Response of hybrid III and Mil-Lx ATD legs to explosively driven vehicle floor loading.

Results are reported of small-scale explosive experiments with Hybrid III and Mil-Lx anthropomorphic test device (ATD) legs. The legs were subject to loadings from deforming metallic plates, driven by explosive loadings to replicate the movement of the floor of a protected vehicle subject to a land-mine strike. The forces measured by the legs are reported and compared between the two different leg types. The benefits of protective measures, including false-floors and commercially available footpads, are compared for their ability to reduce the forces measured in each leg type. It is concluded that the two leg types respond differently to different protective measures and hence cannot be used interchangeably.

Alcohol Clustering Mechanisms in Supercritical Carbon Dioxide Using Pulsed-Field Gradient, Diffusion NMR and Network Analysis: Feedback on Stepwise Self-Association Models.

Co-solvent clustering in complex fluids is fundamental to solution phase processes, influencing speciation, reactivity, and transport. Herein, methanol (MeOH) clustering in supercritical carbon dioxide is explored with pulsed-field gradient, diffusion-ordered nuclear magnetic resonance spectroscopy (DOSY-NMR), and molecular dynamics (MD) simulations. Refinements on the application of self-association models to DOSY-NMR experiments on clustering species are presented. Network analysis of MD simulations reveals an elevated stability of cyclic tetrameric clusters across MeOH concentrations, which is consistent with experimental DOSY-NMR molecular cluster distributions calculated with self-association models that include both cooperative cluster assembly and entropic penalties for the formation of large clusters. Simulations also detail the emergence of cluster-assembly and cluster-disassembly reactions that deviate from stepwise monomer addition or removal. This combination of experiment, simulation, and novel analyses facilitates refinement of models that describe co-solvent aggregation with far-reaching impact on the prediction of solution phase properties of complex fluids.

The development of a quick-running prediction tool for the assessment of human injury owing to terrorist attack within crowded metropolitan environments.

In the aftermath of the London '7/7' attacks in 2005, UK government agencies required the development of a quick-running tool to predict the weapon and injury effects caused by the initiation of a person borne improvised explosive device (PBIED) within crowded metropolitan environments. This prediction tool, termed the HIP (human injury predictor) code, was intended to:--assist the security services to encourage favourable crowd distributions and densities within scenarios of 'sensitivity'; --provide guidance to security engineers concerning the most effective location for protection systems; --inform rescue services as to where, in the case of such an event, individuals with particular injuries will be located; --assist in training medical personnel concerning the scope and types of injuries that would be sustained as a consequence of a particular attack; --assist response planners in determining the types of medical specialists (burns, traumatic amputations, lungs, etc.) required and thus identify the appropriate hospitals to receive the various casualty types. This document describes the algorithms used in the development of this tool, together with the pertinent underpinning physical processes. From its rudimentary beginnings as a simple spreadsheet, the HIP code now has a graphical user interface (GUI) that allows three-dimensional visualization of results and intuitive scenario set-up. The code is underpinned by algorithms that predict the pressure and momentum outputs produced by PBIEDs within open and confined environments, as well as the trajectories of shrapnel deliberately placed within the device to increase injurious effects. Further logic has been implemented to transpose these weapon effects into forms of human injury depending on where individuals are located relative to the PBIED. Each crowd member is subdivided into representative body parts, each of which is assigned an abbreviated injury score after a particular calculation cycle. The injury levels of each affected body part are then summated and a triage state assigned for each individual crowd member based on the criteria specified within the 'injury scoring system'. To attain a comprehensive picture of a particular event, it is important that a number of simulations, using what is substantively the same scenario, are undertaken with natural variation being applied to the crowd distributions and the PBIED output. Accurate mathematical representation of such complex phenomena is challenging, particularly as the code must be quick-running to be of use to the stakeholder community. In addition to discussing the background and motivation for the algorithm and GUI development, this document also discusses the steps taken to validate the tool and the plans for further functionality implementation.