Bone Mineral Change During Experimental Calcination: An X‐ray Diffraction Study

The effects of calcination (400–1200°C) on pig bones have been studied using powder X‐ray diffraction (XRD) and secondary modifications, such as color change and weight loss. The characterisation by powder XRD confirmed the presence of the crystalline phase of hydroxyapatite, and comparison of the results obtained at different temperatures suggested that at 650°C, all the organic components and carbonate substitutions were completely removed. Accordingly, these samples were white. In addition, the crystallinity degree and the crystallite size progressively increased with the calcination temperature until 650°C, remaining stable until 1200°C. Below 650°C, bone samples presented organic compounds, resulting in background noise in the diffractogram and gray or black color. In addition, impurities in the lattice correspond to low crystallite sizes.     

纳米二氧化钛荧光粉末显现潜在手印研究

目的使用荧光染料包覆纳米二氧化钛颗粒,制备具有荧光效果的纳米二氧化钛粉末材料,并探索应用纳米二氧化钛荧光粉末显现潜在手印的方法。方法使用实验室合成的二酰亚胺染料与纳米二氧化钛微粒按照一定质量比混合制备形成荧光粉末,通过扫描电子显微镜对其进行表征,观察颗粒结构特征。在玻璃、瓷砖、透明塑料片、彩色塑料包装、易拉罐5类非渗透性客体上捺印手印,观察纳米二氧化钛荧光粉末对不同非渗透性客体上新鲜潜手印的显现效果。分别在5种客体上制作遗留时间为1、4、7、15d的手印样本,考察遗留时间对纳米二氧化钛荧光粉末显现自然陈旧手印效果的影响。将新鲜手印置于标准大气压100℃条件下分别加热1~72h,使用纳米二氧化钛荧光粉末显现,考察其对高温老化手印的显现效果。结果纳米二氧化钛荧光粉末为粒径100~200nm的圆形颗粒;在蓝绿光激发下可发出较强的荧光,能显现多种非渗透性客体上的新鲜手印,与背景反差明显并且能显著降低复杂背景对手印纹线的影响;显出新鲜手印中80%以上具有鉴定条件。纳米二氧化钛荧光粉末对遗留15d以内的陈旧手印仍具有较好的显现效果。100℃高温环境对手印显现效果没有明显影响。结论纳米二氧化钛荧光粉末经济、环保,显现操作简单,易于推广。     

The Anatomy of a Pipe Bomb Explosion: Measuring the Mass and Velocity Distributions of Container Fragments

Improvised explosive devices such as pipe bombs are prevalent due to the availability of materials and ease of construction. However, little is known about how these devices actually explode, as few attempts to characterize fragmentation patterns have been attempted. In this study, seven devices composed of various pipe materials (PVC, black steel, and galvanized steel) and two energetic fillers (Pyrodex and Alliant Red Dot) were initiated and the explosions captured using high‐speed videography. The video footage was used to calculate fragment velocities, which were represented as particle velocity vector maps. In addition, the fragments were weighed. The results demonstrate a correlation between the type of energetic filler and both the size and velocity of the fragments. Larger fragments were produced by Pyrodex filler indicating a less complete fragmentation, compared with smaller fragments produced by double‐base smokeless powder. Additionally, higher fragment velocities were seen with Alliant Red Dot filler.     

Penetration Depth of Projectiles Fired from a Replica of Colt Navy of 1851 in 20% Gelatin Blocks Correlated with Fatal Injuries Assessed in an Autopsy of a 78‐Year‐Old Man

Pursuant to the Polish Weapons and Ammunitions Law, muzzle‐loading black powder weapons, manufactured before 1885, or their replicas, as well as suitable projectiles, can be possessed legally without registration and special licenses. The aim of the study was to assess the penetration depth of projectiles fired from a black powder weapon, replica of Colt Navy of 1851, in 20% gelatin blocks and to compare the obtained results with the actual injuries found on autopsy of a 78‐year‐old man who had committed suicide. In the experiments, we used the black powder weapon and ammunitions, as well as gelatin blocks serving as a soft tissue model. We ascertained that solid spherical projectiles fired from black powder weapons cause extensive injuries, especially in the initial segment of the wound canal. Additionally, based on the presence and location of the wad in the wound canal, the distance from which the shot was fired can be determined.     

粉末法在指纹显现中的运用

粉末法是现场上显现潜指纹最常用、最方便的方法,即用玻璃纤维刷或毛刷将各种粉末刷到指纹区域,其通过物理机械或静电作用与乳突纹线上的指纹残留物发生吸附,而没有指纹残留物的小犁沟以及指纹承载体则不会吸附上粉末.最终的结果就是粉末粘附到乳突纹线上,与未粘附粉末的小犁沟和承栽体形成反差,从而显出潜指纹.     

