Sample records for extensional deformation implantacao

  1. Microfluidic converging/diverging channels optimised for homogeneous extensional deformation

    Zografos, K.; Oliveira, M. S. N.


    In this work, we optimise microfluidic converging/diverging geometries in order to produce constant strain-rates along the centreline of the flow, for performing studies under homogeneous extension. The design is examined for both two-dimensional and three-dimensional flows where the effects of aspect ratio and dimensionless contraction length are investigated. Initially, pressure driven flows of Newtonian fluids under creeping flow conditions are considered, which is a reasonable approximation in microfluidics, and the limits of the applicability of the design in terms of Reynolds numbers are investigated. The optimised geometry is then used for studying the flow of viscoelastic fluids and the practical limitations in terms of Weissenberg number are reported. Furthermore, the optimisation strategy is also applied for electro-osmotic driven flows, where the development of a plug-like velocity profile allows for a wider region of homogeneous extensional deformation in the flow field. PMID:27478523

  2. Deformation and Stress Response of Carbon Nanotubes/UHMWPE Composites under Extensional-Shear Coupling Flow

    Wang, Junxia; Cao, Changlin; Yu, Dingshan; Chen, Xudong


    In this paper, the effect of varying extensional-shear couple loading on deformation and stress response of Carbon Nanotubes/ ultra-high molecular weight polyethylene (CNTs/UHMWPE) composites was investigated using finite element numerical simulation, with expect to improve the manufacturing process of UHMWPE-based composites with reduced stress and lower distortion. When applying pure extensional loading and pure X-Y shear loading, it was found that the risk of a structural breakage greatly rises. For identifying the coupling between extensional and shear loading, distinct generations of force loading were defined by adjusting the magnitude of extensional loading and X-Y shear loading. It was shown that with the decrement of X-Y shear loading the deformation decreases obviously where the maximal Mises stress in Z-direction at 0.45 m distance is in the range from 24 to 10 MPa and the maximal shear stress at 0.61 m distance is within the range from 0.9 to 0.3 MPa. In addition, all the stresses determined were clearly below the yield strength of CNTs/UHMWPE composites under extensional-shear couple loading.

  3. Deformation and breakup of micro- and nanoparticle stabilized droplets in microfluidic extensional flows.

    Mulligan, Molly K; Rothstein, Jonathan P


    Using a microfluidic flow-focusing device, monodisperse water droplets in oil were generated and their interface populated by either 1 μm or 500 nm amine modified silica particles suspended in the water phase. The deformation and breakup of these Pickering droplets were studied in both pure extensional flow and combined extensional and shear flow at various capillary numbers using a microfluidic hyperbolic contraction. The shear resulted from droplet confinement and increased with droplet size and position along the hyperbolic contraction. Droplet deformation was found to increase with increasing confinement and capillary number. At low confinements and low capillary numbers, the droplet deformation followed the predictions of theory. For fully confined droplets, where the interface was populated by 1 μm silica particles, the droplet deformation increased precipitously and two tails were observed to form at the rear of the droplet. These tails were similar to those seen for surfactant covered droplets. At a critical capillary number, daughter droplets were observed to stream from these tails. Due to the elasticity of the particle-laden interface, these drops did not return to a spherical shape, but were observed to buckle. Although increases in droplet deformation were observed, no tail streaming occurred for the 500 nm silica particle covered droplets over the range of capillary numbers studied.

  4. Droplet Deformation in an Extensional Flow: The Role of Surfactant Physical Chemistry

    Stebe, Kathleen J.


    Surfactant-induced Marangoni effects strongly alter the stresses exerted along fluid particle interfaces. In low gravity processes, these stresses can dictate the system behavior. The dependence of Marangoni effects on surfactant physical chemistry is not understood, severely impacting our ability to predict and control fluid particle flows. A droplet in an extensional flow allows the controlled study of stretching and deforming interfaces. The deformations of the drop allow both Marangoni stresses, which resist tangential shear, and Marangoni elasticities, which resist surface dilatation, to develop. This flow presents an ideal model system for studying these effects. Prior surfactant-related work in this flow considered a linear dependence of the surface tension on the surface concentration, valid only at dilute surface concentrations, or a non-linear framework at concentrations sufficiently dilute that the linear approximation was valid. The linear framework becomes inadequate for several reasons. The finite dimensions of surfactant molecules must be taken into account with a model that includes surfaces saturation. Nonideal interactions between adsorbed surfactant molecules alter the partitioning of surfactant between the bulk and the interface, the dynamics of surfactant adsorptive/desorptive exchange, and the sensitivity of the surface tension to adsorbed surfactant. For example, cohesion between hydrocarbon chains favors strong adsorption. Cohesion also slows the rate of desorption from interfaces, and decreases the sensitivity of the surface tension to adsorbed surfactant. Strong cohesive interactions result in first order surface phase changes with a plateau in the surface tension vs surface concentration. Within this surface concentration range, the surface tension is decoupled from surface concentration gradients. We are engaged in the study of the role of surfactant physical chemistry in determining the Marangoni stresses on a drop in an extensional

  5. Inter-rifting Deformation in an Extensional Rift Segment; the Northern Volcanic Zone, Iceland

    Pedersen, R.; Masterlark, T.; Sigmundsson, F.; Arnadottir, T.; Feigl, K. L.


    The Northern Volcanic Zone (NVZ) in Iceland is an extensional rift segment, forming a sub-aerial exposure of a part of the Mid-Atlantic ridge. The NVZ is bounded to the south by the Icelandic mantle plume, currently beneath the Vatnajökull ice cap, and to the north by the Tjörnes Fracture zone, a transform zone connecting the offset on- and offshore rift segments of the Mid-Atlantic ridge. Based on geologic and tectonic mapping, the NVZ has been divided into five partly overlapping en-echelon fissure swarms, each with a central main volcanic production area. The two fissure swarms with known activity in historic time are, based on geodetic and seismic data, interpreted to have associated shallow crustal magma chambers. These central volcanoes are furthermore the only with caldera collapses associated, reflecting on the maturity of the systems. A series of newly formed InSAR images of the NVZ, spanning the interval from 1993-2006, have been formed, revealing a complex interplay of several tectonic and magmatic processes. Deformation from two subsiding shallow sources appear at the sites of the known crustal magma chambers. Furthermore, subsidence is occurring at varying degrees within the associated relatively narrow fissure swarms (15-20 km). However, the horizontal plate spreading signal is not confined to the fissure systems, and appears to be distributed over a much wider zone (about 100 km). This wide zone of horizontal spreading has previously been measured with campaign GPS surveys. A broad area of uplift situated about 18 km to the north of one of the subsidence centres (Krafla) suggests a deep seated pressurization source near the crust mantle boundary. Movements on previously unrecognized faults are apparent in the data, correlating well with the location of earthquake epicentres from minor seismic activity. Finally, utilization of geothermal resources in the Krafla area affects the deformation fields created by magmatic and tectonic processes, further

  6. Extensional vs contractional Cenozoic deformation in Ibiza (Balearic Promontory, Spain): Integration in the West Mediterranean back-arc setting

    Etheve, Nathalie; Frizon de Lamotte, Dominique; Mohn, Geoffroy; Martos, Raquel; Roca, Eduard; Blanpied, Christian


    Based on field work and seismic reflection data, we investigate the Cenozoic tectono-sedimentary evolution offshore and onshore Ibiza allowing the proposal of a new tectonic agenda for the region and its integration in the geodynamic history of the West Mediterranean. The late Oligocene-early Miocene rifting event, which characterizes the Valencia Trough and the Algerian Basin, located north and south of the study area respectively, is also present in Ibiza and particularly well-expressed in the northern part of the island. Among these two rifted basins initiated in the frame of the European Cenozoic Rift System, the Valencia Trough failed rapidly while the Algerian Basin evolved after as a back-arc basin related to the subduction of the Alpine-Maghrebian Tethys. The subsequent middle Miocene compressional deformation was localized by the previous extensional faults, which were either inverted or passively translated depending on their initial orientation. Despite the lateral continuity between the External Betics and the Balearic Promontory, it appears from restored maps that this tectonic event cannot be directly related to the Betic orogen, but results from compressive stresses transmitted through the Algerian Basin. A still active back-arc asthenospheric rise likely explains the stiff behavior of this basin, which has remained poorly deformed up to recent time. During the late Miocene a new extensional episode reworked the southern part of the Balearic Promontory. It is suggested that this extensional deformation developed in a trans-tensional context related to the westward translation of the Alboran Domain and the coeval right-lateral strike-slip movement along the Emile Baudot Escarpment bounding the Algerian Basin to the north.

  7. Relation between ore-forming hydrothermal systems and extensional deformation in the Solea graben spreading center, Troodos ophiolite, Cyprus

    Bettison-Varga, Lori; Varga, Robert J.; Schiffman, Peter


    Field relations indicate that high-temperature hydrothermal circulation and accumulation of massive sulfide deposits within the Solea graben of the Troodos ophiolite, Cyprus, followed extreme crustal attenuation. Zones of pervasive, massive epidosite strike parallel to the axis of the Solea graben and to the strike of extensional normal faults. Initial fluid flow, evidenced by preferential epidotization in weakly altered areas surrounding massively altered regions, was focused along joints, microfractures, and (now) low-angle normal-fault zones related to graben formation. Permeability within the sheeted-dike section was enhanced by brittle deformation related to extensional structures as well as through volume reduction inherent in the diabase to epidosite mineralogic phase transformations. Intrusion of high-level gabbros into epidosite zones occurred both before and after significant amagmatic tectonic extension. Structural control on epidotization suggests that intrusion of late stocks into attenuated and highly deformed crust is necessary to drive the vigorous hydrothermal circulation that produced the epidosites and ore bodies of the Solea graben. A similar sequence of events is more likely to occur in the modern oceans along ridge crests with ephemeral magmatism, especially at intermediate- to slow-spreading ridges near transform faults.

  8. Extensional deformation of the Guadalquivir Basin: rate of WSW-ward tectonic displacement from Upper Tortonian sedimentary rocks

    Roldán, Francisco J.; Azañón, Jose Miguel; Rodríguez-Fernández, Jose; María Mateos, Rosa


    The Guadalquivir Basin (Upper Tortonian-Quaternary sedimentary infilling) has been considered the foreland basin of the Betic Orogen built up during its collision with the Sudiberian margin. The basin is currently restricted to its westernmost sector, in the Cadiz Gulf, because the Neogene-Quaternary uplift of the Betic Cordillera has produced the emersion of their central and eastern parts. The upper Tortonian chronostratigraphic unit is the oldest one and it was indistinctly deposited on the South Iberian paleomargin and the External units from the Betic Cordillera. However, these rocks are undeformed on the Sudiberian paleomargin while they are deeply affected by brittle deformation on the External Betic Zone. Outcrops of Upper Tortonian sedimentary rocks on External Betic Zone are severely fragmented showing allocthonous characters with regard to those located on the Sudiberian paleomargin. This post- Upper Tortonian deformation is not well known in the External Zones of the Cordillera where the most prominent feature is the ubiquity of a highly deformed tecto-sedimentary unit outcropping at the basement of the Guadalquivir sedimentary infilling. This tecto-sedimentary unit belongs to the Mass Wasting Extensional Complex (Rodríguez-Fernández, 2014) formed during the collision and westward migration of the Internal Zone of the Betic Cordillera (15-8,5 Ma). In the present work, we show an ensemble of tectonic, geophysical and cartographic data in order to characterize the post-Upper Tortonian deformation. For this, seismic reflection profiles have been interpreted with the help of hidrocarbon boreholes to define the thickness of the Upper Tortonian sedimentary sequence. All these data provide an estimation of the geometrical and kinematic characteristics of the extensional faults, direction of movement and rate of displacement of these rocks during Messinian/Pliocene times. References Rodríguez-Fernández, J., Roldan, F. J., J.M. Azañón y Garcia-Cortes, A

  9. Neotectonic deformation within an extensional stepover in El Salvador magmatic arc, Central America: Implication for the interaction of arc magmatism and deformation

    Garibaldi, Nicolás; Tikoff, Basil; Hernández, Walter


    Dominantly westward movement of the El Salvador forearc at rates of 11 mm/yr is accommodated by a series of E-W to WNW oriented, dextral, strike-slip fault zones herein referred to as the El Salvador Fault System (ESFS). The geometry of the ESFS defines a series of extensional step-overs. Along the arc, basaltic volcanism in the stepovers is associated with NNW-oriented normal faults, whereas rhyolitic volcanism is associated with strike-slip fault zones of the ESFS. On the ESFS, the San Salvador Extensional Stepover (SSES) is bound to the south by the San Vicente fault zone, where the rhyolitic Ilopango caldera is located. In the SSES, tephras from Ilopango -the Tierra Blanca (TB) sequence- track long-term elongation. Older TB units (TB5-8) contain abundant normal faults; lying unconformably above these older TB units, younger TB members (TBJ, TB2-4) are generally unfaulted. Analyses of faults in TB5-8 indicate NE- to ENE-oriented elongation in the SSES. Deformation occurred between deposition of the TB4 and TB5 units, during quiescence of the Ilopango eruptive center. Using this temporal constraint, minimum elongation rates of 3.50 × 10- 15 s- 1, 2.06 × 10- 14 s- 1 and 4.42 × 10- 14 s- 1 were calculated for three traverses. From regional geodetic data and fault kinematics throughout El Salvador, we interpret the SSES as part of a series of pull-apart structures along the arc axis. The calculated paleostress orientations are consistent with a pull-apart geometry resulting from forearc movement. The extensional deformation occurs during a 50 k.y. lull in rhyolitic activity, suggesting an interplay between magmatism and deformation within the arc. During significant rhyolitic volcanic activity, only minor elongation is observed in the SSES, despite ongoing translation of the Salvadoran forearc. We speculate that rhyolitic magmatism along upper crustal faults may facilitate strike-slip movement on the ESFS, rather than distributing deformation throughout the

  10. Analysis of Neogene deformation between Beaver, Utah and Barstow, California: Suggestions for altering the extensional paradigm

    Anderson, R. Ernest; Beard, Sue; Mankinen, Edward A.; Hillhouse, John W.


