High-velocity impact of solid objects on Non-Newtonian Fluids.

We investigate which property of non-Newtonian fluids determines the deceleration of a high-speed impacting object. Using high-speed camera footage, we measure the velocity decrease of a high-speed spherical object impacting a typical Newtonian fluid (water) as a reference and compare it with a shear thickening fluid (cornstarch) and a shear thinning viscoelastic fluid (a weakly cross-linked polymer gel). Three models describing the kinetic energy loss of the object are considered: fluid inertia, shear thickening and viscoelasticity.

An image-processing methodology for extracting bloodstain pattern features.

There is a growing trend in forensic science to develop methods to make forensic pattern comparison tasks more objective. This has generally involved the application of suitable image-processing methods to provide numerical data for identification or comparison. This paper outlines a unique image-processing methodology that can be utilised by analysts to generate reliable pattern data that will assist them in forming objective conclusions about a pattern.

A novel, element-based approach for the objective classification of bloodstain patterns.

The classification of bloodstain patterns has been identified as a challenging part of bloodstain pattern analysis due to the lack of a widely accepted and well-defined methodology and the ambiguity often associated with examining bloodstain patterns. The main aim of this study was to develop an objective, science-based method, for classifying bloodstain patterns, through the development of common language that could be used by BPA experts to describe the appearance of the pattern. This novel approach encourages a shift in the mindset of a BPA analyst by bringing them 'back to the basics' by treating components of a bloodstain pattern as discrete, observable and measurable units.

Understanding the visibility of blood on dark surfaces: A practical evaluation of visible light, NIR, and SWIR imaging.

Bloodstains on dark surfaces are often difficult to detect due to a lack of contrast. Infrared photography is in many cases a solution as it enhances the contrast between blood and background. Still, on some surfaces bloodstains cannot be visualized.

Bloodstain Pattern Analysis: implementation of a fluid dynamic model for position determination of victims.

Bloodstain Pattern Analysis is a forensic discipline in which, among others, the position of victims can be determined at crime scenes on which blood has been shed. To determine where the blood source was investigators use a straight-line approximation for the trajectory, ignoring effects of gravity and drag and thus overestimating the height of the source. We determined how accurately the location of the origin can be estimated when including gravity and drag into the trajectory reconstruction.

Effects of CBRN decontaminants in common use by first responders on the recovery of latent fingerprints--assessment of the loss of ridge detail on glass.

Following a CBRN incident, first responders use decontamination procedures to reduce the risk of exposure. The effect of decontamination on forensic trace material has, however, not been fully examined. This study sought to evaluate the effect of five different physical or chemical decontamination materials on the recovery of latent fingerprints.

Forensic quest for age determination of bloodstains.

Bloodstains at crime scenes are among the most important types of evidence for forensic investigators. They can be used for DNA-profiling for verifying the suspect's identity or for pattern analysis in order to reconstruct the crime. However, until now, using bloodstains to determine the time elapsed since the crime was committed is still not possible.

Improving the point of origin determination in bloodstain pattern analysis.

In bloodstain pattern analysis, it is important to know the point of origin (PO) of an impact pattern. This point can be estimated by means of the stringing method, the tangent method, or by commercially available computer programs. In this study, the accuracy of two computer programs was investigated under different conditions.

Comparison of stubbing and the double swab method for collecting offender epithelial material from a victim's skin.

After manual strangulation, epithelial cells originating from the offender can often be found on the skin of the victim. In order to obtain a conclusive DNA profile, it is important to secure as many epithelial cells from the offender and as few epithelial cells from the victim as possible. In this study, two methods for securing offender DNA were compared: the double swab method and an adapted tape-lifting method, so-called stubbing.

Cellular dynamics of EGF receptor-targeted synthetic viruses.

The epidermal growth factor receptor (EGFR) is overexpressed on a high percentage of human carcinomas. EGFR is an attractive therapeutic target for tissue-specific targeting by non-viral vectors in cancer gene therapy. In this study we analyzed and compared the effects of EGFR-targeted and untargeted polyplexes in respect to internalization into EGFR overexpressing HuH7 cells.