Magnetic Fingerprint Powder from a Mineral Indigenous to Thailand

Abstract: A study was conducted to investigate whether natural magnetite (Fe₃O₄), which is an abundant mineral in Thailand, could be used as a magnetic powder in the detection of latent fingerprints. Because of the presence of impurities, powdered magnetite is only weakly attracted by a magnet and cannot be used as a magnetic fingerprint powder by itself. Mixing a small amount of magnetite powder with nickel powder greatly enhances the magnetic attraction. A mixture of magnetite powder and nickel powder in a mass ratio of approximately 1:100 was found to be suitable for use as a magnetic fingerprint powder. Fingerprints developed using the magnetite/nickel mixture on nonporous surfaces were found to exhibit good adherence and clarity. Using an automated fingerprint identification system, the number of minutiae detected in fingerprints developed by using the prepared powder on nonporous surfaces was found to be comparable to those detected in fingerprints developed by using a commercial black magnetic powder. The cost is lowered by more than 60%.     

Development of a quantitative LC-MS/MS method for the analysis of common propellant powder stabilizers in gunshot residue

In traditional scanning electron microscopy/energy dispersive X-ray analysis of gunshot residue (GSR), one has to cope more and more frequently with limitations of this technique due to the use of lead-free ammunition or ammunition lacking heavy metals. New methods for the analysis of the organic components of common propellant powder stabilizers were developed based on liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). A multiple reactions monitoring scanning method was created for the screening of akardite II, ethylcentralite, diphenylamine, methylcentralite, N-nitrosodiphenylamine, 2-nitrodiphenylamine, and 4-nitrodiphenylamine, present in standards mixtures. Five out of seven of these target compounds can be selectively identified and distinguished from the two others with a high accuracy. Samples from the hands of a shooter were collected by swabbing and underwent solid phase extraction prior to analysis. Detection limits ranging from 5 to 115 mug injected were achieved. Results from several firing trials show that the LC-MS/MS method is suitable for the detection of stabilizers in samples collected following the firing of 9 mm Para ammunitions.     

Prosecutorial Discretion: An Examination of Substantial Assistance Departures in Federal Crack‐Cocaine and Powder‐Cocaine Cases

Recently there has been a call for research that explores decision‐making at stages prior to sentencing in the criminal justice process. Particularly research is needed under a determinate sentencing system where judicial dispositions are usually restricted by guidelines, which increases the importance of earlier decision‐making stages. As an answer to this call, and in an attempt to build on currents studies on the effects of departures as an intervening mechanism, and a source of unwarranted disparity, this study explores federal sentencing data on offenders convicted of crack‐cocaine and powder‐cocaine offenses. Although decision‐making of all criminal justice actors generally, and prosecutors specifically, has been the subject of much research, studies have yet to resolve the nature and outcome of their “autonomous” discretion. This autonomy becomes especially salient regarding prosecutorial decisions for substantial assistance departures. In deciding who receives a substantial assistance departure, the prosecutor has carte blanche power.     

A method for enhancing gunshot residue patterns on dark and multicolored fabrics compared with the modified Griess test

In using infrared or infrared-enhanced photography to examine gunshot residue (GSR) on dark-colored clothing, the GSR particles are microscopically examined directly on the fabric followed by the modified Griess test (MGT) for nitrites. In conducting the MGT, the GSR is transferred to treated photographic paper for visualization. A positive reaction yields an orange color on specially treated photographic paper. The examiner also evaluates the size of the powder pattern based on the distribution of nitrite reaction sites or density. A false-positive reaction can occur using the MGT due to contaminants or dyes that produce an orange cloud reaction as well. A method for enhancing visualization of the pattern produced by burned and partially unburned powder is by treatment of the fabric with a solution of sodium hypochlorite. In order to evaluate the results of sodium hypochlorite treatment for GSR visualization, the MGT was used as a reference pattern. Enhancing GSR patterns on dark or multicolored clothing was performed by treating the fabric with an application of 5.25% solution of sodium hypochlorite. Bleaching the dyes in the fabric enhances visualization of the GSR pattern by eliminating the background color. Some dyes are not affected by sodium hypochlorite; therefore, bleaching may not enhance the GSR patterns in some fabrics. Sodium hypochlorite provides the investigator with a method for enhancing GSR patterns directly on the fabric. However, this study is not intended to act as a substitute for the MGT or Sodium Rhodizonate test.     

中药外用治疗膝关节骨性关节炎的临床观察

目的:观察中药外用治疗膝骨性关节炎的疗效.方法:将58例膝骨性关节炎患者随机分为治疗组(35例)和对照组(23例),治疗组采用中药外敷和熏洗,对照组内服芬必得,治疗6周后按JOA的膝骨性关节炎治疗效果判定标准进行打分评估.结果:治疗组优良率为85.7%,对照组优良率为82.6%.治疗组在改善关节屈曲角度及强直挛缩方面优于对照组(P<0.05),且没有内服药的不良反应.结论:中药外治法是非手术治疗膝骨性关节炎的一种可行方法.