Improvised Explosive Research Articles

A REVIEW ON IMPROVISED EXPLOSIVE DEVICES AND THE HUMANITARIAN HARM CAUSED BY THEM

Improvised explosive devices (IEDs) in all their forms have emerged as the most serious threat. These devices can range from simple explosive devices to complex military systems using high-grade explosives. A thorough grasp of the many types of devices and their effects is required for proper mass casualty event planning and management of the complex poly trauma victims that they usually bring. They may wreak havoc on a landscape. Depending on the desired target, they can be initiated in a variety of ways. As a result, there is a pressing need to research and ameliorate the mechanism of extremities harm induced by these devices. These improvised explosive devices are generally uncommonly encountered outside the battlefield. The majorities of vulnerability evaluations presume that an improvised explosive device would attain maximal TNT equivalency and detonate effectively. They are still a popular terrorist weapon. These are unusual explosive weapons that can be used in a variety of ways to cause injury, fatalities, and destruction of property in both military and civilian conditions. IEDs continue to be a domestic menace. The science and damage profile of these devices are described in this review. The humanitarian devastation inflicted by IEDs is thus depicted. KEYWORDS: - improvised explosive devices, explosives, detonation, injury, impact testing, biomechanics, ground penetrating radar, detection, prevention, National Bomb Data Centre

Evaluating Pelvis Response During Simulated Underbody Blast Loading.

In recent conflicts, blast injury from landmines and improvised explosive devices (IEDs) has been the main mechanism of wounding and death. When a landmine or IED detonates under a vehicle (an under-body blast), the seat acceleration rapidly transmits a high load to the pelvis of the occupants, resulting in torso and pelvic injury. Pelvic fractures have high mortality rates, yet their injury mechanism has been poorly researched. Three (3) fresh-frozen male pelvic specimens were tested under axial impact loading. The pelvis was impacted mounted upside down by dropping a 12 kg mass at target impact velocities ranging from 1 to 8.6 m/s with time to peak velocity ranging from 3.8 to 5.8 ms. Resulting fractures were broadly categorized as involving a bilateral pubis rami fracture, a bilateral ischium fracture, and sacroiliac joint disruption. The study provides insights into the type and severity of pelvic injury that may occur over a range of under-body blast (UBB)-relevant loading profiles.

Investigating the combined capability of confocal Raman microscopy and direct analysis in real time-mass spectrometry (DART-MS) for the analysis of intact explosives

The identification of organic and inorganic components used to produce homemade explosives (HMEs) remains a challenge for forensic analysts due to their diverse physicochemical properties that require different instrumentation. This study aims to explore the combined use of direct analysis in real time-mass spectrometry (DART-MS) and Raman microscopy to provide a rapid and reliable analysis of a variety of intact explosives with minimal sample preparation, including 2,4,6-trinitrotoluene (TNT), pentaerythritol tetranitrate (PETN), seven inorganic oxidizing salts, and five smokeless powder constituents. While both techniques were well-suited for the analysis of TNT and PETN, DART-MS had the advantage of being more sensitive compared to Raman spectroscopy for the identification of the organic components contained in smokeless powder. Even though the identification of ammonium-based salts using DART-MS could be achieved, the analysis of low-volatility compounds, such as the inorganic oxidizing salts, was more straightforward with Raman microscopy and did not require sample preparation. This study demonstrates the benefits and limitations of combining Raman microscopy and DART-MS for the analysis of intact explosives and precursors. Using this combined approach enabled the rapid identification of various organic and inorganic explosives and precursors with minimal sample preparation.

Использование различных вычислительных подходов к моделированию показателя санитарных потерь при террористических актах в мире на период до 2030 г.

