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1
Content available remote The idea of quasi-fluidal engine with external catalytic combustion chamber
Jaroszewski A., Kobiałka Sz., Kobiałka A.
Journal of KONES
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2004
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Vol. 11, No. 1-2
276-281
EN
This article shows the used of experiments associated with catalytic combustion chambers as well as problem of external combustion in the piston engines and fluidal combustion, to try to construct the quasi-fluidal engine with external catalytic combustion chamber and make investigations and analysis of this engine.
PL
Niniejszy artykuł przedstawia wykorzystanie doświadczeń związanych ze zastosowaniem katalitycznych komór spalania, jak również problemu spalania zewnętrznego oraz fluidalnego, w celu podjęcia próby konstrukcji oraz przeprowadzenia badań na quasi-fluidalnym silniku z katalityczną zewnętrzną komorą spalania
2
Content available remote The construction of quasi-fluidal engine with external catalytic combustion chamber research stand
Kobiałka Sz., Jaroszewski A., Kobiałka A.
Journal of KONES
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2004
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Vol. 11, No. 1-2
335-340
EN
The experiences accumulated from the previous experiments could permit to make the introductory establishing, who are very useful by the construction of the experimental engine, described in this article. In such way constructed experimental engine, after we11 execute tests, compare w i t h reliability of the "working piston" on the high temperature (in level about 800 ° C) and well obtained self ignition of charge (fuel-air), will be investigated to receive the optimum parameters of combustion, who give as result. extreme reduce of toxic components of' exhaust gases to the atmosphere.
PL
Doświadczenia zawarte w poprzednich badaniach zajmujących się zjawiskiem spalania katalitycznego, pozwalają na stworzenie pewnych założeń pomocnych przy konstrukcji silnika opisanego w niniejszym artykule. Tak skonstruowane stanowisko badawcze, po pozytywnie przeprowadzonych testach związanych z wpływem temperatury (około 800°C) na wytrzymałość "tłoka roboczego" oraz uzyskaniem samoczynnego zapłonu mieszanki, zostanie poddane badaniom związanym z ustaleniem optymalnych parametrów pracy dających w rezultacie radykalne obniżenie emisji toksycznych składników spalin do atmosfery.
3
Content available remote Sound reproduction levels in portable players used by pupils in Warsaw secondary schools
Rogowski P., Rościszewska T., Jaroszewski A.
Archives of Acoustics
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2001
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Vol. 26, no. 1
3-10
EN
Sound pressure levels in insert headphones used by young users of CC and CD players were measured in 421 cases. In 137 of these cases short selections of music were recorded and analysed. The results show SPLs in excess of what is considered as a safe sound pressure level.
4
Content available Resting hearing thresholds in children aged 7-10 years
Jaroszewski A., Rogowski P., Rakowski A.
Archives of Acoustics
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2001
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Vol. 26, no. 3
175-184
EN
Resting hearing thresholds were measured in 107 children in 7-10 years of age category, from primary schools in Warsaw. The children were recruited regardless of the priority of these in which problems with hearing acuity were observed or these in which such problems might have been expected on the grounds of their children-illness history. The measurements were performed with the use of tonal audiometry with intermittent 250/250ms signal, in the range of frequencies from 100Hz to 16kHz. In the children with deeper hearing loss, both air and bone conduction procedures were used. In the tested group normal hearing within š10dB was found in only 13% of the children. In the rest of the group hearing loss of various nature was found, i.e.: wideband hearing loss (8%), high frequency (24%), selective V-dip type (36%), low frequency (54%) and deep hearing loss of various configurations (16%). In the fraction with low frequency hearing loss often conductive hearing loss was found, whilst in the case of high frequency hearing loss, bone conduction audiometry indicated sensorineural type of hearing loss. High frequency hearing loss, selective and low frequency hearing loss in excess of 20dB was found in 25% of the children tested. In the fraction with deep hearing loss in 25% of the children tested, hearing loss of approximately 40dB was found.
5
Content available Gap detection thresholds in young musicians with normal hearing and with very high frequency sloping hearing loss in 1/3-octave white noise centered at 4kHz
Jaroszewski A., Jaroszewska A., Rogowski P.
Archives of Acoustics
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2001
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Vol. 26, no. 4
271-276
EN
Gap detection thresholds in 1/3-octave white noise centred at 4kHz were determined in young musicians with normal hearing preserved and with very high frequency sloping hearing loss. The thresholds were determined in the control group of 20 with normal hearing, i.e. flat audiogram up to 16kHz, and in the experimental group of 15 with high frequency sloping hearing loss exceeding 30dB at 12kHz or at 16kHz, the so called peculiar hearing loss. A group of 7 older subjects exhibiting also peculiar hearing loss was included for comparison. The results show gap detection thresholds in the normal hearing subjects ranging from 1ms to 6ms, which are in good agreement with the earlier data from the present authors. However, few examples of higher gap detection thresholds (11, 26ms) in normal hearing were also observed. For the experimental group with high frequency sloping hearing loss at 12kHz or at 16kHz, the gap detection thresholds found were on the average significantly higher ranging from 6ms to 26ms. In the group of older subjects gap detection thresholds were on the average still significantly higher.
