Explore the vast range of titles available.

With the ever-increasing threat of improvised explosive devices (IEDs) and homemade explosives (HME) both domestically and abroad, detection of explosives and explosive related materials is an area of urgent importance for preventing terrorist activities around the globe. Canines are a common biological detector used in explosive detection due to their enhanced olfactory abilities, high mobility, efficient standoff sampling, and optimal identification of vapor sources. While other sensors based on different principles have emerged, an important concept for the rapid field detection of explosives is understanding key volatile organic compounds (VOCs) associated with these materials. Explosive detection technology needs to be on par with a large number of threats including an array of explosive materials as well as novel chemicals used in the manufacture of IEDs. Within this much needed area of research for law enforcement and homeland security applications, several studies have sought to understand the explosive odor profile from a range of materials. This review aims to provide a foundational overview of these studies to provide a summary of instrumental analysis to date on the various types of explosive odor profiles evaluated focusing on the experimental approaches and laboratory techniques utilized in the chemical characterization of explosive vapors and mixtures. By expanding upon these concepts, a greater understanding of the explosive vapor signature can be achieved, providing for enhanced chemical and biological sensing of explosive threats as well as expanding upon existing laboratory-based models for continued sensor development. [Display omitted] •Detection of explosives and their related materials is an area of urgent importance.•Understanding of volatile organic compounds (VOCs) is key to rapid field detection of explosives.•Enhanced olfactory abilities and high mobility makes canines an excellent tool in biological detection of explosives.•Explosive detection technology must stay up to date with current and expanding threats.•Experimental techniques provide understanding of explosive vapor odor signatures for enhanced sensor development.

\"When Brian Castner, an Iraq War vet, learns that his friend and EOD brother Matt has been killed by an IED in Afghanistan, he goes to console Matt's widow, but he also begins a personal investigation. Is the bomb maker who killed Matt the same man American forces have been hunting since Iraq, known as the Engineer? In this nonfiction thriller Castner takes us inside the manhunt for this elusive figure, meeting maimed survivors, interviewing the forensics teams who gather post-blast evidence, the wonks who collect intelligence, the drone pilots and contractors tasked to kill\"--Dust jacket flap.

Given the frequent use of improvised explosive devices (IEDs) around the world, the study of traumatic blast injuries is of increasing interest. The ear is the most common organ affected by blast injury because it is the body's most sensitive pressure transducer. We fabricated a blast chamber to re-create blast profiles similar to that of IEDs and used it to develop a reproducible mouse model to study blast-induced hearing loss. The tympanic membrane was perforated in all mice after blast exposure and found to heal spontaneously. Micro-computed tomography demonstrated no evidence for middle ear or otic capsule injuries; however, the healed tympanic membrane was thickened. Auditory brainstem response and distortion product otoacoustic emission threshold shifts were found to be correlated with blast intensity. As well, these threshold shifts were larger than those found in control mice that underwent surgical perforation of their tympanic membranes, indicating cochlear trauma. Histological studies one week and three months after the blast demonstrated no disruption or damage to the intra-cochlear membranes. However, there was loss of outer hair cells (OHCs) within the basal turn of the cochlea and decreased spiral ganglion neurons (SGNs) and afferent nerve synapses. Using our mouse model that recapitulates human IED exposure, our results identify that the mechanisms underlying blast-induced hearing loss does not include gross membranous rupture as is commonly believed. Instead, there is both OHC and SGN loss that produce auditory dysfunction.

The use of organic peroxides for the preparation of homemade explosives (HMEs) is common among terrorists due to inexpensive precursor chemicals and simple synthetic procedures. Triacetone triperoxide (TATP) is the most notable peroxide explosive, and has been deployed in several terrorist attacks as explosive filling of improvised explosive devices (IEDs). Forensic identification of TATP in pre-blast and post-blast residues, including on-site analysis, poses significant analytical challenges and induces demand for practicable and sensitive detection techniques. This work presents a concept suitable for laboratory and on-site identification of TATP residues in liquid samples (aqueous TATP synthetic waste) and in gas phase. It is based on TATP enrichment from the aqueous or gas phase using different types of passive samplers (polydimethylsiloxane (PDMS) sampling rods and activated carbon sampling tubes (ACST)) and subsequent identification of the explosive by gas chromatography-mass spectrometry (GC-MS) or GC with positive chemical ionization and tandem MS (GC-PCI-MS/MS) analytical techniques. Additionally, investigation of the stability of TATP in aqueous solutions and of the stability of enriched TATP in passive samplers under different storage conditions, as well as development of TATP re-extraction procedures from passive samplers have been performed in this study. The practical use of passive samplers was demonstrated during and after TATP production processes. Moreover, post-blast sampling of TATP under different conditions of controlled blasting events was investigated using the passive sampling concept. [Display omitted] •A novel sampling approach for triacetone triperoxide (TATP) detection in gas and liquid phase was developed.•Stability and adsorption kinetics of TATP were investigated for activated charcoal and polydimethylsiloxane (PDMS) samplers.•An internal standard GC-PCI-MS/MS quantification method using 13C-labelled TATP was successfully developed.•The application of passive samplers was demonstrated by successful trials in real pre-blast and post-blast scenarios.

An insensitive “fishbone” bridge wire was designed by dividing the bridge wire into a heat collection zone and a heat dissipation zone, leading to the improved safety and reliability of initiating explosive devices. The surface temperature of the bridge wire was investigated by using finite element simulation. The performance of insensitive initiating explosive devices composed of bridge wire was analyzed by using resistance and ignition performance tests. The results show that the designed collector area of the bridge wire is the highest surface temperature during operation, initiating explosive devices consisting of insensitive “fishbone” bridge wires that meet the requirements of insensitivity.

