A Mechanism for the Rare Fluctuation that Powers Protein Conformational Change

Most functional processes of biomolecules are rare events. Key to a rare event is the rare fluctuation that enables the energy activation process, which powers the system across the activation barrier. But the physical nature of this rare fluctuation and how it enables barrier crossing are unknown. With the help of a novel metric, the reaction capacity pC, that rigorously defines the beginning and parameterizes the progress of energy activation, the rare fluctuation was identified as a special phase-space condition that is necessary and sufficient for initiating systematic energy flow from the non-reaction coordinates into the reaction coordinates. The energy activation of a prototype biomolecular isomerization reaction is dominated by kinetic energy transferring into and accumulating in the reaction coordinates, administered by inertial forces alone. The two major reaction coordinates move in precise synergy, with one acting as a gating mechanism on the other. This mechanism is enabled by the structural features of biomolecules and may the cause of their unique functions that are not possible in small molecules.

Minimization of the Electric Energy in Systems Using Ultra-High Density Magnetic Storage

We present an optimization of the thickness of the magnetic layers that serve to record the information of the daily need in order to minimize the useful electrical energy. The study provides details on the energy activation and distribution of the energy barriers in the samples of thickness . We find that distribution of the energy barriers , its distribution width , the real activation field are lowest in the sample of thickness , hence this sample allows to use less electrical energy for information recording.

Kinetics and thermodynamics evaluation of carbon dioxide enhanced oil shale pyrolysis

The 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.

Studies on the effect of Aquo-Dioxan Solvent System on the biochemical behaviour of the Substituted Valerates

Valerates and Substituted Valerates have been found to be useful for humanbeings as its hydrolysis product i.e. valence acid is used in the society in the form of perfumes flavours platister, vinyl stabilizer and pharmaceuyicals. With a views to study the solvent effect of 1:4 dioxan on the biochemical behivour of the hydrolysis product of a substituted valerate, the kinetic of Alkali catalysed of mothyl iso-valerate was studies in aquodioxan media. Increase observed in free energy activation with simultaneous increase in the value of both the activation H* and S*, it is concluded that in the presence of dioxan with reaction media, the reaction becomes enthaipy dominating and entropy controlled. From the evaluated values of the reaction which comes to be 329.0, it is inferred that Barclay-Butler rule is obeyed by the reaction and there is strong solvent- solute interaction in presence of dioxan the reaction media.

Doubly-Charged Negative Ions as Novel Tunable Catalysts: Graphene and Fullerene Molecules Versus Atomic Metals

The fundamental mechanism underlying negative-ion catalysis involves bond-strength breaking in the transition state (TS). Doubly-charged atomic/molecular anions are proposed as novel dynamic tunable catalysts, as demonstrated in water oxidation into peroxide. Density Functional Theory TS calculations have found a tunable energy activation barrier reduction ranging from 0.030 eV to 2.070 eV, with Si2−, Pu2−, Pa2− and Sn2− being the best catalysts; the radioactive elements usher in new application opportunities. C602− significantly reduces the standard C60− TS energy barrier, while graphene increases it, behaving like cationic systems. According to their reaction barrier reduction efficiency, variation across charge states and systems, rank-ordered catalysts reveal their tunable and wide applications, ranging from water purification to biocompatible antiviral and antibacterial sanitation systems.

Doubly-charged Negative Ions as Novel Tunable Catalysts: Graphene and Fullerene Molecules Versus Atomic Metals

The fundamental mechanism underlying negative-ion catalysis involves bond-strength breaking in the transition state (TS). Doubly-charged atomic/molecular anions are proposed as novel dynamic tunable catalysts and demonstrated in water oxidation to peroxide. Density Functional Theory TS calculations have found tunable energy activation barrier reduction ranging from 0.030 eV to 2.070eV, with Si2ˉ, Pu2ˉ, Pa2ˉ and Sn2ˉ the best catalysts; the radioactive elements usher in new application opportunities. C602ˉ reduces significantly the standard C60ˉ TS energy barrier while graphene increases it, behaving like cationic systems. Rank-ordered catalysts according to their reaction barrier reduction efficiency, variation across charge states and systems reveal their tunable and wide applications, ranging from water purification to biocompatible anti-viral and anti-bacterial sanitation systems.

Analysis of shape, size and structure dependent thermodynamic properties of nanowires

A simple model based on thermodynamic variables is used to study the effect of shape, size and structure on the various thermodynamic properties of nanowires. The expression of cohesive energy derived by Qi and Wang [16] is used and ratio of surface atoms to total number of atoms is expressed in terms of shape parameter, radius of nanowire and atomic packing fraction. The variation in cohesive energy, activation energy, melting temperature surface energy, Bulk modulus, Energy band gap Debye temperature and coefficient of volume thermal expansion in nanowires of Zn, β-Sn, TiO 2 (rutile) is studied for cylindrical, triangular, tetragonal, hexagonal and rectangular nanowires using the model. The results obtained are compared with the experimental data available and results from Guisbiers model [11, 12]. The values predicated from the present model are found close to Guisbiers model results and available experimental data.