Siga este link para ver outros tipos de publicações sobre o tema: Orientation des fissures.
Artigos de revistas sobre o tema "Orientation des fissures"
Crie uma referência precisa em APA, MLA, Chicago, Harvard, e outros estilos
Veja os 50 melhores artigos de revistas para estudos sobre o assunto "Orientation des fissures".
Ao lado de cada fonte na lista de referências, há um botão "Adicionar à bibliografia". Clique e geraremos automaticamente a citação bibliográfica do trabalho escolhido no estilo de citação de que você precisa: APA, MLA, Harvard, Chicago, Vancouver, etc.
Você também pode baixar o texto completo da publicação científica em formato .pdf e ler o resumo do trabalho online se estiver presente nos metadados.
Veja os artigos de revistas das mais diversas áreas científicas e compile uma bibliografia correta.
1
Li, Feida, Feiyong Wang, Fujiang Wang e Guoqing Li. "Developmental Characteristics and Genesis of Ground Fissures in Wangjiacun, Emei Plateau, Yuncheng Basin, China". Sustainability 16, n.º 9 (26 de abril de 2024): 3649. http://dx.doi.org/10.3390/su16093649.
Texto completo da fonteResumo:
The Yuncheng Basin is part of the Fenwei Graben System, which has developed ground fissure hazards that have caused serious damage to farmland, houses, and roads and have brought about huge economic losses. Located in Wanrong County on the Emei Plateau in the northwestern part of the Yuncheng Basin in China, the Wangjiacun ground fissure is a typical and special ground fissure developed in loess areas, and its formation is closely related to tectonic joints and the collapsibility of loess. In order to reveal the formation and genesis of the Wangjiacun ground fissure, the geological background, developmental characteristics, and genesis pattern of the Wangjiacun ground fissures were studied in detail. A total of three ground fissures have developed in this area: a linear fissure (f1) is distributed in an NNE-SSW direction, with a total length of 334 m; a circular fissure (f2) is located near the pool, with a total length of 720 m; f2-1, a linear fissure near f2, has a fissure length of 110 m and an NE orientation. This study shows that tectonic joints in loess areas are the main controlling factors of the linear fissure (f1); differential subsidence in the pool caused by collapsible loess is the main source of motivation for the formation of the circular fissures (f2, f2-1), and tensile stresses produced by the edges of subsidence funnels lead to the cracking of shallow rock and soil bodies to form ground fissures (f2, f2-1). This study enriches the theory of ground fissure genesis and is of great significance for disaster prevention and the mitigation of ground fissures in loess areas.
2
Han, Zeng Qiang, Chuan Ying Wang e Heng Yin Zhu. "Investigation of Deep Joints and Analysis of Lode Extension Direction in Shapinggou Molybdenum Mine". Applied Mechanics and Materials 638-640 (setembro de 2014): 2151–54. http://dx.doi.org/10.4028/www.scientific.net/amm.638-640.2151.
Texto completo da fonteResumo:
By investigating on the joints and fissures in Shapinggou molybdenum mine based on digital borehole camera technology, the dominant orientation of joint fissure in surrounding rock and ore body were statistically analyzed. Applying the theory of metallogeny and geostatistics, the relationship between joint fissure and lode’s extension direction is explored. The results indicate that joints in the ore body of ZK61borehole have only one dominant orientation SE126°∠68°, however, the dominant orientations of joints in surrounding rock were SE118°∠73°, SW225°∠70°and SE122°∠65°, NE79°∠63°. Then a preliminary conclusion showed that the lode’s extension direction is specific and it is influenced by joints of surrounding rock. Results of other boreholes are generally agree well with the ZK61, suggesting the analysis reliably reflects the lode’s extension properties and the conclusion presents important references for deep ore prospecting.
3
Han, Zengqiang, Chuanying Wang e Hengyin Zhu. "Research on Deep Joints and Lode Extension Based on Digital Borehole Camera Technology". Polish Maritime Research 22, s1 (1 de setembro de 2015): 10–14. http://dx.doi.org/10.1515/pomr-2015-0025.
Texto completo da fonteResumo:
Abstract Structure characteristics of rock and orebody in deep borehole are obtained by borehole camera technology. By investigating on the joints and fissures in Shapinggou molybdenum mine, the dominant orientation of joint fissure in surrounding rock and orebody were statistically analyzed. Applying the theory of metallogeny and geostatistics, the relationship between joint fissure and lode’s extension direction is explored. The results indicate that joints in the orebody of ZK61borehole have only one dominant orientation SE126° ∠68°, however, the dominant orientations of joints in surrounding rock were SE118° ∠73°, SW225° ∠70° and SE122° ∠65°, NE79° ∠63°. Then a preliminary conclusion showed that the lode’s extension direction is specific and it is influenced by joints of surrounding rock. Results of other boreholes are generally agree well with the ZK61, suggesting the analysis reliably reflects the lode’s extension properties and the conclusion presents important references for deep ore prospecting.
4
Hossain, D., e D. G. McKinlay. "The influence of fissures on the consolidation of a glacial till". Geological Society, London, Engineering Geology Special Publications 7, n.º 1 (1991): 143–49. http://dx.doi.org/10.1144/gsl.eng.1991.007.01.11.
Texto completo da fonteResumo:
AbstractThe influence of fissures on the permeability, compressibility and consolidation rate properties of glacial till at three sites in and near Glasgow, Scotland has been studied. This included both the determination of the orientation and other characteristics of the fissures in the tills, both in-situ and in laboratory specimens, and measurement of the above properties by testing large specimens at various loading/drainage orientations.Comparatively large variations in permeability and consolidation rate and small variations in compressibility were observed for specimens of different sizes and orientations of sampling and testing. The influence of fissures was found to be most marked at the lower effective stresses.
5
Xiao, Runing, e Jinzhi Zhou. "Pulmonary Fissure Detection in 3D CT Images Using a Multiple Section Model". Algorithms 12, n.º 4 (15 de abril de 2019): 75. http://dx.doi.org/10.3390/a12040075.
Texto completo da fonteResumo:
As a typical landmark in human lungs, the detection of pulmonary fissures is of significance to computer aided diagnosis and surgery. However, the automatic detection of pulmonary fissures in CT images is a difficult task due to complex factors like their 3D membrane shape, intensity variation and adjacent interferences. Based on the observation that the fissure object often appears as thin curvilinear structures across 2D section images, we present an efficient scheme to solve this problem by merging the fissure line detection from multiple cross-sections in different directions. First, an existing oriented derivative of stick (ODoS) filter was modified for pulmonary fissure line enhancement. Then, an orientation partition scheme was applied to suppress the adhering clutters. Finally, a multiple section model was proposed for pulmonary fissure integration and segmentation. The proposed method is expected to improve fissure detection by extracting more weak objects while suppressing unrelated interferences. The performance of our scheme was validated in experiments using the publicly available open Lobe and Lung Analysis 2011 (LOLA11) dataset. Compared with manual references, the proposed scheme achieved a high segmentation accuracy, with a median F1-score of 0.8916, which was much better than conventional methods.
6
Tudisco, Erika, Claudia Vitone, Cristina Mondello, Gioacchino Viggiani, Stephen A. Hall, Federica Cotecchia, Alessandra Castellano e Francesco Massaro. "Influence of fissure inclination and confining pressure on the local behaviour of natural clays". E3S Web of Conferences 92 (2019): 03004. http://dx.doi.org/10.1051/e3sconf/20199203004.
Texto completo da fonteResumo:
In this experimental study the influence of fissuring orientation and confinement pressure on the mechanical behaviour of natural clays is investigated. The tested material, the scaly clay from Santa Croce di Magliano (south of Italy), is characterised by an intense network of pre-existing fissures of single orientation. Several plane strain compression tests have been conducted, under different confinement pressures (i.e., from 50 to 600 kPa), on specimens having fissures with vertical, medium and horizontal inclination. Digital Image Correlation has been used to follow the deformation processes of the specimens throughout the tests by measuring incremental shear and volumetric strain maps. The results showed a strong coupling between the total confinement and the fissure inclination, that is controlling both the onset and the development of the patterns of the localisation processes. The new results have been compared with previous ones carried out on the same material without confinement. The comparison shed light on the role of total confinement that becomes particularly relevant from certain levels of pressures and fissuring inclination.
7
Wang, Kun, Bowei Wei, Tongbin Zhao, Gengkun Wu, Junyang Zhang, Liyi Zhu e Letian Wang. "An Automated Approach for Mapping Mining-Induced Fissures Using CNNs and UAS Photogrammetry". Remote Sensing 16, n.º 12 (9 de junho de 2024): 2090. http://dx.doi.org/10.3390/rs16122090.
Texto completo da fonteResumo:
Understanding the distribution and development patterns of mining-induced fissures is crucial for environmental protection and geological hazard prevention. To address labor-intensive manual inspection, an automated approach leveraging Convolutional Neural Networks (CNNs) and Unmanned Aerial System Photogrammetry (UASP) is proposed for fissure identification and mapping. Initially, the ResNet-50 network was employed for the binary classification of the cropped UASP orthophoto images. A comparative analysis was conducted to determine the optimal model between DeepLabv3+ and U-Net. Subsequently, the identified fissures were mosaicked and spatially projected onto the original orthophoto image, incorporating precise projection data, thereby furnishing a spatial reference for environmental governance. The results indicate a classification accuracy of 93% for the ResNet-50 model, with the U-Net model demonstrating a superior identification performance. Fissure orientation and distribution patterns are influenced by the mining direction, ground position of the mining workface, and topographic undulations. Enhancing the CNN performance can be achieved by incorporating variables such as slope indices, vegetation density, and mining workface locations. Lastly, a remote unmanned approach is proposed for the automated mapping of mining-induced fissures, integrated with UAS automated charging station technology. This study contributes to the advancement of intelligent, labor-saving, and unmanned management approaches advocated by the mining industry, with potential for broad applications in mining environmental protection efforts.
8
Fokin, P. A. "Disjunctive dislocations in Upper Cretaceous rocks of the Chufut-Cale plateau northeastern slope (Bakhchisaray distr., Crimea)". Moscow University Bulletin. Series 4. Geology, n.º 3 (7 de agosto de 2023): 22–30. http://dx.doi.org/10.55959/msu0579-9406-4-2023-63-3-22-30.
Texto completo da fonteResumo:
The paper contains description of systems fissures and low-amplitude faults in Upper Cretaceous rocks of Chufut-Cale “cave town” outskirts. Analysis of orientation and kinematics of breaks and fissures’ parageneses allowed to restore stress-fields of Alpine tectonic epoch and their rough order. A guess of sublatitudinal compression appearance in Mountaineous Crimea was suggested.
