Microscopic Imaging and Optical Pressure Measurements of Detonations

2021 ◽  
Author(s):  
I. Emre Gunduz
Keyword(s):  
Pressure Measurements ◽  
Microscopic Imaging ◽  
Optical Pressure

scholarly journals Towards an improved helium-based refractometer for pressure measurements

ACTA IMEKO ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 305
Author(s):  
Z. Silvestri ◽  
D. Bentouati ◽  
P. Otal ◽  
J.-P. Wallerand
Keyword(s):  
Temperature Stability ◽  
Temperature Measurements ◽  
Pressure Measurements ◽  
Short Term ◽  
Term Stability ◽  
Accurate Temperature ◽  
Pressure Standard ◽  
Optical Pressure ◽  
532 Nm ◽  
Better Than

This paper describes a quantum realization of the pascal based a helium absolute refractometer at 532 nm. The short-term stability in pressure is ± 2 mPa with a resolution in pressure of this new optical pressure standard is better than 1 mPa with temperature stability about 1 mK. A new design of the refractometer is presented to have better temperature stability and accurate temperature measurements to reach uncertainties in pressure better than current conventional methods.

Signal Interpretation Considerations When Estimating Subglottal Pressure From Oral Air Pressure

2019 ◽  
Vol 62 (5) ◽  
pp. 1326-1337 ◽  
Author(s):  
Brittany L. Perrine ◽  
Ronald C. Scherer ◽  
Jason A. Whitfield
Keyword(s):  
Standard Condition ◽  
Word Production ◽  
Air Pressure ◽  
Pressure Waveform ◽  
Pressure Measurements ◽  
Air Leak ◽  
Pressure Signal ◽  
Adult Participants ◽  
Syllable Repetition ◽  
Subglottal Pressure

Purpose Oral air pressure measurements during lip occlusion for /pVpV/ syllable strings are used to estimate subglottal pressure during the vowel. Accuracy of this method relies on smoothly produced syllable repetitions. The purpose of this study was to investigate the oral air pressure waveform during the /p/ lip occlusions and propose physiological explanations for nonflat shapes. Method Ten adult participants were trained to produce the “standard condition” and were instructed to produce nonstandard tasks. Results from 8 participants are included. The standard condition required participants to produce /pːiːpːiː.../ syllables smoothly at approximately 1.5 syllables/s. The nonstandard tasks included an air leak between the lips, faster syllable repetition rates, an initial voiced consonant, and 2-syllable word productions. Results Eleven oral air pressure waveform shapes were identified during the lip occlusions, and plausible physiological explanations for each shape are provided based on the tasks in which they occurred. Training the use of the standard condition, the initial voice consonant condition, and the 2-syllable word production increased the likelihood of rectangular oral air pressure waveform shapes. Increasing the rate beyond 1.5 syllables/s improved the probability of producing rectangular oral air pressure signal shapes in some participants. Conclusions Visual and verbal feedback improved the likelihood of producing rectangular oral air pressure signal shapes. The physiological explanations of variations in the oral air pressure waveform shape may provide direction to the clinician or researcher when providing feedback to increase the accuracy of estimating subglottal pressure from oral air pressure.

A Case Study: Using Wireline Pressure Measurements to Improve Reservoir Characterization in Tight Formation Gas - Wamsutter Field, Wyoming

2007 ◽  
Author(s):  
Russ A. Schrooten ◽  
Edward C. Boratko ◽  
Harjinder Singh ◽  
Jim McKay ◽  
Debora L. Hallford
Keyword(s):  
Reservoir Characterization ◽  
Pressure Measurements ◽  
Tight Formation
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