Search for Electron Neutrinos from Gravitational Wave Events at the Baksan Underground Scintillation Telescope

In the data obtained at the Baksan underground scintillation telescope (BUST), electron neutrinos and antineutrinos with energies above 21 MeV have been sought in coincidence with the GW150914, GW151226, GW170104, GW170608, GW170814, and GW170817 gravitational wave events. No neutrino signals from gravitational wave events have been detected in the interval of ±500 s at the Baksan underground scintillation telescope. Bounds on the fluxes of low-energy electron neutrinos and antineutrinos from astrophysical sources of gravitational bursts have been obtained.     

Vibrational modes and structure of (AgI)x (GeS1.5)100−x chalcohalide glasses

We report a structural investigation of bulk Ge-rich Ge–S–AgI chalcohalide glasses. A vibrational spectroscopic study of the quaternary system (AgI)_x (GeS_1.5)_100−x (0  x_AgI  20) has been undertaken using infrared spectroscopy and Fourier transform Raman scattering. It was found that the GeS_1.5 Raman spectrum is compatible with a glass structure composed of corner- and edge-sharing mixed GeS_nGe_4−n (n = 0–4) tetrahedra where units with n = 2–4 dominate, whilst the fraction of corner-sharing units are significantly lower than the corresponding fraction in the stoichiometric GeS₂ glass. The addition of AgI has revealed a subtle but systematic effect in the structure of the Ge-rich glass matrix, manifested by mild decrease of the ES units and the concomitant increase of complex GeS_nI_4−n or GeS_nGe_mI_4-n−m tetrahedra whose vibrational modes form a continuum at low frequencies. Although, AgI seems to cause subtle structural changes due to the formation of Ge–I bonds, it is also evident that AgI does not act as a real modifier that would depolymerize appreciably the Ge–S network structure.     

Investigating hadronic cores of exstensive air showers at the CARPET-2 array

Characteristics of the hadronic component of exstensive air shower (EAS) trunks are investigated at the CARPET-2 array of the Baksan Neutrino Observatory, Institute for Nuclear Research, Russian Academy of Sciences. In this work, we study showers with axes that located within its muon detector (MD). We discuss the procedure for selecting such showers in our experiment. The relationship between the number of thermal neutrons detected by heat detectors installed in the muon detector’s tunnel and the total energy of a cascade generated by hadrons in the magnetic detector’s absorbent matter is presented.     

Role of support-nanoalloy interactions in the atomic-scale structural and chemical ordering for tuning catalytic sites

The understanding of the atomic-scale structural and chemical ordering in supported nanosized alloy particles is fundamental for achieving active catalysts by design. This report shows how such knowledge can be obtained by a combination of techniques including X-ray photoelectron spectroscopy and synchrotron radiation based X-ray fine structure absorption spectroscopy and high-energy X-ray diffraction coupled to atomic pair distribution function analysis, and how the support-nanoalloy interaction influences the catalytic activity of ternary nanoalloy (platinum-nickel-cobalt) particles on three different supports: carbon, silica, and titania. The reaction of carbon monoxide with oxygen is employed as a probe to the catalytic activity. The thermochemical processing of this ternary composition, in combination with the different support materials, is demonstrated to be capable of fine-tuning the catalytic activity and stability. The support-nanoalloy interaction is shown to influence structural and chemical ordering in the nanoparticles, leading to support-tunable active sites on the nanoalloys for oxygen activation in the catalytic oxidation of carbon monoxide. A nickel/cobalt-tuned catalytic site on the surface of nanoalloy is revealed for oxygen activation, which differs from the traditional oxygen-activation sites known for oxide-supported noble metal catalysts. The discovery of such support-nanoalloy interaction-enabled oxygen-activation sites introduces a very promising strategy for designing active catalysts in heterogeneous catalysis.     

