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Academic literature on the topic 'Basin impact ejecta model'

Author: Grafiati

Published: 4 June 2021

Last updated: 2 February 2022

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Journal articles on the topic "Basin impact ejecta model"

Ji, Jinzhu, James W. Head, and Jianzhong Liu. "Pre-Orientale Southwest Peak-Ring Basin: Gravity Structure, Geologic Characteristics, and Influence on Orientale Basin Ring Formation and Ejecta Emplacement." Remote Sensing 13, no. 13 (July 5, 2021): 2635. http://dx.doi.org/10.3390/rs13132635.

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The Orientale impact basin is the youngest and most well-preserved of the lunar multi-ring basins. The generally well-preserved ring structures and basin facies are distinctly anomalous in the southwestern quadrant; the outer Cordillera ring extends significantly outward, the Outer and Inner Rook mountain rings are more poorly developed and show anomalous characteristics, and the Montes Rook Formation varies widely from its characteristics elsewhere in the basin interior. Based on the gravity, image, and topography data, we confirmed that the southwest region of the Orientale basin represents the location of a pre-existing ~320 km rim–crest diameter peak–ring basin centered at 108.8°W, 28.4°S, and characterized by an ~170 km peak–ring diameter. We model the structure and morphology of this large pre-Orientale peak–ring basin (about one-third the diameter of Orientale) and show that its presence and negative relief had a distinctive influence on the development of the basin rings (disrupting the otherwise generally circular continuity and causing radial excursions in their locations) and the emplacement of ejecta (causing filling of the low region represented by the peak–ring basin, creating anomalous surface textures, and resulting in late stage ejecta movement in response to the pre-existing peak–ring basin topography. The location and preservation of the peak–ring basin Bouguer anomaly strongly suggest that the rim crest of the Orientale basin excavation cavity lies at or within the Outer Rook Mountain ring.

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Lin, Honglei, Zhiping He, Wei Yang, Yangting Lin, Rui Xu, Chi Zhang, Meng-Hua Zhu, et al. "Olivine-norite rock detected by the lunar rover Yutu-2 likely crystallized from the SPA-impact melt pool." National Science Review 7, no. 5 (November 14, 2019): 913–20. http://dx.doi.org/10.1093/nsr/nwz183.

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Abstract Chang’E-4 landed in the South Pole-Aitken (SPA) basin, providing a unique chance to probe the composition of the lunar interior. Its landing site is located on ejecta strips in Von Kármán crater that possibly originate from the neighboring Finsen crater. A surface rock and the lunar regolith at 10 sites along the rover Yutu-2 track were measured by the onboard Visible and Near-Infrared Imaging Spectrometer in the first three lunar days of mission operations. In situ spectra of the regolith have peak band positions at 1 and 2 μm, similar to the spectral data of Finsen ejecta from the Moon Mineralogy Mapper, which confirms that the regolith's composition of the landing area is mostly similar to that of Finsen ejecta. The rock spectrum shows similar band peak positions, but stronger absorptions, suggesting relatively fresh exposure. The rock may consist of 38.1 ± 5.4% low-Ca pyroxene, 13.9 ± 5.1% olivine and 48.0 ± 3.1% plagioclase, referred to as olivine-norite. The plagioclase-abundant and olivine-poor modal composition of the rock is inconsistent with the origin of the mantle, but representative of the lunar lower crust. Alternatively, the rock crystallized from the impact-derived melt pool formed by the SPA-impact event via mixing the lunar crust and mantle materials. This scenario is consistent with fast-cooling thermal conditions of a shallow melt pool, indicated by the fine to medium-sized texture (<3 mm) of the rock and the SPA-impact melting model [Icarus 2012; 220: 730–43].

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Gorter, J. D. "THE PETROLEUM POTENTIAL OF AUSTRALIAN PHANEROZOIC IMPACT STRUCTURES." APPEA Journal 38, no. 1 (1998): 159. http://dx.doi.org/10.1071/aj97009.

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This paper examines proven, probable, possible and speculative impact structures in Australian Phanerozoic strata and their petroleum potential. There are two classes of crater: simple and complex. The former usually assumes a bowl shaped depression with a raised and overturned rim with a diameter rarely more than three kilometres, with complex structures generally occurring above diameters of two kilometres in sedimentary rocks and four kilometres in crystalline rocks. Complex craters are characterised by a central uplifted area and a classic 'sombrero' structure and can be very large and have diameters of over 800 km. Criteria for the identification of terrestrial impact structures include: (a) circular plan; (b) faulted rim structure; (c) flat floor with central uplift (may not always be present) or interior ring(s); (d) negative gravity anomaly; (e) magnetic low with subdued magnetic relief; (f) brecciated crater fill; (g) low seismic velocities in the crater fill; (h) shock metamorphism (coesite, multiple sets of planar shock lamellae in quartz grains, shatter cones); (i) meteoric material; (j) presence of melt rock; (k) distal ejecta; and occurrence of an annular trough between the central uplift and the outer faulted rim.Proven impact features, like Gosses Bluff and Mt Toondina, are well exposed, contain indisputable evidence of shock metamorphism, and have had extensive geophysical surveys conducted over them: these structures provide models to interpret completely buried structures. Subsurface impact structures have been detected in areas where there has been intensive seismic surveying in the search for hydrocarbons. The Tookoonooka, Talundilly and Mulkarra structures all occur in the Cooper-Eromanga Basin, an area of high intensity exploration. The best known wholly subsurface impact feature is the 66 km diameter Tookoonooka Structure in southwestern Queensland, which exhibits several of the accepted criteria for an impact origin, including shock metamorphism, and is classified as a probable complex type impact structure. The Talundilly Structure, a possible impact feature, lies 300 km to the northeast of the Tookoonooka Structure and is of the same general age. The two structures could reflect the impact of fragments of the same bolide. The Yallallie Structure lies in a moderately explored hydrocarbon province in the central Perth Basin. It has a classic 'sombrero' shape in section view with a central uplift and evidence of shock metamorphism. Yallallie is a probable complex impact structure. The Mulkarra Structure, located in northeastern South Australia, has been classified as a simple type of impact crater lacking a central uplift, but recent geophysical work indicates a probable complex impact origin. Other possible and speculative impact related features described here owe their recognition to good quality seismic surveying.'there are yet some geologists who, adhering to Lyellian dogma, devoutly refuse to accept that large objects fall out of the sky.' (Shoemaker, 1997).

