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Wyszukujesz frazę "43.50.-x" wg kryterium: Temat


Wyświetlanie 1-5 z 5
Tytuł:
Active Vibration Control of Rectangular Plate with Distributed Piezoelements Excited Acoustically and Mechanically
Autorzy:
Kozupa, M.
Wiciak, J.
Powiązania:
https://bibliotekanauki.pl/articles/1537473.pdf
Data publikacji:
2010-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40.Dx
43.50.-x
Opis:
The paper presents simulations and research results of testing of the aluminium plate with active vibration control. The aim of this paper is to analyze and compare two ways of excitation of the test plate, various influence on its vibrations and active damping control. Vibration control of the smart structure is realized through four piezoceramic PZT actuators and one PZT sensor bonded to the plate. Simulations and numerical computations of the structure are performed in ANSYS environment. Measurements are executed on specialized sound insulation suite for small elements in reverberation chamber. At the beginning white noise sound source is used in purpose to measure basic vibration modes. After numerical computations and measurements three particular frequencies has been chosen and for them active damping is applied. There are two ways of exciting the test plate; first method is sound wave, second is mechanical vibrations via one of piezoceramics. The test results indicate that PZTs can decrease vibrations by approximately 15 dB for a pure sound input with acoustic excitation method, for mechanical excitation method 18 dB for a sinus vibration signal is achieved.
Źródło:
Acta Physica Polonica A; 2010, 118, 1; 95-98
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Random Distribution of Long-Term Indicators of Variable Emission Conditions
Autorzy:
Batko, W.
Przysucha, B.
Powiązania:
https://bibliotekanauki.pl/articles/1504435.pdf
Data publikacji:
2011-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.28.Lv
43.50.-x
02.50.Cw
Opis:
This study is dedicated to the problem of estimating uncertainties of long-term noise indicators, when differences in the sound level emission at various time periods of the calendar year are taken into consideration. This task is defined by referring their influence values - in the determined time intervals - to the year period. Due to the limited possibilities of a total monitoring of parameters necessary for the precise estimation of the long-term sound levels, this estimation process is often limited (in accordance with the EU environmental recommendations) to two condition classes. They are defined by two sound levels occurring with probabilities (frequencies) p and 1-p, in the analyzed reference period. In this paper we present a method of calculating uncertainties of this procedure assuming that frequency of determined events are known. The probability distribution for the estimated value was assessed. The developed model formalism of the estimation of uncertainties of long-term sound levels together with algorithms assigned to it, was analyzed. The proposed solution was illustrated by examples of uncertainty calculations of the averaged sound levels in acoustic assessments of environmental hazards.
Źródło:
Acta Physica Polonica A; 2011, 119, 6A; 1086-1090
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Uncertainty Assessment of Index M
Autorzy:
Batko, W.
Przysucha, B.
Powiązania:
https://bibliotekanauki.pl/articles/1490323.pdf
Data publikacji:
2012-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.28.Lv
43.50.-x
02.50.Cw
Opis:
Administrative decisions, related to the selection of the priority of activities minimising acoustic effects in the analysed areas, are determined by the index M values. This index is also known as the noise protection agents demand. A form of its function is determined by variables describing the number of residents and the level of exceeding the permissible noise in these inhabited regions. Uncertainty of decisions resulting from such assessments is conditioned by numerical measures: inaccurate measurements of exceeding permissible noise indicators as well as errors in the estimation of the number of residents exposed to them, formulated in probabilistic categories and interpreted in an interval way. Thus, the uncertainty assessment of index M, being the function determined by means of those variables, requires the determination of the density of probability distribution function of its occurrence. The method of its determination constitutes the contents of the presented hereby paper. The study concentrates on the derivation of the density of probability distribution function of index M, at the assumption that the distribution of variable errors is in a form of the normal cut distribution. The computational algorithm, allowing to perform necessary numerical calculations assigned to the uncertainty assessment process of index M, is presented. The obtained results are illustrated by the example.
Źródło:
Acta Physica Polonica A; 2012, 121, 1A; A-156-A-159
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Studies on Infrasound Noise Emitted by Wind Turbines of Large Power
Autorzy:
Boczar, T.
Malec, T.
Wotzka, D.
Powiązania:
https://bibliotekanauki.pl/articles/1418027.pdf
Data publikacji:
2012-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.28.Dm
07.10.-h
46.40.-f
43.50.-x
43.50.+y
Opis:
The subject area of this article applies to study of infrasound signals generated by the work of modern wind turbines. Infrasound noise measurements were conducted in accordance with assumptions of the EN 61400-11 standard. The object of study was a newly commissioned wind farm with a total electrical power equal to 30 MW. The considered power station consisted of 15 new wind turbines, each with a capacity of 2 MW. Scope of the analysis performed included designation of time runs, depicting temporal changes, and designation of frequency spectra of the recorded infrasound signals. Evaluation of the impact of changes in wind speed was made. Moreover, the scope of analysis, performed in this field, concerned assessment of the impact on the obtained results values of meteorological parameters related to the applied measurement system. Values obtained from measurements were related to and compared with the limits specified in standards and regulations existing in this field.
Źródło:
Acta Physica Polonica A; 2012, 122, 5; 850-853
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quietness in the Soundscape of the Białowieża National Park
Autorzy:
Wiciak, J.
Mleczko, D.
Ozga, A.
Wszołek, G.
Wierzbicki, J.
Piechowicz, J.
Małecki, P.
Powiązania:
https://bibliotekanauki.pl/articles/1402187.pdf
Data publikacji:
2015-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.66.-x
43.66.+y
87.18.Tt
87.19.lc
43.50.Rq
Opis:
The quietness, defined as the near or complete absence of sound, in the context of the natural environment protection, may be considered a state in which no undesired of foreign sounds occur, and, by analogy to noise, analyzed in two aspects: that pertaining to measurements and the subjective one. The article discusses the lowest levels of sounds recorded at night in the soundscape of the Białowieża Forest. Due to low levels of the examined sounds and the technical problems that occurred while the sounds were being measured and registered, the acoustic examination of the measurement set-up in an anechoic chamber has also been presented. The research is aimed at defining precisely the concept of quietness prevailing in the nature in the subjective aspect by determining both the range of levels and the characteristics of preferred sounds.
Źródło:
Acta Physica Polonica A; 2015, 128, 1A; A-79-A-84
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-5 z 5

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