9
Maulana, Baso Rezki, Muhammad Sulhuzair Burhanuddin e Muh Fikri Akbar. "Lineament Density and Implications for the Distribution of Ground Fissures After 2021 MW 7.3 Flores Sea Earthquake on Kalaotoa Island, Indonesia". Journal of Geoscience, Engineering, Environment, and Technology 8, n.º 1 (27 de março de 2023): 17–26. http://dx.doi.org/10.25299/jgeet.2023.8.1.10849.
Texto completo da fonteResumo:
A 7.3 MW earthquake occurred at 11:20 am on December 14, 2021, in the Flores Sea, and the main shake was centered ±100 km north of Maumere, Indonesia, with a depth of 14.3 km, antecedent a landslide. This research consists of two stages, namely: quantitative data collection in the form of tectonic lineament density measurements using Shuttle Radar Topography Mission (SRTM) data which is extracted manually using GIS-based applications, and qualitative data in the form of field observations which include strike-dip measurements of rocks, lithological data, morphological conditions, ground fissures, and the distribution of damage caused after 2021 earthquake. This study focused on analyzing the value of lineament density, its correlation to the history of seismicity and surface lithological conditions, and the impact after the 2021 earthquake damage. The lineaments of the southern area are dominated by NE – SW orientation along with various lithological conditions and with lineament density values very low – very high. A crack width from 0.5 to 112 cm, and a vertical offset occurs with a depth of up to 270 cm. The western area is dominated by lineament with an orientation NE – SW with a crack width from 8 to 18 cm, and there is a vertical offset with a depth of up to 24 cm. The distribution of ground fissures in the Garaupa Raya area is categorized as low. The orientation of the northern area lineament is relatively NW – SE directional and the lineament density value is categorized as low. Horizontal displacement with an orientation of NW – SE is found at the port of Kalaotoa Island, Kawawo village with measured crack width of ±17 cm, an observable horizontal offset from 15 to 24 cm, and a vertical offset of ±12 cm with a trend of movement towards the south.
10
Einarsson, Páll, e Ásta Rut Hjartardóttir. "Structure and tectonic position of the Eyjafjallajökull volcano, S-Iceland". Jökull 65, n.º 1 (15 de dezembro de 2015): 1–16. http://dx.doi.org/10.33799/jokull2015.65.001.
Texto completo da fonteResumo:
The Eyjafjallajökull volcano, one of the oldest active volcanoes in Iceland, is located in the volcanic flank zone of South Iceland, a few tens of kilometers south of the nearest branch of the mid-Atlantic plate boundary. It is an elongated, broad cone of about 1650 m height. A 100–200 m thick glacier covers the upper part of the volcano and its elliptical 2.5–km-wide summit crater or caldera. An E–W trending rift zone transects the volcano, but a few radial fissures are observed around the summit area. Eruptive fissures on the west flank are curved and tend to be aligned along the maximum gradient of the topography. The E–W orientation of the rift zone and the apparent correlation with the topography suggests strong influence of gravity. Dikes in the older parts of the volcano strike north-easterly and indicate a change in the stress orientation during the last 0.78 My. This change may be related to a southward propagation of the Eastern Volcanic Rift Zone of Iceland and the transfer of spreading from the Western to the Eastern Volcanic Rift Zone. We suggest that the anomalous orientation of the Eyjafjallajökull volcanic system is the result of preexisting topography and gravitational stresses when the volcanic edifice was built up unconformably on old oceanic crust. All known episodes of activity in Eyjafjallajökull have been accompanied by activity in the neighbouring volcano Katla. The most recent examples are the two thermal events, possibly subglacial eruptions, of 1999 and 2011 at Katla following the 1999 sill intrusion and 2010 eruption of Eyjafjallajökull. The coupling mechanism between the volcanoes remains enigmatic. One volcano may be triggered by the other by direct dike or sill injection. Furthermore, pressure perturbation in the mantle may affect the magma sources of both volcanoes.
11
Mo, Genlin, e Yongxi Jin. "Ballistic Wound Evaluation Based on Dye Diffusion Method". Journal of Physics: Conference Series 2470, n.º 1 (1 de março de 2023): 012006. http://dx.doi.org/10.1088/1742-6596/2470/1/012006.
Texto completo da fonteResumo:
Abstract Ballistic gelatin is widely used as a kind of tissue simulants in wound ballistics. Evaluations of the wound tract of gelatin by projectiles are mainly based on fissures in the gelatin slices. For there are difficulties in building relationships between the areas and the fissures, a new method based on dye diffusion is proposed in this paper. Colored regions in the slices are obtained after penetration of a Chinese 7.62mm rifle bullet into the gelatin block. The colored regions can be divided into ‘X’, ‘I’ and branching ‘I’ shapes. In the second half of the penetration, there is a strong correlation between the areas of the regions and the energy dissipation of the bullet. However, the correlation is poor in the first half of the penetration. Branches of the colored regions mainly distributed at the heads and tails of the permanent cavities. The permanent cavities’ shapes have a great dependence on the nutation angles of the bullets. Orientation angles of the permanent cavities are determined by the precession angles of the bullets.
12
Ammar, Ammar A. "Influence of the Lineament Geological Features on the Hydrologic Flow Direction of Wadi Al Kuf Catchment Area, Cyrenaica, Northeastern Libya". AL-MUKHTAR JOURNAL OF SCIENCES 34, n.º 3 (30 de setembro de 2019): 153–64. http://dx.doi.org/10.54172/mjsc.v34i3.276.
Texto completo da fonteResumo:
Wadi Al Kuf Catchment Area WKCA is one of the largest watershed basins on Al Jabal al Akhdar Cyrenaica anticlinorium, the area is more than 960Km2, and considers as a semi-wet basin. This basin highly affected with lineaments geological features just like morphometric and tectonics types including fissures, fault systems and joints set systems in the highly karst lime stones of Al Jabal al Akhdar group lithological formations. These lineaments phenomena were measured and extracted from the radar images of digital terrain model of 30 meters space grid, and the hyper spectral Landsat 8 of 15 meters pixel resolution, they were processed and interpreted by several geospatial geomatics and geological software. The direction orientation and the rock density of these fissures, fractures, joints set systems, faults and the morphometric dendritic drainage pattern had been measured and illustrated from the rose diagram analysis and the geological map. The mainstream of this catchment area WKCA is the 6th order and mainly parallel to the main trend direction with the first escarpment circular fault at the major orogeny tectonic fault of Al Jabal al Akhdar uplift, and these lineaments features is averaged 58.3o with the azimuth degree along the mainstream. The drainage density, lineaments density analysis and distribution of the WKCA have been classified as low lineaments rock fractures in the eastern boundary of the basin, moderate lineaments rock fissures in the middle of the basin and high density of rock fracture in the western and northern boundary of the basin, these had reflected the deep percolations and infiltrations to the ground water-bearing aquifer in the WKCA through the secondary and the tertiary porosity of the hydrological karst system.
13
Clark, Ian, Bernard Lauriol, Mark Marschner, Nicolas Sabourin, Yanie Chauret e André Desrochers. "Endostromatolites from permafrost karst, Yukon, Canada: paleoclimatic proxies for the Holocene hypsithermal". Canadian Journal of Earth Sciences 41, n.º 4 (1 de abril de 2004): 387–99. http://dx.doi.org/10.1139/e04-014.
Texto completo da fonteResumo:
A remarkable biogenic calcite precipitate forms carpets of finely laminated ~1 mm diameter columns lining fissures within limestone bedrock in the permafrost regions of the northern Yukon. This material, "endostromatolite," for its laminated morphology and growth hidden within the carbonate rock, is ubiquitous within limestone terrains of the Arctic and grew during the early Holocene hypsithermal. Dissolution on the interior fissure faces is accompanied by biomineralization of the opposing faces; a previously unrecognized weathering process in permafrost regions. Occurrence is restricted to outcrops with a southern orientation in permafrost regions, in this case, from the Ogilvie Mountains, northern Yukon. Growth occurs in water-saturated talik during periods of permafrost degradation during insolation maxima. Their enriched δ13C values (1.7 to 11.4) are generated in a methanogenic environment during anaerobic degradation of soil-derived organic carbon. A paleotemperature signal extracted from the δ18O values demonstrates that growth occurred during a hypsithermal period with an average summer air temperature 7 ± 2 °C higher than today. Corrected radiocarbon age measurements of the calcite and organic matter preserved within the endostromatolites indicate that biomineralization occurred during the late Pleistocene early Holocene hypsithermal event. Profiles along the columns document late Pleistocene climate improvement, with maximum warmth coincident with the insolation maximum for 65°N, followed by cooling and end of growth in the mid to late Holocene.
14
Stacy, Sean. "Can a Complicated “Consensus” Survive a Dose of Populist Poison? Exploring the Potential Impact of Brexit and Trumpism on the Developed Country Approach to Trade Law and Policy". Law and Development Review 14, n.º 2 (1 de junho de 2021): 689–722. http://dx.doi.org/10.1515/ldr-2021-0048.
Texto completo da fonteResumo:
Abstract Among wealthier, so-called “developed” nations, a consistent and shared policy orientation on trade has generally prevailed over the last three quarters of a century. This consensus has been hallmarked by the promotion of freer trade facilitated by a state-centric, rules-based legal system. While most wealthy countries appear to desire a continued fidelity to that policy orthodoxy, the United Kingdom’s (UK’s) ‘Brexit’ decision and the United States’ (US’) increasingly antagonistic stance toward World Trade Organization (WTO) dispute settlement beg the question as to whether fissures in the consensus are forming. This paper examines the depth of the perceived consensus and the degree to which US and UK actions signify a turning point. As part of this examination, populism’s role in promoting change in the US, UK and beyond, is explored.
15
Chatzipetros, Alexandros, Spyros Pavlides, Michael Foumelis, Sotiris Sboras, Dimitris Galanakis, Christos Pikridas, Stylianos Bitharis, Evangelos Kremastas, Athanasios Chatziioannou e Ioannis Papaioannou. "The northern Thessaly strong earthquakes of March 3 and 4, 2021, and their neotectonic setting". Bulletin of the Geological Society of Greece 58 (26 de outubro de 2021): 222. http://dx.doi.org/10.12681/bgsg.27225.
