Amounts Of Explosives Research Articles

Experimental Investigation of the Explosion Effects on Reinforced Concrete Slabs with Fibers

In today’s world, concrete structures are exposed to various influences, including explosive actions. With the increasing use of fiber-reinforced concrete (FRC), it is essential to investigate its response to blast effects. As there are few studies on this topic worldwide, this research is dedicated to the question of how blast effects affect the damage and properties of six different types of reinforced concrete (RC) slabs. These samples differ in concrete classes (C30/37 and C50/60) and in the type of fibers added (steel and polypropylene). Visual inspections and non-destructive measurements are carried out before and after blasting. The damaged area of the concrete surface is determined by visual inspection, while non-destructive measurements evaluate parameters such as the rebound value of the Schmidt hammer, the electrical resistivity of the concrete, the velocity of the ultrasonic wave, and the dynamic modulus of elasticity. Equal amounts of explosives are applied to five of the RC slabs to enable a comparative analysis of the resulting damage. Based on the comparison of the measured data from these five RC slabs, conclusions are drawn regarding the effects of the explosive impacts on conventionally reinforced concrete slabs compared to those with added fibers. In addition, one of the RC slabs with steel fibers is exposed to approximately three times the amount of explosives to assess the extent of increased damage and to evaluate the suitability of military standards in the calculation of explosive charges for blasting RC elements with fibers.

Thermal response of DNAN based explosives considering thermodynamic coupling：Under different charge quantity and diameter changes

This paper explores the impact of changes in charge quantity and diameter on the thermal response of DNAN-based explosives. To achieve this, we established a method for simulating thermal, chemical, and mechanical coupling. The study focuses on three fixed charge quantities of explosives, each with varying length-to-diameter ratios, examining alterations in ignition position, timing, and temperature changes under different heating rates, as well as the safe thermal response size in various heating environments. The findings show that the maximum discrepancy between the simulation results and experimental data is under 5 %. It was observed that larger charges are less sensitive to variations in external heating rates and aspect ratios. Specifically, at a heating rate of 1 K/min, projectiles with a diameter exceeding their length by the same factor exhibit greater thermal safety than those with a length exceeding their diameter. This research not only enhances the accuracy of simulation experiments but also offers a comprehensive safety analysis for the combustion of ammunition. The findings provide valuable insights for designing low-vulnerability ammunition structures that are subject to significant thermal stress in various environments, and they are useful for guiding ammunition storage and destruction experiments.

On the importance of systems thinking in ERW (explosive remnants of war) risk management

One of the legacies of armed conflict is unexploded ordnance and abandoned ammunition. This legacy will, in many cases, have a severe impact on society and daily life, even for years or decades after hostilities have ended. The millions of tonnes of explosive remnants that remain in nature represent a grave threat in many ways, and, if left in place, the human, societal and environmental impact could prove to be severe. Clearing the ERW represents a serious and complex risk in itself, a risk that could increase if mismanaged. Furthermore, the accumulations of munition contamination hinder and severely endanger areal development, both on land and offshore. However, vast amounts of explosives and accumulations of munitions, such as those in dumping areas and shipwrecks, are systematically neglected. An unintentional detonation at such a site could prove to have disastrous societal and environmental consequences. In the present work, it is shown that systems thinking could be used as a tool to gain better insight into the complexity of managing the risk related to explosive remnants of war, and to better prioritize resources allocated to mitigating this threat, resulting in the optimization of resource allocation and reduced societal risk.

Structural Investigations and Rheology of Convergence of Thick-Wall Shells from Al–Mg Alloy

Abstract—The deformation behavior of thick-walled hollow cylindrical shells made of the AMg6 alloy (Al–6.1% Mg–0.6% Mn–0.1% Ti–0.2% Si, wt %) loaded according to an 8-point initiation scheme of an attached explosive is considered. The intensity of explosive loading was regulated by the amount of explosives. It has been established that, different scenarios for their convergence are observed depending on the intensity of the impact and the geometric characteristics of the shells. The conditions for the formation of spallation internal layers were determined, the evolution of the structure during high-speed deformation along the radius and along the length of the shells and the change in hardness along the radius of the shells were studied. X-ray photography of the dynamics of shell deformation processes was carried out at different time intervals. The speeds of movement of the outer and inner layers of the shells and the speed of their deformation for different amounts of explosives were determined.

