Browsing by Author "Johnson, Stephen"

Now showing 1 - 8 of 8
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    Blast mitigation using polymeric 3D printed auxetic lattice structures - a preliminary study
    (SAGE, 2021-10-18) Critchley, Richard; Hazael, Rachael; Bhatti, Kamran; Wood, David; Peare, Alan; Johnson, Stephen; Temple, Tracey J.
    Protection of critical infrastructure in an urban environment is a challenging task, specifically against the vehicle bourne improvised explosive device threat. To design infrastructure to withstand this evolving threat, novel solutions and advanced materials need to be developed. One such material of interest are auxetics. This study experimentally analysed the mitigation of blast response of auxetic re-entrant honeycomb structures, with geometries varying between −ve 30° and +ve 30° using additive manufacturing (3D printing) techniques and non-explosive loading via shock tube. Re-entrant auxetic structures (−ve 15°) exhibited repeatable blast mitigation of 23% and reduced the transmitted pressure and impulse of the blast wave. Further highlighting their potential application as a protective measure to enhance a structures blast survivability.
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    Chapter 6: Challenges in Fire Investigation
    (Royal Society of Chemistry, 2021-04-15) Johnson, Stephen; Harrison, Karl; Dean, Jason
    This chapter introduces what fire investigation is and why it is necessary. It explores, through a case study and analysis of key issues, the challenges that are faced by fire investigators and those who support them. It finishes with some of the general problems for fire investigation and the more specific issues related to the chemistry of fire scenes.
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    Cranfield University centre of excellence in counter-terrorism
    (2018-10-04) Forth, Shaun A.; Johnson, Stephen; Burrows, Stephanie J.; Sheldon, Robert Philip
    The formation of Cranfield University’s Counterterrorism Centre of Excellence was announced in late summer 2017. It has been established in conjunction with Pool Re, a mutual reinsurer which underwrites over £2 trillion of exposure to terrorism risk in the UK. The centre will provide thought leadership in catastrophic and unconventional terrorism loss assessment and mitigation so as to improve the UK’s economic resilience. We introduce the reinsurance industry for a technical audience to explain the rationale for the Counterterrorism Centre of Excellence. The centre’s aims and some results from preliminary simulations on explosive blast in a complex city centre performed in collaboration with reinsurance broker Guy Carpenter are presented. The prospects for physics-based simulation, for terrorist insurance loss estimation and for encouraging mitigation in reinsurance are outlined.
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    The Emperor's new shroud: international response to CBRN
    (CBRNe World, 2016-02-28) Johnson, Stephen
    Steve Johnson, lecturer on forensic exploitation and intelligence at Cranfield university, wonders whether anyone is coming to help in the event of an international CBRN incident.
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    Fire and Explosives Investigation 2015: Challenges and Opportunities
    (The Knowledge Transfer Network, 2015-10-01) Carlysle, Felicity; Beardah, Matthew; Bryson, David; Johnson, Stephen; Nic Daeid, Niamh; Shipp, Martin
    The Forensic Science Special Interest Group (SIG) has produced this report to provide a resource to the forensic community; identifying the challenges and opportunities within the field of fire and explosives investigation. To produce this report we brought together the fire and explosives community in a day-long workshop, comprising of presentations from a range of speakers, followed by discussion sessions directed by the challenges identified by the speakers and taken from the SIG’s “Forensic Science UK Innovation Database”. The results of these discussions have been compiled into this report.
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    The frequency conundrum: modelling terrorism for the insurance industry
    (Cranfield University, Cranfield Forensic Institute, 2014-12-07) Johnson, Stephen
    Many groups face the challenge of trying to make evidence based decisions about threats such as terrorism. Resource allocation by countries for security and resilience measures are a well-known challenge. While many countries keep this information extremely secret the USA has had its own methods reviewed publically by a number of respected bodies, such as the National Academy of Sciences. As recently as 2010 these reviews have been pretty negative in their conclusions (National Research Council, 2010). The UK and the Netherlands have also had their own national risk register processes reviewed in the open literature. Commensurate with someofthe major national resource allocation challenges; the insurance industry has also faced a need to understand the frequency and impact of terrorism. While some catastrophic terrorism models exist in the market it has been regularly asserted that government backstopping is required because of a number of challenges in terrorism. Data sets are frequently included in this.
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    A review of spiking chemicals used in the first 40 OPCW Proficiency Tests
    (University of Helsinki, 2017-12-11) Johnson, Stephen; Norman, Keith
    From 1997 until 2016, the Organisation for the Prohibition of Chemical Weapons (OPCW) has coordinated 40 proficiency tests for the analysis and identification of intact chemical warfare agents, precursor chemicals, degradation and reaction products. This chapter reviews the chemicals used to spike the proficiency test samples, identifying those that have been used multiple times and the distribution of chemicals based upon the schedules in the chemical warfare convention (CWC). The aim of this chapter is not to provide an easy route to pass the proficiency tests but rather to illustrate the range of chemicals that should be considered during method development and/or validation for laboratories participating in, or considering participating in the OPCW Proficiency Test regime.
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    UAV-assisted real-time evidence detection in outdoor crime scene investigations
    (Wiley, 2022-03-09) Georgiou, Argyrios; Masters, Peter; Johnson, Stephen; Feetham, Luke
    Nowadays, a plethora of unmanned aerial vehicles (UAVs) designs that significantly vary in size, shape, operating flight altitude, and flight range have been developed to provide multidimensional capabilities across a wide range of military and civil applications. In the field of forensic and police applications, drones are becoming increasingly used instead of helicopters to assist field officers to search for vulnerable missing persons or to target criminals in crime hotspots, and also to provide high-quality data for the documentation and reconstruction of the forensic scene or to facilitate evidence detection. This paper aims to examine the contribution of UAVs in real-time evidence detection in outdoor crime scene investigations. It should be highlighted that the project innovates by providing a quantitative comparative analysis of UAV-based and traditional search methods through the simulation of a crime scene investigation for evidence detection. The first experimental phase tested the usefulness of UAVs as a forensic detection tool by posing the dilemma of humans or drones. The second phase examined the ability of the drone to reproduce the obtained performance results in different terrains, while the third phase tested the accuracy in detection by subjecting the drone-recorded videos to computer vision techniques. The experimental results indicate that drone deployment in evidence detection can provide increased accuracy and speed of detection over a range of terrain types. Additionally, it was found that real-time object detection based on computer vision techniques could be the key enabler of drone-based investigations if interoperability between drones and these techniques is achieved.