Texto completo da fonteResumo:
A sequence of earthquakes occurred on March 3rd and 4th in Northern Thessaly, northern Greece, associated with previously unknown, blind normal faults within the crystalline Palaeozoic basement of the Pelagonian geotectonic zone. Surficial ground deformation, such as liquefaction phenomena in fluvial plains, as well as soil fissures and rock falls, have been mapped. Geological indications of the unmapped seismic fault, i.e., reactivated shear zones, open cracks, etc., have been identified within the bedrock. Based on geological indications, the main fault projection to the surface could be considered a 15 km NW-SE trending structure and average dip of 45o to the NE. The seismic source of the main shock was modelled, and the Coulomb static stress changes calculated for receiver faults similar to the source. The determination of the active tectonic regime of the region by geodetic data and the well-known faults of NE Thessaly plain are also presented, as well as the revised historical and instrumental seismicity. This earthquake raises new concerns and challenges, revising some established views, such as the status of main stress orientations, the orientation of active tectonic structures, the occurrence of a seismogenic fault in a mountainous massif of crystalline rocks without typical geomorphological expression and the role of blind faults in Seismic Hazard Assessment.
16
McGuire, W. J., e A. D. Pullen. "Location and orientation of eruptive fissures and feederdykes at Mount Etna; influence of gravitational and regional tectonic stress regimes". Journal of Volcanology and Geothermal Research 38, n.º 3-4 (setembro de 1989): 325–44. http://dx.doi.org/10.1016/0377-0273(89)90046-2.
Texto completo da fonte
17
Zuliani, Andy. "Dirty Windows and Troublesome Things: The Problem of Object-Orientation in Alain Robbe-Grillet’s La Jalousie". Literature 3, n.º 2 (17 de abril de 2023): 217–30. http://dx.doi.org/10.3390/literature3020015.
Texto completo da fonteResumo:
This article investigates the representation of objects in La Jalousie (1957), a novel in the nouveau roman tradition written by French novelist Alain Robbe-Grillet. If the ‘new novel’ sought to render the material world with objective clarity, and positioned itself against traditional fiction, with its reliance on metaphor, allegory, and other ‘projections,’ this article argues that such an aesthetic program is undercut by its own assumptions about the power of description and the primacy of the visual. In an analysis which hybridizes three separate strands of criticism—object-oriented ontology, Heideggerian phenomenology, and the models of ‘resonation’ proposed by Brian Massumi—I will argue that such a treatment of objects, with its exclusive reliance on visual description, measurement, and enumeration, ends up depriving objects of the vitality and dynamism that would justify such a fictional project in the first place. However, traces of this dynamism do survive the flattening sweep of Robbe-Grillet’s narration, and indeed offer from the cracks and fissures of the novel’s otherwise smoothly controlled style the possibility of an alternate ‘object-orientation’—one, I will argue, which suspends its cool optical detachment to allow, however briefly, the eruption of a messy, entangling register of touch.
18
Dionne, Jean-Claude. "Rainures et marques de choc oblongues sur la plate-forme intertidale à Cap-Santé, haut estuaire du Saint-Laurent, Québec". Géographie physique et Quaternaire 50, n.º 1 (30 de novembro de 2007): 109–15. http://dx.doi.org/10.7202/033080ar.
Texto completo da fonteResumo:
On signale ici pour la première fois des formes d'érosion linéaires observées sur une couche de calcaire de la plate-forme intertidale schisteuse, à Cap-Santé. Il s'agit d'une part de rainures ayant jusqu'à 15 m de longueur et 2-3 cm de profondeur et d'autre part de petites dépressions allongées ayant en moyenne 60 à 80 cm de longueur, 8 à 12 cm de largeur et 2 à 3 cm de profondeur. On décrit aussi des stries courtes d'orientation multiple et des éraflures diverses. Les rainures ont une orientation variant de 75° à 115° avec un système principal à 90°, alors que les dépressions linéaires sont orientées de 75° à 85°, soit à peu près dans la même direction (75°-80°) qu'un système de fissures (diaclases) dans les schistes argileux. Ces diverses formes d'érosion du substrat rocheux sont attribuées à l'activité glacielle dans un contexte lithostructural particulier.
19
Honda, Ryou, Yuki Abe, Yohei Yukutake e Shin’ichi Sakai. "Fracture Structures in and Around Hakone Volcano Revealed by Dense Seismic Observations". Journal of Disaster Research 17, n.º 5 (1 de agosto de 2022): 663–69. http://dx.doi.org/10.20965/jdr.2022.p0663.
Texto completo da fonteResumo:
Preexisting fracture systems, including old fissures, dikes, and microfractures in the caldera, are possibly used as channels for magma and hydrothermal fluid intrusions during an eruption. To reveal such a fracture system in the Hakone volcano, we used the fuzzy c-means method to perform clustering on S-wave splitting analysis results. The results show that the fracture system in the Hakone caldera can be divided into two clusters (A and B) or four clusters (A1, A2, B1, and B2). In the central cone vicinity, craters or dikes corresponding to the compressive axis of the regional stress field are dominant, whereas the fault systems with the best orientation to the regional stress field develop around the central cone. Cluster B1 can be explained by the northwest–southeast alignment of micro cracks or dikes corresponding to the direction of maximum horizontal pressure of the regional stress field. The others are likely explained by fault fracture zones, which have an optimal orientation for regional stress fields, or by the alignment of micro cracks affected by the local stress field. Cluster B2 suggests the existence of fracture zones of the Tanna and Hirayama fault systems, which cross the Hakone volcano from north to south. Clusters A1 and A2 are possibly explained by the conjugate system of B2. However, the alignment of micro cracks generated by the local stress field or old volcanic structures can also be a cause of the clusters.
20
Margovsky, A. I., R. S. A. Lord, A. C. Meek e Y. V. Bobryshev. "Artery Wall Damage and Platelet Uptake from So-Called Atraumatic Arterial Clamps: An Experimental Study". Cardiovascular Surgery 5, n.º 1 (fevereiro de 1997): 42–47. http://dx.doi.org/10.1177/096721099700500109.
Texto completo da fonteResumo:
A ‘traumatic’ clamps are routinely used to control arteries during reconstruction, but little is known about the arterial damage caused and the effects on platelet uptake. This experiment used sheep carotid arteries to correlate the degree of histologic damage observed with the level of indium-111-labelled platelet uptake in clamped arterial segments. Scanning electron microscopy and light microscopy enabled three degrees of injury to be recognized. In mild injuries, endothelial cell orientation was changed but local platelet uptake was little different from controls. In moderate injuries, the endothelial cells directly squeezed by the clamp were morphologically altered, superficial fissures developed which extended into the media, and local platelet uptake was usually increased. Severe injuries caused extensive endothelial cell desquamation, formation of deep cavities in the media and increased platelet uptake (mean 5.51 times that of control). Platelet uptake at the site of clamp application was not significantly different from non-clamped carotids for mild injuries. However, the increased platelet uptakes for moderate ( P = 0.007) and severe ( P = 0.005) injuries were statistically significant when compared with non-clamped control arterial segments.
21
Li, Guoqing, Feiyong Wang, Xulong Gong, Yan Zhang e Fujiang Wang. "Characteristics and Formation Mechanism of Water-Eroded Ground Fissures in the Weihe Basin of China". Water 15, n.º 12 (12 de junho de 2023): 2198. http://dx.doi.org/10.3390/w15122198.
Texto completo da fonteResumo:
The Weihe Basin is a crucial part of the Fenwei Graben System and is a typical example of an extensional fault basin. Over time, the region has been developed around 212 ground fissures, with the majority of them being associated with heavy rainfall. These water-eroded ground fissures have caused serious damage to farmland, houses, and roads, with the Liangjiacun ground fissures, Meiyuancun ground fissures, and Dizhentai ground fissures being the most known. To understand the developmental characteristics and formation mechanisms of water-eroded ground fissures in the Weihe Basin, we utilized a variety of methods, including ground surveys, mapping, trenching, drilling, and geophysical exploration. These three ground fissures are distributed along corresponding fault zones, with their orientations being closely linked to local topographic changes. Additionally, the trenching profiles showed that all three typical ground fissure zones have distinct hidden holes above the paleosol. The formation of these ground fissures is closely associated with tectonic activity and heavy rainfall, with soil ruptures resulting from tectonic activity becoming the dominant channels for surface water infiltration. Furthermore, the erosion caused by heavy rainfall accelerates the rupture and expansion of ground fissures in the shallow subsurface. This paper is a valuable resource for disaster prevention and mitigation strategies aimed at mitigating the damage caused by ground fissures in the Weihe Basin.
22
Pradani, Diana Irmawati, Heru Dwiriawan Sutoyo e Agus Suhardono. "Analyzing the roughness of the discontinuous surface in Mt. Semeru Eruption rock". Journal of Earth and Marine Technology (JEMT) 3, n.º 2 (20 de maio de 2023): 48–58. http://dx.doi.org/10.31284/j.jemt.2023.v3i2.4131.
Texto completo da fonteResumo:
From the moment they were formed to the deposition process, the characteristics and properties of rocks that form on the earth's surface vary. The effects of Mount Semeru's eruption will be transported and deposited, eventually solidifying into rock masses. As a result of weak places like joints, fractures, and fissures, where the density, filling, and orientation are not continuous, rock masses in nature have discontinuous or discontinuous qualities. Rock shear strength will be decreased if there are discontinuous planes in the rock bulk. Using Barton's empirical equation and the Joint Roughness Coefficient (JRC) parameter, roughness conditions in discontinuous planes can be measured. Determining the features of the rock mass that are influenced by the shear strength of discontinuous planes in the Mount Semeru eruption rock based on variations in shear roughness in accordance with Barton and Choubey's criterion is therefore crucial. The observation of discontinuous plane roughness conditions in rocks as a result of Mount Semeru's eruption is necessary to get many rock shear strength parameters, which are then used to determine the friction angles, undulation values, and cohesion values in the surface of the discontinuous plane.
23
Bousquet, Jean-Claude, e Gianni Lanzafame. "Nouvelle interpretation des fractures des eruptions laterales de l'Etna; consequences pour son cadre tectonique". Bulletin de la Société Géologique de France 172, n.º 4 (1 de julho de 2001): 455–67. http://dx.doi.org/10.2113/172.4.455.
