Articles de revues : « Arch. evolution »

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Du, Xiao Li, Hong Wei Song et Jie Chen. « Laws of Formation and Evolution of Pressure Arch in Coal Mining Adjoining Rock ». Advanced Materials Research 243-249 (mai 2011) : 2596–600. http://dx.doi.org/10.4028/www.scientific.net/amr.243-249.2596.

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Based on numerical simulation of computing Software ANSYS, the curve of arching coefficient variation of pressure arch due to actual mining was analyzed aiming to a special mining face, the law of stress transfer and change in surrounding rock was discussed, and the evolving features and characteristics of pressure arch was obtained. The analysis and discussion show the following facts: Arch body will become thicker and stress in the arch body increases with working face’s driving distance increasing; the morphology of pressure arch transits from ellipsoid with long axis in the vertical direction to ellipsoid with long axis in the horizontal direction along the trend of working face; along the tendency of working face, the morphology of pressure arch is a ellipsoid with long axis in the vertical direction.

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Wang, S. R., X. G. Wu, Y. H. Zhao, P. Hagan et C. Cao. « Evolution Characteristics of Composite Pressure-Arch in Thin Bedrock of Overlying Strata During Shallow Coal Mining ». International Journal of Applied Mechanics 11, n^o 03 (avril 2019) : 1950030. http://dx.doi.org/10.1142/s1758825119500303.

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Under the shallow coal mining condition and based on the cracking and movement rules of the roof in different mining stages, the mechanical models of symmetrical pressure-arch, stepped pressure-arch, rotating-squeezed pressure-arch in the mining field were established. Then, the instability criterion of each pressure-arch structure was derived. Through the similarity material experiment and numerical simulation, the evolution characteristics of the composite pressure-arches in the near- and far-field were revealed. Results show that the stepped pressure-arch in broken blocks of the basic roof was formed when the horizontal principal stress was greater than the in-situ stress. The broken blocks’ sliding could induce roof cutting off and strong weighting load. The structural characteristics of the overlying strata were determined by the thickness of the bedrock. The upper broken rocks formed a symmetrical pressure-arch in the near- and a far-field pressure-arch formed in the mining field. The median periodic broken rocks formed the rotating-squeezed pressure-arch, bearing the load of the loose layers and protecting the mining panel. After all bedrocks breaking, the latter arch foot of the far-field pressure-arch was transferred to the compacted caving zone. This study can provide a theoretical reference for the similar mining engineering.

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Barske, Lindsey, Peter Fabian, Christine Hirschberger, David Jandzik, Tyler Square, Pengfei Xu, Nellie Nelson et al. « Evolution of vertebrate gill covers via shifts in an ancient Pou3f3 enhancer ». Proceedings of the National Academy of Sciences 117, n^o 40 (21 septembre 2020) : 24876–84. http://dx.doi.org/10.1073/pnas.2011531117.

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Whereas the gill chambers of jawless vertebrates open directly into the environment, jawed vertebrates evolved skeletal appendages that drive oxygenated water unidirectionally over the gills. A major anatomical difference between the two jawed vertebrate lineages is the presence of a single large gill cover in bony fishes versus separate covers for each gill chamber in cartilaginous fishes. Here, we find that these divergent patterns correlate with the pharyngeal arch expression of Pou3f3 orthologs. We identify a deeply conserved Pou3f3 arch enhancer present in humans through sharks but undetectable in jawless fish. Minor differences between the bony and cartilaginous fish enhancers account for their restricted versus pan-arch expression patterns. In zebrafish, mutation of Pou3f3 or the conserved enhancer disrupts gill cover formation, whereas ectopic pan-arch Pou3f3b expression generates ectopic skeletal elements resembling the multimeric covers of cartilaginous fishes. Emergence of this Pou3f3 arch enhancer >430 Mya and subsequent modifications may thus have contributed to the acquisition and diversification of gill covers and respiratory strategies during gnathostome evolution.

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Rusu, Ligia, Mihnea Ion Marin, Michi Mihail Geambesa et Mihai Robert Rusu. « Monitoring the Role of Physical Activity in Children with Flat Feet by Assessing Subtalar Flexibility and Plantar Arch Index ». Children 9, n^o 3 (18 mars 2022) : 427. http://dx.doi.org/10.3390/children9030427.

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Flat foot is a common pediatric foot deformity which involves subtalar flexibility; it can affect the plantar arch. This study analyzes the evolution of two parameters, i.e., plantar index arch and subtalar flexibility, before and after physiotherapy and orthoses interventions, and examines the correlation between these two parameters. Methods: The study included 30 participants (17 boys, 12 girls, average age 9.37 ± 1.42 years) with bilateral flat foot. We made two groups, each with 15 subjects. Assessments of the subtalar flexibility and plantar arch index used RSScan the platform, and were undertaken at two time points. Therapeutic interventions: Group 1—short foot exercises (SFE); Group 2—SFE and insoles. Statistical analyses included Student’s t-test, Cohen’s D coefficient, Pearson and Sperman correlation. Results: Group 1—subtalar flexibility decreased for the left and right feet by 28.6% and 15.9% respectively, indicating good evolution for the left foot. For both feet, a decrease of the plantar index arch was observed. Group 2—subtalar flexibility decreased for the right and left feet by 43.4% and 37.7% respectively, indicating a good evolution for the right foot. For both feet, a decrease of plantar index arch was observed. Between groups, subtalar flexibility evolved well for Group 2; this was attributed to mixt intervention, physical therapy and orthosis. For plantar arch index, differences were not significant between the two groups. We observed an inverse correlation between subtalar flexibility and plantar arch index. Conclusions: Improvement of plantar index arch in static and dynamic situations creates the premise of a good therapeutic intervention and increases foot balance and postural control. The parameter which showed the most beneficial influence was the evolution is subtalar flexibility.

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González Manrique, S. J., C. Kuckein, M. Collados, C. Denker, S. K. Solanki, P. Gömöry, M. Verma, H. Balthasar, A. Lagg et A. Diercke. « Temporal evolution of arch filaments as seen in He I 10 830 Å ». Astronomy & ; Astrophysics 617 (septembre 2018) : A55. http://dx.doi.org/10.1051/0004-6361/201832684.

