Dissociation Constants of Ammonium Ion and Activity Coefficients of Ammonia in Aqueous Ammonium Sulfate Solutions

1997 ◽  
Vol 42 (6) ◽  
pp. 1216-1218 ◽  
Author(s):  
Masunobu Maeda ◽  
Takako Iwata
Keyword(s):  
Ammonium Sulfate ◽  
Activity Coefficients ◽  
Dissociation Constants ◽  
Ammonium Ion ◽  
Sulfate Solutions

Thermodynamic and Transport Properties of Some Disaccharides in Aqueous Ammonium Sulfate Solutions at Various Temperatures

2008 ◽  
Vol 53 (8) ◽  
pp. 1713-1724 ◽  
Author(s):  
Parampaul K. Banipal ◽  
Vickramjeet Singh ◽  
Gurpreet Kaur ◽  
Mandeep Kaur ◽  
Tarlok S. Banipal
Keyword(s):  
Transport Properties ◽  
Ammonium Sulfate ◽  
Sulfate Solutions ◽  
Thermodynamic And Transport Properties

Glyoxal in Aqueous Ammonium Sulfate Solutions: Products, Kinetics and Hydration Effects

2011 ◽  
Vol 45 (15) ◽  
pp. 6336-6342 ◽  
Author(s):  
Ge Yu ◽  
Amanda R. Bayer ◽  
Melissa M. Galloway ◽  
Kyle J. Korshavn ◽  
Charles G. Fry ◽  
...  
Keyword(s):  
Ammonium Sulfate ◽  
Sulfate Solutions

Further studies on the corticosteroid-receptor system of the nasal gland of the domestic duck (Anas platyrhynchos)

1983 ◽  
Vol 61 (7) ◽  
pp. 731-743 ◽  
Author(s):  
Thomas Sandor ◽  
Afzal Z. Mehdi ◽  
John A. DiBattista
Keyword(s):  
Ammonium Sulfate ◽  
Reaction Temperature ◽  
Rate Constants ◽  
Binding Sites ◽  
Dissociation Constants ◽  
Similar Data ◽  
Nuclear Binding ◽  
Ammonium Sulfate Precipitate ◽  
Equilibrium Dissociation Constants ◽  
Equilibrium Dissociation

The interaction of tritiated corticosterone with the nasal gland corticosterone receptor was investigated. Kinetic studies have shown that the association of [3H]corticosterone–receptor followed second-order reaction kinetics and the dissociation of the ligand from the receptor became "pseudo" first order in the presence of large excess of radioinert steroids at 0, 15, 25, and 35 °C. Similar data were obtained with an ammonium sulfate precipitate of the cytosol. Dissociation rate constants varied from 10−5 to 10−3 s−1 and the association rate constants varied from 0.5 × 104 to 3.8 × 105 M−1∙s−1, depending on the reaction temperature and the cytoplasmic receptor preparation. Equilibrium dissociation constants were in 10−8–10−9 M range. Equilibrium dissociation constants, calculated from kinetic data (kd/ka), showed a marked temperature dependence, while those obtained by saturation analysis varied much less with the reaction temperature. Data obtained in these experiments were used to calculate some thermodynamic parameters of the binding of corticosterone to the cytoplasmic receptor. The enthalpy of dissociation was 101.5 and 79.4 kJ∙mol−1 and the entropy of dissociation was 200 and 280 J∙mol−1∙degree−1 for the crude cytoplasmic receptor and the ammonium sulfate precipitate, respectively. From the equilibrium dissociation constants, the enthalpy and entropy of the equilibrium binding was calculated. Polynomial fitting of Ka values versus 1/T yielded enthalpy (ΔH) values from −0.9 to −88.8 kJ∙mol−1, depending on the nature of the receptor preparation. Entropy values were negative for kinetically derived equilibrium association constants from the crude cytosol at all temperatures and for 0 and 15 °C for the precipitate. Entropy values were positive for Ka values obtained from kinetic rates at 25 and 35 °C and for Ka's calculated from saturation analysis. Further experiments with the precipitate confirmed our previous contention that the nasal gland cytoplasmic corticosterone receptor metabolized the bound ligand to 11-dehydrocorticosterone, though the receptor preparation was corticosterone specific. The following hydrodynamic parameters were obtained on the binding macromolecule: molecular weight, 316 000; s20,w, 8.0; Stokes radius (rs), 77.3 Å (1 Å = 0.1 nm); total frictional ratio (f/f0), 1.71. The labeled receptor preparation translocated to homologous nuclear binding sites following heat activation and, at the nuclear binding sites, the ligand was almost exclusively in its oxidized form. Measurement of the nuclear steroid–receptor complex by exchange assay with [3H]corticosterone confirmed the presence of nuclear binding sites. From these studies, it was concluded that the nasal gland of the duck contains specific, glucocorticoid-type corticosterone receptors and that the effector steroid is probably 11-dehydrocorticosterone or a critical mixture of these two steroids, with the oxidized form predominating.

Dissolution Kinetics of Ulexite in Ammonium Sulfate Solutions

2003 ◽  
Vol 42 (5) ◽  
pp. 982-986 ◽  
Author(s):  
Asım Künkül ◽  
Nizamettin Demirkıran ◽  
Ahmet Baysar
Keyword(s):  
Ammonium Sulfate ◽  
Dissolution Kinetics ◽  
Sulfate Solutions ◽  
Kinetics Of
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