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Preliminary Study on the Effect of Heated Surfaces Upon Bloodstain Pattern Analysis
Author(s) -
Larkin Bethany A. J.,
Banks Craig E.
Publication year - 2013
Publication title -
journal of forensic sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.715
H-Index - 96
eISSN - 1556-4029
pISSN - 0022-1198
DOI - 10.1111/1556-4029.12185
Subject(s) - boiling , leidenfrost effect , nucleation , range (aeronautics) , chemistry , materials science , nanotechnology , mechanics , thermodynamics , nucleate boiling , composite material , heat transfer , physics , heat transfer coefficient
Bloodstain pattern analysis ( BPA ) involves the interpretation of distinct blood patterns found at crime scenes following a violent act. In this paper, we explored for the first time the effects of surface temperatures upon blood impacting a horizontal surface (steel) with its implications in BPA explored. Specific surface temperatures were explored over the range 24–250°C which relate to the four major boiling regimes of liquid media; natural convection, nucleate boiling, transition boiling, and film boiling, where a series of blood drops tests were performed at varying impact velocities. Blood was found to separate into its components at temperatures of 50°C+, displayed as temperature induced blood rings , where a single secondary and a series of further inner rings are exhibited. This consequently led to the development of a new constantC dheatedexpressing the decrease in spread factor ( D s / D o ) at the secondary ring.