Dynamics of Vibroprotective Systems with Roller Dampers of Low-Frequency Vibrations

We study low-frequency vibrations of a vibroprotective system of solid bodies formed by a roller damper and a moving load-carrying body under the action of external harmonic excitations. The dynamic equations of combined motion of the working body of the damper over the hinged roller without sliding and the load-carrying body are deduced and numerically analyzed. A new procedure is proposed for the evaluation of the optimal parameters of adjustment of roller dampers in nonlinear systems.     

Dynamics of Vibroprotection Systems with a Ball-Type Low-Frequency Oscillation Absorber

The paper deals with low-frequency vibration of a vibroprotection system consisting of a heavy ball with an air damper in an inverted-pendulum spherical socket under the action of external harmonic excitation. The ball in the spherical socket rolls without sliding and is a working body of the ball-type absorber of the inverted-pendulum forced oscillation. Dynamic equations for joint motions of the heavy ball and the inverted pendulum are formulated and analyzed. The authors have obtained amplitude-frequency characteristics of the absolute deviation of the inverted pendulum upper point and the relative displacement of the ball in the spherical socket. A new procedure for the determination of setting parameters for a ball-type oscillation absorber is proposed.     

The density matrix renormalization group algorithm on kilo-processor architectures: Implementation and trade-offs

In the numerical analysis of strongly correlated quantum lattice models one of the leading algorithms developed to balance the size of the effective Hilbert space and the accuracy of the simulation is the density matrix renormalization group (DMRG) algorithm, in which the run-time is dominated by the iterative diagonalization of the Hamilton operator. As the most time-dominant step of the diagonalization can be expressed as a list of dense matrix operations, the DMRG is an appealing candidate to fully utilize the computing power residing in novel kilo-processor architectures.     

Development and Thermal Modeling of a New Construction Biomass Dryer

A new dryer construction has been developed for drying biomass basic materials for energy purposes (straw, sawdust, and other light granular materials). As a result of its simple design, the machine is perfectly suitable for reducing moisture by heat transfer. Compared to the machine types applied thus far, this new construction provides a better ratio of dryer floor space and drying distance and, as a result, a longer drying time. A differential equation system for convection drying was applied for the thermal modeling of the equipment; the mathematical model produced on the basis there of is suitable for examining the heat and mass transfer processes within the dryer. In the course of experimental measurements performed in an industrial size apparatus, the temperature and moisture content of the drying gas were recorded with the initial and final moisture content and surface temperature of the product. The measured values were compared to the results of calculations using the mathematical model.     

A Mathematical Model of the Dynamic Behavior of a Transportation System with Pendulum Shock Absorbers

Strength of Materials - A new mathematical model is proposed that describes the process of damping longitudinal transport effects, which is based on the use of special shock-absorbing pendulum-type...     

Change in neutrophils in liquidators of the consequences of the accident at the Chernobyl Atomic Electric Power Station

In result of own researches and analysis of the literature? the information about high sensitivity of neutrophils of peripheric blood to infringements of constancy of internal state of body, arising as reply to radiating influence, are received. Ionized radiation modulates greatly properties and functions of neutrophilic granulocytes, which are the most sensitive and high-modulated cells of non-specific resistance system. The changes of the functional-metabolic status of neutrophils in participants of liquidation of consequences of Chernobyl disaster have been saving during 10 years after influence of the extreme, including radiating, factors of failure.     

Analytic Determination of the Amplitude-Frequency Characteristic of a Nonlinear Vibroprotective System with Roller Damper

We consider the dynamic behavior of a nonlinear vibroprotective system with roller damper of low-frequency oscillations. By using the Ritz averaging method, we deduce the equation of the amplitude-frequency characteristic of the nonlinear system. A new graphic method is proposed for the determination of the parameters of adjustment of the roller damper.__________Translated from Problemy Prochnosti, No. 2, pp. 136 – 150, March – April, 2005.     

Efficiency of the vibroprotective system with two-mass pendulum damper

We study forced oscillations of a vibroprotective mechanical system of solid bodies including a pendulum damper in the form of a dumbbell and a load-carrying body subjected to the action of external harmonic excitations. The dynamic equations of simultaneous motion of the elements of the analyzed vibroprotective system are deduced and the vibroprotective effects realized by applying the damper are investigated. __________ Translated from Problemy Prochnosti, No. 5, pp. 121–131, September–October, 2007.