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.

Structural basis of transcription factor YhaJ for DNT detection

Detection of landmines without harming personnel is a global issue. The bacterial transcription factor YhaJ selectively detects metabolites of explosives, and it can be used as a key component of DNT biosensors. However, the wild-type YhaJ has a binding affinity that is not sufficient for the detection of trace amounts of explosives leaked from landmines buried in the soil. Here, we report crystal structures of the effector-binding domain of YhaJ in both the apo- and effector-bound forms. A structural comparison of the two forms revealed that the loop above the primary effector-binding site significantly switches its conformation upon effector binding. The primary effector-binding site involves hydrophobic and polar interactions, having specificity to hydroxyl-substituted benzene compounds. The structures explain the mechanism of activity-enhancing mutations and provide information for the rational engineering of YhaJ biosensors for the sensitive detection of explosives.

Locating geothermal resources using seismic exploration in Xian county, China

The seismic exploration was used to explore the potential geothermal resource and geological structure in Xian County, N China. Micro-logging was used to conduct surveys on the velocity structure near the surface, the static correction models and the observation system was determined by this method. By testing different borehole depths and different quantities of explosives, the best experimental parameters were obtained in a series of test locations and in two test sections. The surface differences were eliminated by the static correction, and an interference wave survey was conducted to improve the data signal to noise ratio (SNR). The post-stack wave equation for the PR splitting finite difference was used for migration imagery, and post-stack, underground imaging profiles were obtained. The corrected seismic signals were then interpreted, and converted into geological information. The results showed that the burial depths and morphology in each layer had been successfully obtained. The areas favorable for heat storage in karst fissures were mainly in the Jixian Formation and the Cambrian–Ordovician. Our investigation allowed us to predict and calibrate favorable locations for two geothermal energy exploration holes.

Metagenomic assessment of nitrate-contaminated mine wastewaters and optimization of complete denitrification by indigenous enriched bacteria

Nitrate contamination in water remains to be on the rise globally due to continuous anthropogenic activities, such as mining and farming, which utilize high amounts of ammonium nitrate explosives and chemical-NPK-fertilizers, respectively. This study presents insights into the development of a bioremediation strategy to remove nitrates (NO3−) using consortia enriched from wastewater collected from a diamond mine in Lesotho and a platinum mine in South Africa. A biogeochemical analysis was conducted on the water samples which aided in comparing and elucidating their unique physicochemical parameters. The chemical analysis uncovered that both wastewater samples contained over 120 mg/L of NO3− and over 250 mg/L of sulfates (SO42-), which were both beyond the acceptable limit of the environmental surface water standards of South Africa. The samples were atypical of mine wastewaters as they had low concentrations of dissolved heavy metals and a pH of over 5. A metagenomic analysis applied to study microbial diversities revealed that both samples were dominated by the phyla Proteobacteria and Bacteroidetes, which accounted for over 40% and 15%, respectively. Three consortia were enriched to target denitrifying bacteria using selective media and then subjected to complete denitrification experiments. Denitrification dynamics and denitrifying capacities of the consortia were determined by monitoring dissolved and gaseous nitrogen species over time. Denitrification optimization was carried out by changing environmental conditions, including supplementing the cultures with metal enzyme co-factors (iron and copper) that were observed to promote different stages of denitrification. Copper supplemented at 50 mg/L was observed to be promoting complete denitrification of over 500 mg/L of NO3−, evidenced by the emission of nitrogen gas (N2) that was more than nitrous oxide gas (N2O) emitted as the terminal by-product. Modification and manipulation of growth conditions based on the microbial diversity enriched proved that it is possible to optimize a bioremediation system that can reduce high concentrations of NO3−, while emitting an environmentally-friendly N2 instead of N2O, that is, a greenhouse gas. Data collected and discussed in this research study can be used to model an upscale NO3− bioremediation system aimed to remove nitrogenous and other contaminants without secondary contamination.

