lower temperatures (240 to 270 C), produces mainly H2O, O2, Cl2, N2O and HCl, and is shown to occur in the solid phase within the AP particles. 200(micro) diameter AP particles undergo 25% decomposition in the solid phase, whereas 20(micro) diameter AP particles undergo only 13% decomposition. The second process is dissociative sublimation of AP to NH3 + HClO4 followed by the decomposition of, and reaction between, these two products in the gas phase. The dissociative sublimation process occurs over the entire temperature range of AP decomposition, but only becomes dominant at temperatures above those for the solid-phase decomposition. AP-based composite propellants are used extensively in both small tactical rocket motors and large strategic rocket systems.

  12. Thermal storage in ammonium alum/ammonium nitrate eutectic for solar space heating

    SciTech Connect

    Goswami, D.Y.; Jotshi, C.K.; Klausner, J.F.; Hsieh, C.K.; Srinivasan, N.

    1995-10-01

    Ammonium alum and ammonium nitrate in the weight ratio of 1:1 forms a eutectic that melts at 53 C and crystallizes at 48 C. The latent heat of fusion of this eutectic was found to be 215 kJ/kg. Its enthalpy as measured by drop calorimetry was found to be 287 kJ/kg in the temperature range of 24--65 C, which is 1.67 times greater than water (172.2 kJ/kg) and 8.75 times greater than rock (32.8 kJ/kg). Upon several heating/cooling cycles, phase separation was observed. However, by adding 5% attapulgite clay to this eutectic mixture, phase separation was prevented. This eutectic was encapsulated in 0.0254m diameter HDPE hollow balls and subjected to about 1,100 heating/cooling cycles in the temperature range between 25 and 65 C. At the end of these cycles, the decrease in enthalpy was found to be 5%. A scale model of the heat storage unit was fabricated to investigate the heat transfer characteristics of this eutectic encapsulated in HDPE balls. The thermal extraction efficiency of the system was measured with the recirculation of hot air during charging and was found to be in the range of 85--98%.

  13. The thermal decomposition behavior of ammonium perchlorate and of an ammonium-perchlorate-based composite propellant

    SciTech Connect

    Behrens, R.; Minier, L.

    1998-03-24

    The thermal decomposition of ammonium perchlorate (AP) and ammonium-perchlorate-based composite propellants is studied using the simultaneous thermogravimetric modulated beam mass spectrometry (STMBMS) technique. The main objective of the present work is to evaluate whether the STMBMS can provide new data on these materials that will have sufficient detail on the reaction mechanisms and associated reaction kinetics to permit creation of a detailed model of the thermal decomposition process. Such a model is a necessary ingredient to engineering models of ignition and slow-cookoff for these AP-based composite propellants. Results show that the decomposition of pure AP is controlled by two processes. One occurs at lower temperatures (240 to 270 C), produces mainly H{sub 2}O, O{sub 2}, Cl{sub 2}, N{sub 2}O and HCl, and is shown to occur in the solid phase within the AP particles. 200{micro} diameter AP particles undergo 25% decomposition in the solid phase, whereas 20{micro} diameter AP particles undergo only 13% decomposition. The second process is dissociative sublimation of AP to NH{sub 3} + HClO{sub 4} followed by the decomposition of, and reaction between, these two products in the gas phase. The dissociative sublimation process occurs over the entire temperature range of AP decomposition, but only becomes dominant at temperatures above those for the solid-phase decomposition. AP-based composite propellants are used extensively in both small tactical rocket motors and large strategic rocket systems.

  14. The ground water ammonium sorption onto Croatian and Serbian clinoptilolite.

    PubMed

    Siljeg, Mario; Foglar, Lucija; Kukucka, Miroslav

    2010-06-15

    The removal of ammonium from the Valpovo region ground water (VGW) with the use of natural clinoptilolite samples from the Donje Jesenje deposit (Croatia) and the Zlatokop deposit in Vranjska Banja (Serbia) was studied. The natural Serbian (SZ) and Croatian zeolites (CZ) were transformed to the Na-form (Na-CZ and Na-SZ) in order to increase the exchange capacity of zeolite. The CZ and SZ theoretic ammonium sorption capacities were 24.24 mg NH(4)(+)/g CZ and 32.55 mg NH(4)(+)/g SZ, respectively. The application of natural and Na-form of clinoptilolite for efficient removal of ammonium ions from VGW was further investigated. For that purpose, the four "filter guard" vessels filled with zeolite samples were set in parallel in the ground water purification pilot plant. The complete ammonium removal, with the use of SZ and Na-SZ was achieved during 20 h. After having observed saturation of clinoptilolite, the samples were regenerated with the use of 2 mol/L NaCl, and reused for determination of ammonium sorption efficiency. The regenerated samples showed to be still very efficient for NH(4)(+) removal and, in addition, the SZ was shown as superior for ammonium removal in comparison to the CZ.

  15. Removal of ammonium from municipal landfill leachate using natural zeolites.

    PubMed

    Ye, Zhihong; Wang, Jiawen; Sun, Lingyu; Zhang, Daobin; Zhang, Hui

    2015-01-01

    Ammonium ion-exchange performance of the natural zeolite was investigated in both batch and column studies. The effects of zeolite dosage, contact time, stirring speed and pH on ammonium removal were investigated in batch experiments. The result showed that ammonium removal efficiency increased with an increase in zeolite dosage from 25 to 150 g/L, and an increase in stirring speed from 200 to 250 r/min. But further increase in zeolite dosage and stirring speed would result in an unpronounced increase of ammonium removal. The optimal pH for the removal of ammonium was found as 7.1. In the column studies, the effect of flow rate was investigated, and the total ammonium removal percentage during 180 min operation time decreased with the flow rate though the ion-exchange capacity varied to a very small extent with the flow rate ranging from 4 to 9 mL/min. The spent zeolite was regenerated by sodium chloride solution and the ammonia removal capacity of zeolite changed little or even increased after three regeneration cycles.

  16. Nitric oxide controls nitrate and ammonium assimilation in Chlamydomonas reinhardtii.

    PubMed

    Sanz-Luque, Emanuel; Ocaña-Calahorro, Francisco; Llamas, Angel; Galvan, Aurora; Fernandez, Emilio

    2013-08-01

    Nitrate and ammonium are major inorganic nitrogen sources for plants and algae. These compounds are assimilated by means of finely regulated processes at transcriptional and post-translational levels. In Chlamydomonas, the expression of several genes involved in high-affinity ammonium (AMT1.1, AMT1.2) and nitrate transport (NRT2.1) as well as nitrate reduction (NIA1) are downregulated by ammonium through a nitric oxide (NO)-dependent mechanism. At the post-translational level, nitrate/nitrite uptake and nitrate reductase (NR) are also inhibited by ammonium, but the mechanisms implicated in this regulation are scarcely known. In this work, the effect of NO on nitrate assimilation and the high-affinity ammonium uptake was addressed. NO inhibited the high-affinity uptake of ammonium and nitrate/nitrite, as well as the NR activity, in a reversible form. In contrast, nitrite reductase and glutamine synthetase activities were not affected. The in vivo and in vitro studies suggested that NR enzyme is inhibited by NO in a mediated process that requires the cell integrity. These data highlight a role of NO in inorganic nitrogen assimilation and suggest that this signalling molecule is an important regulator for the first steps of the pathway.

  17. 40 CFR 418.40 - Applicability; description of the ammonium nitrate subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... ammonium nitrate subcategory. 418.40 Section 418.40 Protection of Environment ENVIRONMENTAL PROTECTION... Ammonium Nitrate Subcategory § 418.40 Applicability; description of the ammonium nitrate subcategory. The provisions of this subpart are applicable to discharges resulting from the manufacture of ammonium...

  18. 76 FR 39847 - Solid Fertilizer Grade Ammonium Nitrate From the Russian Federation; Final Results of the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-07

    ... International Trade Administration Solid Fertilizer Grade Ammonium Nitrate From the Russian Federation; Final... investigation on solid fertilizer grade ammonium nitrate (``ammonium nitrate'') from the Russian Federation... duty investigation and issued an antidumping duty order on ammonium nitrate from Russia. On the...

  19. 77 FR 65532 - Solid Fertilizer Grade Ammonium Nitrate From the Russian Federation: Notice of Rescission of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-29

    ... International Trade Administration Solid Fertilizer Grade Ammonium Nitrate From the Russian Federation: Notice... the antidumping duty order on solid fertilizer grade ammonium nitrate (ammonium nitrate) from the... ammonium nitrate from Russia. On May 29, 2012, the Department published a notice of initiation of...

  20. 40 CFR 418.40 - Applicability; description of the ammonium nitrate subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... ammonium nitrate subcategory. 418.40 Section 418.40 Protection of Environment ENVIRONMENTAL PROTECTION... Ammonium Nitrate Subcategory § 418.40 Applicability; description of the ammonium nitrate subcategory. The provisions of this subpart are applicable to discharges resulting from the manufacture of ammonium...

  1. 40 CFR 418.40 - Applicability; description of the ammonium nitrate subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... ammonium nitrate subcategory. 418.40 Section 418.40 Protection of Environment ENVIRONMENTAL PROTECTION... Ammonium Nitrate Subcategory § 418.40 Applicability; description of the ammonium nitrate subcategory. The provisions of this subpart are applicable to discharges resulting from the manufacture of ammonium...

  2. 40 CFR 418.40 - Applicability; description of the ammonium nitrate subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... ammonium nitrate subcategory. 418.40 Section 418.40 Protection of Environment ENVIRONMENTAL PROTECTION... Ammonium Nitrate Subcategory § 418.40 Applicability; description of the ammonium nitrate subcategory. The provisions of this subpart are applicable to discharges resulting from the manufacture of ammonium...

  3. 40 CFR 418.40 - Applicability; description of the ammonium nitrate subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... ammonium nitrate subcategory. 418.40 Section 418.40 Protection of Environment ENVIRONMENTAL PROTECTION... Ammonium Nitrate Subcategory § 418.40 Applicability; description of the ammonium nitrate subcategory. The provisions of this subpart are applicable to discharges resulting from the manufacture of ammonium...

  4. Early metabolic effects and mechanism of ammonium transport in yeast

    SciTech Connect

    Pena, A.; Pardo, J.P.; Ramirez, J.

    1987-03-01

    Studies were performed to define the effects and mechanism of NH+4 transport in yeast. The following results were obtained. Glucose was a better facilitator than ethanol-H/sub 2/O/sub 2/ for ammonium transport; low concentrations of uncouplers or respiratory inhibitors could inhibit the transport with ethanol as the substrate. With glucose, respiratory inhibitors showed only small inhibitory effects, and only high concentrations of azide or trifluoromethoxy carbonylcyanide phenylhydrazone could inhibit ammonium transport. Ammonium in the free state could be concentrated approximately 200-fold by the cells. Also, the addition of ammonium produced stimulation of both respiration and fermentation; an increased rate of H+ extrusion and an alkalinization of the interior of the cell; a decrease of the membrane potential, as monitored by fluorescent cyanine; an immediate decrease of the levels of ATP and an increase of ADP, which may account for the stimulation of both fermentation and respiration; and an increase of the levels of inorganic phosphate. Ammonium was found to inhibit 86Rb+ transport much less than K+. Also, while K+ produced a competitive type of inhibition, that produced by NH4+ was of the noncompetitive type. From the distribution ratio of ammonium and the pH gradient, an electrochemical potential gradient of around -180 mV was calculated. The results indicate that ammonium is transported in yeast by a mechanism similar to that of monovalent alkaline cations, driven by a membrane potential. The immediate metabolic effects of this cation seem to be due to an increased (H+)ATPase, to which its transport is coupled. However, the carriers seem to be different. The transport system studied in this work was that of low affinity.

  5. Clinoptilolite: a possible support material for nitrifying biofilms for effective control of ammonium effluent quality?

    PubMed

    Inan, H; Beler Baykal, B

    2005-01-01

    Ammonium selective natural zeolite clinoptilolite is suggested as a possible support material for nitrifying biofilms to help improve effluent ammonium quality through its high capacity of ammonium removal in the process of ion exchange. This will especially be helpful in cases where the biofilter receives peak or variable loads routinely or occasionally. At the time of peak loads or shocks of ammonium, ion exchange capacity will provide a buffer for the effluent ammonium quality. Data to support this suggestion is presented.

  6. Simultaneous removal of ammonium and suspended solids in multipurpose filters.

    PubMed

    Alkas, Deniz; Baykal, Bilsen Beler; Kinaci, Cumali

    2012-06-01

    A multipurpose filter in which sand and clinoptilolite are used together as filter material is suggested for the simultaneous removal of suspended solids and ammonium in one single unit. The capacity of the clinoptilolite used was determined as 10.4 mg/g for 20 mg/l initial ammonium concentration. In addition, a packed column ion exchanger with clinoptilolite and a classical sand filter were also investigated for comparison. Ammonium and suspended solids removal rates were observed and compared for all columns. The results of the column analysis have revealed that the ammonium removal rate, which was only 20% in the sand column, was increased to 100% by replacing 50% of the sand with clinoptilolite; similarly, the suspended solids removal, which was only 17% in the clinoptilolite column, was increased to 75% by replacing 50% of the clinoptilolite with sand. As such, when ion exchange and filtration processes were carried out in a multipurpose column, high removals for both parameters could be obtained simultaneously. Multipurpose columns could be an alternative both for the upgrading of existing treatment plants or for new plants for simultaneous removal of ammonium and suspended solids, giving considerable savings in terms of land requirements.

  7. Removing ammonium from water using modified corncob-biochar.

    PubMed

    Vu, Thi Mai; Trinh, Van Tuyen; Doan, Dinh Phuong; Van, Huu Tap; Nguyen, Tien Vinh; Vigneswaran, Saravanamuthu; Ngo, Huu Hao

    2017-02-01

    Ammonium pollution in groundwater and surface water is of major concern in many parts of the world due to the danger it poses to the environment and people's health. This study focuses on the development of a low cost adsorbent, specifically a modified biochar prepared from corncob. Evaluated here is the efficiency of this new material for removing ammonium from synthetic water (ammonium concentration from 10 to 100mg/L). The characteristics of the modified biochar were determined by Brunauer-Emmett-Teller (BET) test, Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM). It was found that ammonium adsorption on modified biochar strongly depended on pH. Adsorption kinetics of NH4(+)-N using modified biochar followed the pseudo-second order kinetic model. Both Langmuir and Sips adsorption isotherm models could simulate well the adsorption behavior of ammonium on modificated biochar. The highest adsorption capacity of 22.6mg NH4(+)-N/g modified biochar was obtained when the biochar was modified by soaking it in HNO3 6M and NaOH 0.3M for 8h and 24h, respectively. The high adsorption capacity of the modified biochar suggested that it is a promising adsorbent for NH4(+)-N remediation from water.

  8. Fractionation of bamboo hemicelluloses by graded saturated ammonium sulphate.

    PubMed

    Guan, Ying; Zhang, Bing; Qi, Xian-Ming; Peng, Feng; Yao, Chun-Li; Sun, Run-Cang

    2015-09-20

    The hemicelluloses were isolated with 10% KOH at 25°C from dewaxed and delignified bamboo powder. The alkali-soluble hemicelluloses from Sinocalamus affinis were fractionated by ammonium sulphate precipitation method. The bamboo alkali-soluble hemicelluloses yielded seven hemicellulosic fractions obtained at 0, 5, 15, 25, 40, 55, and 70% saturation with ammonium sulphate. It was found that the more branched hemicelluloses were precipitated at higher ammonium sulphate concentrations (55 and 70%), the more linear hemicelluloses were precipitated at lower ammonium sulphate concentrations (0, 5, 15, 25, and 40%). The molecular weights of hemicellulosic fractions become lower from 35,270 (H0) to 18,680 (H70)gmol(-1) with the increasing concentrations of saturated ammonium sulphate from 0 to 70%. Based on the FT-IR, (1)H, (13)C and 2D HSQC NMR studies, the alkali-soluble hemicelluloses were 4-O-methyl-glucuronoarabinoxylans composed of the (1→4)-linked β-d-xylopyranosyl backbone with branches at O-3 of α-L-arabinofuranosyl or at O-2 of 4-O-methyl-α-d-glucuronic acid.

  9. Loss of fine particle ammonium from denuded nylon filters

    NASA Astrophysics Data System (ADS)

    Yu, Xiao-Ying; Lee, Taehyoung; Ayres, Benjamin; Kreidenweis, Sonia M.; Malm, William; Collett, Jeffrey L.

    Ammonium is an important constituent of fine particulate mass in the atmosphere, but can be difficult to quantify due to possible sampling artifacts. Losses of semivolatile species such as NH 4NO 3 can be particularly problematic. In order to evaluate ammonium losses from aerosol particles collected on filters, a series of field experiments was conducted using denuded nylon and Teflon filters at Bondville, IL (February 2003), San Gorgonio, CA (April 2003 and July 2004), Grand Canyon NP, AZ (May, 2003), Brigantine, NJ (November 2003), and Great Smoky Mountains National Park (NP), TN (July-August 2004). Samples were collected over 24 h periods. Losses from denuded nylon filters ranged from 10% (monthly average) in Bondville, IL to 28% in San Gorgonio, CA in summer. Losses on individual sample days ranged from 1% to 65%. Losses tended to increase with increasing diurnal temperature and relative humidity changes and with the fraction of ambient total N(-III) (particulate NH 4++gaseous NH 3) present as gaseous NH 3. The amount of ammonium lost at most sites could be explained by the amount of NH 4NO 3 present in the sampled aerosol. Ammonium losses at Great Smoky Mountains NP, however, significantly exceeded the amount of NH 4NO 3 collected. Ammoniated organic salts are suggested as additional important contributors to observed ammonium loss at this location.

  10. Electrospray ionization tandem mass spectrometry of ammonium cationized polyethers.

    PubMed

    Nasioudis, Andreas; Heeren, Ron M A; van Doormalen, Irene; de Wijs-Rot, Nicolette; van den Brink, Oscar F

    2011-05-01

    Quaternary ammonium salts (Quats) and amines are known to facilitate the MS analysis of high molar mass polyethers by forming low charge state adduct ions. The formation, stability, and behavior upon collision-induced dissociation (CID) of adduct ions of polyethers with a variety of Quats and amines were studied by electrospray ionization quadrupole time-of-flight, quadrupole ion trap, and linear ion trap tandem mass spectrometry (MS/MS). The linear ion trap instrument was part of an Orbitrap hybrid mass spectrometer that allowed accurate mass MS/MS measurements. The Quats and amines studied were of different degree of substitution, structure, and size. The stability of the adduct ions was related to the structure of the cation, especially the amine's degree of substitution. CID of singly/doubly charged primary and tertiary ammonium cationized polymers resulted in the neutral loss of the amine followed by fragmentation of the protonated product ions. The latter reveals information about the monomer unit, polymer sequence, and endgroup structure. In addition, the detection of product ions retaining the ammonium ion was observed. The predominant process in the CID of singly charged quaternary ammonium cationized polymers was cation detachment, whereas their doubly charged adduct ions provided the same information as the primary and tertiary ammonium cationized adduct ions. This study shows the potential of specific amines as tools for the structural elucidation of high molar mass polyethers.

  11. Electrospray Ionization Tandem Mass Spectrometry of Ammonium Cationized Polyethers

    NASA Astrophysics Data System (ADS)

    Nasioudis, Andreas; Heeren, Ron M. A.; van Doormalen, Irene; de Wijs-Rot, Nicolette; van den Brink, Oscar F.

    2011-05-01

    Quaternary ammonium salts (Quats) and amines are known to facilitate the MS analysis of high molar mass polyethers by forming low charge state adduct ions. The formation, stability, and behavior upon collision-induced dissociation (CID) of adduct ions of polyethers with a variety of Quats and amines were studied by electrospray ionization quadrupole time-of-flight, quadrupole ion trap, and linear ion trap tandem mass spectrometry (MS/MS). The linear ion trap instrument was part of an Orbitrap hybrid mass spectrometer that allowed accurate mass MS/MS measurements. The Quats and amines studied were of different degree of substitution, structure, and size. The stability of the adduct ions was related to the structure of the cation, especially the amine's degree of substitution. CID of singly/doubly charged primary and tertiary ammonium cationized polymers resulted in the neutral loss of the amine followed by fragmentation of the protonated product ions. The latter reveals information about the monomer unit, polymer sequence, and endgroup structure. In addition, the detection of product ions retaining the ammonium ion was observed. The predominant process in the CID of singly charged quaternary ammonium cationized polymers was cation detachment, whereas their doubly charged adduct ions provided the same information as the primary and tertiary ammonium cationized adduct ions. This study shows the potential of specific amines as tools for the structural elucidation of high molar mass polyethers.

  12. Effects of bisphenol A on ammonium assimilation in soybean roots.

    PubMed

    Sun, Hai; Wang, Li Hong; Zhou, Qing; Huang, Xiao Hua

    2013-12-01

    Bisphenol A (BPA), which is ubiquitous in the environment, is an example of an endocrine-disrupting compound (EDC). Ammonium assimilation has an important function in plant growth and development. However, insufficient information on the potential effect of BPA on ammonium assimilation in plants is available. In this study, the effects of BPA on ammonium assimilation in roots of soybean seedlings were investigated. During the stress period, 1.5 mg L(-1) of BPA improved glutamine synthetase (GS)/glutamate synthase (GOGAT) cycle and glutamate dehydrogenase (GDH) pathway in ammonium assimilation. The amino acid and the soluble protein contents increased in the soybeans. At 17.2 and 50.0 mg L(-1) of BPA, the GS/GOGAT cycle was inhibited and the GDH pathway was promoted. The amino acid content increased and the soluble protein content decreased. During the recovery period, the GS/GOGAT cycle and the GDH pathway recovered at 1.5 and 17.2 mg L(-1) of BPA but not at 50.0 mg L(-1) of BPA. The amino acid content continuously increased and the soluble protein content decreased compared with those in the control treatment. In summary, BPA treatment could affect the contents of soluble protein and amino acid in the soybean roots by regulating ammonium assimilation.

  13. Loss of Fine Particle Ammonium from Denuded Nylon Filters

    SciTech Connect

    Yu, Xiao-Ying; Lee, Taehyoung; Ayres, Benjamin; Kreidenweis, Sonia M.; Malm, William C.; Collett, Jeffrey L.

    2006-08-01

    Ammonium is an important constituent of fine particulate mass in the atmosphere, but can be difficult to quantify due to possible sampling artifacts. Losses of semivolatile species such as NH4NO3 can be particularly problematic. In order to evaluate ammonium losses from aerosol particles collected on filters, a series of field experiments was conducted using denuded nylon and Teflon filters at Bondville, Illinois (February 2003), San Gorgonio, California (April 2003 and July 2004), Grand Canyon National Park, Arizona (May, 2003), Brigantine, New Jersey (November 2003), and Great Smoky Mountains National Park (NP), Tennessee (July–August 2004). Samples were collected over 24-hr periods. Losses from denuded nylon filters ranged from 10% (monthly average) in Bondville, Illinois to 28% in San Gorgonio, California in summer. Losses on individual sample days ranged from 1% to 65%. Losses tended to increase with increasing diurnal temperature and relative humidity changes and with the fraction of ambient total N(--III) (particulate NH4+ plus gaseous NH3) present as gaseous NH3. The amount of ammonium lost at most sites could be explained by the amount of NH4NO3 present in the sampled aerosol. Ammonium losses at Great Smoky Mountains NP, however, significantly exceeded the amount of NH4NO3 collected. Ammoniated organic salts are suggested as additional important contributors to observed ammonium loss at this location.

  14. Modeling of alkyl quaternary ammonium cations intercalated into montmorillonite lattice

    SciTech Connect

    Daoudi, El Mehdi; Boughaleb, Yahia; El Gaini, Layla; Meghea, Irina; Bakasse, Mina

    2013-05-15

    Highlights: ► The modification of montmorillonites by three surfactants increases the basal spacing. ► The model proposed show a bilayer conformation for the surfactant ODTMA. ► The DODMA and TOMA surfactants adopt a paraffin type arrangement. ► Behavior of surfactants in interlayer space was confirmed by TGA and ATR analysis. - Abstract: The objective of this work was to study the conformation of the quaternary ammonium cations viz., octadecyl trimethyl ammonium (ODTMA), dioctadecyl dimethyl ammonium (DMDOA) and trioctadecyl methyl ammonium (TOMA) intercalated within montmorillonite. The modified montmorillonite was characterized by X-ray diffraction in small angle (SAXS), thermal analysis (TGA) and infrared spectroscopy of attenuated total reflection (ATR). The modification of organophilic montmorillonites by the three surfactants ODTMA, DMDOA and TOMA increases the basal spacing from their respective intercalated distances of 1.9 nm, 2.6 nm and 3.4 nm respectively. The increase in the spacing due to the basic organic modification was confirmed by the results of thermal analysis (TGA) and infrared spectroscopy (ATR), and also supported by theoretical calculations of longitudinal and transversal chain sizes of these alkyl quaternary ammonium cations.

  15. A maritime pine antimicrobial peptide involved in ammonium nutrition.

    PubMed

    Canales, Javier; Avila, Concepción; Cánovas, Francisco M

    2011-09-01

    A large family of small cysteine-rich antimicrobial peptides (AMPs) is involved in the innate defence of plants against pathogens. Recently, it has been shown that AMPs may also play important roles in plant growth and development. In previous work, we have identified a gene of the AMP β-barrelin family that was differentially regulated in the roots of maritime pine (Pinus pinaster Ait.) in response to changes in ammonium nutrition. Here, we present the molecular characterization of two AMP genes, PpAMP1 and PpAMP2, showing different molecular structure and physicochemical properties. PpAMP1 and PpAMP2 displayed different expression patterns in maritime pine seedlings and adult trees. Furthermore, our expression analyses indicate that PpAMP1 is the major form of AMP in the tree, and its relative abundance is regulated by ammonium availability. In contrast, PpAMP2 is expressed at much lower levels and it is not regulated by ammonium. To gain new insights into the function of PpAMP1, we over-expressed the recombinant protein in Escherichia coli and demonstrated that PpAMP1 strongly inhibited yeast growth, indicating that it exhibits antimicrobial activity. We have also found that PpAMP1 alters ammonium uptake, suggesting that it is involved in the regulation of ammonium ion flux into pine roots.

  16. Anomalous neutron Compton scattering cross sections in ammonium hexachlorometallates

    NASA Astrophysics Data System (ADS)

    Krzystyniak, M.; Chatzidimitriou-Dreismann, C. A.; Lerch, M.; Lalowicz, Z. T.; Szymocha, A.

    2007-03-01

    The authors have performed neutron Compton scattering measurements on ammonium hexachloropalladate (NH4)2PdCl6 and ammonium hexachlorotellurate (NH4)2TeCl6. Both substances belong to the family of ammonium metallates. The aim of the experiment was to investigate the possible role of electronic environment of a proton on the anomaly of the neutron scattering intensity. The quantity of interest that was subject to experimental test was the reduction factor of the neutron scattering intensities. In both samples, the reduction factor was found to be smaller than unity, thus indicating the anomalous neutron Compton scattering from protons. Interestingly, the anomaly decreases with decreasing scattering angle and disappears at the lowest scattering angle (longest scattering time). The dependence of the amount of the anomaly on the scattering angle (scattering time) is the same in both substances (within experimental error). Also, the measured widths of proton momentum distributions are equal in both metallates. This is consistent with the fact that the attosecond proton dynamics of ammonium cations is fairly well decoupled from the dynamics of the sublattice of the octahedral anions PdCl62- and TeCl62-, respectively. The hypothesis is put forward that proton-electron decoherence processes are responsible for the considered effect. Decoherence processes may have to do rather with the direct electronic environment of ammonium protons and not with the electronic structure of the metal-chlorine bond.

  17. Ammonium as a sustainable proton shuttle in bioelectrochemical systems.

    PubMed

    Cord-Ruwisch, Ralf; Law, Yingyu; Cheng, Ka Yu

    2011-10-01

    This work examines a pH control method using ammonium (NH(4)(+)) as a sustainable proton shuttle in a CEM-equipped BES. Current generation was sustained by adding NH(3) or ammonium hydroxide (NH(4)OH) to the anolyte, controlling its pH at 7. Ammonium ion migration maintained the catholyte pH at approximately 9.25. Such NH(4)(+)/NH(3) migration accounted for 90±10% of the ionic flux in the BES. Reintroducing the volatilized NH(3) from the cathode into the anolyte maintained a suitable anolyte pH for sustained microbial-driven current generation. Hence, NH(4)(+)/NH(3) acted as a proton shuttle that is not consumed in the process.

  18. Cetyltrimethyl ammonium bromide assisted hydrothermal growth of hematite hollow cubes

    SciTech Connect

    Wang, Wei-Wei; Yao, Jia-Liang

    2010-11-15

    Hematite hollow cubes have been prepared by forced hydrolysis of ferric chloride solutions under hydrothermal conditions. The effects of reaction time, reaction temperature and cetyltrimethyl ammonium bromide on the transformation process from akageneite to hematite were investigated in detail. The products were characterized by X-ray powder diffraction, scanning electron microscopy and transmission electron microscopy. It is found that cetyltrimethyl ammonium bromide was a critical factor influencing the phase transformation process of akageneite and the final morphology of the as-prepared products. With cetyltrimethyl ammonium bromide, hematite hollow cubes and porous spheres were obtained. Otherwise only dense cubes were observed even prolonging reaction time or increasing reaction temperature. The mechanism was proposed.

  19. Ammonium and sulfate ion release of histamine from lung fragments.

    PubMed

    Charles, J M; Menzel, D B

    1975-06-01

    In vitro studies with guinea pig lung fragments incubated with 10- to 200-mM concentrations of ammonium ion demonstrated the release of substanial quantities of histamine. Of the anions tested with ammonium ion, sulfate was the most potent, while nitrate and acetate ions were of intermediate potency and chloride was less potent. An osmotic effect is unlikely since equal concentrations of sodium chloride failed to release histamine. Isoproterenol, known to decrease anaphylactic histamine release, and acetycholine, known to increase histamine release, had no effect on the ammonium sulfate-mediated release of histamine. N-6 2'-O-Dibutyryladenosine 3',5' monophosphate (dibutyryl c-AMP) was also ineffective. These studies suggest that the inhalation irritation associated with certain sulfate and other salts, may be a function of their ability to release histamine in the presence of amonium ion.

  20. Study on mechanism of isomerization between ammonium thiocyanate and thiourea

    NASA Astrophysics Data System (ADS)

    Zhang, Chao-Zhi; Niu, Meng-Xiao

    2016-12-01

    Application of ammonium thiocyanate that can be separated from wastewater in coking plant is limited. It may isomerize to thiourea which has widely applied in industry. However, the isomerization yield is low. Moreover, the isomerization temperature is more than 145 °C. In this paper, the isomerization was investigated. The mechanism of the isomerization was supposed based on quantum chemistry calculations. Ammonia was employed as a catalyst to lower isomerization temperature and improved the yield of thiourea in the isomerization reaction. Results of quantum chemical calculation and experiments support the supposed mechanism. The mechanism can be applied in production of thiourea from isomerization of ammonium thiocyanate. The paper suggests a useful way of resourcizing ammonium thiocyanate in wastewater.

  1. Effect of temperature on ammonium removal in Scenedesmus sp.

    PubMed

    Ruiz-Martínez, A; Serralta, J; Seco, A; Ferrer, J

    2015-09-01

    The effect of temperature on microalgal ammonium uptake was investigated by carrying out four batch experiments in which a mixed culture of microalgae, composed mainly of Scenedesmus sp., was cultivated under different temperatures within the usual temperature working range in Mediterranean climate (15-34 °C). Ammonium removal rates increased with temperature up to 26 °C and stabilized thereafter. Ratkowsky and Cardinal temperatures models successfully reproduced the experimental data. Optimum (31.3 °C), minimum (8.8 °C) and maximum (46.1 °C) temperatures for ammonium removal by Scenedesmus sp. under the studied conditions were obtained as model parameters. These temperature-related parameters constitute very useful information for designing and operating wastewater treatment systems using these microalgae.

  2. Exposure to common quaternary ammonium disinfectants decreases fertility in mice

    PubMed Central

    Melin, Vanessa E.; Potineni, Haritha; Hunt, Patricia; Griswold, Jodi; Siems, Bill; Werre, Stephen R.; Hrubec, Terry C.

    2014-01-01

    Quaternary ammonium compounds (QACs) are antimicrobial disinfectants commonly used in commercial and household settings. Extensive use of QACs results in ubiquitous human exposure, yet reproductive toxicity has not been evaluated. Decreased reproductive performance in laboratory mice coincided with the introduction of a disinfectant containing both alkyl dimethyl benzyl ammonium chloride (ADBAC) and didecyl dimethyl ammonium chloride (DDAC). QACs were detected in caging material over a period of several months following cessation of disinfectant use. Breeding pairs exposed for six months to a QAC disinfectant exhibited decreases in fertility and fecundity: increased time to first litter, longer pregnancy intervals, fewer pups per litter and fewer pregnancies. Significant morbidity in near term dams was also observed. In summary, exposure to a common QAC disinfectant mixture significantly impaired reproductive health in mice. This study illustrates the importance of assessing mixture toxicity of commonly used products whose components have only been evaluated individually. PMID:25483128

  3. Handling of Ammonium Nitrate Mother-Liquid Radiochemical Production - 13089

    SciTech Connect

    Zherebtsov, Alexander; Dvoeglazov, Konstantine; Volk, Vladimir; Zagumenov, Vladimir; Zverev, Dmitriy; Tinin, Vasiliy; Kozyrev, Anatoly; Shamin, Dladimir; Tvilenev, Konstantin

    2013-07-01

    The aim of the work is to develop a basic technology of decomposition of ammonium nitrate stock solutions produced in radiochemical enterprises engaged in the reprocessing of irradiated nuclear fuel and fabrication of fresh fuel. It was necessary to work out how to conduct a one-step thermal decomposition of ammonium nitrate, select and test the catalysts for this process and to prepare proposals for recycling condensation. Necessary accessories were added to a laboratory equipment installation decomposition of ammonium nitrate. It is tested several types of reducing agents and two types of catalyst to neutralize the nitrogen oxides. It is conducted testing of modes of the process to produce condensation, suitable for use in the conversion of a new technological scheme of production. It is studied the structure of the catalysts before and after their use in a laboratory setting. It is tested the selected catalyst in the optimal range for 48 hours of continuous operation. (authors)

  4. Steady state growth of E. Coli in low ammonium environment

    NASA Astrophysics Data System (ADS)

    Kim, Minsu; Deris, Barret; Zhang, Zhongge; Hwa, Terry

    2011-03-01

    Ammonium is the preferred nitrogen source for many microorganisms. In medium with low ammonium concentrations, enteric bacteria turn on the nitrogen responsive (ntr) genes to assimilate ammonium. Two proteins in E. coli, Glutamine synthetase (GS) and the Ammonium/methylammonium transporter AmtB play crucial roles in this regard. GS is the major ammonium assimilation enzyme below 1mM of NH4 + . AmtB is an inner membrane protein that transports NH4 + across the cell membrane against a concentration gradient. In order to study ammonium uptake at low NH4 + concentration at neutral pH, we developed a microfluidic flow chamber that maintains a homogenous nutrient environment during the course of exponential cell growth, even at very low concentration of nutrients. Cell growth can be accurately monitored using time-lapse microscopy. We followed steady state growth down to micro-molar range of NH4 + for the wild type and Δ amtB strains. The wild type strain is able to maintain the growth rate from 10mM down to a few uM of NH4 + , while the mutant exhibited reduced growth below ~ 20 ~uM of NH4 + . Simultaneous characterization of the expression levels of GS and AmtB using fluorescence reporters reveals that AmtB is turned on already at 1mM, but contributes to function only below ~ 30 ~uM in the wild-type. Down to ~ 20 ~uM of NH4 + , E.~coli can compensate the loss of AmtB by GS alone.

