Commonly available nonconventional energetic materials such as H2O2, ammonium nitrates (AN), and reactive materials (e.g., mixtures of metals and metal oxides), as well as conventional plastic explosives primarily made of pentaerythritol tetranitrate (PETN), cyclotrimethylene trinitramine (RDX), cyclotetramethylene-tetranitramine (HMX), and triaminotrinitrobenzene (TATB), are often subjected to...

This study investigates combustion clouds embedded in unconfined spherical explosions. Two charge configurations are considered: a 0.5-g spherical PETN booster surrounded by a spherical shell of either 1-g of TNT solid or of 1-g of Aluminum (Al) powder; these provide the fuel for the combustion process. Detonation of booster disperses the fuel, whose expansion drives a blast wave into the surro...

We propose a fluctuation model of the photochemical initiation of an explosive chain reaction in energetic materials. In accordance with the developed model, density fluctuations of photo-excited molecules serve as reaction nucleation sites due to the stochastic character of interactions between photons and energetic molecules. A further development of the reaction is determined by a competitio...

The innovative Proton-Transfer-Reaction Mass Spectrometry (PTR-MS) technology was invented and developed in the 1990s by scientists at the "Institut für Ionenphysik" at the Leopold-Franzens Universität in Innsbruck and was commercialized by the spin-off company IONICON Analytik GmbH. PTR-MS rapidly became a well established analytical technology in the fields of environmental research, atmosphe...

A rapid method of obtaining photoacoustic spectroscopic signals for trace amounts of surface adsorbed molecules using a nanostructured coupled resonator array is described. Explosive molecules adsorbed on a nanoporous anodic aluminum oxide cantilever, which has hexagonally ordered nanowells with diameters and well-to-well distances of 35 nm and 100 nm, respectively, are excited using pulsed inf...

We have developed a computational approach that yields anharmonic vibrational couplings in molecular crystals. The approach is based on anharmonic vibrational potential-energy surface reconstruction starting from a normal-mode vibrational basis. The method was implemented for semiempirical Hamiltonians with periodic boundary conditions, with applications to crystalline naphthalene and pentaeryt...

This study demonstrates the use of solid-phase microextraction (SPME) to extract and pre-concentrate volatile signatures from static air above plastic explosive samples followed by detection using ion mobility spectrometry (IMS) optimized to detect the volatile, non-energetic components rather than the energetic materials. Currently, sample collection for detection by commercial IMS analyzers i...

The purpose of this work is to assess the feasibility of a homogeneous—or defect-free—initiation mechanism for high energetic materials in which initiation is a direct consequence of the heterogeneity of crystal plasticity at the subgrain scale. In order to assess the feasibility of these mechanisms, we develop a multiscale model that explicitly accounts for three scales: i the polycrystalline ...

The application of biocatalysis for the asymmetric reduction of activated C=C is a powerful tool for the manufacture of high-value chemical commodities. The biocatalytic potential of "-ene" reductases from the Old Yellow Enzyme (OYE) family of oxidoreductases is well-known; however, the specificity of these enzymes toward mainly small molecule substrates has highlighted the need to discover "-e...