OSVALDO NEGRINI NETO
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Artigo IPEN-doc 28689 Determinação de características mecânicas de folhas de papel utilizando a técnica de tomografia por coerência óptica, e suas aplicações na área forense2022 - RIBEIRO, LUCAS A.S.; NEGRINI NETO, O.; FREITAS, ANDERSON Z. deApresentamos nesse trabalho, uma metodologia para avaliar a pressão de punho durante o processo de escrita manual. Utilizando a tomografia por coerência óptica, foi possível determinar a deformação sofrida pelo papel durante o processo de escrita manual. Foi realizada uma calibração da deformação sofrida pelo papel em função da pressão exercida pela caneta, tornando possível determinar vários parâmetros de interesse, como por exemplo, o raio da esfera da ponta da caneta R = 488 ± 2μm, o coeficiente de Poisson ν = 0, 30 ± 0, 02 e o módulo de Young efetivo do papel sulfite 75 g/m2. Para tal, desenvolvemos um método de determinação do módulo de Hooke para uma mola, com a qual construímos um dispositivo para aplicação de uma força conhecida a uma caneta esferográfica durante o processo de escrita manual. Realizamos também o estudo em função do tipo de substrato, sendo que cinco voluntários tentaram copiar a mesma assinatura em quatro tipos diferentes de papel. Com o auxílio da técnica de tomografia por coerência óptica demonstramos que é possível diferenciar a autoria de uma assinatura também pela profundidade da deformação no papel. O procedimento experimental tornou possível ainda determinar o coeficiente de Poisson e determinar o Módulo de Young efetivo do papel.Artigo IPEN-doc 27773 A new method for measuring pen pressure in forensic handwriting analysis2021 - NEGRINI NETO, O.; SARKIS, J.E.S.; SIQUEIRA, A.N.; RIBEIRO, L.A.S.; FREITAS, A.Z.This work describes a new method for the analysis of handwritten documents through a system composed of a pre-selector optical analyser equipped with light sources of different wavelengths coupled with bandpass filters combined with an optical coherence tomography (OCT) instrument. The optical analyser identifies regions with different pen pressures on the paper using specific wavelengths from ultraviolet (UV) to infrared (IR) and bandpass filters. Then the selected regions are analysed with a coherence tomography analyser to measure the depth of grooves and capture three-dimensional images. With this methodology, it is possible to identify similarities, or differences, between the pieces of evidence under investigation, increasing the possibility of correct attribution concerning the authorship of the signature and we also showed that this feature is independent of the paper substrate. In this work, a new strategy will be presented to categorize and quantify pen pressure in order to aid a better response for a forensic examiner. Thereby, from the observed areas that display higher pressures (more significant grooves), it is possible to determine the authorship of the signature.Artigo IPEN-doc 27335 Optical-coherence-tomography-based algorithm for handwriting forensic analysis2020 - FREITAS, ANDERSON Z. de; RIBEIRO, LUCAS A. de S.; NEGRINI NETO, OSVALDO; SARKIS, JORGE E.S.; SIQUEIRA, ANDRESSA N.This work describes a new method for handwriting forensic analysis using optical coherence tomography (OCT) images. The region of interest (ROI) in documents signature to be analyzed were pre-selected with a traditional optical analyzer (Docucenter 2000 – Projectina®) equipped with different wavelengths light sources and bandpass filters coupled detector. The ROI where then submitted to OCT to 3D imaging (OCP930SR, Thorlabs Inc.) with optical resolution of 6.0 microns. One original and 5 falsified signatures were produced by 5 different individuals, using a block of 5 sheets of white sulfite paper A4 size and weight of 75 g/m^2, using the same blue ballpoint pen and in the same surface. For pressure pen calibration, were developed a system computer controlled to maintain the pressure constant during writing linear traces, 15 different pressure configuration were applied to each linear trace, resulting in a relation between deformation and applied pressure. An autonomous algorithm was developed to make surface detection, across OCT tomographic images, correct the paper surface curvature, detect and measure deformation on paper due to pen pressure, generating a new image in false color from differential pressure, based in previous calibration. This new image can be considered as a “fingerprint pressure” signature. This methodology may assist the forensic expert in correctly determining the authorship of a signature.Resumo IPEN-doc 20557 Building a nuclear forensic analysis capability in Brazil2014 - SARKIS, JORGE E. de S.; ROSA, DANNIELE S.; GODOY, ANA L.E.; RODRIGUES, DEMERVAL L.; CARVALHO, ELITA F.U. de; MARTINELLI, JOSE R.; COTRIM, MARYCEL E.B.; LIMA, NELSON B.; NEGRINI NETO, OSVALDO; TALHAVINE, MARCELOArtigo IPEN-doc 17137 Identification of gunshot residues by using a high resolution inductively coupled plasma mass spectrometry technique2011 - OLIVEIRA, PATRICIA C.; SARKIS, JORGE E.S.; FREITAS, JOAO C.D.; LEBKUCHEN, ADRIANA; NEGRINI NETO, OSVALDO; VIEBIG, SONIAArtigo IPEN-doc 12328 Multivariate classification based on chemical and stable isotopic profiles in sourcing the origin of marijuana samples seized in Brazil2007 - SHIBUYA, ELISA K.; SARKIS, JORGE E.S.; NEGRINI NETO, OSVALDO; OMETTO, JEAN P.H.B.Artigo IPEN-doc 12277 Carbon and nitrogen stable isotopes as indicative of geographical origin of marijuana samples seized in the city of Sao Paulo (Brazil)2007 - SHIBUYA, ELISA K.; SARKIS, JORGE E.S.; NEGRINI NETO, OSVALDO; MARTINELLI, LUIZ A.Artigo IPEN-doc 11195 Sourcing brazilian marijuana by applying IRMS analysis to seized samples2006 - SHIBUYA, E.K.; SARKIS, J.E.S.; NEGRINI NETO, O.; MOREIRA, M.Z.; VICTORIA, R.L.Artigo IPEN-doc 09594 A new method for collection and identification of gunshot residues from the hands of shooters2003 - REIS, E.L.T.; SARKIS, J.E.S.; NEGRINI NETO, O.; RODRIGUES, C.; KAKAZU, M.H.; VIEBIG, S.Artigo IPEN-doc 10496 Identificacao de residuos de disparos de armas de fogo por meio da tecnica de espectrometria de massas de alta resolucao com fonte de plasma indutivo2004 - REIS, E.L.T.; SARKIS, J.E.S.; RODRIGUES, C.; NEGRINI NETO, O.; VIEBIG, S.