A statistical criterion for the value of evidence: Application to the evaluation of the results of paint spectral analysis

The paper describes a method for the quantitative comparison of slightly differing infrared spectra. The method is based on a comparison of the differences in absorbance of some selected band pairs which represent identification features of infrared spectra. An optimal combination of band pairs was chosen using two methods: a graphical method based on the validity of Beer's law (method I) and a purely statistical method (method II). The spectra characterized by the selected features were compared and the significance of differences between them was tested using the mathematical Hotelling's T² test. It was found that the method developed enables the quantitative and objective evaluation of the statistical significance of differences between compared spectra.     

Application of the micro-FTIR spectroscopy, Raman spectroscopy and XRF method examination of inks

In routine examination of inks on questioned documents non-destructive analytical methods, such as microscopic and optical techniques are applied first. However, they are often insufficient to identify the inks used for the preparation of the document. In such cases, it is necessary to apply chemical methods that normally cause partial destruction of the examined material. The aim of this work was to evaluate the possibility of discrimination between inks by the use of spectrometric methods, i.e. micro-FTIR spectroscopy, Raman spectroscopy and XRF. About 70 samples of blue and black ballpoint pen and gel inks were examined. It was found that about 90% of the samples of the same type and colour could be distinguished using these methods.     

The influence of the type of accelerant, type of burned material, time of burning and availability of air on the possibility of detection of accelerants traces

The presented research consisted in a series of field experiments and laboratory analyses of obtained samples. Their aim was to investigate how different factors influence the possibility of identification of accelerant traces in conditions that are as similar as possible to those of real fires. The studied factors were: type of burned material, type of accelerant, length of time between lighting and extinguishing of fire and the air availability level. The obtained results show that, among investigated factors, the type of burned material has the greatest influence. The other factors, with regard to their influence, could be ranked in descending order as follows: 'other' (hard to determine and regulate factors), type of accelerant, time of burning and air availability. 'Other' factors include arrangement of the burned material and dispersion of the accelerant.     

Targeting the Motivated? Ethnicity and the Pre‐emptive Use of Government Repression

Research on government repression often focuses on the comparison between states over time and provides little insight about the targets of repression within a state. This article unpacks government repression against different ethnic groups. It argues that non‐democratic governments use pre‐emptive and targeted repression against ethnic groups that are discriminated, strong, or have a history of protest or rebellion in order to prevent future ethnic rebellions. For democratic governments, on the other hand, the cost of pre‐emptive repression is too high. The article tests this argument in a quantitative analysis of government‐group dyads. It finds at least partial support for some implications of the argument: Autocratic governments use more repression than democracies against discriminated groups, but only when they are also weak, and against groups with a history of protest. There is little evidence that regimes of either type respond to previous violent mobilization or group strength with repression.     

Attitudes toward Consent-Based and Non-Consent-Based International Law in a Regional Power Context

International legal scholars have identified and argued for and against new forms of non-consent-based international law. We study variation in Brazilian public opinion about adherence to international law created in three different ways: through a consent-based multilateral treaty, by the U.N. Security Council with the participation of Brazil, and by the U.N. Security Council without the participation of Brazil. Information that Brazil has participated in creating the international legal obligation through a multilateral treaty or membership on the Security Council yields levels of support for adherence to the legal obligation that are similar to those found when the origins of the legal obligation are generic. Information that the international legal obligation was created without Brazil’s participation, on the other hand, results in reduced support for compliance. This difference, which is particularly concentrated among highly educated respondents, is not driven by reduced concerns about reputational consequences or sanctions. Our results suggest that the increased use of non-consent-based forms of international law might be challenged by a lack of public support for compliance.     

The expanding galaxy of performing arts: extending theories and questioning practices

This paper introduces the Special Issue on the languages of performing arts and is therefore aimed at designing how the context of the latter can be illuminated by socio-semiotic and multimodal approaches to communication. In this Special Issue, performances and performing arts are described as multimodal semiotic acts that co-deploy a range of semiotic resources to produce and construct meanings across different cultures and ages. Seen as dynamic and interactive processes of meaning-making, their analysis calls for new and multidisciplinary frameworks which are collected in this Special Issue. The introduction gives an overview of these papers and discusses their range of diverse phenomena, both live and recorded, including theatre performances and films, art installations, opera, as well as reading out aloud. By outlining the significance and contribution of different disciplines and fields of studies to the broad area of performance studies, the chapter argues the case for innovative approaches that can extend theories and analyse aesthetic and performative practices in context. With the help of some case studies, it provides guidelines for the reading and interpretation of the several theoretical discussions and practical case studies presented to encourage further multidisciplinary research on these domains.     

A chemical and physicochemical study of an Egyptian mummy 'Iset Iri Hetes' from the Ptolemaic period III-I B.C

Chemical and physicochemical examinations of the fragments of an Egyptian mummy dated between the 3rd and 1st century B.C. were performed. The chemical examinations indicated the presence of resin in the skull and in the fragments of bandages wrapped around the mummy. An analysis of the infrared spectra of the fragments indicated a type of resin originating from the Copal group. Physicochemical investigations showed that main chemical elements such as Ca, Mg, Na, K, P and trace chemical elements such as Fe, Zn, Cu, and Pb occurred in bone fragments in proportions typical for people living today. In tooth fragments, values were similar to normal except for K, P, and Zn, which were lower, and Pb, which was absent. In the fingernails, most elements were found in much higher concentrations except for Cu and Pb, which were lower. The results of the study in terms of their implications on mummification are discussed.     

Characterization of Blue Pigments Used in Automotive Paints by Raman Spectroscopy

Micro‐Raman spectroscopy was applied to forensic identification of pigments in paint chips and provided differentiation between paint samples. Sixty‐six blue automotive paint samples, 26 solid and 40 metallic were examined. It was found that the majority of the collected Raman spectra provided information about the pigments present. However, in some cases, fluorescence precluded pigment identification. Using laser excitation at longer wavelengths or pretreatment to effect photobleaching often resulted in reduced fluorescence, particularly for solid color samples, and allowed pigment identification. The examined samples were compared pairwise taking into account number, location, and intensity of absorption bands in their infrared spectra. The estimated discrimination power ranged from 97% for solid paint samples to 99% for metallic paint samples.