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Zhu, Meng‐Hua, Kai Wünnemann, and Natalia Artemieva. "Effects of Moon's Thermal State on the Impact Basin Ejecta Distribution." Geophysical Research Letters 44, no. 22 (November 27, 2017): 11,292–11,300. http://dx.doi.org/10.1002/2017gl075405.

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Buchner, Elmar, and Martin Schmieder. "The Steinheim Basin impact crater (SW-Germany) – Where are the ejecta?" Icarus 250 (April 2015): 529–43. http://dx.doi.org/10.1016/j.icarus.2014.12.026.

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Wada, K., K. Ishibashi, H. Kimura, M. Arakawa, H. Sawada, K. Ogawa, K. Shirai, et al. "Size of particles ejected from an artificial impact crater on asteroid 162173 Ryugu." Astronomy & Astrophysics 647 (March 2021): A43. http://dx.doi.org/10.1051/0004-6361/202039777.

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A projectile accelerated by the Hayabusa2 Small Carry-on Impactor successfully produced an artificial impact crater with a final apparent diameter of 14.5 ± 0.8 m on the surface of the near-Earth asteroid 162173 Ryugu on April 5, 2019. At the time of cratering, Deployable Camera 3 took clear time-lapse images of the ejecta curtain, an assemblage of ejected particles forming a curtain-like structure emerging from the crater. Focusing on the optical depth of the ejecta curtain and comparing it with a theoretical model, we infer the size of the ejecta particles. As a result, the typical size of the ejecta particles is estimated to be several centimeters to decimeters, although it slightly depends on the assumed size distribution. Since the ejecta particles are expected to come from a depth down to ~1 m, our result suggests that the subsurface layer of Ryugu is composed of relatively small particles compared to the uppermost layer on which we observe many meter-sized boulders. Our result also suggests a deficit of particles of less than ~1 mm in the subsurface layer. These findings will play a key role in revealing the formation and surface evolution process of Ryugu and other small Solar System bodies.

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Yue, Zongyu, Meiping Yang, Mengna Jia, Gregory Michael, Kaichang Di, Sheng Gou, and Jianzhong Liu. "Refined model age for Orientale Basin derived from zonal crater dating of its ejecta." Icarus 346 (August 2020): 113804. http://dx.doi.org/10.1016/j.icarus.2020.113804.

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Premovic, Pavle, Nikola Nikolic, Mirjana Pavlovic, and Katja Panov. "Geochemistry of the cretaceous-tertiary transition boundary at Blake Nose (N. W. Atlantic): Cosmogenic Ni." Journal of the Serbian Chemical Society 69, no. 3 (2004): 205–23. http://dx.doi.org/10.2298/jsc0403205p.

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The Cretaceous-Tertiary (KT) boundary transition at the Blake Nose Plateau recovered by ODP Leg 171B (site 1049, hole A, core 17X, section 2) contains an ejecta bed (thickness ca. 17 cm) marking a late Cretaceous asteroid impact. The nature and geochemical composition of this bed imply that it originated mainly from the target rocks of the Chicxulub impact site (Yucatan Peninsula, Mexico), the site of the presumed asteroid impact. The ejecta bed of hole 1049A contains relatively high concentrations of Ni (up to 165 ppm) within the carbonate fraction. It is reasoned that this enhancement represents a sudden and rapid air fall of high cosmogenic Ni into he Blake Nose Basin. The source of the metal was the Chicxulub impacting (carbonaceous) chondrite. It is suggested that many calcareous planktons in the KT ocean surface water of the Blake Nose Plateau were probably vulnerable to the high influx of superacid rainfall and associated toxic metals (e.g. Ni) created by the impact.

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Dessart, L., D. J. Hillier, and K. D. Wilk. "Impact of clumping on core-collapse supernova radiation." Astronomy & Astrophysics 619 (October 30, 2018): A30. http://dx.doi.org/10.1051/0004-6361/201833278.

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There is both observational and theoretical evidence that the ejecta of core-collapse supernovae (SNe) are structured. Rather than being smooth and homogeneous, the material is made of over-dense and under-dense regions of distinct composition. Here, we have explored the effect of clumping on the SN radiation during the photospheric phase using 1D non-local thermodynamic equilibrium radiative transfer and an ejecta model arising from a blue-supergiant explosion (yielding a Type II-peculiar SN). Neglecting chemical segregation, we adopted a velocity-dependent volume-filling factor approach that assumes that the clumps are small but does not change the column density along any sightline. We find that clumping boosts the recombination rate in the photospheric layers, leading to a faster recession of the photosphere, an increase in bolometric luminosity, and a reddening of the SN colors through enhanced blanketing. The SN bolometric light curve peaks earlier and transitions faster to the nebular phase. On the rise to maximum, the strongest luminosity contrast between our clumped and smooth models is obtained at the epoch when the photosphere has receded to ejecta layers where the clumping factor is only 0.5 – this clumping factor may be larger in nature. Clumping is seen to have a similar influence in a Type II-Plateau SN model. As we neglected both porosity and chemical segregation, our models underestimate the true impact of clumping. These results warrant further study of the influence of clumping on the observables of other SN types during the photospheric phase.

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Nozaki, Kenta, Masahiro Nishida, Koichi Hayashi, and Sunao Hasegawa. "Ejecta Size Distribution Resulting from Hypervelocity Impacts between Aluminum Alloys." Applied Mechanics and Materials 566 (June 2014): 338–43. http://dx.doi.org/10.4028/www.scientific.net/amm.566.338.