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Aims. We study the evolution of an arch filament system (AFS) and of its individual arch filaments to learn about the processes occurring in them. Methods. We observed the AFS at the GREGOR solar telescope on Tenerife at high cadence with the very fast spectroscopic mode of the GREGOR Infrared Spectrograph (GRIS) in the He I 10 830 Å spectral range. The He I triplet profiles were fitted with analytic functions to infer line-of-sight (LOS) velocities to follow plasma motions within the AFS. Results. We tracked the temporal evolution of an individual arch filament over its entire lifetime, as seen in the He I 10 830 Å triplet. The arch filament expanded in height and extended in length from 13″ to 21″. The lifetime of this arch filament is about 30 min. About 11 min after the arch filament is seen in He I, the loop top starts to rise with an average Doppler velocity of 6 km s−1. Only two minutes later, plasma drains down with supersonic velocities towards the footpoints reaching a peak velocity of up to 40 km s−1 in the chromosphere. The temporal evolution of He I 10 830 Å profiles near the leading pore showed almost ubiquitous dual red components of the He I triplet, indicating strong downflows, along with material nearly at rest within the same resolution element during the whole observing time. Conclusions. We followed the arch filament as it carried plasma during its rise from the photosphere to the corona. The material then drained toward the photosphere, reaching supersonic velocities, along the legs of the arch filament. Our observational results support theoretical AFS models and aids in improving future models.

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Wang, Shuren, Xiaogang Wu, Yanhai Zhao et Paul Hagan. « Mechanical Performances of Pressure Arch in Thick Bedrock during Shallow Coal Mining ». Geofluids 2018 (1 octobre 2018) : 1–13. http://dx.doi.org/10.1155/2018/2419659.

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Due to the periodicity of mine pressure, it can easily lead to a wide-range damage of the overburden rock under shallow coal mining conditions, and the falling of the overburden rock is usually a serious threat to the mining safety. Based on the monitoring data of mine pressure in a typical shallow coal mine in northern China, the mechanical model of the surrounding rock in the mining field was built and the identification indicators of the pressure arch after coal mining was defined. Then, the arching mechanism, the stress distribution characteristics in different positions, and the bearing capacity of the pressure arch were analysed, and the evolution characteristics of the pressure arch under shallow horizontal coal mining were verified by numerical simulation and physical experiment. Results show that there is a core-bearing zone in the pressure arch, and the width of the core zone determines the bearing capacity of the pressure arch. The evolution of the pressure arch affects the formation and development of the caving arch of the loose zone in the mining field. The conclusions obtained in the study are of important theoretical value to direct the similar engineering practice.

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Raz, Sagi, Marcel Goodman, Daniel Silverberg et David Planer. « TCT-440 Further Evolution In Aortic Arch Endografting ». Journal of the American College of Cardiology 64, n^o 11 (septembre 2014) : B129. http://dx.doi.org/10.1016/j.jacc.2014.07.491.

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Ding, Yanchao, Zhongfu Xiang, Yayong Li, Xuesong Zhang et Yin Zhou. « Mechanical System Evolution and Reasonable Structural Design Parameters of Long-Span Deck-Type Beam-Arch Composite Rigid Frame Bridge ». International Journal of Design & ; Nature and Ecodynamics 15, n^o 6 (26 décembre 2020) : 885–93. http://dx.doi.org/10.18280/ijdne.150614.

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Long-span deck-type beam-arch composite rigid frame (BACRF) bridge fully integrates the merits of arch bridges and beam bridges, and overcomes the cracking and deflection problems of continuous rigid frame bridges. As a perfect combination of beam bridges and arch bridges, the long-span deck-type BACRF bridge boasts a light structure, a strong bearing capacity, and a powerful spanning capability. From the perspective of mechanical system evolution, this paper theoretically analyzes the structural mechanics of the beam-arch composite system, establishes a half-bridge model for BACRF bridge, and derives the expressions of the internal force and displacement of the beam-arch composite system. Next, finite-element analysis was conducted to analyze how the variation of a single parameter, e.g., rise-span ratio, open web ratio, and side-to-middle span ratio, affects midspan displacement, arch-beam junction displacement, main beam bending moment, and main arch axial force. Finally, the calculation formula for deflection-span ratio of BACRF bridge was proposed based on the maximum hyperplane method. The research results provide a reference for the structural design of similar bridges.

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Wang, Feng, Tong Chen, Bo Ma et Denghong Chen. « Formation mechanism of stress arch during longwall mining based on key strata theory ». Energy Exploration & ; Exploitation 40, n^o 2 (6 octobre 2021) : 816–33. http://dx.doi.org/10.1177/01445987211042701.

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The traditional stress arch hypothesis during longwall mining fails to elucidate the formation mechanism of stress arch, and the morphological characteristics and evolution of stress arch are indefinite. To solve these problems, a mechanical model was established for elucidating the formation mechanism of stress arch in overlaying strata. The influencing of key strata on the morphological characteristics of the stress arch was studied. Finally, the evolution of the stress arch during longwall mining was studied through numerical simulation. The results show that the bearing structure of the overlying strata served as the key strata, and the stress arch was formed when the key strata were subjected to deflection after playing a bearing structure role. This was the result of coordination and redistribution of major principal stress in the key strata. The morphological characteristics of the stress arch changed accordingly with the change in key strata. When the thickness of key strata and the distance between key strata and coal seam were gradually increased, the height and width of the stress arch increased accordingly; however, its height was always terminated at the top interface of key strata. At this time, the peak value of the abutment pressure of the working face gradually decreased while the influencing range gradually increased. During longwall mining, the stress arch developed upward by leaps and bounds with the bearing and fracture of key strata. When the overlying key strata were completely fractured, the stress arch disappeared. The results were verified using the field measurement data on the abutment pressure of the Y485 longwall face in Tangshan Mine.

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Braginsky, V. I. « Evolution of the Verse Structure of the Malay Syair ». Archipel 42, n^o 1 (1991) : 133–54. http://dx.doi.org/10.3406/arch.1991.2754.

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Li, C. L., S. R. Wang, Z. S. Zou, X. L. Liu et D. Q. Li. « Evolution Characteristic Analysis of Pressure - arch of a Double - arch Tunnel in Water - rich Strata ». Journal of Engineering Science and Technology Review 9, n^o 1 (février 2016) : 44–51. http://dx.doi.org/10.25103/jestr.091.07.

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Le Pabic, Pierre, Jean-Luc Scemama et Edmund J. Stellwag. « Role ofHoxPG2 genes in Nile tilapia pharyngeal arch specification : implications for gnathostome pharyngeal arch evolution ». Evolution & ; Development 12, n^o 1 (janvier 2010) : 45–60. http://dx.doi.org/10.1111/j.1525-142x.2009.00390.x.