  5. Precipitation of phenyl and phenoxypenicillin from solutions using ammonium sulfate.

    PubMed

    Luengo, J M

    1985-09-01

    An easy, rapid, and available method for separating 6-aminopenicillanic acid (6-APA), benzylpenicillin (penicillin G), and other related molecules from aqueous solutions or complex industrial broths is described. A high concentration of ammonium sulphate induces partially or totally the precipitation of the penicillin present in the solutions, while 6-APA, phenylacetic, and phenoxyacetic acid always remain in the supernatant. The filtration through No. 4 Pyrex glass-fiber filter or Whatman 3MM paper permits the separation of the compounds present in the supernatant from the other ones precipitated. The precipitated product was identified, in all cases, as ammonium penicillin. This method is described here for the first time.

  6. Mutagenic activity of quaternary ammonium salt derivatives of carbohydrates

    PubMed Central

    Sikora, Karol; Woziwodzka, Anna; Piosik, Jacek; Podgórska, Beata

    2016-01-01

    Summary This paper presents a study on a series of quaternary ammonium salt (QAS) derivatives of glucopyranosides with an elongated hydrophobic hydrocarbon chain. The new N-[6-(β-D-glucopyranosyloxy)hexyl]ammonium bromides and their O-acetyl derivatives were analyzed via 1H and 13C NMR spectroscopy. The mutagenic activity of the newly synthesized QAS was investigated using two different techniques: The Vibrio harveyi luminescence assay and the Ames test. The obtained results support previous findings contesting QAS safety and indicate that QAS, specifically pyridinium derivatives, might be mutagenic. PMID:27559394

  7. Effects of Ammonium and Non-Ammonium Salt Additions on Methane Oxidation by Methylosinus trichosporium OB3b and Maine Forest Soils.

    PubMed

    King, G M; Schnell, S

    1998-01-01

    Additions of ammonium and non-ammonium salts inhibit atmospheric methane consumption by soil at salt concentrations that do not significantly affect the soil water potential. The response of soils to non-ammonium salts has previously raised questions about the mechanism of ammonium inhibition. Results presented here show that inhibition of methane consumption by non-ammonium salts can be explained in part by ion-exchange reactions: cations desorb ammonium, with the level of desorption varying as a function of both the cation and anion added; differential desorption results in differential inhibition levels. Differences in the extent of inhibition among ammonium salts can also be explained in part by the effects of anions on ammonium exchange. In contrast, only minimal effects of cations and anions are observed in liquid cultures of Methylosinus trichosporium OB3b. The comparable level of inhibition by equinormal concentrations of NH(4)Cl and (NH(4))(2)SO(4) and the insensitivity of salt inhibition to increasing methane concentrations (from 10 to 100 ppm) are of particular interest, since both of these patterns are in contrast to results for soils. The greater inhibition of methane consumption for NH(4)Cl than (NH(4))(2)SO(4) in soils can be attributed to increased ammonium adsorption by sulfate; increasing inhibition by non-ammonium salts with increasing methane concentrations can be attributed to desorbed ammonium and a physiological mechanism proposed previously for pure cultures.

  8. Effects of Ammonium and Non-Ammonium Salt Additions on Methane Oxidation by Methylosinus trichosporium OB3b and Maine Forest Soils†

    PubMed Central

    King, G. M.; Schnell, S.

    1998-01-01

    Additions of ammonium and non-ammonium salts inhibit atmospheric methane consumption by soil at salt concentrations that do not significantly affect the soil water potential. The response of soils to non-ammonium salts has previously raised questions about the mechanism of ammonium inhibition. Results presented here show that inhibition of methane consumption by non-ammonium salts can be explained in part by ion-exchange reactions: cations desorb ammonium, with the level of desorption varying as a function of both the cation and anion added; differential desorption results in differential inhibition levels. Differences in the extent of inhibition among ammonium salts can also be explained in part by the effects of anions on ammonium exchange. In contrast, only minimal effects of cations and anions are observed in liquid cultures of Methylosinus trichosporium OB3b. The comparable level of inhibition by equinormal concentrations of NH4Cl and (NH4)2SO4 and the insensitivity of salt inhibition to increasing methane concentrations (from 10 to 100 ppm) are of particular interest, since both of these patterns are in contrast to results for soils. The greater inhibition of methane consumption for NH4Cl than (NH4)2SO4 in soils can be attributed to increased ammonium adsorption by sulfate; increasing inhibition by non-ammonium salts with increasing methane concentrations can be attributed to desorbed ammonium and a physiological mechanism proposed previously for pure cultures. PMID:16349485

  9. Global modeling of nitrate and ammonium aerosols using EQSAM3

    NASA Astrophysics Data System (ADS)

    Xu, L.; Penner, J. E.

    2009-12-01

    Atmospheric aerosols, particles suspending in air, are important as they affect human health, air quality, and visibility as well as climate. Sulfate, nitrate, ammonium, chloride and sodium are among the most important inorganic aerosol species in the atmosphere. These compounds are hygroscopic and absorb water under almost all ambient environmental conditions. The uptake of water alters the aerosol size, and causes water to become the constituent with the largest atmospheric aerosol mass, especially when the aerosols grow into fog, haze or clouds. Furthermore, several global model studies have demonstrated that rapid increases in nitrogen emissions could produce enough nitrate in aerosols to offset the expected decline in sulfate forcing by 2100 for the extreme IPCC A2 scenario (Bauer et al., 2007). Although nitrate and ammonium were identified as significant anthropogenic sources of aerosols by a number of modeling studies, most global aerosol models still exclude ammonium-nitrate when the direct aerosol forcing is studied. In this study, the computationally efficient equilibrium model, EQSAM3, is incorporated into the UMICH-IMPACT-nitrate model using the hybrid dynamical solution method (Feng and Penner, 2007). The partitioning of nitrate and ammonium along with the corresponding water uptake is evaluated by comparing the model to the EQUISOLVE II method used in Feng and Penner (2007). The model is also evaluated by comparison with the AERONET data base and satellite-based aerosol optical depths.

  10. 21 CFR 73.1298 - Ferric ammonium ferrocyanide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... solutions of ferrous sulfate and sodium ferrocyanide in the presence of ammonium sulfate. The oxidized... with smaller amounts of ferric ferrocyanide and ferric sodium ferrocyanide. (2) Color additive mixtures... subpart as safe and suitable for use in color additive mixtures for coloring drugs. (b)...

  11. Glufosinate and Ammonium Sulfate Inhibits Atrazine Degradation in Adapted Soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The co-application of glufosinate with nitrogen fertilizers may alter atrazine co-metabolism, thereby extending the herbicide’s residual weed control in adapted soils. The objective of this study was to assess the effects of glufosinate, ammonium sulfate, and the combination of glufosinate and ammo...

  12. Nitrate, Nitrite, and Ammonium Variability in Drinking Water Distribution Systems.

    PubMed

    Schullehner, Jörg; Stayner, Leslie; Hansen, Birgitte

    2017-03-09

    Accurate assessments of exposure to nitrate in drinking water is a crucial part of epidemiological studies investigating long-term adverse human health effects. However, since drinking water nitrate measurements are usually collected for regulatory purposes, assumptions on (1) the intra-distribution system variability and (2) short-term (seasonal) concentration variability have to be made. We assess concentration variability in the distribution system of nitrate, nitrite, and ammonium, and seasonal variability in all Danish public waterworks from 2007 to 2016. Nitrate concentrations at the exit of the waterworks are highly correlated with nitrate concentrations within the distribution net or at the consumers' taps, while nitrite and ammonium concentrations are generally lower within the net compared with the exit of the waterworks due to nitrification. However, nitrification of nitrite and ammonium in the distribution systems only results in a relatively small increase in nitrate concentrations. No seasonal variation for nitrate, nitrite, or ammonium was observed. We conclude that nitrate measurements taken at the exit of the waterworks are suitable to calculate exposures for all consumers connected to that waterworks and that sampling frequencies in the national monitoring programme are sufficient to describe temporal variations in longitudinal studies.

  13. 21 CFR 573.560 - Iron ammonium citrate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Iron ammonium citrate. 573.560 Section 573.560 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS...

  14. 21 CFR 573.560 - Iron ammonium citrate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Iron ammonium citrate. 573.560 Section 573.560 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS...

  15. 21 CFR 573.560 - Iron ammonium citrate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Iron ammonium citrate. 573.560 Section 573.560 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS...

  16. 21 CFR 573.560 - Iron ammonium citrate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Iron ammonium citrate. 573.560 Section 573.560 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS...

  17. Producing ammonium sulfate from flue gas desulfurization by-products

    USGS Publications Warehouse

    Chou, I.-Ming; Bruinius, J.A.; Benig, V.; Chou, S.-F.J.; Carty, R.H.

    2005-01-01

    Emission control technologies using flue gas desulfurization (FGD) have been widely adopted by utilities burning high-sulfur fuels. However, these technologies require additional equipment, greater operating expenses, and increased costs for landfill disposal of the solid by-products produced. The financial burdens would be reduced if successful high-volume commercial applications of the FGD solid by-products were developed. In this study, the technical feasibility of producing ammonium sulfate from FGD residues by allowing it to react with ammonium carbonate in an aqueous solution was preliminarily assessed. Reaction temperatures of 60, 70, and 80??C and residence times of 4 and 6 hours were tested to determine the optimal conversion condition and final product evaluations. High yields (up to 83%) of ammonium sulfate with up to 99% purity were achieved under relatively mild conditions. The optimal conversion condition was observed at 60??C and a 4-hour residence time. The results of this study indicate the technical feasibility of producing ammonium sulfate fertilizer from an FGD by-product. Copyright ?? Taylor & Francis Inc.

  18. Destruction of 2,4,6-trinitrotoluene using ammonium peroxydisulfate

    SciTech Connect

    Cooper, J.F.; Wang, F.; Shell, T.; King, K.

    1996-07-01

    TNT was destroyed in a small batch reactor, using uncatalyzed 4 N ammonium peroxydisulfate at 95 {degrees}C. The material was destroyed below limit of detection in less that 15 minutes, indicating a formal order rate constant of 0.06 min{sup -1}. A crude estimate of scaleup rates indicates a throughput of 1 tonne/m{sup 3}-day.

  19. Nitrate, Nitrite, and Ammonium Variability in Drinking Water Distribution Systems

    PubMed Central

    Schullehner, Jörg; Stayner, Leslie; Hansen, Birgitte

    2017-01-01

    Accurate assessments of exposure to nitrate in drinking water is a crucial part of epidemiological studies investigating long-term adverse human health effects. However, since drinking water nitrate measurements are usually collected for regulatory purposes, assumptions on (1) the intra-distribution system variability and (2) short-term (seasonal) concentration variability have to be made. We assess concentration variability in the distribution system of nitrate, nitrite, and ammonium, and seasonal variability in all Danish public waterworks from 2007 to 2016. Nitrate concentrations at the exit of the waterworks are highly correlated with nitrate concentrations within the distribution net or at the consumers’ taps, while nitrite and ammonium concentrations are generally lower within the net compared with the exit of the waterworks due to nitrification. However, nitrification of nitrite and ammonium in the distribution systems only results in a relatively small increase in nitrate concentrations. No seasonal variation for nitrate, nitrite, or ammonium was observed. We conclude that nitrate measurements taken at the exit of the waterworks are suitable to calculate exposures for all consumers connected to that waterworks and that sampling frequencies in the national monitoring programme are sufficient to describe temporal variations in longitudinal studies. PMID:28282914

  20. Electrodeposition of Californium Using Isobutanol and Aqueous Ammonium Acetate

    NASA Astrophysics Data System (ADS)

    Matoš, Milan; Boll, Rose A.; Phelps, Clarice E.; Torrico, Matthew N.; van Cleve, Shelley M.; Lewis, Benjamin E.

    2013-10-01

    Californium sources and targets are used in many applications in research and industry. Molecular deposition (commonly referred to as electrodeposition) is an experimental technique suitable for production of californium thin films. We are investigating molecular depositions using isobutanol and aqueous ammonium acetate solvents at various conditions to optimize for the best deposition efficiency and repeatability. Results of those tests will be presented.

  1. Calorimetry Studies of Ammonia, Nitric Acid, and Ammonium Nitrate

    DTIC Science & Technology

    1979-10-01

    block nmmber) Calorimetry Heat of reaction Ammonium nitrate Heat capacity Nitric acid Heat of solution • Amonia 20. ABSTRACT r(Cmrtfe m,.re a N "no•a.•r sd...identical to the literature spectrum of W NO3. Anhydrous nitric acid was prepared by distillation of 90% HNO 3 from fuming sulfuric acid (oxides of nitrogen

  2. Salmonella enterica Strains with Reduced Susceptibility to Quarternary Ammonium Compounds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Salmonella spp. are responsible for 76 million illnesses per year in the U.S. Quaternary ammonium compounds (QAC) are commonly used antimicrobial agents. Reduced susceptibility to these compounds by a broad spectrum of organisms is a concern. Methods: Salmonella enterica strains with r...

  3. 21 CFR 184.1296 - Ferric ammonium citrate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE... brown or garnet red scales or granules or as a brownish-yellowish powder. (2) Ferric ammonium citrate... occurs as thin transparent green scales, as granules, as a powder, or as transparent green crystals....

  4. 21 CFR 184.1296 - Ferric ammonium citrate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE... brown or garnet red scales or granules or as a brownish-yellowish powder. (2) Ferric ammonium citrate... occurs as thin transparent green scales, as granules, as a powder, or as transparent green crystals....

  5. Maximizing ammonium nitrogen removal from solution using different zeolites.

    PubMed

    Penn, Chad J; Warren, Jason G; Smith, Savannah

    2010-01-01

    Zeolite minerals are ideal for removing ammonium nitrogen (NH4(+)-N) from animal wastes, leachates, and industrial effluents. The objectives of this study were to compare NH4+ removal and kinetics among several commercially available zeolites under various conditions and determine if calorimetry could provide information regarding kinetics of NH4+ removal. Ammonium sorption onto potassium (K) saturated zeolites was compared using synthetic vs. natural swine effluent and with either traditional batch-shaken system or a "tea bag" approach in which zeolites were contained in a mesh sack and suspended in a solution of swine effluent. Ammonium sorption was measured at four retention times using a flow-through system, and the resulting heat response was measured using isothermal calorimetry. Ammonium removal was not significantly different in synthetic vs. natural swine effluent. Ammonium removal was lower in batch-stirred compared to batch-shaken systems, suggesting that diffusion between particles was rate-limiting in the former system. Flow-through cells possessing contact times > 100 s displayed greater NH4+ sorption than batch systems, suggesting that maintaining high NH4+ concentration in solution, removal of exchange products, and sufficient reaction time are critical to maximizing NH4+ removal by zeolites. Within 100 s after NH4+ addition, endothermic heat responses indicated that NH4(+)-K+ exchange had peaked; this was followed by significant heat rate reduction for 50 min. This confirmed findings of an initial fast NH4(+)-K+ exchange followed by a slower one and suggests the 100-s period of rapid reaction is an indicator of the minimum flow through retention time required to optimize NH4+ sorption to zeolites used in this study.

  6. Recycle use of magnesium ammonium phosphate to remove ammonium nitrogen from rare-earth wastewater.

    PubMed

    Huang, H M; Xiao, X M; Yan, B

    2009-01-01

    This paper presents a recycle MAP process (magnesium ammonium phosphate) to remove NH4-N from a typical rare-earth wastewater. The optimum conditions for the MAP precipitation and recycle use of the MAP with a newly-designed process were investigated in laboratory. The results showed that the pH value and dosages of P (phosphate) and Mg reagents have a significant influence on NH4-N removal, with a maximum removal efficiency of 99.4% at the conditions of pH=9 and Mg:N:P molar ratio=1.2:1:1.2. In the process of recycle use of the MAP, adding some HCl to dissolve MAP decomposition residues could effectively enhance NH4-N removal. The NH4-N removal efficiency reached 99.6% by adding an HCl amount of H+:OH- molar ratio=0.8 into the reused MAP decomposition residues, whereas the NH4-N removal efficiency without addition of HCl was only 96.4%. Moreover, the residual PO4-P from the end of reaction was recovered and the optimum recovery efficiency was achieved at a Mg:P molar ratio=6 and pH=10. Under these optimum conditions, the residual NH4-N and PO4-P concentrations in the treated wastewater, through 6 times of the recycling, were less than 15 mg/L and 1 mg/L, respectively. On the basis of this, an economic evaluation of the recycling MAP was made, and this recycle process could save 48.6% cost used in the chemicals for treating per cubic meter of the rare-earth wastewater, compared to the conventional MAP process.

  7. γ-Aminobutyric acid addition alleviates ammonium toxicity by limiting ammonium accumulation in rice (Oryza sativa) seedlings.

    PubMed

    Ma, Xiaoling; Zhu, Changhua; Yang, Na; Gan, Lijun; Xia, Kai

    2016-12-01

    Excessive use of nitrogen (N) fertilizer has increased ammonium (NH4(+) ) accumulation in many paddy soils to levels that reduce rice vegetative biomass and yield. Based on studies of NH4(+) toxicity in rice (Oryza sativa, Nanjing 44) seedlings cultured in agar medium, we found that NH4(+) concentrations above 0.75 mM inhibited the growth of rice and caused NH4(+) accumulation in both shoots and roots. Use of excessive NH4(+) also induced rhizosphere acidification and inhibited the absorption of K, Ca, Mg, Fe and Zn in rice seedlings. Under excessive NH4(+) conditions, exogenous γ-aminobutyric acid (GABA) treatment limited NH4(+) accumulation in rice seedlings, reduced NH4(+) toxicity symptoms and promoted plant growth. GABA addition also reduced rhizosphere acidification and alleviated the inhibition of Ca, Mg, Fe and Zn absorption caused by excessive NH4(+) . Furthermore, we found that the activity of glutamine synthetase/NADH-glutamate synthase (GS; EC 6.3.1.2/NADH-GOGAT; EC1.4.1.14) in root increased gradually as the NH4(+) concentration increased. However, when the concentration of NH4(+) is more than 3 mM, GABA treatment inhibited NH4(+) -induced increases in GS/NADH-GOGAT activity. The inhibition of ammonium assimilation may restore the elongation of seminal rice roots repressed by high NH4(+) . These results suggest that mitigation of ammonium accumulation and assimilation is essential for GABA-dependent alleviation of ammonium toxicity in rice seedlings.

  8. 40 CFR 721.9075 - Quaternary ammonium salt of fluorinated alkylaryl amide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Quaternary ammonium salt of... New Uses for Specific Chemical Substances § 721.9075 Quaternary ammonium salt of fluorinated alkylaryl... identified generically as quaternary ammonium salt of fluorinated alkylaryl amide (PMN No. P-92-688)...

  9. 40 CFR 721.10170 - Polyoxyethylene polyalkylarylphenylether sulfate ammonium salt (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... polyalkylarylphenylether sulfate ammonium salt (generic). 721.10170 Section 721.10170 Protection of Environment... polyalkylarylphenylether sulfate ammonium salt (generic). (a) Chemical substance and significant new uses subject to... sulfate ammonium salt (PMN P-03-197) is subject to reporting under this section for the significant...

  10. 40 CFR 721.10170 - Polyoxyethylene polyalkylarylphenylether sulfate ammonium salt (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... polyalkylarylphenylether sulfate ammonium salt (generic). 721.10170 Section 721.10170 Protection of Environment... polyalkylarylphenylether sulfate ammonium salt (generic). (a) Chemical substance and significant new uses subject to... sulfate ammonium salt (PMN P-03-197) is subject to reporting under this section for the significant...

  11. 40 CFR 721.9075 - Quaternary ammonium salt of fluorinated alkylaryl amide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Quaternary ammonium salt of... New Uses for Specific Chemical Substances § 721.9075 Quaternary ammonium salt of fluorinated alkylaryl... identified generically as quaternary ammonium salt of fluorinated alkylaryl amide (PMN No. P-92-688)...

  12. 21 CFR 520.310 - Caramiphen ethanedisulfonate and ammonium chloride tablets.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Caramiphen ethanedisulfonate and ammonium chloride... § 520.310 Caramiphen ethanedisulfonate and ammonium chloride tablets. (a) Specifications. Each tablet contains 10 milligrams of 5st caramiphen ethanedisulfonate and 80 milligrams of ammonium chloride.1 1...

  13. 40 CFR 415.240 - Applicability; description of the ammonium chloride production subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... ammonium chloride production subcategory. 415.240 Section 415.240 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Ammonium Chloride Production Subcategory § 415.240 Applicability; description of the ammonium chloride production subcategory. The provisions of this subpart are applicable to...

  14. 21 CFR 520.310 - Caramiphen ethanedisulfonate and ammonium chloride tablets.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Caramiphen ethanedisulfonate and ammonium chloride... § 520.310 Caramiphen ethanedisulfonate and ammonium chloride tablets. (a) Specifications. Each tablet contains 10 milligrams of 5st caramiphen ethanedisulfonate and 80 milligrams of ammonium chloride.1 1...

  15. 40 CFR 415.240 - Applicability; description of the ammonium chloride production subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... ammonium chloride production subcategory. 415.240 Section 415.240 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Ammonium Chloride Production Subcategory § 415.240 Applicability; description of the ammonium chloride production subcategory. The provisions of this subpart are applicable to...

  16. 40 CFR 415.240 - Applicability; description of the ammonium chloride production subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... ammonium chloride production subcategory. 415.240 Section 415.240 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Ammonium Chloride Production Subcategory § 415.240 Applicability; description of the ammonium chloride production subcategory. The provisions of this subpart are applicable to...

  17. 40 CFR 415.240 - Applicability; description of the ammonium chloride production subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... ammonium chloride production subcategory. 415.240 Section 415.240 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Ammonium Chloride Production Subcategory § 415.240 Applicability; description of the ammonium chloride production subcategory. The provisions of this subpart are applicable to...

  18. 21 CFR 520.310 - Caramiphen ethanedisulfonate and ammonium chloride tablets.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Caramiphen ethanedisulfonate and ammonium chloride... § 520.310 Caramiphen ethanedisulfonate and ammonium chloride tablets. (a) Specifications. Each tablet contains 10 milligrams of 5st caramiphen ethanedisulfonate and 80 milligrams of ammonium chloride.1 1...

  19. 21 CFR 520.310 - Caramiphen ethanedisulfonate and ammonium chloride tablets.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Caramiphen ethanedisulfonate and ammonium chloride... § 520.310 Caramiphen ethanedisulfonate and ammonium chloride tablets. (a) Specifications. Each tablet contains 10 milligrams of 5st caramiphen ethanedisulfonate and 80 milligrams of ammonium chloride.1 1...

  20. 40 CFR 415.240 - Applicability; description of the ammonium chloride production subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... ammonium chloride production subcategory. 415.240 Section 415.240 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Ammonium Chloride Production Subcategory § 415.240 Applicability; description of the ammonium chloride production subcategory. The provisions of this subpart are applicable to...

  1. 40 CFR 721.10443 - Ethoxylated alkylphenol sulfate, ammonium salt (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., ammonium salt (generic). 721.10443 Section 721.10443 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.10443 Ethoxylated alkylphenol sulfate, ammonium salt... identified generically as ethoxylated alkylphenol sulfate, ammonium salt (PMN P-01-470) is subject...

  2. Ecological Risk Assessment of Ammonium Perchlorate on Fish, Amphibians, and Small Mammals

    DTIC Science & Technology

    2003-02-01

    The Effects of Contaminated and Reference Surface Waters on Metamorphosis in Xenopus Laevis ...; 4) Lethal Concentration Determination of Sodium...Perchlorate and Ammonium Chloride on Xenopus Laevis Eggs ... ; 5) Sublethal Effects of Ammonium Chloride, Ammonium Perchlorate, and Sodium Perchlorate on the...Development and Metamorphosis of Xenopus Laevis ; 6) Protocol Development for Determination of Effects of Perchlorate on Growth and Reproduction of

  3. 40 CFR 721.9075 - Quaternary ammonium salt of fluorinated alkylaryl amide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Quaternary ammonium salt of... New Uses for Specific Chemical Substances § 721.9075 Quaternary ammonium salt of fluorinated alkylaryl... identified generically as quaternary ammonium salt of fluorinated alkylaryl amide (PMN No. P-92-688)...

  4. 40 CFR 721.9075 - Quaternary ammonium salt of fluorinated alkylaryl amide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Quaternary ammonium salt of... New Uses for Specific Chemical Substances § 721.9075 Quaternary ammonium salt of fluorinated alkylaryl... identified generically as quaternary ammonium salt of fluorinated alkylaryl amide (PMN No. P-92-688)...

  5. 40 CFR 721.10170 - Polyoxyethylene polyalkylarylphenylether sulfate ammonium salt (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... polyalkylarylphenylether sulfate ammonium salt (generic). 721.10170 Section 721.10170 Protection of Environment... polyalkylarylphenylether sulfate ammonium salt (generic). (a) Chemical substance and significant new uses subject to... sulfate ammonium salt (PMN P-03-197) is subject to reporting under this section for the significant...

  6. 40 CFR 721.10170 - Polyoxyethylene polyalkylarylphenylether sulfate ammonium salt (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... polyalkylarylphenylether sulfate ammonium salt (generic). 721.10170 Section 721.10170 Protection of Environment... polyalkylarylphenylether sulfate ammonium salt (generic). (a) Chemical substance and significant new uses subject to... sulfate ammonium salt (PMN P-03-197) is subject to reporting under this section for the significant...

  7. 40 CFR 721.9075 - Quaternary ammonium salt of fluorinated alkylaryl amide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Quaternary ammonium salt of... New Uses for Specific Chemical Substances § 721.9075 Quaternary ammonium salt of fluorinated alkylaryl... identified generically as quaternary ammonium salt of fluorinated alkylaryl amide (PMN No. P-92-688)...

  8. 40 CFR 721.10170 - Polyoxyethylene polyalkylarylphenylether sulfate ammonium salt (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... polyalkylarylphenylether sulfate ammonium salt (generic). 721.10170 Section 721.10170 Protection of Environment... polyalkylarylphenylether sulfate ammonium salt (generic). (a) Chemical substance and significant new uses subject to... sulfate ammonium salt (PMN P-03-197) is subject to reporting under this section for the significant...

  9. 40 CFR 721.10443 - Ethoxylated alkylphenol sulfate, ammonium salt (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., ammonium salt (generic). 721.10443 Section 721.10443 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.10443 Ethoxylated alkylphenol sulfate, ammonium salt... identified generically as ethoxylated alkylphenol sulfate, ammonium salt (PMN P-01-470) is subject...

  10. 77 FR 32669 - Ammonium Nitrate from Ukraine Institution of a Five-Year Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-01

    ... COMMISSION Ammonium Nitrate from Ukraine Institution of a Five-Year Review AGENCY: United States... determine whether revocation of the antidumping duty order on ammonium nitrate from Ukraine would be likely... ammonium nitrate from Ukraine (66 FR 47451). Following the five-year reviews by Commerce and the...

  11. 75 FR 56489 - Separation Distances of Ammonium Nitrate and Blasting Agents From Explosives or Blasting Agents...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-16

    ... Ammonium Nitrate and Blasting Agents From Explosives or Blasting Agents (2002R-226P) AGENCY: Bureau of... CFR 555.220 set forth a table of separation distances of ammonium nitrate and blasting agents from... specified in the table ``apply to ammonium nitrate that passes the insensitivity test prescribed in...

  12. 78 FR 35258 - Solid Agricultural Grade Ammonium Nitrate from Ukraine: Continuation of Antidumping Duty Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-12

    ... International Trade Administration Solid Agricultural Grade Ammonium Nitrate from Ukraine: Continuation of... revocation of the antidumping duty order \\1\\ on solid agricultural grade ammonium nitrate from Ukraine would... of the Order. \\1\\ See Antidumping Duty Order: Solid Agricultural Grade Ammonium Nitrate from...

  13. 77 FR 21527 - Ammonium Nitrate From Russia: Correction to Notice of Opportunity To Request Administrative Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-10

    ... International Trade Administration Ammonium Nitrate From Russia: Correction to Notice of Opportunity To Request... of the antidumping duty orders and inadvertently omitted Ammonium Nitrate from Russia, POR 5/2/2011-3... include the Ammonium Nitrate from Russia administrative review in the referenced notice. Dated: April...

  14. 77 FR 59377 - Solid Agricultural Grade Ammonium Nitrate from Ukraine: Final Results of the Expedited Second...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-27

    ... Agricultural Grade Ammonium Nitrate from Ukraine: Final Results of the Expedited Second Sunset Review of the... antidumping duty order on solid agricultural grade ammonium nitrate from Ukraine. The Department has conducted... on solid agricultural grade ammonium nitrate from Ukraine, pursuant to section 751(c) of the...

  15. 40 CFR 721.10342 - Quaternary ammonium compounds, fatty alkyl dialkyl hydroxide (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Quaternary ammonium compounds, fatty... Significant New Uses for Specific Chemical Substances § 721.10342 Quaternary ammonium compounds, fatty alkyl... chemical substance identified generically as quaternary ammonium compounds, fatty alkyl dialkyl...

  16. 40 CFR 721.10342 - Quaternary ammonium compounds, fatty alkyl dialkyl hydroxide (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Quaternary ammonium compounds, fatty... Significant New Uses for Specific Chemical Substances § 721.10342 Quaternary ammonium compounds, fatty alkyl... chemical substance identified generically as quaternary ammonium compounds, fatty alkyl dialkyl...

  17. 40 CFR 721.10342 - Quaternary ammonium compounds, fatty alkyl dialkyl hydroxide (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Quaternary ammonium compounds, fatty... Significant New Uses for Specific Chemical Substances § 721.10342 Quaternary ammonium compounds, fatty alkyl... chemical substance identified generically as quaternary ammonium compounds, fatty alkyl dialkyl...

  18. Determination of aerosol ammonium using an aerodyne aerosol mass spectrometer

    NASA Astrophysics Data System (ADS)

    Delia, A. E.; Toohey, D. W.; Worsnop, D. R.

    2003-04-01

    The chemical composition of fine aerosols is a significant issue both because it influences the chemical and radiative properties of the aerosols, which in turn impact the regional and global climate and human health, and because it is difficult to measure accurately. The Aerosol Mass Spectrometer (AMS) developed by Aerodyne Research measures both chemical composition and aerodynamic size of submicron aerosols quantitatively. However, the measurement of aerosol ammonium is more difficult than that of the other major inorganic species, nitrate and sulfate, because of interferences in the mass spectrum from air and water. This presentation will describe the successful procedure developed for dealing with these interferences and accurately determining the ammonium mass. In addition, the application of this procedure to aerosols from a range of ambient conditions will be demonstrated using data from several field studies.

  19. Reverse osmosis separation of radiocontaminants from ammonium diuranate effluents

    SciTech Connect

    Prabhakar, S.; Misra, B.M.; Roy, S.B.; Meghal, A.M.; Mukherjee, T.K. )

    1994-05-01

    A reverse osmosis process has been found to be effective for the separation of radiocontaminants from ammonium diuranate effluents in a uranium metal plant. Pilot-plant-scale experiments were conducted using cellulosic membranes in a plate module system and actual plant effluents containing more than about 40,000 ppm of ammonium and nitrate species and having radiocontaminants corresponding to specific activities of about 10[sup [minus]3] Ci/m[sup 3] beta/gamma emitters. The results indicated that more than 95% by volume of the treated effluents were within disposal limits, while the remaining contained the concentrate, which can be treated for possible containment. 6 refs., 2 figs., 5 tabs.

  20. Transformation of ammonium dicyanamide into dicyandiamide in the solid.

    PubMed

    Jürgens, Barbara; Höppe, Henning A; Irran, Elisabeth; Schnick, Wolfgang

    2002-09-23

    Ammonium dicyanamide NH(4)[N(CN)(2)] was synthesized through aqueous ion exchange. The crystal structure was investigated by single-crystal X-ray diffraction (P2(1)/c, a = 378.67(6) pm, b = 1240.9(3) pm, c = 911.84(14) pm, beta = 91.488(18) degrees, Z = 4). It derives from the CsCl structure type. Medium strong hydrogen bonds between NH(4)(+) and [N(CN)(2)](-) ions are indicative of the observed formation of dicyandiamide H(4)C(2)N(4) during heating. According to DSC and temperature-dependent X-ray powder diffractometry, this isomerization is exothermic and occurs between 102 and 106 degrees C in the solid. The reaction represents the isolobal analogue to the classical synthesis of urea by heating NH(4)OCN. While other alkali and alkaline earth dicyanamides undergo trimerization or polymerization of their anions during heating, ammonium dicyanamide thus shows a different reactivity.

  1. The transformation of outdoor ammonium nitrate aerosols in theindoor environment

    SciTech Connect

    Lunden, Melissa M.; Thatcher, Tracy L.; Littlejohn, David; Fischer, Marc L.; Hering, Susanne V.; Sextro, Richard G.; Brown, Nancy J.

    2002-01-31

    Recent studies associate particulate air pollution with adverse health effects; however, the exposure to indoor particles of outdoor origin is not well characterized, particularly for individual chemical species. In response to this, a field study in an unoccupied, single-story residence in Clovis, California has been conducted. Real-time particle monitors were used both outdoors and indoors to quantify PM2.5 nitrate, sulfate, and carbon. The results show that reduced indoor sulfate and carbon levels are primarily due to deposition and penetration losses. However, measured indoor ammonium nitrate levels were often observed to be at significantly lower levels than expected based solely on penetration and deposition losses. The additional reduction appears to be due to the transformation of ammonium nitrate into ammonia and nitric acid indoors, which are subsequently lost by deposition and sorption to indoor surfaces. The size of the effect is dependent upon factors such as temperature, relative humidity, and ventilation rate.

