Signal enhancement in photoacoustic spectroscopy on powder samples

1978 ◽  
Vol 49 (6) ◽  
pp. 3033-3035 ◽  
Author(s):  
K. Y. Wong
Keyword(s):  
Photoacoustic Spectroscopy ◽  
Signal Enhancement ◽  
Powder Samples

scholarly journals Multi-Quartz Enhanced Photoacoustic Spectroscopy with Different Acoustic Microresonator Configurations

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Huadan Zheng ◽  
Xukun Yin ◽  
Lei Dong ◽  
Hongpeng Wu ◽  
Xiaoli Liu ◽  
...  
Keyword(s):  
Water Vapor ◽  
Absorption Coefficient ◽  
Photoacoustic Spectroscopy ◽  
Atmospheric Pressure ◽  
Noise Level ◽  
Signal Amplitude ◽  
Signal Enhancement ◽  
Vapor Detection ◽  
Water Vapor Detection

Acoustic microresonators were added to the recently developed multi-QTF based QEPAS spectrophone to enhance the signal amplitude. Two kinds of “on-beam” configurations were experimentally investigated in detail. The developed multi-QTF based “on-beam” spectrophone had a signal enhancement of 1.6 times compared with the traditional single QTF based “on-beam” spectrophone, with the approximate noise level. A normalized noise equivalent absorption coefficient (1σ) of 1.24 × 10−9 W·cm−1·Hz−1/2was obtained for water vapor detection at atmospheric pressure.

A study of oxygen and vacancy ordering in YBa2Cu3O7−x

1989 ◽  
Vol 47 ◽  
pp. 164-165
Author(s):  
Y. P. Lin ◽  
A. H. O’Reilly ◽  
J. E. Greedan ◽  
M. Post
Keyword(s):  
Electron Microscopy ◽  
Neutron Diffraction ◽  
Oxygen Content ◽  
Carbon Film ◽  
Nitrogen Atmosphere ◽  
Vacancy Ordering ◽  
Powder Samples ◽  
Vacancy Chains ◽  
Chain Ordering

In the basal planes of the orthorhombic YBa2Cu3O7-X compound with x=0.07, which has a Tc of around 90K, chains of copper-oxygen are formed along the [010] direction. Previous investigations on the variation of Tc with oxygen content have shown the existence of a plateau at Tc = 60K for x=0.3 to 0.4, suggesting the presence of a separate phase. This phase has also been identified to be orthorhombic, but with a 2x superlattice along [100] of the parent structure, and the superlattice has been attributed to the formation of alternating copper-oxygen and copper-vacancy chains. In our work, we have studied the chain ordering phenomenon by electron microscopy and neutron diffraction on samples with different oxygen contents. We report here some of our electron microscopy findings for samples with x=0.4.Powder samples of YBa2Cu3O7-X were prepared by controlled re-oxidation of previously reduced material. For electron microscopy, the sample was dry ground using a mortar and pestle in a dry nitrogen atmosphere without the use of any solvent and transferred dry onto holey carbon film for examination in a Philips CM12 microscope.

Use of the photoacoustic spectroscopy in the investigation of biocompatible magnetic fluids

2005 ◽  
Vol 125 ◽  
pp. 27-30 ◽  
Author(s):  
J. G. Santos ◽  
L. B. Silveira ◽  
A. C. Oliveira ◽  
P. C. Morais
Keyword(s):  
Photoacoustic Spectroscopy ◽  
Magnetic Fluids

IN VIVO PHOTOACOUSTIC SPECTROSCOPY OF THE SKIN

1983 ◽  
Vol 44 (C6) ◽  
pp. C6-413-C6-418 ◽  
Author(s):  
P. Poulet ◽  
J. Chambron
Keyword(s):  
Photoacoustic Spectroscopy
Sign in / Sign up

Export Citation Format

Share Document