    For more than two decades, the paradigm of large-magnitude (~250 km), northwest-directed (~N70°W) Neogene extensional lengthening between the Colorado Plateau and Sierra Nevada at the approximate latitude of Las Vegas has remained largely unchallenged, as has the notion that the strain integrates with coeval strains in adjacent regions and with plate-boundary strain. The paradigm depends on poorly constrained interconnectedness of extreme-case lengthening estimated at scattered localities within the region. Here we evaluate the soundness of the inferred strain interconnectedness over an area reaching 600 km southwest from Beaver, Utah, to Barstow, California, and conclude that lengthening is overestimated in most areas and, even if the estimates are valid, lengthening is not interconnected in a way that allows for published versions of province-wide summations.We summarize Neogene strike slip in 13 areas distributed from central Utah to Lake Mead. In general, left-sense shear and associated structures define a broad zone of translation approximately parallel to the eastern boundary of the Basin and Range against the Colorado Plateau, a zone we refer to as the Hingeline shear zone. Areas of steep-axis rotation (ranging to 2500 km2) record N-S shortening rather than unevenly distributed lengthening. In most cases, the rotational shortening and extension-parallel folds and thrusts are coupled to, or absorb, strike slip, thus providing valuable insight into how the discontinuous strike-slip faults are simply parts of a broad zone of continuous strain. The discontinuous nature of strike slip and the complex mixture of extensional, contractional, and steep-axis rotational structures in the Hingeline shear zone are similar to those in the Walker Lane belt in the west part of the Basin and Range, and, together, the two record southward displacement of the central and northern Basin and Range relative to the adjacent Colorado Plateau. Understanding this province

  11. Extensional Elastica in large deformation as $Gamma $ Γ -limit of a discrete 1D mechanical system

    Alibert, Jean-Jacques; Della Corte, Alessandro; Giorgio, Ivan; Battista, Antonio


    The present paper deals with the rigorous homogenization of a discrete system consisting of extensible rods linked by rotational springs. Specifically, a Γ -convergence result is proven for a sequence of discrete measure functionals En, describing the energy of the discrete system, toward the continuous energy functional for the extensible Euler beam model ( Elastica) in large deformation regime. A relative compactness result for the sequence En is also proven. Moreover, numerical results are shown on the deformed shape and on the total energy of the system when the number of elements of the discrete system increases. The numerical convergence of the energy to a definite value is shown in two cases. The results provide rigorous justification of a very commonly used algorithm for the discretization of the extensible Euler beam, namely Hencky-type beam model.

  12. Extensional Late Paleozoic deformation on the western margin of Pangea, Patlanoaya area, Acatlán Complex, southern Mexico

    Ramos-Arias, M. A.; Keppie, J. D.; Ortega-Rivera, A.; Lee, J. W. K.


    earliest cleavage in the Las Minas unit yielded a plateau age of 347 ± 3 Ma and show low temperature ages of ˜ 260 Ma. Post-dating all of these structures and the Patlanoaya Group are NE-plunging, subvertical folds and kink bands. An E-W, vertical normal fault juxtaposes the low-grade rocks against the Anacahuite amphibolite that is cut by megacrystic granite sheets, both of which were deformed by two penetrative fabrics. Amphibole from this unit has yielded a 40Ar/ 39Ar plateau age of 299 ± 6 Ma, which records cooling through ˜ 490 °C and is probably related to a Permo-Carboniferous reheating event during exhumation. The extensional deformation is inferred to have started in the latest Devonian (˜ 360 Ma) during deposition of the basal Patlanoaya Group, lasting through the rapid exhumation of the Piaxtla Suite at ˜ 350-340 Ma synchronous with cleavage development in the Las Minas unit, deposition of the Patlanoaya Group with active fault-related exhumation suggested by Mississippian and Early Permian conglomerates (˜ 340 and 300 Ma, respectively), and continuing at least into the Middle Permian (≡ 260 Ma muscovite ages). The continuity of Mid-Continent Mississippian fauna from the USA to southern Mexico suggests that this extensional deformation occurred on the western margin of Pangea after closure of the Rheic Ocean.

  13. Extensional deformation of post ultrahigh-pressure metamorphism and exhumation process of ultrahigh-pressure metamorphic rocks in the Dabie massif,China

    索书田; 钟增球; 游振东


    A detailed tectonic analysis demonstrates that the present ob served regional tectonic configuration of the ultrahigh-pressure metamorphic terrane in the Da bie massif was mainly formed by the extension processes of the post-lndosinian continent-continent oblique collision between the Sino-Korean and V’angtze cratons and ultrahigh-pressure metamorphism (UHPM). The configuration is characterized by a regional tectonic pattern similar to metamorphic core complexes and by the development of multi-layered detachment zones. On the basis of the identification of compressional and extensional fabrics, it is indicated that the exhumation and uplift of ultrahigh-pressure (UHP) metamorphic rocks from the mantle depth to the surface can be divided into at least three different decompression retrogressive metamo rphism and tectonic deformation stages, in which the subhorizontal crustal-scale extensional flow in the middle-lower crust under amphibolite facies conditions is an important geodynamic process in the exhu

  14. Extensional deformation of post ultrahigh-pressure metamorphism and exhumation process of ultrahigh-pressure metamorphic rocks in the Dabie massif, China


    A detailed tectonic analysis demonstrates that the present observed regional tectonic configuration of the ultrahigh-pressure metamorphic terrane in the Dabie massif was mainly formed by the extension processes of the post-Indosinian continent-continent oblique collision between the Sino-Korean and Yangtze cratons and ultrahigh-pressure metamorphism (UHPM). The configuration is characterized by a regional tectonic pattern similar to metamorphic core complexes and by the development of multi-layered detachment zones. On the basis of the identification of compressional and extensional fabrics, it is indicated that the exhumation and uplift of ultrahigh-pressure (UHP) metamorphic rocks from the mantle depth to the surface can be divided into at least three different decompression retrogressive metamorphism and tectonic deformation stages, in which the subhorizontal crustal-scale extensional flow in the middle-lower crust under amphibolite facies conditions is an important geodynamic process in the exhumation of UHP metamorphic rocks. Moreover, the extensional flow is probably driven by delamination and magmatic underplating of thickened lithospheric mantle following the continental oblique collision.

  15. Spatio-temporal characteristics of acoustic emission during the deformation of rock samples with compressional and extensional en-echelon faults

    蒋海昆; 马胜利; 张流; 侯海峰; 曹文海


    The spatio-temporal characteristics of acoustic emission (AE) during the deformation of rock samples with compressional and extensional en-echelon faults have been studied. The results show that the pre-existing structure can significantly influence the patterns of AE spatial distribution. With increasing of differential stress, AE events firstly cluster around the two ends of pre-existing faults inside the jog and then along the line joining the two ends. The biggish AE events often occur around one end repeatedly. The image of AE clusters indicates the direction and the area of the fracture propagation. The direction of the macroscopic fracture in extensional and compressional jogs is perpendicular and parallel to the direction of axial stress, respectively. The weakening process before the fracturing of jog area is remarkable, and one of the typical precursors for the instability is that the cumulative frequency of AE events increases exponentially. After the fracturing of the jog the frequency and releasing strain energy of AE events decrease gradually. During the friction period, there is no precursory increasing of AE activity before the big stick-slip events. The change of b value in jog shows a typical change of "decreasing tendentiously →returning quickly" before the instability. The decrease of b value occurs in the process of stress increasing and sometime goes down to the weakening stage, and the quick increase b values appears in a short time just before the instability. The comparative analysis shows that the difference in b value due to the different structures is larger than b value variation caused by increase of the differential stress. For the same sample, the temporal sequence of AE is strongly affected by the mechanical state, and the high loading velocity corresponds to the high release rate of strain energy and low b value. Due to its lower failure strength, the broken area is sensitive to small changes in differential stress. Therefore, it

  16. Geometry and kinematics of extensional structural wedges

    Gui, Baoling; He, Dengfa; Zhang, Yongsheng; Sun, Yanpeng; Huang, Jingyi; Zhang, Wenjun


    Structural wedges in the compressive environment have been recognized and studied in different locations. However, extension structural wedges are less well-understood. Based on the normal fault-bend folding theory and inclined shear model, this paper quantitatively analyses deformations related to extensional structural wedges and builds a series of geometric models for them. An extensional structural wedge is a fault-block held by two or more normal faults, the action of which would fold its overlying strata. Extensional structural wedges of different shapes will lead to different deformation results for the overlying strata, and this paper illustrates both the triangular and quadrangular wedges and their related deformations. This paper also discusses differences between the extensional structural wedges and the normal fault-bend-folding. By analysing two seismic sections from Langfang-Gu'an Sag, East China, this paper provides two natural examples of the triangular and quadrangular extensional structural wedges, where the models can reasonably explain the overlying distinct highs and lows without obvious faults. The establishment of a geometric model of extensional structural wedges can provide reference and theoretical bases for future quantitative analysis of deformations in the extensional environment.

  17. Map pattern and paleostress analysis of extensional faults deforming the Quaternary coral-reef deposits of the southeastern Dominican Republic: Implications for earthquake hazard

    Garcia-Senz, J.; Escuder-Viruete, J.; Perez-Estaun, A.


    uniform stress in the source region, the obtained regional stress ellipsoid that best fit these focal mechanisms is characterized by σ1: 06/348 (plunge, trend) and σ3: 68/172. These results suggest that a compressional to reverse strike-slip type of deformation affects the deep lithosphere of the southeastern Dominican Republic. In conclusion, the studied system of extensional faults is active and differs from the transpressive structures present in western, central and northern Hispaniola. Field evidences point to an extensional stress field affecting the uppermost crustal level, as in the Mona Passage. In contrast, the interpretation of seismicity, fault plane solutions and deep seismic reflection data suggests a compressional to reverse strike-slip stress regime affecting the deep subducting lithospheres. Historical description of destructive earthquakes, field evidences of seismites in the Late Pleistocene reef terraces, and the almost daily seismic activity are indicative of a seismic risk still not yet assessed in southeastern Dominican Republic.

  18. Geochronology Intermediary Laboratory implantation at the Rio Grande do Norte Federal University: the dating of the Serrinha Granitoid (RN) and the correlate Brasiliana extensional deformation; Implantacao do Laboratorio Intermediario de Geocronologia na UFRN: a datacao do granitoide de Serrinha (RN) e da deformacao extensional brasiliana correlata

    Macedo, Maria Helena F.; Sa, Emanuel F. Jardim de; Souza, Zorano S. [Pernambuco Univ., Recife, PE (Brazil). Nucleo de Pesquisa em Geodinamica e Geofisica; Mendes, Franklin S. [Pernambuco Univ., Recife, PE (Brazil). Curso de Quimica; Ramalho, Karlos A.C. [Pernambuco Univ., Recife, PE (Brazil). Curso de Geologia


    The article describes the activities developed by the Geochronology Intermediary Laboratory at the Federal University of the Rio Grande do Norte, a Brazilian university, where there were the preoccupation of establishing strategies for a geochronological development. It relates the Rubidium-Strontium (Rb/Sr) and Samarium-Neodymium (Sm/Nd) methods, describing the analysis realized in these methodologies. Afterward, it presents the geological and petrographic situation of the Granitoide de Serrinha, located at Rio Grande do Norte State, Brazil and its geochronological data 8 refs., 2 figs.

