Synergistic extraction of uranyl ion with β-diketones and sulphoxides

1973 ◽  
Vol 26 (1) ◽  
pp. 77 ◽  
Author(s):  
MS Subramanian ◽  
SA Pai
Keyword(s):  
Equilibrium Constant ◽  
Uranyl Ion ◽  
Synergistic Extraction ◽  
Synergistic Enhancement ◽  
Different Temperatures ◽  
Base Strength ◽  
Entropy Factor ◽  
Enthalpy And Entropy ◽  
Long Chain ◽  
Synergistic Reaction

Distribution measurements of the synergistic extraction of uranyl ion with β-diketones and sulphoxide donors indicate that the long-chain aliphatic sulphoxides are ten times more powerful as synergists than the aromatic sulphoxides. Methods of estimating the relative base strength of the donors by i.r. and N.M.R. studies of the donor hydrates are described and the results have been correlated with the equilibrium constant of the synergistic reaction. For a given sulphoxide donor, the synergistic enhancement seems to be affected by the various substituents changing the acidity of the β-diketone. From the values of enthalpy and entropy factors derived for these systems by distribution measurements at different temperatures, the greater stability of the complexes with aliphatic sulphoxide donors has been attributed to the entropy factor.

Influence des effets inductifs et stériques sur la basicité des amines tertiaires. Détermination et interprétation des ΔH et des ΔS

1968 ◽  
Vol 46 (12) ◽  
pp. 2021-2025 ◽  
Author(s):  
Guy. Perrault
Keyword(s):  
Hydrogen Bonds ◽  
Short Chain ◽  
Tertiary Amines ◽  
Intramolecular Hydrogen Bonds ◽  
Different Temperatures ◽  
New Type ◽  
Entropy Factor ◽  
Intramolecular Hydrogen ◽  
Long Chain ◽  
Thermodynamic Factors

ΔH and ΔS were obtained by pKa measurements in water at different temperatures for a series of dihydroxylated tertiary amines. The thermodynamic factors seem to confirm that the diminution in basicity introduced by long chain substituents is caused by frontal hindrance to solvation, accompanied by a new type of back-strain. With short chain substituents, the formation of intramolecular hydrogen bonds can be seen by the variations of the entropy factor.

scholarly journals Solubility of Butylated Hydroxytoluene (BHT) in Aqueous and Alcohol Solutions from 293.15 to 313.15 K

2014 ◽  
Vol 28 ◽  
pp. 48-58 ◽  
Author(s):  
Shipra Baluja ◽  
Kapil Bhesaniya ◽  
Rahul Bhalodia ◽  
Sumitra Chanda
Keyword(s):  
Gibbs Energy ◽  
Thermodynamic Functions ◽  
Butylated Hydroxytoluene ◽  
Solubility Data ◽  
Different Temperatures ◽  
Enthalpy And Entropy

The solubility of Butylated hydroxyl toluene in aqueous and alcohol solutions were determined at different temperatures (293.15 to 313.15) K. Using Van’t Hoff and Gibb’s equations, some thermodynamic functions such as Gibbs energy, enthalpy and entropy of dissolution, and of mixing of Butylated hydroxyl toluene in aqueous and alcohol solutions, were evaluated from solubility data. The solubility was greater in butanol and minimum in water. The enthalpies, entropy and Gibb’s energy of dissolution were positive for all solvents.

Synergistic extraction of uranyl ion with acylpyrazolones and dicyclohexano-18-crown-6

1987 ◽  
Vol 116 (1) ◽  
pp. 203-211 ◽  
Author(s):  
S. K. Mundra ◽  
S. A. Pai ◽  
M. S. Subramanian
Keyword(s):  
Uranyl Ion ◽  
Synergistic Extraction

Is fluid-phase endocytosis conserved in hepatocytes of species acclimated and adapted to different temperatures?

2000 ◽  
Vol 278 (2) ◽  
pp. R529-R536 ◽  
Author(s):  
David Padrón ◽  
Michael E. Bizeau ◽  
Jeffrey R. Hazel
Keyword(s):  
Lucifer Yellow ◽  
Fluid Phase ◽  
Membrane Lipid ◽  
Primary Objective ◽  
Chain Polyunsaturated Fatty Acid ◽  
Chow Diet ◽  
Sprague Dawley ◽  
Fluid Phase Endocytosis ◽  
Different Temperatures ◽  
Long Chain