Texto completo da fonteResumo:
Abstract Mt Etna is cut by numerous fractures (fissures and faults) of very different origin and orientation. They have been used to define the activity and the tectonic setting of the volcano. After a discussion of the proposed tectonic models for Etna, an examination of the fractures, which are linked to the high flank eruptions, was carried out based on the geological and geophysical studies of the recent eruptions (1983, 1989, 1991-93). All of these surface breaks are of strictly volcanic origin; they open and advance very slowly, in relation to the propagation of the dyke, as well as its width and depth from the volcano surface. If the dyke summit is not too far from the surface (about 200-300 m), fissures and normal faults, arranged in a graben, appear. When the dyke intersects the slope of the volcano, a flank eruption follows. Therefore, these fractures do not have a tectonic or volcano-tectonic origin: they do not cut the entire volcanic edifice, and thus cannot be used to define the rift-zones nor to characterise the tectonic regime controlling the functioning of Etna. They give information on the dyke orientation on the slopes of the volcanic edifice and cannot be used as significative markers of extension [Frazzetta and Villari, 1981; Kieffer 1983a and b; Monaco et al., 1997]. The simultaneous opening of radial fractures, according to various azimuths, is frequent and clearly indicates that, in these cases, the regional stress field is not implicated. But high on Etna, the concentration of flank eruptions, on the eastern side, and the orientation change of the fractures (fig. 6), when they travel away from the summit, have been repeatedly indicated. The repetition of flank eruptions and the azimuth changes can be explained, simply, by the closeness of the Valle del Bove [Murray, 1994], which induces a decrease of the confinement pressure. The dyke emplacements of the summit eruptions cause an eastward displacement of the higher part of Etna. Marine geophysical data indicate that this volcano is, however, not the site of a large scale lateral spreading to the Ionian sea. Consequently, an eastward detachment is present only on the superior part of the volcano (figs. 1B and 7C). In fact, an up to 100 m high and oversteepened east-facing scarp, between the towns of Vena and Presa, extends towards the south for some kilometers [Lanzafame et al., 2000]. It is made up of volcanic rocks affected by strong brecciation. Inverse faults are found in front of the scarp. The base of this one is found at the level of the pre-Etnean clays, which would have helped the displacement of the volcanics. The studies on the tectonic setting in which Etna is located has called the attention of numerous researchers. From the earliest studies, the presence of numerous normal faults has supported the idea that this volcano, as many others, is active in an extensional regime. The most recent geological and geophysical data show a more complex situation. Deep under Etna (more than 10 km), a compressive field (sigma 1 N-S) is present according to focal mechanisms [Cardaci et al.; 1990; Ferrucci et al., 1993; Cocina et al., 1997]. More superficially, instead, extension is usual. The importance of the weight of the volcanic edifice, in the spatial (horizontal and vertical) modification of the compressive stress field, must still be clarified. It is very clear, in any case, that Etna cannot be explained by an extensional regime or kinematics in extension [Monaco et al., 1997] using normal faults, which form during the flank eruptions.
24
Corti, Noemi, Fabio L. Bonali, Federico Pasquaré Mariotto, Alessandro Tibaldi, Elena Russo, Ásta Rut Hjartardóttir, Páll Einarsson, Valentina Rigoni e Sofia Bressan. "Fracture Kinematics and Holocene Stress Field at the Krafla Rift, Northern Iceland". Geosciences 11, n.º 2 (20 de fevereiro de 2021): 101. http://dx.doi.org/10.3390/geosciences11020101.
Texto completo da fonteResumo:
In the Northern Volcanic Zone of Iceland, the geometry, kinematics and offset amount of the structures that form the active Krafla Rift were studied. This rift is composed of a central volcano and a swarm of extension fractures, normal faults and eruptive fissures, which were mapped and analysed through remote sensing and field techniques. In three areas, across the northern, central and southern part of the rift, detailed measurements were collected by extensive field surveys along the post-Late Glacial Maximum (LGM) extension fractures and normal faults, to reconstruct their strike, opening direction and dilation amount. The geometry and the distribution of all the studied structures suggest a northward propagation of the rift, and an interaction with the Húsavík–Flatey Fault. Although the opening direction at the extension fractures is mostly normal to the general N–S rift orientation (average value N99.5° E), a systematic occurrence of subordinate transcurrent components of motion is noticed. From the measured throw at each normal fault, the heave was calculated, and it was summed together with the net dilation measured at the extension fractures; this has allowed us to assess the stretch ratio of the rift, obtaining a value of 1.003 in the central sector, and 1.001 and 1.002 in the northern and southern part, respectively.
25
Soták, Ján, Zuzana Pulišová, Dušan Plašienka e Viera Šimonová. "Stratigraphic and tectonic control of deep-water scarp accumulation in Paleogene synorogenic basins: a case study of the Súľov Conglomerates (Middle Váh Valley, Western Carpathians)". Geologica Carpathica 68, n.º 5 (26 de outubro de 2017): 403–18. http://dx.doi.org/10.1515/geoca-2017-0027.
Texto completo da fonteResumo:
Abstract The Súľov Conglomerates represent mass-transport deposits of the Súľov-Domaniža Basin. Their lithosomes are intercalated by claystones of late Thanetian (Zones P3 - P4), early Ypresian (Zones P5 - E2) and late Ypresian to early Lutetian (Zones E5 - E9) age. Claystone interbeds contain rich planktonic and agglutinated microfauna, implying deep-water environments of gravity-flow deposition. The basin was supplied by continental margin deposystems, and filled with submarine landslides, fault-scarp breccias, base-of-slope aprons, debris-flow lobes and distal fans of debrite and turbidite deposits. Synsedimentary tectonics of the Súľov-Domaniža Basin started in the late Thanetian - early Ypresian by normal faulting and disintegration of the orogenic wedge margin. Fault-related fissures were filled by carbonate bedrock breccias and banded crystalline calcite veins (onyxites). The subsidence accelerated during the Ypresian and early Lutetian by gravitational collapse and subcrustal tectonic erosion of the CWC plate. The basin subsided to lower bathyal up to abyssal depth along with downslope accumulation of mass-flow deposits. Tectonic inversion of the basin resulted from the Oligocene - early Miocene transpression (σ1 rotated from NW-SE to NNW-SSE), which changed to a transpressional regime during the Middle Miocene (σ1 rotated from NNE-SSW to NE-SW). Late Miocene tectonics were dominated by an extensional regime with σ3 axis in NNW-SSE orientation.
26
Angelescu, Mariana Lucia, Elisabeta Mirela Cojocaru, Nicolae Șerban e Vasile Dănuț Cojocaru. "Evaluation of Hot Deformation Behaviour of UNS S32750 Super Duplex Stainless Steel (SDSS) Alloy". Metals 10, n.º 5 (21 de maio de 2020): 673. http://dx.doi.org/10.3390/met10050673.
Texto completo da fonteResumo:
The super-duplex stainless steel UNS S32750 consists of two main phases, austenite and ferrite, which differ not only by their morphology, physical, and mechanical properties, but also by their deformation behaviour. A heterogenous deformation can be obtained during thermomechanical processing, generating internal stresses and sometimes fissures or cracks on sample lateral surfaces, due to ferrite’s phase lower potential of plastic deformation accommodation in comparison with austenite phase. The research objective is to determine the optimum range of the applied deformation degree, during hot deformation processing by upsetting of the super-duplex steel (SDSS) UNS S32750. In the experimental program several samples were hot deformed by upsetting, by applying a deformation degree between 5–50%, at 1050 °C and 1300 °C. The most representative hot-deformed samples were selected and analysed by scanning electron microscope-Electron Backscatter Diffraction (SEM-EBSD), to determine the main microstructural characteristics obtained during thermomechanical processing. When considering the experimental results, the influence of the applied deformation degree on the microstructure has been evaluated. Microstructural features, such as nature, distribution, morphology and relative proportion of constituent phases, Grain Reference Orientation Deviation (GROD), and recrystallization (RX), were analysed, in correlation with the applied deformation degree. Finally, it was concluded that the UNS S32750 alloy can be safely hot deformed, by upsetting, at 1050 °C and 1300 °C, with a maximum applied deformation degree of 20% at 1050 °C and, respectively, by 50% at 1300 °C.
27
Cojocaru, Elisabeta Mirela, Anna Nocivin, Doina Răducanu, Mariana Lucia Angelescu, Ion Cinca, Irina Varvara Balkan, Nicolae Șerban e Vasile Dănuț Cojocaru. "Microstructure Evolution during Hot Deformation of UNS S32750 Super-Duplex Stainless Steel Alloy". Materials 14, n.º 14 (14 de julho de 2021): 3916. http://dx.doi.org/10.3390/ma14143916.
Texto completo da fonteResumo:
The present paper analyzes UNS S32750 Super-Duplex Stainless Steel hot deformation behavior during processing by upsetting. The objective of this paper is to determine the optimum range of deformation temperatures, considering that both austenite and ferrite have different deformation behaviors due to their different morphology, physical, and mechanical properties. Because the capability of plastic deformation accommodation of ferrite is reduced when compared to austenite, side cracks and fissures can form during the hot deformation process. Consequently, it is important to find the optimum conditions of deformation of this type of stainless steel to establish the best processing parameters without deteriorating the material. The experimental program involved the application of hot deformation by the upsetting method on a series of samples between 1000 °C and 1275 °C, with a total degree of deformation of 30%. The resultant samples were examined by SEM-EBSD to establish and analyze the evolution of the phases present in the structure from several points of view: nature, distribution, morphology (size and shape), and their structural homogeneity. The GROD (Grain Reference Orientation Deviation) distribution map was also determined while taking into account the possible precipitation of the secondary austenite phase (γ2-phase) and the analysis of the dynamic recrystallization process according to the applied deformation temperature. The main conclusion was that UNS S32750 SDSS steel can be safely deformed by upsetting between 1050–1275 °C, with an experimented total degree of deformation of 30%.
28
SUNESEN, INES, JONAS A. TARDIVO KUBIS e EUGENIA A. SAR. "A re-investigation of three Frenguelli’s Caloneis taxa (Pinnulariaceae, Bacillariophyta) from Argentina". Phytotaxa 305, n.º 3 (28 de abril de 2017): 165. http://dx.doi.org/10.11646/phytotaxa.305.3.4.
