PHOTOELECTRIC EFFECTS IN DYE-SENSITIZED ARTIFICIAL LIPID MEMBRANES

Using dyes of known redox potentials the specific mechanisms of dark and light potential generation is analyzed in pigmented lipid membranes. The role of the ionic and electronic conductance, as well as the redox potential gradient is specifically related to the observed open circuit voltage developed across the membrane. The results can be most easily explained by the redox electrode model.     

HYDROGEN GENERATION FROM ARTIFICIAL SEA HATER IN A SEMICONDUCTOR SEPTUM ELECTROCHEMICAL PHOTOVOLTAIC CELL

Visible light of the solar spectrum is directly converted to stored chemical energy of hydrogen from artificial sea water in a novel electrochemical photovoltaic cell. The principal element of the cell, modeled after the photosynthetic thylakoid membrane, is a semiconductor septum made of polycrystalline n-CdSe thin film deposited on nickel foil, which separates two aqueous solutions. Under short-circuit conditions, vigorous hydrogen evolution was seen at the Ni surface and continued as long as the cell was operated. The novel cell, the concept of which was derived from pigmented bilayer lipid membrane studies, is easy to construct, simple to operate, and appears to be a practical approach to the photochemical conversion and storage of solar energy.     

Canonical Pattern Ramsey Numbers

A color pattern is a graph whose edges have been partitioned into color classes. A family of color patterns is a Ramsey family provided there is some sufficiently large integer N such that in any edge coloring of the complete graph K_N there is an (isomorphic) copy of at least one of the patterns from . The smallest such N is the Ramsey number of the family . The classical Canonical Ramsey theorem of Erds and Rado asserts that the family of color patterns is a Ramsey family if it consists of monochromatic, rainbow (totally multicolored) and lexically colored complete graphs. In this paper we treat the asymmetric case by studying the Ramsey number of families containing a rainbow triangle, a lexically colored complete graph and a fixed arbitrary monochromatic graph. In particular we give asymptotically tight bounds for the Ramsey number of a family consisting of rainbow and monochromatic triangle and a lexically colored K_N. Among others, we prove some canonical Ramsey results for cycles.     

Sub-Ramsey Numbers for Arithmetic Progressions

Let the integers 1, . . . ,n be assigned colors. Szemerédi's theorem implies that if there is a dense color class then there is an arithmetic progression of length three in that color. We study the conditions on the color classes forcing totally multicolored arithmetic progressions of length 3. Let f(n) be the smallest integer k such that there is a coloring of {1, . . . ,n} without totally multicolored arithmetic progressions of length three and such that each color appears on at most k integers. We provide an exact value for f(n) when n is sufficiently large, and all extremal colorings. In particular, we show that f(n)=8n/17+O(1). This completely answers a question of Alon, Caro and Tuza.     

Rainbows in the Hypercube

Let Q_n be a hypercube of dimension n, that is, a graph whose vertices are binary n-tuples and two vertices are adjacent iff the corresponding n-tuples differ in exactly one position. An edge coloring of a graph H is called rainbow if no two edges of H have the same color. Let f(G,H) be the largest number of colors such that there exists an edge coloring of G with f(G,H) colors such that no subgraph isomorphic to H is rainbow. In this paper we start the investigation of this anti-Ramsey problem by providing bounds on f(Q_n,Q_k) which are asymptotically tight for k = 2 and by giving some exact results.     

Solution for underflow problem in linkage and segregation analysis

Finding genes for complex traits is one of the major challenges of modern human genetics. Current developments of molecular techniques facilitated use of large pedigrees and marker sets of thousands of single-nucleotide polymorphisms (SNPs). However, one of the problems occurring in statistical analysis of such large data sets is that the likelihood is very low and underflow may easily occur. In this work we describe a method permitting to avoid underflow during computation of a likelihood function, using different algorithms. Our method makes practically possible analysis of thousands of individuals and thousands of SNPs. The method is easy to implement without major change of the code of existing programs. It also helps to reduce the amount of computer memory used in analysis without noticeable alteration of the program running time. The algorithm was implemented in the software packages for segregation and linkage analysis, which are available from http://mga.bionet.nsc.ru/.     

Runaway Electron Beam Instability in Slide-Away Discharges in the HT-7 Tokamak

Slide-away discharges are achieved by decreasing the plasma density or ramping down the plasma current in runaway discharges in the HT-7 tokamak. In the case of plasma current ramp down, the ratio of the electron plasma frequency to the electron cyclotron frequency is higher than in the stationary pulses when the discharge goes into a slide-away regime. The instability regime is characterized by relaxations in the electron cyclotron emission due to relativistic anomalous Doppler effect which transfers energy from parallel to perpendicular motion. The triggering of relativistic anomalous Doppler effect at higher density by ramping down of plasma current may provide a alternative runaway energy control scenario.