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Number of results: 70
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Abstract

This paper presents the results of experimental testing of parameters of the flow of an agitated liquid in a stirred tank with an eccentrically positioned shaft and with a Rushton turbine. The investigations were focused on the impact of the stirrer shaft shift in relation to the stirred tank vertical axis on the agitated liquid mean velocities and the liquid turbulent velocity fluctuations, as well as on the turbulence intensity in the tank. All the experiments were carried out in a stirred tank with the inner diameter of 286 mm and a flat bottom. The adopted values of the shaft eccentricity were zero (central position) and half the tank radius. The liquid flow instantaneous velocities were measured using laser Doppler anemometry.

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Authors and Affiliations

Jan Talaga
Piotr Duda
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Abstract

Polychlorinatcd dibenzodioxins and dibcnzofurans (PCDD/Fs) arc present in the air either adsorbed on particulate matter or as vapor (minor part). They arc known to be effective carcinogenic and mutagenie agents. In this study dust samples from Lublin were collected for twelve months and analyzed for PCDD/Fs content. For the analysis of these samples classical extraction with a Soxhlet apparatus, double step clean-up based on SEC and charge-transfer interactions chromatography, and final analysis with GC-MS were applied.
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Authors and Affiliations

Aneta Duda
Jacek Czerwiński
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Abstract

Polychlorinated dibenzodioxins and dibenzofurans are present in the air either adsorbed on particulate matter or as vapor (minor part). They are most known carcinogens and mutagens. In this study dust samples from Lublin were being collected for 12 months and analyzed for the PCDD/Fs content. For the analysis of these samples classical extraction with Soxhlet apparatus, double step clean-up based on SEC and charge-transfer interactions chromatography, and finally analysis with GC-MS were applied. Results of the determinations were compared with results obtained by other authors.
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Authors and Affiliations

Aneta Duda
Jacek Czerwiński
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Abstract

A new solution to the problem of frequency estimation of a single sinusoid embedded in the white Gaussian noise is presented. It exploits, approximately, only one signal cycle, and is based on the well-known 2nd order autoregressive difference equation into which a downsampling is introduced. The proposed method is a generalization of the linear prediction based Prony method for the case of a single undamped sinusoid. It is shown that, thanks to the proposed downsampling in the linear prediction signal model, the overall variance of the least squares solution of frequency estimation is decreased, when compared to the Prony method, and locally it is even close to the Cramér–Rao Lower Bound, which is a significant improvement. The frequency estimation variance of the proposed solution is comparable with, computationally more complex, the Matrix Pencil and the Steiglitz–McBride methods. It is shown that application of the proposed downsampling to the popular smart DFT frequency estimation method also significantly reduces the method variance and makes it even better than the least squares smart DFT. The noise immunity of the proposed solution is achieved simultaneously with the reduction of computational complexity at the cost of narrowing the range of measured frequencies, i.e. a sinusoidal signal must be sufficiently oversampled to apply the proposed downsampling in the autoregressive model. The case of 64 samples per period with downsampling up to 16, i.e. 1/4th of the cycle, is presented in detail, but other sampling scenarios, from 16 to 512 samples per period, are considered as well.
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Bibliography