  2. Ammonium sulphate precipitation overestimates titres of anti-peptide antisera.

    PubMed

    Roth, B; Barkas, T

    1984-01-01

    Precipitation by 50% final saturation of ammonium sulphate, a method commonly used to estimate titres and affinity constants of antibodies, was found consistently to overestimate the titre of anti-peptide antisera when compared with other antibody precipitants. The effect could not be attributed to non-IgG fractions, and similar overestimations were found when pure IgG was used. We suggest that the lower values represent a more physiologically relevant estimation.

  3. Synthesis and Characterization of Perfluoro Quaternary Ammonium Anion Exchange Membranes

    DTIC Science & Technology

    2012-01-01

    which suffer a number hydroxide degradation routes. Quaternary ammonium compounds can undergo Hoff- man elimination to form an amine and an olefin ...nucleophilic substitution to produce an amine and an alcohol , and elimina- tion of hydrogen to form water and an ylide, which further reacts to form an...amine and an olefin .2,4,18 Some of these degra- dation pathways can be avoided or reduced by careful selection of cation species.2 Degradation of

  4. Ammonium photo-production by heterocytous cyanobacteria: potentials and constraints.

    PubMed

    Grizeau, Dominique; Bui, Lan Anh; Dupré, Catherine; Legrand, Jack

    2016-08-01

    Over the last decades, production of microalgae and cyanobacteria has been developed for several applications, including novel foods, cosmetic ingredients and more recently biofuel. The sustainability of these promising developments can be hindered by some constraints, such as water and nutrient footprints. This review surveys data on N2-fixing cyanobacteria for biomass production and ways to induce and improve the excretion of ammonium within cultures under aerobic conditions. The nitrogenase complex is oxygen sensitive. Nevertheless, nitrogen fixation occurs under oxic conditions due to cyanobacteria-specific characteristics. For instance, in some cyanobacteria, the vegetative cell differentiation in heterocyts provides a well-adapted anaerobic microenvironment for nitrogenase protection. Therefore, cell cultures of oxygenic cyanobacteria have been grown in laboratory and pilot photobioreactors (Dasgupta et al., 2010; Fontes et al., 1987; Moreno et al., 2003; Nayak & Das, 2013). Biomass production under diazotrophic conditions has been shown to be controlled by environmental factors such as light intensity, temperature, aeration rate, and inorganic carbon concentration, also, more specifically, by the concentration of dissolved oxygen in the culture medium. Currently, there is little information regarding the production of extracellular ammonium by heterocytous cyanobacteria. This review compares the available data on maximum ammonium concentrations and analyses the specific rate production in cultures grown as free or immobilized filamentous cyanobacteria. Extracellular production of ammonium could be coupled, as suggested by recent research on non-diazotrophic cyanobacteria, to that of other high value metabolites. There is little information available regarding the possibility for using diazotrophic cyanobacteria as cellular factories may be in regard of the constraints due to nitrogen fixation.

  5. Nanomodified vermiculite NMV - a new material for recycling ammonium nitrogen

    NASA Astrophysics Data System (ADS)

    Rama, Miradije; Laiho, Taina; Eklund, Olav; Lehto, Kirsi; Shebanov, Alex; Smått, Jan-Henrik

    2016-04-01

    Vermiculites ((Mg,Fe,Al)3(Al,Si)4O10(OH)24H2O) are naturally occurring minerals from hydromica group with a high cation exchange capacity and large surface area. Since vermiculite is a hydrated mineral, its structure can be changed with heat. In this study vermiculite samples were heated in an oven until the interlayer distance of them diminished from 14 Å to 11.7 Å. This method for improving vermiculites intake of ammonium ions by heating, is an invention made at the University of Turku. Nanomodified vermiculite (NMV) is able to absorb up to 4.7 wt% of ammonium. NMV can be used as an efficient filter and immobilizer of ammonium in different environments. NMV has been efficiently tested on waste water from a biogas plant, human urine, combustion experiments, industrial chimneys, excrements from farms etc. Ammonium doped vermiculite (ADV) is further developed for fertilizer use. Performed experiments have testified the usability of ADV as a fertilizer. At first step the NMV was processed with the reject water from a biogas plant, were it absorbed NH4+ into the lattice. At second, the ADV was used as nutrient source for garden plants. Geraniums and begonias were used as test plants of the work. Plant growth rate was evaluated based on plant weight. Results showed that significant increase of the growth of geraniums and of begonias were observed when comparing to those cultivations where plants have got normal fertilization. Moreover, ADV has been tested as a fertilizer in greenhouse experiments with spruces and pines. After five months, the weight of the plants that had grown in a substrate containing ADV was 10 times the weight of plants growing in the reference substrate.

  6. SWELLING OF ERYTHROCYTES IN SOLUTIONS OF AMMONIUM SALTS

    PubMed Central

    Schiödt, E.

    1933-01-01

    Two rather simple equations have been derived, which make it possible to express in a single number the result of a series of determinations of the volume of erythrocytes swelling in solutions of ammonium salts. In all experiments made with several combinations of different concentrations of permeating and non-permeating salts, the curves calculated from the equations have covered the points found by experiment. PMID:19872754

  7. Ammonium nitrogen in fetuses of urea-treated sheep.

    PubMed

    Yelverton, C C; Roller, M H; Swanson, R N

    1975-02-01

    Eight pregnant Southdown ewes were treated (by drench) with 12.5 ml of 3.3 M urea solution per kilogram of body weight, and ammonium nitrogen concentrations of blood and tissues of these ewes and their fetuses were measured and compared with those of control ewes (given water by drench) and their fetuses. Blood ammonium nitrogen (BAN) and tissue ammonium nitrogen (TAN) concentrations for liver, kidney, spleen, and muscle of ewes and fetuses were determined by an ion-exchange procedure. Samples of blood were collected before treatment, at 30, 90 and 150 minutes after treatment, and at death of the dam. The principal ewes had increasing BAN concentrations with time after drench, and their fetuses had significantly greater (P less than 0.01) BAN concentrations than fetuses from control ewes. All fetuses were alive after death of the dams and had lower TAN values than their dams. The differences in ammonia concentrations between ewes and fetuses were larger in the principal group than in the control group. Except for ewe muscle and fetal liver, all tissues of principals had significantly greater (P less than 0.01) TAN concentrations than those of controls. Muscle of principal ewes and hepatic tissues of their fetuses had greater (P less than 0.05) TAN concentrations than those of control ewes and their fetuses.

  8. Preferential uptake of ammonium ions by zinc ferrocyanide

    NASA Technical Reports Server (NTRS)

    Braterman, P. S.; Arrhenius, G.; Hui, S.; Paplawsky, W.; Miller, S. L. (Principal Investigator)

    1995-01-01

    The concentration of ammonia from dilute aqueous solution could have facilitated many prebiotic reactions. This may be especially true if this concentration involves incorporation into an organized medium. We have shown that (unlike iron(III) ferrocyanide) zinc ferrocyanide,Zn2Fe(CN)6 xH2O, preferentially takes up ammonium ions from 0.01 M NH4Cl to give the known material Zn3(NH4)2[Fe(CN)6]2 xH2O, even in the presence of 0.01 M KCl. KCl alone gave Zn3K2[Fe(CN)6]2 xH2O. Products were characterized by elemental (CHN) analysis and powder X-ray diffraction (XRD). We attribute the remarkable specificity for the ammonium ion to the open framework of the product, which offers enough space for hydrogen-bonded ammonium ions, and infer that other inorganic materials with internal spaces rich in water may show a similar preference.

  9. Glutamate decarboxylase from Lactobacillus brevis: activation by ammonium sulfate.

    PubMed

    Hiraga, Kazumi; Ueno, Yoshie; Oda, Kohei

    2008-05-01

    In this study, the glutamate decarboxylase (GAD) gene from Lactobacillus brevis IFO12005 (Biosci. Biotechnol. Biochem., 61, 1168-1171 (1997)), was cloned and expressed. The deduced amino acid sequence showed 99.6% and 53.1% identity with GAD of L. brevis ATCC367 and L. lactis respectively. The His-tagged recombinant GAD showed an optimum pH of 4.5-5.0, and 54 kDa on SDS-PAGE. The GAD activity and stability was significantly dependent on the ammonium sulfate concentration, as observed in authentic GAD. Gel filtration showed that the inactive form of the GAD was a dimer. In contrast, the ammonium sulfate-activated form was a tetramer. CD spectral analyses at pH 5.5 revealed that the structures of the tetramer and the dimer were similar. Treatment of the GAD with high concentrations of ammonium sulfate and subsequent dilution with sodium glutamate was essential for tetramer formation and its activation. Thus the biochemical properties of the GAD from L. brevis IFO12005 were significantly different from those from other sources.

  10. Removal of chloridazon by natural and ammonium kerolite samples

    NASA Astrophysics Data System (ADS)

    Socías-Viciana, M. M.; Tévar de Fez, J.; Ureña-Amate, M. D.; González-Pradas, E.; Fernández-Pérez, M.; Flores-Céspedes, F.

    2006-06-01

    The adsorption of chloridazon (5-amino-4-chloro-2-phenylpyridazin-3(2H)-one) on natural and ammonium kerolite samples from aqueous solution at 10, 25 and 40 °C has been studied by using batch experiments. The experimental data points were fitted to the Langmuir equation in order to calculate the adsorption capacities ( Xm) of the samples; two straight lines were obtained, which indicates that the adsorption process takes place in two different stages. Values for Xm1 (first stage) ranged from 1.1 × 10 -2 mol kg -1 for natural kerolite at 40 °C up to 5.1 × 10 -2 mol kg -1 for ammonium kerolite at 10 °C and the values for Xm2 (second stage) ranged from 9.1 × 10 -2 mol kg -1 for natural kerolite at 40 °C up to 14 × 10 -2 mol kg -1 for natural kerolite at 10 °C. The adsorption experiments showed on the one hand, that the ammonium kerolite is more effective than natural kerolite to adsorb chloridazon in the range of temperature studied and on the other hand, that the lower temperature, the more effective the adsorption of chloridazon on the adsorbents studied.

  11. Structural basis for Mep2 ammonium transceptor activation by phosphorylation

    PubMed Central

    van den Berg, Bert; Chembath, Anupama; Jefferies, Damien; Basle, Arnaud; Khalid, Syma; Rutherford, Julian C.

    2016-01-01

    Mep2 proteins are fungal transceptors that play an important role as ammonium sensors in fungal development. Mep2 activity is tightly regulated by phosphorylation, but how this is achieved at the molecular level is not clear. Here we report X-ray crystal structures of the Mep2 orthologues from Saccharomyces cerevisiae and Candida albicans and show that under nitrogen-sufficient conditions the transporters are not phosphorylated and present in closed, inactive conformations. Relative to the open bacterial ammonium transporters, non-phosphorylated Mep2 exhibits shifts in cytoplasmic loops and the C-terminal region (CTR) to occlude the cytoplasmic exit of the channel and to interact with His2 of the twin-His motif. The phosphorylation site in the CTR is solvent accessible and located in a negatively charged pocket ∼30 Å away from the channel exit. The crystal structure of phosphorylation-mimicking Mep2 variants from C. albicans show large conformational changes in a conserved and functionally important region of the CTR. The results allow us to propose a model for regulation of eukaryotic ammonium transport by phosphorylation. PMID:27088325

  12. Evaluating Ammonium, Nitrate and Sulfate Aerosols in 3-Dimensions

    NASA Astrophysics Data System (ADS)

    Mezuman, K.; Bauer, S.; Tsigaridis, K.

    2015-12-01

    The spatial distribution of aerosols and their chemical composition dictates whether they would have a cooling or a warming effect on the climate system. Hence, properly modeling the 3-dimensonal distribution of aerosols is a crucial step for coherent climate simulations. Since surface networks only give 2-D data, and most satellites supply integrated column information, it is thus important to integrate aircraft measurements in climate model evaluation. In this study, the vertical distribution of ammonium, nitrate, and sulfate, is constrained against a collection of 14 AMS flight campaigns, and surface measurements from 2000-2010 in the USA and Europe. GISS modelE2, one of the only models to include nitrate aerosol in CIMP5, is used with multiple aerosol microphysics (MATRIX, OMA) and thermodynamic (ISORROPIA-II, EQSAM) configurations. Our results show that the MATRIX microphysical scheme improves the model performance for sulfate and that there is a systematic underestimation of ammonium and nitrate over the USA and Europe. In terms of gaseous precursors, underestimation of nitrate and ammonium is likely tied to ammonia emissions uncertainties, while nitric acid concentrations are largely overestimated in the higher levels of the model, influenced by strong strat-trop exchange. At high altitudes, nitrate formation is calculated to be ammonia limited, whose profile measurements are scarce.

  13. Relevance of ammonium oxidation within biological soil crust communities

    USGS Publications Warehouse

    Johnson, S.L.; Budinoff, C.R.; Belnap, J.; Garcia-Pichel, F.

    2005-01-01

    Thin, vertically structured topsoil communities that become ecologically important in arid regions (biological soil crusts or BSCs) are responsible for much of the nitrogen inputs into pristine arid lands. We studied N2 fixation and ammonium oxidation (AO) at subcentimetre resolution within BSCs from the Colorado Plateau. Pools of dissolved porewater nitrate/ nitrite, ammonium and organic nitrogen in wetted BSCs were high in comparison with those typical of aridosoils. They remained stable during incubations, indicating that input and output processes were of similar magnitude. Areal N2 fixation rates (6.5-48 ??mol C2H2 m-2 h -1) were high, the vertical distribution of N2 fixation peaking close to the surface if populations of heterocystous cyanobacteria were present, but in the subsurface if they were absent. Areal AO rates (19-46 ??mol N m-2 h-1) were commensurate with N2 fixation inputs. When considering oxygen availability, AO activity invariably peaked 2-3 mm deep and was limited by oxygen (not ammonium) supply. Most probable number (MPN)-enumerated ammonia-oxidizing bacteria (6.7-7.9 ?? 103 cells g-1 on average) clearly peaked at 2-3 mm depth. Thus, AO (hence nitrification) is a spatially restricted but important process in the nitrogen cycling of BSC, turning much of the biologically fixed nitrogen into oxidized forms, the fate of which remains to be determined.

  14. Rapid and sensitive Nitrosomonas europaea biosensor assay for quantification of bioavailable ammonium sensu strictu in soil.

    PubMed

    Nguyen, Minh Dong; Risgaard-Petersen, Nils; Sørensen, Jan; Brandt, Kristian K

    2011-02-01

    Knowledge on bioavailable ammonium sensu strictu (i.e., immediately available for cellular uptake) in soil is required to understand nutrient uptake processes in microorganisms and thus of vital importance for plant production. We here present a novel ammonium biosensor approach based on the lithoautotrophic ammonia-oxidizing bacterium Nitrosomonas europaea transformed with a luxAB sensor plasmid. Bioluminescence-based ammonium detection was achieved within 10 min with a quantification limit in liquid samples of ∼20 μM and a linear response range up to 400 μM. Biosensor and conventional chemical quantification of ammonium in soil solutions agreed well across a range of sample and assay conditions. The biosensor was subsequently applied for a solid phase-contact assay allowing for direct interaction of biosensor cells with soil particle-associated (i.e., exchangeable plus fixed) ammonium. The assay successfully quantified bioavailable ammonium even in unfertilized soil and demonstrated markedly higher ratios of bioavailable ammonium to water- or 2 M KCl-exchangeable ammonium in anoxic soil than in corresponding oxic soil. Particle-associated ammonium contributed by at least 74% and 93% of the total bioavailable pool in oxic and anoxic soil, respectively. The N. europaea biosensor should have broad relevance for environmental monitoring of bioavailable ammonium and processes depending on ammonium bioavailability.

  15. Removal of ammonium from aqueous solutions using the residue obtained from struvite pyrogenation.

    PubMed

    Huang, Haiming; Song, Qianwu; Xu, Chunlian

    2011-01-01

    This paper reports the results of laboratory studies on the removal of ammonium from aqueous solutions using struvite pyrogenation residues. A series of experiments were conducted to examine the effects of the pyrogenation temperature (90-210 °C) and time (0.5-4 h) on the ammonium release of struvite. In addition, the pyrolysate of struvite produced at different pyrogenation temperatures and times was recycled for ammonium removal from aqueous solutions. The experimental results indicated that the ammonium release ratio of struvite increased with an increase in the pyrogenation temperature and time, and the struvite pyrolysate used as magnesium and phosphate source for ammonium removal was produced at the optimal condition of pyrogenation temperature of 150 °C for 1 h. Furthermore, experimental results showed that the optimum pH and pyrolysate dosage for ammonium removal from 100 ml synthetic wastewater (1,350 mg ammonium/L) were at pH 9 and 2.4 g of struvite pyrolysate, respectively, and initial ammonium concentration played a significant role in the ammonium removal by the struvite pyrolysate. In order to further reduce the cost of struvite precipitation, the struvite pyrolysate was repeatedly used for four cycles. The results of economic analysis showed that recycling struvite for three process cycles should be reasonable for ammonium removal, with ammonium removal efficiencies of over 50% and a reduction of 40% in the removal cost per kg NH(4)(+).

  16. Concurrence of Anaerobic Ammonium Oxidation and Organotrophic Denitrification in Presence of p-Cresol.

    PubMed

    González-Blanco, G; Cervantes, F J; Beristain-Cardoso, R; Gómez, J

    2015-08-01

    This study was carried out to evaluate the capacity of anaerobic granular sludge for oxidizing ammonium and p-cresol with nitrate as terminal electron acceptor. Kinetics for the anaerobic oxidation of ammonium and p-cresol is described in this paper. The phenolic compound was very efficiently consumed, achieving 65 % of mineralization. Ammonium and nitrate were also consumed at 83 and 92 %, respectively, being the main product N2. Anaerobic ammonium oxidation was promoted owing to accumulation of nitrite, and it allowed the synergy of anaerobic ammonium oxidation and organotrophic denitrification for the simultaneous removal of ammonium, nitrate, and p-cresol. A carbonaceous intermediate partially identified was transiently accumulated, and it transitorily truncated the respiratory process of denitrification. These experimental results might be considered for defining strategies in order to remove nitrate, ammonium, and phenolic compounds from wastewaters.

  17. Evidence for surface nucleation: efflorescence of ammonium sulfate and coated ammonium sulfate aerosol particles

    NASA Astrophysics Data System (ADS)

    Ciobanu, V. Gabriela; Marcolli, Claudia; Krieger, Ulrich K.; Zuend, Andreas; Peter, Thomas

    2010-05-01

    Aerosol particles are ubiquitous in the atmosphere and can undergo different phase transitions, such as deliquescence and efflorescence. Using optical microscopy, we investigated the efflorescence of ammonium sulfate (AS) in supersaturated AS and 1:1 and 8:1 (by weight) poly(ethylene glycol)-400 (PEG-400)/AS particles, which were deposited as droplets with diameters in the 16 - 35 μm range on a hydrophobically coated slide. The PEG-400/AS particles that are exposed to decreasing relative humidity (RH) exhibit a liquid-liquid phase separation below 90 % RH with the PEG-400 phase surrounding the aqueous AS inner phase (Marcolli and Krieger, 2006; Ciobanu et al., 2009). Pure AS particles effloresced in the RH range from 36.3 to 43.7 % RH, in agreement with literature data (31 - 48 % RH). In contrast, 1:1 PEG-400/AS particles with diameters of the AS phase from 7.2 - 19.2 μm effloresced between 26.8 - 33.9 % RH and 8:1 PEG-400/AS particles with diameters of the AS phase from 1.8 - 7.3 μm between 24.3 - 29.3 % RH. Such low efflorescence relative humidity (ERH) values have never been reached before for AS particles of this size range. We show that neither a potential inhibition of water evaporation via anomalously slow diffusion through the PEG coating, nor the presence of low amounts of PEG-400 in the AS phase, nor different timescales between various experimental techniques could possibly explain the low AS ERH values of PEG-400/AS particles in our setup. High-speed photography of the efflorescence process allowed to monitor the proceeding of the AS crystallization fronts within the particles with millisecond time resolution. The nucleation locations were deduced based on the initial crystals growth locations. Statistical analysis of 31 and 19 efflorescence events for pure AS and 1:1 PEG-400/AS particles, respectively, identified the air/droplet/substrate contact line and the air/droplet interface as preferred nucleation locations in the case of pure AS particles

  18. Glycosylation-related genes in NS0 cells are insensitive to moderately elevated ammonium concentrations.

    PubMed

    Brodsky, Arthur Nathan; Caldwell, Mary; Bae, Sooneon; Harcum, Sarah W

    2014-10-10

    NS0 and Chinese hamster ovary (CHO) cell lines are used to produce recombinant proteins for human therapeutics; however, ammonium accumulation can negatively impact cell growth, recombinant protein production, and protein glycosylation. To improve product quality and decrease costs, the relationship between ammonium and protein glycosylation needs to be elucidated. While ammonium has been shown to adversely affect glycosylation-related gene expression in CHO cells, NS0 studies have not been performed. Therefore, this study sought to determine if glycosylation in NS0 cells were ammonium-sensitive at the gene expression level. Using a DNA microarray that contained mouse glycosylation-related and housekeeping genes, these genes were analyzed in response to various culture conditions - elevated ammonium, elevated salt, and elevated ammonium with proline. Surprisingly, no significant differences in gene expression levels were observed between the control and these conditions. Further, the elevated ammonium cultures were analyzed using real-time quantitative reverse transcriptase PCR (qRT-PCR) for key glycosylation genes, and the qRT-PCR results corroborated the DNA microarray results, demonstrating that NS0 cells are ammonium-insensitive at the gene expression level. Since NS0 are known to have elevated nucleotide sugar pools under ammonium stress, and none of the genes directly responsible for these metabolic pools were changed, consequently cellular control at the translational or substrate-level must be responsible for the universally observed decreased glycosylation quality under elevated ammonium.

  19. Environmentally relevant concentrations of ammonium perchlorate inhibit development and metamorphosis in Xenopus laevis.

    PubMed

    Goleman, Wanda L; Urquidi, Lina J; Anderson, Todd A; Smith, Ernest E; Kendall, Ronald J; Carr, James A

    2002-02-01

    We determined whether environmentally relevant concentrations of ammonium perchlorate alter development and metamorphosis in Xenopus laevis. Eggs and larvae were exposed to varying concentrations of ammonium perchlorate or control medium for 70 d. Most treatment-related mortality was observed within 5 d after exposure and was due in large part to reduced hatching success. The 5- and 70-d median lethal concentrations (LC50s) were 510 +/- 36 mg ammonium perchlorate/L and 223 +/- 13 mg ammonium perchlorate/L, respectively. Ammonium perchlorate did not cause any concentration-related developmental abnormalities at concentrations below the 70-d LC50. Ammonium perchlorate inhibited metamorphosis in a concentration-dependent manner as evident from effects on forelimb emergence, tail resorption, and hindlimb growth. These effects were observed after exposure to ammonium perchlorate concentrations in the parts-per-billion range, at or below concentrations reported in surface waters contaminated with ammonium perchlorate. Ammonium perchlorate significantly inhibited tail resorption after a 14-d exposure in the U.S. Environmental Protection Agency (U.S. EPA) Endocrine Disruptor Screening and Testing Committee (EDSTAC) Tier I frog metamorphosis assay for thyroid disruption in amphibians. We believe that ammonium perchlorate may pose a threat to normal development and growth in natural amphibian populations.

  20. Influence of heterogeneous ammonium availability on bacterial community structure and the expression of nitrogen fixation and ammonium transporter genes during in situ bioremediation of uranium-contaminated groundwater

    SciTech Connect

    Mouser, P.J.; N'Guessan, A.L.; Elifantz, H.; Holmes, D.E.; Williams, K.H.; Wilkins, M.J.; Long, P.E.; Lovley, D.R.

    2009-04-01

    The impact of ammonium availability on microbial community structure and the physiological status and activity of Geobacter species during in situ bioremediation of uranium-contaminated groundwater was evaluated. Ammonium concentrations varied by as much as two orders of magnitude (<4 to 400 {micro}M) across the study site. Analysis of 16S rRNA gene sequences suggested that ammonium influenced the composition of the microbial community prior to acetate addition with Rhodoferax species predominating over Geobacter species at the site with the highest ammonium, and Dechloromonas species dominating at sites with lowest ammonium. However, once acetate was added, and dissimilatory metal reduction was stimulated, Geobacter species became the predominant organisms at all locations. Rates of U(VI) reduction appeared to be more related to the concentration of acetate that was delivered to each location rather than the amount of ammonium available in the groundwater. In situ mRNA transcript abundance of the nitrogen fixation gene, nifD, and the ammonium importer gene, amtB, in Geobacter species indicated that ammonium was the primary source of nitrogen during in situ uranium reduction, and that the abundance of amtB transcripts was inversely correlated to ammonium levels across all sites examined. These results suggest that nifD and amtB expression by subsurface Geobacter species are closely regulated in response to ammonium availability to ensure an adequate supply of nitrogen while conserving cell resources. Thus, quantifying nifD and amtB expression appears to be a useful approach for monitoring the nitrogen-related physiological status of Geobacter species in subsurface environments during bioremediation. This study also emphasizes the need for more detailed analysis of geochemical/physiological interactions at the field scale, in order to adequately model subsurface microbial processes.

  1. Stability of ammonium fluoride-treated Si(100)

    NASA Astrophysics Data System (ADS)

    Houston, Michael R.; Maboudian, Roya

    1995-09-01

    X-ray photoelectron spectroscopy (XPS) and contact angle analyses have been employed to investigate the chemical stability of silicon surfaces treated by an ammonium fluoride (NH4F) solution. Consistent with earlier results [Dumas and Chabal, Chem. Phys. Lett. 181, 537 (1991)], it is found that an NH4F final etch produces surfaces exhibiting lower oxygen and carbon contamination levels in comparison to the surfaces obtained with the traditional HF or buffered HF (BHF) etch. In conjunction with lower contamination levels, surfaces treated in ammonium fluoride show higher contact angles with water, indicating lower surface free energies. The Si-H surfaces produced by the ammonium fluoride etch were found to remain hydrophobic for weeks in air and showed no signs of oxidation for several days. After an induction period of about one week in air, oxidation began to occur in a more rapid fashion. The stability of the Si-H surfaces in water was also investigated, and it was found that the oxygen contamination levels measured by x-ray photoelectron spectroscopy were extremely sensitive to the final rinse time. An induction period of approximately one hour in water existed before any signs of oxidation were evident. Despite the fact that the NH4F-treated samples were initially cleaner than the HF-treated samples, both of these surfaces showed similar temporal behavior in air and water. We attribute this finding to the surface topographies produced by these treatments, as well as to the extreme sensitivity of the results to such factors as water rinse time.

  2. Di-ethyl-ammonium di-hydrogen orthophosphate.

    PubMed

    Held, Peter

    2014-02-01

    In the title molecular salt, [NH2(CH2CH3)2][H2PO4], two unique types of cations and anions, which are configurationally very similar, are present in the asymmetric unit. Both ions form sheets approximately parallel to (-1-1) linked by weak hydrogen bonds. The inter-connection within and between the sheets is reinforced by O-H⋯O and N-H⋯O hydrogen bonds involving the tetra-hedral H2PO4 anions and the ammonium groups.

  3. The Properties of Ammonium Dinitramine (ADN): Part 2: Melt Casting

    NASA Astrophysics Data System (ADS)

    Hahma, A.; Edvinsson, H.; Östmark, H.

    2010-04-01

    A melt casting technique for ammonium dinitramine (ADN) and ADN/aluminum was developed. ADN proved relatively easy to cast, when 1% of magnesium oxide was used as a stabilizer and crystallization kernels. Densities of ADN/MgO 99/1 were 92 to 97% of theoretical mean density (TMD) and those of ADN/Al/MgO 64/35/1 were between 95 and 99% of TMD. Sedimentation of Al in the melt was prevented and the particle wetting was ensured by selecting a suitable particle size for Al. No gelling agents or other additives were used. The casting process and factors influencing it are discussed.

  4. Secondary nucleation kinetcs of ammonium sulfate in a CMSMPR crystallizer

    NASA Astrophysics Data System (ADS)

    Daudey, P. J.; van Rosmalen, G. M.; de Jong, E. J.

    1990-01-01

    Secondary nucleation in suspension is most frequently modelled by an empirical "power-law" relating the nucleation rate to supersaturation and to the slurry density of the crystals already present in the solution. In this paper kinetic rate equations are developed based on a general modelling of secondary nucleation employing two mechanisms, surface breeding and mechanical breeding, each consisting of sequential steps. The specific equations gained in this way are used to determine the breeding mechanisms prevailing in suspension crystallization. Ammonium sulfate was used as a test case. For this system it is concluded that surface breeding is the predominant mechanism in both evaporation and cooling experiments.

  5. Hydroxide Degradation Pathways for Substituted Benzyltrimethyl Ammonium: A DFT Study

    DOE PAGES

    Long, Hai; Pivovar, Bryan S.

    2014-11-01

    The stability of cations used in the alkaline exchange membranes has been a major challenge. In this paper, degradation energy barriers were investigated by density functional theory for substituted benzyltrimethyl ammonium (BTMA+) cations. Findings show that electron-donating substituent groups at meta-position(s) of the benzyl ring could result in increased degradation barriers. However, after investigating more than thirty substituted BTMA+ cations, the largest improvement in degradation barrier found was only 6.7 kJ/mol. This suggests a modest (8×) improvement in stability for this type of approach may be possible, but for anything greater other approaches will need to be pursued.

  6. Fish gelatin and ammonium dichromate as photosensitive film

    NASA Astrophysics Data System (ADS)

    Orozco-Muñoz, Rosa Elena; Ortiz-Gutiérrez, Mauricio; Salgado-Verduzco, Marco Antonio; Ibarra-Torres, Juan Carlos; Olivares-Pérez, Arturo; Toxqui-López, Santa; Pérez-Cortés, Mario

    2014-02-01

    In this work we propose a phase material based on fish gelatin from Norland Productsmixed with ammonium dichromate deposited on a glass substrate. The photosensitive film has 110 mm thickness. In this material we record low frequency (264 lines/mm) holographic gratings using a λ=532 nm from an Ar laser and reconstruct the image with λ=594 nm from a He-Ne laser. The diffraction efficiency is approximately15% for the first order. The material no requires developing process and is very easy to make. Experimental results are shown.

  7. Holographic materials composed by rosin with ammonium dichromate

    NASA Astrophysics Data System (ADS)

    Ibarra-Torres, Juan Carlos; Olivares-Perez, Arturo; Ortiz-Gutierrez, Mauricio; Perez-Cortes, Mario; Iturbe Castillo, Marcelo D.

    2000-03-01

    We present a new material with potential application in holography. We have used a film of mixing ammonium dichromate with rosin resin diluted in isopropyl alcohol. This material can be easily elaborate in the laboratory. A phase grating in this material was recording using Argon-Ion laser at (lambda) equals 457 nm, showing good diffraction efficiency. This material is capable of high resolution when we record some diffraction gratings, observing 2,000 l/mm (grooves). A characteristic of the developed process is their simplicity, takes approximately 25 seconds.

  8. Rosin (colophony) holograms sensitized with ammonium dichromate ®

    NASA Astrophysics Data System (ADS)

    Olivares-Pérez, A.; Ibarra-Torres, J. C.; Ortiz-Gutiérrez, M.; Pérez-Cortés, M.; Fuentes-Tapia, I.

    2005-12-01

    We report a photosensitive emulsion by mixing ammonium dichromate with rosin resin diluted in isopropyl alcohol. This material can be easily elaborated. A phase grating in this material was recorded using an argon-ion laser at λ = 457 nm, shows a moderate diffraction efficiency. This material is capable of a high resolution when we record some diffraction gratings, observing the order of 2000 l/mm (grooves). A characteristic of the developed process is its simplicity that it takes approximately 25 s. It describes a hypothesis with respect to some mechanisms of photosensitivity in emulsions.

  9. Molecular recognition of organic ammonium ions in solution using synthetic receptors

    PubMed Central

    Späth, Andreas

    2010-01-01

    Summary Ammonium ions are ubiquitous in chemistry and molecular biology. Considerable efforts have been undertaken to develop synthetic receptors for their selective molecular recognition. The type of host compounds for organic ammonium ion binding span a wide range from crown ethers to calixarenes to metal complexes. Typical intermolecular interactions are hydrogen bonds, electrostatic and cation–π interactions, hydrophobic interactions or reversible covalent bond formation. In this review we discuss the different classes of synthetic receptors for organic ammonium ion recognition and illustrate the scope and limitations of each class with selected examples from the recent literature. The molecular recognition of ammonium ions in amino acids is included and the enantioselective binding of chiral ammonium ions by synthetic receptors is also covered. In our conclusion we compare the strengths and weaknesses of the different types of ammonium ion receptors which may help to select the best approach for specific applications. PMID:20502608

  10. Ammonium and potassium removal for anaerobically digested wastewater using natural clinoptilolite followed by membrane pretreatment.

    PubMed

    Guo, Xuejun; Zeng, Le Larry; Li, Xiaomei; Park, Hung-Suck

    2008-02-28

    On the basis of the wastewater characteristic of anaerobically digested wastewater, this work studied the individual and simultaneous adsorption of ammonium and potassium ions by the natural clinoptilolite. Langmuir, Freundlich, Langmuir-Freundlich, and Toth model were employed to fit the experimental isotherm data and the fitting performances of different models were compared. Both the individual and simultaneous adsorption kinetics of ammonium and potassium were studied at various pHs and temperatures. The individual adsorption of ammonium was very fast and potassium uptake was even faster than that of ammonium. The adsorption approached equilibrium within 1h in most cases. Five models, including pseudo-first-order, pseudo-second-order, Vermeulen's model, squared driving force model and Elovich equation were used to fit the individual and simultaneous adsorption kinetics of ammonium and potassium. The validities of the fittings for the ammonium and potassium adsorption kinetics were also evaluated.

