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Filippov, Vladimir, Andrey Eremenko y Igor Mokrousov. "GEOTECHNOLOGY IMPACT ON SEISMIC ACTIVITY OF THE AREA DURING MINING PROTECTIVE PILLAR IN CONDITIONS OF SHEREGESH DEPOSIT". Interexpo GEO-Siberia 2, n.º 5 (2019): 75–80. http://dx.doi.org/10.33764/2618-981x-2019-2-5-75-80.
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Analysis of blasting works during reserves mining of protective pillar of level-and-room mining and sublevel mining with application of mobile machinery is carried out. It is established that high power explosions, carried out within border of protective pillar, longtime impact on rock solid (up to 2 days and more). Each explosion forms seismic active zone in which shocks occur on the distance up to 400v and more. Converse to technology of sublevel caving with application of mobile machinery has excepted carrying out explosions with large mass of explosive materials (10t and more). Through a month, 20-30 explosions are carried out with mass of explosive material from 800-900kg up to 3000-3500 kg. Increasing of explosion number causes to the explosions produce seismic active zone and Impact to solid condition and near workings. But reduction of mass of explosive materials has caused to low frequent event. Mainly seismic events of 1 and 2 class happen.
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Kondratyev, V. N. "Magic nuclei at explosive dynamo activity". EPJ Web of Conferences 107 (2016): 10006. http://dx.doi.org/10.1051/epjconf/201610710006.
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Corradino, Claudia, Eleonora Amato, Federica Torrisi, Sonia Calvari y Ciro Del Negro. "Classifying Major Explosions and Paroxysms at Stromboli Volcano (Italy) from Space". Remote Sensing 13, n.º 20 (13 de octubre de 2021): 4080. http://dx.doi.org/10.3390/rs13204080.
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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.
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Corradino, Claudia, Eleonora Amato, Federica Torrisi, Sonia Calvari y Ciro Del Negro. "Classifying Major Explosions and Paroxysms at Stromboli Volcano (Italy) from Space". Remote Sensing 13, n.º 20 (13 de octubre de 2021): 4080. http://dx.doi.org/10.3390/rs13204080.
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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.
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Rădoi, Florin, Ion Gherghe y Alexandru Cămărășescu. "Experimental possibilities for industrial ventilation". MATEC Web of Conferences 354 (2022): 00030. http://dx.doi.org/10.1051/matecconf/202235400030.
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The activity of evaluation and verification of industrial ventilation installations has a strong preventive role in terms of explosion risk mainly due to the fact that of the three determining elements that can lead to an explosion phenomenon, ventilation installations can determine the presence of two elements namely the presence of fuel (gases, vapours, dusts, mists) and the source of initiation (hot surface, flame, sparks of mechanical origin, electrical sparks, static electricity, etc.). The development of experimental systems on„ which particular hazardous aspects that may occur during the operation of industrial ventilation systems can be studied are vital to avoid dangerous situations in the current operation of ventilation installations. Knowledge of the dynamics of formation of explosive / toxic / asphyxiating environments is achieved by analysing explosive mixtures in relation to specific explosive intervals and is one of the most important priorities in ensuring optimal health and safety at work in industrial activities. The information obtained by analysing the dynamics of the formation of explosive / toxic / asphyxiating atmospheres is extremely useful for personnel responsible for health and safety at work, because with their help relevant decisions can be made to ensure safety and health conditions at the level of industrial premises. The paper presents an experimental equipment usable for the study of industrial ventilation systems.
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Ripepe, M., M. Rossi y G. Saccorotti. "Image processing of explosive activity at Stromboli". Journal of Volcanology and Geothermal Research 54, n.º 3-4 (enero de 1993): 335–51. http://dx.doi.org/10.1016/0377-0273(93)90071-x.
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De la Cruz-Reyna, Servando. "Poisson-distributed patterns of explosive eruptive activity". Bulletin of Volcanology 54, n.º 1 (diciembre de 1991): 57–67. http://dx.doi.org/10.1007/bf00278206.
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Richards, Paul G., Douglas A. Anderson y David W. Simpson. "A survey of blasting activity in the United States". Bulletin of the Seismological Society of America 82, n.º 3 (1 de junio de 1992): 1416–33. http://dx.doi.org/10.1785/bssa0820031416.
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Abstract Statistical information on chemical explosions is needed in seismology, to evaluate the practical difficulties in identifying this very common type of seismic source from other seismic sources such as small earthquakes and small nuclear explosions. We have obtained data on blasting activity from three different sources: (1) overview information from the U.S. Bureau of Mines (USBM) on the total amount of chemical explosives used in the United States during 1987, with breakdowns into different explosive types, and usage by different states; (2) overview information from the Mine Safety and Health Administration (MSHA) on the numbers of mines, of different types, in the United States; and (3) detailed information from a private company (Vibra-Tech Engineers, Inc.) on total shot size and size of charge per delay for 20,813 blasts carried out in 1987 at 532 locations. Our procedure has been to extrapolate the detailed information contained in the 1987 Vibra-Tech data for a limited number of states and thus to obtain estimates for the whole country on numbers of shots and their size distribution. The extrapolation is constrained by the data from USBM (numbers of shots, sizes) and the MSHA (locations). Blasting activity does not fluctuate greatly from year to year and 1987 was representative of current practice. We find that about 2.2 million metric tons of chemical explosive are used annually in the continental U.S., principally in mining for coal and metal ores. On a typical work day, there are roughly 30 explosions greater than 50 tons, including about one greater than 200 tons. There was one industrial explosion in 1987 at about 1400 tons. For shots between 1 ton and 100 tons, the cumulative distribution has a b-value near unity; that is, if N is the number of shots (per year) greater than or equal to W tons, N ∝ 10 − b log W = W − b with b roughly equal to 1. This result is similar to the size distribution of earthquakes greater than magnitude mb, N ∝ 10 − b m b . Almost all chemical explosions above 1 ton are ripple-fired. The typical shot uses 20 to 50 separate delays.
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Vasilescu, Gabriel, Robert Laszlo, Attila Kovacs, Edward Gheorghiosu, Daniela Rus, Ciprian Jitea, Cristian Radeanu, Stefan Ilici, Bogdan Garaliu-Buşoi y Claudia Miron. "Evaluation of the explosion risk specific to the preparation and storage activity of the simple explosive mixture type ANFO". MATEC Web of Conferences 343 (2021): 10001. http://dx.doi.org/10.1051/matecconf/202134310001.
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The paper presents the results of the theoretical and practical research regarding the evaluation of the explosion risk specific to the activity of preparation/storage activity of the ANFO type explosive mixture, based on the identification and systematic analysis of the potential dangers that can generate explosion events, in order to establish and substantiate the possible accidents main scenarios, as well as reference scenarios. From a structural point of view, each accident scenario, defined at the level of the industrial site analyzed, is configured procedurally in synthetic form, comprising typical sections of methodological approach, respectively: location, description of the consequences (unimportant, important), evaluation of the risk of explosion (identification, estimation and appreciation) and measures to prevent damage/measures to reduce the risk of explosion.
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Newton, Robert U., William J. Kraemer, Keijo Häkkinen, Brendan J. Humphries y Aron J. Murphy. "Kinematics, Kinetics, and Muscle Activation during Explosive Upper Body Movements". Journal of Applied Biomechanics 12, n.º 1 (febrero de 1996): 31–43. http://dx.doi.org/10.1123/jab.12.1.31.
