Explosive Trinitrotoluene Research Articles

The Study on Synthesis and Characterization of Insensitive Energetic Materials Based on 5‐(5‐Nitro‐1H‐1,2,4‐Triazol‐3‐yl)‐1H‐Tetrazole

ABSTRACTThe design and synthesis of insensitive energetic materials are a necessary and challenging work. The synthesis of novel nitrogen‐rich salts based on 5‐(5‐Nitro‐1H‐1,2,4‐triazol‐3‐yl)‐1H‐tetrazole (H2NTT) has been presented. Structural characterization of these two salts was accomplished by utilizing NMR, MS, IR spectroscopy, and X‐ray diffraction. The standard heats of formation were calculated, and the differential scanning calorimetry (DSC) and sensitivity test were carried out. Their detonation performances were estimated by EXPLO 5 program. These newly synthesized salts showed highly positive heat of formation and low sensitivity. It is noteworthy that the diaminoguanidine salt b exhibited good detonation performance superior to traditional explosive TNT (Trinitrotoluene), making it a prospective candidate for insensitive energetic material.

Explosion power evaluation based on the energy absorption characteristics of expansion tube structure

With the rapid advancement of the new generation of ammunition, the evaluation of the explosion power has received worldwide attention. To assess the power of blast waves generated by explosives, an explosion power evaluation method, based on analyzing the energy absorption characteristics of an expansion tube structure (ETS), is proposed in this paper. Explosion experiments and numerical simulations are carried out to investigate the energy absorption characteristics of the ETS under blast loading, and a verified theoretical model is developed to predict the energy absorption per unit area (EAUA) of the ETS. The parametric studies demonstrate a quadratic positive correlation between the EAUA of ETS and the explosive mass/(standoff distance)2, as well as a linear correlation with the reciprocal of areal density of the ETS. However, the effect of equivalent strength of the ETS on the EAUA is less significant. Furthermore, an explosion power model is established using dimensional analysis. The evaluation errors of this model in estimating explosive mass are -11.34 % to 14.67 % when compared with the actual mass of the explosive trinitrotoluene (TNT), and it also shows errors of -13.94 % to 0.97 % when compared with the explosive mass estimated through free field overpressure sensors, which all fall within the range of ±15 %, demonstrating that the proposed method meets the accuracy requirements for explosion power evaluation. This research provides a novel and accurate methodology for evaluating the power of ammunition in explosion field, especially for testing in extreme conditions.

Dinitrophenyl-oxadiazole compounds: Design strategy, synthesis, and properties of a series of new melt-cast explosives

Melt-cast explosives are the most widely used energetic materials in military composite explosives, researchers have been unremittingly exploring high-energy and insensitive melt-cast explosives. In this work, a series of dinitrophenyl-oxadiazole compounds were designed and prepared. These compounds have an ideal low melting point (80–97 °C), good detonation performance (detonation velocity D = 6455–6971 m/s, detonation pressure P = 18–19 GPa) and extreme insensitive nature (impact sensitivity ≥60 J, friction sensitivity >360 N). All these compounds were well characterized by nuclear magnetic resonance, fourier transform infrared spectroscopy, elemental analysis. Compounds 2, 3 were unambiguously confirmed by X-ray single crystal diffraction analysis. As a result, their overall properties are superior to traditional melt-cast explosives trinitrotoluene (TNT) and dinitroanisole (DNAN) which may have excellent potential applications in insensitive melt-cast explosives.

Мodel of diffraction of electromagnetic waves on explosive objects

A model of electromagnetic wave diffraction on an explosive object without metal structural substances is proposed. The properties of the materials of the most common anti-personnel mines were analyzed and it was established that their shell is dielectric, and explosive substances are divided into two groups depending on their dipole moment. In particular, the explosive substances such as hexogen, pentaerythritol tetranitrate, and mercury fulminate with zero dipole moment and according to their electromagnetic properties, they belong to ideal dielectrics. The explosives trinitrotoluene, tetryl, lead trinitroresorcinate, and lead azide should be considered as low-loss dielectrics. An electrodynamic model was built to calculate the reflection coefficients and the passage of electromagnetic plane waves of the microwave range through the multilayer structure of an explosive object. To determine the equivalent wave resistance of the multilayer structure of an explosive object, the use of the theory of long lines is proposed. It is established that for microwave radiation, the layers of the case of explosive objects made of dielectric substances can be neglected due to their small thickness. The modeling results show that most anti-personnel mines have a low reflection coefficient, which makes them difficult to detect, but at the same time increases the amount of energy that can pass deep into the body of the explosive substance. It has been shown that explosive objects with dipole explosive substances are capable of absorbing electromagnetic radiation energy. The obtained results allow us to qualitatively assess the susceptibility of explosive substances to their remote detonation by irradiation with powerful pulses of electromagnetic radiation in the microwave range.