Summary. The aim of the study is to investigate and to justify the application of various computational approaches to forecasting the value of probable sanitary losses as a result of terrorist acts in the world for the period up to 2030. Materials and research methods. Materials of the study were archival data of the generalized database (GTD, Global Terrorism Database), containing information on more than 200 thousand cases of terrorist activities registered in 1970-2020. The methods and ways of committing terrorist attacks, as well as the objects they were aimed at were analyzed. The forecast model of the probable sanitary losses as a result of terrorist acts was built for the period from 2021 to 2030 inclusive. The data set was analyzed by various operators of MS Excel spreadsheet aggregator using the functions “FORECAST SHEET”, “FORECAST”, “TREND”, “GROWTH”, “LINEST” and “LOGEST “. Results of the study and their analysis. It is observed that the number of probable sanitary losses due to terrorist attacks in the world may increase by 35.28% by 2030. The methods of committing terrorist acts most significant in the long term were identified. These are the use of explosives in the form of industrial and improvised explosive devices, as well as firearms, especially against the military and police. It is concluded: the obtained results of the study should be used to correct the established structure of the incoming flow of sanitary losses and to determine the optimal composition of multidepartmental medical forces and means necessary to eliminate medical and sanitary consequences of terrorist acts.

Realistic simulation of GPR for landmine and IED detection including antenna models, soil dispersion and heterogeneity

AbstractGround‐penetrating radar is an effective tool for detecting landmines and improvised explosive devices, but its performance is strongly influenced by subsurface properties as well as the characteristics of the target. To complement or replace labour‐intensive experiments on test sites, cost‐efficient electromagnetic wave propagation simulations using the finite‐difference time‐domain method are being increasingly used. However, to obtain realistic synthetic data, accurate modelling of signal alteration caused by dispersion, scattering from soil material, target contrast, shape, and inner setup, as well as the coupling effects of the antenna to the ground is required. In this study, we present a detailed three‐dimensional model of a shielded ground‐penetrating radar antenna applied to various scenarios containing metallic and non‐metallic targets buried in different soils. The frequency‐dependent intrinsic material properties of soil samples were measured with the coaxial transmission‐line technique, while a discrete random media was used to implement the heterogeneity of a gravel based on its grain‐size distribution. Our simulations show very good agreement with experimental validation data collected under controlled conditions. We accurately reproduce the amplitude, frequency, and phase of target signals, the subsurface background noise, antenna crosstalk and associated interference with target signals, and the effect of antenna elevation. The approach allows for a systematic investigation of the effects of soil, target, and sensor properties on detection performance, providing insight into novel and complex ground‐penetrating radar scenarios and the potential for a wide range of simulation possibilities for demining with ground‐penetrating radar. These investigations have the potential to improve the safety and effectiveness of landmine and improvised explosive device detection in the future, such as building a database for training deminers or developing automatic signal pattern recognition algorithms.

Impact of Blast Overpressure on the Pharmacokinetics of Various Antibiotics in Sprague Dawley Rats.

Combat injuries are complex and multimodal. Most injuries to the extremities occur because of explosive devices such as improvised explosive devices. Blast exposure dramatically increases the risk of infection in combat wounds, and there is limited available information on the best antibiotic treatments for these injuries. We previously demonstrated that mice exposed to blast displayed a delayed clearance of cefazolin from the plasma and liver; further semi-mechanistic modeling determined that cefazolin concentrations in the skin of these mice were reduced. Our objective was to investigate the effects of blast on the pharmacokinetics of antibiotics of different types used for the treatment of combat wounds in the rat model. Male Sprague Dawley rats were exposed to blast overpressure followed by injection of a bolus of animal equivalent doses of an antibiotic (cefazolin, cefepime, ertapenem, or clindamycin) into the tail vein at 1-hour post-blast exposure. Blood was collected at predetermined time points via repeated sampling from the tail vein. Animals were also euthanized at predetermined time points, at which time liver, kidney, skin, and blood via cardiac puncture were collected. Antibiotic concentrations were determined by ultra-performance liquid chromatography-tandem mass spectrometry. Blast-exposed rats exhibited a similar rate of clearance compared to non-blasted rats in the blood, liver, kidney, and skin, which is inconsistent with the data regarding cefazolin in blast-exposed mice. Our results in rats do not recapitulate our previous observation of delayed cefazolin clearance in mice following the blast overpressure exposure. Although using rats permitted us to collect multiple blood samples from the same animals, rats may not be a suitable model for measuring the pharmacokinetics of antibiotics following blast. The interpretation of the results may be challenging because of variation in data among rat subjects in the same sample groups.

