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Sample records for nh4 no3 so4

  1. Study of ZrO2-H2SO4-(NH4)2SO4(NH4Cl)-H2O systems

    International Nuclear Information System (INIS)

    Motov, D.L.; Sozinova, Yu.P.; Rys'kina, M.P.

    1988-01-01

    Regions of formation, composition and solubility of ammonium sulfatozirconates (ASZ) in ZrO 2 -H 2 SO 4 -(NH 4 ) 2 SO 4 (NH 4 Cl)-H 2 O systems at 25 and 75 deg C are studied by the isothermal method. Five ASZ: (NH 4 ) 2 Zr(OH) 2 (SO 4 ) 2 , NH 4 ZrOH(SO 4 ) 2 xH 2 O, NH 4 ZrO 0.5 (OH) 2 SO 4 x1.5H 2 O, (NH 4 ) 2 Zr(SO 4 ) 3 x2H 2 O, (NH 4 ) 4 Zr(SO 4 ) 4 x4H 2 O are detected, their properties are investigated. Main sulfates are new compounds never described ealier

  2. Densities and apparent molar volumes of atmospherically important electrolyte solutions. 1. The solutes H2SO4, HNO3, HCl, Na2SO4, NaNO3, NaCl, (NH4)2SO4, NH4NO3, and NH4Cl from 0 to 50 °C, including extrapolations to very low temperature and to the pure liquid state, and NaHSO4, NaOH, and NH3 at 25 °C.

    Science.gov (United States)

    Clegg, S L; Wexler, A S

    2011-04-21

    Calculations of the size and density of atmospheric aerosols are complicated by the fact that they can exist at concentrations highly supersaturated with respect to dissolved salts and supercooled with respect to ice. Densities and apparent molar volumes of solutes in aqueous solutions containing the solutes H(2)SO(4), HNO(3), HCl, Na(2)SO(4), NaNO(3), NaCl, (NH(4))(2)SO(4), NH(4)NO(3), and NH(4)Cl have been critically evaluated and represented using fitted equations from 0 to 50 °C or greater and from infinite dilution to concentrations saturated or supersaturated with respect to the dissolved salts. Using extrapolated densities of high-temperature solutions and melts, the relationship between density and concentration is extended to the hypothetical pure liquid solutes. Above a given reference concentration of a few mol kg(-1), it is observed that density increases almost linearly with decreasing temperature, and comparisons with available data below 0 °C suggest that the fitted equations for density can be extrapolated to very low temperatures. As concentration is decreased below the reference concentration, the variation of density with temperature tends to that of water (which decreases as temperature is reduced below 3.98 °C). In this region below the reference concentration, and below 0 °C, densities are calculated using extrapolated apparent molar volumes which are constrained to agree at the reference concentrations with an equation for the directly fitted density. Calculated volume properties agree well with available data at low temperatures, for both concentrated and dilute solutions. Comparisons are made with literature data for temperatures of maximum density. Apparent molar volumes at infinite dilution are consistent, on a single ion basis, to better than ±0.1 cm(3) mol(-1) from 0 to 50 °C. Volume properties of aqueous NaHSO(4), NaOH, and NH(3) have also been evaluated, at 25 °C only. In part 2 of this work (ref 1 ) an ion interaction (Pitzer

  3. 1H and 2H NMR relaxation study on the phase transitions of (NH4)3H(SO4)2 and (ND4)3D(SO4)2 single crystals

    International Nuclear Information System (INIS)

    Lim, Ae Ran; Jeong, Se-Young

    2006-01-01

    T 1 , T 1ρ and T 2 for the 1 H and 2 H nuclei in (NH 4 ) 3 H(SO 4 ) 2 and (ND 4 ) 3 D(SO 4 ) 2 single crystals grown using the slow evaporation method were measured for phases I, II, III, IV and V. The 1 H T 1 , T 1ρ , and T 2 values were found to exhibit different trends in phases II and III: T 1 , T 1ρ and T 2 for 1 H do not change significantly near the phase transition at 265 K, whereas near 413 K they change discontinuously. We conclude that the NH 4 + and H(SO 4 ) 2 - ions do not play an important role in the III-II phase transition, but do play important roles in the II-I phase transition. The liquid-like nature of the 1 H T 1ρ and T 2 above 413 K is indicative of the destruction and reconstruction of hydrogen bonds. Moreover, the phase transitions of the (NH 4 ) 3 H(SO 4 ) 2 crystal are accompanied by changes in the molecular motion of the (NH 4 ) + ions. The variations with temperature of the 2 H T 1 and T 2 of (ND 4 ) 3 D(SO 4 ) 2 crystals are not similar to those observed for the 1 H T 1 and T 2 . Our comparison of the results for (NH 4 ) 3 H(SO 4 ) 2 and (ND 4 ) 3 D(SO 4 ) 2 crystals indicates the following: the 1 H T 1ρ and T 2 of the (NH 4 ) + and H(SO 4 ) 2 - ions above T C1 are characteristic of fast, liquid-like motion, which is not the case for (ND 4 ) 3 D(SO 4 ) 2 ; and the 2 H T 1 of D(SO 4 ) 2 - in (ND 4 ) 3 D(SO 4 ) 2 is longer than the 2 H T 1 of (ND 4 ) + in contrast to the results for (NH 4 ) 3 H(SO 4 ) 2 crystals

  4. Comparative genomic and physiological analysis of nutrient response to NH4+, NH4+:NO3- and NO3- in barley seedlings.

    Science.gov (United States)

    Lopes, Marta S; Araus, José L

    2008-09-01

    Long-term differences in photosynthesis, respiration and growth of plants receiving distinct nitrogen (N) sources imply that N metabolism generates signals that regulate metabolism and development. The molecular basis of these signals remains unclear. Here we studied the gene expression profiles of barley (Hordeum vulgare L. cv. Graphic) seedlings fertilized either with ammonium (NH4+), with ammonium and nitrate (NH4+:NO3-), or with nitrate (NO3-) only. Our transcriptome analysis after 48 h of growth in these N sources showed major changes in the expression of genes involved in N metabolism (nitrate reductase), signalling (protein kinases and protein phosphatases), photosynthesis (chlorophyll a/b-binding protein and a PsbQ domain), where increases in NO3- as compared with NH4+ were observed. Moreover, NH4+ assimilation induced genes participating in C and sugars metabolism (phosphoglycerate kinase, glucosyltranferase and galactokinase), respiration (cytochrome c oxidase), protein fate (heat shock proteins) and development (MTN3-like protein). These changes in gene expression could well explain the long-term growth depression observed in NH4+ plants. Even if a few genes participating in protein fate (proteases) and development (OsNAC5) were upregulated in NH4+ as compared with NH4+:NO3-, the general pattern of expression was quite similar between these two N sources. Taken together, these results indicated that other downstream mechanisms should be involved in the synergetic long-term response of NH4+:NO3-.

  5. Thermodynamic modeling of NH_3-CO_2-SO_2-K_2SO_4-H_2O system for combined CO_2 and SO_2 capture using aqueous NH_3

    International Nuclear Information System (INIS)

    Qi, Guojie; Wang, Shujuan

    2017-01-01

    Highlights: • A new application of aqueous NH_3 based combined CO_2 and SO_2 process was proposed. • A thermodynamic model simulated the heat of absorption and the K_2SO_4 precipitation. • The CO_2 content can be regenerated in a stripper with lower heat of desorption. • The SO_2 content can be removed by K_2SO_4 precipitation from the lean NH_3 solvent. - Abstract: A new application of aqueous NH_3 based post-combustion CO_2 and SO_2 combined capture process was proposed to simultaneously capture CO_2 and SO_2, and remove sulfite by solid (K_2SO_4) precipitation method. The thermodynamic model of the NH_3-CO_2-SO_2-K_2SO_4-H_2O system for the combined CO_2 and SO_2 capture process was developed and validated in this work to analyze the heat of CO_2 and SO_2 absorption in the NH_3-CO_2-SO_2-H_2O system, and the K_2SO_4 precipitation characteristics in the NH_3-CO_2-SO_2-K_2SO_4-H_2O system. The average heat of CO_2 absorption in the NH_3-CO_2-H_2O system at 40 °C is around −73 kJ/mol CO_2 in 2.5 wt% NH_3 with CO_2 loading between 0.2 and 0.5 C/N. The average heat of SO_2 absorption in the NH_3-SO_2-H_2O system at 40 °C is around −120 kJ/mol SO_2 in 2.5 wt% NH_3 with SO_2 loading between 0 and 0.5 S/N. The average heat of CO_2 absorption in the NH_3-CO_2-SO_2-H_2O system at 40 °C is 77, 68, and 58 kJ/mol CO_2 in 2.5 wt% NH_3 with CO_2 loading between 0.2 and 0.5 C/N, when SO_2 loading is 0, 0.1, 0.2 S/N, respectively. The solubility of K_2SO_4 increases with temperature, CO_2 and SO_2 loadings, but decreases with NH_3 concentration in the CO_2 and SO_2 loaded aqueous NH_3. The thermodynamic evaluation indicates that the combined CO_2 and SO_2 capture process could employ the typical absorption/regeneration process to simultaneously capture CO_2 and SO_2 in an absorber, thermally desorb CO_2 in a stripper, and feasibly remove sulfite (oxidized to sulfate) content by precipitating K_2SO_4 from the lean NH_3 solvent after the lean/rich heat exchanger.

  6. Treatment for GaSb surfaces using a sulphur blended (NH4)2S/(NH4)2SO4 solution

    International Nuclear Information System (INIS)

    Murape, D.M.; Eassa, N.; Neethling, J.H.; Betz, R.; Coetsee, E.; Swart, H.C.; Botha, J.R.; Venter, A.

    2012-01-01

    A sulphur based chemical, [(NH 4 ) 2 S/(NH 4 ) 2 SO 4 ] to which S has been added, not previously reported for the treatment of (1 0 0) n-GaSb surfaces, is introduced and benchmarked against the commonly used passivants Na 2 S·9H 2 O and (NH 4 ) 2 S. The surfaces of the treated material were studied by scanning electron microscopy (SEM), Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS). It has been found that the native oxides present on the GaSb surface are more effectively removed when treated with ([(NH 4 ) 2 S/(NH 4 ) 2 SO 4 ] + S) than with (NH 4 ) 2 S or Na 2 S·9H 2 O, as evidenced by the ratio of the O 506eV to Sb 457eV AES peaks. XPS results reveal that Sb 2 S 3 /Sb 2 S 5 “replaces” Sb 2 O 3 /Sb 2 O 5 , suggesting that sulphur atoms substitute oxygen atoms in Sb 2 O 3 /Sb 2 O 5 to form Sb-S. It seems sulphurization only partially removes Ga 2 O 3 . Treatment with ([(NH 4 ) 2 S/(NH 4 ) 2 SO 4 ] + S) also results in a noteworthy improvement in the current-voltage (I-V) characteristics of Au/n-GaSb Schottky contacts compared to those fabricated on as-received material.

  7. Preparation of silver chloride nanoparticles by a mechanical treatment of the system NH4Cl−AgNO3NH4NO3

    Directory of Open Access Journals (Sweden)

    Farit Urakaev

    2014-08-01

    Full Text Available Silver chloride nanoparticles dispersed within ammonium nitrate matrix have been prepared though displacement mechanochemical reaction NH4Cl + AgNO3 + z NH4NO3 = (z+1 NH4 NO3 + AgCl at various z coefficients z1 = 7.22 and z2 = 3.64. The intermediate compound of NH4Ag(NO32 were recorded after mechanochemical processing of studied system. By using simultaneous TG and DSC measurements possibilities to prepare silver chloride in its free form have been discussed by using thermal treatment.

  8. Stream water chemistry in watersheds receiving different atmospheric inputs of H+, NH4+, NO3-, and SO42-1

    Science.gov (United States)

    Stottlemyer, R.

    1997-01-01

    Weekly precipitation and stream water samples were collected from small watersheds in Denali National Park, Alaska, the Fraser Experimental Forest, Colorado, Isle Royale National Park, Michigan, and the Calumet watershed on the south shore of Lake Superior, Michigan. The objective was to determine if stream water chemistry at the mouth and upstream stations reflected precipitation chemistry across a range of atmospheric inputs of H+, NH4+, NO3-, and SO42-. Volume-weighted precipitation H+, NH4+, NO3-, and SO42- concentrations varied 4 to 8 fold with concentrations highest at Calumet and lowest in Denali. Stream water chemistry varied among sites, but did not reflect precipitation chemistry. The Denali watershed, Rock Creek, had the lowest precipitation NO3- and SO42- concentrations, but the highest stream water NO3and SO42- concentrations. Among sites, the ratio of mean monthly upstream NO3- concentration to precipitation NO3- concentration declined (p 90 percent inputs) across inputs ranging from 0.12 to > 6 kg N ha-1 y-1. Factors possibly accounting for the weak or non-existent signal between stream water and precipitation ion concentrations include rapid modification of meltwater and precipitation chemistry by soil processes, and the presence of unfrozen soils which permits winter mineralization and nitrification to occur.

  9. Analysis of (NH4)2SO4/(NH4)H2PO4 mixtures by thermogravimetry and X-ray diffraction

    International Nuclear Information System (INIS)

    Perez, Jose; Perez, Eduardo; Vas, Beatriz del; Garcia, Luis; Serrano, Jose Luis

    2006-01-01

    (NH 4 ) 2 SO 4 and (NH 4 )H 2 PO 4 are the principal components in the powder material used in fire extinguishers. In this paper the mutual influence in their thermal decomposition is investigated by thermogravimetry. Two methods for the quantification of both salts in mixtures (NH 4 ) 2 SO 4 /(NH 4 )H 2 PO 4 are proposed. The first employs thermogravimetry and is based on the measurement of the mass fraction in the 500-550 deg. C interval, once (NH 4 ) 2 SO 4 has totally decomposed to yield gaseous products. The second uses some selected peaks in the X-ray diffractogram

  10. Nd(NH2SO3)(SO4) . 1.5 H2O: a non-centrosymmetric amidosulfate-sulfate of neodymium

    International Nuclear Information System (INIS)

    Wickleder, M.S.

    2005-01-01

    The thermal decomposition of Nd(NH 2 SO 3 ) 3 . 2 H 2 O in a closed tube leads to violet single crystals of Nd(NH 2 SO 3 )(SO 4 ) . 1.5 H 2 O. The compound crystallizes with the space group P1 (Z = 2, a = 689.2, b = 691.4, c = 962.0 pm, α = 109.64, β = 97.00, γ = 109.62 ). The triclinic unit cell can be transformed into the respective bodycentered setting I1 (Z = 2, a = 977.9, b = 795.6, c = 1113.0 pm, α = 90.69, β = 115.06, γ = 88.98 ) leading to a nearly monoclinic unit cell for the compound. In the crystal structure of Nd(NH 2 SO 3 )(SO 4 ) . 1.5 H 2 O two Nd 3+ ions are present. Nd(1) 3+ is coordinated by four NH 2 SO 3 - and two SO 4 2- ions, and one H 2 O molecule. Owing to the chelating attack of the sulfate groups, the CN is nine. Nd(2) 3+ is surrounded by four monodentate SO 4 2- and two NH 2 SO 3 - groups. Two H 2 O ligands fill up the coordination sphere and lead to a CN of eight. The linkage of the polyhedra leads to a three-dimensional network. (orig.)

  11. THE KINETICS OF NH(4)+ AND NO3(-) UPTAKE BY DOUGLAS-FIR FROM SINGLE N-SOLUTIONS AND FROM SOLUTIONS CONTAINING BOTH NH(4)+ AND NO3(-)

    NARCIS (Netherlands)

    KAMMINGAVANWIJK, C; PRINS, HBA

    The kinetics of NH4+ and NO3- uptake in young Douglas fir trees (Pseudotsuga menziesii [Mirb.] Franco) were studied in solutions, containing either one or both N species. Using solutions containing a single N species, the V(max) of NH4+ uptake was higher than that of NO3- uptake. The K(m) of NH4+

  12. Evaluation of the phase composition of (NH4)2SO4 + (NH4)H2PO4 mixtures by X-ray diffractometry

    International Nuclear Information System (INIS)

    Ortiz, Angel L.; Cumbrera, Francisco L.; Perez, Jose; Vas, Beatriz del; Perez, Eduardo

    2009-01-01

    The phase composition of standard (NH 4 ) 2 SO 4 + (NH 4 )H 2 PO 4 mixtures was investigated by X-ray diffractometry (XRD) using the internal-standard, reference-intensity-ratio, and Rietveld methods. It was found that the Rietveld method yields the most accurate phase-composition measurements, with an average error of ∼2 wt.%. It was also found that the internal-standard method is only effective in determining the phase composition if the calibration curve for (NH 4 )H 2 PO 4 is used, giving an average error of ∼6.5 wt.%. On the contrary, the internal-standard method with the calibration curve of the (NH 4 ) 2 SO 4 phase and the reference-intensity-ratio method are not valid. The inappropriateness of these two methods was attributed to graininess in the (NH 4 ) 2 SO 4 phase, with the attendant deviation of its diffracted intensities from the theoretical values. Direct scanning electron microscopy observations of the morphology of the powder particles in the mixtures showed clear evidence of the large agglomerates formed because the individual powder particles are partially sintered together during milling, thus corroborating the graininess determined by the XRD analyses. Finally, the implications of the present study for the quantitative phase-composition analysis of (NH 4 ) 2 SO 4 + (NH 4 )H 2 PO 4 mixtures, which are of great technological importance for the fire prevention industry, are discussed.

  13. Asian Dust Observed During the KORUS Air Quality Mission Creates Significant Super-Micron NO3-, NH4+, and SO42- Aerosols.

    Science.gov (United States)

    Heim, E. W.; Dibb, J. E.; Scheuer, E. M.

    2017-12-01

    The KORUS mission was a collaborative effort between the Korean Institute of Environmental Research and NASA. KORUS provided a comprehensive assessment of air quality in Korea during early 2016. The intensive sampling campaign was timed to assess local photochemistry during increasing solar insolation and biogenic emissions; after the April peak in outflow of pollution and dust from central China. Chinese outflow is well characterized by Silica-Calcium rich dust. Despite the effort to avoid the period with strongest dust outflow, Ca2+ was well represented in all bulk (particle diameters up to 4.5 micron) aerosol filter samples filter measurements and submicron measurements of NH4+, SO42, and NO3- made by AMS indicates substantial super-micron fractions of these anthropogenic ions at times during KORUS-AQ. During the dustiest samples (Ca2+ > 1.5ug/m3) we see marked increases in super-micron concentration of NH4+, SO42-, and NO3-, m = 1.113 ug/m3 , 2.621 ug/m3 , 4.413 ug/m3, with the super-micron contribution to total concentration averaging 47%, 45%, and 81% respectively. In contrast, low dust days (Ca2+ < 0.2ug/m3) the super-micron concentrations averaged 0.262 ug/m3, 0.510 ug/m3, -0.029 ug/m3, respectively and accounted for just 20%, 14%, and 8% of total mass. During the dust events, samples that have trajectories passing over industrial centers in eastern China approached equivalence balance between Ca2++ NH4+ and SO42-+NO3-. In contrast dusty samples that did not pass over these industrial centers during transport to the West Sea and Korea maintained excess cations, dominantly Ca2+. This suggests that dust can act as an important carrier of Chinese pollution to Korea when this saturated dust reaches the peninsula.

  14. NO3-/NH4+ proportions affect cadmium bioaccumulation and tolerance of tomato.

    Science.gov (United States)

    Nogueirol, Roberta Corrêa; Monteiro, Francisco Antonio; de Souza Junior, João Cardoso; Azevedo, Ricardo Antunes

    2018-05-01

    With the growth of the world population, cadmium (Cd) concentration in the environment has increased considerably as a result of human activities such as foundry, battery disposal, mining, application of fertilizers containing toxic elements as impurities, and disposal of metal-containing waste. Higher plants uptake N as ammonium (NH 4 + ), nitrate (NO 3 - ), and many other water-soluble compounds such as urea and amino acids, and nourishing plants with N, providing part of it as NH 4 + , is an interesting alternative to the supply of this nutrient in the exclusive form of NO 3 - under Cd toxicity. The objective was to evaluate the influence of NO 3 - /NH 4 + proportions on the development and tolerance of tomato plants grown under the presence of Cd in the culture medium. The experiment was conducted in a completely randomized block design in a 3 × 3 factorial arrangement consisting of three Cd rates (0, 50, and 100 μmol L -1 ) and three NO 3 - /NH 4 + proportions (100/0, 70/30, and 50/50) in the nutrient solution. To this end, we quantified the responses of the antioxidant enzymatic system and productive and functional changes in Solanum lycopersicum var. esculentum (Calabash Rouge). Shoot biomass production decreased with the maximum Cd rate (100 μmol L -1 ) tested in the growth medium, whereas the NO 3 - /NH 4 + proportions and other Cd rates did not significantly influence this variable. The lowest SPAD values were observed at the 100/0 NO 3 - /NH 4 + proportion and in plants exposed to Cd. The largest accumulation of the metal occurred in the shoots at the NO 3 - /NH 4 + proportion of 70/30 and at 100 μmol L -1 Cd and in the roots at 100/0 NO 3 - /NH 4 + and with 50 and 100 μmol L -1 Cd. The concentration and accumulation of NO 3 - were highest at the NO 3 - /NH 4 + proportion of 100/0 in the shoots and at 50/50 NO 3 - /NH 4 + in the roots, whereas for NH 4 + , values were higher as the proportion of N supplied in the form of NH 4 + was

  15. Treatment for GaSb surfaces using a sulphur blended (NH{sub 4}){sub 2}S/(NH{sub 4}){sub 2}SO{sub 4} solution

    Energy Technology Data Exchange (ETDEWEB)

    Murape, D.M., E-mail: Davison.Murape@nmmu.ac.za [Department of Physics, Nelson Mandela Metropolitan University, PO Box 77000, Port Elizabeth, 6031 (South Africa); Eassa, N.; Neethling, J.H. [Department of Physics, Nelson Mandela Metropolitan University, PO Box 77000, Port Elizabeth, 6031 (South Africa); Betz, R. [Department of Chemistry, Nelson Mandela Metropolitan University, PO Box 77000, Port Elizabeth, 6031 (South Africa); Coetsee, E.; Swart, H.C. [Department of Physics, University of the Free State, PO Box 339, Bloemfontein, 9300 (South Africa); Botha, J.R.; Venter, A. [Department of Physics, Nelson Mandela Metropolitan University, PO Box 77000, Port Elizabeth, 6031 (South Africa)

    2012-07-01

    A sulphur based chemical, [(NH{sub 4}){sub 2}S/(NH{sub 4}){sub 2}SO{sub 4}] to which S has been added, not previously reported for the treatment of (1 0 0) n-GaSb surfaces, is introduced and benchmarked against the commonly used passivants Na{sub 2}S{center_dot}9H{sub 2}O and (NH{sub 4}){sub 2}S. The surfaces of the treated material were studied by scanning electron microscopy (SEM), Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS). It has been found that the native oxides present on the GaSb surface are more effectively removed when treated with ([(NH{sub 4}){sub 2}S/(NH{sub 4}){sub 2}SO{sub 4}] + S) than with (NH{sub 4}){sub 2}S or Na{sub 2}S{center_dot}9H{sub 2}O, as evidenced by the ratio of the O{sub 506eV} to Sb{sub 457eV} AES peaks. XPS results reveal that Sb{sub 2}S{sub 3}/Sb{sub 2}S{sub 5} 'replaces' Sb{sub 2}O{sub 3}/Sb{sub 2}O{sub 5}, suggesting that sulphur atoms substitute oxygen atoms in Sb{sub 2}O{sub 3}/Sb{sub 2}O{sub 5} to form Sb-S. It seems sulphurization only partially removes Ga{sub 2}O{sub 3}. Treatment with ([(NH{sub 4}){sub 2}S/(NH{sub 4}){sub 2}SO{sub 4}] + S) also results in a noteworthy improvement in the current-voltage (I-V) characteristics of Au/n-GaSb Schottky contacts compared to those fabricated on as-received material.

  16. Effective identification of (NH4)2CO3 and NH4HCO3 concentrations in NaHCO3 regeneration process from desulfurized waste.

    Science.gov (United States)

    Govindan, Muthuraman; Karunakaran, Kannan; Nallasamy, Palanisami; Moon, Il Shik

    2015-01-01

    This work describes the quantitative analysis of (NH4)2CO3 and NH4HCO3 using a simple solution phase titration method. Back titration results at various (NH4)2CO3-NH4HCO3 ratios demonstrated that 6:4 ratio caused a 3% error in their differentiation, but very high errors were found at other ratios. A similar trend was observed for the double indicator method, especially when strong acid HCl was used as a titrant, where still less errors (2.5%) at a middle ratio of (NH4)2CO3-NH4HCO3 was found. Remaining ratios with low (NH4)2CO3 (2:8, 4:6) show high +ve error (found concentration is less) and high (NH4)2CO3 (7:3, 8:2, and 9:1) show high -ve error (found concentration is higher) and vice versa for NH4HCO3. In replacement titration using Na2SO4, at both higher end ratios of (NH4)2CO3-NH4HCO3 (2:8 and 9:1), both -ve and +ve errors were minimized to 75% by partial equilibrium arrest between (NH4)2CO3 and NH2COONH4, instead of more than 100% observed in back titration and only double indicator methods. In the presence of (NH4)2SO4 both -ve and +ve error% are completely reduced to 3±1 at ratios 2:8, 4:6, and 6:4 of (NH4)2CO3-NH4HCO3, which demonstrates that the equilibrium transformation between NH2COONH4 and (NH4)2CO3 is completely controlled. The titration conducted at lower temperature (5 °C) in the presence of (NH4)2SO4 at higher ratios of (NH4)2CO3-NH4HCO3 (7:3, 8:2,and 9:1) shows complete minimization of both -ve and +ve errors to 2±1%, which explains the complete arresting of equilibrium transformation. Finally, the developed method shows 2±1% error in differentiation of CO3(2-) and HCO3(-) in the regeneration process of NaHCO3 from crude desulfurized sample. The developed method is more promising to differentiate CO3(2-) and HCO3(-) in industrial applications. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Study of various NH4+/NO3- mixtures for enhancing growth of potatoes

    Science.gov (United States)

    Cao, W.; Tibbitts, T. W.

    1993-01-01

    Two experiments were conducted to determine the effects of various NH4(+)-N/NO3(-)-N percentages on growth and mineral concentrations in potato (Solanum tuberosum L.) plants using a non-recirculating nutrient film system in a controlled environment. The first experiment included six NH4(+)-N/NO3(-)-N percentages at 0/100, 20/80, 40/60, 60/40, 80/20, and 100/0 with the same total N concentration of 4 mM. The second experiment included six NH4(+)-N/NO3(-)-N percentages at 0/100, 4/96, 8/92, 12/88, 16/84, and 20/80 again with the same total N of 4 mM. In each experiment, plants were harvested 35 days after transplanting when tubers had been initiated and started to enlarge. Dry weights of shoots, tubers, and whole plant at the harvest were increased significantly with all mixed nitrogen treatments as compared with single NH4+ or NO3- form. The enhanced growth with mixed nitrogen was greatest at 8% to 20% NH4(+)-N. Also, the concentrations and accumulation of total N in the shoots and roots were greater with mixed nitrogen than with separate NH4+ or NO3- nutrition. With NH4+ present in the solutions, the concentrations of P and Cl in the shoots were increased compared to NO3- alone, whereas the tissue concentrations of Ca and Mg were decreased. It was concluded that nitrogen fertilization provided with combined NH4+ and NO3- forms, even at small proportions of NH4+, can enhance nitrogen uptake and productivity in potato plants.

  18. [Seasonal variation patterns of NH4(+) -N/NO3(-) -N ratio and delta 15 NH4(+) value in rainwater in Yangtze River Delta].

    Science.gov (United States)

    Xie, Ying-Xin; Zhang, Shu-Li; Zhao, Xu; Xiong, Zheng-Qin; Xing, Guang-Xi

    2008-09-01

    By using a customized manual rainwater sampler made of polyvinyl chloride plastic, the molar ratio of NH4(+) -N/NO3(-) -N and the natural 15N abundance of NH4(+) (delta 15 NH4(+) in rainwater was monitored all year round from June 2003 to July 2005 at three observation sites (Changshu, Nanjing, and Hangzhou) in the Yangtze River Delta. The results indicated that at the three sites, the NH4(+) -N/NO3(-) -N ratio and the delta 15 NH4(+) value in rainwater had the similar seasonal variation trend, being more obvious in Changshu (rural monitoring type) site than in Nanjing (urban monitoring type) and Hangzhou (urban-rural monitoring type) sites. The NH4(+) -N/NO3(-) -N ratio peaked from early June to early August, declined gradually afterwards, and reached the bottom in winter; while the delta 15 NH4(+) value was negative from late June to mid-August, turned positive from late August to mid or late November, became negative again when winter dominated from December to March, but turned positive again in next May and negative again in next July. These seasonal variation patterns of NH4(+) -N/NO3(-) -N ratio and delta 15 NH4(+) value were found in relation to the application of chemical nitrogen fertilizers during different crop growth periods, and also, the alternation of seasons and the NH3 volatilization from other NH3 emission sources (including excrements of human and animals, nitrogen- polluted water bodies, and organic nitrogen sources, etc.), which could be taken as an indicator of defining the sources and form composition of NH4(+) in atmospheric wet deposition and the intensity of various terrestrial NH3 emission sources.

  19. Neutron single crystal diffraction studies of orientational glass state in the [Rbx(NH4)1-x]3H(SO4)2 mixed crystals

    International Nuclear Information System (INIS)

    Smirnov, L.S.; Reehuis, M.; Loose, A.; Hohlwein, D.; Hoffmann, J.U.; Wozniak, K.; Dominiak, P.; Baranov, A.I.; Dolbinina, V.V.

    2005-01-01

    The [Rb x (NH 4 ) 1-x ] 3 H(SO 4 ) 2 mixed crystal with the concentration x=0.0 at room temperature crystallizes in a monoclinic C2/c with sp.gr. (space group), which is stabilized for x>0.09 down to low temperatures. This system is transformed in the orientational glass state below the freezing temperature T g =30 K. The differential Fourier maps for the [Rb x (NH 4 ) 1-x ] 3 H(SO 4 ) 2 mixed crystals show that if for x=0.0 and 0.11 at 293 K the obtained maps reflect different orientational positions of crystallographically independent NH 4 (1) and NH 4 (2) groups, then the differential Fourier maps for x=0.20 at 9 K in the orientational glass state are similar for both ammonium groups reflecting their static disorder. The existence of the modulated structure in the [Rb x (NH 4 ) 1-x ] 3 H(SO 4 ) 2 mixed crystals with x=0.11 at 2 K is discovered, while the modulated structure for x=0.20 at 2 K is absent. This observation supposes that there should be two different regions of the orientational glass state on x-T phase diagram of the [Rb x (NH 4 ) 1-x ] 3 H(SO 4 ) 2 mixed crystals

  20. Depletion of the heaviest stable N isotope is associated with NH4+/NH3 toxicity in NH4+-fed plants.

    Science.gov (United States)

    Ariz, Idoia; Cruz, Cristina; Moran, Jose F; González-Moro, María B; García-Olaverri, Carmen; González-Murua, Carmen; Martins-Loução, Maria A; Aparicio-Tejo, Pedro M

    2011-05-16

    In plants, nitrate (NO3-) nutrition gives rise to a natural N isotopic signature (δ15N), which correlates with the δ15N of the N source. However, little is known about the relationship between the δ15N of the N source and the 14N/15N fractionation in plants under ammonium (NH4+) nutrition. When NH4+ is the major N source, the two forms, NH4+ and NH3, are present in the nutrient solution. There is a 1.025 thermodynamic isotope effect between NH3 (g) and NH4+ (aq) which drives to a different δ15N. Nine plant species with different NH4+-sensitivities were cultured hydroponically with NO3- or NH4+ as the sole N sources, and plant growth and δ15N were determined. Short-term NH4+/NH3 uptake experiments at pH 6.0 and 9.0 (which favours NH3 form) were carried out in order to support and substantiate our hypothesis. N source fractionation throughout the whole plant was interpreted on the basis of the relative transport of NH4+ and NH3. Several NO3--fed plants were consistently enriched in 15N, whereas plants under NH4+ nutrition were depleted of 15N. It was shown that more sensitive plants to NH4+ toxicity were the most depleted in 15N. In parallel, N-deficient pea and spinach plants fed with 15NH4+ showed an increased level of NH3 uptake at alkaline pH that was related to the 15N depletion of the plant. Tolerant to NH4+ pea plants or sensitive spinach plants showed similar trend on 15N depletion while slight differences in the time kinetics were observed during the initial stages. The use of RbNO3 as control discarded that the differences observed arise from pH detrimental effects. This article proposes that the negative values of δ15N in NH4+-fed plants are originated from NH3 uptake by plants. Moreover, this depletion of the heavier N isotope is proportional to the NH4+/NH3 toxicity in plants species. Therefore, we hypothesise that the low affinity transport system for NH4+ may have two components: one that transports N in the molecular form and is associated with

  1. Depletion of the heaviest stable N isotope is associated with NH4+/NH3 toxicity in NH4+-fed plants

    Science.gov (United States)

    2011-01-01

    Background In plants, nitrate (NO3-) nutrition gives rise to a natural N isotopic signature (δ15N), which correlates with the δ15N of the N source. However, little is known about the relationship between the δ15N of the N source and the 14N/15N fractionation in plants under ammonium (NH4+) nutrition. When NH4+ is the major N source, the two forms, NH4+ and NH3, are present in the nutrient solution. There is a 1.025 thermodynamic isotope effect between NH3 (g) and NH4+ (aq) which drives to a different δ15N. Nine plant species with different NH4+-sensitivities were cultured hydroponically with NO3- or NH4+ as the sole N sources, and plant growth and δ15N were determined. Short-term NH4+/NH3 uptake experiments at pH 6.0 and 9.0 (which favours NH3 form) were carried out in order to support and substantiate our hypothesis. N source fractionation throughout the whole plant was interpreted on the basis of the relative transport of NH4+ and NH3. Results Several NO3--fed plants were consistently enriched in 15N, whereas plants under NH4+ nutrition were depleted of 15N. It was shown that more sensitive plants to NH4+ toxicity were the most depleted in 15N. In parallel, N-deficient pea and spinach plants fed with 15NH4+ showed an increased level of NH3 uptake at alkaline pH that was related to the 15N depletion of the plant. Tolerant to NH4+ pea plants or sensitive spinach plants showed similar trend on 15N depletion while slight differences in the time kinetics were observed during the initial stages. The use of RbNO3 as control discarded that the differences observed arise from pH detrimental effects. Conclusions This article proposes that the negative values of δ15N in NH4+-fed plants are originated from NH3 uptake by plants. Moreover, this depletion of the heavier N isotope is proportional to the NH4+/NH3 toxicity in plants species. Therefore, we hypothesise that the low affinity transport system for NH4+ may have two components: one that transports N in the

  2. The refractometry of the mechanically stressed RbNH4SO4 crystals

    International Nuclear Information System (INIS)

    Stadnik, V.J.; Romanyuk, M.O.

    2001-01-01

    The temperature (77-300K) and spectral (300-700hm) dependencies of refractive indices n i of mechanically unstressed and stressed by the pressures along general crystallophysic directions RbNH 4 SO 4 crystals were studied.the refractive indices were observed to decrease under pressure.The temperature and spectral dependencies of piezooptic constants were investigated.The changes of refraction,electron polarizability and the position of ultraviolet absorption effective center were calculated.The temperature and spectral dependencies of birefringence sign inversion of the mechanically unstressed and stressed RbNH 4 SO 4 crystals were analyzed

  3. Depletion of the heaviest stable N isotope is associated with NH4+/NH3 toxicity in NH4+-fed plants

    Directory of Open Access Journals (Sweden)

    Martins-Loução Maria A

    2011-05-01

    Full Text Available Abstract Background In plants, nitrate (NO3- nutrition gives rise to a natural N isotopic signature (δ15N, which correlates with the δ15N of the N source. However, little is known about the relationship between the δ15N of the N source and the 14N/15N fractionation in plants under ammonium (NH4+ nutrition. When NH4+ is the major N source, the two forms, NH4+ and NH3, are present in the nutrient solution. There is a 1.025 thermodynamic isotope effect between NH3 (g and NH4+ (aq which drives to a different δ15N. Nine plant species with different NH4+-sensitivities were cultured hydroponically with NO3- or NH4+ as the sole N sources, and plant growth and δ15N were determined. Short-term NH4+/NH3 uptake experiments at pH 6.0 and 9.0 (which favours NH3 form were carried out in order to support and substantiate our hypothesis. N source fractionation throughout the whole plant was interpreted on the basis of the relative transport of NH4+ and NH3. Results Several NO3--fed plants were consistently enriched in 15N, whereas plants under NH4+ nutrition were depleted of 15N. It was shown that more sensitive plants to NH4+ toxicity were the most depleted in 15N. In parallel, N-deficient pea and spinach plants fed with 15NH4+ showed an increased level of NH3 uptake at alkaline pH that was related to the 15N depletion of the plant. Tolerant to NH4+ pea plants or sensitive spinach plants showed similar trend on 15N depletion while slight differences in the time kinetics were observed during the initial stages. The use of RbNO3 as control discarded that the differences observed arise from pH detrimental effects. Conclusions This article proposes that the negative values of δ15N in NH4+-fed plants are originated from NH3 uptake by plants. Moreover, this depletion of the heavier N isotope is proportional to the NH4+/NH3 toxicity in plants species. Therefore, we hypothesise that the low affinity transport system for NH4+ may have two components: one that

  4. Densities and apparent molar volumes of atmospherically important electrolyte solutions. 2. The systems H(+)-HSO4(-)-SO4(2-)-H2O from 0 to 3 mol kg(-1) as a function of temperature and H(+)-NH4(+)-HSO4(-)-SO4)2-)-H2O from 0 to 6 mol kg(-1) at 25 °C using a Pitzer ion interaction model, and NH4HSO4-H2O and (NH4)3H(SO4)2-H2O over the entire concentration range.

    Science.gov (United States)

    Clegg, S L; Wexler, A S

    2011-04-21

    A Pitzer ion interaction model has been applied to the systems H(2)SO(4)-H(2)O (0-3 mol kg(-1), 0-55 °C) and H(2)SO(4)-(NH(4))(2)SO(4)-H(2)O (0-6 mol kg(-1), 25 °C) for the calculation of apparent molar volume and density. The dissociation reaction HSO(4)(-)((aq)) ↔ H(+)((aq)) + SO(4)(2-)((aq)) is treated explicitly. Apparent molar volumes of the SO(4)(2-) ion at infinite dilution were obtained from part 1 of this work, (1) and the value for the bisulfate ion was determined in this study from 0 to 55 °C. In dilute solutions of both systems, the change in the degree of dissociation of the HSO(4)(-) ion with concentration results in much larger variations of the apparent molar volumes of the solutes than for conventional strong (fully dissociated) electrolytes. Densities and apparent molar volumes are tabulated. Apparent molar volumes calculated using the model are combined with other data for the solutes NH(4)HSO(4) and (NH(4))(3)H(SO(4))(2) at 25 °C to obtain apparent molar volumes and densities over the entire concentration range (including solutions supersaturated with respect to the salts).

  5. X-ray and neutron single crystal diffraction on (NH4)3H(SO4)2. II. Refinement of crystal structure of phase II at room temperature

    International Nuclear Information System (INIS)

    Reehuis, M.; Wozniak, K.; Dominiak, P.; Smirnov, L.S.; Natkaniec, I.; Baranov, A.I.; Dolbinina, V.V.

    2006-01-01

    The (NH 4 ) 3 H(SO 4 ) 2 is of special interest due to the possible influence of ammonium ions on a series of phase transitions: I => II => III => IV => V => VII. Earlier, the X-ray single crystal diffraction study of phase II of (NH 4 ) 3 H(SO 4 ) 2 showed that the crystal structure of this compound has two crystallographically independent groups of ammonium ions NH 4 (1) and NH 4 (2), but orientational positions of these ammonium ions were not determined exactly. The refinement of NH 4 (1) and NH 4 (2) orientational positions in phase II is carried out with the help of the X-ray and neutron single crystal diffraction study. The analyses of differential Fourier maps of electron charge density and nuclear density point out the possibility of disordering of NH 4 (2) ammonium ions

  6. Effects of urea and (NH4)2SO4 on nitrification and acidification of Ultisols from southern China.

    Science.gov (United States)

    Tong, Deli; Xu, Renkou

    2012-01-01

    The mechanisms for the effects of ammonium-based fertilizers on soil acidification in subtropical regions are not well understood. Two Ultisols collected from cropland and a tea garden in Anhui and Jiangxi Provinces in subtropical southern China, respectively, were used to study the effects of urea and (NH4)2SO4 on the nitrification and acidification of soils with incubation experiments. Nitrification occurred at very low pH with no N fertilizer added and led to lowering of the soil pH by 0.53 and 0.30 units for the soils from Jiangxi and Anhui, respectively. Addition of urea accelerated nitrification and soil acidification in both Ultisols; while nitrification was inhibited by the addition of (NH4)2SO4, and greater input of (NH4)2SO4 led to greater inhibition of nitrification. Ammonia-oxidizing bacteria (AOB) played an important role in nitrification in cropland soil under acidic conditions. Addition of urea increased the soil pH at the early stages of incubation due to hydrolysis and stimulated the increase in the AOB population, and thus accelerated nitrification and soil acidification. At the end of incubation, the pH of Ultisol from Jiangxi had decreased by 1.25, 1.54 and 1.84 units compared to maximum values for the treatments with 150, 300 and 400 mg/kg of urea-N added, respectively; the corresponding figures were 0.95, 1.25 and 1.69 for the Ultisol from Anhui. However, addition of (N-H4)2SO4 inhibited the increase in the AOB population and thus inhibited nitrification and soil acidification. Soil pH for the treatments with 300 and 400 mg/kg of (NH4)2SO4-N remained almost constant during the incubation. AOB played an important role in nitrification of the cropland soil under acidic conditions. Addition of urea stimulated the increase in the AOB population and thus accelerated nitrification and soil acidification; while addition of (NH4)2SO4 inhibited the increase in the AOB population and thus inhibited nitrification.

  7. Effect of NaCl-Stress on Metabolism of NO3-, NH4+ and NO2- at Several Rice Varieties

    Directory of Open Access Journals (Sweden)

    M Zulman Harja Utama

    2010-09-01

    Full Text Available This study was conducted to evaluate the effect of NaCl-stress on metabolism of NO3-, NH4+ and NO2- at several rice varieties. The results showed that an addition of NaCl had lesser effect on NaCl-tolerant varieties as compared to NaCl-sensitive in term of reduction in NO3-, NH4+, and NO2- uptake. Rice adaptation ability to NaCl stress occurred through the mechanism of NO3-, NH4+, and N02- metabolism physiology. It was indicated by the difference concentration of NO3-, NH4+ and N02- between the tolerant (Cisadane, moderate (Batang Lembang, Rendah Kuning, and Batang Piaman and sensitive (IR 66 varieties. Concentration of NH4+ and N02- of tolerant rice (Cisadane at NaCl treatment were about 1.16 and 2.6 times higher than that at control, respectively, while concentration of NO3- was only 0.03 times lower than control. In contrast, concentration of NO3-, NH4+, and N02- of sensitive rice (IR 66, were about 0.09, 0.27, and 0.41 times lower than that in control respecting at NaCl treatment, respectively.

  8. Biochar produced from oak sawdust by Lanthanum (La)-involved pyrolysis for adsorption of ammonium (NH4(+)), nitrate (NO3(-)), and phosphate (PO4(3-)).

    Science.gov (United States)

    Wang, Zhanghong; Guo, Haiyan; Shen, Fei; Yang, Gang; Zhang, Yanzong; Zeng, Yongmei; Wang, Lilin; Xiao, Hong; Deng, Shihuai

    2015-01-01

    A series of biochars were prepared by pyrolyzing oak sawdust with/without LaCl3 involvement at temperature of 300-600 °C, and approximate and ultimate analyses were carried out to check their basic characteristics. Meanwhile, the releases of readily soluble NH4(+), NO3(-) and PO4(3-) from biochars and the adsorption of NH4(+), NO3(-) and PO4(3-) by biochars were investigated. Results indicated that the involvement of LaCl3 in pyrolysis could advance the temperature of maximum mass loss by 10 °C compared with oak sawdust (CK), and potentially promoted biochar yield. Overall, the releases of readily soluble NH4(+), NO3(-) and PO4(3-) from biochars were negatively related to pyrolysis temperature, and the releases were greatly weakened by La-biochars. Additionally, the adsorption to NH4(+) can be promoted by the biochars produced at low temperature. On the contrary, the NO3(-) adsorption can be improved by increasing pyrolysis temperature. The highest PO4(3-) adsorption was achieved by the biochars produced at 500 °C. According to the results of adsorption isotherms, the maximum adsorption capacity of NH4(+), NO3(-) and PO4(3-) can be significantly promoted by 1.9, 11.2, and 4.5 folds using La-biochars. Based on the observations of FT-IR, SEM-EDS, and surface functional groups, the improvement of NH4(+) adsorption was potentially associated with the existing acidic function groups (phenolic-OH and carboxyl C=O). The increased basic functional groups on La-biochars were beneficial to improve NO3(-) and PO4(3-) adsorption. Besides, PO4(3-) adsorption was also potentially related to the formed La2O3. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Rate constants of the equilibrium reactions SO⨪4 + HNO3 ⇄ HSO-4 + NO3 and SO⨪4 + NO-3SO2-4 + NO3

    DEFF Research Database (Denmark)

    Løgager, T.; Sehested, K.; Holcman, J.

    1993-01-01

    Rate constants of the following equilibrium reactions were determined by pulse radiolysis at high solute concentrations: SO4.- + HNO, half arrow right over half arrow left HSO4- + NO3. [k(f) = (2.7 +/- 0.5) x 10(6) M-1 s-1, k(r) = (5.6 +/- 1.0) x 10(3) M-1 s-1] and SO4.- + NO3- half arrow right...

  10. Trends of NO-, NO 2-, and NH 3-emissions from gasoline-fueled Euro-3- to Euro-4-passenger cars

    Science.gov (United States)

    Heeb, Norbert V.; Saxer, Christian J.; Forss, Anna-Maria; Brühlmann, Stefan

    Vehicular emissions of reactive nitrogen compounds (RNCs) such as nitric oxide (NO), nitrogen dioxide (NO 2), and ammonia (NH 3) have a substantial impact on urban air quality. NO and NO 2 support the photochemical formation of ozone, and NH 3 is involved in the atmospheric formation of secondary aerosols. Vehicular NO is mainly formed during combustion, whereas NO 2 and NH 3 are both secondary pollutants of the catalytic converter systems. Herein we report on tail-pipe RNC emissions of gasoline-fueled Euro-3- and Euro-4-passenger cars at transient driving from 0 to 150 km h -1. Two sets of 10 in-use vehicles with comparable engine size and mileage were studied with time-resolved chemical ionization-mass spectrometry (CI-MS). Each vehicle was tested in 7 different driving cycles including the legislative European (EDC) and the US FTP-75 driving cycles. Mean emission factors (EFs) for different traffic situations are reported and effects of cold start, velocity, acceleration, and deceleration are discussed. Furthermore, critical operating conditions supporting the de novo formation of NH 3 have been identified. In the EDC, mean NO- and NH 3-EFs of 57±26 and 16±12 mg km -1 were obtained for Euro-3-vehicles; those of the Euro-4-technology were lower by about 25% and 33% at the levels of 43±46 and 10±7 mg km -1, respectively. NO 2 emissions of the investigated three-way catalyst (TWC) vehicles accounted for exhaust. Velocity and acceleration had pronounced effects on the RNC emission characteristics. Mean velocity-dependent EFs for NO and NH 3 varied by about one order of magnitude from 10 to 74 and 15 to 161 mg km -1 for Euro-3-vehicles and from 12 to 44 and 7 to 144 mg km -1 for the Euro-4 fleet. We conclude that the investigated Euro-3- and Euro-4-vehicles are mainly operated under slightly reducing conditions, where the NH 3 emissions dominate over those of the NO. Under these conditions, both vehicle fleets on an average fulfilled the valid Euro-3 and Euro-4

  11. Gold(I) Complexes with N-Donor Ligands. 2.(1) Reactions of Ammonium Salts with [Au(acac-kappaC(2))(PR(3))] To Give [Au(NH(3))L](+), [(AuL)(2)(&mgr;(2)-NH(2))](+), [(AuL)(4)(&mgr;(4)-N)](+), or [(AuL)(3)(&mgr;(3)-O)](+). A New and Facile Synthesis of [Au(NH(3))(2)](+) Salts. Crystal Structure of [{AuP(C(6)H(4)OMe-4)(3)}(3)(&mgr;(3)-O)]CF(3)SO(3).

    Science.gov (United States)

    Vicente, José; Chicote, María-Teresa; Guerrero, Rita; Jones, Peter G.; Ramírez De Arellano, M. Carmen

    1997-09-24

    The complexes [Au(acac-kappaC(2))(PR(3))] (acac = acetylacetonate, R = Ph, C(6)H(4)OMe-4) react with (NH(4))ClO(4) to give amminegold(I), [Au(NH(3))(PR(3))]ClO(4), amidogold(I), [(AuPR(3))(2)(&mgr;(2)-NH(2))]ClO(4), or nitridogold(I), [(AuPR(3))(4)(&mgr;(4)-N)]ClO(4), complexes, depending on the reaction conditions. Similarly, [Au(acac-kappaC(2))(PPh(3))] reacts with (NH(3)R')OTf (OTf = CF(3)SO(3)) (1:1) or with [H(3)N(CH(2))(2)NH(2)]OTf (1:1) to give (amine)gold(I) complexes [Au(NH(2)R')(PPh(3))]OTf (R' = Me, C(6)H(4)NO(2)-4) or [(AuPPh(3))(2){&mgr;(2)-H(2)N(CH(2))(2)NH(2)}](OTf)(2), respectively. The ammonium salts (NH(2)R'(2))OTf (R' = Et, Ph) react with [Au(acac-kappaC(2))(PR(3))] (R = Ph, C(6)H(4)OMe-4) (1:2) to give, after hydrolysis, the oxonium salts [(AuPR(3))(3)(&mgr;(3)-O)]OTf (R = Ph, C(6)H(4)OMe-4). When NH(3) is bubbled through a solution of [AuCl(tht)] (tht = tetrahydrothiophene), the complex [Au(NH(3))(2)]Cl precipitates. Addition of [Au(NH(3))(2)]Cl to a solution of AgClO(4) or TlOTf leads to the isolation of [Au(NH(3))(2)]ClO(4) or [Au(NH(3))(2)]OTf, respectively. The crystal structure of [(AuPR(3))(3)(&mgr;(3)-O)]OTf.Me(2)CO (R = C(6)H(4)OMe-4) has been determined: triclinic, space group P&onemacr;, a = 14.884(3) Å, b = 15.828(3) Å, c = 16.061(3) Å, alpha = 83.39(3) degrees, beta = 86.28(3) degrees, gamma = 65.54(3) degrees, R1 (wR2) = 0.0370 (0.0788). The [(AuPR(3))(3)(&mgr;(3)-O)](+) cation shows an essentially trigonal pyramidal array of three gold atoms and one oxygen atom with O-Au-P bond angles of ca. 175 degrees and Au.Au contacts in the range 2.9585(7)-3.0505(14) Å. These cations are linked into centrosymmetric dimers through two short Au.Au [2.9585(7), 3.0919(9) Å] contacts. The gold atoms of the dimer form a six-membered ring with a chair conformation.

  12. Systems of Na/sup +/NO/sub 3/, Na/sub 2/SO/sub 4/, RbNO/sub 3/, Rb/sub 2/SO/sub 4/-H/sub 2/O and NaNO/sub 3/, Na/sub 2/SO/sub 4/, CsNO/sub 3/, Cs/sub 2/SO/sub 4/-H/sub 2/O at 25 and 75 deg C

    Energy Technology Data Exchange (ETDEWEB)

    Poletaev, I F; Krasnenkova, L V

    1975-08-01

    Quaternary Na/sup +/, Rb/sup +///NO/sub 3/-, SO/sub 4//sup 2 -/-H/sub 2/O and Nsub(+), Cs/sup +///NO/sub 3/-, SO/sub 4//sup 2 -/-H/sub 2/O mutual systems have been studied isothermally. The following six fields of crystallization have been revealed in these systems at 25 deg C: Cs/sub 2/SO/sub 4/, Na/sub 2/SO/sub 4/, Na/sub 2/SO/sub 4/x10H/sub 2/O, NaNO/sub 3/xNa/sub 2/SO/sub 4/x2H/sub 2/O, NaNO/sub 3/, and CsNO/sub 3/.

  13. Effects of NO3(-) and NH4(+) and urea on each other's uptake and incorporation

    Science.gov (United States)

    Huffaker, R. C.; Ward, M. R.

    1986-01-01

    The purpose was to determine the optimal use by wheat plants of the N sources expected from processing biological waste products, NO3(-),NO2(-)NH4(+), and urea. The approach was to determine the uptake and metabolic products of each N source (from single and multiple component solutions), inhibitory effects of each, feedback inhibition, and overall in vivo regulation of the rates of assimilation of each by wheat plants. Previously, researchers determined the interactions of NO3(-),NO2(-),NH4(+) on each other's uptake and incorporation. The assimilation and some of its effects on NO3(-) and NH4(+) assimilation which have been completed to data are discussed.

  14. Appropriate NH4+: NO3- ratio improves low light tolerance of mini Chinese cabbage seedlings.

    Science.gov (United States)

    Hu, Linli; Liao, Weibiao; Dawuda, Mohammed Mujitaba; Yu, Jihua; Lv, Jian

    2017-01-23

    In northwest of China, mini Chinese cabbage (Brassica pekinensis) is highly valued by consumers, and is widely cultivated during winter in solar-greenhouses where low light (LL) fluence (between 85 and 150 μmol m -2 s -1 in day) is a major abiotic stress factor limiting plant growth and crop productivity. The mechanisms with which various NH 4 + : NO 3 - ratios affected growth and photosynthesis of mini Chinese cabbage under normal (200 μmol m -2 s -1 ) and low (100 μmol m -2 s -1 ) light conditions was investigated. The four solutions with different ratios of NH 4 + : NO 3 - applied were 0:100, 10:90, 15:85 and 25:75 with the set up in a glasshouse in hydroponic culture. The most appropriate NH 4 + : NO 3 - ratio that improved the tolerance of mini Chinese cabbage seedlings to LL was found in our current study. Under low light, the application of NH 4 + : NO 3 - (10:90) significantly stimulated growth compared to only NO 3 - by increasing leaf area, canopy spread, biomass accumulation, and net photosynthetic rate. The increase in net photosynthetic rate was associated with an increase in: 1) maximum and effective quantum yield of PSII; 2) activities of Calvin cycle enzymes; and 3) levels of mRNA relative expression of several genes involved in Calvin cycle. In addition, glucose, fructose, sucrose, starch and total carbohydrate, which are the products of CO 2 assimilation, accumulated most in the cabbage leaves that were supplied with NH 4 + : NO 3 - (10:90) under LL condition. Low light reduced the carbohydrate: nitrogen (C: N) ratio while the application of NH 4 + : NO 3 - (10:90) alleviated the negative effect of LL on C: N ratio mainly by increasing total carbohydrate contents. The application of NH 4 + :NO 3 - (10:90) increased rbcL, rbcS, FBA, FBPase and TK expression and/or activities, enhanced photosynthesis, carbohydrate accumulation and improved the tolerance of mini Chinese cabbage seedlings to LL. The results of this study would provide

  15. Modulated crystal structures of VII and V phases in (NH4)3H(SO4)2. I. Neutron Laue diffraction

    International Nuclear Information System (INIS)

    McIntyre, G.; Smirnov, L.S.; Baranov, A.I.; Dolbinina, V.V.; Frontas'eva, M.V.; Pavlov, S.S.; Pankratova, Yu.S.

    2010-01-01

    The study of crystal structures of VII and V phases of (NH 4 ) 3 H(SO 4 ) 2 by means of neutron Laue diffraction is carried out at temperatures from 5 to 300 K. It is found that crystal structures of VII and V phases have incommensurate modulation with different periods, and phase transition from phase VII to phase V is transition of the first type

  16. Aquaporin 4 as a NH3 Channel

    DEFF Research Database (Denmark)

    Assentoft, Mette; Kaptan, Shreyas; Schneider, Hans-Peter

    2016-01-01

    -brain-interface, participate in the exchange of ammonia, which is required to sustain the glutamate-glutamine cycle. Here we observe that AQP4-expressing Xenopus oocytes display a reflection coefficient NH4Cl at pH 8.0, at which pH an increased amount of the ammonia occurs in the form of NH3 Taken together with an NH4......Cl-mediated intracellular alkalization (or lesser acidification) of AQP4-expressing oocytes, these data suggest that NH3 is able to permeate the pore of AQP4. Exposure to NH4Cl increased the membrane currents to a similar extent in uninjected oocytes and in oocytes expressing AQP4, indicating...... that the ionic NH4 (+) did not permeate AQP4. Molecular dynamics simulations revealed partial pore permeation events of NH3 but not of NH4 (+) and a reduced energy barrier for NH3 permeation through AQP4 compared with that of a cholesterol-containing lipid bilayer, suggesting AQP4 as a favored transmembrane...

  17. Characteristics of NH4+ and NO3- fluxes in tea (Camellia sinensis) roots measured by scanning ion-selective electrode technique.

    Science.gov (United States)

    Ruan, Li; Wei, Kang; Wang, Liyuan; Cheng, Hao; Zhang, Fen; Wu, Liyun; Bai, Peixian; Zhang, Chengcai

    2016-12-05

    As a vital beverage crop, tea has been extensively planted in tropical and subtropical regions. Nitrogen (N) levels and forms are closely related to tea quality. Based on different N levels and forms, we studied changes in NO 3 - and NH 4 + fluxes in tea roots utilizing scanning ion-selective electrode technique. Our results showed that under both single and mixed N forms, influx rates of NO 3 - were much lower than those of NH 4 + , suggesting a preference for NH 4 + in tea. With the increase in N concentration, the influx rate of NO 3 - increased more than that of NH 4 + . The NH 4 + influx rates in a solution without NO 3 - were much higher than those in a solution with NO 3 - , while the NO 3 - influx rates in a solution without NH 4 + were much lower than those in a solution with NH 4 + . We concluded that (1) tea roots showed a preference for NH 4 + , (2) presence of NO 3 - had a negative effect on NH 4 + influx, and (3) NH 4 + had a positive effect on NO 3 - influx. Our findings not only may help advance hydroponic tea experiments but also may be used to develop efficient fertilization protocols for soil-grown tea in the future.

  18. NO3-/NH4+ ratios affect nutritional homeostasis and production of Tanzania guinea grass under Cu toxicity.

    Science.gov (United States)

    de Souza Junior, João Cardoso; Nogueirol, Roberta Corrêa; Monteiro, Francisco Antonio

    2018-05-01

    Nitrogen (N) can alleviate metal toxicity. However, as of yet, there have been no studies showing the efficacy of NO 3 - /NH 4 + in mitigating Cu toxicity. The objective of this study was to evaluate the Cu toxicity on the nutritional and productive attributes of Panicum maximum cv. Tanzania as well as the role of NO 3 - and NH 4 + ratios in nutritional homeostasis. The experiment was conducted using 3 × 4 factorial treatments arranged in a randomized complete block design with three replicates. The treatments were three NO 3 - /NH 4 + ratios (100/0, 70/30, and 50/50) and four Cu rates (0.3, 250, 500, and 1000 μmol L -1 ) in nutrient solution. Copper concentrations in the diagnostic leaves (DL) were highest in plants grown under 70/30 NO 3 - /NH 4 + ratios and a Cu rate of 1000 μmol L -1 . In this combination, it was observed that DL had higher concentrations of NH 4 + , greater glutamine synthetase activity, lower chlorophyll concentration (SPAD value), and lower shoot dry mass, suggesting high disorders of nutritional homeostasis. Plants receiving N in the form of NO 3 - and 1000 Cu μmol L -1 showed that DL had lower concentrations of Cu, higher concentration of chlorophyll, higher NO 3 - concentration, higher nitrate reductase activity, and higher NO 3 - accumulation in the roots, suggesting a reduction in disorders of nutritional homeostasis. The disorders on mineral uptake, N assimilation, and biomass production caused by Cu toxicity are shown to be affected by NO 3 - /NH 4 + ratios, and N supply via NO 3 - allowed for better homeostasis of the forage grass.

  19. Increase in Ice Nucleation Efficiency of Feldspars, Kaolinite and Mica in Dilute NH3 and NH4+-containing Solutions

    Science.gov (United States)

    Kumar, A.; Marcolli, C.; Luo, B.; Krieger, U. K.; Peter, T.

    2017-12-01

    Semivolatile species present in the atmosphere are prone to adhere to mineral dust particle surfaces during long range transport, and could potentially change the particle surface properties and its ice nucleation (IN) efficiency. Immersion freezing experiments were performed with microcline (K-feldspar), known to be highly IN active, suspended in aqueous solutions of ammonia, (NH4)2SO4, NH4HSO4, NH4NO3, NH4Cl, Na2SO4, H2SO4, K2SO4 and KCl to investigate the effect of solutes on the IN efficiency. Freezing of emulsified droplets investigated with a differential scanning calorimeter (DSC) showed that the heterogeneous ice nucleation temperatures deviate from the water activity-based IN theory, describing heterogeneous ice nucleation temperatures as a function of solution water activity by a constant offset with respect to the ice melting point curve (Zobrist et al. 2008). IN temperatures enhanced up to 4.5 K were observed for very dilute NH3 and NH4+-containing solutions while a decrease was observed as the concentration was further increased. For all solutes with cations other than NH4+, the IN efficiency decreased. An increase of the IN efficiency in very dilute NH3 and NH4+-containing solutions followed by a decrease with increasing concentration was also observed for sanidine (K-feldspar) and andesine (Na/Ca-feldspar). This is an important indication towards specific chemical interactions between solutes and the feldspar surface which is not captured by the water activity-based IN theory. A similar trend is present but less pronounced in case of kaolinite and mica, while quartz is barely affected. We hypothesize that the hydrogen bonding of NH3 molecules with surface -OH groups could be the reason for the enhanced freezing temperatures in dilute ammonia and ammonium containing solutions as they could form an ice-like overlayer providing hydrogen bonding groups for ice to nucleate on top of it. This implies to possibilities of enhanced IN efficiency, especially

  20. Effect of cationic substitution on the double-well hydrogen-bond potential in [K1-x(NH4)x]3H(SO4)2 proton conductors: a single-crystal neutron diffraction study.

    Science.gov (United States)

    Choudhury, R R; Chitra, R; Selezneva, E V; Makarova, I P

    2017-10-01

    The structure of the mixed crystal [K 1-x (NH 4 ) x ] 3 H(SO 4 ) 2 as obtained from single-crystal neutron diffraction is compared with the previously reported room-temperature neutron structure of crystalline K 3 H(SO 4 ) 2 . The two structures are very similar, as indicated by the high value of their isostructurality index (94.8%). It was found that the replacement of even a small amount (3%) of K + with NH 4 + has a significant influence on the short strong hydrogen bond connecting the two SO 4 2- ions. Earlier optical measurements had revealed that the kinetics of the superionic transition in the solid solution [K 1-x (NH 4 ) x ] 3 H(SO 4 ) 2 are much faster than in K 3 H(SO 4 ) 2 ; this reported difference in the kinetics of the superionic phase transition in this class of crystal is explained on the basis of the difference in strength of the hydrogen-bond interactions in the two structures.

  1. Comparison of field data with a thermodynamic model for the H/sub 2/SO/sub 4/ - HNO/sub 3/ - NH/sub 3/ system at high humidities and in fogs

    Energy Technology Data Exchange (ETDEWEB)

    Jacob, D.J.; Munger, J.W.; Waldman, J.M.; Hoffmann, M.R.

    1986-04-01

    A systematic characterization of the atmospheric H/sub 2/SO/sub 4/ - NH/sub 2/ system was conducted in the fogwater, the aerosol, and the gas phase at a network of sites in the San Joaquin Valley of California. Spatial patterns of concentrations were established that reflect the distribution of SO/sub 2/, NO/sub X/, and NH/sub 3/ emissions within the valley. The concept of atmospheric alkalinity was introduced to interpret these concentrations in terms of the buffering capacity of the atmosphere with respect to inputs of strong acids. Regions of predominantly acidic and alkaline fogwater were identified. Fogwater was found to be alkaline in most of the valley, but small changes in emission budgets could lead to widespread acid fog. An extended stagnation episode was studied in detail: progressive accumulation of H/sub 2/SO/sub 4/ - HNO/sub 3/ - NH/sub 3/ species was documented over the course of the episode, and interpreted in terms of production and removal mechanisms. Secondary production of strong acids H/sub 2/SO/sub 4/ and HNO/sub 3/ under stagnant conditions resulted in a complete titration of available alkalinity at sites furthest from NH/sub 3/ sources. A steady SO/sub 2/ conversion rate of 0.4 - 1.1% h/sup -1/ was estimated in the stagnant mixed layer of haze aerosol under overcast conditions, and was attributed to non-photochemical heterogeneous processes. Removal of SO/sub 2/ was enhanced in fog as compared to non-foggy conditions. Conversion of NO/sub X/ to HNO/sub 3/ slowed down during the stagnation episode because of reduced photochemical activity: fog did not appear to enhance conversion of NO/sub X/. Decreases in total HNO/sub 3/ concentrations were observed upon acidification of the atmosphere, and were attributed to displacement of NO/sub 3-/ by H/sub 2/SO/sub 4/ in the aerosol followed by rapid deposition of HNO/sub 3/(g). The occurrence of fog was associated with general decreases of aerosol concentrations due to enhanced removal by deposition.

  2. Photocrystallographic structure determination of a new geometric isomer of [Ru(NH3)4(H2O)(eta1-OSO)][MeC6H4SO3]2.

    Science.gov (United States)

    Bowes, Katharine F; Cole, Jacqueline M; Husheer, Shamus L G; Raithby, Paul R; Savarese, Teresa L; Sparkes, Hazel A; Teat, Simon J; Warren, John E

    2006-06-21

    The structure of a new metastable geometric isomer of [Ru(NH3)4(H2O)(SO2)][MeC6H4SO3]2 in which the SO2 group is coordinated through a single oxygen in an eta1-OSO bonding mode has been determined at 13 K; the new isomer was obtained as a 36% component of the structure within a single crystal upon irradiation using a tungsten lamp.

  3. Catalytic reduction of NH4NO3 by NO. Effects of solid acids and implications for low temperature DeNOx processes

    International Nuclear Information System (INIS)

    Savara, Aditya; Li, Mei-Jun; Sachtler, Wolfgang M.H.; Weitz, Eric

    2008-01-01

    Ammonium nitrate is thermally stable below 250 C and could potentially deactivate low temperature NO x reduction catalysts by blocking active sites. It is shown that NO reduces neat NH 4 NO 3 above its 170 C melting point, while acidic solids catalyze this reaction even at temperatures below 100 C. NO 2 , a product of the reduction, can dimerize and then dissociate in molten NH 4 NO 3 to NO + + NO 3 - , and may be stabilized within the melt as either an adduct or as HNO 2 formed from the hydrolysis of NO + or N 2 O 4 . The other product of reduction, NH 4 NO 2 , readily decomposes at ≤100 C to N 2 and H 2 O, the desired end products of DeNO x catalysis. A mechanism for the acid catalyzed reduction of NH 4 NO 3 by NO is proposed, with HNO 3 as an intermediate. These findings indicate that the use of acidic catalysts or promoters in DeNO x systems could help mitigate catalyst deactivation at low operating temperatures (<150 C). (author)

  4. Characteristics of NH4+ and NO3− fluxes in tea (Camellia sinensis) roots measured by scanning ion-selective electrode technique

    Science.gov (United States)

    Ruan, Li; Wei, Kang; Wang, Liyuan; Cheng, Hao; Zhang, Fen; Wu, Liyun; Bai, Peixian; Zhang, Chengcai

    2016-01-01

    As a vital beverage crop, tea has been extensively planted in tropical and subtropical regions. Nitrogen (N) levels and forms are closely related to tea quality. Based on different N levels and forms, we studied changes in NO3− and NH4+ fluxes in tea roots utilizing scanning ion-selective electrode technique. Our results showed that under both single and mixed N forms, influx rates of NO3− were much lower than those of NH4+, suggesting a preference for NH4+ in tea. With the increase in N concentration, the influx rate of NO3− increased more than that of NH4+. The NH4+ influx rates in a solution without NO3− were much higher than those in a solution with NO3−, while the NO3− influx rates in a solution without NH4+ were much lower than those in a solution with NH4+. We concluded that (1) tea roots showed a preference for NH4+, (2) presence of NO3− had a negative effect on NH4+ influx, and (3) NH4+ had a positive effect on NO3− influx. Our findings not only may help advance hydroponic tea experiments but also may be used to develop efficient fertilization protocols for soil-grown tea in the future. PMID:27918495

  5. [Isolation and purification of alpha-glycerophosphate oxidase in a polyethylene glycol/(NH4 )2SO4 aqueous two-phase system].

    Science.gov (United States)

    Meng, Yao; Jin, Jiagui; Liu, Shuangfeng; Yang, Min; Zhang, Qinglian; Wan, Li; Tang, Kun

    2014-02-01

    Alpha-glycerophosphate oxidase (alpha-GPO) from Enterococcus casseli flavus was successfully isolated and purified by using polyethylene glycol (PEG)/(NH4)2SO4 aqueous two-phase system (ATPS). The results showed that the chosen PEG/(NH4)2SO4 ATPS could be affected by PEG molecular weight, pH, concentration of PEG and (NH4)2SO4, and inorganic salt as well as additional amount of crude enzyme. After evaluating these influencing factors, the final optimum purification strategy was formed by 16.5% (m/m) PEG2000, 13.2% (m/m) (NH4)2SO4, pH 7.5 and 30% (m/m) additive crude enzyme, respectively. The NaCl was a negative influencing factor which would lead to lower purification fold and activity recovery. These conditions eventually resulted in the activity recovery of 89% (m/m), distribution coefficient of 1.2 and purification fold of 7.0.

  6. In vitro growth of Brassocattleya orchid hybrid in different concentrations of KNO3, NH4NO3 and benzylaminopurine Cultivo in vitro de Brassocattleya (Orchidaceae em diferentes concentrações de KNO3, NH4NO3 e benzilaminopurina

    Directory of Open Access Journals (Sweden)

    Jean C Cardoso

    2011-09-01

    Full Text Available One of the most important applications of plant tissue culture is mass propagation of ornamental plants. This experiment evaluated the effect of different concentrations of NH4NO3 and KNO3 and BAP on the in vitro growth of orchid hybrid Brassocattleya 'Pastoral'. Seedlings of this orchid hybrid were used as explants and cultivated in medium with mineral salts and vitamins from the MS medium (Murashige & Skoog, 1962, with the macronutrients P, Ca and Mg reduced by half, and with an addition of 25 g L-1 of sucrose, 0.1 g L-1 of myo-inositol and 1.5 g L-1 of activated charcoal. Agar-agar was added (6.5 g L-1 and the pH was adjusted to 5.8. As treatments, four concentrations of the NH4NO3 and KNO3 (2x; 1x; ½ and ¼ MS medium and three concentrations of BAP (0.0; 0.5 and 1.0 mg L-1 were assayed. The multiplication, growth in height, fresh and dry weight and sugar level in dry weight of sprouts were evaluated. There occurred a higher growth in height with 0.25x NH4NO3 and KNO3 salts concentrations of MS medium and higher rate of multiplication with combination of NH4NO3 and KNO3 reduced by half of the MS medium concentration and 1.0 mg L-1 BAP.Entre as maiores aplicações da cultura de tecidos de plantas está a propagação massal de mudas de plantas ornamentais. O objetivo deste trabalho foi avaliar o cultivo in vitro de um híbrido de orquídea Brassocattleya em diferentes concentrações de NH4NO3, KNO3 e BAP. Foram utilizadas sementes do híbrido de orquídea Brassocattleya 'Pastoral' e as plantas foram cultivadas em meio MS com redução pela metade das fontes de P, Mg e Ca e adição de 25 g L-1 de sacarose, 100 mg L-1 de mio-inositol, 1,5 g L-1 de carvão ativo e 6,5 g L-1 de ágar-ágar, sendo o pH ajustado para 5,8. Como tratamentos foram usados quatro concentrações dos sais NH4NO3 e KNO3 (2x; 1x; ½ e ¼ do meio MS e três concentrações de BAP (0,0; 0,5 e 1,0 mg L-1. Avaliou-se a multiplicação, o crescimento em altura, massa fresca

  7. Different fates of deposited NH4+ and NO3- in a temperate forest in northeast China: a 15 N tracer study.

    Science.gov (United States)

    Liu, Jun; Peng, Bo; Xia, Zongwei; Sun, Jianfei; Gao, Decai; Dai, Weiwei; Jiang, Ping; Bai, Edith

    2017-06-01

    Increasing atmospheric reactive nitrogen (N) deposition due to human activities could change N cycling in terrestrial ecosystems. However, the differences between the fates of deposited NH4+ and NO3- are still not fully understood. Here, we investigated the fates of deposited NH4+ and NO3-, respectively, via the application of 15 NH 4 NO 3 and NH 4 15 NO 3 in a temperate forest ecosystem. Results showed that at 410 days after tracer application, most 15NH4+ was immobilized in litter layer (50 ± 2%), while a considerable amount of 15NO3- penetrated into 0-5 cm mineral soil (42 ± 2%), indicating that litter layer and 0-5 cm mineral soil were the major N sinks of NH4+ and NO3-, respectively. Broad-leaved trees assimilated more 15 N under NH 4 15 NO 3 treatment compared to under 15 NH 4 NO 3 treatment, indicating their preference for NO3--N. At 410 days after tracer application, 16 ± 4% added 15 N was found in aboveground biomass under 15NO3- treatment, which was twice more than that under 15NH4+ treatment (6 ± 1%). At the same time, approximately 80% added 15 N was recovered in soil and plants under both treatments, which suggested that this forest had high potential for retention of deposited N. These results provided evidence that there were great differences between the fates of deposited NH4+ and NO3-, which could help us better understand the mechanisms and capability of forest ecosystems as a sink of reactive nitrogen. © 2016 John Wiley & Sons Ltd.

