Showing papers on "Ammonia published in 1972"

Dynamic aspects of ammonia and urea metabolism in sheep

Abstract: 1. To obtain a quantitative model for nitrogen pathways in sheep, a study of ammonia and urea metabolism was made by using isotope dilution techniques with [15N]ammonium sulphate and [15N]urea and [14C]urea.2. Single injection and continuous infusion techniques of isotope dilution were used for measuring ammonia and urea entry rates.3. Sheep were given 33 g of chaffed lucerne hay every hour; the mean dietary N intake was 23.4 g/d.4. It was estimated that 59% of the dietary N was digested in the reticulo-rumen; 29% of the digested N was utilized as amino acids by the micro-organisms, and 71% was degraded to ammonia.5. Of the 14.2 g N/d entering the ruminal ammonia pool, 9.9 g N/d left and did not return to the pool, the difference of 4.3 g N/d represented recycling, largely within the rumen itself (through the pathways: ruminal ammonia → microbial protein → amino acids → ammonia).6. Urea was synthesized in the body at a rate of 18.4 g N/d from 2.0 g N/d of ammonia absorbed through the rumen wall and 16.4 g N/d apparently arising from deamination of amino acids and ammonia absorbed from the lower digestive tract.7. In the 24 h after intraruminal injection of [15N]ammonium salt, 40–50% of the N entering the plasma urea pool arose from ruminal ammonia; 26% of the 15N injected was excreted in urinary N.8. Although 5.1g N/d as urea was degraded apparently in the digestive tract, only 1.2g N/d appeared in ruminal ammonia; it is suggested that the remainder may have been degraded in the lower digestive tract.9. A large proportion of the urea N entering the digestive tract is apparently degraded and absorbed and the ammonia incorporated in the pools of nitrogenous compounds that turn over only slowly. This may be a mechanism for the continuous supply to the liver of ammonia for these syntheses.10. There was incorporation of 15N into bacterial fractions isolated from rumen contents after intraruminal and intravenous administration of [15N]ammonium salts and [15N]urea respectively.11. A model for N pathways in sheep is proposed and, for this diet, many of the pool sizes and turn-over rates have been either deduced or estimated directly.

The Percent Un-Ionized Ammonia in Aqueous Ammonia Solutions at Different pH Levels and Temperatures

Abstract: Previous studies have shown that the un-ionized ammonia molecule and not the ammonium ion is the form of the toxicant harmful to fish. Prior attempts to quantify the amount of un-ionized ammonia in...

Branchial Sodium Exchange and Ammonia Excretion in the Goldfish Carassius Auratus. Effects of Ammonia-Loading and Temperature Changes

Abstract: 1. Sodium influx and efflux and ammonia excretion by the gill have been studied as a function of external sodium chloride concentration in Carassius auratus before and after loading the fish with ammonia. 2. No correlation between net sodium uptake and ammonia excretion is observed, either when the net uptake changes with an external sodium change or when net uptake increases with ammonia-loading. Branchial handling of chlroide ions cannot explain this absence of correlation. 3. Comparison of the concentrations of free base ammonia (NH 3 ) and of ammonium ions (NH 4 + ) in both (dorsal aorta) and external medium at the end of the closed-circuit experiments on control or ammonia-loaded fish demonstrates that the gill is permeable to the ionized form of ammonia. 4. An abrupt temperature decrease (16 → 6 °C) affects the sodium influx ( Q 10 = 3) much more than the sodium efflux ( Q 10 = 1.7). Sodium balance becomes negative unless the fish is ammonia-loaded. The observed effects of temperature are reversible when the fish is returned to 16 °C. Branchial ammonia excretion is highly temperature-sensitive ( Q 10 = 4) in control fish when metabolic production limits ammonia excretion. After ammonia-loading, when most of the ammonia cleared by the gill is exogenous, the effect of temperature on branchial permeability to ammonia ( Q 10 = 1.9) suggests a passive transfer of ammonium ions. 5. The contributors of the kidney and the gill in sodium loss and ammonia excretion are compared in intact and ammonia-loaded fish.

Determination of ammonium in soil extracts and water samples by an ammonia electrode

Abstract: Interference and recovery tests reported indicate that the Orion ammonia electrode can be used satisfactorily for determination of ammonium in soil extracts and water samples. The electrode method of analysis described is rapid, simple, and precise, and its results agree closely with those obtained by a distillation‐titration method of determining ammonium in soil extracts and water samples.