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The aim of this study was to investigate the kinematics, kinetics, and neural activation of the traditional bench press movement performed explosively and the explosive bench throw in which the barbell was projected from the hands. Seventeen male subjects completed three trials with a bar weight of 45% of the subject's previously determined 1RM. Performance was significantly higher during the throw movement compared to the press for average velocity, peak velocity, average force, average power, and peak power. Average muscle activity during the concentric phase for pectoralis major, anterior deltoid, triceps brachii, and biceps brachii was higher for the throw condition. It was concluded that performing traditional press movements rapidly with light loads does not create ideal loading conditions for the neuromuscular system with regard to explosive strength production, especially in the final stages of the movement, because ballistic weight loading conditions where the resistance was accelerated throughout the movement resulted in a greater velocity of movement, force output, and EMG activity.
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Barba, Diego, Claude Robin, Pablo Samaniego y Jean-Philippe Eissen. "Holocene recurrent explosive activity at Chimborazo volcano (Ecuador)". Journal of Volcanology and Geothermal Research 176, n.º 1 (septiembre de 2008): 27–35. http://dx.doi.org/10.1016/j.jvolgeores.2008.05.004.
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Naranjo, José A. y Charles R. Stern. "Holocene explosive activity of Hudson Volcano, southern Andes". Bulletin of Volcanology 59, n.º 4 (4 de febrero de 1998): 291–306. http://dx.doi.org/10.1007/s004450050193.
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Parfitt, E. A. y L. Wilson. "Explosive volcanic eruptions-IX. The transition between Hawaiian-style lava fountaining and Strombolian explosive activity". Geophysical Journal International 121, n.º 1 (abril de 1995): 226–32. http://dx.doi.org/10.1111/j.1365-246x.1995.tb03523.x.
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Kuswandarto, Hery, Muhamad Hendrasto y Masato Iguchi. "Automatic and Real-time Processing of Tilt Records for Prediction of Explosions at Semeru Volcano, East Java, Indonesia". Indonesian Journal of Physics 19, n.º 3 (3 de noviembre de 2016): 69–74. http://dx.doi.org/10.5614/itb.ijp.2008.19.3.2.
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Eruptive activity of Semeru Volcano, East Java, Indonesia, is characterized by intermittent occurrence of strombolian and vulcanian types in intervals of 15 – 45 minutes. The explosive eruptions accompany explosion earthquakes and tilt changes of ground around the summit crater. Prior to the explosions (16 – 300 s before), gradual upward tilts of the crater side were detected with amounts of 0.3 – 20 nrad. The upward tilts turned to downward after start of explosive eruptions and tilt decreased by 0.7 – 50 nrad for 30 – 70 s. In order to detect the precursory tilt changes in real time automatically by using the tilt record, software coded by Visual Basic was developed. The software receives UDP packet data from A/D converter for the tiltmeter and shows the record on PC display. The software judge stages of volcanic activity (pre-eruption or eruption) based on the tilt change. In a test, 72% of increase in tilts prior to explosions was successfully detected.
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Umarov, Farkhodbek, Utkir Nasirov, Gafur Nutfulloev, Zoir Nazarov y Lazizzhon Sharipov. "Improving the efficiency of tunneling underground mine workings with the use of blasthole charges with Munroe effect". Izvestiya vysshikh uchebnykh zavedenii Gornyi zhurnal, n.º 3 (14 de mayo de 2020): 15–23. http://dx.doi.org/10.21440/0536-1028-2020-3-15-23.
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Introduction. Various techniques of breaking rock by explosion have currently been developed when tunneling underground mine workings, but asymmetrically directed stress fields application is of the main interest. Research aim is to study explosion energy distribution and maximum concentration deep down the blasted rock mass. Blast energy concentration may be achieved by using the principle of cumulation in the hole back by means of changing the design of the blasthole explosive charge. Methodology. Based on the analyzed literature and theoretical research it is recommended to use the design of a blasthole explosive charge with the use of Munroe effect, which makes it possible to increase the blasthole efficiency ratio (BER), reduce drilling activity, reach sharper design contours of mine workings and eliminate bootlegs. The action of blasthole explosive charges with Munroe effect has been theoretically investigated, hydrodynamic theory of cumulation has been studied, and the dependences have been determined between the liner’s collapsing angle alternation and the radius of the cone, its height, initial velocity, and cumulative jet velocity. Results. The main factors which determine the efficiency of the proposed new technique of blasting against the basic technique are the blasthole efficiency ratio, face advance pace after one blast, the amount of rock mass detached after one blast, and the granulometric composition of the blasted rock mass. Summary. The developed design of the blasthole explosive charge with Munroe effect makes it possible to increase BER, face advance per one cycle, and increase the amount of the broken rock mass.
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Calvari, Sonia, Flora Giudicepietro, Federico Di Traglia, Alessandro Bonaccorso, Giovanni Macedonio y 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, n.º 5 (3 de marzo de 2021): 944. http://dx.doi.org/10.3390/rs13050944.
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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.
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Gołaś, Artur, Adam Maszczyk, Adam Zajac, Kazimierz Mikołajec y Petr Stastny. "Optimizing post activation potentiation for explosive activities in competitive sports". Journal of Human Kinetics 52, n.º 1 (1 de septiembre de 2016): 95–106. http://dx.doi.org/10.1515/hukin-2015-0197.
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Abstract Post activation potentiation (PAP) has shown improved performance during movements requiring large muscular power output following contractions under near maximal load conditions. PAP can be described as an acute enhancement of performance or an enhancement of factors determining an explosive sports activity following a preload stimulus. In practice, PAP has been achieved by complex training, which involves a combination of a heavy loaded exercise followed by a biomechanically similar explosive activity, best if specific for a particular sport discipline. The main objective of this study was to investigate the effects of PAP on performance in explosive motor activities specific for basketball, luge and athletics throws. The novel approach to the experiments included individualized recovery time (IRT) between the conditioning exercise and the explosive activity. Additionally, the research groups were homogenous and included only competitive athletes of similar age and training experience. Thirty one well trained athletes from 3 different sport disciplines participated in the study. All athletes performed a heavy loaded conditioning activity (80-130%1RM) followed by a biomechanically similar explosive exercise, during which power (W) or the rate of power development (W/s/kg) was evaluated. The results of our experiment confirmed the effectiveness of PAP with well-trained athlets during explosive motor activities such as jumping, throwing and pushing. Additionally, our research showed that eccentric supramaximal intensities (130% 1RM) can be effective in eliciting PAP in strength trained athletes. Our experiments also showed that the IRT should be individualized because athletes differ in the strength level, training experience and muscle fiber structure. In the three experiments conducted with basketball players, track and field athletes and luge athletes, the optimal IRT equaled 6 min. This justifies the need to individualize the volume and intensity of the CA, and especially the IRT, between the CA and the explosive activity.
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Shevtsov, Boris M., Pavel P. Firstov, Nina V. Cherneva, Robert H. Holzworth y Renat R. Akbashev. "Lightning and electrical activity during the Shiveluch volcano eruption on 16 November 2014". Natural Hazards and Earth System Sciences 16, n.º 3 (29 de marzo de 2016): 871–74. http://dx.doi.org/10.5194/nhess-16-871-2016.
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Abstract. According to World Wide Lightning Location Network (WWLLN) data, a sequence of lightning discharges was detected which occurred in the area of the explosive eruption of Shiveluch volcano on 16 November 2014 in Kamchatka. Information on the ash cloud motion was confirmed by the measurements of atmospheric electricity, satellite observations and meteorological and seismic data. It was concluded that WWLLN resolution is enough to detect the earlier stage of volcanic explosive eruption when electrification processes develop the most intensively. The lightning method has the undeniable advantage for the fast remote sensing of volcanic electric activity anywhere in the world. There is a good opportunity for the development of WWLLN technology to observe explosive volcanic eruptions.