Texto completo da fonteResumo:
Caloneis mendosina var. mendosina, Caloneis mendosina var. minor and Caloneis quilinensis from slides of the Frenguelli Collection deposited at the Herbarium of the División Ficología ‘Dr. Sebastián A. Guarrera’ (LPC), were investigated using light microscope (LM). Unmounted material related to these slides was observed using the scanning electron microscope (SEM). Specimens of both varieties of C. mendosina found in the original material show a continuous range of size and stria density, and are ultrastructurally similar; thus the taxa are considered conspecific. Specimens of C. quilinensis found in the original material show more variability than described in the protologue. A continuous range of size, stria density, shape of the frustules and valve outline was observed between C. mendosina and C. quilinensis. Additionally, ultrastructural comparison of both taxa showed numerous features in common including shape of the valve surface, morphology of the valve mantle, shape of the axial area, shape of the fascia, position of the raphe, morphology and orientation of the external central and distal raphe fissures, and size and position of the elliptical apertures of the alveolate striae. The evidence that there is no morphologic and morphometric discontinuity between these Frenguelli taxa and that they come from similar diatomaceous earth deposits, justify considering them conspecific. Based on the principle of priority the correct name of the species is Caloneis mendosina. The description of C. mendosina was emended, a lectotype slide was selected, and a comparison with some allied species was conducted.
29
Benac, Čedomir, Sanja Dugonjić Jovančević, Dražen Navratil, Andrea Tadić e Lovro Maglić. "Large gravitational collapse structure on a rocky coast (Kvarner, NE Adriatic Sea)". Geologia Croatica 76, n.º 3 (16 de outubro de 2023): 105–12. http://dx.doi.org/10.4154/gc.2023.10.
Texto completo da fonteResumo:
The studied rock collapse structure is located on the Liburnian coast (Rijeka Bay, channel zone of the NE Adriatic). The relief of the southern part of this coast, with a length of 6.5 km, is a large escarpment with very steep to vertical slopes reaching heights of 100 m above sea level, as a result of tectonic movements along the Kvarner fault zone. These events probably led to a sudden relaxation of the highly fractured rock mass. The progressive expansion occurred at locations where previously favourably oriented faults and fissures had formed a polygonal rock collapse resembling a rock-slide which is the focus of this study. Another aim of this study is to reconstruct and explain the complex morphological evolution of the studied landslide, from the pre-failure deformations, through the failure itself, to post-failure displacements, as well as possible future instabilities. Recent techniques to survey the instability, location and to analyse the evolution of the rupture surface and its dimensions were combined (Unmanned Aerial Vehicle, Side Scan Sonar and Remotely Operated Vehicles). The estimated total volume of displaced rock mass is 950,000 m3. The lower part of the instability phenomenon was submerged during the Holocene sea level rise. Since then, a large part of the displaced rock mass has been in a stable position, with sporadic rock falls. However, given unfavourable orientation and discontinuity characteristics, as well as unfavourable environmental influences, possible instabilities might also be expected in the future.
30
Leśniak, Andrzej, Elżbieta Śledź e Katarzyna Mirek. "Detailed Recognition of Seismogenic Structures Activated during Underground Coal Mining: A Case Study from Bobrek Mine, Poland". Energies 13, n.º 18 (5 de setembro de 2020): 4622. http://dx.doi.org/10.3390/en13184622.
Texto completo da fonteResumo:
In rock mass disturbed by mining activity, distortions in the stress balance may lead to seismic energy being emitted in reactivated seismogenic structures. One way of increasing the imaging resolution of these seismically active structures is through relocation, which itself can be achieved using the cloud collapsing method. This method partially eliminates perturbations in the location of seismic energy sources concerning the actual positions of these sources. It enables events to be grouped into spatially ordered structures that may correspond to actual tectonic structures, such as fractures, fissures, or faults. We present the results of applying the collapsing method in mining seismology using a cloud of located events recorded during mining activity at one of the coalfaces in the Bobrek hard coal mine. The relocation procedure was applied to all the foci of events recorded during mining activity on face 3/503 between April 2009 and July 2010. In the relocated point cloud, two types of the linear structure responsible for generating events are automatically distinguished using the HDBSCAN algorithm: structures directly related to mining activity and structures associated with local tectonics. The location of the separated structures of the first type corresponds to the range of coalface 3/503 and the shafts delimiting earlier mined seams 507 and 509 located below. The isolated structures of the second type, with almost vertical orientation, are associated with existing zones of discontinuity that become seismically active as a result of mining activity. The identified structures lie near the biggest events recorded, which is evidence that these structures may correspond to real discontinuity zones.
31
Pokalai, Kunakorn, David Kulikowski, Raymond L. Johnson, Manouchehr Haghighi e Dennis Cooke. "Development of a new approach for hydraulic fracturing in tight sand with pre-existing natural fractures". APPEA Journal 56, n.º 1 (2016): 225. http://dx.doi.org/10.1071/aj15017.
Texto completo da fonteResumo:
Hydraulic fracturing in tight gas reservoirs has been performed in the Cooper Basin for decades in reservoirs containing high stress and pre-existing natural fractures, especially near faults. The hydraulic fracture is affected by factors such as tortuosity, high entry pressures, and the rock fabric including natural fractures. These factors cause fracture plane rotation and complexities, leading to fracture disconnection or reduced proppant placement during the treatment. In this paper, rock properties are estimated for a targeted formation using well logs to create a geomechanical model. Natural fracture and stress azimuths within the interval were interpreted from borehole image logs. The image log interpretations inferred that fissures are oriented 30–60° relative to the maximum horizontal stress. Next, diagnostic fracture injection test (DFIT) data was used with the poro-elastic stress equations to predict tectonic strains. Finally, the geomechanical model was history-matched with a planar 3D hydraulic fracturing simulator, and gave more insight into fracture propagation in an environment of pre-existing natural fractures. The natural fracture azimuths and calibrated geomechanical model are input into a framework to evaluate varying scenarios that might result based on a vertical or inclined well design. A well design is proposed based on the natural fracture orientation relative to the hydraulic fracture that minimises complexity to optimise proppant placement. In addition, further models and diagnostics are proposed to aid predicting the hydraulically induced fracture geometry, its impact on gas production, and optimising wellbore trajectory to positively interact with pre-existing natural fractures.
32
Maulana, B. R., M. S. Burhanuddin e M. F. Akbar. "Distribution of the Surface Ruptures in the Kalaotoa Due to the 2021 M w 7.3 Flores Sea Earthquake, Indonesia". IOP Conference Series: Earth and Environmental Science 1272, n.º 1 (1 de dezembro de 2023): 012001. http://dx.doi.org/10.1088/1755-1315/1272/1/012001.
Texto completo da fonteResumo:
Abstract A magnitude 7.3 earthquake occurred at precisely 11:20 on December 14, 2021, within the Flores Sea region of Indonesia, precipitating a consequential landslide event. This seismic incident induced the creation of an extensive rupture zone spanning approximately 8 kilometers along the Kalaotoa fault (KF) system, which exhibits an NNE-NW-SSE trend. The objective of this study was to concentrate specifically on the Kalaotoa Island vicinity, situated approximately 40 kilometers from the earthquake’s epicenter, encompassing meticulous orientation and comprehensive field surveys conducted during the reconnaissance phase. The results of the ground assessment have been combined with spatial analysis data to ascertain the configuration and dispersion of ruptures subsequent to the earthquake, thus delineating the affected region as a prospective area susceptible to seismic events and subsequent calamities. In the vicinity proximate to the northern epicenter, fractures resulting from the seismic activity were consolidated, exhibiting considerable devastation in the form of ground fissures, rock avalanches, landslides, and structural collapses, and were predominantly oriented in a roughly NE-SW direction. Notably significant are the southern beaches of Lato’do and the eastern extremity of the rupture zone in the Lembang Mate’ne area, where coastal transgression and extensive inundation during high tides have been observed due to subsidence of 1.2 meters since the 2021 Flores Sea earthquake. Horizontal displacement around Kalaotoa Port, north of the Karumpa-Kawawo area. Displacement distribution, slip sense, and crustal deformation after earthquake propagate unilaterally to the north, resulting in a movement of the northeast side of the fault concerning SE.
33
King, Quigley e Clark. "Surface-Rupturing Historical Earthquakes in Australia and Their Environmental Effects: New Insights from Re-Analyses of Observational Data". Geosciences 9, n.º 10 (20 de setembro de 2019): 408. http://dx.doi.org/10.3390/geosciences9100408.
Texto completo da fonteResumo:
We digitize surface rupture maps and compile observational data from 67 publications on ten of eleven historical, surface-rupturing earthquakes in Australia in order to analyze the prevailing characteristics of surface ruptures and other environmental effects in this crystalline basement-dominated intraplate environment. The studied earthquakes occurred between 1968 and 2018, and range in moment magnitude (Mw) from 4.7 to 6.6. All earthquakes involved co-seismic reverse faulting (with varying amounts of strike-slip) on single or multiple (1–6) discrete faults of ≥ 1 km length that are distinguished by orientation and kinematic criteria. Nine of ten earthquakes have surface-rupturing fault orientations that align with prevailing linear anomalies in geophysical (gravity and magnetic) data and bedrock structure (foliations and/or quartz veins and/or intrusive boundaries and/or pre-existing faults), indicating strong control of inherited crustal structure on contemporary faulting. Rupture kinematics are consistent with horizontal shortening driven by regional trajectories of horizontal compressive stress. The lack of precision in seismological data prohibits the assessment of whether surface ruptures project to hypocentral locations via contiguous, planar principal slip zones or whether rupture segmentation occurs between seismogenic depths and the surface. Rupture centroids of 1–4 km in depth indicate predominantly shallow seismic moment release. No studied earthquakes have unambiguous geological evidence for preceding surface-rupturing earthquakes on the same faults and five earthquakes contain evidence of absence of preceding ruptures since the late Pleistocene, collectively highlighting the challenge of using mapped active faults to predict future seismic hazards. Estimated maximum fault slip rates are 0.2–9.1 m Myr-1 with at least one order of uncertainty. New estimates for rupture length, fault dip, and coseismic net slip can be used to improve future iterations of earthquake magnitude—source size—displacement scaling equations. Observed environmental effects include primary surface rupture, secondary fracture/cracks, fissures, rock falls, ground-water anomalies, vegetation damage, sand-blows / liquefaction, displaced rock fragments, and holes from collapsible soil failure, at maximum estimated epicentral distances ranging from 0 to ~250 km. ESI-07 intensity-scale estimates range by ± 3 classes in each earthquake, depending on the effect considered. Comparing Mw-ESI relationships across geologically diverse environments is a fruitful avenue for future research.
34
Dahi-Taleghani, Arash, e Jon E. Olson. "Numerical Modeling of Multistranded-Hydraulic-Fracture Propagation: Accounting for the Interaction Between Induced and Natural Fractures". SPE Journal 16, n.º 03 (9 de junho de 2011): 575–81. http://dx.doi.org/10.2118/124884-pa.
