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71.
Comparisons are made between the visualization of fingerprint corrosion ridge detail on fired brass cartridge casings, where fingerprint sweat was deposited prefiring, using both ultraviolet (UV) and visible (natural daylight) light sources. A reflected ultraviolet imaging system (RUVIS), normally used for visualizing latent fingerprint sweat deposits, is compared with optical interference and digital color mapping of visible light, the latter using apparatus constructed to easily enable selection of the optimum viewing angle. Results show that reflected UV, with a monochromatic UV source of 254 nm, was unable to visualize fingerprint ridge detail on any of 12 casings analyzed, whereas optical interference and digital color mapping using natural daylight yielded ridge detail on three casings. Reasons for the lack of success with RUVIS are discussed in terms of the variation in thickness of the thin film of metal oxide corrosion and absorption wavelengths for the corrosion products of brass.  相似文献   
72.
Previous studies on Diptera have shown the potential for the use of cuticular hydrocarbons' analysis in the determination of larval age and hence the postmortem interval (PMI) for an associated cadaver. In this work, hydrocarbon compounds, extracted daily until pupation from the cuticle of the blowfly Lucilia sericata (Diptera: Calliphoridae), have been analyzed using gas chromatography–mass spectrometry (GC–MS). The results show distinguishing features within the hydrocarbon profile over the period of the larvae life cycle, with significant chemical changes occurring from the younger larvae to the postfeeding larvae. Further interpretation of the chromatograms using principal component analysis revealed a strong correlation between the magnitudes of particular principal components and time. This outcome suggests that, under the conditions of this study, the cuticular hydrocarbons evolve in a systematic fashion with time, thus supporting the potential for GC–MS analysis as a tool for establishing PMI where such a species is present.  相似文献   
73.
Fire investigation is a challenging area for the forensic investigator. The aim of this work was to use spectral changes to paint samples to estimate the temperatures to which a paint has been heated. Five paint samples (one clay paint, two car paints, one metallic paint, and one matt emulsion) have been fully characterized by a combination of attenuated total reflectance Fourier transform infrared (ATR‐IR), Raman, X‐ray fluorescence spectroscopy and powder X‐ray diffraction. The thermal decomposition of these paints has been investigated by means of ATR‐IR and thermal gravimetric analysis. Clear temperature markers are observed in the ATR‐IR spectra namely: loss of ν(C = O) band, >300°C; appearance of water bands on cooling, >500°C; alterations to ν(Si–O) bands due to dehydration of silicate clays, >700°C; diminution of ν(CO3) and δ(CO3) modes of CaCO3, >950°C. We suggest the possible use of portable ATR‐IR for nondestructive, in situ analysis of paints.  相似文献   
74.
We have carried out experiments to investigate the aging of latent fingerprints deposited on black PVC over a period of 4–15 weeks. A thumbprint was used in each case and before deposition of the print the donor rubbed their thumb around their nose to add sebaceous deposits. We have studied the effect of heat, light, and moisture and we find that moisture is the most significant factor in the degradation of the latent print. We have attempted to enhance these latent prints by dusting with valine powder or powders composed of valine mixed with gold or red fluorescent commercial fingerprint powders. To make a direct comparison between “treated” and “untreated” prints, the prints were cut in half with one‐half being “treated” and one‐half not. Our studies show the best results being obtained when powders of valine and red fluorescent powders are applied prior to cyanoacrylate fuming.  相似文献   
75.
In the United Kingdom, theft of lead is common, particularly from churches and other public buildings with lead roofs. To assess the potential to distinguish lead from different sources, 41 samples of lead from 24 church roofs in Northamptonshire, U.K, have been analyzed for relative abundance of trace elements and isotopes of lead using X‐ray fluorescence (XRF) and inductively coupled plasma mass spectrometry, respectively. XRF revealed the overall presence of 12 trace elements with the four most abundant, calcium, phosphorus, silicon, and sulfur, showing a large weight percentage standard error of the mean of all samples suggesting variation in the weight percentage of these elements between different church roofs. Multiple samples from the same roofs, but different lead sheets, showed much lower weight percentage standard errors of the mean suggesting similar trace element concentrations. Lead isotope ratios were similar for all samples. Factors likely to affect the occurrence of these trace elements are discussed.  相似文献   
76.
The writ of quare impedit was, until the mid-nineteenth century, a standard real action for the recovery of advowsons. This article argues that the writ was most likely created between 1187 and 1196, and that it was, at least in part, a response to pressure from religious houses that acquired advowsons by charter of gift and were precluded from bringing the writ of right of advowson or the assize of darrein presentment.  相似文献   
77.
This article revisits a crucial episode in the early nineteenth century criminal law reform debate: the appointment and report of the 1819 House of Commons select committee on capital punishment. This committee, which helped shape the reforms of the 1820s and 1830s, has traditionally been interpreted as the result of the campaign for penal reform in parliament over the preceding decade. This article argues that its origins and significance can only be understood by reference to the political circumstances of 1819 and the scandal surrounding the crime of forgery. This contextualized reading suggests new ways of approaching and understanding the early nineteenth century penal reform discourse.  相似文献   
78.
A rapid colorimetric method for detection of p‐phenylenediamine (PPD) in various biological samples is developed. The o‐cresol test for acetaminophen detection has been modified to detect PPD in blood, urine, gastric contents, and liver. After precipitating protein with trichloroacetic acid solution (2 mL, 10% w/v), biological specimens were required to convert PPD metabolites to PPD by acid hydrolysis. Finally, o‐cresol solution (1 mL, 1% w/v), hydrogen peroxide (200 μL, 3%v/v), and concentrated ammonium hydroxide (0.5 mL) were added in the biological samples. The presence of PPD was indicated by formation of violet color which was turned to bluish green color within 10–15 min. The limit of detection was found to be 2 mg/L in blood, urine, and gastric contents and 2 mg/Kg in liver. This method is also free from any potential interference by p‐aminophenol, acetaminophen, and other amine drugs under test conditions. This method was successfully employed to thirteen fatal cases of PPD poisoning.  相似文献   
79.
Swipe and wipe are types of transfer patterns commonly encountered at bloodied scenes. So far, there have been little published data on the reliability of evaluating these patterns. In this study, 36 bloodstain patterns were randomly assigned to 12 analysts in three separate trials, and the analysts were required to evaluate the pattern type and directionality. The results revealed that correct classifications of patterns type were problematic, with an overall error rate of 32%. Wipes created from wet bloodstains were the most difficult to identify due to the absence of signs of alteration. The directionality of swipes made with a gloved finger had a 100% success rate; however, for swipes made with cloth, the analysts mistook the direction in nearly every case, which is of significant concern, considering these are common patterns at crime scenes. This study suggested there is a need for revising the current protocols for interpretation of these pattern types.  相似文献   
80.
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