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Huang, Shunjie, Xiangqian Wang, Yingming Li, Lei Wang, Gang Liu, Fukun Xiao et O. V. Bashkov. « Analysis on Evolution Law of Small Structure Stress Arch and Composite Bearing Arch in Island Gob-Side Entry Driving ». Geofluids 2022 (23 juin 2022) : 1–12. http://dx.doi.org/10.1155/2022/4303681.

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At present, the theory of supporting the surrounding rock small structure of gob-side entry driving has been widely used, but there is no specific quantitative analytical formula for the bearing strength and bearing characteristics of the structure. Construct a small structural stress arch mechanical model based on the arch axis equation, and divide the width of coal pillars (fractured zone-plastic softening zone-plastic hardening zone) and small structural stress arch height. According to the relationship between the stress arch height and the size of the roadway, the anchor cable length is determined to be 7.3 m, and the “anchor mesh + ordinary long anchor cable + grouting anchor cable” coordinated support plan is proposed: anchor net support is used for the first support, and long anchor cable and grouting anchor cable are used for the second support. Combined with the supporting parameters, a mechanical model of the surrounding rock composite bearing stress arch is proposed, and the composite bearing stress arch structure is derived using elastoplastic mechanics to obtain the ultimate bearing strength relationship expression. The results show that the ultimate bearing capacity of the haulage gateway of 17236 island working-face in the north of Zhangji coal mine can reach 29.193 MPa after the composite bearing stress arch support. The feasibility of the supporting scheme is verified, and field monitoring showed that the deformation zone of the surrounding rock of the transportation haulage gateway is stable after being supported by the composite bearing stress arch structure, the maximum shrinkage of the top and bottom of the roadway is 287 mm, and the distance between the two sides is 640 mm.

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Tang, Jian Quan, Yu Ting Hou, Chao Zhang et Jian Hao. « Numerical Simulation of Breaking Arch Evolution Rule of Coal Seams Mining ». Advanced Materials Research 734-737 (août 2013) : 777–80. http://dx.doi.org/10.4028/www.scientific.net/amr.734-737.777.

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Numerical simulation analysis were done on breaking arch developing and evolving process of both single stope and coal seams mining field by FLAC3D. Results show that in single strope's advancing process, breaking arch's height would be different as strope's length changes, and breaking arch's height was decided by strope's length; in composite strope, as the coal pillar increasing, composite strope's breaking arch gradually develops from superposition state to independent state; as the strope's length changing composite strope's superposition state tend to balance

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Yingming, Yang, Li Quansheng, Liu Shiliang, Zhang Kai, Zhao Yongqiang, Zhang Guojun, Zhang Weilong et Liu Gang. « Evolution Mechanism of Thickly Sticky Loose Layered Arch Structure and Prediction Method of Initial Ground Fissure Caused by Underground Coal Mining ». Geofluids 2022 (10 octobre 2022) : 1–16. http://dx.doi.org/10.1155/2022/4933310.

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In view of the problem of taking the loose layer as the uniform cloth load while ignoring thickly sticky loose layered arch (TSLLA) of the traditional mining rock overburden structure analysis, combined with the geological conditions of shallow buried thickly sticky loose layer in Shendong mining area, the mechanical model of the mining TSLLA bearing structure is established, the variation law of arch height under different loose layers is analyzed, and the formation conditions of TSLLA are given. The first theory deduced the dynamic evolution mechanism of TSLLA structure advancing. The dynamic evolution of TSLLA structure in 22207 coalface is simulated. The formula for the limit height of TSLLA is derived. A classification method of mining loose layer structure is proposed. The loose layer structure type is divided into load type, arch beam type damage type, and limit arch height type. On this basis, the mechanical model of “arch beam” is constructed. The influence mechanism of the TSLLA on the surface cracks is revealed. The methods and calculation steps for initial surface cracks are presented. The results are verified by the measured data of surface subsidence of the typical thickly sticky layer in Shendong mining area.

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Muster, Alexander J., Rachid F. Idriss et Carl L. Backer. « The left-sided aortic arch in humans, viewed as the end-result of natural selection during vertebrate evolution ». Cardiology in the Young 11, n^o 1 (janvier 2001) : 111–22. http://dx.doi.org/10.1017/s104795110001252x.

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AbstractAt some point during vertebrate evolution from species dwelling in water to living on land, the ancestral double or right aortic arches became single and left-sided in mammals, including humans, as the result of synchronous developments in cardiovascular and respiratory embryogenesis. Since left-sided aortic arches are unique to mammals, hemodynamics related to the placenta, specifically the requirement for a large arterial duct connecting to the descending aorta, may have led to switching from the right-sided to the left-sided arch. Additionally, development of a trilobar right lung and its bronchial tree, also unique to mammalian evolution, restricted the space above the high eparterial bronchus to a single large vessel. Consequently, mammals that mutated to the left-sided aortic arch avoided respiratory, digestive or circulatory problems that are often associated with an isolated right-sided aortic arch – something which could be considered a successful mistake. Due to natural selection, and survival of the fittest, the left-sided arch became the norm in mammals.In congenital cardiac malformations where a large arterial duct is not mandatory in fetal life, as in Fallot's tetralogy or common arterial trunk, a right-sided aortic arch continues to occur, perhaps as an atavistic reversion to the anatomy seen in ancestral vertebrates.

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Aguilar-Jiménez, Jesús, Juan Manuel García-Guerrero et Juan José Jorquera-Lucerga. « The Diagonal Arch Bridge, a Particular Case of Spatial Arch Bridges ». Applied Sciences 11, n^o 4 (20 février 2021) : 1869. http://dx.doi.org/10.3390/app11041869.

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A diagonal arch bridge (DAB) is a particular case of arch bridge where the arch is rotated about a vertical axis passing through its crown so that each springing lies on a different side of the deck. A perpendicular arch bridge (PAB) is a particular case of DAB where the arch is rotated so that the arch plan is perpendicular to the deck axis. This paper includes a table of built bridges since 1989 and outlines the historical evolution of this type of bridge. Two main trends can be distinguished—one approach is focused on structural efficiency and the other is based on making aesthetics prevail, which often leads to structurally inefficient solutions. The main geometrical parameters are identified and the effect of the angle of rotation about a vertical axis is studied. Design constraints, such as the clearance requirements, are highlighted. In addition, the main structural systems, such as out-of-plane behavior, are identified and qualitatively studied, as an orientation for designers and a first step in future studies.

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Wigston, Pat. « The decorative evolution of the John Adam Dining Room at Arniston House ». Architectural Heritage 15, n^o 1 (novembre 2004) : 20–33. http://dx.doi.org/10.3366/arch.2004.15.1.20.

