Densities and molar volumes of the Ca(NO3)2-CaBr2-H2O system

1980 ◽  
Vol 45 (1) ◽  
pp. 17-20 ◽  
Author(s):  
Zdeněk Kodejš ◽  
Ivo Sláma
Keyword(s):  
Calcium Nitrate ◽  
Molar Ratio ◽  
Molar Volumes ◽  
Temperature Range

Molar volumes and densities of mixtures consisting of water, calcium nitrate, and calcium bromide have been determined in the range of molar ratio of water within 3 to 18 and in the temperature range of 20 to 80° C. The obtained results have been described by an equation derived under the assumption that additivity of molar volumes of the components is valid.

Effect of Fe and Co promoters on CO methanation activity of nickel catalyst prepared by impregnation – co-precipitation method

2020 ◽  
Vol 18 (5-6) ◽  
Author(s):  
Buyan-Ulzii Battulga ◽  
Tungalagtamir Bold ◽  
Enkhsaruul Byambajav
Keyword(s):  
Synergetic Effect ◽  
Space Velocity ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Alumina Support ◽  
Co Methanation ◽  
Temperature Range ◽  
Co Precipitation ◽  
Catalyst Distribution

AbstractNi based catalysts supported on γ-Al2O3 that was unpromoted (Ni/γAl2O3) or promoted (Ni–Fe/γAl2O3, Ni–Co/γAl2O3, and Ni–Fe–Co/γAl2O3) were prepared using by the impregnation – co-precipitation method. Their catalytic performances for CO methanation were studied at 3 atm with a weight hourly space velocity (WHSV) of 3000 ml/g/h of syngas with a molar ratio of H2/CO = 3 and in the temperature range between 130 and 350 °C. All promoters could improve nickel distribution, and decreased its particle sizes. It was found that the Ni–Co/γAl2O3 catalyst showed the highest catalytic performance for CO methanation in a low temperature range (<250 °C). The temperatures for the 20% CO conversion over Ni–Co/γAl2O3, Ni–Fe/γAl2O3, Ni–Fe–Co/γAl2O3 and Ni/γAl2O3 catalysts were 205, 253, 263 and 270 °C, respectively. The improved catalyst distribution by the addition of cobalt promoter caused the formation of β type nickel species which had an appropriate interacting strength with alumina support in the Ni–Co/γAl2O3. Though an addition of iron promoter improved catalyst distribution, the methane selectivity was lowered due to acceleration of both CO methanation and WGS reaction with the Ni–Fe/γAl2O3. Moreover, it was found that there was no synergetic effect from the binary Fe–Co promotors in the Ni–Fe–Co/γAl2O3 on catalytic activity for CO methanation.

An initial investigation on rumen fermentation pattern and methane emission of sheep offered diets containing urea or nitrate as the nitrogen source

2012 ◽  
Vol 52 (7) ◽  
pp. 653 ◽  
Author(s):  
L. Li ◽  
J. Davis ◽  
J. Nolan ◽  
R. Hegarty
Keyword(s):  
Fatty Acid ◽  
Methane Production ◽  
Volatile Fatty Acid ◽  
Rumen Fluid ◽  
Calcium Nitrate ◽  
Rumen Fermentation ◽  
Molar Ratio ◽  
Volatile Fatty Acid Concentration ◽  
Enteric Methane ◽  
Fermentation Pattern

The effects of dietary nitrate and of urea on rumen fermentation pattern and enteric methane production were investigated using 4-month-old ewe lambs. Ten lambs were allocated into two groups (n = 5) and each group was offered one of two isonitrogenous and isoenergetic diets containing either 1.5% urea (T1) or 3% calcium nitrate (T2). Methane production was estimated using open-circuit respiration chambers after 6 weeks of feeding. No difference in nitrogen (N) balance, apparent digestibility of N or microbial N outflow existed between treatments (P > 0.05). Animals offered the T2 diet lost less energy through methane than did those fed the T1 diet (P < 0.05). Total volatile fatty acid concentration, molar proportion of propionate, and the molar ratio of acetate to propionate in rumen fluid were not affected by dietary N source. Compared with urea inclusion, nitrate inclusion caused a significantly higher acetate and lower butyrate percentage in rumen volatile fatty acid. Nitrate supplementation tended to lower methane production by ~7.7 L/day relative to urea supplementation (P = 0.06). Methane yield (L/kg DM intake) was reduced (P < 0.05) by 35.4% when 1.5% urea was replaced by 3% calcium nitrate in the diet. Emission intensity (L methane/kg liveweight gain) was ~17.3% lower in the nitrate-supplemented sheep when compared with urea-fed sheep; however, the reduction was not statistically significant (P > 0.05). This study confirms that the presence of nitrate in the diet inhibits enteric methane production. As no clinical symptoms of nitrite toxicity were observed and sheep receiving nitrate-supplemented diet had similar growth to those consuming urea-supplemented diet, it is concluded that 3% calcium nitrate can replace 1.5% urea as a means of meeting ruminal N requirements and of reducing enteric methane emissions from sheep, provided animals are acclimated to nitrate gradually.

