Time-resolved FTIR studies provide activation free energy, activation enthalpy and activation entropy for GTPase reactions

2004 ◽  
Vol 307 (2-3) ◽  
pp. 227-232 ◽  
Author(s):  
Carsten Kötting ◽  
Klaus Gerwert
Keyword(s):  
Free Energy ◽  
Activation Enthalpy ◽  
Activation Entropy ◽  
Time Resolved ◽  
Activation Free Energy ◽  
Ftir Studies ◽  
Energy Activation

scholarly journals Kinetics and thermodynamics evaluation of carbon dioxide enhanced oil shale pyrolysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shuai Zhao ◽  
Youhong Sun ◽  
Xiaoshu Lü ◽  
Qiang Li
Keyword(s):  
Carbon Dioxide ◽  
Oil Shale ◽  
Activation Enthalpy ◽  
Activation Entropy ◽  
Atmospheric Conditions ◽  
Kinetics And Thermodynamics ◽  
Second Stage ◽  
Oil Shale Pyrolysis ◽  
Volatile Release ◽  
Energy Activation

AbstractThe pyrolysis process of oil shale is significantly affected by atmospheric conditions. In this paper, the pyrolysis experiments of oil shale under non-isothermal conditions are carried out using nitrogen and carbon dioxide as heat-carrying fluids. The results show that the activation energy of the second stage of oil shale pyrolysis under carbon dioxide is less than that under nitrogen. The thermodynamic analysis of the second stage of oil shale pyrolysis shows that Gibbs free energy, activation enthalpy and activation entropy are higher under carbon dioxide than those under nitrogen, which obeys the law of carbon dioxide promoting oil shale pyrolysis. In addition, the volatile release characteristics of oil shale in the second stage of pyrolysis were analyzed, which proves that the volatile release characteristics of oil shale under carbon dioxide are higher than that under nitrogen. Therefore, carbon dioxide is helpful to promote the pyrolysis of oil shale and increases the release of volatile substances during pyrolysis.

scholarly journals Particle Diffusivity and Free-Energy Profiles in Hydrogels from Time-Resolved Penetration Data

2021 ◽  
Author(s):  
Amanuel Wolde-Kidan ◽  
Anna Herrmann ◽  
Albert Prause ◽  
Michael Gradzielski ◽  
Rainer Haag ◽  
...  
Keyword(s):  
Free Energy ◽  
Time Resolved ◽  
Energy Profiles ◽  
Penetration Data ◽  
Free Energy Profiles

scholarly journals Thermodynamic Aspects of Flagellar Activity

1967 ◽  
Vol 47 (2) ◽  
pp. 249-265
Author(s):  
M. E. J. HOLWILL ◽  
N. R. SILVESTER
Keyword(s):  
Regression Line ◽  
Smooth Muscles ◽  
Activation Entropy ◽  
Striated Muscles ◽  
Kcal Mole ◽  
Thermal Dependence ◽  
Activation Free Energy ◽  
The Common ◽  
Cilia And Flagella ◽  
Rate Limiting

1. The frequencies of the beat of cilia and flagella from various organisms have been determined at temperatures in the range 5-35°C. 2. Values of the activation enthalpy (ΔH‡, kcal./mole) and activation entropy (ΔS‡, e.u.) derived from the thermal dependence of frequency show a linear correlation of the form, ΔS‡ = 3·25 ΔH‡-50·75. 3. The corresponding isokinetic activation free energy is 15·6 kcal./mole. 4. The results support a hypothesis that the breakdown of an ATP-ATPase complex could be the common rate-limiting reaction for flagellar activity. 5. Values of ΔH‡ and ΔS‡ for the decay of length or tension in striated muscles also fall on the same regression line but some smooth muscles show deviations.