  11. Biological removal of selenate and ammonium by activated sludge in a sequencing batch reactor.

    PubMed

    Mal, J; Nancharaiah, Y V; van Hullebusch, E D; Lens, P N L

    2017-04-01

    Wastewaters contaminated by both selenium and ammonium need to be treated prior to discharge into natural water bodies, but there are no studies on the simultaneous removal of selenium and ammonium. A sequencing batch reactor (SBR) was inoculated with activated sludge and operated for 90days. The highest ammonium removal efficiency achieved was 98%, while the total nitrogen removal was 75%. Nearly a complete chemical oxygen demand removal efficiency was attained after 16days of operation, whereas complete selenate removal was achieved only after 66days. The highest total Se removal efficiency was 97%. Batch experiments showed that the total Se in the aqueous phase decreased by 21% with increasing initial ammonium concentration from 50 to 100mgL(-1). This study showed that SBR can remove both selenate and ammonium via, respectively, bioreduction and partial nitrification-denitrification and thus offer possibilities for treating selenium and ammonium contaminated effluents.

  12. Optical properties of ammonium uranyl fluoride characterized by photoluminescence and photoacoustic spectroscopy.

    PubMed

    Gupta, Santosh K; Dhobale, A R; Natarajan, V; Godbole, S V

    2014-01-03

    PL and PAS studies were performed on uranyl compounds viz. uranium oxalate, uranium fluoride and ammonium uranyl fluoride. PL and PAS spectrum of ammonium uranyl fluoride is being reported for the first time. Ammonium uranyl fluoride is blue shifted with respect to uranyl fluoride, as a result of ammonium bonding. The vibronic separations were determined in the excited state and the ground state using excitation/PA spectra and emission spectra respectively. Fluorescence decay data could be fitted only with biexponential decay in all of these compounds indicating the presence of two different environments in these compounds. Low temperature luminescence leads to enhancement in emission intensity and lifetime value. The temperature dependence studies of average fluorescence lifetimes of ammonium uranyl are described in this paper. Based on this studies activation energy value for ammonium uranyl fluoride at which (3)∏ and (1)Σ potential surfaces will cross is calculated.

  13. The toxicity of ammonia/ammonium to the vermifiltration wastewater treatment process.

    PubMed

    Hughes, R J; Nair, J; Ho, G

    2008-01-01

    This study was undertaken to assess the toxicity of ammonia/ammonium to key species within the vermifiltration process. The key species, the earthworm Eisenia fetida, was subjected to a series of tests in solid phase mesocosms and full-scale units. The solid phase tests showed a relatively low toxicity to ammonium with ammonium chloride having an LC50 for ammonium of 1.49 g/kg. Ammonium sulfate did not show an effect on mortality at 2 g/kg ammonium. The full-scale units showed that ammonia hydroxide can change the pH and concentration of ammonia in wastewater and while it caused some mortality to the worms its overall affect on system functioning was minimal with no significant difference in terms of worm survival found between treatments. The affect on nitrifying bacteria was also minimal with no linear trend shown with ammonia concentration.

  14. The equilibrium structure of lithium salt solutions in ether-functionalized ammonium ionic liquids.

    PubMed

    Figueiredo, Pedro Henrique; Siqueira, Leonardo J A; Ribeiro, Mauro C C

    2012-10-11

    Molecular dynamics simulations have been performed for ionic liquids based on a ternary mixture of lithium and ammonium cations and a common anion, bis(trifluoromethylsulfonyl)imide, [Tf(2)N](-). We address structural changes resulting from adding Li(+) in ionic liquids with increasing length of an ether-functionalized chain in the ammonium cation. The calculation of static structure factors reveals the lithium effect on charge ordering and intermediate range order in comparison with the neat ionic liquids. The charge ordering is modified in the lithium solution because the coordination of [Tf(2)N](-) toward Li(+) is much stronger than ammonium cations. Intermediate range order is observed in neat ionic liquids based on ammonium cations with a long chain, but in the lithium solutions, there is also a nonhomogenous distribution of Li(+) cations. The presence of Li(+) enhances interactions between the ammonium cations due to correlations between the oxygen atom of the ether chain and the nitrogen atom of another ammonium cation.

  15. Elevated ammonium levels: differential acute effects on three glutamate transporter isoforms.

    PubMed

    Søgaard, Rikke; Novak, Ivana; MacAulay, Nanna

    2012-03-15

    Increased ammonium (NH(4)(+)/NH(3)) in the brain is a significant factor in the pathophysiology of hepatic encephalopathy, which involves altered glutamatergic neurotransmission. In glial cell cultures and brain slices, glutamate uptake either decreases or increases following acute ammonium exposure but the factors responsible for the opposing effects are unknown. Excitatory amino acid transporter isoforms EAAT1, EAAT2, and EAAT3 were expressed in Xenopus oocytes to study effects of ammonium exposure on their individual function. Ammonium increased EAAT1- and EAAT3-mediated [(3)H]glutamate uptake and glutamate transport currents but had no effect on EAAT2. The maximal EAAT3-mediated glutamate transport current was increased but the apparent affinities for glutamate and Na(+) were unaltered. Ammonium did not affect EAAT3-mediated transient currents, indicating that EAAT3 surface expression was not enhanced. The ammonium-induced stimulation of EAAT3 increased with increasing extracellular pH, suggesting that the gaseous form NH(3) mediates the effect. An ammonium-induced intracellular alkalinization was excluded as the cause of the enhanced EAAT3 activity because 1) ammonium acidified the oocyte cytoplasm, 2) intracellular pH buffering with MOPS did not reduce the stimulation, and 3) ammonium enhanced pH-independent cysteine transport. Our data suggest that the ammonium-elicited uptake stimulation is not caused by intracellular alkalinization or changes in the concentrations of cotransported ions but may be due to a direct effect on EAAT1/EAAT3. We predict that EAAT isoform-specific effects of ammonium combined with cell-specific differences in EAAT isoform expression may explain the conflicting reports on ammonium-induced changes in glial glutamate uptake.

  16. Relations of ammonium minerals at several hydrothermal systems in the western U.S.

    NASA Astrophysics Data System (ADS)

    Krohn, M. Dennis; Kendall, Carol; Evans, John R.; Fries, Terry L.

    1993-08-01

    Ammonium bound to silicate and sulfate minerals has recently been located at several major hydrothermal systems in the western U.S. utilizing newly-discovered near-infrared spectral properties. Knowledge of the origin and mineralogic relations of ammonium minerals at known hydrothermal systems is critical for the proper interpretation of remote sensing data and for testing of possible links to mineralization. Submicroscopic analysis of ammonium minerals from two mercury- and gold-bearing hot-springs deposits at Ivanhoe, Nevada and McLaughlin, California shows that the ammonium feldspar, buddingtonite, occurs as fine-grained euhedral crystals coating larger sulfide and quartz crystals. Ammonium feldspar seems to precipitate relatively late in the crystallization sequence and shows evidence for replacement of NH 4 + by K + or other monovalent cations. Some buddingtonite is observed in close association with mercury, but not with gold. Ammonioalunite is found in a variety of isolated crystal forms at both deposits. Nitrogen isotopic values for ammonium-bearing minerals show a 14‰ range in composition, precluding assignment of a specific provenance to the nitrogen. The correlations of nitrogen isotopic values with depth and ammonium content suggest some loss of nitrogen in the oxidizing supergene environment, possibly as a metastable mineral. The high ammonium content in these hydrothermal systems, the close association to mercury, and the small crystal size of the ammonium-bearing minerals all suggest that ammonium may be transported in a late-stage vapor phase or as an organic volatile. Such a process could lead to the formation of a non-carbonaceous organic aureole above a buried geothermal source. The discovery of a 10-km outcrop of ammonium minerals confirms that significant substitution of ammonium in minerals is possible over an extensive area and that remote sensing is a feasible means to detect such aureoles.

  17. Relations of ammonium minerals at several hydrothermal systems in the western U.S.

    USGS Publications Warehouse

    Krohn, M.D.; Kendall, C.; Evans, J.R.; Fries, T.L.

    1993-01-01

    Ammonium bound to silicate and sulfate minerals has recently been located at several major hydrothermal systems in the western U.S. utilizing newly-discovered near-infrared spectral properties. Knowledge of the origin and mineralogic relations of ammonium minerals at known hydrothermal systems is critical for the proper interpretation of remote sensing data and for testing of possible links to mineralization. Submicroscopic analysis of ammonium minerals from two mercury- and gold-bearing hot-springs deposits at Ivanhoe, Nevada and McLaughlin, California shows that the ammonium feldspar, buddingtonite, occurs as fine-grained euhedral crystals coating larger sulfide and quartz crystals. Ammonium feldspar seems to precipitate relatively late in the crystallization sequence and shows evidence for replacement of NH4+ by K+ or other monovalent cations. Some buddingtonite is observed in close association with mercury, but not with gold. Ammonioalunite is found in a variety of isolated crystal forms at both deposits. Nitrogen isotopic values for ammonium-bearing minerals show a 14??? range in composition, precluding assignment of a specific provenance to the nitrogen. The correlations of nitrogen isotopic values with depth and ammonium content suggest some loss of nitrogen in the oxidizing supergene environment, possibly as a metastable mineral. The high ammonium content in these hydrothermal systems, the close association to mercury, and the small crystal size of the ammonium-bearing minerals all suggest that ammonium may be transported in a late-stage vapor phase or as an organic volatile. Such a process could lead to the formation of a non-carbonaceous organic aureole above a buried geothermal source. The discovery of a 10-km outcrop of ammonium minerals confirms that significant substitution of ammonium in minerals is possible over an extensive area and that remote sensing is a feasible means to detect such aureoles. ?? 1993.

  18. Efficient ozone, sulfate, and ammonium free resist stripping process

    NASA Astrophysics Data System (ADS)

    Dattilo, Davide; Dietze, Uwe

    2014-07-01

    In recent years, photomask resist strip and cleaning technology development was substantially driven by the industry's need to prevent surface haze formation through the elimination of sulfuric acid and ammonium hydroxide from these processes. As a result, conventional SPM (H2SO4 + H2O2) was replaced with Ozone water (DIO3) for resist stripping and organic removal to eliminate chemical haze formation [1, 2]. However, it has been shown that DIO3 basted strip and clean process causes oxidative degradation of photomask materials [3, 4]. Such material damage can affect optical properties of funcitional mask layers, causeing CD line-width, phase, transmission and reflection changes, adversely affecting image transfer during the Lithography process. To overcome Ozone induced surface damage, SUSS MicroTec successfully developed a highly efficient strip process, where photolysis of DIO3 is leading to highly reactive hydroxyl radical formation, as the main contribution to hydrocarbon removal without surface damage [5]. This technology has been further extended to a final clean process, which is utilizing pure DI water for residual organic material removal during final clean [6]. Recently, SUS MicroTec did also successfully release strip and clean processes which completely remove NH4OH, eliminating any chemicals known today to induce haze [7]. In this paper we show the benefits of these new technologies for highly efficient sulfate and ammonium free stripping and cleaning processes.

  19. Antibody purification: ammonium sulfate fractionation or gel filtration.

    PubMed

    Grodzki, Ana Cristina; Berenstein, Elsa

    2010-01-01

    Antibodies can be purified by a variety of methods based on their unique physical and chemical properties such as size, solubility, charge, hydrophobicity and binding affinity. This chapter focuses on ammonium sulfate precipitation as a convenient first step in antibody purification in that, it allows the concentration of the starting material and the precipitation of the desired protein. The principle of ammonium sulfate precipitation lies in "salting out" proteins from the solution. The proteins are prevented to form hydrogen bonds with water and the salt facilitates their interaction with each other forming aggregates that afterward precipitate out of solution. Gel filtration or size- exclusion chromatography is also discussed in this chapter. Gel filtration is based on the relative size of protein molecules and it is of great value to separate IgMs, exchange buffers and/or desalt solutions. The columns designed to separate the proteins are composed of porous beads and the proteins will flow through the packed column inside and around the beads, depending on its size.

  20. Low sensitivity of Listeria monocytogenes to quaternary ammonium compounds.

    PubMed

    Mereghetti, L; Quentin, R; Marquet-Van Der Mee, N; Audurier, A

    2000-11-01

    Ninety-seven epidemiologically unrelated strains of Listeria monocytogenes were investigated for their sensitivities to quaternary ammonium compounds (benzalkonium chloride and cetrimide). The MICs for seven serogroup 1/2 strains were high. Three came from the environment and four came from food; none were isolated from human or animal samples. All 97 strains carried the mdrL gene, which encodes a multidrug efflux pump, and the orfA gene, a putative transcriptional repressor of mdrL. The absence of plasmids in four of the seven resistant strains and the conservation of resistance after plasmid curing suggested that the resistance genes are not plasmid borne. Moreover, PCR amplification and Southern blot hybridization experiments failed to find genes phylogenetically related to the qacA and smr genes, encoding multidrug efflux systems previously described for the genus Staphylococcus. The high association between nontypeability by phages and the loss of sensitivity to quaternary ammonium compounds are suggestive of an intrinsic resistance due to modifications in the cell wall.

  1. Ammonium nitrate as an oxidizer in solid composite propellants

    NASA Astrophysics Data System (ADS)

    Manelis, G. B.; Lempert, D. B.

    2009-09-01

    Despite the fact that ammonium nitrate (AN) has the highest hydrogen content and fairly high oxygen balance (compared to other oxidizers), its extremely low formation enthalpy and relatively low density makes it one of the worst power oxidizers in solid composite propellants (SCP). Nevertheless, AN has certain advantages - the combustion of the compositions containing AN is virtually safe, its combustion products are ecologically clean, it is very accessible and cheap, and also very thermostable (far more stable than ammonium dinitramide (ADN)). Besides, its low density stops being a disadvantage if the propellant has to be used in deep space and therefore, must be carried there with other rocket carriers. The low cost of AN may also become a serious advantage in the AN application even in lower stages of multistage space launchers as well as in one-stage space launchers with low mass fraction of the propellant. The main specific features relevant to the creation of AN-based SCPs with the optimal energetic characteristics are discussed. The use of metals and their hydrides and proper fuel-binders as well as the recent successes in phase stabilization of AN are described.

  2. Fabrication and cytocompatibility of spherical magnesium ammonium phosphate granules.

    PubMed

    Christel, Theresa; Geffers, Martha; Klammert, Uwe; Nies, Berthold; Höß, Andreas; Groll, Jürgen; Kübler, Alexander C; Gbureck, Uwe

    2014-09-01

    Magnesium phosphate compounds, as for example struvite (MgNH4PO4·6H2O), have comparable characteristics to calcium phosphate bone substitutes, but degrade faster under physiological conditions. In the present work, we used a struvite forming calcium doped magnesium phosphate cement with the formulation Ca0.75Mg2.25(PO4)2 and an ammonium phosphate containing aqueous solution to produce round-shaped granules. For the fabrication of spherical granules, the cement paste was dispersed in a lipophilic liquid and stabilized by surfactants. The granules were characterized with respect to morphology, size distribution, phase composition, compressive strength, biocompatibility and solubility. In general, it was seen that small granules can hardly be produced by means of emulsification, when the raw material is a hydraulic paste, because long setting times promote coalescence of initially small unhardened cement droplets. Here, this problem was solved by using an aqueous solution containing both the secondary (NH4)2HPO4 and primary ammonium phosphates NH4H2PO4 to accelerate the setting reaction. This resulted in granules with 97 wt.% having a size in the range between 200 and 1,000 μm. The novel solution composition doubled the compressive strength of the cement to 37 ± 5 MPa without affecting either the conversion to struvite or the cytocompatibility using human fetal osteoblasts.

  3. Regulation by ammonium of glutamate dehydrogenase (NADP+) from Saccharomyces cerevisiae.

    PubMed

    Bogonez, E; Satrústegui, J; Machado, A

    1985-06-01

    The activity of glutamate dehydrogenase (NADP+) (EC 1.4.1.4; NADP-GDH) of Saccharomyces cerevisiae is decreased under conditions in which intracellular ammonia concentrations increases. A high internal ammonia concentration can be obtained (a) by increasing the ammonium sulphate concentration in the culture medium, and (b) by growing the yeast either in acetate + ammonia media, where the pH of the medium rises during growth, or in heavily buffered glucose + ammonia media at pH 7.5. Under these conditions cellular oxoglutarate concentrations do not vary and changes in NADP-GDH activity appear to provide a constant rate of oxoglutarate utilization. The following results suggest that the decrease in NADP-GDH activity in ammonia-accumulating yeast cells is brought about by repression of synthesis: (i) after a shift to high ammonium sulphate concentrations, the number of units of activity per cell decreased as the inverse of cell doubling; and (ii) the rate of degradation of labelled NADP-GDH was essentially the same in ammonia-accumulating yeast cells and in controls, whereas the synthesis constant was much lower in the ammonia-accumulating cells than in the controls.

  4. Highly efficient hydrogen storage system based on ammonium bicarbonate/formate redox equilibrium over palladium nanocatalysts.

    PubMed

    Su, Ji; Yang, Lisha; Lu, Mi; Lin, Hongfei

    2015-03-01

    A highly efficient, reversible hydrogen storage-evolution process has been developed based on the ammonium bicarbonate/formate redox equilibrium over the same carbon-supported palladium nanocatalyst. This heterogeneously catalyzed hydrogen storage system is comparable to the counterpart homogeneous systems and has shown fast reaction kinetics of both the hydrogenation of ammonium bicarbonate and the dehydrogenation of ammonium formate under mild operating conditions. By adjusting temperature and pressure, the extent of hydrogen storage and evolution can be well controlled in the same catalytic system. Moreover, the hydrogen storage system based on aqueous-phase ammonium formate is advantageous owing to its high volumetric energy density.

  5. Alternative Pathways for Ammonium Assimilation in Bouvardia ternifolia Cell Suspension Cultures.

    PubMed

    Murillo, E; Sánchez de Jiménez, E

    1984-11-01

    Cell suspension cultures of young leaves (L) and roots (R) of Bouvardia temifolia were cloned and their growth was followed, measuring cell volume and fresh weight. Both cultures were depleted of nitrogen and subcultured in different nitrogen sources. The enzymes for ammonium assimilation and the ammonium pools were measured during the growth cycle. Results indicate that the two ammonium assimilation pathways, the GS/GOGAT, and the GDH-GS, are functional in both cultures. The pathway used is dependent upon the tissue and the nitrogen source in the medium. GDH seems to have an anabolic role on root cultures and is regulated by the internal concentration of ammonium.

  6. Distinct Signaling Pathways and Transcriptome Response Signatures Differentiate Ammonium- and Nitrate-supplied Plants

    PubMed Central

    Patterson, Kurt; Cakmak, Turgay; Cooper, Andrew; Lager, Ida; Rasmusson, Allan G.; Escobar, Matthew A.

    2010-01-01

    Nitrogen is the only macronutrient that is commonly available to plants in both oxidized and reduced forms, mainly nitrate and ammonium. The physiological and molecular effects of nitrate supply have been well studied, but comparatively little is known about ammonium nutrition and its differential effects on cell function and gene expression. We have used a physiologically realistic hydroponic growth system to compare the transcriptomes and redox status of the roots of ammonium- and nitrate-supplied Arabidopsis thaliana plants. While ~60% of nitrogen-regulated genes displayed common responses to both ammonium and nitrate, significant “nitrate-specific” and “ammonium-specific” gene sets were identified. Pathways involved in cytokinin response and reductant generation/distribution were specifically altered by nitrate, while a complex biotic stress response and changes in nodulin gene expression were characteristic of ammonium-supplied plants. Nitrate supply was associated with a rapid decrease in H2O2 production, potentially due to an increased export of reductant from the mitochondrial matrix. The underlying basis of the nitrate- and ammonium-specific patterns of gene expression appears to be different signals elaborated from each nitrogen source, including alterations in extracellular pH that are associated with ammonium uptake, downstream metabolites in the ammonium assimilation pathway, and the presence or absence of the nitrate ion. PMID:20444219

  7. Influence of ammonium on the accumulation of polyhydroxybutyrate (PHB) in aerobic open mixed cultures.

    PubMed

    Johnson, Katja; Kleerebezem, Robbert; van Loosdrecht, Mark C M

    2010-05-17

    Mixed microbial cultures enriched in feast-famine sequencing batch reactors (SBRs) can accumulate large amounts of the bioplastic PHB under conditions of ammonium starvation. If waste streams are to be used as a substrate, nutrient starvation may not always be achievable. The aim of this study was to investigate the influence of ammonium on PHB production in the PHB production stage of the process. The biomass was enriched in an acetate-fed (carbon limited) feast-famine SBR operated at 30 degrees C, 1-d sludge residence time and with a cycle length of 12h. The biomass was used in three fed-batch experiments with medium C/N ratios of infinity (ammonium starvation), 40 Cmol Nmol(-1) (ammonium limitation) and 8 Cmol Nmol(-1) (ammonium excess) and acetate as the carbon source. Under conditions of ammonium starvation the biomass reached a maximum PHB content of 89 wt% after 7.6h, under ammonium limitation 77 wt% after 9.3h and under ammonium excess 69 wt% after 4.4h. PHB contents decreased after these maxima were reached. PHB production slowed down more with time with larger ammonium availability. Growth led to a dilution of the PHB pool after the maximum PHB content was reached. Nutrient starvation seems thus to be the best strategy for maximal PHB production.

  8. Contributions of two cytosolic glutamine synthetase isozymes to ammonium assimilation in Arabidopsis roots.

    PubMed

    Konishi, Noriyuki; Ishiyama, Keiki; Beier, Marcel Pascal; Inoue, Eri; Kanno, Keiichi; Yamaya, Tomoyuki; Takahashi, Hideki; Kojima, Soichi

    2016-12-21

    Glutamine synthetase (GS) catalyzes a reaction that incorporates ammonium into glutamate and yields glutamine in the cytosol and chloroplasts. Although the enzymatic characteristics of the GS1 isozymes are well known, their physiological functions in ammonium assimilation and regulation in roots remain unclear. In this study we show evidence that two cytosolic GS1 isozymes (GLN1;2 and GLN1;3) contribute to ammonium assimilation in Arabidopsis roots. Arabidopsis T-DNA insertion lines for GLN1;2 and GLN1;3 (i.e. gln1;2 and gln1;3 single-mutants), the gln1;2:gln1;3 double-mutant, and the wild-type accession (Col-0) were grown in hydroponic culture with variable concentrations of ammonium to compare their growth, and their content of nitrogen, carbon, ammonium, and amino acids. GLN1;2 and GLN1;3 promoter-dependent green fluorescent protein was observed under conditions with or without ammonium supply. Loss of GLN1;2 caused significant suppression of plant growth and glutamine biosynthesis under ammonium-replete conditions. In contrast, loss of GLN1;3 caused slight defects in growth and Gln biosynthesis that were only visible based on a comparison of the gln1;2 single- and gln1;2:gln1;3 double-mutants. GLN1;2, being the most abundantly expressed GS1 isozyme, markedly increased following ammonium supply and its promoter activity was localized at the cortex and epidermis, while GLN1;3 showed only low expression at the pericycle, suggesting their different physiological contributions to ammonium assimilation in roots. The GLN1;2 promoter-deletion analysis identified regulatory sequences required for controlling ammonium-responsive gene expression of GLN1;2 in Arabidopsis roots. These results shed light on GLN1 isozyme-specific regulatory mechanisms in Arabidopsis that allow adaptation to an ammonium-replete environment.

  9. Assessment of the potential for ammonium nitrate formation and reaction in Tank 241-SY-101

    SciTech Connect

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

    1994-08-01

    Two principal scenarios by which ammonium nitrate may be formed were considered: (a) precipitation of ammonium nitrate in the waste, and (b) ammonium nitrate formation via the gas phase reaction of ammonia and nitrogen dioxide. The first of these can be dismissed because ammonium ions, which are necessary for ammonium nitrate precipitation, can exist only in negligibly small concentrations in strongly alkaline solutions. Gas phase reactions between ammonia, nitrogen dioxide, and water vapor in the gas phase represent the most likely means by which ammonium nitrate aerosols could be formed in Tank 241-SY-101. Predicted ammonium nitrate formation rates are largely controlled by the concentration of nitrogen dioxide. This gas has not been detected among those gases vented from the wastes using Fourier Transform Infrared Spectrometry (FTIR) or mass spectrometry. While detection limits for nitrogen dioxide have not been established experimentally, the maximum concentration of nitrogen dioxide in the gas phase in Tank 241-SY-101 was estimated at 0.1 ppm based on calculations using the HITRAN data base and on FTIR spectra of gases vented from the wastes. At 50 C and with 100 ppm ammonia also present, less than one gram of ammonium nitrate per year is estimated to be formed in the tank. To date, ammonium nitrate has not been detected on HEPA filters in the ventilation system, so any quantity that has been formed in the tank must be quite small, in good agreement with rate calculations. The potential for runaway exothermic reactions involving ammonium nitrate in Tank 241-SY-101 is minimal. Dilution by non-reacting waste components, particularly water, would prevent hazardous exothermic reactions from occurring within the waste slurry, even if ammonium nitrate were present. 41 refs.

  10. Quantitative remote sensing of ammonium minerals, Cedar Mountains, Esmeralda County, Nevada

    NASA Technical Reports Server (NTRS)

    Baugh, William M.; Kruse, Fred A.

    1995-01-01

    Mineral-bound ammonium (NH4+) was discovered by the U.S. Geological Survey in the southern Cedar Mountains of Esmeralda County, Nevada in 1989. At 10 km in length, this site is 100 times larger than any previously known occurrence in volcanic rocks. The ammonium occurs in two hydrothermally altered, crystal-rich rhyolitic tuff units of Oligocene age, and is both structurally and stratigraphically controlled. This research uses Advanced Visible/Infrared Imaging Spectrometer (AVIRIS) data to quantitatively map the mineral-bound ammonium (buddingtonite) concentration in the altered volcanic rocks. Naturally occurring mineral-bound ammonium is fairly rare; however, it has been found to occur in gold-bearing hydrothermal deposits. Because of this association, it is thought that ammonium may be a useful too in exploration for gold and other metal deposits. Mineral-bound ammonium is produced when an ammonium ion (NH4+) replaces the alkali cation site (usually K+) in the crystal structure of silicate minerals such as feldspars, micas and clays. Buddingtonite is an ammonium feldspar. The ammonium originates in buried organic plant matter and is transported to the host rock by hydrothermal fluids. Ammonium alteration does not produce visible changes in the rock, and it is barely detectable with standard x-ray diffraction methods. It is clearly identified, however, by absorption features in short wave-infrared (SWIR) wavelengths (2.0 - 2.5 micrometers). The ammonium absorption features are believed to be caused by N-H vibrational modes and are analogous to hydroxyl (O-H) vibrational modes, only shifted slightly in wavelength. Buddingtonite absorption features in the near- and SWIR lie at 1.56, 2.02 and 2.12 micrometers. The feature at 2.12 micrometer is the strongest of the three and is the only one used in this study. The southern Cedar Mountains are sparsely vegetated and are an ideal site for a remote sensing study.

  11. Single stage biological nitrogen removal by nitritation and anaerobic ammonium oxidation in biofilm systems.

    PubMed

    Helmer, C; Tromm, C; Hippen, A; Rosenwinkel, K H; Seyfried, C F; Kunst, S

    2001-01-01

    In full scale wastewater treatment plants with at times considerable deficits in the nitrogen balances, it could hitherto not be sufficiently explained which reactions are the cause of the nitrogen losses and which micro-organisms participate in the process. The single stage conversion of ammonium into gaseous end-products--which is henceforth referred to as deammonification--occurs particularly frequently in biofilm systems. In the meantime, one has succeeded to establish the deammonification processes in a continuous flow moving-bed pilot plant. In batch tests with the biofilm covered carriers, it was possible for the first time to examine the nitrogen conversion at the intact biofilm. Depending on the dissolved oxygen (DO) concentration, two autotrophic nitrogen converting reactions in the biofilm could be proven: one nitritation process under aerobic conditions and one anaerobic ammonium oxidation. With the anaerobic ammonium oxidation, ammonium as electron donor was converted with nitrite as electron acceptor. The end-product of this reaction was N2. Ammonium and nitrite did react in a stoichiometrical ratio of 1:1.37, a ratio which has in the very same dimension been described for the ANAMMOX-process (1:1.31 +/- 0.06). Via the oxygen concentration in the surrounding medium, it was possible to control the ratio of nitritation and anaerobic ammonium oxidation in the nitrogen conversion of the biofilm. Both processes were evenly balanced at a DO concentration of 0.7 mg/l, so that it was possible to achieve a direct, almost complete elimination of ammonium without addition of nitrite. One part of the provided ammonium did participate in the nitritation, the other in the anaerobic ammonium oxidation. Through the aerobic ammonium oxidation into nitrite within the outer oxygen supplied layers of the biofilm, the reaction partner was produced for the anaerobic ammonium oxidation within the inner layers of the biofilm.

  12. Slow strain rate fracture of high-strength steel at controlled electrochemical potentials in ammonium chloride, potassium chloride, and ammonium nitrate solutions

    SciTech Connect

    Nguyen, D.T.; Nichols, D.E.; Daniels, R.D.

    1992-08-15

    Slow strain rate testing has been undertaken to determine the effects of individual chemical species on the fracture process of high-strength 4340 steel. Test environments included potassium chloride, ammonium nitrate, and ammonium chloride at concentrations from 0.001 to 1.0 mole por liter at ambient temperature. Tests were performed at cathodic and anodic controlled potentials, as well as at the open-circuit potential, to delineate the stress corrosion cracking range.

  13. Antibacterial Activity of Alanine-Derived Gemini Quaternary Ammonium Compounds.

    PubMed

    Piecuch, Agata; Obłąk, Ewa; Guz-Regner, Katarzyna

    The antibacterial activity of alanine-derived gemini quaternary ammonium salts (chlorides and bromides) with various spacer and alkyl chain lengths was investigated. The studied compounds exhibited a strong bactericidal effect, especially bromides with 10 and 12 carbon alkyl chains and 3 carbon spacer groups (TMPAL-10 Br and TMPAL-12 Br), with a short contact time. Both salts dislodged biofilms of Pseudomonas aeruginosa and Staphylococcus epidermidis, and were lethal to adherent cells of S. epidermidis. Bromide with 2 carbon spacer groups and 12 carbon alkyl chains (TMEAL-12 Br) effectively reduced microbial adhesion by coating polystyrene and silicone surfaces. The results obtained suggest that, after further studies, gemini QAS might be considered as antimicrobial agents in medicine or industry.

  14. (Ferrocenylmeth­yl)trimethyl­ammonium perchlorate

    PubMed Central

    Wang, Ying-Chun

    2012-01-01

    The asymmetric unit of the title complex, [Fe(C5H5)(C9H15N)]ClO4, contains one discrete (ferrocenylmeth­yl)trimethyl­ammonium cation and one perchlorate anion. The anion is disordered over two sets of sites, with refined occupancies of 0.776 (8) and 0.224 (8). The distances from the Fe atom to the centroids of the unsubstituted and substituted cyclo­penta­dienyl (Cp) rings are 1.650 (1) and 1.640 (1) Å, respectively. The Cp rings form a dihedral angle of 2.66 (3)°. PMID:22346865

  15. Neutron ESR dosimetry through ammonium tartrate with low Gd content.

    PubMed

    Marrale, M; Brai, M; Longo, A; Panzeca, S; Tranchina, L; Tomarchio, E; Parlato, A; Buttafava, A; Dondi, D

    2014-06-01

    This paper continues analyses on organic compounds for application in neutron dosimetry performed through electron spin resonance (ESR). Here, the authors present the results obtained by ESR measurements of a blend of ammonium tartrate dosemeters and gadolinium oxide (5 % by weight). The choice of low amount of Gd is due to the need of improving neutron sensitivity while not significantly influencing tissue equivalence. A study of the effect of gadolinium presence on tissue equivalence was carried out. The experiments show that the neutron sensitivity is enhanced by more than an order of magnitude even with this small additive content. Monte Carlo simulations on the increment of energy release due to gadolinium presence were carried, and the results were in good agreement with the experimental data.

  16. Dealumination of faujasite, mazzite, and offretite with ammonium hexafluorosilicate

    SciTech Connect

    Chauvin, B.; Boulet, M.; Massiani, P.; Fajula, F.; Figueras, F. ); Des Courieres, T. )

    1990-12-01

    Synthetic faujasite, mazzite, and offretite have been dealuminated with ammonium hexafluorosilicate. The products have been characterized by elemental analysis, X-ray diffraction, volumetry, scanning electron microscopy, stepwise thermal desorption of ammonia, solid-state NMR and IR spectroscopy. Their catalytic activity has been evaluated using isooctane cracking as test reaction. The maximum level of dealumination which can be achieved without loss of X-ray crystallinity corresponds to 50% for faujasite and 30% for mazzite and offretite. This result and the fact that the dealumination capability depends on the texture of the crystals suggest that the reaction is diffusion controlled. The comparison of the acidic and catalytic properties of the parent and dealuminated samples shows small differences indicating that the fluorosilicate treatment replaces weakly bound and weakly acidic aluminium atoms.

  17. Antibacterial effect of composite resins containing quaternary ammonium polyethyleneimine nanoparticles

    NASA Astrophysics Data System (ADS)

    Yudovin-Farber, Ira; Beyth, Nurit; Weiss, Ervin I.; Domb, Abraham J.

    2010-02-01

    Quaternary ammonium polyethyleneimine (QA-PEI)-based nanoparticles were synthesized by crosslinking with dibromopentane followed by N-alkylation with various alkyl halides and further N-methylation with methyl iodide. Insoluble pyridinium-type particles were prepared by suspension polymerization of 4-vinyl pyridine followed by N-alkylation with alkyl halides. Polyamine-based nanoparticles embedded in restorative composite resin at 1% w/w were tested for antibacterial activity against Streptococcus mutans using direct contact test. Activity analysis revealed that the alkyl chain length of the QA-PEI nanoparticles plays a significant role in antibacterial activity of the reagent. The most potent compound was octyl-alkylated QA-PEI embedded in restorative composite resin at 1% w/w that totally inhibited S. mutans growth in 3-month-aged samples. This data indicates that restorative composite resin with antibacterial properties can be produced by the incorporation of QA-PEI nanoparticles.

  18. Salting out of proteins using ammonium sulfate precipitation.

    PubMed

    Duong-Ly, Krisna C; Gabelli, Sandra B

    2014-01-01

    Protein solubility is affected by ions. At low ion concentrations (<0.5 M), protein solubility increases along with ionic strength. Ions in the solution shield protein molecules from the charge of other protein molecules in what is known as 'salting-in'. At a very high ionic strength, protein solubility decreases as ionic strength increases in the process known as 'salting-out'. Thus, salting out can be used to separate proteins based on their solubility in the presence of a high concentration of salt. In this protocol, ammonium sulfate will be added incrementally to an E. coli cell lysate to isolate a recombinantly over-expressed protein of 20 kDa containing no cysteine residues or tags.

  19. Computational Modeling of Degradation of Substituted Benzyltrimethyl Ammonium: Preprint

    SciTech Connect

    Long, H.; Pivovar, B. S.