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Widjil Pangarsa, Galih. « Architectural Evolution in a Changing Hindu Tenggerese Community : The case of Wonokitri ». Archipel 49, n^o 1 (1995) : 161–84. http://dx.doi.org/10.3406/arch.1995.3042.

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Shi, Gui-Qin, Quan-You Yu et Ze Zhang. « ANNOTATION AND EVOLUTION OF THE ANTIOXIDANT GENES IN THE SILKWORM, Bombyx mori ». Archives of Insect Biochemistry and Physiology 79, n^o 2 (février 2012) : 87–103. http://dx.doi.org/10.1002/arch.21014.

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Brattsten, Lena B. « Bioengineering of crop plants and resistant biotype evolution in insects : Counteracting coevolution ». Archives of Insect Biochemistry and Physiology 17, n^o 4 (1991) : 253–67. http://dx.doi.org/10.1002/arch.940170408.

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Yang, Ke, Qiang Fu, Qinjie Liu, Xiang He et Xin Lyu. « Evolution of Mining-Induced Stress in Downward Mining of Short-Distance Multiseam ». Geofluids 2022 (4 mars 2022) : 1–14. http://dx.doi.org/10.1155/2022/3305734.

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The strong disturbance of upward mining of the short-distance multiseam results in frequent fractures in the coal seam to be mined, jeopardizing the operation safety due to the instability of the surrounding rock of the overlying stope and risks of coal and gas outburst. A lucrative alternative is the downward mining of multiseam, which wide implementation is limited by the lack of reliable data on stress evolution characteristics. In this paper, the evolution, nonlinear interaction, and superposition characteristics of mining-induced stress after multiple pressure relief in the short-distance multi-seam were investigated by the numerical simulation and physical simulation, taking the endowment and mining technology characteristics of group B short-distance multiseam in Pan’er Coal Mine in Anhui Province of China as an example. The numerical and physical models of multiple (2—5 times) mining activities in pressure relief multiseam (with five main coal layers) under downward mining are constructed and implemented with the FLAC3D software and 1 : 100 scaling, respectively. The results showed that a pressure relief arch, which bears and transfers stresses, is formed on the coal seam’s roof and floor. In downward mining, the local arch expands to the long arch, which bearing capacity within the influence range of multiple mining disturbances is weak, and the arch structure is prone to instability. If a coal pillar is left in the upper coal seam after its mining, the lower coal seam mining will switch from the large-scale low-stress area under the goaf to the small-scale high-stress area of nonlinear interaction of the multiple mining stresses with the stress under the coal pillar.

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Al-Kindi, Mohammed H. N. « Timing, Mechanics and Controls of the Evolution of the Southernmost Part of the Oman Mountains : The Salakh Arch ». Geosciences 10, n^o 3 (1 mars 2020) : 95. http://dx.doi.org/10.3390/geosciences10030095.

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Regional surface and subsurface mapping of the front range of the Oman Mountains, Salakh Arch’s fold-and-thrust belt, is conducted to understand the timing and nature of its deformation and to analyze the main controls on its position, geometry and evolution. The results from this study can be applied to other fold-and-thrust belts, as the area offers surface and subsurface datasets that allow good understanding of its evolution history. The deformation of the outcropping Middle Miocene to Pliocene deposits and the displacement of the Cenozoic seismic reflections imply that folding and thrusting was active during the Neogene and possibly ceased during the Early Quaternary. The palaeostress-tensor analyses from the kinematic fault data along with the fold-axes trends show that the regional transport direction was, overall, directed to the south. Lateral movements over oblique or lateral ramps, between the frontal ramps, have caused local deflections of the regional stress trajectories. The shortening values measured from restored seismic sections were utilized to restore the arch in map view. The restoration indicates that the arch initiated as a primary arc right from the start of deformation. As the shortening proceeded, clockwise and anticlockwise rotations occurred in some areas as a consequence of displacement gradients across adjacent areas along the arch. This rotation was most likely accommodated by angular shear strain, which results in arch-parallel extension or transtension. Various factors have controlled the position, geometry and segmentation of the fold segments in the Salakh Arch. The folds that developed in areas of thicker deformed sediments are wider and more uplifted and advanced to the foreland than the folds that develop in thin deformed sediments. Pre-existing faults were reactivated as lateral and frontal ramps during the arch’s evolution. They have contributed in the location and segmentation of the fold patches. On the other hand, the depth-to-detachment measurements and restoration results suggest that the folds detach along the Ediacaran-Early Cambrian Ara Salt. Overall, the deformation in the Salakh Arch could be described as an interaction between thin- and thick-skinned tectonics.

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Edwards, Camilla, et David Edwards. « The Evolution of the Shouldered Arch in Medieval Islamic Architecture ». Architectural History 42 (1999) : 68. http://dx.doi.org/10.2307/1568705.

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Shon, Sudeok, et Junhong Ha. « Parameter Estimation of Shallow Arch Using Quantum-Inspired Evolution Algorithm ». Journal of The korean Association For Spatial Structures 20, n^o 1 (15 mars 2020) : 95–102. http://dx.doi.org/10.9712/kass.2020.20.1.95.

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Georgakilas, A. A., Th G. Zachariadis et C. E. Alissandrakis. « Evolution of an active region and associated H ? arch structures ». Solar Physics 146, n^o 2 (août 1993) : 241–58. http://dx.doi.org/10.1007/bf00662012.

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Hou, Chunyao, Dong Chai, Heng Cheng, Shaoqing Ning, Bo Yang et Yi Zhou. « Simulation Feedback of Temperature Field of Super-High Arch Dam during Operation and Its Difference with Design Temperature ». Water 14, n^o 24 (9 décembre 2022) : 4028. http://dx.doi.org/10.3390/w14244028.

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Temperature is one of the main loads of super-high arch dams. (1) Background: a super-high arch dam in southwest China was taken as an example in this paper and the temporal-spatial evolution law of dam temperature was analyzed based on the monitoring data. (2) Methods: the finite element simulation analysis method was adopted to invert the boundary conditions of temperature on the upstream surface and the thermal parameters of the concrete, and the temperature evolution process of the arch dam in long-term operation was simulated and analyzed. After the distribution characteristics of the designed reservoir water temperature and the actual reservoir water temperature were compared, the difference in the temperature field of the arch dam during the impoundment and operation under the designed and actual conditions was studied. (3) Results: the temporal-spatial evolution law of the temperature in the dam operation period accords with the conventional knowledge, and the calculated value through simulation feedback is in good agreement with the monitoring value, which can reflect the actual temperature field distribution of the dam. (4) Conclusions: under the design condition, the dam temperature rose slowly after closure grouting and then tended to be stable. Under the actual condition, the temperature rose by 7.1~9.2 °C after closure grouting, reached the highest temperature in about 8~12 years, and fell back to a stable temperature in 40~80 years.