Vibration Performance of Steel Fiber Concrete Tunnel Lining by Adjacent Tunnel Blasting Construction

When constructing tunnels in mountainous areas, the drilling and blasting method is the most commonly used because of its economy. Ordinary reinforced concrete itself has defects such as poor crack resistance and brittleness. Therefore, when using the drilling and blasting method for ordinary reinforced concrete double-line tunnels, vibration phenomena will occur and cause cracks in the first-line tunnels, which will have adverse effects on the durability and safety of the tunnel. As a response, scholars have proposed the use of steel fiber-reinforced concrete as tunnel lining. In this paper, the LS-DYNA software is used to establish three models of plain concrete, ordinary concrete, and steel fiber-reinforced concrete, and numerical analysis is conducted with different amounts of explosives. The results show that the steel fiber-reinforced concrete tunnel lining has better performance than the other two concretes in tunnel construction.

Correlating vapour uptake with the luminescence quenching of poly(dendrimer)s for the detection of nitro group-containing explosives

Thin films of two poly(dendrimer)s were studied for the detection of trace quantities of nitro-based taggants and explosives. The poly(dendrimer) structures consist of side chain-conjugated triphenylamine-based dendritic chromophores attached to a non-conjugated polymer backbone. The poly(dendrimer)s differ in terms of the conjugation length, steric bulk and surface groups of the chromophores and we investigated the effects of these differences on sensing performance. We found that the addition of first-generation biphenyl-based dendrons to the chromophores of one of the polymers, P2, resulted in greater photoluminescence quenching, sensitivity and recovery to pulses of the vapours of the nitroaliphatic taggant 2,3-dimethyl-2,3-dinitrobutane (DMNB) and the nitroaromatic analyte 2,4-dinitrotoluene (2,4-DNT) compared with the other polymer, P1. We employed neutron reflectometry to characterise the vapour uptake of both poly(dendrimer)s and a structurally similar triphenylamine-based dendrimer D1 for comparison. The results show that the P2 has a mass density of 0.91 ± 0.01 v. 1.01 ± 0.01 g cm−3 for both P1 and D1 and can absorb at least twice the amount of 2,4-DNT. These results show how increasing the dendritic character of the poly(dendrimer) architecture provides a route for optimising vapour uptake and improving sensing performance in the solid state.

Application of Modern Technical Means of Chemical Reconnaissance and Control for the Detection and Identification of Explosives

The analysis of the capabilities of modern technical means of chemical reconnaissance and special equipment of chemical control indicates the possibility of quick detection of mined and explosive devices (EDs) by identification of the explosives included in the EDs and related technological impurities. The purpose of this work is to analyze the possibilities of using modern technical means of chemical reconnaissance and control for the detection and identification of explosives. In order to achieve this goal, the authors assessed the analytical characteristics and features of the technical means of chemical reconnaissance and the indication methods implemented in them to determine the possibility of detecting and identifying the components of the EDs. The article shows the possibility of using special military gas detectors operating on the basis of the ion mobility spectrometry (IMS) method to confirm the presence of the vapor phase of explosives. The assessment was carried out on the basis of an analysis of the physicochemical properties of peroxides and nitrogen-containing explosives and a comparison of the achievable concentrations of the vapor phase of nitrogen-containing explosives (TNT, RDX, pentrite, nitroglycerin, dinitrotoluene) with the results of the calculated sensitivity of the IMS method (~10–10 mg/L). It has been established that trace amounts of explosives in liquid and solid states of aggregation can be identified by portable technical means of chemical control, operating on the basis of infrared Fourier spectroscopy and Raman scattering. The ways of expanding the functionality of these technical means by creating specialized databases of spectral data of explosives and accompanying technological impurities are proposed. The inclusion of an additional spectrum bank in the control software of IMS gas detectors must be combined with the implementation of the possibility of program selection of operating modes and database switching by the operator.