Assessing the strengths and limitations of quantitative micromorphometry for the forensic examination of small arms propellant towards brand identification.

Smalls arms propellants (SAP) also known as canister powders are readily accessible and cost-effective materials that firearms enthusiasts can acquire for the legitimate assembly of ammunition. These attributes also make SAPs advantageous for the construction of improvised explosive devices (IEDs). Thus, there is a need to develop robust metrics for the characterization of propellants to provide investigative leads as well as for comparisons between known and recovered residues. The goal of this research was to investigate the utility of a high-throughput, non-destructive, and low-cost quantitative automated image analysis routine for the characterization and discrimination of SAP. For this project, 204 one-pound canisters of smokeless propellant (powder) were acquired from local and online sources. These samples represent nine manufacturers and 154 unique brands. From this set, five brands were selected to assess the intra- and inter-lot variability. Eight parameters, which encompass size- and shape-dependent metrics were measured for each sample. A total of ∼85,000 granules (∼680,000 measurements) were analyzed using linear discriminant analysis. A detailed assessment of the variables shows that the size-dependent metrics provide the greatest amount of sample discrimination. Overall accuracy of the method to correctly classify a test subset of data to the brand level is ∼84.72%. The results from this study provide a framework in which to interpret smokeless propellant micromorphometry in the context of intelligence purposes for initial stages of criminal investigations, and for traditional comparisons between known and unknown samples.

Chlorate‐based homemade explosives: A review

AbstractChlorates and perchlorates, inorganic salts known for their potent oxidizing properties, find utility in various products such as pyrotechnics, matches, and disinfectants. Their chemical properties also make them suitable for homemade explosives, resulting in their extensive use by criminals. Hence, the forensic analysis of these compounds is vital for investigating crimes involving their utilization. A wide array of analytical techniques is available for detecting and quantifying these substances, offering forensic investigators an extensive toolkit to effectively analyze and identify chlorates and perchlorates in various samples. Recent research highlights the potential for leveraging the information obtained from analyzing these materials, including for intelligence purposes. The future of forensic analysis in this domain lies in extracting additional information, such as source attribution, through methods like chemometrics, thereby enhancing forensic intelligence capabilities.This article is categorized under: Forensic Chemistry and Trace Evidence > Explosive Analysis Forensic Chemistry and Trace Evidence > Trace Evidence Forensic Chemistry and Trace Evidence > Emerging Technologies and Methods