    2014-09-01

    The degradation of cations on the alkaline exchange membranes is the major challenge for alkaline membrane fuel cells. In this paper, we investigated the degradation barriers by density functional theory for substituted benzyltrimethyl ammonium (BTMA+) cations, which is one of the most commonly used cations for alkaline exchange membranes. We found that substituted cations with electron-releasing substituent groups at meta-position of the benzyl ring could result in improved degradation barriers. However, after investigating more than thirty substituted BTMA+ cations with ten different substituent groups, the largest improvement of degradation barriers is only 1.6 kcal/mol. This implies that the lifetime of alkaline membrane fuel cells could increase from a few months to a few years by using substituted BTMA+ cations, an encouraging but still limited improvement for real-world applications.

  20. Giant barocaloric effects at low pressure in ferrielectric ammonium sulphate

    PubMed Central

    Lloveras, P.; Stern-Taulats, E.; Barrio, M.; Tamarit, J.-Ll.; Crossley, S.; Li, W.; Pomjakushin, V.; Planes, A.; Mañosa, Ll.; Mathur, N. D.; Moya, X.

    2015-01-01

    Caloric effects are currently under intense study due to the prospect of environment-friendly cooling applications. Most of the research is centred on large magnetocaloric effects and large electrocaloric effects, but the former require large magnetic fields that are challenging to generate economically and the latter require large electric fields that can only be applied without breakdown in thin samples. Here we use small changes in hydrostatic pressure to drive giant inverse barocaloric effects near the ferrielectric phase transition in ammonium sulphate. We find barocaloric effects and strengths that exceed those previously observed near magnetostructural phase transitions in magnetic materials. Our findings should therefore inspire the discovery of giant barocaloric effects in a wide range of unexplored ferroelectric materials, ultimately leading to barocaloric cooling devices. PMID:26607989

  1. Quaternary ammonium poly(diethylaminoethyl methacrylate) possessing antimicrobial activity.

    PubMed

    Farah, Shady; Aviv, Oren; Laout, Natalia; Ratner, Stanislav; Beyth, Nurit; Domb, Abraham J

    2015-04-01

    Quaternary ammonium (QA) methacrylate monomers and polymers were synthesized from a N-alkylation of N,N-diethylaminoethyl methacrylate (DEAEM) monomer. Linear copolymers, and for the first time reported crosslinked nanoparticles (NPs), based QA-PDEAEM were prepared by radical polymerization of the quaternized QA-DEAEM monomers with either methyl methacrylate (MMA) or a divinyl monomer. QA-PDEAEM NPs of 50-70 nm were embedded in polyethylene vinyl acetate coating. QA-polymers with N-C8 and N-C18 alkyl chains and copolymers with methyl methacrylate were prepared at different molar ratios and examined for their antimicrobial effectiveness. These coatings exhibited strong antibacterial activity against four representative Gram-positive and Gram-negative bacteria.

  2. Synthesis and Antibacterial Activity of Quaternary Ammonium 4-Deoxypyridoxine Derivatives.

    PubMed

    Shtyrlin, Nikita V; Sapozhnikov, Sergey V; Galiullina, Albina S; Kayumov, Airat R; Bondar, Oksana V; Mirchink, Elena P; Isakova, Elena B; Firsov, Alexander A; Balakin, Konstantin V; Shtyrlin, Yurii G

    2016-01-01

    A series of novel quaternary ammonium 4-deoxypyridoxine derivatives was synthesized. Two compounds demonstrated excellent activity against a panel of Gram-positive methicillin-resistant S. aureus strains with MICs in the range of 0.5-2 μg/mL, exceeding the activity of miramistin. At the same time, both compounds were inactive against the Gram-negative E. coli and P. aeruginosa strains. Cytotoxicity studies on human skin fibroblasts and embryonic kidney cells demonstrated that the active compounds possessed similar toxicity with benzalkonium chloride but were slightly more toxic than miramistin. SOS-chromotest in S. typhimurium showed the lack of DNA-damage activity of both compounds; meanwhile, one compound showed some mutagenic potential in the Ames test. The obtained results make the described chemotype a promising starting point for the development of new antibacterial therapies.

  3. Polymerization and photochromism of ammonium molybdate in porous glass

    NASA Astrophysics Data System (ADS)

    Pak, V. N.; Borisov, A. N.

    2016-08-01

    Modification of porous glass (PG) plates is carried out by impregnation with aqueous solutions of ammonium molybdate (NH4)2MoO4 with subsequent removal of water at 120°C. A long-wavelength shift of absorption spectra upon accumulation of the salt in PG indicates polymerization of MoO 4 2- anions at low concentrations of the encapsulated salt. Photochromism manifests itself as the anionic forms in PG become larger. UV irradiation of the modified plates causes enhancement of continuous absorption in the visible range. The proposed mechanism of photoreduction of the polianions in PG involves the removal of oxygen atoms from the bridging-Mo-O-Mo-bonds and stabilization of the colored forms by means of conjugation of the electrons released from the 4 d-levels of pentavalent molybdenum.

  4. Synthesis and Antibacterial Activity of Quaternary Ammonium 4-Deoxypyridoxine Derivatives

    PubMed Central

    Shtyrlin, Nikita V.; Sapozhnikov, Sergey V.; Galiullina, Albina S.; Kayumov, Airat R.; Bondar, Oksana V.; Mirchink, Elena P.; Isakova, Elena B.; Firsov, Alexander A.; Balakin, Konstantin V.

    2016-01-01

    A series of novel quaternary ammonium 4-deoxypyridoxine derivatives was synthesized. Two compounds demonstrated excellent activity against a panel of Gram-positive methicillin-resistant S. aureus strains with MICs in the range of 0.5–2 μg/mL, exceeding the activity of miramistin. At the same time, both compounds were inactive against the Gram-negative E. coli and P. aeruginosa strains. Cytotoxicity studies on human skin fibroblasts and embryonic kidney cells demonstrated that the active compounds possessed similar toxicity with benzalkonium chloride but were slightly more toxic than miramistin. SOS-chromotest in S. typhimurium showed the lack of DNA-damage activity of both compounds; meanwhile, one compound showed some mutagenic potential in the Ames test. The obtained results make the described chemotype a promising starting point for the development of new antibacterial therapies. PMID:27800491

  5. The Use of Quaternary Ammonium to Combat Dental Caries

    PubMed Central

    Ge, Yang; Wang, Suping; Zhou, Xuedong; Wang, Haohao; Xu, Hockin H. K.; Cheng, Lei

    2015-01-01

    Resin composites and adhesives are increasingly popular in dental restorations, but secondary caries is one of the main reasons for restoration failure. Quaternary ammonium monomers (QAMs) have an anti-microbial effect and are widely used in many fields. Since the concept of the immobilized antibacterial effect was put forward, dental restorations containing QAMs have been studied to reduce secondary caries. Previous studies have been struggling to develop novel anti-caries materials which might have triple benefits: good mechanical properties, antibacterial effects and remineralization potentials. Different kinds of QAMs have been proven to be effective in inhibiting the growth and metabolism of biofilms. Combination of QAMs and other nanoparticles in resin composites and adhesives could enhance their anti-caries capability. Therefore, QAMs are promising to show significant impact on the future of restorative and preventive dentistry. PMID:26635932

  6. Large electrocaloric effects in single-crystal ammonium sulfate.

    PubMed

    Crossley, S; Li, W; Moya, X; Mathur, N D

    2016-08-13

    Electrocaloric (EC) effects are typically studied near phase transitions in ceramic and polymer materials. Here, we investigate EC effects in an inorganic salt, namely ammonium sulfate (NH4)2SO4, with an order-disorder transition whose onset occurs at 223 K on cooling. For a single crystal thinned to 50 μm, we use a Maxwell relation to find a large isothermal entropy change of 30 J K(-1) kg(-1) in response to a field change of 400 kV cm(-1) The Clausius-Clapeyron equation implies a corresponding adiabatic temperature change of 4.5 K.This article is part of the themed issue 'Taking the temperature of phase transitions in cool materials'.

  7. Giant barocaloric effects at low pressure in ferrielectric ammonium sulphate.

    PubMed

    Lloveras, P; Stern-Taulats, E; Barrio, M; Tamarit, J-Ll; Crossley, S; Li, W; Pomjakushin, V; Planes, A; Mañosa, Ll; Mathur, N D; Moya, X

    2015-11-26

    Caloric effects are currently under intense study due to the prospect of environment-friendly cooling applications. Most of the research is centred on large magnetocaloric effects and large electrocaloric effects, but the former require large magnetic fields that are challenging to generate economically and the latter require large electric fields that can only be applied without breakdown in thin samples. Here we use small changes in hydrostatic pressure to drive giant inverse barocaloric effects near the ferrielectric phase transition in ammonium sulphate. We find barocaloric effects and strengths that exceed those previously observed near magnetostructural phase transitions in magnetic materials. Our findings should therefore inspire the discovery of giant barocaloric effects in a wide range of unexplored ferroelectric materials, ultimately leading to barocaloric cooling devices.

  8. Giant barocaloric effects at low pressure in ferrielectric ammonium sulphate

    NASA Astrophysics Data System (ADS)

    Lloveras, P.; Stern-Taulats, E.; Barrio, M.; Tamarit, J.-Ll.; Crossley, S.; Li, W.; Pomjakushin, V.; Planes, A.; Mañosa, Ll.; Mathur, N. D.; Moya, X.

    2015-11-01

    Caloric effects are currently under intense study due to the prospect of environment-friendly cooling applications. Most of the research is centred on large magnetocaloric effects and large electrocaloric effects, but the former require large magnetic fields that are challenging to generate economically and the latter require large electric fields that can only be applied without breakdown in thin samples. Here we use small changes in hydrostatic pressure to drive giant inverse barocaloric effects near the ferrielectric phase transition in ammonium sulphate. We find barocaloric effects and strengths that exceed those previously observed near magnetostructural phase transitions in magnetic materials. Our findings should therefore inspire the discovery of giant barocaloric effects in a wide range of unexplored ferroelectric materials, ultimately leading to barocaloric cooling devices.

  9. Lactulose production from cheese whey using recyclable catalyst ammonium carbonate.

    PubMed

    Seo, Yeong Hwan; Sung, Mina; Han, Jong-In

    2016-04-15

    Ammonium carbonate ((NH4)2CO3) was used as an alkaline catalyst of lactulose production from cheese whey. Maximum yield of 29.6% was obtained at reaction time of 28.44 min, (NH4)2CO3 of 0.76% at 97°C. During reaction, (NH4)2CO3 was fully decomposed to NH3 and CO2, and these gases were recovered. To boost up NH3 recovery, various methods such as heating, aeration, and pH adjustment were applied. The optimal condition for the purpose of NH3 retrieval was temperature of up to 60°C alongside aeration. Easy separation and recovery make (NH4)2CO3 a catalyst alternative to common alkaline chemicals especially for the weak alkaline reaction.

  10. Crystal structure of tris-(hydroxyl-ammonium) orthophosphate.

    PubMed

    Leinemann, Malte; Jess, Inke; Boeckmann, Jan; Näther, Christian

    2015-11-01

    The crystal structure of the title salt, ([H3NOH](+))3·[PO4](3-), consists of discrete hydroxyl-ammonium cations and ortho-phos-phate anions. The atoms of the cation occupy general positions, whereas the anion is located on a threefold rotation axis that runs through the phospho-rus atom and one of the phosphate O atoms. In the crystal structure, cations and anions are linked by inter-molecular O-H⋯O and N-H⋯O hydrogen bonds into a three-dimensional network. Altogether, one very strong O-H⋯O, two N-H⋯O hydrogen bonds of medium strength and two weaker bifurcated N-H⋯O inter-actions are observed.

  11. Review of Options for Ammonia/Ammonium Management

    SciTech Connect

    Nash, C. A.

    2016-05-06

    This report is a review of literature supporting practical ammonia/ammonium destruction processes. Melter research supporting Hanford Low Activity Waste (LAW) glass production has shown that significant amounts of ammonia will be in the melter offgas condensate. Further work with secondary waste forms indicates the potential need to remove the ammonia, perhaps by an oxidative process. This review finds likely practical chemical methods to oxidize ammonia in aqueous solution at moderate temperatures and atmospheric pressure, using easily obtained reagents. Leading candidates include nitrite oxidation to produce nitrogen gas, various peroxide oxidative processes, and air stripping. This work reviews many other processes and provides reasoning to not consider those processes further for this application.

  12. Integrated Data Collection Analysis (IDCA) Program — Ammonium Nitrate

    SciTech Connect

    Sandstrom, Mary M.; Brown, Geoffrey W.; Preston, Daniel N.; Pollard, Colin J.; Warner, Kirstin F.; Sorensen, Daniel N.; Remmers, Daniel L.; Phillips, Jason J.; Shelley, Timothy J.; Reyes, Jose A.; Hsu, Peter C.; Reynolds, John G.

    2013-05-17

    The Integrated Data Collection Analysis (IDCA) program is conducting a proficiency study for Small- Scale Safety and Thermal (SSST) testing of homemade explosives (HMEs). Described here are the results for impact, friction, electrostatic discharge, and differential scanning calorimetry analysis of ammonium nitrate (AN). AN was tested, in most cases, as both received from manufacturer and dried/sieved. The participants found the AN to be: 1) insensitive in Type 12A impact testing (although with a wide range of values), 2) completely insensitive in BAM friction testing, 3) less sensitive than the RDX standard in ABL friction testing, 4) less sensitive than RDX in ABL ESD testing, and 5) less sensitive than RDX and PETN in DSC thermal analyses.

  13. Effect of impurities on crystal growth rate of ammonium pentaborate

    NASA Astrophysics Data System (ADS)

    Şahin, Ö.; Özdemir, M.; Genli, N.

    2004-01-01

    The effect of sodium chloride, borax and boric acid of different concentrations on the growth rate of ammonium pentaborate octahydrate crystals (APBO) was measured and was found to depend on supersaturation in a fluidized bed crystallizer. The presence of impurities in APBO solution increases the growth rate compared with growth from pure solution. It was found that the presence of sodium chloride, borax and boric acid decreases the reaction rate constant kr, while it increases the mass-transfer coefficient, K, of APBO crystals. In pure aqueous solution, the crystal growth rate of APBO is mainly controlled by diffusion. However, both diffusion and integration steps affect the growth rate of APBO crystals in the presence of sodium chloride, borax and boric acid. The mass-transfer coefficient, K, reaction rate constant, kr and reaction order, r were calculated from general mass-transfer equation by using genetic algorithm method making no assumption.

  14. Thermophysical properties of two ammonium-based protic ionic liquids

    PubMed Central

    Bhattacharjee, Arijit; Coutinho, João A. P.; Freire, Mara G.; Carvalho, Pedro J.

    2015-01-01

    Experimental data for density, viscosity, refractive index and surface tension are reported, for the first time, in the temperature range between 288.15 K and 353.15 K and at atmospheric pressure for two protic ionic liquids, namely 2-(dimethylamino)-N,N-dimethylethan-1-ammonium acetate, [N11{2(N11)}H][CH3CO2], and N-ethyl-N,N-dimethylammonium phenylacetate, [N112H][C7H7CO2]. The effect of the anion aromaticity and the cation’s aliphatic tails on the studied properties is discussed. From the measured properties temperature dependency the derived properties, such as the isobaric thermal expansion coefficient, the surface entropy and enthalpy, and the critical temperature, were estimated. PMID:26435554

  15. Cold Case: Radar investigation of ammonium sulfate cryovolcanism on Titan

    NASA Astrophysics Data System (ADS)

    Thomann, C.; Hayes, A. G.; Hofgartner, J.; Lunine, J. I.; Le Gall, A.

    2012-12-01

    The detection of a large tidal k2 value from Cassini [1] constitutes very strong evi-dence for a subcrustal ocean, most plausibly dominated by water. However, the secondary constituents are not known. One interesting possibility that has received scant attention in analysis of surface data sets is that the ocean contain aqueous ammonium sulfates, which erupted on the surface in the past to create vast, smooth plains [2]. We adopt the hypothesis that the undifferentiated plains—the "bland-lands" in the mid-latitudes of Titan—are these deposits, and test it using radiometry with SAR data. Lopez et al (this conference) investigate the global distribution and possible origin of this type of unit. We extracted SAR and radiometry-during-SAR data sets from the PDS, and pro-duced maps of brightness temperatures. The SAR imagery was used to identify locations where crossovers exist -some of which are in the undifferentiated plains--and hence where brightness temperatures at different incidence angles are available. We derived emissivities from the data using a simple radiometric model [3] to ac-count for the brightness temperature differences as a function of surface roughness, volume scattering and emissivity. We test the hypothesis by assessing whether the derived emissivities and volume scattering in the bland-lands are consistent with the model cryoclastic ash of ice and ammonium sulfate proposed in [2], distinct from that in other terrains. [1] L. Iess, R.A. Jacobson, M. Ducci, D.J. Stevenson, J.I. Lunine, J.W. Armstrong, S.W. Asmar, P. Racioppa, N.J. Rappaport, P. Tortora, Science, 337, 457 (2012). [2] A.D. Fortes, P.M. Grinrod, S.K. Trickett, L. Vocadlo. Icarus, 188, 139 (2007). [3] T.L. White and J.R. Cogdell. The Moon, 6, 235 (1973).

  16. Modeling the crystallization of magnesium ammonium phosphate for phosphorus recovery.

    PubMed

    Wang, Jiansen; Song, Yonghui; Yuan, Peng; Peng, Jianfeng; Fan, Maohong

    2006-11-01

    The crystallization of magnesium ammonium phosphate (MAP) is one of the main processes for recovering P and N from wastewater. Chemically defined solution systems were designed; the saturation indices (SIs) of the solution systems with respect to MAP were derived by using a geochemical aqueous model Program, PHREEQC 2.11; the effects of the solution conditions were evaluated using thermodynamic theories. The concentrations of P and Mg in the tested solutions were 10-600 mg l(-1) and 24-720 mg l(-1), respectively, the molar ratios of N/P and pH values of the solutions varied in the ranges of 1-40 and 6.0-12.0, respectively. The temperature of all the tests was set at 25 degrees C. The test results show that the SI value of MAP is the logarithmic functions of the concentrations of P, ammonium-N and Mg, and increases with the increase of the concentration of each element. The SI value of MAP is a polynomial function of pH value of the solution, and the optimum pH value for the crystallization of MAP is 9.0 but increases slightly with the increase of the N/P. Moreover, the SI value of MAP is a power law function of the ionic strength of solutions but decreases with its increase. The adjustment of the Mg concentration and the control of solution pH are two effective methods for the control of the crystallization of MAP. The results obtained from the research can be used to guide the design and control of MAP crystallization process for the removal and recovery of P.

  17. Exogenous ammonium inhibits petal pigmentation and expansion in Gerbera hybrida.

    PubMed

    Huang, Zhigang; Liang, Minting; Peng, Jianzong; Xing, Tim; Wang, Xiaojing

    2008-06-01

    Petal pigmentation is the most important aspect in natural flower coloration. In the present study, the inhibition of petal pigmentation by exogenous ammonium was investigated. Ray floret petals detached from inflorescences of Gerbera hybrida (Shenzhen No. 5) were cultured in vitro on media supplied with different forms of nitrogen and its assimilated compounds. The expression of a set of genes involved in anthocyanin biosynthesis and regulation was determined by Northern blotting assay. It was found that ammonium (NH4+), not nitrate (NO3-), in millimolar concentrations inhibited anthocyanin accumulation. The expressions of Gerbera chalcone synthase 1 (GCHS1), Gerbera chalcone synthase 2 (GCHS2) and Gerbera dihydroflavonol-4-reductase (GDFR) decreased, while six other related genes showed no significant changes after NH4+ treatment. Further studies on NH4+ function indicated that glutamine (Gln) acted as a downstream factor of NH4+ to suppress petal pigmentation. Both exogenous Gln and NH4+ were found to inhibit anthocyanin accumulation in the petals, and the application of Gln was also found to inhibit the expressions of GCHS1, GCHS2 and GDFR. The application of NH4+ also resulted in an increase in the activity of Gerbera glutamine synthetase (EC 6.3.1.2) along with a rapid increase of Gln content. When methionine sulfoximine, an inhibitor of glutamine synthetase (GS), was added, it was found to block the NH4+-induced inhibition of pigmentation. From these experiments, we conclude that the NH4+-induced suppression of petal pigmentation is not because of NH4+ toxicity, and the inhibition of pigmentation caused by the addition of exogenous NH4+ is the result of its assimilation into Gln.

  18. Tetracalcium phosphate composite containing quaternary ammonium dimethacrylate with antibacterial properties

    PubMed Central

    Cheng, Lei; Weir, Michael D.; Limkangwalmongkol, Penwadee; Hack, Gary D.; Xu, Hockin H. K.; Chen, Qianming; Zhou, Xuedong

    2012-01-01

    Tooth caries is a carbohydrate-modified bacterial infectious disease, and recurrent caries is a frequent reason for restoration failure. The objective of this study was to develop a novel antibacterial composite using tetracalcium phosphate (TTCP) fillers and bis(2-methacryloyloxy-ethyl) dimethyl-ammonium bromide, which is a quaternary ammonium dimethacrylate (QADM). QADM was synthesized using 2-(N,N-dimethylamino)ethyl methacrylate and 2-bromoethyl methacrylate and incorporated into a resin. The resin was filled with 40% TTCP and 30% glass particles. The following QADM mass fractions in the composite were tested: 0%, 6%, 12%, and 18%. Streptococcus mutans biofilms were formed on the composites and the colony-forming units (CFUs), metabolic activity, and lactic acid production were measured. The TTCP-QADM composite had flexural strength and elastic modulus similar to those of two commercial composites (p > 0.1). Increasing the QADM content in TTCP composite greatly decreased the bacteria growth and biofilm matrix production. There were significantly more dead bacteria with increasing QADM content. TTCP composite containing 18% QADM had biofilm CFU, metabolic activity, and acid production about half of those without QADM. Inversely linear relationships were established between QADM mass fraction and S. mutans biofilm CFU, metabolic activity, and acid production, with correlation coefficients R2 ≥ 0.98. In conclusion, TTCP-QADM composites were developed and the effect of QADM mass fraction on the antibacterial properties of the composite was determined for the first time. The novel TTCP-QADM composites possessing a strong antibacterial capability, together with calcium phosphate ion release and good mechanical properties, are promising for dental restorations to reduce biofilm growth and recurrent caries. PMID:22190356

  19. Irritant contact dermatitis due to ammonium bifluoride in two infant twins.

    PubMed

    Toledo, Fernando; Silvestre, Juan Francisco; Cuesta, Laura; Bañuls, José

    2013-01-01

    Ammonium bifluoride is one of the most corrosive acids that may produce severe chemical burns when in contact with skin. This hazardous chemical is widely used in household products. We report two pediatric cases of irritant contact dermatitis after exposure to a rust remover, which contained ammonium bifluoride.

  20. Ammonium sorption from aqueous solutions by the natural zeolite Transcarpathian clinoptilolite studied under dynamic conditions.

    PubMed

    Sprynskyy, Myroslav; Lebedynets, Mariya; Terzyk, Artur P; Kowalczyk, Piotr; Namieśnik, Jacek; Buszewski, Bogusław

    2005-04-15

    The scope of this study is ammonium-ion uptake from synthetic aqueous solutions onto raw and pretreated forms of the natural zeolite Transcarpathian clinoptilolite under dynamic conditions. Hydrogen ions displaced exchangeable cations on the clinoptilolite in distilled water (sodium ions) and hydrochloric acid (sodium, potassium, and calcium ions) and destroyed the zeolite framework structure in the last case. Ammonium uptake onto the zeolite occurs by exchange with Na(+), Ca(2+), and K(+) ions. Although Na(+) ions were observed to be more easily exchanged for both hydrogen and ammonium ions, the role of Ca(2+) ions increased with zeolite saturation by NH(+)(4) ions. The maximum sorption capacity of the clinoptilolite toward NH(+)(4) ions, estimated under dynamic conditions, is significantly higher than that measured under static conditions; proximity of the values of a distribution coefficient and a retardation factor for different conditions (215-265 dm(3)/kg and 979-1107, respectively) allows us to use these parameters to model ammonium uptake onto the clinoptilolite. Slowing down or interruption in filtration resulted in the improvement of ammonium sorption properties of the zeolite. The ammonium removal improves with use of the finer fractions of the clinoptilolite up to 0.35 mm. A recycling study results confirmed the importance of external diffusion for ammonium sorption by the clinoptilolite. Preliminary treatment of the sorbent confirmed the predominant importance of the ion-exchange mechanism. The advantage of prior NaCl treatment of the clinoptilolite in improvement of ammonium removal over the other techniques was shown.

  1. Racer (40% ammonium nonanoate) broadcast application for broadleaf weed control in spring-transplanted onions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Racer (40% ammonium nonanoate) is a newly approved herbicide for organically grown food crops. Ammonium nonanoate occurs in nature and is primarily formed from biodegradation of higher fatty acids. Field research was conducted in southeast Oklahoma (Atoka County, Lane, OK) to determine the effect ...

  2. Ammonium catalyzed cyclitive additions: evidence for a cation-π interaction with alkynes.

    PubMed

    Nagy, Edith; St Germain, Elijah; Cosme, Patrick; Maity, Pradip; Terentis, Andrew C; Lepore, Salvatore D

    2016-02-07

    The addition of carbamate nitrogen to a non-conjugated carbon-carbon triple bond is catalyzed by an ammonium salt leading to a cyclic product. Studies in homogeneous systems suggest that the ammonium agent facilitates nitrogen-carbon bond formation through a cation-π interaction with the alkyne unit that, for the first time, is directly observed by Raman spectroscopy.

  3. Ammonium Catalyzed Cyclitive Additions: Evidence for a Cation-π Interaction with Alkynes†

    PubMed Central

    Nagy, Edith; St.Germain, Elijah; Cosme, Patrick; Maity, Pradip; Terentis, Andrew C.; Lepore, Salvatore D.

    2016-01-01

    The addition of carbamate nitrogen to a non-conjugated carbon-carbon triple bond is catalyzed by an ammonium salt leading to a cyclic product. Studies in homogeneous systems suggest that the ammonium agent facilitates nitrogen-carbon bond formation through a cation-π interaction with the alkyne unit that, for the first time, is directly observed by Raman spectroscopy. PMID:26728333

  4. 78 FR 14540 - Cyromazine, Silica Silicates (Silica Dioxide and Silica Gel), Glufosinate Ammonium, Dioctyl...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-06

    ... AGENCY Cyromazine, Silica Silicates (Silica Dioxide and Silica Gel), Glufosinate Ammonium, Dioctyl Sodium... ammonium, dioctyl sodium sulfosuccinate (DSS) and undecylenic acid (UDA) and opens a public comment period...-HQ-OPP-2006-0108... Kelly Ballard, (703) 305-8126, Ballard.kelly@epa.gov . Dioctyl...

  5. Computational Analysis of Some Aspects of a Synthetic Route to Ammonium Dinitramide

    DTIC Science & Technology

    1993-12-27

    OF SOME ASPECTS OF A SYNTHETIC ROUTE TO AMMONIUM DINITRAMIDE by Tore Brinck and Peter Politzer D T IC ELECTES JAN1 119943 Department of Chemistry JAN...NO0014-91-J-4057 a Synthetic Route to Ammonium Dinitramide Dr. Richard S. Miller 6. AUTHOR(S) Tore Brinck and Peter Politzer R&T Code 4131D02 7

  6. Electroantennogram and behavioral responses of Anastrepha suspensa (Diptera: Tephritidae) to putrescine and ammonium bicarbonate lures.

    PubMed

    Kendra, Paul E; Montgomery, Wayne S; Epsky, Nancy D; Heath, Robert R

    2009-08-01

    At present, the most effective synthetic lures for pest Anastrepha fruit flies are multicomponent blends that include ammonia and the diamine synergist putrescine (1,4-diaminobutane). Both chemicals generally have been regarded as protein cues that result in female-biased attraction. Using electroantennography (EAG) and flight tunnel bioassays, this study evaluated response of the Caribbean fruit fly, Anastrepha suspensa (Loew) to vapors released from commercial lure formulations of ammonium bicarbonate and putrescine. Over a range of doses tested, EAG response to ammonium bicarbonate was equivalent for both sexes, but female response was significantly greater than male response to putrescine and to a 1:1 mixture of ammonium bicarbonate and putrescine. Amplitude of EAG response to the mixture was approximately equal to the summation of responses to the individual substrates. Using a fixed dose of substrate, EAG measurements from females 1-14 d old indicated that antennal sensitivity to both lures varied according to physiological state of the fly. Peak response to ammonium bicarbonate was recorded from immature females, peak response to putrescine from sexually mature females. In bioassays, more females were captured with ammonium bicarbonate plus putrescine than with ammonium bicarbonate alone. This difference was not observed in males, resulting in a higher female to male ratio in captures with ammonium bicarbonate plus putreseine (3:1) versus ammonium bicarbonate alone (1:1). Results suggest that separate olfactory receptors are involved in detection of the two semiochemicals, and that the putrescine component is primarily responsible for the female-biased attraction.

  7. Ammonium assimilation: An important accessory during aerobic denitrification of Pseudomonas stutzeri T13.

    PubMed

    Sun, Yilu; Feng, Liang; Li, Ang; Zhang, Xuening; Yang, Jixian; Ma, Fang

    2017-03-12

    The present study investigated effect of ammonium utilization on aerobic denitrification by Pseudomonas stutzeri T13. Per nitrogen balance calculation, all consumed ammonium was utilized as nitrogen source for cell propagation by assimilation rather than heterotrophic nitrification. Total organic carbon (TOC) and ammonium were necessary substrates to sustain heterotrophic propagation of P. stutzeri T13 at optimum proportion equal to seven. Under aerobic condition, nitrate was utilized as substitute nitrogen source when ammonium was completely exhausted. Biomass production effectively increased with increasing initial ammonium from 0mg/L to 100mg/L. Owing to enlarged biomass, average nitrate reduction rate increased from 7.36mgL(-1)h(-1) to 11.95mgL(-1)h(-1). Such process also successfully reduced nitrite accumulation from 121.8mg/L to 66.16mg/L during aerobic denitrification. As important accessory during aerobic denitrification, ammonium assimilation efficiently doubled total nitrogen (TN) removal from 54.97mg/L (no ammonium provided) to 113.1mg/L (100mg/L ammonium involved).

  8. Effects of salinity induced by ammonium sulfate fertilizer on root and shoot growth of highbush blueberry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ammonium sulfate fertilizer is commonly used in highbush blueberry (Vaccinium corymbosum L.), but due to a high salt index, it often causes salt damage, particularly in young plants, when too much of the fertilizer is applied. A study was done to determine the sensitivity of blueberry to ammonium su...

  9. Ab initio molecular dynamic study of solid-state transitions of ammonium nitrate

    PubMed Central

    Yu, Hongyu; Duan, Defang; Liu, Hanyu; Yang, Ting; Tian, Fubo; Bao, Kuo; Li, Da; Zhao, Zhonglong; Liu, Bingbing; Cui, Tian

    2016-01-01

    High-pressure polymorphism and phase transitions have wide ranging consequences on the basic properties of ammonium nitrate. However, the phase diagram of ammonium nitrate at high pressure and high temperature is still under debate. This study systematically investigates the phase transitions and structural properties of ammonium nitrate at a pressure range of 5–60 GPa and temperature range of 250–400 K by ab initio molecular dynamics simulations. Two new phases are identified: one corresponds to the experimentally observed phase IV’ and the other is named AN-X. Simultaneously, the lattice strains play a significant role in the formation and stabilization of phase IV’, providing a reasonable explanation for experimental observation of phase IV-IV’ transition which only appears under nonhydrostatic pressure. In addition, 12 O atoms neighboring the NH (N atom in ammonium cation) atom are selected as reference system to clearly display the tanglesome rotation of ammonium cation. PMID:26754622

  10. Interactions between nitrate and ammonium in their uptake, allocation, assimilation, and signaling in plants.

    PubMed

    Hachiya, Takushi; Sakakibara, Hitoshi

    2016-12-21

    Nitrogen (N) availability is a major factor determining plant growth and productivity. Plants acquire inorganic N from the soil, mainly in the form of nitrate and ammonium. To date, researchers have focused on these N sources, and demonstrated that plants exhibit elaborate responses at both physiological and morphological levels. Mixtures of nitrate and ammonium are beneficial in terms of plant growth, as compared to nitrate or ammonium alone, and therefore synergistic responses to both N sources are predicted at different steps ranging from acquisition to assimilation. In this review, we summarize interactions between nitrate and ammonium with respect to uptake, allocation, assimilation, and signaling. Given that cultivated land often contains both nitrate and ammonium, a better understanding of the synergism between these N sources should help to identify targets with the potential to improve crop productivity.

  11. Ab initio molecular dynamic study of solid-state transitions of ammonium nitrate

    NASA Astrophysics Data System (ADS)

    Yu, Hongyu; Duan, Defang; Liu, Hanyu; Yang, Ting; Tian, Fubo; Bao, Kuo; Li, Da; Zhao, Zhonglong; Liu, Bingbing; Cui, Tian

    2016-01-01

    High-pressure polymorphism and phase transitions have wide ranging consequences on the basic properties of ammonium nitrate. However, the phase diagram of ammonium nitrate at high pressure and high temperature is still under debate. This study systematically investigates the phase transitions and structural properties of ammonium nitrate at a pressure range of 5–60 GPa and temperature range of 250–400 K by ab initio molecular dynamics simulations. Two new phases are identified: one corresponds to the experimentally observed phase IV’ and the other is named AN-X. Simultaneously, the lattice strains play a significant role in the formation and stabilization of phase IV’, providing a reasonable explanation for experimental observation of phase IV-IV’ transition which only appears under nonhydrostatic pressure. In addition, 12 O atoms neighboring the NH (N atom in ammonium cation) atom are selected as reference system to clearly display the tanglesome rotation of ammonium cation.

