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Tytuł:
Microwave field strength computing for the resonator designs and filters
Autorzy:
Radmilović-Radjenović, M.
Radjenović, B.
Savić, M.
Powiązania:
https://bibliotekanauki.pl/articles/1070622.pdf
Data publikacji:
2016-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
52.80.-s
52.90.+z
Opis:
Recent development of microwave pulse generators, which are now capable of delivering very short and very intensive pulses requires properly generalized classical breakdown theory. On the other hand, the trend to design microwave devices as small and compact as possible, leads to a concern about the concomitant breakdown strength of the construction, involving more complicated geometries, such as in microwave resonators and filters. In this paper, several aspects of microwave breakdown field strength in commercially available resonator designs and filters are presented and analyzed. The numerical predictions based on the Slater theorem are compared with the analytical results and predictions of the fluid approach, demonstrating very good agreement.
Źródło:
Acta Physica Polonica A; 2016, 129, 3; 289-292
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electron Avalanche Statistics
Autorzy:
Ficker, T.
Powiązania:
https://bibliotekanauki.pl/articles/1585038.pdf
Data publikacji:
2009-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
52.80.-s
52.80.Dy
52.80.Mg
Opis:
A solution of the long-lasting problem with anomalous population statistics of pre-streamer avalanches has been proposed in the form of a new generalized probability density function.
Źródło:
Acta Physica Polonica A; 2009, 116, 6; 1018-1020
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Investigation on Surface and Electrical Properties of Electrical Discharge Machined AISI D2 Tool Steel
Autorzy:
Durmus, A.
Bayram, A.
Gunes, S.
Akay, S.
Powiązania:
https://bibliotekanauki.pl/articles/1182843.pdf
Data publikacji:
2014-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
52.80.-s
81.65.-b
Opis:
The effects of pulse-on duration and finishing operation on the surface roughness and electrical resistivity of AISI D2 tool steel machined by the electrical discharge machining process are investigated. Experimental results indicate that surface roughness increased depending on the pulse-on duration. However, after the specific value, surface roughness is decreased. It can be seen that there are no notable effects of the pulse-on duration on the electrical resistivity, but the resistivity values are affected by the heat treatment and the finishing operation. Also, light microscopy and scanning electron microscopy have been used to study the characteristics of the surfaces.
Źródło:
Acta Physica Polonica A; 2014, 125, 2; 515-517
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characteristics of Acoustic Emission Signals Generated by the Contacts of the Selector
Autorzy:
Cichoń, A.
Borucki, S.
Wotzka, D.
Szmajda, M.
Powiązania:
https://bibliotekanauki.pl/articles/1417945.pdf
Data publikacji:
2012-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
52.80.-s
43.28.Js
Opis:
An important part of electric power transformer is the on load tap changer which enables for voltage regulation in the network. Due to high level of failure frequency of these devices it is necessary to look for new diagnostic methods which enable for theirs technical state estimation under transformer normal operating condition. Presently at the Electric Power Institute at Opole University of Technology there are works in progress aspiring to determine the application possibility of the acoustic emission method for on load tap changer diagnosis. Results of scientifically-research works aiming to characterize the acoustic emission signals generated by a separated selector are presented in the paper. Measurements have been performed in a setup with a model of on load tap changer type VEL-110-27 from ELIN. Acoustic emission signals generated by the selector have been analyzed in detail. Analysis of the time-frequency components of signals generated by on load tap changer has been carried out with the short time Fourier transform and continuous wavelet transform. Based on the comparison outcome of acoustic emission signals generated by the power changer and by the selector two measuring paths endowed with wide band contact transducers have been proposed for the practical application.
Źródło:
Acta Physica Polonica A; 2012, 122, 5; 804-807
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characteristic of Acoustic Signals Generated by Operation of On Load Tap Changers
Autorzy:
Cichon, A.
Fracz, P.
Zmarzly, D.
Powiązania:
https://bibliotekanauki.pl/articles/1493036.pdf
Data publikacji:
2011-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
52.80.-s
43.28.Js
Opis:
Possibilities of application of the acoustic method for the on load tab changers diagnosis has been presented in the paper. The analysis of measurement results gathered during research works performed under laboratory conditions has been presented in detail. The registered acoustic signals have been analyzed in time and time-frequency domains. The time domain analysis has been performed by presentation of time runs and their envelopes determined by use of the Hilbert transform. Evaluation of the time-frequency components has been performed by use of the short-time Fourier transform, the discrete and the continuous wavelet transforms.
Źródło:
Acta Physica Polonica A; 2011, 120, 4; 585-588
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Application of the Selected Time-Frequency Descriptors Detection of the Acoustic Emission Signals Generated by Multisource Partial Discharges
Autorzy:
Cichon, A.
