Algorithms for constructing optimal controllers for gaslift operation

We consider the optimal stabilization problem for delivered gas and gaslift operation debit for oil wells. Under certain natural assumptions, the general problem reduces to a linear-quadratic control problem that lets us find program controls and trajectories on which we further construct the optimal controller with respect to all phase coordinates and a (debit) part of them in both continuous and discrete case. For a special case, numerical results are illustrated with graphs that let us use this method in oilfield practice.     

The effects of laser patterning 10CeTZP-Al2O3 nanocomposite disc surfaces: Osseous differentiation and cellular arrangement in vitro

Customized square grid arrangements of different groove depths (1.0, 1.5 and 3.0?µm) and separations (10 and 30?µm) were successfully laser patterned, using a nanosecond pulsed fibre laser, on the surface of 10?mol% ceria-stabilized zirconia and alumina (10CeTZP-Al₂O₃) nanocomposite discs (diameter: 10?mm; thickness: 1.5?mm). The patterned surfaces and the in vitro biological response of osteoblasts (SAOS-2) towards them were thoroughly analysed. In terms of composition, the laser treatment was found to cause superficial monoclinic-tetragonal zirconia phase transformation and alumina evaporation. In vitro, the most effective grid configuration for osseous differentiation was found to be 1.5?µm groove depth and 10?µm groove separation, and confocal microscopy revealed that the cells show a tendency to be sorted as groove depth increases. It is thought that custom-made patterns could be produced to guide cell attachment in vivo, which could favour implant integration and reduce healing time.     

Production technology and optical absorption characteristics of CuIn<Subscript>0.95</Subscript>Ga<Subscript>0.05</Subscript>Se<Subscript>2</Subscript> semiconductor solid solution films

A production technology of thin CuIn_0.95Ga_0.05Se₂ films has been developed based on the method of two-stage selenization of CuIn_0.95Ga_0.05 precursor by a reactive component (selenium) in a carrier gas (nitrogen) flow. The morphology and structure of obtained films were studied by electron microscopy and X-ray diffraction techniques. The spectral dependence of the optical absorption coefficient was measured.     

The Thermophysical Properties of Solid Solutions of CaLa2S4-La2S3 System

The thermal conductivity coefficient in the temperature range from 275 to 450 K and the coefficient of thermal expansion in the range from 300 to 900 K are experimentally determined for solid solutions of the CaLa₂S₄-La₂S₃ system. The mechanisms of heat transfer in CaLa₂S₄- La₂S₃ samples in the investigated temperature range are discussed, as well as the factors which define the complex concentration dependence of thermal conductivity coefficient. The correlation is treated between the value and temperature dependence of the coefficient of thermal expansion and the variation of the interatomic bond force in the case of variation of the concentration of cation vacancies in the investigated crystals.     

An approach to segmentation of mouse brain images via intermodal registration

One way to perform a segmentation of the images of mouse brain sections is to register them to some reference images with known segmentation. We designed a new registration algorithm for this task. It is based on hierarchical mutual information maximizationand draws on several recent methods. Besides combining them in a novel way, we identify their weak spots and propose new ways to overcome them, resulting in a more robust performance.     

Effect of thallium doping on the parameters of localized states in <Emphasis Type=Italic>p</Emphasis>-GaSe single crystals

Experimental evidence is presented that, at temperatures from 167 to 250 K, electrical transport in undoped and thallium-doped p-GaSe single crystals is due to variable-range hopping. The main parameters of localized states in the band gap of p-GaSe〈T1〉 (0, 1, 2, and 2.5 mol % Tl) have been estimated as functions of doping level.