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Mao, Liang Yan, Chang Qing Wang et Li Yong Zhang. « Analysis to Evolution of Numerical Simulation to the Whole Process of Destroy for Main Arch of Stone Arch Bridge ». Applied Mechanics and Materials 361-363 (août 2013) : 1150–54. http://dx.doi.org/10.4028/www.scientific.net/amm.361-363.1150.

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6m arch board used as test object, this paper introduces the arch in different level of load board cracks, development and production of plastic hinge until the whole process for all the damage simulation numerical simulation analysis then compared with experimental results and analysis of increased with load crack distribution, which can be used to understand the similar in service work condition of the stone bridge.

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Ding, Xiao, Hui He, Yonglong Qu et Yixuan Yang. « Analysis of the Pile-Soil Combined Effect of Micropiles in Strengthening Expansive Soil Landslide in Southern Shaanxi Based on the Dynamic Soil Arch Model ». Advances in Materials Science and Engineering 2022 (14 novembre 2022) : 1–6. http://dx.doi.org/10.1155/2022/8114708.

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Southern Shaanxi region is mountainous and landslide disasters are frequent. Micropile reinforcement technology is widely used in landslide management, especially in landslide emergency rescue projects, due to easy construction, small soil disturbance, and strong site adaptability. Soil arch effect is an important prerequisite for safe and economic performance of the support function of micropile. For the swelling soil landslide of the accumulation layer in southern Shaanxi, firstly, a numerical model is established by means of thermal-mechanical coupling of FLAC3D to explore the variation of the soil arch form with different swelling forces. Then, two theoretical models are proposed under normal working condition and rainfall working condition. The evolution and failure mode of soil arch are analyzed. The results show that the soil expansion after rainfall causes the change of the soil arch mode, the range of pile-soil interaction is obviously reduced, and the soil arch effect is weakened. It should be considered in the design of micropiles in strengthening expansive soil landslide.

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MACGREGOR, CAROLINE A. « Gribloch : The Evolution of the Architectural and Interior Design of a 1930s Scottish Country House ». Architectural Heritage 5, n^o 1 (novembre 1994) : 73–96. http://dx.doi.org/10.3366/arch.1994.5.1.73.

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MACGREGOR, CAROLINE A. « Gribloch : The Evolution of the Architectural and Interior Design of a 1930s Scottish Country House ». Architectural Heritage 5, n^o 5 (janvier 1994) : 73–96. http://dx.doi.org/10.3366/arch.1994.5.5.72.

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Lin, Hai, Renshu Yang, Yongliang Li et Shizheng Fang. « Stability of Coal Pillar and Roof Movement Characteristics in Roadway Backfill Mining ». Advances in Civil Engineering 2021 (22 mars 2021) : 1–13. http://dx.doi.org/10.1155/2021/5588923.

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In order to explore the stability of coal pillar and the characteristics of roof movement during the process of roadway backfill mining (RBM), the 301 backfilling test working face of Ordos Chahasu coal mine is taken as the background. Based on the expansive pressure arch theory, the evolution process of the stope expansive pressure arch in RBM is studied; by establishing a mechanical model for the stability of coal pillars, the interactions between the height, width, and the maximum number of branches are obtained. When the width and height of the branch are both 5 m, the optimal number of the branches is obtained. Then, by establishing a mechanical model for the subsidence of the immediate roof, the process of the immediate roof subsidence is divided into three stages, namely, the formation stage of the local pressure arch, the merge stage of the pressure arch, and the expansion stage of the pressure arch. In addition, using the numerical method, the alternate bearing process of coal pillars and filling bodies and the change of the maximum supporting stress are studied, and the evolution of the pressure arch bearing structure above the stope and the staged subsidence characteristics of the roof are analyzed. The on-site test showed that the coal pillar has a good stability during the mining process. The maximum stress of the coal pillar is 16.5 MPa, and the maximum stress of the filling body is 9 MPa. The maximum settlement of the immediate roof is 102 mm, indicating that the roof control effect is good. This research will play an important role on engineering practice.

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Yeksareva, Nadiya, et Vladimir Yeksarev. « Evolution of the landscape, historical planning and elements of Odessa ». Budownictwo i Architektura 3, n^o 2 (11 décembre 2008) : 119–30. http://dx.doi.org/10.35784/bud-arch.2326.

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Hovorakova, Maria, Oldrich Zahradnicek, Martin Bartos, Pavel Hurnik, Jiri Stransky, Jan Stembirek et Abigail S. Tucker. « Reawakening of Ancestral Dental Potential as a Mechanism to Explain Dental Pathologies ». Integrative and Comparative Biology 60, n^o 3 (3 juin 2020) : 619–29. http://dx.doi.org/10.1093/icb/icaa053.

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Synopsis During evolution, there has been a trend to reduce both the number of teeth and the location where they are found within the oral cavity. In mammals, the formation of teeth is restricted to a horseshoe band of odontogenic tissue, creating a single dental arch on the top and bottom of the jaw. Additional teeth and structures containing dental tissue, such as odontogenic tumors or cysts, can appear as pathologies. These tooth-like structures can be associated with the normal dentition, appearing within the dental arch, or in nondental areas. The etiology of these pathologies is not well elucidated. Reawakening of the potential to form teeth in different parts of the oral cavity could explain the origin of dental pathologies outside the dental arch, thus such pathologies are a consequence of our evolutionary history. In this review, we look at the changing pattern of tooth formation within the oral cavity during vertebrate evolution, the potential to form additional tooth-like structures in mammals, and discuss how this knowledge shapes our understanding of dental pathologies in humans.

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Cheng, Guo Qiang, et Yan Jin Song. « The Evolution Rules of Overlying Strata Porosity Influenced by Mining Activation ». Advanced Materials Research 282-283 (juillet 2011) : 21–25. http://dx.doi.org/10.4028/www.scientific.net/amr.282-283.21.

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Rock is a type of natural material containing microcracks. The evolution of mining-induced fracture field is one of the main problems of gas comprehensive control and rock mass seepage. The distribution of fissures and porosity in overlying strata under the mining influence were studied in this paper. The stratum subsidence was represented quantitatively using elastic thin plate theory and key strata theory. Based on the stratum subsidence, a program calculating porosity in overlying strata was developed based on VB. The results demonstrate that the porosity increase with face advances. The porosity becomes small with the decrease of strata depth, and the bigger separation is located in the strata below the key strata. The amount of the fissures in the middle part of overlying strata is more than that in two ends, and the porosity curves present symmetric arch shape in the initial stage. With face advances, the curves of porosity in the strata located the upper position change symmetric arch shape into saddle shape.