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We investigated the effects of impact velocity on ejecta size when aluminum alloy 2017-T4 spheres with a diameter of 3.2 mm impacted aluminum alloy 6061-T6 targets with a thickness of 30 mm at velocities of 2 to 7 km/s. We used a two-stage light-gas gun at the Institute of Space and Astronautical Science (ISAS)/Japan Aerospace Exploration Agency (JAXA). To examine the scattering angles of the ejecta, the following was placed 50 mm in front of the target: a witness plate (150 mm × 150 mm, 2 mm in thickness) made of copper with a hole of 30 mm. The ejection behaviors of fragments were observed using a high-speed video camera. The size distributions of the ejecta were examined in detail. The cumulative number of ejecta was proportional to the square of the impact velocity; in other words, to the impact energy of the projectiles. An experimental formula was created by curve fitting of the cumulative number distribution of the projected areas to a bilinear exponential distribution model when the aluminum alloy spheres struck the aluminum alloy targets.

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Dissertations / Theses on the topic "Basin impact ejecta model"

Jackson, Noel William. "A compositional study of the lunar global megaregolith using Clementine orbiter data a dissertation /." University of Southern Queensland, Faculty of Sciences, 2005. http://eprints.usq.edu.au/archive/00001452/.

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This thesis presents new information about the global megaregolith of the Moon, using 2059 craters (5 to 50 km diameter) as natural probes. Iron (FeO) and titanium (TiO2) concentrations were obtained from crater ejecta blanket data over an area between 600 North to 600 South latitude derived from the 1994 Clementine mission. The average iron and titanium weight percentages for lunar crater ejecta were calculated using the US Geological Survey's ISIS software, and used to determine the variation with depth of iron (FeO) and titanium (TiO2) in the highlands, mare areas and the South Pole Aitken basin. In addition, megaregolith compositional Iron (FeO) and Titanium (TiO2) Maps and compositional Province Maps were generated, and studied in detail. The Lunar Megaregolith Iron Province Map divides the Highland areas into 2 distinct provinces of low-iron Highland I (0-3.7 FeO weight percentage) and low-medium level iron Highland II (3.8-6.4%), and the Mare and South Pole Aitken Basin each into 3 distinct provinces (6.5-9.7%, 9.8-13.6%, and 13.7-18.3%). Similarly, a Titanium Megaregolith Province Map divides the Moon globally into 5 provinces based on weight percentages of TiO2. A new finding is the Highland II Province of elevated iron concentration which surrounds basins. These elevated iron levels may be explained in terms of an "Intrusion Model". In this model, basin formation fractures the surrounding anorthositic bedrock, and the middle level anorthositic crust allows mafic (basaltic?) magma to intrude. This intrusion into the megaregolith is in the form of sills and dykes from deep mafic sources but generally does not intrude into the surface regolith. In some places however, the mafic (basaltic?) lava may have extruded onto the surface, such as near Crater 846 (15.6N 92.2W). The megaregolith, which consists of large volume breccia, would have voids and vacancies in this structure into which mafic or basaltic material could intrude. "Islands" of Highland I Province material surrounded by Highland II Province indicate this intrusion was non-uniform. Another possible explanation for the Highland II Province iron levels comes from the "Thrust Block" model, where deep mafic material has been broken into large blocks by the basin-forming events, and "thrusted" or uplifted to displace most of the overlying anorthosite bedrock, thereby mechanically mixing with the megaregolith to provide the additional iron input. However, this does entirely fit comfortably with the data in this study. A third explanation for the Highland II Province arises from the "Basin Impact Ejecta Model" such as the Imbrium Impact described by Haskin (1998). The Basin Impact Ejecta model describes the effect of basin impacts around 4.0 billion to 3.8 billion years ago in the Moon's history (Ryder, 1990; Taylor, 2001)). This model implies that basin material was ejected and deposited on a global or similar scale. However, the results of this study place severe limitations on the feasibility of the "Basin Impact Ejecta" model to explain any significant mafic input from such ejecta in forming the Highland II megaregolith material. These Province Maps provide a new dimension to the study of the Moon's crustal development and reveal a highly complex history, providing a basis for future study.

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Norreys, Richard. "Water quality river impact model (RIM) for river basin management." Thesis, University of Salford, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.305863.

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Yang, Yongqian. "Impact of Patchy Vegetation on Wave and Runup Dynamics." Diss., Virginia Tech, 2016. http://hdl.handle.net/10919/72278.

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Coastal regions are vulnerable to various natural processes, ranging from normal waves to extreme events. Given the flourishing development and large population along coastlines, various measures have been taken to mitigate the water-induced damage. Nature-based coastal protection, especially vegetation, has attracted unprecedented studies over the past two decades. To enhance understanding of this subject, this dissertation evaluates the impact of patchy vegetation on wave and runup dynamics along coastlines. Selecting from a prototype in Dalehite Cove, Galveston Bay, TX, results from a Boussinesq model (COULWAVE) showed patchy vegetation reduced up to 75% mean shoreward current in the mound-channel wetland systems. These vegetation patches also reduced the primary circulation around mounds, with a power-form relation between circulation size and various parameters (i.e., bathymetry, incident wave and vegetated roughness). Substituting spectral waves for regular waves in the similar wetlands, more energy was transferred into the higher frequencies. The impact of patchy vegetation on wave energy was frequency- and space-dependent, with increased energy observed in specific harmonics and locations. Comparison with unvegetated horizontal bathymetry demonstrated that mound-channel bathymetry was the dominant factor in transferring and dissipating wave energy, while vegetation patches added a fair contribution. As for extreme events, such as tsunamis, laboratory experiments and numerical simulations were conducted to assess the effectiveness of patchy vegetation with various roughness levels, spacings and sizes. Overall, vegetation patches reduced the most destructive loads onshore by up to 80%. Within-patch roughness variation only caused uncertainty on the hydrodynamics around the seaward patches, while the mitigation of extreme loads was not undermined. A logarithmic relation was observed between the protected area from extreme loads and the vegetated coverage. These findings will fill the knowledge gap of hydrodynamics in the presence patchy vegetation, and improve the engineering practice of coastal protection using nature-based infrastructure.
Ph. D.

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Shem, Willis Otieno. "The impact of Congo basin deforestation on precipitation and other climate parameters -(a Common Land Model simulation)." Thesis, Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/25811.