22 Cognitive and Psychological Profiles of a Specialized Military Force

Objective:The Explosive Ordinance Disposal (EOD) community within the US Military is a specialized force in charge of the most fundamental aspects of the military operations in combat which include disarming and safely disposing explosive threats. EOD technicians have provided critical protection for our military and civilians exposed to improvised explosive devices (IEDs), which became the signature threat of both Afghan and Iraq wars. The nature of the job puts EOD technicians at high risk for blast exposures (from training and combat) resulting in traumatic brain injury (TBI) and sub-concussive head impact. Further, this population is exposed to high levels of combat with psychologically traumatic events. Given the groups neurological and psychological risk factors as well as their critical role in combat, we hypothesized that EOD technicians will present with increased psychological and neurobehavioral symptoms as well decreased cognitive functioning compared to other military personnel.Participants and Methods:Participants were recruited from a military hospital with at least one diagnosed mild traumatic brain injury (MTBI). Exclusion criteria included TBI greater then mild severity and invalid performance on the Rey-15. Final sample included 10 EOD and 90 other military.CognCognitive measures included Hopkins Verbal Learning Test-Reviseitive measures included Hopkins Verbal Learning Test-Revised (HVLT-R); DKEFS Color Word Condition 4 Switching (CW4), Trail Making Condition 3 Letter Sequencing (TM3) and Condition 4 Switching (TM4), and Paced Auditory Serial Addition Test (PASAT). Self-report measures included the Neurobehavioral Symptom Inventory (NSI), Key Behaviors Change Inventory (KBCI), Post-Traumatic Stress Disorder Checklist (PCL-M), Patient Health Questionnaire (PHQ), Combat Exposure Scale (CES) and Blast Exposure Threshold Survey (BETS). The Ohio State University Traumatic Brain Injury Identification Method (OSU) assessed TBI history.Results:EOD were older (EOD M=38.4, SD=4.06; Others M=33.32, SD=8.08; p=0.05), had a higher pre-morbid IQ (EOD M=110.90, SD=7.64; Other M=101.59, SD=10.55; p=0.008), more combat deployments (EOD M=5.5, SD=2.37; Others M=3.55, SD=2.98; p=0.049) and exposure to wartime atrocities (CES, p=0.003). They had greater number of MTBI (OSU EOD M=6.67, SD=3.33; Other M=3.67, SD=2.34; p=0.007), blast related MTBI (OSU-TBI EOD M=2.33, SD=1.63; Other M=0.67, SD=0.91; p<0.001), and exposure to large explosives (BETS p<0.0001). EOD reported better attention skills (KBCI Inattention, p=0.016, d=0.82; Impulsivity p=0.047, d=0.67). There was a trend for EOD to have lower neurobehavioral symptoms (NSI Total, d=0.32), post-traumatic stress (PCL d=0.39), and depression (PHQ d=0.50); however, despite the moderate effect sizes (p’s >0.05). EOD presented with significantly better scores on DKEFS TMT3 (p=0.037, d=0.70), HVLT-R-Total (p=0.001, d=1.10), HVLT-R-Delayed (p=0.03, d=0.74), and attention/executive functioning skills (PASAT p=0.001, d=1.12). DKEFTS CW4 Switching (d=0.51) and TMT4 Switching were approaching significance (d=0.61) with EOD performing better.Conclusions:As expected, the EOD sample in this study had higher number of combat deployments, greater exposure to combat atrocities (e.g., death), higher levels of exposure to large explosives, as well as a higher number of MTBI. Inconsistent with our hypotheses, despite these psychological and neurological risk factors, EOD performed better on cognitive measures of memory, attention and executive functioning. They also reported less problems with inattention and impulsivity. Results may reflect the impact of psychological and cognitive resiliency.

Stationary Explosive Trace Detection System Using Differential Ion Mobility Spectrometry (DMS).

Detecting trace amounts of explosives is important for maintaining national security due to the growing threat of terror attacks. Particularly challenging is the increasing use of homemade explosives. Therefore, there is a constant need to improve existing technologies for detecting trace amounts of explosives. This paper describes the design of a stationary device (a gate) for detecting trace amounts of explosives and explosive taggants and the design of differential ion mobility spectrometers with a focus on the gas system. Nitromethane (NM), trimeric acetone peroxide (TATP), hexamine peroxide (HMTD), and explosive taggants 2,3-dimethyl-2,3-dinitrobutane (DMDNB) and 4-nitrotoluene (4NT) were used in this study. Gate measurements were carried out by taking air from the hands, pocket area, and shoes of the tested person. Two differential ion mobility spectrometers operating in two different modes were used as explosive detectors: a mode with a semi-permeable membrane to detect explosives with high vapor pressures (such as TATP) and a mode without a semi-permeable membrane (using direct introduction of the sample into the measuring chamber) to detect explosives with low vapor pressures (such as HMTD). The device was able to detect trace amounts of selected explosives/explosive taggants in 5 s.