Scaling law of deep-sea trinitrotoluene (TNT) explosion

Understanding the dynamic characteristics of deep-sea explosions is essential to improve the survivability and combat capability of deep-sea equipment. In this paper, by considering the practical underwater conditions, we investigated the mechanical effects of the deep-sea 1-kg-trinitrotoluene (TNT) explosion with charge depths ranging from 1 to 10 km through numerical simulation and dimensional analysis. The shock wave overpressure, the positive overpressure pulse, the bubble pulse, and the energy distribution for various depth explosions were analyzed systematically. The simulation results showed that the charge depth was negligible for the peak overpressure of the shock wave. However, the positive overpressure pulse, the shock wave energy, the maximum bubble radius, the bubble energy, and the bubble period decrease significantly with increasing the charge depth. Then, the dimensional analysis for deep-sea TNT explosion was performed to reveal the key dimensionless parameters, from which the scaling laws of the shock wave overpressure and the overpressure pulse were obtained. By fitting the simulation results, the dimensionless equations were proposed, providing an effective method for predicting the peak overpressure and the positive overpressure pulse of shock wave for underwater TNT explosion over a wide range of water depths.

Chemical Blast Standard (1 kg)

Abstract Chemical explosions create blast waves with large overpressure disturbances. It is important to develop a standard blast model based on data to accurately predict acoustic blast-wave amplitudes near detonations and invert for explosion energy from distant observations of blast-wave signals. However, open data from large, controlled chemical explosions with reliable ground truth can be challenging to find. The lack of access to such data could limit the number of contributions to related research and potentially stifle the rate of discoveries or validation of existing models. To address these data scarcity problem, we have curated and compiled a standardized set of 817 blast-wave waveforms from 19 distinct high-explosive events. The blast-wave waveforms are standardized to a 1 kg trinitrotoluene explosion using scaling laws and corrections for location effects. A brief overview of the dataset is presented along with explosion feature models as well as recommendations for extracting explosion features. The resulting dataset is distributed to an open repository in both Seismic Analysis Code and pandas DataFrame formats containing the waveforms, the scaled distances, and the sample rates.

Boosting Laser-Ignited Combustion Performance of Energetic Materials with Low Sensitivity: Integration of Triazene-Bridged Triazole with Oxygen-Rich Moieties via Noncovalent Self-Assembly

It has long been a driving force in the development of energetic materials to hunt for novel high-energy density materials (HEDMs) with high energy and good stability. Recently, the noncovalent self-assembly strategy of energetic anions and cations to generate HEDMs is an effective strategy for introducing an oxidizer and fuel separately into the energy system. In this study, bis(1,2,4-triazolyl)triazene containing triazene (−N═N═NH−) and oxidant molecules (i.e., HNO3 and HClO4) were selected as high-energy ions to develop new high energy materials by using noncovalent self-assembly. The experimental results showed that three exemplary compounds possess excellent detonation pressure and detonation velocity (PC–J: 22.8–29.3 GPa and D: 7425–8135 m s–1), which are comparable to the classical explosive trinitrotoluene (TNT) (PC–J: 19.5 GPa and D: 6881 m s–1) as well as 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX) (PC–J: 34.9 GPa and D: 8795 m s–1). Moreover, 1 and 3 exhibit low mechanical sensitivities (IS: 40 J and IS: 70 J). Thus, 1 and 3 have great potential as insensitive energetic materials. Especially, these energetic assemblies have excellent laser-ignited combustion properties and can be used as candidates for low sensitivity propellants.