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Wichakul, Supattana. "Development and applications of a distributed hydrological model for water resources assessment at the Chao Phraya River Basin under a changing climate." 京都大学 (Kyoto University), 2014. http://hdl.handle.net/2433/192155.

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Kassa, Asfaw Kebede [Verfasser]. "Downscaling Climate Model Outputs for Estimating the Impact of Climate Change on Water Availability over the Baro-Akobo River Basin, Ethiopia / Asfaw Kebede Kassa." Bonn : Universitäts- und Landesbibliothek Bonn, 2013. http://d-nb.info/1045276510/34.

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Zech, Alraune [Verfasser], Sabine [Akademischer Betreuer] Attinger, and Olaf [Akademischer Betreuer] Kolditz. "Impact of Aqifer Heterogeneity on Subsurface Flow and Salt Transport at Different Scales : from a method determine parameters of heterogeneous permeability at local scale to a large-scale model for the sedimentary basin of Thuringia / Alraune Zech. Gutachter: Sabine Attinger ; Olaf Kolditz." Jena : Thüringer Universitäts- und Landesbibliothek Jena, 2014. http://d-nb.info/1048047229/34.

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Ndoumbe, Berock Isaac Bernard. "Construction de la responsabilité sociétale des entreprises (RSE) dans les pays en développement : une application dans les entreprises d'exploitations forestières au Cameroun." Thesis, Strasbourg, 2017. http://www.theses.fr/2017STRAB004.

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Face à un environnement incertain marqué par une instabilité sans cesse croissante, les entreprises s’efforcent de rechercher la performance à la fois globale et durable considérée désormais comme un levier non seulement de pérennité, mais aussi d’avantage concurrentiel primordial (Porter et Kramer, 2006; Crane et Matten, 2004). Ainsi, la responsabilité sociétale de l’entreprise (RSE) est perçue comme un thème fédérateur en sciences de gestion et de par sa dimension sociétale dans les sciences économiques et sociales prenant tout son sens dans le management opérationnel des entreprises. Considérée comme le prolongement de la prise en compte du développement durable (rapport Brundtland 1987) dans ses implications managériales, la RSE cristallise l’attention de nombreux chercheurs depuis plusieurs décennies, notamment dans sa dimension sociale, environnementale et normative (ISO 14000) depuis une vingtaine d’année et sociétale (ISO 26000) depuis les années 2000. Si la littérature foisonnante sur le concept de RSE reste en débat, force est de constater qu’elle traite très peu des mécanismes de construction des pratiques RSE et moins encore du rôle que les stakeholders jouent dans cette construction. Dans un tel contexte, prenant appui sur la stakeholder theory (Freeman, 1984; Oliver, 1991; Clarkson, 1995; Mitchell et al., 1997; Sethi, 1995; Rowley, 1997), l’analyse des données collectées suite à une investigation de huit mois auprès de six entreprises forestières au Cameroun, révèle d’une part que le modèle de Carroll (1979, 1991) de la RSE est contingent au contexte et que le comportement stratégique orienté RSE des entreprises du secteur de l’industrie forestière au Cameroun est fortement corrélé à la nationalité de l’entreprise. D’autre part, cette étude fait état de ce que la variable « champ d’activité » a un effet non déterminé sur le comportement stratégique adopté par les entreprises de ce secteur forestier. Enfin, cette recherche révèle également que la certification forestière FSC représente le gage d’un engagement volontaire en matière de RSE des entreprises d’exploitations forestières au Cameroun. La présente recherche ouvre la voie aux travaux futurs pour internaliser les pratiques de la RSE par les parties prenantes dans le management stratégique des entreprises les plus confrontées aux défis environnementaux
In an uncertain environment that is also marked by a growing instability, firms try to seek a global and sustainable performance which is considered as a lever not only for longevity but also for competitive advantage (Porter and Kramer, 2006; Crane and Matten, 2004). Thus, corporate social responsibility (CSR) is perceived as a unifying topic in management science and, by its societal dimension, in the economic and social sciences. Considered as an extension to the consideration of sustainable development in its managerial implications (Brundtland report, 1987), CSR has been at the attention of a large number of researchers for several decades now, in particular for twenty years in its social, environmental and normative dimension (ISO 14000) and since the 2000’s in its societal nature.While the concept of CSR is still under debate in its rather large literature, it should also be noted that this literature is usually silent on the construction mechanisms of CSR practices and even more on the role that stakeholders play in this construction.In this context, and relying on stakeholder theory (Freeman, 1984; Oliver, 1991; Clarkson, 1995; Mitchell et al., 1997; Sethi, 1995; Rowley, 1997), the present analysis of the collected data from an eight-month-long in-depth investigation of six forestry firms in Cameroun yields several findings: First, the CSR model in Carroll (1979, 1991) is contingent to the context and the strategic CSR behaviour of the different firms in the forestry industry in Cameroun is strictly correlated to the nationality of these firms. Second, this study shows that the “field of action” variable has a non-significant effect on the strategic behaviour adopted by the firms in this forestry industry. Finally, this research also reveals that the Forest Stewardship Council (FSC) certification represents the deposit of a voluntary commitment in terms of CSR of the forestry exploitation firms in Cameroun. The present work also opens new lines for future research focussing on the internalisation of the CSR practices by the contracting parties in strategic management of the firms that are in direct confrontation to the environmental challenges

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Zimmermann, Karsten. "Prognose und bergschadenkundliche Analyse dynamischer Bodenbewegungen durch oberflächennahen Steinkohlenbergbau in den USA." Doctoral thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2011. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-65009.