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Williams, Richard E., Deborah A. Rathbone, Peter C. E. Moody, Nigel S. Scrutton y Neil C. Bruce. "Degradation of explosives by nitrate ester reductases". Biochemical Society Symposia 68 (1 de agosto de 2001): 143–53. http://dx.doi.org/10.1042/bss0680143.
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Explosive-contaminated land poses a hazard both to the environment and to human health. Microbial enzymes, either in their native or heterologous hosts, are a powerful and low-cost tool for eliminating this environmental hazard. As many explosives have only been present in the environment for 10 years, and with similar molecules not known in Nature, the origin of enzymes specialized for the breakdown of explosives is of particular interest. Screening of environmental isolates resulted in the discovery of flavoproteins capable of denitrating the explosives pentaerythritol tetranitrate (PETN) and glycerol trinitrate. These nitrate ester reductases are related in sequence and structure to Old Yellow Enzyme from Saccharomyces carlsbergenisis. All the members of this family have α/ϐ barrel structures and FMN as a prosthetic group, and reduce various electrophilic substrates. The nitrate ester reductases are, however, unusual in that they display activity towards the highly recalcitrant, aromatic explosive 2,4,6-trinitrotoluene, via a reductive pathway resulting in nitrogen liberation. We have embarked on a detailed study of the structure and mechanism of PETN reductase from a strain of Enterobacter cloacae. Work is focused currently on relating structure and function within this growing family of enzymes, with a view to engineering novel enzymes exhibiting useful characteristics.
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BRYAN, S. E., J. MARTÍ y R. A. F. CAS. "Stratigraphy of the Bandas del Sur Formation: an extracaldera record of Quaternary phonolitic explosive eruptions from the Las Cañadas edifice, Tenerife (Canary Islands)". Geological Magazine 135, n.º 5 (septiembre de 1998): 605–36. http://dx.doi.org/10.1017/s0016756897001258.
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Explosive volcanism has dominated the large phonolitic shield volcano of Tenerife, the Las Cañadas edifice, for the last 1.5 m.y. Pyroclastic deposits of the Bandas del Sur Formation are exposed along the southern flanks, and record the last two of at least three long-term cycles of caldera-forming explosive eruptions. Each cycle began with flank fissure eruptions of alkali basalt lava, followed by minor eruptions of basanite to phonotephrite lavas. Minor phonotephritic to phonolitic lava effusions also occurred on the flanks of the edifice during the latter stages of the second explosive cycle. Non-welded plinian fall deposits and ignimbrites are the dominant explosive products preserved on the southern flanks. Of these, a significant volume has been dispersed offshore. Many pyroclastic units of the second explosive cycle exhibit compositional zonation. Banded pumice occurs in most units of the third (youngest) explosive cycle, and ignimbrites typically contain mixed phenocryst assemblages, indicating the role of magma mixing/mingling prior to eruption. At least four major eruptions of the third cycle began with phreatomagmatic activity, producing lithic-poor, accretionary lapilli-bearing fallout and/or surge deposits. The repeated, brief phase of phreatomagmatism at the onset of these eruptions is interpreted as reflecting an exhaustive water supply, probably a small caldera lake that was periodically established during the third cycle. Accidental syenite becomes an increasingly important lithic clast type in ignimbrites up-sequence, and is interpreted as recording the progressive development of a plutonic complex beneath the summit caldera.Successive eruptions during each explosive cycle increased in volume, with the largest eruption occurring at the end of the cycle. More than ten major explosive eruptions vented moderately large volumes (1−[ges ]10 km3) of phonolitic magma during the last two cycles. Culminating each explosive cycle was the emplacement of relatively large volume (>5−10 km3) ignimbrites with coarse, vent-derived lithic breccias, interpreted to record a major phase of caldera collapse. In the extracaldera record, explosive cycles are separated by ∼0.2 m.y. periods of non-explosive activity. Repose periods were characterized by erosion, remobilization of pyroclastic deposits by discharge events, and pedogenesis. The current period of non-explosive activity is characterized by the construction of the Teide-Pico Viejo stratovolcanic complex within the summit caldera. This suggests that eruptive hiatuses in the extracaldera record may reflect effusive activity and stratovolcano or shield-building phases within the summit caldera. Alternating effusive and explosive cycles have thus been important in the volcanic evolution of the Las Cañadas edifice.
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Cannata, A., P. Montalto y D. Patanè. "Joint analysis of infrasound and seismic signals by cross wavelet transform: detection of Mt. Etna explosive activity". Natural Hazards and Earth System Sciences 13, n.º 6 (26 de junio de 2013): 1669–77. http://dx.doi.org/10.5194/nhess-13-1669-2013.
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Abstract. The prompt detection of explosive volcanic activity is crucial since this kind of activity can release copious amounts of volcanic ash and gases into the atmosphere, causing severe dangers to aviation. In this work, we show how the joint analysis of seismic and infrasonic data by wavelet transform coherence (WTC) can be useful to detect explosive activity, significantly enhancing its recognition that is normally done by video cameras and thermal sensors. Indeed, the efficiency of these sensors can be reduced (or inhibited) in the case of poor visibility due to clouds or gas plumes. In particular, we calculated the root mean square (RMS) of seismic and infrasonic signals recorded at Mt. Etna during 2011. This interval was characterised by several episodes of lava fountains, accompanied by lava effusion, and minor strombolian activities. WTC analysis showed significantly high values of coherence between seismic and infrasonic RMS during explosive activity, with infrasonic and seismic series in phase with each other, hence proving to be sensitive to both weak and strong explosive activity. The WTC capability of automatically detecting explosive activity was compared with the potential of detection methods based on fixed thresholds of seismic and infrasonic RMS. Finally, we also calculated the cross correlation function between seismic and infrasonic signals, which showed that the wave types causing such seismo-acoustic relationship are mainly incident seismic and infrasonic waves, likely with a common source.
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Radeanu, Cristian, Gabriel Vasilescu, Ciprian Jitea, Ladislau Radermacher y Gabriel Ilcea. "Analysis of dangerous situations generated by explosive materials in non-compliant operations performed on industrial locations intended for their storage". MATEC Web of Conferences 373 (2022): 00046. http://dx.doi.org/10.1051/matecconf/202237300046.
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Design and efficient implementation of OSH management in the field of explosives for civilian use, having the effect of optimizing the activity of preventing unwanted events blast type specific to industrial locations intended for the preparation / storage of explosives for civil use, constitutes it explosion risk assessment which represents the integrated expression of the configuration components of this type of risk within the different accident scenarios. No matter what it's about a component within the location or his integral technical infrastructure such an analysis allows the identification and ranking of site specific accident hazards to be assessed, in order to properly allocate security resources for priority measures to prevent and combat / eliminate the causes of these types of dangerous events. To this end, the ”Security Document” specific to the industrial site intended for specific operations with explosive materials must demonstrate that: an appropriate accident prevention policy and an effective safety management system have been implemented; the dangers of injury are identified and the necessary measures are taken to prevent them and to limit their consequences for man and the environment; in design any installations has been incorporated adequate safety and reliability for construction, operation and maintenance; emergency plans have been drawn up.
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Degterev, A. V. y M. V. Chibisova. "Volcanic activity of the Kuril Islands in 2020–2021". Geosystems of Transition Zones 6, n.º 3 (2022): 195–205. http://dx.doi.org/10.30730/gtrz.2022.6.3.195-205.