[1] Kay, S. M. (1993). Fundamentals of Statistical Signal Processing: Estimation Theory. Prentice-Hall
[2] Kay, S. M., & Marple, S. L. (1981). Spectrum analysis – A modern perspective. Proc. IEEE, 69, 1380–1419. https://doi.org/10.1109/PROC.1981.12184
[3] Kay, S. M. (1987). Modern Spectrum Analysis. Prentice-Hall.
[4] Zielinski, T. P., & Duda, K. (2011). Frequency and damping estimation methods - an overview. Metrology and Measurement Systems, 18(3), 505–528. https://doi.org/10.2478/v10178-011-0051-y
[5] Duda, K., & Zielinski, T. P. (2013). Efficacy of the frequency and damping estimation of a real-value sinusoid. IEEE Instrumentation & Measurement Magazine, 16(1), 48–58. https://doi.org/10.1109/ MIM.2013.6495682
[6] Borkowski, J., Kania, D., & Mroczka, J. (2018). Comparison of sine-wave frequency estimation methods in respect of speed and accuracy for a few observed cycles distorted by noise and harmonics. Metrology and Measurement Systems, 25(1), 283–302. https://doi.org/10.24425/119567
[7] Harris, F. J. (1978). On the use of windows for harmonic analysis with the discrete Fourier transform. Proceedings of the IEEE, 66(1), 51–83. https://doi.org/10.1109/PROC.1978.10837
[8] Zygarlicki, J., Zygarlicka, M., Mroczka, J., & Latawiec, K. J. (2010). A reduced Prony’s method in power-quality analysis – parameters selection. IEEE Transactions on Power Delivery, 25(1), 979–986. https://doi.org/10.1109/TPWRD.2009.2034745
[9] Zygarlicki, J., & Mroczka, J. (2014). Prony’s method with reduced sampling – numerical aspects. Metrology and Measurement Systems, 21(2), 521–534. https://doi.org/10.2478/mms-2014-0044
[10] Zygarlicki, J. (2017). Fast second order original Prony’s method for embedded measuring systems. Metrology and Measurement Systems, 24(3), 721–728. https://doi.org/10.1515/mms-2017-0058
[11] Hua, Y., & Sarkar, T. K., (1990). Matrix pencil method for estimating parameters of exponentially damped/undamped sinusoid in noise. IEEE Transactions on Acoustics, Speech, and Signal Processing, 38(4), 814–824. https://doi.org/10.1109/29.56027
[12] Steiglitz, K.,&McBride, L. (1965). A technique for identification of linear systems. IEEE Transactions on Automatic Control, 10(3), 461–464. https://doi.org/10.1109/TAC.1965.1098181
[13] McClellan, J. H., & Lee, D. (1991). Exact equivalence of the Steiglitz–McBride iteration and IQML. IEEE Transactions on Signal Processing, 39(1), 509–512. https://doi.org/10.1109/78.80841
[14] Wu, R. C., & Chiang, C. T. (2010). Analysis of the exponential signal by the interpolated DFT algorithm. IEEE Transactions on Instrumentation and Measurement, 59(12), 3306–3317. https://doi.org/10.1109/TIM.2010.2047301
[15] Derviškadic, A., Romano, & P., Paolone, M. (2018). Iterative-Interpolated DFT for Synchrophasor Estimation: A Single Algorithm for P- and M-Class Compliant PMUs. IEEE Transactions on Instrumentation and Measurement, 67(2), 547–558. https://doi.org/10.1109/TIM.2017.2779378
[16] Jacobsen, E., & Kootsookos, P. (2007). Fast, accurate frequency estimators. IEEE Signal Processing Magazine, 24(2), 123–125. https://doi.org/10.1109/MSP.2007.361611
[17] Duda, K., & Barczentewicz, S. (2014). Interpolated DFT for sin α (x) windows. IEEE Transactions on Instrumentation and Measurement, 63(3), 754–760. https://doi.org/10.1109/TIM.2013.2285795
[18] Yang, J. Z., & Liu, C. W. (2000). A precise calculation of power system frequency and phasor. IEEE Transactions on Power Delivery, 15(1), 494–499. https://doi.org/10.1109/61.852974
[19] Yang, J. Z., & Liu, C. W. (2001). A precise calculation of power system frequency. IEEE Transactions on Power Delivery, 16(2), 361–366. https://doi.org/10.1109/61.924811
[20] Xia, Y., He, Y., Wang, K., Pei, W., Blazic, Z., & Mandic, D. P. (2017). A complex least squares enhanced smart DFT technique for power system frequency estimation. IEEE Transactions on Power Delivery, 32(2), 1270–1278. https://doi.org/10.1109/TPWRD.2015.2418778
[21] Li, Z. (2021). A total least squares enhanced smart DFT technique for frequency estimation of unbalanced three-phase power systems. International Journal of Electrical Power & Energy Systems, 128, 106722. https://doi.org/10.1016/j.ijepes.2020.106722
[22] Xu, S., Liu, H., & Bi, T. (2020). A novel frequency estimation method based on complex Bandpass filters for P-class PMUs with short reporting latency. IEEE Transactions on Power Delivery. https://doi.org/10.1109/TPWRD.2020.3038703
[23] Duda, K., & Zielinski, T. P. (2021). P Class and M Class Compliant PMU Based on Discrete- Time Frequency-Gain Transducer. IEEE Transactions on Power Delivery. https://doi.org/10.1109/TPWRD.2021.3076831
[24] IEC, IEEE. (2018). Measuring relays and protection equipment – Part 118–1: Synchrophasor for power systems – Measurements (IEC/IEEE Standard No. 60255-118-1).
[25] Moon, T. K., & Stirling W. C. (1999). Mathematical Methods and Algorithms for Signal Processing. Prentice Hall.

