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Fundamental to any ballistic armour standard is the reference projectile that is to be defeated. Typically, for certification, consistency of bullets is assumed. Therefore, practical variations in bullet jacket dimensions can have far reaching consequences. Traditionally, internal dimensions could only be analysed by cutting bullets which rules out any subsequent ballistic assessment. Therefore, the use of a non-destructive X-ray computed tomography (CT) method is explored in this paper. A set of 10 bullets (9 mm DM11) was taken for analysing both intra and inter bullet jacket thickness variation. CT measurements of jacket thickness were validated with high resolution scanning electron microscope (SEM) images. An image based analysis methodology has been developed to extract the jacket thickness map and the centre of gravity. Thickness variations of the order of 200 μm were found commonly across all the bullets along the length and an angular variation of up to 100 μm was found in a few bullets. Jacket thickness and centre of gravity were also calculated for the same bullets after impact and the variations between the pre- and post-impacted bullets were compared, by establishing a common physical reference. The results show that the proposed CT scanning approach and subsequent image analysis method can bring out the statistical variations in bullet geometry pre- and post impact effectively.  相似文献   
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Criticism of forensic science, particularly that of bitemark analysis, has become increasingly common in the last decade. Much of the criticism directed at forensic odontology cites cases where miscarriages of justice have occurred when erroneous, over-confident or even false bitemark evidence has been tendered by odontologists. Despite Australia's own experience with such cases in the past, it is postulated that this does not represent the true nature of bitemark analysis as practiced by odontologists today-at least in this country. A review of 119 cases from the last 10 years confirms that 'identification' of a suspect is rarely, if ever, offered, and that conclusions reached by odontologists with respect to bitemark analysis are generally conservative. However, the results of this study also indicate that in a small but significant proportion of cases, there is still some tendency to reach conclusions that could be considered over-confident when considering the overall quality of the physical evidence offered. It is suggested that odontologists should avoid making conclusive remarks regarding the origin of the mark, or the identification of a perpetrator, when such comments are realistically precluded, given the low evidentiary value of the mark itself.  相似文献   
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As is commonly the case in new areas of research, workplace bullying researchers and practitioners have struggled to establish a single agreed-upon definition of this phenomenon. As a consequence, there are numerous definitions of workplace bullying currently in use around the world to investigate this serious workplace issue, to educate the workforce about this form of harassment and to assess claims involving allegations of workplace bullying. Additionally, little is known about how employees and people in general define workplace bullying behaviour, and whether current researcher, practitioner and legal definitions coincide with lay definitions of bullying. To compare researcher, practitioner and legal definitions of workplace bullying with lay definitions, the content of definitions composed by adults from diverse personal and professional backgrounds (N=1095) was analysed. Results confirmed that components commonly used by researchers and practitioners, including the occurrence of harmful and negative workplace behaviours, were frequently cited by participants as central defining components of bullying behaviour. In addition, lay definitions often included themes of fairness and respect. The emergence of these themes has important consequences for organisations responding to, and attempting to prevent the occurrence of workplace bullying behaviour in that organisations in which bullying is tolerated may violate both local laws as well as their ethical responsibility to provide employees with a safe, professional and respectful workplace.  相似文献   
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