The electric charges on an enzyme may move concomitantly with a conformational change. Such an enzyme will absorb energy from an oscillating electric field. If in addition the enzyme has a larger association constant for substrate than for product, as is often true, it can use this energy to drive the catalyzed reaction away from equilibrium. Approximate analytical expressions are given for the...

The interaction of anionic dye Acid Green 25 (AG) with cationic surfactant cetylpyridinium chloride (CPC) was studied by spectrophotometric method in 25oC and conductometric method in 25, 30, 35, 40 and 45oC. The specific conductance of dye – surfactant mixtures was measured. A decrease in measured specific conductance values of dyesurfactant mixture was caused by the formation of nonconducting...

The energy profile, which is the energy of the adsorbed phase as a function of loading, is essential for characterizing the equilibrium behavior of adsorbents. The energy of the adsorbed phase is measured directly by calorimetry or indirectly by differentiating adsorption isotherms at constant loading. The adsorption isotherm and energy profile are sufficient for the determination of thermodyna...

It is shown at a level suitable for an undergraduate student that thermodynamics can be used to deal with certain thermal systems out of equilibrium. The trick cut the system in parts or slides small enough so thermodynamic magnitudes have constant values inside them. As example, ideal gas gradient considered. density appears as consequence one. also briefly considered heat conduction rod; it e...

While the important role of electrostatic interactions in aqueous colloidal suspensions is widely known and reasonably well-understood, the relevance of charge in nonpolar suspensions remains mysterious. We demonstrate that particles can have surprisingly strong electrostatic interactions in low dielectric constant environments when ions are solubilized by reverse micelles. A simple thermodynam...

We present a simple model for scattering properties of polyelectrolyte gels at swelling equilibrium. In the weak screening limit where the Debye-Hfickel screening length is larger than the mesh size of the gel, the direct electrostatic interactions are negligible and the swelling is driven by the osmotic pressure of the counterions. The tension created by this pressure is transmitted through th...

Some cepha antibiotics interfere positively in the Jaffé method for determining creatinine. The extent of this interference differs with the modification used, and its mechanism is unknown. We studied the spectrophotometric and thermodynamic properties of the reaction of picrate with creatinine and two cepha antibiotics, cefoxitin and cephalothin. The absorbance spectra of the chromophore produ...

Simulation schemes for liquids or strongly fluctuating systems that allow to change the molecular representation in a subvolume of the simulation box while preserving the equilibrium with the surroundings introduce conceptual problems of thermodynamic consistency. In this work we present a general scheme based on thermodynamic arguments which ensures a thermodynamic equilibrium among molecules ...

The search for the statistical mechanical underpinning of thermodynamic irreversibility has so far focussed on spontaneous approach to equilibrium. But this is what Brown and Uffink have dubbed ‘minus first law’ thermodynamics. In contrast, second law tells us that certain interventions equilibrium states render initial state ‘irrecoverable’. article, I discuss unusual nature processes in therm...

In a finite system driven out of equilibrium by constant external force the thermodynamic uncertainty relation (TUR) bounds variance conjugate current variable cost maintaining non-equilibrium stationary state. Here we highlight new facet TUR showing that it also time-scale on which can exhibit anomalous kinetics. particular, demonstrate subdiffusion in single file confined to ring as well drag...