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251.
Gas chromatography–mass spectrometry (GC–MS) data of ignitable liquids in the Ignitable Liquids Reference Collection (ILRC) database were processed to obtain 445 total ion spectra (TIS), that is, average mass spectra across the chromatographic profile. Hierarchical cluster analysis, an unsupervised learning technique, was applied to find features useful for classification of ignitable liquids. A combination of the correlation distance and average linkage was utilized for grouping ignitable liquids with similar chemical composition. This study evaluated whether hierarchical cluster analysis of the TIS would cluster together ignitable liquids of the same ASTM class assignment, as designated in the ILRC database. The ignitable liquids clustered based on their chemical composition, and the ignitable liquids within each cluster were predominantly from one ASTM E1618‐11 class. These results reinforce use of the TIS as a tool to aid in forensic fire debris analysis.  相似文献   
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In many criminal and civil cases in China, the most commonly questioned documents are those written with gel pen ink. An important task for forensic document examiners is to identify whether two or more ink entries in one or more documents were written with the same ink type. The identification of the age of gel ink entries made poses an important and difficult problem for forensic document examiners. In this paper, the volatile components of gel ink were determined and the gel ink was classified by gas chromatography with a flame ionization detector. Calibration curves were created to express the relationship between the content of volatile gel ink components and the age of gel ink entries stored under natural and UV‐induced aging conditions. The correspondence between the natural and UV‐induced aging conditions was also established. The experimental results showed that GC was useful in the analysis of black gel ink and applicable for determining the relative age of gel ink entries under certain conditions.  相似文献   
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In this study, the Raman spectra of 21 phenethylamines were obtained using far‐red excitation (785 nm). The distinguishing ability of Raman for phenethylamines, especially for phenethylamine regioisomers and structural analogues, was investigated. Here, the evaluation of a cross section of Raman spectra demonstrated that all types of phenethylamines were distinguishable, even for certain structural analogues with high spectrum similarity. Raman exhibited high distinguishing ability for phenethylamine regioisomers that differ in the substitution position of halogen, methoxy, alkyl, or other substituted groups; as well as for structural analogues containing different groups, such as furanyl, 2,3‐dihydrofuranyl, halogen, and alkyl substituted at the same position. The Raman spectra for homologues with differences in only a methyl group were found to be highly similar; however, their spectra demonstrated small but detectable differences. Four analogue mixtures and 59 seized samples were also analyzed to study the practical use of the Raman method in forensic field. 95% of the seized samples were correctly identified, which significantly validated the ability of Raman method in identifying the correct isomers. Accordingly, this study provides a non‐destructive, high‐throughput and minimal sample preparation technique for the discrimination of phenethylamines.  相似文献   
256.
In this article we present the schools of thought comprising Critical Management Studies (CMS), explore their implications for public administration, and provide an alternate definition of democratic governance. We synthesize and describe the “modern stream,” inspired by the Frankfurt School, and the “postmodern stream,” associated with poststructuralist authors. Despite significant epistemological and ontological differences, these perspectives complement each other and cast new light on democratic governance. We present the respective theories of Foucault and Habermas, explore their implications for public administration, reconcile their views on power as a basis for a normative definition for so‐called good governance, and redefine the concept of “democratic governance.”  相似文献   
257.
This essay analyses how Mexican presidents have interpreted the concepts of drug trafficking and national security and how these particular connotations have redefined national sovereignty and the specific role of the armed forces in protecting this sovereignty. A qualitative technique of discourse analysis is used to examine public speeches by Zedillo (1994–2000), Fox (2000–2006) and Calderón (2006–2012). The conclusions suggest that drug trafficking and US omnipresence are the two main issues that shaped Mexico's national security threats during this period, with qualitatively distinct trajectories.  相似文献   
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Refugee and labour immigration have placed the issue of immigrants’ access to welfare benefits high on the political agenda. This article explores how voter preferences for increases in the child benefit change when respondents are reminded about immigrants’ access to benefits. The survey experiment shows that information about newly arrived immigrants’ access to child benefit has only a small impact on support for increasing the child allowance. By contrast, information about labour migrants’ access to benefits for children living in another European Union country has a strong impact, and the observed sensitivity to this cue is not to the same extent confined to respondents who otherwise support welfare dualism.  相似文献   
260.
Recent literature on bureaucratic structure has gone further than studying discretions given to bureaucrats in policy making, and much attention is now paid to understanding how bureaucratic agencies are managed. This article proposes that the way in which executive governments manage their agencies varies according to their constitutional setting and that this relationship is driven by considerations of the executive's governing legitimacy. Inspired by Charles Tilly (1984), the authors compare patterns of agency governance in Hong Kong and Ireland, in particular, configurations of assigned decision‐making autonomies and control mechanisms. This comparison shows that in governing their agencies, the elected government of Ireland's parliamentary democracy pays more attention to input (i.e., democratic) legitimacy, while the executive government of Hong Kong's administrative state favors output (i.e., performance) legitimacy. These different forms of autonomy and control mechanism reflect different constitutional models of how political executives acquire and sustain their governing legitimacy.  相似文献   
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