Electrical Propagation of Condensed and Diffuse Ions Along Actin Filaments

In this article, we elucidate the role of divalent ion condensation and high polarization of immobile water molecules in the condensed layer on the propagation of ionic calcium waves along actin filaments. We introduced a novel electrical triple layer model and used a non-linear Debye-Huckel theory with a non-linear, dissipative, electrical transmission line model to characterize the physicochemical properties of each monomer in the filament. This characterization is carried out in terms of an electric circuit model containing monomeric flow resistances and ionic capacitances in both the condensed and diffuse layers. In our studies, we characterized the biocylindrical actin filament model using a high resolution molecular structure. We considered resting and excited states of a neuron using representative mono and divalent electrolyte mixtures. Additionally, we used 0.05V and 0.15V voltage inputs to study ionic waves in voltage clamp experiments on actin filaments. Our results reveal that the physicochemical properties characterizing the condensed and diffuse layers lead to different electrical conduction mediums depending on the ionic species and the neuron state. This region specific propagation mechanism provides a more realistic avenue of delivery by way of cytoskeleton filaments for larger charged cationic species. This new direct path for transporting divalent ions might be crucial for many electrical processes that connect different compartments of the neuron to the soma.

Hardenability and Wear Resistance of Carburized to Hypereutectic Concentrations Steels

In this article the experimental data of the hardness and wear resistance of chrome-manganese steels 35H3G2F and 35HGF, which are cemented in a highly active paste-like carburizer and hardened at various temperatures, are presented. Cementation and high temperature carbonitriding of these steels leads to a high content of the carbide phase in the diffuse layers and an increase of hardness and wear resistance. The effect of carbides on the hardenability of diffuse layers are investigated. The hardening temperature ranges of these steels and the effect of alloying elements on hardness are established. The mechanism of the phase formation of the highest hardness structures is described. The carbides influence on the wear mechanism of cemented in various modes steels is studied.

Electro-osmotic flow in hydrophobic nanochannels

An analytical theory of electroosmosis in hydrophobic nanochannels of large surface potential/charge density incorporates a mobility of adsorbed charges and hydrodynamic slip, and is valid both for thin and strongly overlapping diffuse layers.

CaO&CaSO4 and CaO&Al2(SO4)3 as Pectin Precipitants–Model of Overlapping Diffuse Layers

This work is concerned with the theoretical basis of novel sugar beet juice purification method using binary systems CaO&CaSO4 and CaO&Al2(SO4)3. The Gouy–Chapman–Stern (GCS) model of overlapping of diffuse layers of EDLs on pectin surface and that on Ca2+ and Al3+ ions, theoretically explains this method. The change of the zeta potential was used to quantitatively indicate overlapping of diffuse layers. For the experiment two model solutions of pectin (0.1 % w/w) were prepared, while the concentrations of CaO&CaSO4 and CaO&Al2(SO4)3 in the range of 50–500 g dm-3 were used. The greater decrease in the absolute value of zeta potential indicated greater overlapping of diffuse layers between pectin particles and Ca2+ and Al3+ ions and faster coagulation of pectin. The overlapping degree increased with increased concentration of these binary systems. Pectin with a greater surface charge and multivalent Al3+ from CaO&Al2(SO4), exerted a greater impact on the zeta potential. Optimal quantities of the applied binary mixtures were as follows: 256–640 mg g-1 pectin. This is much lower than CaO commonly used in the conventional process of sugar beet juice purification (about 9 g g-1 pectin).