Inconsistency in 9 mm bullets measured with non-destructive X-ray computed tomography

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.     

Effect of various factors on the activity of sucrase from the larvae of Sesamia inferens

Salivary gland sucrase activity fromSesamia inferens Wlk. was optimal at pH 5.8 and temperature 35°. It increased up to 1.5% final sucrose concentration, but higher concentrations had no effect. A dialysed preparation showed a 37.5% reduction in the activity. It was accelerated by tryptophan and inhibited by all other amino acids used. Gut sucrase activity ofS. inferens was optimal at pH 6.2 and temperature 30°. It increased sharply up to 0.66% final sucrose concentration, and then gradually up to 1.5% while further increase in the concentration had no effect. A dialysed preparation showed an 8% increase in activity. Activity was not affected by serine; was accelerated by arginine, cystine, methionine, tryptophan and valine; and inhibited by alanine, glutamine, glycine, hydroxyproline, leucine, phenylalanine, proline and tyrosine. End-products increased with the incubation period and showed inhibitory effects. With the increase of enzyme concentration the rate of sucrose hydrolysis also increased. K⁺ ions accelerated the activity of the dialysed preparation. It was also accelerated by Li⁺⁺ ions up to their final concentration of 0.001 M, but inhibited when their final concentration increased (0.01 M and 0.025 M). TRIS also inhibited the activity.

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Résumé Deux types d'extraits ont été étudiés séparément: la sucrase extraite des glandes salivaires et celle extraite de l'intestin moyen. L'activité optimale de la sucrase salivaire s'observe pour un pH 5,8 et une température de 35°; celle de la sucrase de l'intestin moyen pour un pH 6,2 et une température de 30°. Cependant les extraits dialysés, d' origine salivaire ou d'origine intestinale, ont une activité optimum pour un même pH (5,8). L'activité des deux sucrases s'accro?t proportionnellement à la durée de la période d'incubation. L'activité de la sucrase salivaire s'accro?t nettement, jusqu'à une concentration finale en sucrose de 1.5%, alors que pour la sucrase intestinale, 90% de l'activité maximale est réalisée pour une concentration finale en sucrose de 0.66%. Quand la concentration en sucrose atteint ou dépasse 1,5% il se forme alors un oligosaccharide dont la synthèse équilibre l'hydrolyse du sucrose, ce qui rend l'activité de la sucrase constante au-dessus d'une concentration finale en sucrose≥1,5%. Cette synthèse d'un oligosaccharide intervient quand on utilise une forte concentration de sucrase, ce qui entraine la production de glucose et fructose en grande quantité; avec une faible concentration de l'extrait on n'observe pas la synthèse d'oligosaccharide. Les ions K⁺ accélèrent l'activité des extraits dialysés, d'origine salivarie ou intestinale; les ions Li⁺⁺ sont également favorables jusqu'à une concentration de 0,001 M, cette action devenant inhibitrice à partir de 0,005 ou 0.025 M; les ions TRIS, à 0,025 M ont également un effet inhibiteur. Certains acides aminés accélèrent l'activité de la sucrase salivaire ou intestinale, d'autres au contraire ont une action inhibitrice.

     

Education,human error,and road crash risk: An empirical investigation in the Indian states

This study examines the road accident rates from 29 Indian states and 6 Union Territories during 2006–2015. In this paper, we have employed several empirical techniques such as regression, generalized method of moments (GMM), and threshold regression models to examine how education and attitude of the drivers impact the road accident rates. In our empirical analysis, we demonstrate that lawless driving is found to be positive and statistically significant while incorporating both state and year effects. We also find some interesting result in the context of education and road accidents. We notice positive relationship between higher education and road accident rates across Indian states, which tells us highly educated people are more prone to road accidents as compared with less educated people. In the threshold analysis, the study discovers the positive relationship between road injury and accidents caused by people with higher education, in cases of considering road injury rate from drunken driving as the threshold variable. There appears to be a large number of behavioral issues emanating from higher education, which contributes significantly to the road accident rates in the Indian states. Hence, there is a need for policy intervention.     

Do Crime Hot Spots Exist in Developing Countries? Evidence from India

Objectives

To determine whether concentrations of crime documented in American cities such as Boston, Jacksonville, Minneapolis, Sacramento, and Seattle generalize to unique environments such as India.

Methods

Two years of motor vehicle theft (MVT) and burglary incidents from two police stations in Jaipur, India are analyzed. The degree to which crime clusters is documented using nearest neighborhood hierarchical clustering (NNHC). These results are compared to several widely cited studies documenting concentrations in the United States.

Results

The NNHC procedure identified five MVT hot spots, which accounted for just .09 % of the two station’s land, but over 13 % of these incidents, and four burglary hot spots, which accounted for less than 1 % of its land, but nearly 23 % of the incidents.

Conclusions

Given the stark differences in the built environment and sociological makeup of Jaipur, a better understanding of the forces that cause crime to concentrate to a high degree needs to be discerned before implementing law-enforcement driven policies derived from the scholarship of American cities. Additional research should also seek to replicate not just the degree to which crime clusters in these unique environments, but also its stability over time and micro place variation.

