Wyniki wyszukiwania - BazTech

1

Exact and approximate controllability conditions for the micro-swimmers deflection governed by electric field on a plane: The Green’s function approach

Khurshudyan A. Zh.

Archives of Control Sciences

|

2018

|

Vol. 28, No. 3

335--347

EN

We study the exact and approximate controllabilities of the Langevin equation describing the Brownian motion of particles with a white noise. The Langevin equation is shown to describe also the bacterial run-and-tumble motion. Applying the Green’s function approach to the Green’s function representation of the Langevin equation, we obtain necessary and sufficient conditions for exact controllability in the form of a finite-dimensional problem of moments. For the approximate controllability, we obtain only sufficient conditions. The sets of resolving controls are characterized in both cases. The theoretical derivations are supported by a numerical analysis.

2

Determination of the initial thickness of tubes subjected to bending. Part II. Discussion and analysis of obtained results

Śloderbach Z.

Engineering Transactions

|

2015

|

Vol. 63, iss. 4

497--507

EN

In this second part of the paper, applying epressions derived in Part I, the exemplary calculations of the initial thickness of a metallic tube subject to bending at bending machines are presented. The expressions for calculating of the initial thickness were presented for a suitable measure of the big actual radius Ri in the bending zone for an exact (general) solution and for three formal simplifications of the 1st, 2nd, and 3rd order. In the calculations the external or internal diameter of the tube subjected to bending is applied as a parameter. In this paper, the author shows that the calculated initial thickness of the tube (for the same parameters of bending) depending on the external diameter is lower than that calculated depending on the internal diameter. For example, the expression for calculation of deformations included in the UE Directive [1], contains dependence on dext not on dint. The results of the calculations are presented in the graphs and tables enclosed.

3

The role of quantum-well states and carrier scattering times in discontinuities of opto-electrical characteristics of SCH lasers

Kozioł Z, Matukhin S I, Buduleva E A

Optica Applicata

|

2014

|

Vol. 44, nr 1

135--146

EN

Drift-diffusion computer simulation model available in Synopsys’ Sentaurus TCAD User Guide is used to study electrical and optical characteristics of a separate-confinement heterostructure laser based on AlGaAs. We investigate the role of the width and depth of quantum-well active region, below and above the lasing threshold. The device properties depend on both, the number of bound quantum-well states and on closeness of the highest bound states to conduction or valence band offset. The lasing action may not exist at certain widths or depths of quantum-well, and the threshold current is a discontinuous function of these parameters, at such values of quantum-well width or depth when the highest quantum-well bound states cross conduction or valence band energy offset. The effects are more pronounced at low temperatures. Discontinuities in characteristics are found, at certain conditions, in temperature dependences as well. The carriers scattering time on quantum-well is shown to have a crucial role for the amplitude of discontinuities of these characteristics. The current below the lasing threshold and the threshold current density itself decrease with an increase of quantum-well scattering times and the amplitude of discontinuities decreases then as well.

4

Sporządzanie krzywej DAC (Distance Amplitude Correction) oraz ocena wad materiałowych

Samolczyk J.

Obróbka Plastyczna Metali

|

2005

|

T. 16, nr 1

13-19

PL

W pracy przedstawiono zasady sporządzania krzywej DAC (Distance Amplitude Curve) na ekranie defektoskopu analogowego USIP 11. Podstawą techniki DAC jest wyznaczana dowiadczalnie zależność wysokości echa od odległości wyspecyfikowanego reflektora odniesienia. Sformułowano kilka ogólnych zaleceń dotyczących stosowania tej techniki. Krzywą DAC wykorzystano do oceny nieciągłości.

EN

In this paper has been described rules how to do a curve in the defectoscope screen USIP 11. Cause for DAC has been determined by high of echo to distance of reflector destination. It is formed some of generally rules to use this technique. This curve can be use to estimate of discontinuously too.