6
Content available Gap detection thresholds in 1/3-octave white noise centered at 4kHz in children 7-14 years of age with normal hearing and with very high frequency sloping hearing loss
Jaroszewski A., Jaroszewska A.
Archives of Acoustics
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2001
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Vol. 26, no. 3
167-174
EN
Gap detection thresholds in 1/3-octave white noise were measured in primary school children aged 7-14 with normal hearing and with very high frequency sloping hearing loss. The results show median gap detection thresholds, in the group of normal hearing children of 5.5ms, while in the group of hearing impaired median gap detection thresholds are five times larger, i.e. 25.5ms, reaching 50ms in some cases.
7
Content available remote Sound pressure levels in emission of percussion instruments during training sessions
Jaroszewski A., Rogowski P., Rakowski A.
Archives of Acoustics
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2000
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Vol. 25, no. 3
283-289
EN
Sounds of selected percussion instruments played in individual training sessions of students-percussion players were recorded and analysed. In statistical signal analysis the "impulsiveness" in terms of L max - L eq and in terms of kurtosis, as an alternative measure were determined. Signal recording and spectral analysis were performed in the frequency range up to 96 kHz.
8
Content available remote Impulsiveness of discotheque exposures
Jaroszewski A., Jaroszewska A.
Archives of Acoustics
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2000
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Vol. 25, no. 3
275-281
EN
Long term average spectra, cumulative distribution functions and impulsiveness in terms of L peak - L eq and in terms of kurtosis were determined for 8 Warsaw discotheques. The results are discussed with reference to hearing damage risk.
9
Content available remote Zastosowanie funkcji sklejanej do oceny niezawodności. Prognozowanie niezawodności dwusuwowego silnika z zapłonem iskrowym
Jaroszewski A.
Journal of KONES
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1999
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Vol. 6, No. 3-4
121-134
PL
W artykule przedstawiono problemy starzenia fizycznego silników, omówiono procesy utraty zdatności. Przedstawiono matematyczne modele procesów starzenia fizycznego silnika, zaproponowano metodę identyfikacji modelu fizycznego określającego procesy starzenia silnika w warunkach rzeczywistych. Przedstawiono metodę prognozowania procesu starzenia fizycznego silnika niezależnie od wskaźnika charakteryzującego to starzenie.
EN
The paper discusses the problems of physical ageing of engines and factors which reduce the energy efficiency of engines resulting from the physical ageing processes. The principles of creating and identifying reliability models as well as the principles of examining the compatibility of empirical distribution with statistical distributions applied in machine reliability have been given. The software enabling computer-aided automated identification has also been presented. Examples of the authors' own studies illustrate the difference between the compatibility error of the linear function and splines describing the engine operation parameters. The method of prognosis of physical ageing of engines is also presented.
10
Content available remote High freqency hearing loss in percusion players
Rogowski P., Rakowski A., Jaroszewski A.
Archives of Acoustics
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1999
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Vol. 24, no. 2
119-128
EN
In a number of reports it has been observed that a prolonged exposure to music at sound pressure levels exceeding 1OOdB leads to substantial temporary threshold shifts TTS2, reaching 60-80dB in the range of high frequencies. Cumulative effects of such exposures result in acoustic trauma, affecting the perception of pitch, loudness and time, accompanying the decrease of hearing sensitivity. The hearing threshold in percussion players is affected largely at high frequencies, where substantial decrease of sensitivity between 10 and 16kHz reaching 40 to 75dB has been observed. In the present report a number of hearing thresholds in percussion players and in control group consisting of musicians who have never played percussion instruments or were long exposed to their sounds have been analysed with reference to thein- exposure characteristics.
11
Content available remote Exposures and hearing thresholds in music students due to training sessions
Jaroszewski A., Fidecki T., Rogowski P.
Archives of Acoustics
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1999
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Vol. 24, no. 2
111-118
EN
Measurements of SPL's in sound emission from some wind instruments during training sessions of music students show all in excess of LAmax 110dB and reach LAmax 132dB in some cases. Long time average spectra in 1/3-octave bands and cumulative distribution functions show that e.g. sound pressure levels LA 50 are often around 100-110dB and in most instruments the spectra cover substantial range of frequencies. Resting hearing thresholds in many students show dips of various depths at 6kHz, which in some cases reach over 30dB. TTS2 measured at 6kHz following 4-hrs training session reach 40dB.
12
Content available Hearing damage from exposure to music
Jaroszewski A., Fidecki T., Rogowski P.
Archives of Acoustics
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1998
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Vol. 23, no. 1
3--31
EN
Sound pressure levels and exposures in discotheques and youth clubs and during training sessions of music students were measured and analysed. Effects of exposure in the form of permanent and temporary threshold shift were determined in the samples of young discotheque attendants and in music students. The consequences of the threshold shift in the perception of pitch, loudness, and time are discussed.
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