Primjena nano, instant i magnetnog praha za analizu papilarnih linija

master's thesis

• Title (english): Application of nano, instant and magnetic powder for papillary lines analysis
• Author: Aleksander Nikola Zec
• Mentor: Sanja Lučić Blagojević (mentor)
• Committee member: Sanja Lučić Blagojević (predsjednik povjerenstva)
• Committee member: Mirela Leskovac (član povjerenstva)
• Committee member: Domagoj Vrsaljko (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2016-09-30, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering; Chemical Engineering in Material Development

Abstract

Cilj ovog rada je istražiti i usporediti mogućnosti određenih daktiloskopskih (DKT) prahova za izazivanje latentnih otisaka prsta na šest različitih podloga, pri čemu je uzeto u obzir vrijeme od trenutka nanošenja otiska do trenutka izazivanja otiska. U istraživanju primjenjivani su sljedeći prahovi: Instant crni (engl. Instant Black), supranano crni (engl. Supranano Black), fluorescirajući magnetični crveni (engl. Fluorescent Magnetic Red) i supranano fluorescirajući crveni magnetični (engl. Supranano Fluorecent Red Magnetic). U eksperimentalnom dijelu prvotno je provedena karakterizacija prahova pomoću SEM-a i EDX-a. U sljedećem koraku istraživanja pristupilo se doniranju otisaka, koji su potom periodično izazivani u razmaku od 0, 5, 10, 15 i 20 dana navedenim prahovima na podlozi prozirne plastike, crne plastike, stakla, nehrđajućeg čelika, lakiranog drveta i laminiranog papira. Izazvani otisci su snimljeni profesionalnim fotoaparatom Nikon D7100 i vršene su usporedbe snimaka otisaka s obzirom na podlogu i trenutak izazivanja. Izazvanim otiscima dodijeljivane su određene ocjene (upotrebljiv - 2, upotrebljiv s korekcijom - 1, neupotrebljiv - 0), koje su potom sumirane i grafički izražene u ovisnosti o vrsti podloge i vrsti primjenjivanih prahova. Dobivena su saznanja o dimenziji, obliku i raspodjeli veličine čestica, stupnju aglomeriranosti i elementarnom sastavu prahova. Rezultati su pokazali da nijedan od istraživanih prahova nije univerzalan i ne izaziva otiske na svim podlogama jednako dobro. Najbolju razlučivost daju supranano crni i supranano fluorescirajući crveni magnetični prah. Razlozi kvalitetnijeg izazivanja otisaka nano prahovima su, između ostalog, manja dimenzijie čestica, pravilniji oblik čestica, te manja raspodjela veličina čestica kako je prikazano SEM mikrografijama.

Abstract (english)

The aim of this work is to investigate and compare the capabilities of specific fingerprint powders for latent fingerprint visualization on six different substrates. The time from fingerprint deposition to the moment of visualization was also taken into account. The studied powders were: Instant Black, Supranano Black, Fluorescent Magnetic Red and Supranano Fluorecent Red Magnetic. First of all, characterization of the choosen powders has been carried out with SEM and EDX analysis. The next step of research started with the deposition of fingerprints, which are then periodically developed after 0, 5, 10, 15 and 20 days by using mentioned powders. The investigation on the following substrates: transparent plastic, black plastic, glass, lacquered wood, stainless steel and laminated paper was done. The developed fingerprints are then recorded with a professional camera (Nikon D7100), afterwards the images were compared considering the surface and the moment of development. To visualized latent fingerprints certain marks (usable - 2, usable with a correction - 1, unusable - 0), were ascribed. The marks are then summarized and graphically expressed as a function of the type of substrate and the type of applied powders. Knowledge about influence of dimensions, shape and particle size distribution, degree of aglomeration and elemental composition of the powders on the fingerprint quality was obtained. Results showed that none of the investigated powders is universal and does not produce prints of good quality on very surfaces. The best resolution gives supranano black and supranano red fluorescent magnetic powder. Reasons for better quality of developed prints with nano powders may be, inter alia, due to a lesser dimension of the particles, more regularly shaped particles and a smaller particle size distribution as shown in the SEM micrographs.

• Keywords: nano prah; fluorescirajući magnetični prah; instant prah; SEM; EDX
• Keywords (english): nano powder; fluorescent magnetic powder; instant powder; SEM; EDX
• Language: croatian
• URN:NBN: urn:nbn:hr:149:948235
• Study programme: Title: Chemical Engineering - Graduate study; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka kemijskog inženjerstva (magistar/magistra inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Public note: Neposredni voditelj: Gordan Mršić (Centar za forenzična ispitivanja, istraživanja i vještačenja "Ivan Vučetić", Zagreb)
• Created on: 2017-11-24 12:59:11