A compact single asymmetric coplanar waveguide feed (ACPW‐fed) dual circularly polarized microstrip antenna that operates at 1.8, 3.9, and 5.2 GHz in the entire operating frequency band 600 MHz–6 GHz for the radar detection of the improvised explosive devices (IEDs) carried by a person is introduced. The proposed novel quasi‐omnidirectional antenna consists of single sided rectangular ring microstrip patch antenna. L‐shaped slots are etched at the two opposite corners of the rectangular ring, introducing new resonance and circular polarization waves at the mid and upper bands, respectively. The achieved dual half‐rectangular ring patch antenna (DHRR‐patch) is loaded with strips of various shapes delicately placed at the center of the radiator, providing new resonance at the upper band and the improvement of the CP features. The matching technique designed based on CPW 50 Ω microstrip transmission line combined with the dual broad band matching techniques through quarter‐wave transformer in conjunction with open stubs and distributed lumped element method constitutes the novelty of the study. Based on quasi‐TEM mn (q‐TEM mn ) mode, ACPW‐fed and CP‐slots are employed to generate CP radiations at the q‐TEM 11 and q‐TEM 21 modes, respectively, while the ground plane width is optimized to enhance axial ratio bandwidth (AR‐BW). Input impedance and radiation pattern calculations of the conventional structure using transmission line and cavity model‐based q‐TEM 01 mode are conducted, respectively. Numerical experiments of the studied monolayer antenna are carried out using Advanced Design System (ADS) Version 2009 environment software employing internal one‐port option to excite the antenna. The prototype of the proposed antenna with a compact dimension (0.27 λ g × 0.38 λ g × 0.02 λ g at 1.8 GHz where λ g is the guided wavelength of the q‐TEM 01 mode) is fabricated on high loss laminate FR4 substrate of volume 43 × 38 × 1.6 (mm 3 ) and relative dielectric constant of 4.4 with simple laboratory‐based traditional printed circuit board (PCB) etching process. Measurement results show a fractional impedance bandwidth (FIBW) of 11.1%, 5.9%, and 7.1%, axial ratio (AR) of 4.6, 2.2, and 0.5 dB, and peak gain of 3.7, 4.7, and 6.1 dBic at 1.8, 4.0, and 5.2 GHz, respectively, demonstrating its suitability for IED detection applications. To verify the efficiency of the proposed model, measured results are compared with the simulated results and good agreement has been established.

Improvised explosive devices (IEDs) can be assembled directly from daily items and are easily purchasable and distributable internationally, owing to the absence of government export permits. Hence, their origins are not readily revealed, and they can pose significant adverse effects despite their low manufacturing costs. In this study, the feasibility of identifying fingerprints and deoxyribo nucleic acid (DNA) profiles in various IEDs and samples is investigated. Additionally, the relative positions of debris are identified to set the scope of on-site inspection at terrorist scenes. All samples are categorized into porous and non-porous materials, and LMG test, extraction, quantification, and short tandem repeat (STR) analysis are conducted to view the DNA profile. For fingerprinting, 1,2-IND and CA are utilized for development, followed by quality-control analysis. Although sample acquisition is impossible in some experiments, DNA profiling and fingerprint analysis are possible for all, thus allowing mapping to be performed. This study shows that even when terrorist bombing occurs, if evidence with minimal damage is detected at the scene, then STR profiles and fingerprints can be obtained at a level suitable for AFIS usage. Furthermore, accumulating mapping results from numerous experiments significantly aids in determining the scope of evidence acquisition. •Debris are successfully obtained after explosion for four sets of evidence.•Profiling of blood shows that explosion does not affect deoxyribonucleic acid.•Fingerprints on non-porous materials show better quality than those on porous ones.•Mapping based on explosive types helps identify debris-acquisition site.

Countering improvised explosive devices (C-IED) is a significant theme of the twenty-first century, particularly in regions with limited governance and a fragile rule of law. Many strands of activity are involved, with human interaction proving difficult to predict. However, Bayesian belief updating (used across several academic fields to provide insight into human behaviours) has never been considered. Given the breadth of C-IED, this research focusses on a state affected by conflict, and where illicit diversion of explosive chemical precursors (ECP) for IED manufacture is supported by the population. It aims to represent (both visually and probabilistically) a methodology by which human relationships could be better understood, thereby promoting belief updating as new evidence becomes available. Such belief updating would refine focus and improve resource mobilisation.

This work proposes a novel Ground Penetrating Radar (GPR) system to detect landmines and Improvised Explosive Devices (IEDs). The system, which was numerically evaluated, is composed of a transmitter placed on a vehicle and looking forward and a receiver mounted on a drone and looking downwards. This combination offers both a good penetration and a high resolution, enabling the detection of non-metallic targets and mitigating the clutter at the air–soil interface. First, a fast ray tracing simulator was developed to find proper configurations of the system. Then, these configurations were validated using a full wave simulator, considering a flat and a rough surface. All simulations were post-processed using a fast and accurate Synthetic Aperture Radar (SAR) algorithm that takes into account the constitutive parameters of the soil. The SAR images for all configurations were compared, concluding that the proposed contribution greatly improves the target detection and the surface clutter reduction over conventional forward-looking GPR systems.