Ammonia Photolysis and the Role of Ammonia in Chemical Revolution

Abstract: THE suggestion that the primitive atmosphere was highly reducing and consisted mainly of methane, ammonia and water vapour1 is supported by Miller's observation that amino-acids are formed by electrical discharges through such a mixture2 and the synthesis of various biomolecules under presumed primitive Earth atmospheres containing ammonia3. Bada and Miller4 point out that an ammonium ion concentration of 10−2 to 10−3 M is necessary for the synthesis of these biomolecules while Rasool and McGovern5 suggest that a methane–ammonia atmosphere could have been maintained for 109 years by a low leakage rate of hydrogen.

Influence of ammonium and nitrate nutrition on enzymatic activity in soybean and sunflower.

Abstract: Under conditions of controlled pH, nitrate and ammonium are equally effective in supporting the growth of young soybean (Glycine max var Bansei) and sunflower (Helianthus annuus L var, Mammoth Russian) plans Soybean contains an active nitrate reductase in roots and leaves, but the low specific activity of this enzyme in sunflower leaves indicates a dependency upon the roots for nitrate reduction Suppression of nitrate reductase activity in sunflower leaves may be due to high concentrations of ammonia received from the roots Nitrate reductase activity in leaves of nitrate-supplied soybean and sunflower follows closely the distribution of nitrate reductase For the roots of both species, glutamic acid dehydrogenase activity was greater with ammonium than with nitrate The glutamic acid dehydrogenase of ammonium roots is wholly NADH-dependent, whereas that of nitrate roots is active with NADH and NADPH In leaves, an NADPH-dependent glutamic acid dehydrogenase appears to be responsible for the assimilation of translocated ammonia and ammonia formed by nitrate reductionIn soybean roots ammonia is actively incorporated into amides, much of which remains in the roots Sunflower roots are less active in amide formation but transfer much of it, together with ammonia, into the shoots Glutamine synthetase activity in leaves is 20- to 40-fold lower than in rootsGlucose-6-phosphate dehydrogenase activity appears to be correlated with the activity of the nitrate reducing system in roots, but not in leaves

Production of magnetic fluids by peptization techniques

Abstract: 1. A PROCESS FOR PRODUCING MAGNETIC FLUIDS FROM AQUEOUS INDUSTRIAL WASTE STREAMS CONTAINING FERROUS IRON SALTS WHICH COMSPRISES: OXIDIZING A PORTION OF THE FERROUS IRON CONTAINED IN THE WASTE STREAM TO THE FERRIC STATE; REACTING THE WASTE STREAM, NOW CONTAINING FERROUS AND FERRIC IRON SALTS, WITH AN EXCESS OF AMMONIUM HYDROXIDE TO PRECIPITATE A SLURRY OF COLLOIDAL SIZE FERROSO-FERRIC IRON OXIDE PARTICLES; ADDING A LONG CHAIN FATTY ACID HAVING ABOUT 18 CARBON ATOMS TO THE IRON OXIDE PARTICLE SLURRY WHEREBY THE FATTY ACID REACTS WITH AMMONIUM HYDROXIDE TO FORM AN AMMONIUM SALT OF THE FATTY ACID AND TO THEREAFTER COAT IRON OXIDE PARTICLES CONTAINED IN TH SLURRY WITH AN ADSORBED LAYER OF AMMONIATED FATTY ACID TO HEATING THE SLURRY TO A TEMPERATURE ABOVE THE DECOMPOSITION TEMPERATURE OF THE AMMONIATED FATTY ACID TO CONVERT THE ADSORBED LAYER OF AMMONIATED FATTY ACID TO THE ACID FORM AND TO EXPEL AMMONIA FROM THE SLURRY, AND RECOVERING FROM THE SLURRY A PRODUCT FRACTION COMPRISING FERRIMAGNETIC IRON OXIDE PARTICLES OF COLLOIDAL SIZE COATED WITH AN ADBSORBED LAYER OF FATTY ACID.