Security Aspects of Improvised Explosive Devices. The Ukrainian Case Study

Though Improvised Explosive Devices (IEDs) are commonly attributed to attacks carried out by terrorists in the Middle East, IEDs were also used in the Ukrainian conflict and extremely limited research touches upon the issue. There is a hypothesis that IED events were not mainly focused on killing but rather on striking terror and sowing chaos among the local populace to persuade it to withdraw its support for the Ukrainian government. This article presents an analysis of IEDs as a unique weapon, the possible intensions behind their occurrence in Ukraine at a particular point in time, and the methods of identifying IED use in Ukraine based on the Global Terrorism Database (GTD) and the authors' database (TAD). Both the imprecision and uncertainty relative to GTD’s classification were discussed, as it served only as the starting point for data evaluation, yielding informative results, although containing little information related to the IEDs directly.

Identification of Absorption Spectrum for IED Precursors Using Laser Photoacoustic Spectroscopy.

Among the many commonly encountered hazards, improvised explosive devices (IEDs) remain the primary threat to military and civilian personnel due to the ease of their production and the widespread availability of their raw materials and precursors. Identifying traces of potential precursors is the first step in developing appropriate control measures. An interesting approach is to identify the precursors that are released around the site as they are handled and transformed into the final IEDs. CO2 laser photoacoustic spectroscopy can offer the spectral characterization of a number of explosives-related compounds without sample preparation. Benzene, toluene, acetone, and ethylene glycol absorption spectra were determined in the IR region between 9.2 and 10.8 µm. Each substance emitted a unique photoacoustic response corresponding to its chemical composition that could be further used to identify the explosive material.

Layout considerations on compound survival shelters for blast mitigation: A finite-element approach

The safety of both military personnel and equipment in unstable regions has for a long time been a major issue and concern. Protective shelters with multiple configurations have been widely used to meet safety requirements. Since military compounds are subjected to different types of threats, such as the detonation of improvised explosive devices (IED), a good understanding of the response of such shielding structures to blast waves is critical. A three-dimensional finite element (FE) model of a corner-entry ISO 20 ft container HESCO-Bastion survival shelter is developed, validated and tested under the external detonation of explosive charges. The FE model is validated against experimental data and used to investigate the protective performance of the shelter by considering several design-related parameters, such as charge location, roof extension, interior corridor dimensions and the effect of venting and its location. Results are discussed in terms of peak overpressure and maximum impulse at discrete locations around the container, and it is found that the shelter is the least efficient in mitigating the blast load propagation when the explosive material is at an angle of 45° to the entrance. Also, while the protective roof at the entrance plays a significant role in protecting the container from air-borne threats, it is observed that it contributes to higher pressure and impulse data within the shelter, for detonations at ground level, with impulse amplifications as high as 94% when fully covering the entrance area. Contrarily, varying the distance between the container and the HESCO-Bastions is found to have minimal impact on the impulse, while naturally decreasing the peak pressure for increasing distances. Venting (through openings) can lead to up to 95% reduction in the peak pressure, whilst not affecting the impulse.

Electroanalysis of ethyl-centralite propellant stabiliser at magnetic nanoparticle modified glassy carbon and screen-printed electrodes with extension to forensic firearm residue analysis

Electroanalysis of organic residues of the propellant stabiliser ethyl-centralite (1,3 diethyl-1,3 diphenyl urea, EC) generated from the discharge of a weapon or improvised explosive devices is examined. Comparative effects of an electrode modifier, nanoparticles of magnetite (Fe3O4), on the sensor performance was of interest, with customised printed prototype development and analysis of organic firearm residue (OFAR) samples. Differential pulse voltammetry (DPV) calibration studies realised sensitivity of 6.37 × 10−2 μA∙μM−1 (over the concentration range 2.5–50 μM) at the magnetic nanoparticle modified electrode, representing a 1.65 fold signal increase relative to unmodified electrodes with limit of detection 4.39 µM. Inclusion of the OFAR co-existing diphenylamine (DPA) stabiliser realised signal discrimination and sensitivity of 7.49 × 10−2 and 5.49 × 10−2 μA∙μM −1 for DPA, and EC respectively, using DPV over the same range. The work culminated in the qualitative and quantitative analysis of propellant stabilisers in firearm residue acquired from a single base shotgun shell, with recovery from a target sample cloth, together with unburnt propellant, making promising first steps towards a customised screen-printed prototype for use by forensic professionals. Scanning electron microscopy/energy dispersive spectroscopy and atomic force microscopy were employed for particle confirmatory analysis.