Our primary objective was to determine if rates of fluid-phase endocytosis (FPE) were conserved in hepatocytes from organisms acclimated and adapted to different temperatures. To this aim, the fluorescent dye Lucifer yellow was employed to measure FPE at different assay temperatures (AT) in hepatocytes from 5°C- and 20°C-acclimated trout, Oncorhynchus mykiss (at 5 and 20°C AT), 22°C- and 35°C-acclimated tilapia, Oreochromis nilotica (at 22 and 35°C AT), and the Sprague-Dawley rat (at 10, 20, and 37°C AT). FPE was also studied in rats fed a long-chain polyunsaturated fatty acid (PUFA)-enriched diet (at 10°C AT). Despite being temperature dependent, endocytic rates (values in pl ⋅ cell− 1 ⋅ h− 1) in both species of fish were compensated after a period of acclimation. For example, in 20°C-acclimated trout, the rate of endocytosis declined from 1.84 to 1.07 when the AT was reduced from 20 to 5°C; however, after a period of acclimation at 5°C, the rate (at 5°C AT) was largely restored (1.80) and almost perfectly compensated (95%). In tilapia, endocytic rates were also temperature compensated, although only partially (36%). Relatively similar rates obtained at 5°C in 5°C-acclimated trout (1.8), at 20°C in 20°C-acclimated trout (1.84), and at 22°C in 22°C-acclimated tilapia (2.2) suggest that endocytic rates are somewhat conserved in these two species of fish. In contrast, the rate in rat measured at 37°C (16.83) was severalfold greater than in fish at their respective body temperatures. A role for lipids in determining rates of endocytosis was supported by data obtained at 10°C in hepatocytes isolated from rats fed a long-chain PUFA-enriched diet: endocytic rates were higher (5.35 pl ⋅ cell− 1 ⋅ h− 1) than those of rats fed a standard chow diet (2.33 pl ⋅ cell− 1 ⋅ h− 1). The conservation of endocytic rates in fish may be related to their ability to conserve other membrane characteristics (i.e., order or phase behavior) by restructuring their membrane lipid composition or by modulating the activities of proteins that regulate endocytosis and membrane traffic, whereas the lack of conservation between fish and rat may be due to differences in metabolic rate.

Chemical Thermodynamics

2021 ◽  
pp. 344-364
Author(s):  
Christopher O. Oriakhi
Keyword(s):  
Free Energy ◽  
Phase Change ◽  
Equilibrium Constant ◽  
Gibbs Free Energy ◽  
Chemical Thermodynamics ◽  
Laws Of Thermodynamics ◽  
Core Concepts ◽  
Enthalpy And Entropy Changes ◽  
Enthalpy And Entropy ◽  
The Relationship

Chemical Thermodynamics discusses the fundamental laws of thermodynamics along with their relationships to heat, work, enthalpy, entropy, and temperature. Predicting the direction of a spontaneous change and calculating the change in entropy of a reaction are core concepts. The relationship between entropy, free energy and work is covered. The Gibbs free energy is used quantitatively to predict if reactions or processes are going to be exothermic and spontaneous or endothermic under the stated conditions. Also explored are the enthalpy and entropy changes during a phase change. Finally the Gibbs free energy of a chemical reaction is related to its equilibrium constant and the temperature.

The transport numbers of the ions in solutions of silver dodecyl sulphate

1937 ◽  
Vol 160 (902) ◽  
pp. 440-454 ◽  
Keyword(s):  
Transport Numbers ◽  
Electrical Conductivities ◽  
Different Temperatures ◽  
Long Chain

The electrical conductivities of a number of metallic long-chain alkyl sulphates have been measured at different temperatures (Lottermoser and Piischell 1933; Howell and Robinson 1936). The curve for each salt at each temperature consists of three distinct ranges.

Ethen/1-Hexen- und 1-Octadecen-Copolymerisation mit dem stereorigiden Zirkon-Katalysatorsystem iPr(CpFlu)ZrCl2/MAO: Einfluß der Temperatur / Copolym erization of Ethene/1-Hexene and 1-Oetadecen with the Stereorigid Zirconium Catalyst System iPr(CpFlu)ZrCl2/MAO : Influence of the Temperature

1995 ◽  
Vol 50 (3) ◽  
pp. 423-429 ◽  
Author(s):  
Peter H. Mühlenbrock ◽  
Gerhard Fink
Keyword(s):  
Active Center ◽  
Order Statistic ◽  
Catalyst System ◽  
Polymerization Rate ◽  
Side Chain ◽  
Wide Range ◽  
Different Temperatures ◽  
Sterical Hindrance ◽  
Increasing Temperature ◽  
Long Chain

Ethene was copolymerized with 1-hexene and 1-octadecene at different temperatures to study the influence of the temperature. The stereorigid catalyst [2,4-cyclopentadien-1-yliden- (iso-propyliden)fluoren-9-yliden]zirconium dichloride iPr(CpFlu )ZrCl2 1 in combination with methylalumoxane MAO was used. The polymerization rate of ethene depends in a wide range on the temperature and the com onom er content in solution. In each case a large rate enhancem ent at low ratios [com onom er]/[ethene] was observed. A t 25 °C the polymerization rate of ethene increases continuously with increasing [1-hexene]/[ethene]-ratio. At 40 °C the consumption of ethene is nearly independent of the 1-hexene content in solution. Finally, at 60 °C, similar to the ethene/1-octadecene-copolymerisation at different temperatures, the polymerization rate of ethene decreases with increasing [1-hexene]/[ethene]-ratio. It is suggested that this behavior is caused by the mobility of the side chains in the copolym er near the active center, probably for sterical reasons. W ith increasing temperatures, the side chain becomes more and more flexible and thus the sterical hindrance is increased. This effect is even stronger with long chain α-olefins.The microstructure of the copolymer was investigated with respect to Marcovian statistic 1. and 2. order. The experimental triad distribution is described satisfactorily only with the second order statistic. Independent of the temperature the r22 parameter is considerably greater than the r12 parameter, the insertion of an α-olefin thus being more favored for he sequence {R -(α-olefine)-(α-olefine)-Kat.} than for {R -(ethene)-(α-olefine)-Kat.}. It therefore appears that both last inserted monomers influence the insertion of the subsequent monomer, especially at high comonomer contents. Furthermore, the parameters for the α-olefin insertions r22 and r12 are nearly independent of the temperature of polymerization, whereas the r11 and r21 parameters increase with increasing temperature.

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