Purification, Crystallization and Properties of Tyrosine Phenol Lyase from Erwinia herbicola

Abstract: Crystalline tyrosine phenol lyase was prepared from the cell extract of Erwinia herbicola grown in a medium supplemented with l-tyrosine. The crystalline enzyme was homogeneous by the criteria of ultracentrifugation and acrylamide gel electrophoresis. The molecular weight was determined to be approximately 259,000. The crystalline enzyme catalyzed the conversion of l-tyrosine into phenol, pyruvate and ammonia, in the presence of added pyridoxal phosphate. The enzyme also catalyzed pyruvate formation from d-tyrosine, S-methyl-l-cysteine, 3, 4-dihydroxyphenyl-l-alanine, l- and d-serine, and l- and d-cysteine, but at lower rates than from l-tyrosine. l-Phenyl-alanine, l-alanine, phenol and pyrocatechol inhibited pyruvate formation from l-tyrosine.Crystalline tyrosine phenol lyase from Erwinia herbicola is inactive in the absence of added pyridoxal phosphate. Binding of pyridoxal phosphate to the apoenzyme is accompanied by pronounced increase in absorbance at 340 and 425 mμ. The amount of pyridoxal phosphate...

Catalytic hydrocracking of ammonia containing feedstocks

Abstract: HYDROCARBON FEEDSTOCKS IN ADMIXTURE WITH AMMONIA, AS FOR EXAMPLE THE TOTAL EFFUENT DERIVED FROM THE CATALYTIC HYDROFINING OF A NITROGEN CONTAINING FEEDSTOCK, ARE SUBJECTED TO HYDROCRACKING IN THE PRESENCE OF A STABILIZED, AMMONIA-RESISTANT Y ZEOLITE CATALYST. STABILITY TO STEAM AND AMMONIA IS IMPARTED TO THE ZEOLITE BASE DURING CONVERSION FROM ITS ORIGNAL SODIUM FORM TO A DECATIONIZED AND/OR HYDROGEN FORM BY A NOVEL SEQUENCE OF: (1) PARTIAL EXCHANGE OF AMMONNIUM IONS FOR SODIUM IONS, (2) STEAM CALCINATION, (3) FURTHER ION EXCHANGE OF AMMONIUM IONS FOR SODIUM IONS, AND (4) RECALCINING THE TWICE-EXCHANGED ZEOLITE IN INTIMATE ADMIXTURE WITH A FINELY DIVIDED, HYDROUS METAL OXIDE SUCH AS ALUMINA.

Catalytic synthesis of ammonia by graphite–alkali metal complexes containing transition–metal chloride

Abstract: Graphite forms lamellar compounds with substances such as ferric chloride or potassium, some of which, e.g. the graphite–FeCl3–K system, exhibit high catalytic activity for the synthesis of ammonia.

Reaction between ammonia and nitrogen dioxide

Abstract: The reaction between ammonia and nitrogen dioxide has been studied in the temperature range 615–660 K.The products of reaction are N2, N2O, NO and H2O. A mechanism is proposed which leads to the following parameters: For NH3+ NO2[graphic omitted]NH2+ HNO2k1= 1012.6 ± 0.3 exp (–115.69 ± 0.42/RT)cm3 mol–1 s–1(activation energies are expressed in kJ mol–1) and for NH2+ NO2[graphic omitted] NH + HNO2, NH2+ NO [graphic omitted] N2+ H2O k5/k2= 10–2.30 ± 0.3 exp (26.78 ± 4.18/RT)

Two-stage ammonia absorption refrigeration system with at least three evaporation stages

Abstract: A two-stage ammonia absorption refrigeration system can be operated with at least three evaporators maintained at decreasing temperatures but only two pressures by separating two ammonia streams of different ammonia purities from the strong ammonia water solution produced by the two stages of ammonia absorption. The novel system shows advantages over a three-stage ammonia absorption system previously required for the operation of three evaporators at decreasing temperatures.

Heavy duty aqueous wood preservative

Abstract: An aqueous wood treating and/or preservative composition is provided. The composition has a pH of 9 or more. Of the ions present in the composition, the cations are copper ammonium and/or zinc ammonium ions, while the anions include arsenic or arsenious ions, as well as further anions of an acid ester of phosphoric acid or carbonate or bicarbonate or both such acid ester of phosphoric acid and a, which anions have a solubility of ≧0.2% in concentrated (28%) aqueous ammonia. The further anions are derived from components which are insoluble in water. Wood treating procedures and treated wood products so-provided are also provided.

