Numerical and experimental investigation of a laval nozzle with a cylindrical throat

The results are reported of experimental and numerical investigation of mixed flow and of the parameters of heat transfer in the transonic region of an axisymmetric Laval nozzle whose throat is formed by a cylindrical surface, i.e., the nozzle contour near the minimum cross section contains two bends.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 5, pp. 189–192, September–October, 1984.     

Station for X-ray structural analysis of materials and single crystals (including nanocrystals) on a synchrotron radiation beam from the wiggler at the Siberia-2 storage ring

The design of the station for structural analysis of polycrystalline materials and single crystals (including nanoobjects and macromolecular crystals) on a synchrotron radiation beam from the superconducting wiggler of the Siberia-2 storage ring is described. The wiggler is constructed at the Budker Institute of Nuclear Physics of the Siberian Division of the Russian Academy of Sciences. The X-ray optical scheme of the station involves a (1, ?1) double-crystal monochromator with a fixed position of the monochromatic beam and a sagittal bending of the second crystal, segmented mirrors bent by piezoelectric motors, and a (2θ, ω, φ) three-circle goniometer with a fixed tilt angle. Almost all devices of the station are designed and fabricated at the Shubnikov Institute of Crystallography of the Russian Academy of Sciences. The Bruker APEX11 two-dimensional CCD detector will serve as a detector in the station.     

Stable Silver Nanoparticles in Aqueous Dispersions Obtained from Micellar Solutions

Two methods for obtaining aqueous dispersions of silver nanoparticles, stable during several months, from their reverse micellar solutions in an organic solvent: (i) centrifugation of a two-phase system formed by micellar solution and water and (ii) mixing of micellar solution with water, followed by settling.     

Pyroelectric study of dynamic temperature conductivity

The difference between dynamic and static temperature conductivity for solid-state materials is shown by means of TSWM (Thermal Square Wave Method at a Single Frequency). The study is performed with metallic steel and copper alloys.     

Beam focusing on stations with a Sibir’-2 synchrotron source for single-crystal studies of atomic structures

A scheme for obtaining a stationary monochromatic beam that can be focused in the horizontal and the vertical planes and rapidly tuned to a desirable wavelength with the aid of a bending magnet on a Sibir’-2 synchrotron source has been designed. The channel parameters and the size and profile of a sagittally bent single crystal of the double-crystal monochromator were chosen with the use of numerical simulation.     

Relaxation Mössbauer spectra of polymer composites with magnetic nanoparticles

It is shown that the shape of Mössbauer spectra of composites based on single-domain magnetic particles is defined to a greater degree by interparticle interactions rather than the superparamagnetic properties of individual particles. The characteristic features of the spectra of such systems are described and shown to be adequately described within a three-level relaxation model.     

Iceberg Model of the Structure of Globular Protein Adsorption Layers at the Air–Water Interface. Study by the Tritium Planigraphy Technique

The organization of the adsorption layers of insulin, pancreatic inhibitor of trypsin, ribonuclease S, lysozyme, myoglobin, carboxypeptidase A, subtilisin, and thermolysin at the air–water interface was studied by tritium planigraphy technique. The location of globular protein molecules relative to the interface was determined for solution concentrations corresponding to the formation of saturated adsorption layers (10^–4 M, pH 6). It is established that the fraction of solution surface occupied by protein component is equal to 7–62%. Only a small part of globules with the height from 2 to 19% of their effective diameter is above the solution surface, whereas the main part of globules is submerged into water (the iceberg model).     

A convergent approach to synthesis of bortezomib: the use of TBTU suppresses racemization in the fragment condensation

Bortezomib is a first-in-class therapeutic antineoplastic agent used for treating patients with multiple myeloma and mantle cell lymphoma. In this paper we report an improved method for synthesis of the title compound using a convergent approach. TBTU was found to efficiently suppress racemization in the fragment condensation. In comparison with the original synthesis, the presented one is shorter by two steps, higher in yield, and provides better atom economy.