Task: Text Categorization
Input (English): Polymer samples can be prepared for use in this procedure by dissolution, then deposition on an ionic substrate, then evaporation in a technique known as cast film. More usual preparation techniques include mulling with a heavy paraffin like Nujol and spreading between salt plates; salt is used as a medium for this analytic technique since it is transparent to the probe used. That probe radiation can be understood as inducing motion corresponding to normal modes in the analyte molecular Hamiltonian, so the lines that this techniques produces are, to first order, characteristic of the types of bonds present. For 10 points, name this chemical technique that analyzes bonds by probing absorption and emission of light with wavelengths longer than the visible but shorter than the microwave.  
Output (English): Science