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The data on volcanic activity in the Kuril Islands during 2020–2021 are presented. The activity of Ebeko (Paramushir Island), Chirinkotan (Chirinkotan Island) and Sarychev Peak (Matua Island) volcanoes is characterized on the basis of satellite data and results of visual observations. In 2020–2021 a weak (to moderate) explosive eruption (VEI 1-2), which has begun in autumn 2016, continued on Ebeko volcano. During the period under review, at least 1169 emissions were recorded at a height of 1.5–3 (up to 5) km a.s.l. In the interval from May till July, a sharp increase in the explosive activity of the volcano was noted, during this time more than half of the total number of explosions occurred: 2020 – 298 out of 558, 2021 – 344 out of 611. The ashfalls of varying intensity were periodically observed in Severo-Kurilsk. The active phase of the eruption has ended in December 2021, only 2 weak explosions occurred. A moderate (VEI 2) explosive eruption took place on Chirinkotan volcano from August 8 to August 23, 2021. At least 12 volcanic explosions were recorded at a height of 1.5 to 4.5 km a.s.l. An effusive eruption was observed on the Sarychev Peak volcano from December 2020 till February 2021: the crater was filled with lava, after which it erupted along the northeastern slope of the edifice. In 2021, the activity of the volcano was characterized by manifestations of several episodes of an explosive nature: on June 29, July 1, August 6, and November 26, single, relatively weak ejections to a height of about 2.2–3 km a.s.l. were recorded (VEI 2).
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Degterev, A. V. y M. V. Chibisova. "The activity of Chikurachki volcano (Paramushir Isl., Northern Kuriles) in January–February of 2022". Geosystems of Transition Zones 6, n.º 1 (2022): 13–23. http://dx.doi.org/10.30730/gtrz.2022.6.1.013-018.018-023.
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The article considers a short-term moderate explosive eruption of Chikurachki volcano (Paramushir Isl.) on the basis of satellite data. In the period from January 30 to February 3, 2022, at least 8 steam-gas and ash emissions to a height of 2.5–5 km a.s.l. were recorded. Ash plumes and clouds spread mainly in the south-western, western, southern, and south-eastern directions at a distance up to 250 km from the volcano. Its parameters were similar to the previous explosive eruptions of Chikurachki volcano. Due to high frequency of moderate explosive eruptions of Chikurachki volcano in recent years, when ash clouds rise to a height up to 7.5 km a.s.l. and ash plumes are formed that can spread for several hundred kilometers, the volcano poses a potential hazard to international and local airlines.
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Pioli, Laura, Marco Palmas, Boris Behncke, Emanuela De Beni, Massimo Cantarero y Simona Scollo. "Quantifying Strombolian Activity at Etna Volcano". Geosciences 12, n.º 4 (6 de abril de 2022): 163. http://dx.doi.org/10.3390/geosciences12040163.
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Understanding the dynamics of mild explosive activity is a fundamental tool for hazard assessment at open conduit volcanoes. This is a particularly critical task for Etna volcano. Etna is in fact characterized by frequent, mild explosive activity, punctuated by lava flows and paroxysmal events (‘lava fountains’), which, because of their greater impact, have been the main target for hazard studies, whereas more frequent Strombolian activity has been overlooked. As a result, their impact and associated hazards have been never quantified, despite the extensive monitoring and surveillance activities carried out on this volcano. In this paper, we analyze video recordings of a sequence of Strombolian explosions occurring at the summit craters of Mt. Etna, in Italy, in February 2020. Data were also integrated with a petrographic analysis of collected samples, and drone surveys were performed at the same time as the video recordings. We estimate the frequency of explosions (20–12 per min); particle exit speeds (1–50 m/s), and erupted mass (100–102 kg) of those explosions. A very regular, small-scale activity (marked by a single burst of gas breaking the magma free surface into bombs and lapilli fragments) was occasionally punctuated by larger explosions, (at least one every 5 min), with a longer duration, fed by larger magma volumes, and consisting of two to three distinct pulses followed by a stationary phase. We found that the repose times between explosions follows a log logistic distribution, which is in agreement with the behavior of open vent explosive activity. The four largest explosions of the sequence were analyzed in detail: they emitted particles with median diameters (Mdphi) ranging from −10.1 to −8.8 phi, with bimodal distributions.
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Cole, Paul D., Annamaria Perrotta y Claudio Scarpati. "The volcanic history of the southwestern part of the city of Naples". Geological Magazine 131, n.º 6 (noviembre de 1994): 785–99. http://dx.doi.org/10.1017/s0016756800012863.
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AbstractThe southwestern part of Naples was the site of small volume volcanic activity prior to 12000 y B.P. Lava domes and possibly a lava flow were erupted during the earliest period. Explosive activity followed and produced pyroclastic sequences that are the proximal deposits of tuff cones within the city and at its southwestern extreme. The explosive activity was complex but predominantly phreatomagmatic. As the volcanic activity more than 12000 y B.P. in western Campi Flegrei shows a similar evolution from effusive to explosive, it is suggested that a large volcanic field ‘Paleoflegrei’, encompassing the western part of the city of Naples, existed prior to emplacement of the Neapolitan Yellow Tuff. The Neapolitan Yellow Tuff eruption about 12000 y B.P., from a vent in Campi Flegrei, produced widespread deposits up to 150 m thick that blanketed the area of the city of Naples, although the present day topography is strongly influenced by the pre-Neapolitan Yellow Tuff centres. Following the Neapolitan Yellow Tuff a small explosive eruption occurred in the bay of Chiaia, immediately south of the city, and results in the possibility of future eruptions within the city of Naples, outside the confines of Campi Flegrei and Vesuvius.
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Gapparov, Z. y J. Ishtaev. "Development of Explosive Psychomotor and Personal Activity of Sportsmen". Advanced Science Journal 2014, n.º 3 (10 de febrero de 2014): 42–44. http://dx.doi.org/10.15550/asj.2014.03.042.
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Doyle, J. G., B. Ishak, I. Ugarte-Urra, P. Bryans y H. P. Summers. "Evidence for explosive event activity originating in the chromosphere". Astronomy & Astrophysics 439, n.º 3 (12 de agosto de 2005): 1183–89. http://dx.doi.org/10.1051/0004-6361:20053099.
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Girina, O. A., A. G. Manevich, D. V. Melnikov, A. A. Nuzhdaev y E. G. Petrova. "2016 volcano eruptions in Kamchatka and the Northern Kuriles and their danger to aviation". Вулканология и сейсмология, n.º 3 (14 de mayo de 2019): 34–48. http://dx.doi.org/10.31857/s0203-03062019334-48.
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Strong explosive volcanic eruptions are extremely dangerous to the modern jet aircraft as they can produce several cubic kilometers of volcanic ash and aerosols that can be sent to the atmosphere and the stratosphere in several hours to several days during the eruption. In 2016, five from thirty active volcanoes erupted in Kamchatka (Sheveluch, Klyuchevskoy, Bezymianny, Karymsky, and Zhupanovsky) and three from six active volcanoes in the Northern Kuriles (Alaid, Ebeko, and Chikurachki). Effusive volcanic activity was noted at Sheveluch, Klyuchevskoy, Bezymianny and Alaid. All the volcanoes produced explosive activity. Strong explosive events occurred at Sheveluch mainly from September till December. Moderate ash emission had accompanied of Klyuchevskoy’s eruption through March till November. Explosive activity at Karymsky, Zhupanovsky, Alaid, and Chikurachki volcanoes was observed mainly in the first half of the year. The total area covered by ash in 2016 was estimated 600,000 km2, from which 460,000 km2 were related to the eruptions of Kamchatka volcanoes and 140,000 km2 were attributed to the eruption of the North Kuriles volcanoes. The activity at Sheveluch, Klyuchevskoy, and Zhupanovsky was dangerous to international and local airlines as explosions produced ash up to 10-12 km above sea level. The activity at Bezymianny, Karymsky, Alaid, Ebeko, and Chikurachki posed a threat to local aircrafts when explosions sent ash up to 5 km above sea level.
