Master of Science in Mechanical Engineering (MSME)
The radiative properties of the rough surfaces are important both from fundamental and practical standpoint. Thus, there is a need to determine the effect of roughness on radiative properties of materials accurately, as these properties effect the performance of electronic devices, communication devices, optical sensors, and furnaces, amongst others. The effects of roughness are assessed by measuring the reflection coefficients from the carbon rod surfaces and steel 1086 samples over the range of angles 25 to 75 in the visible range and near infrared region. Different levels of roughness are induced on the surfaces by utilizing different grid size sand-paper and different size aluminum powder. The measured reflectivities were inverted for the real and imaginary parts the refractive index by an optimization procedure over the angle range of 25 to 75 and for the different wavelengths under the assumption that the roughness factor is independent of polarization state of the reflected Electromagnetic energy. The most suitable model for the data inversion was found to be the ratio of parallel component of the reflectivity to the perpendicular component of the reflectivity. This result was clear for the carbon rod surface. However, for the steel 1086 sample no clear trend was identified from the measurements. More work is required to fully assess the effect of roughness on the inference of the optical properties of such surfaces.
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Mutukulla, Raghu Nandan, "A new method to determine radiative properties of rough solid surfaces" (2006). LSU Master's Theses. 3803.