Texto completo da fonteResumo:
Summary Recent examples of hydraulic-fracture diagnostic data suggest that complex, multistranded hydraulic-fracture geometry is a common occurrence. This reality is in stark contrast to the industry-standard design models based on the assumption of symmetric, planar, biwing geometry. The interaction between pre-existing natural fractures and the advancing hydraulic fracture is a key condition leading to complex fracture patterns. Performing hydraulic-fracture-design calculations under these less-than-ideal conditions requires modeling fracture intersections and tracking fluid fronts in the network of reactivated fissures. Whether a hydraulic fracture crosses or is arrested by a pre-existing natural fracture is controlled by shear strength and potential slippage at the fracture intersections, as well as potential debonding of sealed cracks in the near-tip region of a propagating hydraulic fracture. We present a complex hydraulic-fracture pattern propagation model based on the extended finite-element method (XFEM) as a design tool that can be used to optimize treatment parameters under complex propagation conditions. Results demonstrate that fracture-pattern complexity is strongly controlled by the magnitude of anisotropy of in-situ stresses, rock toughness, and natural-fracture cement strength, as well as the orientation of the natural fractures relative to the hydraulic fracture. Analysis shows that the growing hydraulic fracture may exert enough tensile and shear stresses on cemented natural fractures that the latter may be debonded, opened, and/or sheared in advance of hydraulic-fracture-tip arrival, while under other conditions, natural fractures will be unaffected by the hydraulic fracture. Detailed aperture distributions at the intersection between fracture segments show the potential for difficulty in proppant transport under complex fracture-propagation conditions.
35
Dill, H. G., B. Weber, A. Gerdes e F. Melcher. "The Fe-Mn phosphate aplite ‘Silbergrube’ near Waidhaus, Germany: epithermal phosphate mineralization in the Hagendorf-Pleystein pegmatite province". Mineralogical Magazine 72, n.º 5 (outubro de 2008): 1119–44. http://dx.doi.org/10.1180/minmag.2008.072.5.1119.
Texto completo da fonteResumo:
AbstractThe Silbergrube Aplite (SA) in the Hagendorf-Pleystein Pegmatite District, near Waidhaus, Germany, is a mildly peraluminous NW-SE directed leucogranite dyke. It occurs in association with quartz dykes and aplitic metamorphic mobilizates in the NE Bavarian crystalline basement. The SA differs from other aplitic mobilizates in the region in having a less well developed strain-related mineral orientation and in containing only minor amounts of garnet and tourmaline. The aplitic metamorphic mobilizates and the SA are chemically and mmeralogically almost identical and yield the same age of formation of ∼302 Ma (stage I). The age of formation of the Hagendorf pegmatites seemingly post-dates the emplacement of the SA. The SA was emplaced at the boundary between fine-grained biotite granites and metamorphic country rocks within a zone of structural weakness, favouring the formation of disseminated late magmatic to hydrothermal mineralization of Li-bearing Fe-Mn phosphates (stages II and III). Brittle deformation along this zone was conducive to the faultbound Fe-Mn-Ca phosphates. Mineral telescoping is evident from the presence of Fe2+, Fe3+and Mn2+phosphates in fissures and vugs in a texturally highly variable host-rock environment (stage IV). This intimate intergrowth of phosphate minerals reflects contrasting physical and chemical conditions prevailing in a near-surface/ shallow epithermal S-deficient phosphate system (stage IV), similar to what is known from Cu-Au epithermal systems. The most recent mineral assemblages that formed under predominantly oxidizing conditions are correlated with the subtropical weathering during the Neogene which resulted in the formation of a peneplain truncating the SA and its country rocks (stage V). The SA is the root zone of the felsic aplitic-pegmatitic mobilizates in this region and is overprinted by an epithermal phosphate system.
36
Matýsek, Dalibor, Jakub Jirásek, Aneta Minaříková e Petr Skupien. "Ranciéit a doprovodné minerály z Rychaltic u Frýdku-Místku (Morava, Česká republika)". Bulletin Mineralogie Petrologie 29, n.º 1 (2021): 41–48. http://dx.doi.org/10.46861/bmp.29.041.
Texto completo da fonteResumo:
Recently described small outcrop of the upper part of the Barnasiówka Formation yielded several manganese oxidic minerals. Outcrop at the bank of the Krnalovice Stream (GPS N 49°38.623’ E 018°14.630’) consists of Lower Turonian greenish to grey-black laminated claystone alternating with grey chert. The whole sequence is a part of the Baška facies of the Silesian Unit, Outer Western Carpathians. In the middle part of the profile occur concretional aggregates containing manganese minerals. The central pale part of these aggregates is composed of quartz (ca. 90 wt.%), albite (ca. 9 wt.%), and muscovite, the darker rim of quartz (ca. 80 wt.%), goethite (ca. 10 wt.%), illite, todorokite, plagioclase, K-feldspar, and pyrite. Occasionally, remains of Mn-rich siderite were preserved in the cores. We suppose that they are in fact weathering products of carbonate-rich silicites. Manganese oxides also enter fissures in form of thin black coatings. Powder X-ray diffraction proved the presence of todorokite, ranciéite, pyrolusite, and possible vernadite. Todorokite forms black coatings with submetallic lustre, often associating with ranciéite. Ranciéite is dark pink to pinkish-brown, with a metallic lustre. Back-scattered electron images reveal its extremely thin tabular, sometimes undulated crystals and hexagonally oriented intergrowths. Powder diffraction data are strongly affected by preferred orientation, with dominating basal reflections of 001 plane at 7.4849 Å and plane 002 at 3.7424 Å. Its average formula from nine WDS spots (Ca0.14Mg0.01Ba0.01K0.01)Σ0.17(Mn4+0.86Si0.02Al0.03Fe0.01)Σ0.92O2.00·0.88H2O (based on 2 anions, water calculated from the ratio of cation sum / H2O in the formula according to Post et al. 2008) and CaO/MnO2 ratio 9 to 12 correspond well to the published data for this phase. Ranciéite is a rather common phyllomanganate from various geological environments, but this locality represents its first unambiguous occurrence in the Czech Republic. It closely resembles the one from Polish flysch Carpathians from Nowa Wieś near Rzesów.
37
Grey, Ian E., Rupert Hochleitner, Christian Rewitzer, Alan Riboldi-Tunnicliffe, Anthony R. Kampf, Colin M. MacRae, W. Gus Mumme, Melanie Kaliwoda, Henrik Friis e Carlos U. Martin. "The walentaite group and the description of a new member, alcantarillaite, from the Alcantarilla mine, Belalcázar, Córdoba, Andalusia, Spain." Mineralogical Magazine 84, n.º 3 (18 de março de 2020): 412–19. http://dx.doi.org/10.1180/mgm.2020.18.
Texto completo da fonteResumo:
AbstractThe general structural formula for the walentaite group is [((A1yA1’1–y), A2)(H2O)n][Bx(As2)2–x(As3)M1(M2)2(TO4)2(O,OH)7], based on heteropolyhedral layers of configuration [M1(M2)2(TO4)2(O,OH)6], with surface-coordinated species at the B, As2 and As3 sites, and with interlayer hydrated cation groups centred at the A sites. The group is divided into walentaite and halilsarpite subgroups based on T = P5+ and As5+, respectively. Alcantarillaite, (IMA2019-072), [Fe3+0.5□0.5(H2O)4][CaAs3+2(Fe3+2.5W6+0.5)(AsO4)2O7], is a new member of the walentaite group from the Alcantarilla wolframite mine, Belalcázar, Córdoba, Andalusia, Spain. It occurs most commonly as lemon-yellow fillings together with massive scorodite in fissures and cracks in quartz adjacent to löllingite. It is also found as tiny yellow rosettes lining vugs and as spheroids of ultrathin blades. It is associated with scorodite, pharmacosiderite, ferberite and schneiderhöhnite. Optically it is biaxial (–), with α = 1.703(calc), β = 1.800(5), γ = 1.850(5) and 2V = 68(1)° (white light). Dispersion is r > v, moderate. The optical orientation is X = a, Y = c and Z = b. The calculated density is 3.06 g cm–3. Electron microprobe analyses together with crystal structure refinement results gives the empirical formula [Fe3+0.52□0.48(H2O)4][(Ca0.44K0.11Na0.05Fe2+0.24□0.42)As3+1.83][Fe3+2.54Al0.03W6+0.43)((As0.65P0.35)O4)2O5.86(OH)1.14]. Alcantarillaite is orthorhombic, with an average structure described in Imma, and with a = 24.038(8) Å, b = 7.444(3) Å, c = 10.387(3) Å, V = 1858.6(11) Å3 and Z = 4. The structure (wRobs = 0.078 for 651 reflections to a resolution of 0.91 Å) differs most significantly from other walentaite-group members in having an interlayer A2 site occupied. Square-pyramidal polyhedra centred at the A2 sites form edge-shared dimers, (Fe3+)2O4(H2O)4. The dimers share vertices with TO4 anions in the layers on either side to form 8-sided channels along [010] occupied by H2O molecules.
38
Chen, Wenge, Tom Bartlett e Huiling Peng. "Drilling for fissures and exploiting common ground in the discourse of oil production". Pragmatics and Society 12, n.º 2 (3 de junho de 2021): 167–87. http://dx.doi.org/10.1075/ps.20033.che.
Texto completo da fonteResumo:
Abstract This is the second part of a two-part article which proposes an enhanced approach to eco-discourses after weighing the (dis)advantages of mainstream Critical Discourse Analysis (CDA) and Positive Discourse Analysis (PDA). Part I explored the theoretical grounding for an enhanced PDA, introduced the research method and then, based on the adapted analytic framework of Stibbe (2016), undertook a critical analysis of the discourses of Shell Oil Company (SOC). Part II uses the same analytic framework to analyse Greenpeace USA’s (GPU) discourse and compare it to the SOC discourse. The emphasis in Part II is on the exploration of potential fissures in the discourses across difference, and the possible common grounds upon which to design alternative discourses that are empathetic, comprehensible and legitimate to a coalition of social forces. Practically, Part II finds that the two groups use similar discourse strategies, such as salience and framing, but with different orientations. Methodologically, Part II argues that corpus-aided comparative discourse analysis, with a focus on discourse semantics, will facilitate the identification of ‘greenwashing’ strategies that strengthen and stabilize current hegemonic social order; this part also points to avenues of alternative discourses which exploit the inherent contradictions or fissures within that hegemonic order. Theoretically, the paper suggests that within an enhanced Positive Discourse Analysis approach, it is also important to seek out points of convergence between progressive positions and to articulate these within a hybrid, counter-hegemonic discourse that maximizes its potential for uptake, while it destabilizes the prevailing discourses at precisely the fissure points identified.
