On the formation of Basu’s Type Ⅲ(peeled orange) gunshot residues
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摘要
In a famous paper published in 1982, a very special class of gunshot residue particles(GSR) was named by Samarendra Basu "peeled orange", due to their particular structure, consisting of a barium/antimony core covered by an outer lead leaflet. In this class of GSR particles the surface may show nodular structures of lead. Basu proposed an explanation in terms of a nucleus of antimony and barium that captures lead vapours produced after the explosion of a cartridge into a firearm: as solidification points of antimony and barium are close one another, both higher than solidification point of lead, he stated that lead occurs as a layer around the core in peeled orange GSR particles. In this paper we study the thermodynamic of the barium/antimony alloy and we hypothesize a formation process in terms of colloidal metal growth, charged particles and electrostatic attraction. We propose an updated model of formation for peeled orange GSR particles that explains the existence of outer lead leaflet and nodules in terms of electrostatic attraction of lead nanoparticles and instability of lead droplets.
In a famous paper published in 1982, a very special class of gunshot residue particles(GSR) was named by Samarendra Basu "peeled orange", due to their particular structure, consisting of a barium/antimony core covered by an outer lead leaflet. In this class of GSR particles the surface may show nodular structures of lead. Basu proposed an explanation in terms of a nucleus of antimony and barium that captures lead vapours produced after the explosion of a cartridge into a firearm: as solidification points of antimony and barium are close one another, both higher than solidification point of lead, he stated that lead occurs as a layer around the core in peeled orange GSR particles. In this paper we study the thermodynamic of the barium/antimony alloy and we hypothesize a formation process in terms of colloidal metal growth, charged particles and electrostatic attraction. We propose an updated model of formation for peeled orange GSR particles that explains the existence of outer lead leaflet and nodules in terms of electrostatic attraction of lead nanoparticles and instability of lead droplets.
In a famous paper published in 1982, a very special class of gunshot residue particles(GSR) was named by Samarendra Basu "peeled orange", due to their particular structure, consisting of a barium/antimony core covered by an outer lead leaflet. In this class of GSR particles the surface may show nodular structures of lead. Basu proposed an explanation in terms of a nucleus of antimony and barium that captures lead vapours produced after the explosion of a cartridge into a firearm: as solidification points of antimony and barium are close one another, both higher than solidification point of lead, he stated that lead occurs as a layer around the core in peeled orange GSR particles. In this paper we study the thermodynamic of the barium/antimony alloy and we hypothesize a formation process in terms of colloidal metal growth, charged particles and electrostatic attraction. We propose an updated model of formation for peeled orange GSR particles that explains the existence of outer lead leaflet and nodules in terms of electrostatic attraction of lead nanoparticles and instability of lead droplets.
引文
[1] Romolo FS, Margot P. Identification of gunshot residue:a critical review.Forensic Sci Int 2001;119:195-211.
[2] Nunziata F, Morin M. On the formation and on the surface of inorganic lead,barium and antimony based gunshot residues:a thermodynamic approach.J Forensic Sci Criminol 2017;5(3):303.
[3] Basu S. formation of gunshot residues. J Forensic Sci 1982;27:72-91.
[4] Ter Haseborg JL, Trinks H. Electrical charging and discharging processes of moving projectiles. IEEE Trans Aerospace Electr Syst AES 1980;16:227-31.
[5] Breton DJ, Lamie NJ, Asenath-Smith E. Triboelectric charge variability in firearm particulates and projectiles. J. Electrostat 2017;89:13-9.
[6] D. J. Breton, E. Asenath-Smith, Nathan J. Lamie, Tribocharging and materials analysis of firearm propellants, Proc. 2017 Annual Meeting of the Electrostatics Society of America.
[7] S. Vinci, J. Zhu, D. Hull, Analysis of electrostatic charge on small-arms projectiles, Proc of SPIE, Vol. 8382.
[8] Lichtenstein T, Gesualdi J, Nigl TP, Yu CT, Kim H. Thermodynamic properties of barium-antimony alloys determined by emf measurements. Electrochim Acta2017;251:203-11.
[9] Bell GM, Levine S, McCartney LN. Approximate methods of determining the double-layer free energy of interaction between two charged colloidal spheres. J Colloid Interface Sci 1970;33:335-59.
[10] Denkov N, Velev O, Kralchevski P, Ivanov I, Yoshimura H, Nagayama K.Mechanism of formation of two-dimensional crystals from latex particles on substrates. Langmuir 1992;8:3183-90.
[11] Sageman DR. Surface tension of molten metals using the sessile drop method.Retrospective Theses and Dissertations 6117. Digital Repository@Iowa State University; 1972. http://lib.dr.iastate.edu/rtd/6117.[Accessed 27 December2017].
[2] Nunziata F, Morin M. On the formation and on the surface of inorganic lead,barium and antimony based gunshot residues:a thermodynamic approach.J Forensic Sci Criminol 2017;5(3):303.
[3] Basu S. formation of gunshot residues. J Forensic Sci 1982;27:72-91.
[4] Ter Haseborg JL, Trinks H. Electrical charging and discharging processes of moving projectiles. IEEE Trans Aerospace Electr Syst AES 1980;16:227-31.
[5] Breton DJ, Lamie NJ, Asenath-Smith E. Triboelectric charge variability in firearm particulates and projectiles. J. Electrostat 2017;89:13-9.
[6] D. J. Breton, E. Asenath-Smith, Nathan J. Lamie, Tribocharging and materials analysis of firearm propellants, Proc. 2017 Annual Meeting of the Electrostatics Society of America.
[7] S. Vinci, J. Zhu, D. Hull, Analysis of electrostatic charge on small-arms projectiles, Proc of SPIE, Vol. 8382.
[8] Lichtenstein T, Gesualdi J, Nigl TP, Yu CT, Kim H. Thermodynamic properties of barium-antimony alloys determined by emf measurements. Electrochim Acta2017;251:203-11.
[9] Bell GM, Levine S, McCartney LN. Approximate methods of determining the double-layer free energy of interaction between two charged colloidal spheres. J Colloid Interface Sci 1970;33:335-59.
[10] Denkov N, Velev O, Kralchevski P, Ivanov I, Yoshimura H, Nagayama K.Mechanism of formation of two-dimensional crystals from latex particles on substrates. Langmuir 1992;8:3183-90.
[11] Sageman DR. Surface tension of molten metals using the sessile drop method.Retrospective Theses and Dissertations 6117. Digital Repository@Iowa State University; 1972. http://lib.dr.iastate.edu/rtd/6117.[Accessed 27 December2017].