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Physical Sciences and Mathematics Commons

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Chemistry

Theses and Dissertations

Theses/Dissertations

2021

Forensic science

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Full-Text Articles in Physical Sciences and Mathematics

Sparse Modeling For Predicting Class Assignments For Trace Forensic Evidence, Dayla Christine Rich Apr 2021

Sparse Modeling For Predicting Class Assignments For Trace Forensic Evidence, Dayla Christine Rich

Theses and Dissertations

Numerous disciplines in forensic science utilize various types of spectral data when analyzing evidence. Spectral techniques are particularly critical for the analysis of trace evidence, as these methods are normally non-destructive. Preserving evidence, especially trace evidence, is of high priority in a forensic laboratory setting. Once a piece of evidence has been fully consumed, no more analyses can be performed. Typically, visual comparison, or spectral overlay, is performed to compare questioned samples (evidence) to standards or knowns. However, such an approach may not be optimal in distinguishing the subtle, yet highly important, discriminating characteristics present in the spectra. As statistical …


Detection Of 2,4,6-Trinitrotoluene Using A Colorimetric Gold Nanoparticle Air Cassette Filter, Andrea I. Ferrer Vega Jan 2021

Detection Of 2,4,6-Trinitrotoluene Using A Colorimetric Gold Nanoparticle Air Cassette Filter, Andrea I. Ferrer Vega

Theses and Dissertations

Trinitrotoluene (TNT) is an explosive commonly used during military and terrorist activities. Current methods to identify this compound require sampling, transport and analysis at a forensic lab using analytical instrumentation. However, on-site detection is needed to assist efforts to prevent detonation. Gold nanoparticles have been used as sensors throughout the years due to their versatility and surface enhanced Raman scattering properties in the presence of an analyte and low limits of detection. By taking advantage of the Meisenheimer complex that TNT forms in the presence of amines, it is possible to determine its presence at picogram levels. Subsequently, adhering amine …