Excluded volume effects in macromolecular forces and ion-interface interactions

A charged Yukawa liquid confined in a slit nanopore is studied in order to understand excluded volume effects in the interaction force between the pore walls. A previously developed self-consistent scheme (S. Buyukdagli el al., J. Stat. Mech. P05033 (2011)) and a new simpler variational procedure that self-consistently couple image forces, surface charge induced electric field and pore modified core interactions are used to this aim. For neutral pores, it is shown that with increasing pore size, the theory predicts a transition of the interplate pressure from an attractive to a strongly repulsive regime associated with an ionic packing state, an effect observed in previous Monte Carlo simulations for hard core charges. The role of the range of core interactions in the ionic rejection and interplate pressure is thoroughly analyzed. We show that the physics of the system can be split into two screening regimes. The ionic packing effect takes place in the regime of moderately screened core interactions characterized with the bare screening parameter of the Yukawa potential b<3/lB, where lB is the Bjerrum length. In the second regime of strongly screened core interactions b>3/lB, solvation forces associated with these interactions positively contribute to the ionic rejection driven by electrostatic forces and enhance the magnitude of the attractive pressure. The pronounced dependence of the interplate pressure and ionic partition coefficients on the magnitude and the range of core interactions indicates excluded volume effects as an important ion specificity and a non-negligible ingredient for the stability of macromolecules in electrolyte solutions.Comment: Accepted for publication in J. Chem. Phy

Methods and techniques for identifying signs of extremism

In the present reality, the public distribution of audio, video and printed materials containing signs of extremism causes serious social and state danger. In this regard, it is important to determine a clear algorithm for the activity of an expert in organizing research in order to identify signs of extremism, namely the determination of the most important methods and techniques for working with disputed material

Photoinduced ordering and anchoring properties of azo-dye films

We study both theoretically and experimentally anchoring properties of photoaligning azo-dye films in contact with a nematic liquid crystal depending on photoinduced ordering of azo-dye molecules. In the mean field approximation, we found that the bare surface anchoring energy linearly depends on the azo-dye order parameter and the azimuthal anchoring strength decays to zero in the limit of vanishing photoinduced ordering. From the absorption dichroism spectra measured in the azo-dye films that are prepared from the azo-dye derivative with polymerizable terminal groups (SDA-2) we obtain dependence of the dichroic ratio on the irradiation dose. We also measure the polar and azimuthal anchoring strengths in nematic liquid crystal (NLC) cells aligned by the azo-dye films and derive the anchoring strengths as functions of the dichroic ratio. Though linear fitting of the experimental data for both anchoring strengths gives reasonably well results, it, in contradiction with the theory, predicts vanishing of the azimuthal anchoring strength at certain nonzero value of the azo-dye order parameter. By using a simple phenomenological model we show that this discrepancy can be attributed to the difference between the surface and bulk order parameters in the films.Comment: revtex4, 25 pages, 9 figure

Problem of photoalignment in the lcd’s development: Synthetic routes in its solving. Molecular Crystals and Liquid Crystals 486

Hereinafter we discuss our last five years investigations in the field of new highly efficient polymers for liquid crystal (LC) photoalignment. New polymers finally 10 proposed are based on methacryloylaminoarylmethacrylates with two methacryloyl groups of different reactivity. Fries rearrangement and photocrosslinking= photopolymeryzation are such photochemical reactions which take place in their films under the action of UV light. In a case of polarized light irradiation rearrangement results in LC photoalignment. The problem of pretilt angle and 15 anchoring energy control as well as thermal stability of the induced alignment are discussed

Tracer diffusion in sintered stainless steel filters : Measurement of effective diffusion coefficients and implications for diffusion studies with compacted clays

The use of porous filters is indispensable in laboratory- and field-scale diffusion studies, where sample confinement is needed for mechanical reasons. Examples are diffusion studies with compacted swelling clays or brittle clay stones. Knowledge of the diffusion properties of these filters is important in cases where they contribute significantly to the overall diffusive resistance in the experimental setup. In the present study, measurements of effective diffusion coefficients (D) in porous, stainless steel filter discs are reported for tritiated HO (HTO), Na, Cs, and Sr before and after use of the filters in diffusion experiments with different clay minerals. The D values for used filters were found to be less than those of the as-received filters by ~30-50%. The D values measured for the diffusion of HTO, Na, Cs, and Sr in unused and used stainless steel filter discs correlated fairly well with the respective molecular diffusion coefficients in bulk water. Although such correlations are inherently associated with some uncertainties, they allow reasonable estimates to be made for diffusants for which no D values are available. For the first time, a procedure is outlined that allows an integrative assessment to be made for the impact of the uncertainties in the filter diffusion properties on the combined standard uncertainties of the diffusion parameters obtained from through-diffusion experiments. This procedure can be used in the design and optimization of through-diffusion experiments in which the diffusive resistance of the porous filters must not be ignored. Shown here, as a general rule of thumb, is that, if the effective diffusion coefficient in the porous filter is at least three times larger than that in the clay, the choice of geometrical boundary conditions is rather uncritical, as long as the thickness of the clay sample is greater than that of the porous filters

Associative and image Framework of the Creolized Text as an Object of the Linguistic Research

The authors of the article consider the associative and image framework of the creolized text from a position of discursive and pragmatic, intentional analysis which reveals a synergetic complex essence, a role of verbal and non-verbal elements of the creolized text. Our research is based upon a knowledge of linguistics: communicative pragmatics, cognitive linguisticstext linguistics, the theory of a discourse. There are specialized journals devoted to the discursive analysis, e.g. “Text” and “Discourse Processes”. The most known centers of discourse researches are situated in the USA. For example, the California University in Santa Barbara, in Los Angeles, the Oregon University in Eugene, the Georgetown University