Tomas Jirku

Model of a Reactor Chamber with Microwave Heating

This contribution brings the results obtained by numerical modeling of a reactor chamber design. The reactor chamber is intended for the preparation of oil. The chamber is designed for the operating frequency f = 2:4GHz with regulated microwave power. The power regulation allows the optimization of heat distribution in non-homogenous material with respect to chemical and physical material changes | phase changes. The paper presents a numerical model of a coupled problem. The coupled problem includes the radio frequency model and thermal fleld with non-linear thermal material. It was solved using sophisticated combined numerical method | the flnite element method (FEM) and the flnite volume method (FVM). The used material respects its own phase change from the liquid condition to the gas phase. The apparatus serves as an experimental prototype of the commercial one, that is currently being used by the ARS | Altman Recovery System Company.

A Passive Optical Location with Limited Range

We know active and passive methods of a location. This article deals only with a passive location of dynamic targets. The passive optics location is suitable just for tracking of targets with mean velocity which is limited by the hardware basis. The aim of this work is to recognize plasma, particles etc. It is possible to propose such kind of evaluation methods which improve the capture probability markedly. Suggested method is dealing with the short-distance evaluation of targets. We suppose the application of three independent principles how to recognize an object in a scanned picture. These principles use similar stochastic functions in order to evaluate an object location by means of simple mathematical operations. Methods are based on direct evaluation of picture sequence by the help of the histogram and frequency spectrum. We find out the probability of unidentified moving object in pictures. If the probability reaches a setting value we will get a signal.

The Design of LVDS Bus with High EMC Compliance

The article deals with results which were obtained during the design of LVDS (low voltage differential signaling) bus. This bus is very resistant to interference from the environment and to spurious emission of electromagnetic fields. According to requirements we prepared designs of LVDS by means of numerical methods. The design was realized and its parameters verified experimentally. The basic parameter of bus impedance Z = 100 Omega, frequency f1 = 100 MHz of the first harmonic of rectangle signal.

Experiments of Accuracy Air Ion Field Measurement

This article presents the capability of methods for measuring of the air ion concentration and principles of ion spectral analysis methods. The analysis of the electric state of air shows the presence of various ion sorts. The therapeutic effect of negative high-mobility ions of proper concentration is known. This positive effect was observed in caves that are used for speleotherapy.

Numerical Model of Inductive Flowmeter

This article deals with physical and chemical processes during measurement with an inductive ∞owmeter. A theoretical model and an example of numerical solution are presented here. We prepared numerical models based on the combined flnite element method (FEM) and the flnite volume method (FVM) of one of the three variants and computed the output voltage of the ∞owmeter electrodes. The model joins the magnetic, the electric and the current flelds, the ∞ow fleld and a chemical nonlinear ion model. The results were obtained by means of the FEM/FVM as a main application in ANSYS software.

Optical methods for extreme level measurement

There are certain optical methods for the measurement of ultra-short solitary electromagnetic pulses or low-level measurement. The measurement methods properties have to correspond to the fact of whether we want to measure pulses of voltage, current or a free-space electromagnetic wave. The need for specific measurement methods occurred owing to the development of high power microwave pulse generator. Certain applicable methods are presented in this paper. For the same purpose, the magneto-optic method can be utilized with respect to its advantages. For the measurement of the output microwave pulse of the generator, the optical method was designed and realized. Low-level optical measurement methods were used for nano-layers measurement and experimentally verified with regard to air ion concentration test.

The Optimal Design of the LVDS Bus with High EMS

The article deals with results which were obtained during the process of designing the LVDS (low voltage difierential signal) bus. This bus is very resistant to interference from the environment and to spurious emission of electromagnetic waves. According to the concrete requirements we prepared a design of the LVDS by means of numerical methods. The design was realized and its parameters verifled experimentally. The basic parameter of bus is its impedance Z = 100›, up to frequency f1 = 100MHz of the flrst harmonic of rectangle signal. DOI: 10.2529/PIERS060901103255