Method for Analysis of Different Oligosacchiride Structures

In this study, an improved, rapid, high yield synthesis of N,N’-4,4’-bis(benzyl-2-boronic acid)-bipyridinium dibromide (o-BBV) is described. The obtained o-BVV is applied in a two-component saccharide sensing system (complex) where it serves as a fluorescence quencher and a saccharide receptor. This system was applied to different natural oligosaccharides isolated from molluscan Rapana venosa (RvH1-a) and arthropodan Carcinus aestuarii (CaeH) hemocyanins (Hcs) and cyclodextrins (CDs). The carbohydrate contents of both Hcs were calculated in our previous work to be 1,6 % and 7 % for CaeH and RvH1-a, respectively. We propose that the difference in fluorescence increase of the native CaeH and RvH1-a when titrating them with the complex is due to the fact that the carbohydrate content of CaeH is lower and the carbohydrate chains are buried in between the structural subunits of the native molecule, while the glycans of the functional unit RvH1-a are exposed on the surface of the molecule leading to a 4-fold fluorescence’s intensity change.     

Thermal degradation of rice husks on a pilot plant

This study is an attempt to establish the possibilities to obtain black rice husk ash (BRHA) and white rice husk ash (WRHA) via pyrolysis of wasted raw rice husks in a pilot plant fluidized-bed reactor at different conditions. The process course auto thermally, without outer fuel. The released heat may be used for steam obtaining or drying. The solid products obtained (BRHA or WRHA) are characterized using X-ray diffraction patterns, thermal analysis, and low temperature nitrogen adsorption. Using batch adsorption technique, the kinetics was studied and the adsorption capacities of crude oil and diesel fuel at different temperatures as well as some hydrocarbons at 298?K onto BRHA and WRHA are determined. It was established that BRHA have been higher adsorption capacity than WRHA. At a given temperature, BRHA sorbed more crude oil than diesel fuel. The results obtained showed that the material studied has high adsorption capacity and low cost and may successfully be used as an effective adsorbent to cleanup of bilge water and spills of oil and oil products in water basins. Because the saturated BRHA with crude oil, diesel fuel or different hydrocarbons are characterized with high calorific, they can be burnt in incinerators, industrial ovens or steam generators. By this way, we attain not only ecological but also economical effect.     

On the boundary behavior of solutions of the Beltrami equations

We show that any homeomorphic solution of the Beltrami equation v from the Sobolev class W _loc^1,1 is a so-called lower Q-homeomorphism with Q(z) = K _μ(z), where K _μ(z) is the dilatation ratio of this equation. On this basis, we develop the theory of boundary behavior and removing of singularities of these solutions.     

Effect of water hardness on surface tension and dilational visco-elasticity of sodium dodecyl sulphate solutions

The complementary drop and bubble profile analysis and maximum bubble pressure tensiometry are used to measure the dynamic surface tension of aqueous SDS solutions in the presence of hardness salts (CaCl(2) and MgCl(2) in the ratio of 2:1 at concentrations of 6 and 40FH). The presence of hardness salts results in an essential increase of the SDS adsorption activity, which indicates the formation of Ca(DS)(2) and Mg(DS)(2) in the SDS solutions. The surface tension isotherms of SDS in presence of Ca(DS)(2) and Mg(DS)(2) are described using the generalised Frumkin model. The presence of hardness salts accelerates the ageing of SDS solutions as compared with the addition of 0.01 M NaCl due to a faster hydrolysis and hence formation of dodecanol. These results are used to estimate the possible concentration of dodecanol in the studied SDS solutions. The buoyant bubble profile method with harmonic surface oscillations is used to measure the dilational rheology of SDS solutions in presence of hardness salts in the frequency range between 0.005 Hz and 0.2 Hz. The visco-elasticity modulus in the presence of hardness salts is higher as compared with its values in the presence of 0.01 M NaCl additions. The ageing of SDS solutions leads to an essential increase of the visco-elastic modulus.     

Photochemical behaviour of polyacryloylacetone;and polyethylacrylacetate monolayers at the air–water interface

The surface organization of enol units of polyacryloylacetone (PAA) and polyethylacrylacetate (PEAA) monolayers at the air–water interface is examined using surface pressure, surface potential and rheological measurements and theoretical calculations based on molecular models. The mechanism and kinetics of the photochemical enol–keto tautomerization of PAA and PEAA polymers organized in a monolayer of closely packed monomer units are studied by measuring the surface area increase at constant surface pressure. The results indicate an increase in the area per unit during the consecutive enol-to-keto photoconversion and the slow interfacial reorganization of these ¶forms to a more favourable state.