  19. Producao de fitomassa e acumulo de nutrientes pela aveia-preta em funcao da aplicacao de calcario e gesso em superficie na implantacao do sistema plantio direto

    Peres Soratto, Rogerio; Costa Crusciol, Carlos Alexandre


    Com o objetivo de avaliar a influencia da aplicacao de calcario e gesso em superficie, na implantacao do sistema plantio direto, sobre a producao de materia seca e ciclagem de nutrientes pela aveia...

  20. Shear zones developed between extensional and compressional tectonic regimes: recent deformation of the Burdur Fethiye Shear Zone as a case study

    Elitez, İrem; Yaltırak, Cenk; Aktuǧ, Bahadır


    The southwestern Turkey is one of the most tectonically active areas of the eastern Mediterranean and therefore is a controversial region from the geodynamic point of view. This complex tectonic regime is dominated by the westward escape of Anatolia related to North Anatolian Fault, Aegean back-arc extension regime due to roll-back of Hellenic Arc, the subduction transform edge propagator (STEP) fault zone related to the motion of Hellenic and Cyprus arcs and compressional regime of Tauride Mountains. In addition to that, an active subduction and seamounts moving towards the north determine the tectonic frame of the Eastern Mediterranean. Many researchers suggest either the existence of a single left lateral fault or the nonexistence of a fault zone between Western Anatolia and Western Taurides. According to the integration of digital elevation data, non-commercial GoogleEarth satellite images and field studies, a 300 km-long 75-90 km-wide NE-SW-trending left lateral shear zone, the Burdur-Fethiye Shear Zone, is located among these tectonic structures. By using GPS velocities and focal mechanism solutions of earthquakes, it is understood that most of the previous studies turn a blind eye to the hundreds of faults related to a left-lateral shear zone which will have an important role in the Mediterrenean tectonics. The Burdur-Fethiye Shear Zone is like a zipper driven by the relative velocity differences due to the Aegean back-arc extensional system and Western Taurides compressional region and presents a high seismic activity. The GPS vectors reflect remarkable velocity differences on land and relatedly the significant topographic differences can be clearly observed. According to the GPS vectors, the Aegean region moves 4-12 mm/yr faster than the wesward escape of the Anatolia towards southwest and the velocities are low in the Western Taurides. The left-lateral differential motion across the Burdur-Fethiye Shear Zone varies from 3-4 mm/yr in the north side to 8

  1. Modelización de la deformación extensional ocasionada por el avance catastrófico (surge del glaciar Horcones Inferior, Aconcagua, Mendoza Modelling of the extensional deformation caused by the catastrophic advance (surge of the lower Horcones Glacier, Mendoza

    Juan P. Milana


    mechanisms involved in this surge. This is possible because the glacier had a continuous debris cover over its top, previous to the surge-driven deformation. After the surge, the glacier surface was characterised by evenly separated and equally rotated blocks, pointing to a possible domino-like fault system. The inclination of the limiting faults and the block rotation, were used to estimate glacier stretching under a domino system. Besites, values of glacier-front advance and glacier thinning offer two other ways to control roughly the extension of the system. All these data suggest that a domino system was considered insufficient to explain the minimum amount of stretching observed. Instead, the deformation has been interpreted as being caused by a system of linked planar rotational extensional faults, using a model that explains equally rotated blocks by applying an important amount of internal shear within each block. The deformation of a glacier in relation to a fault system linked to a basal detachment explains the fast advance of the glacier and provides a reasonable explanation for the origin of this event, which was a gravitational collapse produced by an unbalanced accumulation in the up-glacier area with respect to the normal glacier flow. This model explains the initiation of the collapse but does not explain the fast basal sliding. This instead, is interpreted as being related to a phenomenon comparable to a linked-cavity system or a high-pore pressure due to the possibility that this glacier slides over a soft-bed.

  2. Asymmetric Vesicle Instability in Extensional Flow

    Spann, Andrew; Zhao, Hong; Shaqfeh, Eric


    Previous researchers have chronicled the breakup of drops in an extensional flow as they stretch into a dumbbell shape with a long thin neck. Motivated by recent experimental observations, we study an apparently similar problem with vesicles, which are deformable but incompressible membranes that conserve area and volume. First, we simulate vesicles in an unbounded uniaxial extensional flow which are given general radial perturbations from an initially stable symmetric equilibrium state. For sufficiently low reduced volume (outer viscosity) there exists a capillary number at which an asymmetric perturbation mode will grow, resulting in the formation of an asymmetric dumbbell shape with a thin connecting cylindrical bridge analogous to the shapes associated with drop breakup. Our simulations help elucidate a mechanism for this instability based on a competition between internal pressure differentials in the vesicle resulting from the membrane bending force and ambient flow. We compare and contrast this transition to the ``standard'' drop breakup transition. Funded by NSF GRFP and Stanford Graduate Fellowship.

  3. Transient Overshoot Extensional Rheology: Experimental and Numerical Comparisons

    Hoyle, David; Huang, Qian; Auhl, Dietmar

    rheometer (FSR) and the cross-slot extensional rheometer (CSER). The first two are uni-axial stretching rheometers and the third is a planar extensional rheometer. The FSR and CSER are capable of achieving steady state flows, although in different strain-rate regimes. The SER has been a widely adopted tool....... Although we are comparing uni-axial to planar flow, these flows produce the same polymer deformation and hence stress in the strain hardening regime. The techniques show a good quantitative agreement where the two experimental windows overlap. In comparing the FSR to the CSER we are able to explain...

  4. Quantum Ontology and Extensional Mereology

    Calosi, Claudio; Fano, Vincenzo; Tarozzi, Gino


    The present paper has three closely related aims. We first argue that Agazzi's scientific realism about Quantum Mechanics is in line with Selleri's and Tarozzi's proposal of Quantum Waves. We then go on to formulate rigorously different metaphysical principles such as property compositional determinateness and mereological extensionalism. We argue that, contrary to widespread agreement, realism about Quantum Mechanics actually refutes only the former. Indeed we even formulate a new quantum mechanical argument in favor of extensionalism. We conclude by noting that, given the results of the work, Agazzi's particular attitude towards Quantum Mechanics is still one of the most promising theoretical perspectives.

  5. An outline of tectonic, igneous, and metamorphic events in the Goshute-Toano Range between Silver Zone Pass and White Horse Pass, Elko County, Nevada; a history of superposed contractional and extensional deformation

    Ketner, Keith Brindley; Day, Warren C.; Elrick, Maya; Vaag, Myra K.; Zimmerman, Robert A.; Snee, Lawrence W.; Saltus, Richard W.; Repetski, John E.; Wardlaw, Bruce R.; Taylor, Michael E.; Harris, Anita G.


    Seven kinds of fault-bounded tracts are described. One of the tracts provides a good example of Mesozoic contractional folding and faulting; six exemplify various aspects of Miocene extensional faulting. Massive landslide deposits resulting from Tertiary faulting are described. Mesozoic intrusive rocks and extensive exposures of Miocene volcanic rocks are described and dated. The age ranges of stratigraphic units were based on numerous conodont collections, and ages of igneous rocks were determined by argon/argon and fission-track methods. The geologic complexity of the Goshute-Toano Range provides opportunities for many additional productive structural studies.

  6. Pressure Effect on Extensional Viscosity

    Christensen, Jens Horslund; Kjær, Erik Michael


    The primary object of these experiments was to investigate the influence of hydrostatic pressure on entrance flow. The effect of pressure on shear and extensional viscosity was evaluated using an axis symmetric capillary and a slit die where the hydrostatic pressure was raised with valves...

  7. Sandbox Modeling of the Fault-increment Pattern in Extensional Basins

    Geng Changbo; Tong Hengmao; He Yudan; Wei Chunguang


    Three series of sandbox modeling experiments were performed to study the fault-increment pattern in extensional basins.Experimental results showed that the tectonic action mode of boundaries and the shape of major boundary faults control the formation and evolution of faults in extensional basins.In the process of extensional deformation,the increase in the number and length of faults was episodic,and every 'episode' experienced three periods,strain-accumulation period,quick fault-increment period and strain-adjustment period.The more complex the shape of the boundary fault,the higher the strain increment each 'episode' experienced.Different extensional modes resulted in different fault-increment patterns.The horizontal detachment extensional mode has the 'linear' style of fault-increment pattern,while the extensional mode controlled by a listric fault has the 'stepwise' style of fault-increment pattern,and the extensional mode controlled by a ramp-flat boundary fault has the 'stepwise-linear' style of fault-increment pattern.These fault-increment patterns given above could provide a theoretical method of fault interpretation and fracture prediction in extensional basins.

  8. Deriving Extensional Spatial Composition Tables

    El-Geresy, Baher; Abdelmoty, Alia I.; Ware, Andrew J.

    Spatial composition tables are fundamental tools for the realisation of qualitative spatial reasoning techniques. Studying the properties of these tables in relation to the spatial calculi they are based on is essential for understanding the applicability of these calculi and how they can be extended and generalised. An extensional interpretation of a spatial composition table is an important property that has been studied in the literature and is used to determine the validity of the table for the models it is proposed for. It provides means for consistency checking of ground sets of relations and for addressing spatial constraint satisfaction problems. Furthermore, two general conditions that can be used to test for extensionality of spatial composition tables are proposed and applied to the RCC8 composition table to verify the allowable models in this calculus.

  9. Extensionality of simply typed logic programs

    M.A. Bezem


    textabstractWe set up a framework for the study of extensionality in the context of higher-order logic programming. For simply typed logic programs we propose a novel declarative semantics, consisting of a model class with a semi-computable initial model, and a notion of extensionality. We show that

  10. Shear and extensional properties of bread doughs affected by their minor components

    Rouillé, J.; Valle, Della G.; Lefebvre, J.; Sliwinski, E.L.; Vliet, van T.


    The importance of the soluble fraction in flour in determining the rheological properties of dough subjected to large deformations and its possible consequence for breadmaking performance was investigated by measuring shear and extensional viscosities of native wheat flour and reconstituted doughs

  11. Extensional Information Articulation from the Universe

    Yasufumi Saruwatari


    Full Text Available Information must have physical support and this physical universe comprisesphysical interactions. Hence actual information processes should have a description byinteractions alone, i.e., an extensional description. In this paper, such a model of the processof information articulation from the universe is developed by generalizing the extensivemeasurement theory in metrology. Moreover, a model of the attribute creation processis presented to exemplify a step of the informational articulation process. These modelsdemonstrate the valuableness of the extensional view and are expected to enhance theunderstanding of the extensional aspects of fundamentals of information.

  12. Extensional scientific realism vs. intensional scientific realism.

    Park, Seungbae


    Extensional scientific realism is the view that each believable scientific theory is supported by the unique first-order evidence for it and that if we want to believe that it is true, we should rely on its unique first-order evidence. In contrast, intensional scientific realism is the view that all believable scientific theories have a common feature and that we should rely on it to determine whether a theory is believable or not. Fitzpatrick argues that extensional realism is immune, while intensional realism is not, to the pessimistic induction. I reply that if extensional realism overcomes the pessimistic induction at all, that is because it implicitly relies on the theoretical resource of intensional realism. I also argue that extensional realism, by nature, cannot embed a criterion for distinguishing between believable and unbelievable theories.

  13. Capillary break-up, gelation and extensional rheology of hydrophobically modified cellulose ethers

    Sharma, Vivek; Haward, Simon; Pessinet, Olivia; Soderlund, Asa; Threlfall-Holmes, Phil; McKinley, Gareth


    Cellulose derivatives containing associating hydrophobic groups along their hydrophilic polysaccharide backbone are used extensively in the formulations for inks, water-borne paints, food, nasal sprays, cosmetics, insecticides, fertilizers and bio-assays to control the rheology and processing behavior of multi-component dispersions. These complex dispersions are processed and used over a broad range of shear and extensional rates. The presence of hydrophobic stickers influences the linear and nonlinear rheology of cellulose ether solutions. In this talk, we systematically contrast the difference in the shear and extensional rheology of a cellulose ether: ethy-hydroxyethyl-cellulose (EHEC) and its hydrophobically-modified analog (HMEHEC) using microfluidic shear rheometry at deformation rates up to 10^6 inverse seconds, cross-slot flow extensional rheometry and capillary break-up during jetting as a rheometric technique. Additionally, we provide a constitutive model based on fractional calculus to describe the physical gelation in HMEHEC solutions.