Powiązania:
https://bibliotekanauki.pl/articles/1795791.pdf
Data publikacji:
2009-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
52.80.-s
43.28.Js
Opis:
The paper presents the comparative analysis results of the acoustic emission signals generated by various forms of partial discharges occurring in multisource systems. Modern methods of the signal digital processing: a short-time Fourier transform and continuous and discrete wavelet transforms were applied for the assessment of the results in the time-frequency domain. The acoustic emission signals generated by partial discharges were registered with a WD AH17 contact transducer by the Physical Acoustics Corporation placed on the external part of the tub.
Źródło:
Acta Physica Polonica A; 2009, 116, 3; 290-293
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of Acoustic Wave Propagation in a Power Transformer Model
Autorzy:
Wotzka, D.
Boczar, T.
Zmarzły, D.
Powiązania:
https://bibliotekanauki.pl/articles/1807760.pdf
Data publikacji:
2009-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
52.80.-s
43.28.Js
Opis:
Analyses of acoustic wave propagation in a model power transformer are presented in the paper. The acoustic wave is induced by partial discharges that are simulated at predefined coordinates in the core and winding. Propagation of the numerical calculated acoustic wave is analyzed within the transient state. Achieved results indicate that the space and time distributions of the acoustic pressure depend on the induction position. Furthermore, a greater pressure gradient is observed in domains with higher speed of sound while the largest amplitude occurs at the vicinity of the induction position.
Źródło:
Acta Physica Polonica A; 2009, 116, 3; 428-431
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synchronization Study and Introductory Experiment οf Laser-Triggered Surface Flashover in Voltage Pulse
Autorzy:
Pan, R.
Wang, J.
Sun, Y.
Sun, G.
Yan, P.
Zhang, D.
Powiązania:
https://bibliotekanauki.pl/articles/1807974.pdf
Data publikacji:
2009-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
52.80.-s
51.50.+v
Opis:
With the aim of studying the characteristics of laser-triggered surface flashover in voltage pulse, synchronization problem of laser pulse and voltage pulse should be solved. A single/double harmonic, with wavelength λ of 1064/532 nm, Q-switched Nd:YAG laser is used to trigger the surface flashover. The synchronization problem is solved using a self-made digital delay/pulse generator. The delay time and jitter of Marx's trigger input and output, Marx's trigger output and Marx's output, laser input and output are respectively measured. Based on the result of the delay time and the timing sequence of the laser triggering system, the synchronization of laser pulse and voltage pulse is obtained through adjusting the channel delay time of digital delay/pulse generator. In addition, introductory experiment of laser-triggered surface flashover is carried out using the flat electrodes and columned insulators.
Źródło:
Acta Physica Polonica A; 2009, 115, 6; 1167-1169
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Measurements of Cu Atoms Diffusion Coefficients in He and Ne - Optimalisation of a Novel Method
Autorzy:
Kwaśniewski, W.
Dzieciołowski, K.
Adamowicz, T. M.
Powiązania:
https://bibliotekanauki.pl/articles/2035632.pdf
Data publikacji:
2002-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
42.55.Lt
42.60.Lh
52.80.-s
Opis:
A novel method based on two-pulse excitation of a hollow cathode discharge to determine metal atoms diffusion coefficients in noble gases was tested in Cu-He and Cu-Ne systems. The excitation conditions such as time duration of the discharge current pulses and configurations of the hollow cathode discharge were checked. Measurements carried out over the wide range gas pressures allowed obtaining the Cu atoms time-decay curves from which the diffusion coefficients were calculated. The values for Cu atom diffusion coefficients of 570 and 310 cm$\text{}^{2}$ s$\text{}^{-1}$ mbar in He and Ne, respectively were in a good agreement with earlier reported data achieved by using the absorption spectroscopy method. The diffusion coefficient of Cu in $\text{}^{3}$He, the lighter isotope of helium, was also found to be 670 cm$\text{}^{2}$ s$\text{}^{-1}$ mbar that agreed well with the kinetic theory of gases. To authors believe this value was not reported previously.
Źródło:
Acta Physica Polonica A; 2002, 102, 6; 747-757
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of Properties of Chosen Acoustic Emission Descriptors Describing Acoustic Signals Measured by Means of Acoustic Emission Method within Oil Transformers
Autorzy:
Witos, F.
Olszewska, A.
Powiązania:
https://bibliotekanauki.pl/articles/1506870.pdf
Data publikacji:
2010-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
52.80.-s
77.22.Jp
84.70.+p
Opis:
Authors of the paper present investigation results concerning properties of ADP, ADC and ADNC descriptors which have been obtained during measurements made within three oil transformers and then tested also by other methods (electric and dissolved gas analysis ones). Methodology which makes easier an analysis and identification of acoustic emission signals generated by partial discharges is presented. Results obtained by acoustic emission method have been referred to results coming from other measuring methods.
Źródło:
Acta Physica Polonica A; 2010, 118, 6; 1267-1271
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Measuring Picosecond Flashover in Closing Coaxial Spark Gap Switch
Autorzy:
Klüss, J.