  8. Electrochemical formation of GaAs honeycomb structure using a fluoride-containing (NH{sub 4}){sub 2}SO{sub 4} solution

    Energy Technology Data Exchange (ETDEWEB)

    Morishita, Yoshitaka, E-mail: morisita@cc.tuat.ac.jp; Yamamoto, Hitoshi; Yokobori, Kuniyuki

    2014-04-01

    GaAs substrates were anodized in the (NH{sub 4}){sub 2}SO{sub 4} electrolyte with various fluoride concentrations. Scanning electron microscope (SEM) observation showed that highly regular honeycomb hollows were formed on the substrates anodized in the (NH{sub 4}){sub 2}SO{sub 4} electrolyte with a small amount of HF concentration. The regularity of hollows decreased with the increase of HF concentration. The average diameter of hollows increased with increasing anodizing voltage. The regularity of hollow diameters increased with the increase of anodizing time, irrespective of the anodizing voltage. Cross-sectional SEM image showed that the average depth of regular hollows was about 5 nm. In addition to the peak in the region of fundamental adsorption of GaAs with the peak wavelength at about 870 nm, photoluminescence spectra of samples anodized in the (NH{sub 4}){sub 2}SO{sub 4} electrolyte with HF concentration of 0.5 ml showed several peaks at about 610, 635, 670 and 720 nm. - Highlights: • We report on the electrochemical formation of GaAs honeycomb structure. • High regular hollows were formed by anodization in HF-containing (NH{sub 4}){sub 2}SO{sub 4} solution. • A thin porous layer was formed by anodization in HF-containing (NH{sub 4}){sub 2}SO{sub 4} solution. • This process is useful for preparing patterned substrate with a thin porous layer.

  9. Leach of the weathering crust elution-deposited rare earth ore for low environmental pollution with a combination of (NH4)2SO4 and EDTA.

    Science.gov (United States)

    Tang, Jie; Qiao, Jiyang; Xue, Qiang; Liu, Fei; Chen, Honghan; Zhang, Guochen

    2018-05-01

    High concentration of ammonium sulfate, a typical leaching agent, was often used in the mining process of the weathering crust elution-deposited rare earth ore. After mining, a lot of ammonia nitrogen and labile heavy metal fractions were residual in tailings, which may result in a huge potential risk to the environment. In this study, in order to achieve the maximum extraction of rare earth elements and reduce the labile heavy metal, extraction effect and fraction changes of lanthanum (La) and lead (Pb) in the weathering crust elution-deposited rare earth ore were studied by using a compound agent of (NH 4 ) 2 SO 4 -EDTA. The extraction efficiency of La was more than 90% by using 0.2% (NH 4 ) 2 SO 4 -0.005 M EDTA, which was almost same with that by using 2.0% (NH 4 ) 2 SO 4 solution. In contrast, the extraction efficiency of Pb was 62.3% when use 0.2% (NH 4 ) 2 SO 4 -0.005 M EDTA, which is much higher than that (16.16%) achieved by using 2.0% (NH 4 ) 2 SO 4 solution. The released Pb fractions were mainly acid extractable and reducible fractions, and the content of reducible fraction being leached accounted for 70.45% of the total reducible fraction. Therefore, the use of 0.2% (NH 4 ) 2 SO 4 -0.005 M EDTA can not only reduce the amount of (NH 4 ) 2 SO 4 , but also decrease the labile heavy metal residues in soil, which provides a new way for efficient La extraction with effective preventing and controlling environmental pollution in the process of mining the weathering crust elution-deposited rare earth ore. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Comparative study of wheat utilization of NH4 and NO3 as sources of N-fertilizer using N15 technique

    International Nuclear Information System (INIS)

    Khalifa, Kh.

    1993-05-01

    Two field experiments were conducted separately on wheat (Cultivar ACSAD-65) in 1987/1988 at the Research Station of Arabic Center for the Studies of Arid Zones and Dry Lands (ACSAD) in Deir-Ezzor, Using N 15 methodology to compare the efficient utilization of N 15 -NO 3 and N 15 -N H 4 radicals as sources of nitrogen applied in three different levels (50, 100 and 200 Kg N/ha and two placement methods (Top-dressed and Side-dressed). The results indicate that Ndff % in the from of N 15 -NH 4 was higher than N 15 -NO 3 in both placements, at different growth stages, consequently, when using N-NH 4 form, N-uptake was higher than N-NO 3 form; the efficiency of N-NH 4 was higher than N-NO 3 in most cases regardless of the method of placement; the rate of applied nitrogen in both forms (N-NH 4 and N-NO 3 ) had higher effect on yield more than the placements; side-dressed placement had higher effect on the efficiency of the utilization of N-NO 3 and N-NH 4 as well as on crop yield than the Top-dressed; using N-NO 3 , A-values in the three growth stages of crop at the nitrogen levels used, were higher than using N-NH 4 in both placements; and finally using N-NO 3 in the second and third stages of crop growth, the yield was higher than using N-NH 4 and almost similar in the first stages. (author). 9 refs., 26 tabs

  11. A novel method of simultaneous NH4+ and NO3- removal using Fe cycling as a catalyst: Feammox coupled with NAFO.

    Science.gov (United States)

    Li, Xiang; Yuan, Yan; Huang, Yong; Liu, Heng-Wei; Bi, Zhen; Yuan, Yi; Yang, Peng-Bin

    2018-08-01

    The feasibility of using Feammox coupled with nitrate-dependent Fe(II) oxidizing (NAFO) to cause the simultaneous conversion of NH 4 + and NO 3 - was explored by inoculation with Feammox sludge and the use Fe cycling as catalyst. After 61days operation, the simultaneous conversion of NO 3 - and NH 4 + occurred with the presence of interconversion between Fe(III) and Fe(II). The conversion ratio of NH 4 + to NO 3 - stabilized at 0.9-1. The results of isotopic tracing and microbial diversity analysis indicated that NH 4 + was first oxidized to NO 2 - by Fe(III), then NO 3 - was reduced to NO 2 - and N 2 by the Fe(II) produced in Feammox process, and finally, the NO 2 - produced in NAFO process underwent an Anammox process with the remaining NH 4 + to yield N 2 . The results showed the simultaneous continuous conversion process of NO 3 - and NH 4 + with limited Fe as a catalyst was a coupled process of Feammox, Anammox, and NAFO under the anaerobic conditions. Copyright © 2018 Elsevier B.V. All rights reserved.

  12. NH3 and NH4+ permeability in aquaporin-expressing Xenopus oocytes

    DEFF Research Database (Denmark)

    Holm, Lars M.; Jahn, Thomas Paul; Møller, Anders Laurell Blom

    2005-01-01

    We have shown recently, in a yeast expression system, that some aquaporins are permeable to ammonia. In the present study, we expressed the mammalian aquaporins AQP8, AQQP9, AQP3, AQP1 and a plant aquaporin TIP2;1 in Xenopus oocytes to study the transport of ammonia (NH3) and ammonium (NH4+) under...... inwards currents carried by NH4+. This conductivity increased as a sigmoid function of external [NH3]: for AQP8 at a bath pH (pH(e)) of 6.5, the conductance was abolished, at pH(e) 7.4 it was half maximal and at pH(e) 7.8 it saturated. NY4+ influx was associated with oocyte swelling. In comparison, native...... oocytes as well as AQP1 and tip2;1-expressing oocytes showed small currents that were associated with small and even negative volume changes. We conclude that AQP8, AQP9, AQP3, and TIP2;1, apart from being water channels, also support significant fluxes of NH3. These aquaporins could support NH4...

  13. Crystal structure of NH4[La(SO42(H2O

    Directory of Open Access Journals (Sweden)

    Meriem Benslimane

    2015-06-01

    Full Text Available The principal building units in the crystal structure of ammonium aquabis(sulfatolanthanate(III are slightly distorted SO4 tetrahedra, LaO9 polyhedra in the form of distorted tricapped trigonal prisms, and NH4+ ions. The La3+ cation is coordinated by eight O atoms from six different sulfate tetrahedra, two of which are bidentate coordinating and four monodentate, as well as one O atom from a water molecule; each sulfate anion bridges three La3+ cations. These bridging modes result in the formation of a three-dimensional anionic [La(SO42(H2O]− framework that is stabilized by O—H...O hydrogen-bonding interactions. The disordered ammonium cations are situated in the cavities of this framework and are hydrogen-bonded to six surrounding O atoms.

  14. Different transport behaviors of NH4 (+) and NH3 in transmembrane cyclic peptide nanotubes.

    Science.gov (United States)

    Zhang, Mingming; Fan, Jianfen; Xu, Jian; Weng, Peipei; Lin, Huifang

    2016-10-01

    Two water-filled transmembrane cyclic peptide nanotubes (CPNTs) of 8×cyclo-(WL)n=4,5/POPE were chosen to investigate the dependences of the transport properties of the positive NH4 (+) and neutral NH3 on the channel radius. Molecular dynamic simulations revealed that molecular charge, size, ability to form H-bonds and channel radius all significantly influence the behaviors of NH4 (+) and NH3 in a CPNT. Higher electrostatic interactions, more H-bonds, and water-bridges were found in the NH4 (+) system, resulting in NH4 (+) meeting higher energy barriers, while NH3 can enter, exit and permeate the channels effortlessly. This work sheds a first light on the differences between the mechanisms of NH4 (+) and NH3 moving in a CPNT at an atomic level. Graphical Abstract Snapshot of the simulation system of NH4 (+)_octa-CPNT with an NH4 (+) initially positioned at one mouth of the tube, PMF profiles for single NH4 (+) ion and NH3 molecule moving through water-filled transmembrane CPNTs of 8×cyclo-(WL)n=4,5/POPE and sketch graphs of the possible H-bond forms of NH3 and NH4 (+) with the neighboring water.

  15. Reconstruction of spatially detailed global map of NH4+ and NO3- application in synthetic nitrogen fertilizer

    Science.gov (United States)

    Nishina, Kazuya; Ito, Akihiko; Hanasaki, Naota; Hayashi, Seiji

    2017-02-01

    Currently, available historical global N fertilizer map as an input data to global biogeochemical model is still limited and existing maps were not considered NH4+ and NO3- in the fertilizer application rates. This paper provides a method for constructing a new historical global nitrogen fertilizer application map (0.5° × 0.5° resolution) for the period 1961-2010 based on country-specific information from Food and Agriculture Organization statistics (FAOSTAT) and various global datasets. This new map incorporates the fraction of NH4+ (and NO3-) in N fertilizer inputs by utilizing fertilizer species information in FAOSTAT, in which species can be categorized as NH4+- and/or NO3--forming N fertilizers. During data processing, we applied a statistical data imputation method for the missing data (19 % of national N fertilizer consumption) in FAOSTAT. The multiple imputation method enabled us to fill gaps in the time-series data using plausible values using covariates information (year, population, GDP, and crop area). After the imputation, we downscaled the national consumption data to a gridded cropland map. Also, we applied the multiple imputation method to the available chemical fertilizer species consumption, allowing for the estimation of the NH4+ / NO3- ratio in national fertilizer consumption. In this study, the synthetic N fertilizer inputs in 2000 showed a general consistency with the existing N fertilizer map (Potter et al., 2010) in relation to the ranges of N fertilizer inputs. Globally, the estimated N fertilizer inputs based on the sum of filled data increased from 15 to 110 Tg-N during 1961-2010. On the other hand, the global NO3- input started to decline after the late 1980s and the fraction of NO3- in global N fertilizer decreased consistently from 35 to 13 % over a 50-year period. NH4+-forming fertilizers are dominant in most countries; however, the NH4+ / NO3- ratio in N fertilizer inputs shows clear differences temporally and geographically. This

  16. The influence of NO3- and NH4+ on the sites of nitrogen assimilation of F1 hybrid cauliflower (Brassica oleracea. L. botrytis)

    International Nuclear Information System (INIS)

    Asiah Ahmad; Parsons, R.; Md Razi Ismail

    2002-01-01

    The sites of Nitrogen assimilation of Fl hybrid cauliflower (Brassica oleracea L.) grown in vermiculite: pearlite on either NO 3 or NH 4 nutrition was investigated using 15 N techniques. Labelling studies using 15 NO 3 Or 15 NH 4 alone to follow a time course of 15 NO 3 or 15 NH 4 incorporated into amino compounds in Fl hybrid cauliflower was conducted over periods of up to 24 hours. The 15 N enrichment of amino compounds in various plant parts was measured using GC-MS and isotopic abundance mass spectrometry techniques. In roots of 15 NH 4 -N fed plant, the 15 N label rapidly appears in glutamate at high enrichment within 30 minutes and increased substantially up to 6 hours after feeding. The labelled glutamate appears to decrease slowly after 6 hours. In leaves, the glutamate shows much lower labelling within 30 minutes than in the roots and became slowly enriched 6 hours after feeding. Labelled glutamate was only detected in the curd 6 hours later. This may indicate that in NH 4 -N fed plants, most NH 4 is assimilated in the roots and translocated as amino acids to the leaves and curd. In contrast to 15 NO 3 -N fed plant, both the roots and leaves showed significant label in glutamate within 30 minutes and subsequently increased in labelled enrichment over the time period of 6 hours. The leaves contained higher labelled glutamate than the roots. The labelled glutamate in the leaves decreased significantly at 24 hours after feeding. Label was incorporated in glutamate at low level in the curd after 2 hours and became highly enriched at 6 and 24 hours after feeding. Thus in NO 3 -N fed plants, NO 3 reduction and assimilation occurred both in root and leaf which mainly occur in the leaf. Therefore differences in the response of plant growth to NO3 - and NH 4 + nutrition observed in other studies could be due to the fact that NO 3 is primarily assimilated in the leaf whereas NH 4 is root based. No significant labelling was found in serine in both roots of 15 NH 4 -N

  17. Cs2SO4-Pr2(SO4)3-H2O and NiSO4-Pr2(SO4)3-H2O systems at 75 deg C

    International Nuclear Information System (INIS)

    Onishchenko, M.K.; Skorikov, V.M.; Shevchuk, V.G.; AN SSSR, Moscow. Inst. Obshchej i Neorganicheskoj Khimii)

    1979-01-01

    To investigate physico-chemical properties of equilibrium saturated solutions and to elucidate the chemical changes under way, the aqueous systems of cesium, nickel and praseodymium (3) sulfates are studied. The method of isothermal saturation of salts at 75 deg C is used. It has been found that in the system Cs 2 SO 4 -Pr 2 (SO 4 ) 3 -H 2 O in a wide concentration range the soluble binary salt Cs 2 SO 4 xPr 2 (SO 4 ) 3 csytallizes in a congruent way. For the system NiSO 4 -Pr 2 (SO 4 ) 3 -H 2 O a solubility curve of the eutonic type is obtained, there being no chemical interaction between the components. The solubility isotherms for the system are given

  18. Reassessment of the NH4 NO3 thermal decomposition technique for calibration of the N2 O isotopic composition.

    Science.gov (United States)

    Mohn, Joachim; Gutjahr, Wilhelm; Toyoda, Sakae; Harris, Eliza; Ibraim, Erkan; Geilmann, Heike; Schleppi, Patrick; Kuhn, Thomas; Lehmann, Moritz F; Decock, Charlotte; Werner, Roland A; Yoshida, Naohiro; Brand, Willi A

    2016-09-08

    In the last few years, the study of N 2 O site-specific nitrogen isotope composition has been established as a powerful technique to disentangle N 2 O emission pathways. This trend has been accelerated by significant analytical progress in the field of isotope-ratio mass-spectrometry (IRMS) and more recently quantum cascade laser absorption spectroscopy (QCLAS). Methods The ammonium nitrate (NH 4 NO 3 ) decomposition technique provides a strategy to scale the 15 N site-specific (SP ≡ δ 15 N α - δ 15 N β ) and bulk (δ 15 N bulk  = (δ 15 N α  + δ 15 N β )/2) isotopic composition of N 2 O against the international standard for the 15 N/ 14 N isotope ratio (AIR-N 2 ). Within the current project 15 N fractionation effects during thermal decomposition of NH 4 NO 3 on the N 2 O site preference were studied using static and dynamic decomposition techniques. The validity of the NH 4 NO 3 decomposition technique to link NH 4 + and NO 3 - moiety-specific δ 15 N analysis by IRMS to the site-specific nitrogen isotopic composition of N 2 O was confirmed. However, the accuracy of this approach for the calibration of δ 15 N α and δ 15 N β values was found to be limited by non-quantitative NH 4 NO 3 decomposition in combination with substantially different isotope enrichment factors for the conversion of the NO 3 - or NH 4 + nitrogen atom into the α or β position of the N 2 O molecule. The study reveals that the completeness and reproducibility of the NH 4 NO 3 decomposition reaction currently confine the anchoring of N 2 O site-specific isotopic composition to the international isotope ratio scale AIR-N 2 . The authors suggest establishing a set of N 2 O isotope reference materials with appropriate site-specific isotopic composition, as community standards, to improve inter-laboratory compatibility. This article is protected by copyright. All rights reserved.

  19. X-ray and neutron single-crystal diffraction on [Rbx(NH4)1-x]3H(SO4)2. I. Refinement of crystal structure of phase II with x=0.11 at 300 K

    International Nuclear Information System (INIS)

    Loose, A.; Wozniak, K.; Dominiak, P.; Smirnov, L.S.; Natkaniec, I.; Frontas'eva, M.V.; Pomyakushina, E.V.; Baranov, A.I.; Dolbinina, V.V

    2006-01-01

    The study of [Rb x (NH 4 ) 1-x ] 3 H(SO 4 ) 2 mixed crystals by X-ray single-crystal diffraction is known up to now only for x=0.57 at the temperatures 293 and 180 K. The crystal structures at these temperatures as was determined [1] belong to monoclinic phase II (C2/c sp. gr., Z=4). In accordance with this work, ammonium ions should be considered as deformed tetrahedra. Monoclinic phase II on the x-T phase diagram of [Rb x (NH 4 ) 1-x ] 3 H(SO 4 ) 2 mixed crystals, which has earlier been determined by the dielectric spectroscopy, is stabilized below room temperature if Rb concentration exceeds 9%. The presented results of X-ray and neutron single-crystal diffraction of the [Rb 0.11 (NH 4 ) 0.89 ] 3 H(SO 4 ) 2 mixed crystal at T= 300 K show that ammonium ions could be considered as regular tetrahedra

  20. Efeitos de relações CaSO4/CaCO3 na mobilidade de nutrientes no solo e no crescimento do algodoeiro

    Directory of Open Access Journals (Sweden)

    A. A. Silva

    1998-09-01

    Full Text Available O experimento, realizado em casa de vegetação no Departamento de Ciência do Solo da Universidade Federal de Lavras, teve por objetivo estudar o efeito de diferentes relações de CaSO4/CaCO3, que simulam o uso de gesso e calcário, na movimentação de nutrientes no solo e no crescimento do algodoeiro, cultivar IAC-20. As proporções de CaSO4/CaCO3 utilizadas foram: 0/100, 25/75, 50/50, 75/25 e 100/0, com base em peso equivalente, além de um tratamento-testemunha, sem aplicação de CaSO4 e CaCO3. Observou-se acentuada movimentação de cálcio e de sulfato em profundidade, como íons acompanhantes, com o aumento da relação CaSO4/CaCO3. Para o N-NO3- e Mg2+, ao contrário do N-NH4+ e K+, observou-se um acúmulo em profundidade, com a elevação da relação CaSO4/CaCO3. Neste estudo, o gesso teve pouco ou nenhum efeito sobre a acidez e Al trocável presentes nas camadas subsuperficiais. A produção de matéria seca do algodoeiro foi reduzida com o aumento da relação CaSO4/CaCO3, porém, quando comparada à do tratamento-testemunha, a aplicação de gesso aumentou-a significativamente, atestando o potencial de uso do gesso agrícola.

  1. Comparison of NH4+-N and NO3--N nutrition in hybrid and conventional rice at the late growth stage

    International Nuclear Information System (INIS)

    Yang Xiaoe; Sun Xi

    1990-01-01

    The difference of NH 4 + -N/NO 3 - -N nutrition between hybrid and conventional rice varieties at the late growth stage was studied by using 15 N-tracer technique. The results showed that the nitrate fertilizer utilization efficiency by the hybrid rice after anthesis was 7.8% higher than that by the ordinary rice variety, and the nitrate fertilizer recovery fraction by the former was 13.2% greater than that by the latter. The varietal difference in NO 3 - -N uptake and utilization was almost twice as that in NH 4 + -N. It was also showed that 15 N distribution in ear of the hybrid rice was about 20% greater than that of the conventional variety, but there were no obvious differences between NO 3 - -N and NH 4 + -N. However, 15 N distribution in the lower node leaves and root was found to be significant higher with NO 3 - -N than that with NH 4 + -N in both rice varieties, particularly in the hybrid rice. Compared with NH 4 + -N, NO 3 - -N top-dressing before anthesis was observed to have much greater positive effects on the uptake of calcium and magnesium and the growth of the superficial root and the grain yield of the tested rice varieties, especially of the hybrid rice

  2. FTIR studies of plasticized poly(vinyl alcohol)-chitosan blend doped with NH 4NO 3 polymer electrolyte membrane

    Science.gov (United States)

    Kadir, M. F. Z.; Aspanut, Z.; Majid, S. R.; Arof, A. K.

    2011-03-01

    Fourier transform infrared (FTIR) spectroscopy studies of poly(vinyl alcohol) (PVA), and chitosan polymer blend doped with ammonium nitrate (NH 4NO 3) salt and plasticized with ethylene carbonate (EC) have been performed with emphasis on the shift of the carboxamide, amine and hydroxyl bands. 1% acetic acid solution was used as the solvent. It is observed from the chitosan film spectrum that evidence of polymer-solvent interaction can be observed from the shifting of the carboxamide band at 1660 cm -1 and the amine band at 1591 cm -1 to 1650 and 1557 cm -1 respectively and the shift of the hydroxyl band from 3377 to 3354 cm -1. The hydroxyl band in the spectrum of PVA powder is observed at 3354 cm -1 and is observed at 3343 cm -1 in the spectrum of the PVA film. On addition of NH 4NO 3 up to 30 wt.%, the carboxamide, amine and hydroxyl bands shifted from 1650, 1557 and 3354 cm -1 to 1642, 1541 and 3348 cm -1 indicating that the chitosan has complexed with the salt. In the PVA-NH 4NO 3 spectrum, the hydroxyl band has shifted from 3343 to 3272 cm -1 on addition of salt from 10 to 30 wt.%. EC acts as a plasticizing agent since there is no shift in the bands as observed in the spectrum of PVA-chitosan-EC films. The mechanism of ion migration is proposed for the plasticized and unplasticized PVA-chitosan-NH 4NO 3 systems. In the spectrum of PVA-chitosan-NH 4NO 3-EC complex, the doublet C dbnd O stretching in EC is observed in the vicinity 1800 and 1700. This indicates that there is some interaction between the salt and EC.

  3. The uptake of NO3-, NO2-, and NH4+ by intact wheat (Triticum aestivum) seedlings. I. Induction and kinetics of transport systems

    Science.gov (United States)

    Goyal, S. S.; Huffaker, R. C.

    1986-01-01

    The inducibility and kinetics of the NO3-, NO2-, and NH4+ transporters in roots of wheat seedlings (Triticum aestivum cv Yercora Rojo) were characterized using precise methods approaching constant analysis of the substrate solutions. A microcomputer-controlled automated high performance liquid chromatography system was used to determine the depletion of each N species (initially at 1 millimolar) from complete nutrient solutions. Uptake rate analyses were performed using computerized curve-fitting techniques. More precise estimates were obtained for the time required for the extent of the induction of each transporter. Up to 10 and 6 hours, respectively, were required to achieve apparent full induction of the NO3- and NO2- transporters. Evidence for substrate inducibility of the NH4+ transporters requiring 5 hours is presented. The transport of NO3- was mediated by a dual system (or dual phasic), whereas only single systems were found for transport of NO2- and NH4+. The Km values for NO3-, NO2-, and NH4+ were, respectively, 0.027, 0.054, and 0.05 millimolar. The Km for mechanism II of NO3- transport could not be defined in this study as it exhibited only apparent first order kinetics up to 1 millimolar.

  4. Modeling impacts of NH3 on uptake of H2SO4 by charged nucleating nanoparticles in the Earth's atmosphere

    International Nuclear Information System (INIS)

    Nadykto, A. B.; Nazarenko, K. M.; Markov, P. N.; Yu, F.

    2016-01-01

    The understanding of the role of ammonia, a well-known stabilizer of binary sulfuric acid-water clusters, in the gas-to-nanoparticle conversion in the Earth atmosphere is critically important for the assessment of aerosol radiative forcing associated with the climate changes. The sulfuric acid H 2 SO 4 is present in the atmosphere in the form of the gas-phase hydrates (H 2 SO 4 )(H 2 O) n , whose interaction with NH 3 leads to the formation of more stable bisulfate clusters (NH 3 )(H 2 SO 4 )(H 2 O) n . Although the impact of NH 3 on the thermochemical stability of binary clusters nucleating homogeneously has been studied in some detail in the past, the effect of ammonia on other microphysical properties relevant to nucleation remains insufficiently well understood. In the present study, the effect of ammonia on the electrical dipole moment controlling the nucleation of airborne ions via the dipole-charge interaction has been investigated using the Density Functional Theory (DFT), ab initio MP2 and model chemistry G3 methods. The presence of ammonia in (H 2 SO 4 )(H 2 O) n is found to lead to very large enhancement in the dipole moment, which exceeds 2.0-2.5 Debyes (∼60-80%), 3.7-5.0 Debyes (∼90-180%), 1.4-4.5 Debyes (∼50-150%) and 2.1-5.5 Debyes (∼60-700%) for n = 0, n = 1, n = 2 and n = 3, respectively. The implications of this include the significantly increased uptake of the sulfuric acid, the key atmospheric nucleation precursor, by airborne ions and neutrals (due to dipole-dipole interaction), enhanced nucleation rates and the elevated production of ultrafine particles, which cause adverse health impacts.

  5. NH{sub 4}-doped anodic WO{sub 3} prepared through anodization and subsequent NH{sub 4}OH treatment for water splitting

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yong-Wook; Kim, Sunkyu; Seong, Mijeong; Yoo, Hyeonseok; Choi, Jinsub, E-mail: jinsub@inha.ac.kr

    2015-01-01

    Highlights: • NN{sub 4}-doped WO{sub 3} was successfully fabricated by a wet-based method using ammonium hydroxide (NH{sub 4}OH). • (NH{sub 4}){sub 10}W{sub 12}O{sub 41} phase was formed during the NH{sub 4}OH treatment. • Over-doped NH{sub 4} in WO{sub 3} led to reduced photo-electrochemical performance for OER. • The optimized surface was achieved by thermal treatment of anodic WO{sub 3} with 2 g of NH{sub 4}OH solution. - Abstract: Tungsten trioxide (WO{sub 3}) prepared by anodization of a W foil was doped with NH{sub 4} through NH{sub 4}OH treatment at 450 °C. Since aqueous NH{sub 4}OH was used during doping instead of NH{sub 3} gas, the treatment step does not require complicated annealing facilities. Moreover, the state of doped N is a form of NH{sub 3}-W instead of W{sub 2}N, which lowers the bandgap but increases photocorrosion. We found that incorporation of NH{sub 4} into WO{sub 3} leads to reduction of the bandgap from 2.9 eV to 2.2 eV, regardless of the amount of NH{sub 4}OH treatment, lowering the onset potential and increasing the current density at fixed potential for oxygen evolution reaction under illumination. Scanning electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy were employed to investigate the surface morphologies, crystallinities of tungsten oxides and existence of NH{sub 4} doping, respectively. The bandgap energy was determined by UV–Vis spectroscopy to measure the transmittance and refraction. The water splitting performance of each sample was measured by electrochemical linear sweep voltammetry in a 3-electrode configuration under illumination.

  6. Avaliação da liberação de NH4NO3 ocluido em zeólita 4A a partir de soluções salinas Assessment of release of NH4NO3 occluded zeolite 4A in solutions from salinas

    Directory of Open Access Journals (Sweden)

    Jardel Cavalcante Rolim de Almeida Andrade

    2010-01-01

    Full Text Available The zeolite 4A was used to evaluate the thermo kinetics parameters of NH4+ and NO3- ions occluded in its structure. The Osawa method for activation energy calculation was used to evaluate its thermal stability, and the results shown that the ion species interact differently depending on the zeolite pores, which determines the controlled release by its structure.

  7. The effects of H2SO4 and (NH42SO4 treatments on the chemistry of soil drainage water and pine seedlings in forest soil microcosms

    Directory of Open Access Journals (Sweden)

    M. I. Stutter

    2004-01-01

    Full Text Available An experiment comparing effects of sulphuric acid and reduced N deposition on soil water quality and on chemical and physical growth indicators for forest ecosystems is described. Six H2SO4 and (NH42SO4 treatment loads, from 0 – 44 and 0 – 25 kmolc ha-1 yr-1, respectively, were applied to outdoor microcosms of Pinus sylvestris seedlings in 3 acid to intermediate upland soils (calc-silicate, quartzite and granite for 2 years. Different soil types responded similarly to H2SO4 loads, resulting in decreased leachate pH, but differently to reduced N inputs. In microcosms of calc-silicate soil, nitrification of NH4 resulted in lower pH and higher cation leaching than in acid treatments. By contrast, in quartzite and granite soils, (NH42SO4 promoted direct cation leaching, although leachate pH increased. The results highlighted the importance of soil composition on the nature of the cations leached, the SO4 adsorption capacities and microbial N transformations. Greater seedling growth on calc-silicate soils under both treatment types was related to sustained nutrient availability. Reductions in foliar P and Mg with higher N treatments were observed for seedlings in the calc-silicate soil. There were few treatment effects on quartzite and granite microcosm tree seedlings since P limitation precluded seedling growth responses to treatments. Hence, any benefits of N deposition to seedlings on quartzite and granite soils appeared limited by availability of co-nutrients, exacerbated by rapid depletion of soil exchangeable base cations. Keywords: acidification, manipulation, nitrogen, ammonium, deposition, soil, drainage, pine, microcosms, forest

  8. MINERAL NITROGEN SOURCES (N-NO3- AND N-NH4+ ON GROWTH OF GRÁPIA (Apuleia leiocarpa (Vog. Macbride SEEDLINGS

    Directory of Open Access Journals (Sweden)

    Fernando Teixeira Nicoloso

    2010-08-01

    Full Text Available Grápia (Apuleia leiocarpa (Vog. Macbride is an important native forest species that has been in extinction process. The aim of this study was to evaluate the effect of mineral nitrogen source on growth of grápia seedlings. Five variations in the concentration of N-NO3- and N-NH4+ (5:0, 4:1, 2,5:2,5, 1:4, and 0:5 mM of N were tested in an entirely random statistical design with 16 replicates. The experimental unity consisted of a vessel containing 3,0 kg of a Paleudalf soil and two plants, under glasshouse conditions. From 60 to 150 days after fertilization (DAF, the plant growth and soil pH were monthly analyzed from four replicates randomly taken. Independently of the nitrogen source used, the soil pH decreased, and on 150 DAF the smallest pH variation was 0.33 and the largest one was 0.47 pH units, respectively, on treatments with 5 N-NO3-:0 N-NH4+ and 0 N-NO3-:5 N-NH4+ ratios. The presence of N-NH4+, from 1 to 5 mM, induced necrosis in old leaves and their ulterior abscission. To 150 DAF, in the presence of 5 mM N-NH4+, the plant survival was reduced to 31%. The effect of nitrogen sources on plant growth appeared to be depended on plant age and/or of their transformations in the soil. To 120 DAF, the presence of N-NH4+ from 2,5 to 5 mM reduced the number of stalk nodes, plant height, stem diameter, dry weight of leaves, of stem, of roots, and of the whole plant. However, to 150 DAF, because of the regain on the growth rate, these differences were not observed, with exception of the root/shoot dry weight ratio that was reduced on the exclusive presence of N-NH4+. The suitable N-NO3-:N-NH4+ ratio in the fertilization to grow grápia seedlings, can not exceed, respectively, 4:1.

  9. Nitrogen uptake by wheat seedlings, interactive effects of four nitrogen sources: NO3-, NO2-, NH4+, and urea

    Science.gov (United States)

    Criddle, R. S.; Ward, M. R.; Huffaker, R. C.

    1988-01-01

    The net influx (uptake) rates of NO3-, NH4+, NO2-, and urea into roots of wheat (Triticum aestivum cv Yecora Rojo) seedlings from complete nutrient solutions containing all four compounds were monitored simultaneously. Although urea uptake was too slow to monitor, its presence had major inhibitory effects on the uptake of each of the other compounds. Rates of NO3-, NH4+, and NO2- uptake depended in a complex fashion on the concentration of all four N compounds. Equations were developed which describe the uptake rates of each of the compounds, and of total N, as functions of concentrations of all N sources. Contour plots of the results show the interactions over the range of concentrations employed. The coefficients of these equations provide quantitative values for evaluating primary and interactive effects of each compound on N uptake.

  10. Role of NH3 and NH4+ transporters in renal acid-base transport.

    Science.gov (United States)

    Weiner, I David; Verlander, Jill W

    2011-01-01

    Renal ammonia excretion is the predominant component of renal net acid excretion. The majority of ammonia excretion is produced in the kidney and then undergoes regulated transport in a number of renal epithelial segments. Recent findings have substantially altered our understanding of renal ammonia transport. In particular, the classic model of passive, diffusive NH3 movement coupled with NH4+ "trapping" is being replaced by a model in which specific proteins mediate regulated transport of NH3 and NH4+ across plasma membranes. In the proximal tubule, the apical Na+/H+ exchanger, NHE-3, is a major mechanism of preferential NH4+ secretion. In the thick ascending limb of Henle's loop, the apical Na+-K+-2Cl- cotransporter, NKCC2, is a major contributor to ammonia reabsorption and the basolateral Na+/H+ exchanger, NHE-4, appears to be important for basolateral NH4+ exit. The collecting duct is a major site for renal ammonia secretion, involving parallel H+ secretion and NH3 secretion. The Rhesus glycoproteins, Rh B Glycoprotein (Rhbg) and Rh C Glycoprotein (Rhcg), are recently recognized ammonia transporters in the distal tubule and collecting duct. Rhcg is present in both the apical and basolateral plasma membrane, is expressed in parallel with renal ammonia excretion, and mediates a critical role in renal ammonia excretion and collecting duct ammonia transport. Rhbg is expressed specifically in the basolateral plasma membrane, and its role in renal acid-base homeostasis is controversial. In the inner medullary collecting duct (IMCD), basolateral Na+-K+-ATPase enables active basolateral NH4+ uptake. In addition to these proteins, several other proteins also contribute to renal NH3/NH4+ transport. The role and mechanisms of these proteins are discussed in depth in this review.

  11. Process for uranium separation and preparation of UO4.2NH3.2HF

    International Nuclear Information System (INIS)

    Dokuzoguz, H.Z.

    1976-01-01

    A process for treating the aqueous effluents that are produced in converting gaseous UF 6 (uranium hexafluoride) into solid UO 2 (uranium dioxide) by way of an intermediate (NH 4 ) 4 UO 2 (CO 3 ) 3 (''AUC'' Compound) is disclosed. These effluents, which contain large amounts of NH 4 + , CO 3 2- , F - , and a small amount of U are mixed with H 2 SO 4 (sulfuric acid) in order to expel CO 2 (carbon dioxide) and thereby reduce the carbonate concentration. The uranium is precipitated through treatment with H 2 O 2 (hydrogen peroxide) and the fluoride is easily recovered in the form of CaF 2 (calcium fluoride) by contacting the process liquid with CaO (calcium oxide). The presence of SO 4 2- (sulfate) in the process liquid during CaO contacting seems to prevent the development of a difficult-to-filter colloid. The process also provides for NH 3 recovery and recycling. Liquids discharged from the process, moreover, are essentially free of environmental pollutants. The waste treatment products, i.e., CO 2 , NH 3 , and U are economically recovered and recycled back into the UF 6 → UO 2 conversion process. The process, moreover, recovers the uranium as a precipitate in the second stage. This precipitate is a new inorganic chemical compound UO 4 .2NH 3 .2HF [uranyl peroxide-2-ammonia-2-(hydrogen fluoride)

  12. Influence of chromium III ions on the electrical properties of NaNH4SO4.2H2O crystals

    International Nuclear Information System (INIS)

    Kassem, M.E.; El-Wahidy, E.F.; Hedewy, S.; Darwish, H.G.; Ramadan, T.

    1991-07-01

    The dielectric constant, ε, and electric conductivity, σ, of pure and Cr +3 doped samples of NaNH 4 SO 4 .2H 2 O are measured in the temperature range 20-300 K. The maximum value of dielectric constant in different crystallographic axes is presented and discussed. The effect of foreign ions on the critical behaviour and transition temperature T c is studied. (author). 18 refs, 2 figs, 1 tab

  13. Improved GaSb surfaces using a (NH4)2S/(NH4)2S04 solution

    International Nuclear Information System (INIS)

    Murape, D.M.; Eassa, N.; Nyamhere, C.; Neethling, J.H.; Betz, R.; Coetsee, E.; Swart, H.C.; Botha, J.R.; Venter, A.

    2012-01-01

    Bulk (1 0 0) n-GaSb surfaces have been treated with a sulphur based solution ((NH 4 ) 2 S/(NH 4 ) 2 SO 4 ) to which sulphur has been added, not previously reported for the passivation of GaSb surfaces. Au/n-GaSb Schottky barrier diodes (SBDs) fabricated on the treated material show significant improvement compared to that of the similar SBDs on the as-received material as evidenced by the lower ideality factor (n), higher barrier height (φ b ) and lower contact resistance obtained. Additionally, the reverse leakage current, although not saturating, has been reduced by almost an order of magnitude at −0.2 V. The sample surfaces were studied by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The native oxide, Sb–O, present on the as-received material is effectively removed on treating with ([(NH 4 ) 2 S/(NH 4 ) 2 SO 4 ]+S) and (NH 4 ) 2 S. Analysis of the as-received surface by XPS, prior to and after argon sputtering, suggests that the native oxide layer is ≤8.5 nm.

  14. Hyperhydricity Phenomena Problem in Embryonic Callus of Date Palm, Solving by Glutamine and NH4+: No3- Ratio in Basal Nutrient Medium

    International Nuclear Information System (INIS)

    El-Dawayaty, M.M.; Zayed, Z.E.; Abdel-Gelil, L.M.

    2012-01-01

    Hyperhydricity is a serious problem faced in vitro date palm propagation which directly effects on the commercial production. So we try to solve this problem by studying, the effect of glutamine as the organic source of nitrogen and NH 4 + :NO 3- ratio as the inorganic source of nitrogen to decrease hyperhydricity phenomena and to produce normal somatic embryos of date palm cv. Gondila.Vitrified embryonic callus were inoculated on MS basal nutrient medium modified with glutamine levels and NH 4 + : NO 3 - ratio. Five concentration ratios of NH 4 : NO 3 (10:15, 15:10, 0:20, 20:0, 0:0 ml/l) were used with 0.1 mg/l NAA for 8 weeks throughout 2 recultures. There were gradually increasing in the percentage of vitrified embryonic callus differentiation to normal somatic embryos by increasing glutamine levels from 0.0 to 400 mg/l. Glutamine at the lowest level (50 mg/l) increased significantly the number of vitrified somatic embryos. Ammonium as the sole source of N resulted in depression in somatic embryos differentiation and escalated the frequency of hyperhydricity whereas,if nitrate was used as the sole N source, somatic embryos good quality were produced and hyperhydricity was eliminated

  15. In situ attenuated total reflection infrared (ATR-IR) study of the adsorption of NO2-, NH2OH, and NH4+ on Pd/Al2O3 and Pt/Al2O3.

    NARCIS (Netherlands)

    Ebbesen, S.D.; Mojet, Barbara; Lefferts, Leonardus

    2008-01-01

    In relation to the heterogeneous hydrogenation of nitrite, adsorption of NO2-, NH4+, and NH2OH from the aqueous phase was examined on Pt/Al2O3, Pd/Al2O3, and Al2O3. None of the investigated inorganic nitrogen compounds adsorb on alumina at conditions presented in this study. NO2-(aq) and NH4+(aq) on

  16. Physiological Responses to N-NO3 and N-NH4 of Triazine Resistant and Susceptible Plants of Horseweed (Erigeron canadensis L.

    Directory of Open Access Journals (Sweden)

    Ryszard Stanek

    2013-12-01

    Full Text Available Triazine resistant and susceptible biotypes of horseweed (Erigeron canadensis L. were grown under controlled conditions in nutrient solution with NH4 or NO3 ions as nitrogen source. Indicators such as: dry matter, CO2 assimilation, chloroplasts activity, dark respiration and the content of K, Ca, Mg in the above ground parts displayed lower levels when plants were fed with NH4 than with NO ions. Reduction of these indicators was stronger for the triazine susceptible plants which grew better than their resistant counterparts when fed with N-NO3. The triazine resistant plants grown with N-NH4 contained more protein-N and K than the susceptible ones. Chloroplasts of the resistant plants were also less sensitive to NH4CL treatment. It is concluded that the resistant plants appear to be more tolerant to NH4 ions as compared with their susceptible counterparts. For this reason application of ammonium forms of nitrogen fertilization in horticultural practice could favour spreading of triazine resistant horseweed.

  17. Combined effects Na and SO{sub 2} in flue gas on Mn-Ce/TiO{sub 2} catalyst for low temperature selective catalytic reduction of NO by NH{sub 3} simulated by Na{sub 2}SO{sub 4} doping

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Aiyi [Department of Environmental Science and Engineering, Nanjing Normal University, Nanjing 210023 (China); Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing 210023 (China); Yu, Danqing [School of Chemical Engineering and Technology, Wuhan University of Science and Technology, Wuhan 430081 (China); Yang, Liu [Department of Environmental Science and Engineering, Nanjing Normal University, Nanjing 210023 (China); Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing 210023 (China); Sheng, Zhongyi, E-mail: 09377@njnu.edu.cn [Department of Environmental Science and Engineering, Nanjing Normal University, Nanjing 210023 (China); Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing 210023 (China)

    2016-08-15

    Highlights: • Sodium sulfate (Na{sub 2}SO{sub 4}) was deposited on Mn-Ce/TiO{sub 2} catalyst to simulate the co-existing of sodium and SO{sub 2} in the flue gas. • Na{sub 2}SO{sub 4} had strong and fluctuant influence on Mn-Ce/TiO{sub 2} catalyst’s performance in SCR of NOx with NH{sub 3}, due to the combined effect of the deactivation of sodium salts and the enhanced performance of ceria with surface sulfation. • The changes of the surface chemical species and acid sites on the Na{sub 2}SO{sub 4} deposited catalysts could be considered as the main reasons for the fluctuation changes with the catalytic activity. - Abstract: A series of Mn-Ce/TiO{sub 2} catalysts were synthesized through an impregnation method and used for low temperature selective catalytic reduction (SCR) of NOx with ammonia (NH{sub 3}). Na{sub 2}SO{sub 4} was added into the catalyst to simulate the combined effects of alkali metal and SO{sub 2} in the flue gas. Experimental results showed that Na{sub 2}SO{sub 4} had strong and fluctuant influence on the activity of Mn-Ce/TiO{sub 2}, because the effect of Na{sub 2}SO{sub 4} included pore occlusion and sulfation effect simultaneously. When Na{sub 2}SO{sub 4} loading content increased from 0 to 1 wt.%, the SCR activities of Na{sub 2}SO{sub 4}-doped catalysts decreased greatly. With further increasing amount of Na{sub 2}SO{sub 4}, however, the catalytic activity increased gradually. XRD results showed that Na{sub 2}SO{sub 4} doping could induce the crystallization of MnOx phases, which were also confirmed by TEM and SEM results. BET results showed that the surface areas decreased and a new bimodal mesoporous structure formed gradually with the increasing amount of Na{sub 2}SO{sub 4}. XPS results indicated that part of Ce{sup 4+} and Mn{sup 3+} were transferred to Ce{sup 3+} and Mn{sup 4+} due to the sulfation after Na{sub 2}SO{sub 4} deposition on the surface of the catalysts. When the doped amounts of Na{sub 2}SO{sub 4} increased, NH{sub 3

  18. [Effect of NH4(+) -N/NO3(-)-N ratio in applied supplementary fertilizer on nitrogen metabolism and main chemical composition of Pinellia ternata].

    Science.gov (United States)

    Hu, Long-Jiao; Wang, Kang-Cai; Li, Can-Wen

    2013-07-01

    To study the effect of nitrogen forms on nitrogen metabolism and main chemical composition of Pinellia ternate. Through the soilless cultivation experiment and based at the same nitrogen level and different NH4(+) -N/NO3(-) -N ratios, nitrate reductase (NR) activity, glutamine synthetase (GS) activity, the content of nitrate nitrogen and ammonium nitrogen in different parts of P. ternate were determined. The contents of total alkaloid, free total organic acids and guanosine in the tuber were determined. The yield of bulbil and tuber was calculated. The test results showed that, with the NH4(+) -N/NO3(-) -N ratio increasing, the activity of nitrate reductase decreased, the content of nitrate nitrogen in the leaves, petioles and tuber increasing initially, then decreased, and the content of nitrate nitrogen in the root decreased. Meanwhile, with the NH4(+) -N/NO3(-) -N ratio increasing, the activity of glutamine synthetase in the leaves, petioles and root increased, the activity of glutamine synthetase in the tuber increasing initially, then decreased. The contents of ammonium nitrogen in the leaves, tuber and root increased initially, then decreased, and the contents of ammonium nitrogen in the petioles increased with the NH4(+)(-N/NO3(-)-N ratio increasing. The yield of bulbil and tuber were the highest at the NH4(+)-N/NO3(-) -N ratio of 75: 25. The content of total alkaloid and guanosine in the tuber were the highest at the NH4(+)-N/NO3(-) -N ratio of 0: 100, and the contents were 0.245% and 0.0197% respectively. With the NH4(+)-N/NO3(-) -N ratio of 50: 50, the content of free total organic acids was the highest, it reached 0.7%, however, the content of free total organic acids was the lowest at the NH4(+) -N/NO3(-) -N ratio of 0: 100. Nitrogen fertilization significant influences the nitrogen metabolism, the yield and main chemical composition of P. ternate.

  19. [Effects of different NO3--N/NH4+-N ratios on cucumber seedlings growth, nitrogen absorption and metabolism under suboptimal temperature and light intensity].

    Science.gov (United States)

    Zhang, Xiao Cui; Liu, Yu Mei; Bai, Long Qiang; He, Chao Xing; Yu, Xian Chang; Li, Yan Su

    2016-08-01

    Cucumber (cv. Zhongnong 26) was used as material, the effects of NO 3 - -N/NH 4 + -N ratios on growth and physiological characteristics of cucumber seedlings under suboptimal temperature and light intensity (18 ℃/10 ℃,180 ± 20 μmol·m -2 ·s -1 ) were studied. Total nitrogen in the nutrient solution was equal and three NO 3 - -N/NH 4 + -N ratios, 26:2, 21:7 and 14:14, were applied as treatments. The results showed that cucumber treated by NO 3 - -N/NH 4 + -N=21:7 had the longest total root length, the biggest root volume and root surface area, and the maximum number of root tips. H + -ATPase activity and relative expression of genes encoding nitrate transporter (NRT) and ammonium transporter (AMT) in cucumber roots were increased significantly by the treatment of NO 3 - -N/NH 4 + -N=21:7. In addition, nitrate reductase (NR), glutamine synthetase (GS) and glutamate synthase (GOGAT) in cucumber leaves under the treatment of NO 3 - -N/NH 4 + -N=21:7 were higher. As a result, the nitrogen content and biomass of cucumber were significantly increased. Compared with the plants under the treatment of NO 3 - -N/NH 4 + -N=26:2 or 14:14, cucumber seedlings under the treatment of NO 3 - -N/NH 4 + -N=21:7 had the highest biomass and total dry mass (DM) which were increased by 14.0% and 19.3% respectively under suboptimal temperature and light intensity. In conclusion, under suboptimal environmental conditions, NO 3 - -N/NH 4 + -N ratio could be adjusted to increase nitrogen absorption and metabolism of cucumber and alleviate the de-trimental effects caused by suboptimal conditions and promoted the cucumber growth.

  20. Nature of phase transitions in ammonium oxofluorovanadates, a vibrational spectroscopy study of (NH4)3VO2F4 and (NH4)3VOF5.

    Science.gov (United States)

    Gerasimova, Yu V; Oreshonkov, A S; Laptash, N M; Vtyurin, A N; Krylov, A S; Shestakov, N P; Ershov, A A; Kocharova, A G

    2017-04-05

    Two ammonium oxofluorovanadates, (NH 4 ) 3 VO 2 F 4 and (NH 4 ) 3 VOF 5 , have been investigated by temperature-dependent infrared and Raman spectroscopy methods to determine the nature of phase transitions (PT) in these compounds. Dynamics of quasioctahedral groups was simulated within the framework of semi-empirical approach, which justified the cis-conformation of VO 2 F 4 3- (C 2v ) and the C 4v geometry of VOF 5 3- . The observed infrared and Raman spectra of both compounds at room temperature (RT) revealed the presence at least of two crystallographically independent octahedral groups. The first order PT at elevated temperatures is connected with a complete dynamic disordering of these groups with only single octahedral state. At lower temperatures, the octahedra are ordered and several octahedral states appear. This PT is the most pronounced in the case of (NH 4 ) 3 VOF 5 , when at least seven independent VOF 5 3- octahedra are present in the structure below 50K, in accordance with the Raman spectra. Ammonium groups do not take part in PTs at higher and room temperatures but their reorientational motion freezes at lower temperatures. Copyright © 2017. Published by Elsevier B.V.

  1. Improved GaSb surfaces using a (NH{sub 4}){sub 2}S/(NH{sub 4}){sub 2}S0{sub 4} solution

    Energy Technology Data Exchange (ETDEWEB)

    Murape, D.M., E-mail: Davison.Murape@live.nmmu.ac.za [Department of Physics, Nelson Mandela Metropolitan University, PO Box 77000, Port Elizabeth 6031 (South Africa); Eassa, N.; Nyamhere, C.; Neethling, J.H. [Department of Physics, Nelson Mandela Metropolitan University, PO Box 77000, Port Elizabeth 6031 (South Africa); Betz, R. [Department of Chemistry, Nelson Mandela Metropolitan University, PO Box 77000, Port Elizabeth 6031 (South Africa); Coetsee, E.; Swart, H.C. [Department of Physics, University of the Free State, PO Box 339, Bloemfontein 9300 (South Africa); Botha, J.R.; Venter, A. [Department of Physics, Nelson Mandela Metropolitan University, PO Box 77000, Port Elizabeth 6031 (South Africa)

    2012-05-15

    Bulk (1 0 0) n-GaSb surfaces have been treated with a sulphur based solution ((NH{sub 4}){sub 2}S/(NH{sub 4}){sub 2}SO{sub 4}) to which sulphur has been added, not previously reported for the passivation of GaSb surfaces. Au/n-GaSb Schottky barrier diodes (SBDs) fabricated on the treated material show significant improvement compared to that of the similar SBDs on the as-received material as evidenced by the lower ideality factor (n), higher barrier height ({phi}{sub b}) and lower contact resistance obtained. Additionally, the reverse leakage current, although not saturating, has been reduced by almost an order of magnitude at -0.2 V. The sample surfaces were studied by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The native oxide, Sb-O, present on the as-received material is effectively removed on treating with ([(NH{sub 4}){sub 2}S/(NH{sub 4}){sub 2}SO{sub 4}]+S) and (NH{sub 4}){sub 2}S. Analysis of the as-received surface by XPS, prior to and after argon sputtering, suggests that the native oxide layer is {<=}8.5 nm.

  2. Thermal Annealing of Paramagnetic Defects Induced by Gamma Irradiation in (NH{sub 4}){sub 2}SO{sub 4} and (ND{sub 4}){sub 2}SO{sub 4} Single Crystals: Experimental Verification of the Theory of Fletcher and Brown; Recuit Thermique des Defauts Paramagnetiques Induits par Irradiation Gamma dans des Monocristaux de (NH{sub 4}){sub 2}SO{sub 4} et (ND{sub 4}){sub 2}SO{sub 4}: Verification Experimentale de la Theorie de Fletcher et Brown; 0422 0415 0420 041c 0414 ; Regeneracion Termica de los Defectos Paramagneticos Inducidos por Irradiacion Gamma en Monocristales de (NH{sub 4}){sub 2}SO{sub 4} y (ND{sub 4}){sub 2}SO{sub 4}: Verificacion Experimental de la Teoria de Fletcher y Brown

    Energy Technology Data Exchange (ETDEWEB)

    Calusaru, A.; Barbur, I.; Ursu, I. [Institut de Physique Atomique, Bucarest (Romania); Universite ' Babes' , Cluj (Romania)

    1965-04-15

    kinetika s edinym plato, sootvetstvujushhim obshhej rekombinacii radikalov. Dlja kazhdoj izotermy predstavljaetsja vozmozhnym sostavit' sootvetstvujushhee uravnenie, ispol'zuja pri jetom funkciju oshibok, vyvedennuju Fletcherom i Braunom pri rassmotrenii modeli i rekombinacii par, vnachale korrelirovannyh, a zatem vydelennyh v sootvetstvii s processom besporjadochnogo dvizhenija. Posle ispravlenija jetoj funkcii s uchetom kojefficienta q dannaja funkcija byla privedena v sootvetstvie s opytom. Sostavnaja krivaja otzhiga ochen' horosho otrazhaet funkciju ispravlennyh oshibok. Pri primenenii fenomenologicheskogo metoda Fletchera i Brauna dlja rascheta jenergii aktivacii bylo najdeno znachenie 1,594 jev, sootvetstvujushhee pervomu radikalu v (NH{sub 4}){sub 2}SO{sub 4}. Ispol'zuja izmenenie kojefficienta diffuzii'v zavisimosti ot temperatury, dlja toj zhe jenergii aktivacii bylo ustanovleno znachenie v 1,592 jev. S pomoshh'ju metoda Vand-Primak bylo najdeno znachenie v 1,45 jev, kotoroe javljaetsja men'shim po sravneniju s dvumja predydushhimi. V zakljuchenie otmechaetsja, chto model' rekombinacii par, korrelirovannyh v sootvetstvii s processom besporjadochnogo dvizhenija, primenima v forme, privedennoj v teorii, kogda imeetsja dovol'no slaboe vzaimodejstvie mezhdu obrazovavshimisja vidami i reshetkoj; takim putem pervonachal'no korrelirovannye pary mogut byt' vydeleny. (author)

  3. Imaging a multidimensional multichannel potential energy surface: Photodetachment of H(-)(NH3) and NH4 (.).

    Science.gov (United States)

    Hu, Qichi; Song, Hongwei; Johnson, Christopher J; Li, Jun; Guo, Hua; Continetti, Robert E

    2016-06-28

    Probes of the Born-Oppenheimer potential energy surfaces governing polyatomic molecules often rely on spectroscopy for the bound regions or collision experiments in the continuum. A combined spectroscopic and half-collision approach to image nuclear dynamics in a multidimensional and multichannel system is reported here. The Rydberg radical NH4 and the double Rydberg anion NH4 (-) represent a polyatomic system for benchmarking electronic structure and nine-dimensional quantum dynamics calculations. Photodetachment of the H(-)(NH3) ion-dipole complex and the NH4 (-) DRA probes different regions on the neutral NH4 PES. Photoelectron energy and angular distributions at photon energies of 1.17, 1.60, and 2.33 eV compare well with quantum dynamics. Photoelectron-photofragment coincidence experiments indicate dissociation of the nascent NH4 Rydberg radical occurs to H + NH3 with a peak kinetic energy of 0.13 eV, showing the ground state of NH4 to be unstable, decaying by tunneling-induced dissociation on a time scale beyond the present scope of multidimensional quantum dynamics.

  4. Modeling impacts of NH{sub 3} on uptake of H{sub 2}SO{sub 4} by charged nucleating nanoparticles in the Earth's atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Nadykto, A. B., E-mail: anadykto@gmail.com [Atmospheric Science Research Center, State University of New York at Albany, 251 Fuller Road, Albany, NY 12203 (United States); Department of Applied Mathematics, Moscow State University of Technology “STANKIN”, Vadkovsky per. 1, Moscow 127055 (Russian Federation); Nazarenko, K. M.; Markov, P. N. [Department of Applied Mathematics, Moscow State University of Technology “STANKIN”, Vadkovsky per. 1, Moscow 127055 (Russian Federation); Yu, F. [Atmospheric Science Research Center, State University of New York at Albany, 251 Fuller Road, Albany, NY 12203 (United States)

    2016-06-08

    The understanding of the role of ammonia, a well-known stabilizer of binary sulfuric acid-water clusters, in the gas-to-nanoparticle conversion in the Earth atmosphere is critically important for the assessment of aerosol radiative forcing associated with the climate changes. The sulfuric acid H{sub 2}SO{sub 4} is present in the atmosphere in the form of the gas-phase hydrates (H{sub 2}SO{sub 4})(H{sub 2}O){sub n}, whose interaction with NH{sub 3} leads to the formation of more stable bisulfate clusters (NH{sub 3})(H{sub 2}SO{sub 4})(H{sub 2}O){sub n}. Although the impact of NH{sub 3} on the thermochemical stability of binary clusters nucleating homogeneously has been studied in some detail in the past, the effect of ammonia on other microphysical properties relevant to nucleation remains insufficiently well understood. In the present study, the effect of ammonia on the electrical dipole moment controlling the nucleation of airborne ions via the dipole-charge interaction has been investigated using the Density Functional Theory (DFT), ab initio MP2 and model chemistry G3 methods. The presence of ammonia in (H{sub 2}SO{sub 4})(H{sub 2}O){sub n} is found to lead to very large enhancement in the dipole moment, which exceeds 2.0-2.5 Debyes (∼60-80%), 3.7-5.0 Debyes (∼90-180%), 1.4-4.5 Debyes (∼50-150%) and 2.1-5.5 Debyes (∼60-700%) for n = 0, n = 1, n = 2 and n = 3, respectively. The implications of this include the significantly increased uptake of the sulfuric acid, the key atmospheric nucleation precursor, by airborne ions and neutrals (due to dipole-dipole interaction), enhanced nucleation rates and the elevated production of ultrafine particles, which cause adverse health impacts.

  5. Real-time observation of formation and relaxation dynamics of NH4 in (CH3OH)m(NH3)n clusters.

    Science.gov (United States)

    Yamada, Yuji; Nishino, Yoko; Fujihara, Akimasa; Ishikawa, Haruki; Fuke, Kiyokazu

    2009-03-26

    The formation and relaxation dynamics of NH4(CH3OH)m(NH3)n clusters produced by photolysis of ammonia-methanol mixed clusters has been observed by a time-resolved pump-probe method with femtosecond pulse lasers. From the detailed analysis of the time evolutions of the protonated cluster ions, NH4(+)(CH3OH)m(NH3)n, the kinetic model has been constructed, which consists of sequential three-step reaction: ultrafast hydrogen-atom transfer producing the radical pair (NH4-NH2)*, the relaxation process of radical-pair clusters, and dissociation of the solvated NH4 clusters. The initial hydrogen transfer hardly occurs between ammonia and methanol, implying the unfavorable formation of radical pair, (CH3OH2-NH2)*. The remarkable dependence of the time constants in each step on the number and composition of solvents has been explained by the following factors: hydrogen delocalization within the clusters, the internal conversion of the excited-state radical pair, and the stabilization of NH4 by solvation. The dependence of the time profiles on the probe wavelength is attributed to the different ionization efficiency of the NH4(CH3OH)m(NH3)n clusters.

  6. Rapid ammonia gas transport accounts for futile transmembrane cycling under NH3/NH4+ toxicity in plant roots.

    Science.gov (United States)

    Coskun, Devrim; Britto, Dev T; Li, Mingyuan; Becker, Alexander; Kronzucker, Herbert J

    2013-12-01

    Futile transmembrane NH3/NH4(+) cycling in plant root cells, characterized by extremely rapid fluxes and high efflux to influx ratios, has been successfully linked to NH3/NH4(+) toxicity. Surprisingly, the fundamental question of which species of the conjugate pair (NH3 or NH4(+)) participates in such fluxes is unresolved. Using flux analyses with the short-lived radioisotope (13)N and electrophysiological, respiratory, and histochemical measurements, we show that futile cycling in roots of barley (Hordeum vulgare) seedlings is predominately of the gaseous NH3 species, rather than the NH4(+) ion. Influx of (13)NH3/(13)NH4(+), which exceeded 200 µmol g(-1) h(-1), was not commensurate with membrane depolarization or increases in root respiration, suggesting electroneutral NH3 transport. Influx followed Michaelis-Menten kinetics for NH3 (but not NH4(+)), as a function of external concentration (Km = 152 µm, Vmax = 205 µmol g(-1) h(-1)). Efflux of (13)NH3/(13)NH4(+) responded with a nearly identical Km. Pharmacological characterization of influx and efflux suggests mediation by aquaporins. Our study fundamentally revises the futile-cycling model by demonstrating that NH3 is the major permeating species across both plasmalemma and tonoplast of root cells under toxicity conditions.

  7. Reactions of 11C recoil atoms in the systems H2O-NH3, H2O-CH4 and NH3-CH4

    International Nuclear Information System (INIS)

    Nebeling, B.

    1988-11-01

    In this study the chemical reactions of recoil carbon 11 in the binary gas mixtures H 2 O-NH 3 , H 2 O-CH 4 and NH 3 -CH 4 in different mixing ratios as well as in solid H 2 O and in a solid H 2 O-NH 3 mixture were analyzed in dependence of the dose. The analyses were to serve e.g. the simulation of chemical processes caused by solar wind, solar radiation and cosmic radiation in the coma and core of comets. They were to give further information about the role of the most important biogeneous element carbon, i.e. carbon, in the chemical evolution of the solar system. Besides the actual high energy processes resulting in the so-called primary products, also the radiation-chemical changes of the primary products were also observed in a wide range of dosing. The generation of the energetic 11 C atoms took place according to the target composition by the nuclear reactions 14 N(p,α) 11 C, 12 C( 3 He,α) 11 C or the 16 O(p,αpn) 11 C reaction. The identification of the products marked with 11 C was carried out by means of radio gas chromatography or radio liquid chromatography (HPLC). (orig./RB) [de

  8. Increasing Hydrogen Density with the Cation-Anion Pair BH4−-NH4+ in Perovskite-Type NH4Ca(BH43

    Directory of Open Access Journals (Sweden)

    Pascal Schouwink

    2015-08-01

    Full Text Available A novel metal borohydride ammonia-borane complex Ca(BH42·NH3BH3 is characterized as the decomposition product of the recently reported perovskite-type metal borohydride NH4Ca(BH43, suggesting that ammonium-based metal borohydrides release hydrogen gas via ammonia-borane-complexes. For the first time the concept of proton-hydride interactions to promote hydrogen release is applied to a cation-anion pair in a complex metal hydride. NH4Ca(BH43 is prepared mechanochemically from Ca(BH42 and NH4Cl as well as NH4BH4 following two different protocols, where the synthesis procedures are modified in the latter to solvent-based ball-milling using diethyl ether to maximize the phase yield in chlorine-free samples. During decomposition of NH4Ca(BH43 pure H2 is released, prior to the decomposition of the complex to its constituents. As opposed to a previously reported adduct between Ca(BH42 and NH3BH3, the present complex is described as NH3BH3-stuffed α-Ca(BH42.

  9. Synthesis and properties of ternary (K, NH4, H3O)-jarosites precipitated from Acidithiobacillus ferrooxidans cultures in simulated bioleaching solutions

    International Nuclear Information System (INIS)

    Sandy Jones, F.; Bigham, Jerry M.; Gramp, Jonathan P.; Tuovinen, Olli H.

    2014-01-01

    The purpose of this study was to synthesize a series of solid solution jarosites by biological oxidation of ferrous iron at pH 2.2–4.4 and ambient temperature in media containing mixtures of K + (0, 1, 4, 6, 12, 31 mM) and NH 4 + (6.1, 80, 160, 320 mM). The starting material was a liquid medium for Acidithiobacillus ferrooxidans comprised of 120 mM FeSO 4 solution and mineral salts at pH 2.2. Following inoculation with A. ferrooxidans, the cultures were incubated in shake flasks at 22 °C. As bacteria oxidized ferrous iron, ferric iron hydrolyzed and precipitated as jarosite-group minerals (AFe 3 (SO 4 ) 2 (OH) 6 ) and/or schwertmannite (idealized formula Fe 8 O 8 (OH) 6 (SO 4 )·nH 2 O). The precipitates were characterized by X-ray diffraction (XRD), elemental analysis, and Munsell color. Schwertmannite was the dominant mineral product at low combinations of K + (≤ 4 mM) and NH 4 + (≤ 80 mM) in the media. At higher single or combined concentrations, yellowish jarosite phases were produced, and Munsell hue provided a sensitive means of detecting minor schwertmannite in the oxidation products. Although the hydrated ionic radii of K + and NH 4 + are similar, K + greatly facilitated the formation of a jarosite phase compared to NH 4 + . Unit cell and cell volume calculations from refinements of the powder XRD patterns indicated that the jarosite phases produced were mostly ternary (K, NH 4 , H 3 O)-solid solutions that were also deficient in structural Fe, especially at low NH 4 contents. Thus, ferric iron precipitation from the simulated bioleaching systems yielded solid solutions of jarosite with chemical compositions that were dependent on the relative concentrations of K + and NH 4 + in the synthesis media. No phase separations involving discrete, end-member K-jarosite or NH 4 -jarosite were detected in the un-aged precipitates. - Highlights: • Fe(III) precipitates formed in A. ferrooxidans culture solutions were characterized. • The monovalent cation

  10. Dynamics of N-NH4 +, N-NO3 -, and total soil nitrogen in paddy field with azolla and biochar

    Science.gov (United States)

    Dewi, W. S.; Wahyuningsih, G. I.; Syamsiyah, J.; Mujiyo

    2018-03-01

    Nitrogen (N) is one of macronutrients which is dynamic in the soil and becomes constraint factor for rice crops. The addition of nitrogen fertilizers and its absorption in paddy field causes the dynamics of nitrogen, thus declines of N absorption efficiency. The aim of this research is to know influence Azolla, biochar and different varieties application on N-NH4 +, N-NO3 -, and total soil N in paddy field. This research was conducted in a screen house located in Jumantono Laboratory, Faculty of Agriculture, Universitas Sebelas Maret (UNS) with altitude 170 m asl from April to June 2016. Treatment factors that were examined consisted of azolla (0 and 10 tons/ha), biochar (0 and 2 tons/ha), and rice varieties (Cisadane, Memberamo, Ciherang, IR64). The results of this research showed that there was no interaction between azolla, biochar and varieties. Nevertheless, azolla treatment with dose of 10 tons/ha increased soil NH4 + content (41 days after planting, DAP) by 13.4% but tend to decrease at 70 and 90 DAP. Biochar treatment with dose of 2 ton/ha increases NO3 - soil content (70 DAP) by 1.7% but decreases total N soil by 5.8% (41 DAP) and 4.7% (90 DAP). Different rice varieties generated different soil NH4 + content (41 DAP) and rice root volume. Cisadane variety can increase soil NH4 + content (41 DAP) by 52.08% and root volume by 51.80% (90 DAP) compared with Ciherang variety. Organic rice field management with azolla and biochar affects the availability of N in the soil and increase N absorption efficiency through its role in increasing rice root volume.

  11. Infrared spectra of the ammonium ion in ammonium metavanadate NH 4VO 3

    Science.gov (United States)

    de Waal, D.; Heyns, A. M.; Range, K.-J.; Eglmeier, C.

    The ND stretching modes of isotopically dilute NH 3D + ions in NH 4VO 3 are in agreement with the predicted splitting into C s, C s and C1(2) components under C s site symmetry for the NH +4 ion. The three bands observed represent the three NH bonding distances in the crystal, and the position, shape and low temperature behaviour of each band confirms the existence of two types of hydrogen bonding in NH 4VO 3. The low temperature infrared modes of NH +4 and ND +4 in NH 4VO 3 and ND 4VO 3, respectively, can be assigned under space group Pbcm. Temperature dependence of these modes also reflects the presence of both normal and bifurcated hydrogen bonds in NH 4VO 3.

  12. A liquid-based eutectic system: LiBH4·NH 3-nNH3BH3 with high dehydrogenation capacity at moderate temperature

    KAUST Repository

    Tan, Yingbin

    2011-01-01

    A novel eutectic hydrogen storage system, LiBH4·NH 3-nNH3BH3, which exists in a liquid state at room temperature, was synthesized through a simple mixing of LiBH 4·NH3 and NH3BH3 (AB). In the temperature range of 90-110 °C, the eutectic system showed significantly improved dehydrogenation properties compared to the neat AB and LiBH 4·NH3 alone. For example, in the case of the LiBH4·NH3/AB with a mole ratio of 1:3, over 8 wt.% hydrogen could be released at 90 °C within 4 h, while only 5 wt.% hydrogen released from the neat AB at the same conditions. Through a series of experiments it has been demonstrated that the hydrogen release of the new system is resulted from an interaction of AB and the NH3 group in the LiBH4·NH3, in which LiBH4 works as a carrier of ammonia and plays a crucial role in promoting the interaction between the NH3 group and AB. The enhanced dehydrogenation of LiBH 4·NH3/AB may result from the polar liquid state reaction environments and the initially promoted formation of the diammoniate of diborane, which will facilitate the B-H⋯H-N interaction between LiBH4·NH3 and AB. Kinetics analysis revealed that the rate-controlling steps of the dehydrogenation process are three-dimensional diffusion of hydrogen at temperatures ranging from 90 to 110 °C. This journal is © The Royal Society of Chemistry.

  13. A Low Temperature Infrared Study Of Deuterated NH4VO3

    Science.gov (United States)

    de Waal, D.; Heyns, A. M.

    1989-12-01

    The existence of (NH4)2V6016 as an intermediate in the thermal decomposition of NH4V03 to V205 has been confirmed by vibrational spectroscopy, resulting in the following reaction in an open systeml: NH4VO3 1 bar, air, 50-200°C/(1) (NH4)2v6o16 1 bar, air, ca.360°C/(2) V205 The kinetics of reaction (1) was studied by means of Raman spectroscopy, and structural information on NH4V03 and (N114)V60 16 was required to obtain an accurate description of the reaction mechanism2. Information on the site symmetry of an ammonium ion and hydrogen bonding in a crystal can be obtained by considering the infrared spectra of isotopically dilute NH3D+ ions in the lattice at liquid nitrogen temperatures3, especially as the position of hydrogen atoms in (NHO2V6016 could not be determined by X-ray methods.

  14. NH4+-NH3 removal from simulated wastewater using UV-TiO2 photocatalysis: effect of co-pollutants and pH.

    Science.gov (United States)

    Vohra, M S; Selimuzzaman, S M; Al-Suwaiyan, M S

    2010-05-01

    The main objective of the present study was to investigate the efficiency of titanium dioxide (TiO2) assisted photocatalytic degradation (PCD) process for the removal of ammonium-ammonia (NH4(+)-NH3) from the aqueous phase and in the presence of co-pollutants thiosulfate (S2O3(2-)) and p-cresol (C6H4CH3OH) under varying mixed conditions. For the NH4(+)-NH3 only PCD experiments, results showed higher NH4 -NH3 removal at pH 12 compared to pH 7 and 10. For the binary NH4(+)-NH3/S2O3(2-) studies the respective results indicated a significant lowering in NH4(+)-NH3 PCD in the presence of S2O32- at pH 7/12 whereas at pH 10 a marked increase in NH4(+)-NH3 removal transpired. A similar trend was noted for the p-cresol/NH4(+)-NH3 binary system. Comparing findings from the binary (NH4(+)-NH3/S2O3(2-) and p-cresol/NH4(+)-NH3) and tertiary (NH4(+)-NH3/S2O3(2-)/p-cresol) systems, at pH 10, showed fastest NH4(+)-NH3 removal transpiring for the tertiary system as compared to the binary systems, whereas both the binary systems indicated comparable NH4(+)-NH3 removal trends. The respective details have been discussed.