Evaluation of canine training aids containment for homemade explosive and components by headspace analysis and canine testing.

While canines are most commonly trained to detect traditional explosives, such as nitroaromatics and smokeless powders, homemade explosives (HMEs), such as fuel-oxidizer mixtures, are arguably a greater threat. As such, it is imperative that canines are sufficiently trained in the detection of such HMEs. The training aid delivery device (TADD) is a primary containment device that has been used to house HMEs and HME components for canine detection training purposes. This research assesses the odor release from HME components, ammonium nitrate (AN), urea nitrate (UN), and potassium chlorate (PC), housed in TADDs. Canine odor recognition tests (ORTs) were used with analytical data to determine the detectability of TADDs containing AN, UN, or PC. Headspace analysis by gas chromatography/mass spectrometry (GC/MS) with solid-phase microextraction (SPME) or online cryotrapping were used to measure ammonia or chlorine, as well as other unwanted odorants, emanating from bulk AN, UN, and PC in TADDs over 28 weeks. The analytical data showed variation in the amount of ammonia and chlorine over time, with ammonia from AN and UN decreasing slowly over time and the abundance of chlorine from PC TADDs dependent on the frequency of exposure to ambient air. Even with these variations in odor abundance, canines previously trained to detect bulk explosive HME components were able to detect all three targets in glass and plastic TADDs for at least 18 months after loading. Detection proficiency ranged from 64% to 100% and was not found to be dependent on either age of material.

Blast resistance of ultra high performance concrete-filled steel tube (UHPC-FST) pier against vehicular bombs

Bridge piers will lose axial bearing capacities under accidental or deliberate explosions, which may cause partial or even multi-span collapse of the bridges. Compared with the conventional RC pier, the ultra high performance concrete-filled steel tube (UHPC-FST) pier exhibits superior strength, ductility, and durability, thus having promising applications in the field of blast-resistant bridges. This study aims to experimentally and numerically examine the blast-resistant performance of the UHPC-FST pier under the near-range explosion of Vehicle-Borne Improvised Explosive Devices (VBIED). Firstly, a prototype UHPC-FST pier with earthquake intensity VII was designed following the Chinese specifications, and four 1/4-scale UHPC-FST specimens were scaled and fabricated accordingly. The near-range explosion and succeeding axial compression test were carried out on the specimens with TNT masses of 3 kg, 4 kg, 7 kg, and 10 kg, respectively. Then, full parameters of the Karagozian & Case (K&C) concrete material model applicable to UHPC were systematically calibrated based on the available test data, and the refined finite element (FE) models were established correspondingly based on the explosion and axial compression test. The verification of FE modeling approach was verified by comparing the failure modes and axial force–displacement curves of specimens obtained from the numerical simulation with the test. Finally, two types of VBIED (compact sedan and cargo van) and three standoff distances were selected from the report FEMA-428 and Chinese specifications, and six explosion scenarios were designed correspondingly. The shock wave propagation, shock wave-pier interaction, and the damage evolutions of prototype piers were numerically reproduced. The blast-resistant performance of the prototype UHPC-FST pier was assessed from the aspect of the failure modes and residual axial bearing capacities, which were quantitatively compared with those of conventional RC pier with identical earthquake intensity.