Hällström, J.
Powiązania:
https://bibliotekanauki.pl/articles/1807883.pdf
Data publikacji:
2009-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
51.50.+v
52.70.Gw
52.80.-s
Opis:
Flashover voltage and picosecond risetime of breakdown in pressurized $SF_{6}$ gas is studied on a coaxial line. Gas pressure is varied from 1 to 19 bar. The homogeneous field gap has an opening from ca. 0.2 to 0.9 mm, and flashover voltages reach 120 kV. Measurements are performed using a D-dot probe with 16 to 20 GHz real-time oscilloscopes and a 50 GHz sampling oscilloscope. Measured risetimes are down to ca. 50 ps, and the dependence of voltage collapse on gas density and electric field between the electrodes is reported. Integrity of data is analyzed and experimental results are compared with present theory found in literature and previous results measured with alternative real-time systems.
Źródło:
Acta Physica Polonica A; 2009, 115, 6; 1004-1006
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Uncertainty Evaluation of Measurement Data Processing Algorithm Based on Its Matrix Form
Autorzy:
Konopka, K.
Topór-Kamiński, T.
Powiązania:
https://bibliotekanauki.pl/articles/1493241.pdf
Data publikacji:
2011-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
52.80.-s
77.22.Jp
84.70.+p
Opis:
Data processing algorithms are important parts of modern measurement systems. These algorithms are often delivered to the user as complex program and their numerical structure is not known. Therefore also influence of algorithm on processed data accuracy is not known. One of the methods to evaluate uncertainty propagation through algorithm is based on matrix form of algorithm. Coefficient matrix of algorithm represents its numerical operations and it is a basis to algorithm accuracy evaluation. The paper presents a method how to identify this coefficient matrix when algebraic form of the algorithm is known or is difficult to use. Identified matrix form of algorithm is then used to estimate uncertainty propagation through exemplary algorithms. Results are compared with experiments.
Źródło:
Acta Physica Polonica A; 2011, 120, 4; 666-670
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Decay of Electric Charge on Corona Discharge Polyethylene
Autorzy:
Zhang, L.
Xu, Z.
Chen, G.
Powiązania:
https://bibliotekanauki.pl/articles/1807998.pdf
Data publikacji:
2009-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
52.80.-s
81.05.Lg
84.30.Jc
Opis:
In this paper, surface potential decay after corona charge deposition has been investigated for low density polyethylene (LDPE) films. We believe that the three ways of electron charge decay on the surface of insulating polyethylene film is reasonable. The factor of neutralizing with opposite charge in air is negligible, and leakage along insulator surface or through the body is much more important for electron charge decay. Both ways are related with surface voltage of the sample. When the voltage is lower than a critical value, surface leakage contributes most. If the voltage is higher than this value, the electron energy on the surface of the sample exceeds the critical value and it is easy to cross the "deep trap". In this situation, the body leakage is more important, and the decay on the surface of sample speeds. That is why there exists decay curve crossing phenomenon.
Źródło:
Acta Physica Polonica A; 2009, 115, 6; 1197-1200
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microbial Inactivation by Electric Discharge with Metallic Grid
Autorzy:
Scholtz, V.
Kvasničková, E.
Julák, J.
Powiązania:
https://bibliotekanauki.pl/articles/1399503.pdf
Data publikacji:
2013-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
52.50.Dg
52.75.-d
52.80.Hc
52.80.-s
87.19.xb
Opis:
The area of microbial inactivation by the low-temperature plasma produced by DC electric cometary discharge is increased by insertion of an electrically insulated metallic grid between the discharge and the target object. Gram-negative bacteria are almost fully inactivated; an additional zone of incomplete inactivation appears for Gram-positive bacteria and yeasts.
Źródło:
Acta Physica Polonica A; 2013, 124, 1; 62-65
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electric Field Modelling in Gas-Insulated Substation for Analysis of Conditions for Partial Discharge Phenomena
Autorzy:
Florkowska, B.
Zydroń, P.
Jackowicz-Korczyński, A.
Powiązania:
https://bibliotekanauki.pl/articles/1401877.pdf
Data publikacji:
2015-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
51.50.+v
52.80.-s
84.70.+p
41.20.-q
Opis:
The paper refers to diagnostics problems connected with the presence of partial discharges in gas-insulated substation. The basic stimulus for partial discharges generation is local, high value electric field, greater than the inception one. The numerical simulations of the electric field distribution in the part of the gas insulating system and in the vicinity of the metallic protrusion located on high voltage conductor are presented. Such defects are often present in SF₆ insulated constructions and are the cause of a local increase of the electric field. Theoretical analysis of physical mechanism of partial discharges initiation and development in the case of micro-needle type defects is described.
Źródło:
Acta Physica Polonica A; 2015, 128, 3; 319-325
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł

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