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Authors and Affiliations

Krzysztof Duda
1
Tomasz P. Zieliński
2

  1. AGH University of Science and Technology, Faculty of Electrical Engineering, Automatics, Computer Science and Biomedical Engineering, Department of Measurement and Electronics, al. Mickiewicza 30, 30-059 Kraków, Poland
  2. AGH University of Science and Technology, Faculty of Computer Science, Electronics and Telecommunications, Institute of Telecommunications, al. Mickiewicza 30, 30-059 Kraków, Poland
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Abstract

Rhizoctonia solani was isolated from 91 % of alder and birch seedlings with stem rot symptoms and 2-3% of seeds. Sowing of seeds to substratum infested with R. solani resulted in pre-and postemergence damping off. On leaves and stem parts of alder and birch, inoculated with 3 isolates of R. solani, necrosis spread from 0.22 to 0.52 mm/hr.
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Authors and Affiliations

Leszek B. Orlikowski
Barbara Duda
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Abstract

Abstract In the paper a Lyapunov matrices approach to the parametric optimization problem of time-delay systems with two commensurate delays and a P-controller is presented. The value of integral quadratic performance index of quality is equal to the value of the Lyapunov functional for the initial function of time-delay system. The Lyapunov functional is determined by means of the Lyapunov matrix.
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Authors and Affiliations

Jozef Duda
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Abstract

Abstract In the paper a state filtration in a decentralized discrete time Linear Quadratic Gaussian problem formulated for a multisensor system is considered. Local optimal control laws depend on global state estimates and are calculated by each node. In a classical centralized information pattern the global state estimators use measurements data from all nodes. In a decentralized system the global state estimates are computed at each node using local state estimates based on local measurements and values of previous controls, from other nodes. In the paper, contrary to this, the controls are not transmitted between nodes. It leads to nonconventional filtration because the controls from other nodes are treated as random variables for each node. The cost for the additional reduced transmission is an increased filter computation at each node.
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Authors and Affiliations

Zdzisław Duda
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Abstract

Abstract In the paper construction of a Lyapunov functional for time delay system with both lumped and distributed delay is presented. The Lyapunov functional is determined by means of the Lyapunov matrix. The method of determination of the Lyapunov matrix for time delay system with both lumped and distributed delay is presented. It is given the example illustrating the method.
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Authors and Affiliations

Jozef Duda
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Abstract

In the paper the parametric optimization problem for a linear system with two delays and a PD-controller is presented. In the parametric optimization problem the quadratic performance index is considered. The value of the quadratic index of quality is calculated due to the Lyapunov functional and is equal to the value of that functional for the initial function of the neutral system with two delays. The Lyapunov functional is determined by means of the Lyapunov matrix.

