This project examined the feasibility of determining the features of glass in a forensic examination using cathodoluminescence and CIE LAB color coordinates.
Cathodoluminescence (CL) spectroscopy has been shown to be useful for differentiating typical evidentiary glass samples. CL occurs when a surface is bombarded with an electron beam as in scanning electron microscopy and most of this luminescence is in the visible range. In effect, CL imparts color to colorless evidence and as a result, proven methods of forensic color analysis can be applied. In this work, spectral data dimensions were reduced to three and plotted in the CIE LAB color space. This approach allows for incorporation of uncertainties generated principally by intra-sample variation. NIST glass standards were used for method development and validation while potential case applications were studied with collections of window, consumer, and auto headlamp glasses. Using refractive index as the initial grouping variable, all of the window and consumer glasses were differentiated as were 6 of 10 automobile headlamp glasses. The potential advantages of CL include low-cost instrumentation, its non-destructive nature, and ease of operation. The current limitations of CL in this context are the lack of databases and standards and the relatively low resolution of typical CL spectra. (Published Abstract Provided)
Downloads
Similar Publications
- Modeling and Inference for Measured Crystal Orientations and a Tractable Class of Symmetric Distributions for Rotations in Three Dimensions
- The Use of Elemental Databases in Forensic Science: Studies on Vehicle Glass Interpretation and Milk Powder Provenancing
- A novel fluorescence imaging technique combining deconvolution microscopy and spectral analysis for quantitative detection of opportunistic pathogens