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Girina, O. A., A. G. Manevich, D. V. Melnikov, A. A. Nuzhdaev y E. G. Petrova. "2016 volcano eruptions in Kamchatka and the Northern Kuriles and their danger to aviation". Вулканология и сейсмология, n.º 3 (14 de mayo de 2019): 34–48. http://dx.doi.org/10.31857/s0205-96142019334-48.
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Strong explosive volcanic eruptions are extremely dangerous to the modern jet aircraft as they can produce several cubic kilometers of volcanic ash and aerosols that can be sent to the atmosphere and the stratosphere in several hours to several days during the eruption. In 2016, five from thirty active volcanoes erupted in Kamchatka (Sheveluch, Klyuchevskoy, Bezymianny, Karymsky, and Zhupanovsky) and three from six active volcanoes in the Northern Kuriles (Alaid, Ebeko, and Chikurachki). Effusive volcanic activity was noted at Sheveluch, Klyuchevskoy, Bezymianny and Alaid. All the volcanoes produced explosive activity. Strong explosive events occurred at Sheveluch mainly from September till December. Moderate ash emission had accompanied of Klyuchevskoy’s eruption through March till November. Explosive activity at Karymsky, Zhupanovsky, Alaid, and Chikurachki volcanoes was observed mainly in the first half of the year. The total area covered by ash in 2016 was estimated 600,000 km2, from which 460,000 km2 were related to the eruptions of Kamchatka volcanoes and 140,000 km2 were attributed to the eruption of the North Kuriles volcanoes. The activity at Sheveluch, Klyuchevskoy, and Zhupanovsky was dangerous to international and local airlines as explosions produced ash up to 10-12 km above sea level. The activity at Bezymianny, Karymsky, Alaid, Ebeko, and Chikurachki posed a threat to local aircrafts when explosions sent ash up to 5 km above sea level.
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Тобратов, С. А., О. С. Железнова y А. В. Водорезов. "Natural Cyclicity of Explosive Volcanism". Вестник Рязанского государственного университета имени С.А. Есенина, n.º 1(74) (1 de abril de 2022): 138–69. http://dx.doi.org/10.37724/rsu.2022.74.1.013.
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Рассмотрены причины, факторы и закономерности пульсаций вулканической активности (для извержений с VEI не менее 5, без учета вулканов со щелочными лавами). Установлено соответствие эксплозивных событий 1650-летним (ритмы Петтерсона — Шнитникова) и 60–70-летним циклам природной динамики, порождаемым гравитационными взаимодействиями Земли со смежными объектами Солнечной системы (Луной, Солнцем, Венерой, Юпитером). Отмечено, что максимальные по магнитуде извержения концентрируются на стыках смежных циклов; данная закономерность может иметь прогностическое значение. Обоснование вулкано-климатических взаимосвязей осуществлено с использованием теоретических разработок Н. С. Сидоренкова, устанавливающих ведущую роль в подобных процессах закона сохранения момента импульса; индикаторную роль при этом играет замедление осевого вращения Земли, с эпизодами которого синхронизируются крупные эруптивные события. Подчеркнуто, что совместная динамика вулканизма и климата существует, но объясняется не причинно-следственными, а генетическими связями. Выявлено, что максимальные проявления вулканизма соответствуют холодным и гумидным фазам климатической динамики, захватывая часть последующего потепления, а аридные фазы отличаются минимальной эруптивностью. При этом гидроклиматическим индикатором роста опасности крупных извержений может служить трансгрессивный режим Каспийского моря. Рассмотрены особенности Одинцовского межледниковья и середины теплой эпохи викингов (900–950 годы н. э.), которые, вопреки общим закономерностям, отличались повышенным вулканизмом. На примере горизонтов раннеголоценового реликтового торфяника дана характеристика совместной динамики вулканической активности и климата атлантического периода (эруптивный максимум голоцена), взаимосвязей глобального вулканизма и палеоландшафтных процессов на Русской равнине. Установлено наличие двух гумидных подфаз климатического оптимума голоцена — около 6,5–6,3 и 6,2–6,0 тысяч лет назад. На основании выявленных циклических закономерностей выдвинуто предположение о постепенном ослаблении вулканической активности в ближайшие 600 лет, но в холодные фазы 70-летних циклов и при резком снижении массы полярных ледников следует ожидать локальной активизации вулканизма (ближайший этап активизации — 2035–2045 годы). The article treats the causes, factors and patterns of volcanic activity (eruptions rated at least 5 on the Volcanic Explosivity Index, excluding alkaline volcanoes). The article underlines that volcanic eruptions occurring every 1,650 years or 60–70 years (the Petterson-Shnitnikov pattern) are triggered off by the influence of the celestial bodies of the Solar system (Moon, Sun, Venus, Jupiter). It is highlighted that most powerful eruptions occur when volcanic cycle is over and another is about to begin. This information may have prognostic significance. The connection between volcanic eruptions and climate variability is investigated on the basis of N. S. Sidorenkov’s theoretical research, which underlines the leading role of the law of conservation of angular momentum. The slowdown in the Earth’s axial rotation is an indicator synchronized with major eruptive events. The authors emphasize that the connection between volcanic eruptions and climate variability cannot be explained in the simple cause and effect terms, but are of genetic character. The authors underline that most powerful volcanic eruptions coincide with cold and humid climatic conditions, while arid conditions are associated with minimal eruptive activity. The transgression of the Caspian Sea can serve as a hydro-climatic indicator of increasing hazardous effects of powerful volcanic eruptions. The article investigates the peculiarities of the Odintsovo interglacial period and the mid-Viking Age (900–950 AD), which, contrary to general laws, were characterized by excessive volcanism. The article investigates peat relicts to analyze the connection between volcanic eruptions and climate variability in the Atlantic period (Holocene eruptive maximum), as well as to analyze the interconnection between global volcanism and paleolandscapes on the Russian Plain. The article underlines that there are two humid subphases of the Holocene climatic optimum: 6.5-6.3 and 6.2-6.0 thousand years ago. Relying on the discovered patterns, the authors assume that volcanic activity will gradually weaken during the next 600 years. However, it can be predicted that volcanic activity will increase during cold phases (70 years) accompanied by a sharp decrease in the mass of polar glaciers (the nearest phase of activation is 2035–2045).
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Unguras, Camelia Lavinia, Doru Anghelache, Victor Gabriel Vasilescu, Florian Stoian y Gabriel Ioan Ilcea. "The generalized risk scale – a scalar integrated tool for developing risk criteria by consensus, in the field of explosives for civil uses". MATEC Web of Conferences 305 (2020): 00078. http://dx.doi.org/10.1051/matecconf/202030500078.
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The paper highlights the result of the critical analysis upon criteria regarding the safety of explosives based on the quantification of risks specific for handling explosive materials, for the proper criteria selection and for defining the integrated concept “how safe is safe enough?”, applicable to complex work systems whose activity object involves the use of hazardous substances such as explosives for civil use. In this regard are conceptual and applicative presented judicial precedents and standards which are used for establishing risk acceptance criteria. These data and information are represented graphically along a series of logarithmic scales which ensure an objective manner for risk quantification based on scientific reasoning, real information derived from a data base which is specific for a deep knowledge of morbidity indicators recorded over an a statistically acceptable.