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Authors and Affiliations

Józef Duda
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Abstract

In the paper a Lyapunov matrices approach to the parametric optimization problem of a time-delay system with two commensurate delays and a PI-controller is presented. The value of integral quadratic performance index is equal to the value of the Lyapunov functional for the initial function of the time-delay system. The Lyapunov functional is determined by means of the Lyapunov matrix. In the paper is presented the example of a scalar system with two delays and a PI controller.

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Authors and Affiliations

Jozef Duda
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Abstract

In the paper a Lyapunov matrices approach to the parametric optimization problem of a neutral system with a P-controller is presented. The value of integral quadratic performance index of quality is equal to the value of Lyapunov functional for the initial function of the neutral system. The Lyapunov functional is determined by means of the Lyapunov matrix.
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Authors and Affiliations

Jozef Duda
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Abstract

Abstract In the paper a Lyapunov matrices approach to the parametric optimization problem of time-delay systems with a P-controller is presented. The value of integral quadratic performance index of quality is equal to the value of Lyapunov functional for the initial function of the time-delay system. The Lyapunov functional is determined by means of the Lyapunov matrix
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Authors and Affiliations

Józef Duda
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Abstract

Abstract A fusion hierarchical state filtration with k−step delay sharing pattern for a multisensor system is considered. A global state estimate depends on local state estimates determined by local nodes using local information. Local available information consists of local measurements and k−step delay global information - global estimate sent from a central node. Local estimates are transmitted to the central node to be fused. The synthesis of local and global filters is presented. It is shown that a fusion filtration with k−step delay sharing pattern is equivalent to the optimal centralized classical Kalman filtration when local measurements are transmitted to the center node and used to determine a global state estimate. It is proved that the k−step delay sharing pattern can reduce covariances of local state errors.
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Authors and Affiliations

Zdzisław Duda
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Abstract

The subject of the research is one of the largest World’s mine tailings disposal sites, i.e. Żelazny Most in the Legnica-Głogów Copper Mining District (south-western Poland), where flotation tailings are poured out after copper ore treatment. The protective hydraulic barrier made of 46 vertical drainage wells was characterized and evaluated in view of reduction of major contaminants (Cl, Na, SO4, Ca) migrating from the facility to its foreground. The efficiency of groundwater protection was determined on the basis of a new approach. In applied method the loads of characteristic and commonly recognizable compounds, i.e. salt (NaCl) and gypsum (CaSO4) were calculated, instead their chemical components. The temporal and spatial variability of captured main contaminants loads as well as its causes are discussed. The paper ends with the results of efficiency analyses of the barrier and with respect to the predicted increase in contaminant concentrations in the pulp poured out to the tailings site.
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Authors and Affiliations

Robert Duda
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Abstract

The article discusses the book Zmiana perspektywy. Gawęda nie tylko językoznawcza [Change of perspective. More than a tale of linguistics] by Zuzanna Topolińska (Cracow 2015). The author of this text emphasizes that the word gawęda [tale] in the book’s subtitle is misleading, given that, despite the style of language used in the book, Topolińska discusses important issues of a linguistic and intercultural nature. In her short essays in the fi rst part of the book Topolińska addresses the organizational structure of philology studies in Poland and Macedonia, she confronts the Polish and Macedonian approach to the dialectgeneral language relationship, she talks about language standards, about the differences between politeness in Poland and Macedonia, as well as the attitude towards women and the outlook toward religion in both countries. In the second part of the book Topolińska takes up lexical issues, giving examples of how under the infl uence of spiritual culture certain words in Polish and Macedonian that derive from the same core have taken on a different meaning. The author of the article concludes that this short and very personal book by Topolińska fulfi lls its task and subsequently alters his view on the linguistic and non-linguistic world of the Slavs.

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Authors and Affiliations

Henryk Duda

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