  15. Sequence of phase transitions in (NH4)3SiF7.

    Science.gov (United States)

    Mel'nikova, S V; Molokeev, M S; Laptash, N M; Pogoreltsev, E I; Misyul, S V; Flerov, I N

    2017-02-21

    Single crystals of silicon double salt (NH 4 ) 3 SiF 7 = (NH 4 ) 2 SiF 6 ·NH 4 F = (NH 4 ) 3 [SiF 6 ]F were grown and studied by the methods of polarization optics, X-ray diffraction and calorimetry. A sequence of symmetry transformations with the temperature change was established: P4/mbm (Z = 2) (G 1 ) ↔ Pbam (Z = 4) (G 2 ) ↔ P2 1 /c (Z = 4) (G 3 ) ↔ P1[combining macron] (Z = 4) (G 4 ) ↔ P2 1 /c (Z = 8) (G 5 ). Crystal structures of different phases were determined. The experimental data were also interpreted by a group-theoretical analysis of the complete condensate of order parameters taking into account critical and noncritical atomic displacements. Strengthening of the N-HF hydrogen bonds can be a driving force of the observed phase transitions.

  16. Interactions of NH4+ and L-glutamate with NO3- transport processes of non-mycorrhizal Fagus sylvatica roots

    NARCIS (Netherlands)

    Kreuzwieser, J; Herschbach, C; Stulen, [No Value; Wiersema, P; Vaalburg, W; Rennenberg, H

    The processes of NO3- uptake and transport and the effects of NH4+ or L-glutamate on these processes were investigated with excised non-mycorrhizal beech (Fagus sylvatica L,) roots, NO3- net uptake followed uniphasic Michaelis-Menten kinetics in a concentration range of 10 mu M to 1 mM with an

  17. Solid-phase synthesis of NH-1,2,3-triazoles using 4,4′- bismethoxybenzhydryl azide

    DEFF Research Database (Denmark)

    Cohrt, Anders Emil O'Hanlon; Le Quement, Sebastian Thordal; Nielsen, Thomas Eiland

    2014-01-01

    Readily available 4,4′-bismethoxybenzhydryl azide was found to be a useful building block for the synthesis of NH-1,2,3-triazoles through copper(I)-catalyzed cycloaddition reactions with solid-supported terminal alkynes, followed by acid-mediated deprotection. Peptide-containing NH-1,2,3-triazole...

  18. Separation and Recovery of Iron and Rare Earth from Bayan Obo Tailings by Magnetizing Roasting and (NH42SO4 Activation Roasting

    Directory of Open Access Journals (Sweden)

    Yan Zhou

    2017-05-01

    Full Text Available A novel approach for recovery of iron and rare earth elements (REEs from Bayan Obo tailings of Baotou, China, was developed by combining magnetizing roasting, magnetic separation, (NH42SO4 activation roasting, and water leaching. Thermodynamic analysis of carbothermal reduction was conducted to determine the temperature of magnetizing roasting, and it agreed well with the experimental results. The maximum recovery of Fe reached 77.8% at 600 °C, and the grade of total Fe in the magnetic concentrate was 56.3 wt. %. An innovative approach, using water to leach REEs after (NH42SO4 activation roasting, was used to extract REEs from magnetic separation tailings. The main influence factors of the leaching recovery during (NH42SO4 activation roasting, were investigated with the mass ratio of (NH42SO4 to magnetic separation tailings, roasting temperature and roasting time. The leaching recoveries of La, Ce and Nd reached 83.12%, 76.64% and 77.35%, respectively, under the optimized conditions: a mass ratio of 6:1, a roasting temperature of 400 °C and a roasting time of 80 min. Furthermore, the phase composition and reaction process during the (NH42SO4 activation roasting were analyzed with X-ray diffraction (XRD, energy dispersive X-ray spectroscopy & scanning electron microscopy (EDS-SEM and thermogravimetry & differential scanning calorimetry (TG-DSC, and the leaching solution and leaching residue were also characterized.

  19. Crystal structure of [UO2(NH35]NO3·NH3

    Directory of Open Access Journals (Sweden)

    Patrick Woidy

    2016-12-01

    Full Text Available Pentaammine dioxide uranium(V nitrate ammonia (1/1, [UO2(NH35]NO3·NH3, was obtained in the form of yellow crystals from the reaction of caesium uranyl nitrate, Cs[UO2(NO33], and uranium tetrafluoride, UF4, in dry liquid ammonia. The [UO2]+ cation is coordinated by five ammine ligands. The resulting [UO2(NH35] coordination polyhedron is best described as a pentagonal bipyramid with the O atoms forming the apices. In the crystal, numerous N—H...N and N—H...O hydrogen bonds are present between the cation, anion and solvent molecules, leading to a three-dimensional network.

  20. Low-Temperature NH3–SCR of NO on Mesoporous Mn0.6Fe0.4/TiO2 Prepared by a Hydrothermal Method

    DEFF Research Database (Denmark)

    Schill, Leonhard; Putluru, Siva Sankar Reddy; Fehrmann, Rasmus

    2014-01-01

    higher (NH4)2SO4 tolerance at 150 °C compared to the impregnation preparation method. Regeneration of the (NH4)2SO4 loaded samples by heating to 400 °C was not possible whereas water washing yielded better regeneration. The catalysts are significantly more active than a commercial VWT SCR catalyst...

  1. Gas-particle interactions above a Dutch heathland: I. Surface exchange fluxes of NH3, SO2, HNO3 and HCl

    Directory of Open Access Journals (Sweden)

    E. Nemitz

    2004-01-01

    Full Text Available A field measurement campaign was carried out over a Dutch heathland to investigate the effect of gas-to-particle conversion and ammonium aerosol evaporation on surface/atmosphere fluxes of ammonia and related species. Continuous micrometeorological measurements of the surface exchange of NH3, SO2, HNO3 and HCl were made and are analyzed here with regard to average fluxes, deposition velocities (Vd, canopy resistances (Rc and canopy compensation point for NH3. Gradients of SO2, HNO3 and HCl were measured with a novel wet-denuder system with online anion chromatography. Measurements of HNO3 and HCl indicate an Rc of 100 to 200 s m-1 during warm daytime periods, probably at least partly due to non-zero acid partial pressures above NH4NO3 and NH4Cl on the leaf surfaces. Although it is likely that this observation is exacerbated by the effect of the evaporation of airborne NH4+ on the gradient measurements, the findings nevertheless add to the growing evidence that HNO3 and HCl are not always deposited at the maximum rate. Ammonia (NH3 fluxes show mainly deposition, with some periods of significant daytime emission. The net exchange could be reproduced both with an Rc model (deposition fluxes only using resistance parameterizations from former measurements, as well as with the canopy compensation point model, using parameterizations derived from the measurements. The apoplastic ratio of ammonium and hydrogen concentration (Γs=[NH4+]/[H+] of 1200 estimated from the measurements is large for semi-natural vegetation, but smaller than indicated by previous measurements at this site.

  2. Gas-particle interactions above a Dutch heathland: I. Surface exchange fluxes of NH3, SO2, HNO3 and HCl

    Science.gov (United States)

    Nemitz, E.; Sutton, M. A.; Wyers, G. P.; Jongejan, P. A. C.

    2004-07-01

    A field measurement campaign was carried out over a Dutch heathland to investigate the effect of gas-to-particle conversion and ammonium aerosol evaporation on surface/atmosphere fluxes of ammonia and related species. Continuous micrometeorological measurements of the surface exchange of NH3, SO2, HNO3 and HCl were made and are analyzed here with regard to average fluxes, deposition velocities (Vd), canopy resistances (Rc) and canopy compensation point for NH3. Gradients of SO2, HNO3 and HCl were measured with a novel wet-denuder system with online anion chromatography. Measurements of HNO3 and HCl indicate an Rc of 100 to 200 s m-1 during warm daytime periods, probably at least partly due to non-zero acid partial pressures above NH4NO3 and NH4Cl on the leaf surfaces. Although it is likely that this observation is exacerbated by the effect of the evaporation of airborne NH4+ on the gradient measurements, the findings nevertheless add to the growing evidence that HNO3 and HCl are not always deposited at the maximum rate. Ammonia (NH3) fluxes show mainly deposition, with some periods of significant daytime emission. The net exchange could be reproduced both with an Rc model (deposition fluxes only) using resistance parameterizations from former measurements, as well as with the canopy compensation point model, using parameterizations derived from the measurements. The apoplastic ratio of ammonium and hydrogen concentration (Γs=[NH4+]/[H+]) of 1200 estimated from the measurements is large for semi-natural vegetation, but smaller than indicated by previous measurements at this site.

  3. Solvothermal indium fluoride chemistry: Syntheses and crystal structures of K5In3F14, β-(NH4)3InF6 and [NH4]3[C6H21N4]2[In4F21

    International Nuclear Information System (INIS)

    Jayasundera, Anil C.A.; Goff, Richard J.; Li Yang; Finch, Adrian A.; Lightfoot, Philip

    2010-01-01

    The solvothermal syntheses and crystal structures of three indium fluorides are presented. K 5 In 3 F 14 (1) and β-(NH 4 ) 3 InF 6 (2) are variants on known inorganic structure types chiolite and cryolite, respectively, with the latter exhibiting a complex and apparently novel structural distortion. [NH 4 ] 3 [C 6 H 21 N 4 ] 2 [In 4 F 21 ] (3) represents a new hybrid composition displaying a unique trimeric metal fluoride building unit. - Graphical abstract: Solvothermal synthesis has been used to prepare three indium fluorides, including a novel hybrid material containing a unique [In 3 F 15 ] trimer templated by tren.

  4. The Cs2SO4-Ce2(SO4)3-H2SO4-H2O system at 150 and 200 deg C

    International Nuclear Information System (INIS)

    Bondar', S.A.; Belokoskov, V.I.; Trofimov, G.V.

    1982-01-01

    Solubility in the system Cs 2 SO 4 -Ce 2 (SO 4 ) 3 -H 2 SO 4 -H 2 O using the isothermal method at 150 and 200 deg C at molar ratios Cs 2 SO 4 :Ce 2 (SO 4 ) 3 =1:5 and conditions of sulfate crystallization Cs 2 SO 4 xCe 2 (SO 4 ) 3 , Ce 2 (SO 4 ) 3 x0.5H 2 SO 4 xnH 2 O (n=2-3) and Ce 2 (SO 4 ) 3 x3H 2 SO 4 are determined. Double sulfate Cs 2 SO 4 xCe 2 (SO 4 ) 3 is studied using the methods of crystallooptical, thermal, X-ray phase analyses and IR spectroscopy

  5. A liquid-based eutectic system: LiBH4·NH 3-nNH3BH3 with high dehydrogenation capacity at moderate temperature

    KAUST Repository

    Tan, Yingbin; Guo, Yanhui; Li, Shaofeng; Sun, Weiwei; Zhu, Yihan; Li, Qi; Yu, Xuebin

    2011-01-01

    A novel eutectic hydrogen storage system, LiBH4·NH 3-nNH3BH3, which exists in a liquid state at room temperature, was synthesized through a simple mixing of LiBH 4·NH3 and NH3BH3 (AB). In the temperature range of 90-110 °C, the eutectic system

  6. The ternary system K2SO4MgSO4CaSO4

    Science.gov (United States)

    Rowe, J.J.; Morey, G.W.; Silber, C.C.

    1967-01-01

    Melting and subsolidus relations in the system K2SO4MgSO4CaSO4 were studied using heating-cooling curves, differential thermal analysis, optics, X-ray diffraction at room and high temperatures and by quenching techniques. Previous investigators were unable to study the binary MgSO4CaSO4 system and the adjacent area in the ternary system because of the decomposition of MgSO4 and CaSO4 at high temperatures. This problem was partly overcome by a novel sealed-tube quenching method, by hydrothermal synthesis, and by long-time heating in the solidus. As a result of this study, we found: (1) a new compound, CaSO4??3MgSO4 (m.p. 1201??C) with a field extending into the ternary system; (2) a high temperature form of MgSO4 with a sluggishly reversible inversion. An X-ray diffraction pattern for this polymorphic form is given; (3) the inversion of ??-CaSO4 (anhydrite) to ??-CaSO4 at 1195??C, in agreement with grahmann; (1) (4) the melting point of MgSO4 is 1136??C and that of CaSO4 is 1462??C (using sealed tube methods to prevent decomposition of the sulphates); (5) calcium langbeinite (K2SO4??2CaSO4) is the only compound in the K2SO4CaSO4 binary system. This resolved discrepancies in the results of previous investigators; (6) a continuous solid solution series between congruently melting K2SOP4??2MgSO4 (langbeinite) and incongruently melting K2SO4??2CaSO4 (calcium langbeinite); (7) the liquidus in the ternary system consists of primary phase fields of K2SO4, MgSO4, CaSO4, langbeinite-calcium langbeinite solid solution, and CaSO4??3MgSO4. The CaSO4 field extends over a large portion of the system. Previously reported fields for the compounds (K2SO4??MgSO4??nCaSO4), K2SO4??3CaSO4 and K2SO4??CaSO4 were not found; (8) a minimum in the ternary system at: 740??C, 25% MgSO4, 6% CaSO4, 69% K2SO4; and ternary eutectics at 882??C, 49% MgSO4, 19% CaSO4, 32% K2SO4; and 880??, 67??5% MgSO4, 5% CaSO4, 27??5% K2SO4. ?? 1967.

  7. Structural determinants of NH3 and NH4+ transport by mouse Rhbg, a renal Rh glycoprotein.

    Science.gov (United States)

    Abdulnour-Nakhoul, Solange; Le, Trang; Rabon, Edd; Hamm, L Lee; Nakhoul, Nazih L

    2016-12-01

    Renal Rhbg is localized to the basolateral membrane of intercalated cells and is involved in NH 3 /NH 4 + transport. The structure of Rhbg is not yet resolved; however, a high-resolution crystal structure of AmtB, a bacterial homolog of Rh, has been determined. We aligned the sequence of Rhbg to that of AmtB and identified important sites of Rhbg that may affect transport. Our analysis positioned three conserved amino acids, histidine 183 (H183), histidine 342 (H342), and tryptophan 230 (W230), within the hydrophobic pore where they presumably serve to control NH 3 transport. A fourth residue, phenylalanine 128 (F128) was positioned at the upper vestibule, presumably contributing to recruitment of NH 4 + We generated three mutations each of H183, H342, W230, and F128 and expressed them in frog oocytes. Immunolabeling showed that W230 and F128 mutants were localized to the cell membrane, whereas H183 and H342 staining was diffuse and mostly intracellular. To determine function, we compared measurements of NH 3 /NH 4 + and methyl amine (MA)/methyl ammonium (MA + )-induced currents, intracellular pH, and surface pH (pHs) among oocytes expressing the mutants, Rhbg, or injected with H 2 O. In H183 and W230 mutants, NH 4 + -induced current and intracellular acidification were inhibited compared with that of Rhbg, and MA-induced intracellular alkalinization was completely absent. Expression of H183A or W230A mutants inhibited NH 3 /NH 4 + - and MA/MA + -induced decrease in pHs to the level observed in H 2 O-injected oocytes. Mutations of F128 did not significantly affect transport of NH 3 or NH 4 + These data demonstrated that mutating H183 or W230 caused loss of function but not F128. H183 and H342 may affect membrane expression of the transporter.

  8. Fourier transform infrared study of the phase transitions in (NH4)3VO2FO4

    Science.gov (United States)

    de Waal, D.; Heyns, A. M.

    1994-01-01

    Ammonium oxofluorovanadate compounds are known to show some potential as ferroelectric materials. The whole series of ammonium and sodium oxofluorovanadate compounds including Na3VO2F4 have already been prepared and investigated by means of various techniques including x-ray diffraction, EPR, and vibrational spectroscopy. It was established that the pure ammonium compound shows the two above mentioned transitions from phase A (below 200 K) to phase B (between 200 and 400 K) and phase C (above 400 K) while Na(NH4)2VO2F4 has only one transition from phase A to phase B around 400 K4. In the present study various aspects regarding the nature of the structures of (NH4)3VO2F3 and Na(NH4)2VO2F4 and its influence on the phase transitions have been investigated.

  9. Pressure induced polymorphism in ammonium azide (NH{sub 4}N{sub 3})

    Energy Technology Data Exchange (ETDEWEB)

    Medvedev, S.A., E-mail: s.medvedev@mpic.de [Max-Planck-Institute for Chemistry, Postfach 3060, D-55020 Mainz (Germany); Institute fuer Anorganische und Analytische Chemie, Johannes Gutenberg-Universitaet, D-55099 Mainz (Germany); Eremets, M.I. [Max-Planck-Institute for Chemistry, Postfach 3060, D-55020 Mainz (Germany); Evers, J.; Klapoetke, T.M. [Energetic Materials Research, Ludwig-Maximilian University Munich (LMU), Butenandtstrasse 5-13(D), D-81377 Munich (Germany); Palasyuk, T. [Max-Planck-Institute for Chemistry, Postfach 3060, D-55020 Mainz (Germany); Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw (Poland); Trojan, I.A. [Max-Planck-Institute for Chemistry, Postfach 3060, D-55020 Mainz (Germany)

    2011-07-28

    Graphical abstract: Polymorph phase transition is observed in NH{sub 4}N{sub 3} at {approx}3 GPa by pressure dependent Raman studies. The strength of hydrogen bond appears to be modified at the phase transition as illustrated by dependence of N-H stretching frequency on pressure shown on figure. Highlights: {yields} Ammonium azide (NH{sub 4}N{sub 3}) studied at high pressures by Raman spectroscopy. {yields} Phase transition is observed at pressure {approx}3 GPa. {yields} Strength of hydrogen bond appears to be modified at the phase transition. {yields} NH{sub 4}N{sub 3} remain in molecular form up to pressures above 50 GPa. - Abstract: Pressure-dependent Raman spectroscopy studies reveal polymorph phase transition in simple molecular ionic crystal NH{sub 4}N{sub 3} at pressure {approx}3 GPa unobserved by recent abinitio evolutionary structure searches. Hydrogen bonding is spectroscopically evident in both low- and high-pressure phases. The strength of hydrogen bond appears to be modified at the phase transition: in the low-pressure phase NH{sub 4}N{sub 3} behaves as system with very strong hydrogen bonding whereas changes of spectra with pressure in the high-pressure phase are indicative of weak or medium-strength hydrogen bonds. The high pressure phase is most likely thermodynamically stable at least up to pressure {approx}55 GPa contradicting the abinitio studies predicting transformation of NH{sub 4}N{sub 3} to nonmolecular hydronitrogen solid at 36 GPa.

  10. Rydberb bonding in (NH4)2

    International Nuclear Information System (INIS)

    Boldyrev, A.I.; Simons, J.

    1992-01-01

    Chemical binding of two monovalent Rydberg species to form a singlet-state Rydberg dimer molecule is predicted to be possible Ab initio electronic structure methods that include electron correlation (at levels up through QCISD(T)/6-31++G** MP2(full)/6-31++G** + ZPE) are shown to be essential to achieving a proper description of such bonding. The (NH 4 ) molecule, selected as the prototype for this study, is shown to be bound with respect to its Rydberg-species fragments, 2NH 4 by 7.5-9.7 kcal/mol, depending on the level of treatment of electron correlation, and to be electronically stable (by ca.4 eV) with respect to (NH 4 ) 2 + at the neutral's equilibrium geometry. The (NH 4 ) 2 Rydberg dimer is thermodynamically unstable with respect to 2NH 3 + H 2 by 86-89 kcal/mol mol yet possesses all real vibrational frequencies; it is thus a metastable molecular held together by a weak Rydberg bond. The dissociation energy of the (NH 4 ) 2 + cation to form NH 4 + + NH 4 is found to be larger than that of the neutral (NH 4 ) 2 . 12 refs., 4 figs., 9 tabs

  11. Rapid Ammonia Gas Transport Accounts for Futile Transmembrane Cycling under NH3/NH4+ Toxicity in Plant Roots1[C][W

    Science.gov (United States)

    Coskun, Devrim; Britto, Dev T.; Li, Mingyuan; Becker, Alexander; Kronzucker, Herbert J.

    2013-01-01

    Futile transmembrane NH3/NH4+ cycling in plant root cells, characterized by extremely rapid fluxes and high efflux to influx ratios, has been successfully linked to NH3/NH4+ toxicity. Surprisingly, the fundamental question of which species of the conjugate pair (NH3 or NH4+) participates in such fluxes is unresolved. Using flux analyses with the short-lived radioisotope 13N and electrophysiological, respiratory, and histochemical measurements, we show that futile cycling in roots of barley (Hordeum vulgare) seedlings is predominately of the gaseous NH3 species, rather than the NH4+ ion. Influx of 13NH3/13NH4+, which exceeded 200 µmol g–1 h–1, was not commensurate with membrane depolarization or increases in root respiration, suggesting electroneutral NH3 transport. Influx followed Michaelis-Menten kinetics for NH3 (but not NH4+), as a function of external concentration (Km = 152 µm, Vmax = 205 µmol g–1 h–1). Efflux of 13NH3/13NH4+ responded with a nearly identical Km. Pharmacological characterization of influx and efflux suggests mediation by aquaporins. Our study fundamentally revises the futile-cycling model by demonstrating that NH3 is the major permeating species across both plasmalemma and tonoplast of root cells under toxicity conditions. PMID:24134887

  12. Parallel Changes in Intracellular Water Volume and pH Induced by NH3/NH4+ Exposure in Single Neuroblastoma Cells

    Directory of Open Access Journals (Sweden)

    Víctor M. Blanco

    2013-12-01

    Full Text Available Background: Increased blood levels of ammonia (NH3 and ammonium (NH4+, i.e. hyperammonemia, leads to cellular brain edema in humans with acute liver failure. The pathophysiology of this edema is poorly understood. This is partly due to incomplete understanding of the osmotic effects of the pair NH3/NH4+ at the cellular and molecular levels. Cell exposure to solutions containing NH3/NH4+ elicits changes in intracellular pH (pHi, which can in turn affect cell water volume (CWV by activating transport mechanisms that produce net gain or loss of solutes and water. The occurrence of CWV changes caused by NH3/NH4+ has long been suspected, but the mechanisms, magnitude and kinetics of these changes remain unknown. Methods: Using fluorescence imaging microscopy we measured, in real time, parallel changes in pHi and CWV caused by brief exposure to NH3/NH4+ of single cells (N1E-115 neuroblastoma or NG-108 neuroblastoma X glioma loaded with the fluorescent indicator BCECF. Changes in CWV were measured by exciting BCECF at its intracellular isosbestic wavelength (∼438 nm, and pHi was measured ratiometrically. Results: Brief exposure to isosmotic solutions (i.e. having the same osmolality as that of control solutions containing NH4Cl (0.5- 30 mM resulted in a rapid, dose-dependent swelling, followed by isosmotic regulatory volume decrease (iRVD. NH4Cl solutions in which either extracellular [NH3] or [NH4+] was kept constant while the other was changed by varying the pH of the solution, demonstrated that [NH3]o rather than [NH4+]o is the main determinant of the NH4Cl-induced swelling. The iRVD response was sensitive to the anion channel blocker NPPB, and partly dependent on external Ca2+. Upon removal of NH4Cl, cells shrank and displayed isosmotic regulatory volume increase (iRVI. Regulatory volume responses could not be activated by comparable CWV changes produced by anisosmotic solutions, suggesting that membrane stretch or contraction by themselves are

  13. Electron paramagnetic resonance of gamma irradiated (CH3)3NHClO4 and CH3NH3ClO4 single crystals

    International Nuclear Information System (INIS)

    Yavuz, Metin; Koeksal, Fevzi

    1999-01-01

    Gamma irradiation damage centers in (CH 3 ) 3 NHClO 4 and CH 3 NH 3 ClO 4 single crystals have been investigated at room temperature by the electron paramagnetic resonance (EPR) technique. It has been found that γ-irradiation produces the (CH 3 ) 3 N + radical in the first, and NH + 3 and ClO 3 radicals in the second compound. The EPR parameters of the observed radicals have been determined and discussed

  14. NH4NO3 extractable trace element contents of soil samples prepared for proficiency testing--a stability study.

    Science.gov (United States)

    Traub, H; Scharf, H

    2001-06-01

    In view of its intended use as a sample for proficiency testing or as a reference material the stability of the extractable trace element contents of a soil from an irrigation field was tested using the extraction with 1 mol/L ammonium nitrate solution according to DIN 19730. Therefore, changes of the extractability of sterilized and non sterilized soil samples stored at different temperatures were evaluated over a period of 18 months. Sets of bottles were kept at -20 degrees C, +4 degrees C, about +20 degrees C and +40 degrees C, respectively. The NH4NO3 extractable contents of Cd, Cr, Cu, Ni, Pb and Zn were determined immediately after bottling and then after 3, 6, 12 and 18 months with ICP-AES or ETAAS. Appropriate storage conditions are of utmost importance to prevent deterioration of soil samples prepared for the determination of NH4NO3 extractable trace element contents. Temperatures above +20 degrees C must be avoided. The observed changes in the extractability of the metals (especially for Cr and Cu) most likely could be related to thermal degradation of the organic matter of the soil. There is no need to sterilize dry soil samples, because microbiological activity in soils with a low moisture content appears to be negligible with regard to trace element mobilization.

  15. Evaluation of the SO(2) and NH(3) gas adsorption properties of CuO/ZnO/Mn(3)O(4) and CuO/ZnO/NiO ternary impregnated activated carbon using combinatorial materials science methods.

    Science.gov (United States)

    Romero, Jennifer V; Smith, Jock W H; Sullivan, Braden M; Macdonald, Landan; Croll, Lisa M; Dahn, J R

    2013-02-11

    Impregnated activated carbons (IAC) are widely used materials for the removal of toxic gases in personal respiratory protection applications. The combinatorial method has been employed to prepare IACs containing different types of metal oxides in various proportions and evaluate their adsorption performance for low molecular weight gases, such as SO(2) and NH(3), under dry conditions. Among the metal oxides used for the study, Mn(3)O(4) was found to have the highest capacity for retaining SO(2) gas under dry conditions. NiO and ZnO were found to have similar NH(3) adsorption capacities which are higher than the NH(3) capacities observed for the other metal oxide impregnants used in the study. Although Cu- or Zn-based impregnants and their combinations have been extensively studied and used as gas adsorbents, neither Mn(3)O(4) nor NiO have been incorporated in the formulations used. In this study, ternary libraries of IACs with various combinations of CuO/ZnO/Mn(3)O(4) and CuO/ZnO/NiO were studied and evaluated for their adsorption of SO(2) and NH(3) gases. Combinations of CuO, ZnO, and Mn(3)O(4) were found to have the potential to be multigas adsorbents compared to formulations that contain NiO.

  16. Synthesis and properties of ternary (K, NH{sub 4}, H{sub 3}O)-jarosites precipitated from Acidithiobacillus ferrooxidans cultures in simulated bioleaching solutions

    Energy Technology Data Exchange (ETDEWEB)

    Sandy Jones, F.; Bigham, Jerry M. [School of Environment and Natural Resources, Ohio State University, 2021 Coffey Road, Columbus, OH 43210 (United States); Gramp, Jonathan P. [Department of Microbiology, Ohio State University, 484 West 12th Avenue, Columbus, OH 43210 (United States); Tuovinen, Olli H., E-mail: tuovinen.1@osu.edu [Department of Microbiology, Ohio State University, 484 West 12th Avenue, Columbus, OH 43210 (United States)

    2014-11-01

    The purpose of this study was to synthesize a series of solid solution jarosites by biological oxidation of ferrous iron at pH 2.2–4.4 and ambient temperature in media containing mixtures of K{sup +} (0, 1, 4, 6, 12, 31 mM) and NH{sub 4}{sup +} (6.1, 80, 160, 320 mM). The starting material was a liquid medium for Acidithiobacillus ferrooxidans comprised of 120 mM FeSO{sub 4} solution and mineral salts at pH 2.2. Following inoculation with A. ferrooxidans, the cultures were incubated in shake flasks at 22 °C. As bacteria oxidized ferrous iron, ferric iron hydrolyzed and precipitated as jarosite-group minerals (AFe{sub 3}(SO{sub 4}){sub 2}(OH){sub 6}) and/or schwertmannite (idealized formula Fe{sub 8}O{sub 8}(OH){sub 6}(SO{sub 4})·nH{sub 2}O). The precipitates were characterized by X-ray diffraction (XRD), elemental analysis, and Munsell color. Schwertmannite was the dominant mineral product at low combinations of K{sup +} (≤ 4 mM) and NH{sub 4}{sup +} (≤ 80 mM) in the media. At higher single or combined concentrations, yellowish jarosite phases were produced, and Munsell hue provided a sensitive means of detecting minor schwertmannite in the oxidation products. Although the hydrated ionic radii of K{sup +} and NH{sub 4}{sup +} are similar, K{sup +} greatly facilitated the formation of a jarosite phase compared to NH{sub 4}{sup +}. Unit cell and cell volume calculations from refinements of the powder XRD patterns indicated that the jarosite phases produced were mostly ternary (K, NH{sub 4}, H{sub 3}O)-solid solutions that were also deficient in structural Fe, especially at low NH{sub 4} contents. Thus, ferric iron precipitation from the simulated bioleaching systems yielded solid solutions of jarosite with chemical compositions that were dependent on the relative concentrations of K{sup +} and NH{sub 4}{sup +} in the synthesis media. No phase separations involving discrete, end-member K-jarosite or NH{sub 4}-jarosite were detected in the un-aged precipitates

  17. Isotopic effect in phase transitions of (NH4)2HPO4 and (ND4)2DPO4

    International Nuclear Information System (INIS)

    Diosa, J.E.; Coral, E.E.; Vargas, R.A.

    1996-01-01

    Specific heat and dielectric constant measurements at low frequency, have shown two transitions in the ionic systems (NH4)2HPO4 and (ND4)2DPO4 bellow 300 K. For (NH4)2HPO4, the transition are observed at 174 K and 246 K, while (ND4)2DPO4, they are observed at 147 K and 229 K. We have also found a shift of the transition temperatures to smaller values when the hydrogen is replaced by deuterium. The specific heat anomalies associated with these transitions are reversible in successive thermal cycles (heating and cooling) and we did not detect latent heat through them. Furthermore, we have detected anomalies in the dielectric constant in the same transition points. We have attributed these transition phases to reorientations of the tetrahedra of NH4 and ND4, so that the activation energy Ea for these process that we associated with the thermal energy KBTt required for the transition, is inversely related to the mass of the hydrogen isotope

  18. submitter Thermodynamics of the formation of sulfuric acid dimers in the binary (H2SO4–H2O) and ternary (H2SO4–H2O–NH3) system

    CERN Document Server

    Kürten, A; Rondo, L; Bianchi, F; Duplissy, J; Jokinen, T; Junninen, H; Sarnela, N; Schobesberger, S; Simon, M; Sipilä, M; Almeida, J; Amorim, A; Dommen, J; Donahue, N M; Dunne, E M; Flagan, R C; Franchin, A; Kirkby, J; Kupc, A; Makhmutov, V; Petäjä, T; Praplan, A P; Riccobono, F; Steiner, G; Tomé, A; Tsagkogeorgas, G; Wagner, P E; Wimmer, D; Baltensperger, U; Kulmala, M; Worsnop, D R; Curtius, J

    2015-01-01

    Sulfuric acid is an important gas influencing atmospheric new particle formation (NPF). Both the binary $(H_2SO_4–H_2O)$ system and the ternary system involving ammonia $(H_2SO_4–H_2O–NH_3)$ may be important in the free troposphere. An essential step in the nucleation of aerosol particles from gas-phase precursors is the formation of a dimer, so an understanding of the thermodynamics of dimer formation over a wide range of atmospheric conditions is essential to describe NPF. We have used the CLOUD chamber to conduct nucleation experiments for these systems at temperatures from 208 to 248 K. Neutral monomer and dimer concentrations of sulfuric acid were measured using a chemical ionization mass spectrometer (CIMS). From these measurements, dimer evaporation rates in the binary system were derived for temperatures of 208 and 223 K. We compare these results to literature data from a previous study that was conducted at higher temperatures but is in good agreement with the present study. For the ternary sys...

  19. Thin-Film Transformation of NH4 PbI3 to CH3 NH3 PbI3 Perovskite: A Methylamine-Induced Conversion-Healing Process.

    Science.gov (United States)

    Zong, Yingxia; Zhou, Yuanyuan; Ju, Minggang; Garces, Hector F; Krause, Amanda R; Ji, Fuxiang; Cui, Guanglei; Zeng, Xiao Cheng; Padture, Nitin P; Pang, Shuping

    2016-11-14

    Methylamine-induced thin-film transformation at room-temperature is discovered, where a porous, rough, polycrystalline NH 4 PbI 3 non-perovskite thin film converts stepwise into a dense, ultrasmooth, textured CH 3 NH 3 PbI 3 perovskite thin film. Owing to the beneficial phase/structural development of the thin film, its photovoltaic properties undergo dramatic enhancement during this NH 4 PbI 3 -to-CH 3 NH 3 PbI 3 transformation process. The chemical origins of this transformation are studied at various length scales. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Evaluation of nutrients removal (NO3-N, NH3-N and PO4-P) with Chlorella vulgaris, Pseudomonas putida, Bacillus cereus and a consortium of these microorganisms in the treatment of wastewater effluents.

    Science.gov (United States)

    Gómez-Guzmán, Abril; Jiménez-Magaña, Sergio; Guerra-Rentería, A Suggey; Gómez-Hermosillo, César; Parra-Rodríguez, F Javier; Velázquez, Sergio; Aguilar-Uscanga, Blanca Rosa; Solis-Pacheco, Josue; González-Reynoso, Orfil

    2017-07-01

    In this research removal of NH 3 -N, NO 3 -N and PO 4 -P nutrients from municipal wastewater was studied, using Chlorella vulgaris, Pseudomonas putida, Bacillus cereus and an artificial consortium of them. The objective is to analyze the performance of these microorganisms and their consortium, which has not been previously studied for nutrient removal in municipal wastewater. A model wastewater was prepared simulating the physicochemical characteristics found at the wastewater plant in Chapala, Mexico. Experiments were carried out without adding an external carbon source. Results indicate that nutrient removal with Chlorella vulgaris was the most efficient with a removal of 24.03% of NO 3 -N, 80.62% of NH 3 -N and 4.30% of PO 4 -P. With Bacillus cereus the results were 8.40% of NO 3 -N, 28.80% of NH 3 -N and 3.80% of PO 4 -P. The removals with Pseudomonas putida were 2.50% of NO 3 -N, 41.80 of NH 3 -N and 4.30% of PO 4 -P. The consortium of Chlorella vulgaris-Bacillus cereus-Pseudomonas putida removed 29.40% of NO 3 -N, 4.2% of NH 3 -N and 8.4% of PO 4 -P. The highest biomass production was with Bacillus cereus (450 mg/l) followed by Pseudomonas putida (444 mg/l), the consortium (205 mg/l) and Chlorella vulgaris (88.9 mg/l). This study highlights the utility of these microorganisms for nutrient removal in wastewater treatments.

  1. In vitro growth of Brassocattleya orchid hybrid in different concentrations of KNO3, NH4NO3 and benzylaminopurine

    OpenAIRE

    Cardoso,Jean C; Ono,Elizabeth O

    2011-01-01

    One of the most important applications of plant tissue culture is mass propagation of ornamental plants. This experiment evaluated the effect of different concentrations of NH4NO3 and KNO3 and BAP on the in vitro growth of orchid hybrid Brassocattleya 'Pastoral'. Seedlings of this orchid hybrid were used as explants and cultivated in medium with mineral salts and vitamins from the MS medium (Murashige & Skoog, 1962), with the macronutrients P, Ca and Mg reduced by half, and with an additi...

  2. Hygroscopicity of internally mixed particles composed of (NH4)2SO4 and citric acid under pulsed RH change.

    Science.gov (United States)

    Shi, Xiao-Min; Wu, Feng-Min; Jing, Bo; Wang, Na; Xu, Lin-Lin; Pang, Shu-Feng; Zhang, Yun-Hong

    2017-12-01

    In this research, we applied a pulsed RH controlling system and a rapid scan vacuum FTIR spectrometer (PRHCS-RSVFTIR) to investigate hygroscopicity of internally mixed (NH 4 ) 2 SO 4 (AS)/citric acid (CA) particles. The water content and efflorescence ratio of AS in the particles and ambient relative humidity (RH) as a function of time were obtained with a subsecond time resolution. The hygroscopic behavior of AS aerosols in two different RH control processes (equilibrium and RH pulsed processes) showed that AS droplets crystallize with RH ranging from 42% to 26.5%. It was found that the half-life time ratio between the water content in the CA particles and the gas phase under RH pulsed change was greater than one under low RH conditions (humidity (ERH) of the mixed particles with AS/CA by molar ratio 3:1 was found between 22.7% and 5.9%, which was much lower than AS particles. No efflorescence process was observed for the 1:1 mixed particles, indicating that CA greatly suppressed nucleation of AS. Our results have shown that the PRHCS-RSVFTIR is effective to simulate hygroscopicity and water transport of aerosols under fast variations in RH in atmosphere. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Lead-free Perovskite Materials (NH4 )3 Sb2 Ix Br9-x.

    Science.gov (United States)

    Zuo, Chuantian; Ding, Liming

    2017-06-01

    A family of perovskite light absorbers (NH 4 ) 3 Sb 2 I x Br 9-x (0≤x≤9) was prepared. These materials show good solubility in ethanol, a low-cost, hypotoxic, and environmentally friendly solvent. The light absorption of (NH 4 ) 3 Sb 2 I x Br 9-x films can be tuned by adjusting I and Br content. The absorption onset for (NH 4 ) 3 Sb 2 I x Br 9-x films changes from 558 nm to 453 nm as x changes from 9 to 0. (NH 4 ) 3 Sb 2 I 9 single crystals were prepared, exhibiting a hole mobility of 4.8 cm 2  V -1  s -1 and an electron mobility of 12.3 cm 2  V -1  s -1 . (NH 4 ) 3 Sb 2 I 9 solar cells gave an open-circuit voltage of 1.03 V and a power conversion efficiency of 0.51 %. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Effects of N source concentration and NH4(+)/NO3(-) ratio on phenylethanoid glycoside pattern in tissue cultures of Plantago lanceolata L.: a metabolomics driven full-factorial experiment with LC-ESI-MS(3.).

    Science.gov (United States)

    Gonda, Sándor; Kiss-Szikszai, Attila; Szűcs, Zsolt; Máthé, Csaba; Vasas, Gábor

    2014-10-01

    Tissue cultures of a medicinal plant, Plantago lanceolata L. were screened for phenylethanoid glycosides (PGs) and other natural products (NPs) with LC-ESI-MS(3). The effects of N source concentration and NH4(+)/NO3(-) ratio were evaluated in a full-factorial (FF) experiment. N concentrations of 10, 20, 40 and 60mM, and NH4(+)/NO3(-) ratios of 0, 0.11, 0.20 and 0.33 (ratio of NH4(+) in total N source) were tested. Several peaks could be identified as PGs, of which, 16 could be putatively identified from the MS/MS/MS spectra. N source concentration and NH4(+)/NO3(-) ratio had significant effects on the metabolome, their effects on individual PGs were different despite these metabolites were of the same biosynthethic class. Chief PGs were plantamajoside and acteoside (verbascoside), their highest concentrations were 3.54±0.83% and 1.30±0.40% of dry weight, on media 10(0.33) and 40(0.33), respectively. NH4(+)/NO3(-) ratio and N source concentration effects were examined on a set of 89 NPs. For most NPs, high increases in abundance were observed compared to Murashige-Skoog medium. Abundances of 42 and 10 NPs were significantly influenced by the N source concentration and the NH4(+)/NO3(-) ratio, respectively. Optimal media for production of different NP clusters were 10(0), 10(0.11) and 40(0.33). Interaction was observed between NH4(+)/NO3(-) ratio and N source concentration for many NPs. It was shown in simulated experiments, that one-factor at a time (OFAT) experimental designs lead to sub-optimal media compositions for production of many NPs, and alternative experimental designs (e.g. FF) should be preferred when optimizing medium N source for optimal yield of NPs. If using OFAT, the N source concentration is to be optimized first, followed by NH4(+)/NO3(-) ratio, as this reduces the likeliness of suboptimal yield results. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Catalysts for selective hydrogenation of furfural derived from the double complex salt [Pd(NH 3 ) 4 ](ReO 4 ) 2 on γ-Al 2 O 3

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Simon T.; Lamb, H. Henry

    2017-06-01

    The double complex salt [Pd(NH3)4](ReO4)2 was employed as precursor of supported bimetallic catalysts for selective hydrogenation of furfural. Direct reduction of [Pd(NH3)4](ReO4)2 on γ-Al2O3 in flowing H2 at 400 °C yields bimetallic nanoparticles 1–2 nm in size that exhibit significant interaction between the metals, as evidenced by temperature-programmed hydride decomposition (complete suppression of β-PdHx formation), extended X-ray absorption fine structure spectroscopy at the Pd K and Re LIII edges (PdRe distance = 2.72 Å), and scanning transmission electron microscopy with energy dispersive X-ray analysis. In contrast, calcination of [Pd(NH3)4](ReO4)2 on γ-Al2O3 at 350 °C in air and subsequent reduction in H2 at 400 °C results in metal segregation and formation of large (>50 nm) supported Pd particles; Re species cover the Pd particles and γ-Al2O3 support. A PdRe 1:2 catalyst prepared by sequential impregnation and calcination using HReO4 and [Pd(NH3)4](NO3)2 has a similar morphology. The catalyst derived by direct reduction of [Pd(NH3)4](ReO4)2 on γ-Al2O3 exhibits remarkably high activity for selective hydrogenation of furfural to furfuryl alcohol (FAL) at 150 °C and 1 atm. Suppression of H2 chemisorption via elimination of Pd threefold sites, as evidenced by CO diffuse-reflectance infrared Fourier transform spectroscopy, correlates with increased FAL selectivity.

  6. Synthesis and structural characterization of two cobalt phosphites: 1-D (H3NC6H4NH3)Co(HPO3)2 and 2-D (NH4)2Co2(HPo3)3

    International Nuclear Information System (INIS)

    Cheng, C.-C.; Chang, W.-K.; Chiang, R.-K.; Wang, S.-L.

    2010-01-01

    Two new cobalt phosphites, (H 3 NC 6 H 4 NH 3 )Co(HPO 3 ) 2 (1) and (NH 4 ) 2 Co 2 (HPO 3 ) 3 (2), have been synthesized and characterized by single-crystal X-ray diffraction. All the cobalt atoms of 1 are in tetrahedral CoO 4 coordination. The structure of 1 comprises twisted square chains of four-rings, which contain alternating vertex-shared CoO 4 tetrahedra and HPO 3 groups. These chains are interlinked with trans-1,4-diaminocyclohexane cations by hydrogen bonds. The 2-D structure of 2 comprises anionic complex sheets with ammonium cations present between them. An anionic complex sheet contains three-deck phosphite units, which are interconnected by Co 2 O 9 to form complex layers. Magnetic susceptibility measurements of 1 and 2 showed that they have a weak antiferromagnetic interaction. - Graphical abstract: The 2-D structure of (NH 4 ) 2 Co 2 (HPO 3 ) 3 comprises anionic complex sheets with ammonium cations present between them. An anionic complex sheet contains three-deck phosphite units, which are interconnected by dimmeric Co 2 O 9 to form complex layers.

  7. Polyacrylamide+Al2(SO4)3 and polyacrylamide+CaO remove coliform bacteria and nutrients from swine wastewater

    International Nuclear Information System (INIS)

    Entry, J.A.; Phillips, Ian; Stratton, Helen; Sojka, R.E.

    2003-01-01

    Polyacrylamide mixture may be able to reduce run-off of enteric bacteria from animal wastes. - Animal wastes are a major contributor of nutrients and enteric microorganisms to surface water and ground water. Polyacrylamide (PAM) mixtures are an effective flocculent, and we hypothesized that they would reduce transport of microorganisms in flowing water. After waste water running at 60.0 l min -1 flowed over PAM+Al 2 (SO 4 ) 3 , or PAM+CaO in furrows, total coliform bacteria (TC) and fecal coliform bacteria (FC) were reduced by 30-50% at 1 and 50 m downstream of the treatments compared to the control. In a column study, PAM+Al 2 (SO 4 ) 3 , and PAM+CaO applied to sandy, sandy loam, loam, and clay soils reduced NH 4 + and ortho-P concentrations in leachate compared to the source waste water and the control. PAM+Al 2 (SO 4 ) 3 and PAM+CaO applied to sandy, sandy loam and loam soils reduced both total and ortho-P, concentrations in leachate compared to the source wastewater and control treatment. In a field study, PAM+Al 2 (SO 4 ) 3 , or PAM+CaO treatments did not consistently reduce NH 4 + , NO 3 - , ortho-P, and total P concentrations in wastewater flowing over any soil compared to inflow wastewater or the control treatment. With proper application PAM+ Al 2 (SO 4 ) 3 and PAM+CaO may be able to reduce the numbers of enteric bacteria in slowly flowing wastewater running off animal confinement areas, reducing the amount of pollutants entering surface water and groundwater

  8. Importance of including ammonium sulfate ((NH42SO4 aerosols for ice cloud parameterization in GCMs

    Directory of Open Access Journals (Sweden)

    P. S. Bhattacharjee

    2010-02-01

    Full Text Available A common deficiency of many cloud-physics parameterizations including the NASA's microphysics of clouds with aerosol-cloud interactions (hereafter called McRAS-AC is that they simulate lesser (larger than the observed ice cloud particle number (size. A single column model (SCM of McRAS-AC physics of the GEOS4 Global Circulation Model (GCM together with an adiabatic parcel model (APM for ice-cloud nucleation (IN of aerosols were used to systematically examine the influence of introducing ammonium sulfate (NH42SO4 aerosols in McRAS-AC and its influence on the optical properties of both liquid and ice clouds. First an (NH42SO4 parameterization was included in the APM to assess its effect on clouds vis-à-vis that of the other aerosols. Subsequently, several evaluation tests were conducted over the ARM Southern Great Plain (SGP and thirteen other locations (sorted into pristine and polluted conditions distributed over marine and continental sites with the SCM. The statistics of the simulated cloud climatology were evaluated against the available ground and satellite data. The results showed that inclusion of (NH42SO4 into McRAS-AC of the SCM made a remarkable improvement in the simulated effective radius of ice cloud particulates. However, the corresponding ice-cloud optical thickness increased even more than the observed. This can be caused by lack of horizontal cloud advection not performed in the SCM. Adjusting the other tunable parameters such as precipitation efficiency can mitigate this deficiency. Inclusion of ice cloud particle splintering invoked empirically further reduced simulation biases. Overall, these changes make a substantial improvement in simulated cloud optical properties and cloud distribution particularly over the Intertropical Convergence Zone (ITCZ in the GCM.

  9. Effect of interactions between carbon dioxide enrichment and NH4+/NO3- ratio on pH of culturing nutrient solution,growth and vigor of tomato root system

    Institute of Scientific and Technical Information of China (English)

    Juan LI; Jianmin ZHOU

    2008-01-01

    A growth chamber experiment was conducted to investigate the influence of NH4+/NO3- ratio and elevated CO2 concentration on the pH in nutrient solution,growth and root vigor system of tomato seedling roots,which attempts to understand whether the elevated CO2 concentration can alleviate the harmful effects of higher NH4+-N concentration in nutrient solutions on the tomato root system.Tomato (Lycopersicon esculenturn Mill.var.Hezuo 906) was grown in pots with nutrient solutions varying in NH4+/NO3- ratio (0:1,1:3,1:1,3:1and 1:0) and the growth chambers were supplied with with the growth process and CO2 concentration increased.At both CO2 levels,pH increased when 100% NO3--N was supplied and decreased in other treatments.The pH decrease in the nutrient solution was directly correlated to the NH4+-N proportion.The pH value was more reduced in 100% NH4+-N nutrient solution than increased in the 100% NO3--N nutrient solution.CO2 enrichment increased the dry weight of shoots and roots,root vigor system,total absorbing area and active absorbing area of tomato seedlings.All the measurement indexes above were increased in the elevated CO2 concentration treatment with the NO3- proportion increase in the nutrient solutions.Thus,under the elevated CO2 concentration,the dry weights of shoots and roots,root vigor system,total root absorbing area and active absorbing area were found to be inversely correlated to NH4+/NO3- ratio,leading to about 65.8%,78.0%,18.9%,12.9% and 18.9% increase,respectively,compared with that under the ambient CO2 concentration.Our results indicated that tomato seedling roots may benefit mostly from CO2 enrichment when 100% NO3--N nutrient solutions was supplied,but the CO2 concentration elevation did not alleviate the harmful effects when 100% NHa+-N was supplied.

  10. Thermal properties and phase transition in the fluoride, (NH4)3SnF7

    International Nuclear Information System (INIS)

    Kartashev, A.V.; Gorev, M.V.; Bogdanov, E.V.; Flerov, I.N.; Laptash, N.M.

    2016-01-01

    Calorimetric, dilatometric and differential thermal analysis studies were performed on (NH 4 ) 3 SnF 7 for a wide range of temperatures and pressures. Large entropy (δS 0 =22 J/mol K) and elastic deformation (δ(ΔV/V) 0 =0.89%) jumps have proven that the Pa-3↔Pm-3m phase transition is a strong first order structural transformation. A total entropy change of ΔS 0 =32.5 J/mol K is characteristic for the order–disorder phase transition, and is equal to the sum of entropy changes in the related material, (NH 4 ) 3 TiF 7 , undergoing transformation between the two cubic phases through the intermediate phases. Hydrostatic pressure decreases the stability of the high temperature Pm-3m phase in (NH 4 ) 3 SnF 7 , contrary to (NH 4 ) 3 TiF 7 , characterised by a negative baric coefficient. The effect of experimental conditions on the chemical stability of (NH 4 ) 3 SnF 7 was observed. - Graphical abstract: Strong first order structural transformation Pa-3↔Pm-3m in (NH 4 ) 3 SnF 7 is associated with very large total entropy change of ΔS 0 =32.5 J/mol K characteristic for the ordering processes and equal to the sum of entropy changes in the related (NH 4 ) 3 TiF 7 undergoing transformation between the same two cubic phases through the intermediate phases. - Highlights: • (NH 4 ) 3 SnF 7 undergoes strong first order Pa-3↔Pm-3m phase transition. • Anomalous behaviour of ΔC p and ΔV/V exists far below phase transition temperature. • Structural distortions are accompanied by huge total entropy change ΔS≈Rln50. • High pressure strongly increases the stability of Pa-3 phase in (NH 4 ) 3 SnF 7 . • Entropy of the Pa-3↔Pm-3m phase transition does not depend on pressure.

  11. Surface study of platinum decorated graphene towards adsorption of NH_3 and CH_4

    International Nuclear Information System (INIS)

    Rad, Ali Shokuhi; Pazoki, Hossein; Mohseni, Soheil; Zareyee, Daryoush; Peyravi, Majid

    2016-01-01

    To distinguish the potential of graphene sensors, there is a need to recognize the interaction between graphene sheet and adsorbing molecules. We used density functional theory (DFT) calculations to study the properties of pristine as well as Pt-decorated graphene sheet upon adsorption of NH_3 and CH_4 on its surface to exploit its potential to be as gas sensors for them. We found much higher adsorption, higher charge transfer, lower intermolecular distance, and higher orbital hybridizing upon adsorption of NH_3 and CH_4 gas molecules on Pt-decorated graphene compared to pristine graphene. Also our calculations reveal that the adsorption energies on Pt-decorated graphene sheet are in order of NH_3 >CH_4 which could be corresponded to the order of their sensitivity on this modified surface. We used orbital analysis including density of states as well as frontier molecular orbital study for all analyte-surface systems to more understanding the kind of interaction (physisorption or chemisorption). Consequently, the Pt-decorated graphene can transform the existence of NH_3 and CH_4 molecules into electrical signal and it may be potentially used as an ideal sensor for detection of NH_3 and CH_4 in ambient situation. - Highlights: • Pt-decorated graphene was investigated as an adsorbent for NH_3 and CH_4. • Much higher adsorption of NH_3 and CH_4 on Pt-decorated graphene than pristine graphene. • Higher adsorption of NH_3 compared to CH_4 on Pt-decorated graphene. • Pt influences the electronic structure of graphene.

  12. Nitrogen fertilization (15NH4NO3 of palisadegrass and residual effect on subsequent no-tillage corn

    Directory of Open Access Journals (Sweden)

    Emerson Borghi

    2014-10-01

    Full Text Available Nitrogen is required in large amounts by plants and their dinamics in corn and perennial forages intercropped is little known. This study analyzed the efficiency of nitrogen fertilization (15NH4NO3 applied after corn grain harvest to palisadegrass (Brachiaria brizantha cv. Marandu in intercrops sown at two times, as well as the N residual effect on the subsequent corn crop. The field experiment was performed in Botucatu, São Paulo State, in southeastern Brazil, on a structured Alfisol under no-tillage. The experiment was arranged in a randomized block design in a split plot scheme with four replications. The main plots consisted of two intercropping systems (corn and palisadegrass sown together and palisadegrass sown later, at corn top-dressing fertilization. The subplots consisted of four N rates (0, 30, 60, and 120 kg ha-1 N. The subplots contained microplots, in which enriched ammonium nitrate (15NH4NO3 was applied at the same rates. The time of intercrop sowing affected forage dry matter production, the amount of fertilizer-derived N in and the N use efficiency by the forage plants. Nitrogen applied in autumn to palisadegrass intercropped with corn, planted either at corn sowing or at N top-dressing fertilization, increased the forage yield up to a rate of 60 kg ha-1. The amount of fertilizer-derived N by the forage plants and the fertilizer use efficiency by palisadegrass were highest 160 days after fertilization for both intercrop sowing times, regardless of N rates. Residual N did not affect the N nutrition of corn plants grown in succession to palisadegrass, but increased grain yield at rates of 60 and 120 kg ha-1 N, when corn was grown on palisadegrass straw from the intercrop installed at corn fertilization (top-dressing. Our results indicated that the earlier intercropping allowed higher forage dry matter production. On the other hand, the later intercrop allowed a higher corn grain yield in succession to N-fertilized palisadegrass.

  13. Biomass accumulation, photochemical efficiency of photosystem II, nutrient contents and nitrate reductase activity in young rosewood plants (Aniba rosaeodora Ducke submitted to different NO3-:NH4+ ratios Acúmulo de biomassa, eficiência fotoquímica do fotossistema II, conteúdo de nutrientes e atividade da redutase do nitrato em plantas jovens de pau-rosa (Aniba rosaeodora Ducke submetidas a diferentes relações NO3-:NH4+

    Directory of Open Access Journals (Sweden)

    Denize Caranhas de Sousa Barreto

    2007-01-01

    Full Text Available The rosewood (Aniba rosaeodora Ducke is a native tree species of Amazon rainforest growing naturally in acidic forest soils with reduced redox potential. However, this species can also been found growing in forest gaps containing oxide soils. Variations in the forms of mineral nitrogen (NO3- or NH4+ may be predicted in these different edaphic conditions. Considering that possibility, an experiment was carried out to analyze the effects of different NO3-:NH4+ ratios on the growth performance, mineral composition, chloroplastid pigment contents, photochemical efficiency photosystem II (PSII, and nitrate redutase activity (RN, E.C.1.6.6.1 on A. rosaeodora seedlings. Nine-month-old seedlings were grown in pots with a washed sand capacity of 7.5 kg and submitted to different NO3-:NH4+ ratios (T1 = 0:100%, T2 = 25:75%, T3 = 50:50%, T4 = 75:25%, and T5 = 100:0%. The lowest relative growth rate was observed when the NO3-:NH4+ ratio was equal to 0:100%. In general, high concentrations of NO3- rather than NH4+ favored a greater nutrient accumulation in different parts of the plant. For the chloroplastid pigment, the highest Chl a, Chl b, Chl tot, Chl a/b and Chl tot/Cx+c contents were found in the treatment with 75:25% of NO3-:NH4+, and for Chl b and Cx+c it was observed no difference. In addition, there was a higher photochemical efficiency of PSII (Fv/Fm when high NO3- concentrations were used. A linear and positive response for the nitrate reductase activity was recorded when the nitrate content increased on the culture substrate. Our results suggest that A. rosaeodora seedlings have a better growth performance when the NO3- concentrations in the culture substrate were higher than the NH4+ concentrations.O pau-rosa (Aniba rosaeodora Ducke habita, naturalmente, solos florestais ácidos com potencial redox reduzido. No entanto, estas espécies têm sido encontradas também em clareiras que, teoricamente, apresentam solos mais oxidados. Nestas diferentes

  14. Nitrogen-Utilization by Plant-Species from Acid Heathland Soils .2. Growth and Shoot/Root Partitioning of No3- Assimilation at Constant Low Ph and Varying No3-/Nh4+ Ratio

    NARCIS (Netherlands)

    Troelstra, S.R.; Wagenaar, R.; Smant, W.

    1995-01-01

    The growth of four heathland species, two grasses (D. flexuosa, M. caerulea) and two dwarf shrubs (C. vulgaris, E. tetralix), was tested in solution culture at pH 4.0 with 2 mol m(-3) N, varying the NO3-/NH4+ ratio up to 40% nitrate. In addition, measurements of NRA, plant chemical composition, and

  15. Ferroelectric TGS ((NH sub 2 CH sub 2 COOH) sub 3 centre dot H sub 2 SO sub 4) under high pressure

    CERN Document Server

    Kobayashi, Y; Furuta, H; Endo, S; Deguchi, K

    2002-01-01

    The ferroelectric transition temperature T sub c of (NH sub 2 CH sub 2 COOH) sub 3 centre dot H sub 2 SO sub 4 (TGS), which is a typical order-disorder-type ferroelectric, was determined by dielectric constant and Raman scattering measurements under high pressure. T sub c increased, passed through a maximum and then decreased slightly with increasing pressure, and then abruptly dropped at about 2.5 GPa, where a transition to a new high-pressure phase was confirmed to exist. A tentative p-T phase diagram was proposed for TGS.

  16. The preferential form of nitrogen absorption (15NH4+ or 15NO3-) by soy beans, beans, rice and corn crops

    International Nuclear Information System (INIS)

    Heinrichs, Reges; Gava, Glauber Jose; Corazza, Edemar Joaquim; Duete, Robson Rui Cotrin; Villanueva, Felipe Carlos Alvarez; Muraoka, Takashi

    2006-01-01

    In annual crops, the nitrogen fertilizer application practice can supply the nitrogen needed for maximum yield. However, taking into account the damaging effects on the environment of improperly planned fertilizer use, it is necessary to adjust the amount and the forms of N to be applied according to crop requirement. Viewing to determine the N form which is preferentially absorbed by the plants at their initial growth stage, an experiment was carried out under green house conditions in a Hapludox soil. Ammonium nitrate (AN) in which 2% of the N was labelled N ( 15 N) either as NH 4+ or as NO 3- was used. The AN solution was then applied onto the soil surface of each vase at the rate of 100 mg of N either at sowing or 10 days later. The results showed that the soybean plants, when fertilization was made at sowing, had no preferred form of N. But, if fertilization took place 10 days after sowing, the NH 4+ form was the preferred one. Common bean plants showed no preferred form. Rice plants preferred the NH 4+ form irrespective of fertilization time. Corn plants preferred the ammoniacal form when fertilization was made at sowing. (author)

  17. Synthesis and crystal structure of 4-fluorobenzylammonium dihydrogen phosphate, [FC6H4CH2NH3]H2PO4

    Directory of Open Access Journals (Sweden)

    Ali Rayes

    2016-12-01

    Full Text Available The asymmetric unit of the title salt, [p-FC6H4CH2NH3]+·H2PO4−, contains one 4-fluorobenzylammonium cation and one dihydrogen phosphate anion. In the crystal, the H2PO4− anions are linked by O—H...O hydrogen bonds to build corrugated layers extending parallel to the ab plane. The FC6H4CH2NH3+ cations lie between these anionic layers to maximize the electrostatic interactions and are linked to the H2PO4− anions through N—H...O hydrogen bonds, forming a three-dimensional supramolecular network. Two hydrogen atoms belonging to the dihydrogen phosphate anion are statistically occupied due to disorder along the OH...HO direction.

  18. Preparation and characterization of organic-inorganic hybrid perovskite (C4H9NH3)2CuCl4

    International Nuclear Information System (INIS)

    Xiao Zelong; Chen Hongzheng; Shi Minmin; Wu Gang; Zhou Renjia; Yang Zhisheng; Wang Mang; Tang Benzhong

    2005-01-01

    Organic-inorganic hybrid perovskite (C 4 H 9 NH 3 ) 2 CuCl 4 was prepared via the reaction between copper chloride and butylammonium chloride. Its chemical structure was characterized by FT-IR and elemental analysis. Its thin film was obtained by spin-coating, and X-ray diffraction (XRD) measurements indicated the formation of two-dimensional layered perovskites structure, with the c-axis perpendicular to the substrate surface. The electronic structure, thermal properties and electrical properties of the hybrid perovskite (C 4 H 9 NH 3 ) 2 CuCl 4 were also studied by UV-vis, photoluminescience (PL), TGA, DSC, and Hall measurement

  19. Effect of sulfated CaO on NO reduction by NH{sub 3} in the presence of excess oxygen

    Energy Technology Data Exchange (ETDEWEB)

    Tianjin Li; Yuqun Zhuo; Yufeng Zhao; Changhe Chen; Xuchang Xu [Tsinghua University, Beijing (China). Key Laboratory for Thermal Science and Power Engineering of Ministry of Education

    2009-04-15

    The effect of sulfated CaO on NO reduction by NH{sub 3} in the presence of excess oxygen was investigated to evaluate the potential of simultaneous SO{sub 2} and NO removal at the temperature range of 700-850{sup o}C. The physical and chemical properties of the CaO sulfation products were analyzed to investigate the NO reduction mechanism. Experimental results showed that sulfated CaO had a catalytic effect on NO reduction by NH{sub 3} in the presence of excess O{sub 2} after the sulfation reaction entered the transition control stage. With the increase of CaO sulfation extent in this stage, the activity for NO reduction first increased and then decreased, and the selectivity of NH{sub 3} for NO reduction to N{sub 2} increased. The byproduct (NO{sub 2} and N{sub 2}O) formation during NO reduction experiments was negligible. X-ray photoelectron spectroscopy (XPS) analysis showed that neither CaSO{sub 3} nor CaS was detected, indicating that the catalytic activity of NO reduction by NH{sub 3} in the presence of excess O{sub 2} over sulfated CaO was originated from the CaSO{sub 4} product. These results revealed that simultaneous SO{sub 2} and NOx control by injecting NH{sub 3} into the dry flue gas desulfurization process for NO reduction might be achieved. 38 refs., 6 figs., 1 tab.

  20. 1/4-BPS M-theory bubbles with SO(3) x SO(4) symmetry

    International Nuclear Information System (INIS)

    Kim, Hyojoong; Kim, Kyung Kiu; Kim, Nakwoo

    2007-01-01

    In this paper we generalize the work of Lin, Lunin and Maldacena on the classification of 1/2-BPS M-theory solutions to a specific class of 1/4-BPS configurations. We are interested in the solutions of 11 dimensional supergravity with SO(3) x SO(4) symmetry, and it is shown that such solutions are constructed over a one-parameter familiy of 4 dimensional almost Calabi-Yau spaces. Through analytic continuations we can obtain M-theory solutions having AdS 2 x S 3 or AdS 3 x S 2 factors. It is shown that our result is equivalent to the AdS solutions which have been recently reported as the near-horizon geometry of M2 or M5-branes wrapped on 2 or 4-cycles in Calabi-Yau threefolds. We also discuss the hierarchy of M-theory bubbles with different number of supersymmetries

  1. Imaging a multidimensional multichannel potential energy surface: Photodetachment of H{sup −}(NH{sub 3}) and NH{sub 4}{sup −}

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Qichi; Johnson, Christopher J.; Continetti, Robert E., E-mail: hguo@umn.edu, E-mail: rcontinetti@ucsd.edu [Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0340 (United States); Song, Hongwei; Guo, Hua, E-mail: hguo@umn.edu, E-mail: rcontinetti@ucsd.edu [Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131 (United States); Li, Jun [School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044 (China)

    2016-06-28

    Probes of the Born-Oppenheimer potential energy surfaces governing polyatomic molecules often rely on spectroscopy for the bound regions or collision experiments in the continuum. A combined spectroscopic and half-collision approach to image nuclear dynamics in a multidimensional and multichannel system is reported here. The Rydberg radical NH{sub 4} and the double Rydberg anion NH{sub 4}{sup −} represent a polyatomic system for benchmarking electronic structure and nine-dimensional quantum dynamics calculations. Photodetachment of the H{sup −}(NH{sub 3}) ion-dipole complex and the NH{sub 4}{sup −} DRA probes different regions on the neutral NH{sub 4} PES. Photoelectron energy and angular distributions at photon energies of 1.17, 1.60, and 2.33 eV compare well with quantum dynamics. Photoelectron-photofragment coincidence experiments indicate dissociation of the nascent NH{sub 4} Rydberg radical occurs to H + NH{sub 3} with a peak kinetic energy of 0.13 eV, showing the ground state of NH{sub 4} to be unstable, decaying by tunneling-induced dissociation on a time scale beyond the present scope of multidimensional quantum dynamics.

  2. A non-typical sequence of phase transitions in (NH4)3GeF7: optical and structural characterization.

    Science.gov (United States)

    Mel'nikova, S V; Molokeev, M S; Laptash, N M; Misyul, S V

    2016-03-28

    Single crystals of germanium double salt (NH4)3GeF7 = (NH4)2GeF6·NH4F = (NH4)3[GeF6]F were grown and studied by the methods of polarization optics and X-ray diffraction. The birefringence Δn = (no - ne), the rotation angle of the optical indicatrix ϕ(T) and unit cell parameters were measured in the temperature range 100-400 K. Three structural phase transitions were found at the temperatures: T1↓ = 279.2 K (T1↑ = 279.4 K), T2↑ = 270 K (T2↓ = 268.9 K), T3↓ = 218 K (T3↑ = 227 K). An unusual sequence of symmetry transformations with temperature change was established: P4/mbm (Z = 2) (G1) ↔ Pbam (Z = 4) (G2) ↔ P21/c (Z = 4) (G3) ↔ Pa3[combining macron] (Z = 8) (G4). The crystal structures of different phases were determined. The experimental data were additionally interpreted by a group-theoretical analysis of the complete condensate of order parameters taking into account the critical and noncritical atomic displacements. Strengthening of the N-HF hydrogen bonds can be a driving force of the observed phase transitions.

  3. Изучение фазовых равновесий в четверных системах Co(NH2)2 - NH4Cl - (NH4)2SO4 - H2O и Co(NH2)2 - NH4Cl - (NH4)2HPO4 - H2O при 25C° оптимизированным методом сечений

    OpenAIRE

    Носков, М.; Мазунин, С.

    2012-01-01

    Оптимизированным методом сечений впервые были изучены фазовые равновесия в четверных системах CO(NH2)2 − NH4Cl − (NH4)2SO4 − H2O и CO(NH2)2 − NH4Cl − (NH4)2HPO4 − H2O и оконтуривающих трехкомпонентных системах CO(NH2)2 − NH4Cl − H2O (с образованием инконгруэнтно растворимого химического соединения), CO(NH2)2 − (NH4)2SO4 − H2O и CO(NH2)2 − (NH4)2HPO4 − H2O (изотермы простого эвтонического типа) при 25°C. Установлены составы равновесных жидких и твердых фаз, находящихся в эвтоническом и перитон...

  4. Electrochemical and SEM studies of tetra-ammine platinum (II) (Pt(NH3)4)(OH)2 solution

    International Nuclear Information System (INIS)

    Wan Jeffrey Basirun

    2002-01-01

    Electrochemical studies include cyclic voltammetry with microelectrodes were done on a solution of tetra-ammine platinum (II) (Pt(NH 3 ) 4 )(OH) 2 at pH 13 and showed that the electrochemical reduction of this compound was no different from the tetra-ammine platinum (II) (Pt(NH 3 ) 4 )(HPO 4 ) at pH 10.4. The solution was instable to high temperatures and results have shown that electroplating can be done at a limited temperature range for longer periods of time or at higher temperatures for short periods of time. Scanning electron microscopy was done on some of the constant current electrodeposited samples at high temperatures and result obtained was satisfactory. (Authors)

  5. Separation and Recovery of Iron and Rare Earth from Bayan Obo Tailings by Magnetizing Roasting and (NH4)2SO4 Activation Roasting

    OpenAIRE

    Yan Zhou; He Yang; Xiang-xin Xue; Shuai Yuan

    2017-01-01

    A novel approach for recovery of iron and rare earth elements (REEs) from Bayan Obo tailings of Baotou, China, was developed by combining magnetizing roasting, magnetic separation, (NH4)2SO4 activation roasting, and water leaching. Thermodynamic analysis of carbothermal reduction was conducted to determine the temperature of magnetizing roasting, and it agreed well with the experimental results. The maximum recovery of Fe reached 77.8% at 600 °C, and the grade of total Fe in the magnetic conc...

  6. Investigation of the Dynamics Of NH{sup +}{sub 4} and H{sub 2}O Molecular Groups in Crystals; Etude de la Dynamique des Groupes Moleculaires NH{sup +}{sub 4} et H{sub 2}O dans les Cristaux; 0418 0421 0421 041b 0415 0414 041e 0412 0410 041d 0418 0415 0414 0418 041d 0410 041c 0418 041a 0418 041c 041e 041b 0415 041a 0423 041b 042f 0420 041d 042b 0425 0413 0420 0423 041f 041f NH{sup +}{sub 4} H H{sub 2}O 0412 041a 0420 0418 0421 0422 0410 041b 041b 0410 0425 ; Estudio de la Dinamica de los Grupos Moleculares NH{sup +}{sub 4} Y H{sub 2}O en Cristales

    Energy Technology Data Exchange (ETDEWEB)

    Bajorek, A.; Machehina, T. A.; Parlin' Ski, K. [Ob' edinennyj Institut Jadernyh Issledovanij, Dubna, SSSR (Russian Federation)

    1965-06-15

    The authors give the results of thermal neutron scattering measurements in crystals containing ammonium ion (NH{sub 4}CI, NH{sub 4}Br, NH{sub 4}I, NH{sub 4}F, NH{sub 4}NO{sub 3}, NH{sub 4}CNS, (NH{sub 4}){sub 2}SO{sub 4}, (NH{sub 4}){sub 2}S{sub 2}O{sub 8}, (NH{sub 4}){sub 2}Cr{sub 2}O{sub 7}, (NH{sub 4}){sub 2}CO{sub 3}) and water of crystallization (BaCl{sub 2} * 2H{sub 2}O, SrCl{sub 2} * 6H{sub 2}O, CuSO{sub 4} * 5H{sub 2}O) . The investigations were made to study the influence of various crystal lattices on the dynamics of these groups and the connection between scattering processes and phase transitions. In spite of the structural differences of the substances examined, the spectra obtained at the temperature of liquid nitrogen proved to be similar. As a rule, there are two peaks, one in the 15-20 meV energy transfer range, and the other in the 35-70 meV range, associated with the torsional vibrations of.ammonium ions. The intensity of the peaks depends on the structure of the substances under examination and falls as the sample temperature rises. It was found that there is a jump in the elastic region of the spectrum at certain phase transitions (in the cases of NH{sub 4}I, NH{sub 4}NO{sub 3} and (NH{sub 4}){sub 2}SO{sub 4}). At increased temperatures an additional peak appears in NH{sub 4}Cl, NH{sub 4}Br and (NH{sub 4}){sub 2}(COO){sub 2} to the lower energy side of the rotational retardation peak. The spectra of neutrons scattered in crystals containing water of crystallization also resemble one another. Three groups of peaks are observed in the spectra, associated with optical vibrations and rotational retardation of the water molecules. (author) [French] Us auteurs indiquent les resultats qu'ils ont obtenus en mesurant la diffusion des neutrons thermiques par des cristaux contenant un ion ammonium (NH{sub 4}CI, NH{sub 4}Br, NH{sub 4}I, NH{sub 4}F, NH{sub 4}NO{sub 3}, NH{sub 4}CNS, (NH{sub 4}){sub 2}SO{sub 4}, (NH{sub 4}){sub 2}S{sub 2}O{sub 8}, (NH{sub 4

  7. Infrared spectra of the ammonium ion in ammonium hexavanadate (NH 4) 2V 6O 16

    Science.gov (United States)

    de Waal, D.; Heyns, A. M.; Range, K.-J.; Eglmeier, C.

