Nuclear Power System Based on Fission and Fusion Reactors is the Strategic Line of Nuclear Power Industry Development

Physics of Atomic Nuclei - The strategic line of development of a nuclear power system based on fission and fusion reactors which ensures electricity generation on a specified scale, solves the...     

Effect of buoyancy on appearance and characteristics of surface tension repeated auto-oscillations

The effect of buoyancy on spontaneous repeated nonlinear oscillations of surface tension, which appear at the free liquid interface by dissolution of a surfactant droplet under the interface, is considered on the basis of direct numerical simulation of the model system behavior. The oscillations are the result of periodically rising and fading Marangoni instability. The buoyancy force per se cannot lead to the oscillatory behavior in the considered system, but it influences strongly both the onset and decay of the instability and therefore, affects appearance and characteristics of the oscillations. If the surfactant solution density is smaller than the density of the pure liquid, then the buoyancy force leads to a considerable decrease of the induction period and the period of oscillations. The buoyancy force affects also the dependence of the oscillation characteristics on the system dimensions. The results of the simulations are compared with the available experimental data.     

A charge transfer-type fluorescent molecular sensor that "lights up" in the visible upon hydrogen bond-assisted complexation of anions

A charge transfer-type fluorescent molecular sensor consisting of a bisamidopyridine receptor and two styryl base chromophores shows H(2)PO(4)(-) and acetate-enhanced fluorescence due to the conversion of weak intramolecular hydrogen bonds into strong ones in the host-guest ensemble.     

Studies on the V?Ti?O system obtained by thermal decomposition of vanadyl and titanyl oxalates in argon atmosphere

The V–Ti–O system as a product of thermal decomposition of vanadyl and titanyl oxalates at 873 and 1173 K in argon atmosphere was studied by X-ray diffraction and infrared spectroscopy. The results obtained, the analysis and surface measurement data suggest that a V³⁺–V⁴⁺–Ti⁴⁺–O solid solution is formed. Spectroscopic measurements reveal the presence of a V=O bond in the system obtained at 873 K.

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V–Ti–O, 873 1173 - . , , V⁺³–V⁺⁴–O . V=O , 873 .

     

Influence of Sn added to Pt catalysts on the adsorption heats of hydrogen

It has been established that supported Pt–Sn catalysts adsorb hydrogen at 330 K at least in two forms. They are weak and strong forms with the binding energies of about 50–70 and above 100 kJ/mol, respectively. On catalyst surface weak forms transform into strongly bound hydrogen.

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330 K, , : 50–70 / 100 /. .

     

Microscopic description of diffractive deuteron breakup by <Superscript>3</Superscript>He nuclei

A microscopic formalism for describing observed cross sections for deuteron breakup by threenucleon nuclei was developed on the basis of the diffraction nuclear model. A general formula that describes the amplitude for the reaction ²H(³He, ³Hep)n and which involves only one adjustable parameter was obtained by using expansions of the integrands involved in terms of a Gaussian basis. This formula was used to analyze experimental data on the exclusive cross sections for deuteron breakup by ³He nuclei at the projectile energy of 89.4MeV. The importance of employing, in calculations, a deuteron wave function that has a correct asymptotic behavior at large nucleon–nucleon distances was demonstrated.     

Surfactant accumulation within the top foam layer due to rupture of external foam films

The analysis of processes taking place in a steady pneumatic (dynamic) foam shows the possibility of different modes of surfactant accumulation within the top layers of bubbles due to rupture of external foam films. An increasing surfactant concentration within the top layers promotes the stabilisation of bubbles and the foam as a whole. Considering the balance of surfactant and water during the bursting of films it is possible to estimate the accumulated surfactant loss caused by a downwards flow through the Plateau borders of the subsurface bubble layer. This effect depends on the particular conditions, especially on the surfactant activity and concentration of the surfactant, water volume fraction in the foam and size of foam bubbles. The process of surfactant accumulation in the top foam bubble layer can be complicated due to the removal of part of the accumulated surfactant through transport with droplets spread out during bubble bursting.     

Bovine serum albumin as a universal suppressor of non-specific peptide binding in vials prior to nano-chromatography coupled mass-spectrometry analysis

Non-specific binding (NSB) is a well-known problem for any application that deals with ultralow analyte quantities. The modern nano-flow chromatography coupled tandem mass-spectrometry (nanoLC-MS/MS) works with the lowest conceivable analyte concentrations. However, while the NSB problem is widely accepted and investigated for metabolomics and single-peptide medicine-related assays, its impact is not studied for complex peptide mixtures in proteomic applications. In this work peptide NSB to a common plastic autosampler vial was studied for a model mixture of 46 synthetic peptides. A significant NSB level was demonstrated for total peptide concentrations of up to 1 mg mL⁻¹. Different agents were tried for NSB suppression and compatibility with nanoLC-MS/MS analysis: a chaotropic agent, an amino acid mixture, a peptide mixture and a protein solution. The first two were inefficacious. The peptide matrix blocked NSB, however, it also led to analyte ionization suppression in nanoLC-MS/MS. The protein solution (0.1% BSA) efficiently eliminated NSB, while a trap-elute nanoHPLC configuration together with a small-pore reverse-phased sorbent effectively and quantitatively extracted the model peptides and depleted protein material from the sample. Higher protein concentration partially impeded peptide extraction. Thus, the 0.1% BSA solution might be regarded as an effective non-interfering blockader of NSB for sample resuspension and storage in an autosampler prior to LC-MS/MS analysis.     

Research Reactor PIK: The First Experiments

Crystallography Reports - The parameters and current status of development of the highest-power neutron source of the PIK research reactor (Petersburg Nuclear Physics Institute named by B.P....