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Data from the Infrared Astronomical Satellite (IRAS) are used to explore the composition of interstellar dust grains in H II regions. The IRAS data, broad band photometry at 12, 25, 60 and 100 microns, are compared to emission from various grain models placed in the radiation field of the H II region. The grain models are taken from the literature and must produce the UV extinction curve measured for the central OB cluster. The radiation field is found by solving the radiative transfer equations for both the ionizing and non-ionizing radiation emitted by the central cluster. Only H II regions resolved by IRAS (resolution of 1-5 arminutes) are considered. The emission calculated from the grain models must match both the spectral and spatial features of the H II regions. Existing data at ultra-violet, optical and radio wavelengths are used to limit the number of free parameters in the emission calculations. Results for Rosette Nebula are presented.
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