Explosion Debris Research Articles

Investigating sol–gel matrix loading capacity toward producing surrogate nuclear explosive debris with realistic composition

Investigating sol–gel matrix loading capacity toward producing surrogate nuclear explosive debris with realistic composition

FEATURES AND ADVANTAGES OF THE MINI METAL DETECTOR IN MODERN REALITIES

The article explores a wide range of applications of portable metal detectors, focusing on their advantages, accuracy and versatility in various industries. These devices, in particular mini metal detectors, have become an important tool in modern medical practice, military operations, rescue missions and security. Their compact size, ease of use and high efficiency in detecting small metal objects make them indispensable for quick screening and prompt response in extreme situations. The main focus of the article is on the medical application of metal detectors. In the field, during emergency situations, combat operations or disasters, the mini metal detector allows you to quickly detect and localize metal foreign bodies, which reduces the risk of complications for patients. This is particularly useful in settings where there is no access to x-ray equipment. Such devices make it possible to quickly assess the situation and make a decision on the need for surgical intervention or further diagnostics. Mini metal detectors are also effective in military operations and rescue missions, where it is necessary to quickly and accurately detect dangerous objects, such as explosive remnants, debris or mines. This significantly increases the level of security for both military personnel and the civilian population. The article emphasizes that the use of such devices can significantly reduce the risk of injury and death in high-danger areas. In addition, mini metal detectors are an affordable and cost-effective tool, which makes them attractive for use in humanitarian missions and in conditions of limited funding. This makes them not only a tool for medical or military purposes, but also an important component of safety at public events, in transport or in production. The article concludes that mini metal detectors are an effective and reliable tool that has great potential in various areas of modern life, providing quick diagnostics, increased security and prompt response to calls. A comparative analysis of algorithms for laser line center determination and recognition has been conducted. The issues in this area are described, outlining the principles, pros, and cons of each method. Additionally, the possibilities of their application using programming code are demonstrated. Algorithm testing was performed using Python language tools and the OpenCV library. It is shown that the quality of the result in the extremum method significantly depends on the quality of the selected parameters for the Butterworth filter. In contrast, the gray gravity method substantially relies on the accuracy of determining the laser incidence angle. The computational efficiency and accuracy for each algorithm are also analyzed.

The Serendipitous Discovery of the New Elements Einsteinium and Fermium from the Debris of the Mike Thermonuclear Test

On October 31, 1952, the United States successfully detonated the Los Alamos Mike thermonuclear device on the surface of Elugelab Island at Eniwetok Atoll in the Pacific Ocean. This test was the first demonstration of a high-yield thermonuclear explosion on Earth. The 10.4-Mt device yield obliterated Elugelab Island and left a 6240-ft-diameter underwater crater. Later, radiochemical analysis of the explosion debris produced the unanticipated discovery of 15 new heavy transuranic isotopes and two new elements, which were later named einsteinium and fermium. Initially, the discovery of these elements was classified, but in 1955, the results were declassified and announced to the world. The Mike results later led to the development of the Heavy Element and Isotope Effort under the U.S. Plowshare Peaceful Nuclear Explosions Program, under which additional new heavy transuranic isotopes were produced.

Retention of radionuclides in sol–gel surrogate nuclear explosive debris

Retention of radionuclides in sol–gel surrogate nuclear explosive debris

Assessment of gas explosion risk in underground spaces adjacent to a gas pipeline

With the increased number and scale of gas pipelines, gas explosions in underground spaces adjacent to pipelines occur occasionally. A method was proposed in this study for evaluating the explosion risk in underground spaces adjacent to gas pipelines. The method was established on the basis of a full-scale independent underground space (IUS) explosion experiment and the whole-chain accident evolution model of “leak-diffused aggregation-ignition-explosion,” which consists of the possibility, consequence, and correction factors of an underground space explosion was proposed. Explosion possibility assessment included pipeline leakage, diffusion aggregation, and ignition probabilities. In particular, the diffusion aggregation probability assessment method, as the focus here for explosion possibility assessment, was proposed based on the method of micro-elements and behavior of gas diffusion in soil. A manhole explosion experiment was carried out for IUS explosion consequence assessment, including the extent and intensity of explosion flame, overpressure, and debris effects. The experiment also confirmed the conclusion that the explosion overpressure of the manhole was not sufficient to cause harm to people. Flame and fragmentation damage should be paid attention to, especially for an underground space with deep depth(hL ≥ 2 m), large volume, no hinge and light quality manhole cover. The risk assessment method proposed here was applied in H city, and 24,830 underground spaces with high explosion risk were assessed from 510,835 underground spaces. Over the past three years, more than 200 dangerous cases of natural gas leaks and accumulations have been identified.

Fragmentation analysis of a break-up event in low earth orbit

Fragmentations in space due to explosion or collision spawn multifarious Debris particles in space that exponentially populate the space environment and pose a threat to space activities. Therefore, for pragmatic assessment of space situation and timely dissemination of Space Situational Awareness (SSA) information, fragmentation analysis is of high significance. The Low Earth Orbit (LEO) region is the most crucial area for fragmentation studies as the spatial density is much higher in LEO as compared to the other regions of space. LEO region is also the most suited to analyze fragmentations as more small debris can be tracked compared to higher orbits. The current manuscript therefore embodies a methodology wherein it detects a fragmentation event time, location and identifies the sources for the event.

Photosensitive Composite Inks for Digital Light Processing Four-Dimensional Printing of Shape Memory Capture Devices.

High-performance shape memory thermosetting polymers and their composites for four-dimensional (4D) printing are essential in practical applications. To date, most printable thermosets suffer from complicated processes, poor thermodynamic performances, and low printing speed. Here, photosensitive composite inks for fast photocuring printing are developed. The inks consist of epoxy acrylate (EPAc), polyethylene glycol dimethacrylate (PEGDMA), and carbon fillers, which form a firm network structure when exposed to UV light. EPAc is synthesized via addition esterification of epoxy resin and acrylic acid under mild conditions. It is worth noting that raw materials for the reaction are diverse, including not only various epoxy resins but also molecules with epoxy groups. The 4D printing speed of up to 180 mm/h is mainly attributed to the exothermic reaction initiated by free radicals, which accelerates the polymerization of EPAc and PEGDMA. Most importantly, by increasing the exposure time of each layer from 1 s to 3 s during the printing process, the epoxy composite-infilled carbon nanotubes and carbon fibers are printed to ensure the integrity of the microlayer structure. Furthermore, we design a claw-like catcher device based on the above printable composite inks to demonstrate its potential applications in aerospace, such as grasping end-of-service spacecraft or explosive debris. Undoubtedly, 4D printing technology opens up a new portal for the manufacturing of thermoset epoxy composites and complex structures, which make the shape memory thermosetting epoxy resins and their composites possess excellent properties and good engineering application prospects.

Development of nuclear underground engineered test surrogates (NUGETS): preliminary composition study and production method

A method for formulation and production of a new variety of surrogate nuclear explosive melt debris (NEMD), Nuclear UnderGround Engineered Test Surrogates (NUGETS), based on detonation of a notional improvised nuclear device in an underground environment analogous to the Nevada National Security Site is presented. Extensive statistical analyses of precursory geochemical and geophysical characteristics are combined with an augmented surrogate debris cooling technique. Comparison of NUGETS formulation to those of other NEMD surrogates is reported. Application of NUGETS methodology to future studies in urban, underground, post-detonation technical nuclear forensic analysis is suggested.

Vegetation responses to Quaternary volcanic and hydrothermal disturbances in the Northern Rocky Mountains and Greater Yellowstone Ecosystem (USA)

Volcanic and hydrothermal processes produce disturbances by diverse mechanisms and ecological responses are varied. New and published pollen records from the Northern Rocky Mountains and Greater Yellowstone Ecosystem document the response of vegetation to three different types of volcanic and hydrothermal disturbances: (1) Pleistocene rhyolite lava flows in the central Greater Yellowstone Ecosystem created infertile landscapes that have shaped vegetation since rhyolite emplacement. Nutrient-poor, well-drained soils that developed on these flows supported low-diversity grassland during late-glacial time and Pinus contorta forests in interglacial periods. (2) Ash layers from eruptions of Pacific Northwest stratovolcanoes are commonly preserved in lake-sediment records in the Northern Rocky Mountains, and associated pollen records show enhancement of steppe vegetation for years to decades. (3) Local hydrothermal explosions have resulted in vegetation changes in hydrothermal areas that indicate tree mortality following deposition of explosion debris, followed by recovery in years. Thus, the type and duration of the vegetation response to volcanic and hydrothermal disturbances are highly contextual and governed by the antecedent plant communities and the magnitude and mechanism of the volcanic or hydrothermal disturbance. Vegetation resilience varied between disturbances, ranging from enduring ecosystem parameter changes to short-lived state changes in resilient plant communities.

Short-term Effect of Intelsat-29e Explosion on GEO Environment

Geosynchronous Orbit (GEO) space environment model of the orbital targets with a size above 10 cm was established according to the amended data and space density. The situation of satellite explosion on GEO is simulated, including the number of fragments generated by the explosion, the size distribution as well as the corresponding mass distribution of the fragments. Under the conditions of selecting fragments of different size for analyzing, the area to mass ratio, discrete velocity, and apogee-perigee distribution can be obtained. By simulating the collisions of targets in different size and mass, and the evolution of the space environment when different size thresholds are selected, the necessity of establishing the GEO space environment and evolution model with the threshold size of 10 cm is demonstrated. The feedback collision caused by the fragments generated by the GEO satellite explosion is simulated under the conditions of different collision probability thresholds. The results show that the explosion fragments would cause a high collision risk environment for other GEO orbital targets, and the risky circumstance would last for hours. The impact of explosive debris on the security of the future space environment is analyzed

Experimental research on explosion resistance of masonry structures reinforced with modified polyurea elastomer

In order to improve the explosion resistance performance of masonry structures during the terrorist attacks and accidental disasters, clay brick and concrete block walls are reinforced by modified polyurea materials. Explosion resistance tests of these two kinds of masonry wall structures are carried out to analyze the failure modes and anti-explosion effects of reinforced masonry walls under different thickness and reinforcement modes. The results show that modified polyurea elastomer not only has good spraying adhesion and compatibility with the base material surface, but also can effectively encapsulate the explosive debris generated by the back blasting surface of the masonry wall under explosive load, which reduces the deformation and displacement of the wall.

A prediction model for debris scattering in vented gas deflagration

As one of the main modes of damage caused by gas explosions in industrial production, the debris generated by the explosion threatens the safety of surrounding personnel and buildings. By means of experimental research and theoretical modelling, the debris generated by the vented component was experimentally studied, and a predictive model of the scattering range of explosion-induced debris was proposed. Through experiments using a self-designed explosion test apparatus, it is found that the gas explosion exerts a quasi-static pressure, and the vented plate is cracked by the plastic hinge under deflagration load. According to the force and the motion equation of the debris, the predictive model of the debris trajectory was proposed by differentiating the scattering process. The distribution of random variables in the model was determined by experimental data, and the scattering range of explosive debris was obtained using the Monte Carlo method. By comparing the calculated results with experimental data gathered under three typical conditions, the model values were seen to agree with the experimental values, and this model can predict the scattering range of debris. The proposed prediction model for debris scattering can provide a reference for the design of works used to protect against debris damage and subsequent domino effect.

The Initial Physical Conditions of the Orion BN/KL Fingers

Orion BN/KL is an example of a poorly understood phenomena in star forming regions involving the close encounter of young stellar objects. The explosive structure, the great variety of molecules observed, the energy involved in the event and the mass of the region suggest a contribution in the {chemical diversity} of the local interstellar medium. Nevertheless, the frequency and duration of other events like this have not been determined. In this paper, we explore a recent analytic model that takes into account the interaction of a clump with its molecular environment. We show that the widespread kinematic ages of the Orion fingers -- 500 to 4000 years -- is a consequence of the interaction of the explosion debris with the surrounding medium. This model explains satisfactorily the age discrepancy of the Orion fingers, and infers the initial conditions together with the lifetime of the explosion. Moreover, our model can explain why some CO streamers do not have a H$_2$ finger associated.

Collision risk prediction for constellation design

INDEMN is an object-oriented program dedicated to the modeling of the evolution of the densities of space objects. Following the work achieved by D. Kessler (1978) and by other authors more recently (G. L. Somma, IAC 2016, A6-IP3; A. Rossi, DPPS 2004, 197), the dynamical model is based on a source and sink approach for various altitudes. The source terms represent the future launches, the explosion of intact spacecrafts, and the collision between objects. Different collision cross sections are used for the various types of objects and the number of debris generated is based on the NASA break-up model. The sink terms are the drag and the end-of-life de-orbitation for the satellites launched after 2009, with a controllable success rate. The code was validated against former simulations performed with statistical and semi-deterministic models. In addition to the classical object types featured in several statistical codes, which are intact objects, explosion debris, and collision debris, a new type representing the satellites of a specific constellation is included. These satellites orbit with altitudes close to 1200 km and they can perform collision avoidance maneuvers as long as they are fully operational. It is shown that, under realistic assumptions, if only one primary collision occurs at an altitude of 800 km, the probability of a collision involving a constellation satellite becomes larger than 2% by 2035, which highly jeopardizes the satellite constellation as a whole.

Generating aerodynamic surrogate nuclear explosion debris (SNED)

“Aerodynamic debris” has often been observed from explosion debris collected on the fringe of surface nuclear tests. The material forms small glassy particulates, ranging in shape from near perfectly spherical glassy beads and occasionally agglomerates of two or more particles. Producing material with a similar range of characteristics in the laboratory is quite challenging, as the temperatures required exceed 1800 K. In this paper, we describe an apparatus that can heat lofted sediment particulates very rapidly above their melting points, for seconds to minutes. Examples of the different material forms produced will be compared to real aerodynamic debris recovered from nuclear explosions described in the literature.