  12. Pre-exposure to nitrite in the absence of ammonium strongly inhibits anammox.

    PubMed

    Carvajal-Arroyo, José M; Puyol, Daniel; Li, Guangbin; Lucero-Acuña, Armando; Sierra-Álvarez, Reyes; Field, Jim A

    2014-01-01

    Anaerobic ammonium oxidizing bacteria (Anammox) are known to be inhibited by their substrate, nitrite. However, the mechanism of inhibition and the physiological conditions under which nitrite impacts the performance of anammox bioreactors are still unknown. This study investigates the role of pre-exposing anammox bacteria to nitrite alone on their subsequent activity and metabolism after ammonium has been added. Batch experiments were carried out with anammox granular biofilm pre-exposed to nitrite over a range of concentrations and durations in the absence of ammonium. The effect of pre-exposure to nitrite alone compared to nitrite simultaneously fed with ammonium was evaluated by measuring the anammox activity and the accumulation of the intermediate, nitric oxide. The results show that the inhibitory effect was more dramatic when bacteria were pre-exposed to nitrite in absence of ammonium, as revealed by the lower activity and the higher accumulation of nitric oxide. The nitrite concentration causing 50% inhibition was 53 and 384 mg N L(-1) in the absence or the presence of ammonium, respectively. The nitrite inhibition was thus 7.2-fold more severe in the absence of ammonium. Biomass exposure to nitrite (25 mg N L(-1)), in absence of ammonium, led to accumulation of nitric oxide. On the other hand when the biomass was exposed to nitrite in presence of ammonium, accumulation of nitric oxide was only observed at much higher nitrite concentrations (500 mg N L(-1)). The inhibitory effect of nitrite in the absence of ammonium was very rapid. The rate of decay of the anammox activity was equivalent to the diffusion rate of nitrite up to 46% of activity loss. The results taken as a whole suggest that nitrite inhibition is more acute when anammox cells are not actively metabolizing. Accumulation of nitric oxide in the headspace most likely indicates disruption of the anammox biochemistry by nitrite inhibition, caused by an interruption of the hydrazine synthesis step.

  13. Anaerobic ammonium oxidation in traditional municipal wastewater treatment plants with low-strength ammonium loading: Widespread but overlooked.

    PubMed

    Wang, Shanyun; Peng, Yongzhen; Ma, Bin; Wang, Shuying; Zhu, Guibing

    2015-11-01

    Occurrence of anaerobic ammonium oxidation (anammox) in marine and freshwater systems has greatly changed our understanding of global nitrogen (N) cycle and promoted the investigation of the role and ecological features of anammox in anthropogenic ecosystems. This study focused on the spatio-temporal abundance, activity, and biodiversity of anammox bacteria in full-scale municipal wastewater treatment plants (WWTPs) via traditional nitrification/denitrification route with low-strength ammonium loading. The anammox bacteria were detected in all the treatment units at the five WWTPs tested, even in aerobic zones (dissolved oxygen >2 mg L(-1)) with abundance of 10(5)-10(7) hydrazine synthase (hzs) gene copies g(-1). The (15)N-isotope tracing technology revealed that the anammox rates in WWTPs ranged from 0.08 to 0.36 μmol N g(-1) h(-1) in winter and 0.12-1.20 μmol N g(-1) h(-1) in summer with contributions of 2.05-6.86% and 1.71-7.26% to N2 production, respectively. The diversity of anammox bacteria in WWTPs was distributed over only two genera, Brocadia and Kuenenia. Additionally, the exploration of potential interspecies relationships indicated that ammonia oxidation bacteria (AOB) was the major nitrite-substrate producer for anammox during nitrification, while Nitrospira, a nitrite oxidation bacteria (NOB), was the potential major competitor for nitrite. These results suggested the contribution of N-removal by the widespread of anammox has been overlooked in traditional municipal WWTPs, and the ecological habitats of anammox bacteria in anthropogenic ecosystems are much more abundant than previously assumed.

  14. Phase transitions in potassium ammonium dihydrogen phosphate single crystals

    NASA Astrophysics Data System (ADS)

    Bromberek, Marek

    An apparatus for growing single crystals from aqueous solution by the slow evaporation method was constructed. Mixed crystals of K1-x(NH 4)xH2PO4 (KADP) with (NH4)H 2PO4 (ADP) fractions of 0.021 and 0.12 were successfully grown. Their composition was determined by means of the x-ray powder diffraction method. This analysis also suggests that those crystals are a mixture of two phases even at room temperature. The details of the structure of the additional phase could not be determined. The dielectric constant epsilon of the mixed crystals as well as pure KH2PO4 (KDP) was measured along the polar axis in the temperature range from 20 K to 300 K. The frequency range of the applied electric field was from 100 Hz to 10 MHz. The data were analyzed by means of the standard Landau theory of phase transitions with coupling terms reflecting the interaction between the electric and elastic degrees of freedom. The temperature dependence of epsilon follows a typical Curie-Weiss behavior in the range of approximately 30 K aboveTc for all crystals studied. The value of the critical temperature decreases with increasing ammonium ion content in agreement with previously published results. The analysis of the frequency dependence of the dielectric susceptibility clearly indicates the existence of two dispersion processes: resonant and relaxational. The former is attributed to the piezoelectric activity of all the crystals studied. The latter is the result of the response of the permanent dipole moments present in ferroelectric crystals to the applied electric field. In the case of mixed crystals the relaxational dispersion is characterized by a distribution of relaxation times. Its mean relaxation time as well as its width increases with decreasing T. This is a typical behavior for mixed crystals for which the two end members of the solid solution in their pure form undergo ferroelectric and antiferroelectric phase transitions, respectively. This behavior is a result of competing

  15. Environmental Factors Affecting Ammonium Oxidation Under Iron Reducing Conditions

    NASA Astrophysics Data System (ADS)

    Jaffe, P. R.; Huang, S.; Ruiz-Urigüen, M.

    2014-12-01

    Ammonium (NH4+) oxidation coupled to iron (Fe) reduction in the absence of oxygen and nitrate/nitrite (NO3-/NO2-) has been reported by several investigators and referred to as Feammox. Feammox is a biological reaction, where Fe(III) is the electron acceptor, which is reduced to Fe(II), and NH4+ is the electron donor, which is oxidized to NO2-. Through a 180-day anaerobic incubation experiment, and using PCR-DGGE, 454-pyosequecing and qPCR analysis, we have shown that an Acidimicrobiaceae bacterium A6, a previously unreported species in the Acidimicrobiaceae family, might be either responsible or plays a key role in the Feammox process, We have enriched these Feammox bacteria (65.8% in terms of cell numbers) in a membrane reactor, and isolated the pure Acidimicrobiaceae bacterium A6 strain in an autotrophic medium. In samples collected and then incubated from a series of local wetland-, upland-, as well as storm-water detention pond-sediments, Feammox activity was only detected in acidic soil environments that contain Fe oxides. Using primers we developed for this purpose, Acidimicrobiaceae bacterium A6 was detected in all incubations where Feammox was observed. Anaerobic incubations of Feammox enrichment cultures adjusted to different pH, revealed that the optimal pH for Feammox is 4 ~ 5, and the reaction does not proceed when pH > 7. Feammox was still proceeding at pH as low as 2. In Feammox culture amended with different Fe(III) sources, Feammox reaction proceeded only when Fe oxides (ferrihydrite or goethite ) were supplied, whereas samples incubated with ferric chloride or ferric citrate showed no measurable NH4+ oxidation. Furthermore, we have also determined from incubation experiments conducted with a temperature gradient (10 ~ 35℃), that the Feammox process was active when the temperature is above 15℃, and the optimal temperature is 20℃. Incubations of enrichment culture with 79% Feammox bacteria appeared to remove circa 8% more NH4+ at 20ºC than at

  16. 27 CFR 555.220 - Table of separation distances of ammonium nitrate and blasting agents from explosives or blasting...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... distances of ammonium nitrate and blasting agents from explosives or blasting agents. 555.220 Section 555... ammonium nitrate and blasting agents from explosives or blasting agents. Table: Department of Defense... Not over Minimum separation distance of acceptor from donor when barricaded (ft.) Ammonium...

  17. 27 CFR 555.220 - Table of separation distances of ammonium nitrate and blasting agents from explosives or blasting...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... distances of ammonium nitrate and blasting agents from explosives or blasting agents. 555.220 Section 555... ammonium nitrate and blasting agents from explosives or blasting agents. Table: Department of Defense... Not over Minimum separation distance of acceptor from donor when barricaded (ft.) Ammonium...

  18. 27 CFR 555.220 - Table of separation distances of ammonium nitrate and blasting agents from explosives or blasting...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... distances of ammonium nitrate and blasting agents from explosives or blasting agents. 555.220 Section 555... ammonium nitrate and blasting agents from explosives or blasting agents. Table: Department of Defense... Not over Minimum separation distance of acceptor from donor when barricaded (ft.) Ammonium...

  19. 77 FR 73674 - Ammonium Nitrate From Ukraine; Notice of Revised Schedule of the Five-year Review Concerning the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-11

    ...)] Ammonium Nitrate From Ukraine; Notice of Revised Schedule of the Five-year Review Concerning the Antidumping Duty Order on Ammonium Nitrate From Ukraine AGENCY: United States International Trade Commission... established a schedule for the conduct of the 5-year review of Ammonium Nitrate from Ukraine (77 FR...

  20. 27 CFR 555.220 - Table of separation distances of ammonium nitrate and blasting agents from explosives or blasting...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... distances of ammonium nitrate and blasting agents from explosives or blasting agents. 555.220 Section 555... ammonium nitrate and blasting agents from explosives or blasting agents. Table: Department of Defense... Not over Minimum separation distance of acceptor from donor when barricaded (ft.) Ammonium...

  1. 76 FR 34749 - Ammonium Nitrate From Russia; Scheduling of an expedited five-year review concerning the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-14

    ... COMMISSION Ammonium Nitrate From Russia; Scheduling of an expedited five- year review concerning the antidumping duty order on ammonium nitrate From Russia AGENCY: United States International Trade Commission... whether revocation of the antidumping duty order on ammonium nitrate from Russia would be likely to...

  2. 27 CFR 555.220 - Table of separation distances of ammonium nitrate and blasting agents from explosives or blasting...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... distances of ammonium nitrate and blasting agents from explosives or blasting agents. 555.220 Section 555... ammonium nitrate and blasting agents from explosives or blasting agents. Table: Department of Defense... Not over Minimum separation distance of acceptor from donor when barricaded (ft.) Ammonium...

  3. Ammonium nitrogen removal from wastewater with a three-dimensional electrochemical oxidation system.

    PubMed

    Ding, Jing; Zhao, Qing-Liang; Wei, Liang-Liang; Chen, Yang; Shu, Xin

    2013-01-01

    Ammonium-containing wastewater could cause the promotion of eutrophication and a hindrance to the disinfection of water supplies. In this study, the feasibility of removing low-concentration ammonium nitrogen from synthetic and real wastewater by electrochemical oxidation was investigated. Using laboratory-scale electrochemical systems, the effects of chloride concentration, current density, anode materials, cathode materials, electrode gap, initial ammonium concentration and three-dimensional particles on the removal of ammonium nitrogen and current efficiency (CE) were evaluated. Ammonium nitrogen removal was mainly dependent upon anode materials and current density. The performance of two- and three-dimensional electrochemical oxidation systems was comparatively discussed. Both particle electrodes could enhance ammonium nitrogen removal and increase CE. However, the mechanism of the process seemed to be different. Moreover, the interaction of zeolites adsorption and electrochemical oxidation on the anode in a three-dimensional system could favor the regeneration of zeolites. Surface morphology of the used Ru-Ir-Sn/Ti anode revealed its longer working life of electrocatalysis. The result of ammonium degradation for a real wastewater treatment plant effluent showed the degradation rates in a three-dimensional system increased by 1.4 times those in a two-dimensional system.

  4. Upgrading fertilizer production wastewater effluent quality for ammonium discharges through ion exchange with clinoptilolite.

    PubMed

    Beler-Baykal, B; Allar, A D

    2008-06-01

    It had previously been shown that ammonium selective natural zeolite clinoptilolite may be used successfully as an ion exchanger for ammonium removal and nitrogen control from domestic wastewater. The process had been reported to be acceptable either by itself alone or as an upgrade. In this work, the possibility of using clinoptilolite for ammonium removal from fertilizer production wastewater was investigated. The fertilizer plant under consideration was rather a non-typical one with a lower ammonium strength than what is normally expected, and a variable effluent concentration. Batch experiments were performed to assess the capacity of clinoptilolite towards ammonium removal from an industrial wastewater at two different pHs. Flow experiments for the characterization of system behavior under continuous feeding conditions at different contact times were conducted for breakthrough analysis. Both real and simulated fertilizer wastewater samples were investigated and the results have shown that the real one may successfully be represented by the simulated one. Experimental results have shown that surface capacities exceeding 14 mg ammonium g(-1) clinoptilolite could be attained, complete removal of ammonium may be achieved with empty bed contact times of 10 min or higher and ion exchange with clinoptilolite could be used successfully to comply with the effluent standards given for the fertilizer plant.

  5. Ammonium and potassium removal from swine liquid manure using clinoptilolite, chabazite and faujasite zeolites.

    PubMed

    Montégut, Gaëtan; Michelin, Laure; Brendlé, Jocelyne; Lebeau, Bénédicte; Patarin, Joël

    2016-02-01

    This study concerns cationic exchanges performed in order to remove ammonium and potassium cations from manure by using various zeolites: clinoptilolite, chabazite and NaX faujasite. First, the effect of temperature (25 °C and 40 °C) on the exchange rate between zeolites and an ammonium chloride solution was investigated. Then, cationic exchanges were performed on these three zeolites using on one side a mixed ammonium and potassium chloride solution reproducing the chemical composition of a swine manure and on the other side the corresponding liquid manure. No significant difference was observed on the exchange rate and the trapping of ammonium cations by changing the temperature (25 or 40 °C). Clinoptilolite showed a good selectivity towards ammonium cations using model (NH4Cl, and mixed NH4Cl/KCl) solutions but is less efficient with the liquid manure. Chabazite and faujasite were found more efficient than clinoptilolite for trapping ammonium cations. However, NaX faujasite enables trapping 3 times more ammonium cations than chabazite from manure (60 and 20 mg/g, respectively). Moreover, chabazite allowed to trap the same amount of potassium cations than NaX faujasite (33 and 35 mg/g, respectively).

  6. Coastal water column ammonium and nitrite oxidation are decoupled in summer

    NASA Astrophysics Data System (ADS)

    Heiss, Elise M.; Fulweiler, Robinson W.

    2016-09-01

    Water column nitrification is a key process in the nitrogen cycle as it links reduced and oxidized forms of nitrogen and also provides the substrate (nitrate) needed for reactive nitrogen removal by denitrification. We measured potential water column ammonium and nitrite oxidation rates at four sites along an estuary to continental shelf gradient over two summers. In most cases, nitrite oxidation rates outpaced ammonium oxidation rates. Overall, ammonium and nitrite oxidation rates were higher outside of the estuary, and this trend was primarily driven by higher oxidation rates in deeper waters. Additionally, both ammonium and nitrite oxidation rates were impacted by different in situ variables. Ammonium oxidation rates throughout the water column as a whole were most positively correlated to depth and salinity and negatively correlated to dissolved oxygen and light. In contrast, nitrite oxidation rates throughout the water column were negatively correlated with light and pH. Multivariate regression analysis revealed that while both surface (<20 m) and deep (>20 m) ammonium oxidation rates were most strongly predicted by depth and light, surface rates were also regulated by salinity and deep rates by temperature. Surface (<20 m) nitrite oxidation rates were best explained by [H+] (i.e. pH) alone, while salinity, [H+], temperature, and depth all played a role in predicting deep (>20 m) nitrite oxidation rates. These results support the growing body of evidence that ammonium oxidation and nitrite oxidation are not always coupled, should be measured separately, and are influenced by different environmental conditions.

  7. Removal of mercury (II), elemental mercury and arsenic from simulated flue gas by ammonium sulphide.

    PubMed

    Ning, Ping; Guo, Xiaolong; Wang, Xueqian; Wang, Ping; Ma, Yixing; Lan, Yi

    2015-01-01

    A tubular resistance furnace was used as a reactor to simulate mercury and arsenic in smelter flue gases by heating mercury and arsenic compounds. The flue gas containing Hg(2+), Hg(0) and As was treated with ammonium sulphide. The experiment was conducted to investigate the effects of varying the concentration of ammonium sulphide, the pH value of ammonium sulphide, the temperature of ammonium sulphide, the presence of SO2 and the presence of sulphite ion on removal efficiency. The prepared adsorption products were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscopy. The results showed that the optimal concentration of ammonium sulphide was 0.8 mol/L. The optimal pH value of ammonium sulphide was 10, and the optimal temperature of ammonium sulphide was 20°C.Under the optimum conditions, the removal efficiency of Hg(2+), Hg(0) and As could reach 99%, 88.8%, 98%, respectively. In addition, SO2 and sulphite ion could reduce the removal efficiency of mercury and arsenic from simulated flue gas.

  8. Microbial nitrate-dependent cyclohexane degradation coupled with anaerobic ammonium oxidation.

    PubMed

    Musat, Florin; Wilkes, Heinz; Behrends, Astrid; Woebken, Dagmar; Widdel, Friedrich

    2010-10-01

    An anaerobic nitrate-reducing enrichment culture was established with a cyclic saturated petroleum hydrocarbon, cyclohexane, the fate of which in anoxic environments has been scarcely investigated. GC-MS showed cyclohexylsuccinate as a metabolite, in accordance with an anaerobic enzymatic activation of cyclohexane by carbon-carbon addition to fumarate. Furthermore, long-chain cyclohexyl-substituted cell fatty acids apparently derived from cyclohexane were detected. Nitrate reduction was not only associated with cyclohexane utilization but also with striking depletion of added ammonium ions. Significantly more ammonium was consumed than could be accounted for by assimilation. This indicated the occurrence of anaerobic ammonium oxidation (anammox) with nitrite from cyclohexane-dependent nitrate reduction. Indeed, nitrite depletion was stimulated upon further addition of ammonium. Analysis of 16S rRNA genes and subsequent cell hybridization with specific probes showed that approximately 75% of the bacterial cells affiliated with the Geobacteraceae and approximately 18% with Candidatus 'Brocadia anammoxidans' (member of the Planctomycetales), an anaerobic ammonium oxidizer. These results and additional quantitative growth experiments indicated that the member of the Geobacteraceae reduced nitrate with cyclohexane to nitrite and some ammonium; the latter two and ammonium added to the medium were scavenged by anammox bacteria to yield dinitrogen. A model was established to quantify the partition of each microorganism in the overall process. Such hydrocarbon oxidation by an alleged 'denitrification' ('pseudo-denitrification'), which in reality is a dissimilatory loop through anammox, can in principle also occur in other microbial systems with nitrate-dependent hydrocarbon attenuation.

  9. Paleosols in central Illinois as potential sources of ammonium in groundwater

    USGS Publications Warehouse

    Glessner, J.J.G.; Roy, W.R.

    2009-01-01

    Glacially buried paleosols of pre-Holocene age were evaluated as potential sources for anomalously large concentrations of ammonium in groundwater in East Central Illinois. Ammonium has been detected at concentrations that are problematic to water treatment facilities (greater than 2.0 mg/L) in this region. Paleosols characterized for this study were of Quaternary age, specifically Robein Silt samples. Paleosol samples displayed significant capacity to both store and release ammonium through experiments measuring processes of sorption, ion exchange, and weathering. Bacteria and fungi within paleosols may significantly facilitate the leaching of ammonium into groundwater by the processes of assimilation and mineralization. Bacterial genetic material (DNA) was successfully extracted from the Robein Silt, purified, and amplified by polymerase chain reaction to produce 16S rRNA terminal restriction fragment length polymorphism (TRFLP) community analyses. The Robein Silt was found to have established diverse and viable bacterial communities. 16S rRNA TRFLP comparisons to well-known bacterial species yielded possible matches with facultative chemolithotrophs, cellulose consumers, nitrate reducers, and actinomycetes. It was concluded that the Robein Silt is both a source and reservoir for groundwater ammonium. Therefore, the occurrence of relatively large concentrations of ammonium in groundwater monitoring data may not necessarily be an indication of only anthropogenic contamination. The results of this study, however, need to be placed in a hydrological context to better understand whether paleosols can be a significant source of ammonium to drinking water supplies. ?? 2009 National Ground Water Association.

  10. Ammonium is a key determinant on the dietary restriction of yeast chronological aging in culture medium.

    PubMed

    Santos, Júlia; Leitão-Correia, Fernanda; Sousa, Maria João; Leão, Cecília

    2015-03-30

    New evidences have recently emerged from studies in yeast and in higher eukaryotes showing the importance of nutrient balance in dietary regimes and its effects on longevity regulation.We have previously shown that manipulation of ammonium concentration in the culture and/or aging medium can drastically affect chronological lifespan (CLS)of Saccharomyces cerevisiae, especially in amino acid restricted cells. Here we describe that the CLS shortening under amino acid restriction can be completely reverted by removing ammonium from the culture medium. Furthermore, the absence of ammonium, and of any rich nitrogen source, was so effective in extending CLS that no beneficial effect could be observed by further imposing calorie restriction conditions. When present in the culture medium,ammonium impaired the consumption of the auxotrophy-complementing amino acids and caused in an improper cell cycle arrest of the culture.TOR1 deletion reverted ammonium effects both in amino acid restricted and non-restricted cultures, whereas, Ras2p and Sch9p seem to have only a milder effect in the mediation of ammonium toxicity under amino acid restriction and no effect on non-restricted cultures.Our studies highlight ammonium as a key effector in the nutritional equilibrium between rich and essential nitrogen sources and glucose required for longevity promotion.

  11. High irradiance improves ammonium tolerance in wheat plants by increasing N assimilation.

    PubMed

    Setién, Igor; Fuertes-Mendizabal, Teresa; González, Azucena; Aparicio-Tejo, Pedro Ma; González-Murua, Carmen; González-Moro, María Begoña; Estavillo, José María

    2013-05-15

    Ammonium is a paradoxical nutrient ion. Despite being a common intermediate in plant metabolism whose oxidation state eliminates the need for its reduction in the plant cell, as occurs with nitrate, it can also result in toxicity symptoms. Several authors have reported that carbon enrichment in the root zone enhances the synthesis of carbon skeletons and, accordingly, increases the capacity for ammonium assimilation. In this work, we examined the hypothesis that increasing the photosynthetic photon flux density is a way to increase plant ammonium tolerance. Wheat plants were grown in a hydroponic system with two different N sources (10mM nitrate or 10mM ammonium) and with two different light intensity conditions (300 μmol photon m(-2)s(-1) and 700 μmol photon m(-2)s(-1)). The results show that, with respect to biomass yield, photosynthetic rate, shoot:root ratio and the root N isotopic signature, wheat behaves as a sensitive species to ammonium nutrition at the low light intensity, while at the high intensity, its tolerance is improved. This improvement is a consequence of a higher ammonium assimilation rate, as reflected by the higher amounts of amino acids and protein accumulated mainly in the roots, which was supported by higher tricarboxylic acid cycle activity. Glutamate dehydrogenase was a key root enzyme involved in the tolerance to ammonium, while glutamine synthetase activity was low and might not be enough for its assimilation.

  12. Application of natural zeolite for phosphorus and ammonium removal from aqueous solutions.

    PubMed

    Karapinar, Nuray

    2009-10-30

    Removal of both nutrients ammonium and phosphorus by natural zeolite has been studied in lab scale by using a mechanically stirred batch system (1000 ml). Zeolite, a mean particle size of 13 microm, was used as an adsorbent for the removal of ammonium and then as a seed material for the precipitation of calcium phosphate. A relationship was established between the uptake of ammonium by zeolite and the ratio of initial ammonium concentration to zeolite dosage. Ammonium uptake of zeolite was almost completed within initial 5 min of adsorption period. There is no pronounced effect of zeolite and ammonium, neither positive nor negative on the amount of calcium phosphate precipitation. The extent of the precipitation of phosphate increased with rising pH. It was also observed that when the system was allowed to relax at constant pH (i.e. under relatively low super saturations), a certain lag time was noted to elapse at the onset of the precipitation. At the pH 7.2, the amount of initial fast precipitation within 5 min and total precipitation within 120 min were around 34% and 93%, respectively. Precipitation of calcium phosphate on to ammonium-loaded zeolite was achieved at low super saturations (< pH 7.5) through secondary nucleation and crystal growth, leading to an increase in particle size.

  13. A case of fatal intoxication with ammonium sulfate and a toxicological study using rabbits.

    PubMed

    Sato, A; Gonmori, K; Yoshioka, N

    1999-04-26

    Agricultural fertilizers such as ammonium sulfate are widely used in house gardens as well as in agriculture, but few case reports or toxicological studies of ingested fertilizers have been reported. This paper investigates a fatal case of ammonium sulfate poisoning and demonstrates its clinical and biochemical findings in rabbits. An 85-year-old woman was found dead lying on the ground outside her house in the middle of March, but the autopsy could not determine the cause of her death. Examination at the police laboratory of the solution in the beer can found next to her showed that it was very likely ammonium sulfate. Our measurement showed a significant increase of ammonium and sulfate ions in serum and gastric contents. The cause of her death was determined as poisoning by ammonium sulfate. The total dose of 1500 mg/kg of ammonium sulfate was administered to three rabbits, all of which showed similar symptoms such as mydriasis, irregular respiratory rhythms, local and general convulsions, until they fell into respiratory failure with cardiac arrest. EEG showed slow, suppressive waves and high-amplitude slowing wave pattern, which is generally observed clinically in hyperammonemia in man and animal. There was a remarkable increase in the concentration of ammonium ion and inorganic sulfate ion in serum, and blood gas analysis showed severe metabolic acidosis. These results, mainly findings by EEG, have shown that a rapid increase in ammonium ions in blood can cause damaging the central nervous system without microscopic change. When the cause of death can not be determined, measurement of ammonium ion, inorganic ion and electrolytes in blood as well as in stomach contents at forensic autopsy is necessary.

  14. Monthly variations in nitrogen isotopes of ammonium and nitrate in wet deposition at Guangzhou, south China

    NASA Astrophysics Data System (ADS)

    Jia, Guodong; Chen, Fajin

    2010-06-01

    Monthly nitrogen isotopes of ammonium and nitrate in wet deposition in the city of Guangzhou, and the causes of their variability, are reported in this paper. Nitrate δ 15N showed nearly constant values around zero in the dry season (October to April), but oscillating values from negative to positive in the rainy season (May to September). By contrast, ammonium δ 15N displayed lower values during the rainy season than in the dry season. The rural area north of the city was considered as the prominent source of ammonium and nitrate in spring and early summer (May and June), as suggested by their concurrent negative isotopic trends and higher NH 4+/NO 3- ratios. From July to September, different dominating sources from the city, i.e., fossil fuel combustion for nitrate, and sewage and waste emission for ammonium, caused disparate δ 15N trends of the two species, showing positive nitrate δ 15N, but still negative ammonium δ 15N. During the cool dry season, the high values of ammonium δ 15N and concurrently low NH 4+/NO 3- ratios suggested the decrease in NH 3 volatilization and relatively important thermogenic origin of ammonium, but the intermediate nitrate δ 15N values around zero may be a result of a balanced emission of NO x from the city and the rural areas. The isotopic effects of chemical conversion of NO x to nitrate and washout of nitrate were ruled out as significant causes of nitrate δ 15N variability, but ammonium washout, during which 15N is assumed to be preferentially removed, may partly contribute to the ammonium δ 15N variability.

  15. Natural attenuation potential of tricholoroethene in wetland plant roots: role of native ammonium-oxidizing microorganisms.

    PubMed

    Qin, Ke; Struckhoff, Garrett C; Agrawal, Abinash; Shelley, Michael L; Dong, Hailiang

    2015-01-01

    Bench-scale microcosms with wetland plant roots were investigated to characterize the microbial contributions to contaminant degradation of trichloroethene (TCE) with ammonium. The batch system microcosms consisted of a known mass of wetland plant roots in aerobic growth media where the roots provided both an inoculum of root-associated ammonium-oxidizing microorganisms and a microbial habitat. Aqueous growth media, ammonium, and TCE were replaced weekly in batch microcosms while retaining roots and root-associated biomass. Molecular biology results indicated that ammonium-oxidizing bacteria (AOB) were enriched from wetland plant roots while analysis of contaminant and oxygen concentrations showed that those microorganisms can degrade TCE by aerobic cometabolism. Cometabolism of TCE, at 29 and 46 μg L(-1), was sustainable over the course of 9 weeks, with 20-30 mg L(-1) ammonium-N. However, at 69 μg L(-1) of TCE, ammonium oxidation and TCE cometabolism were completely deactivated in two weeks. This indicated that between 46 and 69 μg L(-1) TCE with 30 mg L(-1) ammonium-N there is a threshold [TCE] below which sustainable cometabolism can be maintained with ammonium as the primary substrate. However, cometabolism-induced microbial deactivation of ammonium oxidation and TCE degradation at 69 μg L(-1) TCE did not result in a lower abundance of the amoA gene in the microcosms, suggesting that the capacity to recover from TCE inhibition was still intact, given time and removal of stress. Our study indicates that microorganisms associated with wetland plant roots can assist in the natural attenuation of TCE in contaminated aquatic environments, such as urban or treatment wetlands, and wetlands impacted by industrial solvents.

  16. The metabolic waste ammonium regulates mTORC2 and mTORC1 signaling

    PubMed Central

    Merhi, Ahmad; Delrée, Paul; Marini, Anna Maria

    2017-01-01

    Two structurally and functionally distinct mammalian TOR complexes control cell growth and metabolism in physiological and pathological contexts including cancer. Upregulated glutaminolysis is part of the metabolic reprogramming occurring in cancer, providing fuels for growth but also liberating ammonium, a potent neurotoxic waste product. Here, we identify ammonium as a novel dose-dependent signal mediating rapid mTORC2 activation and further regulating mTORC1. We show that ammonium induces rapid RICTOR-dependent phosphorylation of AKT-S473, a process requiring the PI3K pathway and further involving the Src-family kinase YES1, the FAK kinase and the ITGβ1 integrin. Release of calcium from the endoplasmic reticulum store triggers rapid mTORC2 activation, similar to ammonium-induced activation, the latter being conversely prevented by calcium chelation.Moreover, in analogy to growth factors, ammonium triggers the AKT-dependent phosphoinhibition of the TSC complex and of PRAS40, two negative regulators of mTORC1. Consistent with mTORC1 stimulation, ammonium induces the inhibitory phosphorylation of 4EBP1, a negative regulator of protein biogenesis. Ammonium however dually impacts on the phosphorylation of p70S6K1 triggering a transient AKT-independent decrease in the phosphorylation of this second mTORC1 readout. Finally, we reveal ammonium as a dose-dependent stimulator of proliferation. This study underscores an mTORC2 and mTORC1 response to the so-called ammonium waste. PMID:28303961

  17. Conductometric determination of ammonium ion with a mobile drop.

    PubMed

    Jaikang, Pheeraya; Grudpan, Kate; Kanyanee, Tinakorn

    2015-01-01

    A mobile drop based approach was utilized for the conductometric determination of aqueous ammonium ion. A liquid drop was manipulated by gravity to remain or move out of a conductivity measurement zone located on a hydrophobic path. A dilute sulfuric acid drop functioned as a micro gas absorber. Gaseous NH3 was liberated from a sample containing NH4(+) by adding NaOH and purged to flow over the absorber drop. As H(+) in the absorber drop was converted to NH4(+), the conductivity decreased. The rate of the conductivity decrease thus ultimately depended on the NH4(+) concentration in the sample. While the sample could be complex, the liberation of NH3 gas essentially freed the analyte of interest from the matrix and allowed the use of an otherwise nonselective detector. The system was applied to the determination of NH4(+) in some natural waters without prior filtration; the results agreed well with those from a manual indophenol blue method. The approach exhibited a limit of detection (LOD) of 5 μM and a relative standard deviation (RSD) of<5%. The mobile drop gave a constant volume of the gas absorbing solution and provided a cost-effective and simple analytical platform.

  18. An ammonium sulfate sensitive chitinase from Streptomyces sp. CS501.

    PubMed

    Rahman, Md Arifur; Choi, Yun Hee; Pradeep, G C; Yoo, Jin Cheol

    2014-12-01

    A chitinase from Streptomyces sp. CS501 was isolated from the Korean soil sample, purified by single-step chromatography, and biochemically characterized. The extracellular chitinase (Ch501) was purified to 4.60 fold with yield of 28.74 % using Sepharose Cl-6B column. The molecular mass of Ch501 was approximately 43 kDa as estimated by SDS-PAGE and zymography. The enzyme (Ch501) was found to be stable over a broad pH range (5.0-10.0) and temperature (up to 50 °C), and have an optimum temperature of 60 °C. N-terminal sequence of Ch501 was AAYDDAAAAA. Intriguingly, Ch501 was highly sensitive to ammonium sulfate but it's completely suppressed activity was recovered after desalting out. TLC analysis of Ch501 showed the production of N-acetyl D-glucosamine (GlcNAc) and Diacetylchitobiose (GlcNAc)2, as a principal hydrolyzed product. Ch501 shows antifungal activity against Fusarium solani and Aspergillus brasiliensis, which can be used for the biological control of fungus. As has been simple in purification, stable in a broad range of pH, ability to produce oligosaccharides, and antifungal activity showed that Ch501 has potential applications in industries as for chitooligosaccharides production used as prebiotics and/or for the biological control of plant pathogens in agriculture.

  19. Tricritical point in ferroelastic ammonium titanyl fluoride: NMR study

    SciTech Connect

    Kavun, V.Ya.; Kozlova, S.G.; Laptash, N.M; Tkachenko, I.A.; Gabuda, S.P

    2010-09-15

    Ionic mobility and phase transitions in ammonium titanyl pentafluoride (NH{sub 4}){sub 3}TiOF{sub 5} were studied using the {sup 19}F and {sup 1}H NMR data. The high-temperature phase (I) is characterized by spherically symmetric (isotropic) reorientation of [TiOF{sub 5}]{sup 3-} anions and by uniaxial reorientation of these anions in the ferroelastic phase II. A previously unknown second-order phase transition to the low-temperature modification (NH{sub 4}){sub 3}TiOF{sub 5}(III) was found at 205 K. The transition is accompanied by hindering of uniaxial rotations of [TiOF{sub 5}]{sup 3-} anions and by noticeable change of {sup 19}F magnetic shielding tensor associated with the influence of pseudo-Jahn-Teller effect. A pressure-induced tricritical point with coordinates p{sub TCR{approx}}2 kbar and T{sub TCR{approx}}170 K is estimated on the base of {sup 19}F NMR chemical shift data, and previously studied p-T diagram of (NH{sub 4}){sub 3}TiOF{sub 5}. - Graphical abstract: p-T phase diagram of (NH{sub 4}){sub 3}TiOF{sub 5}.