Ship Blast Analysis

Naval vessels and Submarines structures in their fighting role are susceptible to explosion of torpedoes, mines, TNT etc. The damage inflicted by Contact explosion consists of direct shock wave damage to hull, whipping damage to keel and mechanical damage to onboard equipment and associated systems. The order to design a shock resistant structure, it is important to simulate these structures and loads and then subsequently analyze the same to predict the response (as performing experiments would be expensive). The TNT (Trinitrotoluene) explosion analysis of large structures like ships could be considered as one of the most complicated numerical analysis. Loads can be calculated by using published empirical formulas, which are complicated if calculated the large structure. By using of the FE Software ANSYS, backed up with in the developed software, for Explosion analysis of structures.

Integrating the MasSpec Pen with Sub-Atmospheric Pressure Chemical Ionization for Rapid Chemical Analysis and Forensic Applications.

Analytical methods that allow rapid, sensitive, and specific chemical measurements are central to forensic analysis and essential to accelerating compound screening and confirmation. We have previously reported the development of the MasSpec Pen technology as an easy-to-use and disposable hand-held device integrated to a mass spectrometer for direct analysis and molecular profiling of biological samples. In this Technical Note, we describe a new apparatus that integrates the MasSpec Pen device with a subatmospheric pressure chemical ionization (sub-APCI) source and an ion trap mass spectrometer for detection and semiquantitative analysis of forensic-related compounds. Coupling the MasSpec Pen device to a sub-APCI source allowed semiquantitative analysis of the drugs cocaine and oxycodone, the agrochemicals atrazine and azoxystrobin, and the explosives trinitrotoluene and dinitroglycerin in under 20 s. Using chemical ionization, improved reproducibility and sensitivity for targeted chemical detection and compound identification was achieved while maintaining the user-friendly features of the hand-held MasSpec Pen device. Limits of detection in the high picogram to low nanogram range were obtained for the compounds analyzed, which are within the range of federal screening cutoffs and those reported for other ambient ionization MS techniques. Altogether, the MasSpec Pen sub-APCI system described enabled rapid and semiquantitative chemical analysis for forensic applications and could be further adapted and applied to other areas of chemical testing.

Analysis of the biodegradation and phytotoxicity mechanism of TNT, RDX, HMX in alfalfa (Medicago sativa)

The aim of this study was to reveal the mechanism underlying the toxicity of TNT (trinitrotoluene), RDX (cyclotrimethylene trinitroamine), and HMX (cyclotetramethylene tetranitramine) explosives pollution in plants. Here, the effects of exposure to these three explosives were examined on chlorophyll fluorescence, antioxidant enzyme activity, and the metabolite spectrum in alfalfa (Medicago sativa) plants. The degradation rates for TNT, RDX, and HMX by alfalfa were 26.8%, 20.4%, and 18.4%, respectively, under hydroponic conditions. TNT caused damage to the microstructure of the plant roots and inhibited photosynthesis, whereas RDX and HMX induced only minor changes. Exposure to any of the three explosives caused disturbances in the oxidase system. Non-targeted metabolomics identified a total of 6185 metabolites. TNT exposure induced the appearance of 609 differentially expressed metabolites (189 upregulated, 420 downregulated), RDX exposure induced 197 differentially expressed metabolites (155 upregulated and 42 downregulated), and HMX induced 234 differentially expressed metabolites (132 upregulated and 102 downregulated). Of these differentially expressed metabolites, lipids and lipid-like molecules were the main metabolites induced by explosives poisoning. TNT mainly caused significant changes in the alanine, aspartate, and glutamate metabolism metabolic pathways, RDX mainly caused disorders in the arginine biosynthesis metabolic pathway, and HMX disrupted the oxidative phosphorylation metabolic pathway. Taken together, the results show that exposure to TNT, RDX, and HMX leads to imbalances in plant photosynthetic characteristics and antioxidant enzyme systems, changes the basic metabolism of plants, and has significant ecotoxicity effects.