    The infrared bands of the NH +4 and ND +4 groups in (NH 4) 2V 6O 16 and its deuterated analogue can be assigned with a fair amount of certainty at 90 K under the space group P2 1/ m( C22 h). The ND stretching modes of isotopically dilute NH 3D + ions in the crystal are in agreement with the predicted splitting into Cs, Cs and C1(2) components. The frequencies, shapes and temperature dependence of these modes suggest that both normal and bifurcated hydrogen bonds are formed. The latter closely resembles corresponding bonds in NH 4VO 3, but the normal hydrogen bonds are not as strong as the similar bonds in NH 4VO 3. This can be expected as NH +4 ions are dynamic in character in (NH 4) 2V 6O 16 and remain so down to temperatures of 90 K.

  8. Complexing in (NH4)2SeO4-UO2SeO4 H2O system

    International Nuclear Information System (INIS)

    Serezhkina, L.B.

    1994-01-01

    Isotherm of solubility in the (NH 4 ) 2 SeO 4 -UO 2 SeO 4 -H 2 O system has been constructed at 25 deg C. (NH 4 ) 2 (UO 2 ) 2 (SeO 4 ) 3 x6H 2 O formation is established for the first time and certain its physicochemical properties are determined. Regularities of complexing in the R 2 Se) 4 -UO 2 SeO 4 -H 2 O systems, where R-univalent cation are under discussion. 6 refs.; 3 tabs

  9. Potential NH{sub 4}{sup +} and NO{sub 3}{sup -} uptake on various Sphagnum species

    Energy Technology Data Exchange (ETDEWEB)

    Jauhiainen, J [Joensuu Univ. (Finland). Dept. of Biology; Wallen, B; Malmer, N [Lund Univ. (Sweden). Dept. of Plant Ecology

    1997-12-31

    The objective of this research is to test differences in NH{sub 4}{sup +} and NO{sub 3}{sup -} uptake on various Sphagnum species under laboratory conditions. The studied species represent two gradients: the minerotrophy-ombrotrophy (mire margin - mire expanse) gradient, and the hummock-hollow gradient. There are distinct differences in the uptake rate between various Sphagnum species and these differences seem to be due to both structural and environmental factors: (1) on individual basis the highest uptake rate is in species with large capitulum and high number of ion exchange sites i.e. lawn species, (2) on dry mass basis the most effective species are the hummock species though they have a low DM, (3) from the ecosystem point of view, hummock species with high number of shoots per unit area and high uptake rate on dry mass basis, are the most effective species in filtering available nitrogen. (1 ref.)

  10. Potential NH{sub 4}{sup +} and NO{sub 3}{sup -} uptake on various Sphagnum species

    Energy Technology Data Exchange (ETDEWEB)

    Jauhiainen, J. [Joensuu Univ. (Finland). Dept. of Biology; Wallen, B.; Malmer, N. [Lund Univ. (Sweden). Dept. of Plant Ecology

    1996-12-31

    The objective of this research is to test differences in NH{sub 4}{sup +} and NO{sub 3}{sup -} uptake on various Sphagnum species under laboratory conditions. The studied species represent two gradients: the minerotrophy-ombrotrophy (mire margin - mire expanse) gradient, and the hummock-hollow gradient. There are distinct differences in the uptake rate between various Sphagnum species and these differences seem to be due to both structural and environmental factors: (1) on individual basis the highest uptake rate is in species with large capitulum and high number of ion exchange sites i.e. lawn species, (2) on dry mass basis the most effective species are the hummock species though they have a low DM, (3) from the ecosystem point of view, hummock species with high number of shoots per unit area and high uptake rate on dry mass basis, are the most effective species in filtering available nitrogen. (1 ref.)

  11. NH4HCO3 gas-generating liposomal nanoparticle for photoacoustic imaging in breast cancer

    Directory of Open Access Journals (Sweden)

    Xia J

    2017-03-01

    Full Text Available Jizhu Xia, Gang Feng, Xiaorong Xia, Lan Hao, Zhigang Wang Chongqing Key Laboratory of Ultrasound Molecular Imaging, Department of Ultrasound, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, People’s Republic of China Abstract: In this study, we have developed a biodegradable nanomaterial for photoacoustic imaging (PAI. Its biodegradation products can be fully eliminated from a living organism. It is a gas-generating nanoparticle of liposome-encapsulating ammonium bicarbonate (NH4HCO3 solution, which is safe, effective, inexpensive, and free of side effects. When lasers irradiate these nanoparticles, NH4HCO3 decomposes to produce CO2, which can absorb much of the light energy under laser irradiation with a specific wavelength, and then expand under heat to generate a thermal acoustic wave. An acoustic detector can detect this wave and show it as a photoacoustic signal on a display screen. The intensity of the photoacoustic signal is enhanced corresponding to an increase in time, concentration, and temperature. During in vivo testing, nanoparticles were injected into tumor-bearing nude mice through the caudal vein, and photoacoustic signals were detected from the tumor, reaching a peak in 4 h, and then gradually disappearing. There was no damage to the skin or subcutaneous tissue from laser radiation. Our developed gas-generating nanomaterial, NH4HCO3 nanomaterial, is feasible, effective, safe, and inexpensive. Therefore, it is a promising material to be used in clinical PAI. Keywords: Photoacoustic tomography, CO2, NH4HCO3, contrast agent, cancer

  12. Order-disorder phase transition in the peroxidovanadium complex NH4[VO(O2)2(NH3)].

    Science.gov (United States)

    Schwendt, Peter; Gyepes, Róbert; Chrappová, Jana; Němec, Ivan; Vaněk, Přemysl

    2018-07-05

    Complex NH 4 [VO(O 2 ) 2 (NH 3 )] (1) undergoes an order-disorder phase transition at T c ~258K. This transition is accompanied by change in the space group of the orthorhombic lattice and also by significant structural rearrangements of the constituent molecules, which are pertinent mostly to their NH 4 + ions and their ammonia ligands. The low-temperature solid state IR and Raman spectra of 1 were corroborated by solid-state computations that employed Gaussian functions as the basis set. Results of these computations yielded excellent agreement with experimental data. On the curves of temperature dependence of vibrational modes, the phase transition is expressed by an abrupt change of the slope above T c . Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Surface study of platinum decorated graphene towards adsorption of NH{sub 3} and CH{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Rad, Ali Shokuhi, E-mail: a.shokuhi@gmail.com [Department of Chemical Engineering, Qaemshahr Branch, Islamic Azad University, Qaemshahr (Iran, Islamic Republic of); Pazoki, Hossein; Mohseni, Soheil [Department of Chemical Engineering, Qaemshahr Branch, Islamic Azad University, Qaemshahr (Iran, Islamic Republic of); Zareyee, Daryoush [Department of Chemistry, Qaemshahr Branch, Islamic Azad University, Qaemshahr (Iran, Islamic Republic of); Peyravi, Majid [Faculty of Chemical Engineering, Babol University of Technology, Babol (Iran, Islamic Republic of)

    2016-10-01

    To distinguish the potential of graphene sensors, there is a need to recognize the interaction between graphene sheet and adsorbing molecules. We used density functional theory (DFT) calculations to study the properties of pristine as well as Pt-decorated graphene sheet upon adsorption of NH{sub 3} and CH{sub 4} on its surface to exploit its potential to be as gas sensors for them. We found much higher adsorption, higher charge transfer, lower intermolecular distance, and higher orbital hybridizing upon adsorption of NH{sub 3} and CH{sub 4} gas molecules on Pt-decorated graphene compared to pristine graphene. Also our calculations reveal that the adsorption energies on Pt-decorated graphene sheet are in order of NH{sub 3} >CH{sub 4} which could be corresponded to the order of their sensitivity on this modified surface. We used orbital analysis including density of states as well as frontier molecular orbital study for all analyte-surface systems to more understanding the kind of interaction (physisorption or chemisorption). Consequently, the Pt-decorated graphene can transform the existence of NH{sub 3} and CH{sub 4} molecules into electrical signal and it may be potentially used as an ideal sensor for detection of NH{sub 3} and CH{sub 4} in ambient situation. - Highlights: • Pt-decorated graphene was investigated as an adsorbent for NH{sub 3} and CH{sub 4}. • Much higher adsorption of NH{sub 3} and CH{sub 4} on Pt-decorated graphene than pristine graphene. • Higher adsorption of NH{sub 3} compared to CH{sub 4} on Pt-decorated graphene. • Pt influences the electronic structure of graphene.

  14. A feasible process for simultaneous removal of CO2, SO2 and NOx in the cement industry by NH3 scrubbing

    International Nuclear Information System (INIS)

    Dong, Ruifeng; Lu, Hongfang; Yu, Yunsong; Zhang, Zaoxiao

    2012-01-01

    Highlights: ► Simultaneous removal of CO 2 , SO 2 and NO x is realized by NH 3 scrubbing with NaClO 2 . ► The crystallization process of NH 4 HCO 3 is employed instead of CO 2 regeneration. ► Energy consumption reduces hugely while CO 2 removal rate remains higher than 90%. ► Exergy calculation reveals that a higher thermodynamic perfection degree is achieved. -- Abstract: With the rapid economic and industrial development, the concentration of carbon dioxide in the atmosphere is increasing enormously, which has greatly affected the global climate and human living environment. At present, a lot of technologies have been applied to CO 2 removal in fossil fuel-fired power plants, which are one of the main CO 2 emission sources. But few researches have been done in the cement industry, which is the third largest CO 2 emission source. There is no mature technology of CO 2 removal in cement industry mentioned before. This paper proposes a feasible process for simultaneous removal of CO 2 , SO 2 and NO x in the cement industry by NH 3 scrubbing. As there is no ready steam source for the regeneration of CO 2 -rich loading solvent after absorption, a process with the final product of ammonium bicarbonate is developed. With the oxidative additive of NaClO 2 added in the aqueous ammonium absorbent, the simultaneous removal of CO 2 , SO 2 and NO x is feasible by NH 3 scrubbing. The products of the process are mainly ammonium bicarbonate, ammonium sulfate and ammonium nitrate, which are all good fertilizers for crops and plants. The crystallization of NH 4 HCO 3 is easier for storage and transportation than that for liquid carbon dioxide, which becomes more stable when dicyandiamide (DCD) is added. The thermodynamic analysis proves that the proposed process has the advantages of energy conservation and high thermodynamic perfection degree compared with the traditional ones.

  15. The influence of a silica pillar in lamellar tetratitanate for selective catalytic reduction of NO{sub x} using NH{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Nogueira da Cunha, Beatriz; Gonçalves, Alécia Maria; Gomes da Silveira, Rafael [Institute of Chemistry, Federal University of Goiás, C. Postal 131, CEP 74001-970 Goiânia, GO (Brazil); Urquieta-González, Ernesto A. [Laboratory of Applied Catalysis, Department of Chemical Engineering, Federal University of Sao Carlos, Rodovia Washington Luis Km 235, C. Postal 676, CEP 13565-905 São Carlos, SP (Brazil); Magalhães Nunes, Liliane, E-mail: lilianemnunes@gmail.com [Institute of Chemistry, Federal University of Goiás, C. Postal 131, CEP 74001-970 Goiânia, GO (Brazil)

    2015-01-15

    Highlights: • Potassium ions significantly affected the SCR. • The introduction of silica in the catalyst promotes the NH{sub 3}-SCR reaction. • The catalysts activities were not significantly influenced by SO{sub 2} addition. - Abstract: Silica-pillared layered titanate (SiO{sub 2}–Ti{sub 4}O{sub 9}) was prepared by intercalating organosilanes into the interlayers of a layered K{sub 2}Ti{sub 4}O{sub 9} followed by calcination at 500 °C. The lamellar titanates produced were used as a support to prepare vanadium catalysts (1 and 2 wt%) through wet impregnation for selective catalytic reduction (SCR) of NO. The catalysts were characterized using nitrogen adsorption (BET), X-ray diffraction (XRD), temperature programmed reduction (H{sub 2}-TPR), nuclear magnetic resonance ({sup 29}Si NMR), and infrared spectroscopy (FT-IR). Reduction of NO by NH{sub 3} was studied in a fixed-bed reactor packed with the catalysts and fed a mixture comprising 1% NH{sub 3}, 1% NO, 10% O{sub 2}, and 34 ppm SO{sub 2} (when used) in helium. The results demonstrate that activity is correlated with the support, i.e., with acidic strength of catalysts. The potassium in the support, K{sub 2}Ti{sub 4}O{sub 9}, significantly affected the reaction and level of vanadium species reduction. The catalyst (1VSiT) with 1 wt% vanadium impregnated on the SiO{sub 2}–Ti{sub 4}O{sub 9} support reduced ∼80% of the NO. Approximately the same conversion rate was generated on the catalyst (2VSiT) with 2 wt% vanadium using the same support. The increased NH{sub 3} adsorption demonstrate that introduction of silica in the catalyst promotes the NH{sub 3}-SCR reaction. More importantly, 2VSiT and 1VSiT were strongly resistant to SO{sub 2} poisoning.

  16. Chemiluminescence of the Ce{sup 3+}* ions, and the {sup 1}ГђЕѕ{sub 2} and ({sup 1}ГђЕѕ{sub 2}){sub 2} molecular species of oxygen induced by active surface of the (NH{sub 4}){sub 2}Ce(NO{sub 3}){sub 6} crystals at reduction of Ce{sup 4+} to Ce{sup 3+} by water in heterogeneous system «(NH{sub 4}){sub 2}Ce(NO{sub 3}){sub 6}-C{sub 6}H{sub 6}-H{sub 2}O»

    Energy Technology Data Exchange (ETDEWEB)

    Bulgakov, Ramil G., E-mail: profbulgakov@yandex.ru [Laboratory of Negative Ions Mass Spectrometry, Institute of Molecule and Crystal Physics, Ufa Research Centre of the Russian Academy of Sciences, 71, Oktyabrya Prosp., 450054 Ufa (Russian Federation); Gazeeva, Dilara R., E-mail: galimovdi@mail.ru [Laboratory of High Energy Chemistry and Catalysis, Institute of Petrochemistry and Catalysis Russian Academy of Sciences, 141 Prosp. Oktyabrya, 450075 Ufa (Russian Federation); Galimov, Dim I. [Laboratory of High Energy Chemistry and Catalysis, Institute of Petrochemistry and Catalysis Russian Academy of Sciences, 141 Prosp. Oktyabrya, 450075 Ufa (Russian Federation)

    2017-03-15

    We have discovered an unusual new chemiluminescence (CL) in the title system, which is different from other known CL by unusual combination of various in nature emitters, namely, electronically excited state of the Ce{sup 3+}* ion (λ{sub max}=335 nm), singlet oxygen {sup 1}ГђЕѕ{sub 2} (emission near 1270 nm) and its dimer ({sup 1}ГђЕѕ{sub 2}){sub 2} (λ{sub max}=490, 645, 715 nm). The Ce{sup 3+}* ions and oxygen emitters {sup 1}O{sub 2} and ({sup 1}O{sub 2}){sub 2} are generated in the reaction of Ce{sup 4+} with water and hydrogen peroxide, respectively. CL is generated only in a heterogeneous system «(NH{sub 4}){sub 2}Ce(NO{sub 3}){sub 6}-C{sub 6}H{sub 6}-H{sub 2}O» and completely absent in a homogeneous solution (NH{sub 4}){sub 2}Ce(NO{sub 3}){sub 6} in water containing benzene. This is due to the fact that the redox processes and CL in the «(NH{sub 4}){sub 2}Ce(NO{sub 3}){sub 6}-C{sub 6}H{sub 6}-H{sub 2}O» system are induced by active surface of the (NH{sub 4}){sub 2}Ce(NO{sub 3}){sub 6} crystals. It is through the action of the active surface of the (NH{sub 4}){sub 2}Ce(NO{sub 3}){sub 6} crystals is carried out population of such a high energy level of 5d{sup 1} excited state of Ce{sup 3+}* ion (λ{sub max}=353 nm, 3.7 eV). Discovered CL is the first example of an experimental registration of the Ce{sup 3+}* ion emission in a chemical reaction, because formation of Ce{sup 3+}* ion previously assumed to be in a great many works on the study of CL in reactions of Ce{sup 4+} compounds with various reducing agents, including the reaction with water, initiated by light or catalysts. Possible mechanism generation of new CL in the system under study has been proposed in the paper. - Highlights: • A new chemiluminescence (CL) in the (NH{sub 4}){sub 2}Ce(NO{sub 3}){sub 2}-C{sub 6}H{sub 6}-H{sub 2}O system was discovered. • The emission of the Ce{sup 3+}* ion as a CL emitter has been registered for the first time. • Other emitters of this CL are

  17. Polyacrylamide+Al{sub 2}(SO{sub 4}){sub 3} and polyacrylamide+CaO remove coliform bacteria and nutrients from swine wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Entry, J.A.; Phillips, Ian; Stratton, Helen; Sojka, R.E

    2003-03-01

    Polyacrylamide mixture may be able to reduce run-off of enteric bacteria from animal wastes. - Animal wastes are a major contributor of nutrients and enteric microorganisms to surface water and ground water. Polyacrylamide (PAM) mixtures are an effective flocculent, and we hypothesized that they would reduce transport of microorganisms in flowing water. After waste water running at 60.0 l min{sup -1} flowed over PAM+Al{sub 2}(SO{sub 4}){sub 3}, or PAM+CaO in furrows, total coliform bacteria (TC) and fecal coliform bacteria (FC) were reduced by 30-50% at 1 and 50 m downstream of the treatments compared to the control. In a column study, PAM+Al{sub 2}(SO{sub 4}){sub 3}, and PAM+CaO applied to sandy, sandy loam, loam, and clay soils reduced NH{sub 4}{sup +} and ortho-P concentrations in leachate compared to the source waste water and the control. PAM+Al{sub 2}(SO{sub 4}){sub 3} and PAM+CaO applied to sandy, sandy loam and loam soils reduced both total and ortho-P, concentrations in leachate compared to the source wastewater and control treatment. In a field study, PAM+Al{sub 2}(SO{sub 4}){sub 3}, or PAM+CaO treatments did not consistently reduce NH{sub 4}{sup +}, NO{sub 3}{sup -}, ortho-P, and total P concentrations in wastewater flowing over any soil compared to inflow wastewater or the control treatment. With proper application PAM+ Al{sub 2}(SO{sub 4}){sub 3} and PAM+CaO may be able to reduce the numbers of enteric bacteria in slowly flowing wastewater running off animal confinement areas, reducing the amount of pollutants entering surface water and groundwater.

  18. SO 2 Phototriggered Crystalline Nanomechanical Transduction of Aromatic Rotors in Tosylates: Rationalization via Photocrystallography of [Ru(NH 3 ) 4 SO 2 X]tosylate 2 (X = pyridine, 3-Cl-pyridine, 4-Cl-pyridine)

    Energy Technology Data Exchange (ETDEWEB)

    Sylvester, Sven O.; Cole, Jacqueline M.; Waddell, Paul G.; Nowell, Harriott; Wilson, Claire

    2014-07-24

    Thermally-reversible solid-state linkage SO2 photoisomers of three complexes in the [Ru(NH3)4SO2X]tosylate2 family are captured in their metastable states using photocrystallography, where X = pyridine (1), 3-Cl-pyridine (2) and 4-Cl-pyridine (3). This photoisomerism only exists in the single-crystal form; accordingly, the nature of the crystalline environment surrounding the photo-active species controls its properties. In particular, the structural role of the tosylate anion needs to be understood against possible chemical influences due to varying the trans ligand, X. The photo-excited geometries, photoconversion levels and thermal stabilities of the photoisomers that form in 1-3 are therefore studied. 1 and 2 yield two photo-isomers at 100 K: the O-bound end-on n1-SO2 Page 1 of 32 ACS Paragon Plus Environment The Journal of Physical Chemistry (MS1) configuration and the side-bound n2-SO2 (MS2), while 3 only exhibits the more thermally stable MS2 geometry. The decay kinetics of the MS2 geometry for 1-3 demonstrate that the greater the free volume of the GS SO2 ligand for a given counterion, the greater the MS2 thermal stability. Furthermore, a rationalization is sought for the SO2 phototriggered molecular rotation of the phenyl ring in the tosylate anion; this is selectively observed in 2, manifesting as nanomechanical molecular transduction. This molecular transduction was not observed in 1, despite the presence of the MS1 geometry due to the close intermolecular interactions between the MS1 SO2 and the neighbouring tosylate ion. The decay of this anionic molecular rotor in 2, however, follows a non-traditional decay pathway, as determined by time-resolved crystallographic analysis; this contrasts with the well-behaved first-order kinetic decay of its MS1 SO2 phototrigger.

  19. Формирование кристаллов систем NH4C1+H20 и NH4CI+c11so4+H2O

    OpenAIRE

    Фокин, Андрей; Брызгалов, Александр; Волков, Петр

    2010-01-01

    Экспериментально исследованы закономерности формирования кристаллов систем NH4Cl+H2O и NH4Cl+CuSO4+H2O. Выявлен переход кристаллов дендритной формы к ограненной путем замещения ионов (NH4)+ на Сu2+.

  20. Rate-based modelling of combined SO2 removal and NH3 recycling integrated with an aqueous NH3-based CO2 capture process

    International Nuclear Information System (INIS)

    Li, Kangkang; Yu, Hai; Qi, Guojie; Feron, Paul; Tade, Moses; Yu, Jingwen; Wang, Shujuan

    2015-01-01

    Highlights: • A rigorous, rate-based model for an NH 3 –CO 2 –SO 2 –H 2 O system was developed. • Model predictions are in good agreement with pilot plant results. • >99.9% of SO 2 was captured and >99.9% of slipped ammonia was reused. • The process is highly adaptable to the variations of SO 2 /NH 3 level, temperatures. - Abstract: To reduce the costs of controlling emissions from coal-fired power stations, we propose an advanced and effective process of combined SO 2 removal and NH 3 recycling, which can be integrated with the aqueous NH 3 -based CO 2 capture process to simultaneously achieve SO 2 and CO 2 removal, NH 3 recycling and flue gas cooling in one process. A rigorous, rate-based model for an NH 3 –CO 2 –SO 2 –H 2 O system was developed and used to simulate the proposed process. The model was thermodynamically and kinetically validated by experimental results from the open literature and pilot-plant trials, respectively. Under typical flue gas conditions, the proposed process has SO 2 removal and NH 3 reuse efficiencies of >99.9%. The process is strongly adaptable to different scenarios such as high SO 2 levels in flue gas, high NH 3 levels from the CO 2 absorber and high flue gas temperatures, and has a low energy requirement. Because the process simplifies flue gas desulphurisation and resolves the problems of NH 3 loss and SO 2 removal, it could significantly reduce the cost of CO 2 and SO 2 capture by aqueous NH 3

  1. Statistical generation of training sets for measuring NO3(-), NH4(+) and major ions in natural waters using an ion selective electrode array.

    Science.gov (United States)

    Mueller, Amy V; Hemond, Harold F

    2016-05-18

    Knowledge of ionic concentrations in natural waters is essential to understand watershed processes. Inorganic nitrogen, in the form of nitrate and ammonium ions, is a key nutrient as well as a participant in redox, acid-base, and photochemical processes of natural waters, leading to spatiotemporal patterns of ion concentrations at scales as small as meters or hours. Current options for measurement in situ are costly, relying primarily on instruments adapted from laboratory methods (e.g., colorimetric, UV absorption); free-standing and inexpensive ISE sensors for NO3(-) and NH4(+) could be attractive alternatives if interferences from other constituents were overcome. Multi-sensor arrays, coupled with appropriate non-linear signal processing, offer promise in this capacity but have not yet successfully achieved signal separation for NO3(-) and NH4(+)in situ at naturally occurring levels in unprocessed water samples. A novel signal processor, underpinned by an appropriate sensor array, is proposed that overcomes previous limitations by explicitly integrating basic chemical constraints (e.g., charge balance). This work further presents a rationalized process for the development of such in situ instrumentation for NO3(-) and NH4(+), including a statistical-modeling strategy for instrument design, training/calibration, and validation. Statistical analysis reveals that historical concentrations of major ionic constituents in natural waters across New England strongly covary and are multi-modal. This informs the design of a statistically appropriate training set, suggesting that the strong covariance of constituents across environmental samples can be exploited through appropriate signal processing mechanisms to further improve estimates of minor constituents. Two artificial neural network architectures, one expanded to incorporate knowledge of basic chemical constraints, were tested to process outputs of a multi-sensor array, trained using datasets of varying degrees of

  2. Synthesis and molecular structure of [Cu(NH3)4][Ni(CN)4]: A missing piece in the [Cu(NH3)n][Ni(CN)4] story

    Science.gov (United States)

    Solanki, Dina; Hogarth, Graeme

    2015-11-01

    Reaction of CuCl2·2H2O and K2[Ni(CN)4]·2H2O in aqueous ammonia gave blue rod-like crystals of [Cu(NH3)4][Ni(CN)4]. An X-ray crystallographic reveals that square-planar anions and cations are weakly associated through coordination of a cis pair of cyanide ligands to copper, with one short and one long contact and thus the copper centre is best described as a square-based pyramid. Crystals lose ammonia readily upon removal from the solvent and this has been probed by TGA and DSC measurements. For comparison we have also re-determined the structure of the related ethylenediamine (en) complex [Cu(en)2][Ni(CN)4] at 150 K. This consists of a 1D chain in which a trans pair of cyanide ligands bind to copper such that the latter has an overall tetragonally distorted octahedral coordination geometry.

  3. [Effect of humic acids on migration and transformation of NH4(+) -N in saturated aquifer].

    Science.gov (United States)

    Meng, Qing-Jun; Zhang, Yan; Feng, Qi-Yan; Zhang, Shuang-Sheng

    2011-11-01

    Isothermal adsorption experiment was used to study the adsorbing process of NH4(+) -N in quartz sands under the conditions with and without humic acid; the Langmuir and Freundlich equations were used to fit the absorption result and the maximum adsorption capacity of NH4(+) -N by quarts sands was calculated. Through the soil column experiments, the concentration of NH4(+) -N, NO3(-) -N and NO2(-) -N in effluent water in the tested soil column was investigated, and the effect of humic acid on migration and transformation of NH4(+) -N in saturated aquifer was analyzed, and Pseudo-second-order Kinetics Equation and Two-step Adsorption Kinetics Rate Equation were applied to fit the kinetic processes. The results showed that both Langmuir and Freundlich models can well describe the isothermal adsorption process of NH4(+) -N on the surface of quartz sands, which means that NH4(+) -N adsorbed by the quartz sand was mainly in the form of monolayer adsorption. The humic acid could increase the adsorption capacity of NH4(+) -N on quartz sand, and the saturated adsorption capacity was 0.354 mg x g(-1) under the condition with humic acid and 0.205 mg x g(-1) with the absence of humic acid. The experiment indicated that humic acid increased the adsorption capacity of NH4(+) -N on the surface of quartz sand by increasing adsorption space in the initial stage. After saturation, humic acid influenced the migration and transformation of NH4(+) -N to NO3(-) -N and NO2(-) -N probably through providing carbon source and energy for microorganisms such as nitrifying bacteria and then resulting in lower NH4(+) -N concentration in effluent water. Both Pseudo-second-order Kinetics Equation and Two-step Adsorption Kinetics Rate Equations can well describe the process of NH4(+) -N adsorption kinetics on quartz sand (R2 = 0.997 7 and R2 = 0.998 1 with humic acid; R2 = 0.992 3 and R2 = 0.994 4 without humic acid), indicating that this process was chemical adsorption. By comparing the

  4. Hydrogen generation behaviors of NaBH4-NH3BH3 composite by hydrolysis

    Science.gov (United States)

    Xu, Yanmin; Wu, Chaoling; Chen, Yungui; Huang, Zhifen; Luo, Linshan; Wu, Haiwen; Liu, Peipei

    2014-09-01

    In this work, NH3BH3 (AB) is used to induce hydrogen generation during NaBH4 (SB) hydrolysis in order to reduce the use of catalysts, simplify the preparation process, reduce the cost and improve desorption kinetics and hydrogen capacity as well. xNaBH4-yNH3BH3 composites are prepared by ball-milling in different proportions (from x:y = 1:1 to 8:1). The experimental results demonstrate that all composites can release more than 90% of hydrogen at 70 °C within 1 h, and their hydrogen yields can reach 9 wt% (taking reacted water into account). Among them, the composites in the proportion of 4:1 and 5:1, whose hydrogen yields reach no less than 10 wt%, show the best hydrogen generation properties. This is due to the impact of the following aspects: AB additive improves the dispersibility of SB particles, makes the composite more porous, hampers the generated metaborate from adhering to the surface of SB, and decreases the pH value of the composite during hydrolysis. The main solid byproduct of this hydrolysis system is NaBO2·2H2O. By hydrolytic kinetic simulation of the composites, the fitted activation energies of the complexes are between 37.2 and 45.6 kJ mol-1, which are comparable to the catalytic system with some precious metals and alloys.

  5. H2 dilution effect in the Cat-CVD processes of the SiH4/NH3 system

    International Nuclear Information System (INIS)

    Ansari, S.G.; Umemoto, Hironobu; Morimoto, Takashi; Yoneyama, Koji; Izumi, Akira; Masuda, Atsushi; Matsumura, Hideki

    2006-01-01

    Gas-phase diagnostics in the catalytic chemical vapor deposition processes of the SiH 4 /NH 3 /H 2 system were carried out to examine the effect of H 2 dilution. The decomposition efficiency of NH 3 showed a sharp decrease with the introduction of a small amount of SiH 4 , but this decrease was recovered by the addition of H 2 when the NH 3 pressure was low. On the other hand, at higher NH 3 pressures, the decomposition efficiency showed a minor dependence on the H 2 partial pressure. The addition of SiH 4 to the NH 3 system decreases the H-atom density by one order of magnitude, but this decrease is also recovered by H 2 addition. H atoms produced from H 2 must re-activate the catalyzer surfaces poisoned by SiH 4 when the NH 3 pressure is low

  6. Comparison of measured NH4 level and NO emission to declared tar and nicotine values of hundred cigarette brands

    NARCIS (Netherlands)

    Brunt TM; Verlaan APJ; Cleven RFMJ; Rambali B; Vleeming W; LEO; LAC; LPI

    2003-01-01

    De algemene hypothese bestaat dat NH4 gehalte in sigaretten en NO concentratie in sigarettenrook de nicotine beschikbaarheid in de longen beinvloedt en daardoor ook een factor speelt bij de tabaksverslaving. Een correlatie tussen het NH4 gehalte, de NO emissie en de gedeclareerde nicotine waarde

  7. Interaction of (NH4)2ZrF6 and (NH4)3ZrF7 with strontium and lead nitrates

    International Nuclear Information System (INIS)

    Krysenko, G.F.; Mel'nichenko, E.I.; Ehpov, D.G.; Polishchuk, S.A.

    1991-01-01

    Methods of chemical, X-ray phase, thermogravimetric analysis and IR spectroscopy were used to study reactions between ammonium fluorozirconates and strontium and lead nitrates. Formation of anhydrous hexa- and octafluorozirconates of strontium and lead in the form of MZrF 6 ·0.5NH 4 F and M 2 ZrF 8 ·0.5NH 4 F double salts, which decompose at 315-430 deg C to corresponding hexa- and octafluorozirconates, was established. Effect of hydrofluoric acid on composition of lead fluorozirconates was studied

  8. SO4--SO3- radical pair formation in Ce doped and Ce, U co-doped K3Na(SO4)2: EPR evidence and its role in TSL

    International Nuclear Information System (INIS)

    Natarajan, V.; Seshagiri, T.K.; Kadam, R.M.; Sastry, M.D.

    2002-01-01

    Thermally stimulated luminescence (TSL) and electron paramagnetic resonance (EPR) studies were carried out on cerium doped and cerium-uranium co-doped K 3 Na(SO 4 ) 2 samples after γ-irradiation. Three glow peaks around 352, 415 and 475 K were observed and their spectral characteristics have shown that Ce 3+ and UO 2 2+ act as the emission centres in K 3 Na(SO 4 ) 2 :Ce and K 3 Na(SO 4 ) 2 :Ce, U, respectively. In Ce-U co-doped sample, energy transfer from cerium to uranium takes place. The commonly occurring radiation-induced centres in sulphates, viz SO 3 - and SO 4 - were observed by EPR and SO 4 - radical ion was found to take part in the TSL emission at 415 K. The hitherto unknown information, however, is the formation of SO 4 - -SO 3 - radical pair creating deep traps in these lattices, apparently assisted by the dopants. This is the first observation of such radical pair formation leading to the identification of deep traps in this lattice. The radical pair, (SO 3 - -SO 4 - ) which is stable up to 970 K, decreases the intensity of the peak at 415 K due to the depletion of SO 4 - centres

  9. Thermal properties and phase transition in the fluoride, (NH{sub 4}){sub 3}SnF{sub 7}

    Energy Technology Data Exchange (ETDEWEB)

    Kartashev, A.V. [Kirensky Institute of Physics, Siberian Department of the Russian Academy of Sciences, 660036 Krasnoyarsk (Russian Federation); Astafijev Krasnoyarsk State Pedagogical University, 660049 Krasnoyarsk (Russian Federation); Gorev, M.V. [Kirensky Institute of Physics, Siberian Department of the Russian Academy of Sciences, 660036 Krasnoyarsk (Russian Federation); Institute of Engineering Physics and Radio Electronics, Siberian State University, 660074 Krasnoyarsk (Russian Federation); Bogdanov, E.V. [Kirensky Institute of Physics, Siberian Department of the Russian Academy of Sciences, 660036 Krasnoyarsk (Russian Federation); Krasnoyarsk State Agrarian University, 660049 Krasnoyarsk (Russian Federation); Flerov, I.N. [Kirensky Institute of Physics, Siberian Department of the Russian Academy of Sciences, 660036 Krasnoyarsk (Russian Federation); Institute of Engineering Physics and Radio Electronics, Siberian State University, 660074 Krasnoyarsk (Russian Federation); Laptash, N.M. [Institute of Chemistry, Far Eastern Department of the Russian Academy of Sciences, 690022 Vladivostok (Russian Federation)

    2016-05-15

    Calorimetric, dilatometric and differential thermal analysis studies were performed on (NH{sub 4}){sub 3}SnF{sub 7} for a wide range of temperatures and pressures. Large entropy (δS{sub 0}=22 J/mol K) and elastic deformation (δ(ΔV/V){sub 0}=0.89%) jumps have proven that the Pa-3↔Pm-3m phase transition is a strong first order structural transformation. A total entropy change of ΔS{sub 0}=32.5 J/mol K is characteristic for the order–disorder phase transition, and is equal to the sum of entropy changes in the related material, (NH{sub 4}){sub 3}TiF{sub 7}, undergoing transformation between the two cubic phases through the intermediate phases. Hydrostatic pressure decreases the stability of the high temperature Pm-3m phase in (NH{sub 4}){sub 3}SnF{sub 7}, contrary to (NH{sub 4}){sub 3}TiF{sub 7}, characterised by a negative baric coefficient. The effect of experimental conditions on the chemical stability of (NH{sub 4}){sub 3}SnF{sub 7} was observed. - Graphical abstract: Strong first order structural transformation Pa-3↔Pm-3m in (NH{sub 4}){sub 3}SnF{sub 7} is associated with very large total entropy change of ΔS{sub 0}=32.5 J/mol K characteristic for the ordering processes and equal to the sum of entropy changes in the related (NH{sub 4}){sub 3}TiF{sub 7} undergoing transformation between the same two cubic phases through the intermediate phases. - Highlights: • (NH{sub 4}){sub 3}SnF{sub 7} undergoes strong first order Pa-3↔Pm-3m phase transition. • Anomalous behaviour of ΔC{sub p} and ΔV/V exists far below phase transition temperature. • Structural distortions are accompanied by huge total entropy change ΔS≈Rln50. • High pressure strongly increases the stability of Pa-3 phase in (NH{sub 4}){sub 3}SnF{sub 7}. • Entropy of the Pa-3↔Pm-3m phase transition does not depend on pressure.

  10. LPG and NH3 sensing characteristics of DC electrochemically deposited Co3O4 films

    Science.gov (United States)

    Shelke, P. N.; Khollam, Y. B.; Gunjal, S. D.; Koinkar, P. M.; Jadkar, S. R.; Mohite, K. C.

    2015-03-01

    Present communication reports the LPG and NH3 sensing properties of Co3O4 films prepared on throughly cleaned stainless steel (SS) and copper (CU) substrates by using DC electrochemical deposition method followed by air annealing at 350°C/2 h. The resultant films are characterized by using X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy (SEM). The LPG and NH3 gas sensing properties of these films are measured at room temperature (RT) by using static gas sensing system at different concentrations of test gas ranging from 25 ppm to 350 ppm. The XRD and Raman spectroscopy studies clearly indicated the formation of pure cubic spinel Co3O4 in all films. The LPG and NH3 gas sensing properties of films showed (i) the increase in sensitivity factor (S.F.) with gas concentrations and (ii) more sensibility to LPG as compared to NH3 gas. In case of NH3 gas (conc. 150 ppm) and LPG gas (conc. 60 ppm) sensing, the maximum S.F. = 270 and 258 are found for the films deposited on CU substrates, respectively. For all films, the response time (3-5 min.) is found to be much higher than the recovery time (30-50 sec). For all films, the response and recovery time are found to be higher for LPG as compared to NH3 gas. Further, repeatability-reproducibility in gas sensing properties is clearly noted by analysis of data for number of cycles recorded for all films from different set of depositions.

  11. ISORROPIA II: a computationally efficient thermodynamic equilibrium model for K+─Ca²+─Mg²+─NH4+─Na+─SO4²-─NO3-─Cl-─H2O aerosols

    Directory of Open Access Journals (Sweden)

    C. Fountoukis

    2007-09-01

    Full Text Available This study presents ISORROPIA II, a thermodynamic equilibrium model for the K+–Ca2+–Mg2+–NH4+–Na+–SO42−–NO3−–Cl−–H2O aerosol system. A comprehensive evaluation of its performance is conducted against water uptake measurements for laboratory aerosol and predictions of the SCAPE2 thermodynamic module over a wide range of atmospherically relevant conditions. The two models agree well, to within 13% for aerosol water content and total PM mass, 16% for aerosol nitrate and 6% for aerosol chloride and ammonium. Largest discrepancies were found under conditions of low RH, primarily from differences in the treatment of water uptake and solid state composition. In terms of computational speed, ISORROPIA II was more than an order of magnitude faster than SCAPE2, with robust and rapid convergence under all conditions. The addition of crustal species does not slow down the thermodynamic calculations (compared to the older ISORROPIA code because of optimizations in the activity coefficient calculation algorithm. Based on its computational rigor and performance, ISORROPIA II appears to be a highly attractive alternative for use in large scale air quality and atmospheric transport models.

  12. Distribution of complemented 15N - (NH4)2SO4 in an ethanolic fermentation process on insolube-N and solube-N fractions

    International Nuclear Information System (INIS)

    Lara Cabejas, W.A.R.; Trivelin, P.C.O.

    1990-01-01

    Looking for stillage labeling with 15 N for further utilization in studies of mineral fertilization of sugar-cane, 15 N-(NH 4 ) 2 SO 4 (43.5ppm, 45.401 atoms% 15 N) was supplemented in a single fermentative cycle, in a laboratory scale. A nitrogen fractionation was made between insoluble-N and soluble-N in several componentes of the fermentative process (yeast, sugar-cane juice, centrifugate wine, centrifugate yeast and stillage) with the objective of studying the added nitrogen distribution and its isotopic abundance composition. The nitrogen fractionation, and the isotopic analysis by mass spectrometry of 15 N, in the fractions of the several components of the fermentative process, showed 81.1% of N recovery, being 3.2% in stillage and mainly in a soluble-N fraction (71.4%), and the rest found in centrifugate yeast (77.9%), distributed mainly in a insoluble-N fraction (92.0%). Desuniform isotopic label was found in stillage, between soluble-N (1.333 atoms% 15 N) and insoluble-N fractions (0.744 atoms% 15 N). Means to improve the isotopic uniformity in these fractions is discussed. (autor) [pt

  13. Nitrogen leaching and acidification during 19 years of NH4NO3 additions to a coniferous-forested catchment at Gardsjoen, Sweden (NITREX)

    International Nuclear Information System (INIS)

    Moldan, Filip; Wright, Richard F.

    2011-01-01

    The role of nitrogen (N) in acidification of soil and water has become relatively more important as the deposition of sulphur has decreased. Starting in 1991, we have conducted a whole-catchment experiment with N addition at Gardsjoen, Sweden, to investigate the risk of N saturation. We have added 41 kg N ha -1 yr -1 as NH 4 NO 3 to the ambient 9 kg N ha -1 yr -1 in fortnightly doses by means of sprinkling system. The fraction of input N lost to runoff has increased from 0% to 10%. Increased concentrations of NO 3 in runoff partially offset the decreasing concentrations of SO 4 and slowed ecosystem recovery from acid deposition. From 1990-2002, about 5% of the total N input went to runoff, 44% to biomass, and the remaining 51% to soil. The soil N pool increased by 5%. N deposition enhanced carbon (C) sequestration at a mean C/N ratio of 42-59 g g -1 . - Research highlights: → The fraction of input N lost to runoff has increased from 0% to 10%. → Increased concentrations of NO 3 in runoff slowed ecosystem recovery from acid deposition. → About 5% of the total N input went to runoff, 44% to biomass, and the remaining 51% to soil. → N deposition enhanced carbon (C) sequestration at a mean C/N ratio of 42-59 g g -1 . - N addition has led to increased flux of N and increased C sequestration at a forested catchment in Sweden; the NO 3 released has partially offset recovery from acidification.

  14. Response to Comment on "Synthesis and characterization of the pentazolate anion cyclo-N5- in (N5)6(H3O)3(NH4)4Cl".

    Science.gov (United States)

    Jiang, Chao; Zhang, Lei; Sun, Chengguo; Zhang, Chong; Yang, Chen; Chen, Jun; Hu, Bingcheng

    2018-03-16

    Huang and Xu argue that the cyclo -N 5 - ion in (N 5 ) 6 (H 3 O) 3 (NH 4 ) 4 Cl we described in our report is theoretically unfavorable and is instead protonated. Their conclusion is invalid, as they use an improper method to assess the proton transfer in a solid crystal structure. We present an in-depth experimental and theoretical analysis of (N 5 ) 6 (H 3 O) 3 (NH 4 ) 4 Cl that supports the results in the original paper. Copyright © 2018, American Association for the Advancement of Science.

  15. Effect of trace elements (ZnSO/sub 4/, MnSO/sub 4//sub /and Al/sub 2/(SO/sub 4/)/sub 3/) on soil Ph, Zinc and manganese concentrations in case of mature teat bushes

    International Nuclear Information System (INIS)

    Nosheen, M.; Riaz, A.K.

    2005-01-01

    A field experiment was conducted to study the effect of trace elements on growth and yield of mature tea bushes, at National Tea Research Inst., Shinkiari, Mansehra, Pakistan, during 2003. The treatments included control (no fertilizer), recommended dose of NPK (432:111:74 kg ha/sup -1/ alone and NPK in combination with either two doses of (5.5 and 11 kg ha/sup -1/) ZnSO/sub 4/ or (2.0 and 4.0 kg ha/sup -1/)MnSO/sub 4/ or (0.225 and 0.45 kg ha/sup -1/) Al/sub 2/(SO/sub 4/)/sub 3/ to soil and one dose of each (11 kg ha/sup -1/) ZnSO/sub 4/, (4.0 kg ha/sup -1) MnSO/sub 4/ and (0.45 kg ha/sup -1/) Al/sub 2/(SO/sub 4/)/sub 3/ applied as spray solution. Treatments including soil application of NPK alone and NPK + either ZnSO/sub 4/, MnSO/sub 4/ or Al/sub 2/(SO/sub 4/)/sub 3/ significantly (P < 0.001) increased tea yield (fresh weight of three leaves + bud), shoot height and tissue Zn and Mn concentrations with significant interactions (T x t) on tissue Zn and Mn levels. As compared to control the yield increased by 7.0,30,.37,42,37 and 34% with NPK alone, NPK + 5.5, + 11.0 ZnSO/sub 4/, + 2.0, + 4.0 MnSO/sub 4/, + 0.225, + 0.45 kg ha/sup -1/ Al/sub 2/(SO/sub 4/)/sub 3/, respectively during fist three months while the yield of six months plucking showed similar response to treatments but was significantly lower than the first three months. Soil pH, Zn and Mn concentrations were significantly affected by treatments, time of sampling, and depth of sampling. Except ZnSO/sub 4/, lower doses of MnSO/sub 4/ (2.0 kg ha-l) and Al/sub 2/(SO/sub 4/)/sub 3/ (0.225 kg ha/sup -1/), were more effective as compared to their higher doses when applied to soil, regarding tea yield and shoot height. Foliar application of 11 kg ha-l ZnSO/sub 4/ significantly increased yield as compared to its both levels when applied to soil. It is concluded that MnSO/sub 4/ and Al/sub 2/(SO/sub 4/)/sub 3/ should be applied at the rate of 2.0 and 0.225 kg ha/sup -l/. (author)

  16. Neutron scattering studies of K3H(SO4)2 and K3D(SO4)2: the particle-in-a-box model for the quantum phase transition.

    Science.gov (United States)

    Fillaux, François; Cousson, Alain

    2012-08-21

    In the crystal of K(3)H(SO(4))(2) or K(3)D(SO(4))(2), dimers SO(4)···H···SO(4) or SO(4)···D···SO(4) are linked by strong centrosymmetric hydrogen or deuterium bonds whose O···O length is ≈2.50 Å. We address two open questions. (i) Are H or D sites split or not? (ii) Is there any structural counterpart to the phase transition observed for K(3)D(SO(4))(2) at T(c) ≈ 85.5 K, which does not exist for K(3)H(SO(4))(2)? Neutron diffraction by single-crystals at cryogenic or room temperature reveals no structural transition and no resolvable splitting of H or D sites. However, the width of the probability densities suggest unresolved splitting of the wavefunctions suggesting rigid entities H(L1/2)-H(R1/2) or D(L1/2)-D(R1/2) whose separation lengths are l(H) ≈ 0.16 Å or l(D) ≈ 0.25 Å. The vibrational eigenstates for the center of mass of H(L1/2)-H(R1/2) revealed by inelastic neutron scattering are amenable to a square-well and we suppose the same potential holds for D(L1/2)-D(R1/2). In order to explain dielectric and calorimetric measurements of mixed crystals K(3)D((1-ρ))H(ρ)(SO(4))(2) (0 ≤ ρ ≤ 1), we replace the classical notion of order-disorder by the quantum notion of discernible (e.g., D(L1/2)-D(R1/2)) or indiscernible (e.g., H(L1/2)-H(R1/2)) components depending on the separation length of the split wavefunction. The discernible-indiscernible isostructural transition at finite temperatures is induced by a thermal pure quantum state or at 0 K by ρ.

  17. Experimental study of H2SO4 aerosol nucleation at high ionization levels

    DEFF Research Database (Denmark)

    Tomicic, Maja; Bødker Enghoff, Martin; Svensmark, Henrik

    2018-01-01

    One hundred and ten direct measurements of aerosol nucleation rate at high ionization levels were performed in an 8 m3 reaction chamber. Neutral and ion-induced particle formation from sulfuric acid (H2SO4) was studied as a function of ionization and H2SO4 concentration. Other species that could...... have participated in the nucleation, such as NH3 or organic compounds, were not measured but assumed constant, and the concentration was estimated based on the parameterization by Gordon et al. (2017). Our parameter space is thus [H2SO4]  = 4×106 − 3×107 cm−3, [NH3+ org]  =  2.2 ppb, T = 295 K, RH......  =  38 %, and ion concentrations of 1700–19 000 cm−3. The ion concentrations, which correspond to levels caused by a nearby supernova, were achieved with gamma ray sources. Nucleation rates were directly measured with a particle size magnifier (PSM Airmodus A10) at a size close to critical cluster size...

  18. Physical Properties of (NH4)2Pt(CN)4[Clo.42].3H2O: A new Quasi-One-Dimensional Conductor

    DEFF Research Database (Denmark)

    Carneiro, Kim; Petersen, A. S.; Underhill, A. E.

    1979-01-01

    The quasi-one-dimensional conductor (NH4)2[Pt(CN)4]Cl0.42·3H2O, ACP(Cl), has been studied experimentally by means of electrical conduction measurements, x-ray diffuse scattering, and neutron inelastic scattering. This allows the determination of all the physical parameters of interest for the the......The quasi-one-dimensional conductor (NH4)2[Pt(CN)4]Cl0.42·3H2O, ACP(Cl), has been studied experimentally by means of electrical conduction measurements, x-ray diffuse scattering, and neutron inelastic scattering. This allows the determination of all the physical parameters of interest...

  19. Formation of condensed phosphates when heating CdO with NH4H2PO4

    International Nuclear Information System (INIS)

    Atstinya, L.Zh.; Dindune, A.P.; Konstant, Z.A.

    1987-01-01

    A study was made on process of CdO thermal condensation with NH 4 H 2 PO 4 depending on the ratio of basic substances and temperature synthesis conditions. It was established that reaction between CdO and NH 4 H 2 PO 4 of pure for analysis grade was initiated when basic mixtures were pounded with a pestle. Heating of cadmium-ammonium triphosphate with products of ammonium dihydrophosphate polycondensation in 330-350 deg C range resulted to CdNH 4 (PO 3 ) 3 formation. Exoeffect on DTA curves corresponded at 540 deg C to formation of α-Cd(PO 3 ) 2 . α-Cd(PO 3 ) 2 → β-Cd(PO 3 ) 2 transition took place at 810 deg C with successive melting of β-Cd(PO 3 ) 2 at 850 deg C, which was supported by the DTA curve and sharp change of the relative electric conductivity

  20. Response of eight tropical plants to enhanced ammonia deposition under field, conditions prevalent with SO{sub 2} and NH{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Rao, M.V.; Khijneri, S.; Dubey, P.S.; Kumawat, D.M. [Vikram University, Ujjain (India). School of Studies in Botany

    1993-12-01

    The impact of SO{sub 2} on the deposition of ammonia and the response of eight tropical tree species to excess deposition of ammonia was investigated. This was achieved by studying physiological aspects like total sugars, protein, nitrate reductace (NR) activity, organic/inorganic nitrogen ratio, specific leaf area and foliar injury in plants growing under field conditions prevalent with SO{sub 2} and NH{sub 3}. Analysis of water soluble substances present on foliar surfaces of the trees indicated enhanced NH{sub 4}{sup +} deposition and thereby result in enhanced foliar protein contents. Though the enhanced nitrogen was almost the same in different plants, the plants exhibited differential metabolic disturbances. Critical analysis of the reults indicated three distinct types of plant response. Plants like {ital Azadirachta indica}, {ital Acacia auriculiformis} and {ital Bambusa arundinaceae} maintained enhanced total sugars and NR activity and incorporated excess NH{sub 4}{sup +} into proteins, thus enabling the plant to compensate/alleviate SO{sub 2} induced injury. Ficus benghalensis and Ficus religiosa maintained unaltered total sugars and NR activity and could partly incorporate NH{sub 4}{sup +} into proteins, thus modifying rhe SO{sub 2} impact to some extent. {ital Dalbergia sissoo}, {ital Eucalyptus rostrat}a and {ital Mangifera indica} could not incorporate the excess NH{sub 4}{sup +}, mainly due to declined total sugars. The results indicate the ability of a plant to undergo species specific metabolic changes in order to cope with the excess nitrogen deposition, which may ultimately result in increasing or decreasing tolerance to SO{sub 2}. 23 refs., 3 figs., 9 tabs.

  1. The influence of Uranium-Thorium ratio and heating time during gelation using as a CCl4(NH3) on the Gel quality

    International Nuclear Information System (INIS)

    Indra-Suryawan; Sukarsono, R; Setyo-Sulardi

    1996-01-01

    Gel has been prepared from a uranium-thorium sol using CCI 4 (NH 3 ) as a gelling medium. The uranium-thorium ratio and the heating time during gelation have been chosen as variables. The sol was prepared by mixing Th(NO 3 ) 4 and UO 2 (NO 3 ) 2 solutions, heating the solution at 95 o C and adding NH 4 OH solution drop by drop until colloidal particles were formed. Sol was then fed into a gelation column containing CCI 4 (NH 3 ), where the sol was transformed into gel. A good gel has properties such as sphere in shape and elastic which it will not crack when it is dropped from 2 metres height. The experimental work resulted a good gel when the percentage of uranium was about 15 - 25 % at heating time of 40 - 50 minutes

  2. Lithium insertion into Fe 2(SO 4) 3 frameworks

    Science.gov (United States)

    Manthiram, A.; Goodenough, J. B.

    1989-05-01

    The two polymorphs of Fe 2(SO 4) 3 consist of framework structures built up of tetrahedra sharing corners with octahedra and vice versa. One is rhombohedral, the other is monoclinic. Two moles of lithium insert rapidly into both structures at room temperature. However, lithium insertion into the rhombohedral phase is topotactic without any change of symmetry of the framework, whereas the monoclinic modification is converted to an orthorombic Li 2Fe 2(SO 4) 3 phase via a displacement transition; the existence of a two-phase region between Fe 2(SO 4) 3 and Li 2Fe 2(SO 4) 3 results in a flat OCV of 3.6 V versus lithium, which is 600 mV higher than is found for Li xFFe 2(WO 4) 3 or Li xFe 2(MoO 4) 3. This difference is discussed in terms of the influence of the counter cation on the solid-state Fe {3+}/{2+} redox couple.

  3. Application of stable isotopes (δ{sup 34}S-SO{sub 4}, δ{sup 18}O-SO{sub 4,} δ{sup 15}N-NO{sub 3}, δ{sup 18}O-NO{sub 3}) to determine natural background and contamination sources in the Guadalhorce River Basin (southern Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Urresti-Estala, Begoña, E-mail: b.urresti@uma.es [Universidad de Málaga, Facultad de Ciencias, Grupo de Geodinámica Externa, Campus de Teatinos s/n, 29071 Málaga (Spain); Vadillo-Pérez, Iñaki; Jiménez-Gavilán, Pablo [Universidad de Málaga, Facultad de Ciencias, Grupo de Geodinámica Externa, Campus de Teatinos s/n, 29071 Málaga (Spain); Soler, Albert [Grup de Mineralogia Aplicada i Medi Ambient, Fac. Geologia, Universitat de Barcelona, Barcelona (Spain); Sánchez-García, Damián; Carrasco-Cantos, Francisco [Universidad de Málaga, Facultad de Ciencias, Grupo de Geodinámica Externa, Campus de Teatinos s/n, 29071 Málaga (Spain)

    2015-02-15

    The integrated use of isotopes (δ{sup 34}S-SO{sub 4}, δ{sup 18}O-SO{sub 4,} δ{sup 15}N-NO{sub 3}, δ{sup 18}O-NO{sub 3}), taking into account existing hydrogeological knowledge of the study area (mainly hydrochemical), was applied in the Guadalhorce River Basin (southern Spain) to characterise SO{sub 4}{sup 2−} and NO{sub 3}{sup −} sources, and to quantify natural background levels (NBLs) in groundwater bodies. According to Water Framework Directive 2000/60/EC and, more recently, Groundwater Directive 2006/118/EC, it is important to determine NBLs, as their correct assessment is the first, essential step to characterising groundwater bodies, establishing threshold values, assessing chemical status and identifying trends in pollutant concentrations. In many cases, NBLs are high for some parameters and types of groundwater, making it difficult to distinguish clearly between factors of natural or human origin. The main advantages of using stable isotopes in a complex area like the Guadalhorce River Basin that exhibits widely varying hydrogeological and hydrochemical conditions and longstanding anthropogenic influences (mainly agriculture, but also many others) is accurate determination of pollution sources and precise quantification of NBLs. Since chemical analyses only provides the concentration of pollutants in water and not the source, three isotopic sampling campaigns for sulphates (δ{sup 34}S-SO{sub 4}, δ{sup 18}O-SO{sub 4}) were carried out, in 2006, 2007 and 2012, and another one was conducted for nitrates (δ{sup 15}N-NO{sub 3}, δ{sup 18}O-NO{sub 3}), in 2009, in groundwater bodies in order to trace the origins of each pollutant. The present study identified different pollution sources of dissolved NO{sub 3}{sup −} in groundwater using an isotopic composition and quantified the percentage of natural (lithology, chemical and biological processes) and anthropogenic (fertilisers, manure and sewage) SO{sub 4}{sup 2−} and matched a concentration

  4. Structure-controlled synthesis and electrochemical properties of NH_4V_3O_8 as cathode material for Lithium ion batteries

    International Nuclear Information System (INIS)

    Cheng, Yayi; Huang, Jianfeng; Li, Jiayin; Cao, Liyun; Xu, Zhanwei; Wu, Jianpeng; Cao, Shanshan; Hu, Hailing

    2016-01-01

    NH_4V_3O_8 flower, nanobelt, lath and sheet were synthesized using a facile microwave hydrothermal method. The formation mechanism of NH_4V_3O_8 with various structures was proposed. As an cathode in Li-ion battery, the NH_4V_3O_8 nanobelt with one-dimensional structure as well as nanosized morphology, presents excellent cycling stability and enhanced rate capability when comparing with other NH_4V_3O_8 structures. Further study finds that the NH_4V_3O_8 nanobelt could provide high Li ion diffusion, excellent structural stability and good reversibility during the charge/discharge process, indicating a strong connection between the morphology and the electrochemical performance of NH_4V_3O_8 cathode.

  5. Crystal structure and characterization of the novel NH+⋯N hydrogen bonded polar crystal [NH2(CH2)4NH][BF4

    International Nuclear Information System (INIS)

    Wojtaś, M.; Gagor, A.; Czupiński, O.; Medycki, W.; Jakubas, R.

    2012-01-01

    Dielectric properties and phase transitions of the piperazinium tetrafluoroborate ([NH 2 (CH 2 ) 4 NH][BF 4 ], abbreviated as PFB) crystal are related to the one-dimensional arrangement of the cations linked by the bistable NH + ⋯N hydrogen bonds and molecular motions of the [BF 4 ] − units. The crystal structure of [NH 2 (CH 2 ) 4 NH][BF 4 ] is monoclinic at room temperature with the polar space group Pn. The polar/acentric properties of the room temperature phase IV have been confirmed by the piezoelectric and pyroelectric measurements. DSC measurements show that the compound undergoes three first-order structural phase transitions: at 421/411 K (heating/cooling), at 386/372 K and at 364/349 K. 1 H and 19 F NMR measurements indicate the reorientational motions of [BF 4 ] − anions and piperazinium(+) cations as well as the proton motion in the hydrogen-bonded chains of piperazine along the [001] direction. Over the phase I the isotropic reorientational motions or even self-diffusion of the cations and anions are expected. The conductivity measurements in the vicinity of the II–I PT indicate a superionic phase over the phase I. - Graphical abstract: It must be emphasized that the titled compound represents the first organic–inorganic simple salt containing the single-protonated piperazinium cation which was studied by means of the wide variety of experimental techniques. A survey of Cambridge Structural Database (CSD version 5.32 (November 2010) and updates (May 2011)) for structure containing the piperazinium cations yields 248 compounds with the doubly protonated piperazinium(2+) cations and only eight compounds with the singly protonated piperazinium(+) cations. Among these structures only one is the hybrid organic–inorganic material. This is piperazinium nitrate characterized structurally. The crystal packing of [NH 2 (CH 2 ) 4 NH][BF 4 ], phase IV. The dashed lines stand for the hydrogen bonds. The hydrogen bonds to BF4 groups are not included for

  6. Structure, phonon properties, and order-disorder transition in the metal formate framework of [NH4][Mg(HCOO)3].

    Science.gov (United States)

    Mączka, Mirosław; Pietraszko, Adam; Macalik, Bogusław; Hermanowicz, Krzysztof

    2014-01-21

    We report the synthesis, crystal structure, thermal, dielectric, IR, and Raman studies of [NH4][Mg(HCOO)3] formate. Single-crystal X-ray diffraction shows that it crystallizes in the hexagonal space group P6322, with orientationally disordered NH4(+) ions located in the cages of the network. Upon cooling, [NH4][Mg(HCOO)3] undergoes a phase transition at around 255 K to the ferroelectric P63 structure. Raman and IR spectra show a strong increase in intensity of the N-H stretching bands as well as narrowing of the bands related to the NH4(+) ions upon cooling. These changes indicate that the phase transition is due to orientational ordering of the NH4(+) ions. Analysis of the Raman data show, however, that the rotational and translational motions of NH4(+) do not freeze completely at the phase transition but exhibit further slowing down below 255 K, and the motional freezing becomes nearly complete below 140 K.

  7. Crystal structure and characterization of the novel NH+⋯N hydrogen bonded polar crystal [NH2(CH2)4NH][BF4

    Science.gov (United States)

    Wojtaś, M.; Gaģor, A.; Czupiński, O.; Medycki, W.; Jakubas, R.

    2012-03-01

    Dielectric properties and phase transitions of the piperazinium tetrafluoroborate ([NH2(CH2)4NH][BF4], abbreviated as PFB) crystal are related to the one-dimensional arrangement of the cations linked by the bistable NH+⋯N hydrogen bonds and molecular motions of the [BF4]- units. The crystal structure of [NH2(CH2)4NH][BF4] is monoclinic at room temperature with the polar space group Pn. The polar/acentric properties of the room temperature phase IV have been confirmed by the piezoelectric and pyroelectric measurements. DSC measurements show that the compound undergoes three first-order structural phase transitions: at 421/411 K (heating/cooling), at 386/372 K and at 364/349 K. 1H and 19F NMR measurements indicate the reorientational motions of [BF4]- anions and piperazinium(+) cations as well as the proton motion in the hydrogen-bonded chains of piperazine along the [001] direction. Over the phase I the isotropic reorientational motions or even self-diffusion of the cations and anions are expected. The conductivity measurements in the vicinity of the II-I PT indicate a superionic phase over the phase I.

  8. Reconstructive phase transition in (NH4)3TiF7 accompanied by the ordering of TiF6 octahedra.

    Science.gov (United States)

    Molokeev, Maxim; Misjul, S V; Flerov, I N; Laptash, N M

    2014-12-01

    An unusual phase transition P4/mnc → Pa\\bar 3 has been detected after cooling the (NH4)3TiF7 compound. Some TiF6 octahedra, which are disordered in the room-temperature tetragonal structure, become ordered in the low-temperature cubic phase due to the disappearance of the fourfold axis. Other TiF6 octahedra undergo large rotations resulting in huge displacements of the F atoms by 1.5-1.8 Å that implies a reconstructive phase transition. It was supposed that phases P4/mbm and Pm\\bar 3m could be a high-temperature phase and a parent phase, respectively, in (NH4)3TiF7. Therefore, the sequence of phase transitions can be written as Pm\\bar 3m → P4/mbm → P4/mnc → Pa\\bar 3. The interrelation between (NH4)3TiF7, (NH4)3GeF7 and (NH4)3PbF7 is found, which allows us to suppose phase transitions in relative compounds.

  9. The effect of pressure on the conductivity behavior of the (NH4)3H(SeO4)2 superprotonic crystal

    Science.gov (United States)

    Lindner, Ł.; Zdanowska-Frączek, M.; Pawłowski, A.; Frączek, Z. J.; Masłowski, T.

    2017-07-01

    The impedance spectra of (NH4)3 H(SeO4)2 in low and high-conductive phases under various thermodynamic conditions were analyzed. The measurements were performed by the ac admittance technique along the trigonal c axis of the crystal, i.e., along the direction perpendicular to the plane in which, in the superionic phases, a dynamically disordered H-bond network was formed. Activation energies and activation volumes were calculated for different phases of the (NH4)3 H(SeO4)2 crystal from the baric dependencies of dc conductivity and they were correlated with pressure coefficients of the phase transitions. The experimental results were analyzed within the classical hopping model, in terms of the strong proton-phonon coupling and polaronic effect.

  10. Kinetics of 15NH4+ assimilation in Zea mays

    International Nuclear Information System (INIS)

    Magalhaes, J.R.; Ju, G.C.; Rich, P.J.; Rhodes, D.

    1990-01-01

    Comparative studies of 15 NH 4 + assimilation were undertaken with a GDH1-null mutant of Zea mays and a related (but not strictly isogenic) GDH1-positive wild type from which this mutant was derived. The kinetics of 15 NH 4 + assimilation into free amino acids and total reduced nitrogen were monitored in both roots and shoots of 2-week-old seedlings supplied with 5 millimolar 99% ( 15 NH 4 ) 2 SO 4 via the aerated root medium in hydroponic culture over a 24-h period. The GDH1-null mutant, with a 10- to 15-fold lower total root GDH activity in comparison to the wild type, was found to exhibit a 40 to 50% lower rate of 15 NH 4 + assimilation into total reduced nitrogen. The lower rates of 15 NH 4 + assimilation in the mutant was associated with lower rates of labeling of several free amino acids (including glutamate, glutamine-amino N, aspartate, asparagine-amino N, and alanine) in both roots and shoots of the mutant in comparison to the wild type. Qualitatively, these labeling kinetics appear consistent with a reduced flux of 15 N via glutamate in the GDH1-null mutant. However, the responses of the two genotypes to the potent inhibitor of glutamine synthetase, methionine sulfoximine, and differences in morphology of the two genotypes (particularly a lower shoot:root ratio in the GDH1-null mutant) urge caution in concluding that GDH1 is solely responsible for these differences in ammonia assimilation rate

  11. Estimates of emissions of SO sub 2 , NO sub x , HCl and NH sub 3 from Greater Manchester and the North-West of England

    Energy Technology Data Exchange (ETDEWEB)

    Lee, D.S.; Longhurst, J.W.S.

    1990-11-01

    Estimates of emissions of SO{sub 2}, NO{sub x}, HCl and NH{sub 3} have been made for Greater Manchester and the North West of England. These estimates were made using data on power generation, fuel useage, animal and human population statistics. A large fossil fuel fired power station is the largest known point source for emissions of SO{sub 2}, NO{sub x} and HCl. However, emissions from motor vehicles make the largest contribution to NO{sub x} emissions in the North-West as a whole. The largest contribution to NH{sub 3} emissions in the North-West is from cattle. However in the Metropolitan Counties of Merseyside and Greater Manchester, it has been calculated that humans could contribute 73% and 81%, respectively, to the emissions of NH{sub 3}. The uncertainties in the methodologies used are highlighted, and where possible, recommendations made as to how future emissions estimates might be improved. 33 refs., 9 figs., 7 tabs.

  12. Limited overshooting of NH{sub 4}{sup +} ions in ammonium perchlorate; Ograniczene przeskoki jonow NH{sub 4}{sup +} w nadchloranie amonowym

    Energy Technology Data Exchange (ETDEWEB)

    Birczynski, A.; Lalowicz, Z.T. [Inst. of Nuclear Physics, Cracow (Poland); Ingman, L.P.; Punkkinen, M.; Ylinen, E.E. [Wihuri Physical Lab., Turku Univ., Turku (Finland)

    1995-12-31

    The interpretation of NMR spectra for polycrystalline sample of ammonium perchlorate in helium temperature assumes the tunneling of NH{sub 4}{sup +}. Such interpretation does not agree with experimental data. The hypothesis of additional motion (fast rotation around one of C3 axis) has been checked and discussed on the base of NMR spectra of NH{sub 4}ClO{sub 4} monocrystal for the temperature range 2.1-25 K. 9 refs, 1 fig.

  13. Limited overshooting of NH{sub 4}{sup +} ions in ammonium perchlorate; Ograniczene przeskoki jonow NH{sub 4}{sup +} w nadchloranie amonowym

    Energy Technology Data Exchange (ETDEWEB)

    Birczynski, A; Lalowicz, Z T [Inst. of Nuclear Physics, Cracow (Poland); Ingman, L P; Punkkinen, M; Ylinen, E E [Wihuri Physical Lab., Turku Univ., Turku (Finland)

    1996-12-31

    The interpretation of NMR spectra for polycrystalline sample of ammonium perchlorate in helium temperature assumes the tunneling of NH{sub 4}{sup +}. Such interpretation does not agree with experimental data. The hypothesis of additional motion (fast rotation around one of C3 axis) has been checked and discussed on the base of NMR spectra of NH{sub 4}ClO{sub 4} monocrystal for the temperature range 2.1-25 K. 9 refs, 1 fig.

  14. Effect of dispersed SiO2 on the phase behaviour of NH4HSO4

    Directory of Open Access Journals (Sweden)

    Vargas, R. A.

    2002-02-01

    Full Text Available Phase equilibria and electrical conductivity of (1-xNH4HSO4-xSiO2 composites were studied by thermal and impedance measurements. Silica with particle size of 14 nm was used. The phase transitions of NH4HSO4 (AHS at 154 K and 420 K (melting point were not affected by the silica doping. No large changes in the low-temperature (T Estudiamos el equilibrio de fases y la conductividad eléctrica de las compositas (1-xNH4HSO4-xSiO2 por medidas térmicas y de impedancia. Se utilizaron partículas de silica de diámetro 14 nm. Las transiciones de fase del NH4HSO4 (AHS en 154 K y 420 K (punto de fusión no fueron afectadas con el dopaje de silica. No se observaron grandes cambios a bajas temperaturas (T < 420 K en la conductividad dc y la relajación eléctrica de las compositas al ser dopadas con silica. La parte imaginaria de la conductividad corregida (después de haber substraído la contribución de la conductividad dc, ε″(ω,T, como función de la frecuencia (f = ω/ 2π y la temperatura muestra un pico de dispersión alrededor de 1 MHz para pequeñas concentraciones de silica, cuya posición (fmax esta también térmicamente activada. Los resultados dieléctricos se discuten en términos del efecto de la polarización de las celdas sobre el movimiento de los protones.

  15. Soil solution and sugar maple response to NH(4)NO (3) additions in a base-poor northern hardwood forest of Québec, Canada.

    Science.gov (United States)

    Moore, Jean-David; Houle, Daniel

    2009-08-01

    Nitrogen additions (NH4NO3) at rates of three- and ten-fold ambient atmospheric deposition (8.5 kg ha(-1) year(-1)) were realised in an acid- and base-poor northern hardwood forest of Québec, Canada. Soil solution chemistry, foliar chemistry, crown dieback and basal area growth of sugar maple (Acer saccharum Marsh.) were measured. Except for a transitory increase of NO3 and NH4 concentrations, there was no persistent increase in their level in soil solution 3 years after N treatments, with the exception of one plot out of three, that received the highest N addition, beginning to show persistent and high NO3 concentrations after 2 years of N additions. Three years of N additions have significantly increased the N DRIS index of sugar maple but not N foliar concentration. Potassium, Ca and Mn foliar concentrations, as well as P and Ca DRIS indices, decreased in treated plots after 3 years. No treatment effect was observed for basal area growth and dieback rate. One unexpected result was the significant decrease in foliar Ca even in the treated plots that received low N rates, despite the absence of significant NO3-induced leaching of Ca. The mechanism responsible for the decrease in foliar Ca is not known. Our results, however, clearly demonstrate that increased N deposition at sites with low base saturation may affect Ca nutrition even when clear signs of N saturation are not observed.

  16. DESENVOLVIMENTO INICIAL DO MILHO PIPOCA CULTIVADO SOB DIFERENTES RELAÇÕES NH4 +:NO3-

    Directory of Open Access Journals (Sweden)

    Francisco de Assis de Oliveira

    2008-01-01

    Full Text Available The culture of the popcorn comes as a promising culture for region of the Brazilian northeast, however they are still scarce studies to make possible the expansion of this culture, especially as the fertilization. This experiment was accomplished in the department of Environmental Sciences of the Rural Federal University of the Semi-arid (UFERSA, Mossoró, RN, with the objective of evaluating the effect in different ammonium:nitrate ratios in the initial development of the popcorn. The design was used randomized entirely with five treatments and four repetitions, with the treatments being constituted of ratios different NH4 +: NO3 - (0/100, 25/75, 50/50, 75/25 and 100/0 and the experimental unit acted by a plant/vase. To the 45 DAS the plants were collected and appraised, as for the height, number of leaves, leave area, diameter the stem and matter total dry. The results obtained in this work evidence that plants of popcorn present a larger development when the supply of nitrogen is accomplished with application of this nutritious one in the form ammonium.

  17. AMT1;1 transgenic rice plants with enhanced NH4(+) permeability show superior growth and higher yield under optimal and suboptimal NH4(+) conditions.

    Science.gov (United States)

    Ranathunge, Kosala; El-Kereamy, Ashraf; Gidda, Satinder; Bi, Yong-Mei; Rothstein, Steven J

    2014-03-01

    The major source of nitrogen for rice (Oryza sativa L.) is ammonium (NH4(+)). The NH4(+) uptake of roots is mainly governed by membrane transporters, with OsAMT1;1 being a prominent member of the OsAMT1 gene family that is known to be involved in NH4(+) transport in rice plants. However, little is known about its involvement in NH4(+) uptake in rice roots and subsequent effects on NH4(+) assimilation. This study shows that OsAMT1;1 is a constitutively expressed, nitrogen-responsive gene, and its protein product is localized in the plasma membrane. Its expression level is under the control of circadian rhythm. Transgenic rice lines (L-2 and L-3) overexpressing the OsAMT1;1 gene had the same root structure as the wild type (WT). However, they had 2-fold greater NH4(+) permeability than the WT, whereas OsAMT1;1 gene expression was 20-fold higher than in the WT. Analogous to the expression, transgenic lines had a higher NH4(+) content in the shoots and roots than the WT. Direct NH4(+) fluxes in the xylem showed that the transgenic lines had significantly greater uptake rates than the WT. Higher NH4(+) contents also promoted higher expression levels of genes in the nitrogen assimilation pathway, resulting in greater nitrogen assimilates, chlorophyll, starch, sugars, and grain yield in transgenic lines than in the WT under suboptimal and optimal nitrogen conditions. OsAMT1;1 also enhanced overall plant growth, especially under suboptimal NH4(+) levels. These results suggest that OsAMT1;1 has the potential for improving nitrogen use efficiency, plant growth, and grain yield under both suboptimal and optimal nitrogen fertilizer conditions.