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Leucci, Giovanni, Raffaele Persico, Lara De Giorgi, Maurizio Lazzari, Emanuele Colica, Salvatore Martino, Roberto Iannucci, Luciano Galone et Sebastiano D’Amico. « Stability Assessment and Geomorphological Evolution of Sea Natural Arches by Geophysical Measurement : The Case Study of Wied Il-Mielah Window (Gozo, Malta) ». Sustainability 13, n^o 22 (12 novembre 2021) : 12538. http://dx.doi.org/10.3390/su132212538.

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The Wied il-Mielaħ Window (Gozo–Malta) is a limestone natural arch on the north-western coast of the island of Gozo in Malta. It is located at the end of the Wied il-Mielaħ valley north of the village of Għarb. This natural arch is less well known than the Azure Window, which collapsed in March 2017 following a heavy storm, but notwithstanding, it is an imposing and important natural monument too. In the past, the Wied il-Mielah valley was responsible for discharging wastewater from the surrounding localities to the Mediterranean directly at the Wied il-Mielah Window. The sewage flag was often clearly visible underneath the archway into the open sea. The natural features of the arch provide an outstanding touristic attraction. To avoid what happened to the Azure Window, a methodology for the evaluation of the collapse hazard, combining passive seismic, ground penetrating radar (GPR), geological/geomorphological surveys and mine engineering methods, is here proposed. In this study, a methodological approach was applied, based on the following: (i) passive seismic method to study the physical–mechanical characteristics of the rock mass that constitutes the window; (ii) GPR method in order to demonstrate the conservation state (i.e., the intensity of fracturing); (iii) geological/geomorphological surveys in order to obtain a crack pattern; and (iv) scaled span empirical analysis in order to evaluate the stability of the arch. The calculation of the safety factor, with a static method, gave a value equal to 3.75 with a probability of collapse of the marine arch within 50 and 100 years.

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Huang, R. F., C. Y. Ho et J. K. Chen. « Pulsatile Flow Patterns and Wall Shear Stresses in Arch of a Turn-Around Tube With/Without Stenosis ». Journal of Mechanics 27, n^o 1 (mars 2011) : 79–94. http://dx.doi.org/10.1017/jmech.2011.10.

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ABSTRACTThe temporal/spatial evolution processes of the flow pattern, velocity distribution, and wall shear stress of pulsatile water flows in the arch of 180o turn-around tubes with/without stenosis were experimentally studied by using the particle image velocimetry (PIV). Three transparent tubes made of glass were used: A tube without stenosis in the arch, a tube with a 25% stenosis at the inner wall of arch, and a tube with a 50% stenosis at the inner wall of arch. Here the percentage of stensis denoted the ratio between the stenosis height to inner diameter of arch in the diametral cross section across mid-arch of the central plane. The flow was provided by a pump which approximately simulated the pulsatile pressure waves of human heart beats. The systole to diastole time period ratio is set at 35%:65%. The Womersley parameter, Dean number, and time-averaged Reynolds number were 14, 2348, and 3500, respectively. In the arch of the turn-around tube without stenosis, no boundary layer separation was found during the systolic phase. The reverse flow and recirculation bubble appeared in the arch only during the diastolic phase. The inner wall of the arch experienced lower wall shear stress during the diastolic phase due to the formation of recirculation bubble and secondary flow. In the arch with stenosis, the boundary layer separated from the inner wall and formed a recirculation bubble downstream the stenosis during the systolic phase. Lower stenosis (25%) did not cause drastic variation of the wall shear stresses. At higher stenosis (50%), however, the wall shear stress around the inner wall downstream the stenosis became extraordinarily low, whereas the wall shear stress around the upstream region of the outer wall of the downstream branch of the tube became anomalously large.

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Wen, Zhijie, Guanglong Qu, Jinhao Wen, Yongkui Shi et Chuanyang Jia. « Deformation Failure Characteristics of Coal Body and Mining Induced Stress Evolution Law ». Scientific World Journal 2014 (2014) : 1–8. http://dx.doi.org/10.1155/2014/714507.

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The results of the interaction between coal failure and mining pressure field evolution during mining are presented. Not only the mechanical model of stope and its relative structure division, but also the failure and behavior characteristic of coal body under different mining stages are built and demonstrated. Namely, the breaking arch and stress arch which influence the mining area are quantified calculated. A systematic method of stress field distribution is worked out. All this indicates that the pore distribution of coal body with different compressed volume has fractal character; it appears to be the linear relationship between propagation range of internal stress field and compressed volume of coal body and nonlinear relationship between the range of outburst coal mass and the number of pores which is influenced by mining pressure. The results provide theory reference for the research on the range of mining-induced stress and broken coal wall.

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Venkadesan, Madhusudhan, Ali Yawar, Carolyn M. Eng, Marcelo A. Dias, Dhiraj K. Singh, Steven M. Tommasini, Andrew H. Haims, Mahesh M. Bandi et Shreyas Mandre. « Stiffness of the human foot and evolution of the transverse arch ». Nature 579, n^o 7797 (26 février 2020) : 97–100. http://dx.doi.org/10.1038/s41586-020-2053-y.

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Ismail-Zadeh, Alik, Helmut Wilhelm et Yuri Volozh. « Geothermal evolution of the Astrakhan Arch region of the Pricaspian basin ». International Journal of Earth Sciences 97, n^o 5 (17 octobre 2007) : 1029–43. http://dx.doi.org/10.1007/s00531-007-0258-z.

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Kossakowski, Paweł. « The numerical analysis of micro-damage evolution in damaged element with structural discontinuity ». Budownictwo i Architektura 12, n^o 1 (11 mars 2013) : 235–42. http://dx.doi.org/10.35784/bud-arch.2204.

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The numerical analysis of microdamage evolution in S235JR steel is presented in the paper. The simulation was performed basing on the Gurson-Tvergaard-Needleman material model which takes into consideration the influence of microdamage to the material strength. The plate element with a central hole was considered. It modelled the structure discontinuity which may occur in structural element due to such a phenomenon as corrosion. The numerical simulation and analysis of micro-damage evolution for this element made of S235JR steel was carried out, which allowed to show and detect the micro-crack initiation and area subjected to final failure.

