Experimental Study of Low‐Frequency Effects on the Dynamic Modulus of a Buna‐N Rubber

1954 ◽  
Vol 25 (3) ◽  
pp. 350-354 ◽  
Author(s):  
Allen Q. Hutton ◽  
A. W. Nolle
Keyword(s):  
Experimental Study ◽  
Dynamic Modulus ◽  
Low Frequency ◽  
Frequency Effects

Experimental Study of Low-Frequency Effects on the Dynamic Modulus of a Buna-N Rubber

1955 ◽  
Vol 28 (1) ◽  
pp. 131-138 ◽  
Author(s):  
Allen Q. Hutton ◽  
A. W. Nolle
Keyword(s):  
Dynamic Modulus ◽  
Room Temperature ◽  
Temperature Scale ◽  
Dynamic Properties ◽  
Low Frequency ◽  
Frequency Range ◽  
Frequency Increase ◽  
Frequency Effects ◽  
Similar Compound ◽  
Linear Dynamic

Abstract The linear dynamic Young's modulus of a vulcanized Buna-N gum rubber was measured at frequencies of 0.05, 0.10, and 1.00 cps, in the temperature range − 22° C to 30° C, by a method in which a small differential sinusoidal elongation is superimposed on a 5 per cent static elongation. The width of the dispersion range on the temperature scale (the range in which the logarithm of the modulus increases steeply with decreasing temperature) is only about 10° C, contrasted with widths as great as 25° C found in previous measurements on a similar compound at frequencies of several kilocycles. The modulus-temperature plot shifts upward by only about 4° C per decade of frequency increase of the present range, contrasted with about 10° C per decade in the previous measurements at higher frequencies. It is concluded that this elastomer cannot be described properly by means of the “method of reduced variables”, in which the dynamic properties are ascribed to mechanisms having identical temperature dependence, and that the low-temperature behavior is governed by mechanisms distinct from those effective in the audio-frequency range at room temperature.

Real Ear Sound Pressure Levels Developed by Three Portable Stereo System Earphones

1992 ◽  
Vol 1 (4) ◽  
pp. 52-55 ◽  
Author(s):  
Gail L. MacLean ◽  
Andrew Stuart ◽  
Robert Stenstrom
Keyword(s):  
High Frequency ◽  
Sound Pressure ◽  
Low Frequency ◽  
Test System ◽  
Output Frequency ◽  
Frequency Effects ◽  
Adult Men ◽  
Frequency Responses ◽  
Significant Difference ◽  
Sound Pressure Levels

Differences in real ear sound pressure levels (SPLs) with three portable stereo system (PSS) earphones (supraaural [Sony Model MDR-44], semiaural [Sony Model MDR-A15L], and insert [Sony Model MDR-E225]) were investigated. Twelve adult men served as subjects. Frequency response, high frequency average (HFA) output, peak output, peak output frequency, and overall RMS output for each PSS earphone were obtained with a probe tube microphone system (Fonix 6500 Hearing Aid Test System). Results indicated a significant difference in mean RMS outputs with nonsignificant differences in mean HFA outputs, peak outputs, and peak output frequencies among PSS earphones. Differences in mean overall RMS outputs were attributed to differences in low-frequency effects that were observed among the frequency responses of the three PSS earphones. It is suggested that one cannot assume equivalent real ear SPLs, with equivalent inputs, among different styles of PSS earphones.

The driving frequency effects on the atmospheric pressure corona jet plasmas from low frequency to radio frequency

2011 ◽  
Vol 18 (4) ◽  
pp. 043503 ◽  
Author(s):  
Dan Bee Kim ◽  
H. Jung ◽  
B. Gweon ◽  
S. Y. Moon ◽  
J. K. Rhee ◽  
...  
Keyword(s):  
Radio Frequency ◽  
Atmospheric Pressure ◽  
Low Frequency ◽  
Driving Frequency ◽  
Frequency Effects

scholarly journals An EEG Experimental Study Evaluating the Performance of Texas Instruments ADS1299

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3721 ◽  
Author(s):  
Usman Rashid ◽  
Imran Niazi ◽  
Nada Signal ◽  
Denise Taylor
Keyword(s):  
Experimental Study ◽  
Mixed Models ◽  
Signal To Noise Ratio ◽  
Low Cost ◽  
Low Frequency ◽  
Low Power Consumption ◽  
Motor Tasks ◽  
Negative Peak ◽  
Eeg Data ◽  
Healthy Participants

Texas Instruments ADS1299 is an attractive choice for low cost electroencephalography (EEG) devices owing to its low power consumption and low input referred noise. To date, there have been no rigorous evaluations of its performance. In this EEG experimental study we evaluated the performance of the ADS1299 against a high quality laboratory-based system. Two self-paced lower limb motor tasks were performed by 22 healthy participants. Recorded power across delta, theta, alpha, and beta EEG bands, the power ratio across the motor tasks, pre-movement noise, and signal-to-noise ratio were obtained for evaluation. The amplitude and time of the negative peak in the movement-related cortical potentials (MRCPs) extracted from the EEG data were also obtained. Using linear mixed models, no statistically significant differences (p > 0.05) were found in any of these measures across the two systems. These findings were further supported by evaluation of cosine similarity, waveform differences, and topographic maps. There were statistically significant differences in MRCPs across the motor tasks in both systems. We conclude that the performance of the ADS1299 in combination with wet Ag/AgCl electrodes is analogous to that of a laboratory-based system in a low frequency (<40 Hz) EEG recording.

scholarly journals Diagnostics of concrete plate in bending with ultrasonic waves modulated by low frequency oscillations

2013 ◽  
Vol 12 (1) ◽  
pp. 243-250
Author(s):  
Błażej Meronk ◽  
Krzysztof Wilde
Keyword(s):  
Experimental Study ◽  
Low Frequency ◽  
Ultrasonic Waves ◽  
Modulation Method ◽  
Frequency Spectra ◽  
Concrete Plate ◽  
Low Frequency Oscillations ◽  
Damaged Zone ◽  
Nonlinear Acoustic ◽  
Concrete Elements

The paper presents the experimental study on the inter-modulation method for the diagnostics of concrete elements. The tests were conducted on a concrete plate subjected to ultrasonic waves and low frequency vibrations. The nonlinear acoustic effects, recorded in the experiments, made it possible to detect the presence of damaged zones. Further studies are necessary to establish the relation between the sidebanes of frequency spectra and the size of the damaged zone.

Experimental Study of the Liquid-Glass Transition in an Inorganic Polymer Li0.5Na0.5PO3

1995 ◽  
Vol 407 ◽  
Author(s):  
B. Rufflé ◽  
S. Beaufils ◽  
Y. Délugeard ◽  
G. Coddens ◽  
J. Etrillard ◽  
...  
Keyword(s):  
Experimental Study ◽  
Glass Transition ◽  
Raman Scattering ◽  
Viscous Flow ◽  
Liquid Glass ◽  
Low Frequency ◽  
Glass Forming ◽  
Scattering Spectra ◽  
Temperature Ranges ◽  
Raman Scattering Spectra

ABSTRACTNew experimental results obtained with various techniques on a less-studied glass-forming system are presented. At low frequency, a secondary βslow-process, decoupled from the viscous flow, is observed by 3 1P NMR. Raman scattering spectra and coherent neutron scattering spectra has been obtained in wide frequency and temperature ranges showing the same qualitative features for the Boson peak while the quasielastic contribution seems to differ markedly.

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