Empirical Attenuation Law for Air Blast Waves Due to the Detonation of Explosives Outdoors

The detonation of explosives in the open air was studied, analyzing different amounts of explosives detonated at different distances, monitoring the overpressure or air blast wave generated with the aim of determining a model, which allows to establish safety zones. A series of tests measuring the air wave with different loads and sensors placed at various distances from the origin of the explosion were carried out. The work was focused on designing full-scale trials that allowed to develop a predictive empirical method based on the calculation model of the equivalent mass of TNT. A total of 18 different gelatinous dynamite charges, placing the sensor at six different distances from the origin of the explosion, produced a total of 90 tests measuring the air wave produced by the detonation of gelatinous dynamite. Later, the outdoor detonation of 10 TNT explosive charges was analyzed to extend the model and improve its scope. With all this, it has been possible to develop a predictive model that allows assessing the overpressure generated by the detonation of a TNT-equivalent explosive charge. The results are useful to predict the air blast wave in common open-air blasts, such as those carried out with shaped charges to demolish metallic structures. On the other hand, the results are also useful to determine the air blast wave overpressure in the case of large explosive charges detonated in the open air, such as accidental explosive detonation or terrorist bombs. It is important to point out the relevance of the results achieved after the detonation of large explosive charges (more than 80 kg) simulating a type of bomb frequently used by terrorists. Reproducing the explosion on a real scale, the results are fully representative of the overpressure produced by an explosion of these characteristics without the need of extrapolating the results of tests with small loads. In addition, the detonation was carried out with TNT, which can serve as a standard to compare with any other type of explosive.

유도탄의 안전성 설계를 위한 정량적 관리 지표 개발

Purpose: Accidents related to explosives are infrequent, but when they occur, they can be fatal. In the case of missiles containing large amounts of explosives, safety design is of utmost importance. However, researches on quantitative indexes for managing safety design activities and interest in safety design are lacking. Therefore, it is necessary to develop quantitative management indexes for implementing safety controls at the design level and secure safety through the safety design process in the development of missiles.BRMethods: In this study, we propose a safety design process for missile development with hazard identification and risk assessment based on the MIL-STD-882E standard. Moreover, we develop quantitative management indexes (SMR, RAR) for controlling safety at the design level. The feasibility and effectiveness of these indexes are verified through case studies.BRResults: A hazard analysis was performed on a missile system under development, and 26 unacceptable hazards were identified. Then, the problems affecting the existing safety protocols were identified using the proposed quantitative management indexes (SMR, RAR).BRConclusion: The implementation of a safety design process based on quantitative management indexes (SMR, RAR) from the early stages of research and development can improve the safety of missiles.

유도탄 안전성 제고를 위한 체크리스트 개발

Purpose: Safety and performance are important goals in system development. However, in reality, safety is often considered secondary to performance requirements in the R&D stage of weapon systems development. In the case of missile systems that contain large quantities of explosives, safety requirements are especially important because they are directly connected to incidents such as human damage and a lot of cost handling negligent accidents. Therefore, it is necessary to develop a checklist that can improve the safety of missiles by reflecting the safety requirements from the outset of development.<BR>Methods: In this study, the types of such checklists were identified, and research data related to missile development were analyzed. Finally, the contents of the missile checklist that were focused on safety were identified, and it was concluded that these contents can be used as basic data for hazard analysis.<BR>Results: Through research and data analysis, a total of 145 checklists were identified across the design, production, and operation domains. In addition, the requirements of each major component were checked. The feasibility and effectiveness of the proposed missile checklist were confirmed by conducting a case study.<BR>Conclusion: By applying the missile checklist, it is possible to respond to safety requirements in advance, and the safety of missiles can be secured and improved.

Raman spectroscopic and advanced signal processing analyses for real time standoff detection and identification of explosives

Laser Raman spectroscopy is a powerful instrument commonly used for detection of bulk and trace amounts of explosives. The work carried out in this paper is divided into two phases; the first phase is to propose a real time standoff explosive detection and identification system based on Raman spectroscopy that can be deployed in static checkpoints. The measurement is performed for samples placed in contact and at distances up to 1 m in ambient light conditions. The second phase is to propose a novel sophisticated signal processing and pattern recognition techniques for accurate identification and classification of the investigated materials.

