Ammonium nitrate fuel oil is an explosive mixture found in most antipersonnel landmines (APL) buried throughout the Colombian territory. During more than 50 years of internal conflict, the Colombian government has found that trained dogs are the most effective method to detect APL. However, the olfactive signature in ANFO is unknown and also if there are differences in detection related to the explosive manufacturing origin. Therefore, this work begins with the analytical validation of the method used to determine ammonia, in its derivatized form as carbamate, released by home-made ANFO using HS-SPME-GC-FID. Once validated, the method was used to identify ammonia and other organic volatile compounds present in ANFO, under laboratory and simulated field conditions. The validation process includes the evaluation of the optimum conditions for the derivation and extraction of butylcarbamate, the determination of the working ranges with linear response in FID, the limits of detection and quantification, the sensitivity, and the precision. The results of the validation established linearity and sensitivity in a concentration between 20 and 120 mg/L, as well as low limits of detection and quantification of 6.4 and 21.4 mg/L, respectively. Also, an intermediate precision of 11% for butylcarbamate with a repeatability of 8%. The validated method showed in real samples of home-made ANFO besides ammonia, the presence of low molecular methylamines, and also exhibited differences in volatile compositions according to the origin. The objective of this work is to offer a reliable analytical methodology for the extraction and analysis of volatile compounds from ANFO. 相似文献
Gunshot residue (GSR) analysis and their interpretation provide crucial information on a criminal investigation involving the use of firearms. To date, several approaches have been proposed for the implementation of a combined sampling and analysis of inorganic (IGSR) and organic GSR (OGSR). However, it is not clear at this stage if concurrent analyses of both types of residue might be detrimental to the analysis of IGSR currently applied in forensic laboratories. Thus, this work aims to compare and evaluate three different protocols for the combined collection and analysis of IGSR and OGSR. These methods, respectively, involve the use of a modified stub (with two halves, one for the detection of IGSR and the other for the analysis of OGSR); the sequential recovery of GSR with two stubs mounted with different adhesives (double-sided carbon tape and Tesa® TACK) and the sequential analysis of IGSR and OGSR from a single carbon stub following carbon deposition. The detection of IGSR was carried out using SEM-EDX, while OGSR analysis was performed using ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS). Obtained results for experiments performed using Geco Sinoxid® ammunition indicated that sequential analysis was the most suitable protocol for the combined collection and analysis of both IGSR and OGSR. A higher number of inorganic (characteristic and consistent) particles and higher concentrations of ethylcentralite, N-nitrosodiphenylamine, diphenylamine, and nitroglycerin were recovered with this method. 相似文献
The aim of this paper is to examine the influence of the right to information laws on sustainability transparency in European local governments. This goal is novel, in that previous studies have examined the effects of various factors on the dissemination of government information (demographic, socioeconomic, political and financial) but not the contribution of legal factors to online transparency on environmental, social and economic sustainability. Our research question is this: Do information laws contribute to transparency on sustainability? Using the Global Reporting Initiative guidelines and a statistical regression analysis, we studied the websites of 106 local governments in ten European countries. The results obtained show that when transparency laws clearly stipulate the rules applicable and the procedures established for appeals, exceptions, refusals and requests, this can favour transparency on environmental, social and economic sustainability. Our findings advance understanding of this field and reinforce the basis for legal reforms to enhance sustainability transparency.
Document examiners sometimes eliminate writers on the basis of differences which are given too much weight. This article is an attempt to explain some conditions whereby differences in the writing of one individual are misinterpreted as significant differences, when they are actually caused by conditions which are unknown to the examiner. 相似文献
A method for the routine profiling of illicit heroin samples received in casework has been developed which depends on simple and straightforward sample pretreatment, followed by gas chromatography on a capillary column using flame-ionization detection. The factors affecting the choice of each aspect of the procedure are discussed, as are the statistical data for sampling and the chromatography. Components of illicit heroin derived from opium and other adulterants have been identified. The significance of data from samples examined in 1986 is discussed. 相似文献
Persistent underperformance of public policy and program implementation in Aboriginal affairs is widely recognised. We analysed the results of two case studies of attempted reforms in public administration of Aboriginal primary health care in the Northern Territory, using a framework based on the institutionalist and systemic racism literatures, with the aim of better understanding the sources of implementation failure. Implementation of the agreed reforms was unsuccessful. Contributing factors were as follows: strong recognition of the need for change was not sustained; the seeds of change, present in the form of alternative practices, were not built on; there was a notable absence of sustained political/bureaucratic authorisation; and, interacting with all of these, systemic racism had important consequences and implications. Our framework was useful for making sense of the results. It is clear that reforms in Aboriginal affairs will require government authorities to engage with organisations and communities. We conclude that there are four requirements for improved implementation success: clear recognition of the need for change in ‘business as usual’; sustainable commitment and authorisation; the building of alternative structures and methods to enable effective power sharing (consistent with the requirements of parliamentary democracy); and addressing the impact of systemic racism on decision-making, relationships, and risk management. 相似文献
Certified aircraft mechanics represent the largest gender-based demographic disparity in aviation with a 49-to-1 male-to-female ratio. Recent research into women’s perspective on the aircraft mechanic career field revealed that a large majority of women felt unsure or negatively about their potential promotion opportunities and social acceptance. The purpose of this follow-on mixed-methods concurrent triangulation study was to explore the perspectives of men regarding the aforementioned topics to see if they differ from previously published research on women perceptions. A total of 587 men and 431 women completed an eight-question survey containing 5-point Likert-type and open-ended questions. The quantitative comparison consisted of the total 1018 responses, while only the survey responses from the 587 men were analysed for correlations and qualitative codes. Results indicated that there was a significant difference between the perceptions of men from those of the women regarding work environment safety and social acceptance. Additional correlation analysis revealed social acceptance to be a key variable when predicting career appropriateness, advancement opportunity and work environment safety. The 587 qualitative responses yielded results that differed from those of women, citing an assumption that women have the same advancement opportunities or be as socially accepted as men entering the field. 相似文献
Housework and childcare have been considered mechanisms for ‘doing gender’ through the allocation of different functions to women and to men. Women continue to devote more time and effort to this type of work, in spite of their progressive incorporation into the labour market. Same-sex couples escape this gender binarism, and so this study set out to learn the distribution criteria work, as well as the influence of gender socialization when it comes to establishing this distribution. A qualitative investigation was carried out with 21 Spanish same-sex families. The results indicate that the majority of couples position themselves in an egalitarian discourse based on the absence of differentiated gender roles and a low level of specialization. No differences were found between male and female couples. Nevertheless, the female couples show higher levels of discontent when the distribution was not egalitarian. In conclusion, it is proposed that the effects of gender socialization are perpetuated beyond heterosexual relationships and also affect same-sex couples. 相似文献