Ambiguous Dependence Of Minimal Plant Generation Time On Nuclear DNA Content

AMBIGUOUS DEPENDENCE OF MINIMAL PLANT GENERATION TIME ON NUCLEAR DNA CONTENT Victor B. Ivanov The minimum generation time (MGT) of plant development was suggested to depend on nuclear DNA content, which varies in plants over wide limits1. In ephemeral species with the shortest MGT, the average C values were significantly lower than in annual species, whereas the average C values in annual species were lower than those in perennial plants. However, nobody has paid attention to the ratio of annual to perennial species number as a function of C values. Here I show that with increasing C the ratio of annual to perennial species increases to C values equal to 7-8 pg (monocots) and 6-7 pg (eudicots) and then decreases and that the fraction of annuals is abundant not at the lowest, but at some higher C levels. Hence, C value increase exerts an ambiguous effect on MGT. The C value is not the only factor, which determines the duration of the plant development. Nevertheless, the nuclear DNA content exerts a pronounced effect on MGT together with other diverse factors affecting the rate of plant development, especially at higher C values

Multiple Volume Reflection from Different Planes Inside One Bent Crystal

It is shown that multiple volume reflections from different planes of one bent crystal becomes possible when particles move at a small angle with respect to a crystal axis. Such a Multiple Volume Reflection makes it possible to increase the particle deflection angle inside one crystal by more than four times and can be used to increase the efficiency of beam extraction and collimation at the LHC and many other accelerators.Comment: 17 pages, 6 figure

Upper and Lower Bounds on Bit-Error Rate for Convolutional Codes

In this paper, we provide a new approach to the analytical estimation of the bit-error rate (BER) for convolutional codes for Viterbi decoding in the binary symmetric channel (BSC). The expressions we obtained for lower and upper BER bounds are based on the active distances of the code and their distance spectrum. The estimates are derived for convolutional codes with the rate $R=\frac{1}{2}$ but can be easily generalized for any convolutional code with rate $R=\frac 1n$ and systematic encoder. The suggested approach is not computationally expensive for any crossover probability of BSC channel and convolutional code memory, and it allows to obtain precise estimates of BER

Research poster: Architecture and usability aspects of environmental data portals

Research poste

Phase Composition and Defect Substructure of Strengthening Layer Surfaced on Low Alloyed Steel

The microstructure and microhardness distribution in surface of low carbon Hardox 450 steel coated with alloyed powder wires of different chemical compositions are studied. It is shown that the microhardness of 6-8 mm thickness surfaced layer exceeds that of base metal by more than 2 times. The increased mechanical properties of surfaced layer are caused by the submicro and nanoscale dispersed martensite, containing the niobium carbides Nb2C, NbC and iron borides Fe2B. In the bulk plates a dislocation substructure of the net-like type with scalar islocation density of 10^11 cm^-2 is observed. The layer surfaced with the wire containing B possesses the highest hardness. The possible mechanisms of niobium and boron carbides formation in surfacing are discusse

ANNUAL REPORT 2002 of the National Ecological Fund

The 2002 Annual Report of the National Ecological Fund (NEF) of the Republic of Moldova describes the Fund’s activities during 2002. The main goal was to make public the information about the Fund’s activity, programmes and achievements in promoting the projects for environmental quality improvement in Republic of Moldova. The Annual Report was prepared as an official document of NEF, by the Fund’s personnel, with support from MECTD experts, who are carrying out the Fund management and by the consultants

New Photo-Thermo-Refractive Glasses for Holographic Optical Elements: Properties and Applications

This chapter presents a survey of recent achievements of the ITMO University (St. Petersburg, Russia) in developing new holographic media such as fluoride, chloride, and bromide silicate photo-thermo-refractive (PTR) glasses as well as the holographic diffractive optical elements that are the volume Bragg gratings recorded in the glasses for improving dramatically the parameters of laser systems of different types. The photo-thermo-induced crystallization process and the properties of fluoride, chloride, and bromide PTR glasses are demonstrated. This new technology enabled recording high-efficiency phase volume holograms in the optical quality silicate glass. These holograms are used for developing a number of unique diffractive optical elements that provide new opportunities for the laser technique. Some examples of designing and fabricating of holographic optical elements such as the super-narrowband filters for solid-state lasers and laser diodes, laser beam combiners, and collimator sights are demonstrated in this chapter. It is shown that the PTR glass doped with rare earth ions can be used for designing lasers with Bragg reflectors and distributed feedback