&nbsp;Real-time pulsed photoacoustics-molecular <br>relaxation time measurements* <br>

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Journal of Nanjing University(Natural Sciences) ›› 2013, Vol. 49 ›› Issue (1) : 5-12.

Real-time pulsed photoacoustics-molecular
relaxation time measurements*

Markushev Dragan¹，Rabasovic Mihailo¹，Lukic Mladena²
Cojbasic Zarko³，Todorovic Dragan⁴

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Abstract

Determination of the vibrational-to-translational relaxation time τv-_^T in gases is one of the applications of
pulsed photoacoustic spectroscopy. Because the spatial profile of the laser beam R(r)，can significantly influence the
accuracy of the photoacoustic mcasurements,we developed the method for simultaneous determination of the R(r)，
and τv-_^T，.It is based on the temporal shape of the photoacoustic pulse and utilizes a mathematical algorithm devel
opcd for photoacoustic tomography.The possibilities of computational intelligence application for simultaneous and
real-time determination of R(r)and τv-^_T values of polyatomic molecules in gases by pulsed photoacoustic are also
discussed. Feed forward multilayer perception networks are trained in an offlinc batch training regime to estimate
simultancously,and in real-time,R(r)，(profile shape class)and τv-^_T，from a givcn(thcorctical)photoacoustic signals.
Proposed method significantly shortens the time required for the simultaneous determination of the aforementioned quantities.

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Markushev Dragan¹，Rabasovic Mihailo¹，Lukic Mladena²
Cojbasic Zarko³，Todorovic Dragan⁴
. Real-time pulsed photoacoustics-molecular
relaxation time measurements*
[J]. Journal of Nanjing University(Natural Sciences), 2013, 49(1): 5-12

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