scholarly journals UPDATED VERSION OF THE SIMPLIFIED MODEL OF INTENSIVELY BLASTED ELECTRIC ARC

2018 ◽  
Vol 58 (4) ◽  
pp. 264 ◽  
Author(s):  
Josef Senk ◽  
Ilona Laznickova ◽  
Ivana Jakubova
Keyword(s):  
Measured Data ◽  
Electric Arc ◽  
Optimum Combination ◽  
The State ◽  
Simplified Model ◽  
Cathode Layer ◽  
State Variables ◽  
Channel Axis ◽  
Arc Heater

The article deals with an improvement of a simplified model of intensively blasted electric arc burning in argon in an anode channel of a modular-type arc heater. Gradually gained experience in the application of the model with various input data has revealed that some refinement is needed. The contribution focuses especially on the process of searching for an optimum combination of the state variables, which are the exponent determining the arc radius development along the anode channel axis, the current density at the cathode, and the arc temperature at the end of the near-cathode layer. The limiting relations for the state variables are set and discussed. Three constituent parts of the used objective function are analysed and compared. The procedure is demonstrated on a chosen set of experimental data. Further computations with many sets of measured data are necessary to test the designed procedure and to confirm the determination of the state variables’ range.

scholarly journals Estimation of the Intensively Blasted Electric Arc Model Sensitivity to Selected Variables

2019 ◽  
Vol 6 (1) ◽  
pp. 47-50
Author(s):  
J. Senk ◽  
I. Laznickova ◽  
I. Jakubova ◽  
O. Coufal
Keyword(s):  
Input Data ◽  
Electric Arc ◽  
Simplified Model ◽  
Individual State ◽  
State Variables ◽  
Arc Model ◽  
Electric Arc Model ◽  
Arc Heater ◽  
Vector Of State ◽  
Cathode Boundary Layer

<p>Results of measurements carried out on the fabricated experimental modular-type arc heater serve as input data for the designed simplified model of the intensively blasted electric arc burning in argon inside the cylindrical arc heater's anode channel. The axial dependence of the arc temperature and radius is expressed using the exponent, the current density on the cathode tip and the arc temperature at the end of the near-cathode boundary layer. These quantities form the vector of state variables that is sought to minimize the value of the objective function expressing the deviations between measured and computed values. On a typical example, the paper demonstrates the sensitivity of the modelling to individual state variables.</p>

scholarly journals Steady State Response of Linear Time Invariant Systems Modeledby Multibond Graphs

2021 ◽  
Vol 11 (4) ◽  
pp. 1717
Author(s):  
Gilberto Gonzalez Avalos ◽  
Noe Barrera Gallegos ◽  
Gerardo Ayala-Jaimes ◽  
Aaron Padilla Garcia
Keyword(s):  
Steady State ◽  
Linear Time ◽  
Direct Determination ◽  
The State ◽  
Steady State Response ◽  
State Variables ◽  
Linear Time Invariant ◽  
State Response ◽  
Time Invariant

The direct determination of the steady state response for linear time invariant (LTI) systems modeled by multibond graphs is presented. Firstly, a multiport junction structure of a multibond graph in an integral causality assignment (MBGI) to get the state space of the system is introduced. By assigning a derivative causality to the multiport storage elements, the multibond graph in a derivative causality (MBGD) is proposed. Based on this MBGD, a theorem to obtain the steady state response is presented. Two case studies to get the steady state of the state variables are applied. Both cases are modeled by multibond graphs, and the symbolic determination of the steady state is obtained. The simulation results using the 20-SIM software are numerically verified.

scholarly journals ANALYSIS OF INTENSIVELY BLASTED ELECTRIC ARC BURNING IN THE ARC HEATER'S ANODE CHANNEL

2016 ◽  
Vol 56 (5) ◽  
pp. 395-401 ◽  
Author(s):  
Josef Senk ◽  
Ivana Jakubova ◽  
Ilona Laznickova
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Power Loss ◽  
Gas Flow ◽  
Measured Data ◽  
Electric Arc ◽  
Gas Flow Rate ◽  
Voltage Distribution ◽  
Current Voltage ◽  
Arc Heater

