Identification of iron-gall inks with near-infrared Raman microspectroscopy

Στο καινούργιο τευχος του Journal of Raman Spectroscopy (May 2008), οι Alana S. Lee, Vincent Otieno-Alego & Dudley C. Creagh παρουσιάζουν μια εργασία με τίτλο: "Ταυτοποίηση μελανιών μεταλλικής ακίδας με near-infrared Raman μικρο-φασματοσκοπία μεταλικής Identification of iron-gall inks with near-infrared Raman microspectroscopy ".

In the new Issue of Journal of Raman Spectroscopy (May 2008), Alana S. Lee, Vincent Otieno-Alego and Dudley C. Creagh present a paper titled: "Identification of iron-gall inks with near-infrared Raman microspectroscopy".

Περίληψη/Abstract: The identification of iron-gall inks on a number of 18th, 19th, and 20th century documents and a 12th century manuscript has been conducted using near-infrared Raman microspectroscopy. These historic iron-gall inks were found to display characteristic Raman bands generally occurring around 1475 cm^-1, between 1310 and 1350 cm^-1 (variable), 490-640 cm^-1 (combined broad band), and 400 cm^-1. These bands have promise as analytical spectroscopic markers for in situ non-destructive Raman identification of iron-gall ink on historic collections and were in good agreement with Raman data collected for laboratory-prepared iron-gall ink complexes and inks prepared following traditional iron-gall ink recipes. All historic ink spectra contained a fluorescent background, the degree of which varied between samples.

Article

Περί διαχωρισμού της γραφής διδύμων/ On the Discriminability of the Handwriting of Twins

Στο καινούργιο τευχος του Journal of Forensic Sciences ( Volume 53 Issue 2 Page 430-446, March 2008), οι Sargur Srihari, Chen Huang και Harish Srinivasan παρουσιάζουν μια εργασία με τίτλο: "Περί διαχωρισμού της γραφής διδύμων/On the Discriminability of the Handwriting of Twins ".

In the new Issue of Journal of Forensic Sciences International ( Volume 53 Issue 2 Page 430-446, March 2008),Sargur Srihari, Chen Huang and Harish Srinivasan present a paper titled: "On the Discriminability of the Handwriting of Twins".

Περίληψη/Abstract: As handwriting is influenced by physiology, training, and other behavioral factors, a study of the handwriting of twins can shed light on the individuality of handwriting. This paper describes the methodology and results of such a study where handwriting samples of twins were compared by an automatic handwriting verification system. The results complement that of a previous study where a diverse population was used. The present study involves samples of 206 pairs of twins, where each sample consisted of a page of handwriting. The verification task was to determine whether two half-page documents (where the original samples were divided into upper and lower halves) were written by the same individual. For twins there were 1236 verification cases—including 824 tests where the textual content of writing was different, and 412 tests where it was the same. An additional set of 1648 test cases were obtained from handwriting samples of nontwins (general population). To make the handwriting comparison, the system computed macro features (overall pictorial attributes), micro features (characteristics of individual letters), and style features (characteristics of whole-word shapes and letter pairs). Four testing scenarios were evaluated: twins and nontwins writing the same text and writing different texts. Results of the verification tests show that the handwriting of twins is less discriminable than that of nontwins: an overall error rate of 12.91% for twins and 3.7% for nontwins. Error rates with identical twins were higher than with fraternal twins. Error rates in all cases can be arbitrarily reduced by rejecting (not making a decision on) borderline cases. A level of confidence in the results obtained is given by the fact that system error rates are comparable to that of humans (lower than that of lay persons and higher than that of questioned document examiners [QDEs]).


http://www.blackwell-synergy.com/doi/abs/10.1111/j.1556-4029.2008.00682.x

Classification and individualisation of black ballpoint pen inks using principal component analysis of UV–vis absorption spectra

Στο καινούργιο τευχος του Journal of Forensic Sciences International (Volume 174, Issue 1, 15 January 2008, Pages 16-25 ), οι Craig D. Adam, Sarah L. Sherratt & Vladimir L. Zholobenko παρουσιάζουν μια εργασία με τίτλο: "Classification and individualisation of black ballpoint pen inks using principal component analysis of UV–vis absorption spectra ".

In the new Issue of Journal of Forensic Sciences International (Volume 174, Issue 1, 15 January 2008, Pages 16-25 ), οι Craig D. Adam, Sarah L. Sherratt and Vladimir L. Zholobenko Meenakshi Mahajan & S.P. Arya present a paper titled: "Classification and individualisation of black ballpoint pen inks using principal component analysis of UV–vis absorption spectra Tape".

Περίληψη/Abstract: The technique of principal component analysis has been applied to the UV–vis spectra of inks obtained from a wide range of black ballpoint pens available in the UK market. Both the pen ink and material extracted from the ink line on paper have been examined. Here, principal component analysis characterised each spectrum within a group through the numerical loadings attached to the first few principal components. Analysis of the spectra from multiple measurements on the same brand of pen showed excellent reproducibility and clear discrimination between inks that was supported by statistical analysis. Indeed it was possible to discriminate between the pen ink and the ink line from all brands examined in this way, suggesting that the solvent extraction process may have an influence on these results. For the complete set of 25 pens, interpretation of the loadings for the first few principal components showed that both the pen inks and the extracted ink lines may be classified in an objective manner and in agreement with the results of parallel thin layer chromatography studies. Within each class almost all inks could be individualised. Further work has shown that principal component analysis may be used to identify a particular ink from a database of reference UV–vis spectra and a strategy for developing this approach is suggested.

Forensic Science International: http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T6W-4NF2NHG-1&_user=10&_coverDate=01%2F15%2F2008&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=522be83d3ff75cde594bc4371ada28f4