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Der untertägige Abbau von Steinkohle führt zu Bewegungen des überlagernden Gebirges und der Tagesoberfläche. Eine Bewegungsprognose ist im Hinblick auf entstehende Bergschäden weltweit von großer Bedeutung. In dieser Arbeit wird untersucht, ob eine Prognose von Bodenbewegungen im amerikanischen Steinkohlenbergbau mit einem in Europa bewährten Verfahren, einem dynamischen stochastischen Senkungsmodell, möglich ist. Dazu wurde eine Literaturstudie über den bisherigen Kenntnisstand in den USA durchgeführt, abbaubegleitende Bodenbewegungsmessungen aus dem Steinkohlengebiet der Appalachen ausgewertet und durch Modellrechnungen nachgebildet. Es wurde darüber hinaus untersucht, welchen Einfluss die spezifischen Abbaubedingungen und die räumliche und zeitliche Abbauführung auf die Größe und Dynamik von Bodenbewegungen haben. Die theoretischen und praktischen Untersuchungen zeigen einen deutlichen Know-how Vorsprung des europäischen Bergbaus in den Bereichen der Senkungsmodellierung und Bewertung abbauinduzierter Bodenbewegungen und belegen die Anwendbarkeit des Senkungsmodells. Es wurden wichtige Erkenntnisse gewonnen, die Möglichkeiten und Grenzen einer Optimierung des Abbauzuschnitts und der zeitlichen Abbauführung im Sinne einer bergschadensmindernden Abbauplanung aufzeigen. Die Arbeit trägt zur Verbesserung der bergmännischen und markscheiderischen Abbauplanung im Steinkohlenbergbau bei.

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Chawla, Ila. "Hydrologic Response of Upper Ganga Basin to Changing Land Use and Climate." Thesis, 2013. http://etd.iisc.ernet.in/2005/3416.

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Numerous studies indicate that the hydrology of a river basin is influenced by Land Use Land Cover (LULC) and climate. LULC affects the quality and quantity of water resources through its influence on Evapotranspiration (ET) and initiation of surface runoff while climate affects the intensity and spatial distribution of rainfall and temperature which are major drivers of the hydrologic cycle. Literature reports several works on either the effect of changing LULC or climate on the hydrology. However, changes in LULC and climate occur simultaneously in reality. Thus, there is a need to perform an integrated impact assessment of such changes on the hydrological regime at a basin scale. In order to carry out the impact assessment, physically-based hydrologic models are often employed. The present study focuses on assessment of the effect of changing LULC and climate on the hydrology of the Upper Ganga basin (UGB), India, using the Variable Infiltration Capacity (VIC) hydrologic model. In order to obtain the changes that have occurred in the LULC of the basin over a time period, initially LULC analysis is carried out. For this purpose, high resolution multispectral satellite imageries from Landsat are procured for the years 1973, 1980, 2000 and 2011. The images are pre-processed to project them to a common projection system and are then co-registered. The processed images are used for classification into different land cover classes. This step requires training sites which are collected during the field visit as part of this work. The classified images, thus obtained are used to analyse temporal changes in LULC of the region. The results indicate an increase in crop land and urban area of the region by 47% and 122% respectively from 1973 to 2011. After initial decline in dense forest for the first three decades, an increase in the dense forest is observed between 2000- 2011 (from 11.44% to 14.8%). Scrub forest area and barren land are observed to decline in the study region by 62% and 96% respectively since 1973. The land cover information along with meteorological data and soil data are used to drive the VIC model to investigate the impact of LULC changes on streamflow and evapotranspiration (ET) components of hydrology in the UGB. For the simulation purpose, the entire basin is divided into three regions (1) upstream (with Bhimgodha as the outlet), (2) midstream (with Ankinghat as the outlet) and (3) downstream (with Allahabad as the outlet). The VIC model is calibrated and validated for all the three regions independently at monthly scale. Model performance is assessed based on the criterion of normalized root mean square error (NRMSE), coefficient of determination (R2) and Nash-Sutcliffe efficiency (NSE). It is observed that the model performed well with reasonable accuracy for upstream and midstream regions. In case of the downstream region, due to lack of observed discharge data, model performance could not be assessed. Hence, the simulations for the downstream region are performed using the calibrated model of the midstream region. The model outputs from the three regions are aggregated appropriately to generate the total hydrologic response of the UGB. Using the calibrated models for different region of the UGB, sensitivity analysis is performed by generating hydrologic scenarios corresponding to different land use (LU) and climate conditions. In order to investigate the impact of changing LU on hydrological variables, a scenario is generated in which climate is kept constant and LU is varied. Under this scenario, only the land cover related variables are altered in the model keeping the meteorological variables constant. Thus, the effect of LU change is segregated from the effect of climate. The results obtained from these simulations indicated that the change in LU significantly affects peak streamflow depth which is observed to be 77.58% more in August 2011 in comparison with the peak streamflow of August, 1973. Furthermore, ET is found to increase by 46.44% since 1973 across the entire basin. In order to assess the impact of changing climate on hydrological variables, a scenario is generated in which LU is kept constant and climate is varied from 1971-2005. Under this scenario, land cover related variables are kept constant in the model and meteorological variables are varied for different time periods. The results indicate decline in the simulated discharge for the years 1971, 1980, 1990, 2000 and 2005, which is supported by decline in observed annual rainfall for the respective years. Amongst 1971 and 2005, year 2005 received 26% less rainfall resulting in 35% less discharge. Furthermore, ET is observed to be negligibly affected. To understand the integrated impact of changing LU and climate on hydrological variables, a scenario is generated in which both climate and LU are altered. Based on the data available, three years (1973, 1980 and 2000) are considered for the simulations. Under this scenario, both land cover and meteorological variables are varied in the model. The results obtained showed that the discharge hydrograph for the year 1980 has significantly higher peak compared to the hydrographs of years 1973 and 2000. This could be due to the fact that the year 1980 received maximum rainfall amongst the three years considered for simulations. Although the basin received higher rainfall in the year 1980 compared to that in 2000, ET from the basin in the year 1980 is found to be 21% less than that of the year 2000. This could be attributed to the change in LU that occurred between the years 1980 and 2000. Amongst the years 1973 and 2000, there is not much difference in the observed rainfall but ET for the year 2000 is observed to be significantly higher than that of year 1973. It is concluded from the present study that in the UGB, changing LULC contributes significantly to the changes in peak discharge and ET while rainfall pattern considerably influences the runoff pattern of the region. Future work proposed includes assessment of hydrologic response of basin under future LULC and climate scenarios. Also the model efficiency can be assessed by performing hydrologic simulations at different grid sizes.

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Books on the topic "Basin impact ejecta model"

Norreys, Richard. Water quality river impact model (RIM) for river basin management. Salford: University of Salford, 1991.