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Liu, Keming, et Xizhen Sun. « Bearing Capacity of Concrete Filled Steel Tube Circular Arch under the Six-Point Uniformly Distributed Loading and Its Engineering Application ». Advances in Materials Science and Engineering 2021 (13 décembre 2021) : 1–13. http://dx.doi.org/10.1155/2021/8288648.

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The influence of rise-span ratio on the bearing performance of concrete filled steel tube (CFST) circular arch was studied in this paper, three groups of CFST circular arch specimens with different rise-span ratios (0.154, 0.207, and 0.26) were selected, the six-point uniformly distributed loading was performed, and bearing performance experiments on CFST circular arch specimens with fixed ends were carried out. In this study, the ultimate bearing capacity and deformation failure characteristics of CFST circular arch specimens were obtained. The comparative analysis shows that the deformation evolution of CFST circular arch specimens has experienced compaction stage, elastic stage, elastic-plastic stage, and plastic stage. In the elastic-plastic and plastic deformation stages, the circular arch shows good ductility and bearing capacity. The bearing capacity of the circular arch is significantly affected by the rise-span ratio. Compared with circular arch specimens with a rise-span ratio of 0.154, the yield load of specimens with a rise-span ratio of 0.207 and 0.26 is increased by 50.8% and 61.5%, and the ultimate bearing capacity is increased by 42.7% and 68.3%, respectively. The larger the rise-span ratio, the greater the yield load and ultimate bearing capacity of the specimen and the stronger the deformation resistance of circular arch. The numerical simulation on the bending resistance process of circular arch was performed by ABAQUS to present the compression failure process of steel tube and core concrete. The simulation results are in good agreement with the experimental results. The experimental and simulation results show that the circular arch first yields at the inner side of the arch foot, and the curvature of different positions of the specimen is no longer consistent. When the ultimate bearing capacity is reached, the steel pipe at the arch foot obviously heaves, and the hooping effect of the steel pipe on the concrete is invalid. Based on the above research results, a closed composite support scheme of “bolt mesh shotcrete + vertical elliptical CFST support + steel fiber concrete shotcrete layer + reinforced anchor cable” was proposed for the extremely soft rock roadway and successfully applied in the Qingshuiying coal mine.

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Velilla, Cristina, Alfredo Alcayde, Carlos San-Antonio-Gómez, Francisco G. Montoya, Ignacio Zavala et Francisco Manzano-Agugliaro. « Rampant Arch and Its Optimum Geometrical Generation ». Symmetry 11, n^o 5 (3 mai 2019) : 627. http://dx.doi.org/10.3390/sym11050627.

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Gothic art was developed in western Europe from the second half of the 12th century to the end of the 15th century. The most characteristic Gothic building is the cathedral. Gothic architecture uses well-carved stone ashlars, and its essential elements include the arch. The thrust is transferred by means of external arches (flying buttresses) to external buttresses that end in pinnacles, which accentuates the verticality. The evolution of the flying buttresses should not only be considered as an aesthetic consideration, but also from a constructive point of view as an element of transmission of forces or loads. Thus, one evolves from a beam-type buttress to a simple arch, and finally to a rampant arch. In this work, we study the geometry of the rampant arch to determine which is the optimum from the constructive point of view. The optimum rampant arch obtained is the one with the common tangent to the two arches parallel to the slope line. A computer program was created to determine this optimal rampant arch by means of a numerical or graphical input. It was applied to several well-known and representative cases of Gothic art in France (church of Saint Urbain de Troyes) and Spain (Cathedral of Palma de Mallorca), establishing if they were designs of optimal rampant arches or not.

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He, Fulian, Liang Li, Kai Lv, Binbin Qin, Xuhui Xu, Qing Ma et Yongqiang Chen. « Study on Evolution of Front Abutment Pressure at Working Face in Repeated Mining of Close-Distance Coal Seams ». Sustainability 14, n^o 19 (29 septembre 2022) : 12399. http://dx.doi.org/10.3390/su141912399.

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In order to determine the reasonable width of a stopping coal pillar in close-distance coal seams, the evolution law of front abutment pressure of the working face with repeated mining was studied. Based on the actual engineering project, we conducted field measurement, theoretical analyses, numerical simulations and a physical similarity simulation test to study. The results show that: (1) according to field measurement, the influence range of front abutment pressure increases from 60 m to 75 m with repeated mining; (2) according to theoretical analysis, the arch height and span are negatively and positively correlated with the influence range of front abutment pressure, respectively; (3) with repeated mining, the arch height increased to 165 m, the arch span to 235 m and the influence range to 83.5 m by 14.5 m relative to that before repeated mining; (4) if it is necessary to ensure that the main roadway is less affected by the mining stress, the width of the stopping coal pillar in 2214 working face should be greater than 80 m. The influence range of front abutment pressure increases obviously with repeated mining in close-distance coal seams. The study provides a reference for similar engineering projects.

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McIntyre, D. B., et F. J. Ward. « Estimating Fork Lengths of Fathead Minnows, Pimephales promelas, from Measurement of Pharyngeal Arches ». Canadian Journal of Fisheries and Aquatic Sciences 43, n^o 6 (1 juin 1986) : 1294–97. http://dx.doi.org/10.1139/f86-161.

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The pharyngeal arches of fathead minnows (Pimephales promelas) are persistent in the gut of juvenile walleye (Stizostedion vitreum vitreum). The relationship of fork length to GAP (chord length between the dorsal and ventral extremities of the left pharyngeal arch) measurements of left pharyngeal arches of fathead minnows is linear, positive, and highly significant. Fish lengths calculated from arches recovered from stomachs after a period of up to 8 h generally fell within the prediction intervals established for the regression of fork lengths on arch measurements of freshly killed minnows. The relationship between length and arch measurement will permit the length of ingested fathead minnows to be calculated aiding in food size selection and energetic studies. Other minnow species, sharing the same habitats with fathead minnows, have distinctive pharyngeal arches which can be used to identify species in stomach contents. Length may also be correlated with pharyngeal arch measurements in these species.

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Jiang, Haibo, Yuhang Huang, Kebin Shi, Pengfei Xiang et Gang Wei. « Analysis of Malignant Expansion of Plastic Zone of Surrounding Rocks in High Ground Temperature Hydraulic Tunnels and the Mechanical Characteristics of the Support Structure ». Symmetry 14, n^o 12 (9 décembre 2022) : 2606. http://dx.doi.org/10.3390/sym14122606.