  18. AMT1;1 transgenic rice plants with enhanced NH4 + permeability show superior growth and higher yield under optimal and suboptimal NH4 + conditions

    Science.gov (United States)

    Rothstein, Steven J.

    2014-01-01

    The major source of nitrogen for rice (Oryza sativa L.) is ammonium (NH4 +). The NH4 + uptake of roots is mainly governed by membrane transporters, with OsAMT1;1 being a prominent member of the OsAMT1 gene family that is known to be involved in NH4 + transport in rice plants. However, little is known about its involvement in NH4 + uptake in rice roots and subsequent effects on NH4 + assimilation. This study shows that OsAMT1;1 is a constitutively expressed, nitrogen-responsive gene, and its protein product is localized in the plasma membrane. Its expression level is under the control of circadian rhythm. Transgenic rice lines (L-2 and L-3) overexpressing the OsAMT1;1 gene had the same root structure as the wild type (WT). However, they had 2-fold greater NH4 + permeability than the WT, whereas OsAMT1;1 gene expression was 20-fold higher than in the WT. Analogous to the expression, transgenic lines had a higher NH4 + content in the shoots and roots than the WT. Direct NH4 + fluxes in the xylem showed that the transgenic lines had significantly greater uptake rates than the WT. Higher NH4 + contents also promoted higher expression levels of genes in the nitrogen assimilation pathway, resulting in greater nitrogen assimilates, chlorophyll, starch, sugars, and grain yield in transgenic lines than in the WT under suboptimal and optimal nitrogen conditions. OsAMT1;1 also enhanced overall plant growth, especially under suboptimal NH4 + levels. These results suggest that OsAMT1;1 has the potential for improving nitrogen use efficiency, plant growth, and grain yield under both suboptimal and optimal nitrogen fertilizer conditions. PMID:24420570

  19. Ionothermal synthesis of β-NH4AlF4 and the determination by single crystal X-ray diffraction of its room temperature and low temperature phases

    International Nuclear Information System (INIS)

    Parnham, Emily R.; Slawin, Alex M.Z.; Morris, Russell E.

    2007-01-01

    β-NH 4 AlF 4 has been synthesised ionothermally using 1-ethyl-3-methylimidazolium hexafluorophosphate as solvent and template provider. β-NH 4 AlF 4 crystals were produced which were suitable for single crystal X-ray diffraction analysis. A phase transition occurs between room temperature (298 K) and low temperature (93 K) data collections. At 298 K the space group=I4/mcm (no. 140), α=11.642(5), c=12.661(5) A, Z=2 (10NH 4 AlF 4 ), wR(F 2 )=0.1278, R(F)=0.0453. At 93 K the space group=P4 2 /ncm (no. 138), α=11.616(3), c=12.677(3) A, Z=2 (10NH 4 AlF 4 ), wR(F 2 )=0.1387, R(F)=0.0443. The single crystal X-ray diffraction study of β-NH 4 AlF 4 shows the presence of two different polymorphs at low and room temperature, indicative of a phase transition. The [AlF 4/2 F 2 ] - layers are undisturbed except for a small tilting of the AlF 6 octahedra in the c-axis direction. -Ionothermal synthesis, the use of an ionic liquid as the solvent in materials preparation, has been used to prepare β-NH 4 AlF 4 , and structural characterisation indicates that there are two versions of the structure, a low temperature primitive phase at 93 K and a high temperature body-centered phase at 298 K

  20. The bovine TRPV3 as a pathway for the uptake of Na+, Ca2+, and NH4.

    Science.gov (United States)

    Schrapers, Katharina T; Sponder, Gerhard; Liebe, Franziska; Liebe, Hendrik; Stumpff, Friederike

    2018-01-01

    Absorption of ammonia from the gastrointestinal tract results in problems that range from hepatic encephalopathy in humans to poor nitrogen efficiency of cattle with consequences for the global climate. Previous studies on epithelia and cells from the native ruminal epithelium suggest functional involvement of the bovine homologue of TRPV3 (bTRPV3) in ruminal NH4+ transport. Since the conductance of TRP channels to NH4+ has never been studied, bTRPV3 was overexpressed in HEK-293 cells and investigated using the patch-clamp technique and intracellular calcium imaging. Control cells contained the empty construct. Divalent cations blocked the conductance for monovalent cations in both cell types, with effects higher in cells expressing bTRPV3. In bTRPV3 cells, but not in controls, menthol, thymol, carvacrol, or 2-APB stimulated whole cell currents mediated by Na+, Cs+, NH4+, and K+, with a rise in intracellular Ca2+ observed in response to menthol. While only 25% of control patches showed single-channel events (with a conductance of 40.8 ± 11.9 pS for NH4+ and 25.0 ± 5.8 pS for Na+), 90% of bTRPV3 patches showed much larger conductances of 127.8 ± 4.2 pS for Na+, 240.1 ± 3.6 pS for NH4+, 34.0 ± 1.7 pS for Ca2+, and ~ 36 pS for NMDG+. Open probability, but not conductance, rose with time after patch excision. In conjunction with previous research, we suggest that bTRPV3 channels may play a role in the transport of Na+, K+, Ca2+ and NH4+ across the rumen with possible repercussions for understanding the function of TRPV3 in other epithelia.

  1. The bovine TRPV3 as a pathway for the uptake of Na+, Ca2+, and NH4+

    Science.gov (United States)

    Liebe, Franziska; Liebe, Hendrik

    2018-01-01

    Absorption of ammonia from the gastrointestinal tract results in problems that range from hepatic encephalopathy in humans to poor nitrogen efficiency of cattle with consequences for the global climate. Previous studies on epithelia and cells from the native ruminal epithelium suggest functional involvement of the bovine homologue of TRPV3 (bTRPV3) in ruminal NH4+ transport. Since the conductance of TRP channels to NH4+ has never been studied, bTRPV3 was overexpressed in HEK-293 cells and investigated using the patch-clamp technique and intracellular calcium imaging. Control cells contained the empty construct. Divalent cations blocked the conductance for monovalent cations in both cell types, with effects higher in cells expressing bTRPV3. In bTRPV3 cells, but not in controls, menthol, thymol, carvacrol, or 2-APB stimulated whole cell currents mediated by Na+, Cs+, NH4+, and K+, with a rise in intracellular Ca2+ observed in response to menthol. While only 25% of control patches showed single-channel events (with a conductance of 40.8 ± 11.9 pS for NH4+ and 25.0 ± 5.8 pS for Na+), 90% of bTRPV3 patches showed much larger conductances of 127.8 ± 4.2 pS for Na+, 240.1 ± 3.6 pS for NH4+, 34.0 ± 1.7 pS for Ca2+, and ~ 36 pS for NMDG+. Open probability, but not conductance, rose with time after patch excision. In conjunction with previous research, we suggest that bTRPV3 channels may play a role in the transport of Na+, K+, Ca2+ and NH4+ across the rumen with possible repercussions for understanding the function of TRPV3 in other epithelia. PMID:29494673

  2. Response to nitrate/ammonium nutrition of tomato (Solanum lycopersicum L.) plants overexpressing a prokaryotic NH4(+)-dependent asparagine synthetase.

    Science.gov (United States)

    Martínez-Andújar, Cristina; Ghanem, Michel Edmond; Albacete, Alfonso; Pérez-Alfocea, Francisco

    2013-05-01

    Nitrogen availability is an important limiting factor for plant growth. Although NH4(+) assimilation is energetically more favorable than NO3(-), it is usually toxic for plants. In order to study if an improved ammonium assimilatory metabolism could increase the plant tolerance to ammonium nutrition, tomato (Solanum lycopersicum L. cv P-73) plants were transformed with an NH4(+)-dependent asparagine synthetase (AS-A) gene from Escherichia coli (asnA) under the control of a PCpea promoter (pea isolated constitutive promotor). Homozygous (Hom), azygous (Az) asnA and wild type (WT) plants were grown hydroponically for 6 weeks with normal Hoagland nutrition (NO3(-)/NH4(+)=6/0.5) and high ammonium nutrition (NO3(-)/NH4(+)=3.5/3). Under Hoagland's conditions, Hom plants produced 40-50% less biomass than WT and Az plants. However, under NO3(-)/NH4(+)=3.5/3 the biomass of Hom was not affected while it was reduced by 40-70% in WT and Az plants compared to Hoagland, respectively. The Hom plants accumulated 1.5-4 times more asparagine, glycine, serine and soluble proteins and registered higher glutamine synthetase (GS) and glutamate synthase (GOGAT) activities in the light-adapted leaves than the other genotypes, but had similar NH4(+) and NO3(-) levels in all conditions. In the dark-adapted leaves, a protein catabolism occurred in the Hom plants with a concomitant 25-40% increase in organic acid concentration, while asparagine accumulation registered the highest values. The aforementioned processes might be responsible for a positive energetic balance as regards the futile cycle of the transgenic protein synthesis and catabolism. This explains growth penalty under standard nutrition and growth stability under NO3(-)/NH4(+)=3.5/3, respectively. Copyright © 2013 Elsevier GmbH. All rights reserved.

  3. A pilot study of gaseous pollutants' measurement (NO2, SO2, NH3, HNO3 and O3) in Abidjan, Côte d'Ivoire: contribution to an overview of gaseous pollution in African cities

    Science.gov (United States)

    Bahino, Julien; Yoboué, Véronique; Galy-Lacaux, Corinne; Adon, Marcellin; Akpo, Aristide; Keita, Sékou; Liousse, Cathy; Gardrat, Eric; Chiron, Christelle; Ossohou, Money; Gnamien, Sylvain; Djossou, Julien

    2018-04-01

    This work is part of the DACCIWA FP7 project (Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa) in the framework of the Work Package 2 Air Pollution and Health. This study aims to characterize urban air pollution levels through the measurement of NO2, SO2, NH3, HNO3 and O3 in Abidjan, the economic capital of Côte d'Ivoire. Measurements of inorganic gaseous pollutants, i.e. NO2, SO2, NH3, HNO3 and O3 were performed in Abidjan during an intensive campaign within the dry season (15 December 2015 to 16 February 2016), using INDAAF (International Network to study Deposition and Atmospheric chemistry in AFrica) passive samplers exposed in duplicate for 2-week periods. Twenty-one sites were selected in the district of Abidjan to be representative of various anthropogenic and natural sources of air pollution in the city. Results from this intensive campaign show that gas concentrations are strongly linked to surrounding pollution sources and show a high spatial variability. Also, NH3, NO2 and O3 gases were present at relatively higher concentrations at all the sites. NH3 average concentrations varied between 9.1 ± 1.7 ppb at a suburban site and 102.1 ± 9.1 ppb at a domestic fires site. NO2 mean concentration varied from 2.7 ± 0.1 ppb at a suburban site to 25.0 ± 1.7 ppb at an industrial site. Moreover, we measured the highest O3 concentration at the two coastal sites of Gonzagueville and Félix-Houphouët-Boigny International Airport located in the southeast of the city, with average concentrations of 19.1 ± 1.7 and 18.8 ± 3.0 ppb, respectively. The SO2 average concentration never exceeded 7.2 ± 1.2 ppb over all the sites, with 71.5 % of the sampling sites showing concentrations ranging between 0.4 and 1.9 ppb. The HNO3 average concentration ranged between 0.2 and 1.4 ppb. All these results were combined with meteorological parameters to provide the first mapping of gaseous pollutants on the scale of the district of Abidjan using geostatistical analysis

  4. ??????????? ????????? ???????????? ???????????? NH4X (?=??,?1) ??? ??????????? CdxHgi-xTe ??????? ???????? ???????????? ???????

    OpenAIRE

    ??????, ?. ?.; ?????????, ?. ?.; ???????, ?. ?.; ?????????, ?. ?.; ?????????, ?. ?.

    2004-01-01

    ?? ?????? ??????????? ?????????? ???????????? ?????? ??????? ???? ??????? CdxHgi_xTe-Hg-NH4Br ??? ??????? ?????? Hg ? ????????? ?????????? 560-860? ? ??????????? ?????? ?? = 103-=-105 ?? ????????? ????????, ??? ??????? ???????? ????? ? ??????????????? ??????, ????? ? ?????? - CdBr2, Hg, ??2. ??? ????????? ??????? ??????? ???????????? CdxHgi_xTe ??????? ? = 0.2; 0.3; 0.4 ?? ????????? ??? ??? ? ??? ?????????? ??????? ???????? ??????? (??? ?????? ?????? ????? ? ???????) ????????? ??????????? ???...

  5. Solid-State Synthesis and Structure of the Enigmatic Ammonium Octaborate: (NH4)2[B7O9(OH)5]·3/4B(OH)3·5/4H2O.

    Science.gov (United States)

    Neiner, Doinita; Sevryugina, Yulia V; Schubert, David M

    2016-09-06

    The compound known since the 19th century as ammonium octaborate was structurally characterized revealing the ammonium salt of the ribbon isomer of the heptaborate anion, [B7O9(OH)5](2-), with boric acid and water molecules. Of composition (NH4)2B7.75O12.63·4.88H2O, it approximates the classical ammonium octaborate composition (NH4)2B8O13·6H2O and has the structural formula {(NH4)2[B7O9(OH)5]}4·3B(OH)3·5H2O. It spontaneously forms at room temperature in solid-state mixtures of ammonium tetraborate and ammonium pentaborate. It crystallizes in the monoclinic space group P21/c with a = 11.4137(2) Å, b = 11.8877(2) Å, c = 23.4459(3) Å, β = 90.092(1)°, V = 3181.19(8) Å(3), and Z = 2 and contains well-ordered ammonium cations and [B7O9(OH)5](2-) anions and disordered B(OH)3 and H2O molecules linked by extensive H bonding. Expeditious solid-state formation of the heptaborate anion under ambient conditions has important implications for development of practical syntheses of industrially useful borates.

  6. Effect of organic matter and of a nitrification inhibitor in the absorption of a 15NH4+ and 15NO3- by maize

    International Nuclear Information System (INIS)

    Saito, S.M.T.; Neptune, A.M.L.

    1977-01-01

    An experiment is discussed, carried out in greenhouse, aiming at verilying the effect of 15 NH4 + and 15 NO 3 - in presence or absence of organic matter, and of a nitrifiction inhibitor 'AM' (2-amino-4-cloro-6-metil-pyrimidine) in the mass production and nitrogen content of the plant, taken from the soil and the fertilizer. The test plant is hybrid maize 'Centralmex' and three soils of different physical and chemical characteristicas are used:'Regossol intergrade', 'Latossol roxo' and 'Podzolizado de Lins e Marilia, var. Marilia' [pt

  7. [Co(NH3)6]3[Cu4(OH)(CO3)8].2H2O--a new carbonato-copper(II) anion stabilized by extensive hydrogen bonding.

    Science.gov (United States)

    Abrahams, Brendan F; Haywood, Marissa G; Robson, Richard

    2004-04-21

    Addition of Co(NH3)6(3+) to aqueous solutions of Cu(II) in excess carbonate promotes the assembly of a new highly charged carbonato-copper(II) anion, [Cu4(OH)(CO3)8](9-), which contains an unusual mu4 hydroxo-bridged square Cu4 arrangement, stabilised in the crystal by no less than forty hydrogen bonds (< 3 Angstrom) to hexammine cations.

  8. Solid-state thermal decomposition of the [Co(NH3)5CO3]NO3·0.5H2O complex: A simple, rapid and low-temperature synthetic route to Co3O4 nanoparticles

    International Nuclear Information System (INIS)

    Farhadi, Saeid; Safabakhsh, Jalil

    2012-01-01

    Highlights: ► [Co(NH 3 ) 5 CO 3 ]NO 3 ·0.5H 2 O complex was used for preparing pure Co 3 O 4 nanoparticles. ► Co 3 O 4 nanoparticles were prepared at low temperature of 175 °C. ► Co 3 O 4 nanoparticles show a weak ferromagnetic behaviour at room temperature. ► The method is simple, low-cost and suitable for the production of Co 3 O 4 . - Abstract: Co 3 O 4 nanoparticles were easily prepared via the decomposition of the pentammine(carbonato)cobalt(III) nitrate precursor complex [Co(NH 3 ) 5 CO 3 ]NO 3 ·0.5H 2 O at low temperature (175 °C). The product was characterized by thermal analysis, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), UV–visible spectroscopy, transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), Raman spectroscopy, Brunauer–Emmett–Teller (BET) specific surface area measurements and magnetic measurements. The FT-IR, XRD, Raman and EDX results indicated that the synthesized Co 3 O 4 nanoparticles are highly pure and have a single phase. The TEM analysis revealed nearly uniform and quasi-spherical Co 3 O 4 nanoparticles with an average particle size of approximately 10 nm. The optical absorption spectrum of the Co 3 O 4 nanoparticles showed two direct band gaps of 2.18 and 3.52 eV with a red shift in comparison with previous reported values. The prepared Co 3 O 4 nanoparticles showed a weak ferromagnetic behaviour that could be attributed to uncompensated surface spins and/or finite-size effects. Using the present method, Co 3 O 4 nanoparticles can be produced without expensive organic solvents and complicated equipment. This simple, rapid, safe and low-cost synthetic route can be extended to the synthesis of other transition-metal oxides.

  9. Utilizing Laser-Induced Breakdown Spectroscopy Method to recognize chemical composition of low-carbon steel in NH3(NO)4 material

    Science.gov (United States)

    Saud Oraibi, Nissan

    2018-05-01

    A standoff laser Induced Break down Spectroscopy (L.I.B.S) technique has been used to characterization the organic material such as NH3(NO)4, a Q-switched Nd:YAG laser (1064 nm wavelength, 9 ns pulse width and 1 Hz repetition rate, 300 mJ is focused to the targets to generate plasma. HR 4000 CG-UV-NIR spectrum analyzer was used to collect the generated plasma emissions, specific signature of each targets material can be obtained by analysis the plasma emission spectrum Peak ratio analysis technique is used for the identification of energetic materials.

  10. Prediction on electronic structure of CH3NH3PbI3/Fe3O4 interfaces

    Science.gov (United States)

    Hou, Xueyao; Wang, Xiaocha; Mi, Wenbo; Du, Zunfeng

    2018-01-01

    The interfacial electronic structures of CH3NH3PbI3(MAPbI3)/Fe3O4 heterostructures are predicted by density functional theory. Four models (MAI/FeBO, PbI2/FeBO, MAI/FeA and PbI2/FeA) are included. Especially, a half-metal to semiconductor transition of Fe3O4 appears in PbI2/FeA model. A series of electric field is added to PbI2/FeA model, and a direct-indirect bandgap transition of Fe3O4 appears at a 500-kV/cm field. The electric field can control the bandgap of Fe3O4 in PbI2/FeA model by modulating the hybridization. The prediction of spin-related bandgap characteristic in MAPbI3/Fe3O4 is meaningful for further study.

  11. Synthesis, vibrational and optical properties of a new three-layered organic-inorganic perovskite (C4H9NH3)4Pb3I4Br6

    International Nuclear Information System (INIS)

    Dammak, T.; Elleuch, S.; Bougzhala, H.; Mlayah, A.; Chtourou, R.; Abid, Y.

    2009-01-01

    An organic-inorganic hybrid perovskite (C 4 H 9 NH 3 ) 4 Pb 3 I 4 Br 6 was synthesized and studied by X-ray diffraction, Raman and infrared spectroscopies, optical transmission and photoluminescence. The title compound, abbreviated (C 4 ) 4 Pb 3 I 4 Br 6 , crystallises in a periodic two-dimensional multilayer structure with P2 1 /a space group. The structure is built up from alternating inorganic and organic layers. Each inorganic layer consists of three sheets of PbX 6 (X=I, Br) octahedra. Raman and infrared spectra of the title compound were recorded in the 100-3500 and 400-4000 cm -1 frequency ranges, respectively. An assignment of the observed vibration modes is reported. Optical transmission measurements, performed on thin films of (C 4 ) 4 Pb 3 I 4 Br 6 , revealed two absorption bands at 474 and 508 nm. Photoluminescence measurements have shown a green emission peak at 519 nm.

  12. Thermodynamic modeling of Cl(-), NO3(-) and SO4(2-) removal by an anion exchange resin and comparison with Dubinin-Astakhov isotherms.

    Science.gov (United States)

    Dron, Julien; Dodi, Alain

    2011-03-15

    The removal of chloride, nitrate, and sulfate ions from wastewaters by a macroporous ion-exchange resin is studied through the experimental results obtained for six ion exchange systems, OH(-)/Cl(-), OH(-)/NO3(-), OH(-)/SO4(2-), and HCO3(-)/Cl(-), Cl(-)/NO3(-), Cl(-)/SO4(2-). The results are described through thermodynamic modeling, considering either an ideal or a nonideal behavior of the ionic species in the liquid and solid phases. The nonidealities are determined by the Davies equation and Wilson equations in the liquid and solid phases, respectively. The results show that the resin has a strong affinity for all the target ions, and the order of affinity obtained is OH(-) < HCO3(-) < Cl(-) < NO3(-) < SO4(2-). The calculation of the changes in standard Gibbs free energies (ΔG(0)) shows that even though HCO3(-) has a lower affinity to the resin, it may affect the removal of Cl(-), and in the same way that Cl(-) may affect the removal of NO3(-) and SO4(2-). The application of nonidealities in the thermodynamic model leads to an improved fit of the model to the experimental data with average relative deviations below 1.5% except for the OH(-)/SO4(2-) system. On the other hand, considering ideal or nonideal behaviors has no significant impact on the determination of the selectivity coefficients. The thermodynamic modeling is also compared with the Dubinin-Astakhov adsorption isotherms obtained for the same ion exchange systems. Surprisingly, the latter performs significantly better than the ideal thermodynamic model and nearly as well as the nonideal thermodynamic model.

  13. CO2 Absorption and Magnesium Carbonate Precipitation in MgCl2–NH3NH4Cl Solutions: Implications for Carbon Capture and Storage

    Directory of Open Access Journals (Sweden)

    Chen Zhu

    2017-09-01

    Full Text Available CO2 absorption and carbonate precipitation are the two core processes controlling the reaction rate and path of CO2 mineral sequestration. Whereas previous studies have focused on testing reactive crystallization and precipitation kinetics, much less attention has been paid to absorption, the key process determining the removal efficiency of CO2. In this study, adopting a novel wetted wall column reactor, we systematically explore the rates and mechanisms of carbon transformation from CO2 gas to carbonates in MgCl2–NH3NH4Cl solutions. We find that reactive diffusion in liquid film of the wetted wall column is the rate-limiting step of CO2 absorption when proceeding chiefly through interactions between CO2(aq and NH3(aq. We further quantified the reaction kinetic constant of the CO2–NH3 reaction. Our results indicate that higher initial concentration of NH4Cl ( ≥ 2 mol · L − 1 leads to the precipitation of roguinite [ ( NH 4 2 Mg ( CO 3 2 · 4 H 2 O ], while nesquehonite appears to be the dominant Mg-carbonate without NH4Cl addition. We also noticed dypingite formation via phase transformation in hot water. This study provides new insight into the reaction kinetics of CO2 mineral carbonation that indicates the potential of this technique for future application to industrial-scale CO2 sequestration.

  14. Mild hydrothermal synthesis, crystal structure, thermal behavior, spectroscopic and magnetic properties of the (NH4)[Fe(AsO4)1-x(PO4)xF] (x=0.3, 0.6, 0.8) series. Thermal transformation of (NH4)[Fe(AsO4)0.7(PO4)0.3F] into the textural porous orthorhombic Fe(AsO4)0.7(PO4)0.3

    International Nuclear Information System (INIS)

    Berrocal, Teresa; Mesa, Jose L.; Pizarro, Jose L.; Bazan, Begona; Lezama, Luis; Arriortua, Maria I.; Rojo, Teofilo

    2009-01-01

    The (NH 4 )[Fe(AsO 4 ) 1-x (PO 4 ) x F] (x=0.3, 0.6, 0.8) series of compounds has been synthesized under mild hydrothermal conditions. The compounds crystallize in the orthorhombic Pna2 1 space group, with the unit-cell parameters a=13.1718(1), b=6.5966(6), c=10.797(1) A for x=0.3; a=13.081(1), b=6.5341(6), c=10.713(1) A for x=0.6 and a=13.0329(9), b=6.4994(4), c=10.6702(6) A for x=0.8, with the volumes 938.6(1), 915.7(1) and 903.8(1) A 3 , respectively, with Z=8. Single crystals of (NH 4 )[Fe(AsO 4 ) 0.7 (PO 4 ) 0.3 F] heated under air atmosphere at 465 deg. C remain as single crystals, changing the composition to Fe(AsO 4 ) 0.7 (PO 4 ) 0.3 . This later phase belongs to the orthorhombic Imam space group, with the unit cell parameters a=13.328(2), b=6.5114(5), c=10.703(1) A, V=928.9(2) A 3 and Z=12. The crystal structure of the ammonium phases consists of a KTP three-dimensional framework constructed by chains formed by alternating Fe(2)O 4 F 2 or Fe(1)O 4 F 2 octahedra and As/P(2)O 4 or As/P(1)O 4 tetrahedra, respectively. These octahedra and tetrahedra are linked by a common oxygen vertex. The chains run along the 'a' and 'b' crystallographic axes. The crystal structure of Fe(AsO 4 ) 0.7 (PO 4 ) 0.3 is a three-dimensional skeleton derived from that of the precursor, formed from (100) sheets stacked along the [001] direction, and interconnected by chains of alternating Fe(2)O 6 octahedra and As/P(2)O 4 tetrahedra sharing a vertex in the 'a' direction. Transmission electronic microscopy of this compound indicates the existence of unconnected external cavities with a BET surface area of 3.91(3) m 2 g -1 . The diffuse reflectance spectra in the visible region show the forbidden electronic transitions characteristic of the Fe(III) d 5 -high spin cation in slightly distorted octahedral geometry, for all the compounds. The ESR spectra for all the compounds, carried out from room temperature to 4.2 K, remain isotropic with variation in temperature; the g-value is 1

  15. Wet Mechanochemical Processing of Celestine using (NH42CO3

    Directory of Open Access Journals (Sweden)

    Deniz Bingöl

    2017-06-01

    Full Text Available In this study, traditional (univariate method of processing to the wet mechanochemical treatment were applied to obtain both SrCO3 and (NH42SO4 from celestite (SrSO4-(NH42CO3-H2O mixtures in a planetary ball mill. X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and chemical analysis were used to analyze products formed during wet milling. A hydrometallurgical process was carried out to examine milling time, ball to grinding material mass ratio, (NH42CO3 to SrSO4 mole ratio and rotational speed of the mill in a planetary mill. Under optimum conditions, a conversion approaching 100% of SrCO3 was obtained.

  16. Modelling of catalytic oxidation of NH3 and reduction of NO on limestone during sulphur capture

    DEFF Research Database (Denmark)

    Kiil, Søren; Bhatia, Suresh K.; Dam-Johansen, Kim

    1996-01-01

    activity with respect to each species involved. An existing particle model, the Grain-Micrograin Model, which simulates sulphur capture on limestone under oxidizing conditions is considered in the modelling. Simulation results in good qualitative agreement with experimental data are obtained here......A theoretical study of the complex transient system of simultaneous sulphur capture and catalytic reactions of N-containing compounds taking place on a single limestone particle is conducted. The numerical technique developed previously by the authors (Kiil et al. 1994) based on collocation...... for the catalytic chemistry of NH3 during simultaneous sulphur capture on a Stevns Chalk particle. The reduction of NO by NH3 over CaSO4 (which is the product of the reaction between SO2, O2 and limestone) was found to be important because this reaction could explain the change in selectivity with increased solid...

  17. Effects of hypoxia on 13NH4+ fluxes in rice roots: kinetics and compartmental analysis

    International Nuclear Information System (INIS)

    Kronzucker, H.J.; Kirk, G.J.D.; Siddiqi, M.Y.; Glass, A.D.M.

    1998-01-01

    Techniques of compartmental (efflux) and kinetic influx analyses with the radiotracer 13NH4+ were used to examine the adaptation to hypoxia (15, 35, and 50% O2 saturation) of root N uptake and metabolism in 3-week-old hydroponically grown rice (Oryza sativa L., cv IR72) seedlings. A time-dependence study of NH4+ influx into rice roots after onset of hypoxia (15% O2) revealed an initial increase in the first 1 to 2.5 h after treatment imposition, followed by a decline to less than 50% of influx in control plants by 4 d. Efflux analyses conducted 0, 1, 3, and 5 d after the treatment confirmed this adaptation pattern of NH4+ uptake. Half-lives for NH4+ exchange with subcellular compartments, cytoplasmic NH4+ concentrations, and efflux (as percentage of influx) were unaffected by hypoxia. However, significant differences were observed in the relative amounts of N allocated to NH4+ assimilation and the vacuole versus translocation to the shoot. Kinetic experiments conducted at 100, 50, 35, and 15% O2 saturation showed no significant change in the K(m) value for NH4+ uptake with varying O2 supply. However, V(max) was 42% higher than controls at 50% O2 saturation, unchanged at 35%, and 10% lower than controls at 15% O2. The significance of these flux adaptations is discussed

  18. NH4In(SeO4)2x4H2O crystal structure interpretation

    International Nuclear Information System (INIS)

    Soldatov, E.A.; Kuz'min, Eh.A.; Ilyukhin, V.V.

    1979-01-01

    The rhomb method has been applied to interpret the structure of monoclinic ammonium indium selenate NH 4 In(SeO 4 ) 2 x4H 2 O the elementary cell of which contains Z=4 formula units (a=10.728, b=9.434, c=11.086 A, γ=101.58). The space group is P2 1 /b. The structure foundation is composed of [In(SeO 4 ) 2 x2H 2 O] 1- mixed layers parallel to (100). ''Free'' H 2 O molecules and NH 4 + cations are situated between the layers

  19. Research of lignite oxidation kinetic parameters modified by CuSO4 and NaNO3 initiation additives

    Directory of Open Access Journals (Sweden)

    Larionov Kirill

    2017-01-01

    Full Text Available An experimental study and subsequent analytical assessment of activation energy change in lignite oxidation process with addition of NaNO3 and CuSO4 mineral salts were conducted. The results showed that injection of catalytic additives leads to reduction of coal activation energy and reaction initial temperature.

  20. Structure of (NH4)3H(SeO4)2 in high-temperature phases I and II

    International Nuclear Information System (INIS)

    Lukaszewicz, K.; Pietraszko, A.; Augustyniak, M.A.

    1993-01-01

    Triammonium hydrogenbis(tetraoxoselenate), (NH 4 ) 3 H(SeO 4 ) 2 , M r =341.04, Z=3, λ(Mo K anti α)=0.71073 A, F(000)=498. Phase I: trigonal, R anti 3m, a=6.090(1), c=22.759(5) A, V=731.0(2) A 3 , D x =2.32 g cm -3 , μ=68.7 cm -1 , T=355 K, R=0.0336 for 241 unique reflections with I>4σ(I). Phase II: trigonal, R anti 3, a=6.064(1), c=22.904(5) A, V=729.4(2) A 3 , D x =2.33 g cm -3 , μ=68.8 cm -1 , T=310 K, R=0.0374 for 397 unique reflections with I>4σ(I). In both phases, SeO 4 tetrahedra are linked by a dynamic system of symmetrically disordered hydrogen bonds in planes perpendicular to the trigonal axis. In phase II, SeO 4 tetrahedra deviate from the (210) plane owing to a small rotation of about 4 about the trigonal axis. In phase I, owing to symmetry enhancement, both orientations of SeO 4 tetrahedra are equally probable on both sides of (210), which is therefore a mirror plane. (orig.)

  1. Ammonothermal synthesis and characterization of Cs{sub 2}[Zn(NH{sub 2}){sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Richter, Theresia M.M.; Niewa, Rainer [Institut fuer Anorganische Chemie, Universitaet Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart (Germany); Alt, Nicolas S.A.; Schluecker, Eberhard [Lehrstuhl fuer Prozessmaschinen und Anlagentechnik, Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Cauerstrasse 4, 91058, Erlangen (Germany)

    2016-10-15

    Cs{sub 2}[Zn(NH{sub 2}){sub 4}] was synthesized under ammonothermal conditions (sc-NH{sub 3}, 523 K, 155 MPa) from CsNH{sub 2} and Zn. Growth of cm-sized crystals succeeded upon application of a temperature gradient. The crystal structure is based on the motif of a hexagonal closed packing of [Zn(NH{sub 2}){sub 4}]{sup 2-} ions with occurrence of no significant hydrogen bridges according to distances and vibrational spectroscopy. Cs{sup +} ions are located within octahedral and tetrahedral holes of the packing. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. On phase transitions in NH_{4HSeO4} and ND{4}DSeO{4}

    Science.gov (United States)

    Dvořák, V.; Quilichini, M.; Le Calvé, N.; Pasquier, B.; Heger, G.; Schweiss, P.

    1991-10-01

    We propose a hypothetical prototype phase (space group Imm) from which all observed phases in NH{4}HSeO{4} and ND{4}DSeO{4} can be deduced by introducing order parameters of definite symmetries. Following this hypothesis the symmetry of the superionic phase should be P2/n in disagreement with recent experimental results. Free energies of Landau type are derived by means of which particular phase transitions could be described. The large dielectric anomaly near 252 K in NH{4}HSeO{4} is discussed in some detail. The first order phase transition in ND{4}DSeO{4} from the room temperature phase P2{1}2121 into commensurate lock-in phase (with the wave-vector k {z}(0,0, frac{π}{c})) has been investigated by neutron elastic scattering and the symmetry of the latter has been found to be P112{1} in agreement with our theoretical prediction. Nous proposons une phase prototype hypothétique (de groupe d'espace Immm) à partir de laquelle on peut déduire toutes les phases observées dans NH{4}HSeO{4} et ND{4}DSeO{4} par l'introduction de paramètres d'ordre ayant une symétrie définie. D'après cette hypothèse le groupe d'espace de la phase superionique doit être P2/n ce qui est en désaccord avec des résultats expérimentaux récents. Pour chaque transition de phase on écrit l'énergie libre de type Landau à partir de laquelle elle peut être décrite. La grande anomalie diélectrique au voisinage de 252 K dans le composé NH{4}HSeO{4} est discutée de façon détaillée. Dans le composé ND{4}DSeO{4}, nous avons étudié par diffusion élastique de neutrons la transition de phase du premier ordre qui transforme le cristal de la structure P2{1}2121 dans la phase commensurable d'accrochage (de vecteur d'onde k {z}(0,0, frac{π}{c})). Nous avons montré que la symétrie de cette phase est P112{1}, ce qui en accord avec nos prévisions théoriques.

  3. Analytic models of NH4+ uptake and regeneration experiments

    International Nuclear Information System (INIS)

    Laws, E.A.

    1985-01-01

    Differential equations describing the uptake and regeneration of NH 4 + in both laboratory and field experiments are shown to have analytic solutions which can easily be inverted to determine the rate constants of interest. The solutions are used to study the descriptive ability of two fundamentally different models of NH 4 + cycling, one in which NH 4 + regeneration is regarded as a process that transfers N from participate N to NH 4 + , the other in which regeneration is regarded as a process that introduced NH 4 + to the dissolved phase without removing N from the particulate phase. The former model was found to give a good description of experimental field data and reasonable parameter values in all cases studied. The latter model was much less successful in describing the data and in producing reasonable parameter values. It is concluded that transfer of nitrogen from particulate N to NH 4 + is a process which must be taken into account in analyzing NH 4 + uptake and regeneration experiments

  4. Semiconducting perovskites (2-XC6H4C2H4NH3)2SnI4 (X = F, Cl, Br): steric interaction between the organic and inorganic layers.

    Science.gov (United States)

    Xu, Zhengtao; Mitzi, David B; Dimitrakopoulos, Christos D; Maxcy, Karen R

    2003-03-24

    Two new semiconducting hybrid perovskites based on 2-substituted phenethylammonium cations, (2-XC(6)H(4)C(2)H(4)NH(3))(2)SnI(4) (X = Br, Cl), are characterized and compared with the previously reported X = F compound, with a focus on the steric interaction between the organic and inorganic components. The crystal structure of (2-ClC(6)H(4)C(2)H(4)NH(3))(2)SnI(4) is solved in a disordered subcell [C2/m, a = 33.781(7) A, b = 6.178(1) A, c = 6.190(1) A, beta = 90.42(3)(o), and Z = 2]. The structure is similar to the known (2-FC(6)H(4)C(2)H(4)NH(3))(2)SnI(4) structure with regard to both the conformation of the organic cations and the bonding features of the inorganic sheet. The (2-BrC(6)H(4)C(2)H(4)NH(3))(2)SnI(4) system adopts a fully ordered monoclinic cell [P2(1)/c, a = 18.540(2) A, b = 8.3443(7) A, c = 8.7795(7) A, beta = 93.039(1)(o), and Z = 2]. The organic cation adopts the anti conformation, instead of the gauche conformation observed in the X = F and Cl compounds, apparently because of the need to accommodate the additional volume of the bromo group. The steric effect of the bromo group also impacts the perovskite sheet, causing notable distortions, such as a compressed Sn-I-Sn bond angle (148.7(o), as compared with the average values of 153.3 and 154.8(o) for the fluoro and chloro compounds, respectively). The optical absorption features a substantial blue shift (lowest exciton peak: 557 nm, 2.23 eV) relative to the spectra of the fluoro and chloro compounds (588 and 586 nm, respectively). Also presented are transport properties for thin-film field-effect transistors (TFTs) based on spin-coated films of the two hybrid semiconductors.

  5. Integrable quadratic classical Hamiltonians on so(4) and so(3, 1)

    International Nuclear Information System (INIS)

    Sokolov, Vladimir V; Wolf, Thomas

    2006-01-01

    We investigate a special class of quadratic Hamiltonians on so(4) and so(3, 1) and describe Hamiltonians that have additional polynomial integrals. One of the main results is a new integrable case with an integral of sixth degree

  6. Crystal structure of (NH4)2[Fe(II) 5(HPO3)6], a new open-framework phosphite.

    Science.gov (United States)

    Berrocal, Teresa; Mesa, Jose Luis; Larrea, Edurne; Arrieta, Juan Manuel

    2014-11-01

    Di-ammonium hexa-phosphito-penta-ferrate(II), (NH4)2[Fe5(HPO3)6], was synthesized under mild hydro-thermal conditions and autogeneous pressure, yielding twinned crystals. The crystal structure exhibits an [Fe(II) 5(HPO3)6](2-) open framework with NH4 (+) groups as counter-cations. The anionic skeleton is based on (001) sheets of [FeO6] octa-hedra (one with point-group symmetry 3.. and one with .2.) linked along [001] through [HPO3](2-) oxoanions. Each sheet is constructed from 12-membered rings of edge-sharing [FeO6] octa-hedra, giving rise to channels with a radius of ca 3.1 Å in which the disordered NH4 (+) cations are located. The IR spectrum shows vibrational bands typical for phosphite and ammonium groups.

  7. An empirical, quantitative approach to predict the reactivity of some substituted aromatic compounds towards reactive radical species (Cl2-*, Br2-*, *NO2, SO3-*, SO4-*) in aqueous solution.

    Science.gov (United States)

    Minero, Claudio; Maurino, Valter; Pelizzetti, Ezio; Vione, Davide

    2006-07-01

    The Hammett approach, applied to the reaction of various classes of aromatic compounds with the radicals Cl2-*, Br2-*, *NO2, SO3-*, and SO4-* yielded good predictive models, supported by high values of the correlation coefficient r2 in the case of phenols with Cl2-* and of phenolates with *NO2 and SO3-*. Lower but statistically significant correlation coefficients could be obtained for benzoates with Cl2-*, phenolates with Br2-*, and benzoates and anisoles with SO4-*.

  8. Characterizing isotopic compositions of TC-C, NO3--N, and NH4+-N in PM2.5 in South Korea: Impact of China's winter heating.

    Science.gov (United States)

    Park, Yu-Mi; Park, Kwang-Su; Kim, Hyuk; Yu, Seok-Min; Noh, Seam; Kim, Min-Seob; Kim, Jee-Young; Ahn, Joon-Young; Lee, Min-do; Seok, Kwang-Seol; Kim, Young-Hee

    2018-02-01

    The origin of PM 2.5 has long been the subject of debate and stable isotopic tools have been applied to decipher. In this study, weekly PM 2.5 samples were simultaneously collected at an urban (Seoul) and rural (Baengnyeong Island) site in Korea from January 2014 through February 2016. The seasonal variation of isotopic species showed significant seasonal differences with sinusoidal variation. The isotopic results implied that isotope species from Baengnyeong were mostly originated from coal combustion during China's winter heating seasons, whereas in summer, the isotopic patterns observed that were more likely to be from marine. In Seoul, coal combustion related isotopic patterns increased during China's winter heating period while vehicle related isotopic patterns were dominated whole seasons by default. Therefore, aerosol formation was originated from long-range transported coal combustion-related NO x by vehicle-related NH 3 in Seoul. δN-NH 4 + in Seoul showed highly enriched 15 N compositions in all seasons, indicating that NH 3 from vehicle emission is the important source of NH 4 + in PM 2.5 in Seoul. In addition, Baengnyeong should be consistently considered as a key region for observing the changes of isotopic features depend on the contribution of individual emissions to the atmospheric as a result of the reduction of coal consumption in China. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Refinement of hydrogen positions in (NH4)2SeO4

    International Nuclear Information System (INIS)

    Loose, A.; Mel'nik, G.; Zink, N.; Wozniak, K.; Dominiak, P.; Smirnov, L.S.; Pawlukojc, A.; Shuvalov, L.A.

    2005-01-01

    The crystal structure of ammonium selenate has been studied by means of single crystal X-ray and neutron diffraction with the purpose of the refinement of hydrogen positions. The refined hydrogen positions obtained by single crystal neutron diffraction show that N-H bond lengths form a regular tetrahedron in an ammonium ion. The single crystal X-ray diffraction data show that N-H bond lengths are shorter than those obtained by neutron diffraction and are not equal between themselves. Thus, the comparison of the results of X-ray and neutron diffraction allows one to suggest that the shorter N-H bond lengths by X-ray diffraction reflect the distribution of the electron charge density of ammonium ions within the (NH 4 ) 2 SeO 4 crystal lattice

  10. Experimental study of H2SO4 aerosol nucleation at high ionization levels

    Directory of Open Access Journals (Sweden)

    M. Tomicic

    2018-04-01

    Full Text Available One hundred and ten direct measurements of aerosol nucleation rate at high ionization levels were performed in an 8 m3 reaction chamber. Neutral and ion-induced particle formation from sulfuric acid (H2SO4 was studied as a function of ionization and H2SO4 concentration. Other species that could have participated in the nucleation, such as NH3 or organic compounds, were not measured but assumed constant, and the concentration was estimated based on the parameterization by Gordon et al. (2017. Our parameter space is thus [H2SO4]  = 4×106 − 3×107 cm−3, [NH3+ org]  =  2.2 ppb, T = 295 K, RH  =  38 %, and ion concentrations of 1700–19 000 cm−3. The ion concentrations, which correspond to levels caused by a nearby supernova, were achieved with gamma ray sources. Nucleation rates were directly measured with a particle size magnifier (PSM Airmodus A10 at a size close to critical cluster size (mobility diameter of  ∼  1.4 nm and formation rates at a mobility diameter of  ∼  4 nm were measured with a CPC (TSI model 3775. The measurements show that nucleation increases by around an order of magnitude when the ionization increases from background to supernova levels under fixed gas conditions. The results expand the parameterization presented in Dunne et al. (2016 and Gordon et al. (2017 (for [NH3 + org]  =  2.2 ppb and T = 295 K to lower sulfuric acid concentrations and higher ion concentrations. The results make it possible to expand the parameterization presented in Dunne et al. (2016 and Gordon et al. (2017 to higher ionization levels.

  11. Tetraammineplatinum(II) aquapentachloroiridate(III) dihydrate, [Pt(NH3)4][IrCl5(H2O)

    International Nuclear Information System (INIS)

    Garnier, E.; Bele, M.

    1994-01-01

    The crystal is built up from planar Pt(NH 3 ) 4 2+ cations, octahedral IrCl 5 (H 2 O) 2- anions and two H 2 O molecules. The coordination of these ions is 6/6, thus leading to a NaCl crystal structure. Electrostatic interactions and N..Cl, N..O and N..N short contacts (possible hydrogen bonds) take part in the packing of the structure and form a three-dimensional network. (orig.)

  12. Porous Ni3(NO3)2(OH)4 nano-sheets for supercapacitors: Facile synthesis and excellent rate performance at high mass loadings

    Science.gov (United States)

    Shi, Mingjie; Cui, Mangwei; Kang, Litao; Li, Taotao; Yun, Shan; Du, Jing; Xu, Shoudong; Liu, Ying

    2018-01-01

    For supercapacitors, pores in electrode materials can accelerate chemical reaction kinetics by shortening ion diffusion distances and by enlarging electrolyte/electrode interfaces. This article describes a simple one-step route for the preparation of pure-phase porous Ni3(NO3)2(OH)4 nano-sheets by directly heating a mild Ni(NO3)2 and urea solution. During heating, urea decomposed into NH3·H2O, which provided a suitable alkaline environment for the formation of Ni3(NO3)2(OH)4 nano-sheets. Meanwhile, the side product, NH4NO3, created numerous pores as a pore-forming agent. After NH4NO3 removal, the specific surface areas and pore volumes of products were boosted by ∼180-times (from 0.61 to 113.12 m2/g) and ∼90-times (from 3.40 × 10-3 to 3.17 × 10-1 m2/g), respectively. As a cathode material of supercapacitor, the porous Ni3(NO3)2(OH)4 nano-sheets exhibited a high specific capacitance of 1094 F/g at an ultrahigh mass loading of 17.55 mg/cm2, leading to an impressive areal capacitance of 19.2 F/cm2. Furthermore, a Ni3(NO3)2(OH)4 nano-sheet//commercial active carbon asymmetric supercapacitor was constructed and delivered an energy density of 33.2 Wh/Kg at a power density of 190.5 W/Kg, based on the mass of active materials on both electrodes.

  13. Effect of cupric salts (Cu (NO{sub 3}){sub 2}, CuSO4{sub ,} Cu(CH{sub 3}COO){sub 2}) on Cu{sub 2}(OH)PO{sub 4} morphology for photocatalytic degradation of 2,4-dichlorophenol under near-infrared light irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Chao; Li, Pei; Zhang, Wei; Che, Yanhao; Sun, Yaxin; Chi, Fangli; Ran, Songlin; Liu, Xianguo; Lv, Yaohui, E-mail: yaohui2015@163.com [School of Materials Science and Engineering, Anhui Key Laboratory of Metal Materials and Processing, Anhui University of Technology (China)

    2017-03-15

    Cu{sub 2}(OH)PO{sub 4} microstructures were synthesized by the hydrothermal method using three different types cupric salts (Cu (NO{sub 3}){sub 2}, CuSO{sub 4}, Cu(CH{sub 3}COO){sub 2}) as raw materials. The X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-visible-NIR absorption spectra were used to characterize the as-obtained products. The different anions (SO{sub 4}{sup 2-}, CH{sub 3}COO-, NO{sub 3-}) have different shapes and polarities, which can generate different interactions in reaction bath, induced the difference of structure and morphology of the prepared Cu{sub 2}(OH)PO{sub 4}. The Cu{sub 2}(OH)PO{sub 4} microstructures prepared form Cu(NO{sub 3}){sub 2} ·3H{sub 2}O showed the best photocatalytic activity induced by near-infrared light to degrade 2,4-dichlorophenol (2,4-DCP) solution. Our work suggests that the active morphological surfaces as well as different coordination environments for the metal ions has an important influence on the photocatalytic performance of Cu{sub 2}(OH)PO{sub 4} microstructure. (author)

  14. Interactions of methylamine and ammonia with atmospheric nucleation precursor H{sub 2}SO{sub 4} and common organic acids: Thermodynamics and atmospheric implications

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Y.; Jiang, L.; Bai, Z. [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Science, Beijing 100012 (China); Nadykto, A. B., E-mail: anadykto@gmail.com [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Science, Beijing 100012 (China); Department of Applied Mathematics, Moscow State University of Technology “STANKIN”, Vadkovsky per. 1, Moscow 127055 (Russian Federation); Atmospheric Science Research Center, State University of New York at Albany, 251 Fuller Road, Albany, NY 12203 (United States)

    2016-06-08

    Interactions of the two common atmospheric bases, ammonia (NH{sub 3}) and methylamine MA (CH{sub 3}NH{sub 2}), which are considered to be important stabilizers of binary clusters in the Earth’s atmosphere, with H{sub 2}SO{sub 4}, the key atmospheric precursor, and 14 common atmospheric organic acids (COA) (formic (CH{sub 2}O{sub 2}), acetic (C{sub 2}H{sub 4}O{sub 2}), oxalic (C{sub 2}H{sub 2}O{sub 4}), malonic (C{sub 3}H{sub 4}O{sub 4}), succinic (C{sub 4}H{sub 6}O{sub 4}), glutaric acid (C{sub 5}H{sub 8}O{sub 4}), adipic (C{sub 6}H{sub 10}O{sub 4}), benzoic (C{sub 6}H{sub 5}COOH), phenylacetic (C{sub 6}H{sub 5}CH{sub 2}COOH), pyruvic (C{sub 3}H{sub 4}O{sub 3}), maleic acid (C{sub 4}H{sub 4}O{sub 4}), malic (C{sub 4}H{sub 6}O{sub 5}), tartaric (C{sub 4}H{sub 6}O{sub 6}) and pinonic acid (C{sub 10}H{sub 16}O{sub 3})) have been studied using the composite high-accuracy G3MP2 method. The thermodynamic stability of mixed (COA) (H{sub 2}SO{sub 4}), (COA)(B1) and (COA)(B2) dimers and (COA) (H{sub 2}SO{sub 4}) (B1) and (COA) (H{sub 2}SO{sub 4}) (B1) trimers, where B1 and B2 represent methylamine (CH{sub 3}NH{sub 2}) and ammonia (NH{sub 3}), respectively, have been investigated and their impacts on the thermodynamic stability of clusters containing H{sub 2}SO{sub 4} have been analyzed. It has been shown that in many cases the interactions of H{sub 2}SO{sub 4} with COA, ammonia and methylamine lead to the formation of heteromolecular dimers and trimers, which are certainly more stable than (H{sub 2}SO{sub 4}){sub 2} and (H{sub 2}SO{sub 4}){sub 3}. It has also been found that free energies of (COA) (H{sub 2}SO{sub 4})+ CH{sub 3}NH{sub 2}⇔(COA) (H{sub 2}SO{sub 4})(CH{sub 3}NH{sub 2}) reactions exceed 10-15 kcal mol{sup −1}. This is a clear indication that mixed trimers composed of COA, H{sub 2}SO{sub 4} and methylamine are very stable and can thus serve as possible nucleation sites. The present study leads us to conclude that the interactions of COA coexisting with H

  15. NH4+ triggers the release of astrocytic lactate via mitochondrial pyruvate shunting

    Science.gov (United States)

    Lerchundi, Rodrigo; Fernández-Moncada, Ignacio; Contreras-Baeza, Yasna; Sotelo-Hitschfeld, Tamara; Mächler, Philipp; Wyss, Matthias T.; Stobart, Jillian; Baeza-Lehnert, Felipe; Alegría, Karin; Weber, Bruno; Barros, L. Felipe

    2015-01-01

    Neural activity is accompanied by a transient mismatch between local glucose and oxygen metabolism, a phenomenon of physiological and pathophysiological importance termed aerobic glycolysis. Previous studies have proposed glutamate and K+ as the neuronal signals that trigger aerobic glycolysis in astrocytes. Here we used a panel of genetically encoded FRET sensors in vitro and in vivo to investigate the participation of NH4+, a by-product of catabolism that is also released by active neurons. Astrocytes in mixed cortical cultures responded to physiological levels of NH4+ with an acute rise in cytosolic lactate followed by lactate release into the extracellular space, as detected by a lactate-sniffer. An acute increase in astrocytic lactate was also observed in acute hippocampal slices exposed to NH4+ and in the somatosensory cortex of anesthetized mice in response to i.v. NH4+. Unexpectedly, NH4+ had no effect on astrocytic glucose consumption. Parallel measurements showed simultaneous cytosolic pyruvate accumulation and NADH depletion, suggesting the involvement of mitochondria. An inhibitor-stop technique confirmed a strong inhibition of mitochondrial pyruvate uptake that can be explained by mitochondrial matrix acidification. These results show that physiological NH4+ diverts the flux of pyruvate from mitochondria to lactate production and release. Considering that NH4+ is produced stoichiometrically with glutamate during excitatory neurotransmission, we propose that NH4+ behaves as an intercellular signal and that pyruvate shunting contributes to aerobic lactate production by astrocytes. PMID:26286989

  16. NH4(+) triggers the release of astrocytic lactate via mitochondrial pyruvate shunting.

    Science.gov (United States)

    Lerchundi, Rodrigo; Fernández-Moncada, Ignacio; Contreras-Baeza, Yasna; Sotelo-Hitschfeld, Tamara; Mächler, Philipp; Wyss, Matthias T; Stobart, Jillian; Baeza-Lehnert, Felipe; Alegría, Karin; Weber, Bruno; Barros, L Felipe

    2015-09-01

    Neural activity is accompanied by a transient mismatch between local glucose and oxygen metabolism, a phenomenon of physiological and pathophysiological importance termed aerobic glycolysis. Previous studies have proposed glutamate and K(+) as the neuronal signals that trigger aerobic glycolysis in astrocytes. Here we used a panel of genetically encoded FRET sensors in vitro and in vivo to investigate the participation of NH4(+), a by-product of catabolism that is also released by active neurons. Astrocytes in mixed cortical cultures responded to physiological levels of NH4(+) with an acute rise in cytosolic lactate followed by lactate release into the extracellular space, as detected by a lactate-sniffer. An acute increase in astrocytic lactate was also observed in acute hippocampal slices exposed to NH4(+) and in the somatosensory cortex of anesthetized mice in response to i.v. NH4(+). Unexpectedly, NH4(+) had no effect on astrocytic glucose consumption. Parallel measurements showed simultaneous cytosolic pyruvate accumulation and NADH depletion, suggesting the involvement of mitochondria. An inhibitor-stop technique confirmed a strong inhibition of mitochondrial pyruvate uptake that can be explained by mitochondrial matrix acidification. These results show that physiological NH4(+) diverts the flux of pyruvate from mitochondria to lactate production and release. Considering that NH4(+) is produced stoichiometrically with glutamate during excitatory neurotransmission, we propose that NH4(+) behaves as an intercellular signal and that pyruvate shunting contributes to aerobic lactate production by astrocytes.

  17. Eliminating amino acid interference during spectrophotometric NH4+ analysis

    NARCIS (Netherlands)

    Ros, G.H.; Leeuwen, van A.G.; Temminghoff, E.J.M.

    2011-01-01

    Amino acids can interfere with NH4+ in spectrophotometric NH4+ determination hampering accurate quantification of the fate of NH4+ and dissolved organic N in soils. Serious interference has been reported for soils rich in organic matter, and for soils that have been fumigated, oven-dried or

  18. Structural Studies of NH4-exchanged Natrolites at Ambient Conditions and High Temperature

    Energy Technology Data Exchange (ETDEWEB)

    Y Lee; D Seoung; Y Jang; J Bai; Y Lee

    2011-12-31

    We report here for the first time that fully and partially NH{sub 4}-exchanged natrolites can be prepared in hydrated states using the solution exchange method with potassium-natrolite. The structural models of the as-prepared hydrated phases and their dehydrated forms at elevated temperature were refined in space group Fdd2 using in situ synchrotron X-ray powder diffraction data and Rietveld methods. The unit-cell volumes of the hydrated NH{sub 4}-exchanged natrolites at ambient conditions, (NH{sub 4}){sub 16(2)}Al{sub 16}Si{sub 24}O{sub 80}{center_dot}14.1(9)H{sub 2}O and (NH{sub 4}){sub 5.1(1)}K{sub 10.9(1)}Al{sub 16}Si{sub 24}O{sub 80}{center_dot}15.7(3)H{sub 2}O, are found to be larger than that the original sodium-natrolite by ca. 15.6% and 12.8%, respectively. Upon temperature increase, the fully NH{sub 4}-exchanged natrolite undergoes dehydration at ca. 150 C with ca. 16.4% contraction in the unit-cell volume. The dehydrated phase of the fully NH{sub 4}-exchanged natrolite exhibits marginal volume expansion up to 425 C and then becomes amorphized during temperature decrease and exposure to atmospheric condition. In the case of the partially NH{sub 4}-exchanged natrolite, the dehydration starts from ca. 175 C with {approx}15.1% volume contraction and leads to a partial phase separation to show a phase related to the dehydrated K-natrolite. The degree of the phase separation decreases with temperature increase up to 475 C, concomitant to the gradual volume contraction occurring in the partially NH{sub 4}-exchanged natrolite in the dehydrared state. Upon temperature decrease and exposure to atmospheric condition, only the dehydrated K-natrolite is recovered as a crystalline phase from the partially NH{sub 4}-exchanged natrolite. In the hydrated model of the fully NH{sub 4}-exchanged natrolite, the ammonium cations and water molecules are statistically distributed along the elliptical channels, similar to the disordered pattern observed in natrolites exchanged

  19. Comments on the ''Effect of γ-radiation on the phase transition temperature of Li0.5(NH4)0.5SO4'' by Badr and El-Guiziri

    International Nuclear Information System (INIS)

    Tomaszewski, P.E.

    1990-01-01

    A paper published previously by Badr and El-Guiziri concerns LiNH 4 SO 4 crystals. However, the unit cell parameters given by these authors (a = 6.34, b = 6.24 and c = 5.02 A) are wrong due to an improper choice of the unit cell. The correct parameters are well known in the literature (a 0 = 5.2783, b 0 = 9.1262 and c 0 8.7747 A). The same wrong data were published in an earlier paper by Badr, El-Guiziri and Hammad. A detailed comment on this paper, including a possible explanation of the source of such an error, has been published by the present author. (author)

  20. Bulk Kosterlitz-Thouless Type Molecular Superconductor β″-(BEDT-TTF)2[(H2O)(NH4)2Cr(C2O4)3]·18-crown-6.

    Science.gov (United States)

    Martin, Lee; Lopez, Jordan R; Akutsu, Hiroki; Nakazawa, Yasuhiro; Imajo, Shusaku

    2017-11-20

    A new molecular superconductor, β″-(BEDT-TTF) 2 [(H 2 O)(NH 4 ) 2 Cr(C 2 O 4 ) 3 ]·18-crown-6, has been synthesized from the organic donor molecule BEDT-TTF with the anion Cr(C 2 O 4 ) 3 3- . The crystal structure consists of conducting organic layers of BEDT-TTF molecules which adopt the β″ packing motif (layer A), layers of NH 4 + and Λ-Cr(C 2 O 4 ) 3 3- (layer B), layers of (H 2 O)(NH 4 )18-crown-6 (layer C), and layers of NH 4 + and Δ-Cr(C 2 O 4 ) 3 3- (layer D) which produce a superstructure with a repeating pattern of ABCDABCDA. As a result of this packing arrangement, this is the 2D superconductor with the widest gap between conducting layers where only a single donor packing motif is present (β″). Superconducting critical temperatures at ambient pressure observed by electrical transport and magnetic measurements are 4.0-4.9 and 2.5 K, respectively. The strong 2D nature of this system, the broad transition to T zero at 1.8K, and the transition of α of V ∝ I α from 1 to 3 on I-V curves strongly suggest that the superconducting transition is very close to a Kosterlitz-Thouless transition. The magnetic field dependence of the superconducting critical temperature parallel to the conducting plane gives an upper critical field μ 0 H c2∥ > 8 T, which is over the calculated Pauli-Clogston limit for this material.

  1. Na+/H+ and Na+/NH4+ exchange activities of zebrafish NHE3b expressed in Xenopus oocytes

    Science.gov (United States)

    Ito, Yusuke; Kato, Akira; Hirata, Taku; Hirose, Shigehisa

    2014-01-01

    Zebrafish Na+/H+ exchanger 3b (zNHE3b) is highly expressed in the apical membrane of ionocytes where Na+ is absorbed from ion-poor fresh water against a concentration gradient. Much in vivo data indicated that zNHE3b is involved in Na+ absorption but not leakage. However, zNHE3b-mediated Na+ absorption has not been thermodynamically explained, and zNHE3b activity has not been measured. To address this issue, we overexpressed zNHE3b in Xenopus oocytes and characterized its activity by electrophysiology. Exposure of zNHE3b oocytes to Na+-free media resulted in significant decrease in intracellular pH (pHi) and intracellular Na+ activity (aNai). aNai increased significantly when the cytoplasm was acidified by media containing CO2-HCO3− or butyrate. Activity of zNHE3b was inhibited by amiloride or 5-ethylisopropyl amiloride (EIPA). Although the activity was accompanied by a large hyperpolarization of ∼50 mV, voltage-clamp experiments showed that Na+/H+ exchange activity of zNHE3b is electroneutral. Exposure of zNHE3b oocytes to medium containing NH3/NH4+ resulted in significant decreases in pHi and aNai and significant increase in intracellular NH4+ activity, indicating that zNHE3b mediates the Na+/NH4+ exchange. In low-Na+ (0.5 mM) media, zNHE3b oocytes maintained aNai of 1.3 mM, and Na+-influx was observed when pHi was decreased by media containing CO2-HCO3− or butyrate. These results provide thermodynamic evidence that zNHE3b mediates Na+ absorption from ion-poor fresh water by its Na+/H+ and Na+/NH4+ exchange activities. PMID:24401990

  2. Penggunaan zeolit alam untuk mengurangi kandungan krom dan nh4+ dalam air limbah penyamakan kulit

    Directory of Open Access Journals (Sweden)

    Supraptiningsih Supraptiningsih

    2006-07-01

    Full Text Available Leather tanning waste water contains chemical compounds, such as chromium and NH4+ in high concentration, so if they are thrown away without treatment they will make some problems. The aims of this research is to adsorb the cations in leather tanning waste water i.e chromium and NH4+ used natural zeolite as an adsorbent. Research was done by comparing amount of chromium and NH4+ in effluent waste water treatment unit with amount of chromium and NH4+ after being adsorbed by zeolite in a batch system. The result of this research showed that efficiency difference between using zeolite and waste water treatment unit was significant. The optimal condition to reduce chromium and NH4+ was by using 300 grams per liter waste, zeolite particle size was 50-60 mesh, contact time was 24 hours and pH 8±0,1. In this condition, zeolites could reduce chromium from 3728,56mg/l to 365,39 mg/l or 90,20%, and NH4+ from 3040,02 mg/l menjadi 209,76 mg/l or 93,10%. Waste water treatment unit could reduce chromium 63,55% and NH4+ 56,75%.

  3. SCR activity of conformed CuOx/ZrO2-SO4 catalysts

    DEFF Research Database (Denmark)

    Rasmussen, Søren Birk; Yates, Malcolm; Due-Hansen, Johannes

    2010-01-01

    CuOX/ZrO2-SO4 catalysts have been synthesised as conformed materials with the use of sepiolite as agglomerant and the performance in the NH3-SCR reaction with relation to biomass fired boiler units have been studied. The optimal Cu-loading of the catalysts is 3 wt.% CuO, both in terms of activity...

  4. ?????????? ?????, ?????????? ??????????? ?? ?????????? ?????????? ????? ? ?????? ???????? ZnCl2 +NH4Cl

    OpenAIRE

    Kuntyi, Orest; Zozulya, Galyna

    2010-01-01

    Zinc cementation by magnesium from ZnCl2 + NH4Cl aqueous solutions has been investigated. The amount of magnesium has been established as 0.8?2.0 g per 1 g of conditioned zinc to obtain recovery degree ? 99 %. At low concentrations of Zn2+ ions (0.025?0.1 M ZnCl2) dispersed deposit is formed with nanoparticles of reduced metal; at high concentrations (0.25?0.5 M) coarse-crystalline and fern-shaped deposit is formed. ?????????? ?????????? ????? ??????? ? ?????? ???????? ZnCl2 + NH4Cl. ????????...

  5. A pilot study of gaseous pollutants' measurement (NO2, SO2, NH3, HNO3 and O3 in Abidjan, Côte d'Ivoire: contribution to an overview of gaseous pollution in African cities

    Directory of Open Access Journals (Sweden)

    J. Bahino

    2018-04-01

    Full Text Available This work is part of the DACCIWA FP7 project (Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa in the framework of the Work Package 2 Air Pollution and Health. This study aims to characterize urban air pollution levels through the measurement of NO2, SO2, NH3, HNO3 and O3 in Abidjan, the economic capital of Côte d'Ivoire. Measurements of inorganic gaseous pollutants, i.e. NO2, SO2, NH3, HNO3 and O3 were performed in Abidjan during an intensive campaign within the dry season (15 December 2015 to 16 February 2016, using INDAAF (International Network to study Deposition and Atmospheric chemistry in AFrica passive samplers exposed in duplicate for 2-week periods. Twenty-one sites were selected in the district of Abidjan to be representative of various anthropogenic and natural sources of air pollution in the city. Results from this intensive campaign show that gas concentrations are strongly linked to surrounding pollution sources and show a high spatial variability. Also, NH3, NO2 and O3 gases were present at relatively higher concentrations at all the sites. NH3 average concentrations varied between 9.1 ± 1.7 ppb at a suburban site and 102.1 ± 9.1 ppb at a domestic fires site. NO2 mean concentration varied from 2.7 ± 0.1 ppb at a suburban site to 25.0 ± 1.7 ppb at an industrial site. Moreover, we measured the highest O3 concentration at the two coastal sites of Gonzagueville and Félix-Houphouët-Boigny International Airport located in the southeast of the city, with average concentrations of 19.1 ± 1.7 and 18.8 ± 3.0 ppb, respectively. The SO2 average concentration never exceeded 7.2 ± 1.2 ppb over all the sites, with 71.5 % of the sampling sites showing concentrations ranging between 0.4 and 1.9 ppb. The HNO3 average concentration ranged between 0.2 and 1.4 ppb. All these results were combined with meteorological parameters to provide the first mapping of gaseous pollutants

  6. Phase transitions in (NH4)2MoO2F4 crystal

    Science.gov (United States)

    Krylov, Alexander; Laptash, Natalia; Vtyurin, Alexander; Krylova, Svetlana

    2016-11-01

    The mechanisms of temperature and high pressure phase transitions have been studied by Raman spectroscopy. Room temperature (295 K) experiments under high hydrostatic pressure up to 3.6 GPa for (NH4)2 MoO2 F4 have been carried out. Experimental data indicates a phase transition into a new high-pressure phase for (NH4)2 MoO2 F4 at 1.2 GPa. This phase transition is related to the ordering anion octahedron groups [MoO2 F4]2- and is not associated with ammonium group. Raman spectra of small non-oriented crystals ranging from 10 to 350 K have been observed. The experiment shows anion groups [MoO2 F4]2- and ammonium in high temperature phase are disordered. The phase transition at T1 = 269.8 K is of the first-order, close to the tricritical point. The first temperature phase transition is related to the ordering anion octahedron groups [MoO2 F4]2-. Second phase transitions T2 = 180 K are associated with the ordering of ammonium. The data presented within this study demonstrate that 2D correlation analysis combined with traditional Raman spectroscopy are powerful tool to study phase transitions in the crystals.

  7. Comparison of adsorption equilibrium models for the study of CL-, NO3- and SO4(2-) removal from aqueous solutions by an anion exchange resin.

    Science.gov (United States)

    Dron, Julien; Dodi, Alain

    2011-06-15

    The removal of chloride, nitrate and sulfate ions from aqueous solutions by a macroporous resin is studied through the ion exchange systems OH(-)/Cl(-), OH(-)/NO(3)(-), OH(-)/SO(4)(2-), and HCO(3)(-)/Cl(-), Cl(-)/NO(3)(-), Cl(-)/SO(4)(2-). They are investigated by means of Langmuir, Freundlich, Dubinin-Radushkevitch (D-R) and Dubinin-Astakhov (D-A) single-component adsorption isotherms. The sorption parameters and the fitting of the models are determined by nonlinear regression and discussed. The Langmuir model provides a fair estimation of the sorption capacity whatever the system under study, on the contrary to Freundlich and D-R models. The adsorption energies deduced from Dubinin and Langmuir isotherms are in good agreement, and the surface parameter of the D-A isotherm appears consistent. All models agree on the order of affinity OH(-)3)(-)NO(3)(-)<SO(4)(2-), and distinguish high energy processes (OH(-)/Cl(-), OH(-)/NO(3)(-), OH(-)/SO(4)(2-), Cl(-)/SO(4)(2-)) from lower energy systems (HCO(3)(-)/Cl(-), Cl(-)/NO(3)(-)). The D-A and D-R models provide the best fit to the experimental points, indicating that the micropore volume filling theory is the best representation of the ion exchange processes under study among other adsorption isotherms. The nonlinear regression results are also compared with linear regressions. While the parameter values are not affected, the evaluation of the best fitting model is biased by linearization. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. [H3N(CH2)4NH3]2[Al4(C2O4)(H2PO4)2(PO4)4].4[H2O]: A new layered aluminum phosphate-oxalate

    International Nuclear Information System (INIS)

    Peng Li; Li Jiyang; Yu Jihong; Li Guanghua; Fang Qianrong; Xu Ruren

    2005-01-01

    A new layered inorganic-organic hybrid aluminum phosphate-oxalate [H 3 N(CH 2 ) 4 NH 3 ] 2 [Al 4 (C 2 O 4 )(H 2 PO 4 ) 2 (PO 4 ) 4 ].4[H 2 O](AlPO-CJ25) has been synthesized hydrothermally, by using 1,4-diaminobutane (DAB) as structure-directing agent. The structure has been solved by single-crystal X-ray diffraction analysis and further characterized by IR, 31 P MAS NMR, TG-DTA as well as compositional analyses. Crystal data: the triclinic space group P-1, a=8.0484(7) A, b=8.8608(8) A, c=13.2224(11) A, α=80.830(6) deg. , β=74.965(5) deg. , γ=78.782(6) deg. , Z=2, R 1[ I >2 σ ( I )] =0.0511 and wR 2(alldata) =0.1423. The alternation of AlO 4 tetrahedra and PO 4 tetrahedra gives rise to the four-membered corner-sharing chains, which are interconnected through AlO 6 octahedra to form the layered structure with 4,6-net sheet. Interestingly, oxalate ions are bis-bidentately bonded by participating in the coordination of AlO 6 , and bridging the adjacent AlO 6 octahedra. The layers are held with each other through strong H-bondings between the terminal oxygens. The organic ammonium cations and water molecules are located in the large cavities between the interlayer regions. -- Graphical abstract: The alternation of AlO 4 tetrahedra and PO 4 tetrahedra gives rise to the four-membered corner-sharing chains, which are interconnected through AlO 6 octahedra to form the layered structure with 4,6-net sheet. Oxalate ions are bis-bidentately boned by participating in the coordination of AlO 6 , and bridging the adjacent AlO 6 octahedra

  9. Insight to the Thermal Decomposition and Hydrogen Desorption Behaviors of NaNH2-NaBH4 Hydrogen Storage Composite.

    Science.gov (United States)

    Pei, Ziwei; Bai, Ying; Wang, Yue; Wu, Feng; Wu, Chuan

    2017-09-20

    The lightweight compound material NaNH 2 -NaBH 4 is regarded as a promising hydrogen storage composite due to the high hydrogen density. Mechanical ball milling was employed to synthesize the composite NaNH 2 -NaBH 4 (2/1 molar ratio), and the samples were investigated utilizing thermogravimetric-differential thermal analysis-mass spectroscopy (TG-DTA-MS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) analyses. The full-spectrum test (range of the ratio of mass to charge: 0-200) shows that the released gaseous species contain H 2 , NH 3 , B 2 H 6 , and N 2 in the heating process from room temperature to 400 °C, and possibly the impurity gas B 6 H 12 also exists. The TG/DTA analyses show that the composite NaNH 2 -NaBH 4 (2/1 molar ratio) is conductive to generate hydrogen so that the dehydrogenation process can be finished before 400 °C. Moreover, the thermal decomposition process from 200 to 400 °C involves two-step dehydrogenation reactions: (1) Na 3 (NH 2 ) 2 BH 4 hydride decomposes into Na 3 BN 2 and H 2 (200-350 °C); (2) remaining Na 3 (NH 2 ) 2 BH 4 reacts with NaBH 4 and Na 3 BN 2 , generating Na, BN, NH 3 , N 2 , and H 2 (350-400 °C). The better mechanism understanding of the thermal decomposition pathway lays a foundation for tailoring the hydrogen storage performance of the composite complex hydrides system.