     

Eyewitness susceptibility to co-witness misinformation is influenced by co-witness confidence and own self-confidence

If an eyewitness is exposed to a co-witness statement that incorrectly blames an innocent bystander for a crime, the eyewitness can be influenced by this statement and also blame the innocent bystander for the crime. This effect is known as blame conformity. In two studies, we examined whether or not this effect is influenced by the degree of confidence a co-witness expresses in her incorrect statement (Study 1) and an eyewitness’s own level of self-confidence (Study 2). Participant eyewitnesses first watched a crime video featuring a perpetrator and an innocent bystander, then read a co-witness statement about the crime that either correctly blamed the perpetrator, incorrectly blamed the innocent bystander, or blamed nobody (a control condition). They were then asked who committed the crime. In Study 1, participants who read an incorrect statement were at increased risk of engaging in blame conformity when the co-witness expressed a high level of confidence, compared to a low level of confidence, in the accuracy of her statement. In Study 2, participants who were lowest in self-confidence were at increased risk of engaging in blame conformity. The theoretical underpinnings of these effects are considered.     

Test-extractor marks under low pressure on shotgun cartridges

The necessity for firing high pressure test rounds to imprint extractor marks on shotgun cartridges in cases involving improvised or non-standard locally made firearms has been obviated. A suitable method for obtaining desired extractor marks on shotgun cartridges under low pressure has been suggested.     

An investigation into pellet dispersion ballistics.

Existing works on pellet dispersion ballistics are confined to some data-based models derived from statistical analysis of observed patterns on targets but the underlying process causing the dispersion lacks due attention. The present article delves into the relatively unexplored areas of dispersion phenomena, and attempts to develop a theoretical model for general application. The radial velocity distribution of pellets has been worked out by probing into the physical process of dispersion based on transfer of momentum from undispersed shot mass to dispersed pellets. The ratio 2u/v0 (u = root mean square (r.m.s.) radial velocity and v0 = muzzle velocity of the pellets) is found to be fairly constant for a fixed gun-ammunition combination and has been suitably designated as 'Dispersion Index' (DI) characterising its dispersion capability. The present model adequately accounts for pellet distribution on targets and it appears that 'Effective Shot Dispersion' (ESD) as introduced by Mattoo and Nabar [ESD = [(4/N0)sigma Ri2]1/2, where N(0) is the total number of pellets and Ri is the radial distance of the i-th pellet from centre of pattern], gives a faithful numerical measure of overall dispersion at a given distance. A relationship between ESD and firing distance, incorporating the effects of air resistance and gravity has been worked out, which reveals that DI controls the dispersion at a given distance. For small distances (less than 20 m) the relation reduces to a linear one, as already observed empirically and looks like ESD = E0+DI x firing distance, E0 being a parameter dependent on gun and ammunition. The present model, unlike earlier ones, is versatile enough to explain the natures of the dependence of dispersion on firing distance as well as on gun-ammunition parameters, which are essential for a faithful reconstruction of a crime scene. The model has been tested with such experimental data as are available and reasonable agreement is observed.     

Analysis of Indian blue ballpoint pen inks tagged with rare-earth thenoyltrifluoroacetonates by inductively coupled plasma-mass spectrometry and instrumental neutron activation analysis

Characterization and assessment of inks on sensitive documents for absolute/relative age determination is the challenging forensic problem in spite of practical difficulties. Tagging of ballpoint pen ink with suitable taggant(s) is a unique method to come out with definitive inferences on the detection of forgery in documents written with ballpoint pens. Selection of a proper taggant primarily depends on sensitivity of analytical determination and their absence in normal varieties of ink used for document writing. Rare-earth elements, from all technical considerations can be potential taggant(s) for inks. To ensure more compatibility with ink, 13 rare-earth thenoyltrifluoroacetonate chelates were prepared and characterized. The ballpoint pen inks were tagged with rare-earth thenoyltrifluoroacetonate chelates individually at about 1-100 ppm level depending on sensitivity of element under suitable optimized experimental conditions and instrumental sensitivity. Aliquots of such tagged ink having varying amounts of taggants were analyzed by ICP-MS and INAA. Satisfactory recoveries and a good linear relationship of intensity (signal) against concentrations/amounts were observed. Under the optimized experimental conditions, the detection limits were worked out. This study of tagging metal ions in combination with ICP-MS and NAA as an analytical tool can allow to draw various combination options based on different rare-earth chelates as suitable materials for tagging of ballpoint pen inks for absolute/relative age determination to aid in document related crime examination. The advantages and limitations of proposed analytical techniques are discussed.     

An unusual case of cranial image recognition

We encountered an unusual practical case of craniofacial identification recently. The peculiarity of the case was that the skull itself was not available for examination unlike other such common cases. The supplied material exhibits were, a nearly front view photograph of a skeletonized face and a front view face photograph of the suspected victim. Further, the condition of the skull during taking its photograph was such that its lower and the upper jaws were not in a normal closed condition. The procedure involved in dealing with such a complicated craniofacial identification problem would be quite interesting from a forensic investigator's point of view, since standard methods of skull identification like photo/video superimposition techniques were not at all applicable here. As such, the present case report provides the details of the multiphase procedure adapted by us in dealing with this abnormal case. A solution to this unprecedented craniofacial identification problem was worked out by appropriate exploration of a newly introduced digital image processing technique that is based on craniofacial symmetry perception. The procedure leads to the reconstruction of a superimposable cranial image with upper and lower teeth in normal closed condition for establishment of its identity in usual way.