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040 _aEG-GiCUC
_beng
_cEG-GiCUC
041 0 _aeng
049 _aDeposite
097 _aM.Sc
099 _aCai01.24.05.M.Sc.2020.Za.S
100 0 _aZakaria Elsayed Abdelhamid Ahmed
245 1 0 _aStudy of different toner types used in questioned documents via laser spectrochemical analytical techniques /
_cZakaria Elsayed Abdelhamid Ahmed ; Supervised Mohamed Abdel Harith Mohamed , Zienab Abdelfatah Mohamed Abdelsalam , Shaimaa Mostafa Ibrahim
246 1 5 _aدراسة أنواع مختلفة من أحبار الطباعة المستخدمة فى الوثائق المشكوك فى صحتها باستخدام تقنيات التحليل
260 _aCairo :
_bZakaria Elsayed Abdelhamid Ahmed ,
_c2020
300 _a116 P. :
_bcharts , facimiles ;
_c25cm
500 _aOn message stub Ph.D thesis and on the title page M.Sc degree
502 _aThesis (M.Sc.) - Cairo University - National Institute of Laser Enhanced Science (NILES) - Department of Laser Applications in Environmental Metrology Photochemistry and Agriculture
520 _aQuestioned documents examination (QDE) is considered a practical branch of forensic sciences. It is concerned with signatures, handwriting, typewriting, as well as laser printers and photocopiers outputs.The simplicity of using laser printers and photocopiers and its high resolution made them used on a large scale in the counterfeiting and forgery by alteration and/or addition in questioned documents. In the present work, Video Spectral Comparator (VSC), as a common technique in forensics laboratories and laser-induced breakdown spectroscopy (LIBS), as a spectrochemical analytical technique were used to differentiate between different black toners of printers and photocopiers given their absorption and reflection of light, and their elemental composition.The principal component analysis (PCA) chemometric method was used to analyze the spectroscopic data statistically. Measurements were performed on twenty-three different printers and photocopiers (brands and models). VSC investigation is based on different photochemical absorption and reflection properties of toners samples. The LIBS spectra were compared to characterize each toner type. The multivariate statistical analysis based on Principal Component Analysis (PCA) has developed a model of discriminating the toners in questioned documents. Results revealed that VSC offers relatively poor discrimination capability at the same time LIBS has succeeded in the discrimination between different toner types of printers and photocopiers brands. However, it has little power to discriminate between toners of different models of the same brand
530 _aIssued also as CD
653 4 _aPrincipal Component Analysis (PCA)
653 4 _aQuestioned documents examination (QDE)
653 4 _aVideo Spectral Comparator (VSC)
700 0 _aMohamed Abdelharith Mohamed ,
_eSupervisor
700 0 _aShaimaa Mostafa Ibrahim ,
_eSupervisor
700 0 _aZienab Abdelfatah Mohamed Abdelsalam ,
_eSupervisor
856 _uhttp://172.23.153.220/th.pdf
905 _aNazla
_eRevisor
905 _aShimaa
_eCataloger
942 _2ddc
_cTH
999 _c79942
_d79942