Every latin hypercube of order 5 has transversals

We prove that for all n>1 every latin n-dimensional cube of order 5 has transversals. We find all 123 paratopy classes of layer-latin cubes of order 5 with no transversals. For each $n\geq 3$ and $q\geq 3$ we construct a (2q-2)-layer latin n-dimensional cuboid with no transversals. Moreover, we find all paratopy classes of nonextendible and noncompletable latin cuboids of order 5.Comment: Supplementary data https://zenodo.org/records/1020402

Physicochemical investigation of anodic processes involved in silver electrowinning in refining technology

During silver electrowinning in refining technology, irrespectively of the nature of electrolyte and anode material, an anode deposit is formed due to oxidation of singly charged silver ions to higher degrees of oxidation (+2 and +3) under polarization. Absorption spectra of Ag(II) have been obtained in solutions with various concentrations of silver ions and nitric acid using anodic polarization in combination with electronic absorption spectroscopy; silver ions of high oxidation degrees were found to be unstable in solutions. At anode potentials φa ≥ 1.15-1.22 V, Ag(I) ions in liquid phase are oxidized to Ag(II), which paint the anolyte; their content depends on silver and nitric acid concentrations in the electrolyte. The deposit crystallizes on anode at potential φa ≈ 1.5 V. Chemical analysis, X-ray powder diffraction, and a thermogravimetric study of the anode deposit have made it possible to identify its initial composition as Ag 7O8NO3. The deposit composition varies in time as a result of reduction of highly oxidized silver. © 2013 Pleiades Publishing, Ltd

Synthesis of 2H-pyrano[3,2-g]quinolin-2-ones containing a pyrimidinone moiety and characterization of their anticoagulant activity via inhibition of blood coagulation factors Xa and XIa

The reactions of 7-hydroxy-1,2,2,4-tetramethylhydroquinoline-6-carbaldehydes with methyl 3-oxopentanedioate were used to synthesize 3-oxo-3-(6,8,8,9-tetramethyl-2-oxo-2H-pyrano[3,2-g]quinolin-3-yl)propanoates with various degrees of hydrogenation in the pyridine ring, the condensation of which with carboximidamides provided a series of new 6,8,8,9-tetramethyl-3-(6-oxo-1,6-dihydropyrimidin- 4-yl)-2H-pyrano[3,2-g]quinolin-2-ones. It was found that some compounds of this class exhibited relatively high inhibitory activity against the blood coagulation factors Xа and XI

Differential neutron energy spectra measured on spacecraft low Earth orbit

Two methods for measuring neutrons in the range from thermal energies to dozens of MeV were used. In the first method, alpha-particles emitted from the (sup 6) Li(n.x)T reaction are detected with the help of plastic nuclear track detectors, yielding results on thermal and resonance neutrons. Also, fission foils are used to detect fast neutrons. In the second method, fast neutrons are recorded by nuclear photographic emulsions (NPE). The results of measurements on board various satellites are presented. The neutron flux density does not appear to correlate clearly with orbital parameters. Up to 50% of neutrons are due to albedo neutrons from the atmosphere while the fluxes inside the satellites are 15-20% higher than those on the outside. Estimates show that the neutron contribution to the total equivalent radiation dose reaches 20-30%

Infinite-dimensional pp-adic groups, semigroups of double cosets, and inner functions on Bruhat--Tits builldings

We construct $p$-adic analogs of operator colligations and their characteristic functions. Consider a $p$-adic group $G=GL(\alpha+k\infty, Q_p)$, its subgroup $L=O(k\infty,Z_p)$, and the subgroup $K=O(\infty,Z_p)$ embedded to $L$ diagonally. We show that double cosets $\Gamma= K\setminus G/K$ admit a structure of a semigroup, $\Gamma$ acts naturally in $K$-fixed vectors of unitary representations of $G$. For each double coset we assign a 'characteristic function', which sends a certain Bruhat--Tits building to another building (buildings are finite-dimensional); image of the distinguished boundary is contained in the distinguished boundary. The latter building admits a structure of (Nazarov) semigroup, the product in $\Gamma$ corresponds to a point-wise product of characteristic functions.Comment: new version of the paper, 47pp, 3 figure

Neutron influences and energy spectra in the Cosmos-2044 biosatellite orbit

Joint Soviet-American measurements of the neutron component of space radiation (SR) were carried out during the flight of the Soviet biosatellite Cosmos-2044. Neutron flux densities and differential energy spectra were measured inside and on the external surface of the spacecraft. Three energy intervals were employed: thermal (E(sub n) less than or equal to 0.2 eV), resonance (0.2 eV less than E(sub n) less than 1.0 MeV) and fast (E(sub n) greater than or equal to 1.0 MeV) neutrons. The first two groups were measured with U.S. (6)LiF detectors, while fast neutrons were recorded both by U.S. fission foils and Soviet nuclear emulsions. Estimations were made of the contributions to absorbed and equivalent doses from each neutron energy interval and a correlation was presented between fast neutron fluxes, measured outside the satellite, and the phase of solar activity (SA). Average dose equivalent rates of 0.018 and 0.14 mrem d(exp -1) were measured for thermal and resonance neutrons, respectively, outside the spacecraft. The corresponding values for fast neutrons were 3.3 (U.S.) and 1.8 (U.S.S.R.) mrem d(exp -1). Inside the spacecraft, a value of 3.5 mrem d(exp -1) was found

Synthesis and study of new 2H-pyranoquinolin-2-one-based inhibitors of blood coagulation factors Xa and XIa

Condensation of 7-hydroxy-1,2,2,4-tetramethylhydroquinoline-6-carbaldehydes with various hetaryl-substituted 3-oxo esters aff orded a series of hybrid hydro-6,8,8,9-tetramethyl-2H-pyrano[3,2-g]quinolin-2-ones. A number of these compounds exhibited relatively high inhibitory activity against blood coagulation factors Xa and XI

Ring switching tricomponent synthesis of pyrano[2,3-b]pyridine multifunctional derivatives

New 3-acylamino-7-hydroxy-5-methyl-2-oxo-2H-pyrano[2,3-b]pyridine-6-carbonitriles were synthesized via a tricomponent condensation of 3-cyano-4-methyl-1,2,5,6-tetrahydropyridine- 2,6-dione, triethyl orthoformate and N-acylglycines under the Erlenmeyer-Plöchl reaction conditions. According to X-ray data, in the solid phase they exist as hydroxypyridine tautomer for