  20. Evaluation of a cesium adsorbent grafted with ammonium 12-molybdophosphate

    NASA Astrophysics Data System (ADS)

    Shibata, Takuya; Seko, Noriaki; Amada, Haruyo; Kasai, Noboru; Saiki, Seiichi; Hoshina, Hiroyuki; Ueki, Yuji

    2016-02-01

    A fibrous cesium (Cs) adsorbent was developed using radiation-induced graft polymerization with a cross-linked structure containing a highly stable adsorption ligand. The ligand, ammonium 12-molybdophosphate (AMP), was successfully introduced onto the fibrous polyethylene trunk material. The resulting Cs adsorbent contained 36% nonwoven fabric polyethylene (NFPE), 1% AMP, 2% triallyl isocyanurate (TAIC) and 61% glycidyl methacrylate (GMA). The adsorbent's Cs adsorption capacity was evaluated using batch and column tests. It was determined that the adsorbent could be used in a wide pH range. The amount of desorbed molybdenum, which can be used as an estimate for AMP stability on the Cs adsorbent, was minimized at the standard drinking water pH range of 5.8-8.6. Based from the inspection on the adherence of these results to the requirements set forth by the Food Sanitation Act by a third party organization, it can be concluded that the developed Cs adsorbent can be safely utilized for drinking water.

  1. Lung Function Changes in Mice Sensitized to Ammonium ...

    EPA Pesticide Factsheets

    Occupational exposure to halogenated platinum salts can trigger the development of asthma. The risk to the general population that may result from the use of platinum in catalytic converters and its emerging use as a diesel fuel additive is unclear. To investigate pulmonary responses to platinum, we developed a mouse model of platinum hypersensitivity. Mice were sensitized through application of ammonium hexachloroplatinate (AHCP) to the shaved back on days 0, 5 and 19, and to each ear on days 10, 11 and 12. On days 24 and 29, mice were challenged by oropharyngeal aspiration with AHCP in saline. Before and immediately after challenge, pulmonary responses were assessed using whole body plethysmography (WBP). A dose-dependentincrease in immediate responses was observed in AHCP-sensitized and challenged mice. On days 26 and 31, changes in ventilatory responses to methacholine (Mch) aerosol were assessed by WBP; dose-dependent increases in Mch responsiveness occurred in sensitized mice. Lymph node cell counts indicate a proliferative response in lymph nodes drainng the sites of application. Bronchoalveolar lavage fluid harvested from sensitized mice contained an average of 5% eosinophils compared to less than 0.5% in non-sensitized mice (p < 0.05); significant increases in total serum immunoglobulin E were observed for all sensitized mice. Although a second airway challenge on day 29 affected some results, only one airway challenge was needed to observe changes in l

  2. Anaerobic Ammonium Oxidation: From Laboratory to Full-Scale Application

    PubMed Central

    Zhang, Jian

    2013-01-01

    From discovery in the early 1990s to completion of full-scale anammox reactor, it took almost two decades to uncover the secret veil of anammox bacteria. There were three milestones during the commercialization of anammox: the development of the first enrichment culture medium, the completion of the first commercial anammox reactor, and the fast start-up of full-scale anammox plant. Till now, the culture of anammox bacteria experienced a big progress through two general strategies: (a) to start up a reactor from scratch and (b) to seed the reactor with enriched anammox sludge. The first full-scale anammox reactor took 3.5 years to realize full operation using the first approach due to several reasons besides the lack of anammox sludge. On the other hand, the first Asian anammox reactor started up in two months, thanks to the availability of anammox seed. Along with the implementation of anammox plants, anammox eventually becomes the priority choice for ammonium wastewater treatment. PMID:23956985

  3. Intensification of sonochemical degradation of ammonium perfluorooctanoate by persulfate oxidant.

    PubMed

    Hao, Feifei; Guo, Weilin; Wang, Anqi; Leng, Yanqiu; Li, Helian

    2014-03-01

    Ammonium perfluorooctanoate (APFO) is an emerging environmental pollutant attracting significant attention due to its global distribution, high persistence, and bioaccumulation properties. The decomposition of APFO in aqueous solution with a combination of persulfate oxidant and ultrasonic irradiation was investigated. The effects of operating parameters, such as ultrasonic power, persulfate concentration, APFO concentration, and initial media pH on APFO degradation were discussed. In the absence of persulfate, 35.5% of initial APFO in 46.4 μmol/L solution under ultrasound irradiation, was decomposed rapidly after 120 min with the defluorination ratio reaching 6.73%. In contrast, when 10 mmol/L persulfate was used, 51.2% of initial APFO (46.4 μmol/L) was decomposed and the defluorination ratio reached 11.15% within 120 min reaction time. Enhancement of the decomposition of APFO can be explained by acceleration of substrate decarboxylation, induced by sulfate radical anions formed from the persulfate during ultrasonic irradiation. The SO4(-•)/APFO reactions at the bubble-water interface appear to be the primary pathway for the sonochemical degradation of the perfluorinated surfactants.

  4. Betaines and related ammonium compounds in chestnut (Castanea sativa Mill.).

    PubMed

    Servillo, Luigi; Giovane, Alfonso; Casale, Rosario; Balestrieri, Maria Luisa; Cautela, Domenico; Paolucci, Marina; Siano, Francesco; Volpe, Maria Grazia; Castaldo, Domenico

    2016-04-01

    Chestnut fruits, being poor of simple sugars and consisting mainly of fibers and starch, are among the constituents of Mediterranean diet. While numerous studies report on content of proteins and amino acids in chestnut, no one has appeared so far on betaines, an important class of nitrogen compounds ubiquitous in plants for their protective action in response to abiotic stress. In this study, we analyzed by HPLC-ESI-tandem mass spectrometry, in fruits and flours of varieties of chestnut cultivated in Italy, the composition of betaines and ammonium compounds intermediates of their biosynthesis. Besides the parent amino acids, the compounds quantified were choline, glycerophosphocholine, phosphocholine, glycine betaine, N-methylproline, proline betaine (stachydrine), β-alanine betaine, 4-guanidinobutyric acid, trigonelline, N,N,N-trimethyllysine. Interestingly, some uncommon derivatives of pipecolic acid, such as N-methylpipecolic acid, 4-hydroxypipecolic acid and 4-hydroxy-N-methylpipecolic acid were identified for the first time in chestnut samples and characterized by MS(n) tandem mass spectrometry.

  5. Adaptation of Aquatic Microbial Communities to Quaternary Ammonium Compounds

    PubMed Central

    Ventullo, Roy M.; Larson, Robert J.

    1986-01-01

    The effects of long-chain (C12 to C18) quaternary ammonium compounds (QACs) on the density, heterotrophic activity, and biodegradation capabilities of heterotrophic bacteria were examined in situ in a lake ecosystem. Monoalkyl and dialkyl substituted QACs were tested over a range of concentrations (0.001 to 10 mg/liter) in both acute (3 h) and chronic (21 day) exposures. In general, none of the QACs tested had significant adverse effects on bacterial densities in either acute or chronic studies. However, significant decreases in bacterial heterotrophic activity were noted in acute studies at QAC concentrations from 0.1 to 10 mg/liter. Chronic exposure of lake microbial communities to a specific monoalkyl QAC resulted in an adaptive response and recovery of heterotrophic activity. No-observable-effect level in the adapted populations was >10 mg/liter. Chronic exposure also resulted in significant increases in the number and activity of bacteria capable of biodegrading the material. The increase in biodegradation capability was observed at low (microgram per liter) concentrations which are approximately the same as realistic environmental levels. In general, our studies indicated that exposure of lake microbial communities to QACs results in the development of adapted communities which are less sensitive to potential toxic effects and more active in the biodegradation of these materials. PMID:16346991

  6. [Treatment of cetyltrimethyl ammonium bromide wastewater by potassium ferrate].

    PubMed

    Yang, Wei-hua; Wang, Hong-hui; Zeng, Xiao-xu; Huang, Ting-ting

    2009-08-15

    A novel oxidant potassium ferrate (K2FeO4) was used to remove cetyltrimethyl ammonium bromide (CTAB) at room temperature. The effects of various conditions on the removal ratio, such as reaction time, dosing quantity of K2FeO4 and initial pH, were investigated. The experiments results show that the removal ratio reaches 79.4% when the reaction time is 30 min, the dosing quantity of K2FeO4 to CTAB is 1:1, the initial pH of the solution is 7. In the reaction progress, the oxidation of K2FeO4 and the flocculation of the reduction product have synergistic effect on the removal of CTAB. In addition, infrared spectra of CTAB before and after being treated with K2FeO4 were further studied. The results indicate that the degradation process involves the interruption of chain and the subsequent mineralization to inorganic molecules. Furthermore, the reaction of K2FeO4 and CTAB follows second order kinetics law.

  7. Resistance to quaternary ammonium compounds in food-related bacteria.

    PubMed

    Sidhu, Maan Singh; Sørum, Henning; Holck, Askild

    2002-01-01

    Microbial resistance to antimicrobial agents continues to be a major problem. The frequent use and misuse of disinfectants based on quaternary ammonium compounds (QACs) in food-processing industries have imposed a selective pressure and may contribute to the emergence of disinfectant-resistant microorganisms. A total number of 1,325 Gram-negative isolates (Escherichia coli, other coliforms Vibrio spp., and Aeromonas spp.) and 500 Enterococcus spp. from food and food-processing industries and fish farming were screened for natural resistance to the QAC-based disinfectant benzalkonium chloride (BC). Of the 1,825 isolates, 16 strains, mainly from meat retail shops, showed low-level resistance to BC. None of the Enterococcus spp. from broiler, cattle, and pigs, the antibiotic-resistant E. coli from pig intestine and fish pathogens Vibrio spp. and Aeromonas spp. from the Norwegian fish farming industry were resistant to BC. The BC-resistant strains were examined for susceptibility to 15 different antibiotics, disinfectants, and dyes. No systematic cross-resistance between BC and any of the other antimicrobial agents tested was detected. Stable enhanced resistance in Enterobacter cloacae isolates was demonstrated by step-wise adaptation in increasing concentrations of BC. In conclusion, BC resistance among food-associated Gram-negative bacteria and Enterococcus spp. is not frequent, but resistance may develop to user concentrations after exposure to sublethal concentrations of BC.

  8. Proton transfer in gas-phase ammonium dinitramide clusters

    NASA Astrophysics Data System (ADS)

    Alavi, Saman; Thompson, Donald L.

    2003-02-01

    Proton transfer in gaseous ammonium dinitramide (ADN) clusters up to (ADN)2 is studied by using density-functional theory. Proton transfer between the hydrogen dinitramide and ammonia units does not occur in the ADN monomer, rather the ammonia-hydrogen dinitramide complex is stabilized by strong hydrogen bonding. However, proton transfer between hydrogen dinitramide and ammonia is observed in the ADN dimer [NH3HN(NO2)2]2, ADN solvated with a single ammonia molecule [NH3NH(NO2)2]NH3, and ADN solvated with a hydrogen dinitramide molecule [NH3HN(NO2)2]HN(NO2)2. Structural changes in the complexes relative to the free molecules and the binding energies of the clusters are given. Using population analysis, the total electrostatic interaction energy in each cluster is calculated. The electrostatic energy is a measure that distinguishes between the ionic or hydrogen-bonded nature of the clusters. Some implications of proton transfer in ADN clusters on the decomposition mechanism of ADN are discussed.

  9. Crystallization of Chicken Egg-White Lysozyme from Ammonium Sulfate

    NASA Technical Reports Server (NTRS)

    Forsythe, Elizabeth L.; Snell, Edward H.; Pusey, Marc L.

    1997-01-01

    Chicken egg-white lysozyme was crystallized from ammonium sulfate over the pH range 4.0-7.8, with protein concentrations from 100 to 150 mg/ml. Crystals were obtained by vapor-diffusion or batch-crystallization methods. The protein crystallized in two morphologies with an apparent morphology dependence on temperature and protein concentration. In general, tetragonal crystals could be grown by lowering the protein concentration or temperature. Increasing the temperature or protein concentration resulted in the growth of orthorhombic crystals. Representative crystals of each morphology were selected for X-ray analysis. The tetragonal crystals belonged to the P4(sub 3)2(sub 1)2 space group with crystals grown at ph 4.4 having unit-cell dimensions of a = b = 78.7 1, c=38.6 A and diffracting to beyond 2.0 A. The orthorhombic crystals, grown at pH 4.8, were of space group P2(sub 1)2(sub 1)2 and had unit-cell dimensions of a = 30.51, b = 56.51 and c = 73.62 A.

  10. Measuring and modeling ammonium adsorption by calcareous soils.

    PubMed

    Ranjbar, F; Jalali, M

    2013-04-01

    The aim of this study was assessment of ammonium (NH 4(+) ) adsorption isotherms in some agricultural calcareous soils and modeling of that by using the mechanistic exchange model. Ten surface soils (0-30 cm) were collected from areas covered with different land uses in Hamedan, western Iran. Isotherm experiments were carried out by concentrations of NH 4(+) prepared from NH4Cl salt (0, 10, 20, 30, 40, 50, 100, and 150 mg NH 4(+)  l(-1)) in presence of 0.01 M CaCl2 solution. The empirical models including simple adsorption isotherm and Freundlich equations were fitted well to the experimental data. The average amounts of adsorbed NH 4(+) in studied soils varied from 8.95 to 35.23 %. Adsorption percentage indicated positive correlation with pH, cation-exchange capacity (CEC), equivalent calcium carbonate, and clay content and had negative correlation with sand content. In order to predict and model NH 4(+) adsorption, cation-exchange model in PHREEQC program was used. The model could simulate the NH 4(+) adsorption very well in all studied soils. The values of CEC played the major role in modeling of NH 4(+) adsorption in this study indicating that cation-exchange process was the major mechanism controlling NH 4(+) adsorption in studied soils.

  11. Effects of quaternary ammonium chain length on antibacterial bonding agents.

    PubMed

    Li, F; Weir, M D; Xu, H H K

    2013-10-01

    The objectives of this study were to synthesize new quaternary ammonium methacrylates (QAMs) with systematically varied alkyl chain lengths (CL) and to investigate, for the first time, the CL effects on antibacterial efficacy, cytotoxicity, and dentin bond strength of bonding agents. QAMs were synthesized with CL of 3 to 18 and incorporated into Scotchbond Multi-Purpose (SBMP) bonding agent. The cured resins were inoculated with Streptococcus mutans. Bacterial early attachment was investigated at 4 hrs. Biofilm colony-forming units (CFU) were measured after 2 days. With CL increasing from 3 to 16, the minimum inhibitory concentration and minimum bactericidal concentration were decreased by 5 orders of magnitude. Incorporating QAMs into SBMP reduced bacterial early attachment, with the least colonization at CL = 16. Biofilm CFU for CL = 16 was 4 log lower than SBMP control (p < .05). All groups had similar dentin bond strengths (p > .1). The new antibacterial materials had fibroblast/odontoblast viability similar to that of commercial controls. In conclusion, increasing the chain length of new QAMs in bonding agents greatly increased the antibacterial efficacy. A reduction in Streptococcus mutans biofilm CFU by 4 log could be achieved, without compromising bond strength and cytotoxicity. New QAM-containing bonding agents are promising for a wide range of restorations to inhibit biofilms.

  12. Quaternary ammonium sulfanilamide: a membrane-impermeant carbonic anhydrase inhibitor.

    PubMed

    Henry, R P

    1987-05-01

    A novel carbonic anhydrase (CA) inhibitor, quaternary ammonium sulfanilamide (QAS), was tested for potency as a CA inhibitor and for its ability to be excluded from permeating biological membranes. Inhibitor titration plots of QAS vs. pure bovine CA II and CA from the gills of the blue crab, Callinectes sapidus, yielded Ki values of approximately 15 microM; thus QAS is a relatively weak but effective CA inhibitor. Permeability of the QAS was directly tested by two independent methods. The inhibitor was excluded from human erythrocytes incubated in 5 mM QAS for 24 h as determined using an 18O-labeled mass spectrometer CA assay for intact cells. Also QAS injected into the hemolymph of C. sapidus (1 or 10 mM) did not cross the basal membrane of the gill. The compound was cleared from the hemolymph by 96 h after injection, and at no time during that period could the QAS be detected in homogenates of gill tissue. Total branchial CA activity was only slightly reduced following the QAS injection. These data indicate that QAS is a CA inhibitor to which biological membranes are impermeable and that can be used in vivo or in vitro in the study of membrane-associated CA.

  13. Serial ammonia measurement in patients poisoned with glufosinate ammonium herbicide.

    PubMed

    Moon, J M; Chun, B J

    2016-05-01

    This study investigated whether ammonia concentrations can predict delayed neurotoxicity development and neurotoxicity latency in glufosinate ammonium (GLA) herbicide-poisoned patients presenting with an alert mental state and stable hemodynamics. This retrospective observational case study included 26 patients divided into 2 groups: neurotoxicity during hospitalization (complicated group) and without neurotoxicity (noncomplicated group). Thirteen patients (50.0%) experienced neurotoxicity at 16 h post-ingestion. Although ammonia concentrations at presentation did not differ significantly between the two groups, the ammonia level in the complicated group increased significantly at the next measurement and remained significantly higher than that in the noncomplicated group until 48 h after ingestion. The peak ammonia concentration before neurotoxicity development was an independent predictor of neurotoxicity (odds ratio: 1.047, 95% confidence interval: 1.010-1.087, p value = 0.014), and the optimal cutoff value of peak ammonia concentration for predicting neurotoxicity was 101.5 μg/dL. The rate of ammonia increase was not associated with the time latency from ingestion to neurotoxicity development. This study showed that serial ammonia measurements in GLA-poisoned patients may identify those who are at high risk of developing neurotoxicity. However, as this study enrolled few patients, further qualified trials are required to confirm our results and to reveal the etiology of hyperammonemia and its causality in neurotoxicity.

  14. Effect of ammonium metavanadate on the murine immune response

    SciTech Connect

    Cohen, M.D.; Wei, C.I.; Tan, H.; Kao, K.J.

    1986-01-01

    Female B/sub 6/C/sub 3/F/sub 1/ mice were exposed to ammonium metavanadate (NH/sub 4/VO/sub 3/) by intraperitoneal injection every 3 d at 2.5, 5.0, or 10 mg V/kg for 3, 6, or 9 w and were then assayed for alterations in immunoresponsiveness. Resistance to Escherichia coli endotoxin lethality increased in a dose-dependent manner up to 6 w of exposure, while resistance to viable gram-positive Listeria lethality was depressed in a dose-dependent manner. Comparison of LD20 values indicated a 250-fold decrease in resistance to Listeria at the lowest vanadium exposure and a 40% increase in resistance to endotoxin after the highest vanadium exposure. Peritoneal macrophage phagocytic capacities were decreased in a dose-dependent manner, but viabilities remained unaffected. Rosetting capacity of splenic lymphocytes was increased following vanadium exposure. Liver and splenic enlargement was observed, and examination of splenic tissue indicated enhanced formation of megakaryocytes and red blood cell precursors. Subchronic exposure to vanadium may thus disrupt the normal function of the immune system.

  15. Alanine synthesis from glyceraldehyde and ammonium ion in aqueous solution

    NASA Technical Reports Server (NTRS)

    Weber, A. L.

    1985-01-01

    The formation of alanine (ala) form C(14)-glyceraldehyde and ammonium phosphate in the presence or absence of a thiol is reported. At ambient temperature, ala synthesis was six times more rapid in the presence of 3-mercaptopropionic acid than in its absence (0.6 and 0.1 percent, respectively, after 60 days). Similarly, the presence of another thiol, N-acetylcysteinate, increased the production of ala, as well as of lactate. The reaction pathway of thiol-catalyzed synthesis of ala, with the lactic acid formed in a bypath, is suggested. In this, dehydration of glyceraldehyde is followed by the formation of hemithioacetal. In the presence of ammonia, an imine is formed, which eventually yields ala. This pathway is consistent with the observation that the rate ratio of ala/lactate remains constant throughout the process. The fact that the reaction takes place under anaerobic conditions in the presence of H2O and with the low concentrations of simple substrates and catalysts makes it an attractive model prebiotic reaction in the process of molecular evolution.

  16. AMMONIUM AND FORMATE IONS IN INTERSTELLAR ICE ANALOGS

    SciTech Connect

    Galvez, Oscar; Mate, Belen; Herrero, Victor J.; Escribano, Rafael

    2010-11-20

    The so-called hyperquenching technique has been applied to generate water ices containing ammonium and formate ions by sudden freezing of droplets of NH{sub 4}Cl, NH{sub 4}COOH, and NaCOOH solutions. Salt deposits were obtained after heating the ices to 210 K to sublimate all water content. All stages are controlled by IR transmission spectroscopy. The NH{sub 4} {sup +} bands are very much broadened and smeared in the frozen droplets, but stand out strongly when water is eliminated. This fact hints toward the difficulty in ascertaining the presence of this species in astrophysical water-containing ices. Vapor-deposited ices of NH{sub 3}/HCOOH and H{sub 2}O/NH{sub 3}/HCOOH mixtures have also been studied for comparison. HCOO{sup -} and NH{sub 4} {sup +} ions are found to be formed in small proportion even at the lowest temperature, 14 K. By thermal processing, their IR bands become stronger, and at 210 K, after water sublimation, they yield IR spectra similar to those obtained from hyperquenched samples. The observations are interpreted in terms of the varying ion arrangement within the solids along the warming process. A direct comparison to laboratory spectra of irradiated samples, as performed by other groups, is not straightforward.

  17. Quaternary ammonium substituted agarose as surface coating for capillary electrophoresis.

    PubMed

    Ullsten, Sara; Söderberg, Lennart; Folestad, Staffan; Markides, Karin E

    2004-05-01

    A novel positively charged polymer of quaternary ammonium substituted agarose (Q-agarose) has been synthesized and explored for use as a coating in capillary electrophoresis. The fast and simple coating procedure is based on a multi-site electrostatic interaction between the polycationic agarose polymer and the negatively charged fused-silica surface. By simply flushing fused-silica capillaries with hot polymer solution a positively charged, hydrophilic deactivation layer is achieved. The polymer surface provides an intermediate electroosmotic flow of reversed direction, over a range of pH 2-11, compared to unmodified fused-silica. The coating procedure was highly reproducible with an RSD of 4%, evaluated as the electroosmotic flow mobility for 30 capillaries prepared at 10 different occasions. The application of Q-agarose coated capillaries in separation science was investigated using a set of basic drugs and model proteins and peptides. Due to the intermediate electroosmotic flow generated, the resolution of basic drugs could be increased, compared to using bare fused-silica capillaries. Moreover, the coating enabled separation of proteins and peptides with efficiencies up to 300.000 plates m(-1).

  18. Effects of Quaternary Ammonium Chain Length on Antibacterial Bonding Agents

    PubMed Central

    Li, F.; Weir, M.D.; Xu, H.H.K.

    2013-01-01

    The objectives of this study were to synthesize new quaternary ammonium methacrylates (QAMs) with systematically varied alkyl chain lengths (CL) and to investigate, for the first time, the CL effects on antibacterial efficacy, cytotoxicity, and dentin bond strength of bonding agents. QAMs were synthesized with CL of 3 to 18 and incorporated into Scotchbond Multi-Purpose (SBMP) bonding agent. The cured resins were inoculated with Streptococcus mutans. Bacterial early attachment was investigated at 4 hrs. Biofilm colony-forming units (CFU) were measured after 2 days. With CL increasing from 3 to 16, the minimum inhibitory concentration and minimum bactericidal concentration were decreased by 5 orders of magnitude. Incorporating QAMs into SBMP reduced bacterial early attachment, with the least colonization at CL = 16. Biofilm CFU for CL = 16 was 4 log lower than SBMP control (p < .05). All groups had similar dentin bond strengths (p > .1). The new antibacterial materials had fibroblast/odontoblast viability similar to that of commercial controls. In conclusion, increasing the chain length of new QAMs in bonding agents greatly increased the antibacterial efficacy. A reduction in Streptococcus mutans biofilm CFU by 4 log could be achieved, without compromising bond strength and cytotoxicity. New QAM-containing bonding agents are promising for a wide range of restorations to inhibit biofilms. PMID:23958761

  19. Polyclonal antibodies mediated immobilization of a peroxidase from ammonium sulphate fractionated bitter gourd (Momordica charantia) proteins.

    PubMed

    Fatima, Aiman; Husain, Qayyum

    2007-06-01

    Polyclonal antibody bound Sepharose 4B support has been exploited for the immobilization of bitter gourd peroxidase directly from ammonium sulphate precipitated proteins. Immunoaffinity immobilized bitter gourd peroxidase exhibited high yield of immobilization. IgG-Sepharose 4B bound bitter gourd peroxidase showed a higher stability against heat, chaotropic agents (urea and guanidinium chloride), detergents (cetyl trimethyl ammonium bromide and Surf Excel), proteolytic enzyme (trypsin) and water-miscible organic solvents (propanol, THF and dioxane). The activity of immobilized bitter gourd peroxidase was significantly enhanced in the presence of cetyl trimethyl ammonium bromide and after treatment with trypsin as compared to soluble enzyme.

  20. Thermal cyclic etching of silicon nitride using formation and desorption of ammonium fluorosilicate

    NASA Astrophysics Data System (ADS)

    Shinoda, Kazunori; Izawa, Masaru; Kanekiyo, Tadamitsu; Ishikawa, Kenji; Hori, Masaru

    2016-10-01

    Novel selective cyclic etching of SiN over SiO2 via the formation and desorption of ammonium fluorosilicate was developed. The formation of ammonium fluorosilicate was observed using X-ray photoelectron spectroscopy after hydrofluorocarbon-based radical exposure. Etching of SiN was observed after ammonium fluorosilicate was removed by thermal annealing. Cyclic etching tests were carried out by repeated radical exposure and thermal annealing. The etching depth increased on increasing the number of cycles. It was found that the cyclic etching is self-limiting because the etching depth does not depend on the radical exposure time but on the number of cycles.

  1. Noncovalent Complexation of Monoamine Neurotransmitters and Related Ammonium Ions by Tetramethoxy Tetraglucosylcalix[4]arene

    NASA Astrophysics Data System (ADS)

    Torvinen, Mika; Kalenius, Elina; Sansone, Francesco; Casnati, Alessandro; Jänis, Janne

    2012-02-01

    The noncovalent complexation of monoamine neurotransmitters and related ammonium and quaternary ammonium ions by a conformationally flexible tetramethoxy glucosylcalix[4]arene was studied by electrospray ionization Fourier transform ion cyclotron resonance (ESI-FTICR) mass spectrometry. The glucosylcalixarene exhibited highest binding affinity towards serotonin, norepinephrine, epinephrine, and dopamine. Structural properties of the guests, such as the number, location, and type of hydrogen bonding groups, length of the alkyl spacer between the ammonium head-group and the aromatic ring structure, and the degree of nitrogen substitution affected the complexation. Competition experiments and guest-exchange reactions indicated that the hydroxyl groups of guests participate in intermolecular hydrogen bonding with the glucocalixarene.

  2. Ammonium sulfate and MALDI in-source decay: a winning combination for sequencing peptides.

    PubMed

    Delvolve, Alice; Woods, Amina S

    2009-12-01

    In previous papers, we highlighted the role of ammonium sulfate in increasing peptide fragmentation by in-source decay (ISD). The current work systematically investigated effects of matrix assisted laser desorption ionization (MALDI) extraction delay, peptide amino acid composition, matrix, and ammonium sulfate concentration on peptide ISD fragmentation. The data confirmed that ammonium sulfate increased peptides signal-to-noise ratio as well as their in-source fragmentation, resulting in complete sequence coverage regardless of the amino acid composition. This method is easy, inexpensive, and generates the peptides sequence instantly.

  3. [Evaluation of phenol ammonium sulfate sedimentation method for diagnosis of pulmonary tuberculosis].

    PubMed

    Akgüneş, Alper; Coban, Ahmet Yilmaz; Taşdelen Fişgin, Nuriye; Acuner, Ibrahim Cağatay; Durupinar, Belma

    2005-01-01

    In the study, the results of culture have been accepted as a gold standard and the specificity and sensitivity of phenol ammonium sulfate sedimentation method has been evaluated. When it is evaluated according to the results of culture, it has been found that the specificity and sensitivity of phenol ammonium sulfate sedimentation method is 90%, the specificity of the process which is made through the N-acetyl-L-cysteine NaOH method is 90% and the sensitivity of it is 85%. In conclusion, the phenol ammonium sulfate method seems to be as a secure method that can only be used in the laboratories in which microscopic studies are made.

  4. Effects of nitrate and ammonium on larvae of Rana temporaria from the Pyrenees.

    PubMed

    Oromí, Neus; Sanuy, Delfí; Vilches, Marcel

    2009-05-01

    In order to investigate the effects of nitrate and ammonium on the amphibians in a pasture zone of the Catalonian Pyrenees, larvae of Rana temporaria from several ponds were exposed to different concentrations of nitrate (0-500 mg/L) and ammonium (0-1.2 mg/L). High concentrations of nitrate in the water caused mortality and reduced larval size of R. temporaria, whereas no effects on larvae were observed in ammonium conditions. The results suggest that, if the levels of nitrate reach about 100 mg/L, the possibility of survival of R. temporaria larvae may be reduced.

  5. Molecular characterization, function and regulation of ammonium transporters (Amt) and ammonium-metabolizing enzymes (GS, NADP-GDH) in the ectomycorrhizal fungus Hebeloma cylindrosporum.

    PubMed

    Javelle, Arnaud; Morel, Mélanie; Rodríguez-Pastrana, Blanca-Rosa; Botton, Bernard; André, Bruno; Marini, Anne-Marie; Brun, Annick; Chalot, Michel

    2003-01-01

    External hyphae, which play a key role in nitrogen nutrition of trees, are considered as the absorbing structures of the ectomycorrhizal symbiosis. Here, we have cloned and characterized Hebeloma cylindrosporum AMT1, GLNA and GDHA genes, which encode a third ammonium transporter, a glutamine synthetase and an NADP-dependent glutamate dehydrogenase respectively. Amt1 can fully restore the pseudohyphal growth defect of a Saccharomyces cerevisiae mep2 mutant, and this is the first evidence that a heterologous member of the Mep/Amt family complements this dimorphic change defect. Dixon plots of the inhibition of methylamine uptake by ammonium indicate that Amt1 has a much higher affinity than the two previously characterized members (Amt2 and Amt3) of the Amt/Mep family in H. cylindrosporum. We also identified the intracellular nitrogen pool(s) responsible for the modulation of expression of AMT1, AMT2, AMT3, GDHA and GLNA. In response to exogenously supplied ammonium or glutamine, AMT1, AMT2 and GDHA were downregulated and, therefore, these genes are subjected to nitrogen repression in H. cylindrosporum. Exogenously supplied nitrate failed to induce a downregulation of the five mRNAs after transfer of mycelia from a N-starved condition. Our results demonstrate that glutamine is the main effector for AMT1 and AMT2 repression, whereas GDHA repression is controlled by intracellular ammonium, independently of the intracellular glutamine or glutamate concentration. Ammonium transport activity may be controlled by intracellular NH4+. AMT3 and GLNA are highly expressed but not highly regulated. A model for ammonium assimilation in H. cylindrosporum is presented.

  6. Effect of Sodium Sulfate, Ammonium Chloride, Ammonium Nitrate, and Salt Mixtures on Aqueous Phase Partitioning of Organic Compounds.

    PubMed

    Wang, Chen; Lei, Ying Duan; Wania, Frank

    2016-12-06

    Dissolved inorganic salts influence the partitioning of organic compounds into the aqueous phase. This influence is especially significant in atmospheric aerosol, which usually contains large amounts of ions, including sodium, ammonium, chloride, sulfate, and nitrate. However, empirical data on this salt effect are very sparse. Here, the partitioning of numerous organic compounds into solutions of Na2SO4, NH4Cl, and NH4NO3 was measured and compared with existing data for NaCl and (NH4)2SO4. Salt mixtures were also tested to establish whether the salt effect is additive. In general, the salt effect showed a decreasing trend of Na2SO4 > (NH)2SO4 > NaCl > NH4Cl > NH4NO3 for the studied organic compounds, implying the following relative strength of the salt effect of individual anions: SO4(2-) > Cl(-) > NO3(-) and of cations: Na(+) > NH4(+). The salt effect of different salts is moderately correlated. Predictive models for the salt effect were developed based on the experimental data. The experimental data indicate that the salt effect of mixtures may not be entirely additive. However, the deviation from additivity, if it exists, is small. Data of very high quality are required to establish whether the effect of constituent ions or salts is additive or not.

  7. Ammonium first: natural mosses prefer atmospheric ammonium but vary utilization of dissolved organic nitrogen depending on habitat and nitrogen deposition.

    PubMed

    Liu, Xue-Yan; Koba, Keisuke; Makabe, Akiko; Li, Xiao-Dong; Yoh, Muneoki; Liu, Cong-Qiang

    2013-07-01

    Mosses, among all types of terrestrial vegetation, are excellent scavengers of anthropogenic nitrogen (N), but their utilization of dissolved organic N (DON) and their reliance on atmospheric N remain uncharacterized in natural environments, which obscures their roles in N cycles. Natural (15) N abundance of N sources (nitrate (NO(3)(-)), ammonium (NH(4)(+)) and DON in deposition and soil) for epilithic and terricolous mosses was analyzed at sites with different N depositions at Guiyang, China. Moss NO(3)(-) assimilation was inhibited substantially by the high supply of NH(4)(+) and DON. Therefore, contributions of NH(4)(+) and DON to moss N were partitioned using isotopic mass-balance methods. The N contributions averaged 56% and 46% from atmospheric NH(4)(+), and 44% and 17% from atmospheric DON in epilithic and terricolous mosses, respectively. In terricolous mosses, soil NH(4)(+) and soil DON accounted for 16% and 21% of bulk N, which are higher than current estimations obtained using (15) N-labeling methods. Moreover, anthropogenic NH(4)(+) deposition suppressed utilization of DON and soil N because of the preference of moss for NH(4)(+) under elevated NH(4)(+) deposition. These results underscore the dominance of, and preference for, atmospheric NH(4)(+) in moss N utilization, and highlight the importance of considering DON and soil N sources when estimating moss N sequestration and the impacts of N deposition on mosses.

  8. Purification of IgG from serum with caprylic acid and ammonium sulphate precipitation is not superior to ammonium sulphate precipitation alone.

    PubMed

    Mohanty, J G; Elazhary, Y

    1989-01-01

    Immunoglobulin G (IgG) from bovine serum raised against Aeromonas Salmonicida was purified by ammonium sulphate precipitation (ASP) or caprylic acid treatment followed by ammonium sulphate precipitation (CAAS). Purity of IgG samples prepared by both methods were examined by High Performance Gel Permeation Chromatography, electrophoresis and antibody activity assay. Results suggest that IgG prepared by ASP is better than that obtained by CAAS method in terms of the yield of the IgG monomers and the recovery of the antibody activity.