Phase diagram of the system CaSO4—K2SO4—KNO3—Ca(NO3)2—H2O

2014 ◽  
Vol 7 (1) ◽  
pp. 20-24 ◽  
Author(s):  
Jana Jurišová ◽  
Vladimír Danielik ◽  
Pavel Fellner ◽  
Marek Lencsés ◽  
Milan Králik
Keyword(s):  
Phase Diagram ◽  
Quantitative Determination ◽  
Solid Phase ◽  
Calcium Nitrate ◽  
Primary Crystallization ◽  
Potassium Nitrate ◽  
Molar Ratio ◽  
Calcium Cations ◽  
Lower Ratio

Abstract Potassium nitrate as a fertilizer suitable for greenhouse and hydroponic applications can be prepared by the reaction of potassium sulphate with calcium nitrate. However, it may happen that simultaneously with the precipitation of gypsum (CaSO4·2H2O) also two other binary salts, viz. syngenite (K2SO4·CaSO4·H2O) and görgeyite (K2SO4·5CaSO4·H2O) can crystallize. This would lower the yield of KNO3. For minimization of potassium loss we have to determine the conditions under which syngenite and görgeyite crystallize. As a useful tool for the quantitative determination of specific hydrates, simultaneous DTA/TG technique appeared. Each hydrate decomposes at a certain temperature. The loss of water at dehydration can be used for a quantitative determination of the amount of the hydrate in the precipitating solid phase. Based on the experimental data several conclusions can be drawn: (i) excess of calcium cations lowers the concentration of sulphate ions in the liquid phase together with lowering of contents of syngenite and görgeyite in the solid phase; (ii) higher content of water results in a higher solubility of sulphate ions; (iii) joint crystallization of syngenite and gypsum occurs in the composition area interesting from the point of KNO3 production; (iv) area of the primary crystallization of görgeyite does not exist in the phase diagram at 80 °C. However, görgeyite crystallizes at the molar ratio Ca(NO3)2:K2SO4 = 1:1 by ternary crystallization; (v) area of crystallization of pure gypsum is shifted to lower ratio Ca(NO3)2:K2SO4 by the addition of water to the system.

Densities and Excess Molar Volumes of the Ternary Mixture 2-Butanol + Chloroform + Benzene and Binary Mixtures 2-Butanol + Chloroform, or + Benzene over the Temperature Range (288.15 to 313.15) K

2008 ◽  
Vol 53 (8) ◽  
pp. 1965-1969 ◽  
Author(s):  
Jelena D. Smiljanić ◽  
Mirjana Lj. Kijevčanin ◽  
Bojan D. Djordjević ◽  
Dušan K. Grozdanić ◽  
Slobodan P. Šerbanović
Keyword(s):  
Binary Mixtures ◽  
Ternary Mixture ◽  
Excess Molar Volumes ◽  
Molar Volumes ◽  
Temperature Range

Kinetic Characteristics of Si3N4 CVD

1991 ◽  
Vol 250 ◽  
Author(s):  
W. Y. Lee ◽  
J. R. Strife ◽  
R. D. Veltri
Keyword(s):  
Deposition Rate ◽  
Mass Spectroscopy ◽  
Flow Rate ◽  
Molar Ratio ◽  
Kinetic Characteristics ◽  
Temperature Range ◽  
Time Flow ◽  
Effects Of Temperature ◽  
Temperature Time

AbstractThe CVD of Si3N4 from SiF4 and NH3 gaseous precursors was studied using a hotwall reactor in the temperature range of 1340 to 1490°C. The effects of temperature, time, flow rate, and SiF4/NH3 molar ratio on deposition rate and axial and radial deposition profiles were identified. The decomposition characteristics of pure NH3 and SiF4 were studied utilizing mass spectroscopy and compared to thermodynamic predictions.

Density and Excess Molar Volumes of 1-Butanol + Methanol + Electrolyte Systems in the Temperature Range 293.15–308.15 K

2016 ◽  
Vol 61 (4) ◽  
pp. 1368-1377 ◽  
Author(s):  
W. Gul Khan ◽  
Hafiz-ur-Rehman ◽  
Saira Siddique ◽  
M. Shahid Ansari
Keyword(s):  
Excess Molar Volumes ◽  
Molar Volumes ◽  
Temperature Range

Synthesis and characterization of pure and nanosized hydroxyapatite bioceramics

2017 ◽  
Vol 6 (2) ◽  
pp. 149-157 ◽  
Author(s):  
Aneela Anwar ◽  
Qudsia Kanwal ◽  
Samina Akbar ◽  
Aisha Munawar ◽  
Arjumand Durrani ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Calcium Nitrate ◽  
Temperature Stability ◽  
Molar Ratio ◽  
Calcium Nitrate Tetrahydrate ◽  
High Temperature Stability ◽  
X Ray ◽  
Transmission Electron ◽  
Nanosized Hydroxyapatite ◽  
Co Precipitation

AbstractSynthetic nanosized hydroxyapatite (HA) particles (<120 nm) were prepared using a co-precipitation technique by adopting two different routes – one from an aqueous solution of calcium nitrate tetrahydrate and diammonium hydrogen phosphate at pH 10 and the other by using calcium hydroxide and phosphoric acid as precursors at pH 8.5 and reaction temperature of 50°C. The lattice parameters of HA nanopowder were analogous to reference [Joint Committee on Powdered Diffraction Standards (JCPDS)] pattern no. 09-432. No decomposition of HA into other phases was observed even after heating at 1000°C in air for 1 h. This observation revealed the high-temperature stability of the HA nanopowder obtained using co-precipitation route. The effects of preliminary Ca/P molar ratio, precipitation, pH and temperature on the evolution of phase and crystallinity of the nanopowder were systematically examined and optimized. The product was evaluated by techniques such as X-ray-diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) and Raman spectroscopy analyses. The chemical structural analysis of the as-prepared HA sample was performed using X-ray photoelectron spectroscopy (XPS). After heat treatment at 1000°C for 1 h and ageing for 15 h, the product was obtained as a phase-pure, highly crystalline HA nanorods.

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