000			02166nam a2200277 4500
001			376010
090			_a376010
100			_a20151020u y0pory50 ba
101			_aeng
200			_aRestoration of obliterated numbers on 40NiCrMo4 steel by etching method _bRecurso eletrónico _emetallurgical and statistical approaches _fAnnalisa Fortini... [et al.]
311			_a(*) CD 294. Resumo inserto na publicação. Ficheiro de 1,79 MB em formato PDF (10 p.).
330			_aThe restoration of obliterated serial numbers is a problem of common occurrence in the forensic field. Among several restoration techniques, chemical etching is the most frequently used. The present research is aimed at studying the restoration of serial numbers, stamped on 40NiCrMo4 steel plates, by means of chemical etching. Microstructural characterization was firstly carried out to study the plastically deformed regions surrounding the marks. The obliteration was performed by controlled removals of material at increasing depths of erasure, and five etching reagents were considered to analyze their sensitivity and effectiveness. Experimental results revealed that Fry’s reagent was the most sensitive, able to restore erased marks up to 60 lm under the depth of the imprint. The reagent comprising 25 mL HNO3 and 75 mL H2O provided good results, recovering the major numbers of characters. A descriptive statistical analysis was conducted to study the operator’s influence on the recovered marks’ identification.
461			_cHoboken _dJanuary 2016 _vVol. 61, n. 1 _tJournal of Forensic Sciences _x1556-4029 _pp. 160-169
606			_aVEÍCULO AUTOMÓVEL _9241256
606			_aMARCAÇÃO DE OBJECTOS _9343973
606			_aCIÊNCIA FORENSE _9321508
606			_aQUÍMICA FORENSE _9343048
606			_aESTATÍSTICA _9232358
710			_aRESTORATION OF OBLITERATED NUMBERS ON 40NICRMO4 STEEL BY ETCHING METHOD _9350456