  14. Extensional unroofing of the Veliki Jastrebac dome (Serbia

    Marović Milun


    Full Text Available This paper presents the basic structural elements of the dome of Veliki Jastrebac, as well as the chronology and mechanisms of the deformational events responsible for its formation. It was determined that the dome of Veliki Jastrebac consists of two large sequences which are, in the vertical section, in the inverse position. The lower part is made of Late Cretaceous and Cretaceous-Palaeogene low-grade to medium-grade metamorphic rocks, which are intruded by Paleogene granitoid (probably the Vardar Zone, which are covered with a large overthrust consisting metamorphics of the Serbian-Macedonian Mass. The low-grade to medium-grade metamorphosed complex of Veliki Jastrebac, with the granitoid, represents a metamorphic core complex, exhumed by mechanisms of extensional tectonics in the Paleogene.

  15. Transpressive inversion of a Mesozoic extensional forced fold system with an intermediate décollement level in the Basque-Cantabrian Basin (Spain)

    Tavani, Stefano; Carola, Eloi; Granado, Pablo; Quintã, Anna; MuñOz, Josep Anton


    In the Basque-Cantabrian Basin (Spain), normal faulting and associated folding occurred during Late Jurassic to Early Cretaceous rifting. Cenozoic Pyrenean thick-skinned transpressive inversion in the western parts of the basin preserved the first-order extensional architecture. Integration of geological maps and seismic profiles has permitted to fully constrain the style of extensional deformation and subsequent inversion in the western portion of the Basque-Cantabrian Basin. Extensional faults offset the Paleozoic basement up to Lower Triassic rocks. The presence of an efficient décollement level represented by Triassic evaporites produced the decoupling between basement rocks and the Upper Triassic to Middle Jurassic prerift cover sequence. Extensional forced folding occurred in the cover, driven by basement faulting and the migration of evaporites toward the hanging wall of the extensional faults, with salt welds developing away from them. Upper Jurassic to Lower Cretaceous syn-rift sediments deposited synchronously with forced folding, which led to the development of extensional growth geometries associated with both master faults and nearly-transverse faults. Syn-rift growth sequences are characterized by downlap and onlap relationships with the underlying prerift units, interpreted as the result of along-strike variations of master fault extensional displacement rate. Cenozoic Pyrenean contraction generated the right-lateral transpressive inversion of basement master faults and the almost dip-slip reactivation of transverse extensional faults.

  16. Extensional Information Articulation from the Universe

    Yasufumi Saruwatari; Makoto Yoshitake


    Information must have physical support and this physical universe comprisesphysical interactions. Hence actual information processes should have a description byinteractions alone, i.e., an extensional description. In this paper, such a model of the processof information articulation from the universe is developed by generalizing the extensivemeasurement theory in metrology. Moreover, a model of the attribute creation processis presented to exemplify a step of the informational articulation p...

  17. An Extensional CPS Transform (Preliminary Report)

    Filinski, Andrzej


    We shoe that, in a language wihg general continuation-effects, the syntactic, or intensional, CPS transform is mirrored by a semantic, or extensional, functional term. In other words, form only the observable behavior any direct-style term (possibly containing the usual first-class continuation...... primitives), we can uniformly extract the observable behavior of its CPS counterpart. As a consequence of this result, we show that the computational lambda-calculus is complete for observational equivalence of pure, simply typed lambda-terms in Scheme-like contexts....

  18. Hyperbolic contraction measuring systems for extensional flow

    Nyström, M.; Tamaddon Jahromi, H. R.; Stading, M.; Webster, M. F.


    In this paper an experimental method for extensional measurements on medium viscosity fluids in contraction flow is evaluated through numerical simulations and experimental measurements. This measuring technique measures the pressure drop over a hyperbolic contraction, caused by fluid extension and fluid shear, where the extensional component is assumed to dominate. The present evaluative work advances our previous studies on this experimental method by introducing several contraction ratios and addressing different constitutive models of varying shear and extensional response. The constitutive models included are those of the constant viscosity Oldroyd-B and FENE-CR models, and the shear-thinning LPTT model. Examining the results, the impact of shear and first normal stress difference on the measured pressure drop are studied through numerical pressure drop predictions. In addition, stream function patterns are investigated to detect vortex development and influence of contraction ratio. The numerical predictions are further related to experimental measurements for the flow through a 15:1 contraction ratio with three different test fluids. The measured pressure drops are observed to exhibit the same trends as predicted in the numerical simulations, offering close correlation and tight predictive windows for experimental data capture. This result has demonstrated that the hyperbolic contraction flow is well able to detect such elastic fluid properties and that this is matched by numerical predictions in evaluation of their flow response. The hyperbolical contraction flow technique is commended for its distinct benefits: it is straightforward and simple to perform, the Hencky strain can be set by changing contraction ratio, non-homogeneous fluids can be tested, and one can directly determine the degree of elastic fluid behaviour. Based on matching of viscometric extensional viscosity response for FENE-CR and LPTT models, a decline is predicted in pressure drop for

  19. Hyperbolic contraction measuring systems for extensional flow

    Nyström, M.; Tamaddon Jahromi, H. R.; Stading, M.; Webster, M. F.


    In this paper an experimental method for extensional measurements on medium viscosity fluids in contraction flow is evaluated through numerical simulations and experimental measurements. This measuring technique measures the pressure drop over a hyperbolic contraction, caused by fluid extension and fluid shear, where the extensional component is assumed to dominate. The present evaluative work advances our previous studies on this experimental method by introducing several contraction ratios and addressing different constitutive models of varying shear and extensional response. The constitutive models included are those of the constant viscosity Oldroyd-B and FENE-CR models, and the shear-thinning LPTT model. Examining the results, the impact of shear and first normal stress difference on the measured pressure drop are studied through numerical pressure drop predictions. In addition, stream function patterns are investigated to detect vortex development and influence of contraction ratio. The numerical predictions are further related to experimental measurements for the flow through a 15:1 contraction ratio with three different test fluids. The measured pressure drops are observed to exhibit the same trends as predicted in the numerical simulations, offering close correlation and tight predictive windows for experimental data capture. This result has demonstrated that the hyperbolic contraction flow is well able to detect such elastic fluid properties and that this is matched by numerical predictions in evaluation of their flow response. The hyperbolical contraction flow technique is commended for its distinct benefits: it is straightforward and simple to perform, the Hencky strain can be set by changing contraction ratio, non-homogeneous fluids can be tested, and one can directly determine the degree of elastic fluid behaviour. Based on matching of viscometric extensional viscosity response for FENE-CR and LPTT models, a decline is predicted in pressure drop for

  20. An Extensional CPS Transform (Preliminary Report)

    Filinski, Andrzej


    We shoe that, in a language wihg general continuation-effects, the syntactic, or intensional, CPS transform is mirrored by a semantic, or extensional, functional term. In other words, form only the observable behavior any direct-style term (possibly containing the usual first-class continuation...... primitives), we can uniformly extract the observable behavior of its CPS counterpart. As a consequence of this result, we show that the computational lambda-calculus is complete for observational equivalence of pure, simply typed lambda-terms in Scheme-like contexts....

  1. Extensional rheometry with a handheld mobile device

    Marshall, Kristin A.; Liedtke, Aleesha M.; Todt, Anika H.; Walker, Travis W.


    The on-site characterization of complex fluids is important for a number of academic and industrial applications. Consequently, a need exists to develop portable rheometers that can provide in the field diagnostics and serve as tools for rapid quality assurance. With the advancement of smartphone technology and the widespread global ownership of smart devices, mobile applications are attractive as platforms for rheological characterization. The present work investigates the use of a smartphone device for the extensional characterization of a series of Boger fluids composed of glycerol/water and poly(ethylene oxide), taking advantage of the increasing high-speed video capabilities (currently up to 240 Hz capture rate at 720p) of smartphone cameras. We report a noticeable difference in the characterization of samples with slight variations in polymer concentration and discuss current device limitations. Potential benefits of a handheld extensional rheometer include its use as a point-of-care diagnostic tool, especially in developing communities, as well as a simple and inexpensive tool for assessing product quality in industry.

  2. Extensional properties of mobile polymer solutions

    Tirel, Christophe; Renoult, Marie-Charlotte; Dumouchel, Christophe; Crumeyrolle, Olivier; Lisiecki, Denis; Mutabazi, Innocent


    A deep understanding of the influence of viscoelasticity on the dynamics of liquid flows remains a challenge in the non-Newtonian fluid mechanics field. Previous work has revealed that the addition of minute amount (2.5 part per million) of high molecular weight polymer to water, forming a viscoelastic solution with strong extensional properties, modifies the fission process during droplet snap off with spectacular effects: inhibition of the singularity observed in the reference Newtonian case and formation of a long-lived (milli-second) filament. The measurement of the extensional properties for such mobile polymer solutions is one of the most pressing problem. Here, a global measurement technique, based on the multi-scale analysis of the capillary instability of a free falling jet of a mobile polymer solution, is introduced. The method of analysis allows the characterisation of the jet breakup mechanism from which the relaxation time of the polymer solution can be extracted. One of the advantages of the technique is the simple experiment it requires.

  3. Dumbbell formation for elastic capsules in nonlinear extensional Stokes flows

    Dimitrakopoulos, P.


    Cross-slot and four-roll-mill microdevices are commonly used for particle manipulation and characterization owing to the stagnation-point flow at the device center. Because of the solid boundaries, these devices may generate extensional Stokes flows where the velocity is a nonlinear function of position associated with a decreased pressure at the particle edges and an increased pressure at the particle middle. Our computational investigation shows that in this class of Stokes flows, an elastic capsule made of a strain-hardening membrane develops two distinct steady-state conformations at strong flows, i.e., an elongated weak dumbbell shape with rounded edges at low flow nonlinearity and a laterally extended dumbbell shape at high flow nonlinearity. These effects are more pronounced for the less strain-hardening capsules which develop a flat extended middle where the two sides of the membrane approach each other. The strong stability properties of the strain-hardening capsules (owing to the development of strong membrane tensions) contrast significantly with the behavior of droplets in these nonlinear flows which are unable to achieve highly deformed steady-state dumbbell shapes owing to their constant surface tension.

  4. A Note on Spector's Quantifier-Free Rule of Extensionality

    Kohlenbach, Ulrich


     In this note we show that the so-called weakly extensional arithmetic in all finite types, which is based on a quantifier-free rule of extensionality due to C. Spector and which is of significance in the context of Gödel’s functional interpretation, does not satisfy the deduction theorem...

  5. 3D modeling of dual wind-up extensional rheometers

    Yu, Kaijia; Román Marín, José Manuel; Rasmussen, Henrik K.


    Fully three-dimensional numerical simulations of a dual wind-up drum rheometer of the Sentmanat Extensional Rheometer (SER; Sentmanat, 2004 [1]) or the Extensional Viscosity Fixture (EVF; Garritano and Berting, 2006 [2]) type have been performed. In the SER and EVF a strip of rectangular shape is...

  6. Paleoproterozoic Extensional Structure and Its Controlling on Mineralization in the East of Liaoning Province

    Yang Zhongzhu; Chen Shuliang; Li Xiandong; Wang Zhongjiang; Qu Hongxiang; Gang Jiang


    The palaeoproterozoic extensional structure in the east of Liaoning Province underwent sub - bedding ductile shear flowing deformation with metamorphism and magmatic emplacement. The reversal structure following the processes constructed the present framework of palaeoproterozoic orogenic belt. As a result of the ductile shearing along the layers, the gold in the Liaohe group was activated, migrated upward to the interface between the Dashiqiao rock formation, which was lower green schist facies and the Gaixian rock formation, so the gold deposit was formed in the space of brittle - ductile shear zone as ductile - shear - zone - typed stratabound gold deposit.

  7. Extremely Shallow Extensional Faulting Near Geothermal Fields

    Hudnut, K. W.; Wei, S.; Donnellan, A.; Fielding, E. J.; Graves, R. W.; Helmberger, D. V.; Liu, Z.; Parker, J. W.; Treiman, J. A.


