Radiative Transfer and its Impact on Thermal Diffusivity Determined in Remote Sensing
| Parent link: | Horizons in World Physics. Vol. 267. [P. 1-67].— , 2012 |
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| Резюме: | Title screen Thermal diffusivity is usually determined from measured temperature evolution when a sample is exposed to a transient energy source. In almost all cases reported in the literature, heat flow through the sample is considered as purely conductive. Instead, this paper, on an introductory level, investigates to which extent conduction coupled to radiation is reflected by the temperature evolution of thin films, and how this alters diffusivity if it is extracted using standard procedures from transient temperature. The analysis is applied to flash experiments using constant or wavelength-dependent extinction properties of thin films, and to periodic (intensity modulated) energy sources. Focussed on samples with optical thickness between 1 and 50, the results demonstrate that coupling between conduction and radiation may significantly alter thermal diffusivity. This would occur if diffusivity is extracted from data taken at single surface positions only, or by any other technique that relies on coupling between surface temperature and temperature of a medium above the surface, like in mirage experiments. Uncertainties are expected also in intensity modulated experiments when diffusivity is determined from correlations with phase shifts. A front-face flash method recently introduced by the authors can be more reliable. |
| Мова: | Англійська |
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2012
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| Онлайн доступ: | https://www.novapublishers.com/catalog/product_info.php?products_id=31650 |
| Формат: | Електронний ресурс Частина з книги |
| KOHA link: | https://koha.lib.tpu.ru/cgi-bin/koha/opac-detail.pl?biblionumber=636293 |