scholarly journals Determination of distortion corrections for a fixed length optical cavity pressure standard

2021 ◽  
Vol 18 ◽  
pp. 100286
Author(s):  
Jacob Ricker ◽  
Kevin O. Douglass ◽  
Jay Hendricks ◽  
Sarah White ◽  
Sergei Syssoev
Keyword(s):  
Optical Cavity ◽  
Cavity Pressure ◽  
Fixed Length ◽  
Pressure Standard

Numerical Analysis of Cavitation Inception and Desinence Behind Orifices

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
E. L. Amromin
Keyword(s):  
Experimental Data ◽  
Numerical Analysis ◽  
Separated Flow ◽  
Computational Procedure ◽  
Cavitation Number ◽  
Laminar Flows ◽  
Cavity Pressure ◽  
Cavitation Inception ◽  
Separation Zones

Abstract Experimental results and trends for cavitation inception and desinence behind orifices in microchannels are quite different from the data obtained during previous experiments in much larger facilities. The objective of this paper is to explain these differences via a numerical analysis. The employed computational procedure is divided into two parts. The first part is computation of an axisymmetric separated flow around the orifice. The second part is determination of characteristics of cavities appearing within separation zones. The provided analysis of the experimental data of other researchers pointed out two sources of the above-mentioned differences. First, for larger orifices, the cavities appear in the cores of drifting vortices. For such a situation, cavitation inception and desinence number increases with the inflow speed due to an impact of turbulence, but there is no such an increase for microbubbles with laminar flows. Second, because of the difficulty to measure the cavity pressure in microbubbles, cavitation number is usually defined with employment of the vapor pressure, and this leads to misinterpretation of the measurements and their trends.

scholarly journals Determination of the Number of Atoms Trapped in an Optical Cavity

2004 ◽  
Vol 93 (14) ◽  
Author(s):  
J. McKeever ◽  
J. R. Buck ◽  
A. D. Boozer ◽  
H. J. Kimble
Keyword(s):  
Optical Cavity

Improved determination of the Boltzmann constant using a single, fixed-length cylindrical cavity

Metrologia ◽  
2013 ◽  
Vol 50 (5) ◽  
pp. 417-432 ◽  
Author(s):  
H Lin ◽  
X J Feng ◽  
K A Gillis ◽  
M R Moldover ◽  
J T Zhang ◽  
...  
Keyword(s):  
Cylindrical Cavity ◽  
Boltzmann Constant ◽  
Fixed Length

scholarly journals A vibration-insensitive optical cavity and absolute determination of its ultrahigh stability

2009 ◽  
Vol 17 (11) ◽  
pp. 8970 ◽  
Author(s):  
Y. N. Zhao ◽  
J. Zhang ◽  
A. Stejskal ◽  
T. Liu ◽  
V. Elman ◽  
...  
Keyword(s):  
Optical Cavity ◽  
Absolute Determination

Finite Element Determination of Beam Surface Stresses Due to Multiple Delamination

2009 ◽  
Author(s):  
Benjamin Dauda ◽  
S. Olutunde Oyadiji ◽  
Prassad Potluri
Keyword(s):  
Finite Element ◽  
Spatial Distributions ◽  
Distribution Characteristics ◽  
The Finite Element Method ◽  
Element Determination ◽  
Fixed Length ◽  
Beam Surface ◽  
Multiple Delamination ◽  
Maximum Stresses

The finite element method is used to analyse the through-the-width stress distribution characteristics of single and multiple delaminated cantilevered composite beams. Single delaminations of fixed length, which are located at different through-the-thickness locations, and multiple delaminations of sequential and diagonal configurations are investigated. The total length of multiple delaminations in a beam was made equal to the fixed length of a single delamination. The results show that the configurations and spatial distributions of multiple delaminations have significant effects on the magnitude of the maximum stresses induced in the beams. Beams in which most of the delaminations are concentrated around the mid-plane of the beam show higher stresses than beams in which most of the delaminations are concentrated close to the surface of the laminate. However, delaminations close to the surfaces of the beams exhibit higher stresses at the tips of the delaminations.

scholarly journals Algorithm for error-free determination of the variance of all contiguous subsequences and fixed-length contiguous subsequences for a sequence of industrial measurement data

2021 ◽  
Author(s):  
Andrzej Chmielowiec
Keyword(s):  
Measurement Data ◽  
Sliding Window ◽  
Arithmetic Mean ◽  
Fixed Length ◽  
Window Method ◽  
Integer Representation ◽  
Mean And Variance ◽  
Sliding Window Method ◽  
Industrial Measurement

AbstractThe article presents an algorithm for fast and error-free determination of statistics such as the arithmetic mean and variance of all contiguous subsequences and fixed-length contiguous subsequences for a sequence of industrial measurement data. Additionally, it shows that both floating-point and integer representation can be used to perform this kind of statistical calculations. The author proves a theorem on the number of bits of precision that an arithmetic type must have to guarantee error-free determination of the arithmetic mean and variance. The article also presents the extension of Welford’s formula for determining variance for the sliding window method—determining the variance of fixed-length contiguous subsequences. The section dedicated to implementation tests shows the running times of individual algorithms depending on the arithmetic type used. The research shows that the use of integers in calculations makes the determination of the aforementioned statistics much faster.

scholarly journals Quasi-Simultaneous Sensitive Detection of Two Gas Species by Cavity-Ringdown Spectroscopy with Two Lasers

Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7622
Author(s):  
Guosheng Ma ◽  
Yabai He ◽  
Bing Chen ◽  
Hao Deng ◽  
Ying Liu ◽  
...  
Keyword(s):  
Optical Cavity ◽  
Detection Sensitivity ◽  
Cavity Ringdown Spectroscopy ◽  
Cavity Ringdown ◽  
Optical Resonances ◽  
Precision Determination ◽  
Ringdown Time ◽  
High Detection ◽  
High Precision Determination

We developed a cavity ringdown spectrometer by utilizing a step-scanning and dithering method for matching laser wavelengths to optical resonances of an optical cavity. Our approach is capable of working with two and more lasers for quasi-simultaneous measurements of multiple gas species. The developed system was tested with two lasers operating around 1654 nm and 1658 nm for spectral detections of 12CH4 and its isotope 13CH4 in air, respectively. The ringdown time of the empty cavity was about 340 µs. The achieved high detection sensitivity of a noise-equivalent absorption coefficient was 2.8 × 10−11 cm−1 Hz−1/2 or 1 × 10−11 cm−1 by averaging for 30 s. The uncertainty of the high precision determination of δ13CH4 in air is about 1.3‰. Such a system will be useful for future applications such as environmental monitoring.

Sign in / Sign up

Export Citation Format

Share Document