    Surface faulting has been discovered in association with a shallow extensional M 4.9 earthquake, the source properties of which have also been studied by modeling of broadband seismic data and geodetic imagery. This M 4.9 and also a M 4.6 shallow normal event occurred late in the Brawley Swarm of August 2012, a dominantly strike-slip sequence with events up to M 5.5 (Hauksson et al., SRL 2013 and Wei et al., GRL 2013). The point source waveform inversions reveal normal mechanisms and centroid depths of ~2.5 km for both events, while the modeling of the geodetic data indicates a compatible depth of ~2.0 km. The M 4.9 event had unusually large (~40 cm) and sudden (~1.0 - 1.5 km/sec) slip, considering its extremely shallow depth. The earlier and larger strike-slip events during the Aug. 2012 swarm were on a left-lateral SW-NE oriented vertical planar cross-fault, whereas the M 4.6 and M 4.9 occurred on a SSW-NNE oriented, west-dipping plane. Airborne imagery obtained using Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) revealed a surface fault rupture that was subsequently confirmed and documented in the field in May 2013. A pre-existing but previously un-mapped fault sustained west-down surface slip of up to 18 × 2 cm along breaks extending ~3.5 km along a NNE orientation, and ruptured beneath and under a railroad track and pipeline (without breaking them). UAVSAR and seismological data were used jointly to image the source properties of the M 4.9 earthquake in detail. Typically, the uppermost few kms of right-lateral faults in the Salton Trough exhibit creep, especially after larger earthquakes, as in 1979 and 1987. On this basis, general models of stable sliding within the uppermost few kms have been developed. In this case, however, the joint inversion indicates that seismic energy was radiated by slip of up to 40 cm on a fault plane extending from the surface to a depth of only ~3 km, extending ~4 km along-strike, and dipping ~45° west, with west

  8. Discrete element modeling of Martian pit crater formation in response to extensional fracturing and dilational normal faulting

    Smart, Kevin J.; Wyrick, Danielle Y.; Ferrill, David A.


    Pit craters, circular to elliptical depressions that lack a raised rim or ejecta deposits, are common on the surface of Mars. Similar structures are also found on Earth, Venus, the Moon, and smaller planetary bodies, including some asteroids. While it is generally accepted that these pits form in response to material drainage into a subsurface void space, the primary mechanism(s) responsible for creating the void is a subject of debate. Previously proposed mechanisms include collapse into lave tubes, dike injection, extensional fracturing, and dilational normal faulting. In this study, we employ two-dimensional discrete element models to assess both extensional fracturing and dilational normal faulting as mechanisms for forming pit craters. We also examine the effect of mechanical stratigraphy (alternating strong and weak layers) and variation in regolith thickness on pit morphology. Our simulations indicate that both extensional fracturing and dilational normal faulting are viable mechanisms. Both mechanisms lead to generally convex (steepening downward) slope profiles; extensional fracturing results in generally symmetric pits, whereas dilational normal faulting produces strongly asymmetric geometries. Pit width is established early, whereas pit depth increases later in the deformation history. Inclusion of mechanical stratigraphy results in wider and deeper pits, particularly for the dilational normal faulting, and the presence of strong near-surface layers leads to pits with distinct edges as observed on Mars. The modeling results suggest that a thicker regolith leads to wider but shallower pits that are less distinct and may be more difficult to detect in areas of thick regolith.

  9. Factors That Influence the Extensional Rheological Property of Saliva

    Vijay, Amrita; Inui, Taichi; Dodds, Michael; Proctor, Gordon; Carpenter, Guy


    The spinnbarkeit of saliva reflects the ability of saliva to adhere to surfaces within the mouth, thereby serving as a protective role and aiding in lubrication. Therefore, alterations in the extensional rheology of saliva may result in the loss in adhesiveness or the ability to bind onto surfaces. Mucin glycoproteins and their structures are known to be important factors for the extensional rheological properties of saliva. The conformation of mucin depends on factors such as pH and ionic st...

  10. Two-stage partial melting during the Variscan extensional tectonics (Montagne Noire, France)

    Poujol, Marc; Pitra, Pavel; Van Den Driessche, Jean; Tartèse, Romain; Ruffet, Gilles; Paquette, Jean-Louis; Poilvet, Jean-Charles


    One of the striking features that characterise the late stages of the Variscan orogeny is the development of gneiss and migmatite domes, as well as extensional Late Carboniferous and Permian sedimentary basins. It remains a matter of debate whether the formation of domes was related to the well-documented late orogenic extension or to the contractional tectonics that preceded. Migmatization and magmatism are expected to predate extension if the domes are compression-related regional anticlines, but they must both precede and be contemporaneous with extension if they are extensional core complexes. In the Montagne Noire area (southern French Massif Central), where migmatization, magmatism and the deformation framework are well documented, the age of the extensional event was unequivocally constrained to 300-290 Ma. Therefore, dating migmatization in this area is a key point for discriminating between the two hypotheses and understanding the Late Palaeozoic evolution of this part of the Variscan belt. For this purpose, a migmatite and an associated anatectic granite from the Montagne Noire dome were dated by LA-ICP-MS (U-Th-Pb on zircon and monazite) and laser probe 40Ar-39Ar (K-Ar on muscovite). Although zircon did not record any Variscan age unequivocally related to compression (380-330 Ma), two age groups were identified from the monazite crystals. A first event, at ca. 319 Ma (U-Th-Pb on monazite), is interpreted as a first stage of migmatization and as the emplacement age of the granite, respectively. A second event at ca. 298-295 Ma, recorded by monazite (U-Th-Pb) and by the muscovite 40Ar-39Ar system in the migmatite and in the granite, could be interpreted as a fluid-induced event, probably related to a second melting event identified through the syn-extensional emplacement of the nearby Montalet leucogranite ca. 295 Ma ago. The ages of these two events post-date the Variscan compression and agree with an overall extensional context for the development of the


    王世文; 冯继玲; 杨兆建; 连香姣


    This paper describes a general model for the mechanical behavior studying of general wire rope strand. An exact solution of the deformation characteristics was given when the strands is under tensile and torsional loads. The theoretical results are useful in evaluating the extensional and torsional moduli of rigidity for the strands. Finally, a simple design criterion is established for the nonrotating ropes.

  12. Large deformation properties of short doughs: Effect of sucrose in relation to mixing time

    Baltsavias, A.; Jurgens, A.; Vliet, T. van


    Large deformation rheological properties of short doughs of various composition prepared under various mixing times were determined in uniaxial compression. Sucrose-syrup doughs exhibited prominent yielding and flow behaviour. Their apparent biaxial extensional viscosity decreased with increasing su

  13. The newest observational evidence on asymmetrical deformation of the Earth

    黄立人; 马宗晋; 朱建新


    Based on the coordinates, velocities and their error estimations of 595 GPS, SLR and VLBI stations issued by IERS in March 2001, the current asymmetrical deformation of the Earth is studied. The results show that the northern hemisphere of the Earth is undergoing compressive deformation, and the southern hemisphere is undergoing extensional deformation with the equator as the boundary. If the longitude line of 90(E and 90(W is taken as the boundary, the Pacific hemisphere (with 180( as its central longitude) is undergoing compressive deformation, and the Atlantic hemisphere (with 0( as its central longitude) is undergoing extensional deformation. The deformation patterns indicate again that the Earth is undergoing some dual-asymmetrical deformation. Moreover, taking 6 366.740 km as the standard mean curvature radius of the Earth, the velocity of volume change calculated from the data of space geodesy is 6.65(1011 m3/a.

  14. A portable and affordable extensional rheometer for field testing

    Hallmark, Bart; Bryan, Matthew; Bosson, Ed; Butler, Simon; Hoier, Tom; Magens, Ole; Pistre, Nicolas; Pratt, Lee; Ward, Betsy-Ann; Wibberley, Sam; Wilson, D. Ian


    Extensional shear testing is often needed to characterise the behaviour of complex fluids found in industry and nature. Traditional extensional rheometers are typically expensive, fragile and heavy and are only suited to making measurements in a laboratory environment. For some applications, it is necessary to make in situ rheological measurements where, for example, fluid properties change rapidly over time or where laboratory facilities are unavailable. This paper reports the development and validation of an inexpensive, lightweight and robust ‘open source’ extensional rheometer, Seymour II. Validation was carried out experimentally and computationally. Measurements on a Newtonian fluid (492 mPa s Brookfield silicone oil) yielded results of 510  ±  51 mPa s; these are comfortably within the range of  ±10% which other authors have quoted for extensional techniques using laboratory rheometers. Comparison of the observed filament thinning dynamics to those obtained using computational fluid dynamics (CFD) gave good qualitative agreement. Use of Seymour II at the University of Cambridge Botanic Gardens revealed that the mucilage of the ‘crane flower’, Strelitzia reginae, was a viscoelastic fluid whose extensional response could be described by a two-mode Giesekus equation. Engineering drawings and image analysis code for Seymour II are available for download at the project website,

  15. Non-standard coupled extensional and bending bias tests for planar pantographic lattices. Part I: numerical simulations

    Turco, Emilio; Barcz, Katarzyna; Pawlikowski, Marek; Rizzi, Nicola Luigi


    In dell'Isola et al. (Zeitschrift für Angewandte Math und Physik 66(6):3473-3498, 2015, Proc R Soc Lond A Math Phys Eng Sci 472(2185), 2016), the concept of pantographic sheet is proposed. The aim is to design a metamaterial showing: (i) a large range of elastic response; (ii) an extreme toughness in extensional deformation; (iii) a convenient ratio between toughness and weight. However, these required properties must coexist with non-detrimental mechanical characteristics in the presence of other kinds of imposed displacements. The aim of this paper is to prove via numerical simulations that pantographic sheets may effectively resist to coupled bending and extensional deformations. The four-parameter model introduced shows its versatility as it is able to encompass all the considered types of (large) deformations. The numerical integration scheme which we use is based on the same concepts exploited in Turco et al. (Zeitschrift für Angewandte Math und Physik 67(4):1-28, 2016): They prove that the Hencky-type discretization is very efficient also in nonlinear large deformations and large displacements regimes. In Part II of this paper, we will show that the used models are very effective to describe experimental evidence.

  16. Extensional Rheology Experiment Developed to Investigate the Rheology of Dilute Polymer Solutions in Microgravity

    Logsdon, Kirk A.


    A fundamental characteristic of fluid is viscosity; that is, the fluid resists forces that cause it to flow. This characteristic, or parameter, is used by manufacturers and end-users to describe the physical properties of a specific material so that they know what to expect when a material, such as a polymer, is processed through an extruder, a film blower, or a fiber-spinning apparatus. Normally, researchers will report a shear viscosity that depends on the rate of an imposed shearing flow. Although this type of characterization is sufficient for some processes, simple shearing experiments do not provide a complete picture of what a processor may expect for all materials. Extensional stretching flows are common in many polymer-processing operations such as extrusion, blow molding, and fiber spinning. Therefore, knowledge of the complete rheological (ability to flow and be deformed) properties of the polymeric fluid being processed is required to accurately predict and account for the flow behavior. In addition, if numerical simulations are ever able to serve as a priori design tools for optimizing polymer processing operations such as those described above, an accurate knowledge of the extensional viscosity of a polymer system and its variation with temperature, concentration, molecular weight, and strain rate is critical.

  17. The importance of flow history in mixed shear and extensional flows

    Wagner, Caroline; McKinley, Gareth


    Many complex fluid flows of experimental and academic interest exhibit mixed kinematics with regions of shear and elongation. Examples include flows through planar hyperbolic contractions in microfluidic devices and through porous media or geometric arrays. Through the introduction of a ``flow-type parameter'' α which varies between 0 in pure shear and 1 in pure elongation, the local velocity fields of all such mixed flows can be concisely characterized. It is tempting to then consider the local stress field and interpret the local state of stress in a complex fluid in terms of shearing or extensional material functions. However, the material response of such fluids exhibit a fading memory of the entire deformation history. We consider a dilute solution of Hookean dumbbells and solve the Oldroyd-B model to obtain analytic expressions for the entire stress field in any arbitrary mixed flow of constant strain rate and flow-type parameter α. We then consider a more complex flow for which the shear rate is constant but the flow-type parameter α varies periodically in time (reminiscent of flow through a periodic array or through repeated contractions and expansions). We show that the flow history and kinematic sequencing (in terms of whether the flow was initialized as shearing or extensional) is extremely important in determining the ensuing stress field and rate of dissipated energy in the flow, and can only be ignored in the limit of infinitely slow flow variations.

  18. The role of extensional viscosity in frog tongue projection

    Noel, Alexis; Wagner, Caroline; McKinley, Gareth; Mendelson, Joe; Hu, David


    Frogs and other amphibians capture insects through high-speed tongue projection, some achieving tongue accelerations of over fifty times gravity. In this experimental study, we investigate how a frog's sticky saliva enables high-speed prey capture. At the Atlanta zoo, we used high-speed video to film the trajectory of frog tongues during prey capture. We have also designed and built a portable extensional rheometer; by following the capillary-driven thinning in the diameter of a thread of saliva we characterize the relaxation time and extensional viscosity and so infer the adhesive force between the frog tongue and prey.

