An Investigation of Spatial Distribution of Characteristics of a Plasma Stream Formed by a Hall Discharge in a Channel with Metal Walls

The effect of the system of delivery of the working medium on the characteristics of a plasma stream in a Hall accelerator with closed azimuthal current is experimentally investigated. The gas delivery system utilizes a porous diaphragm from a carbon–carbon composite material whose pore size is comparable with the Debye radius of the electrons of plasma formed in a discharge channel. The calorimetric method is used to determine the degree of azimuthal and radial nonuniformity of distribution of the energy of plasma stream developed by the accelerator, namely, the distribution of temperature of a titanium target mounted perpendicularly to the incident stream is taken with the aid of an infrared imager. The probe method is used to measure the spatial distribution of temperature and the concentration of charge-exchange plasma at the accelerator channel exit. It is shown that the ratio of the kinetic energy of the flow of heavy particles to the expended electric energy (energy efficiency) exceeds 0.5.     

Structure of steel 40kh10S2M after treating the surface by a continuous CO2-laser

This paper is concerned with the reasons for the higher set of properties of steel 40Khl0S2M subjected to laser treatment with fusion compared to the properties after laser treatment without fusion. A comparative analysis of the properties of the steel after the two kinds of surface treatment is presented.     

An alternative solution to the H∞-optimal control problem

In this paper we present an alternative solution to the problem min _{X ε H^n×n∞} |A + BXC|_∞ where A, B, rmand C are rational matrices in H^n×n_∞. The solution circumvents the need to extract the matrix inner factors of B and C, providing a multivariable extension of Sarason's H^∞-interpolation theory [1] to the case of matrix-valued B(s) and C(s). The result has application to the diagonally-scaled optimization problem int |D(A + BXC)D⁻¹|_∞, where the infimum is over D, X εH^n×n_∞, D diagonal.     

Synthesis of positive real feedback systems: a simple derivationvia Parrott's theorem

A simple derivation of the formulas for controller rendering a closed-loop system strongly positive real is presented. The derivation is based on Parrott's theorem and the positive real lemma. When the positive real lemma is applied to the closed loop system, a bilinear matrix inequality results. The significance of Parrott's theorem in the context of a strongly positive real synthesis problem is that it allows one to convert this bilinear matrix inequality into two linear matrix inequalities     

Shearing interferometer based on second-harmonic generation and a novel technique of n(2) direct measurements

We present a new wave-front sensitive interferometry technique (called dispersion shearing interferometry) for the measurement of both the sign and the magnitude of n(2). The interference pattern is produced by two laterally shifted second harmonics of the laser source. Only the fundamental wave passes through the nonlinear sample, which is placed before the interferometer. We demonstrate this technique on an aggregated colloidal silver solution using a YAG:Nd laser and KTiOPO(4) frequency doublers.     

Design optimization of truss bridge structures of composite materials

In this paper the problem of optimizing a distribution of carbon fiber content in hybrid glass/carbon fiber reinforced (GFRP/CFRP) structural elements of plane, statically determinate regular elastic truss structure is discussed. A modification of genetic algorithm combined with the method of mathematical induction is proposed. A criterion of structural materials cost minimization while satisfying elastic strength requirements is used as an optimality criterion.     

Dyeing of polyamide—wool fibre blend with acid dyes using α-cyclodextrin

The colors of polyamide fibre obtained in dyeing with α-cyclodextrin (CD) additive are uniform and saturated. This effect is also obtained on wool fibre and wool—polyamide fibre blend. It was found that the dyeability of the samples with α-CD is much higher than for samples without the additive with an increase in the temperature. In spectrophotometric determination of complexation in the dye—α-CD aqueous system, it was found that the dyeability of the samples was highest in a 1:1 ratio than with the standard dyeing method. α-CD thus acts as a process booster. __________ Translated from Khimicheskie Volokna, No. 3, pp. 37–39, May–June, 2007.     

Algorithms for photo book authoring

Photo books are a convenient and attractive product for printing and storage of personal photographs. However, the creation of a photo book requires a lot of manual work and time. The automation of operations will attract new users and will make it possible to create more photo books. Algorithms should be sufficiently fast enough, tune in to the tastes and habits of the user, and ensure a quality of work that satisfies the user. We propose several adaptive algorithms for creating photo books, i.e., the recognition of normal quality photos based on active learning, clustering images by event, selection of the most attractive photos, automatic placement of images on the page, and creation of collages. Approaches are also proposed for the adjustment of algorithms to the tastes and habits of the user in the process of operation.     

Algorithm for segmentation of documents based on texture features

The ascending approach to segmentation of scanned documents in the area of background, text, and photographs is considered. In the first stage, the image is divided into blocks. For each block, a series of texture features is calculated. On the basis of these features, the type of the block is determined. Various positions and sizes of blocks, 26 texture features, and 4 algorithms of classification of blocks were considered. In the second stage, the type of block was corrected on the basis of the analysis of neighboring regions. For estimating the results, the error matrix and the ICDAR 2007 criterion are used.