The paper deals with the description of the intensively blasted electric arc burning in Ar in the anode channel of the arc heater operated under various conditions. Directly measured experimental data (current, voltage, gas flow rate, power loss) characterize the operation of the device as a whole, but important parameters describing the electric arc inside (its geometry, temperature and voltage distribution) must be revealed using a mathematical model of the arc. An updated version of the model is introduced and used for analysis of two exemplary sets of measured data. The results are given in figures and commented.

Simultaneous Sorption of Chelates of Elements with Organic Reagents on Amberlite XAD-2 as a Preconcentration Step for the Emission Spectrometric Determination of the Elements

1993 ◽  
Vol 58 (8) ◽  
pp. 1821-1831 ◽  
Author(s):  
Jaroslav Jambor ◽  
Tomáš Javorek
Keyword(s):  
Nitrous Oxide ◽  
Argon Plasma ◽  
Electric Arc ◽  
Emission Spectrometry ◽  
Organic Reagents ◽  
Inductively Coupled ◽  
Simultaneous Sorption

The macrophorous hydrophobic sorbent Amberlite XAD-2 proved to be well suited to the preconcentration of minority amounts of Al, Au, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sn, Ti and V in the form of their chelates with organic reagents. From among 14 reagents tested, 8-hydroxyquinoline and diethyldithiocarbamate appeared most suitable for the quantitative sorption up to level of 1 μg l-1 of analyte. Emission spectrometry served as the analytical finish; the nitrous oxide-acetylene flame, electric arc and inductively coupled argon plasma were chosen according to the nature of the element. The procedure is convenient for the determination of the minority analytes in waters

Non Linear State and Parameters Estimation in Chemical Processes: Analysis and Improvement of Three Estimation Structures Applied to a CSTR

2011 ◽  
Vol 9 (1) ◽  
Author(s):  
Héctor Botero ◽  
Hernán Álvarez
Keyword(s):  
Parameter Estimation ◽  
Chemical Process ◽  
Chemical Processes ◽  
The State ◽  
Convergence Speed ◽  
Parameters Estimation ◽  
State Variables ◽  
Input Output ◽  
On Line ◽  
Linear State

This paper proposes a new composite observer capable of estimating the states and unknown (or changing) parameters of a chemical process, using some input-output measurements, the phenomenological based model and other available knowledge about the process. The proposed composite observer contains a classic observer (CO) to estimate the state variables, an observer-based estimator (OBE) to obtain the actual values of the unknown or changing parameters needed to tune the CO, and an asymptotic observer (AO) to estimate the states needed as input to the OBE. The proposed structure was applied to a CSTR model with three state variables. With the proposed structure, the concentration of reactants and other CSTR parameters can be estimated on-line if the reactor and jacket temperatures are known. The procedure for the design of the proposed structure is simple and guarantees observer convergence. In addition, the convergence speed of state and parameter estimation can be adjusted independently.

Filippov solutions of vector Dirichlet problems

2020 ◽  
Vol 70 (2) ◽  
pp. 401-416
Author(s):  
Hana Machů
Keyword(s):  
Differential Equations ◽  
The State ◽  
State Variables ◽  
Dirichlet Problems ◽  
Filippov Solutions ◽  
Natural Notion ◽  
Growth Restrictions ◽  
The One ◽  
The Right ◽  
Effective Growth

Abstract If in the right-hand sides of given differential equations occur discontinuities in the state variables, then the natural notion of a solution is the one in the sense of Filippov. In our paper, we will consider this type of solutions for vector Dirichlet problems. The obtained theorems deal with the existence and localization of Filippov solutions, under effective growth restrictions. Two illustrative examples are supplied.

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