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Hanna, R. Blair. Water quality modeling in the systems impact assessment model for the Klamath River basin - Keno, Oregon to Seiad Valley, California. Ft. Collins, CO: U.S. Dept. of the Interior, U.S. Geological Survey, 2000.

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A simple model for the light curve generated by a Shoemaker-Levy 9 impact. [Washington, D.C: National Aeronautics and Space Administration, 1995.

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L, Sharpton Virgil, and United States. National Aeronautics and Space Administration., eds. A model of the Chicxulub impact basin based on evaluation of geophysical data, well logs, and drill core samples. [Washington, DC: National Aeronautics and Space Administration, 1996.

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Busuioc, Aristita, and Alexandru Dumitrescu. Empirical-Statistical Downscaling: Nonlinear Statistical Downscaling. Oxford University Press, 2018. http://dx.doi.org/10.1093/acrefore/9780190228620.013.770.

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This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Climate Science. Please check back later for the full article.The concept of statistical downscaling or empirical-statistical downscaling became a distinct and important scientific approach in climate science in recent decades, when the climate change issue and assessment of climate change impact on various social and natural systems have become international challenges. Global climate models are the best tools for estimating future climate conditions. Even if improvements can be made in state-of-the art global climate models, in terms of spatial resolution and their performance in simulation of climate characteristics, they are still skillful only in reproducing large-scale feature of climate variability, such as global mean temperature or various circulation patterns (e.g., the North Atlantic Oscillation). However, these models are not able to provide reliable information on local climate characteristics (mean temperature, total precipitation), especially on extreme weather and climate events. The main reason for this failure is the influence of local geographical features on the local climate, as well as other factors related to surrounding large-scale conditions, the influence of which cannot be correctly taken into consideration by the current dynamical global models.Impact models, such as hydrological and crop models, need high resolution information on various climate parameters on the scale of a river basin or a farm, scales that are not available from the usual global climate models. Downscaling techniques produce regional climate information on finer scale, from global climate change scenarios, based on the assumption that there is a systematic link between the large-scale and local climate. Two types of downscaling approaches are known: a) dynamical downscaling is based on regional climate models nested in a global climate model; and b) statistical downscaling is based on developing statistical relationships between large-scale atmospheric variables (predictors), available from global climate models, and observed local-scale variables of interest (predictands).Various types of empirical-statistical downscaling approaches can be placed approximately in linear and nonlinear groupings. The empirical-statistical downscaling techniques focus more on details related to the nonlinear models—their validation, strengths, and weaknesses—in comparison to linear models or the mixed models combining the linear and nonlinear approaches. Stochastic models can be applied to daily and sub-daily precipitation in Romania, with a comparison to dynamical downscaling. Conditional stochastic models are generally specific for daily or sub-daily precipitation as predictand.A complex validation of the nonlinear statistical downscaling models, selection of the large-scale predictors, model ability to reproduce historical trends, extreme events, and the uncertainty related to future downscaled changes are important issues. A better estimation of the uncertainty related to downscaled climate change projections can be achieved by using ensembles of more global climate models as drivers, including their ability to simulate the input in downscaling models. Comparison between future statistical downscaled climate signals and those derived from dynamical downscaling driven by the same global model, including a complex validation of the regional climate models, gives a measure of the reliability of downscaled regional climate changes.

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Book chapters on the topic "Basin impact ejecta model"

Byrne, Charles J. "A Model of Large Impact Craters and Basins: Their Cavities, Rims, and Ejecta Deposits." In The Moon's Near Side Megabasin and Far Side Bulge, 23–38. New York, NY: Springer New York, 2013. http://dx.doi.org/10.1007/978-1-4614-6949-0_4.

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Du, Hongyan, Xiaoping Bai, Qiming Wei, and Yawei Mao. "Application Method Study of Erica Model and R&D128 Model in Radiological Impact Assessment of Terrestrial Organisms." In Proceedings of The 20th Pacific Basin Nuclear Conference, 431–40. Singapore: Springer Singapore, 2017. http://dx.doi.org/10.1007/978-981-10-2314-9_38.

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Bhunia, Partha Sarathi, and Kanhu Charan Patra. "Impact of Land Use–Land Cover Changes on the Streamflow of the Kolab River Basin Using SWAT Model." In Climate Change Impacts on Water Resources, 319–31. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-64202-0_28.

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Siderius, Christian, Robel Geressu, Martin C. Todd, Seshagiri Rao Kolusu, Julien J. Harou, Japhet J. Kashaigili, and Declan Conway. "High Stakes Decisions Under Uncertainty: Dams, Development and Climate Change in the Rufiji River Basin." In Climate Risk in Africa, 93–113. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-61160-6_6.

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AbstractThe need to stress test designs and decisions about major infrastructure under climate change conditions is increasingly being recognised. This chapter explores new ways to understand and—if possible—reduce the uncertainty in climate information to enable its use in assessing decisions that have consequences across the water, energy, food and environment sectors. It outlines an approach, applied in the Rufiji River Basin in Tanzania, that addresses uncertainty in climate model projections by weighting them according to different skill metrics; how well the models simulate important climate features. The impact of different weighting approaches on two river basin performance indicators (hydropower generation and environmental flows) is assessed, providing an indication of the reliability of infrastructure investments, including a major proposed dam under different climate model projections. The chapter ends with a reflection on the operational context for applying such approaches and some of the steps taken to address challenges and to engage stakeholders.

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SALLES, T., S. LOPEZ, R. ESCHARD, T. MULDER, T. EUZEN, and M. C. CACAS. "A Turbidity-Current Model to Simulate Impact of Basin-Scale Forcing Parameters." In External Controls of Deep-Water Depositional Systems, 363–83. SEPM (Society for Sedimentary Geology), 2009. http://dx.doi.org/10.2110/sepmsp.092.363.

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Alemaw, Berhanu F., and Thebeyame Ronald Chaoka. "Climate Change Impact on the Water Resources of the Limpopo Basin." In Advances in Geospatial Technologies, 177–200. IGI Global, 2018. http://dx.doi.org/10.4018/978-1-5225-3440-2.ch012.