  9. Interface Engineering of Metal Oxides using Ammonium Anthracene in Inverted Organic Solar Cells.

    PubMed

    Jeon, Il; Zeljkovic, Sasa; Kondo, Kei; Yoshizawa, Michito; Matsuo, Yutaka

    2016-11-09

    In this work, by casting water-soluble ammonium anthracene on metal oxides, the organic surface modifier re-engineered the interface of the metal oxide to improve charge transport. The energy level of ammonium anthracene increased the work function of indium tin oxide (ITO), functioning as a hole-blocker (electron-transporter). Solar cells in which ITO was treated by the ammonium anthracene produced an average power conversion efficiency (PCE) of 5.8% without ZnO, the electron-transporting layer. When the ammonium anthracene was applied to ZnO, an average PCE of 8.1% was achieved, which is higher than the average PCE of 7.5% for nontreated ZnO-based devices.

  10. Determination of ammonium in a buddingtonite sample by ion-chromatography

    USGS Publications Warehouse

    Klock, P.R.; Lamothe, P.J.

    1986-01-01

    An ion-chromatographic method for the direct determination of ammonium, potassium, and sodium in geologic materials is described. Samples are decomposed with a mixture of hydrofluoric and hydrochloric acids in a sealed polycarbonate bottle heated in a microwave oven. The ion-chromatograph separates the cations and determines them by conductivity measurement. The ammonium concentrations thus determined have been verified by use of an ammonia-specific electrode. A total of 32 analyses of ammonium salts by both techniques showed an average error of -4%, with a relative standard deviation (RSD) of 6%. The ammonium concentrations found in a buddingtonite sample had an RSD of 2.2% and their mean agreed with that obtained by the Kjeldahl method. By use of the prescribed dilution of the sample, detection limits of 0.1% can be achieved for all three cations. ?? 1986.

  11. Branched quaternary ammonium amphiphiles: nematic ionic liquid crystals near room temperature.

    PubMed

    Li, Wen; Zhang, Jing; Li, Bao; Zhang, Mingliang; Wu, Lixin

    2009-09-21

    Branched quaternary ammonium molecules were synthesized and characterized by calorimetric, optical and X-ray diffraction studies; two of the molecules exhibited interesting nematic liquid crystalline behavior close to room temperature.

  12. [Effect of ammonium sulfate aerosol on the photochemical reaction of toluene/ NO(x)/air mixture].

    PubMed

    Wu, Shan; Hao, Ji-Ming; Lü, Zi-Feng; Zhao, Zhe; Li, Jun-Hua

    2007-06-01

    The effect of ammonium sulfate aerosol on the photochemical reaction of toluene/NO(x)/air mixture was evaluated with Tsinghua Smog Chamber facility. The results indicate that the presence of concentrated preexisting ammonium sulfate aerosol shortens the time to reach maximum PM (particle matter) concentration and increases the aerosol yield of toluene. And under the presence of high concentrated ammonium sulfate aerosol seed, the concentration of aerosol does not have significant effects on NO(x), NO and O3 variation, but affects the formation of secondary organic aerosol (SOA). The SOA yield increases with the increasing initial ammonium sulfate seed concentration (< 160 microg x m(-3)). From the minimum 7.2% to the maximum 11.7%, the percentage increase of SOA yield is more than 60%.

  13. The logistic growth of duckweed (Lemna minor) and kinetics of ammonium uptake.

    PubMed

    Zhang, Kun; Chen, You-Peng; Zhang, Ting-Ting; Zhao, Yun; Shen, Yu; Huang, Lei; Gao, Xu; Guo, Jin-Song

    2014-01-01

    Mathematical models have been developed to describe nitrogen uptake and duckweed growth experimentally to study the kinetics of ammonium uptake under various concentrations. The kinetics of duckweed ammonium uptake was investigated using the modified depletion method after plants were grown for two weeks at different ammonium concentrations (0.5-14 mg/L) in the culture medium. The maximum uptake rate and Michaelis-Menten constant for ammonium were estimated as 0.082 mg/(g fresh weight x h) and 1.877 mg/L, respectively. Duckweed growth was assessed when supplied at different total nitrogen (TN) concentrations (1-5 mg/L) in the culture medium. The results showed that the intrinsic growth rate was from 0.22 to 0.26 d(-1), and TN concentrations had no significant influence on the duckweed growth rate.

  14. The anomalous solid state decomposition of ammonium dinitramide: a matter of surface polarization.

    PubMed

    Rahm, Martin; Brinck, Tore

    2009-05-28

    Polarized dinitramide anions on the surface of solid ammonium dinitramide (ADN) have a decomposition barrier that is reduced by 16 kcal mol(-1) and explain the anomalous solid state decomposition of ADN.

  15. Properties of the Nafion membrane impregnated with hydroxyl ammonium based ionic liquids

    NASA Astrophysics Data System (ADS)

    Garaev, Valeriy; Kleperis, Janis; Pavlovica, Sanita; Vaivars, Guntars

    2012-08-01

    In this work, the Nafion 112 membrane impregnated with nine various hydroxyl ammonium based ionic liquids have been investigated. The used ionic liquids were combined from hydroxyl ammonium cations (2-hydroxyethylammonium/HEA, bis(2- hydroxyethyl)ammonium/BHEA, tris(2-hydroxyethyl)ammonium/THEA) and carboxylate anions (formate, acetate, lactate). The membranes are characterized by conductivity and thermal stability measurements. It was found, that almost all composites have 10 times higher ion conductivity than a pure Nafion 112 at 90 °C in ambient environment due to the higher thermal stability. The thermal stability of Nafion membrane was increased by all studied nine ionic liquids. In this work, only biodegradable ionic liquids were used for composite preparation.

  16. Treatment of ammonium-rich swine waste in modified porphyritic andesite fixed-bed anaerobic bioreactor.

    PubMed

    Wang, Qinghong; Yang, Yingnan; Li, Dawei; Feng, Chuanping; Zhang, Zhenya

    2012-05-01

    In this study, a modified porphyritic andesite (WRS) was developed as ammonium adsorbent and bed material for the anaerobic digestion of ammonium-rich swine waste. The performance in bioreactors with modified WRS, natural WRS, calcium chloride and no additives was investigated. The bioreactor with modified WRS exhibited the best performance, with start-up time on the 7th day, methane yield of 359.71 ml/g-VS, and COD removal of 67.99% during all 44 days of the experiment at 35°C. The effective ammonium adsorption and essential ions dissociation for microorganisms by modified WRS, as well as the immobilization of microbial on the surface of the modified WRS play a great role on the high efficiency anaerobic digestion of ammonium-rich swine waste.

  17. Enantioselective [4 + 1] Annulation Reactions of α-Substituted Ammonium Ylides To Construct Spirocyclic Oxindoles.

    PubMed

    Zheng, Peng-Fei; Ouyang, Qin; Niu, Sheng-Li; Shuai, Li; Yuan, Yi; Jiang, Kun; Liu, Tian-Yu; Chen, Ying-Chun

    2015-07-29

    Ammonium ylides have a long history in organic synthesis, but their application in asymmetric catalysis is still underdeveloped in regard to both substrate scope and reaction pathways compared with phosphorus and sulfur ylides. Here a previously unreported asymmetric [4 + 1] annulation reaction of 3-bromooxindoles and electron-deficient 1-azadienes has been developed through ammonium ylide catalysis of a newly designed 2'-methyl α-isocupreine (α-MeIC), efficiently delivering spirocyclic oxindole compounds incorporating a dihydropyrrole motif in excellent enantioselectivity (up to 99% ee). To the best of our knowledge, this work represents the first example of asymmetric catalysis of ammonium ylides bearing α-substitutions, and the catalytic [4 + 1] annulation pathway of ammonium ylides is also unprecedented. Moreover, (1)H NMR, mass spectroscopy, and computational calculation studies were conducted, and the catalytic cycle and a tentative explanation of the enantioselective mechanism have been successfully elucidated.

  18. Nano-biphasic ionic liquid systems composed of hydrophobic phosphonium salts and a hydrophilic ammonium salt.

    PubMed

    Taguchi, Satomi; Ichikawa, Takahiro; Kato, Takashi; Ohno, Hiroyuki

    2012-05-28

    A combination of a phosphonium-type-zwitterions-lithium bis(trifluoromethanesulfonyl)imide complex and a hydrophilic ammonium salt provides a nanosegregated liquid-crystalline matrix consisting of hydrophilic ionic liquid (IL) domains and hydrophobic IL domains.

  19. Anatase-brookite mixed phase nano TiO2 catalyzed homolytic decomposition of ammonium nitrate.

    PubMed

    Vargeese, Anuj A; Muralidharan, Krishnamurthi

    2011-09-15

    Compared to the conventional ammonium perchlorate based solid rocket propellants, burning of ammonium nitrate (AN) based propellants produce environmentally innocuous combustion gases. Application of AN as propellant oxidizer is restricted due to low reactivity and low energetics besides its near room temperature polymorphic phase transition. In the present study, anatase-brookite mixed phase TiO(2) nanoparticles (~ 10 nm) are synthesized and used as catalyst to enhance the reactivity of the environmental friendly propellant oxidizer ammonium nitrate. The activation energy required for the decomposition reactions, computed by differential and non-linear integral isoconversional methods are used to establish the catalytic activity. Presumably, the removal of NH(3) and H(2)O, known inhibitors of ammonium nitrate decomposition reaction, due to the surface reactions on active surface of TiO(2) changes the decomposition pathway and thereby the reactivity.

  20. Ammonium recovery from reject water combined with hydrogen production in a bioelectrochemical reactor.

    PubMed

    Wu, Xue; Modin, Oskar

    2013-10-01

    In this study, a bioelectrochemical reactor was investigated for simultaneous hydrogen production and ammonium recovery from reject water, which is an ammonium-rich side-stream produced from sludge treatment processes at wastewater treatment plants. In the anode chamber of the reactor, microorganisms converted organic material into electrical current. The electrical current was used to generate hydrogen gas at the cathode with 96±6% efficiency. Real or synthetic reject water was fed to the cathode chamber where proton reduction into hydrogen gas resulted in a pH increase which led to ammonium being converted into volatile ammonia. The ammonia could be stripped from the solution and recovered in acid. Overall, ammonium recovery efficiencies reached 94% with synthetic reject water and 79% with real reject water. This process could potentially be used to make wastewater treatment plants more resource-efficient and further research is warranted.

  1. Modeling light and temperature influence on ammonium removal by Scenedesmus sp. under outdoor conditions.

    PubMed

    Ruiz-Martínez, Ana; Serralta, Joaquin; Seco, Aurora; Ferrer, Jose

    2016-10-01

    The ammonium removal rate of the microalga Scenedesmus sp. was studied under outdoor conditions. Microalgae were grown in a 500 L flat-plate photobioreactor and fed with the effluent of a submerged anaerobic membrane bioreactor. Temperature ranged between 9.5 °C and 32.5 °C and maximum light intensity was 1,860 μmol·m(-2)·s(-1). A maximum specific ammonium removal rate of 3.71 mg NH4(+)-N·g TSS(-1)·h(-1) was measured (at 22.6 °C and with a light intensity of 1,734 μmol·m(-2)·s(-1)). A mathematical model considering the influence of ammonium concentration, light and temperature was validated. The model successfully reproduced the observed values of ammonium removal rate obtained and it is thus presented as a useful tool for plant operation.

  2. Evaluation of chitosan quaternary ammonium salt-modified resin denture base material.

    PubMed

    Song, Rong; Zhong, Zhaohua; Lin, Lexun

    2016-04-01

    Chitosan quaternary ammonium salt displays good antioxidant and antibacterial characteristics and it shows appreciable solubility in water. When added to the traditional denture material to form a resin base, it could promote good oral health by improving the oral environment. In this study, chitosan quaternary ammonium salt was added to the denture material following two different methods. After three months of immersion in artificial saliva, the specimens were tested for tensile strength and were scanned by electron microscope. The murine fibroblast cytotoxicity and antibacterial properties were also tested. The result showed no significant differences in the tensile strength and in the proliferation of murine L929 fibroblast cells. The two structures of chitosan quaternary ammonium salt-modified denture material had different degrees of corrosion resistance and antimicrobial properties. These results indicate that chitosan quaternary ammonium salt-modified resin denture base material has the potential to become a new generation oral denture composite material.

  3. Induction of contact drematitis in guinea pigs by quaternary ammonium compounds: the mechanisms of antigen formation

    SciTech Connect

    Schallreuter, K.R.; Schulz, K.H.; Wood, J.M.

    1986-12-01

    Eight quaternary ammonium compounds were tested for their ability to induce contact dermatitis in guinea pigs by using a modified Freund's complete adjuvant test together with the guinea pig maximization test. Only two quaternary ammonium salts of eight tested could be designated as strong allergens. These two active substances were shown to be capable of stable association with membrane lipids in forming immunogenic complexes. This surface complexation phenomenon was confirmed by using a spin-labeled quaternary ammonium salt which competed for binding sites to the surface of epidermal cells in vivo. Electron spin resonance was used to demonstrate that stable ion-pairs are formed between binding sites and the two allergenic preservatives. Furthermore, information was obtained on the kinetics of immunogenic complex formation as well as on the position and orientation of the quaternary ammonium ion at the cell surface.

  4. Combined anaerobic ammonium and methane oxidation for nitrogen and methane removal.

    PubMed

    Zhu, Baoli; Sánchez, Jaime; van Alen, Theo A; Sanabria, Janeth; Jetten, Mike S M; Ettwig, Katharina F; Kartal, Boran

    2011-12-01

    Anammox (anaerobic ammonium oxidation) is an environment-friendly and cost-efficient nitrogen-removal process currently applied to high-ammonium-loaded wastewaters such as anaerobic digester effluents. In these wastewaters, dissolved methane is also present and should be removed to prevent greenhouse gas emissions into the environment. Potentially, another recently discovered microbial pathway, n-damo (nitrite-dependent anaerobic methane oxidation) could be used for this purpose. In the present paper, we explore the feasibility of simultaneously removing methane and ammonium anaerobically, starting with granules from a full-scale anammox bioreactor. We describe the development of a co-culture of anammox and n-damo bacteria using a medium containing methane, ammonium and nitrite. The results are discussed in the context of other recent studies on the application of anaerobic methane- and ammonia-oxidizing bacteria for wastewater treatment.

  5. Nitrogen loss by anaerobic ammonium oxidation in unconfined aquifer soils

    PubMed Central

    Wang, Shanyun; Radny, Dirk; Huang, Shuangbing; Zhuang, Linjie; Zhao, Siyan; Berg, Michael; Jetten, Mike S. M.; Zhu, Guibing

    2017-01-01

    Anaerobic ammonium oxidation (anammox) is recognized as an important process for nitrogen cycling, yet little is known about its role in the subsurface biosphere. In this study, we investigated the presence, abundance, and role of anammox bacteria in upland soil cores from Tianjin, China (20 m depth) and Basel, Switzerland (10 m depth), using isotope-tracing techniques, (q)PCR assays, and 16 S rRNA & hzsB gene clone libraries, along with nutrient profiles of soil core samples. Anammox in the phreatic (water-saturated) zone contributed to 37.5–67.6% of the N-loss (up to 0.675 gN m−2 d−1), with anammox activities of 0.005–0.74 nmolN g−1 soil h−1, which were even higher than the denitrification rates. By contrast, no significant anammox was measured in the vadose zone. Higher anammox bacterial cell densities were observed (0.75–1.4 × 107 copies g−1 soil) in the phreatic zone, where ammonia-oxidizing bacteria (AOB) maybe the major source of nitrite for anammox bacteria. The anammox bacterial cells in soils of the vadose zone were all <103 copies g−1 soil. We suggest that the subsurface provides a favorable niche for anammox bacteria whose contribution to N cycling and groundwater nitrate removal seems considerably larger than previously known. PMID:28071702

  6. Nitrogen loss by anaerobic oxidation of ammonium in rice rhizosphere

    PubMed Central

    Nie, San'an; Li, Hu; Yang, Xiaoru; Zhang, Zhaoji; Weng, Bosen; Huang, Fuyi; Zhu, Gui-Bing; Zhu, Yong-Guan

    2015-01-01

    Anaerobic oxidation of ammonium (anammox) is recognized as an important process for nitrogen (N) cycling, yet its role in agricultural ecosystems, which are intensively fertilized, remains unclear. In this study, we investigated the presence, activity, functional gene abundance and role of anammox bacteria in rhizosphere and non-rhizosphere paddy soils using catalyzed reporter deposition–fluorescence in situ hybridization, isotope-tracing technique, quantitative PCR assay and 16S rRNA gene clone libraries. Results showed that rhizosphere anammox contributed to 31–41% N2 production with activities of 0.33–0.64 nmol N2 g−1 soil h−1, whereas the non-rhizosphere anammox bacteria contributed to only 2–3% N2 production with lower activities of 0.08–0.26 nmol N2 g−1 soil h−1. Higher anammox bacterial cells were observed (0.75–1.4 × 107 copies g−1 soil) in the rhizosphere, which were twofold higher compared with the non-rhizosphere soil (3.7–5.9 × 106 copies g−1 soil). Phylogenetic analysis of the anammox bacterial 16S rRNA genes indicated that two genera of ‘Candidatus Kuenenia' and ‘Candidatus Brocadia' and the family of Planctomycetaceae were identified. We suggest the rhizosphere provides a favorable niche for anammox bacteria, which are important to N cycling, but were previously largely overlooked. PMID:25689022

  7. Dual-setting calcium phosphate cement modified with ammonium polyacrylate.

    PubMed

    dos Santos, Luís Alberto; Carrodeguas, Raúl García; Boschi, Anselmo Ortega; de Arruda, Antônio Celso

    2003-05-01

    alpha-Tricalcium phosphate bone cement, as formerly designed and developed by Driessens et al., consists of a powder composed by alpha-tricalcium phosphate (alpha-TCP) and hydroxyapatite (HA) seeds, and an aqueous solution of Na2HPO4 as mixing liquid. After mixing powder and liquid, alpha-TCP dissolves into the liquid and calcium deficient hydroxyapatite (CDHA), more insoluble than the former, precipitates as an entanglement of crystals, which causes the setting and hardening of the cement. alpha-TCP bone cement offers several advantages in comparison to calcium phosphate bioceramics and acrylic bone cements as bone graft and repairing material, like perfect adaptability to the defect size and shape, osteotransductibility, and absence of thermal effect during setting. The main handicap is its low mechanical strength. Therefore, approaching its mechanical strength to that of human bone could considerably extend its applications. In the present work, an in situ polymerization system based on acrylamide (AA) and ammonium polyacrylate (PA) as liquid reducer was added to alpha-TCP cement to increase its mechanical strength. The results showed that the addition of 20 wt% of acrylamide and 1 wt% AP to the liquid increased the compressive and tensile strength of alpha-TCP bone cement by 149 and 69% (55 and 21 MPa), respectively. The improvement in mechanical strength seems to be caused by a decrease of porosity and the reinforcing effect of a polyacrylamide network coexisting with the entanglement of CDHA crystals. The studied additives do not affect the nature of the final product of the setting reaction, CDHA, but promote the reduction of its crystal size.

  8. Occurrence of Anaerobic Ammonium Oxidation in the Yangtze Estuary

    NASA Astrophysics Data System (ADS)

    Hou, L.

    2013-12-01

    Over the past several decades, a large quantity of reactive nitrogen has been transported into the Yangtze estuarine and coastal water, due to intense human activities in the Yangtze River Basin. At present, it annually receives a high load of anthropogenic inorganic nitrogen (about 1.1 × 1011 mol N) from increased agricultural activities, fish farming, and domestic and industrial wastewater discharge in the Yangtze River Basin, consequently leading to severe eutrophication and frequent occurrences of harmful algal blooms in the estuary and adjacent coastal areas. Hence, the microbial nitrogen transformations are of major concern in the Yangtze Estuary. Anaerobic ammonium oxidation (anammox) has been reported to play a significant role in the removal of reactive nitrogen in aquatic ecosystems. In this study, the occurrences of anammox bacteria and associated activity in the Yangtze Estuary were evidenced with molecular and isotope-tracing techniques. It is observed that the anammox bacteria at the study area mainly consisted of Candidatus Scalindua, Brocadia, Kuenenia. Salinity was found to be a key environmental factor controlling distribution and diversity of the anammox bacterial community at the estuarine ecosystem. Also, temperature and organic carbon had significant influences on anammox bacterial biodiversity. Q-PCR assays of anammox bacteria indicated that their abundance had a range of 2.63 ×106 - 9.48 ×107 copies g-1 dry sediment, with high spatiotemporal heterogeneity. The potential anammox activities measured in the present work varied between 0.94 - 6.61nmol N g-1 dry sediment h-1, which were related to temperature, nitrite and anammox bacterial abundance. On the basis of the 15N tracing experiments, the anammox process was estimated to contribute 6.6 - 12.9 % to the total nitrogen loss whereas the remainder was attributed to denitrification.

  9. Nitrogen loss by anaerobic ammonium oxidation in unconfined aquifer soils

    NASA Astrophysics Data System (ADS)

    Wang, Shanyun; Radny, Dirk; Huang, Shuangbing; Zhuang, Linjie; Zhao, Siyan; Berg, Michael; Jetten, Mike S. M.; Zhu, Guibing

    2017-01-01

    Anaerobic ammonium oxidation (anammox) is recognized as an important process for nitrogen cycling, yet little is known about its role in the subsurface biosphere. In this study, we investigated the presence, abundance, and role of anammox bacteria in upland soil cores from Tianjin, China (20 m depth) and Basel, Switzerland (10 m depth), using isotope-tracing techniques, (q)PCR assays, and 16 S rRNA & hzsB gene clone libraries, along with nutrient profiles of soil core samples. Anammox in the phreatic (water-saturated) zone contributed to 37.5–67.6% of the N-loss (up to 0.675 gN m‑2 d‑1), with anammox activities of 0.005–0.74 nmolN g‑1 soil h‑1, which were even higher than the denitrification rates. By contrast, no significant anammox was measured in the vadose zone. Higher anammox bacterial cell densities were observed (0.75–1.4 × 107 copies g‑1 soil) in the phreatic zone, where ammonia-oxidizing bacteria (AOB) maybe the major source of nitrite for anammox bacteria. The anammox bacterial cells in soils of the vadose zone were all <103 copies g‑1 soil. We suggest that the subsurface provides a favorable niche for anammox bacteria whose contribution to N cycling and groundwater nitrate removal seems considerably larger than previously known.

  10. Nitrogen loss by anaerobic ammonium oxidation in unconfined aquifer soils.

    PubMed

    Wang, Shanyun; Radny, Dirk; Huang, Shuangbing; Zhuang, Linjie; Zhao, Siyan; Berg, Michael; Jetten, Mike S M; Zhu, Guibing

    2017-01-10

    Anaerobic ammonium oxidation (anammox) is recognized as an important process for nitrogen cycling, yet little is known about its role in the subsurface biosphere. In this study, we investigated the presence, abundance, and role of anammox bacteria in upland soil cores from Tianjin, China (20 m depth) and Basel, Switzerland (10 m depth), using isotope-tracing techniques, (q)PCR assays, and 16 S rRNA &hzsB gene clone libraries, along with nutrient profiles of soil core samples. Anammox in the phreatic (water-saturated) zone contributed to 37.5-67.6% of the N-loss (up to 0.675 gN m(-2 )d(-1)), with anammox activities of 0.005-0.74 nmolN g(-1 )soil h(-1), which were even higher than the denitrification rates. By contrast, no significant anammox was measured in the vadose zone. Higher anammox bacterial cell densities were observed (0.75-1.4 × 10(7 )copies g(-1 )soil) in the phreatic zone, where ammonia-oxidizing bacteria (AOB) maybe the major source of nitrite for anammox bacteria. The anammox bacterial cells in soils of the vadose zone were all <10(3 )copies g(-1 )soil. We suggest that the subsurface provides a favorable niche for anammox bacteria whose contribution to N cycling and groundwater nitrate removal seems considerably larger than previously known.

  11. Assessing the Damaging Potential of Non-Ideal Explosives Based Upon Ammonium Nitrate Fertilizer

    DTIC Science & Technology

    1996-08-01

    ASSESSING THE DAMAGING POTENTIAL OF NON-IDEAL EXPLOSIVES BASED UPON AMMONIUM NITRATE FERTILIZER Peter J Hubbard Maurice Marshall DERA Fort Halstead...a similar massive bomb this time allegedly based upon a mixture of prilled agricultural ammonium nitrate fertilizer and fuel oil (ANFO) was used in...explosives tested were measured using fibre optic probes in some experiments and ionisation probes in others. An array of pressure gauges was used to

  12. Exploiting the Imidazolium Effect in Base-free Ammonium Enolate Generation: Synthetic and Mechanistic Studies.

    PubMed

    Young, Claire M; Stark, Daniel G; West, Thomas H; Taylor, James E; Smith, Andrew D

    2016-11-07

    N-Acyl imidazoles and catalytic isothiourea hydrochloride salts function as ammonium enolate precursors in the absence of base. Enantioselective Michael addition-cyclization reactions using different α,β-unsaturated Michael acceptors have been performed to form dihydropyranones and dihydropyridinones with high stereoselectivity. Detailed mechanistic studies using RPKA have revealed the importance of the "imidazolium" effect in ammonium enolate formation and have highlighted key differences with traditional base-mediated processes.

  13. Synthesis of sodium, potassium cesium, and ammonium O,O-dialkyl phosphoroselenothioates

    SciTech Connect

    Mel'nik, Ya.I.; Prots, D.I.; Kolodii, Ya.I.; Slavich, V.M.

    1986-10-20

    In search for a simpler method for the preparation of the title compounds and in continuation of the investigations on methods of synthesis and properties of organic derivatives of phosphorus seleno acids the authors have investigated the reactions of O,O-dialkyl hydrogen phosphorothioites with selenium and alkali-metal and ammonium carbonates, leading to the corresponding metal (ammonium) O,O-dialkyl phosphoroselenothioates.

  14. Use of quaternary ammonium salts of nitrogen containing polymers for improved carburetor detergency

    SciTech Connect

    Biasotti, J.B.; Vartanian, P.F.

    1980-01-15

    A quaternary ammonium salt is described of a copolymer, said copolymer being the olefin polymerization product of: (A) a nitrogen amine free ester of a C/sub 1/-C/sub 6/ olefinically unsaturated aliphatic mono-, di-, or polycarboxylic acid having a tertiary nitrogen atom; and (B) an olefinically unsaturated co-monomer containing a basic nitrogen atom in a side chain; a fuel component, especially gasoline, containing such quaternary ammonium salt of such copolymer as a detergent.

  15. Microbial communities involved in biological ammonium removal from coal combustion wastewaters.

    PubMed

    Vishnivetskaya, Tatiana A; Fisher, L Suzanne; Brodie, Greg A; Phelps, Tommy J

    2013-07-01

    The efficiency of a novel integrated treatment system for biological removal of ammonium, nitrite, nitrate, and heavy metals from fossil power plant effluent was evaluated. Microbial communities were analyzed using bacterial and archaeal 16S rRNA gene clone libraries (Sanger sequences) and 454 pyrosequencing technology. While seasonal changes in microbial community composition were observed, the significant (P = 0.001) changes in bacterial and archaeal communities were consistent with variations in ammonium concentration. Phylogenetic analysis of 16S rRNA gene sequences revealed an increase of potential ammonium-oxidizing bacteria (AOB), Nitrosomonas, Nitrosococcus, Planctomycetes, and OD1, in samples with elevated ammonium concentration. Other bacteria, such as Nitrospira, Nitrococcus, Nitrobacter, Thiobacillus, ε-Proteobacteria, Firmicutes, and Acidobacteria, which play roles in nitrification and denitrification, were also detected. The AOB oxidized 56 % of the ammonium with the concomitant increase in nitrite and ultimately nitrate in the trickling filters at the beginning of the treatment system. Thermoprotei within the phylum Crenarchaeota thrived in the splitter box and especially in zero-valent iron extraction trenches, where an additional 25 % of the ammonium was removed. The potential ammonium-oxidizing Archaea (AOA) (Candidatus Nitrosocaldus) were detected towards the downstream end of the treatment system. The design of an integrated treatment system consisting of trickling filters, zero-valent iron reaction cells, settling pond, and anaerobic wetlands was efficient for the biological removal of ammonium and several other contaminants from wastewater generated at a coal burning power plant equipped with selective catalytic reducers for nitrogen oxide removal.

  16. Ammonium nitrogen removal from coking wastewater by chemical precipitation recycle technology.

    PubMed

    Zhang, Tao; Ding, Lili; Ren, Hongqiang; Xiong, Xiang

    2009-12-01

    Ammonium nitrogen removal from wastewater has been of considerable concern for several decades. In the present research, we examined chemical precipitation recycle technology (CPRT) for ammonium nitrogen removal from coking wastewater. The pyrolysate resulting from magnesium ammonium phosphate (MAP) pyrogenation in sodium hydroxide (NaOH) solution was recycled for ammonium nitrogen removal from coking wastewater. The objective of this study was to investigate the conditions for MAP pyrogenation and to characterize of MAP pyrolysate for its feasibility in recycling. Furthermore, MAP pyrolysate was characterized by scanning electron microscope (FESEM), transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FTIR) as well as X-ray diffraction (XRD). The MAP pyrolysate could be produced at the optimal condition of a hydroxyl (OH(-)) to ammonium molar ratio of 2:1, a heating temperature of 110 degrees C, and a heating time of 3h. Surface characterization analysis indicated that the main component of the pyrolysate was amorphous magnesium sodium phosphate (MgNaPO(4)). The pyrolysate could be recycled as a magnesium and phosphate source at an optimum pH of 9.5. When the recycle times were increased, the ammonium nitrogen removal ratio gradually decreased if the pyrolysate was used without supplementation. When the recycle times were increased, the ammonium nitrogen removal efficiency was not decreased if the added pyrolysate was supplemented with MgCl(2).6H(2)O plus Na(2)HPO(4).12H(2)O during treatment. A high ammonium nitrogen removal ratio was obtained by using pre-formed MAP as seeding material.

  17. Ammonium nitrate and iron nutrition effects on some nitrogen assimilation enzymes and metabolites in Spirulina platensis.

    PubMed

    Esen, Merve; Ozturk Urek, Raziye

    2015-01-01

    The effect of various concentrations of ammonium nitrate (5-60 mM), an economical nitrogen source, on the growth, nitrate-ammonium uptake rates, production of some pigments and metabolites, and some nitrogen assimilation enzymes such as nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS), and glutamate synthase (GOGAT) in Spirulina platensis (Gamont) Geitler was investigated. Ten millimolars of ammonium nitrate stimulated the growth, production of pigments and the other metabolites, and enzyme activities, whereas 30 and 60 mM ammonium nitrate caused inhibition. In the presence of 10 mM ammonium nitrate, different concentrations of iron were tried in the growth media of S. platensis. After achieving the best growth, levels of metabolite and pigment production, and enzyme activities in the presence of 10 mM ammonium nitrate as a nitrogen source, different iron concentrations (10-100 µM) were tried in the growth medium of S. platensis. The highest growth, pigment and metabolite levels, and enzyme activities were determined in the medium containing 50 µM iron and 10 mM ammonium nitrate. In this optimum condition, the highest dry biomass level, chlorophyll a, and pyruvate contents were obtained as 55.42 ± 3.8 mg mL(-1) , 93.114 ± 7.9 µg g(-1) , and 212.5 ± 18.7 µg g(-1) , respectively. The highest NR, NiR, GS, and GOGAT activities were 67.16 ± 5.1, 777.92 ± 52, 0.141 ± 0.01, and 44.45 ± 3.6, respectively. Additionally, 10 mM ammonium nitrate is an economical and efficient nitrogen source for nitrogen assimilation of S. platensis, and 50 µM iron is optimum for the growth of S. platensis.

  18. Field Dissipation and Storage Stability of Glufosinate Ammonium and Its Metabolites in Soil

    PubMed Central

    Zhang, Yun; Wang, Kai; Wu, Junxue; Zhang, Hongyan

    2014-01-01

    A simple analytical method was developed to measure concentrations of glufosinate ammonium and its metabolites, 3-methylphosphinico-propionic acid (MPP) and 2-methylphosphinico-acetic acid (MPA), in field soil samples. To determine the minimum quantification limit, samples were spiked at different levels (0.1, 0.5, and 1.0 mg/kg). Soil samples were extracted with ammonium hydroxide solution 5% (v/v), concentrated, and reacted with trimethyl orthoacetate (TMOA) in the presence of acetic acid for derivatization. The derivatives were quantified by gas chromatography (GC) using a flame photometric detector (FPD). The linear correlation coefficients of glufosinate ammonium, MPP, and MPA in soil were 0.991, 0.999, and 0.999, respectively. The recoveries of this method for glufosinate ammonium, MPP, and MPA in soil were 77.2–95.5%, 98.3–100.3%, and 99.3–99.6% with relative standard deviations (RSD) of 1.8–4.1%, 0.4–1.4%, and 1.3–2.0%, respectively. Glufosinate ammonium dissipated rapidly in soil to MPA in hours and gradually degraded to MPP. The half-life of glufosinate ammonium degradation in soil was 2.30–2.93 days in an open field. In soil samples stored at −20°C glufosinate ammonium was stable for two months. The results of this study should provide guidance for the safe application of the herbicide glufosinate ammonium to agricultural products and the environment. PMID:25374604

  19. Crystal structure of cyclo­hexyl­ammonium thio­cyanate

    PubMed Central

    Bagabas, Abdulaziz A.; Alhoshan, Sultan B.; Ghabbour, Hazem A.; Chidan Kumar, C. S.; Fun, Hoong-Kun

    2015-01-01

    In the title salt, C6H11NH3 +·SCN−, the cyclo­hexyl­ammonium ring adopts a slightly distorted chair conformation. The ammonium group occupies an equatorial position to minimize 1,3 and 1,5 diaxial inter­actions. In the crystal, the components are linked by N—H⋯N and N—H⋯S hydrogen-bonding inter­actions, resulting in a three-dimensional network. PMID:25705511

  20. Transkarbams as transdermal permeation enhancers: effects of ester position and ammonium carbamate formation.

    PubMed

    Novotný, Michal; Hrabálek, Alexandr; Janůsová, Barbora; Novotný, Jakub; Vávrová, Katerina

    2010-05-01

    Transkarbam 12, an ammonium carbamate formed by the reaction of dodecyl 6-aminohexanoate with carbon dioxide, is a highly active, broad-spectrum, nontoxic, and nonirritant transdermal permeation enhancer. It probably acts by a dual mechanism: a part of its activity is associated with the carbamic acid salt and/or its decomposition in the acidic stratum corneum. The ammonium ester thereby released is an active enhancer species as well, and its activity highly depends on the position of the ester group.