  19. Late Proterozoic extensional collapse in the Arabian-Nubian Shield

    Blasband, B.B.; White, S H; Brooijmans, P.; Boorder, H. de; Visser, W.


    A structural and petrological study of the Late Proterozoic rocks in the Wadi Kid area, Sinai, Egypt indicates the presence of an extensional metamorphic core complex in the northern Arabian–Nubian Shield. Gneissic domes throughout the Arabian–Nubian Shield resemble the core complex of the Wadi Kid area and as a result, they are interpreted as extensional metamorphic core complexes. The presence of a widespread phase of extension at the end of the Pan-African period in the Arabian–Nubian Shie...

  20. Extensional crustal tectonics and crust-mantle coupling, a view from the geological record

    Jolivet, Laurent; Menant, Armel; Clerc, Camille; Sternai, Pietro; Ringenbach, Jean-Claude; Bellahsen, Nicolas; Leroy, Sylvie; Faccenna, Claudio; Gorini, Christian


    In passive margins or back-arc regions, extensional deformation is often asymmetric, i.e. normal faults or extensional ductile shear zones dip in the same direction over large distances. We examine a number of geological examples in convergent or divergent contexts suggesting that this asymmetry results from a coupling between asthenospheric flow and crustal deformation. This is the case of the Mediterranean back-arc basins, such as the Aegean Sea, the northern Tyrrhenian Sea, the Alboran domain or the Gulf of Lion passive margin. Similar types of observation can be made on some of the Atlantic volcanic passive margins and the Afar region, which were all formed above a mantle plume. We discuss these contexts and search for the main controlling parameters for this asymmetric distributed deformation that imply a simple shear component at the scale of the lithosphere. The different geodynamic settings and tectonic histories of these different examples provide natural case-studies of the different controlling parameters, including a pre-existing heterogeneity of the crust and lithosphere (tectonic heritage) and the possible contribution of the underlying asthenospheric flow through basal drag or basal push. We show that mantle flow can induce deformation in the overlying crust in case of high heat flow and thin lithosphere. In back-arc regions, the cause of asymmetry resides in the relative motion between the asthenosphere below the overriding plate and the crust. When convergence and slab retreat work concurrently the asthenosphere flows faster than the crust toward the trench and the sense of shear is toward the upper plate. When slab retreat is the only cause of subduction, the sense of shear is opposite. In both cases, mantle flow is mostly the consequence of slab retreat and convergence. Mantle flow can however result also from larger-scale convection, controlling rifting dynamics prior to the formation of oceanic crust. In volcanic passive margins, in most cases

  1. Factors That Influence the Extensional Rheological Property of Saliva.

    Vijay, Amrita; Inui, Taichi; Dodds, Michael; Proctor, Gordon; Carpenter, Guy


    The spinnbarkeit of saliva reflects the ability of saliva to adhere to surfaces within the mouth, thereby serving as a protective role and aiding in lubrication. Therefore, alterations in the extensional rheology of saliva may result in the loss in adhesiveness or the ability to bind onto surfaces. Mucin glycoproteins and their structures are known to be important factors for the extensional rheological properties of saliva. The conformation of mucin depends on factors such as pH and ionic strength. Chewing is one of the main stimuli for salivary secretion but creates significant sheer stress on the salivary film which could influence mouthfeel perceptions. The current study investigates the possible factors which affect the extensional rheological properties of saliva by comparing submandibular/sublingual saliva with different oral stimuli within the same group of subjects. Unstimulated and stimulated saliva (chew, smell and taste) salivas were collected primarily from submandibular/sublingual glands. The saliva samples were measured for Spinnbarkeit followed by the measuring mucin, total protein, total calcium and bicarbonate concentrations. The results indicated correlations between rheological properties and mucin/ion concentrations. However, chewing stimulated submandibular/sublingual saliva is shown to have significantly lower Spinnbarkeit, but factors such as mucin, protein and calcium concentrations did not account for this variation. Analysis of the concentration of bicarbonate and pH appears to suggest that it has a prominent effect on extensional rheology of saliva.

  2. Late Proterozoic extensional collapse in the Arabian-Nubian Shield

    Blasband, B.B.; White, S.H.; Brooijmans, P.; Boorder, H. de; Visser, W.


    A structural and petrological study of the Late Proterozoic rocks in the Wadi Kid area, Sinai, Egypt indicates the presence of an extensional metamorphic core complex in the northern Arabian–Nubian Shield. Gneissic domes throughout the Arabian–Nubian Shield resemble the core complex of the Wadi Kid

  3. Factors That Influence the Extensional Rheological Property of Saliva.

    Amrita Vijay

    Full Text Available The spinnbarkeit of saliva reflects the ability of saliva to adhere to surfaces within the mouth, thereby serving as a protective role and aiding in lubrication. Therefore, alterations in the extensional rheology of saliva may result in the loss in adhesiveness or the ability to bind onto surfaces. Mucin glycoproteins and their structures are known to be important factors for the extensional rheological properties of saliva. The conformation of mucin depends on factors such as pH and ionic strength. Chewing is one of the main stimuli for salivary secretion but creates significant sheer stress on the salivary film which could influence mouthfeel perceptions. The current study investigates the possible factors which affect the extensional rheological properties of saliva by comparing submandibular/sublingual saliva with different oral stimuli within the same group of subjects. Unstimulated and stimulated saliva (chew, smell and taste salivas were collected primarily from submandibular/sublingual glands. The saliva samples were measured for Spinnbarkeit followed by the measuring mucin, total protein, total calcium and bicarbonate concentrations. The results indicated correlations between rheological properties and mucin/ion concentrations. However, chewing stimulated submandibular/sublingual saliva is shown to have significantly lower Spinnbarkeit, but factors such as mucin, protein and calcium concentrations did not account for this variation. Analysis of the concentration of bicarbonate and pH appears to suggest that it has a prominent effect on extensional rheology of saliva.

  4. Factors That Influence the Extensional Rheological Property of Saliva

    Vijay, Amrita; Inui, Taichi; Dodds, Michael; Proctor, Gordon; Carpenter, Guy


    The spinnbarkeit of saliva reflects the ability of saliva to adhere to surfaces within the mouth, thereby serving as a protective role and aiding in lubrication. Therefore, alterations in the extensional rheology of saliva may result in the loss in adhesiveness or the ability to bind onto surfaces. Mucin glycoproteins and their structures are known to be important factors for the extensional rheological properties of saliva. The conformation of mucin depends on factors such as pH and ionic strength. Chewing is one of the main stimuli for salivary secretion but creates significant sheer stress on the salivary film which could influence mouthfeel perceptions. The current study investigates the possible factors which affect the extensional rheological properties of saliva by comparing submandibular/sublingual saliva with different oral stimuli within the same group of subjects. Unstimulated and stimulated saliva (chew, smell and taste) salivas were collected primarily from submandibular/sublingual glands. The saliva samples were measured for Spinnbarkeit followed by the measuring mucin, total protein, total calcium and bicarbonate concentrations. The results indicated correlations between rheological properties and mucin/ion concentrations. However, chewing stimulated submandibular/sublingual saliva is shown to have significantly lower Spinnbarkeit, but factors such as mucin, protein and calcium concentrations did not account for this variation. Analysis of the concentration of bicarbonate and pH appears to suggest that it has a prominent effect on extensional rheology of saliva. PMID:26305698

  5. The Pinto shear zone; a Laramide synconvergent extensional shear zone in the Mojave Desert region of the southwestern United States

    Wells, Michael L.; Beyene, Mengesha A.; Spell, Terry L.; Kula, Joseph L.; Miller, David M.; Zanetti, Kathleen A.


    The Pinto shear zone is one of several Late Cretaceous shear zones within the eastern fringe of the Mesozoic magmatic arc of the southwest Cordilleran orogen that developed synchronous with continued plate convergence and backarc shortening. We demonstrate an extensional origin for the shear zone by describing the shear-zone geometry and kinematics, hanging wall deformation style, progressive changes in deformation temperature, and differences in hanging wall and footwall thermal histories. Deformation is constrained between ˜74 and 68 Ma by 40Ar/ 39Ar thermochronology of the exhumed footwall, including multi-diffusion domain modeling of K-feldspar. We discount the interpretations, applied in other areas of the Mojave Desert region, that widespread Late Cretaceous cooling results from refrigeration due to subduction of a shallowly dipping Laramide slab or to erosional denudation, and suggest alternatively that post-intrusion cooling and exhumation by extensional structures are recorded. Widespread crustal melting and magmatism followed by extension and cooling in the Late Cretaceous are most consistent with production of a low-viscosity lower crust during anatexis and/or delamination of mantle lithosphere at the onset of Laramide shallow subduction.

  6. Consistency and axiomatization of a natural extensional combinatory logic



    In the light of a question of J. L. Krivine about the consistency of an extensional λ-theory,an extensional combinatory logic ECL+U(G)+RU_∞+ is established, with its consistency model provedtheoretically and it is shown the it is not equivalent to any system of universal axioms. It is expressed bythe theory in first order logic that, for every given group G of order n, there simultaneously exist infinitelymany universal retractions and a surjective n-tuple notion, such that each element of G acts as a permutationof the components of the n-tuple, and as an Ap-automorphism of the model; further each of the universalretractions is invarian under the action of the Ap-automorphisms induced by G The difference between thetheory and that of Krivine is the G need not be a symmetric group.

  7. Development and modeling of novel extensional ionic polymer transducers

    Akle, Barbar; Wallmersperger, Thomas; Leo, Donald


    Ionic polymer transducers (IPT), sometimes referred to as artificial muscles, are known to generate a large bending strain and a moderate stress at low applied voltages. Bending actuators have limited engineering applications due to the low forcing capabilities and the need for complicated external devices to convert the bending action into rotating or linear motion desired in most devices. Recently Akle and Leo (2006) reported extensional actuation in ionic polymer transducers. Model prediction indicates that such actuators can produce strain up to 10% and a blocked stress up to 20MPa under a +/- 2V applied electric potential. Compared to other smart materials, IPT is a flexible membrane and it has a reliability of over one million cycles. In this work novel extensional IPT actuators are developed for the purpose of increasing the overall displacement of the actuator. The electromechanical coupling is measured and a correlation of the experimental data with the active areas model by Akle and Leo (2006) and the numerical electromechanical model by Wallmersperger and Leo (2004) are presented. The coupling between each test case with the model parameters enables further understanding of the physical actuation phenomena as the role of diffusion of ions and diluents and the electrostatic forces between the charged species. In this study the displacement of an extensional ionic polymer transducer is measured and compared to the bending of the same IPT actuator. The bending strain is measured to be approximately 2.5%, while the extensional strain for the same ionomer is in the order of 17.5%. Finally an interesting behavior, reported for the first time is the steady expansion of the IPT sample due to the application of a symmetrical sine wave. This indicates that charge accumulation is occurring at the electrode.

  8. Tumbling of a Brownian particle in an extensional flow

    Plan, Emmanuel Lance Christopher VI Medillo


    The phenomenon of tumbling of microscopic objects is commonly associated with shear flows. We address the question of whether tumbling can also occur in stretching-dominated flows. To answer this, we study the dynamics of a semi-flexible trumbbell in a planar extensional velocity field. We show that the trumbbell undergoes a random tumbling-through-folding motion. The probability distribution of long tumbling times is exponential with a time scale exponentially increasing with the Weissenberg number.

  9. Non-standard coupled extensional and bending bias tests for planar pantographic lattices. Part II: comparison with experimental evidence

    Turco, Emilio; Barcz, Katarzyna; Rizzi, Nicola Luigi


    In dell'Isola et al. (Zeitschrift für Angewandte Math und Physik 66(6):3473-3498, 2015, Proc R Soc Lond A Math Phys Eng Sci 472(2185):1-23, 2016) pantographic sheets are proposed as a basic constituent for a novel metamaterial. In Part I, see Turco et al. (Zeitschrift für Angewandte Math und Physik, doi: 10.1007/s00033-016-0713-4, 2016), two different numerical models are applied in order to design an experimental setup aimed to prove the effectiveness of introduced concept. The aim of this paper is to prove that the Hencky-type model introduced for planar pantographic sheets allows for the correct prediction, in a large range of imposed displacements, of the experimental measurements concerning specimens undergoing coupled bending and extensional deformations. The four-parameter numerical model introduced is shown to have a large range of applicability: Indeed without changing the values of the material parameters previously attributed in simple extensional tests to a specific specimen by a best-fit procedure, it is possible to forecast its behavior in all the considered type of imposed deformations. The measurements performed include the determination of reactive forces exerted by used hard devices, and the numerical modeling is able to predict very carefully quantitatively and qualitatively also this complex aspect of phenomenology, where previously attempted models seem to have failed.