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This chapter aims to evaluate the impacts of climate change on both hydrologic regimes and water resources of the Limpopo River Basin in southern Africa. Water resources availability in the basin, in terms of, seasonal and annual runoff (R), soil moisture (S) and actual evapotranspiration (Ea) is simulated and evaluated using the hydrological model, HATWAB. These water balances were computed from precipitation (P), potential evapotranspiration (Ep) and other variables that govern the soil-water-vegetation-atmospheric processes at 9.2km latitude/ longitude gird cells covering the basin. The 1961-90 simulated mean annual runoff reveals mixed patterns of high and low runoff across the region. Although relatively small changes in runoff simulations are prevalent among the three climate change scenarios, generally the OSU simulated relatively high runoff compared to the UKTR and HADCM2 GCMs.

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Sharpton, Virgil L., Luis E. Marin, John L. Carney, Scott Lee, Graham Ryder, Benjamin C. Schuraytz, Paul Sikora, and Paul D. Spudis. "A model of the Chicxulub impact basin based on evaluation of geophysical data, well logs, and drill core samples." In The Cretaceous-Tertiary Event and Other Catastrophes in Earth History. Geological Society of America, 1996. http://dx.doi.org/10.1130/0-8137-2307-8.55.

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Bayissa, Yared Ashenafi. "Developing a combined drought index and prediction model to monitor drought-related crop yield reduction 3." In Developing an Impact-Based Combined Drought Index for Monitoring Crop Yield Anomalies in the Upper Blue Nile Basin, Ethiopia, 59–80. CRC Press, 2018. http://dx.doi.org/10.1201/9780429399510-4.

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Bayissa, Yared Ashenafi. "Application of Earth observation data for developing a combined drought index and crop yield prediction model 4." In Developing an Impact-Based Combined Drought Index for Monitoring Crop Yield Anomalies in the Upper Blue Nile Basin, Ethiopia, 81–102. CRC Press, 2018. http://dx.doi.org/10.1201/9780429399510-5.

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Inogwabini, Bila-Isia. "Congo Basin's Shrinking Watersheds." In Reconsidering the Impact of Climate Change on Global Water Supply, Use, and Management, 211–26. IGI Global, 2017. http://dx.doi.org/10.4018/978-1-5225-1046-8.ch012.

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Rainfall time series data from three sites (Kinshasa, Luki, and Mabali) in the western Democratic Republic of Congo were analyzed using regression analysis; rainfall intensities decreased in all three sites. The Congo Basin waters will follow the equation y = -20894x + 5483.16; R2 = 0.7945. The model suggests 18%-loss of the Congo Basin water volume and 7%-decrease for fish biomasses by 2025. Financial incomes generated by fishing will decrease by 11% by 2040 compared with 1998 levels. About 51% of women (N= 408,173) from the Lake Tumba Landscape fish; their revenues decreased by 11% between 2005 and 2010. If this trend continues, women's revenues will decrease by 59% by 2040. Decreased waters will severely impact women (e.g. increasing walking distances to clean waters). Increasing populations and decreasing waters will lead to immigrations to this region because water resources will remain available and highly likely ignite social conflicts over aquatic resources.

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Conference papers on the topic "Basin impact ejecta model"

Zheng, Wei, and Baojun Pang. "The ejecta model for hypervelocity impact on 5A06 aluminum sheet." In Fourth International Conference on Experimental Mechanics, edited by Chenggen Quan, Kemao Qian, Anand K. Asundi, and Fook S. Chau. SPIE, 2009. http://dx.doi.org/10.1117/12.851269.

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Nypaver, Cole, Bradley J. Thomson, Devon M. Burr, and Caleb I. Fassett. "RADAR PROPERTIES OF IMPACT EJECTA ON THE LUNAR MARIA: A MODEL FOR DEGRADATION AND AGE." In 67th Annual Southeastern GSA Section Meeting - 2018. Geological Society of America, 2018. http://dx.doi.org/10.1130/abs/2018se-313217.

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Petrović, Branislav, Milan Gojak, and Đorđe Kozić. "Numerical Analysis of the Influence of Basic Operating Parameters on the Performance Characteristics of Solar-Driven Ejector Cooling." In 51st International HVAC&R Congress and Exhibition. SMEITS, 2020. http://dx.doi.org/10.24094/kghk.020.51.1.129.

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Researchers are becoming growingly interested in the development of solar-driven ejector cooling systems, primarily due to their potential to be used as renewable energy sources. Absorption and adsorption refrigeration systems not only involve considerable investment but are also much less reliable than the ejector refrigeration sys-tems, which do not contain any movable parts. In adition, ejector refrigeration has the advantage of low capital cost, simple design, reliable operation, long lifespan and almost no maintance. The only weakness of this system is the low efficiency and its intolerance to deviations from design operation condition.The paper develops a mathematical mod-el with an algorithm which is based on the laws of thermodynamics and the principles of mass and momentum conser-vation. Based on the obtained model, the influence of temperature on the basic system parameters for two working fluids, R134a and R290, is presented. The working fluid temperature ranges are 80-100°C in the generator, 5-15°C in the evaporator and 33-40°C in the condenser. The important performace indicators are the characteristic ejector area ratio Ar (as a geometrical ejector parameter), ejector entrainment ratio, ejector efficiency and the COP. The results indicate that ejector geometry and working fluid type have a major impact on the ejector cooling system’s performance.

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Sollier, Arnaud, and Emilien Lescoute. "Characterization of the ballistic properties of ejecta from laser shock-loaded samples using high resolution picosecond imaging." In 2019 15th Hypervelocity Impact Symposium. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/hvis2019-097.