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Eroshenko, D. V. y G. S. Kharin. "Cyclic explosive activity of the Iceland plume in the quaternary". Oceanology 54, n.º 1 (febrero de 2014): 66–80. http://dx.doi.org/10.1134/s0001437014010032.
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Marchetti, E., M. Ripepe, D. Delle Donne, R. Genco, A. Finizola y E. Garaebiti. "Blast waves from violent explosive activity at Yasur Volcano, Vanuatu". Geophysical Research Letters 40, n.º 22 (20 de noviembre de 2013): 5838–43. http://dx.doi.org/10.1002/2013gl057900.
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Bennett, Kristen A., Briony H. N. Horgan, Lisa R. Gaddis, Benjamin T. Greenhagen, Carlton C. Allen, Paul O. Hayne, James F. Bell y David A. Paige. "Complex explosive volcanic activity on the Moon within Oppenheimer crater". Icarus 273 (julio de 2016): 296–314. http://dx.doi.org/10.1016/j.icarus.2016.02.007.
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Baguet, Audrey, Inge Everaert, Benito Yard, Verena Peters, Johannes Zschocke, Ana Zutinic, Emile De Heer, Tomasz Podgórski, Katarzyna Domaszewska y Wim Derave. "Does low serum carnosinase activity favor high-intensity exercise capacity?" Journal of Applied Physiology 116, n.º 5 (1 de marzo de 2014): 553–59. http://dx.doi.org/10.1152/japplphysiol.01218.2013.
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Given the ergogenic properties of β-alanyl-L-histidine (carnosine) in skeletal muscle, it can be hypothesized that elevated levels of circulating carnosine could equally be advantageous for high-intensity exercises. Serum carnosinase (CN1), the enzyme hydrolyzing the dipeptide, is highly active in the human circulation. Consequently, dietary intake of carnosine usually results in rapid degradation upon absorption, yet this is less pronounced in subjects with low CN1 activity. Therefore, acute carnosine supplementation before high-intensity exercise could be ergogenic in these subjects. In a cross-sectional study, we determined plasma CN1 activity and content in 235 subjects, including 154 untrained controls and 45 explosive and 36 middle- to long-distance elite athletes. In a subsequent double-blind, placebo-controlled, crossover study, 12 men performed a cycling capacity test at 110% maximal power output (CCT 110%) following acute carnosine (20 mg/kg body wt) or placebo supplementation. Blood samples were collected to measure CN1 content, carnosine, and acid-base balance. Both male and female explosive athletes had significantly lower CN1 activity (14% and 21% lower, respectively) and content (30% and 33% lower, respectively) than controls. Acute carnosine supplementation resulted only in three subjects in carnosinemia. The CCT 110% performance was not improved after carnosine supplementation, even when accounting for low/high CN1 content. No differences were found in acid-base balance, except for elevated resting bicarbonate following carnosine supplementation and in low CN1 subjects. In conclusion, explosive athletes have lower serum CN1 activity and content compared with untrained controls, possibly resulting from genetic selection. Acute carnosine supplementation does not improve high-intensity performance.
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Šarabon, Nejc, Jurij Hostnik y Goran Markovic. "Acute effects of aerobic activity, static stretching, and explosive exercises on muscular performance and range of motion of young soccer players". International Journal of Sports Science & Coaching 15, n.º 5-6 (21 de julio de 2020): 706–16. http://dx.doi.org/10.1177/1747954120942895.
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The current study aims to investigate the acute effects of light aerobic activity, static stretching (SS), strengthening and explosive exercises on lower-body muscular performance and range of motion (ROM). Dose-response effect of SS on performance and ROM was also studied. Nineteen young male soccer players (age: 13.9 ± 0.46 years) participated in a cross-over randomized trial. Participants performed 5-minute aerobic activity, followed by seven bouts of SS of calf, quadriceps, adductor and hamstring muscles lasting 20 seconds each. Additionally, two sets of strengthening and explosive exercises were performed after SS in the experimental condition. Power and strength were assessed by counter-movement jump (CMJ) and maximal voluntary contraction of hip adductors, while 3 flexibility tests were used for assessing ROM of lower body. Repeated-measures ANOVA revealed an increase in CMJ performance after aerobic activity, followed by a decrease after SS in a dose-dependent manner that continued to be present 15 minutes post-SS. Strengthening and explosive exercises did not neutralize the acute negative effects of SS on CMJ performance. No significant acute effect of selected interventions on maximal and explosive strength of hip adductors was observed. Finally, sit-and-reach and hip abduction ROM increased after aerobic activity and continued to increase throughout the SS protocol, and was preserved 15 minutes post-SS. Our results confirm that SS can impair lower-body power in young soccer players, and that these negative effects last at least 15 minutes. Excessive use of SS, as performed in this study, should be avoided during warm-up of young soccer players.
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Pistolesi, Marco, Antonella Bertagnini, Alessio Di Roberto, Maurizio Ripepe y Mauro Rosi. "Tsunami and tephra deposits record interactions between past eruptive activity and landslides at Stromboli volcano, Italy". Geology 48, n.º 5 (14 de febrero de 2020): 436–40. http://dx.doi.org/10.1130/g47331.1.
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Abstract Devastation associated with tsunamis is well known on the global scale. Flank collapse at volcanic islands is among the mechanisms triggering tsunamis, but very few examples document interaction between landslides and volcanic activity. The study of three well-preserved medieval tsunami deposits recently discovered along the coast of Stromboli volcano (Aeolian Islands, southern Italy) enabled a detailed characterization of the tsunami sequences intercalated with volcaniclastic deposits and primary tephra and allowed reconstruction of the likely sequence of volcanic events. In one case, a violent explosion possibly preceded the tsunami, whereas in the youngest event, the lateral collapse of the volcano flank triggered a tsunami wave that was rapidly followed by sustained explosive magmatic activity and ensuing prolonged ash venting. The hypothesized tsunami-triggering dynamics suggests a close link between volcanic activity and flank collapse, further confirming that the persistent activity at Stromboli makes the volcano particularly susceptible to tsunami generation.
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Mangler, Martin F., Chiara Maria Petrone y Julie Prytulak. "Magma recharge patterns control eruption styles and magnitudes at Popocatépetl volcano (Mexico)". Geology 50, n.º 3 (5 de enero de 2022): 366–70. http://dx.doi.org/10.1130/g49365.1.
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Abstract Diffusion chronometry has produced petrological evidence that magma recharge in mafic to intermediate systems can trigger volcanic eruptions within weeks to months. However, less is known about longer-term recharge frequencies and durations priming magma reservoirs for eruptions. We use Fe-Mg diffusion modeling in orthopyroxene to show that the duration, frequency, and timing of pre-eruptive recharge at Popocatépetl volcano (Mexico) vary systematically with eruption style and magnitude. Effusive eruptions are preceded by 9–13 yr of increased recharge activity, compared to 15–100 yr for explosive eruptions. Explosive eruptions also record a higher number of individual recharge episodes priming the plumbing system. The largest explosive eruptions are further distinguished by an ~1 yr recharge hiatus directly prior to eruption. Our results offer valuable context for the interpretation of ongoing activity at Popocatépetl, and seeking similar correlations at other arc volcanoes may advance eruption forecasting by including constraints on potential eruption size and style.