  10. Theoretical investigation on the molecular structure, Infrared, Raman and NMR spectra of para-halogen benzenesulfonamides, 4-X-C 6H 4SO 2NH 2 (X = Cl, Br or F)

    Science.gov (United States)

    Karabacak, Mehmet; Çınar, Mehmet; Çoruh, Ali; Kurt, Mustafa

    2009-02-01

    In the present study, the structural properties of para-halogen benzenesulfonamides, 4-XC 6H 4SO 2NH 2 (4-chlorobenzenesulfonamide (I), 4-bromobenzenesulfonamide (II) and 4-fluorobenzenesulfonamide (III)) have been studied extensively utilizing ab initio Hartree-Fock (HF) and density functional theory (DFT) employing B3LYP exchange correlation. The vibrational frequencies were calculated and scaled values were compared with experimental values. The complete assignments were performed on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method. The effects of the halogen substituent on the characteristic benzenesulfonamides bands in the spectra are discussed. The 1H and 13C nuclear magnetic resonance (NMR) chemical shifts of the molecules were calculated using the Gauge-Invariant Atomic Orbital (GIAO) method. Finally, geometric parameters, vibrational bands and chemical shifts were compared with available experimental data of the molecules. The fully optimized geometries of the molecules were found to be consistent with the X-ray crystal structures. The observed and calculated frequencies and chemical shifts were found to be in very good agreement.

  11. Sodium intercalation in the phosphosulfate cathode NaFe2(PO4)(SO4)2

    Science.gov (United States)

    Ben Yahia, Hamdi; Essehli, Rachid; Amin, Ruhul; Boulahya, Khalid; Okumura, Toyoki; Belharouak, Ilias

    2018-04-01

    The compound NaFe2(PO4)(SO4)2 is successfully synthesized via a solid state reaction route and its crystal structure is determined using powder X-ray diffraction data. NaFe2(PO4)(SO4)2 phase is also characterized by cyclic voltammetry, galvanostatic cycling and electrochemical impedance spectroscopy. NaFe2(PO4)(SO4)2 crystallizes with the well-known NASICON-type structure. SAED and HRTEM experiments confirm the structural model, and no ordering between the PO4-3 and SO4-2 polyanions is detected. The electrochemical tests indicate that NaFe2(PO4)(SO4)2 is a 3 V sodium intercalating cathode. The electrical conductivity is relatively low (2.2 × 10-6 Scm-1 at 200 °C) and the obtained activation energy is ∼0.60eV. The GITT experiments indicate that the diffusivity values are in the range of 10-11-10-12 cm2/s within the measured sodium concentrations.

  12. Insulators containing CuCl4X22- (X=H2O, NH3) units: Origin of the orthorhombic distortion observed only for CuCl4(H2O)22-

    DEFF Research Database (Denmark)

    García-Fernández, P.; García Lastra, Juan Maria; Trueba, A.

    2012-01-01

    The origin of the difference in structure between compounds containing CuCl4X22- (X=H2O, NH3) units is analyzed by means of first-principles calculations. While NH3-containing compounds display tetragonal symmetry, H2O-containing ones display an orthorhombic distortion at low temperature where...... the equatorial Cl- ions are no longer equivalent. Our simulations of optical and vibrational transitions show good agreement with all available experimental optical absorption and Raman data. As a salient feature, the value of the force constant for the B1g mode, K(B1g), driving the orthorhombic distortion......CuCl4(H2O)2 has a local origin....

  13. New hydrogen-rich ammonium metal borohydrides, NH4[M(BH4)4], M = Y, Sc, Al, as potential H2 sources.

    Science.gov (United States)

    Starobrat, A; Jaroń, T; Grochala, W

    2018-03-26

    Three metal-ammonium borohydrides, NH4[M(BH4)4] M = Y, Sc, Al, denoted 1, 2, 3, respectively, were prepared via a low temperature mechanochemical synthesis and characterized using PXRD, FTIR and TGA/DSC/MS. The compounds 1 and 2 adopt the P21/c space group while the compound 3 crystallizes in an orthorhombic unit cell (Fddd). The first decomposition step of all three derivatives of ammonium borohydride has the maximum rate at 48 °C, 53 °C and 35 °C for 1, 2 and 3, respectively, which are comparable to that for NH4BH4 (53 °C). The thermal decomposition of these metal-ammonium borohydrides is a multistep process, with predominantly exothermic low-temperature stages. The compound 1 decomposes via known Y(BH4)3, however, some of the solid decomposition products of the other two compounds have not been fully identified. In the system containing compound 2, a new, more dense polymorph of the previously reported LiSc(BH4)4 has been detected as the intermediate of slow decomposition at room temperature.

  14. Discovery of Mixed Pharmacology Melanocortin-3 Agonists and Melanocortin-4 Receptor Tetrapeptide Antagonist Compounds (TACOs) Based on the Sequence Ac-Xaa1-Arg-(pI)DPhe-Xaa4-NH2.

    Science.gov (United States)

    Doering, Skye R; Freeman, Katie T; Schnell, Sathya M; Haslach, Erica M; Dirain, Marvin; Debevec, Ginamarie; Geer, Phaedra; Santos, Radleigh G; Giulianotti, Marc A; Pinilla, Clemencia; Appel, Jon R; Speth, Robert C; Houghten, Richard A; Haskell-Luevano, Carrie

    2017-05-25

    The centrally expressed melanocortin-3 and -4 receptors (MC3R/MC4R) have been studied as possible targets for weight management therapies, with a preponderance of studies focusing on the MC4R. Herein, a novel tetrapeptide scaffold [Ac-Xaa 1 -Arg-(pI)DPhe-Xaa 4 -NH 2 ] is reported. The scaffold was derived from results obtained from a MC3R mixture-based positional scanning campaign. From these results, a set of 48 tetrapeptides were designed and pharmacologically characterized at the mouse melanocortin-1, -3, -4, and -5 receptors. This resulted in the serendipitous discovery of nine compounds that were MC3R agonists (EC 50 DPhe-Tic-NH 2 ], 1 [Ac-His-Arg-(pI)DPhe-Tic-NH 2 ], and 41 [Ac-Arg-Arg-(pI)DPhe-DNal(2')-NH 2 ] were more potent (EC 50 DPhe-Arg-Trp-NH 2 . This template contains a sequentially reversed "Arg-(pI)DPhe" motif with respect to the classical "Phe-Arg" melanocortin signaling motif, which results in pharmacology that is first-in-class for the central melanocortin receptors.

  15. One for two: conversion of waste chicken feathers to carbon microspheres and (NH4)HCO3.

    Science.gov (United States)

    Gao, Lei; Hu, Haibo; Sui, Xuelin; Chen, Changle; Chen, Qianwang

    2014-06-03

    Pyrolysis of 1 g of waste chicken feathers (quills and barbs) in supercritical carbon dioxide (sc-CO2) system at 600 °C for 3 h leads to the formation of 0.25 g well-shaped carbon microspheres with diameters of 1-5 μm and 0.26 g ammonium bicarbonate ((NH4)HCO3). The products were characterized by powder X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), Raman spectroscopic, FT-IR spectrum, X-ray electron spectroscopy (XPS), and N2 adsorption/desorption measurements. The obtained carbon microspheres displayed great superhydrophobicity as fabric coatings materials, with the water contact angle of up to 165.2±2.5°. The strategy is simple, efficient, does not require any toxic chemicals or catalysts, and generates two valuable materials at the same time. Moreover, other nitrogen-containing materials (such as nylon and amino acids) can also be converted to carbon microspheres and (NH4)HCO3 in the sc-CO2 system. This provides a simple strategy to extract the nitrogen content from natural and man-made waste materials and generate (NH4)HCO3 as fertilizer.

  16. Synthesis of a novel 'smart' bifunctional chelating agent 1-(2-[beta,D-galactopyranosyloxy]ethyl)-7-(1-carboxy-3-[4-aminophenyl]propyl)-4,10-bis(carboxymethyl)-1,4,7,10-tetraazacyclododecane (Gal-PA-DO3A-NH2) and its Gd(III) complex.

    Science.gov (United States)

    Wardle, Nick J; Herlihy, Amy H; So, Po-Wah; Bell, Jimmy D; Bligh, S W Annie

    2007-07-15

    A new synthetic pathway to 1-(2-[beta,D-galactopyranosyloxy]ethyl)-7-(1-carboxy-3-[4-aminophenyl]propyl)-4,10-bis(carboxymethyl)-1,4,7,10-tetraazacyclododecane (Gal-PA-DO3A-NH2) and 1-(2-[beta,D-galactopyranosyloxy]ethyl)-4,7,10-tris(carboxymethyl)-1, 4,7,10-tetraazacyclododecane (Gal-DO3A) chelating agents was developed involving full hydroxyl- and carboxyl-group protection in precursors to product. Two sequences of cyclen-N-functionalisation were subsequently investigated, one successfully, towards synthesis of the novel 'smart' bifunctional Gal-PA-DO3A-NH2 chelate. The longitudinal proton relaxivities of the neutral [Gd-(Gal-PA-DO3A-NH2)] and [Gd-(Gal-DO3A)] complexes were increased by 28% and 37% in the presence of beta-galactosidase, respectively.

  17. A Layered Solution Crystal Growth Technique and the Crystal Structure of (C 6H 5C 2H 4NH 3) 2PbCl 4

    Science.gov (United States)

    Mitzi, D. B.

    1999-07-01

    Single crystals of the organic-inorganic perovskite (C6H5C2H4NH3)2PbCl4 have been grown at room temperature using a layered solution approach. The bottom solution layer, contained within a long straight tube, consists of PbCl2 dissolved in concentrated aqueous HCl. A less dense layer of methanol is carefully placed on top of the HCl/PbCl2 solution using a syringe. Finally, a stoichiometric quantity of C6H5C2H4NH2 (relative to the PbCl2) is added to the top of the column. As the layers slowly diffuse together, well-formed crystals of (C6H5C2H4NH3)2PbCl4 appear near the interface between the HCl/PbCl2 and C6H5C2H4NH2 solutions. The thick, plate-like crystals are well suited for X-ray crystallography studies. Room temperature intensity data were refined using a triclinic (Poverline1) cell (a=11.1463(3) Å, b=11.2181(3) Å, c=17.6966(5) Å, α= 99.173(1)°, β=104.634(1)°, γ=89.999(1)°, V=2111.8(1) Å3, Z=4, Rf/Rw=0.031/0.044). The organic-inorganic layered perovskite structure features well-ordered sheets of corner-sharing distorted PbCl6 octahedra separated by bilayers of phenethylammonium cations. Tilting and rotation of the PbCl6 octahedra within the perovskite sheets, coupled with organic cation ordering, leads to the unusual in-sheet 2ap×2ap superstructure, where ap is the lattice constant for the ideal cubic perovskite.

  18. Chemical and electrical properties of (NH4)2S passivated GaSb surface

    International Nuclear Information System (INIS)

    Tao Dongyan; Cheng Yu; Liu Jingming; Su Jie; Liu Tong; Yang Fengyun; Wang Fenghua; Cao Kewei; Dong Zhiyuan; Zhao Youwen

    2015-01-01

    The surface chemical properties of gallium antimonide (GaSb) after ammonium sulfide ((NH 4 ) 2 S) solution passivation have been studied by X-ray photoelectron spectroscopy (XPS), time of flight secondary ion mass spectroscopy (TOF-SIMS) and I–V measurement. An advantage of neutral (NH 4 ) 2 S + S solution over pure (NH 4 ) 2 S solution and alkaline (NH 4 ) 2 S + S solution has been found in the ability to passivate the GaSb surface by contrast and comparison. It has been found that alkaline (NH 4 ) 2 S + S solution passivation effectively removes oxides of the GaSb surface and forms sulfide products to improve device performance. TOF-SIMS complementally demonstrates that pure (NH 4 ) 2 S passivation did form sulfide products, which are too soluble to really exist. The lowest roughness determined using a 3D optical profilometer and the highest improved SBD quality proved that neutral (NH 4 ) 2 S + S solution passivation worked much better in improving the surface properties of GaSb. (paper)

  19. Crystal structure and dynamics of K2-x(NH4)xSeO4 mixed crystals studied by x-ray and neutron scattering

    International Nuclear Information System (INIS)

    Smirnov, L.S.; Natkaniec, I.; Loose, A.

    2006-01-01

    The K 2-x (NH 4 ) x SeO 4 mixed crystals have been studied by powder X-ray and neutron diffraction and inelastic incoherent neutron scattering in a wide temperature range from 300 to 16 K. No phase transition is observed in (NH 4 ) 2 SeO 4 in the range from room temperature to 20 K. The reorientation potential barriers of ammonium ions in the K 2-x (NH 4 ) x SeO 4 mixed crystals increase with the increasing concentration of ammonium ions

  20. A P25/(NH4)xWO3 hybrid photocatalyst with broad spectrum photocatalytic properties under UV, visible, and near-infrared irradiation.

    Science.gov (United States)

    Yang, Linfen; Liu, Bin; Liu, Tongyao; Ma, Xinlong; Li, Hao; Yin, Shu; Sato, Tsugio; Wang, Yuhua

    2017-04-03

    In this study, a series of hybrid nanostructured photocatalysts P25/(NH 4 ) x WO 3 nanocomposites with the average crystallite size of P25 and (NH 4 ) x WO 3 of the sample was calculated to be about 30 nm and 130 nm, were successfully synthesized via a simple one-step hydrothermal method. The as-obtained samples was characterized by transmission electron microscopy (TEM), which implies that the P25/(NH 4 ) x WO 3 nanocomposites are fabricated with favourable nanosizd interfacial. The XPS results confirmed that the obtained sample consists of mixed chemical valences of W 5+ and W 6+ , the low-valance W 5+ sites could be the origin of NIR absorption. As revealed by optical absorption results, P25/(NH 4 ) x WO 3 nanocomposites possess high optical absorption in the whole solar spectrum of 200-2500 nm. Benefiting from this unique photo-absorption property and the synergistic effect of P25 and (NH 4 ) x WO 3 , broad spectrum response photocatalytic activities covering UV, visible and near infrared regions on degradation of Rhodamine B have been realized by P25/(NH 4 ) x WO 3 nanocomposites. Meanwhile, the stability of photocatalysts was examined by the XRD and XPS of the photocatalysts after the reaction. The results show that P25/(NH 4 ) x WO 3 photocatalysts has a brilliant application prospect in the energy utilization to solve deteriorating environmental issues.

  1. Mössbauer Study of Relaxation Phenomena in (NH4)3FeF6

    DEFF Research Database (Denmark)

    Mørup, Steen; Thrane, N.

    1973-01-01

    the magnitudes of other terms of the ionic Hamiltonian. Measurements on the two phases of (NH4)3FeF6 demonstrate differences between cubic and noncubic surroundings of the ferric ion. In the cubic phase we have found a temperature-independent spin-correlation time τ≃1.19×10-10 sec....

  2. Projection of SO{sub 2}, NO{sub X}, NH{sub 3} and particle emissions - 2010-2030

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, O -K; Plejdrup, M; Winther, M; Hjorth Mikkelsen, M; Albrektsen, R; Nielsen, M; Fauser, P; Hoffmann, L; Hjelgaard, K; Gyldenkaerne, S

    2012-01-15

    This report contains a description of models and background data for projection of SO{sub 2}, NO{sub x}, NH{sub 3}, NMVOC, TSP, PM{sub 10} and PM{sub 25} for Denmark. The emissions are projected to 2030 using basic scenarios together with the expected results of a few individual policy measures. Official Danish forecasts of activity rates are used in the models for those sectors for which the forecasts are available, i.e. the latest official forecast from the Danish Energy Agency. The emission factors refer either to international guidelines or are country-specific and refer to Danish legislation, Danish research reports or calculations based on emission data from a considerable number of plants. The projection models are based on the same structure and method as the Danish emission inventories in order to ensure consistency. (Author)

  3. PEGylated (NH4)xWO3 nanorods as efficient and stable multifunctional nanoagents for simultaneous CT imaging and photothermal therapy of tumor.

    Science.gov (United States)

    Macharia, Daniel K; Tian, Qiyun; Chen, Liang; Sun, Yingqi; Yu, Nuo; He, Chuanglong; Wang, Han; Chen, Zhigang

    2017-09-01

    The simultaneous imaging and photothermal therapy of tumors have attracted much attention, and a prerequisite is to obtain multifunctional nanomaterials. Ideally, one kind of nanoparticles with single component can be used as both imaging agent and photothermal agent. Herein, we have developed the PEGylated (NH 4 ) x WO 3 (denoted as (NH 4 ) x WO 3 -PEG) nanorods as multifunctional nanoparticles with single semiconductor component. (NH 4 ) x WO 3 -PEG nanorods with about 30nm diameter and length of several hundred nanometers have been obtained through a solvothermal synthesis-PEGylation two-step route. Under the irradiation of 980-nm laser with intensity of 0.72Wcm -2 , aqueous dispersion of (NH 4 ) x WO 3 -PEG nanorods (0.67-5.44mmol/L) displays high elevation (17.6-34.5°C) of temperature in 400s, accompanied by an excellent long-term photothermal stability. Furthermore, (NH 4 ) x WO 3 -PEG nanorods exhibit as high as 6 times X-ray attenuation ability compared to that of the clinically used iodine-based X-ray computed tomography (CT) contrast agent (Iopromide). More importantly, after PBS solution of (NH 4 ) x WO 3 -PEG nanorods is injected into the tumor of mice, the tumor can be effectively detected by CT imaging. Moreover, cancer cells in vivo can be further destroyed by the photothermal effects of (NH 4 ) x WO 3 -PEG nanorods, under the irradiation of 980-nm laser with the safe intensity of 0.72Wcm -2 for 10min. Therefore, (NH 4 ) x WO 3 -PEG nanorods can be used as a new kind of stable and efficient multifunctional nanoagent with single component for simultaneous CT imaging and photothermal therapy of tumor. Copyright © 2017. Published by Elsevier B.V.

  4. Energetics of fragmentation of CH5, H3O, and NH4 from neutralized ion-beam experiments

    International Nuclear Information System (INIS)

    Williams, B.W.; Porter, R.F.

    1980-01-01

    Fragmentation energies for radicals of the type RH 2 (RH=CH 4 , NH 3 , and H 2 O) produced by electron capture interactions of 5 keV RH 2 + ion with Na or K atoms are reported. The experimental technique involves measurement of spatial beam profiles resulting from dissociation of neutral radicals following their formation in a near resonant electron transfer process. Cross sections for RH 2 + --Na capture reactions are typically 1x10 -14 cm 2 . Fragmentation energies from measurements with Na target atoms are -2.65 +- 0.14, -0.22 +- 0.03, and -1.12 +- 0.07 eV for CH 5 , NH 4 , and H 3 O, respectively. From our results with Na and K targets and published values for proton affinities, the vertical electron affinities of CH 5 + and H 3 O + are calculated to be 5.3 +- 0.2 eV and 5.1 +- 0.3 eV, respectively. Beam profiles for ND 4 show this species to be metastable with a lifetime of about 1 μs. From this we estimate a potential barrier to dissociation in NH 4 (ND 4 ) between 0.36 and 0.48 eV, indicating this species should be stable at low temperatures. Comparison of these experimental results with theoretical calculations indicates areas of disagreement

  5. Studies on SO/sub 2/, NO/sub 2/ and NH/sub 3/: effect on ciliary activity in rabbit trachea of single in vitro exposure and resorption in rabbit nasal cavity

    Energy Technology Data Exchange (ETDEWEB)

    Dalhamm, T; Sjoeholm, J

    1963-01-01

    Absorption in nasal cavity was tested by drawing gas through tracheal cannula at 1 liter/min for 45 min (...simple and is not intended to give accurate quantitative results.). Both SO/sub 2/ and NH/sub 3/ were strongly absorbed, even at high concentrations, whereas NO/sub 2/ was not. Required concentration to arrest ciliary activity after 5 min was 500 to 1000 mg/liter for NH/sub 3/, 150 to 200 for NO/sub 2/, and 20 to 30 for SO/sub 2/. Some evidence of dose-time-effect for this action was observed.

  6. X-ray and NQR studies of bromoindate(III) complexes. [C2H5NH3]4InBr7, [C(NH2)3]3InBr6, and [H3NCH2C(CH3)2CH2NH3]InBr5

    International Nuclear Information System (INIS)

    Iwakiri, Takeharu; Ishihara, Hideta; Terao, Hiromitsu; Lork, Enno; Gesing, Thorsten M.

    2017-01-01

    The crystal structures of [C 2 H 5 NH 3 ] 4 InBr 7 (1), [C(NH 2 ) 3 ] 3 InBr 6 (2), and [H 3 NCH 2 C(CH 3 ) 2 CH 2 NH 3 ]InBr 5 (3) were determined at 100(2) K: monoclinic, P2 1 /n, a=1061.94(3), b=1186.40(4), c=2007.88(7) pm, β= 104.575(1) , Z=4 for 1; monoclinic, C2/c, a=3128.81(12), b=878.42(3), c=2816.50(10) pm, β=92.1320(10) , Z=16 for 2; orthorhombic, P2 1 2 1 2 1 , a=1250.33(5), b=1391.46(6), c=2503.22(9) pm, Z=4 for 3. The structure of 1 contains an isolated octahedral [InBr 6 ] 3- ion and a Br - ion. The structure of 2 contains three different isolated octahedral [InBr 6 ] 3- ions. The structure of 3 has a corner-shared double-octahedral [In 2 Br 11 ] 5- ion and an isolated tetrahedral [InBr 4 ] - ion. The 81 Br nuclear quadrupole resonance (NQR) lines of the terminal Br atoms of the compounds are widely spread in frequency, and some of them show unusual positive temperature dependence. These observations manifest the N-H..Br-In hydrogen bond networks developed between the cations and anions to stabilize the crystal structures. The 81 Br NQR and differential thermal analysis (DTA) measurements have revealed the occurrence of unique phase transitions in 1 and 3. When the bond angles were estimated from the electric field gradient (EFG) directions calculated by the molecular orbital (MO) methods, accurate values were obtained for [InBr 6 ] 3- of 1 and for [In 2 Br 11 ] 5- and [InBr 4 ] - of 3, except for several exceptions in those for the latter two ions. On the other hand, the calculations of 81 Br NQR frequencies have produced up to 1.4 times higher values than the observed ones.

  7. Synthesis and crystal structures of nitratocobaltates Na2[Co(NO3)4], K2[Co(NO3)4], and Ag[Co(NO3)3] and potassium nitratonickelate K2[Ni(NO3)4

    International Nuclear Information System (INIS)

    Morozov, I. V.; Fedorova, A. A.; Albov, D. V.; Kuznetsova, N. R.; Romanov, I. A.; Rybakov, V. B.; Troyanov, S. I.

    2008-01-01

    The cobalt(II) and nickel(II) nitrate complexes with an island structure (Na 2 [Co(NO 3 ) 4 ] (I) and K 2 [Co(NO 3 ) 4 ] (II)] and a chain structure [Ag[Co(NO 3 ) 3 ] (III) and K 2 [Ni(NO 3 ) 4 ] (IV)] are synthesized and investigated using X-ray diffraction. In the anionic complex [Co(NO 3 ) 4 ] 2− of the crystal structure of compound I, the Co coordination polyhedron is a twisted tetragonal prism formed by the O atoms of four asymmetric bidentate nitrate groups. In the anion [Co(NO 3 ) 4 ] 2− of the crystal structure of compound II, one of the four NO 3 groups is monodentate and the other NO 3 groups are bidentate (the coordination number of the cobalt atom is equal to seven, and the cobalt coordination polyhedron is a monocapped trigonal prism). The crystal structures of compounds III and IV contain infinite chains of the compositions [Co(NO 3 ) 2 (NO 3 ) 2/2 ] − and [Ni(NO 3 ) 3 (NO 3 ) 2/2 ] 2− , respectively. In the crystal structure of compound III, seven oxygen atoms of one monodentate and three bidentate nitrate groups form a dodecahedron with an unoccupied vertex of the A type around the Co atom. In the crystal structure of compound IV, the octahedral polyhedron of the Ni atom is formed by five nitrate groups, one of which is terminal bidentate. The data on the structure of Co(II) coordination polyhedra in the known nitratocobaltates are generalized.

  8. Synthesis and crystal structures of nitratocobaltates Na2[Co(NO3)4], K2[Co(NO3)4], and Ag[Co(NO3)3] and potassium nitratonickelate K2[Ni(NO3)4

    International Nuclear Information System (INIS)

    Morozov, I. V.; Fedorova, A. A.; Albov, D. V.; Kuznetsova, N. R.; Romanov, I. A.; Rybakov, V. B.; Troyanov, S. I.

    2008-01-01

    The cobalt(II) and nickel(II) nitrate complexes with an island structure (Na 2 [Co(NO 3 ) 4 ] (I) and K 2 [Co(NO 3 ) 4 ] (II)] and a chain structure [Ag[Co(NO 3 ) 3 ] (III) and K 2 [Ni(NO 3 ) 4 ] (IV)] are synthesized and investigated using X-ray diffraction. In the anionic complex [Co(NO 3 ) 4 ] 2- of the crystal structure of compound I, the Co coordination polyhedron is a twisted tetragonal prism formed by the O atoms of four asymmetric bidentate nitrate groups. In the anion [Co(NO 3 ) 4 ] 2- of the crystal structure of compound II, one of the four NO 3 groups is monodentate and the other NO 3 groups are bidentate (the coordination number of the cobalt atom is equal to seven, and the cobalt coordination polyhedron is a monocapped trigonal prism). The crystal structures of compounds III and IV contain infinite chains of the compositions [Co(NO 3 ) 2 (NO 3 ) 2/2 ] - and [Ni(NO 3 ) 3 (NO 3 ) 2/2 ] 2- , respectively. In the crystal structure of compound III, seven oxygen atoms of one monodentate and three bidentate nitrate groups form a dodecahedron with an unoccupied vertex of the A type around the Co atom. In the crystal structure of compound IV, the octahedral polyhedron of the Ni atom is formed by five nitrate groups, one of which is terminal bidentate. The data on the structure of Co(II) coordination polyhedra in the known nitratocobaltates are generalized

  9. Sources of SO{sub 2}, SO{sub 4}{sup 2-}, NO{sub x} and NO{sub 3}{sup -} in the air of four Spanish remote stations

    Energy Technology Data Exchange (ETDEWEB)

    Rua, A.; Hernandez, E.; Parras, J. de las; Martin, I.; Gimeno, L. [Complutense University, Madrid (Spain). Dept. of Statistic and Operative Investigation II

    1998-09-01

    In this study we have analyzed the sources of SO{sub 2}, SO{sub 4}{sup 2-}, NO{sub x}, and NO{sub 3}{sup -} in the air of four remote Spanish stations belonging to the European Monitoring and Evaluation Programme (EMEP) network. Information about trajectories has been used together with the conditional probability functions (CPFs). The most remarkable result is that the Mediterranean area is the main source of these pollutants in the air of the Spanish EMEP stations. Northern Africa and Central Europe are also important sources while the Atlantic Ocean and British Islands are, in general terms, low sources of these pollutants. The role of the Iberian Peninsula as a source of these pollutants in one of the stations, Logrono, is analyzed with more details using smaller regions to define CPFs. 26 refs., 12 figs., 2 tabs.

  10. Monitoring and understanding the paraelectric-ferroelectric phase transition in the metal-organic framework [NH4 ][M(HCOO)3 ] by solid-state NMR spectroscopy.

    Science.gov (United States)

    Xu, Jun; Lucier, Bryan E G; Sinelnikov, Regina; Terskikh, Victor V; Staroverov, Viktor N; Huang, Yining

    2015-10-05

    The paraelectric-ferroelectric phase transition in two isostructural metal-organic frameworks (MOFs) [NH4 ][M(HCOO)3 ] (M=Mg, Zn) was investigated by in situ variable-temperature (25) Mg, (67) Zn, (14) N, and (13) C solid-state NMR (SSNMR) spectroscopy. With decreasing temperature, a disorder-order transition of NH4 (+) cations causes a change in dielectric properties. It is thought that [NH4 ][Mg(HCOO)3 ] exhibits a higher transition temperature than [NH4 ][Zn(HCOO)3 ] due to stronger hydrogen-bonding interactions between NH4 (+) ions and framework oxygen atoms. (25) Mg and (67) Zn NMR parameters are very sensitive to temperature-induced changes in structure, dynamics, and dielectric behavior; stark spectral differences across the paraelectric-ferroelectric phase transition are intimately related to subtle changes in the local environment of the metal center. Although (25) Mg and (67) Zn are challenging nuclei for SSNMR experiments, the highly spherically symmetric metal-atom environments in [NH4 ][M(HCOO)3 ] give rise to relatively narrow spectra that can be acquired in 30-60 min at a low magnetic field of 9.4 T. Complementary (14) N and (13) C SSNMR experiments were performed to probe the role of NH4 (+) -framework hydrogen bonding in the paraelectric-ferroelectric phase transition. This multinuclear SSNMR approach yields new physical insights into the [NH4 ][M(HCOO)3 ] system and shows great potential for molecular-level studies on electric phenomena in a wide variety of MOFs. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. The use of NH4+ rather than NO3- affects cell stoichiometry, C allocation, photosynthesis and growth in the cyanobacterium Synechococcus sp. UTEX LB 2380, only when energy is limiting.

    Science.gov (United States)

    Ruan, Zuoxi; Giordano, Mario

    2017-02-01

    The assimilation of N-NO 3 - requires more energy than that of N-NH 4 + . This becomes relevant when energy is limiting and may impinge differently on cell energy budget depending on depth, time of the day and season. We hypothesize that N-limited and energy-limited cells of the oceanic cyanobacterium Synechococcus sp. differ in their response to the N source with respect to growth, elemental stoichiometry and carbon allocation. Under N limitation, cells retained almost absolute homeostasis of elemental and organic composition, and the use of NH 4 + did not stimulate growth. When energy was limiting, however, Synechococcus grew faster in NH 4 + than in NO 3 - and had higher C (20%), N (38%) and S (30%) cell quotas. Furthermore, more C was allocated to protein, whereas the carbohydrate and lipid pool size did not change appreciably. Energy limitation also led to a higher photosynthetic rate relative to N limitation. We interpret these results as an indication that, under energy limitation, the use of the least expensive N source allowed a spillover of the energy saved from N assimilation to the assimilation of other nutrients. The change in elemental stoichiometry influenced C allocation, inducing an increase in cell protein, which resulted in a stimulation of photosynthesis and growth. © 2016 John Wiley & Sons Ltd.

  12. Co-adsorption of NH3 and SO2 on quartz : Formation of a stabilized complex

    NARCIS (Netherlands)

    Grecea, M.L.; Gleeson, M.A.; van Schaik, W.; Kleyn, A.W.; Bijkerk, Frederik

    2011-01-01

    We have investigated the co-adsorption of NH3 and SO2 on the quartz(0 0 0 1) surface by TPD and RAIRS. A surface complex is formed as a result of various relative exposures of NH3 and SO2, irrespective of dosage order. However, the relative molecular composition of the complex is dependent on the

  13. Projection of SO2, NOx, NMVOC, NH3 and particulate matter

    DEFF Research Database (Denmark)

    Nielsen, Ole-Kenneth; Plejdrup, Marlene Schmidt; Winther, Morten

    2012-01-01

    This report contains a description of models and background data for projection of SO2, NOX, NH3, NMVOC, TSP, PM10 and PM2.5 for Denmark. The emissions are projected to 2030 using basic scenarios together with the expected results of a few individual policy measures. Official Danish forecasts...

  14. Controllable synthesis of Co3O4/polyethyleneimine-carbon nanotubes nanocomposites for CO and NH3 gas sensing at room temperature

    International Nuclear Information System (INIS)

    Lin, Yufei; Kan, Kan; Song, Wanzhen; Zhang, Guo; Dang, Lifang; Xie, Yu; Shen, Peikang; Li, Li; Shi, Keying

    2015-01-01

    Graphical abstract: Co 3 O 4 /polyethyleneimine-carbon nanotubes composites (CoPCNTs) have been successfully controllable synthesized via hydrothermal method at different temperature. The CoPCNTs sensors exhibited the highest response to CO and NH 3 gases with response time of 4 s and 4.3 s, low detection limit of 5 ppm and 1 ppm at room temperature, respectively. The enhanced gas sensing could be ascribed to the synergistic effect between the tiny size of Co 3 O 4 and good conductivity of carbon nanotubes functionalized by polyethyleneimine. - Highlights: • The CNTs functionalized by polyethyleneimine provided a new functional structural. • The novel 1D structure could capture and migrate electrons quickly. • The Co 3 O 4 nanoparticles liked a snake winding around CNTs. • The gas sensor could work at room temperatures, which suit to practical application. - Abstract: A novel 1D Co 3 O 4 /polyethyleneimine-carbon nanotubes composites (CoPCNTs) have been successfully synthesized via hydrothermal method at different temperature. The CNTs functionalized by polyethyleneimine (PCNTs) provided a new material with new structural and functional properties. The PCNTs was used as loading guider and electron transfer path. The Co 3 O 4 nanoparticles (NPs) loaded on the PCNTs surface liked a snake winding around CNTs, and the size was about 5–10 nm. The gas sensing characteristics of the CoPCNTs sensors to carbon monoxide (CO) and ammonia (NH 3 ) were evaluated with different gas concentration. The CoPCNTs sensors grown at 160 °C exhibited the highest response to CO and NH 3 gases with response time of 4 s and 4.3 s at room temperature (RT), respectively. Hence, the approach developed in this work would be important for the low-cost and large-scale production of the CoPCNTs materials with highly promising applications in gas sensors

  15. Effects of atmospheric ammonia (NH3) on terrestrial vegetation: a review

    International Nuclear Information System (INIS)

    Krupa, S.V.

    2003-01-01

    A review of atmospheric ammonia (NH 3 ) and ammonium (NH 4 + ) deposition and their effects on plants. - At the global scale, among all N (nitrogen) species in the atmosphere and their deposition on to terrestrial vegetation and other receptors, NH 3 (ammonia) is considered to be the foremost. The major sources for atmospheric NH 3 are agricultural activities and animal feedlot operations, followed by biomass burning (including forest fires) and to a lesser extent fossil fuel combustion. Close to its sources, acute exposures to NH 3 can result in visible foliar injury on vegetation. NH 3 is deposited rapidly within the first 4-5 km from its source. However, NH 3 is also converted in the atmosphere to fine particle NH 4 + (ammonium) aerosols that are a regional scale problem. Much of our current knowledge of the effects of NH 3 on higher plants is predominantly derived from studies conducted in Europe. Adverse effects on vegetation occur when the rate of foliar uptake of NH 3 is greater than the rate and capacity for in vivo detoxification by the plants. Most to least sensitive plant species to NH 3 are native vegetation > forests > agricultural crops. There are also a number of studies on N deposition and lichens, mosses and green algae. Direct cause and effect relationships in most of those cases (exceptions being those locations very close to point sources) are confounded by other environmental factors, particularly changes in the ambient SO 2 (sulfur dioxide) concentrations. In addition to direct foliar injury, adverse effects of NH 3 on higher plants include alterations in: growth and productivity, tissue content of nutrients and toxic elements, drought and frost tolerance, responses to insect pests and disease causing microorganisms (pathogens), development of beneficial root symbiotic or mycorrhizal associations and inter species competition or biodiversity. In all these cases, the joint effects of NH 3 with other air pollutants such as all-pervasive O 3 or

  16. Integrated dry NO{sub x}/SO{sub 2} emissions control system: integrated system test report

    Energy Technology Data Exchange (ETDEWEB)

    Smith, R.A.; Muzio, L.J. [Fossil Energy Research Corp., Laguna Hills, CA (United States); Hunt, T. [Public Service Co. of Colorado, Denver, CO (United States)

    1997-04-01

    The DOE sponsored Integrated Dry NO{sub x}/SO{sub 2} Emissions Control System Program, is a Clean Coal Technology III demonstration, being conducted by Public Service Company of Colorado. The test site is Arapahoe Generating Station Unit 4, a 100 MWe, down-fired utility boiler burning a low-sulfur Western coal. The project goal is to demonstrate up to 70 percent reductions in NO{sub x} and SO{sub 2} emissions through the integration of: (1) down-fired low NO{sub x} burners with overfire air; (2) Selective Non-Catalytic Reduction (SNCR) for additional NO{sub x} removal; and (3) Dry Sorbent Injection (DSI) and duct humidification for SO{sub 2} removal. This report documents the final phase of the test program, in which the overall performance of the integrated system was evaluated. Previous testing has shown that the goal of 70 percent NO{sub x} removal was easily achieved with the combination of low-NO{sub x} burners, overfire air, and urea-based SNCR. Similarly, the ability of the sodium-based DSI system to achieve 70 percent SO{sub 2} removal was also demonstrated previously. The integrated tests demonstrated the synergistic benefit of operating the SNCR and sodium-based DSI systems concurrently. With the automatic control system set to limit the NH{sub 3} emissions to less than 8 ppm, the NO{sub 2} emissions from the sodium-based DSI system were reduced by nominally 50 percent compared to operation with the DSI system alone. Comparably, the combined operation reduced NH{sub 3} emissions, as reflected by a higher urea injection rate for a fixed NH{sub 3} emission limit. With combined DSI and SNCR operation, an ammonia odor problem was encountered around the Unit 4 ash silo (this did not occur with the SNCR system operated alone at comparable NH{sub 3} slip levels). This odor problem is attributed to the sodium changing the rate at which NH{sub 3} is released from the ash when it is wetted for truck transport to the disposal site.

  17. Growth and optical, magnetic and transport properties of (C4H9NH3)2MCl4 organic-inorganic hybrid films (M = Cu, Sn)

    Science.gov (United States)

    Aruta, C.; Licci, F.; Zappettini, A.; Bolzoni, F.; Rastelli, F.; Ferro, P.; Besagni, T.

    2005-10-01

    Films of (C4H9NH3)2MCl4 (M=Cu and Sn) organic-inorganic hybrid perovskites have been deposited in-situ by a single-source thermal ablation technique on glassy, crystalline and polymeric substrates. Independently of the substrate, the films were well crystallized, c-axis oriented and with a narrow rocking curve of the (0010) reflection (full width at half maximum photoluminescence spectra of typical (C4H9NH3)2SnCl4 films at 12 K had a broad yellow band, which did not correspond to any significant peak in the absorption spectrum. The films were semiconducting down to 250 K or, in the case of the best samples, down to 200 K and became insulating at lower temperature. The resistivity of the best films was (5±1) 104 Ω cm at 300 K, and the energy gap was 1.11 eV.

  18. Cathodoluminescence and Raman characteristics of CaSO{sub 4}:Tm{sup 3+}, Cu phosphor

    Energy Technology Data Exchange (ETDEWEB)

    Ekdal, E. [Ege University, Institute of Nuclear Sciences, 35100 Bornova, İzmir (Turkey); Guinea, J. Garcia [MuseoNacional Ciencias Naturales, Jose Gutierrez Abascal 2, Madrid 28006 (Spain); Kelemen, A. [Centre for Energy Research, Radiation Safety Laboratory, P.O. Box 49, H-1121 Budapest (Hungary); Ayvacikli, M. [Celal Bayar University, Faculty of Arts and Sciences, Department of Physics, Muradiye, Manisa (Turkey); Canimoglu, A. [Nigde University, Faculty of Arts and Sciences, Department of Physics, Nigde (Turkey); Jorge, A. [MuseoNacional Ciencias Naturales, Jose Gutierrez Abascal 2, Madrid 28006 (Spain); Karali, T. [Ege University, Institute of Nuclear Sciences, 35100 Bornova, İzmir (Turkey); Can, N., E-mail: cannurdogan@yahoomail.com [Celal Bayar University, Faculty of Arts and Sciences, Department of Physics, Muradiye, Manisa (Turkey); Physics Department, Jazan University, P.O. Box 114, 45142 Jazan (Saudi Arabia)

    2015-05-15

    The physical characterization and phosphor emission spectra are presented for CaSO{sub 4} doped with Tm and Cu. All spectral wavelengths are related to electronic transitions of Tm{sup 3+} ions. The powder X-ray diffraction pattern showed that the compound exhibits orthorhombic structure and all reflections were indexed without any other secondary impurity phases. Chemical and structural properties of the samples have been characterized by means of Raman spectroscopy and environmental scanning electron microscope (ESEM) with an attached X-ray energy dispersive system (EDS). Group frequencies concept is essential point to the interpretation of the bands due to the main SO{sub 4} vibrational units and these displayed main characteristic intensive Raman bands including typical strong intensity at 1016 cm{sup −1} that corresponds to ν{sub 1}SO{sub 4} vibrational mode. From the spatially-resolved cathodoluminescence (CL) spectrum, main emission bands of Tm{sup 3+} centered at 346, 362, and 452 nm, due to the respective transitions of {sup 3}P{sub 0}→{sup 3}H{sub 4}, {sup 1}D{sub 2}→{sup 3}H{sub 6}, {sup 1}D{sub 2}→{sup 3}F{sub 4} were clearly identified. The study is novel as no such CL-ESEM data are available for this doped compound. - Highlights: • Characteristic and cathodoluminescence properties of CaSO{sub 4}:Tm{sup 3+}, Cu have been investigated. • Several sharp and strong CL emission bands due to rare earth ion were observed for rare earth doped sample. • The nature and limitation of the interaction between CaSO{sub 4} and the activator ions were discussed.

  19. Crystal structure and characterization of the novel NH{sup +} Midline-Horizontal-Ellipsis N hydrogen bonded polar crystal [NH{sub 2}(CH{sub 2}){sub 4}NH][BF{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Wojtas, M., E-mail: maciej.wojtas@chem.uni.wroc.pl [Faculty of Chemistry, University of Wroclaw, Joliot-Curie 14, 50-383 Wroclaw (Poland); Gagor, A. [W. Trzebiatowski Institute of Low Temperature and Structure Research, Polish Academy of Science, PO Box 1410, 50-950 Wroclaw (Poland); Czupinski, O. [Faculty of Chemistry, University of Wroclaw, Joliot-Curie 14, 50-383 Wroclaw (Poland); Medycki, W. [Institute of Molecular Physics, Polish Academy of Science, Smoluchowskiego 17, 60-179 Poznan (Poland); Jakubas, R. [Faculty of Chemistry, University of Wroclaw, Joliot-Curie 14, 50-383 Wroclaw (Poland)

    2012-03-15

    Dielectric properties and phase transitions of the piperazinium tetrafluoroborate ([NH{sub 2}(CH{sub 2}){sub 4}NH][BF{sub 4}], abbreviated as PFB) crystal are related to the one-dimensional arrangement of the cations linked by the bistable NH{sup +} Midline-Horizontal-Ellipsis N hydrogen bonds and molecular motions of the [BF{sub 4}]{sup -} units. The crystal structure of [NH{sub 2}(CH{sub 2}){sub 4}NH][BF{sub 4}] is monoclinic at room temperature with the polar space group Pn. The polar/acentric properties of the room temperature phase IV have been confirmed by the piezoelectric and pyroelectric measurements. DSC measurements show that the compound undergoes three first-order structural phase transitions: at 421/411 K (heating/cooling), at 386/372 K and at 364/349 K. {sup 1}H and {sup 19}F NMR measurements indicate the reorientational motions of [BF{sub 4}]{sup -} anions and piperazinium(+) cations as well as the proton motion in the hydrogen-bonded chains of piperazine along the [001] direction. Over the phase I the isotropic reorientational motions or even self-diffusion of the cations and anions are expected. The conductivity measurements in the vicinity of the II-I PT indicate a superionic phase over the phase I. - Graphical abstract: It must be emphasized that the titled compound represents the first organic-inorganic simple salt containing the single-protonated piperazinium cation which was studied by means of the wide variety of experimental techniques. A survey of Cambridge Structural Database (CSD version 5.32 (November 2010) and updates (May 2011)) for structure containing the piperazinium cations yields 248 compounds with the doubly protonated piperazinium(2+) cations and only eight compounds with the singly protonated piperazinium(+) cations. Among these structures only one is the hybrid organic-inorganic material. This is piperazinium nitrate characterized structurally. The crystal packing of [NH{sub 2}(CH{sub 2}){sub 4}NH][BF{sub 4}], phase IV. The

  20. An assay of the utilization of the residual use of a N fertilizer [(15NH4)2SO4] made by a wheat crop, using an isotope technique

    International Nuclear Information System (INIS)

    Bujan, A.; Quitegui, M.I.; Quitegui, M.C.; Ghelfi, L.E.P. de; Deybe, D.

    1982-01-01

    An experimental study was carried out in order to determine the residual use of a N fertilizer made by wheat during a year. Wheat was seeded in plots which had been cropped the year before with inoculated soybean (glycine max), non-inoculated soybean and sorghum (sorghum caffrorum) fertilized with (NH 4 ) 2 SO 4 at two different levels: 20 and 100kg N/ha tagged with 5% excess 15 N and 1% respectively. It was concluded that:1) the % excess 15 N used in the previous crops were sufficient to determine residuality from the N fertilizer. 2)when the previous crop was non-inoculated soybean, the total nitrogen content of the wheat grains was significantly higher than when the previous crop was either inoculated soybean or sorghum. The total N content was significantly higher on the plots fertilized with 100KgN/ha than on those with 20kgN/ha.3) non-inoculated - and inoculated soybeans determined higher wheat grain yields than sorghum as previous crops. Higher wheat grain yields ocurred on the 100kgN/ha fertilized plots. Higher residual N content ocurred on the 100KgN/ha fertilized plots. Non-inoculated soybean determined higher residual N content in grain than inoculated soybean and sorghum; inoculated soybean determined higher content than sorghum. There were no significant differences in residual N content in the plants depending on the previous crop. (Author) [pt

  1. Influence of bulking agents on CH4, N2O, and NH3 emissions during rapid composting of pig manure from the Chinese Ganqinfen system*

    Science.gov (United States)

    Sun, Xiang-ping; Lu, Peng; Jiang, Tao; Schuchardt, Frank; Li, Guo-xue

    2014-01-01

    Mismanagement of the composting process can result in emissions of CH4, N2O, and NH3, which have caused severe environmental problems. This study was aimed at determining whether CH4, N2O, and NH3 emissions from composting are affected by bulking agents during rapid composting of pig manure from the Chinese Ganqinfen system. Three bulking agents, corn stalks, spent mushroom compost, and sawdust, were used in composting with pig manure in 60 L reactors with forced aeration for more than a month. Gas emissions were measured continuously, and detailed gas emission patterns were obtained. Concentrations of NH3 and N2O from the composting pig manure mixed with corn stalks or sawdust were higher than those from the spent mushroom compost treatment, especially the sawdust treatment, which had the highest total nitrogen loss among the three runs. Most of the nitrogen was lost in the form of NH3, which accounts for 11.16% to 35.69% of the initial nitrogen. One-way analysis of variance for NH3 emission showed no significant differences between the corn stalk and sawdust treatments, but a significant difference was noted between the spent mushroom compost and sawdust treatments. The introduction of sawdust reduced CH4 emission more than the corn stalks and spent mushroom compost. However, there were no significant differences among the three runs for total carbon loss. All treatments were matured after 30 d. PMID:24711356

  2. Pore design of pelletised VOX/ZrO2-SO4/Sepiolite composite catalysts

    DEFF Research Database (Denmark)

    Rasmussen, Søren Birk; Due-Hansen, Johannes; Yates, M.

    2010-01-01

    The NH3-SCR activities of a series of extruded and calcined VOX/ZrO2-SO4 - sepiolite catalysts were determined. The pore structures were heavily influenced by the clay content with macropore sizes ranging from 50 to >1000 nm. Mechanical strength and SCR activity measurements suggested that 25% w/....../w sepiolite is the optimal catalyst composition....

  3. AN ASSESSMENT OF WATER QUALITY (NH4+, NO2-, NO3-, TP, SO4, COLIFORM BACTERIA AND HEAVY METALS OF THE MAIN WATER SUPPLIES IN THE STATE OF CAMPECHE

    Directory of Open Access Journals (Sweden)

    Jorge Arturo Benitez

    2011-04-01

    Full Text Available Water quality testing (in situ and in laboratory was conducted on 50 wells across the state of Campeche. Further to this (to aid in water quality management and policy, a GIS was implemented to i approximate Zones of Contribution (ZOC for well recharge which in turn supplies water for main cities in the state and ii perform predictive land change modeling on these ZOC’s to predict the future effect of non-point source pollution. Due to natural geohydrological conditions, values of TDS, pH, and SO4 exceeded Mexican regulations in roughly one third of the wells. Although most wells do not exceed the permissible limits of nutrients and heavy metals, some wells show worryingly high levels of NO2-, TP, and Pb, indicators of pollution from anthropogenic sources. All wells were contaminated by coliform bacteria. Poor water quality in some of the main water sources in the state is mainly due to the proliferation of open dumps and the lack of sewage infrastructure, as well as the ongoing conversion of vegetated land to agriculture into the ZOC’s. It is shown that unless remedial measures are implemented, human activities will continue to extend into these areas, placing the state’s water supply at even higher risk of contamination.Â

  4. Heterogeneous microchemistry between CdSO4 and CaCO3 particles under humidity and liquid water

    International Nuclear Information System (INIS)

    Falgayrac, Guillaume; Sobanska, Sophie; Brémard, Claude

    2013-01-01

    Highlights: ► Raman analysis of chemical reactions between CdSO 4 and CaCO 3 particles. ► Under humid air no changes of morphology and chemical composition were observed. ► Condensation of liquid water generates an insoluble CdCO 3 layer on CaCO 3 surface. ► Addition of water previously equilibrated with CaCO 3 generates CdCO 3 and CaSO 4 . -- Abstract: Laboratory experiments using in situ Raman imaging combined with ex situ TOF-S-SIMS demonstrate the behavior of CdSO 4 ·8/3H 2 O microparticles in contact with {101 ¯ 4} CaCO 3 (calcite) surface under three different experimental conditions representative of unpolluted atmosphere. The contact of CdSO 4 ·8/3H 2 O particles with CaCO 3 surface in humid air (RH ∼ 40–80%) does not induce any chemical reaction. In contrast, the condensation of a water drop on CdSO 4 ·8/3H 2 O/CaCO 3 interface causes the free dissolution of CdSO 4 ·8/3H 2 O particle in the drop. A CdSO 4 ·8/3H 2 O microcrystal is reformed after gentle drying with a CdSO 4 ·H 2 O coating of the CaCO 3 surface. The TOF-S-SIMS image of the CaCO 3 surface provides evidence of a thin layer corresponding probably to insoluble coating of CdCO 3 (otavite) or Cd x Ca 1−x CO 3 solid solution at the liquid–solid interface. This layer armours the CaCO 3 from further dissolution and stops the reaction. The deposition of CdSO 4 ·8/3H 2 O particle in water drop previously in contact with CaCO 3 for a long time generates CdCO 3 small rhombohedral crystals while gentle drying provokes the crystallization of bar shape crystals of CaSO 4 ·2H 2 O (gypsum). These laboratory results provide valuable chemical prediction for a possible fate of cadmium rich particles emitted in the atmosphere and thus, can contribute to realistic assessment of human exposure to Cd hazard

  5. Crystal structure and phase transition in (NH4)3WO2F5: from dynamic to static orientational disorder.

    Science.gov (United States)

    Udovenko, Anatoly; Laptash, Natalia

    2015-08-01

    Single crystals of tungsten double salt (NH4)3WO2F5 = (NH4)3[WO2F4]F have been synthesized by solid-state reaction or from fluoride solution and its crystal structures at 296 and 193 K were determined by X-ray diffraction. At room temperature, the crystal structure of the compound is dynamically disordered with the ligand atoms statistically distributed on two positions (6e and 24m) of the Pm3m unit cell [a = 6.0298 (1) Å], and the tungsten atom dynamically disordered on 12 orientations forming a spatial cuboctahedron [W12] that enables the real geometry of cis-WO2F4 octahedron to be determined with two short W-O distances. On cooling, the compound undergoes a first-order phase transition with the symmetry change Pm3m → Pa3 and a doubling of the unit-cell parameter [a = 11.9635 (7) Å]. The ligand F(O) atoms statistically occupy two general 24d sites and form W1X6 and W2X6 octahedra, in which the O and F atoms are not crystallographically different that means a static orientational disorder of (NH4)3WO2F5.

  6. The influence of a silica pillar in lamellar tetratitanate for selective catalytic reduction of NOx using NH3

    International Nuclear Information System (INIS)

    Nogueira da Cunha, Beatriz; Gonçalves, Alécia Maria; Gomes da Silveira, Rafael; Urquieta-González, Ernesto A.; Magalhães Nunes, Liliane

    2015-01-01

    Highlights: • Potassium ions significantly affected the SCR. • The introduction of silica in the catalyst promotes the NH 3 -SCR reaction. • The catalysts activities were not significantly influenced by SO 2 addition. - Abstract: Silica-pillared layered titanate (SiO 2 –Ti 4 O 9 ) was prepared by intercalating organosilanes into the interlayers of a layered K 2 Ti 4 O 9 followed by calcination at 500 °C. The lamellar titanates produced were used as a support to prepare vanadium catalysts (1 and 2 wt%) through wet impregnation for selective catalytic reduction (SCR) of NO. The catalysts were characterized using nitrogen adsorption (BET), X-ray diffraction (XRD), temperature programmed reduction (H 2 -TPR), nuclear magnetic resonance ( 29 Si NMR), and infrared spectroscopy (FT-IR). Reduction of NO by NH 3 was studied in a fixed-bed reactor packed with the catalysts and fed a mixture comprising 1% NH 3 , 1% NO, 10% O 2 , and 34 ppm SO 2 (when used) in helium. The results demonstrate that activity is correlated with the support, i.e., with acidic strength of catalysts. The potassium in the support, K 2 Ti 4 O 9 , significantly affected the reaction and level of vanadium species reduction. The catalyst (1VSiT) with 1 wt% vanadium impregnated on the SiO 2 –Ti 4 O 9 support reduced ∼80% of the NO. Approximately the same conversion rate was generated on the catalyst (2VSiT) with 2 wt% vanadium using the same support. The increased NH 3 adsorption demonstrate that introduction of silica in the catalyst promotes the NH 3 -SCR reaction. More importantly, 2VSiT and 1VSiT were strongly resistant to SO 2 poisoning

  7. NH4+ adsorption and adsorption kinetics by sediments in a drinking water reservoir

    Directory of Open Access Journals (Sweden)

    Suna Hongyan

    2016-12-01

    Full Text Available The sorption isotherm and sorption kinetics of NH4+ by the Fen River reservoir sediment were investigated for a better understanding of the NH4+ sorption characteristics and parameters. The results showed that Q (adsorption content increased with the increase of Ceq (equilibrium concentration, sorption isotherms could be described by Freundlich equation (R2 from 0.97 to 0.99. Cation exchange capacity (CEC had a significant correlation with the parameters K and n (R2 was 0.85 and 0.95, respectively. The ENC0 (Ceq as Q was zero of S1, S2, S3 and S4 was 1.25, 0.57, 1.15 and 1.14 mg L-1, respectively, and they were less than the NH4+ concentrations in reservoir water. The sediments released NH4+ to the Fen River reservoir water and acted as a pollution source, in the form of complex and heterogeneous adsorbents. The NH4+ adsorption kinetic process was composed of ‘fast’ and ‘slow’ reaction patterns and could be fitted using both Elovich equation and Pseudo second-equation. More than one-step may be involved in the NH4+ sorption processes, and interior diffusion was not dominant ion action.

  8. Crescimento e produtividade do almeirão em concentrações de N total contendo NH4+ na solução nutritiva Growth and yield of chicory plants under total N concentrations containing NH4+ in the nutrient solution

    Directory of Open Access Journals (Sweden)

    Rodrigo dos Santos Godoi

    2007-08-01

    Full Text Available O crescimento e a produtividade do almeirão foram determinados em cultivo hidropônico fechado com cinco concentrações de N contendo NH4+ na solução nutritiva. As cultivares "Amarelo" e "Pão de Açúcar" foram semeadas diretamente em fileiras distanciadas de 0,05m, em uma camada de areia de 0,15m, distribuída sobre telhas de fibrocimento. Após a emergência, foi efetuado o desbaste, mantendo-se uma densidade de 1.600plantas m-2. Foi empregada uma solução nutritiva padrão com a composição de, em mmol L-1, 11,0 de NO3-; 1,5 de H2PO4-; 6,5 de SO4-2; 7,5 de Ca+2; 10,0 de K+ e 1,5 de Mg+2 e, em mg L-1, 0,42 de Mn; 0,26 de Zn; 0,05 de Cu; 0,50 de B; 0,04 de Mo, e 4,82 de Fe quelatizado. Os tratamentos foram constituídos por concentrações totais de N de 11,0 (T1; 16,0 (T2; 21,0 (T3; 26,0 (T4 e 31,0 (T5mmol L-1, contendo concentrações de NH4+ de, zero; 2,5; 5,0; 7,5 e 10,0mmol L-1, respectivamente. O delineamento experimental inteiramente casualizado foi empregado, com quatro repetições e parcelas subdivididas. Foram efetuadas colheitas aos 35, 59, 76 e 97 dias após a semeadura, mediante corte da parte aérea das plantas a 0,02m acima da superfície da areia, para determinar a matéria seca e fresca. A maior produtividade foi obtida com a solução nutritiva contendo 16mmol L-1 de N total e 2,5mmol L-1 de NH4+.Chicory plants, cv. Amarela and Pão de Açúcar, were hidroponically grown to determine growth and yield under five ammonium and nitrate N concentrations in the nutrient solution. Sowing was made in rows placed 0.05m apart, over a 0.15m deep sand growing bed supported by fibber cement tiles. After emergency, plants were thinned to a plant density of 1,600plants m-2. A standard nutrient solution was used, with the composition of, in mmol L-1, 11.0 de NO3-; 1.5 H2PO4-; 6.5 SO4-2; 7.5 Ca+2; 10.0 K+ and 1.5 Mg+2, and, in mg L-1, 0.42 Mn; 0.26 Zn; 0.05 Cu; 0.50 B; 0.04 Mo, and 4.82 chelated Fe. Treatments were total N

  9. Aluminum (III) and gallium (III) complexes with methyliminodiacetic acid: Crystal structures of Cat[M(Mida)2] (Cat+=Na, K, NH4; M3+=Al, Ga) and Me4N[Ga(Mida)2]·H2O

    International Nuclear Information System (INIS)

    Ilyukhin, A.B.; Petrosyants, S.P.; Milovanov, S.V.; Malyarik, M.A.

    1997-01-01

    The bis chelate complexes Cat[M(Mida) 2 ] and Me 4 N[Ga(Mida) 2 ]·H 2 O are synthesized from aqueous solutions M(NO 3 ) 3 -2H 2 Mida-CatOH (M 3+ =Al, Ga; Cat + =Na, K, NH 4 ) and Ga(OH) 3 -2H 2 Mida-Me 4 NOH. The crystal structures of the isostructural compounds Cat[M(Mida) 2 ] (Cat=Na, M=Al; Cat=K, M=Al; Cat=Na, M=Ga) and Me 4 N[Ga(Mida) 2 ]·H 2 O are determined by X-ray structure analysis. According to the X-ray powder diffraction analysis, all the six compounds Cat[M(Mida) 2 ] (Cat=Na, K, NH 4 ; M=Al, Ga) are isostructural. The octahedral anion in Cat[M(Mida) 2 ] and Me 4 N[Ga(Mida) 2 ]·H 2 O exhibits a trans(N)- fac configuration

  10. NH4(+) Resides Inside the Water 20-mer Cage As Opposed to H3O(+), Which Resides on the Surface: A First Principles Molecular Dynamics Simulation Study.

    Science.gov (United States)

    Willow, Soohaeng Yoo; Singh, N Jiten; Kim, Kwang S

    2011-11-08

    Experimental vibrational predissociation spectra of the magic NH4(+)(H2O)20 clusters are close to those of the magic H3O(+)(H2O)20 clusters. It has been assumed that the geometric features of NH4(+)(H2O)20 clusters might be close to those of H3O(+)(H2O)20 clusters, in which H3O(+) resides on the surface. Car-Parrinello molecular dynamics simulations in conjunction with density functional theory calculations are performed to generate the infrared spectra of the magic NH4(+)(H2O)20 clusters. In comparison with the experimental vibrational predissociation spectra of NH4(+)(H2O)20, we find that NH4(+) is inside the cage structure of NH4(+)(H2O)20 as opposed to on the surface structure. This shows a clear distinction between the structures of NH4(+)(H2O)20 and H3O(+)(H2O)20 as well as between the hydration phenomena of NH4(+) and H3O(+).

  11. Experimental studies of the formation of cluster ions formed by corona discharge in an atmosphere containing SO2, NH3, and H2O

    DEFF Research Database (Denmark)

    Hvelplund, Preben; Pedersen, Jens Olaf Pepke; Støchkel, Kristian

    2013-01-01

    Abstract We report on studies of ion-induced nucleation in a corona discharge taking place in an atmosphere containing SO2, NH3, and H2O at standard temperature and pressure. Positive ions such as H3O+(H2O)n, NH4+(H2O)n, and H+(H2SO4)(H2O)n and negative ions such as HSO5-(H2O)n, SO4-(H2O)n, HSO4-(H......5-, which has been observed in many studies, in our experiments is contaminated by O2-(HNO3)(H2O) ions, and this may also have been the case in other experiments. Finally an ion with m/z = 232 (where m is the cluster mass in amu and z is the charge state), capable of attaching H2O...

  12. Direct observation of electrogenic NH4(+) transport in ammonium transport (Amt) proteins.

    Science.gov (United States)

    Wacker, Tobias; Garcia-Celma, Juan J; Lewe, Philipp; Andrade, Susana L A

    2014-07-08

    Ammonium transport (Amt) proteins form a ubiquitous family of integral membrane proteins that specifically shuttle ammonium across membranes. In prokaryotes, archaea, and plants, Amts are used as environmental NH4(+) scavengers for uptake and assimilation of nitrogen. In the eukaryotic homologs, the Rhesus proteins, NH4(+)/NH3 transport is used instead in acid-base and pH homeostasis in kidney or NH4(+)/NH3 (and eventually CO2) detoxification in erythrocytes. Crystal structures and variant proteins are available, but the inherent challenges associated with the unambiguous identification of substrate and monitoring of transport events severely inhibit further progress in the field. Here we report a reliable in vitro assay that allows us to quantify the electrogenic capacity of Amt proteins. Using solid-supported membrane (SSM)-based electrophysiology, we have investigated the three Amt orthologs from the euryarchaeon Archaeoglobus fulgidus. Af-Amt1 and Af-Amt3 are electrogenic and transport the ammonium and methylammonium cation with high specificity. Transport is pH-dependent, with a steep decline at pH values of ∼5.0. Despite significant sequence homologies, functional differences between the three proteins became apparent. SSM electrophysiology provides a long-sought-after functional assay for the ubiquitous ammonium transporters.

  13. Mechanochemical transformations in Li(Na)AlH4-Li(Na)NH2 systems

    International Nuclear Information System (INIS)

    Dolotko, Oleksandr; Zhang Haiqiao; Ugurlu, Ozan; Wiench, Jerzy W.; Pruski, Marek; Scott Chumbley, L.; Pecharsky, Vitalij

    2007-01-01

    Mechanochemical transformations of tetrahydroaluminates and amides of lithium and sodium have been investigated using gas volumetric analysis, X-ray powder diffraction, solid-state nuclear magnetic resonance (NMR) and transmission electron microscopy. In a transformation of LiAlH 4 and LiNH 2 taken in an 1:1 molar ratio, the amount of released hydrogen (6.6 wt.% after 30 min ball milling) was higher than in any known one pot mechanochemical process involving a hydrogen-containing solid. A total of 4.3 wt.% of hydrogen is released by the NaAlH 4 -NaNH 2 system after 60 min ball milling; and 5.2 wt.% H 2 is released when LiAlH 4 and NaNH 2 or NaAlH 4 and LiNH 2 are ball milled for 90 min and 120 min, respectively. All transformations proceed at room temperature. The mechanism of the overall transformation MAlH 4 (s) + MNH 2 (s) → 2MH(s) + AlN(s) + 2H 2 (g) was identified based on detailed spectroscopic analysis of the intermediate (M 3 AlH 6 ) and final products of the ball milling process

  14. Synthesis, crystal structure, thermal analysis and dielectric properties of Rb4(SO4)(HSO4)2(H3AsO4) compound

    Science.gov (United States)

    Belhaj Salah, M.; Nouiri, N.; Jaouadi, K.; Mhiri, T.; Zouari, N.

    2018-01-01

    A new inorganic Rb4(SO4)(HSO4)2(H3AsO4) compound was prepared. It was found to crystallize in the monoclinic system (P21 space group) with the following lattice parameters: a = 5868 (1) Å, b = 13,579(2) Å, c = 11,809 (3) Å and β = 94,737 (1)°. The structure is characterized by SO42-, HSO4- and H3AsO4 tetrahedra connected by hydrogen bridge to form two types of dimmer (H(8)S(2)O4- … S(1)O42- and H(12)S(2)O4- … H3AsO4). These dimmers are interconnected by both hydrogen bonds O(14)sbnd H(14)· · ·O(4) and O(15)sbnd H(15)· · ·O(2). They are also linked by the hydrogen bridge assured by the hydrogen atoms H(2), H(3) and H(4) of the H3AsO4 group to build the chain S(1)O4⋯H3AsO4 which are parallel to the ''a'',direction. The rubidium cations are coordinated by eight oxygen atoms with Rbsbnd O distance ranging from 2893(8) to 3.415(6) Å. The existence of Osbnd H and (S/As)sbnd O bonds in the structure at room temperature has been confirmed by IR and Raman spectroscopy in the frequency ranges 4000-400 cm-1and 1200 - 50 cm-1, respectively. Thermal analysis of Rb4(HSO4)(HSO4)2(H3AsO4) showed that the transformation to high temperature phase occurs at 407 K by one-step process. Thermal decomposition of the product takes place at much higher temperatures, with an onset of approximately 522 K. The first transition detected by differential scanning calorimetry (DSC) was also analyzed by dielectric and conductivity measurements using the impedance spectroscopy techniques. The conductivity in the high temperature phase at 428 K is 1.04 × 10-3 Ω-1 cm-1, and the activation energy for the proton transport is 0.36 eV. The conductivity relaxation parameters associated with the high disorder protonic conduction have been examined from analysis of the M"/M"max spectrum measured in a wide temperature range. Transport properties of this material appear to be due to the proton hopping mechanism. The obtained results show that this transition is protonic by nature.

  15. Phase formation in the systems ZrO2-H2SO4-Na2SO4 (NaCl)-H2O

    International Nuclear Information System (INIS)

    Sozinova, Yu.P.; Motov, D.L.; Rys'kina, M.P.

    1988-01-01

    Formation of solid phases in the systems ZrO 2 - H 2 SO 4 - Na 2 SO 4 (NaCl) - H 2 O at 25 and 75 deg C is studied. Three basic Na 2 Zr(OH) 2 (SO 4 ) 2 x (0.2 - 0.4)H 2 O, NaZrOH(SO 4 ) 2 x H 2 O, NaZrO 0.5 (OH) 2 SO 4 x 2H 2 O and three normal sodium sulfatozirconates Na 2 Zr(SO 4 ) 3 x 3H 2 O, Na 4 Zr(SO 4 ) 4 x 3H 2 O, Na 6 Zr(SO 4 ) 5 x 4H 2 O have been isolated, their solubility and crystal optical properties are determined

  16. Effects of atmospheric ammonia (NH3) on terrestrial vegetation: a review.

    Science.gov (United States)

    Krupa, S V

    2003-01-01

    At the global scale, among all N (nitrogen) species in the atmosphere and their deposition on to terrestrial vegetation and other receptors, NH3 (ammonia) is considered to be the foremost. The major sources for atmospheric NH3 are agricultural activities and animal feedlot operations, followed by biomass burning (including forest fires) and to a lesser extent fossil fuel combustion. Close to its sources, acute exposures to NH3 can result in visible foliar injury on vegetation. NH3 is deposited rapidly within the first 4-5 km from its source. However, NH3 is also converted in the atmosphere to fine particle NH4+ (ammonium) aerosols that are a regional scale problem. Much of our current knowledge of the effects of NH3 on higher plants is predominantly derived from studies conducted in Europe. Adverse effects on vegetation occur when the rate of foliar uptake of NH3 is greater than the rate and capacity for in vivo detoxification by the plants. Most to least sensitive plant species to NH3 are native vegetation > forests > agricultural crops. There are also a number of studies on N deposition and lichens, mosses and green algae. Direct cause and effect relationships in most of those cases (exceptions being those locations very close to point sources) are confounded by other environmental factors, particularly changes in the ambient SO2 (sulfur dioxide) concentrations. In addition to direct foliar injury, adverse effects of NH3 on higher plants include alterations in: growth and productivity, tissue content of nutrients and toxic elements, drought and frost tolerance, responses to insect pests and disease causing microorganisms (pathogens), development of beneficial root symbiotic or mycorrhizal associations and inter species competition or biodiversity. In all these cases, the joint effects of NH3 with other air pollutants such as all-pervasive O3 or increasing CO2 concentrations are poorly understood. While NH3 uptake in higher plants occurs through the shoots, NH4

  17. On the structural phase transitions of the perovskite-type layer structures (Csub(n)Hsub(2n+1)NH3)2MeCl4

    International Nuclear Information System (INIS)

    Heger, G.

    1978-01-01

    The perovskite-type layer compounds (Csub(n)Hsub(2n+1)NH 3 ) 2 MeCl 4 show a variety of different structural modifications. They differ from oneanother by the order and dynamical behaviour of the CH 3 -CH 2 -...-CH 2 -NH 3 chain molecules and the [MeCl 6 ] octahedra layers. These two structural members are coupled together by N-H...Cl hydrogen bonds. According to group theoretical relations the modifications of (Csub(n)Hsub(2n+1)NH 3 ) 2 MeCl 4 were ordered in the scheme of a 'family tree'. Taking (CH 3 NH 3 ) 2 MnCl 4 as an example, various experimental investigations incorporated neutron diffraction are reported. They lead to a sequence of phase transitions. For these phase transitions a model is developed based on the orientations of the CH 3 NH 3 dump-bell molecules and their interactions with the [MnCl 6 ] layers. (orig./HPOE) [de

  18. Immobilization of Mn and NH4 (+)-N from electrolytic manganese residue waste.

    Science.gov (United States)

    Chen, Hongliang; Liu, Renlong; Liu, Zuohua; Shu, Jiancheng; Tao, Changyuan

    2016-06-01

    The objective of this work was the immobilization of soluble manganese (Mn) and ammonium nitrogen (NH4 (+)-N) leached from electrolytic manganese residue (EMR). Immobilization of Mn was investigated via carbonation using carbon dioxide (CO2) and alkaline additives. NH4 (+)-N immobilization was evaluated via struvite precipitation using magnesium and phosphate sources. Results indicated that the immobilization efficiency of Mn using CO2 and quicklime (CaO) was higher than using CO2 and sodium hydroxide (NaOH). This higher efficiency was likely due to the slower release of OH(-) during CaO hydrolysis. The immobilization efficiency of Mn was >99.99 % at the CaO:EMR mass ratio of 0.05:1 for 20-min reaction time. The struvite precipitation of NH4 (+)-N was conducted in the carbonated EMR slurry and the immobilization efficiency was 89 % using MgCl2 · 6H2O + Na3PO4 · 12H2O at the Mg:P:N molar ratio of 1.5:1.5:1 for 90-min reaction time. A leaching test showed that the concentrations of Mn and NH4 (+)-N in the filtrate of the treated EMR were 0.2 and 9 mg/L, respectively. The combined immobilization of Mn and NH4 (+)-N was an effective pretreatment method in the harmless treatment of the EMR.

  19. Tellurium sulfates from reactions in oleum and sulfur trioxide: syntheses and crystal structures of TeO(SO_4), Te_4O_3(SO_4)_5, and Te(S_2O_7)_2

    International Nuclear Information System (INIS)

    Logemann, Christian; Bruns, Joern; Schindler, Lisa Verena; Zimmermann, Vanessa; Wickleder, Mathias S.