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To explore the development process of the plastic zone of hydraulic tunnels and the mechanical characteristics of the support structure in a high ground temperature environment during construction period, methods, including theoretical analysis, numerical calculation, field monitoring test, etc., are used to analyze the generation and formation process of the plastic zone of surrounding rocks in the hydraulic tunnel under high ground temperature environment. The evolution law of mechanical characteristics of the support structure in surrounding rocks is studied. The development process and shape of the plastic zone in the tunnel under various high ground temperatures are simulated. The results show that after the excavation of the high ground temperature hydraulic tunnel, the plastic zone first appears at the arch waist in a crescent pattern, then extends to both sides and the spandrel, and connects with the plastic zone in the arch crown, forming a pattern of circle or butterfly. A higher initial temperature of the surrounding rock indicates a larger range and plastic strain of the plastic zone in the surrounding rock. At the same time, the plastic zone is easier to appear at the spandrel and arch foot and develop to the depth of the surrounding rock. The higher is the initial temperature of the surrounding rock, the greater will be the axial force and bending moment of supported shotcrete, the more obviously the bending moment of arch abutment and arch foot will grow, the greater will be the axial force value of the bolt and the farther the neutral point will be from the tunnel wall. While strengthening the arch waist, the support of the arch shoulder and arch foot should also be strengthened at a high temperature.

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Ma, Zi-min, Yan-jun Wang, Long Huang, Hao-hao Wang, Jiong Wang, Zhao-xuan Wang, Yan-long Wang et Bo-tao Wang. « Research on the Stability Mechanism of the Surrounding Rock of Gob-Side Entry Retaining by Roof Cutting in Dianping Coal Mine ». Minerals 12, n^o 8 (29 juillet 2022) : 965. http://dx.doi.org/10.3390/min12080965.

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According to the movement characteristics of the surrounding rock of the gob-side entry retaining by roof cutting (GERRC), the structural evolution mechanism and stability control countermeasures are studied in this paper. Taking the roof cutting and bulking as the core point, the movement process of the surrounding rock of GERRC is divided into five stages: roof cutting, dynamic pressure support, gangue bulking, double arch roadway support, and roadway formation. Combined with mechanical analysis, the roof pressure of the mechanical model of the short-arm beam formed by roof cutting is calculated, and the roof breaking criterion is obtained, which provides a basis for roof control design and reasonable support strength calculation. A structural model of double-arch roadway protection under the action of hydrostatic roof cutting and gangue bulking was established, and the mechanism of roadway formation stability was studied. The gob-side bulking gangue and short-arm beam are formed by roof cutting, and the solid coal seam forms the immediate balance arch, the bulking gangue in goaf, articulated transfer rock beam, and solid coal seam forms the main balance arch. The two together are called double balance arch. With the support of the double-balanced arch on the overlying rock strata, the roadway below is located in the low-stress zone, which ensures the stability of the roadway surrounding rock. Through mechanical analysis and field observation, the law of bulking and deformation and mechanical characteristics of gob-side gangue in the above structural model are analyzed, and the reasonableness of the structural model of the double-arch guard lane is verified through numerical simulation of the cut top into lanes. and the reasonableness of the structural model of double-arch protection in GERRC is verified by using numerical simulation. In this paper, a mechanical double-arch model has been developed that allows us to understand the mechanism of stress transfer of roof cutting roadway from the perspective of a dynamic balance of roadway surrounding rock and overlying rock strata, helping us to specify efficient support countermeasures.

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Ren, Xiang, Lijuan Luo, Yunxin Zheng, Jiakuan Ma et Xuexu An. « Morphological Evolution of Passive Soil Arch in Front of Horizontal Piles in Three Dimensions ». Buildings 12, n^o 7 (21 juillet 2022) : 1056. http://dx.doi.org/10.3390/buildings12071056.

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The anti-slide pile is a primary method of landslide control. The effect of the passive soil arch in front of the embedded section of piles has a significant effect on the anti-slide pile’s bearing capacity. The upgraded model test scheme was used to conduct model tests with a pile spacing four times the width of the pile and a geometric scale ratio of 1:15. The anti-slide pile stress, pile bending strain, and soil stress in front of the pile were all studied in relation to the loading amount. In addition to the model test, the numerical simulation method was utilized to investigate the three-dimensional morphological change of the passive soil arch in front of the pile. The results indicated that: clearly, the side piles can eliminate the border effect. The distribution of pile bending strain along the pile after loading is referred to as a parabola. Bending failure occurred at a depth of 40 mm, approximately 0.9 m from the pile top. Under the condition that the pile spacing is four times the pile width, a passive soil arch occurs in front of the anti-slide pile’s fixed part, and its development can be split into four stages: formation, development, completion, and destruction. The passive soil arches in front of the piles are generated and destroyed gradually along the buried depth, and the three-dimensional surface of the space drops gradually along the buried depth with the loading amount and advances toward the loading direction until the anti-slide pile system fails. The research findings and experiences can serve as a basis for future research.

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Ivanyisky III, Stephen J., et James S. Albert. « Systematics and biogeography of Sternarchellini (Gymnotiformes : Apteronotidae) : Diversification of electric fishes in large Amazonian rivers ». Neotropical Ichthyology 12, n^o 3 (26 août 2014) : 565–84. http://dx.doi.org/10.1590/1982-0224-20130159.

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The Sternarchellini (Gymnotiformes, Apteronotidae) is a clade of 10 electric fish species that inhabit deep river channels of the Amazon and Orinoco basins, attain moderate adult body sizes (15-50 cm TL), and have a predatory life style. Here we trace the evolutionary origin and diversification of Sternarchellini using standard phylogenetic and biogeographic procedures and a dataset of 70 morphological characters. The main results are: 1) the genus Sternarchellaincludes both species currently assigned to the genus Magosternarchus; and 2) neither of the multi-species assemblages of Sternarchellini in the Amazon and Orinoco basins are monophyletic. Historical biogeographic analysis suggests that sternarchelline evolution was linked to the large-scale river capture event that formed the modern Amazon and Orinoco basins, i.e. the Late Miocene rise of the Vaupes structural arch and concomitant breaching of the Purus structural arch. This event is hypothesized to have contributed to formation of the modern sternarchelline species, and to the formation of the modern basin-wide sternarchelline species assemblages. The results indicate that cladogenesis (speciation) and anagenesis (adaptive evolution) were decoupled processes in the evolution of Sternarchellini.

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Wang, S. R., N. Li, C. L. Li et P. Hagan. « Mechanics Evolution Characteristics Analysis of Pressure - arch in Fully - mechanized Mining Field ». Journal of Engineering Science and Technology Review 7, n^o 4 (octobre 2014) : 40–45. http://dx.doi.org/10.25103/jestr.074.07.

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