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Gel ink pens have become a common writing instrument in the United States. Questioned document examiners often attempt to optically differentiate gel inks from each other and from other non-ballpoint ink writings (e.g., those from roller-ball pens). Since early formulations were primarily pigment-based, they do not elute when analyzed by thin-layer chromatography. However, recent gel ink formulations (i.e., within the past five years) include dye-based inks that can be easily separated. This study differentiates black gel inks using optical and chemical techniques. The techniques include: microscopy, visible and near infrared reflectance, near infrared luminescence, thin-layer chromatography (TLC), spot tests, and gas chromatography/mass spectrometry (GC/MS). As a result of this study a flow chart has been developed allowing for a systematic determination of a questioned ink. In addition, an analysis of volatile compounds found in gel inks revealed that there are some unique ingredients that may be found in gel inks that are not typically found in other non-ballpoint inks. 相似文献
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We report on a sample of 135 deliberate self-harm (DSH) patients who were assessed by a general hospital DSH service, and on those who were offered aftercare by, or telephone open access to, the service. Patients' satisfaction with assessment and treatment, and their outcome were investigated at follow-up 12-20 months later. Four-fifths of patients reported the assessment following DSH to have been helpful and the assessor sympathetic. Thirty-three (24%) of the 135 patients assessed were offered treatment by the DSH service but 13 declined or failed to attend. Of the 20 who engaged in treatment, 17 (94%) were satisfied with their care. Open access to the DSH service by telephone was offered to 53 (39%) patients, nine (22%) of whom reported at follow-up that they had used this facility. A specialist DSH service can effectively assess and treat patients following DSH. It is important that the service is accessible and acceptable to patients. 相似文献
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LaPorte GM Wilson JD Mancke SA Payne JA Ramotowski RS Fortunato SL 《Journal of forensic sciences》2003,48(5):1163-1171
Thermal transfer printing refers to printing processes that utilize heat to produce an image by either physical or chemical means or by a combination of both. As the technology has improved and the supplies have become less expensive, the use of thermal printing in the personal and business markets has increased significantly. Specifically, dye diffusion thermal transfer and thermal mass transfer have become predominant in the production of counterfeit credit cards, drivers' licenses, and other types of documents produced on plastic media. Chemical analysis by means of thin layer chromatography (TLC) has proven to be useful in characterizing various types of inks (e.g., writing and inkjet inks). In this study, the authors examined 81 different samples that included a total of 54 printer samples (43 photographic prints on paper and eleven plastic card samples) and 27 printer ribbons. A new TLC method was developed and tested utilizing a solvent system (80% n-hexane, 3% methyl ethyl ketone, and 17% ethyl acetate) that is capable of producing excellent resolution. 相似文献
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For the first time, the UK Criminal Justice Act (1991) allowed the videotaped evidence of a child to be substituted for the child's evidence-in-chief in a criminal court. The present study is an evaluation of that legislation. One hundred and fifty children were observed testifying in a criminal court in the UK. The use of the videotaped evidence and subsequent cross-examination of the child witness (usually via the closed circuit television system) was also observed. The data base from the Lord Chancellor's Department of all trials involving child witnesses in England and Wales was also analysed. The results showed that the introduction of the video technology into the criminal courts reduced the levels of stress of child witnesses but did not increase the conviction rates. 相似文献
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Keith Snavely 《国际公共行政管理杂志》2013,36(2):127-151
States closely regulate the policies of their local units of government through the imposition of direct order mandates. The general literature on state as well as federal mandate activities suggests that such regulations seriously constrain local autonomy and add to local financial burdens. A case study of the application of California's planning mandates in a sample of small nonmetropolitan cities suggests that major programmatic mandates are not always restrictive; mandates can be beneficial by empowering local officials. 相似文献