39
Chen, Hong Kai, Hong Mei Tang e Xiao Ying He. "Stability Analysis of Perilous Rock in Views of Damage and Fracture Mechanics". Advanced Materials Research 455-456 (janeiro de 2012): 1561–66. http://dx.doi.org/10.4028/www.scientific.net/amr.455-456.1561.
Texto completo da fonteResumo:
Perilous rock rupture is dominated by damage and fracture of the dominant fissure. Define factor of safety of perilous rock as the ratio of the damage fracture tenacity at the end area of the dominant fissure to the union fracture strength factor; Transfer loads acting on perilous rock to the dominant fissure, and divide them into four components, i.e., water pressure in fissure, average shear stress, moment around the end of the dominant fissure, and average tension stress, further, contribute methods to calculate fracture strength factor every components in view of fracture mechanics; Based on these individual fracture strength factors, establish the method to calculate the union fracture strength factor along fracture orientation near the end area of the dominant fissure. Further, on the basis of damage duration of the dominant fissure, provide the formula to solve the fracture tenacity of rock in damage area near the end of the dominant fissure in detal. Case analyses identify that it is reasonable to consider orientation earthquake force in stability analysis of perilous rock, which promulgates the stability status of perilous rock more effective than that by the limit equilibrium principle.
40
Gross, B. H., D. L. Spizarny e D. S. Granke. "Sagittal orientation of the anterior minor fissure: radiography and CT." Radiology 166, n.º 3 (março de 1988): 717–19. http://dx.doi.org/10.1148/radiology.166.3.3340767.
Texto completo da fonte
41
Sousa, Gisele Carvalho de Mello, Milena Leão Roque, Michele Guimarães, Monica Freitas Clemente, Nídia Helena Alves Santana, Janize Silva Maia e Luiz Faustino dos Santos Maia. "As intercorrências mamárias e as condutas de enfermagem". Revista Remecs - Revista Multidisciplinar de Estudos Científicos em Saúde 2, n.º 2 (15 de julho de 2017): 30. http://dx.doi.org/10.24281/rremecs2526-2874.2017.2.2.30-40.
Texto completo da fonteResumo:
O aleitamento materno é fundamental para a saúde materna e infantil, apesar de serem difundidos os benefícios do aleitamento materno, ocorrem fatores que podem interferir e influenciar negativamente neste processo, dentre eles são: conhecimento insuficiente população em geral e profissional de saúde, práticas culturais e crenças, atuação materna extra domicílio e intercorrências mamárias, como a pega incorreta, ingurgitamento, fissuras e mastite, há uma interrupção do aleitamento causando danos e perdas ao binômio, diminuindo o vínculo materno-infantil e os benefícios na saúde que a amamentação produz. Este trabalho tem como objetivo evidenciar as causas das intercorrências mamárias e as ações de enfermagem para a prevenção das mesmas e promoção do aleitamento materno. Para este estudo, preferiu-se o método da revisão integrativa da literatura científica em bases de dados SCIELO e LILACS. Após a leitura de 20 artigos, foram selecionados dez artigos para compor a sumarização dos resultados. Como resultado foi observado que a técnica incorreta, as condições socioeconômicas e as primíparas são fatores causadores das intercorrências mamárias e interrupção do aleitamento. Logo, a Enfermagem tem papel fundamental de orientação, prevenção e das intercorrências mamárias e atuar para prevenir e corrigir o desmame precoce e promover a saúde materno-infantil.Descritores: Aleitamento Materno, Intercorrências Mamárias, Interrupção do Aleitamento. Mammary intercorrhences and nursing conductAbstract: Breastfeeding is fundamental for maternal and child health, although the benefits of breastfeeding are widespread, factors that may interfere with and negatively influence this process, among which are: insufficient knowledge of the general population and health professionals, practices Cultural and beliefs, maternal extra-domicile and breast intercurrences, such as incorrect handing, engorgement, fissures and mastitis, there is an interruption of breastfeeding causing damage and loss to the binomial, reducing the maternal-infant bond and the health benefits that breastfeeding produces . This study aims to highlight the causes of breast complications and nursing actions to prevent them and promote breastfeeding. For this study, the method of integrative review of the scientific literature in SCIELO and LILACS databases was preferred. After reading 20 articles, ten articles were selected to compose the summarization of the results. As a result, it was observed that the incorrect technique, the socioeconomic conditions and the primiparous are factors that cause breast intercurrences and interruption of breastfeeding. Therefore, Nursing has a fundamental role of orientation, prevention and breast intercurrences and act to prevent and correct early weaning and promote maternal and child health.Descriptors: Breastfeeding, Breast Intercurrences, Interruption of Breastfeeding. Las intercuencias mamarias y las conductas de enfermeríaResumen: La lactancia materna y fundamental para la salud materna e infantil, a pesar de ser difundidos los beneficios de la lactancia materna, ocurren factores que pueden interferir e influir negativamente en este proceso, entre ellos: insuficiente población en general y profesional de salud, prácticas culturales relacionadas a las creencias, la actuación materna extra domicilio e intercurrencias mortales, como el agarre incorrecto, ingurgitación, fisuras y mastitis, hay una interrupción de la lactancia causando daños y pérdidas al binomio, disminuyendo el vínculo materno-infantil y los beneficios en la salud que la lactancia produce. Este trabajo tiene como objetivo evidenciar las causas de las intercurrencias mamarias y las acciones de enfermería para la prevención de las mismas y promoción de la lactancia materna. Para este estudio, se prefirió el método de la revisión integrativa de la literatura científica en bases de datos SCIELO y LILACS. Después de la lectura de 20 artículos, se seleccionaron apenas diez para componer el sumario de los resultados. Como repuesta se observó que la técnica incorrecta, las condiciones socioeconómicas y primíparas son factores causantes de las interferencias mamarias y la interrupción de la lactancia. Por lo tanto, la enfermería tiene un papel fundamental de orientación, prevención de las interferencias mamarias y actuar para prevenir y corregir el destete precoz promoviendo la salud materno-infantil.Descriptores: Lactancia Materna, Interacción Mamaria, Interrupción de la Lactancia.
42
Abderrahmane, Taleb Hosni, e Guemidi Ismahene. "The influence of fissured material on tunnel stability (a numerical study)". Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu, n.º 6 (25 de dezembro de 2022): 59–67. http://dx.doi.org/10.33271/nvngu/2022-6/059.
Texto completo da fonteResumo:
Purpose. To understand the effect of fissured material on tunnels. These infrastructure tunnels must be safe in all respects, including construction, materials, and more. One of the challenges which engineers face is the need to consider material types as well as fissured material. As a result, in order to ensure the safety of the tunnel, it is important for us to anticipate possible precipitation, displacements, stresses and strains caused by the construction of tunnels in fractured environments. Methodology. The OPTUMG2 software was used for thisnumerical study, the tunnel was modeled applying the hypothesis of two-dimensional plane deformation with the use of the finite element method, which is used to model continuous media. The Mohr-Coulomb criterium was considered to simulate the elastoplastic nonlinear behaviour of this model. Findings. The ndings demonstrate that the orientation of weakness planes can have a major impact on tunnel stability. Thus, it was observed that 45, and 60 for angle 1, and 110, and 135 for the second angle 2 present the most critical situations. The influence of fissured material (soil) on civil engineering projects such as tunneling should be taken into consideration. Originality. The tunnels stability is determined by the measuring of the displacement (settlement), stresses, and deformation, under the effect of the fissured material in the environment. In this paper we simulated a model with various crack angles. As for the orientation of plane, for the angl3e 1 the values are changed to 0, 20, 45, 65, and 90, the second angle 2 was changed from 110, 135, 155, 175, to 180. Practical value. The number of tunnels and infrastructure projects is constantly increasing. This is because they are important for the development of countries and for accelerating economic growth, shortening distances and travel time by linking urban areas that have natural obstacles such as mountains. We found that the orientation planes can have a major impact on tunnel stability. Thus, it was observed that 45, and 60 for first angle, and 110, and 135 for the second angle present the most critical situations.
43
Joshi, Mukund Raj, Tanka Prasad Bohara e Shail Rupakheti. "Comparison of Fissure Healing and The Incidence of Headache Among the Patients Treated with Endo- and Perianal Application of 0.2% Glyceryl Trinitrate for Chronic Anal Fissure". Journal of Nepal Medical Association 55, n.º 204 (23 de dezembro de 2016): 45–50. http://dx.doi.org/10.31729/jnma.2878.
Texto completo da fonteResumo:
Introduction: Chronic anal fissure is associated with significant morbidity and reduction in quality of life mostly in young healthy adults. Glyceryl Trinitrate, a most commonly used agent for treatment, is associated with incidence of headache causing discontinuation of treatment. There is belief that endoanal application instead of perianal is associated with lower incidence of headache. This study is to compare the incidence and severity of headache in between perianal and endoanal application of GTN ointment.Methods: Thirty patients were taken in each perianal and endoanal group. They were given orientation to apply 375gm of ointment either endoanally or perianally and to record severity of headache according to visual analogue scale. This record was noted by independent observer in telephonic conversation. Patients were followed up at 6 weeks for evaluation fissure. Results: The mean age, male female ratio and features of chronicity was similar in both the group however the duration of symptoms between the group was different. Regarding outcome, Overall incidence of headache was seen in two-third of patient with severe headache in approx. 10%. Severity of headache was slightly lower in endoanal group but the difference was not significant. Healing rate was comparable. Two patient in perianal and 3 in endoanal group were lost for follow up. Conclusions: Endoanal application of GTN ointment is associated with slight decrease in intensity of headache and is comparable with perianal application for fissure healing.
Keywords: anal fissure; endoanal; glyceryl trinitrate;headache; perianal.| PubMed
44
Husain, Marwah A., e Mohsin A. Al-shammari. "Effect of Cracks on the Natural Frequency of Cylindrical Shell Structures". Engineering and Technology Journal 38, n.º 12A (25 de dezembro de 2020): 1808–17. http://dx.doi.org/10.30684/etj.v38i12a.1513.