    2015-01-01

    The reaction of K_2TeO_4 with fuming sulfuric acid (65 % SO_3) in sealed glass ampoules at 250 C led to colorless single crystals of TeO(SO_4) [triclinic, P anti 1, Z = 8, a = 819.89(3) pm, b = 836.95(4) pm, c = 1179.12(5) pm, α = 82.820(2) , β = 70.645(2) , γ = 81.897(2) , V = 753.11(6) x 10"6 pm"3]. A horseshoe type [Te_4O_3] fragment is the basic motif in the layer structure of the compound. The [Te_4O_3] moieties are linked to infinite chains by further oxide ions. Monomeric [Te_4O_3] horseshoes are found in the crystal structure of Te_4O_3(SO_4)_5 [trigonal, P3_221, Z = 3, a = 859.05(2) pm, c = 2230.66(7) pm, V = 1425.61(6) x 10"6 pm"3], which was obtained from TeO_2 and fuming sulfuric acid (65 % SO_3) at 200 C as colorless single crystals. By switching to neat SO_3 as reaction medium colorless crystals of Te(S_2O_7)_2 [P2_1/n, Z = 4, a = 1065.25(3) pm, b = 818.50(2) pm, c = 1206.27(3) pm, β = 102.097(1) , V = 1028.40(5) x 10"6 pm"3] form when ortho-telluric acid, H_6TeO_6, is used as the tellurium source. The compound was reported previously, however, obviously with a wrong crystallographic description. In the crystal structure the tellurium atoms are coordinated by two chelating disulfate ions. Further Te-O contacts link the [Te(S_2O_7)_2] units to an extended network. (Copyright copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Comparison of measured NH4 level and NO emission to declared tar and nicotine values of hundred cigarette brands

    NARCIS (Netherlands)

    Brunt TM; Verlaan APJ; Cleven RFMJ; Rambali B; Vleeming W; LEO; LAC; LPI

    2003-01-01

    The general hypothesis exists that NH4 level in cigarettes and NO level in cigarette smoke do affect the nicotine availability in the lungs and subsequently play a role in the tobacco addiction. The objective of this report was to investigate whether correlations exist between the cigarette

  1. Electrodeposition of Fe_3O_4 layer from solution of Fe_2(SO_4)_3 with addition ethylene glycol

    International Nuclear Information System (INIS)

    Dahlan, Dahyunir; Asrar, Allan

    2016-01-01

    The electrodeposition of Fe_3O_4 layer from the solution Fe_2(SO_4)_3 with the addition of ethylene glycol on Indium Tin Oxide (ITO) substrate has been performed. The electrodeposition was carried out using a voltage of 5 volts for 120 seconds, with and without the addition of 2% wt ethylene glycol. Significant effects of temperature on the resulting the samples is observed when they are heated at 400 °C. Structural characterization using X-ray diffraction (XRD) shows that all samples produce a layer of Fe_3O_4 with particle size less than 50 nanometers. The addition of ethylene glycol and the heating of the sample causes a shrinkage in particle size. The scanning electron microscopy (SEM) characterization shows that Fe_3O_4 layer resulting from the process of electrodeposition of Fe_2(SO_4)_3 without ethylene glycol, independent of whether the sample is heated or not, is uneven and buildup. Layer produced by the addition of ethylene glycol without heating produces spherical particles. On contrary, when the layer is heated the spherical particles transform to irregularly-shaped particles with smaller size.

  2. Electron excitation cross sections for the 2s(2)2p(3)4S(O) -- 2s(2)2p(3)2D(O) (forbidden) and 4S(O) -- 2s2p(4) 4P (resonance) transitions in O II

    Science.gov (United States)

    Zuo, M.; Smith, Steven J.; Chutjian, A.; Williams, I. D.; Tayal, S. S.; Mclaughlin, Brendan M.

    1995-01-01

    Experimental and theoretical excitation cross sections are reported for the first forbidden transition 4S(O) -- 2S(2)2p(3) 2D(O) (lambda-lambda 3726, 3729) and the first allowed (resonance) transition 4S(O) -- 2s2p(4) 4P(lambda-833) in O II. Use is made of electron energy loss and merged-beams methods. The electron energy range covered is 3.33 (threshold) to 15 eV for the S -- D transition, and 14.9 (threshold) to 40 eV for the S -- P transition. Care was taken to assess and minimize the metastable fraction of the O II beam. An electron mirror was designed and tested to reflect inelastically backscattered electrons into the forward direction to account for the full range of polar scattering angles. Comparisons are made between present experiments and 11-state R-matrix calculations. Calculations are also presented for the 4S(O) -- 2s(2)2p(3)2P(O) (lambda-2470) transition.

  3. Giant-Planet Chemistry: Ammonium Hydrosulfide (NH4SH), Its IR Spectra and Thermal and Radiolytic Stabilities

    Science.gov (United States)

    Loeffler, Mark J.; Hudson, Reggie L.; Chanover, Nancy J.; Simon, Amy A.

    2015-01-01

    Here we present our recent studies of proton-irradiated and unirradiated ammonium hydrosulfide, NH4SH, a compound predicted to be an important tropospheric cloud component of Jupiter and other giant planets. We irradiated both crystalline and amorphous NH4SH at 10-160 K and used IR spectroscopy to observe and identify reaction products in the ice, specifically NH3 and long-chained sulfur-containing ions. Crystalline NH4SH was amorphized during irradiation at all temperatures studied with the rate being the fastest at the lowest temperatures. Irradiation of amorphous NH4SH at approximately 10-75 K showed that 60-80% of the NH4 + remained when equilibrium was reached, and that NH4SH destruction rates were relatively constant within this temperature range. Irradiations at higher temperatures produced different dose dependence and were accompanied by pressure outbursts that, in some cases, fractured the ice. The thermal stability of irradiated NH4SH was found to be greater than that of unirradiated NH4SH, suggesting that an irradiated giant-planet cloud precipitate can exist at temperatures and altitudes not previously considered.

  4. Optical spectroscopy of two-dimensional layered (C(6)H(5)C(2)H(4)-NH(3))(2)-PbI(4) perovskite.

    Science.gov (United States)

    Gauthron, K; Lauret, J-S; Doyennette, L; Lanty, G; Al Choueiry, A; Zhang, S J; Brehier, A; Largeau, L; Mauguin, O; Bloch, J; Deleporte, E

    2010-03-15

    We report on optical spectroscopy (photoluminescence and photoluminescence excitation) on two-dimensional self-organized layers of (C(6)H(5)C(2)H(4)-NH(3))(2)-PbI(4) perovskite. Temperature and excitation power dependance of the optical spectra gives a new insight into the excitonic and the phononic properties of this hybrid organic/inorganic semiconductor. In particular, exciton-phonon interaction is found to be more than one order of magnitude higher than in GaAs QWs. As a result, photoluminescence emission lines have to be interpreted in the framework of a polaron model.

  5. Projection of SO{sub 2}, NO{sub X}, NMVOC, NH{sub 3} and particle emissions - 2005 to 2030

    Energy Technology Data Exchange (ETDEWEB)

    Boll Illerup, J; Nielsen, Ole-Kenneth; Winther, M; Hjorth Mikkelsen, M; Nielsen, Malene; Fauser, P; Gyldenkaerne, S

    2008-05-15

    This report contains a description of models and background data for projection of SO{sub 2}, NO{sub X}, NH{sub 3}, NMVOC, TSP, PM{sub 10} and PM{sub 2.5} for Denmark. The emissions are projected to 2030 using basic scenarios together with the expected results of a few individual policy measures. Official Danish forecasts of activity rates are used in the models for those sectors for which the forecasts are available, i.e. the latest official forecast from the Danish Energy Authority. The emission factors refer to international guidelines and some are country-specific and refer to Danish legislation, Danish research reports or calculations based on emission data from a considerable number of plants. The projection models are based on the same structure and method as the Danish emission inventories in order to ensure consistency. (au)

  6. ZnCl 2- and NH 4Cl-hydroponics gel electrolytes for zinc-carbon batteries

    Science.gov (United States)

    Khalid, N. H.; Ismail, Y. M. Baba; Mohamad, A. A.

    Absorbency testing is used to determine the percentage of ZnCl 2 or NH 4Cl solution absorbed by a hydroponics gel (HPG). It is found that the absorbency of ZnCl 2 or NH 4Cl solution decreases with increasing solution concentration. The conductivity of ZnCl 2- and NH 4Cl-HPG electrolytes is dependent on the solution concentration. A mixture of salt solution with HPG yields excellent gel polymer electrolytes with conductivities of 0.026 and 0.104 S cm -1 at 3 M ZnCl 2 and 7 M NH 4Cl, respectively. These gel electrolytes are then used to produce zinc-carbon cells. The fabricated cells give capacities of 8.8 and 10.0 mAh, have an internal resistance of 25.4 and 19.8 Ω, a maximum power density of 12.7 and 12.2 mW cm -2, and a short-circuit current density of 29.1 and 33.9 mA cm -2 for ZnCl 2- and NH 4Cl-HPG electrolytes, respectively.

  7. Effect of metal ions doping (M = Ti4+, Sn4+) on the catalytic performance of MnOx/CeO2 catalyst for low temperature selective catalytic reduction of NO with NH3

    Science.gov (United States)

    Xiong, Yan; Tang, Changjin; Dong, Lin

    2015-04-01

    Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, PR China The abatement of nitrogen oxides (NOx) emission from exhaust gases of diesel and stationary sources is a significant challenge for economic and social development. Ceria-based solid solutions were synthesized and used as supports to prepare MnOx/Ce0.8Ti0.2O2 and MnOx/Ce0.8Sn0.2O2 catalysts (Mn/CeTi and Mn/CeSn) for low temperature selective catalytic reduction of NO by NH3 (NH3-SCR). The effects of Ti or Sn doping on the catalytic performance of MnOx/CeO2 catalyst were investigated. Experimental results show that doping of Ti or Sn increases the NO removal efficiency of MnOx/CeO2. The NO conversion of Mn/CeTi catalyst is more than 90 % at temperature window of 175 ~ 300 °C under a gas hour space velocity of 60,000 mL.g-1.h-1. Modified catalysts are also found to exhibit greatly improved resistance to sulfur-poisoning. NH3-TPD results suggest that NH3 desorption on the catalysts is observed over a wide temperature range, due to the variability of adsorbed NH3 species with different thermal stabilities. Doping of Ti and Sn into Mn/CeO2 greatly increased the NH3 adsorption ability of the composites which could promote the SCR reaction. Characterization results also indicate that doping of Ti or Sn brings about catalysts with higher BET surface area, enhanced oxygen storage capacity and increased surface acidity.

  8. Et2NH2C6H3(CO23SnBr2.4H2O: SYNTHESIS AND INFRARED STUDY

    Directory of Open Access Journals (Sweden)

    DAOUDA NDOYE

    2014-01-01

    Full Text Available The title compound has been obtained on allowing [C6H3(CO23(Et2NH23] to react with SnBr4. The molecular structure of Et2NH2C6H3(CO23SnBr2.4H2O has been determined on the basis of the infrared data. The suggested structure is a dimer in which each tin atom is hexacoordinated by two chelating C6H3(CO233- anions and two Br atoms. Cy2NH2+cations are involved through hydrogen bonds with non-coordinating CO2 groups. The suggested structure is a cage.

  9. Synthesis of NH4-Substituted Muscovite at 6.3 GPa and 1000°C: Implications for Nitrogen Transport to the Earth's Mantle

    Science.gov (United States)

    Sokol, A. G.; Sokol, E. V.; Kupriyanov, I. N.; Sobolev, N. V.

    2018-03-01

    The synthesis of NH4-bearing muscovite at P = 6.3 GPa and T = 1000°C in equilibrium with NH3-H2O fluid is performed. It is determined that the newly formed muscovite is enriched in celadonite minal and contains 370 ppm of NH4. The obtained data make it possible to conclude that ammonium-bearing micas have sufficient thermal stability and can transport crustal nitrogen to the mantle in the presence of a reduced water-ammonia fluid at fO2 less than the values of IW + 2 log units even in the regime of "hot" subduction. The key parameter that determines the efficiency of this mechanism for the deep nitrogen cycle is redox stability of NH4-bearing muscovite at the mantle PT-parameters.

  10. Deposition of ZnSO4 · 3Zn(OH2 · 4H2O films by SILAR method and their study by XRD, SEM and µ-Raman Depósito de películas de ZnSO43Zn(OH2 • 4H2O por el método SILAR y su estudio por DRX, SEM Y μ-RAMAN

    Directory of Open Access Journals (Sweden)

    F N Jiménez García

    2012-06-01

    Full Text Available ZnSO4 · 3Zn(OH2 · 4H2O(Zinc Sulfate Hidroxide Hidrate films were obtained on glass substrates by SILAR method. It was employed a precursorsolution of ZnSO4 and MnSO4 and water near boiling point complexed with 1 ml of NH4OH as a second solution. Films were treated on air at 300oC by 1 hour. Both films ZnSO4·3Zn(OH2·4H2O as ZnO are important protective against zinc corrosion because they are passive films that give a longer duration to material, it is therefore relevant to study their response to temperature changes. For those reasons films were analyzed before and after thermal treatment to study the structural and morphological changes by X ray diffraction (XRD, Scanning electron microscopy (SEM and Raman Microscopy techniques. It was found before thermal treatment by XRD thepresence of ZnSO4 · 3Zn(OH2 · 4H2O triclinic phase and after such treatment the ZnO hexagonal phase was evidenced. The morphology identified by SEM before thermal treatment was sheets formed by platelet like structure of micrometric size which changes after thermal treatment to a combination ofthose sheets with flowers like structure characteristic of ZnO hexagonal. By µ-Raman the hexagonal ZnO phase before thermal treatment as the triclinicZnSO4 · 3Zn(OH2 · 4H2O phase after thermal treatment were confirmed.One objective of this study was to obtain this protective corrosion material in a controlled manner by techiniques of low cost and high simplicity as Silarmethod. Which, even under temperture increases continue being protective corrosion although suffers phase changes because new phases have protectivecorrosive characteristics too.Se obtuvieron películas de ZnSO4 · 3Zn(OH2 · 4H2O (Zinc Sulfate Hidroxide Hidrate sobre sustratos de vidrio mediante procedimiento SILAR. Se empleó una solución precursora de ZnSO4 y MnSO4 y una segunda solución de agua a ebullición acomplejada con 1 ml de NH4OH. Se realizó tratamiento térmico en aire a 300oC por

  11. Empirical and mechanistic evaluation of NH4(+) release kinetic in calcareous soils.

    Science.gov (United States)

    Ranjbar, F; Jalali, M

    2014-05-01

    Release, fixation, and distribution of ammonium (NH4(+)) as a source of nitrogen can play an important role in soil fertility and plant nutrition. In this study, ten surface soils, after addition of 1,000 mg NH4(+) kg(-1,) were incubated for 1 week at the field capacity moisture and 25 ± 2 °C temperature, and then NH4(+) release kinetic was investigated by sequential extractions with 10 mM CaCl2. Furthermore, NH4(+) distribution among three fractions, including water-soluble, exchangeable, and non-exchangeable, was determined in all soil samples. NH4(+) release was initially rapid followed by a slower reaction, and this was described well with the Elovich equation as an empirical model. The cumulative NH4(+) concentration released in spiked soil samples had a positive significant correlation with sand content and negative ones with pH, exchangeable Ca(2+)m and K(+), cation exchange capacity (CEC), equivalent calcium carbonate (ECC), and clay content. The cation exchange model in the PHREEQC program was successful in mechanistic simulation of the release trend of native and added NH4(+) in all control and spiked soil samples. The results of fractionation experiments showed that the non-exchangeable fraction in control and spiked soil samples was greater than that in water-soluble and exchangeable fractions. Soil properties, such as pH, exchangeable Ca(2+) and K(+), CEC, ECC, and contents of sand and clay, had significant influences on the distribution of NH4(+) among three measured fractions. This study indicated that both native and recently fixed NH4(+), added to soil through the application of fertilizers, were readily available for plant roots during 1 week after exposure.

  12. Light induces changes in activities of Na+/K+(NH4+-ATPase, H+/K+(NH4+-ATPase and glutamine synthetase in tissues involved directly or indirectly in light-enhanced calcification in the giant clam Tridacna squamosa

    Directory of Open Access Journals (Sweden)

    Alex Y K Ip

    2015-03-01

    Full Text Available The objective of this study was to determine the effects of 12 h of exposure to light, as compared with 12 h of exposure to darkness (control, on enzymatic activities of transporters involved in the transport of NH4+ or H+, and activities of enzymes involved in converting NH4+ to glutamate/glutamine in inner mantle, outer mantle and ctenidia of the giant clam, Tridacna squamosa. Exposure to light resulted in a significant increase in the effectiveness of NH4+ in substitution for K+ to activate Na+/K+-ATPase (NKA, manifested as a significant increase in the Na+/NH4+-activated-NKA activity in the inner mantle. However, similar phenomena were not observed in the extensible outer mantle, which contained abundant symbiotic zooxanthellae. Hence, during light-enhanced calcification, H+ released from CaCO3 deposition could react with NH3 to form NH4+ in the extrapallial fluid, and NH4+ could probably be transported into the shell-facing inner mantle epithelium through NKA. Light also induced an increase in the activity of glutamine synthetase, which converts NH4+ and glutamate to glutamine, in the inner mantle. Taken together, these results explained observations reported elsewhere that light induced a significant increase in pH and a significant decrease in ammonia concentration in the extrapallial fluid, as well as a significant increase in the glutamine concentration in the inner mantle, of T. squamosa. Exposure of T. squamosa to light also led to a significant decrease in the N-ethylmaleimide (NEM-sensitive-V-H+-ATPase (VATPase in the inner mantle, and significant increases in the Na+/K+-activated-NKA, H+/NH4+-activated-H+/K+-ATPase and NEM-sensitive-VATPase activities in ctenidia, indicating that light-enhanced calcification might perturb Na+ homeostasis and acid/base balance in the hemolymph, and might involve the active uptake of NH4+ from the environment. This is the first report on light having direct enhancing effects on activities of certain

  13. Transcriptomic and physiological analysis of common duckweed Lemna minor responses to NH4(+) toxicity.

    Science.gov (United States)

    Wang, Wenguo; Li, Rui; Zhu, Qili; Tang, Xiaoyu; Zhao, Qi

    2016-04-18

    Plants can suffer ammonium (NH4 (+)) toxicity, particularly when NH4 (+) is supplied as the sole nitrogen source. However, our knowledge about the underlying mechanisms of NH4 (+) toxicity is still largely unknown. Lemna minor, a model duckweed species, can grow well in high NH4 (+) environment but to some extent can also suffer toxic effects. The transcriptomic and physiological analysis of L. minor responding to high NH4 (+) may provide us some interesting and useful information not only in toxic processes, but also in tolerance mechanisms. The L. minor cultured in the Hoagland solution were used as the control (NC), and in two NH4 (+) concentrations (NH4 (+) was the sole nitrogen source), 84 mg/L (A84) and 840 mg/L (A840) were used as stress treatments. The NH4 (+) toxicity could inhibit the growth of L. minor. Reactive oxygen species (ROS) and cell death were studied using stained fronds under toxic levels of NH4 (+). The malondialdehyde content and the activities of superoxide dismutase and peroxidase increased from NC to A840, rather than catalase and ascorbate peroxidase. A total of 6.62G nucleotides were generated from the three distinct libraries. A total of 14,207 differentially expressed genes (DEGs) among 70,728 unigenes were obtained. All the DEGs could be clustered into 7 profiles. Most DEGs were down-regulated under NH4 (+) toxicity. The genes required for lignin biosynthesis in phenylpropanoid biosynthesis pathway were up-regulated. ROS oxidative-related genes and programmed cell death (PCD)-related genes were also analyzed and indicated oxidative damage and PCD occurring under NH4 (+) toxicity. The first large transcriptome study in L. minor responses to NH4 (+) toxicity was reported in this work. NH4 (+) toxicity could induce ROS accumulation that causes oxidative damage and thus induce cell death in L. minor. The antioxidant enzyme system was activated under NH4 (+) toxicity for ROS scavenging. The phenylpropanoid pathway was stimulated under

  14. Synthesis, vibrational and optical properties of a new three-layered organic-inorganic perovskite (C{sub 4}H{sub 9}NH{sub 3}){sub 4}Pb{sub 3}I{sub 4}Br{sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Dammak, T., E-mail: thameurlpa@yahoo.f [Laboratoire de Physique appliquee (LPA), Faculte des Sciences de Sfax, 3018, BP 802 (Tunisia); Elleuch, S. [Laboratoire de Physique appliquee (LPA), Faculte des Sciences de Sfax, 3018, BP 802 (Tunisia); Bougzhala, H. [Laboratoire de cristallochimie et des materiaux, Faculte des Sciences de Tunis (Tunisia); Mlayah, A. [Centre d' Elaboration de Materiaux et d' Etudes Structurales, CNRS-Universite Paul Sabatier, 29 rue Jeanne Marvig, 31055 Toulouse, Cedex 4 (France); Chtourou, R. [Centre de Recherche et des Technologies de l' Energie CRTEn BP. 95, Hammam-Lif 2050, Laboratoire de Photovoltaique et de Semiconducteur (Tunisia); Abid, Y. [Laboratoire de Physique appliquee (LPA), Faculte des Sciences de Sfax, 3018, BP 802 (Tunisia)

    2009-09-15

    An organic-inorganic hybrid perovskite (C{sub 4}H{sub 9}NH{sub 3}){sub 4}Pb{sub 3}I{sub 4}Br{sub 6} was synthesized and studied by X-ray diffraction, Raman and infrared spectroscopies, optical transmission and photoluminescence. The title compound, abbreviated (C{sub 4}){sub 4}Pb{sub 3}I{sub 4}Br{sub 6}, crystallises in a periodic two-dimensional multilayer structure with P2{sub 1}/a space group. The structure is built up from alternating inorganic and organic layers. Each inorganic layer consists of three sheets of PbX{sub 6} (X=I, Br) octahedra. Raman and infrared spectra of the title compound were recorded in the 100-3500 and 400-4000 cm{sup -1} frequency ranges, respectively. An assignment of the observed vibration modes is reported. Optical transmission measurements, performed on thin films of (C{sub 4}){sub 4}Pb{sub 3}I{sub 4}Br{sub 6}, revealed two absorption bands at 474 and 508 nm. Photoluminescence measurements have shown a green emission peak at 519 nm.

  15. High-Pressure Synthesis and Characterization of the Ammonium Yttrium Borate (NH4)YB8O14.

    Science.gov (United States)

    Schmitt, Martin K; Podewitz, Maren; Liedl, Klaus R; Huppertz, Hubert

    2017-11-20

    The first high-pressure yttrium borate (NH 4 )YB 8 O 14 was synthesized at 12.8 GPa/1300 °C using a Walker-type multianvil module. The compound crystallizes in the orthorhombic space group Pnma (no. 62) with the lattice parameters a = 17.6375(9), b = 10.7160(5), and c = 4.2191(2) Å. (NH 4 )YB 8 O 14 constitutes a novel structure type but exhibits similarities to the crystal structure of β-BaB 4 O 7 . X-ray single-crystal and powder diffraction, EDX, vibrational spectroscopy as well as quantum chemical calculations were used to characterize (NH 4 )YB 8 O 14 .

  16. DFT study of adsorption behavior of NO, CO, NO2, and NH3 molecules on graphene-like BC3: A search for highly sensitive molecular sensor

    Science.gov (United States)

    Mehdi Aghaei, Sadegh; Monshi, M. M.; Torres, I.; Zeidi, S. M. J.; Calizo, I.

    2018-01-01

    The adsorption behaviors of toxic gas molecules (NO, CO, NO2, and NH3) on the graphene-like boron carbide (BC3) are investigated using first-principle density functional theory. The graphene-like BC3 monolayer is a semiconductor with a band gap of 0.733 eV. It is discovered that all the above gas molecules are chemisorbed on the BC3 sheet while they retain their molecular forms. It is also revealed that the NO2 gas molecule could be dissociated into NO and O species through the adsorption process. The amounts of charge transfer upon adsorption of CO and NH3 gas molecules on the BC3 are found to be small. The band gap changes in BC3 as a result of interactions with CO and NH3 are only 4.63% and 16.7%, indicating that the BC3-based sensor has a low and moderate sensitivity to CO and NH3, respectively. Contrariwise, upon adsorption of NO or NO2 on the BC3, significant charges are transferred from the molecules to the BC3 sheet, causing a semiconductor-metal and semiconductor-p type semiconductor transition. Our study suggests that the BC3-based sensor has a high potential for NO and NO2 detection due to the significant conductance changes, moderate adsorption energy, and short recovery time. More excitingly, the BC3 is a likely catalyst for dissociation of the NO2 gas molecule.

  17. Nuclear Overhauser effect studies of the conformation of Co(NH3)4ATP bound to kidney Na,K-ATPase

    International Nuclear Information System (INIS)

    Stewart, J.M.; Jorgensen, P.L.; Grisham, C.M.

    1989-01-01

    Transferred nuclear Overhauser effect measurements (in the two-dimensional mode) have been used to determine the three-dimensional conformation of an ATP analogue, Co(NH3)4ATP, at the active site of sheep kidney Na,K-ATPase. Previous studies have shown that Co(NH3)4ATP is a competitive inhibitor with respect to MnATP for the Na,K-ATPase. Nine unique proton-proton distances on ATPase-bound Co(NH3)4ATP were determined from the initial build-up rates of the cross-peaks of the 2D-TRNOE data sets. These distances, taken together with previous 31P and 1H relaxation measurements with paramagnetic probes, are consistent with a single nucleotide conformation at the active site. The bound (Co(NH3)4ATP) adopts an anti conformation, with a glycosidic torsion angle of 35 degrees, and the conformation of the ribose ring is slightly N-type (C2'-exo, C3'-endo). The delta and gamma torsional angles in this conformation are 100 degrees and 178 degrees, respectively. The nucleotide adopts a bent configuration, in which the triphosphate chain lies nearly parallel to the adenine moiety. Mn2+ bound to a single, high-affinity site on the ATPase lies above and in the plane of the adenine ring. The distances from enzyme-bound Mn2+ to N6 and N7 are too large for first coordination sphere complexes, but are appropriate for second-sphere complexes involving, for example, intervening hydrogen-bonded water molecules. The NMR data also indicate that the structure of the bound ATP analogue is independent of the conformational state of the enzyme

  18. Nuclear Overhauser effect studies of the conformation of Co(NH3)4ATP bound to kidney Na,K-ATPase

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, J.M.; Jorgensen, P.L.; Grisham, C.M. (Univ. of Virginia, Charlottesville (USA))

    1989-05-30

    Transferred nuclear Overhauser effect measurements (in the two-dimensional mode) have been used to determine the three-dimensional conformation of an ATP analogue, Co(NH3)4ATP, at the active site of sheep kidney Na,K-ATPase. Previous studies have shown that Co(NH3)4ATP is a competitive inhibitor with respect to MnATP for the Na,K-ATPase. Nine unique proton-proton distances on ATPase-bound Co(NH3)4ATP were determined from the initial build-up rates of the cross-peaks of the 2D-TRNOE data sets. These distances, taken together with previous 31P and 1H relaxation measurements with paramagnetic probes, are consistent with a single nucleotide conformation at the active site. The bound (Co(NH3)4ATP) adopts an anti conformation, with a glycosidic torsion angle of 35{degrees}, and the conformation of the ribose ring is slightly N-type (C2'-exo, C3'-endo). The delta and gamma torsional angles in this conformation are 100 degrees and 178 degrees, respectively. The nucleotide adopts a bent configuration, in which the triphosphate chain lies nearly parallel to the adenine moiety. Mn2+ bound to a single, high-affinity site on the ATPase lies above and in the plane of the adenine ring. The distances from enzyme-bound Mn2+ to N6 and N7 are too large for first coordination sphere complexes, but are appropriate for second-sphere complexes involving, for example, intervening hydrogen-bonded water molecules. The NMR data also indicate that the structure of the bound ATP analogue is independent of the conformational state of the enzyme.

  19. Estudio del Sistema Li2SO4 – Na2SO4. Diagrama de fases y caracterización del LiNaSO4

    Directory of Open Access Journals (Sweden)

    Font-Bardia, M.

    2004-08-01

    Full Text Available An exhaustive study of the phase diagram of binary system Li2SO4-Na2SO4 is presented. Phase diagram was determined using thermo-X-ray diffraction in powder samples and calorimetry ATD. A new phase with formula Li2-xNaxSO4 has been obtained, with 1 ≤ x ≤ 1.22. The crystal structure of β-LiNaSO4 was determined from single-crystal X-ray diffraction. This study shows that the crystals usually become twinned when the growth is by solution; which explains the poor spontaneous polarization. The Raman dispersion of Li2SO4, Na2SO4 and LiNaSO4 compounds is explained from the structural data. The measurements have been made at different heating and cooling rate.Se presenta un estudio exhaustivo del diagrama de fase del sistema binario Li2SO4-Na2SO4. El diagrama de fases se determinó mediante termo-difractometría de rayos-X en muestras de polvo y calorimetría ATD. Se obtiene una nueva fase de fórmula Li2-xNaxSO4, con 1 ≤ x ≤ 1.22. La estructura cristalina de β-LiNaSO4 se determinó por difracción de rayos-X sobre un monocristal. Este estudio muestra que los cristales usualmente se maclan cuando el crecimiento es por solución, lo cual explica la baja polarización espontánea. Se explica la dispersión Raman de los compuestos Li2SO4, Na2SO4 y LiNaSO4, a partir de los datos estructurales. Las medidas experimentales se han efectuado a diferentes velocidades de calentamiento y enfriamiento.

  20. Effects of atmospheric ammonia (NH{sub 3}) on terrestrial vegetation: a review

    Energy Technology Data Exchange (ETDEWEB)

    Krupa, S.V

    2003-07-01

    A review of atmospheric ammonia (NH{sub 3}) and ammonium (NH{sub 4}{sup +}) deposition and their effects on plants. - At the global scale, among all N (nitrogen) species in the atmosphere and their deposition on to terrestrial vegetation and other receptors, NH{sub 3} (ammonia) is considered to be the foremost. The major sources for atmospheric NH{sub 3} are agricultural activities and animal feedlot operations, followed by biomass burning (including forest fires) and to a lesser extent fossil fuel combustion. Close to its sources, acute exposures to NH{sub 3} can result in visible foliar injury on vegetation. NH{sub 3} is deposited rapidly within the first 4-5 km from its source. However, NH{sub 3} is also converted in the atmosphere to fine particle NH{sub 4}{sup +} (ammonium) aerosols that are a regional scale problem. Much of our current knowledge of the effects of NH{sub 3} on higher plants is predominantly derived from studies conducted in Europe. Adverse effects on vegetation occur when the rate of foliar uptake of NH{sub 3} is greater than the rate and capacity for in vivo detoxification by the plants. Most to least sensitive plant species to NH{sub 3} are native vegetation > forests > agricultural crops. There are also a number of studies on N deposition and lichens, mosses and green algae. Direct cause and effect relationships in most of those cases (exceptions being those locations very close to point sources) are confounded by other environmental factors, particularly changes in the ambient SO{sub 2} (sulfur dioxide) concentrations. In addition to direct foliar injury, adverse effects of NH{sub 3} on higher plants include alterations in: growth and productivity, tissue content of nutrients and toxic elements, drought and frost tolerance, responses to insect pests and disease causing microorganisms (pathogens), development of beneficial root symbiotic or mycorrhizal associations and inter species competition or biodiversity. In all these cases, the joint

  1. Insight into the local magnetic environments and deuteron mobility in jarosite (AFe3(SO4)2(OD)6, A = K, Na, D3O) and hydronium alunite ((D3O)Al3(SO4)2(OD,OD2)6), from variable temperature 2H MAS NMR spectroscopy

    DEFF Research Database (Denmark)

    Nielsen, Ulla Gro; Heinmaa, Ivo; Samoson, Ago

    2011-01-01

    to the different temperature dependence of their isotropic shifts. An activation energy of 6.3(4) kJ/mol is determined for the D3O+ motion in the isostructural compound D3OAl3(SO4)2(OD)6. Our NMR results support theories that ascribes the spin glass behavior of (H3O)Fe3(SO4)2(OD)6 is to disorder of the D3O+ ion...... and/or a less distorted Fe coordination environment. No sign of proton transfer reactions from the D3O+ ion to the framework is observed....

  2. Formation of simple nitrogen hydrides NH and NH2 at cryogenic temperatures through N + NH3NH + NH2 reaction: dark cloud chemistry of nitrogen.

    Science.gov (United States)

    Nourry, Sendres; Krim, Lahouari

    2016-07-21

    Although NH3 molecules interacting with ground state nitrogen atoms N((4)S) seem not to be a very reactive system without providing additional energy to initiate the chemical process, we show through this study that, in the solid phase, at very low temperature, NH3 + N((4)S) reaction leads to the formation of the amidogen radical NH2. Such a dissociation reaction previously thought to occur exclusively through UV photon or energetic particle irradiation is in this work readily occurring just by stimulating the mobility of N((4)S)-atoms in the 3-10 K temperature range in the solid sample. The N((4)S)-N((4)S) recombination may be the source of metastable molecular nitrogen N2(A), a reactive species which might trigger the NH3 dissociation or react with ground state nitrogen atoms N((4)S) to form excited nitrogen atoms N((4)P/(2)D) through energy transfer processes. Based on our obtained results, it is possible to propose reaction pathways to explain the NH2 radical formation which is the first step in the activation of stable species such as NH3, a chemical induction process that, in addition to playing an important role in the origin of molecular complexity in interstellar space, is known to require external energy supplies to occur in the gas phase.

  3. A Concise Li/liq. NH{sub 3} Mediated Synthesis of (4E,10Z)-Tetradeca-4,10-dienyl Acetate: The Major Sex Pheromone of Apple Leafminer Moth, Phyllonorycter ringoniella

    Energy Technology Data Exchange (ETDEWEB)

    Prem Kumar, B.; Vijaykumar, B. V. D.; Harshavardhan, S. J.; Jung, Haedong; Xie, Yongsheng; Shin, Dongsoo; Jang, Kiwan [Changwon National Univ., Changwon (Korea, Republic of); Lee, Dong Ha [Hanbat National Univ., Daejeon (Korea, Republic of); Yoon, Yongjin [Gyeongsang National Univ., Jinju (Korea, Republic of)

    2014-01-15

    We have accomplished a protection free, concise, Li/liq. NH3 mediated and gram scale synthesis of (4E,10Z)-tetradeca-4,10-dienyl acetate (1), the major sex pheromone of apple leafminer moth, Phyllonorycter ringoniella starting from commercially available 1-pentyne, 1,4- dibromobutane and 4-petyne-1-ol in 24% overall yield. The Li/liq. NH3 based mono-alkynylation of dibromobutane has been introduced for the first time. The stereoselective formation of 10(Z) and 4(E) olefins are accomplished by partial hydrogenation (Lindlar's catalyst) and birch reduction respectively. The economy, efficiency, simplicity and high stereo chemical purity of this synthesis allow the potential use of pheromone 1 in integrated field studies to understand the behavioral responses of male apple leaf miner moth.

  4. Investigations on the properties of NH4HCO3 filled natural rubber based magnetorheological elastomers (MREs)

    Science.gov (United States)

    Fan, Lili; Wang, Guoping; Wang, Wenju; Shi, Guanxin; Yang, Fufeng; Rui, Xiaoting

    2018-04-01

    Various anisotropic magnetorheological elastomers (MREs) were synthesized using the rubber mixing technique. Magnetic and temperature distributions of the experimental equipment and test instruments were analyzed by the ANSYS. NH4HCO3 was filled in the natural rubber matrix to modify properties of MREs. Microstructures and compositions of samples were studied by the scanning electron microscope (SEM), the energy dispersive x-ray spectroscopy (EDAX) analysis and x-ray powder diffraction (XRD). Via vibrating sample magnetometer (VSM) and density functional theory (DFT) method, the magnetic property of carbonyl iron (CI) was illuminated. The shear storage modulus and MR effect of MREs were investigated by the dynamic mechanical analyzer (DMA). It indicated that distributions of magnetic and temperature in the experimental and testing devices were uniform. Before vulcanization, CI particles were uniformly distributed in the matrix, while a CI chain structure was formed and embedded in the matrix after the vulcanization process. Moderate addition of NH4HCO3 accelerated the rubber vulcanization and enhanced the MR effect.

  5. Importance of the Cu oxidation state for the SO2-poisoning of a Cu-SAPO-34 catalyst in the NH3-SCR reaction

    DEFF Research Database (Denmark)

    Hammershøi, Peter S.; Vennestrøm, Peter N. R.; Falsig, Hanne

    2018-01-01

    behavior and mechanisms of a Cu-SAPO-34 catalyst were studied with reactor tests and DFT calculations. Exposure of the catalyst to two different SO2 concentrations and durations, but with the same total SO2 exposure, calculated as the product of partial pressure of SO2 and exposure time, lead to the same...... degree of deactivation. Exposure of the Cu-SAPO-34 catalyst to SO2 in the presence and absence of NO and NH3 at different temperatures between 200–600 °C showed different trends for the deactivation. Below 400 °C, the S/Cu ratio on the catalyst increased with temperature in absence of NO and NH3, while...... showing that SO2 and SO3, which is possibly formed by oxidation of SO2 over Cu sites, interact similar with Cu in Cu-SAPO-34 and Cu-SSZ-13....

  6. Species turnover (β-diversity) in ectomycorrhizal fungi linked to NH4+ uptake capacity.

    Science.gov (United States)

    Kranabetter, J M; Hawkins, B J; Jones, M D; Robbins, S; Dyer, T; Li, T

    2015-12-01

    Ectomycorrhizal (EcM) fungal communities may be shaped by both deterministic and stochastic processes, potentially influencing ecosystem development and function. We evaluated community assembly processes for EcM fungi of Pseudotsuga menziesii among 12 sites up to 400 km apart in southwest British Columbia (Canada) by investigating species turnover (β-diversity) in relation to soil nitrogen (N) availability and physical distance. We then examined functional traits for an N-related niche by quantifying net fluxes of NH4+, NO3- and protons on excised root tips from three contrasting sites using a microelectrode ion flux measurement system. EcM fungal communities were well aligned with soil N availability and pH, with no effect of site proximity (distance-decay curve) on species assemblages. Species turnover was significant (β(1/2) = 1.48) along soil N gradients, with many more Tomentella species on high N than low N soils, in contrast to Cortinarius species. Ammonium uptake was greatest in the spring on the medium and rich sites and averaged over 190 nmol/m(2)/s for Tomentella species. The lowest uptake rates of NH4+ were by nonmycorrhizal roots of axenically grown seedlings (10 nmol/m(2)/s), followed by Cortinarius species (60 nmol/m(2)/s). EcM roots from all sites displayed only marginal uptake of nitrate (8.3 nmol/m(2)/s). These results suggest NH4+ uptake capacity is an important functional trait influencing the assembly of EcM fungal communities. The diversity of EcM fungal species across the region arguably provides critical belowground adaptations to organic and inorganic N supply that are integral to temperate rainforest ecology. © 2015 John Wiley & Sons Ltd.

  7. Solid-state thermal decomposition of the [Co(NH{sub 3}){sub 5}CO{sub 3}]NO{sub 3}{center_dot}0.5H{sub 2}O complex: A simple, rapid and low-temperature synthetic route to Co{sub 3}O{sub 4} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Farhadi, Saeid, E-mail: sfarhad2001@yahoo.com [Department of Chemistry, Lorestan University, Khorramabad 68135-465 (Iran, Islamic Republic of); Safabakhsh, Jalil [Department of Chemistry, Lorestan University, Khorramabad 68135-465 (Iran, Islamic Republic of)

    2012-02-25

    Highlights: Black-Right-Pointing-Pointer [Co(NH{sub 3}){sub 5}CO{sub 3}]NO{sub 3}{center_dot}0.5H{sub 2}O complex was used for preparing pure Co{sub 3}O{sub 4} nanoparticles. Black-Right-Pointing-Pointer Co{sub 3}O{sub 4} nanoparticles were prepared at low temperature of 175 Degree-Sign C. Black-Right-Pointing-Pointer Co{sub 3}O{sub 4} nanoparticles show a weak ferromagnetic behaviour at room temperature. Black-Right-Pointing-Pointer The method is simple, low-cost and suitable for the production of Co{sub 3}O{sub 4}. - Abstract: Co{sub 3}O{sub 4} nanoparticles were easily prepared via the decomposition of the pentammine(carbonato)cobalt(III) nitrate precursor complex [Co(NH{sub 3}){sub 5}CO{sub 3}]NO{sub 3}{center_dot}0.5H{sub 2}O at low temperature (175 Degree-Sign C). The product was characterized by thermal analysis, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), UV-visible spectroscopy, transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), Raman spectroscopy, Brunauer-Emmett-Teller (BET) specific surface area measurements and magnetic measurements. The FT-IR, XRD, Raman and EDX results indicated that the synthesized Co{sub 3}O{sub 4} nanoparticles are highly pure and have a single phase. The TEM analysis revealed nearly uniform and quasi-spherical Co{sub 3}O{sub 4} nanoparticles with an average particle size of approximately 10 nm. The optical absorption spectrum of the Co{sub 3}O{sub 4} nanoparticles showed two direct band gaps of 2.18 and 3.52 eV with a red shift in comparison with previous reported values. The prepared Co{sub 3}O{sub 4} nanoparticles showed a weak ferromagnetic behaviour that could be attributed to uncompensated surface spins and/or finite-size effects. Using the present method, Co{sub 3}O{sub 4} nanoparticles can be produced without expensive organic solvents and complicated equipment. This simple, rapid, safe and low-cost synthetic route can be extended to the synthesis of other

  8. Raman study of molecular motions in relation to phase transitions in [Ni(NH3)6](NO3)2

    International Nuclear Information System (INIS)

    Janik, J.M.; Pick, R.M.; Le Postollec, M.

    1987-01-01

    A Raman band at 710 cm -1 has been used for the study of the NO 3 - ions reorientation and of the phase transitions in [Ni(NH 3 ) 6 ](NO 3 ) 2 . The strong temperature dependence of the width of this band in phase 1 gives evidence for the NO 3 - reorientations in this phase. The reorientations stop in phase 2. The same band was used for studying the phase 2/phase 3 transition. The large thermal hysteresis of this transition has ben confirmed. 16 refs., 4 figs. (author)

  9. Laboratory study on new particle formation from the reaction OH + SO2: influence of experimental conditions, H2O vapour, NH3 and the amine tert-butylamine on the overall process

    Directory of Open Access Journals (Sweden)

    J. Curtius

    2010-08-01

    Full Text Available Nucleation experiments starting from the reaction of OH radicals with SO2 have been performed in the IfT-LFT flow tube under atmospheric conditions at 293±0.5 K for a relative humidity of 13–61%. The presence of different additives (H2, CO, 1,3,5-trimethylbenzene for adjusting the OH radical concentration and resulting OH levels in the range (4–300 ×105 molecule cm−3 did not influence the nucleation process itself. The number of detected particles as well as the threshold H2SO4 concentration needed for nucleation was found to be strongly dependent on the counting efficiency of the used counting devices. High-sensitivity particle counters allowed the measurement of freshly nucleated particles with diameters down to about 1.5 nm. A parameterization of the experimental data was developed using power law equations for H2SO4 and H2O vapour. The exponent for H2SO4 from different measurement series was in the range of 1.7–2.1 being in good agreement with those arising from analysis of nucleation events in the atmosphere. For increasing relative humidity, an increase of the particle number was observed. The exponent for H2O vapour was found to be 3.1 representing an upper limit. Addition of 1.2×1011 molecule cm−3 or 1.2×1012 molecule cm−3 of NH3 (range of atmospheric NH3 peak concentrations revealed that NH3 has a measureable, promoting effect on the nucleation rate under these conditions. The promoting effect was found to be more pronounced for relatively dry conditions, i.e. a rise of the particle number by 1–2 orders of magnitude at RH = 13% and only by a factor of 2–5 at RH = 47% (NH3 addition: 1.2×1012 molecule cm−3. Using the amine tert-butylamine instead of NH3, the enhancing impact of the base for nucleation and particle growth appears to be stronger. Tert-butylamine addition of about 1010 molecule cm−3 at RH = 13% enhances particle formation by about two orders of magnitude, while for NH3 only a small or negligible

  10. Crystal structure and electrical conduction of the new organic-inorganic compound (CH2)2(NH3)2CdI4

    Science.gov (United States)

    Zhang, Liuqi; Wang, Jilin; Han, Feifei; Mo, Shuyi; Long, Fei; Gao, Yihua

    2018-03-01

    The new organic-inorganic compound (CH2)2(NH3)2CdI4 was prepared by slow evaporation method using a mixture solution of CdI2 and ethylenediamine iodide (EDAI) in the γ-butyrolactone (GBL). The synthesized compound was further characterized by single crystal diffraction, Infrared (IR) and Raman spectroscopy, energy dispersive spectrometer (EDS), X-Ray photoelectron spectroscopy (XPS) and thermogravimetric analysis. The relaxation behavior and conductivity mechanism of (CH2)2(NH3)2CdI4 was studied by the electrical impedance spectroscopy. The results indicated that (CH2)2(NH3)2CdI4 had a monoclinic structure with space group P21/c at room temperature. The complex impedance plotted as semicircle arcs and the proposed electrical equivalent circuit was to interpret the impedance behavior at different temperatures. The electrical equivalent circuit was made of a parallel combination of resistance (R) and fractal capacitance (CPE). Furthermore, the alternating current conductivity of the sample obeyed the Jonscher's law: σf =σdc + Afs and the conduction could be attributed to the correlated barrier hopping (CBH) model.

  11. A new crystal modification of diammonium hydrogen phosphate, (NH42(HPO4

    Directory of Open Access Journals (Sweden)

    Bernhard Spingler

    2010-04-01

    Full Text Available The addition of hexafluoridophosphate salts (ammonium, silver, thallium or potassium is usually used to precipitate complex cations from aqueous solutions. It has long been known that PF6− is sensitive towards hydrolysis under acidic conditions [Gebala & Jones (1969. J. Inorg. Nucl. Chem. 31, 771–776; Plakhotnyk et al. (2005. J. Fluorine Chem. 126, 27–31]. During the course of our investigation into coinage metal complexes of diphosphine ligands, we used ammonium hexafluoridophosphate in order to crystallize [Ag(diphosphine2]PF6 complexes. From these solutions we always obtained needle-like crystals which turned out to be the title compound, 2NH4+·HPO42−. It was received as the hydrolysis product of NH4PF6. The crystals are a new modification of diammonium hydrogen phosphate. In contrast to the previously published polymorph [Khan et al. (1972. Acta Cryst. B28, 2065–2069], Z′ of the title compound is 2. In the new modification of the title compound, there are eight molecules of (NH42(HPO4 in the unit cell. The structure consists of PO3OH and NH4 tetrahedra, held together by O—H...O and N—H...O hydrogen bonds.

  12. H2SO4-HNO3-H2O ternary system in the stratosphere

    Science.gov (United States)

    Kiang, C. S.; Hamill, P.

    1974-01-01

    Estimation of the equilibrium vapor pressure over the ternary system H2SO4-HNO3-H2O to study the possibility of stratospheric aerosol formation involving HNO3. It is shown that the vapor pressures for the ternary system H2SO4-HNO3-H2O with weight composition around 70-80% H2SO4, 10-20% HNO3, 10-20% H2O at -50 C are below the order of 10 to the minus 8th mm Hg. It is concluded that there exists more than sufficient nitric acid and water vapor in the stratosphere to participate in ternary system aerosol formation at -50 C. Therefore, HNO3 should be present in stratospheric aerosols, provided that H2SO4 is also present.

  13. Singlet ground state in the spin-1/2 weakly coupled dimer compound NH4[ (V2O3)2(4,4'-b p y ) 2(H2PO4)(PO4)2] .0.5 H2O

    Science.gov (United States)

    Arjun, U.; Kumar, Vinod; Anjana, P. K.; Thirumurugan, A.; Sichelschmidt, J.; Mahajan, A. V.; Nath, R.

    2017-05-01

    We present the synthesis and a detailed investigation of structural and magnetic properties of polycrystalline NH4[(V2O3)2(4,4'-b p y ) 2(H2PO4) (PO4)2] .0.5 H2O by means of x-ray diffraction, magnetic susceptibility, electron spin resonance, and 31P nuclear magnetic resonance measurements. Temperature-dependent magnetic susceptibility could be described well using a weakly coupled spin-1/2 dimer model with an excitation gap Δ /kB≃26.1 K between the singlet ground state and triplet excited states and a weak interdimer exchange coupling J'/kB≃4.6 K. A gapped chain model also describes the data well with a gap of about 20 K. The electron spin resonance intensity as a function of temperature traces the bulk susceptibility nicely. The isotropic Landé g factor is estimated to be about g ≃1.97 , at room temperature. We are able to resolve the 31P NMR signal as coming from two inequivalent P sites in the crystal structure. The hyperfine coupling constant between 31P nucleus and V4 + spins is calculated to be Ahf(1 ) ≃2963 Oe/μB and Ahf(2 ) ≃1466 Oe/μB for the P(1) and P(2) sites, respectively. Our NMR shift and spin-lattice relaxation rate for both the 31P sites show an activated behavior at low temperatures, further confirming the singlet ground state. The estimated value of the spin gap from the NMR data measured in an applied field of H =9.394 T is consistent with the gap obtained from the magnetic susceptibility analysis using the dimer model. Because of a relatively small spin gap, NH4[(V2O3)2(4,4'-b p y ) 2(H2PO4) (PO4)2] .0.5 H2O is a promising compound for further experimental studies under high magnetic fields.

  14. The mitigating effect of calcification-dependent of utilization of inorganic carbon of Chara vulgaris Linn on NH4-N toxicity.

    Science.gov (United States)

    Wang, Heyun; Ni, Leyi; Xie, Ping

    2013-09-01

    Increased ammonium (NH4-N) concentrations in water bodies have been reported to adversely affect the dominant species of submersed vegetation in meso-eutrophic waters worldwide. However calcareous plants were lowly sensitive to NH4-N toxicity. In order to make clear the function of calcification in the tolerance of calcareous plants to NH4-N stress, we studied the effects of increased HCO3(-) and additional NH4-N on calcification and utilization of dissolve inorganic carbon (DIC) in Chara vulgaris Linn in a 7-d sub-acute experiment (light:dark 12:12h) carried out in an open experimental system in lab. Results revealed that calcification was dependent of utilization of dissolve inorganic carbon. Additional HCO3(-) significantly decreased the increase of pH while additional NH4-N did not. And additional HCO3(-) significantly improved calcification while NH4-N did in versus in relation to the variation of DIC concentration. However, addition of both HCO3(-) and NH4-N increased utilization of DIC. This resulted in calcification to utilization of DIC ratio decreased under additional NH4-N condition while increased under additional HCO3(-) conditions in response to the variation of solution pH. In the present study, external HCO3(-) decreased the increase of solution pH by increasing calcification, which correspondingly mitigated the toxic effect of high NH4-N. And we argue that the mitigating effect of increased HCO3(-) on NH4-N toxicity is dependent of plant calcification, and it is a positive feedback mechanism, potentially leading to the dominance of calcareous plants in meso-eutrophic water bodies. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Sensitivity of the mayfly Adenophlebia auriculata (Ephemeroptera: Leptophlebiidae) to MgSO4 and Na2SO4

    Science.gov (United States)

    Vellemu, E. C.; Mensah, P. K.; Griffin, N. J.; Odume, O. N.

    2017-08-01

    Acid mine drainage (AMD) continues to deteriorate water quality in freshwater ecosystems. Sulphates, a major salt component in AMD, can exacerbate AMD effects in freshwater because salts are toxic to aquatic life in high concentrations. Sulphates are predominant in South African AMD impacted freshwater ecosystems. In this study, the sensitivity of nymphs of the mayfly Adenophlebia auriculata (Ephemeroptera: Leptophlebiidae) was investigated by exposing the organisms to magnesium sulphate (MgSO4) and sodium sulphate (Na2SO4) as models of mining salinisation in short-term (96 h) and long-term (240 h) in static system tests. Short-term and long-term lethal concentrations of each salt were estimated using regression analyses. The results indicated that A. auriculata was more sensitive to MgSO4 (LC50 = 3.81 g/L) than Na2SO4 (LC50 = 8.78 g/L) after short-term exposures. However, this species became sensitive to Na2SO4 (LC10 = 0.19 g/L) but tolerant to MgSO4 (LC10 = 0.35 g/L) after long-term exposures. These results suggest that the 0.25 g/L sulphate compliance limit for South Africa is inadequate to protect A. auriculata from Na2SO4 toxicity in the long-term, yet it overprotects this species from MgSO4 exposures in the short-term. The findings of this study are an important major step in understanding the ecological effects of AMD to aquatic life.

  16. NH4SH and cloud cover in the atmospheres of the giant planets

    Science.gov (United States)

    Ibragimov, K. Iu.; Solodovnik, A. A.

    1991-02-01

    The probability of the formation of NH4SH and (NH4)2S is examined on the basis of the Le Chatelier principle. It is shown that it is very doubtful if NH4SH can be created in the atmospheres of the giant planets in quantities sufficient for cloud formation. Thus (NH4)2S is considered as a more likely candidate for cloud formation in the atmospheres of these planets, inasmuch as the conditions for its production there are more favorable.

  17. Glycine formation in CO2:CH4:NH3 ices induced by 0-70 eV electrons

    Science.gov (United States)

    Esmaili, Sasan; Bass, Andrew D.; Cloutier, Pierre; Sanche, Léon; Huels, Michael A.

    2018-04-01

    Glycine (Gly), the simplest amino-acid building-block of proteins, has been identified on icy dust grains in the interstellar medium, icy comets, and ice covered meteorites. These astrophysical ices contain simple molecules (e.g., CO2, H2O, CH4, HCN, and NH3) and are exposed to complex radiation fields, e.g., UV, γ, or X-rays, stellar/solar wind particles, or cosmic rays. While much current effort is focused on understanding the radiochemistry induced in these ices by high energy radiation, the effects of the abundant secondary low energy electrons (LEEs) it produces have been mostly assumed rather than studied. Here we present the results for the exposure of multilayer CO2:CH4:NH3 ice mixtures to 0-70 eV electrons under simulated astrophysical conditions. Mass selected temperature programmed desorption (TPD) of our electron irradiated films reveals multiple products, most notably intact glycine, which is supported by control measurements of both irradiated or un-irradiated binary mixture films, and un-irradiated CO2:CH4:NH3 ices spiked with Gly. The threshold of Gly formation by LEEs is near 9 eV, while the TPD analysis of Gly film growth allows us to determine the "quantum" yield for 70 eV electrons to be about 0.004 Gly per incident electron. Our results show that simple amino acids can be formed directly from simple molecular ingredients, none of which possess preformed C—C or C—N bonds, by the copious secondary LEEs that are generated by ionizing radiation in astrophysical ices.

  18. Thermodynamic properties of tooeleite, Fe63+(As3+O3)4(SO4)(OH)4·4H2O

    DEFF Research Database (Denmark)

    Majzlan, Juraj; Dachs, Edgar; Benisek, Artur

    2016-01-01

    -As-S-O-H. In this contribution, we report the thermodynamic properties of synthetic tooeleite. The sample was characterized by powder X-ray diffraction, scanning electron microscopy, extended X-ray absorption fine-structure spectroscopy, and Mössbauer spectroscopy. These methods confirmed that the sample is pure, devoid...... capacity data measured by relaxation calorimetry, is 899.0 ± 10.8 J mol−1 K−1. The calculated standard Gibbs free energy of formation is −5396.3 ± 9.3 kJ mol−1. The log Ksp value, calculated for the reaction Fe6(AsO3)4(SO4)(OH)4·4H2O + 16H+ = 6Fe3+ + 4H3AsO3 + SO42− + 8H2O, is −17.25 ± 1.80. Tooeleite has...

  19. A cluster DFT study of NH{sub 3} and NO adsorption on the (MoO{sub 2}){sup 2+}/HZSM-5 surface: Lewis versus Brønsted acid sites

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Zhifeng [College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024, Shanxi (China); College of Material Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, Shanxi (China); Zuo, Zhijun [Key Laboratory of Coal Science and Technology of Ministry of Education and Shanxi Province, Taiyuan University of Technology, Taiyuan 030024, Shanxi (China); Li, Zhe, E-mail: lizhe@tyut.edu.cn [College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024, Shanxi (China); Zhang, Jinshan [College of Material Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, Shanxi (China)

    2014-12-01

    Graphical abstract: - Highlights: • NH{sub 3} adsorption is found to be more favorable energetically than NO adsorption on both Lewis and Brønsted acid sites. • Lewis and Brønsted acid sites are competitive energetically for NH{sub 3} adsorption. • Reduced-state Mo{sup 5+} is suggested to play a key role in adsorption and activation of NO{sub x} together with the adsorbed NH{sub 4}{sup +}. - Abstract: A systematic DFT study was carried out to investigate NH{sub 3} and NO adsorption on both Lewis and Brønsted acid sites of (MoO{sub 2}){sup 2+}/HZSM-5 catalyst by using cluster models. The adsorption energy results indicate that NH{sub 3} could strongly adsorb on both Lewis and Brønsted acid sites in the form of coordinated NH{sub 3} and NH{sub 4}{sup +}, respectively, whereas NO represents poorer adsorption ability. It is also found that Lewis and Brønsted acid sites are competitive energetically for NH{sub 3} adsorption. According to the difference in the proposed mechanisms for NH{sub 3} adsorption on different acid sites, particular attention has been focused on the first dissociation of coordinated NH{sub 3} for Lewis acid site and the effect of Mo site on the introduction of NO for Brønsted acid site. For the coordinated NH{sub 3} on Lewis acid site, the more electron donation from NH{sub 3} is, the greater its adsorption stability is and the higher active its H atoms are. In addition, DOS results show that stability of the H atoms is enhanced by interacting with framework oxygen and especially the H atoms chemical-bonded with framework oxygen. For the NH{sub 4}{sup +} on Brønsted acid site, reduced-state Mo{sup 5+} holds stronger reducibility and oxidizability than terminal oxygen, which is suggested to play a key role in adsorption and activation of NO{sub x} together with the adsorbed NH{sub 4}{sup +}.

  20. Low Temperature Growth of In2O3and InN Nanocrystals on Si(111 via Chemical Vapour Deposition Based on the Sublimation of NH4Cl in In

    Directory of Open Access Journals (Sweden)

    Tsokkou Demetra

    2009-01-01

    Full Text Available Abstract Indium oxide (In2O3 nanocrystals (NCs have been obtained via atmospheric pressure, chemical vapour deposition (APCVD on Si(111 via the direct oxidation of In with Ar:10% O2at 1000 °C but also at temperatures as low as 500 °C by the sublimation of ammonium chloride (NH4Cl which is incorporated into the In under a gas flow of nitrogen (N2. Similarly InN NCs have also been obtained using sublimation of NH4Cl in a gas flow of NH3. During oxidation of In under a flow of O2the transfer of In into the gas stream is inhibited by the formation of In2O3around the In powder which breaks up only at high temperatures, i.e.T > 900 °C, thereby releasing In into the gas stream which can then react with O2leading to a high yield formation of isolated 500 nm In2O3octahedrons but also chains of these nanostructures. No such NCs were obtained by direct oxidation forT G < 900 °C. The incorporation of NH4Cl in the In leads to the sublimation of NH4Cl into NH3and HCl at around 338 °C which in turn produces an efficient dispersion and transfer of the whole In into the gas stream of N2where it reacts with HCl forming primarily InCl. The latter adsorbs onto the Si(111 where it reacts with H2O and O2leading to the formation of In2O3nanopyramids on Si(111. The rest of the InCl is carried downstream, where it solidifies at lower temperatures, and rapidly breaks down into metallic In upon exposure to H2O in the air. Upon carrying out the reaction of In with NH4Cl at 600 °C under NH3as opposed to N2, we obtain InN nanoparticles on Si(111 with an average diameter of 300 nm.

  1. Facile one-pot synthesis of Ni2+-doped (NH4)2V3O8 nanoflakes@Ni foam with visible-light-driven photovoltaic behavior for supercapacitor application

    Science.gov (United States)

    Zhou, Qingfeng; Gong, Yun; Lin, Jianhua

    2018-05-01

    In the present work, Ni2+-doped (NH4)2V3O8 nanoflakes are in situ grown on Ni foam through a facile one-pot hydrothermal technique in a NH4VO3 aqueous solution. The Ni2+-doped (NH4)2V3O8@Ni foam composite material can be used as binder- and conductivity agent-free electrode in supercapacitor, it manifests a large specific capacitance of 465.5 F g-1 at a current density of 0.2 A g-1 and a superior rate capability of 317.5 F g-1 at 10 A g-1, which is beneficial from its three-dimensional porous architecture cross-linked by the ultrathin Ni2+-doped (NH4)2V3O8 nanoflakes on Ni foam. Meanwhile, the Ni2+-doped (NH4)2V3O8@Ni foam//Activated carbon asymmetric supercapacitor can deliver a maximum energy density of 20.1 W h kg-1 at a power density of 752.0 W kg-1. Significantly, the Ni2+-doped (NH4)2V3O8@Ni foam electrode possesses reversible electrochromic behavior, and it shows obvious visible light-driven photoresponse with much higher specific capacitance (645.3 F g-1 at 0.5 A g-1) under illumination (650 nm > λ > 350 nm, 100 mW cm-2), which is probably associated with the semiconducting characteristics of the spin-polarized (NH4)2V3O8 and the quantum confinement effect of the nanoflakes.

  2. Hydrogen-bonded Three-Dimensional Networks Encapsulating One-dimensional Covalent Chains: [Cu(3-ampy)(H2O)4](SO4)·(H2O) (3-ampy = 3-Aminopyridine)

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A three-dimensional complex [Cu(3-ampy)(H2O)4](SO4)·(H2O) (3-ampy = 3-aminopyridine) has been synthesized. Crystallographic data: C5H16CuN2O9S, Mr = 343.80, triclinic, space group P, a = 7.675(2), b = 8.225(3), c = 10.845(3) (A), α= 86.996(4), β = 76.292(4),γ = 68.890(4)°, V = 620.0(3) (A)3, Z = 2, Dc = 1.841 g/cm3, F(000) = 354 and μ = 1.971 mm-1. The structure was refined to R = 0.0269 and wR = 0.0659 for 1838 observed reflections (I > 2σ(Ⅰ)). The structure consists of [Cu(3-ampy)(H2O)4]2+ cations, SO42- anions and lattice water molecules. 3-Ampy acting as a bidentate bridging ligand generates a 1D covalent chain. A supramolecular 2D framework is formed through π-π stacking of pyridine rings. The lattice water molecules and SO42- anions are located between the adjacent 2D frameworks. The hydrogen bonding interactions from lattice water molecules and SO42- anions to coordinate water extend the 2D framework into a 3D network.

  3. NH4+ protects tomato plants against Pseudomonas syringae by activation of systemic acquired acclimation.

    Science.gov (United States)

    Fernández-Crespo, Emma; Scalschi, Loredana; Llorens, Eugenio; García-Agustín, Pilar; Camañes, Gemma

    2015-11-01

    NH4 (+) nutrition provokes mild toxicity by enhancing H2O2 accumulation, which acts as a signal activating systemic acquired acclimation (SAA). Until now, induced resistance mechanisms in response to an abiotic stimulus and related to SAA were only reported for exposure to a subsequent abiotic stress. Herein, the first evidence is provided that this acclimation to an abiotic stimulus induces resistance to later pathogen infection, since NH4 (+) nutrition (N-NH4 (+))-induced resistance (NH4 (+)-IR) against Pseudomonas syringae pv tomato DC3000 (Pst) in tomato plants was demonstrated. N-NH4 (+) plants displayed basal H2O2, abscisic acid (ABA), and putrescine (Put) accumulation. H2O2 accumulation acted as a signal to induce ABA-dependent signalling pathways required to prevent NH4 (+) toxicity. This acclimatory event provoked an increase in resistance against later pathogen infection. N-NH4 (+) plants displayed basal stomatal closure produced by H2O2 derived from enhanced CuAO and rboh1 activity that may reduce the entry of bacteria into the mesophyll, diminishing the disease symptoms as well as strongly inducing the oxidative burst upon Pst infection, favouring NH4 (+)-IR. Experiments with inhibitors of Put accumulation and the ABA-deficient mutant flacca demonstrated that Put and ABA downstream signalling pathways are required to complete NH4 (+)-IR. The metabolic profile revealed that infected N-NH4 (+) plants showed greater ferulic acid accumulation compared with control plants. Although classical salicylic acid (SA)-dependent responses against biotrophic pathogens were not found, the important role of Put in the resistance of tomato against Pst was demonstrated. Moreover, this work revealed the cross-talk between abiotic stress acclimation (NH4 (+) nutrition) and resistance to subsequent Pst infection. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  4. Controllable synthesis of Co{sub 3}O{sub 4}/polyethyleneimine-carbon nanotubes nanocomposites for CO and NH{sub 3} gas sensing at room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yufei [Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080 (China); Kan, Kan [Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080 (China); Institute of Advanced Technology, Heilongjiang Academy of Sciences, Harbin 150000 (China); Song, Wanzhen; Zhang, Guo; Dang, Lifang [Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080 (China); Xie, Yu [Department of Materials Chemistry, Nanchang Hangkong University, Nanchang 330063 (China); Shen, Peikang [Department of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Li, Li, E-mail: llwjjhlju@sina.cn [Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080 (China); Key Laboratory of Chemical Engineering Process & Technology for High-efficiency Conversion, School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080 (China); Shi, Keying, E-mail: shikeying2008@163.com [Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080 (China)

    2015-08-05

    Graphical abstract: Co{sub 3}O{sub 4}/polyethyleneimine-carbon nanotubes composites (CoPCNTs) have been successfully controllable synthesized via hydrothermal method at different temperature. The CoPCNTs sensors exhibited the highest response to CO and NH{sub 3} gases with response time of 4 s and 4.3 s, low detection limit of 5 ppm and 1 ppm at room temperature, respectively. The enhanced gas sensing could be ascribed to the synergistic effect between the tiny size of Co{sub 3}O{sub 4} and good conductivity of carbon nanotubes functionalized by polyethyleneimine. - Highlights: • The CNTs functionalized by polyethyleneimine provided a new functional structural. • The novel 1D structure could capture and migrate electrons quickly. • The Co{sub 3}O{sub 4} nanoparticles liked a snake winding around CNTs. • The gas sensor could work at room temperatures, which suit to practical application. - Abstract: A novel 1D Co{sub 3}O{sub 4}/polyethyleneimine-carbon nanotubes composites (CoPCNTs) have been successfully synthesized via hydrothermal method at different temperature. The CNTs functionalized by polyethyleneimine (PCNTs) provided a new material with new structural and functional properties. The PCNTs was used as loading guider and electron transfer path. The Co{sub 3}O{sub 4} nanoparticles (NPs) loaded on the PCNTs surface liked a snake winding around CNTs, and the size was about 5–10 nm. The gas sensing characteristics of the CoPCNTs sensors to carbon monoxide (CO) and ammonia (NH{sub 3}) were evaluated with different gas concentration. The CoPCNTs sensors grown at 160 °C exhibited the highest response to CO and NH{sub 3} gases with response time of 4 s and 4.3 s at room temperature (RT), respectively. Hence, the approach developed in this work would be important for the low-cost and large-scale production of the CoPCNTs materials with highly promising applications in gas sensors.

  5. NMR Spectroscopic Characterization of Methylcobalt(III) Compounds with Classical Ligands. Crystal Structures of [Co(NH(3))(5)(CH(3))]S(2)O(6), trans-[Co(en)(2)(NH(3))(CH(3))]S(2)O(6) (en = 1,2-Ethanediamine), and [Co(NH(3))(6)]-mer,trans-[Co(NO(2))(3)(NH(

    DEFF Research Database (Denmark)

    Kofod, Pauli; Harris, Pernille; Larsen, Sine

    1997-01-01

    magnetic resonance spectroscopy and by absorption spectroscopy. Single-crystal X-ray structure determinations at 122.0(5) K were performed on [Co(NH(3))(5)(CH(3))]S(2)O(6) (1), trans-[Co(en)(2)(NH(3))(CH(3))]S(2)O(6) (2), and [Co(NH(3))(6)]-mer,trans-[Co(NO(2))(3)(NH(3))(2)(CH(3))](2)-trans-[Co(NO(2...

  6. An experimental and kinetic modeling study of premixed NH3/CH4/O-2/Ar flames at low pressure

    DEFF Research Database (Denmark)

    Tian, Z.Y.; Li, Y. Y.; Zhang, L. D.

    2009-01-01

    An experimental and modeling study of 11 premixed NH3/CH4/O-2/Ar flames at low pressure (4.0 kPa) with the same equivalence ratio of 1.0 is reported. Combustion intermediates and products are identified using tunable synchrotron vacuum Ultraviolet (VUV) photoionization and molecular-beam mass...

  7. Ferroelectric phase transition in hydrogen-bonded 2-aminopyridine phosphate (NC sub 4 H sub 4 NH sub 2)centre dot H sub 3 PO sub 4

    CERN Document Server

    Czapla, Z; Waskowska, A

    2003-01-01

    A new crystal of 2-aminopyridine phosphate (NC sub 4 H sub 4 NH sub 2)centre dot H sub 3 PO sub 4 has been grown and its x-ray structure and physical properties were studied. At room temperature the crystals are monoclinic, space group C2/c. The flat 2-aminopyridine cations are hydrogen bonded to the anionic [PO sub 4 ] groups. The interesting feature of the crystal structure is the three-dimensional network of hydrogen bonds including, among others, two strong, symmetrical O centre dot centre dot centre dot H, H centre dot centre dot centre dot O interactions with disordered proton locations. Symmetrically related PO sub 4 anions linked through these protons form infinite (PO sub 4) subinfinity chains along the crystal a-axis. The anomalies in the temperature dependence of the electric permittivity showed that the crystal undergoes ferroelectric phase transition at T sub c = 103.5 K. The spontaneous polarization takes place along the crystal a-axis, being parallel to the chains of the hydrogen-bonded PO sub ...

  8. The effect of CO2, H2O and SO2 on the kinetics of NO reduction by CH4 over La2O3

    International Nuclear Information System (INIS)

    Toops, Todd J.; Walters, Arden B.; Vannice, M.A.

    2002-01-01

    The effect of CO 2 , H 2 O and SO 2 on the kinetics of NO reduction by CH 4 over unsupported La 2 O 3 has been examined between 773 and 973K in the presence of O 2 in the feed. La 2 O 3 can maintain a stable, high specific activity (mol/(sm 2 )) for NO reduction with high concentrations of CO 2 and H 2 O in the feed; however, either of these two products reversibly inhibits the activity by about one-half in the presence of excess O 2 . The catalyst is poisoned by SO 2 at these temperatures and an oxysulfate phase is formed, but partial regeneration can be achieved at 1023K. CO 2 in the feed causes the formation of lanthanum oxycarbonate, which reverts to La 2 O 3 when CO 2 is removed, but no bulk La oxyhydroxide is detected after quenching with H 2 O in the feed. The influence of CO 2 and H 2 O on kinetic behavior can be described by assuming they compete with reactants for adsorption on surface sites, including them in the site balance equation, and using the rate expression proposed previously for NO reduction by CH 4 in excess O 2 . With O 2 in the feed, integral conversions of CH 4 and O 2 frequently occurred due to the direct combustion of CH 4 by O 2 , although NO conversions remained differential; thus, an integral reactor model was chosen to analyze the data which utilized a recently determined rate equation for CH 4 combustion on La 2 O 3 in conjunction with a previously proposed model for NO reduction by CH 4 . The following rate expression described the rate of N 2 formation: N 2 T = ' NO P NO P CH 4 P O 2 0.5 / 1 + K NO P NO + K CH 4 P CH 4 + K O 2 0.5 P O 2 0.5 + K CO 2 P CO 2 + K H 2 O P H 2 O 2 . It gave a good fit to the experimental rate data for NO reduction, as well as providing enthalpies and entropies of adsorption obtained from the fitting parameters that demonstrated thermodynamic consistency and were similar to previous values. The heats of adsorption were altered somewhat when either CO 2 or H 2 O was added to the feed, and the following

  9. Infrared and Raman spectroscopic studies of interlayer CO32-, NO3-, SO42- and ClO4-in layered double hydroxides (LDHs)

    International Nuclear Information System (INIS)

    Kloprogge, J.T.; Wharton, D.; Frost, R.L.

    1998-01-01

    Full text: Hydrotalcites (HTs) are also described as layered double hydroxides or anionic clays, due to their layered structure with a charge opposite to that of cationic clays. The number of counterbalancing anions or anionic complexes is essentially unlimited provided that the anion does not form a complex with the cations in the octahedral sheets during the formation. The majority of especially the synthetic but also naturally occurring HTs contain CO 3 2- as the interlayer anion. Other regularly used anions include NO 3 - , OH - , SO 4 2- and Cl - in addition to ClO 4 - and CrO 4 2- . When CO 3 2- is present as a free ion it will exhibit a space group of D 3h . As a result the bending non-planar mode ν 2 (A'2), the antisymmetrical stretching mode ν 3 (E') and the bending angular mode ν 4 (E'), will be observed in the IR spectrum at 880, 1415 and 680 cm -1 , while the symmetric stretching mode ν 1 (A'1) is IR inactive. In the Raman spectrum one will observe ν 1 (A'1), ν 3 (E') and ν 4 (E') (Nakamoto, 1997; Farmer, 1974). In comparison to free CO 3 2- a shift towards lower wavenumbers is generally observed. A band around 3000-3100 cm -1 has been attributed to the bridging mode H 2 O-CO 3 2- . The shift towards lower wavenumbers indicates a lowering of the symmetry from D 3h , to probably C 2s or C ν . As a result the IR inactive ν 1 mode will be activated. Indeed, a weak band has been observed around 1050-1060 cm -1 . In addition, the ν 3 mode shows a small splitting in the order of 30-60 cm -1 . In accordance to the findings of Moroz and Arkhipenko (1991), Kloprogge and Frost (1999) and Hickey et al. (2000) observed weak Raman ν 3 and νv 4 modes at 1053 and 1403 cm -1 . Like in the IR spectra, both ν 3 and νv 4 show a minor shift of 10 to 15 cm -1 . Like free CO 3 2- free nitrate NO 3 - will exhibit a spacegroup of D 3h with A 1 ' Raman actively only, A 2 '' IR active only and 2E' Raman and IR active. This means that the out-of-plane symmetric

  10. Effective control of modified palygorskite to NH4+-N release from sediment.

    Science.gov (United States)

    Chen, Lei; Zheng, Tianyuan; Zhang, Junjie; Liu, Jie; Zheng, Xilai

    2014-01-01

    Sediment capping is an in situ treatment technology that can effectively restrain nutrient and pollutant release from the sediment in lakes and reservoirs. Research on sediment capping has focused on the search for effective, non-polluting and affordable capping materials. The efficiency and mechanism of sediment capping with modified palygorskite in preventing sediment ammonia nitrogen (NH4+-N) release to surface water were investigated through a series of batch and sediment capping experiments. Purified palygorskite and different types of modified palygorskite (i.e. heated, acid-modified and NaCI-modified palygorskite) were used in this investigation. Factors affecting control efficiency, including the temperature, thickness and grain size of the capping layer, were also analysed. The batch tests showed that the adsorption of NH4+-N on modified palygorskite achieved an equilibration in the initial 45 min, and the adsorption isotherm followed the Freundlich equation. Sediment capping experiments showed that compared with non-capped condition, covering the sediment with modified palygorskite and sand both inhibited NH4+-N release to the overlying water. Given its excellent chemical stability and strong adsorption, heated palygorskite, which has a NH4+-N release inhibition ratio of 41.3%, is a more effective sediment capping material compared with sand. The controlling effectiveness of the modified palygorskite increases with thicker capping layer, lower temperature and smaller grain size of the capping material.