A novel standard for forensic elemental profiling of polymers by LA-ICP-TOF-MS

Plastic materials are often found on crime scenes in improvised explosive devices. Determining the trace-elemental composition of polymer parts may yield discrimination between samples from different sources. Although quantitative laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) is well established for forensic glass analysis, the lack of sufficiently reproducible and homogeneous reference standards hampers accurate quantification of trace elements in polymers. Therefore, the present study introduces a new standard for quantitative elemental profiling of polymers. A novel approach was developed for producing polyethylene (PE), polystyrene (PS), and polyvinyl chloride (PVC) standards containing 23 elements at three concentrations. The LA-ICP-TOF-MS measurements showed excellent linear response with R2 > 0.99 for almost all elements and polymer matrices. Additionally, homogeneity was significantly improved to an average of 10% within-, and 17% between-sample variation. PVC and PE matrices presented the best homogeneity which was confirmed by line ablations. The added value of the standards was demonstrated by evaluating a set of realistic forensic polymer evidence items. The between-run variation was substantially reduced from 42% in absence of calibration to 30% when correcting with an elemental internal standard and even to 24% when applying the novel standards. In addition, its discriminating power between different classes was increased, as demonstrated by ANOVA and principal component analysis. In conclusion, this study shows the feasibility of using a novel standard for quantitative analysis of chemical attribution signatures of trace elements in polymers by LA-ICP-TOF-MS. The use of the polymer standards significantly improves classification and forensic comparison of polymer-based evidence.

Drones in Modern Warfare: Utilization in India-Pakistan Cross-Border Terrorism and Security Implications

The drone is the latest entrant in the ever-volatile India-Pakistan cross-border terrorism imbroglio. According to media reports, the use of the drones to send payloads, weapons, and improvised explosive devices (IEDs) has substantially increased in the last two years. This technology has been a boon for the terrorist outfits based in Pakistan which are using Chinese drones to drop payloads and plan terrorist attacks in Indian cities. This article discusses how the drone is emerging as a new frontier of warfare; drone development in India and Pakistan; emerging instances of cross-border terrorism via drones; security implications therein and also possible solutions which lie ahead.

Experimental and numerical investigation on alternatives to sandy gravel

The NATO agreement STANAG 4569 defines the protection levels for the occupants of logistic and light armored vehicle. The Allied Engineering Publication, AEP-55, Volume 2 document outlines the test conditions for underbelly improvised explosive device (IEDs), which must be buried in water-saturated sandy gravel. The use of sandy gravel has some drawbacks, for instance reproducibility, time consumption, and cost.This paper focuses on the investigation of four alternatives to sandy gravel, which could produce similar specific and cumulative impulses: a concrete pot filled with water, a concrete pot filled with quartz sand, a steel pot without filling and a concrete pot filled with glass spheres (diameter 200 μm–300 μm) and different water contents. The impulses are measured with a ring technology developed at the Fraunhofer EMI.A numerical soil model based on the work of Marrs, 2014 and Fišerová, 2006 and considering the soil moisture was used to simulate the experiments with glass spheres at different water contents, showing much better agreement with the experiments than the classical Laine & Sandvik model, even for high saturation levels. These results can be used to create new test conditions at original scale that are more cost-effective, more reproducible and simpler to manage in comparison to the current tests carried out with STANAG sandy gravel.

Silica Nanoparticle/Fluorescent Dye Assembly Capable of Ultrasensitively Detecting Airborne Triacetone Triperoxide: Proof-of-Concept Detection of Improvised Explosive Devices in the Workroom.

We describe the proof of concept of a portable testing setup for the detection of triacetone triperoxide (TATP), a common component in improvised explosive devices. The system allows for field testing and generation of real-time results to test for TATP vapor traces in air by simply using circulation of the air samples through the sensing mechanism under the air conditioning system of an ordinary room. In this way, the controlled trapping of the analyte in the chemical sensor gives reliable results at extremely low concentrations of TATP in air under real-life conditions, suitable for daily use in luggage storage for airlines or a locker room for a major sporting event. The reported fluorescent methodology is very sensitive and selective, allowing for the trapping of triacetone triperoxide in the chemical sensor to give reliable results at very low concentrations in air under ambient conditions, by comparing the fluorescence of the material before and after exposition to TATP traces in air.