Recent advances in stable isotope ratio analysis of common explosives

炸药的深度比对与溯源对于爆炸案事件的侦破具有重大意义,以不同地域来源的原料或不同生产工艺生产的炸药,其组成元素的稳定同位素比值具有差异,因而稳定同位素比值可作为炸药深度比对与溯源的重要指标。稳定同位素比值质谱法(IRMS)作为一种高精度的稳定同位素比值测量手段,已逐渐发展成熟,与元素分析仪、气相色谱仪、液相色谱仪等仪器联用,在食品安全、环境保护、法庭科学等领域应用广泛。IRMS在炸药比对与溯源上亦发挥了重要作用,自1975年IRMS被应用于区分不同国家生产的三硝基甲苯(TNT)以来,IRMS已成功用于多种炸药的分析。但目前尚未见有文献系统地总结常见炸药的稳定同位素比值分析研究进展。该文介绍了稳定同位素比值分析的相关原理、仪器组成及特点,分别总结了硝酸铵、黑火药、TNT、太恩、黑索金等常见炸药的稳定同位素比值分析方法,汇总了文献报道的不同国家生产的硝酸铵、黑火药、TNT等炸药的稳定同位素比值。文章就不同炸药的稳定同位素比值差异、炸药生产、存储过程中相关因素对同位素比值的影响,爆炸前后稳定同位素比值的变化情况等内容进行了分析。本文还指出了目前炸药的稳定同位素比值分析研究中存在的问题,对可能的解决办法进行了讨论,对未来的发展方向提出了建议。

Exposure to dissolved TNT causes multilevel biological effects in Baltic mussels (Mytilus spp.)

Baltic mussels (Mytilus spp.) were exposed to the explosive trinitrotoluene (TNT) for 96 h (0.31–10.0 mg/L) and 21 d (0.31–2.5 mg/L). Bioaccumulation of TNT and its degradation products (2- and 4-ADNT) as well as biological effects ranging from the gene and cellular levels to behaviour were investigated. Although no mortality occurred in the concentration range tested, uptake and metabolism of TNT and responses in antioxidant enzymes and histochemical biomarkers were observed already at the lowest concentrations. The characteristic shell closure behaviour of bivalves at trigger concentrations led to complex exposure patterns and non-linear responses to the exposure concentrations. Conclusively, exposure to TNT exerts biomarker reponses in mussels already at 0.31 mg/L while effects are recorded also after a prolonged exposure although no mortality occurs. Finally, more attention should be paid on shell closure of bivalves in exposure studies since it plays a marked role in definining toxicity threshold levels.

Effects of Concrete Strength and Openings in Infill Walls on Blasting Responses of RC Buildings Subjected to TNT Explosive

The explosions caused by terrorism and/or accidental lead to serious damage and/or collapse in structures, economic losses, and most importantly endanger public safety. The blasting loads that can be larger than design loads are generally neglected in the design stage of civil engineering structures, despite these catastrophic effects. For these reasons, especially strategically important structures such as hospitals, military buildings, and bridges should be designed considering the blasting effects. To this aim, the effects of design parameters such as concrete strength and openings in infill walls on blasting responses of reinforced concrete (RC) buildings are investigated in this study. In situ experimental tests are firstly conducted on a test specimen constructed with brick elements to verify the finite element (FE) model criteria and assumptions. The blasting experiments are performed using 40, 150, and 290 g trinitrotoluene (TNT) explosives. Then, two RC buildings are selected as application, and blasting analyses are done with numerical and empirical methods. FE models of the buildings including structural and non-structural elements are constituted in ANSYS Workbench software. The blasting analyses are carried out with ANSYS AUTODYN software using 100 kg TNT explosives. In the analyses, two different openings in infill walls and six different concrete classes are considered. The blasting pressures, displacements, absorbed and released total energies, and damage ratios are obtained and presented as comparison parameters. The results obtained from the blasting analyses are presented with graphics and tables, comparatively. The study shows that peak pressures and maximum displacements decrease by 22.50% and 32.16% with the increase in concrete strength. Also, it is observed from numerical analyses that openings in infill walls lead to a change of 8.16% in peak pressures and 13.92% in maximum displacements.

Quantifying evolving toxicity in the TAML/peroxide mineralization of propranolol.

