Rational multiplier IQCs for uncertain time-delays and LMI stability conditions

Describes a set of delay-dependent integral quadratic constraint (IQC) stability conditions for time-delay uncertainty. The IQCs are linearly parameterized in terms of a pair of rational stability multipliers, each active over one of a pair of complementary frequency intervals. Using the finite-frequency positive real lemma, each of these finite-frequency IQC conditions are shown to be equivalent to a frequency-independent linear matrix inequality condition, thereby dispensing with the need for frequency-sweeping.     

Ways of improving wet cyclone performance

Wet cyclone operation is analyzed. General data are given on d₅₀ (diameter of particles trapped in an inertial equipment with a performance of 0.5) in relation to the hydraulic resistance coefficient, and also on d₅₀ in relation to hydraulic resistance for scrubbers of various types. __________ Translated from Khimicheskoe i Neftegazovoe Mashinostroenie, No. 7, pp. 29–30, July, 2006.     

The Effect of Phonon Anharmonicity on the Thermodynamic Properties of Nonmetallic Solid

Germanium is used as an example for developing a self-consistent thermodynamic approach to the construction of a model of crystal lattice of a nonmetallic nonmagnetic solid. This approach takes into account the effect of anharmonicity of thermally excited phonons. The calculations of temperature dependences of basic thermodynamic functions reveal, for a model substance, very adequate agreement with the available experimental data in a wide temperature range of hundreds of kelvins.     

Pecularities of using carbon glass—reinforced plastic in pultrusion composite profiles for bridge engineering

An example of selecting carbon fibers with such physicomechanical characteristics which provide increased rigidity without a considerable rise in the price of the constructions when being introduced into the structure of glass-reinforced plastic profiles is described. The technical requirements of carbon fibers are formulated based on the cost criterion of the main materials, the volume content of the carbon fiber in the profile sections are defined, and the pultrusion technology of a large-sized carbon glass—reinforced plastic channel bar is elaborated.     

Distribution of metal particles in a slag during argon blowing of a melt in a ladle

The distribution of metal particles in a slag is studied during argon blowing of steel in a ladle. It is established that the fraction of the metallic phase in the top slag layer is 3.5–5 times smaller than that in the middle and bottom layers. A microscopic analysis of the fraction composition and the geometric shape of the metallic particles show that all portions of the slag part of samples contain significantly larger amounts (by a factor of approximately 4–5) of irregular plane particles along with fine spherical particles.     

Effect of chitosan on dyeing of chemical fibres

Treatment with chitosan before dyeing significantly improves the properties of fabrics made of polyester and polyamide fibres: it increases the intensity and fastness of the colors of the fabrics; the capillary and sorption properties of the fabrics are improved due to swelling of the chitosan film on the fibre; the mechanism of dyeing textile materials is significantly altered by not requiring penetration of the dye into the depth of the fabric.     

Effect of laser treatment on the wear resistance of steels

It is known that laser hardening increases the wear resistance of friction parts quite substantially. At the same time, many problems connected with the effect of the treatment process and the special features of laser hardening on the characteristics of wear resistance require detailed consideration. The present paper is devoted to the development of recommendations on choosing the optimum location and proportion of the areas of the hardened and unhardened regions of the surface of structural steels after their treatment with radiation of a continuous CO₂ laser. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 10, pp. 10–12, October, 1998.