Texto completo da fonteResumo:
Shell structures are liable to different kinds of defects and damage like cracking and corrosion which may destroy their structural safety and affect the service life. The cracks' effects are significant considerations in the design of cylindrical shell structures as they influence the vibration characteristics and safety. This present work is an experimental study on the free vibration analysis of a cylindrical shell involving circumferential surface crack. The influence of the ratio of shell’s radius to a shell’s thickness (R/h)of the shell structure, crack length in the shell, crack depth in the shell, crack location of the shell, and crack orientation in the shell are investigated under a clamped - clamped and simply supported boundary conditions at each end in the shell. Results showed that the minimum impact of the crack is at the angle of crack 75, and the circumferential fissure has more effect than a longitudinal fissure, In addition to this, under SS-SS, C-C the natural frequency will decrease if the fissure is located in the middle of the shell is greater than other locations. but when crack animated across in the ends of the limits the decrease in the natural frequency under C-C only. Results were compared with the literature there was a close agreement.
45
Husain, Marwah A., e Mohsin A. Al-shammari. "Effect of Cracks on the Natural Frequency of Cylindrical Shell Structures". Engineering and Technology Journal 38, n.º 12A (25 de dezembro de 2020): 1808–17. http://dx.doi.org/10.30684/etj.v38i12a.1513.
Texto completo da fonteResumo:
Shell structures are liable to different kinds of defects and damage like cracking and corrosion which may destroy their structural safety and affect the service life. The cracks' effects are significant considerations in the design of cylindrical shell structures as they influence the vibration characteristics and safety. This present work is an experimental study on the free vibration analysis of a cylindrical shell involving circumferential surface crack. The influence of the ratio of shell’s radius to a shell’s thickness (R/h)of the shell structure, crack length in the shell, crack depth in the shell, crack location of the shell, and crack orientation in the shell are investigated under a clamped - clamped and simply supported boundary conditions at each end in the shell. Results showed that the minimum impact of the crack is at the angle of crack 75, and the circumferential fissure has more effect than a longitudinal fissure, In addition to this, under SS-SS, C-C the natural frequency will decrease if the fissure is located in the middle of the shell is greater than other locations. but when crack animated across in the ends of the limits the decrease in the natural frequency under C-C only. Results were compared with the literature there was a close agreement.
46
Gao, Han, Xuanping Gong, Xiaoyu Cheng, Rui Yu e Hui Wang. "Reasonable Arrangement of High-Level Orientation Extraction Boreholes of Pressure Relief Gas in Overlying Strata under High-Strength Fully Mechanized Mining in Low-Gas-Thick-Coal Seam". Shock and Vibration 2021 (1 de março de 2021): 1–16. http://dx.doi.org/10.1155/2021/5574917.
Texto completo da fonteResumo:
In order to solve the problem of pressure relief gas control under high-strength fully mechanized top-coal caving in low-gas-thick-coal seams, this paper studies the evolution of overburden structures and the distribution characteristics of fissure fields during the initial and stable period of working face by physical simulation and numerical analysis. The mathematical model of coupling between mining fracture field and pressure relief gas field is established. The results reveal the distribution characteristics of pressure relief gas field that considers mining-induced fissure field. According to the distribution of mining gas accumulation area, the high directional long boreholes have been put forward to control the pressure relief gas in goafs, and the effect has been tested. The results show that the initial pressure and three periodic pressures occurred from the cutting hole to 135 m in the initial mining period of the working face. The height of collapse zone developed to 22 m, and fracture height developed to 75 m. The development height of caving zone is stable at 25∼27 m, and the development height of fissure zone is stable at 75∼95 m. The process and distribution of pressure relief gas flow in goaf are obtained by solving the numerical model of pressure relief gas flow in mining fissure field. The gas accumulation area is located within 25∼55 m from return laneway and 25∼50 m from the roof of coal seam. After the implementation of high directional long drilling gas drainage technology in the initial mining period and the stable mining period, good results have been obtained in the gas control, where the average concentration of gas extraction is 5.8%, the average gas flow rate is 0.71 m3/min, and the gas concentration in upper corner and return air is less than 0.8%. The results can provide a reference for pressure relief gas control under similar conditions.
47
Cruwys, Liz, e Gareth Rees. "The Polar Record Glacier". Polar Record 37, n.º 201 (abril de 2001): 154–56. http://dx.doi.org/10.1017/s0032247400026991.
Texto completo da fonteResumo:
AbstractThe name for the Polar Record Glacier was approved in February 1952. At that time, the glacier was reported to possess an ice tongue that flowed into Sandefjord Ice Bay. In autumn 2000, AVHRR images were examined to assess whether the Polar Record ice tongue was still extant. It was found that there is an ice feature currently about 15 miles in length at the end of the glacier, although its orientation has changed since it was first surveyed in 1947. A fissure indicates that the tongue has calved to form an iceberg that is probably grounded.
48
Krylov, I. A., e V. N. Smirnov. "Напряженные состояния Нагаевского активного разлома (Северное Приохотье)". Bulletin of the North-East Science Center, n.º 3 (30 de setembro de 2024): 3–7. http://dx.doi.org/10.34078/1814-0998-2024-3-3-7.
Texto completo da fonteResumo:
New data on the tectonic stress field in the active fault running along the northern shore of Nagayev Bay have been obtained. It has been established that the stress field responsible for the formation of the fault fissure structure belongs to the shear type, but the presence of the normal fault component is also noted. The compression axis has a northeast orientation (azimuth 50°, dip angle 12°), while the extension axis is oriented to the northwest (azimuth 133°, dip angle 29°). Based on the obtained results, the kinematics of the Nagayev Bay fault can be defined as a strike-slip fault.
49
Flávia Silva Pereira Mendes, Laís Alonso Gomes, Geraldo Mota de Carvalho e Rosemeire dos Santos Vieira. "Dificuldades encontradas pelas mães em relação ao aleitamento materno nos primeiros dias de puerpério". Europub Journal of Health Research 3, n.º 1 (29 de março de 2022): 31–54. http://dx.doi.org/10.54747/ejhrv3n1-003.
Texto completo da fonteResumo:
Objetivo: Identificar dificuldades relacionadas ao aleitamento materno (AM) encontradas pelas puérperas nos primeiros três dias pós-parto. Método: Pesquisa de campo, descritiva, quantitativa. Resultados e discussão: Foram entrevistadas 20 puérperas, a maioria brasileira, em média 32 anos, em união consensual, desempregada, secundípara, com neonato a termo, no 2º dia pós-parto e não planejou a gestação. Quanto às orientações sobre o AM, 85% as receberam. 78% mencionou ter recebido orientações no pré-natal e 100% no Alojamento Conjunto. Citaram, em especial, orientação sobre posição, pega e intervalo da amamentação e o enfermeiro o principal orientador. Entre as que amamentaram, 60% o fez por 7 a 18 meses, período menor que o recomendado pelo Ministério da Saúde que preconiza que o AM exclusivo seja mantido até os seis meses e complementado até os dois anos. Quase a totalidade delas referiu saber identificar a pega adequada pelo bebê, e sentiu-se confiante para aleitar, sem impedimentos na continuidade. Observou-se 35% com dificuldades como mamilos doloridos (71%), fissura mamilar (42%) e baixa produção láctea (28,5%). Os fatores facilitadores relatados são caracterizados por questões emocionais, como o desenvolvimento da relação binomial mãe-bebê, com o fortalecimento do vínculo que faz com que percebam se a pega está adequada (95%) e sintam-se confiante para manter o AM. Conclusão: As principais dificuldades das nutrizes foram os mamilos doloridos e fissura mamilar, sendo que estas receberam orientações adequadas para a manutenção do AM e do cuidado mamário. A enfermagem tem um papel fundamental não só nas orientações, mas no acompanhamento do binômio.
Objective: To identify breastfeeding-related difficulties encountered by mothers in the first three days postpartum. Method: Field research, descriptive, quantitative. Results and discussion: 20 postpartum women were interviewed, mostly Brazilian, on average 32 years old, in consensual union, unemployed, para 2, with full term newborn, on the 2nd postpartum day and did not plan pregnancy. As for the guidelines on breastfeeding, 85% received them. 78% mentioned having received prenatal counseling and 100% Rooming-in. They cited, in particular, guidance on breastfeeding position, grip and interval, and the nurse as the main advisor. Among those who breastfed, 60% did so for 7 to 18 months, a shorter period than recommended by the Ministry of Health, which recommends that exclusive breastfeeding be maintained until six months and supplemented until two years. Almost all of them reported knowing how to identify the appropriate grip for the baby, and felt confident to breastfeed, without hindrance in continuity. 35% had difficulties such as sore nipples (71%), nipple fissure (42%) and low milk production (28.5%). The facilitating factors reported are characterized by emotional issues, such as the development of the mother-baby binomial relationship, with the strengthening of the bond that makes them understand if the grip is adequate (95%) and feel confident to maintain breastfeeding. Conclusion: The main difficulties of nursing mothers were sore nipples and nipple fissure, and they received adequate guidelines for the maintenance of breastfeeding and breast care. Nursing plays a fundamental role not only in orientations, but in monitoring the binomial.
50
Yang, He, Zhen Liu, Danliang Zhu, Wenzhi Yang, Dawei Zhao e Wendi Wang. "Study on the Fractal Characteristics of Coal Body Fissure Development and the Law of Coalbed Methane Migration of around the Stope". Geofluids 2020 (22 de julho de 2020): 1–15. http://dx.doi.org/10.1155/2020/9856904.
Texto completo da fonteResumo:
Due to the complicated coalbed methane (CBM) occurrence conditions and the diverse geological structures in China, the promotion and application of the coal and gas simultaneous extraction technology have been seriously restricted. In view of this, this paper chooses Qingdong Coal Mine protection layer mining and CBM extraction field practice as the research background. Firstly, based on the similar material simulation experiment that simulates coal mining, the dynamic changing pattern of a mining field’s overburdened strata and corresponding stress are obtained, the relationship between gas desorption and stress can then be clarified. Further, with the help of the fractal theory and box counting method, the fracture development characteristics of the overlying strata are quantitatively described on the basis of experimental images. Finally, by building a model for calculating the penetrability coefficient of coal seam based on fractal dimension of mining fissure and analyzing the relationship between fissure development and fractal dimension, the gas migration law and the fissure development areas of #7 and #8 overburden strata where CBM concentrates can be revealed and determined. According to the orientation of the area mentioned above, the location of the CBM pumping field in relation to the coal seam roof and the arrangement of CBM extraction boreholes can be optimized, which make CBM extraction efficient. Meanwhile, the risk of coal and gas outburst is significantly reduced when the CBM concentration is controlled within 0.2% to 0.6% outside the corner of the working face and 0.1% to 0.35% in return flow, which is lower than 0.8%, the threshold of CBM concentration.