SummaryOxidative water purification of micropollutants (MPs) can proceed via toxic intermediates calling for procedures for connecting degrading chemical mixtures to evolving toxicity. Herein, we introduce a method for projecting evolving toxicity onto composite changing pollutant and intermediate concentrations illustrated through the TAML/H2O2 mineralization of the common drug and MP, propranolol. The approach consists of identifying the key intermediates along the decomposition pathway (UPLC/GCMS/NMR/UV-Vis), determining for each by simulation and experiment the rate constants for both catalytic and noncatalytic oxidations and converting the resulting predicted concentration versus time profiles to evolving composite toxicity exemplified using zebrafish lethality data. For propranolol, toxicity grows substantially from the outset, even after propranolol is undetectable, echoing that intermediate chemical and toxicity behaviors are key elements of the environmental safety of MP degradation processes. As TAML/H2O2 mimics mechanistically the main steps of peroxidase catalytic cycles, the findings may be relevant to propranolol degradation in environmental waters.

ANALYSIS OF MATHEMATICAL RELATIONS FOR CALCULATION OF EXPLOSION WAVE OVERPRESSURE

The explosion of an explosive system causes primary and secondary effects on people and objects near its site. The most devastating is the pressure effect of the explosion, especially the overpressure. Individual parameters of pressure wave (overpressure size, duration impulse) can be determined by mathematical or virtual modeling or can also be measured under real conditions.
 The authors focused on the parameters of the positive phase of the shock wave propagating from the source of the explosion towards the object. The article covers the description and analysis of selected mathematical relations, which are used to determine the magnitude of the explosion overpressure. The results are based on selected formulas. The source of the explosion referred in the study is an explosive system containing a reference explosive trinitrotoluene (TNT). TNT is a military explosive that is used as a reference explosive in technical standards dedicated to the certification of explosion-proof elements, and at the same time, a TNT equivalent is known to allow the mass of an explosive charge to be recalculated.
 The results obtained by mathematical modeling according to individual approaches have been compared and the possibilities of using computational models in the area of security management and education of security managers have been identified. The results of the study confirm that prediction of pressure wave parameters at different distances and weights can assist security managers in creating attack scenarios and designing a suitable object protection system.

Helmet chinstrap protective role in maxillofacial blast injury.

The protective role of helmet accessories in moderating stress load generated by explosion shock waves of explosive devices is usually neglected. In the presented study, the protective role of the helmet chinstrap against the impulse and overpressure experienced by the maxillofacial region were examined. The explosion shock wave and skull interaction were investigated under three different configurations: (1)unprotected skull, (2) skull with helmet (3) skull with helmet and chinstrap. For this purpose, a 3D finite element model (FEM) was constructed to mimic the investigated biomechanics module. Three working conditions were set according to different explosive charges and distances to represent different load conditions. Case 1: 500 mg explosive trinitrotoluene (TNT), 3 cm, case 2: 1000 mg TNT, 3 cm, and case 3: 1000 mg TNT and 6 cm distance to the studied object. The explosion effect was discussed by examining the shock wave stress flow pattern. Three points were selected on the skull and the stress curve of each point position were illustrated for each case study. The results showed that the helmet chinstrap can reduce the explosive injuries and plays a protective role in the maxillofacial region, especially for the mandible.

Nonlinear dynamic response and deformation analysis of soil under the explosion shock loading

Energy is released during explosions, and this creates shock waves. The dynamic pressure generated from an explosion is transmitted through soil in the form of compression waves. In military engineering and industrial safety protection, soil, a blast-resistant material, is used to achieve blast resistance. This study used the blast pressure and ground acceleration measured in an experimental explosion to verify the results of finite element numerical analysis. A fluid–solid interaction numerical analysis method was employed to simulate a trinitrotoluene explosion on the ground. Through analysis of the dynamic characteristics of soil after an explosion, the relationship between the dynamic stress wave formed by the explosion and the plastic deformation of the soil was studied. The results may provide a reference for the design of blast-resistant protective soil layers.

The explosive trinitrotoluene (TNT) induces gene expression of carbonyl reductase in the blue mussel (Mytilus spp.): a new promising biomarker for sea dumped war relicts?