  10. Extensional extrusion: Insights into south-eastward expansion of Tibetan Plateau from magnetotelluric array data

    Dong, Hao; Wei, Wenbo; Jin, Sheng; Ye, Gaofeng; Zhang, Letian; Jing, Jian'en; Yin, Yaotian; Xie, Chengliang; Jones, Alan G.


    Despite extensive effort over many decades to understand the tectonic evolution of the Tibetan Plateau, the geodynamic processes creating the iconic south-eastward expansion of the plateau at the Eastern Himalayan Syntaxis (EHS) are still unclear and are hotly debated. Two popular (but not necessarily exclusive) geodynamic models, namely crustal flow at mid-to-lower crustal depths and coherent deformation between the crust and lithospheric mantle, are commonly invoked to explain the expansion mechanism. However, neither of these is able to reconcile all of the abundant geological and geophysical data. Here we present a three-dimensional (3D) geo-electrical model, derived from new SINOPROBE magnetotelluric (MT) array data, that reveals the geo-electrical, and by inference rheological, structure of southeast Tibet. Instead of NW-SE conductive channels proposed in prior two-dimensional (2D) MT studies, distinct NNE-SSW directed quasi-linear conductive anomalies are identified in the mid-to-lower crust, which are separated by a large-scale electrically resistive structure that extends from the crust to the upper mantle. This argues against the prior proposed model of south-eastward conductive anomalies, and hence against the southeast lower crust flow of material. To interpret our observations and resultant model, a new mechanism of "extensional extrusion" is proposed to address the lithospheric deformation of the south-eastward expansion of Tibetan Plateau.

  11. Marangoni Effects of a Drop in an Extensional Flow: The Role of Surfactant Physical Chemistry

    Stebe, Kathleen J.; Balasubramaniam, R. (Technical Monitor)


    While the changes in stresses caused by surfactant adsorption on non-deforming interfaces have been fairly well established, prior to this work, there were few studies addressing how surfactants alter stresses on strongly deforming interfaces. We chose the model problem of a drop in a uniaxial extensional flow to study these stress conditions To model surfactant effects at fluid interfaces, a proper description of the dependence of the surface tension on surface concentration, the surface equation of state, is required. We have adopted a surface equation of state that accounts for the maximum coverage limit; that is, because surfactants have a finite cross sectional area, there is an upper bound to the amount of surfactant that can adsorb in a monolayer. The surface tension reduces strongly only when this maximum coverage is approached. Since the Marangoni stresses go as the derivative of the surface equation of state times the surface concentration gradient, the non-linear equation of state determines both the effect of surfactants in the normal stress jump, (which is balanced by the product of the mean curvature of the interface times the surface tension), and the tangential stress jump, which is balanced by Marangoni stresses. First, the effects of surface coverage and intermolecular interactions among surfactants which drive aggregation of surfactants in the interface were studied. (see Pawar and Stebe, Physics of Fluids).

  12. Post-Collisional Ductile Extensional Tectonic Framework in the UHP and HP Metamorphic Belts in the Dabie-Sulu Region, China

    索书田; 钟增球; 游振东; 张泽明


    The present-day observable tectonic framework of the ultrahigh-pressure (UHP) and high-pressure (HP) metamorphic belts in the Dabie-Sulu region was dominantly formed by an extensional process, mostly between 200 and 170 Ma, following the Triassic collision between the Sino-Korean and Yangtze cratons. The framework that controls the present spatial distribution of UHP and HP metamorphic rocks in particular displays the typical features of a Cordilleran-type metamorphic core complex, in which at least four regional-scale, shallow-dipping detachment zones are recognized. Each of these detachment zones corresponds to a pressure gap of 0.5 to 2.0 GPa. The detachment zones separate the rocks exposed in the region into several petrotectonic units with different P-T conditions. The geometry and kinematics of both the detachment zones and the petrotectonic units show that the exhumation of UHP and HP metamorphic rocks in the Dabie-Sulu region was achieved, at least in part, by non-coaxial ductile flow in the multi-layered detachment zones, and by coaxial vertical shortening and horizontal stretching in the metamorphic units, under amphibolite- to greenschist-facies conditions, and in an extensional regime. All ductile extensional deformations occurred at depths below 10 to 15 km, i.e. below the brittle/ductile deformation transition.

  13. Constraints on deformation of the Southern Andes since the Cretaceous from anisotropy of magnetic susceptibility

    Maffione, Marco; Hernandez-Moreno, Catalina; Ghiglione, Matias C.; Speranza, Fabio; van Hinsbergen, Douwe J.J.; Lodolo, Emanuele


    The southernmost segment of the Andean Cordillera underwent a complex deformation history characterized by alternation of contractional, extensional, and strike-slip tectonics. Key elements of southern Andean deformation that remain poorly constrained, include the origin of the orogenic bend known a

  14. Extensional Collapse Situations I: non-termination and unrecoverable errors

    Bucciarelli, Antonio


    We consider a simple model of higher order, functional computation over the booleans. Then, we enrich the model in order to encompass non-termination and unrecoverable errors, taken separately or jointly. We show that the models so defined form a lattice when ordered by the extensional collapse situation relation, introduced in order to compare models with respect to the amount of "intensional information" that they provide on computation. The proofs are carried out by exhibiting suitable applied {\\lambda}-calculi, and by exploiting the fundamental lemma of logical relations.

  15. A new look at extensional rheology of low-density polyethylene

    Huang, Qian; Mangnus, Marc; Alvarez, Nicolas J.


    The nonlinear rheology of three selected commercial low-density polyethylenes (LDPE) is measured in uniaxial extensional flow. The measurements are performed using three different devices including an extensional viscosity fixture (EVF), a homemade filament stretching rheometer (DTU-FSR) and a co......The nonlinear rheology of three selected commercial low-density polyethylenes (LDPE) is measured in uniaxial extensional flow. The measurements are performed using three different devices including an extensional viscosity fixture (EVF), a homemade filament stretching rheometer (DTU....... With the capability of the filament stretching rheometers, we show that LDPEs with quite different linear viscoelastic properties can have very similar steady extensional viscosity. This points to the potential for independently controlling shear and extensional rheology in certain rate ranges....

  16. The Montalet granite, Montagne Noire, France: An Early Permian syn-extensional pluton as evidenced by new U-Th-Pb data on zircon and monazite

    Poilvet, Jean-Charles; Poujol, Marc; Pitra, Pavel; Van Den Driessche, Jean; Paquette, Jean-Louis


    Dating the magmatism in the Montagne Noire gneiss dome in the southern French Massif Central is a key point for understanding the Late Palaeozoic evolution of this part of the Variscan belt, which is characterised by compressive tectonics during the Carboniferous and extensional tectonics during Stephanian-Permian times. The Montalet granite crops out in the north-western part of the dome and was first considered as an early syntectonic intrusion related to compressive deformation. More recently, it has been dated at 327 Ma and considered as contemporaneous with the diapiric ascent of the Montagne Noire gneiss dome before the Stephanian-Permian extension. We show that in fact, this pluton was emplaced 294 ± 1 Ma ago and is therefore contemporaneous with the Stephanian-Permian extension. This age is consistent with the interpretation of the Montagne Noire Massif as an extensional gneiss dome.

  17. Dynamics of Star Polymers in Fast Extensional Flow and Stress Relaxation

    Huang, Qian; Agostini, Serena; Hengeller, Ludovica;


    We confirm the observation from Ianniruberto and Marrucci [ Macromolecules 2013, 46, 267-275 ] that entangled melts of branched polystyrenes behave like linear polystyrenes in the steady state of fast extensional flow, by measuring a linear, an asymmetric star, and a symmetric star polystyrene...... with the same span molecular weight (180 kg/mol). We show that all three melts reach the same extensional steady-state viscosity in fast extensional flow (faster than the inverse Rouse time). We further measure stress relaxation following steady extensional flow for the three melts. We show that initially...

  18. Buckling of thin viscous sheets with inhomogenous viscosity under extensional flows

    Srinivasan, Siddarth; Wei, Zhiyan; Mahadevan, L.


    We investigate the dynamics, shape and stability of a thin viscous sheet subjected to an extensional flow under an imposed non-uniform temperature field. Using finite element simulations, we first solve for the stretching flow to determine the pre-buckling sheet thickness and in-plane flow velocities. Next, we use this solution as the base state and solve the linearized partial differential equation governing the out-of-plane deformation of the mid-surface as a function of two dimensionless operating parameters: the normalized stretching ratio α and a dimensionless width of the heating zone β. We show the sheet can become unstable via a buckling instability driven by the development of localized compressive stresses, and determine the global shape and growth rates of the most unstable mode. The growth rate is shown to exhibit a transition from stationary to oscillatory modes in region upstream of the heating zone. Finally, we investigate the effect of surface tension and present an operating diagram that indicates regions of the parameter space that minimizes or entirely suppresses the instability while achieving desired outlet sheet thickness. Therefore, our work is directly relevant to various industrial processes including the glass redraw & float-glass method.

  19. Mechanical Models of Bed-Perpendicular Fractures in Layered Rocks Subjected to Extensional Strain

    Sanz, P.; Pollard, D. D.; Borja, R. I.


    Natural fractures (joints) enhance permeability and therefore are important for the economical production of low-permeability hydrocarbon reservoirs and aquifers. In this work we investigate the formation of bed-perpendicular joints during extension in a stiff brittle layer surrounded by thick softer layers. The quasi-static finite element models consist of three elasto-plastic layers with frictional bedding interfaces and the middle layer contains layer-perpendicular fractures that can accommodate opening at the bedding surface accompanied by interface sliding. The upper and lower boundaries are subject to normal tractions appropriate for the depth of burial. Lateral boundaries are displaced horizontally to represent the extensional tectonic regime. We use an interface model that captures the most important mechanical features during sliding of bedding interfaces and opening of joints: unilateral contact, elastic and plastic relative deformation, tensile strength, cohesion, frictional sliding, and non-associative plastic flow. The constitutive law extends the Coulomb slip criterion to the tensile regime to capture opening of fractures in a quasi-brittle manner. The finite element implementation employs a penalty scheme to impose the contact constraints along the interfaces. The numerical simulations show the effects of mechanical properties of layers and interfaces in the development and spacing of bed-perpendicular joints. We evaluate the concepts of fracture saturation and sequential infilling, and the relationship between joint spacing and layer thickness in the context of the new modeling capabilities.

  20. A New Accumulation Model of Coal Seams in France Extensional Basins


    This paper, based on the sedimentary features of the coal seams in the typical extensional (faulted) coal basins between two inland mountainous areas of the Central Massif (France) deals with the accumulation mechanism and the corresponding sedimentary-tectonic conditions of these thick coalbeds, and proposes a new coal accumulation model for the inland lacustrine-basin thick coalbeds. The presence of a great number of gravity-flow sediments such as detrital flow, diluted slurry flow or turbidity-current sediments in the coal seams, and that of the contemporaneous gravity slump and deformation structure in the coal seam itself bath indicate that thelacustrine environment in the accumulation of the thick coalbeds was characterized by the relatively deep flood and violent sedimentation. This model can not only interpret reasonably the accumulation mecha nism of the thick coalbeds developed in the fault basins in the Central Massif, France, but also show its features distinctively from those of the accumulation model of the traditional thick coalbeds.

  1. Modifying the pom-pom model for extensional viscosity overshoots

    Hawke, L. D. G.; Huang, Qian; Hassager, Ole;


    We have developed a variant of the pom-pom model that qualitatively describes two surprising features recently observed in filament stretching rheometer experiments of uniaxial extensional flow of industrial branched polymer resins: (i) Overshoots of the transient stress during steady flow and (ii......) strongly accelerated stress relaxation upon cessation of the flow beyond the overshoot. Within the context of our model, these overshoots originate from entanglement stripping (ES) during the processes of normal chain retraction and branch point withdrawal. We demonstrate that, for a single mode...... a reasonable, but not perfect, fit to the data. With regard the stress relaxation after (kinematically) steady flow, we demonstrate that the differential version of tube orientation dynamics in the original pom-pom model performs anomalously. We discuss the reasons for this and suggest a suitable alternative....

