Changes in the orientation of the smooth-muscle cells of the tunica media from major arteries under constant lengthwise stretching in situ

It has been shown that changes in the orientation of arterial smooth muscle cells during a constant longitudinal stretching of the artery in vivo are not similar in different sections of the stretching zone. Cells in the proximal and distal sections keep their orientation but this orientation differs from that of smooth muscle cells in the control arteries. Cells in the central part of the stretching region lose their definite orientation to settle randomly.     

IR Spectroscopic Study of the Organic Component of Ultrafine Diamond Produced by Detonation Synthesis

IR spectra of ultrafine diamonds produced by different teams of researchers are studied. The effects of heating and radiation on the properties of ultrafine diamonds are studied. Quantitative assumptions on the kinetics of formation of ultrafine diamonds are made from analysis of IR spectra.     

Manufacture of Granulated Chitosan

Conditions for dry-wet spinning of spherical chitosan granules 0.5–2.0 mm in diameter into a two-layer spinning bath consisting of immiscible liquids are proposed, where an organic liquid, decane in particular, is the upper layer of the bath while a solution of ammonium hydroxide is the lower layer. The possibility of obtaining chitosan microgranules from 2 to 30 µm in diameter by emulsification of a solution of chitosan in decane or a solution of an anion-active surfactant — sodium dodecyl sulfate — is demonstrated. The effect of the molecular weight and concentration of the solutions on the granule-forming power of chitosan is established. A 6% solution of chitosan with a molecular weight of 200 kD is recommended for further studies.__________Translated from Khimicheskie Volokna, No. 5, pp. 26–29, January–February, 2005.     

Production of submicrocrystalline structure in large-scale Ti–6Al–4V billet by warm severe deformation processing

The “abc” deformation method for production of large-scale billets with submicrocrystalline structure was developed. A large billet of Ti–6Al–4V alloy (150-mm diameter × 200-mm length) with a homogeneous submicrocrystalline structure was produced. The refined structure with a grain/subgrain size of about 0.4 μm leads to a substantial mechanical properties improvement.     

Investigation of the structure of supersonic nitrogen microjets

Results of research on microjets escaping into an ambient space from nozzles with diameters of 341–10.4 μm are described. A special Pitot microtube is used for studying the structure of supersonic microjets. The main feature of this microtube is a small diameter of the intake hole (12 μm). The main parameters of supersonic underexpanded microjets are identified, including the size of shock cells and the supersonic core length of the microjet. The results show a significant increase in the supersonic core length of microjets compared to macrojets. The Reynolds numbers of the laminar–turbulent transition in microjets are found to be in the range of 1,100–2,100. In addition, a classification of supersonic underexpanded axisymmetric microjets escaping into the ambient space is proposed.     

A Similarity Criterion for Supersonic Flow Past a Cylinder with a Frontal High-Porosity Cellular Insert

We have experimentally and numerically studied the influence of the ratio of the diameter of a cylinder with a frontal gas-permeable porous insert made of nickel sponge to the average pore diameter in the insert on the aerodynamic drag of this model body in supersonic airflow (M_∞ = 4.85, 7, and 21). The analytical dependence of the normalized drag coefficient on a parameter involving the Mach number and the ratio of cylinder radius to average pore radius in the insert is obtained. It is suggested to use this parameter as a similarity criterion in the problem of supersonic airflow past a cylinder with a frontal high-porosity cellular insert.     

Optimal control of the two-state Markov process in discrete time

Using the control problem of a two-state Markov process in discrete time as an example, we consider the basic stages concerning the application of theory of conditional Markov processes to synthesize optimal algorithms of the control of stochastic systems. It is assumed that the control changes the statistical properties of the states of a controlled plant. The numerical method for solving the problem and the results of solving particular example are presented. The special features of the solution of this problem compared to the well-known problem in continuous time are discussed.     

One‐pot synthesis of {Mo6I8}4+‐doped polystyrene microspheres via a free radical dispersion copolymerisation reaction

Molybdenum octahedral clusters, when incorporated into an appropriate polymer matrix, are considered as promising agents for a range of biological applications. This work describes the one‐pot synthesis, morphology and cellular toxicity of nano‐sized polystyrene beads doped with luminescent cluster complexes [{Mo₆X₈}(NO₃)₆]^2? (X = Cl, Br or I). Specifically, the particles were obtained by free radical dispersion copolymerisation of styrene and methacrylic acid or 4‐vinylpyridine in the presence of the cluster complexes. The effects of the cluster loading in the reaction mixture on both the content of the final material and number‐average molar mass of the copolymers were evaluated. © 2017 Society of Chemical Industry