Generalized model of polypeptide chain with limitations on the length of helical fractions

A model is proposed described by a Hamiltonian consisting of two terms corresponding to Hamiltonians of the generalized model of polypeptide chain (GMPC) with different scales of interaction. We consider a case where the long-scale interaction corresponds to attraction, while the short-scale interaction corresponds to repulsion; this case models the melting of the system in compact packing conditions (globularized polypeptide or DNA in capsid). In the framework of the transfer-matrix approach we calculate the correlation length and the helicity degree. It is shown that the temperature dependence of the correlation length is determined by the complex second eigenvalue of the transfer-matrix. In this regime the system displays a new type of correlations when the melting interval cannot be a measure of the system cooperativity.     

Storage of ultracold neutrons in vessels whose walls are made from graphite,fluorine polymer oil,or heavy-water ice

The possibility of attaining the calculated probabilities of the losses of ultracold neutrons (UCN) stored in vessels whose walls are made from graphite, fluorine polymer oil, or heavy-water ice is tested experimentally. It is found that UCN hitting the walls of a graphite vessel undergo additional inelastic scattering not predicted by the theory. It is shown that this scattering may be due to the presence of surface hydrogen that provides a channel of UCN leakage slightly varying with temperature. For vessels whose walls are coated with fluorine polymer oil, additional inelastic UCN scattering is also observed and is found to be efficiently suppressed with decreasing temperature. The experimentally observed and calculated values of the probabilities of UCN losses are shown to be in good agreement for vessels whose walls are made from heavy-water ice.     

Synthesis,structure, and complexing ability of pyrrole-2-carbaldehyde ferrocenoylhydrazone

A new ligand system based on pyrrole-2-carbaldehyde and ferrocenecarboxylic acid hydrazide was synthesized. Its tautomerism and complexing ability with respect to ions of bivalent metals: zinc, cadmium, and palladium were studied. The structure of the synthesized compounds was investigated by means of the density functional theory (DFT) calculations and spectral methods.     

Optimal Loan Management

Optimal loan repayment is posed as a linear programming problem. Reduction of problem size is achieved by decomposition and introduction of additional constraints.     

WDVV Equations for 6d Seiberg–Witten Theory and Bi-Elliptic Curves

We present a generic derivation of the WDVV equations for 6d Seiberg–Witten theory, and extend it to the families of bi-elliptic spectral curves. We find that the elliptization of the naive perturbative and nonperturbative 6d systems roughly “doubles” the number of moduli describing the system.