Continuous measurements of chlorophyll-a concentration in the Pacific Ocean by shipborne laser fluorometer and radiometer: Comparison with SeaWiFS data

The results of comparisons of chlorphyll-a concentrations, measured using different methods in various regions of the Pacific, are presented. The measurements were made simultaneously from a moving ship using both a laser fluorometer and a spectrometer for measurements of the spectral distribution of the upwelling radiation. Two-band and multispectral algorithms were used to derive the pigment concentration from the upwelling radiation. The chlorophyll a concentrations measured by the shipborne instruments are compared with data obtained by SeaWiFS (the Sea-viewing Wide Field-of-View Sensor).     

Features of the collision of plasma fronts upon laser breakdown in normal atmosphere

The collision of plasma fronts upon laser breakdown in atmosphere under normal conditions has been studied. This interaction leads to an increase in the integral luminosity (which can be 85% higher than that for the noninteracting plasmas, depending on the regime of motion of the colliding plasma fronts) and in the intensity of emission lines on the background of continuous emission from laser plasma.     

A data acquisition system of the SND detector for experiments on the BЭΠΠ-2000

A new data acquisition system for the SND detector is presented. The digitizing electronics, the detector triggering and monitoring subsystems, and the organization of the data transmission to the computer are described. The architecture of the software part of the data acquisition system, the operator’s interface, and the processes of event acquisition, processing, and monitoring are presented. The results of system testing on cosmic events and a random-triggering generator are described.     

A Shipborne Laser Fluorimeter for Studying Sea-Water Fluorescence Spectra

A shipborne laser fluorimeter making it possible to determine promptly the concentration of chlorophyll A in sea water is described. The measurement error is 35% at chlorophyll concentrations of 0.1–3 g/l, and the single-measurement duration is 1 min.     

Genomic Determinants Potentially Associated with Clinical Manifestations of Human-Pathogenic Tick-Borne Flaviviruses

The tick-borne flavivirus group contains at least five species that are pathogenic to humans, three of which induce encephalitis (tick-borne encephalitis virus, louping-ill virus, Powassan virus) and another two species induce hemorrhagic fever (Omsk hemorrhagic fever virus, Kyasanur Forest disease virus). To date, the molecular mechanisms responsible for these strikingly different clinical forms are not completely understood. Using a bioinformatic approach, we performed the analysis of each amino acid (aa) position in the alignment of 323 polyprotein sequences to calculate the fixation index (F_st) per site and find the regions (determinants) where sequences belonging to two designated groups were most different. Our algorithm revealed 36 potential determinants (F_st ranges from 0.91 to 1.0) located in all viral proteins except a capsid protein. In an envelope (E) protein, most of the determinants were located on the virion surface regions (domains II and III) and one (absolutely specific site 457) was located in the transmembrane region. Another 100% specific determinant site (E63D) with F_st = 1.0 was located in the central hydrophilic domain of the NS2b, which mediates NS3 protease activity. The NS5 protein contains the largest number of determinants (14) and two of them are absolutely specific (T226S, E290D) and are located near the RNA binding site 219 (methyltransferase domain) and the extension structure. We assume that even if not absolutely, highly specific sites, together with absolutely specific ones (F_st = 1.0) can play a supporting role in cell and tissue tropism determination.     

Isotope Purification of Gases Containing Deuterium and Tritium by the Method of the Phase Isotopic Exchange of Water

The study of the method of the phase isotopic exchange (PIE) for the purification of gas flows containing deuterium and tritium is carried out. The experimental data obtained for a column with a diameter of 32 mm on a Sulzer copper oxidized packing showed that the mass transfer characteristics do not depend on the deuterium concentration. Based on these results, a mathematical model for separating three-isotope mixtures, which makes it possible to calculate the column parameters under different initial conditions, is developed.     

Liquid Holdup and Axial Mixing in a Mixed Bed of Hydrophobic Catalyst and Hydrophilic Packing

Theoretical Foundations of Chemical Engineering - The dynamics of fluid motion in a mixed bed of the hydrophobic RCTU-3SM catalyst and hydrophilic SPP packing (3 × 3 × 0.2 mm) was...