Conversion process for waste nitrogen-containing compounds

Abstract: This presents a process for converting nitrogen-containing compounds in which at least a portion of the nitrogen has a positive valence to molecular nitrogen by calcining the nitrogen-containing compounds in a fluidized bed in the presence of a reducing agent selected from the group consisting of ammonia, ammonium compounds and mixtures thereof

Ammonia elimination system

Abstract: THE NITROGEN CONTENT OF WASTE WATER IS REMOVED BY AIR STRIPPING AMMONIA FROM WASTE WATER. THE AMMONIA IS THEN ABSORBED IN WATER CONTAINING NITRIFYING MICROORGANISM, SO THAT THE AMMONIA IS OXIDIZED INTHE ABSORBER WATER. THE ABSORBER AND NITRIFIER WATER BECOMES FAR MORE CONCENTRATED IN NITROGEN THAN THE ORIGINAL WASTE WATER AND CAN BE DENITRIFIED BY DENITRIFYING MICROORGANISMS IN A SALLL REACTOR. AIR AND WATER CAN BE RECYLED IN THE SYSTEM.

The determination of ammonia in boiler feed-water with an ammonium-selective glass electrode

Abstract: An investigation has been made into the accuracy of ammonium-selective (ammonium-responsive) glass electrodes for determining ammonia (10 to 1000 µg 1–1) in boiler feed-water and similar high-purity water samples from power stations. The electrode potential follows the Nernst equation in samples containing up to 10 000 mg 1–1 of ammonia, the pH of which is controlled between 8·0 and 8·4 by the addition of triethanolamine-hydrochloric acid buffer solution. However, interfering species in the buffer solution cause a detectable deviation from Nernstian response at low ammonia concentrations (less than 1000 µg 1–1). By use of a calomel-0·1 N hydrochloric acid reference electrode, reproducible results have been obtained in static buffered solutions containing 10 to 1000 µg 1–1 of ammonia. Of the other impurities likely to be present in power-station waters only sodium caused a serious effect (100 µg 1–1 of sodium is equivalent to 25 µg 1–1 of ammonia). The within-batch standard deviations of analytical results were 2, 7, 17 and 33 µg 1–1 at concentrations of 10, 100, 500 and 1000 µg 1–1 of ammonia, respectively. Details of a recommended analytical procedure for discrete samples are given, and the application of the ammonium-selective electrode to continuous on-stream analysis is briefly discussed.

Analysis of Reaction Products of Nitrogen Tetroxide with Hydrazines under Nonignition Conditions

Abstract: Products formed by reaction of nitrogen tetroxide and hydrazine or methylhydrazines at low temperatures were collected and analyzed, using mass spectroscopy, gas chromatography and infrared absorption spectroscopy. It was found that hydrazine and nitrogen tetroxide form water, nitrogen, nitric oxide, hydrazinium nitrate, and ammonia. When monomethylhydrazine is used instead of hydrazine, the products include methylamine, dimethylamine, methanol, methylnitrosamine, dimethylnitro samine, N-methylformamide, water, methylhydrazinium nitrate, nitrogen, and dissolved oxides of carbon and nitrogen. When 1,1-dimethylhydrazine is used in place of hydrazine, the products include methylamine, dimethylamine, methanol, dimethylnitrosamine, dimethylformamide, formamide, nitrogen, water, dimethylhydrazinium nitrate, and dissolved oxides of carbon and nitrogen. Between 6Q% and 8Q% of the liquid portion of the products is dimethylnitro samine. Based on the evidence provided by these analyses, reaction mechanisms are proposed.

Process for the removal of hydrogen cyanide from gas streams

Abstract: Hydrogen cyanide contained in gas streams such as coke oven gas streams, is eliminated by catalytically hydrolyzing the hydrogen cyanide in the presence of water to ammonia and using as the catalyst one or more of the alkali metal hydroxides supported on alumina, alumina-silica, or silica. The formed ammonia is readily separated from the gas stream by any conventional technique. When unsaturated hydrocarbons and oxygen are present in the treated gas stream, the gas stream may be hydrogenated to eliminate oxygen and at least partially saturate the unsaturated hydrocarbons to prevent catalyst degradation.