Introduction of quorum sensing elements into bacterial bioreporter circuits enhances explosives' detection capabilities.

A possible solution for the standoff detection of buried landmines is based on the use of microbial bioreporters, genetically engineered to emit a remotely detectable optical signal in response to trace amounts of explosives’ signature chemicals, mostly 2,4‐dinitrotoluene (DNT). Previously developed DNT sensor strains were based on the fusion of a DNT‐inducible gene promoter to a reporting element, either a fluorescent protein gene or a bacterial bioluminescence gene cassette. In the present study, a different approach was used: the DNT‐inducible promoter activates, in Escherichia coli, the quorum‐sensing luxI and luxR genes of Aliivibrio fischeri. N‐Acyl homoserine lactone (AHL), synthesized by LuxI, combines with LuxR and activates the bioluminescence reporter genes. The resulting bioreporter displayed a dose‐dependent luminescent signal in the presence of DNT. Performance of the sensor strain was further enhanced by manipulation of the sensing element (combining the E. coli DNT‐inducible azoR and yqjF gene promoters), by replacing the luminescence gene cassette of Photorhabdus luminescens luxCDABE with A. fischeri luxCDABEG, and by introducing two mutations, eutE and ygdD, into the host strain. DNT detection sensitivity of the final bioreporter was over 340‐fold higher than the original construct.

Creation of Breaches, with the Help of Explosives, in Metal Structures under Water and on the Ground Surface

The present research-development (CD) paper is a multidisciplinary study requested by thedivers belonging to the Diving Center. This study was initiated out of the need to make, with the helpof the smallest possible quantities of explosives of very good quality, cutting/sectioning of bars,chains, metal pipes, etc. and breaches of certain shapes and sizes, to enter, as soon as possible, closedenclosures under water (shipwrecks, planes, etc.) in order to recover documents, objects, and so on.

Technical solutions for the evaluation of the effect of explosion pressure when detoning various explosive loads in view of increasing the degree of societal security

The scientific article highlights the synthesis of the research results to assess the effect of explosive pressure on the detonation of various quantities of explosives in order to ensure a predictable level of societal security. The results of the experimental researches highlighted in the scientific papers were obtained following the tests with explosive materials performed on different specially configured experimental assemblies in order to analyze the propagation of the pressure wave on a mobile platform with specially configured pressure and gas sensors as well as on the explosion pressure measuring sensors within two modern Kistler systems. The visualization of air pressure waves for the experiments performed with these working montages was done by using a high-speed camera based on the BOS effect applied on fast video filming with adequate quality characteristics on the number of frames per second and the resolution obtained.

Detection of Trace Amounts of Explosives in the Presence of Lactic Acid by Ion Mobility Spectrometry

Detection of Trace Amounts of Explosives in the Presence of Lactic Acid by Ion Mobility Spectrometry

Study of Crater in the Gobi Desert Induced by Ground Explosion of Large Amounts of TNT Explosive up to 10 Tons

Explosion craters on the ground surface induced by contact or near-field explosions have important implications, which can be used to assess blast consequences, guide the design of the explosion, or develop a protective strategy. In this study, to understand the crater characteristics induced by the contact explosion of large weight explosives, four field contact explosion tests were conducted on the surface of the Gobi Desert with large TNT charge weights of 1 ton, 3 tons, and 10 tons (test conducted twice). Cratering on the ground surface generated by large amounts of explosives was measured and evaluated, including the shape, depth, and diameter. A fine-mesh numerical model was developed and validated on the AUTODYN software platform, and a detailed parametric study was performed on the resulting craters. The effects of sand and gravel density, initiation method, shear modulus, and failure criteria were analyzed and discussed. An energy conversion coefficient was determined, and the corresponding theoretical equations were derived to predict the dimensions of the craters resulting from the large weight contact explosion. The calculated cratering characteristics were consistent with previous data and hence can be used in future engineering applications.