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Ibadov, S., F. S. Ibodov y S. S. Grigorian. "Explosion of sungrazing comets in the solar atmosphere and solar flares". Proceedings of the International Astronomical Union 4, S257 (septiembre de 2008): 341–43. http://dx.doi.org/10.1017/s1743921309029524.
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AbstractExplosive evolution of nuclei of sungrazing comets near the solar surface, which occurs at conditions of intense interaction between the solar atmosphere and falling high-velocity comet nuclei as well as the relation of the phenomenon to the character of solar activity are analytically considered. It is found that, due to aerodynamic fragmentation of the falling body in the solar chromosphere and transversal expansion of the fragmented mass under the action of pressure gradient on the frontal surface, thermalization of the kinetic energy of the body occurs by sharp stopping of the disklike hypervelocity fragmented mass near the solar surface within a relatively very thin subphotospheric layer and has, therefore, an essentially impulsive and strongly explosive character. The specific energy release in the explosion region, erg/g, considerably exceeds the evaporation/sublimation heat of the body so that the process is accompanied by production of a high-temperature plasma. The energetics of such an explosive process corresponds to that of very large solar flares for falling bodies having masses equal to the mass of the nucleus of Comet Halley. Spectral observations of sungrazing comets by SOHO-like telescopes in a wide spectral range, including X rays, with a high time resolution, of the order of 0.1–10 s, are important for revealing solar activity in the form of an impact-generated photospheric flare.
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Prado, Cynthia, Masao Uetanabaro y Célio Haddad. "Breeding activity patterns, reproductive modes, and habitat use by anurans (Amphibia) in a seasonal environment in the Pantanal, Brazil". Amphibia-Reptilia 26, n.º 2 (2005): 211–21. http://dx.doi.org/10.1163/1568538054253375.
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AbstractAnnual patterns of breeding activity, reproductive modes, and habitat use are described for a frog community in a seasonal environment, in the southern Pantanal, Mato Grosso do Sul, Brazil. Data were collected monthly between January 1995 and December 1998. A total of 24 species from four families; Bufonidae (3 species), Hylidae (10 species), Leptodactylidae (9 species), and Microhylidae (2 species) were registered. Three reproductive activity patterns are recognized among these species: continuous, explosive, and prolonged; 50% of the species were explosive breeders. Seasonal pattern of reproduction was verified for three analyzed years (1995-1997); most species reproduced during the rainy season (Nov-Jan). The reproduction was aseasonal in 1998; unexpected rains in the dry season lead to an unusual breeding activity. Five reproductive modes were noted — 62.5% of the species have the generalized aquatic mode, and 33.3% deposit eggs embedded in foam nests. Many species used the same sites for reproduction, although temporal partitioning and calling site segregation was observed. The occurrence of many species that exhibit explosive breeding early in the rainy season is common in seasonal and open environments with variable and unpredictable rainfall, as is the case in the Pantanal.
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Shulepov, A. V., I. A. Shperling, Yu V. Yurkevich, N. V. Shperling, M. V. Vinogradov, A. S. Kourov, P. A. Romanov y S. B. Vasiliev. "Microcirculatory Status and Metabolic Activity of Tissues after Local Administration of Autologous Plasma on the Model of Explosive Soft Tissue Wound in Rats". Kuban Scientific Medical Bulletin 29, n.º 4 (29 de agosto de 2022): 53–74. http://dx.doi.org/10.25207/1608-6228-2022-29-4-53-74.
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Background. The possibility of local application of autologous blood plasma (ABP) in soft tissue injuries is currently of particular interest.Objectives. Evaluation of the effects of peri-wound (perifocal) administration of ABP on red blood parameters, microcirculation and oxygen supply of soft tissues of the limb in experimental explosive wound (EW) in rats.Methods. EW was simulated on male Wistar rats (n=146) using a firecracker with a pyrotechnic mixture (patent RU No. 2741238 dated 22.01.2021). Animals were divided into 4 groups: control (2), comparison (1), main (1). The volume of blood loss in explosive wounds was 8 and 15% of the estimated circulating blood volume (CBV) of the animal. Blood was drawn from the rat tail to obtain ABP. 3 hours after the injury, ABP or 0.9% sodium chloride solution was injected intramuscularly into the explosive wound area at a rate of 2.0 ml/kg of animal weight. After 3, 7, 14, 28 days, the number of red blood cells, haemoglobin content, haematocrit were determined in the blood, and microcirculation and oxidative metabolism parameters were determined in the skeletal muscles of the injured area. The data were processed using Microsoft Excel 2013 (Microsoft, USA) and Statistica 10.0 (StatSoft Inc., USA).Results. Blood loss of 8% of the CBV in injured animals did not lead to changes in the quantitative composition of peripheral red blood. After an explosive wound with a blood loss of 15% of the CBV, there was a moderate decrease in the number of red blood cells (from 8.3×1012/l to 6.5×1012/l, p < 0.02), haemoglobin level (from 149.5 g/l to 118 g/l, p < 0.01), haematocrit (from 43.8% to 33.6%, p < 0.01) with recovery by day 7 of observation. The explosive soft tissue wound was characterized by marked post-traumatic microcirculatory disorders irrespective of the amount of blood loss. Perifocal intramuscular administration of ABP in animals with an explosive wound and blood loss of 15% CBV reduced the severity of post-traumatic microcirculatory and oxidative metabolic disorders mainly in the early post-traumatic period, as evidenced by an increase in the perfusion variation coefficient Kv by 1.2–1.3 times (p < 0.05), tissue oxygen consumption U by 20–22% (p < 0.05) and fluorescent oxygen consumption by FPC by 48% (p < 0.05).Conclusion. With an experimental explosive wound of the soft tissues of the thigh in rats, a single early (3 hours after the injury) peri-wound intramuscular administration of ABP reduces the severity of local post-traumatic microcirculatory and metabolic disorders in skeletal muscle.
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Firstov, P. P., D. Fee y E. R. Makhmudov. "The explosive activity of Karymskii Volcano, Kamchatka: Acoustic and seismic observations". Journal of Volcanology and Seismology 7, n.º 4 (julio de 2013): 252–64. http://dx.doi.org/10.1134/s0742046313040039.
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S.D. YAKOVLEV. "Doing Away with Explosive Articles in Areas of Russia's Maritime Activity". Military Thought 28, n.º 002 (30 de junio de 2019): 120–22. http://dx.doi.org/10.21557/mth.54208784.
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Lane, S. J. y J. S. Gilbert. "Electric potential gradient changes during explosive activity at Sakurajima volcano, Japan". Bulletin of Volcanology 54, n.º 7 (septiembre de 1992): 590–94. http://dx.doi.org/10.1007/bf00569942.
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Giammello, Giuseppe, Marco Firetto Carlino y Mauro Coltelli. "Automatic Detection of the Explosive Activity of the Mt. Etna Volcano through Doppler Radar Monitoring". Remote Sensing 14, n.º 22 (9 de noviembre de 2022): 5663. http://dx.doi.org/10.3390/rs14225663.
