MétaCan
Menu
Back to cohort
Record W2972747140 · doi:10.22215/etd/2019-13644

Exploring Applicability of Direct Analysis in Real Time with Mass Spectrometry (DART-MS) to Identify Homemade Explosive Residues Post-Blast

2019· dissertation· en· W2972747140 on OpenAlexaff
Chelsea Black

Bibliographic record

Venuenot available
Typedissertation
Languageen
FieldSocial Sciences
TopicForensic Fingerprint Detection Methods
Canadian institutionsCarleton University
Fundersnot available
KeywordsDART ion sourceExplosive materialDartMass spectrometryChemistryAnalytical Chemistry (journal)ChromatographyIonizationComputer scienceElectron ionizationOrganic chemistry

Abstract

fetched live from OpenAlex

Application of Direct-Analysis-in-Real-Time (DART) ionization with mass spectrometry (DART-MS) to identify explosives from post-blast residues is presented.Explosives of interest represent real current threats encountered in criminal investigations in North America and Europe: homemade organic peroxides, binary explosives and smokeless powder.A series of simulated improvised explosive devices (IEDs) were manufactured using triacetone triperoxide (TATP), hexamethylene triperoxide diamine (HMTD), methyl ethyl ketone peroxide (MEKP), homemade binary explosives (composed of a fuel-oxidizer) and single and double-base smokeless powders.Each IED was configured to yield bomb fragments representative of actual materials recovered from bombing investigations.The goal of this study was to demonstrate the validity of DART-MS for identification of homemade explosives using real world samples (i.e.not laboratory simulations) and develop a quality assured method for use in accredited forensic laboratory settings.Smokeless powder was of specific interest as there is currently no reported method to identify nitrocellulose (NC) post-blast, unless unconsumed material is recovered.Therefore, this study aimed to demonstrate the validity of DART-MS to characterize thermal breakdown products of NC.All recovered fragments were analyzed directly and in directly (i.e.cotton swabs and solvent extraction methods) using full scan high resolution mass spectrometry (HRMS).This work demonstrates the forensic validity of DART-MS to provide rapid and quality assured identification of explosive residues from real post-blast IED fragments.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame machine prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.

metaresearch head score (Codex)0.001
metaresearch head score (Gemma)0.001
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Bench or experimental · Consensus signal: Bench or experimental
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.002
Threshold uncertainty score0.005

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0010.001
Meta-epidemiology (narrow)0.0010.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0010.000
Science and technology studies0.0000.000
Scholarly communication0.0010.000
Open science0.0000.000
Research integrity0.0010.001
Insufficient payload (model declined to judge)0.0020.001

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.044
GPT teacher head0.359
Teacher spread0.316 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designBench or experimental
Domainnot available
GenreEmpirical

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

Quick stats

Citations4
Published2019
Admission routes1
Has abstractyes

Explore more

Same topicForensic Fingerprint Detection MethodsFrench-language works237,207