Gus'Kov O.B.,RAS Institute of Applied Mechanics
Doklady Physics | Year: 2014
The problem of drag of an arbitrary-size solid sphere with its motion in a uniform monodispersed viscous suspension is considered in the Stokes approximation. The expression for the effective suspension viscosity is derived in the first approximation over the volume concentration of the viscous suspension. The coefficient before the concentration is found in the form of an explicit analytical function, which depends on the ratio of sizes of the dispersed particles and the body. The found coefficient coincides with Einstein's result at the limit of "point" dispersed particles, the size of which is negligibly small compared with the size of the moving sphere, but can substantially differ from it in the case of finite-size particles. © 2014 Pleiades Publishing, Ltd.
Surzhikov S.T.,RAS Institute of Applied Mechanics
Doklady Physics | Year: 2014
Flight experiments were performed within the framework of the RAM-C (Radio-Wave Attenuation Measurement for Study of Communication Blackout) program. Based on an additional numerical experiment, it was possible to reconstruct data related to electron concentrations in the shock layer on the surface of the experimental space module. Data on this flight experiment remain virtually unique well-documented flight data and are extremely valuable, insofar as a significant portion of them corresponds to conditions when thermodynamic equilibrium is absent. Navier-Stokes equations, and equations of energy conservation for translational motion of particles in the form of the Fourier-Kirch-hoff conduction equation, and the equations of both mass conservation for chemical components and conservation of the vibration energy in certain modes.
Yankovskii A.P.,RAS Institute of Applied Mechanics
Applied Physics | Year: 2011
The model of thermal conductivity of spatially reinforced fibrous medium with a disperse reinforcement bonding agent is offered at the general anisotropy of materials a component of a composition. Comparison of calculated values of effective coefficients of thermal conductivity is lead is unidirectional and is cross the reinforced composites with experimental data. The satisfactory concord of calculated and experimental values of these magnitudes is shown.
Lurie S.,RAS Institute of Applied Mechanics |
Minhat M.,National University of Malaysia
Composites Part B: Engineering | Year: 2014
A self-consistent Eshelby method based on the three-phase model is developed to examine the behavior of bristled fiber composite material where the fibers are radially coated with micro/nanostructures such as microwhiskers, nanowires or carbon nanotubes (fuzzy fiber). The effective mechanical properties are determined by taking into account the additional bristled interphase layer that is formed between fiber and matrix due to the presence of these micro/nanofibers. The features of the proposed method are emphasized and comparative study with other methods is conducted. In addition, several parameters of the micro/nanofibers such as length, density, diameter and material affecting the effective properties of composites are examined. In general, the presence of bristled fibers can significantly improve the shear and transverse characteristics of composite materials. © 2014 Elsevier Ltd. All rights reserved.
Parshikov I.A.,RAS Institute of Applied Mechanics |
Sutherland J.B.,U.S. Food and Drug Administration
Process Biochemistry | Year: 2014
Aspergillus niger is a well-known fungus that has been used for many different biotransformations of organic compounds. The terpenoids include a large variety of natural hydrocarbons and their derivatives, mostly obtained from plant essential oils, but some obtained from animals or fungi. They may be acyclic or have one or more rings of various sizes, and they show a variety of biological activities that include antibacterial, antifungal, antiparasitic, antiviral, and anticancer activities. Terpenoids are classified as monoterpenoids (C10), sesquiterpenoids (C15), diterpenoids (C20), triterpenoids (C30), and others. This review summarizes experimental processes that use cultures of various A. niger strains to carry out stereoselective biochemical reactions in terpenoids, including related epoxides, lactones, N-phenylcarbamates, and saponins, to produce metabolites that may be useful as flavors and fragrances or as new experimental drug candidates. Cultures of A. niger that add hydroxyl, carbonyl, and other groups at specific positions or reduce double bonds have resulted in the production of valuable new compounds.