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Improving the capability to detect volcanic explosive activity could be strategic for the task of a volcano observatory to inform civil protection authorities and air traffic controllers. The detection of explosive volcanic activity can be done in real time and also under bad visibility conditions by using the radar remote sensing technique. Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Etneo (Catania, Italy) installed an S-band pulse Doppler radar in a shelter located at about 3 km south of the active volcanic vents in order to enhance the Etna volcano’s surveillance. Here, we describe the realisation of a system that exploits such device, aimed at continuously monitoring the explosive eruptive activity at the Mt. Etna summit craters through an automatic processing flow of the radar data. We analysed the signals recorded during 23 eruptive episodes that occurred at the Etna South-East Crater during the second half of 2021; these episodes were characterised by an opening Strombolian activity and the subsequent evolution into a lava fountain. To identify the onset of both volcanic phenomena, empirical thresholds of radar time series were extracted with the help of thermal and visible images acquired by the INGV-OE cameras’ network. The resulting monitoring tool automatically operates 24/7 for volcanic surveillance, providing real-time data to the INGV-OE control room.
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Laiolo, Marco, Maurizio Ripepe, Corrado Cigolini, Diego Coppola, Massimo Della Schiava, Riccardo Genco, Lorenzo Innocenti et al. "Space- and Ground-Based Geophysical Data Tracking of Magma Migration in Shallow Feeding System of Mount Etna Volcano". Remote Sensing 11, n.º 10 (18 de mayo de 2019): 1182. http://dx.doi.org/10.3390/rs11101182.
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After a month-long increase in activity at the summit craters, on 24 December 2018, the Etna volcano experienced a short-lived lateral effusive event followed by a rapid resumption of low-level explosive and degassing activity at the summit vents. By combining space (Moderate Resolution Imaging Spectroradiometer; MODIS and SENTINEL-2 images) and ground-based geophysical data, we track, in near real-time, the thermal, seismic and infrasonic changes associated with Etna’s activity during the September–December 2018 period. Satellite thermal data reveal that the fissural eruption was preceded by a persistent increase of summit activity, as reflected by overflow episodes in New SouthEast Crater (NSE) sector. This behavior is supported by infrasonic data, which recorded a constant increase both in the occurrence and in the energy of the strombolian activity at the same crater sectors mapped by satellite. The explosive activity trend is poorly constrained by the seismic tremor, which shows instead a sudden increase only since the 08:24 GMT on the 24 December 2018, almost concurrently with the end of the infrasonic detections occurred at 06:00 GMT. The arrays detected the resumption of infrasonic activity at 11:13 GMT of 24 December, when tremors almost reached the maximum amplitude. Infrasound indicates that the explosive activity was shifting from the summit crater along the flank of the Etna volcano, reflecting, with the seismic tremor, the intrusion of a gas-rich magma batch along a ~2.0 km long dyke, which reached the surface generating an intense explosive phase. The dyke propagation lasted for almost 3 h, during which magma migrated from the central conduit system to the lateral vent, at a mean speed of 0.15–0.20 m s−1. Based on MODIS and SENTINEL 2 images, we estimated that the summit outflows erupted a volume of lava of 1.4 Mm3 (±0.5 Mm3), and that the lateral effusive episode erupted a minimum volume of 0.85 Mm3 (±0.3 Mm3). The results presented here outline the support of satellite data on tracking the evolution of volcanic activity and the importance to integrate satellite with ground-based geophysical data in improving assessments of volcanic hazard during eruptive crises.
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Waythomas, Christopher. "Simultaneous effusive and explosive cinder cone eruptions at Veniaminof Volcano, Alaska". Volcanica 4, n.º 2 (1 de diciembre de 2021): 295–307. http://dx.doi.org/10.30909/vol.04.02.295307.
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Historical eruptions of Veniaminof Volcano, Alaska have all occurred at a 300-m-high cinder cone within the icefilled caldera that characterizes the volcano. At least six of nineteen historical eruptions involved simultaneous explosive and effusive activity from separate vents. Eruptions in 1944, 1983–1984, 1993–1994, 2013, 2018 and 2021 included periods of explosive ash-producing Strombolian activity from summit vents and simultaneous nonexplosive effusion of lava from flank vents on either the southern or northeast sides of the cone. A T-junction conduit network is proposed to explain the simultaneous eruptive styles and as a mechanism for gas-magma segregation that must occur to produce the observed activity. Historical eruptions with simultaneous summit and flank activity produced slightly higher rising ash clouds compared to historical eruptions where simultaneous activity did not occur. This could be a consequence of the partitioning of more gas-charged magma into the vertical conduit of a T-junction conduit system.
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Burton, Mike, Catherine Hayer, Craig Miller y Bruce Christenson. "Insights into the 9 December 2019 eruption of Whakaari/White Island from analysis of TROPOMI SO2 imagery". Science Advances 7, n.º 25 (junio de 2021): eabg1218. http://dx.doi.org/10.1126/sciadv.abg1218.
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Small, phreatic explosions from volcanic hydrothermal systems pose a substantial proximal hazard on volcanoes, which can be popular tourist sites, creating casualty risks in case of eruption. Volcano monitoring of gas emissions provides insights into when explosions are likely to happen and unravel processes driving eruptions. Here, we report SO2 flux and plume height data retrieved from TROPOMI satellite imagery before, during, and after the 9 December 2019 eruption of Whakaari/White Island volcano, New Zealand, which resulted in 22 fatalities and numerous injuries. We show that SO2 was detected without explosive activity on separate days before and after the explosion, and that fluxes increased from 10 to 45 kg/s ~40 min before the explosion itself. High temporal resolution gas monitoring from space can provide key insights into magmatic degassing processes globally, aiding understanding of eruption precursors and complementing ground-based monitoring.
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Boudal, Christian y Claude Robin. "Relations entre dynamismes éruptifs et réalimentations magmatiques d'origine profonde au Popocatépetl". Canadian Journal of Earth Sciences 25, n.º 7 (1 de julio de 1988): 955–71. http://dx.doi.org/10.1139/e88-096.
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The modern volcano Popocatépetl is 30 000 – 50 000 years old. Until 5000 years BP, its volcanic activity led to the construction of a 2000 m high cone, the El Fraile volcano. This edifice was later topped by the Popocatépetl summit. The volcanic activity was characterized by long-term construction by lava flows, alternating with periods of 1000–2000 years of mixed explosive and effusive activity. The El Fraile volcano experienced three periods of this type, marked by back-falling pyroclastic flows with heterogeneous magma products and thick air-fall deposits (ash and scoria). The first one occurred more than 10 000 years BP; the second, between 10 000 and 8000 years BP; the third, from 5000 to 3800 years BP. Each of these periods showed violent explosive episodes alternating with lava flows in cycles of 100 to several hundreds of years in duration. Whenever the explosive activity occurred, it destroyed the upper part of the volcano, opening large craters. After a ~ 2500 year period of lava-flow construction (from ~ 3800 to 1200 years BP), the Popocatépetl summit began a similar activity. The last event, producing pyroclastic flows, occurred just before me Hispanic Conquest, and since that time the activity has been effusive and Plinian.Heterogeneous to subhomogeneous pyroclastic flow products exhibit a complex mineralogy: Fe clinopyroxene, Mg clinopyroxene, Fe orthopyroxene, Mg orthopyroxene, plagioclase in equilibrium or disequilibrium, and scarce olivine. All lava flows show a similar paragenesis, suggesting magma-mixing processes. A model in which a basaltic magma is periodically injected in a differentiated chamber at the beginning of each explosive period (or each cycle?) is proposed to explain the heterogeneous products. However, calculations of mixing models do not agree with the high Mg and Ni values observed in some hybrid lavas. This excess is probably due to the remobilization of cumulative olivine by basic magma supplies in the lower part of the reservoir. On the other hand, lava flows emitted during the long phases of effusive activity correspond to evolution in a closed and zoned chamber, partly affected by convective movements. The convection explains the complex mineralogy of these lavas, which result from differentiation of a previously homogenized magma rather than directly from magma mixing.