Millions of tons of all kind of munitions, including mines, bombs and torpedoes have been dumped after World War II in the marine environment and do now pose a new threat to the seas worldwide. Beside the acute risk of unwanted detonation, there is a chronic risk of contamination, because the metal vessels corrode and the toxic and carcinogenic explosives (trinitrotoluene (TNT) and metabolites) leak into the environment. While the mechanism of toxicity and carcinogenicity of TNT and its derivatives occurs through its capability of inducing oxidative stress in the target biota, we had the idea if TNT can induce the gene expression of carbonyl reductase in blue mussels. Carbonyl reductases are members of the short-chain dehydrogenase/reductase (SDR) superfamily. They metabolize xenobiotics bearing carbonyl functions, but also endogenous signal molecules such as steroid hormones, prostaglandins, biogenic amines, as well as sugar and lipid peroxidation derived reactive carbonyls, the latter providing a defence mechanism against oxidative stress and reactive oxygen species (ROS). Here, we identified and cloned the gene coding for carbonyl reductase from the blue mussel Mytilus spp. by a bioinformatics approach. In both laboratory and field studies, we could show that TNT induces a strong and concentration-dependent induction of gene expression of carbonyl reductase in the blue mussel. Carbonyl reductase may thus serve as a biomarker for TNT exposure on a molecular level which is useful to detect TNT contaminations in the environment and to perform a risk assessment both for the ecosphere and the human seafood consumer.

Finite element modeling of the eyeglass-related traumatic ocular injuries due to high explosive detonation

Traumatic ocular injury due to glass shards is a challenging issue that might occur due to automobile crashes, airbag expansions, military operations, sports, etc. Eyeglass breakage due to a high explosive detonation, shoot a group of randomly sized shards into the eye at a dramatically high speed along with a primary blast wave (PBW) propagation which might invoke extensive scarring and damage to the internal ocular tissues following by permanent visual impairment. Understanding the mechanisms of this injury and its following complications in each component of the eye might not be achievable experimentally unless using numerical simulations, i.e., finite element method (FEM). Although our group performed two separate studies to investigate the ocular injury because of glass shards and high explosive detonation, it would be interesting to understand how the combination of these two together damage the components of the eye. Therefore, this study was aimed to compute the stresses and deformations in the eye components, including the cornea, aqueous body, iris, ciliary body, lens, vitreous body, retina, sclera, optic nerve, orbital muscle, and orbital fat (intraconal and extraconal), attributed to glass shards breaking down because of PBW induced by trinitrotoluene (TNT) explosion. A three-dimensional (3D) FE model of the eye globe was established using CT/MRI data and subjected to glass shards at a high speed resulted from a TNT explosion. The injury to the components of the eye and the skull were calculated right after the blast wave and right after the glass shards reach to the eye/skull to reveal the role of each factor separately. The highest amount of stresses/injuries occurred in the sclera, which might trigger eye globe rupture. These findings may contribute in understanding of the mechanisms of ocular injury aiding in the management of the eyeglass-related traumatic injuries due to explosion, car accident injuries and or combat injuries.

Numerical Review of Jones–Wilkins–Lee Parameters for Trinitrotoluene Explosive in Free-Air Blast

AbstractThe analysis of complex blast scenarios typically requires advanced computational methods such as multi-material Eulerian and coupled Eulerian–Lagrangian (CEL) analysis where Jones–Wilkins–Lee (JWL) equation of state is used to model the explosive material. While multiple sets of empirical JWL parameters for trinitrotoluene (TNT) explosives have been published over the past few decades, there is also a lack of guidelines and comparative studies on their applications for the blast analysis. A standardized description of the explosive material behavior allows for a better interpretation of results from research studies involving different blast scenarios and JWL parameters. In this paper, the authors utilize numerical finite element (FE) simulations to investigate the influence of different TNT JWL parameter sets on the blast wave characteristics of a free-air blast across different scaled distances. Utilizing multi-material Eulerian analysis, a series of spherical free-air blasts involving a 100-kg TNT charge modeled with different TNT JWL parameters are conducted. The blast wave characteristics including the incident overpressure, impulse, and time of arrival (TOA) are benchmarked against the empirical-based Kingery–Bulmash air blast formulations through the conventional weapon effect calculator conwep. It was found that the incident overpressure and impulse are highly sensitive to the JWL parameters, with differences as high as 40% at smaller scaled distances, while the influence on TOA is much less significant. This paper hopes to provide a guide for future users on the appropriate JWL parameter sets to model the air blast events involving TNT explosives.