  11. Preparation and characterization of a layered perovskite-type organic-inorganic hybrid compound (C8NH6-CH2CH2NH3)2CuCl4

    International Nuclear Information System (INIS)

    Zheng Yingying; Wu Gang; Deng Meng; Chen Hongzheng; Wang Mang; Tang, B.-Z.

    2006-01-01

    The organic-inorganic hybrid compound (C 8 NH 6 -CH 2 CH 2 NH 3 ) 2 CuCl 4 (AEI-CuCl 4 ) was synthesized from ethanol solution containing copper chloride and 3-2-(aminoethyl) indole hydrochloride (AEI-HCl). High order diffraction peaks corresponding to (0 0 l; l = 2, 4, 6, ...) observed in the X-ray diffraction profile of AEI-CuCl 4 indicated the formation of hybrid crystal with layered perovskite structure. The organic-inorganic hybrid crystal thin film can be easily prepared by spin-coating method from the ethanol solution of the AEI-CuCl 4 perovskite and it showed characteristic absorptions of CuCl-based layered perovskite centered at 288 and 388 nm, as well as the photoluminescence peak at around 420 nm. The unaided-eye-detectable blue fluorescence emission comes from the cooperation of AEI-HCl and AEI-CuCl 4 perovskite, in which protonized aminoethyl indole dominates the shape of the spectrum and the enhancement of emission intensity is due to the formation of the perovskite structure. The thermal analysis presented that the AEI-CuCl 4 perovskite started to melt at 182 deg. C, together with the beginning of the decomposition of the hybrids. Compared with the organic-inorganic perovskite hybrids reported previously, the AEI-CuCl 4 perovskite shows a novel stepwise decomposition behavior

  12. Nitrogen and carbon pools in an agricultural soil amended with natural and NH4-enriched K-Chabazite zeolitite

    Science.gov (United States)

    Ferretti, Giacomo; Faccini, Barbara; Vittori Antisari, Livia; Di Giuseppe, Dario; Massimo, Coltorti

    2015-04-01

    -enriched zeolitite, the lowest C/N ratio is detected and the mineralization of organic C was enhanced as evidenced by the decrease of Humic Acids (HA) and the increase of Fulvic Acids (FA) contents; a total organic C depletion was also observed. iv) In the first month, after the enriched-zeolitite spreading, a reduction in the exchangeable NH4 was noticed. At the same time no significant NO3 loss was observed in the porewaters and drainage waters, suggesting that the microbial biomass played a crucial role in the immobilization of the NH4 contained in the zeolitite. v) A significant increase of Cation Exchangeable Capacity and OC content in the soil treated with zeolitite at the end of the agronomic year was also evidenced. In summary, this study emphasizes that notwithstanding the fertilization reduction the crop yield can be maintained adding natural and NH4-enriched K-Chabazite zeolitite in an agricultural field. This addition contributes also to improve the soil properties and the porewater and superficial water qualities.

  13. A Raman spectroscopic determination of the kinetics of decomposition of ammonium chromate (NH 4) 2CrO 4

    Science.gov (United States)

    De Waal, D.; Heyns, A. M.; Range, K.-J.

    1989-06-01

    Raman spectroscopy was used as a method in the kinetic investigation of the thermal decomposition of solid (NH 4) 2CrO 4. Time-dependent measurements of the intensity of the totally symmetric stretching CrO mode of (NH 4) 2CrO 4 have been made between 343 and 363 K. A short initial acceleratory period is observed at lower temperatures and the decomposition reaction decelerates after the maximum decomposition rate has been reached at all temperatures. These results can be interpreted in terms of the Avrami-Erofe'ev law 1 - (χ r) {1}/{2} = kt , where χr is the fraction of reactant at time t. At 358 K, k is equal to 1.76 ± 0.01 × 10 -3 sec -1 for microcrystals and for powdered samples. Activation energies of 97 ± 10 and 49 ± 0.9 kJ mole -1 have been calculated for microcrystalline and powdered samples, respectively.

  14. Solvent-Dependent Delamination, Restacking, and Ferroelectric Behavior in a New Charge-Separated Layered Compound: [NH4 ][Ag3 (C9 H5 NO4 S)2 (C13 H14 N2 )2 ]⋅8 H2 O.

    Science.gov (United States)

    Sushrutha, Sringeri Ramesh; Mohana, Shivanna; Pal, Somnath; Natarajan, Srinivasan

    2017-01-03

    A new anionic coordination polymer, [NH 4 ][Ag 3 (C 9 H 5 NO 4 S) 2 (C 13 H 14 N 2 ) 2 ]⋅8 H 2 O, with a two-dimensional structure, has been synthesized by a reaction between silver nitrate, 8-hydroxyquinoline-5-sulfonic acid (HQS), and 4,4'-trimethylene dipyridine (TMDP). The compound stabilizes in a noncentrosymmetric space group, and the lattice water molecules and the charge-compensating [NH 4 ] + group occupy the inter-lamellar spaces. The lattice water molecules can be fully removed and reinserted, which is accompanied by a crystalline-amorphous-crystalline transformation. This transformation resembles the collapse/delamination and restacking of the layers. To the best of our knowledge, this is the first observation of delamination and restacking in an inorganic coordination polymer that contains silver. The presence of a natural dipole (the anionic framework and cationic ammonium ions) along with the noncentrosymmetric space group gives rise to the room-temperature ferroelectric behavior of the compound. The ferroelectric behavior is also water-dependent and exhibits a ferroelectric-paraelectric transformation. The temperature-dependent dielectric measurements indicate that the ferroelectric/ paraelectric transformation occurs at 320 K. This transformation has also been investigated by using in-situ IR spectroscopy and PXRD studies. The second-harmonic generation (SHG) study indicated values that are comparable to some of the known SHG solids, such as potassium dihydrogen phosphate (KDP) and urea. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Toxicity and carcinogenicity of acidogenic or alkalogenic diets in rats; effects of feeding NH4Cl, KHCO3 or KCl

    NARCIS (Netherlands)

    Lina, B.A.R.; Kuijpers, M.H.M.

    2004-01-01

    The effects of diet-induced acid-base disturbances were examined in 4-week, 13-week and 18-month toxicity studies, and in a 30-month carcinogenicity study. Rats were fed a natural ingredient diet (controls), supplemented with 2% or 4% KHCO3 (base-forming diets), or with 1% or 2.1% NH4Cl

  16. Mechanochemical transformations in Li(Na)AlH{sub 4}-Li(Na)NH{sub 2} systems

    Energy Technology Data Exchange (ETDEWEB)

    Dolotko, Oleksandr [Ames Laboratory of the U.S. DOE, Iowa State University, Ames, IA 50011-3020 (United States); Zhang Haiqiao [Ames Laboratory of the U.S. DOE, Iowa State University, Ames, IA 50011-3020 (United States); Department of Materials Science and Engineering, Iowa State University, Ames, IA 50011-2300 (United States); Ugurlu, Ozan [Ames Laboratory of the U.S. DOE, Iowa State University, Ames, IA 50011-3020 (United States); Department of Materials Science and Engineering, Iowa State University, Ames, IA 50011-2300 (United States); Wiench, Jerzy W. [Ames Laboratory of the U.S. DOE, Iowa State University, Ames, IA 50011-3020 (United States); Pruski, Marek [Ames Laboratory of the U.S. DOE, Iowa State University, Ames, IA 50011-3020 (United States); Scott Chumbley, L. [Ames Laboratory of the U.S. DOE, Iowa State University, Ames, IA 50011-3020 (United States); Department of Materials Science and Engineering, Iowa State University, Ames, IA 50011-2300 (United States); Pecharsky, Vitalij [Ames Laboratory of the U.S. DOE, Iowa State University, Ames, IA 50011-3020 (United States) and Department of Materials Science and Engineering, Iowa State University, Ames, IA 50011-2300 (United States)]. E-mail: vitkp@ameslab.gov

    2007-05-15

    Mechanochemical transformations of tetrahydroaluminates and amides of lithium and sodium have been investigated using gas volumetric analysis, X-ray powder diffraction, solid-state nuclear magnetic resonance (NMR) and transmission electron microscopy. In a transformation of LiAlH{sub 4} and LiNH{sub 2} taken in an 1:1 molar ratio, the amount of released hydrogen (6.6 wt.% after 30 min ball milling) was higher than in any known one pot mechanochemical process involving a hydrogen-containing solid. A total of 4.3 wt.% of hydrogen is released by the NaAlH{sub 4}-NaNH{sub 2} system after 60 min ball milling; and 5.2 wt.% H{sub 2} is released when LiAlH{sub 4} and NaNH{sub 2} or NaAlH{sub 4} and LiNH{sub 2} are ball milled for 90 min and 120 min, respectively. All transformations proceed at room temperature. The mechanism of the overall transformation MAlH{sub 4}(s) + MNH{sub 2}(s) {sup {yields}} 2MH(s) + AlN(s) + 2H{sub 2}(g) was identified based on detailed spectroscopic analysis of the intermediate (M{sub 3}AlH{sub 6}) and final products of the ball milling process.

  17. Electron transport in NH3/NO2 sensed buckled antimonene

    Science.gov (United States)

    Srivastava, Anurag; Khan, Md. Shahzad; Ahuja, Rajeev

    2018-04-01

    The structural and electronic properties of buckled antimonene have been analysed using density functional theory based ab-initio approach. Geometrical parameters in terms of bond length and bond angle are found close to the single ruffle mono-layer of rhombohedral antimony. Inter-frontier orbital analyses suggest localization of lone pair electrons at each atomic centre. Phonon dispersion along with high symmetry point of Brillouin zone does not signify any soft mode. With an electronic band gap of 1.8eV, the quasi-2D nano-surface has been further explored for NH3/NO2 molecules sensing and qualities of interaction between NH3/NO2 gas and antimonene scrutinized in terms of electronic charges transfer. A current-voltage characteristic has also been analysed, using Non Equilibrium Green's function (NEGF), for antimonene, in presence of incoming NH3/NO2 molecules.

  18. Effect of He pressure on the superconducting transition temperatures of Na2CsC60 and (NH3)4Na2CsC60

    International Nuclear Information System (INIS)

    Schirber, J.E.; Bayless, W.R.; Rosseinsky, M.J.; Zhou, O.; Fleming, R.M.; Murphy, D.; Fischer, J.E.

    1994-01-01

    The Na based mixed alkali doped C 60 superconductors show anomalous behavior with respect to the ''universal'' superconducting transition temperature T c vs lattice constant a 0 relation followed by most of the fcc A 3 C 60 superconductors. We have measured dt c /dP for Na 2 CsC 60 and (NH 3 ) 4 Na 2 CsC 60 using solid He as the pressure medium to ∼ 6 kbar finding dT c /dP equal to -0.8±(0.01) K/kbar and -1.0(±0.1)K/kbar for Na 2 CsC 60 and Na 2 (NH 3 ) 4 C 60 respectively. Our value for Na 2 CsC 60 differs markedly from that obtained by Mizuki et al of about -1.3 K/kbar. However, using N 2 or Ar, we obtain values for dT c /dP in substantial agreement with Mizuki et al who used fluorinert to generate their pressure. This work emphasizes the need for compressibility measurements with the same pressure medium in the appropriate temperature range so that meaningful comparisons can be made between various pressure measurements and models which are based on lattic spacing

  19. Regulating NH4+, N0-, and K+ concentration and proportions improves in vitro tissue growth.

    Science.gov (United States)

    A mixture-amount experiment that simultaneously varied both the ratios and total ionic concentration (from 20-100 mM) of NH4+, NO3+, and K+ was used to maximize sweet orange callus growth cv. ‘Hamlin.’ These experiments were free of ion confounding effects, i.e. ions added via pH adjustments and sa...

  20. Preparation, Characterization, and Structure of Two Layered Molybdenum(VI) Phosphates: KMo(H 2O)O 2PO 4 and NH 4Mo(H 2O)O 2PO 4

    Science.gov (United States)

    Millini, Roberto; Carati, Angela

    1995-08-01

    New layered Mo(VI) compounds, KMo(H 2O)O 2PO 4 (I) and NH 4Mo(H 2O)O 2PO 4 (II), were synthesized hydrothermally and their structures were determined from single-crystal X-ray analysis. Compounds (I) and (II) are isostructural and crystallize in the monoclinic P2 1/ n space group with a = 12.353(3), b = 8.623(2), c = 5.841(1) Å, β = 102.78(1)°, V = 606.8(2) Å 3, Z = 4, and R = 0.027 ( Rw = 0.030) for compound (I) and a = 12.435(3), b = 8.761(2), c = 6.015(1), β = 103.45(1)°, V = 637.3(2) Å 3, Z = 4, and R = 0.040 ( Rw = 0.041) for compound (II). The structure consists of layers built up of eight- and four-membered rings resulting from the alternation of corner-sharing [MoO 6] octahedra and [PO 4] tetrahedra. The layers stack along the (1¯01) direction by intercalating K and NH 4 ions.

  1. Simultaneous absorption of SO2 and NO from flue gas with KMnO4/NaOH solutions

    International Nuclear Information System (INIS)

    Chu, H.; Chien, T.W.; Li, S.Y.

    2001-01-01

    The wet scrubbing combined SO x /NO x removal system is an advanced air pollution control device. This study attempts to understand the absorption kinetics in the system. The absorption of diluted SO 2 and simultaneous absorption of diluted SO 2 and NO, as occurs in flue gases, in a stirred tank reactor with KMnO 4 /NaOH solutions were carried out at 50C. The liquid-side and gas-side mass transfer coefficients of the system were determined. The results indicate that the absorption of SO 2 is close to completely gas-film controlled where the NaOH concentration is greater than 0.1 M or the KMnO 4 concentration is greater than 0.05 M. The increasing gas flow rate has a positive effect on the absorption rate of SO 2 . The existence of O 2 has no significant effect on the absorption rate of SO 2 . Adding SO 2 would decrease the absorption rate of NO; however, the addition of NO has no effect on the absorption rate of SO 2

  2. A combined HRND and HREM study of degradation collapse in NH4+/H3O+ β"-alumina

    DEFF Research Database (Denmark)

    Thomas, John O.; Eriksson, Anders; Kjems, Jørgen

    1986-01-01

    High resolution neutron diffraction (HRND) from single crystals, and high resolution electron microscopy (HREM) are combined to study the deammoniation of NH4+/H3O+ β"-alumina on heating above 200°C. HRND shows the emergence of extra reflections which cannot be indexed in terms of the original β...

  3. Adsorption behavior of Co anchored on graphene sheets toward NO, SO2, NH3, CO and HCN molecules

    International Nuclear Information System (INIS)

    Tang, Yanan; Chen, Weiguang; Li, Chenggang; Pan, Lijun; Dai, Xianqi; Ma, Dongwei

    2015-01-01

    Graphical abstract: - Highlights: • In contrast to the pristine graphene, a vacancy defect in graphene strongly stabilizes the Co atom. • The positively charged of Co atom on graphene can regulate the stability of gas molecules. • Different gas molecules can modulate the electronic structure of Co–graphene systems. • The adsorbed NO on Co–graphene can effectively regulate the magnetic properties of systems. - Abstract: Based on the first-principles of density-functional theory (DFT), the effects of gas adsorption on the change in geometric stability, electronic structure and magnetic properties of graphene with anchored Co (Co–graphene) systems were investigated. A single Co adatom interacts much weaker with pristine graphene (Co/pri–graphene) than with the graphene containing a single vacancy (Co/SV–graphene). The Co dopant provides more electrons to the dangling bonds of carbon atom at defective site and exhibits more positive charges, which makes Co/SV–graphene less prone to be adsorbed by gas molecules in comparison to Co/pri–graphene. It is found that the electronic structure and magnetic properties of Co–graphene systems can be modulated by adsorbing gas molecules. Except the NH 3 molecule, the adsorbed NO, SO 2 , CO or HCN as electron acceptors on the Co/pri–graphene can exhibit semiconducting properties. Among the gas molecules, the strong adsorption of NO molecule can effectively regulate the magnetic properties of Co–graphene systems. Moreover, the stable configuration of Co/SV–graphene is more likely to be the gas sensor for detecting NO and SO 2 . The results validate that the reactivity of atomic-scale catalyst is supported on graphene sheets, which is expected to be potentially efficient in the gas sensors and electronic device

  4. [NH4+-N removal stability of zeolite media packed multistage-biofilm system for coke-plant wastewater treatment].

    Science.gov (United States)

    Zhao, Wen-Tao; Huang, Xia; He, Miao; Zhang, Peng-Yi; Zuo, Chen-Yan

    2009-02-15

    The practical ammonia stripping effectiveness of coke-plant wastewater treatment may vary widely, and high NH4+-N shock loading will lead to the fluctuation of residual NH4+-N concentration of biological effluent. A zeolite media packed multistage-biofilm system (ZMBS) was used for coke-plant wastewater treatment for enhancing the NH4+-N treatment ability of the bio-system to shock loading, as well as achieving high COD removal efficiency. Treatment performance during steady-state and shock loading and transformation of organic pollutants in the system were investigated systematically. The experiment results indicated that when the system was operated at NH4+-N loading 0.21 kg/(m3 x d) and COD loading NH4+-N and COD concentrations were (2.2 +/- 1.2) mg/L, (228 +/- 60) mg/L with average removal efficiencies of (99.1 +/- 0.5)% and (86.0 +/- 2.6)%. During the twice NH4+-N shock loadings [0.03 kg/(m3 x d) and 0.06 kg/(m3 x d)], ZMBS showed a strong resisting ability with average removal efficiencies of 99.0% and 92.9% higher than those of a compared system's 96.8% and 89.3%. By monitoring the change of water quality along the length of the ZMBS's cells, two function zones for different pollutant removal were found to exist, named as decarbonization/nitrification (C/N) zone and nitrification (N) zone, and the NH4+-N removal rate in N zone was 2-8 times as that in C/N zone. TOC concentrations of organic matters with relative molecular weight 1 x 10(4), were 227.6, 104.8 and 35.0 mg/L in raw wastewater, and 31.2, 22.9 and 31.5 mg/L in the effluent, respectively. Organic matters with relative molecular weight 1x 10(3) were the main remained substances in the effluent.

  5. Is Electronegativity a Useful Descriptor for the 'Pseudo-Alkali-Metal' NH4?

    International Nuclear Information System (INIS)

    Whiteside, Alexander; Xantheas, Sotiris S.; Gutowski, Maciej S.

    2011-01-01

    Molecular ions in the form of 'pseudo-atoms' are common structural motifs in chemistry, with properties that are transferrable between different compounds. We have determined the electronegativity of the 'pseudo-alkali metal' ammonium (NH4) and evaluated its reliability as a descriptor in comparison to the electronegativities of the alkali metals. The computed properties of its binary complexes with astatine and of selected borohydrides confirm the similarity of NH4 to the alkali metal atoms, although the electronegativity of NH4 is relatively large in comparison to its cationic radius. We paid particular attention to the molecular properties of ammonium (angular anisotropy, geometric relaxation, and reactivity), which can cause deviations from the behaviour expected of a conceptual 'true alkali metal' with this electronegativity. These deviations allow for the discrimination of effects associated with the polyatomic nature of NH4.

  6. Co-adsorption of NH3 and SO2 on quartz(0 0 0 1): Formation of a stabilized complex

    NARCIS (Netherlands)

    Grecea, M.L.; Gleeson, M.A.; van Schaik, W.; Kleyn, A.W.; Bijkerk, F.

    2011-01-01

    We have investigated the co-adsorption of NH3 and SO2 on the quartz(0 0 0 1) surface by TPD and RAIRS. A surface complex is formed as a result of various relative exposures of NH3 and SO2, irrespective of dosage order. However, the relative molecular composition of the complex is dependent on the

  7. Regeneration of porous nickel elements. [an aqueous solution of NH/sub 3/--NH/sub 4/Cl is passed through cell to remove nickel oxides

    Energy Technology Data Exchange (ETDEWEB)

    Winsel, A; Von Doehren, H H

    1972-01-27

    A method for regenerating a fuel cell with Ag-catalyzed O electrodes containing Ni and H electrodes containing Raney Ni where the voltage had dropped from 750 to 630 mV within 3200 hr at 50 mA/cm/sup 2/ is described. An aqueous NH/sub 3/-NH/sub 4/Cl solution was passed through the cell under 1 atm H at 60/sup 0/, whereby 27 g Ni was dissolved as the hydroxide. The voltage of the regenerated cell was 770 mV and remained constant during 500 hr operation. The Ni ions in the regenerating solutions were removed by electrolysis.

  8. Conductivity studies of biopolymer electrolytes based on chitosan incorporated with NH4Br

    International Nuclear Information System (INIS)

    Shukur, M F; Azmi, M S; Zawawi, S M M; Majid, N A; Illias, H A; Kadir, M F Z

    2013-01-01

    A polymer electrolyte system based on chitosan complexed with ammonium bromide (NH 4 Br) salt was prepared by the solution cast technique. 30 wt% NH 4 Br added electrolyte gave a room temperature conductivity of (4.38 ± 1.26) × 10 −7  S cm −1 and increased to (2.15 ± 0.47) × 10 −4  S cm −1 with addition of 40 wt% glycerol. The dependence of the conductivity on temperature proves that both chitosan–NH 4 Br and chitosan–NH 4 Br–glycerol systems are Arrhenian. The activation energy (E a ) value for 70 wt% chitosan–30 wt% NH 4 Br film is 0.31 eV and the E a value for 42 wt% chitosan–18 wt% NH 4 Br–40 wt% glycerol film is 0.20 eV. The carboxamide band at 1640 cm −1 and the amine band at 1549 cm −1 in the spectrum of pure chitosan film shifted to 1617 and 1516 cm −1 , respectively, in the spectrum of 70 wt% chitosan–30 wt% NH 4 Br film, indicating the occurrence of complexation between polymer and salt. The band at 1024 cm −1 in the pure chitosan film spectrum, which corresponds to the C–O stretching vibration, shifted to lower wavenumbers on addition of salt. A new band appears at 997 cm −1 on addition of 40 wt% glycerol. (paper)

  9. Zn(II) coordination polymer of an in situ generated 4-pyridyl (4Py) attached bis(amido)phosphate ligand, [PO2(NH4Py)2]- showing preferential water uptake over aliphatic alcohols.

    Science.gov (United States)

    Gupta, Arvind K; Nagarkar, Sanjog S; Boomishankar, Ramamoorthy

    2013-08-14

    Two polymorphic 2D-coordination polymers of composition [ZnL(HCO2)]∞ were synthesized from an in situ generated ligand [PO2(NH(4)Py)2](-) (L(-)). The ligand L(-) was generated by a facile metal-assisted P-N bond hydrolysis reaction from the corresponding phosphonium salt 1, [P(NH(4)Py)4]Cl, or from the neutral phosphoric triamide 2, [PO(NH(4)Py)3]. The de-solvated sample of the polymer [ZnL(HCO2)]∞ features polar micropores and shows a type I isotherm for CO2 sorption whereas a type II behaviour was observed for N2. The vapour sorption isotherm of the de-solvated sample of [ZnL(HCO2)]∞ shows preferential adsorption of water vapour over aliphatic alcohols.

  10. Na2SO4-based solid electrolytes for SOx sensors

    DEFF Research Database (Denmark)

    Rao, N.; Schoonman, J.; Toft Sørensen, O.

    1992-01-01

    on the phases present and the structure of the specimens. From a point of view of practical application as SOx sensor material, the Na2SO4 + 5 mol% Y2(SO4)3 + Na2WO4 and Na2SO4+ 4 mol% La2(SO4)3 + Na2WO4 materials are better than undoped Na2SO4 because of their higher conductivity, and absence of a phase...

  11. NQR and X-ray crystal structure studies of cadmium halide complexes: [C(NH2)3]CdI3 and [4-ClC6H5NH3]3CdBr5

    International Nuclear Information System (INIS)

    Gesing, Thorsten M.; Lork, Enno; Terao, Hiromitsu; Ishihara, Hideta

    2016-01-01

    The crystal structures of [C(NH 2 ) 3 ]CdI 3 (1) and [4-ClC 6 H 5 NH 3 ] 3 CdBr 5 (2) have been determined at 100 K: monoclinic, Cc, a = 828.75(3) pm, b = 1615.31(5) pm, c = 810.64(3) pm, and β = 106.5820(10) for 1; monoclinic, P2 1 /c, a = 1486.93(5) pm, b = 794.31(3) pm, c = 2290.59(7) pm, and β = 99.6830(10) for 2. The structure of 1 has an infinite chain of anions consisting of [CdI 4 ] tetrahedra sharing two corners. The structure of 2 has an infinite chain of anions consisting of [CdBr 6 ] octahedra sharing two corners in cis positions. In both structures, isolated cations are connected to the anion chains through weak hydrogen bonds Cd-X..H to result in three-dimensional network structures. In accordance with the crystal structures, three 127 I (m = ±1/2 <-> m = ±3/2), five 81 Br, and three 35 Cl nuclear quadrupole resonance (NQR) lines were observed for 1 and 2. The NQR spectra reflect the anion chain structures and their weak hydrogen bonds. The MO calculations of the models [Cd 5 I 16 ] 6- for 1 and [Cd 3 Br 16 ] 10- for 2 estimate only about half the values for the NQR frequencies but give accurate electric field gradient directions.

  12. Observation of pH Value in Electrokinetic Remediation using various electrolyte (MgSO4, KH2PO4 and Na(NO3)) for Barren Acidic Soil at Ayer Hitam, Johor, Malaysia

    Science.gov (United States)

    Norashira, J.; Zaidi, E.; Aziman, M.; Saiful Azhar, A. T.

    2016-07-01

    Barren acidic soil collected at Ayer Hitam, Johor Malaysia was recorded at pH value of 2.36 with relative humidity of 86%. This pH value is not suitable for the growth of any plants especially for the soil stabilization purposes. Gradation weathering within the range of 4 to 6 indicates an incomplete/partial weathering process. The soil grade in this range is known as a black shale mudstone. Beside, this also influences to a factor of the high surface water runoff at this particular soil species. As the acidic pH become a major problem for soil fertilizing hence an appropriate technique was implemented known as using ‘Electrokinetic Remediation’, EKR. This technique has a great potential in changing the soil pH value from acidic to less acidic and also kept maintain the pH at the saturated rate of electrochemical process. This research study presents the monitoring data of pH value due to the effect of various electrolyte consist of 0.5M of MgSO4, KH2PO4, and Na(NO3). Here, the distilled water (DW) was used as reference solution. The electric field was provided by dipping two pieces of identical rectangular aluminum foil as anode and cathode. The EKR was conducted under a constant voltage gradient of 50 V/m across the sample bulk at 0.14 m length measured between both electrodes. The data collection was conducted during the total period of 7 days surveillance. The variation of pH values at the remediation area between anode and cathode for various type of electrolyte indicates that there are a significant saturated value as it reaches 7 days of treatment. During the analysis, it is found that the highest pH value at the remediation area after 7 days treatment using Na(NO3), KH2PO4 and MgSO4 was 3.93, 3.33 and 3.39 respectively. Hence from the last stage of pH value observation, it can be conclude that the best electrolyte for barren soil treatment is Na(NO3) whereby it contribute to highest pH value and turn the soil to be less acidic.

  13. ZnCl{sub 2}- and NH{sub 4}Cl-hydroponics gel electrolytes for zinc-carbon batteries

    Energy Technology Data Exchange (ETDEWEB)

    Khalid, N.H.; Ismail, Y.M. Baba; Mohamad, A.A. [School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia)

    2008-01-21

    Absorbency testing is used to determine the percentage of ZnCl{sub 2} or NH{sub 4}Cl solution absorbed by a hydroponics gel (HPG). It is found that the absorbency of ZnCl{sub 2} or NH{sub 4}Cl solution decreases with increasing solution concentration. The conductivity of ZnCl{sub 2}- and NH{sub 4}Cl-HPG electrolytes is dependent on the solution concentration. A mixture of salt solution with HPG yields excellent gel polymer electrolytes with conductivities of 0.026 and 0.104 S cm{sup -1} at 3 M ZnCl{sub 2} and 7 M NH{sub 4}Cl, respectively. These gel electrolytes are then used to produce zinc-carbon cells. The fabricated cells give capacities of 8.8 and 10.0 mAh, have an internal resistance of 25.4 and 19.8 {omega}, a maximum power density of 12.7 and 12.2 mW cm{sup -2}, and a short-circuit current density of 29.1 and 33.9 mA cm{sup -2} for ZnCl{sub 2}- and NH{sub 4}Cl-HPG electrolytes, respectively. (author)

  14. Behavior of sheet-like crystalline ammonium trivanadate hemihydrate (NH4V3O8×0.5H2O) as a novel ammonia sensing material

    International Nuclear Information System (INIS)

    Leonardi, S.G.; Primerano, P.; Donato, N.; Neri, G.

    2013-01-01

    This work reports the use of ammonium trivanadate hemihydrate (NH 4 V 3 O 8 ×0.5H 2 O) as a novel sensing material for ammonia resistive sensors. It was prepared by a simple and fast hydrothermal method from V 2 O 5 as a precursor and characterized by SEM, FT-IR, XRD and TG techniques. The as-synthesized material showed a sheet-like morphology and was found thermally stable up to 250–280 °C. It reacted promptly and irreversibly when exposed to ammonia at room temperature. A full reversibility was instead registered undergoing the formed ammonia adduct at a temperature higher than 200 °C. A NH 4 V 3 O 8 ×0.5H 2 O-based resistive gas sensor was fabricated and its sensing properties were evaluated. Experimental results obtained have given a preliminary demonstration of the feasibility of using NH 4 V 3 O 8 ×0.5H 2 O as a novel ammonia sensing material since it yields several advantages including easy synthesis of the sensing layer, good sensitivity and reproducibility and fast response. - Graphical abstract: Sheet-like morphology of the synthesized trivanadate hemihydrate (NH 4 V 3 O 8 ×0.5H 2 O). Inset: Its electrical response to different ammonia concentrations in air. - Highlights: • A simple hydrothermal method for the fast synthesis of trivanadate hemihydrate (NH 4 V 3 O 8 ×0.5H 2 O) is reported. • Sheet particles could be obtained. • A preliminary demonstration of the feasibility of using NH 4 V 3 O 8 ×0.5H 2 O as a novel ammonia sensing material is presented

  15. Nanoparticles of [Fe(NH2-trz)3]Br2.3H2O (NH2-trz=2-amino-1,2,4-triazole) prepared by the reverse micelle technique: influence of particle and coherent domain sizes on spin-crossover properties.

    Science.gov (United States)

    Forestier, Thibaut; Kaiba, Abdellah; Pechev, Stanislav; Denux, Dominique; Guionneau, Philippe; Etrillard, Céline; Daro, Nathalie; Freysz, Eric; Létard, Jean-François

    2009-06-15

    This paper describes the synthesis of iron(II) spin-crossover nanoparticles prepared by the reverse micelle technique by using the non-ionic surfactant Lauropal (Ifralan D0205) from the polyoxyethylenic family. By changing the surfactant/water ratio, the size of the particles of [Fe(NH2-trz)3]Br2.3H2O (with NH2trz=4-amino-1,2,4-triazole) can be controlled. On the macroscopic scale this complex exhibits cooperative thermal spin crossovers at 305 and 320 K. We find that when the size is reduced down to 50 nm, the spin transition becomes gradual and no hysteresis can be detected. For our data it seems that the critical size, for which the existence of a thermal hysteresis can be detected, is around 50 nm. Interestingly, the change of the particle size induces almost no change in the temperature of the thermal spin transition. A systematic determination of coherent domain size carried out on the nanoparticles by powder X-ray diffraction indicates that at approximately 30 nm individual particles consist of one coherent domain.

  16. Long-term stability of FeSO{sub 4} and H{sub 2}SO{sub 4} treated chromite ore processing residue (COPR): Importance of H{sup +} and SO{sub 4}{sup 2−}

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xin [School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Zhang, Jingdong [School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Wang, Linling, E-mail: wanglinling@mail.hust.edu.cn [School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Chen, Jing, E-mail: chenjing@mail.hust.edu.cn [School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Hou, Huijie; Yang, Jiakuan [School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Lu, Xiaohua [School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2017-01-05

    Highlights: • The long-term stability of the FeSO{sub 4}-H{sub 2}SO{sub 4} treated COPR was evaluated. • Reliable long-term stability for samples curing 400 days was achieved. • H{sub 2}SO{sub 4} significantly enhanced the stabilization efficiency of COPR using FeSO{sub 4}. • H{sup +} and SO{sub 4}{sup 2−} both reinforced Cr(VI) release from COPR core to react with Fe(II). - Abstract: In this study, the long-term stability of Cr(VI) in the FeSO{sub 4} and H{sub 2}SO{sub 4} (FeSO{sub 4}-H{sub 2}SO{sub 4}) treated chromite ore processing residue (COPR) after 400 curing days and the stabilization mechanisms were investigated. FeSO{sub 4}-H{sub 2}SO{sub 4} treatment significantly reduced toxicity characteristic leaching procedure (TCLP) and synthetic precipitation leaching procedure (SPLP) Cr(VI) concentrations to lower than the regulatory limit of 1.5 mg L{sup −1} (HJ/T 301-2007, China EPA) even for the samples curing 400 days, achieving an outstanding long-term stability. Our independent leaching tests revealed that H{sup +} and SO{sub 4}{sup 2−} have synergistic effect on promoting the release of Cr(VI), which would make Cr(VI) easier accessed by Fe(II) during stabilization. The contributions of H{sup +} and SO{sub 4}{sup 2−} to Cr(VI) release ratio were 25%–44% and 19%–38%, respectively, as 5 mol H{sub 2}SO{sub 4} per kg COPR was used. X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and alkaline digestion analyses were also employed to interpret the possible stabilization mechanism. Cr(VI) released from COPR solid was reduced to Cr(III) by Fe(II), and then formed stable Fe{sub x}Cr{sub (1−x)}(OH){sub 3} precipitate. This study provides a facile and reliable scheme for COPR stabilization, and verifies the excellent long-term stability of the FeSO{sub 4}-H{sub 2}SO{sub 4} treated COPR.

  17. On the importance of the phase distribution and acidity of VOx-ZrO2-SO4-sepiolite catalysts for the NH3-SCR process in relation to biomass fueled power plants

    DEFF Research Database (Denmark)

    Due-Hansen, Johannes; Rasmussen, Søren Birk; Riisager, Anders

    A series of V2O5-ZrO2-SO42- - sepiolite mixtures were extruded, calcined and characterized. NH3-SCR activity was related to the phase distribution of the agglomerant and active VOX-ZrO2-SO42- phase, as well as the acidity of the composite material. Electrophoretic migration results showed...

  18. A wet effluent denuder/mist-chamber coupled to ion chromatography for the continuous measurement of atmospheric HONO, HNO{sub 3}, NO{sub 3}{sup -} and SO{sub 4}{sup 2-}.

    Energy Technology Data Exchange (ETDEWEB)

    Zellweger, C.; Baltensperger, U. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Hofer, P. [EMPA, Duebendorf (Switzerland)

    1997-09-01

    A denuder/mist chamber system has been developed for the continuous automated measurement of low level concentrations of HONO, HNO{sub 3} as well as of NO{sub 3}{sup -} and SO{sub 4}{sup 2-}. (author) 2 figs., 1 ref.

  19. Composite of K-doped (NH4)2V3O8/graphene as an anode material for sodium-ion batteries.

    Science.gov (United States)

    Liu, Xin; Li, Zhiwei; Fei, Hailong; Wei, Mingdeng

    2015-11-21

    A layer structured K-doped (NH4)2V3O8/graphene (K-NVG) was prepared via a hydrothermal route and then used as an anode material for sodium-ion batteries for the first time. The K-NVG nanosheets have a diameter in the range of 200-500 nm. The K-NVG electrode exhibited stable cycling and a good rate performance with a reversible capacity of 235.4 mA h g(-1), which is much higher than the 90.5 mA h g(-1) value of the (NH4)2V3O8/graphene electrode after 100 cycles at a current density of 100 mA g(-1). Simultaneously, the retention rate was maintained at 82% even after 250 cycles at the current density of 300 mA g(-1). Such good electrochemical properties may be attributed to the K-NVG's stable layered structure.

  20. Toxic effects of NH4+-N on embryonic development of Bufo gargarizans and Rana chensinensis.

    Science.gov (United States)

    Deng, Hongzhang; Chai, Lihong; Luo, Pingping; Zhou, Meimei; Nover, Daniel; Zhao, Xiaohong

    2017-09-01

    Although nitrogen fertilizer is commonly used worldwide, little information is currently available about NH 4 + -N toxicity on amphibians. This study determined the acute and chronic toxic effects of NH 4 + -N on two native Chinese amphibian species (Bufo gargarizans and Rana chensinensis), and compared the negative sensitivity of different embryos to NH 4 + -N. Static renewal aqueous exposures were performed using B. gargarizans and R. chensinensis embryos at Gosner stage 2 over 96 h. In terms of 96 h-LC 50 , B. gargarizans and R. chensinensis embryos had significantly different responses to NH 4 + -N, and the latter was more sensitive to NH 4 + -N than the former. In the chronic toxicity test, exposure to 10 mg L -1 NH 4 + -N or higher significantly decreased the hatching rate of embryos in both species. Significant increases in the abnormality rate of embryos at 50 mg L -1 NH 4 + -N or higher were observed and morphological abnormalities were characterized by axial flexures, yolk sac edema, and hyperplasia in both species. Additionally, the total length of embryos decreased in a dose-dependent manner after exposure to NH 4 + -N. The results indicate that NH 4 + -N exposure can increase abnormality and inhibit the hatching and development of embryos in B. gargarizans and R. chensinensis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Elevated electrochemical performance of (NH4)3AlF6-coated 0.5Li2MnO3·0.5LiNi1/3Co1/3Mn1/3O2 cathode material via a novel wet coating method

    International Nuclear Information System (INIS)

    Xu, Guofeng; Li, Jianling; Xue, Qingrui; Dai, Yu; Zhou, Hongwei; Wang, Xindong; Kang, Feiyu

    2014-01-01

    A novel wet method of (NH 4 ) 3 AlF 6 coating was explored to enhance the electrochemical performance of Mn-based solid-solution cathode material 0.5Li 2 MnO 3 ·0.5LiNi 1/3 Co 1/3 Mn 1/3 O 2 . The X-ray powder diffraction patterns show that the coating material is pure-phase (NH 4 ) 3 AlF 6 and both pristine and coated samples can be indexed to hexagonal α-NaFeO 2 layered structure with space group of R-3 m. The field-emission scanning electron microscope images and the energy dispersive X-ray spectroscopy show that (NH 4 ) 3 AlF 6 is successfully coated on the surface of active particle. The (NH 4 ) 3 AlF 6 coated electrodes exhibit improved electrochemical performance, for instance, the initial charge-discharge efficiency was promoted by 5% (NH 4 ) 3 AlF 6 coating, the 1 wt.% and 3 wt.% coated electrodes deliver elevated cycling ability which is ascribed to the lower resistance between electrode and electrolyte as indicated by AC impedance measurement at different cycles. In addition, the coated-electrodes also give enhanced rate capability particularly for 1 wt.% NAF-coated electrode performing surprising capacity of 143.4 mAh g −1 at 5 C higher than that of 109.4 mAh g −1 for pristine electrode. Furthermore, the 1 wt.% NAF-coated electrode also shows improved cycle and rate performance at 55°C

  2. Experimentally determined standard thermodynamic properties of synthetic MgSO(44H(2)O (Starkeyite) and MgSO(43H(2)O: a revised internally consistent thermodynamic data set for magnesium sulfate hydrates.

    Science.gov (United States)

    Grevel, Klaus-Dieter; Majzlan, Juraj; Benisek, Artur; Dachs, Edgar; Steiger, Michael; Fortes, A Dominic; Marler, Bernd

    2012-11-01

    The enthalpies of formation of synthetic MgSO(44H(2)O (starkeyite) and MgSO(43H(2)O were obtained by solution calorimetry at T=298.15 K. The resulting enthalpies of formation from the elements are [Formula: see text] (starkeyite)=-2498.7±1.1 kJ·mol(-1) and [Formula: see text] (MgSO(43H(2)O)=-2210.3±1.3 kJ·mol(-1). The standard entropy of starkeyite was derived from low-temperature heat capacity measurements acquired with a physical property measurement system (PPMS) in the temperature range 5 Kcalorimetry (DSC) measurements with a Perkin Elmer Diamond DSC in the temperature range 270 Klimitations of kieserite formation, metastable occurrence of starkeyite might be possible under martian conditions.

  3. [Pd(NH{sub 3}){sub 4}]MoO{sub 4} as a precursor for Pd–Mo-containing catalysts: Thermal behavior, X-ray analysis of the thermolysis products and related catalytic studies

    Energy Technology Data Exchange (ETDEWEB)

    Gubanov, Alexander I., E-mail: gubanov@niic.nsc.su [Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, Akad. Lavrentiev Prospekt 3, 630090 Novosibirsk (Russian Federation); Novosibirsk State University, Pirogova str. 2, 630090 Novosibirsk (Russian Federation); Filatov, Eugeny Yu.; Semitut, Eugeny Yu.; Smolentsev, Anton I. [Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, Akad. Lavrentiev Prospekt 3, 630090 Novosibirsk (Russian Federation); Novosibirsk State University, Pirogova str. 2, 630090 Novosibirsk (Russian Federation); Snytnikov, Pavel V.; Potemkin, Dmitry I. [Novosibirsk State University, Pirogova str. 2, 630090 Novosibirsk (Russian Federation); Boreskov Institute of Catalysis, Siberian Branch of the Russian Academy of Sciences, Akad. Lavrentiev Prospekt 5, 630090 Novosibirsk (Russian Federation); Korenev, Sergey V. [Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, Akad. Lavrentiev Prospekt 3, 630090 Novosibirsk (Russian Federation); Novosibirsk State University, Pirogova str. 2, 630090 Novosibirsk (Russian Federation)

    2013-08-20

    Highlights: • [Pd(NH{sub 3}){sub 4}]MoO{sub 4} as a precursor for Pd–Mo-containing catalysts. • Different products are formed depending on atmosphere of thermal decomposition. • Thermolysis in He atmosphere affords finely mixed two-phase nanosized system Pd–MoO{sub 2}. • Pd–MoO{sub 2} system can be a promising catalyst both in pure and supported form. - Abstract: Compound [Pd(NH{sub 3}){sub 4}]MoO{sub 4} (1) has been synthesized and characterized by IR spectroscopy, analytical data, powder and single-crystal X-ray crystallography. Thermal properties of 1 have been examined by thermogravimetry. Powder X-ray diffraction has been applied to investigate the nanosized products of thermal decomposition of the precursor in hydrogen (Pd–Mo) and helium (Pd–MoO{sub 2}) atmospheres. Pd–Mo catalysts supported with γ-Al{sub 2}O{sub 3} have been tested in oxidation of CO and H{sub 2} mixtures.

  4. Spectrophotometric Determination of the CuSO4 Soret Coefficient of a CuSO4-H2O Binary Solutions System

    Directory of Open Access Journals (Sweden)

    Ijang Rohman

    2010-06-01

    Full Text Available A spectrophotometric technique for the determination of the CuSO4 soret coefficient of a CuSO4-water binary solutions system is described. A short column of solutions is placed between horizontal metal plates that are held at different temperatures. The subsequent changes in composition due to thermal diffusion are followed by monitoring changes of transmittance near the end of the solutions column. In water, CuSO4 diffuses to the warm compartment of column. The soret coefficient of CuSO4 0.0254 molal in water agrees with the appropriate theory, i.e. 17.60x10-3 °C-1 on the average.

  5. Parameter estimation for mathematical models of a nongastric H+(Na+)-K+(NH4+)-ATPase

    Science.gov (United States)

    Nadal-Quirós, Mónica; Moore, Leon C.

    2015-01-01

    The role of nongastric H+-K+-ATPase (HKA) in ion homeostasis of macula densa (MD) cells is an open question. To begin to explore this issue, we developed two mathematical models that describe ion fluxes through a nongastric HKA. One model assumes a 1H+:1K+-per-ATP stoichiometry; the other assumes a 2H+:2K+-per-ATP stoichiometry. Both models include Na+ and NH4+ competitive binding with H+ and K+, respectively, a characteristic observed in vitro and in situ. Model rate constants were obtained by minimizing the distance between model and experimental outcomes. Both 1H+(1Na+):1K+(1NH4+)-per-ATP and 2H+(2Na+):2K+(2NH4+)-per-ATP models fit the experimental data well. Using both models, we simulated ion net fluxes as a function of cytosolic or luminal ion concentrations typical for the cortical thick ascending limb and MD region. We observed that 1) K+ and NH4+ flowed in the lumen-to-cytosol direction, 2) there was competitive behavior between luminal K+ and NH4+ and between cytosolic Na+ and H+, 3) ion fluxes were highly sensitive to changes in cytosolic Na+ or H+ concentrations, and 4) the transporter does mostly Na+/K+ exchange under physiological conditions. These results support the concept that nongastric HKA may contribute to Na+ and pH homeostasis in MD cells. Furthermore, in both models, H+ flux reversed at a luminal pH that was <5.6. Such reversal led to Na+/H+ exchange for a luminal pH of <2 and 4 in the 1:1-per-ATP and 2:2-per-ATP models, respectively. This suggests a novel role of nongastric HKA in cell Na+ homeostasis in the more acidic regions of the renal tubules. PMID:26109090

  6. Parameter estimation for mathematical models of a nongastric H+(Na+)-K(+)(NH4+)-ATPase.

    Science.gov (United States)

    Nadal-Quirós, Mónica; Moore, Leon C; Marcano, Mariano

    2015-09-01

    The role of nongastric H(+)-K(+)-ATPase (HKA) in ion homeostasis of macula densa (MD) cells is an open question. To begin to explore this issue, we developed two mathematical models that describe ion fluxes through a nongastric HKA. One model assumes a 1H(+):1K(+)-per-ATP stoichiometry; the other assumes a 2H(+):2K(+)-per-ATP stoichiometry. Both models include Na+ and NH4+ competitive binding with H+ and K+, respectively, a characteristic observed in vitro and in situ. Model rate constants were obtained by minimizing the distance between model and experimental outcomes. Both 1H(+)(1Na(+)):1K(+)(1NH4 (+))-per-ATP and 2H(+)(2Na(+)):2K(+)(2NH4 (+))-per-ATP models fit the experimental data well. Using both models, we simulated ion net fluxes as a function of cytosolic or luminal ion concentrations typical for the cortical thick ascending limb and MD region. We observed that (1) K+ and NH4+ flowed in the lumen-to-cytosol direction, (2) there was competitive behavior between luminal K+ and NH4+ and between cytosolic Na+ and H+, 3) ion fluxes were highly sensitive to changes in cytosolic Na+ or H+ concentrations, and 4) the transporter does mostly Na+ / K+ exchange under physiological conditions. These results support the concept that nongastric HKA may contribute to Na+ and pH homeostasis in MD cells. Furthermore, in both models, H+ flux reversed at a luminal pH that was <5.6. Such reversal led to Na+ / H+ exchange for a luminal pH of <2 and 4 in the 1:1-per-ATP and 2:2-per-ATP models, respectively. This suggests a novel role of nongastric HKA in cell Na+ homeostasis in the more acidic regions of the renal tubules. Copyright © 2015 the American Physiological Society.

  7. Copper-Substituted Lead Perovskite Materials Constructed with Different Halides for Working (CH3NH3)2CuX4-Based Perovskite Solar Cells from Experimental and Theoretical View.

    Science.gov (United States)

    Elseman, Ahmed Mourtada; Shalan, Ahmed Esmail; Sajid, Sajid; Rashad, Mohamed Mohamed; Hassan, Ali Mostafa; Li, Meicheng

    2018-04-11

    Toxicity and chemical instability issues of halide perovskites based on organic-inorganic lead-containing materials still remain as the main drawbacks for perovskite solar cells (PSCs). Herein, we discuss the preparation of copper (Cu)-based hybrid materials, where we replace lead (Pb) with nontoxic Cu metal for lead-free PSCs, and investigate their potential toward solar cell applications based on experimental and theoretical studies. The formation of (CH 3 NH 3 ) 2 CuX 4 [(CH 3 NH 3 ) 2 CuCl 4 , (CH 3 NH 3 ) 2 CuCl 2 I 2 , and (CH 3 NH 3 ) 2 CuCl 2 Br 2 ] was discussed in details. Furthermore, it was found that chlorine (Cl - ) in the structure is critical for the stabilization of the formed compounds. Cu-based perovskite-like materials showed attractive absorbance features extended to the near-infrared range, with appropriate band gaps. Green photoluminescence of these materials was obtained because of Cu + ions. The power conversion efficiency was measured experimentally and estimated theoretically for different architectures of solar cell devices.

  8. K2SO4 and LiKSO4 crystals luminescence

    International Nuclear Information System (INIS)

    Charapiev, B.; Nurakhmetov, T.N.

    2002-01-01

    In the paper a nature of X-ray and tunnel luminescence in LiKSO 4 and Li 2 SO 4 ·H 2 O crystals are discussed. It is shown, that X-ray luminescence and Li 2 SO 4 ·H 2 O and LiKSO 4 appeals in the result of electrons recombination with auto-localized holes (SO 4 - ), and tunnel luminescence appeals at electrons transfer from ground state of electron center into hole center capture ground state. Under heating of irradiated crystal de-localized holes at recombination moment with electron capture centers are forming auto-localized excitons, which are disintegrating with photon emitting, and so X-ray luminescence spectrum and thermally induces luminescence peaks are coinciding. Nature of radiation appealing in LiKSO 4 at ultraviolet excitation is discussing

  9. Structures, energetics, vibrational spectra of NH4+ (H2O)(n=4,6) clusters: Ab initio calculations and first principles molecular dynamics simulations.

    Science.gov (United States)

    Karthikeyan, S; Singh, Jiten N; Park, Mina; Kumar, Rajesh; Kim, Kwang S

    2008-06-28

    Important structural isomers of NH(4) (+)(H(2)O)(n=4,6) have been studied by using density functional theory, Moller-Plesset second order perturbation theory, and coupled-cluster theory with single, double, and perturbative triple excitations [CCSD(T)]. The zero-point energy (ZPE) correction to the complete basis set limit of the CCSD(T) binding energies and free energies is necessary to identify the low energy structures for NH(4) (+)(H(2)O)(n=4,6) because otherwise wrong structures could be assigned for the most probable structures. For NH(4) (+)(H(2)O)(6), the cage-type structure, which is more stable than the previously reported open structure before the ZPE correction, turns out to be less stable after the ZPE correction. In first principles Car-Parrinello molecular dynamics simulations around 100 K, the combined power spectrum of three lowest energy isomers of NH(4) (+)(H(2)O)(4) and two lowest energy isomers of NH(4) (+)(H(2)O)(6) explains each experimental IR spectrum.

  10. Methanesulfonates of high-valent metals. Syntheses and structural features of MoO_2(CH_3SO_3)_2, UO_2(CH_3SO_3)_2, ReO_3(CH_3SO_3), VO(CH_3SO_3)_2, and V_2O_3(CH_3SO_3)_4 and their thermal decomposition under N_2 and O_2 atmosphere

    International Nuclear Information System (INIS)

    Betke, Ulf; Neuschulz, Kai; Wickleder, Mathias S.

    2011-01-01

    Oxide methanesulfonates of Mo, U, Re, and V have been prepared by reaction of MoO_3, UO_2(CH_3COO)_2.2 H_2O, Re_2O_7(H_2O)_2, and V_2O_5 with CH_3SO_3H or mixtures thereof with its anhydride. These compounds are the first examples of solvent-free oxide methanesulfonates of these elements. MoO_2(CH_3SO_3)_2 (Pbca, a=1487.05(4), b=752.55(2), c=1549.61(5) pm, V=1.73414(9) nm"3, Z=8) contains [MoO_2] moieties connected by [CH_3SO_3] ions to form layers parallel to (100). UO_2(CH_3SO_3)_2 (P2_1/c, a=1320.4(1), b=1014.41(6), c=1533.7(1) pm, β=112.80(1) "c"i"r"c"l"e, V=1.8937(3) nm"3, Z=8) consists of linear UO_2"2"+ ions coordinated by five [CH_3SO_3] ions, forming a layer structure. VO(CH_3SO_3)_2 (P2_1/c, a=1136.5(1), b=869.87(7), c=915.5(1) pm, β=113.66(1) "c"i"r"c"l"e, V=0.8290(2) nm"3, Z=4) contains [VO] units connected by methanesulfonate anions to form corrugated layers parallel to (100). In ReO_3(CH_3SO_3) (P anti 1, a=574.0(1), b=1279.6(3), c=1641.9(3) pm, α=102.08(2), β=96.11(2), γ=99.04(2) "c"i"r"c"l"e, V=1.1523(4) nm"3, Z=8) a chain structure exhibiting infinite O-[ReO_2]-O-[ReO_2]-O chains is formed. Each [ReO_2]-O-[ReO_2] unit is coordinated by two bidentate [CH_3SO_3] ions. V_2O_3(CH_3SO_3)_4 (I2/a, a=1645.2(3), b=583.1(1), c=1670.2(3) pm, β=102.58(3), V=1.5637(5) pm"3, Z=4) adopts a chain structure, too, but contains discrete [VO]-O-[VO] moieties, each coordinated by two bidentate [CH_3SO_3] ligands. Additional methanesulfonate ions connect the [V_2O_3] groups along [001]. Thermal decomposition of the compounds was monitored under N_2 and O_2 atmosphere by thermogravimetric/differential thermal analysis and XRD measurements. Under N_2 the decomposition proceeds with reduction of the metal leading to the oxides MoO_2, U_3O_7, V_4O_7, and VO_2; for MoO_2(CH_3SO_3)_2, a small amount of MoS_2 is formed. If the thermal decomposition is carried out in a atmosphere of O_2 the oxides MoO_3 and V_2O_5 are formed. (Copyright copyright 2011 WILEY-VCH Verlag

  11. Enhanced superconductivity and anisotropy of FeTe0.6Se0.4 single crystals with Li -NH3 intercalation

    Science.gov (United States)

    Li, Chenghe; Sun, Shanshan; Wang, Shaohua; Lei, Hechang

    2017-10-01

    We report a systematic study of anisotropy resistivity, magnetoresistance, and Hall effect of Li0.32(NH3)yFe2Te1.2Se0.8 single crystals. When compared to the parent compound FeTe0.6Se0.4 , the Li-NH3 intercalation not only increases the superconducting transition temperature but also enhances the electronic anisotropy in both normal and superconducting states. Moreover, in contrast to the parent compound, the Hall coefficient RH becomes negative at low temperature, indicating electron-type carriers are dominant due to Li doping. On the other hand, the sign reverse of RH at high temperature and the failure of scaling behavior of magnetoresistance imply that hole pockets may be still crossing or just below the Fermi energy level, leading to the multiband behavior in Li0.32(NH3)yFe2Te1.2Se0.8 .

  12. Electrical properties and conduction mechanism of [C2H5NH3]2CuCl4 compound

    Science.gov (United States)

    Mohamed, C. Ben; Karoui, K.; Jomni, F.; Guidara, K.; Rhaiem, A. Ben

    2015-02-01

    The [(C2H5)NH3]2CuCl4 compound was prepared and characterized by several technique: the X-ray powder diffraction confirms the purity of the synthetized compound, the differential scanning calorimetric show several phase transitions at 236 K, 330 K, 357 K and 371 K, the dialectical properties confirms the ferroelectric-paraelectric phase transition at 238 K, which is reported by V. Kapustianyk et al. (2007) [1]. The two semi-circles observed in the complex impedance identify the presence of the grain interior and grain boundary contributions to the electrical response in this material. The equivalent circuit is modeled by a combination series of two parallel RP-CPE circuits. The temperature dependence of the alternative current conductivity (σg) and direct current conductivity (σdc) confirm the observed transitions in the calorimetric study. The (AC) electrical conduction in [(C2H5)NH3]2CuCl4 was studied by two processes that can be attributed to a hopping transport mechanism: the non-overlapping small polaron tunneling (NSPT) model in phase III and the correlated barrier hopping (CBH) model in phases I, II, IV, V and VI.

  13. Estimation of Satellite-Based SO42- and NH4+ Composition of Ambient Fine Particulate Matter Over China Using Chemical Transport Model

    Science.gov (United States)

    Si, Y.; Li, S.; Chen, L.; Yu, C.; Zhu, W.

    2018-04-01

    Epidemiologic and health impact studies have examined the chemical composition of ambient PM2.5 in China but have been constrained by the paucity of long-term ground measurements. Using the GEOS-Chem chemical transport model and satellite-derived PM2.5 data, sulfate and ammonium levels were estimated over China from 2004 to 2014. A comparison of the satellite-estimated dataset with model simulations based on ground measurements obtained from the literature indicated our results are more accurate. Using satellite-derived PM2.5 data with a spatial resolution of 0.1° × 0.1°, we further presented finer satellite-estimated sulfate and ammonium concentrations in anthropogenic polluted regions, including the NCP (the North China Plain), the SCB (the Sichuan Basin) and the PRD (the Pearl River Delta). Linear regression results obtained on a national scale yielded an r value of 0.62, NMB of -35.9 %, NME of 48.2 %, ARB_50 % of 53.68 % for sulfate and an r value of 0.63, slope of 0.67, and intercept of 5.14 for ammonium. In typical regions, the satellite-derived dataset was significantly robust. Based on the satellite-derived dataset, the spatial-temporal variation of 11-year annual average satellite-derived SO42- and NH4+ concentrations and time series of monthly average concentrations were also investigated. On a national scale, both exhibited a downward trend each year between 2004 and 2014 (SO42-: -0.61 %; NH4+: -0.21 %), large values were mainly concentrated in the NCP and SCB. For regions captured at a finer resolution, the inter-annual variation trends presented a positive trend over the periods 2004-2007 and 2008-2011, followed by a negative trend over the period 2012-2014, and sulfate concentrations varied appreciably. Moreover, the seasonal distributions of the 11-year satellite-derived dataset over China were presented. The distribution of both sulfate and ammonium concentrations exhibited seasonal characteristics, with the seasonal concentrations ranking as

  14. Pb4(OH)4(BrO3)3(NO3): An Example of SHG Crystal in Metal Bromates Containing π-Conjugated Planar Triangle.

    Science.gov (United States)

    Kong, Fang; Hu, Chun-Li; Liang, Ming-Li; Mao, Jiang-Gao

    2016-01-19

    The first example of SHG crystal in the metal bromates containing π-conjugated planar triangle systems, namely, Pb4(OH)4(BrO3)3(NO3), was successfully synthesized via the hydrothermal method. Furthermore, a single crystal of centrosymmetric Pb8O(OH)6(BrO3)6(NO3)2·H2O was also obtained. Both compounds contain similar [Pb4(OH)4] cubane-like tetranuclear clusters, but they display different one-dimensional (1D) chain structures. Pb4(OH)4(BrO3)3(NO3) features a zigzag [Pb4(OH)4(BrO3)3](+) 1D chain, while Pb8O(OH)6(BrO3)6(NO3)2·H2O is composed of two different orthogonal chains: the linear [Pb4(OH)4(BrO3)2](2+) 1D chain along the b-axis and the zigzag [Pb4O2(OH)2(BrO3)4](2-) 1D chain along the a-axis. The NO3 planar triangles of the compounds are all isolated and located in the spaces of the structures. Pb4(OH)4(BrO3)3(NO3) exhibits the first example of SHG crystal in the metal bromates with π-conjugated planar triangle. The second-harmonic generation (SHG) efficiency of Pb4(OH)4(BrO3)3(NO3) is approximately equal to that of KDP and it is phase-matchable. Dipole moment and theory calculations indicate that BrO3, NO3, and PbO4 groups are the origin of its SHG efficiency, although some of the contributions cancel each other out.

  15. K+ and NH4(+) modulate gill (Na+, K+)-ATPase activity in the blue crab, Callinectes ornatus: fine tuning of ammonia excretion.

    Science.gov (United States)

    Garçon, D P; Masui, D C; Mantelatto, F L M; McNamara, J C; Furriel, R P M; Leone, F A

    2007-05-01

    To better comprehend the mechanisms of ionic regulation, we investigate the modulation by Na+, K+, NH4(+) and ATP of the (Na+, K+)-ATPase in a microsomal fraction from Callinectes ornatus gills. ATP hydrolysis obeyed Michaelis-Menten kinetics with KM=0.61+/-0.03 mmol L(-1) and maximal rate of V=116.3+/-5.4 U mg(-1). Stimulation by Na+ (V=110.6+/-6.1 U mg(-1); K0.5=6.3+/-0.2 mmol L(-1)), Mg2+ (V=111.0+/-4.7 U mg(-1); K0.5=0.53+/-0.03 mmol L(-1)), NH4(+) (V=173.3+/-6.9 U mg(-1); K0.5=5.4+/-0.2 mmol L(-1)) and K+ (V=116.0+/-4.9 U mg(-1); K0.5=1.5+/-0.1 mmol L(-1)) followed a single saturation curve, although revealing site-site interactions. In the absence of NH4(+), ouabain (K(I)=74.5+/-1.2 micromol L(-1)) and orthovanadate inhibited ATPase activity by up to 87%; the inhibition patterns suggest the presence of F0F1 and K+-ATPases but not Na+-, V- or Ca2+-ATPase as contaminants. (Na+, K+)-ATPase activity was synergistically modulated by K+ and NH4(+). At 10 mmol L(-1) K+, increasing NH4(+) concentrations stimulated maximum activity to V=185.9+/-7.4 U mg(-1). However, at saturating NH4(+) (50 mmol L(-1)), increasing K+ concentrations did not stimulate activity further. Our findings provide evidence that the C. ornatus gill (Na+, K+)-ATPase may be particularly well suited for extremely efficient active NH4(+) excretion. At elevated NH4(+) concentrations, the enzyme is fully active, regardless of hemolymph K+ concentration, and K+ cannot displace NH4(+) from its exclusive binding sites. Further, the binding of NH4(+) to its specific sites induces an increase in enzyme apparent affinity for K+, which may contribute to maintaining K+ transport, assuring that exposure to elevated ammonia concentrations does not lead to a decrease in intracellular potassium levels. This is the first report of modulation by ammonium ions of C. ornatus gill (Na+, K+)-ATPase, and should further our understanding of NH4(+) excretion in benthic crabs.

  16. Thickness distributions and evolution of growth mechanisms of NH4-illite from the fossil hydrothermal system of Harghita Bai, Eastern Carpathians, Romania

    Science.gov (United States)

    Bobos, Iuliu; Eberl, Dennis D.

    2013-01-01

    The crystal growth of NH4-illite (NH4-I) from the hydrothermal system of Harghita Bãi (Eastern Carpathians) was deduced from the shapes of crystal thickness distributions (CTDs). The 4-illite-smectite (I-S) interstratified structures (R1, R2, and R3-type ordering) with a variable smectite-layer content. The NH4-I-S (40–5% S) structures were identified underground in a hydrothermal breccia structure, whereas the K-I/NH4-I mixtures were found at the deepest level sampled (−110 m). The percentage of smectite interlayers generally decreases with increasing depth in the deposit. This decrease in smectite content is related to the increase in degree of fracturing in the breccia structure and corresponds to a general increase in mean illite crystal thickness. In order to determine the thickness distributions of NH4-I crystals (fundamental illite particles) which make up the NH4-I-S interstratified structures and the NH4,-I/K-I mixtures, 27 samples were saturated with Li+ and aqueous solutions of PVP-10 to remove swelling and then were analyzed by X-ray diffraction. The profiles for the mean crystallite thickness (Tmean) and crystallite thickness distribution (CTD) of NH4-I crystallites were determined by the Bertaut-Warren-Averbach method using the MudMaster computer code. The Tmean of NH4-I from NH4-I-S samples ranges from 3.4 to 7.8 nm. The Tmean measured for the NH4-I/K-I mixture phase ranges from 7.8 nm to 11.7 nm (NH4-I) and from 12.1 to 24.7 nm (K-I).The CTD shapes of NH4-I fundamental particles are asymptotic and lognormal, whereas illites from NH4-I/K-I mixtures have bimodal shapes related to the presence of two lognormal-like CTDs corresponding to NH4-I and K-I.The crystal-growth mechanism for NH4-I samples was simulated using the Galoper code. Reaction pathways for NH4-I crystal nucleation and growth could be determined for each sample by plotting their CTD parameters on an α–β2 diagram constructed using Galoper. This analysis shows that NH4-I crystals

  17. Intrinsic and extrinsic photoluminescence in the NH sub 4 MnCl sub 3 cubic perovskite: a spectroscopic study

    CERN Document Server

    Hernandez, I

    2003-01-01

    This work investigates the photoluminescence (PL) properties of the cubic chloroperovskite NH sub 4 MnCl sub 3. Like in most concentrated materials, the Mn sup 2 sup + PL which is located at 2.10 eV at T = 10 K strongly depends on the temperature. Optical absorption (OA), emission, and excitation spectroscopy, as well as lifetime measurements, performed on NH sub 4 MnCl sub 3 indicate that the PL is mainly intrinsic at T = 10 K and consists of a broad band located at 2.10 eV. Above this temperature, the PL gradually transforms to extrinsic PL due to exciton migration and subsequent trapping. Further temperature increase above 100 K yields transfer to killers of excitation which are responsible for the PL quenching, and hence the absence of PL at ambient conditions. The exciton traps are identified with perturbed Mn sup 2 sup + sites with the effective activation energy of 52 meV, whilst the activation energy for energy transfer is 47 meV. The existence of these traps has been directly revealed by time-resolve...

  18. Nitric acid titration in the presence of UO2(NO3)2, Th(NO3)4, U(NO3)4 or Zr(NO3)4

    International Nuclear Information System (INIS)

    Nakashima, T.; Lieser, K.H.

    1986-01-01

    Procedures are described for titration of HNO 3 in presence of UO 2 2+ , Th 4+ , U 4+ and Zr 4+ without formation of interfering precipitates. In the first step the hydrolysable ions are masked by addition of complexing agents and in the second step the acid is titrated by NaOH as usual. (orig.)

  19. Ni(NH32(NO32—A 3-D Network through Bridging Nitrate Units Isolated from the Thermal Decomposition of Nickel Hexammine Dinitrate

    Directory of Open Access Journals (Sweden)

    Joachim Breternitz

    2018-06-01

    Full Text Available Nickel nitrate diammine, Ni(NH32(NO32, can be synthesised from the thermal decomposition of nickel nitrate hexammine, Ni[(NH36](NO32. The hexammine decomposes in two distinct major stages; the first releases 4 equivalents of ammonia while the second involves the release of NOx, N2, and H2O to yield NiO. The intermediate diammine compound can be isolated following the first deammoniation step or synthesised as a single phase from the hexammine under vacuum. Powder X-ray diffraction (PXD experiments have allowed the structure of Ni(NH32(NO32 to be solved for the first time. The compound crystallises in orthorhombic space group Pca21 (a = 11.0628 (5 Å, b = 6.0454 (3 Å, c = 9.3526 (4 Å; Z = 4 and contains 11 non-hydrogen atoms in the asymmetric unit. Fourier transform infrared (FTIR spectroscopy demonstrates that the bonding in the ammine is consistent with the structure determined by PXD.

  20. Synthesis of flower-like LiMnPO4/C with precipitated NH4MnPO4·H2O as precursor

    International Nuclear Information System (INIS)

    Liu Jiali; Hu Dongge; Huang Tao; Yu Aishui

    2012-01-01

    Highlights: ► Flower-like NH 4 MnPO 4 ·H 2 O is obtained by novel precipitating method. ► It is used as the precursor to synthesize LiMnPO 4 /C. ► Subsequent heat treatment would not destroy the precursor morphology. ► As-prepared LiMnPO 4 /C showed discharge capacity of 85 mAh/g at 0.05 C. - Abstract: Ammonium magnesium phosphate monohydrate (NH 4 MnPO 4 ·H 2 O) precursor was prepared by a novel precipitating process with manganese citrate complexes as intermediate. The morphology of the precursor observed by Scanning Electron Microscope (SEM) was flower-like which was self-assembled by plate-like particles. Further analysis by X-ray diffraction (XRD) revealed that the lattice of the plate crystal was orientated along (0 1 0) plane. By solid-state reaction of the precursor, with lithium acetate and glucose as carbon source, pure olivine structured LiMnPO 4 /C composite was obtained and meanwhile, the original flower-like morphology could be retained.

  1. A neodymium(III)-ammonium complex involving oxalate and carbonate ligands: (NH4)2[Nd2(C2O4)3(CO3)(H2O)].H2O.

    Science.gov (United States)

    Trombe, Jean-Christian; Galy, Jean; Enjalbert, Renée

    2002-10-01

    The title compound, diammonium aqua-mu-carbonato-tri-mu-oxalato-dineodymium(III) hydrate, (NH(4))(2)[Nd(2)(CO(3))(C(2)O(4))(3)(H(2)O)].H(2)O, involving the two ligands oxalate and carbonate, has been prepared hydrothermally as single crystals. The Nd atoms form a tetranuclear unit across the inversion centre at (1/2, 1/2, 1/2). Starting from this tetranuclear unit, the oxalate ligands serve to develop a three-dimensional network. The carbonate group acts as a bis-chelating ligand to two Nd atoms, and is monodentate to a third Nd atom. The oxalate groups are all bis-chelating. The two independent Nd atoms are ninefold coordinated and the coordination polyhedron of these atoms is a distorted monocapped antiprism.

  2. Selective Catalytic Reduction of NO with NH3 Over V-MCM-41 Catalyst.

    Science.gov (United States)

    Kwon, Woo Hyun; Park, Sung Hoon; Kim, Ji Man; Park, Su Bin; Jung, Sang-Chul; Kim, Sang Chai; Jeon, Jong-Ki; Park, Young-Kwon

    2016-02-01

    V-MCM-41, a mesoporous catalyst doped with V2O5, was applied for the first time to the removal of atmospheric NO. The quantity of V2O5 added was 10 wt% and 30 wt%. The characteristics of the synthesized catalysts were examined using XRD, N2 soprtion, and NH3-TPD. With increasing quantity of V2O5 added, specific surface area decreased and pore size increased. When the quantity of V2O5 was 10 wt%, the MCM-41 structure was retained, whereas considerable collapse of mesoporous structure was observed when 30 wt% V2O5 was added. The examination of acid characteristics using NH3-TPD showed that 30 wt% V-MCM-41 had the higher NH3 adsorption ability, implying that it would exhibit high activity for NH3 SCR reaction. In the NO removal experiments, 30 wt% V-MCM-41 showed much higher NO removal efficiency than 10 wt% V-MCM-41, which was attributed to its high NH3 adsorption ability.

  3. Synthesis and formation process of SrSO{sub 4}:Sm{sup 3+} phosphors with hierarchical structures and its electron trapping luminescence properties

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Jiayue, E-mail: jiayue_sun@126.com; Sun, Guangchao; Xue, Bing; Cui, Dianpeng

    2013-10-15

    Highlights: •SrSO{sub 4} flower-like structures were synthesized by a aqueous solution route. •The as-prepared SrSO{sub 4} crystals have high crystalline. •The flower-like structures are composed of well aligned microtablets. •SrSO{sub 4} nuclei spontaneous attach by an “oriented attachment” process. •The SrSO{sub 4} crystals have excellent electron trapping luminescence properties. -- Abstract: Novel three-dimensional (3D) flower-like Strontium sulfate (SrSO{sub 4}) microstructures with hierarchical architecture were successfully fabricated by using Sr(NO{sub 3}){sub 2} react with N