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Abstract Anticipating the generation of high velocity debris from shock-loaded specimens and the damage that their impacts may cause to nearby equipment is a major safety issue in applications involving shock waves, such as pyrotechnics [1] or inertial confinement fusion (ICF) experiments on large scale laser facilities [2]. Microjetting is one of the processes governing such debris generation. It is due to the interaction of a shock wave with a free surface presenting geometrical defects such as pits, cavities, scratches, or grooves, leading to material ejection from these defects, in the form of thin jets expanding ahead of the main surface and breaking up into small particles [3]. Over the last few years, we have used laser shock loading in order to expand microjetting investigations over ranges of small spatial scales (μm scale), extremely high loading rates (~ 107 s-1) and very short pressure pulses (a few ns) [4-11]. Optical shadowgraphy and Photonic Doppler Velocimetry (PDV) have been used to measure both jet tip and planar surface velocities [4-6], while attempts to infer fragments size distributions, to be compared with model predictions, have been made using either fast transverse shadowgraphy [7] or ejecta recovery [8]. More recently, picosecond x-ray radiography has been used to provide estimates of the density gradients along the jets and of the total ejected mass at different times after shock breakout [9-11]. Here, we present the development of a new picosecond laser imaging diagnostic intended to overcome the limitations of our current transverse optical shadowgraphy setup. We describe our experimental setup and show the results of our first experiments performed using both visible (532 nm) and UV (355 nm) lightning of the sample. These results are compared to those obtained at LANL under high explosive loading using ultraviolet in-line Fraunhofer holography [12], and also to molecular dynamics (MD) simulations performed by our colleagues at lower space and time scales [15-18].

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Robb, Kevin R., and Michael L. Corradini. "Towards Understanding Melt Eruption Phenomena During Molten Corium Concrete Interactions." In 18th International Conference on Nuclear Engineering. ASMEDC, 2010. http://dx.doi.org/10.1115/icone18-30116.

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A defense-in-depth feature for advanced light water reactors to cope with beyond design basis accidents is the ability to cool and stabilize ex-vessel core melt debris. Several international experimental programs have investigated core-concrete interactions and debris cooling of ex-vessel core melts. These experimental programs have identified various phenomena which affect melt coolability and may enhance it. One such phenomenon, melt eruptions, occurs when gas from the underlying decomposing concrete entrains melt up through and onto a solidified crust, which separates the molten melt from the cooling water. Previous modeling and experimental work have shown this cooling mechanism can have a large impact on melt coolability. Previous melt eruption models are reviewed and a new synthesis model is proposed. Reviewing past experimental evidence and modeling efforts indicate the geometry of the flow area impacts the amount of melt ejected. To understand the potential flow area available for melt eruptions, past experimental evidence is reviewed, a steady state analysis of flow area is performed and non-steady state considerations are discussed.

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Schwab, A. L., and M. Wisse. "Basin of Attraction of the Simplest Walking Model." In ASME 2001 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2001. http://dx.doi.org/10.1115/detc2001/vib-21363.

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Abstract Passive dynamic walking is an important development for walking robots, supplying natural, energy-efficient motions. In practice, the cyclic gait of passive dynamic prototypes appears to be stable, only for small disturbances. Therefore, in this paper we research the basin of attraction of the cyclic walking motion for the simplest walking model. Furthermore, we present a general method for deriving the equations of motion and impact equations for the analysis of multibody systems, as in walking models. Application of the cell mapping method shows the basin of attraction to be a small, thin area. It is shown that the basin of attraction is not directly related to the stability of the cyclic motion.

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Sudeshika, Pavithra, and Lalith Rajapakse. "Impact of Digital Elevation Model on Rainfall-Runoff-Inundation modelling - A Case Study of Lower Kelani River Basin." In 2021 Moratuwa Engineering Research Conference (MERCon). IEEE, 2021. http://dx.doi.org/10.1109/mercon52712.2021.9525704.

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Chuang, Wei-Liang, Kuang-An Chang, and Richard Mercier. "Green Water on a Fixed Model in a Large Wave Basin: Flow Velocity, Void Fraction, and Impact Pressure Distributions." In ASME 2017 36th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/omae2017-61229.

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Green water impact due to extreme waves impinging on a fixed, rectangular shaped model structure was investigated experimentally. The experiment was carried out in the large wave basin of the Offshore Technology Research Center at Texas A&M University. In the study, two wave conditions were considered: a plunging breaking wave impinging on the frontal vertical wall (referred as wall impingement) and a breaking wave directly impinging on the deck surface (referred as deck impingement). The aerated flow velocity was measured by employing the bubble image velocimetry (BIV) technique with high speed cameras. The pressure distribution on the deck surface was measured by four differential pressure sensors. The fiber optic reflectometer (FOR) technique was employed to measure the void fraction in front of each pressure sensor end face. The flow velocity, void fraction, and impact pressure, were synchronized and simultaneously measured. Comparisons between an earlier study by Ryu et al. (2007) and the present study were performed to examine the scale effect. Results between Song et al. (2015) and the present results were also compared to investigate the influence of structure geometry on green water flow and impact pressure. To examine the role of air bubbles during the impact, the velocity, pressure, and void fraction were correlated. Correlation between the peak pressure and the aeration level shows a negative trend before the wave impingement but a positive linear relationship after the impingement.

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Huang, Zhenjia (Jerry), Don Spencer, Robert Oberlies, Gracie Watts, and Wenting Xiao. "Wave Impact Experiment of a GBS Model in Large Waves." In ASME 2017 36th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/omae2017-61473.

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For the design of offshore structures in harsh wave environments, model testing continues to be the recommended industry practice for determining wave impact forces on offshore structures. Accurate measurements of wave impacts in model tests have been a challenge for several decades. Transducers are required to accurately capture the short duration, high magnitude, and dynamic nature of impact loads. The structural model, transducers, and the transducer mountings need to be designed such that mechanical vibrations in the integrated transducer-mounting-structural model system do not contaminate the wave impact measurements. In this work, the dynamic oscillations in the measurements were controlled through the design and fabrication of transducers, their mounting and the GBS model. Wave crest probability distributions were developed that included fully nonlinear effects. These distributions were used as a benchmark to qualify the waves in the wave calibration tests. The highly stochastic nature of impact loads makes it challenging to obtain converged probability distributions of the maximum impact loads (i.e. forces or pressures) from model tests. To increase the confidence in the statistical values of wave impact loads, a large number of realizations were used for a given sea state. Variability of the maximum pressure due to wave basin effects (such as wait-time between tests) was examined with fifteen repeat tests using the same wave maker control signal. These tests provided insights into the random behavior of the impact loads.

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