Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "Olszewski, Ryszard" wg kryterium: Autor


Tytuł:
Accuracy of prediction methods for sound insulation of homogeneous single baffles
Autorzy:
Kosała, Krzysztof
Majkut, Leszek
Mleczko, Dominik
Olszewski, Ryszard
Wszołek, Tadeusz
Powiązania:
https://bibliotekanauki.pl/articles/2146553.pdf
Data publikacji:
2020
Wydawca:
Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:
sound insulation
homogeneous single baffles
calculation models
izolacyjność akustyczna
pojedyncze przegrody jednorodne
modele obliczeniowe
Opis:
The article presents a comparative analysis of determined spectral responses of the airborne sound insulation of single homogeneous baffles using computational and experimental methods. Calculations using theoretical models, such as mass law, the Sharp and Davy models, SoundFlow software and laboratory tests concerned nine plates made of plastic, steel, aluminium and rubber, which are homogeneous materials. These materials are used in the construction of walls in vibroacoustic protection, such as acoustic barriers, machine operating field shields and sound insulating enclosures. Apart from analysing the spectral responses of the sound insulation of the plates, the weighted single-number sound reduction indices Rw, calculated by using prediction methods and laboratory measurements, were compared. Research has shown computational errors of about 6-7 dB for mass law and the Sharp model and about 3 dB for the Davy and Davy-Sharp models and SoundFlow software.
Źródło:
Vibrations in Physical Systems; 2020, 31, 2; art. no. 2020210
0860-6897
Pojawia się w:
Vibrations in Physical Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of High Frequency Imaging and Doppler System for the Measurements of the Radial Artery Flow-Mediated Dilation
Autorzy:
Nowicki, Andrzej
Gambin, Barbara
Secomski, Wojciech
Trawiński, Zbigniew
Szubielski, Michał
Tymkiewicz, Ryszard
Olszewski, Robert
Powiązania:
https://bibliotekanauki.pl/articles/176847.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
flow mediated dilation
shear rate
axial resolution
elevation resolution
pulsed Doppler
ultrasonic imaging
Opis:
Objectives: In the article we describe the new, high frequency, 20 MHz scanning/Doppler probe designed to measure the flow mediated dilation (FMD) and shear rate (SR) close to the radial artery wall. Methods: We compare two US scanning systems, standard vascular modality working below 12 MHz and high frequency 20 MHz system designed for FMD and SR measurements. Axial resolutions of both systems were compared by imaging of two closely spaced food plastic foils immersed in water and by measuring systolic/diastolic diameter changes in the radial artery. The sensitivities of Doppler modalities were also determined. The diagnostic potential of a high frequency system in measurements of FMD and SR was studied in vivo, in two groups of subjects, 12 healthy volunteers and 14 patients with stable coronary artery disease (CAD). Results: Over three times better axial resolution was demonstrated for a high frequency system. Also, the sensitivity of the external single transducer 20 MHz pulse Doppler proved to be over 20 dB better (in terms of a signal-to-noise ratio) than the pulse Doppler incorporated into the linear array. Statistically significant differences in FMD and FMD/SR values for healthy volunteers and CAD patients were confirmed, p-values < 0:05. The areas under Receiver Operating Characteristic (ROC) curves for FMD and FMD/SR for the prediction CAD had the values of 0.99 and 0.97, respectively. Conclusions: These results justify the usefulness of the designed high-frequency scanning system to determine the FMD and SR in the radial artery as predictors of coronary arterial disease.
Źródło:
Archives of Acoustics; 2019, 44, 4; 637-644
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies