Articles de revues sur le sujet « Major explosions »
Pour voir les autres types de publications sur ce sujet consultez le lien suivant : Major explosions.
Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres
Consultez les 50 meilleurs articles de revues pour votre recherche sur le sujet « Major explosions ».
À côté de chaque source dans la liste de références il y a un bouton « Ajouter à la bibliographie ». Cliquez sur ce bouton, et nous générerons automatiquement la référence bibliographique pour la source choisie selon votre style de citation préféré : APA, MLA, Harvard, Vancouver, Chicago, etc.
Vous pouvez aussi télécharger le texte intégral de la publication scolaire au format pdf et consulter son résumé en ligne lorsque ces informations sont inclues dans les métadonnées.
Parcourez les articles de revues sur diverses disciplines et organisez correctement votre bibliographie.
1
Kuracina, Richard, et Zuzana Szabová. « Design of Dust Dispersion System for Explosion Chamber KV-150 M2 ». European Journal of Engineering Research and Science 3, no 12 (12 décembre 2018) : 32–35. http://dx.doi.org/10.24018/ejers.2018.3.12.988.
Texte intégralRésumé :
Dust explosions are a major hazard in many industrial processes. In operations such as crushing and grinding, conveying, classifying and storage, an explosion may occur in the presence of combustible dusts or powders. Such explosions can result in loss of production, process equipment and quite possibly human life. This paper is oriented on design of dust dispersion system for explosion chamber KV-150 M2. The explosion chamber KV-150 M2 is designed to measure the explosion parameters of dispersed dusts.
2
Kuracina, Richard, et Zuzana Szabová. « Design of Dust Dispersion System for Explosion Chamber KV-150 M2 ». European Journal of Engineering and Technology Research 3, no 12 (12 décembre 2018) : 32–35. http://dx.doi.org/10.24018/ejeng.2018.3.12.988.
Texte intégralRésumé :
Dust explosions are a major hazard in many industrial processes. In operations such as crushing and grinding, conveying, classifying and storage, an explosion may occur in the presence of combustible dusts or powders. Such explosions can result in loss of production, process equipment and quite possibly human life. This paper is oriented on design of dust dispersion system for explosion chamber KV-150 M2. The explosion chamber KV-150 M2 is designed to measure the explosion parameters of dispersed dusts.
3
Corradino, Claudia, Eleonora Amato, Federica Torrisi, Sonia Calvari et Ciro Del Negro. « Classifying Major Explosions and Paroxysms at Stromboli Volcano (Italy) from Space ». Remote Sensing 13, no 20 (13 octobre 2021) : 4080. http://dx.doi.org/10.3390/rs13204080.
Texte intégralRésumé :
Stromboli volcano has a persistent activity that is almost exclusively explosive. Predominated by low intensity events, this activity is occasionally interspersed with more powerful episodes, known as major explosions and paroxysms, which represent the main hazards for the inhabitants of the island. Here, we propose a machine learning approach to distinguish between paroxysms and major explosions by using satellite-derived measurements. We investigated the high energy explosive events occurring in the period January 2018–April 2021. Three distinguishing features are taken into account, namely (i) the temporal variations of surface temperature over the summit area, (ii) the magnitude of the explosive volcanic deposits emplaced during each explosion, and (iii) the height of the volcanic ash plume produced by the explosive events. We use optical satellite imagery to compute the land surface temperature (LST) and the ash plume height (PH). The magnitude of the explosive volcanic deposits (EVD) is estimated by using multi-temporal Synthetic Aperture Radar (SAR) intensity images. Once the input feature vectors were identified, we designed a k-means unsupervised classifier to group the explosive events at Stromboli volcano based on their similarities in two clusters: (1) paroxysms and (2) major explosions. The major explosions are identified by low/medium thermal content, i.e., LSTI around 1.4 °C, low plume height, i.e., PH around 420 m, and low production of explosive deposits, i.e., EVD around 2.5. The paroxysms are extreme events mainly characterized by medium/high thermal content, i.e., LSTI around 2.3 °C, medium/high plume height, i.e., PH around 3330 m, and high production of explosive deposits, i.e., EVD around 10.17. The centroids with coordinates (PH, EVD, LSTI) are: Cp (3330, 10.7, 2.3) for the paroxysms, and Cme (420, 2.5, 1.4) for the major explosions.
4
Corradino, Claudia, Eleonora Amato, Federica Torrisi, Sonia Calvari et Ciro Del Negro. « Classifying Major Explosions and Paroxysms at Stromboli Volcano (Italy) from Space ». Remote Sensing 13, no 20 (13 octobre 2021) : 4080. http://dx.doi.org/10.3390/rs13204080.
Texte intégralRésumé :
Stromboli volcano has a persistent activity that is almost exclusively explosive. Predominated by low intensity events, this activity is occasionally interspersed with more powerful episodes, known as major explosions and paroxysms, which represent the main hazards for the inhabitants of the island. Here, we propose a machine learning approach to distinguish between paroxysms and major explosions by using satellite-derived measurements. We investigated the high energy explosive events occurring in the period January 2018–April 2021. Three distinguishing features are taken into account, namely (i) the temporal variations of surface temperature over the summit area, (ii) the magnitude of the explosive volcanic deposits emplaced during each explosion, and (iii) the height of the volcanic ash plume produced by the explosive events. We use optical satellite imagery to compute the land surface temperature (LST) and the ash plume height (PH). The magnitude of the explosive volcanic deposits (EVD) is estimated by using multi-temporal Synthetic Aperture Radar (SAR) intensity images. Once the input feature vectors were identified, we designed a k-means unsupervised classifier to group the explosive events at Stromboli volcano based on their similarities in two clusters: (1) paroxysms and (2) major explosions. The major explosions are identified by low/medium thermal content, i.e., LSTI around 1.4 °C, low plume height, i.e., PH around 420 m, and low production of explosive deposits, i.e., EVD around 2.5. The paroxysms are extreme events mainly characterized by medium/high thermal content, i.e., LSTI around 2.3 °C, medium/high plume height, i.e., PH around 3330 m, and high production of explosive deposits, i.e., EVD around 10.17. The centroids with coordinates (PH, EVD, LSTI) are: Cp (3330, 10.7, 2.3) for the paroxysms, and Cme (420, 2.5, 1.4) for the major explosions.
5
Chapman, M. C., G. A. Bollinger et M. S. Sibol. « Modeling delay-fired explosion spectra at regional distances ». Bulletin of the Seismological Society of America 82, no 6 (1 décembre 1992) : 2430–47. http://dx.doi.org/10.1785/bssa0820062430.
Texte intégralRésumé :
Abstract The objectives of this study are to model the observed seismic spectra from large industrial explosions using information obtained from blaster's logs and to compare the explosion spectra with those of small earthquake signals from the same source region. The data set consists of digital waveforms from four mining explosions (200,000 + lb. of explosives each) and two earthquakes (M = 3.5 and 4.0) in eastern Kentucky. The data were recorded on a short-period regional network at distances ranging from 180 to 400 km and have good signal-to-noise ratios at frequencies from 0.5 to 10 Hz. The explosion amplitude spectra differ markedly from those of the earthquakes, by exhibiting strong time-independent amplitude modulations. This spectral modulation is directly attributable to the explosive charge geometry and firing sequence and is largely independent of source-station path and recording site. Modeling of the explosion source spectra shows that the major contributor to the modulated character of the spectra are amplitude minima at frequencies related to the total duration of the explosion sequence. Another important effect is amplitude reinforcement at low frequencies (e.g., 5 Hz) due to the comparatively long delay (0.2 sec) between the firing of individual rows of explosives. These features dominate both Pg and Lg amplitude spectra at frequencies less than 7 Hz. Accurate modeling of the observed spectra at frequencies greater than a few Hertz requires that the azimuth of the recording site be taken into account. Also, the spectra at higher frequencies become sensitive to random variations in the firing times of any of the various subexplosions.
6
Galante, Nicola, Lorenzo Franceschetti, Sara Del Sordo, Michelangelo Bruno Casali et Umberto Genovese. « Explosion-related deaths : An overview on forensic evaluation and implications ». Forensic Science, Medicine and Pathology 17, no 3 (1 juillet 2021) : 437–48. http://dx.doi.org/10.1007/s12024-021-00383-z.
Texte intégralRésumé :
Abstract Purpose Explosion-related deaths are uncommon events which require expertise and confidence so that an appropriate death investigation can be performed. The present study aims to provide a detailed forensic analysis of the issues and implications arising in the event of an explosion. Methods A retrospective review of casualty data was conducted on electronic literature databases. Cases concerning deadly explosions registered at the Milan Institute of Legal Medicine were examined and analyzed altogether. Results Explosions may involve closed or open systems. A security assessment of the site is always necessary. Alterations of the site due to rescue procedures can occur; thus, on-site forensic investigation should be adapted to the environment. Then, a study protocol based on autopsy procedures is presented. Application of the postmortem radiology enforces forensic procedures both for the analysis of blast injuries and skeleton fractures, and for identification purposes. Blast injuries typically cause lacerations of the lungs, intestine and major vessels; moreover, hyoid fractures can be documented. Histopathology may help to define blast injuries effectively. Forensic chemistry, toxicology and ballistics provide useful investigative evidence as well as anthropology and genetics. Different forensic topics regarding explosions are discussed through five possible scenarios that forensic pathologists may come across. Scenarios include self-inflicted explosion deaths, domestic explosions, work-related explosions, terrorist events, and explosions caused by accidents involving heavy vehicles. Conclusion The scenarios presented offer a useful instrument to avoid misinterpretations and evaluation errors. Procedural notes and technical aspects are provided to the readers, with an insight on collaboration with other forensic experts.
7
Giudicepietro, Flora, Sonia Calvari, Salvatore Alparone, Francesca Bianco, Alessandro Bonaccorso, Valentina Bruno, Teresa Caputo et al. « Integration of Ground-Based Remote-Sensing and In Situ Multidisciplinary Monitoring Data to Analyze the Eruptive Activity of Stromboli Volcano in 2017–2018 ». Remote Sensing 11, no 15 (2 août 2019) : 1813. http://dx.doi.org/10.3390/rs11151813.
Texte intégralRésumé :
After a period of mild eruptive activity, Stromboli showed between 2017 and 2018 a reawakening phase, with an increase in the eruptive activity starting in May 2017. The alert level of the volcano was raised from “green” (base) to “yellow” (attention) on 7 December 2017, and a small lava overflowed the crater rim on 15 December 2017. Between July 2017 and August 2018 the monitoring networks recorded nine major explosions, which are a serious hazard for Stromboli because they affect the summit area, crowded by tourists. We studied the 2017–2018 eruptive phase through the analysis of multidisciplinary data comprising thermal video-camera images, seismic, geodetic and geochemical data. We focused on the major explosion mechanism analyzing the well-recorded 1 December 2017 major explosion as a case study. We found that the 2017–2018 eruptive phase is consistent with a greater gas-rich magma supply in the shallow system. Furthermore, through the analysis of the case study major explosion, we identified precursory phases in the strainmeter and seismic data occurring 77 and 38 s before the explosive jet reached the eruptive vent, respectively. On the basis of these short-term precursors, we propose an automatic timely alarm system for major explosions at Stromboli volcano.
8
Aiuppa, A., M. Burton, P. Allard, T. Caltabiano, G. Giudice, S. Gurrieri, M. Liuzzo et G. Salerno. « First experimental evidence for the CO<sub>2</sub>-driven origin of Stromboli's major explosions ». Solid Earth Discussions 3, no 1 (19 avril 2011) : 411–30. http://dx.doi.org/10.5194/sed-3-411-2011.
Texte intégralRésumé :
Abstract. We report on the first detection of CO2 flux precursors of the till now unforecastable larger than normal ("major") explosions that intermittently occur at Stromboli volcano (Italy). Automated survey of the crater plume emissions in the period 2006–2010, during which 12 such explosions happened, demonstrate that these events are systematically preceded by a brief phase of increasing CO2/SO2 weight ratio (up to >40) and CO2 flux (>1300 t/d) with respect to the time-averaged values of 3.7 and ~500 t/d typical for standard Stromboli's activity. These signals are best explained by the accumulation of CO2-rich gas at a discontinuity of the plumbing system (decreasing CO2 emission at the surface), followed by increasing gas leakage prior to the explosion. Our observations thus support the recent model of Allard (2010) for a CO2-rich gas trigger of recurrent major explosions at Stromboli, and demonstrate the possibility to forecast these events in advance from geochemical precursors. These observations and conclusions have clear implications for monitoring strategies at other open-vent basaltic volcanoes worldwide.
9
Aiuppa, A., M. Burton, P. Allard, T. Caltabiano, G. Giudice, S. Gurrieri, M. Liuzzo et G. Salerno. « First observational evidence for the CO<sub>2</sub>-driven origin of Stromboli's major explosions ». Solid Earth 2, no 2 (19 juillet 2011) : 135–42. http://dx.doi.org/10.5194/se-2-135-2011.
Texte intégralRésumé :
Abstract. We report on the first detection of CO2 flux precursors of the till now unforecastable "major" explosions that intermittently occur at Stromboli volcano (Italy). An automated survey of the crater plume emissions in the period 2006–2010, during which 12 such explosions happened, demonstrated that these events are systematically preceded by a brief phase of increasing CO2/SO2 weight ratio (up to >40) and CO2 flux (>1300 t d−1) with respect to the time-averaged values of 3.7 and ~500 t d−1 typical for standard Stromboli's activity. These signals are best explained by the accumulation of CO2-rich gas at a discontinuity of the plumbing system (decreasing CO2 emission at the surface), followed by increasing gas leakage prior to the explosion. Our observations thus supports the recent model of Allard (2010) for a CO2-rich gas trigger of recurrent major explosions at Stromboli, and demonstrates the possibility to forecast these events in advance from geochemical precursors. These observations and conclusions have clear implications for monitoring strategies at other open-vent basaltic volcanoes worldwide.
10
Taylor, Steven R., et Farid U. Dowla. « Spectral yield estimation of NTS explosions ». Bulletin of the Seismological Society of America 81, no 4 (1 août 1991) : 1292–308. http://dx.doi.org/10.1785/bssa0810041292.
Texte intégralRésumé :
Abstract The yields of 299 NTS explosions have been estimated from Pn, Pg and Lg spectra (between 0.1 and 10 Hz) at four regional seismic stations. A spectral template matching technique is used where the spectra from an explosion of unknown yield are compared with the spectra of explosions of known yield. A matching function is defined that is a scaled inverse of the difference between the spectra from the known and unknown explosions. The yields from the seven closest matching explosions are then averaged to estimate the yield of the unknown event. The spectral matching technique appears to perform as well as standard regression techniques utilizing mb(Pn) and mb(Lg) measurements except that no geologic information (such as gas-filled porosity) is required. However, the spectral matching technique is only applicable to very well-calibrated test sites. The key to spectral matching is that the spectral shape is sensitive to the near-source geology. In addition to affecting the absolute spectral levels (i.e., coupling), the dynamic response of the near source material to the radiated shock wave is a major factor controlling the shape of the radiated spectra. The spectral shape can therefore be used as an indicator for predicting the coupling of an explosion, which can be subsequently used to predict its yield.
11
Ogunfuye, Samuel, Hayri Sezer, Furkan Kodakoglu, Hamed Farmahini Farahani, Ali S. Rangwala et V’yacheslav Akkerman. « Dynamics of Explosions in Cylindrical Vented Enclosures : Validation of a Computational Model by Experiments ». Fire 4, no 1 (15 février 2021) : 9. http://dx.doi.org/10.3390/fire4010009.
Texte intégralRésumé :
Recent explosions with devastating consequences have re-emphasized the relevance of fire safety and explosion research. From earlier works, the severity of the explosion has been said to depend on various factors such as the ignition location, type of a combustible mixture, enclosure configuration, and equivalence ratio. Explosion venting has been proposed as a safety measure in curbing explosion impact, and the design of safety vent requires a deep understanding of the explosion phenomenon. To address this, the Explosion Venting Analyzer (EVA)—a mathematical model predicting the maximum overpressure and characterizing the explosion in an enclosure—has been recently developed and coded (Process Saf. Environ. Prot. 99 (2016) 167). The present work is devoted to methane explosions because the natural gas—a common fossil fuel used for various domestic, commercial, and industrial purposes—has methane as its major constituent. Specifically, the dynamics of methane-air explosion in vented cylindrical enclosures is scrutinized, computationally and experimentally, such that the accuracy of the EVA predictions is validated by the experiments, with the Cantera package integrated into the EVA to identify the flame speeds. The EVA results for the rear-ignited vented methane-air explosion show good agreement with the experimental results.
12
Li, Juan, et Baofeng Tian. « Refined locations of major explosions in Tianjin Harbor ». Science Bulletin 60, no 21 (novembre 2015) : 1868–70. http://dx.doi.org/10.1007/s11434-015-0913-x.
Texte intégral
13
Bradley, D., G. A. Chamberlain et D. D. Drysdale. « Large vapour cloud explosions, with particular reference to that at Buncefield ». Philosophical Transactions of the Royal Society A : Mathematical, Physical and Engineering Sciences 370, no 1960 (13 février 2012) : 544–66. http://dx.doi.org/10.1098/rsta.2011.0419.
Texte intégralRésumé :
This paper first briefly surveys the energy releases in some major accidents. It then examines the analyses of the explosion at the Buncefield fuel storage site in the UK, one of the most intense accidental explosions in recent times. This followed the release of approximately 300 tonnes of winter-grade gasoline, when a 15 m high storage tank was overfilled for about 40 min before ignition of the resulting flammable mixture. The ensuing explosion was of a severity that had not been identified previously in a major hazard assessment of this type of facility. It was therefore imperative to investigate the event thoroughly and develop an understanding of the underlying mechanisms to inform future prevention, mitigation and land-use planning issues. The investigation of the incident was overseen by the Buncefield Major Incident Investigation Board. A separate Explosion Mechanism Advisory Group examined the evidence and reported on the severity of the explosion. It concluded that additional work was necessary and recommended that a two-stage project be initiated, phase 1 of which has been completed. The analyses of the damage and the derivation of explosion over-pressures are described. Possible explosion mechanisms and the evidence for them at Buncefield are discussed, in the light of other major incidents. Mechanisms that are reviewed include high-speed turbulent combustion, quasi-detonations, fully developed detonations, the generation of fireballs, flame instabilites, radiative heat transfer and aspects of two-phase burning. Of particular importance is the acceleration of turbulent flames along the line of trees and hedgerows. A number of conclusions are drawn and suggestions made for further research.
14
FRYER, CHRIS L. « STELLAR COLLAPSE ». International Journal of Modern Physics D 12, no 10 (décembre 2003) : 1795–835. http://dx.doi.org/10.1142/s0218271803004298.
Texte intégralRésumé :
The collapse of massive stars have been used to explain many of the largest outbursts known to mankind, from supernovae to hypernovae to gamma-ray bursts. These explosions differ in their level of asymmetry and the spectral energy of the photons they emit. It is likely that such a wide range in the nature of these explosions requires more than one explosion mechanism to extract the gravitational potential energy released during the collapse. Three major classes of mechanisms have been proposed: neutrino-driven, magnetic-field driven, collapsar (black hole accretion disk) driven. This review discusses each mechanism in turn, discussing the current state-of-the-art calculations along with their observational predictions. We conclude with a summary of the current observational constraints on these models.
15
Li, Feng Xu, et Yue Fang Yang. « Study on Safety Evaluation of Flammable Solid Railway Transportation Based on the Bayesian Network ». Applied Mechanics and Materials 409-410 (septembre 2013) : 1419–22. http://dx.doi.org/10.4028/www.scientific.net/amm.409-410.1419.
Texte intégralRésumé :
Taking the fact that the fire explosion is the major danger during the transportation of flammable solid into account, the paper proposes a Fault Tree (FT) model about fire explosions affected greatly by packing, loading and unloading, vehicles, management and other factors, and converts the FT model into Bayesian Network (BN) one for quantitative analysis. Finally, the paper uses the data based on the BN model to prove that the model and algorithm are feasible.
16
Ruiter, Ashley J. « Type Ia supernova sub-classes and progenitor origin ». Proceedings of the International Astronomical Union 15, S357 (octobre 2019) : 1–15. http://dx.doi.org/10.1017/s1743921320000587.
Texte intégralRésumé :
AbstractThis paper presents a short review on the current state of SN Ia progenitor origin. Type Ia supernova explosions (meaning thermonuclear disruption of a white dwarf) are observed to be widely diverse in peak luminosity, lightcurve width and shape, spectral features, and host stellar population environment. In the last decade alone, theoretical simulations and observational data have come together to seriously challenge the long-standing paradigm that all SNe Ia arise from explosions of Chandrasekhar mass white dwarfs. In this review I highlight some of the major developments (and changing views) of our understanding of the nature of SN Ia progenitor systems. I give a brief overview of binary star configurations and their plausible explosion mechanisms, and infer links between some of the various (observationally-categorized) SN Ia sub-classes and their progenitor origins from a theoretical standpoint.
17
Moore, Ronald L., Navdeep K. Panesar, Alphonse C. Sterling et Sanjiv K. Tiwari. « Bipolar Ephemeral Active Regions, Magnetic Flux Cancellation, and Solar Magnetic Explosions ». Astrophysical Journal 933, no 1 (28 juin 2022) : 12. http://dx.doi.org/10.3847/1538-4357/ac6181.
Texte intégralRésumé :
Abstract We examine the cradle-to-grave magnetic evolution of 10 bipolar ephemeral active regions (BEARs) in solar coronal holes, especially aspects of the magnetic evolution leading to each of 43 obvious microflare events. The data are from the Solar Dynamics Observatory: 211 Å coronal EUV images and line-of-sight photospheric magnetograms. We find evidence that (1) each microflare event is a magnetic explosion that results in a miniature flare arcade astride the polarity inversion line (PIL) of the explosive lobe of the BEAR’s anemone magnetic field; (2) relative to the BEAR’s emerged flux-rope Ω loop, the anemone’s explosive lobe can be an inside lobe, an outside lobe, or an inside-and-outside lobe; (3) 5 events are confined explosions, 20 events are mostly confined explosions, and 18 events are blowout explosions, which are miniatures of the magnetic explosions that make coronal mass ejections (CMEs); (4) contrary to the expectation of Moore et al., none of the 18 blowout events explode from inside the BEAR’s Ω loop during the Ω loop’s emergence; and (5) before and during each of the 43 microflare events, there is magnetic flux cancellation at the PIL of the anemone’s explosive lobe. From finding evident flux cancellation at the underlying PIL before and during all 43 microflare events—together with BEARs evidently being miniatures of all larger solar bipolar active regions—we expect that in essentially the same way, flux cancellation in sunspot active regions prepares and triggers the magnetic explosions for many major flares and CMEs.
18
Giurcan, Venera, Domnina Razus, Maria Mitu et Codina Movileanu. « Dynamics of Pressure Variation in Closed Vessel Explosions of Diluted Fuel/Oxidant Mixtures ». Processes 10, no 12 (16 décembre 2022) : 2726. http://dx.doi.org/10.3390/pr10122726.
Texte intégralRésumé :
Nitrous oxide is widely used as oxidizer or nitriding agent in numerous industrial activities such as production of adipic acid and caprolactam and even for production of some semiconductors. Further, it is used as an additive in order to increase the power output of engines, and as an oxidizer in propulsion systems of rockets, because it has a large heat of formation (+81.6 kJ mol−1). N2O is highly exothermic, and during its decomposition a supplementary heat amount is released, so it needs special handling conditions. The combustion of fuels in nitrous oxide atmosphere can lead to high unstable and turbulent deflagrations that speedily self-accelerate and therefore a deflagration can change to a detonation. The peak explosion pressure and the maximum rate of pressure rise of explosions in confined spaces are key safety parameters to evaluate the hazard of processes running in closed vessels and for design of enclosures able to withstand explosions or of their vents used as relief devices. The present study reports some major explosion parameters such as the maximum (peak) explosion pressures pmax, explosion times θmax, maximum rates of pressure rise (dp/dt)max and severity factors KG for ethylene-nitrous oxide mixtures (lean and stoichiometric) diluted with various amounts of N2, at various initial pressures (p0 = 0.50–1.50 bar), in experiments performed in a spherical vessel centrally ignited by inductive-capacitive electric sparks. The influence of the initial pressure and composition on pmax, θmax and (dp/dt)max is discussed. The data are compared with similar values referring to ethylene-air mixtures measured in the same initial conditions. It was found that at identical C/O ratios with ethylene-air, ethylene-N2O-N2 mixtures develop higher explosion pressures and higher rates of pressure rise, due to the exothermic dissociation of N2O under flame conditions.
19
Calvari, Sonia, Flora Giudicepietro, Federico Di Traglia, Alessandro Bonaccorso, Giovanni Macedonio et Nicola Casagli. « Variable Magnitude and Intensity of Strombolian Explosions : Focus on the Eruptive Processes for a First Classification Scheme for Stromboli Volcano (Italy) ». Remote Sensing 13, no 5 (3 mars 2021) : 944. http://dx.doi.org/10.3390/rs13050944.
Texte intégralRésumé :
Strombolian activity varies in magnitude and intensity and may evolve into a threat for the local populations living on volcanoes with persistent or semi-persistent activity. A key example comes from the activity of Stromboli volcano (Italy). The “ordinary” Strombolian activity, consisting in intermittent ejection of bombs and lapilli around the eruptive vents, is sometimes interrupted by high-energy explosive events (locally called major or paroxysmal explosions), which can affect very large areas. Recently, the 3 July 2019 explosive paroxysm at Stromboli volcano caused serious concerns in the local population and media, having killed one tourist while hiking on the volcano. Major explosions, albeit not endangering inhabited areas, often produce a fallout of bombs and lapilli in zones frequented by tourists. Despite this, the classification of Strombolian explosions on the basis of their intensity derives from measurements that are not always replicable (i.e., field surveys). Hence the need for a fast, objective and quantitative classification of explosive activity. Here, we use images of the monitoring camera network, seismicity and ground deformation data, to characterize and distinguish paroxysms, impacting the whole island, from major explosions, that affect the summit of the volcano above 500 m elevation, and from the persistent, mild explosive activity that normally has no impact on the local population. This analysis comprises 12 explosive events occurring at Stromboli after 25 June 2019 and is updated to 6 December 2020.
20
Mozaffarpour Taromi, MohammadReza, et Hossein Khosravi. « The Response of Residents of the Building and Non-structural Components, in Contrast to Explosions at Ground Level from the Standpoint of Passive Defense ». Civil Engineering Journal 5, no 2 (26 février 2019) : 495. http://dx.doi.org/10.28991/cej-2019-03091262.
Texte intégralRésumé :
The research by non-military research associations and assemblies on explosion have increased due to the growth in the death and damage rates resulting from explosion, particularly blasts induced by terroristic invasions which mostly occur on the ground. Most studies are conducted with a major focus on strengthening the structures against explosions. Further, scholars have focused on resistance and ductility criteria required for the design and control over structural elements. Now, the question is whether the health of a structure can represent its inhabitants’ health. Few studies have been done on the convenience of inhabitants and response of non-structural elements, which are limited to impact of vibrations on high-rise structures caused by the loads imposed by wind and earthquake. The important factors relevant to the health and convenience of building inhabitants are as follows: speed, acceleration, and variations in the acceleration of floors.In this paper, the aforementioned parameters are measured, according to which the convenience and health of inhabitants were assessed. For this purpose, two 4-story and 8-story buildings were selected on which four selective explosions were applied. The results were then presented in two forms of maximum values and dynamic response by performing dynamic modal linear time history analysis. The building's response under typical forces such as dead and live and earthquake forces was remarkably desirable and the behavior remained linear, but the building’s acceleration may cause serious injuries in terms of human comfort criteria. The obtained results indicated that the healthy state of the structure does not represent the health of the building inhabitants. Further, although the building was safe against the elective blasts, the lateral accelerations were capable of imposing significant damages to the building residents. This can be considered as a criterion for control and future designs from a passive defense point of view, as the explosions induced by terroristic attacks is increasing.
21
Cioca, Ionel-Lucian, et Roland Iosif Moraru. « Explosion and/or fire risk assessment methodology : a common approach, structured for underground coalmine environments / Metoda szacowania ryzyka wybuchu i pożarów : podejście ogólne, dostosowane do środowiska kopalni podziemnej ». Archives of Mining Sciences 57, no 1 (29 octobre 2012) : 53–60. http://dx.doi.org/10.2478/v10267-012-0004-7.
Texte intégralRésumé :
In order to meet statutory requirements concerning the workers health and safety, it is necessary for mine managers within Valea Jiului coal basin in Romania to address the potential for underground fires and explosions and their impact on the workforce and the mine ventilation systems. Highlighting the need for a unified and systematic approach of the specific risks, the authors are developing a general framework for fire/explosion risk assessment in gassy mines, based on the quantification of the likelihood of occurrence and gravity of the consequences of such undesired events and employing Root-Cause analysis method. It is emphasized that even a small fire should be regarded as being a major hazard from the point of view of explosion initiation, should a combustible atmosphere arise. The developed methodology, for the assessment of underground fire and explosion risks, is based on the known underground explosion hazards, fire engineering principles and fire test criteria for potentially combustible materials employed in mines.
22
Ngo, Tuan, Priyan Mendis, A. Gupta et J. Ramsay. « Blast Loading and Blast Effects on Structures – An Overview ». Electronic Journal of Structural Engineering, no 1 (1 janvier 2007) : 76–91. http://dx.doi.org/10.56748/ejse.671.
Texte intégralRésumé :
The use of vehicle bombs to attack city centers has been a feature of campaigns by terrorist organizations around the world. A bomb explosion within or immediately nearby a building can cause catastrophic damage on the building's external and internal structural frames, collapsing of walls, blowing out of large expanses of windows, and shutting down of critical life-safety systems. Loss of life and injuries to occupants can result from many causes, including direct blast-effects, structural collapse, debris impact, fire, and smoke.The indirect effects can combine to inhibit or prevent timely evacuation, thereby contributing to additional casualties. In addition, major catastrophes resulting from gas-chemical explosions result in large dynamic loads, greater than the original design loads, of many structures. Due to the threat from such extreme loading conditions, efforts have been made during the past three decades to develop methods of structural analysis and design to resist blast loads. The analysis and design of structures subjected to blast loads require a detailed understanding of blast phenomena and the dynamic response of various structural elements. This paper presents a comprehensive overview of the effects of explosion on structures. An explanation of the nature of explosions and the mechanism of blast waves in free air is given. This paper also introduces different methods to estimate blast loads and structural response.
23
Baldino, Gennaro, Chiara Stassi, Cristina Mondello, Antonio Bottari, Stefano Vanin et Elvira Ventura Spagnolo. « Forensic investigative issues in a fireworks production factory explosion ». International Journal of Legal Medicine 135, no 4 (12 mai 2021) : 1647–54. http://dx.doi.org/10.1007/s00414-021-02564-5.
Texte intégralRésumé :
AbstractSince their discovery in ancient China, fireworks rapidly spread throughout the world, where they have always been used to celebrate either popular or private events. Their use is nonetheless related to several risks, especially within production factories, since several injuries or even death can occur following an accidental ignition. In cases of major disasters related to fireworks explosions, stating the accidental or intentional nature of the event might prove challenging, thus raising the need of a multidisciplinary approach. In this regard, we here discuss the case of an accidental explosion that occurred in a fireworks production factory, accountable for five deaths and two hospitalisations.
24
Jane Arthur, S. « Supernova explosions in stellar wind bubbles ». Symposium - International Astronomical Union 148 (1991) : 331–33. http://dx.doi.org/10.1017/s0074180900200715.
Texte intégralRésumé :
Type II supernovae play a major role in the dynamics of the interstellar medium. The interstellar medium in which such supernovae evolve is often considerably modified by the strong stellar winds both from the progenitor and other nearby stars. The result is that the appearance and energetics of the remnants can be very different from that of remnants in a uniform medium. In this paper we will consider the evolution of supernova remnants in stellar wind bubbles including the effect of departures from spherical symmetry. The aim is to understand both the appearance of such remnants and their effect on the overall energetics of the interstellar medium.
25
Králik, Juraj, et Michal Baran. « Numerical Analysis of the Exterior Explosion Effects on the Buildings with Barriers ». Applied Mechanics and Materials 390 (août 2013) : 230–34. http://dx.doi.org/10.4028/www.scientific.net/amm.390.230.
Texte intégralRésumé :
Generation and transmission of blast waves in real terrains is of major importance for risk analysis procedures involving accidental explosion scenarios. This paper aims to show the approach to addressing air pressure waves from explosions using empirical formulas and compare them with numerical computations, which is solved using the computational program AUTODYN. Simulation of a simple model of the building is presented in the interaction with the air pressure wave caused by the explosion, which is initiated at a distance of 30 meters from the front of the building. The explosion process will be shown in 2D axial plane which is then remapped into Eulerian multi-material 3D space using the interaction of the rigid obstacles. The weight of 1000 kg TNT charge is used, which is located one meter above the ground and represents the explosive placed in a car in accordance with FEMA requirements. The effects of the protection structures are investigated.
26
KRZYSTAŁA, Edyta, Arkadiusz MĘŻYK et Sławomir KCIUK. « ANALYSIS OF THREAT TO CREW POSED BY EXPLOSION OF CHARGE PLACED UNDER WHEELED ARMOURED VEHICLE ». Scientific Journal of the Military University of Land Forces 159, no 1 (3 janvier 2011) : 145–54. http://dx.doi.org/10.5604/01.3001.0002.2892.
Texte intégralRésumé :
Provision of proper protection against landmines is a major aim of modern military vehicle designs. The point of developing the methods and means of countermine protection is to identify the shock wave impact on a vehicle construction and its crew. Information on overload coming from landmine explosions on a person are strictly confidential or not detailed enough. The basis to obtain them is to carry out experimental and numerical tests. This article presents basic issues and threats to crews as a result of landmine, IED or EFP explosions carried out by terrorists. The literature published has helped the authors to identify the main parts of body prone to the impulse load of a shock wave explosion on a wheeled military vehicle. The methodology and sample results of experimental tests identifying the shock wave load on a vehicle and its crew in a characteristic anthropometrics points of body are presented as well. Injury criteria and crew threat levels resulting from explosive load under a vehicle and its close area are outlined. The aim of such a complex analysis of shock wave load over wheeled military vehicles and their crews is the development of modern and effective protection devices.
27
NAKHAEI, Jalal, Mahdi BITARAFAN, Shahin LALE AREFI et Oleg KAPLIŃSKI. « MODEL FOR RAPID ASSESSMENT OF VULNERABILITY OF OFFICE BUILDINGS TO BLAST USING SWARA AND SMART METHODS (A CASE STUDY OF SWISS RE TOWER) ». JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT 22, no 6 (8 juin 2016) : 831–43. http://dx.doi.org/10.3846/13923730.2016.1189457.
Texte intégralRésumé :
Accidental and intentional explosions are incidents often destroying buildings and leaving casualties. As a result of these blasts all over the world, demand of safe constructions with less vulnerability to explosions is rising. A large number of office buildings are built each year in many countries, housing large numbers of staff and clients, and due to specific nature and function, activities and services, these buildings are usually centrally located. Their architectural form being vital, therefore the article attempts, firstly, to present indices depicting the building form from the viewpoint of vulnerability to explosion. Secondly, the article presents such indexes as: capability to reduce blast effects, economic factors, simplicity of implementation, relationship among spaces in the crisis condition, and creating the least unusable space. The model of rapid assessment of vulnerability of office buildings forms to blast, SMART (simple multi attribute ranking technique) procedure is used and, applying the SWARA method, the weight of each major index and sub-index is arrived at. The model presented in the paper shows the assessment systems using figures between zero and a hundred, and four levels of vulnerability: weak, medium, good and excellent. The closer the figure to a hundred, the lower the vulnerability of the office building forms to blast. Swiss Re Tower case study was presented in the article rating of vulnerability of this building against explosion. It was found to be equal to 62.11%, and its standing was at medium level.
28
Librescu, Liviu, Sang-Yong Oh et Jorg Hohe. « Implication of Nonclassical Effects on Dynamic Response of Sandwich Structures Exposed to Underwater and In-Air Explosions ». Journal of Ship Research 51, no 02 (1 juin 2007) : 83–93. http://dx.doi.org/10.5957/jsr.2007.51.2.83.
Texte intégralRésumé :
A study devoted to the dynamic response of sandwich panels to underwater and in-air explosions is presented. The study is carried out in the context of a geometrically nonlinear model of sandwich structures featuring anisotropic laminated face sheets and a transversely compressible orthotropic core. The unsteady pressure generated by the explosion and acting on the face of the sandwich panel includes the effect of the pressure wave transmission through the core. Its implications on the structural time-histories as corresponding to the underwater and in-air explosions are put into evidence. The effects of the transverse core compressibility on dynamic response are highlighted. In this sense, one of its major implications is the possibility to capture interactively the global and local (wrinkling) dynamic response of the panel. It is shown that implementation of the structural tailoring technique in the face sheets can constitute an important mechanism for enhancing the dynamic load-carrying capacity of sandwich panels when exposed to blast pulses. Effects of the core, the composite architecture of face sheets, orthotropy of the material of the core, geometrical non-linearities, initial geometric imperfection, and the damping ratio are investigated, and their implications for the dynamic response are highlighted. The comprehensive structural model considered in conjunction with the time-dependent loads generated by the underwater and in-air explosions, and the results obtained in this context, are expected to contribute to a better understanding of the response behavior and to be instrumental toward a better design of these structures.
29
Kontogeorgos, Miltiadis, et Clemente Fuggini. « Meta-Material Layout for the Protection of Buried Steel Pipes against Surface Explosion ». Geotechnics 2, no 2 (31 mai 2022) : 427–40. http://dx.doi.org/10.3390/geotechnics2020020.
Texte intégralRésumé :
This paper reports on preliminary yet consistent studies and results around the concept of meta-material applied to the protection of buried gas transmission pipelines. The capacity of the proposed meta-material layout in attenuating and dissipating the energy induced by a surface explosion is described in general terms, and then it is examined for a set of nine realistic cases. The formulation of the band gaps, which are considered zones of mitigation for the incident waves of certain frequencies, composes the core of the analysis. For the calculation of the band gaps that target a specific range of frequencies, the 1D periodic structures’ theory is adopted, and the results have been verified numerically via COMSOL. The layout is tested for nine cases of surface explosions via finite element analyses in ABAQUS, using the CONWEP model for simulating the surface explosions. Extremely satisfying results are demonstrated regarding the reduction in the vertical and horizontal displacements of the buried steel pipe. The outer goal of the present study is to spotlight the implementation of meta-material concepts for the efficient blast protection of underground structures, addressing a major hazard for this type of structure and a gap in the current literature.
30
Eckhoff, Rolf K. « Dust Explosion Prevention and Mitigation, Status and Developments in Basic Knowledge and in Practical Application ». International Journal of Chemical Engineering 2009 (2009) : 1–12. http://dx.doi.org/10.1155/2009/569825.
Texte intégralRésumé :
Right from the early days of the process industries, continuous efforts have been made to develop and improve measures for prevention and mitigation of dust explosions in these industries. Nevertheless this hazard continues to threaten industries that manufacture, use and/or handle powders and dusts of a wide range of combustible materials. To improve methods for predicting explosion development in real industrial plant has been one major challenge. Hence, during the last years comprehensive numerical simulation codes, for addressing this problem, have been developed. Progress has also been made in other areas, for example, ignition source prevention. The importance of adopting inherently safer process design, by building on firm knowledge in powder science and technology, and of systematic education/training of personnel, is also emphasized.
31
Lloyd, David, David Yates et Tim Coats. « Preparing the country for another major terrorist event ». Bulletin of the Royal College of Surgeons of England 88, no 1 (1 janvier 2006) : 10–11. http://dx.doi.org/10.1308/147363506x85840.
Texte intégralRésumé :
The explosions in London on 7 July 2005 led to scenes of human and structural devastation not experienced since the second world war. The blast injuries that predominated were outside the experience of most contemporary emergency workers. Nevertheless, the general impression is that the response by the various emergency services seems to have been well organised and effective. However, there will no doubt also be lessons to be learned for the future. This successful response can be attributed to the level of disaster preparedness that has been developed in London (as in other parts of the country) following previous terrorist attacks and transport accidents; in addition, in the case of the emergency care of the injured there was the availability of medical expertise and facilities.
32
Vătavu, Niculina, Mihaela Părăian, Sorin Vătavu et Mihai Popa. « Considerations regarding test methods against dust and water ingress protection for Ex equipment ». MATEC Web of Conferences 354 (2022) : 00048. http://dx.doi.org/10.1051/matecconf/202235400048.
Texte intégralRésumé :
The explosion danger in all industries where explosive atmospheres generated by the mixture of combustible dusts or flammable gases with air may form, must be treated as a major hazard, as the explosions that may occur can seriously affect both health and safety people, as well as the environment. It is therefore necessary to assess the explosion risk and to establish appropriate measures to reduce it to acceptable levels in accordance with the requirements of the European Directives. An essential element in the assessment of the explosion risk for electrical and non-electrical equipment intended for use in potentially explosive atmospheres is the way in which an appropriate normal degree of protection is provided through the equipment housing (protection against touching of dangerous parts inside the equipment housing and protection against the ingress of dust and water inside it). The aim of the paper is to highlight compliance with the requirements of the ATEX Directive, given that this protection is a basic requirement for explosion protection and to present the important elements to be considered for the assessment of the normal degree of protection and the development of harmonized test methods with the requirements of European standards.
33
Park, Sang-Hyun, Kwang-Hyun Bang et Jong-Rae Cho. « Structural Integrity Evaluation of a Reactor Cavity during a Steam Explosion for External Reactor Vessel Cooling ». Energies 14, no 12 (17 juin 2021) : 3605. http://dx.doi.org/10.3390/en14123605.
Texte intégralRésumé :
Nuclear power is a major source of electricity in the international community. However, a significant problem with nuclear power is that, if a severe nuclear accident occurs, radiation may leak and cause great damage. As such, research on nuclear safety has become increasingly popular worldwide. In this paper, the structural integrity of a reactor cavity during a steam explosion—one kind of the aforementioned severe nuclear accidents—was evaluated. Steam explosions are primarily caused by fuel–coolant interactions (FCI), and result from issues in the cooling system that discharges the melt from the reactor core to the outside. A steam explosion can damage the nuclear power plant, and radiation leakage, the greatest concern, may occur. In the Chernobyl or Fukushima Daiichi accidents, significant radiation leakages resulted in damages extending beyond the country of origin. In this paper, a steam explosion was simulated using values given by the transient analysis code for explosive reactions (TRACER-II)—the only steam explosion code in Korea. The walls of the reactor cavity were modeled after the APR-1400 currently operating in Korea. The integrity of the concrete, rebars, and liner plate in the reactor cavity during a steam explosion was evaluated in terms of stress and ductile failure strain limits.
34
Novozhilov, V. « Some aspects of the mathematical modelling of fireballs ». Proceedings of the Institution of Mechanical Engineers, Part E : Journal of Process Mechanical Engineering 217, no 2 (1 mai 2003) : 103–21. http://dx.doi.org/10.1243/095440803766612775.
Texte intégralRésumé :
The development of large-scale fireballs is a typical result of explosions associated with accidental fuel releases in the oil and process industries. The two major mechanisms that lead to fireball formation are vapour cloud explosions and boiling liquid expanding vapour explosions (BLEVEs). An ability to model fireballs is extremely important from the point of view of safety and risk analysis. The present paper provides a state-of-the-art review of the computational techniques available for the mathematical modelling of fireballs. The emphasis is placed on computational fluid dynamics (CFD) modelling, based on Reynolds-averaged Navier—Stokes (RANS) equations for reactive flow. The results of calculations and estimations of fireball hazards are compared with available experimental data. New results are presented for problems that are usually given less attention in fireball studies. These concern estimations of air entrainment rates into fireballs and potential strategies for fireball suppression.
35
Katarína Mäkká, Katarína Kampová et Jacek Dworzecki. « Prevention of Major Accidents of Mobile Risk Sources ». Communications - Scientific letters of the University of Zilina 23, no 3 (1 juillet 2021) : F116—F122. http://dx.doi.org/10.26552/com.c.2021.3.f116-f122.
Texte intégralRésumé :
At present, the issue of public safety in the production and manipulation of hazardous chemicals deserves more attention, since various major accidents such as fires, explosions and toxic gas releases take place frequently. The issue of prevention of emergency events has become more and more topical. The growing amount of hazardous substances transported leads to increased risk of emergencies. In order to reduce this risk in the transport of hazardous substances, a number of technical, operational, traffic and safety conditions and requirements must be fulfilled. These all contribute to the reduction of hazards and risks. The aim of the presented article was to determine the extent of the danger zone in the event of a gasoline leak due to a traffic accident in a built-up urban area with a high frequency of traffic and population movement.
36
Shemer, Joshua, Ori Heller et Jakov Adler. « Lessons from the Israel Defense Forces Medical Corps' Experience in the Organization of International Medical Disaster Relief Forces ». Prehospital and Disaster Medicine 7, no 3 (septembre 1992) : 282–84. http://dx.doi.org/10.1017/s1049023x00039649.
Texte intégralRésumé :
Natural and man-made disasters continue to be a major cause of morbidity and mortality. Natural disasters include earthquakes, storms such as hurricanes, floods, fires, drought. Man-made disasters include fires, explosions, chemical and radioactive releases, major transportation accidents, terrorism, and war. The effects of disaster include injury, death, damage to infrastructure, environmental exposure, population movement, and increased incidence of communicable diseases.
37
KORSHUNOV, Gennady I., Marat L. RUDAKOV et Eugeniy I. KABANOV. « The Use of a Risk-Based Approach in Safety Issues of Coal Mines ». Journal of Environmental Management and Tourism 9, no 1 (24 juin 2018) : 181. http://dx.doi.org/10.14505//jemt.v9.1(25).23.
Texte intégralRésumé :
The paper contains the analysis of the data on major industrial accidents and occupational injuries at the coal mine industry enterprises of Russia in order to reveal statistically significant correlations between the indicators impacting the accident rate and the employees’ death risk level. As the risk criteria, the values of the methane-air resultant mixtures (MARM) explosions frequency and the frequency of the staff exposure at MARM explosions in the mines (observed levels of personal risks) are taken. The Kolmogorov–Smirnov test and Kruskal–Wallis test are used to analyze the categorized data samplings over the period from 2005 to 2016. The authors have defined the influence of relative gas content and hazard of layers regarding spontaneous combustion on the MARM explosions frequency. The regression models that take into consideration the impact of hazardous factors on the risk indicators have been received. The results of the performed coal mines ranging in Russia have been presented according to the level of individual risk, caused by MARM explosions; the received results have been compared with the acceptable tolerable risk level. The relevance of applying the research findings has been shown at the implementation of the dynamic model of the risk-based approach for ensuring coal mines safe exploitation.
38
Vashchenko, Volodymyr M., Volodymyr I. Skalozubov, Iryna B. Korduba, Serhiy I. Kosenko et Olena H. Zhukova. « Criteria of thermochemical conditions of steam gas explosions in dynamic accident modes at nuclear power units with WWER reactors ». Environmental safety and natural resources 44, no 4 (29 décembre 2022) : 128–34. http://dx.doi.org/10.32347/2411-4049.2022.4.128-134.
Texte intégralRésumé :
The main lessons of the major accident at the Fukushima-Daiichi NPP in 2011 for the nuclear power industry identify the need to model, analyze and develop emergency measures for relatively unlikely events with catastrophic environmental consequences, taking into account multiple failures of safety systems. Steam-gas explosions became one of the main causes of the catastrophic environmental consequences of the Chernobyl and Fukushima accidents. Criteria and conditions for the occurrence of steam-gas explosions in dynamic emergency modes in the "tight" reactor circuit of nuclear power reactor units (NPP) with water-water reactors (WWER) with failures of safety systems valves and emergency steam gas removal are determined by the rate of change of thermodynamic and physico-chemical parameters. A method for determining the criteria and conditions for the occurrence of steam-gas explosions in dynamic accident modes with a "tight" reactor circuit and failure of safety valves for modeling the initial emergency events – seismic effects, falling of massive objects, etc. is presented. The conditions for the occurrence of hydrogen explosions are determined by the maximum rate of increase in the temperature of fuel oil shells, and the conditions for steam explosions are determined by the maximum rate of pressure increase as a result of the intensification of vaporization processes. The criteria for the occurrence of steam explosions in dynamic emergency modes are determined by the maximum pressure amplitude and the propagation speed of acoustic disturbances in the steam volume. And the criteria for hydrogen detonation in dynamic emergency modes are determined by the maximum amplitude of the increase in the temperature of the fuel shells and the average flow rate of the coolant in the active zone of the reactor.
39
Hinton, J. A., et R. L. C. Starling. « High-energy emission from transients ». Philosophical Transactions of the Royal Society A : Mathematical, Physical and Engineering Sciences 371, no 1992 (13 juin 2013) : 20120279. http://dx.doi.org/10.1098/rsta.2012.0279.
Texte intégralRésumé :
Cosmic explosions dissipate energy into their surroundings on a very wide range of time scales: producing shock waves and associated particle acceleration. The historical culprits for the acceleration of the bulk of Galactic cosmic rays are supernova remnants: explosions on approximately 10 4 year time scales. Increasingly, however, time-variable emission points to rapid and efficient particle acceleration in a range of different astrophysical systems. Gamma-ray bursts have the shortest time scales, with inferred bulk Lorentz factors of approximately 1000 and photons emitted beyond 100 GeV, but active galaxies, pulsar wind nebulae and colliding stellar winds are all now associated with time-variable emission at approximately teraelectron volt energies. Cosmic photons and neutrinos at these energies offer a powerful probe of the underlying physical mechanisms of cosmic explosions, and a tool for exploring fundamental physics with these systems. Here, we discuss the motivations for high-energy observations of transients, the current experimental situation, and the prospects for the next decade, with particular reference to the major next-generation high-energy observatory, the Cherenkov Telescope Array.
40
Vătavu, Niculina, Sorin Vătavu et Mihai Popa. « Quality assurance issues for normal grade testing protection provided by equipment housings Ex ». MATEC Web of Conferences 373 (2022) : 00045. http://dx.doi.org/10.1051/matecconf/202237300045.
Texte intégralRésumé :
Potentially explosive atmospheres generated by the raw materials used, intermediate / final products or the resulting waste may form in all industries involving flammable / combustible substances. Thecreation of these atmospheres must be treated as a major risk, as the fires or explosions that may occur affect human health and safety as well as the environment. Reducing these risks requires the assessment of the risk of explosion and the establishment of measures to reduce it to acceptablelevels in accordance with the requirements of European standards and the ATEX Directive.The general standard SR EN 60079-0 requires that only electrical / non-electrical equipment, certified for safe use, be used in hazardous areas Ex, which must ensure an appropriate normal degree of protection through the outer casing, as this protection is a requirement basic explosion protection.The tests for determining the degree of protection were carried out in accordance with harmonized European requirements and in the area of high-performance stands in accordance with SR EN ISO / IEC 17025, and the validity of the test results was demonstrated by successful participation in interlaboratory competitions and test of laboratory competition.
41
Inguaggiato, Salvatore, Fabio Vita, Marianna Cangemi et Lorenzo Calderone. « Changes in CO2 Soil Degassing Style as a Possible Precursor to Volcanic Activity : The 2019 Case of Stromboli Paroxysmal Eruptions ». Applied Sciences 10, no 14 (10 juillet 2020) : 4757. http://dx.doi.org/10.3390/app10144757.
Texte intégralRésumé :
Paroxysmal explosions are some of the most spectacular evidence of volcanism on Earth and are triggered by the rapid ascent of volatile-rich magma. These explosions often occur in persistently erupting basaltic volcanoes located in subduction zones and represent a major hazard due to the sudden occurrence and wide impact on the neighboring populations. However, the recognition of signals that forecast these blasts remains challenging even in the best-monitored volcanoes. Here, we present the results of the regular monitoring of soil CO2 flux from a fumarole field at the summit of Stromboli (Italy), highlighting that the 2016–2019 period was characterized by two important phases of strong increases of volatile output rate degassing (24 g m2 d−2 and 32 g m2 d−2, respectively) and moreover by significant changes in the degassing style few months before the last paroxysmal explosions occurred in the summer 2019 (3 July and 28 August). Establish that the deep portions of a volcano plumbing system are refilled by new volatiles-rich magma intruding from the mantle is therefore a key factor for forecasting eruptions and helping in recognizing possible precursors of paroxysmal explosions and could be highlighted by the monitoring of soil CO2 flux. The abrupt increase of degassing rate coupled with the strong increase of fluctuating signal (daily natural deviation) recorded during 2019 at Stromboli could be the key to predicting the occurrence of paroxysmal events.
42
Sahni, Varun. « Ya. B. Zeldovich (1914-1987) Chemist, Nuclear Physicist, Cosmologist ». Proceedings of the International Astronomical Union 11, S308 (juin 2014) : 25–31. http://dx.doi.org/10.1017/s1743921316009583.
Texte intégralRésumé :
Yakov Borisovich Zeldovich was remarkably talented.† His active scientific career included major contributions in fields as diverse as chemical physics (adsorption & catalysis), the theory of shock waves, thermal explosions, the theory of flame propogation, the theory of combustion & detonation, nuclear & particle physics, and, during the latter part of his life: gravitation, astrophysics and cosmology (Zeldovich 1992).
43
Moriya, Takashi J., Akihiro Suzuki, Tomoya Takiwaki, Yen-Chen Pan et Sergei I. Blinnikov. « Systematic investigation of the effect of 56Ni mixing in the early photospheric velocity evolution of stripped-envelope supernovae ». Monthly Notices of the Royal Astronomical Society 497, no 2 (3 août 2020) : 1619–26. http://dx.doi.org/10.1093/mnras/staa2060.
Texte intégralRésumé :
ABSTRACT Mixing of 56Ni, whose nuclear decay energy is a major luminosity source in stripped-envelope supernovae, is known to affect the observational properties of stripped-envelope supernovae such as light-curve and colour evolution. Here we systematically investigate the effect of 56Ni mixing on the photospheric velocity evolution in stripped-envelope supernovae. We show that 56Ni mixing significantly affects the early photospheric velocity evolution. The photospheric velocity, which is often used to constrain the ejecta mass and explosion energy, significantly varies by just changing the degree of 56Ni mixing. In addition, the models with a small degree of 56Ni mixing show a flattening in the early photospheric velocity evolution, while the fully mixed models show a monotonic decrease. The velocity flattening appears in both helium and carbon+oxygen progenitor explosions with a variety of ejecta mass, explosion energy, and 56Ni mass. Some stripped-envelope supernovae with early photospheric velocity information do show such a flattening. We find that Type Ib SN 2007Y, which has early photospheric velocity information, has a signature of a moderate degree of 56Ni mixing in the photospheric velocity evolution and about half of the ejecta is mixed in it. The immediate spectroscopic follow-up observations of stripped-envelope supernovae shortly after the explosion providing the early photospheric evolution give an important clue to constrain 56Ni mixing in the ejecta.
44
Thivaharan, Yalini, et Indira Deepthi Gamage Kitulwatte. « Medico-Legal Opinion Based on Autopsy Findings of a Victim of an Explosion Involving Mass Fatality ». Academic Forensic Pathology 10, no 3-4 (décembre 2020) : 158–65. http://dx.doi.org/10.1177/1925362120983669.
Texte intégralRésumé :
Introduction: Investigation into explosions is one of the major areas in forensic medicine and pathology. Medico legal issues associated with these deaths are diverse and forensic experts are often expected to make clarifications. Assistance of a methodical scientific investigation of such a death in evaluation of unanswered medico legal issues, of an autopsy of one of the victims of Easter Sunday explosions is discussed. Case history: The deceased was a 15-year-old girl who was participating in the Easter mass at St. Sebastian’s Church - Kattuwapaitya, Negombo, Sri Lanka when a suicide bomber blew himself up. The mother of the deceased noticed the deceased being rushed to the hospital. However, she was pronounced dead on admission. Pre-autopsy radiology revealed spherical shrapnel in the temporal region. At autopsy, the fatal injury was found on the head and a detailed study revealed skull fractures associated with penetration by 3 shrapnels. There was a keyhole lesion among the penetrations. Internal examination revealed an extensive dural tear underlying the compound fracture. The brain was grossly edematous with lacerations on the frontal and parietal lobes associated with localized subarachnoid hemorrhage. There were multiple underlying contusions on bilateral frontal white matter. Small subarachnoid haemorrhage was noted on the basal aspect of the brain. Discussion: Careful evaluation of the autopsy findings assisted in formulating the opinion scientifically on event reconstruction including the proximity of the victim to the epicenter of explosion and nature of explosive device, period of survival, mechanism of causation of skull fractures and the mechanism of death in addition to the cause of death. Conclusion: A forensic pathologist following a meticulous autopsy examination, along with a team of ballistic experts and specially trained police personnel play a pivotal task in analyzing a scene of explosion and an autopsy of a victim, in concluding the case and in bringing justice to all the victims and survivors of the catastrophe.
45
Ling, June. « The Evolution of the ASME Boiler and Pressure Vessel Code ». Journal of Pressure Vessel Technology 122, no 3 (7 avril 2000) : 242–46. http://dx.doi.org/10.1115/1.556180.
Texte intégralRésumé :
This paper describes the evolution of the ASME Boiler and Pressure Vessel Code from its inception in 1911 to the year 2000. It begins with the need of State government to protect its citizenry from the growing frequency of boiler explosions to its current stature as an international standard that facilitates global trade and commerce. A description of the major milestones in code development is provided. [S0094-9930(00)01803-5]
46
Valenti, Michael. « Nowhere to Hide ». Mechanical Engineering 121, no 07 (1 juillet 1999) : 57–59. http://dx.doi.org/10.1115/1.1999-jul-4.
Texte intégralRésumé :
This article discusses about a global monitoring system that detects nuclear detonations either in remote areas or underground. Scientists at the US Department of Energy’s Pacific Northwest National Laboratory have developed the Automated Radioxenon Sampler/Analyzer (ARSA), and the Radionuclide Aerosol Sampler/Analyzer (RASA), to provide more detailed and accurate data on surreptitious nuclear detonations faster than other systems. According to the test ban treaty, in the event of a valid question regarding whether a nuclear detonation has taken place, any member state may request onsite inspections of any other state party, or in any area beyond government jurisdiction , such as the open ocean. ARSA analyzes air samples for radioactive xenon, or xenon isotopes, primarily xenon 133 and xenon 135, which are major indicators of fission that seep into the atmosphere from underground nuclear explosions. Detonating atomic weapons beneath the earth is the primary method of avoiding detection. RASA is designed to detect fission products from atmospheric nuclear explosions that attach themselves to dust particles.
47
Scott, Christopher J., et Patrick Major. « The ionospheric response over the UK to major bombing raids during World War II ». Annales Geophysicae 36, no 5 (26 septembre 2018) : 1243–54. http://dx.doi.org/10.5194/angeo-36-1243-2018.
Texte intégralRésumé :
Abstract. The Earth's ionosphere is subject to disturbance from above (via solar variability and space-weather effects) and from below (such as tectonic activity, thunderstorms and sudden stratospheric warmings). Identifying the relative contribution of these effects remains challenging, despite recent advances in spacecraft monitoring near-Earth space. Man-made explosions provide a quantifiable proxy for natural terrestrial sources, enabling their impact on ionospheric variability to be studied. In this paper, the contribution of ground-based disturbances to ionospheric variability is investigated by considering the response of the ionospheric F2 layer over Slough, UK, to 152 major bombing raids over Europe during World War II, using a superposed epoch analysis. The median response of the F2 layer is a significant decrease in peak electron concentration (∼0.3 MHz decrease in foF2). This response is consistent with wave energy heating the thermosphere, enhancing the (temperature-dependent) loss rate of O+ ions. The analysis was repeated for a range of thresholds in both time of bombing before the (noon) ionospheric measurement and tonnage of bombs dropped per raid. It was found that significant (∼2–3σ) deviations from the mean occurred for events occurring between approximately 3 and 7 h ahead of the noon ionospheric measurements and for raids using a minimum of between 100 and 800 t of high explosives. The most significant ionospheric response (2.99σ) occurred for 20 raids up to 5 h before the ionospheric measurement, each with a minimum of 300 t of explosives. To ensure that the observed ionospheric response cannot be attributable to space-weather sources, the analysis was restricted to those events for which the geomagnetic Ap index was less than 48 (Kp<5). Digitisation of the early ionospheric data would enable the investigation into the response of additional ionospheric parameters (sporadic E, E and F1 layer heights and peak concentrations). One metric ton of TNT has an explosive energy of 4.184×109 J, which is of the same order of energy as a cloud to ground lightning stroke. Since the occurrence of lightning has distinctive diurnal and seasonal cycles, it is feasible that a similar mechanism could contribute to the observed seasonal anomaly in ionospheric F-region electron concentrations. Further investigation, using less extreme examples, is required to determine the minimum explosive energy required to generate a detectable ionospheric response.
48
WOLFENDALE, ARNOLD. « Risks in space ». European Review 11, no 1 (février 2003) : 77–90. http://dx.doi.org/10.1017/s1062798703000097.
Texte intégralRésumé :
The human species is beset by ‘risks’; one of which is related to its exposed position on the Earth as it travels through cosmic space. An examination is made of the major risks – those associated with cometary impact, with solar emissions and with the explosions of nearby stars. Estimates are given of the risks associated with trying to avoid the effect of these phenomena. Not surprisingly it is concluded that more work is necessary.
49
Mather, T. A., R. G. Harrison, V. I. Tsanev, D. M. Pyle, M. L. Karumudi, A. J. Bennett, G. M. Sawyer et E. J. Highwood. « Observations of the plume generated by the December 2005 oil depot explosions and prolonged fire at Buncefield (Hertfordshire, UK) and associated atmospheric changes ». Proceedings of the Royal Society A : Mathematical, Physical and Engineering Sciences 463, no 2081 (6 février 2007) : 1153–77. http://dx.doi.org/10.1098/rspa.2006.1810.
Texte intégralRésumé :
The explosions and subsequent fire at the Buncefield oil depot in December 2005 afforded a rare opportunity to study the atmospheric consequences of a major oil fire at close range, using ground-based remote-sensing instruments. Near-source measurements (less than 10 km) suggest that plume particles were approximately 50% black carbon (BC) with refractive index 1.73−0.42i, effective radius ( R eff ) 0.45–0.85 μm and mass loading approximately 2000 μg m −3 . About 50 km downwind, particles were approximately 60–75% BC with refractive index between 1.80−0.52i and 1.89−0.69i, R eff ∼1.0 μm and mass loadings 320–780 μg m −3 . Number distributions were almost all monomodal with peak at r <0.1 μm. Near-source UV spectroscopy revealed elevated trace gas concentrations of SO 2 (70 ppbv), NO 2 (140 ppbv), HONO (20 ppbv), HCHO (160 ppbv) and CS 2 (40 ppbv). Our measurements are consistent with others of the Buncefield plume, and with studies of the 1991 Kuwaiti oil-fire plumes; differences from the latter reflecting in part contrasts in combustion efficiency and source composition (refined fuels versus crude oils) leading to important potential differences in atmospheric impacts. Other measurements made as the plume passed overhead approximately 50 km downwind showed a reduced solar flux reaching the surface, but little effect on the atmospheric potential gradient (electric field). The wind speed data from the day of the explosion hint at a possible explosion signature.
50
Shan, Xian, Kang Liu et Pei-Liang Sun. « Risk Analysis on Leakage Failure of Natural Gas Pipelines by Fuzzy Bayesian Network with a Bow-Tie Model ». Scientific Programming 2017 (2017) : 1–11. http://dx.doi.org/10.1155/2017/3639524.
Texte intégralRésumé :
Pipeline is the major mode of natural gas transportation. Leakage of natural gas pipelines may cause explosions and fires, resulting in casualties, environmental damage, and material loss. Efficient risk analysis is of great significance for preventing and mitigating such potential accidents. The objective of this study is to present a practical risk assessment method based on Bow-tie model and Bayesian network for risk analysis of natural gas pipeline leakage. Firstly, identify the potential risk factors and consequences of the failure. Then construct the Bow-tie model, use the quantitative analysis of Bayesian network to find the weak links in the system, and make a prediction of the control measures to reduce the rate of the accident. In order to deal with the uncertainty existing in the determination of the probability of basic events, fuzzy logic method is used. Results of a case study show that the most likely causes of natural gas pipeline leakage occurrence are parties ignore signage, implicit signage, overload, and design defect of auxiliaries. Once the leakage occurs, it is most likely to result in fire and explosion. Corresponding measures taken on time will reduce the disaster degree of accidents to the least extent.