Laboratory study of collisionless coupling between explosive debris plasma and magnetized ambient plasma

The explosive expansion of a localized plasma cloud into a relatively tenuous, magnetized, ambient plasma characterizes a variety of astrophysical and space phenomena. In these rarified environments, collisionless electromagnetic processes rather than Coulomb collisions typically mediate the transfer of momentum and energy from the expanding “debris” plasma to the surrounding ambient plasma. In an effort to better understand the detailed physics of collisionless coupling mechanisms, compliment in situ measurements of space phenomena, and provide validation of previous computational and theoretical work, the present research jointly utilizes the Large Plasma Device and the Raptor laser facility at the University of California, Los Angeles to study the super-Alfvénic, quasi-perpendicular expansion of laser-produced carbon (C) and hydrogen (H) debris plasma through preformed, magnetized helium (He) ambient plasma via a variety of diagnostics, including emission spectroscopy, wavelength-filtered imaging, and a magnetic flux probe. Doppler shifts detected in a He1+ ion spectral line indicate that the ambient ions initially accelerate transverse to both the debris plasma flow and the background magnetic field. A qualitative analysis in the framework of a “hybrid” plasma model (kinetic ions and inertia-less fluid electrons) demonstrates that the ambient ion trajectories are consistent with the large-scale laminar electric field expected to develop due to the expanding debris. In particular, the transverse ambient ion motion provides direct evidence of Larmor coupling, a collisionless momentum exchange mechanism that has received extensive theoretical and numerical investigation. In order to quantitatively evaluate the observed Doppler shifts, a custom simulation utilizing a detailed model of the laser-produced debris plasma evolution calculates the laminar electric field and computes the initial response of a distribution of ambient test ions. A synthetic Doppler-shifted spectrum constructed from the simulated test ion velocities excellently reproduces the experimental measurements, verifying that the observed ambient ion motion corresponds to collisionless coupling through the laminar electric field.

Synthesis and characterization of surrogate nuclear explosion debris: urban glass matrix

Surrogate nuclear explosive debris was synthesized and characterized for major, minor, and trace elemental composition as well as uranium isotopics. The samples consisted of an urban glass matrix, equal masses soda lime and cement, doped with 500 ppm uranium with varying enrichments. The surface and cross section morphology were measured with SEM, and the major elemental composition was determined by XPS. LA-ICP-MS was used to measure the uranium isotopic abundance comparing different sampling techniques. The results provide an example of the utility of LA-ICP-MS for forensics applications.

The preparation of non-radioactive glassy surrogate nuclear explosion debris (SNED) loaded with isotopically altered Xe

The measurement of Kr and Xe isotope ratios in nuclear explosion debris can be performed requiring little sample preparation. Fragments of debris are simply crushed or heated to release trapped gases Kr and Xe arising from fission product decay. As a suitable test material for this measurement, we have been investigating a method to incorporate isotopically enriched 129Xe in glassy materials that mimic nuclear explosion debris. The approach used to prepare these materials will be described along with some of the example results obtained.

Long‐term explosive degassing and debris flow activity at West Mata submarine volcano

AbstractWest Mata is a 1200 m deep submarine volcano where explosive boninite eruptions were observed in 2009. The acoustic signatures from the volcano's summit eruptive vents Hades and Prometheus were recorded with an in situ (~25 m range) hydrophone during ROV dives in May 2009 and with local (~5 km range) moored hydrophones between December 2009 and August 2011. The sensors recorded low frequency (1–40 Hz), short duration explosions consistent with magma bubble bursts from Hades, and broadband, 1–5 min duration signals associated with episodes of fragmentation degassing from Prometheus. Long‐term eruptive degassing signals, recorded through May 2010, preceded a several month period of declining activity. Degassing episodes were not recorded acoustically after early 2011, although quieter effusive eruption activity may have continued. Synchronous optical measurements of turbidity made between December 2009 and April 2010 indicate that turbidity maxima resulted from occasional south flank slope failures triggered by the collapse of accumulated debris during eruption intervals.

The formation of trinitite-like surrogate nuclear explosion debris (SNED) and extreme thermal fractionation of SRM-612 glass induced by high power CW CO2 laser irradiation

We describe a new approach to the bench top production of surrogate nuclear explosion debris by employing high power continuous wave CO2 laser irradiation. High surface temperatures >2,500 K can be rapidly attained, allowing virtually any combination of materials to be fused into a glassy matrix that can display high levels of elemental fractionation. Examples of the laser fused glasses will be presented and compared to trinitite nuclear explosion glass along with the elemental fractionation effects that were induced in the NIST glass standard SRM-612 by this method.