Kinetic Studies on the Polymerization of Dicyclohexylmethylmethane-4,4'-Diisocyanate with Polyoxytetramethylene Diol

2013 ◽  
Vol 791-793 ◽  
pp. 32-35
Author(s):  
Jian Cheng Wang
Keyword(s):  
Rate Constant ◽  
Arrhenius Equation ◽  
Activation Enthalpy ◽  
Kinetic Studies ◽  
Activation Entropy ◽  
Dimethyl Acetamide ◽  
Different Temperatures ◽  
Ft Ir ◽  
Temperature Activation

Dicyclohexylmethylmethane-4,4'-diisocyanate is used to react with polyoxytetramethylene diol at different temperatures. N,N-Dimethyl acetamide is used as solvent.In situFT-IR is used to monitor the reaction to work out rate constant, Arrhenius equation and Eyring equation. The polymerization has been found to be a second order reaction, and the rate constant increases with the rise of temperature. Activation energy (Ea), activation enthalpy (ΔH) and activation entropy (ΔS) for the polymerization are respectively calculated out, which are very useful to reveal the reaction mechanism.

Elucidating the role of solvents in acid catalyzed dehydration of biorenewable hydroxy-lactones

2020 ◽  
Vol 5 (4) ◽  
pp. 651-662 ◽  
Author(s):  
Gourav Shrivastav ◽  
Tuhin S. Khan ◽  
Manish Agarwal ◽  
M. Ali Haider
Keyword(s):  
Free Energy ◽  
Transition State ◽  
Energy Barrier ◽  
Free Energy Barrier ◽  
Activation Free Energy ◽  
Acid Catalyzed

Utilizing the differential stabilization of reactant and transition state in the polar and apolar solvents to lower the activation free energy barrier for acid-catalyzed dehydration of hydroxy lactones.

Activation free energy and entropy for the normal and exchange selfdiffusion processes on Cu(100)

1993 ◽  
Vol 289 (1-2) ◽  
pp. A501
Author(s):  
L.B. Hansen ◽  
P. Stoltze ◽  
K.W. Jacobsen ◽  
J.K. Nørskov
Keyword(s):  
Free Energy ◽  
Activation Free Energy

Thermodynamic studies in solution. Part IV. Solvent effect on the solvolysis of tert-butyl chloride. A new treatment of the experimental data

1979 ◽  
Vol 57 (5) ◽  
pp. 500-502 ◽  
Author(s):  
Joaquim Jose Moura Ramos ◽  
Jacques Reisse ◽  
M. H. Abraham
Keyword(s):  
Free Energy ◽  
Solvent Effect ◽  
Free Energies ◽  
Butyl Chloride ◽  
Activation Free Energy ◽  
Tert Butyl ◽  
New Treatment ◽  
The One ◽  
Activated Complex ◽  
Tert Butyl Chloride

A new treatment of the solvent effect on the solvolysis of tert-butyl chloride is proposed. This treatment is based on activation free energy measurements and on transfer free energy measurements of the reactant (R) on the one hand and of a model (M) of the activated complex (AC) on the other hand. Solute–solvent interaction free energies for the reactant, the activated complex and the model compound are estimated. This estimation involves the calculation of the free energy of cavity formation of these various solutes (R, AC, and M) in all the solvents. These cavity terms, which are a function of the cohesive properties of the solvent and of the surface of the cavity do not reflect the electronic structure of the solute whereas the interaction free energy term does. The method we propose can be described as a new 'experimental' approach for the study of the charge separation in an activated complex.

Effect of Preferential Solvation on the Kinetics and Thermodynamics of Oxidation of Anilines by Nicotinium Dichromate

2005 ◽  
Vol 60 (10) ◽  
pp. 1105-1111 ◽  
Author(s):  
Durvas S. Bhuvaneshwari ◽  
Kuppanagounder P. Elango
Keyword(s):  
Free Energy ◽  
Preferential Solvation ◽  
Zero Order ◽  
Substituted Anilines ◽  
Isokinetic Relationship ◽  
Solvent Interactions ◽  
Activation Free Energy ◽  
First Order ◽  
Linear Free Energy ◽  
Energy Relationships

The nicotinium dichromate (NDC) oxidation of anilines, in varying mole fractions of benzene/2- methylpropan-2-ol mixtures, in the presence of p-toluenesulfonic acid (TsOH) is first order in NDC and TsOH and zero order with respect to anilines in the concentration range investigated. The NDC oxidation of 15 meta- and para-substituted anilines complies with the isokinetic relationship but not to any of the linear free energy relationships. The activation free energy data failed to correlate with macroscopic solvent parameters such as εr and ENT. Correlation of ΔG# with Kamlet-Taft solvatochromic parameters (α, β , π*) suggests that the specific solute-solvent-solvent interactions play a major role in governing the reactivity.

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