  2. Shear and Extensional Rheology of Polystyrene Melts and Solutions with the Same Number of Entanglements

    Costanzo, Salvatore; Huang, Qian; Ianniruberto, Giovanni


    We investigate the nonlinear shear and uniaxial extensional rheology of entangled polystyrene (PS) melts and solutions having the same number Z of entanglements, hence identical linear viscoelasticity. While experiments in extensional flows confirm that PS melts and solutions with the same Z behave...

  3. Extensional Relaxation Times and Pinch-off Dynamics of Dilute Polymer Solutions

    Dinic, Jelena; Zhang, Yiran; Jimenez, Leidy; Sharma, Vivek


    We show that visualization and analysis of capillary-driven thinning and pinch-off dynamics of the columnar neck in an asymmetric liquid bridge created by dripping-onto-substrate can be used for characterizing the extensional rheology of complex fluids. Using a particular example of dilute, aqueous PEO solutions, we show the measurement of both the extensional relaxation time and extensional viscosity of weakly elastic, polymeric complex fluids with low shear viscosity ηsessile drop to a nozzle is detected optically, and the extensional response for viscoelastic fluids is characterized by analyzing their elastocapillary self-thinning, we refer to this technique as optically-detected elastocapillary self-thinning dripping-onto-substrate (ODES-DOS) extensional rheometry.

  4. Strain modelling of extensional fault-propagation folds based on an improved non-linear trishear model: A numerical simulation analysis

    Zhao, Haonan; Guo, Zhaojie; Yu, Xiangjiang


    This paper focuses on the strain modelling of extensional fault-propagation folds to reveal the effects of key factors on the strain accumulation and the relationship between the geometry and strain distribution of fault-related folds. A velocity-geometry-strain method is proposed for the analysis of the total strain and its accumulation process within the trishear zone of an extensional fault-propagation fold. This paper improves the non-linear trishear model proposed by Jin and Groshong (2006). Based on the improved model, the distribution of the strain rate within the trishear zone and the total strain are obtained. The numerical simulations of different parameters performed in this study indicate that the shape factor R, the total apical angle, and the P/S ratio control the final geometry and strain distribution of extensional fault-propagation folds. A small P/S ratio, a small apical angle, and an R value far greater or far smaller than 1 produce an asymmetric, narrow, and strongly deformed trishear zone. The velocity-geometry-strain analysis method is applied to two natural examples from Big Brushy Canyon in Texas and the northwestern Red Sea in Egypt. The strain distribution within the trishear zone is closely related to the geometry of the folds.

  5. Hydrodynamic extensional stress during the bubble bursting process for bioreactor system design

    Tran, Thanh Tinh; Lee, Eun Gyo; Lee, In Su; Woo, Nam Sub; Han, Sang Mok; Kim, Young Ju; Hwang, Wook Ryol


    Cell damage, one of critical issues in the bioreactor design for animal cell culture, is caused mainly from the bubble bursting at the free surface subjected to strong extensional flows. In this work, extensive computational studies are performed to investigate bubble bursting process in great details. Extensive numerical simulations are performed for a wide range of bubble diameters (from 0.5 to 6 mm) and the surface tension values (from 0.03 to 0.072 N/m), with which effects of the bubble size and surfactant (PF68) concentration on the hydrodynamic stress are investigated. For all the cases, the maximum extensional stress appears at the instance when receding films impact each other at the bottom of the bubble. A model equation based on numerical simulations is presented to predict the maximum extensional stress as a function of the bubble diameter and the surface tension. The bubble diameter has turned out to contribute significantly the maximum hydrodynamic extensional stress. In addition, the bubble collapsed time and the affected volume around a bubble subjected to the critical extensional stress are investigated. The extensional stress estimation is reported as a function of the bubble size and the surface tension. The influence of the bubble size on the maximum stress dominates and extensional stress reaches up to the order of 104 Pa for bubble size of 0.5 mm.

  6. What do we learn from extensional tectonics in the Western Alps?

    Sue, C.; Champagnac, J.-D.


    The Western Alps' active tectonics are characterized by ongoing widespread extension in the highest parts of the belt and transpressive/compressive tectonics along its borders (Sue et al., 1999; Delacou et al., 2004). We examine these contrasting tectonic regimes, as well as the role of erosional processes, using a multidisciplinary approach including seismotectonics, numerical modelling, GPS, morphotectonics, fieldwork, and brittle deformation analysis. Extension appears to be the dominant process in the present-day tectonic activity in the Western Alps, affecting its internal areas all along the arc. Shortening, in contrast, is limited to small areas located along at the outer borders of the chain. Strike-slip is observed throughout the Alpine realm and in the foreland. The stress-orientation pattern is radial for σ3 in the inner, extensional zones, and for σ1 in the outer, transcurrent/tranpressional ones. Extensional areas can be correlated with the parts of the belt with the thickest crust. Quantification of seismic strain in tectonically homogeneous areas shows that only 10 to 20% of the geodesy-documented deformation can be explained by the Alpine seismicity. We show that Alpine active tectonics are ruled by buoyancy forces rather than ongoing shortening along the Alpine Europe/Adria collision zone. Numerical modeling corroborates this interpretation. The Neogene extensional structures in the Alps formed under increasingly brittle conditions. A synthesis of paleostress tensors for the internal parts of the West-Alpine arc documents major orogen-parallel extension with a continuous change in σ3 directions from ENE-WSW in the Simplon area, to N-S in the Vanoise area and to NNW-SSE in the Briançon area (Champagnac et al., 2006). Minor orogen-perpendicular extension increases from N to S. This second signal correlates with present-day geodynamics as revealed by focal-plane mechanisms analysis. The orogen-parallel extension could be related to the opening of

  7. Extensional Tectonic Regime of Garut Basin based on Magnetotelluric Analysis

    Lina Handayani


    Full Text Available DOI: 10.17014/ijog.v8i3.162Garut Basin are is part of Bandung-Garut Greater Basin (Bandung Zone characterized by a large basin surrounded by mountain ranges. Active volcanoes had distributed their material as pyroclastic deposits around the outer border of the zone and as lava flow deposit separating the two basins. Bouguer gravity anomaly data had also indicated the presence of several low anomaly closures at about the area of Bandung and Garut Basins that were surrounded by high gravity anomaly zones. Two magnetotelluric surveys were completed to acquire the subsurface model that might explain the tectonic evolution of studied area. The first stage was characterized sby the presence of horst - graben structures that might imply an extensional regime of the area. The next stage of evolutionwas indicated by the horizontal layering correlated to the relative non-active tectonic. In addition, a most recent structure that appeared near the surface might suggest a possible extension force as the current stage.

  8. Peeling flexible beams in viscous fluids: Rigidity and extensional compliance

    Dhong, Charles; Fréchette, Joëlle


    We describe small angle peeling measurements in completely submerged environments to study the coupling between viscous forces and the mechanical properties of the plates being peeled. During the experiments, the plates resist motion because of lubrication forces while van der Waals forces between the plates and the static surface are negligible. In particular, we study the role played by flexural rigidity in the force-displacement curves and in the energy release rate. We show that the coupling between the viscous forces and the flexural rigidity of the plates dictates the shape and magnitude of the force-displacement curves. We develop simple scaling relationships that combine the lubrication forces with an Euler-Bernoulli beam to extract how the peak force and energy release rates depend on the ratio between rigidity and viscosity, and show good agreement between the predictions and experimental results. We also show that increasing the extensional compliance leads to a decrease in both the force-displacement curve and in the energy release rate. We then demonstrate that this reduction can be interpreted in terms of a stress decay length.

  9. Extensional Tectonics Evidenced in Recent Sediments of Lake Van, Eastern Turkey

    Sengul, M. Alper; Koral, Hayrettin; Elmas, M. Ali


    The Lake Van region is characterized by NE-SW trending faults with a left-lateral normal-slip component, NW-SE trending faults with a right-lateral normal-slip component and E-W trending reverse/thrust-slip faults, suggesting a N-S trending compressional stress orientation. Tectonic effects in the region continue to be manifested by recent seismicity as in the earthquake of October 23, 2011 (Mw=7.1). Although this earthquake has not produced many earthquake-related surface deformation, evidences of recent tectonics are rather extensive in the Quaternary sediments surrounding the lake. Therefore ages of sediments are important in determining the timing of tectonic activity. Optically stimulated luminescence (OSL) method was used to determine the age of lake sediments to the north of the lake. Also, shells of gastropods available in the sediments are dated by C14. Ages suggest that to the NE of Lake Van youngest activity on the NW-SE trending Erciş Fault with right-lateral normal-slip component is to be 34 ka. Activity on other normal faults in the same area is dated between 10-14 ka and 20 ka. Also, samewhat to the south of this region in vicinity of the Canik area, reverse faulting is dated to be younger than 40 ka. All ages indicate the region has been affected during the Pleistocene locally by an extensional regime contemporaneously with the contractional regime. The evidence of a one meter dip-slip displacement measured on a fault plane in a quarry supports the view of local extension in the NE sector of the lake. Key Words: Lake Van, OSL dating, neotectonics, active tectonics

  10. A new look at extensional rheology of low-density polyethylene

    Huang, Qian; Mangnus, Marc; Alvarez, Nicolas J.


    The nonlinear rheology of three selected commercial low-density polyethylenes (LDPE) is measured in uniaxial extensional flow. The measurements are performed using three different devices including an extensional viscosity fixture (EVF), a homemade filament stretching rheometer (DTU-FSR) and a co......The nonlinear rheology of three selected commercial low-density polyethylenes (LDPE) is measured in uniaxial extensional flow. The measurements are performed using three different devices including an extensional viscosity fixture (EVF), a homemade filament stretching rheometer (DTU......-FSR) and a commercial filament stretching rheometer (VADER-1000). We show that the measurements from the EVF are limited by a maximum Hencky strain of 4, while the two filament stretching rheometers are able to probe the nonlinear behavior at larger Hencky strain values where the steady state is reached...

  11. Active Extensional Faulting at the Southern Half-Graben Belt of the Tepic-Zacoalco Rift, Western Mexico

    Rosas-Elguera, J.; Ferrari, L.; Delgado, M.; Uribe, A.; Valdivia, L.; Castillo, R.


    In the past decade much debate has centered upon the kinematics and the mechanism of continental deformation in western Mexico and the motion of the Jalisco block relative to North America. Two distinct models have been proposed. The first one suggest a NW-motion of the Jalisco block that would implies a right-lateral faulting along the Tepic-Zacoalco rift (TZR). More recently others authors have documented a N-NE extensional tectonics active since late Miocene and suggested that the continental boundaries of the Jalisco block, are older structures reactivated by plate boundary forces. Studies on the crustal seismicity and the kinematics of Quaternary faults provide another constraint on the direction of motion between the Jalisco block and North America. On November 4, 5, 6, and 7, 1995, one month after the October 09, 1995, Manzanillo earthquake (Mw = 8.0), a swarm of small events was felt in the Amatlan de Ca¤as half-graben and recorded by the regional seismic network of Comision Federal de Electricidad. The coda magnitude of the largest event was Mc = 2.5-3.6 and the events were located depth ranging from 6 to 10 km. This seismic activity provoked that people from Pie de la Cuesta and Yerbabuena villages were evacuated. After that a seismic station equipped with an analogic seismograph MEQ-800 at Pie de la Cuesta was installed for three months. During the same time, October, 1995, some houses distributed along a WNW trend in Ameca city underwent severe damages, they are. The digital elevations model of the Ameca city suggest that several structures tectonics are shorter than 2 km are present in the area. The present direction of motion of the Rivera plate relative to North America plate along Middle America Trench has been estimated between N19° E to N48° E (e.g. Bandy et al., 1996). During the October 09, 1995, subduction-related earthquake (Mw = 8.0) a GPS network recorded a SW motion of the Jalisco block which could be associated to an elastic deformation

  12. Shear History Extensional Rheology Experiment II (SHERE II) Microgravity Rheology with Non-Newtonian Polymeric Fluids

    Jaishankar, Aditya; Haward, Simon; Hall, Nancy Rabel; Magee, Kevin; McKinley, Gareth


    The primary objective of SHERE II is to study the effect of torsional preshear on the subsequent extensional behavior of filled viscoelastic suspensions. Microgravity environment eliminates gravitational sagging that makes Earth-based experiments of extensional rheology challenging. Experiments may serve as an idealized model system to study the properties of lunar regolith-polymeric binder based construction materials. Filled polymeric suspensions are ubiquitous in foods, cosmetics, detergents, biomedical materials, etc.

  13. Facies composition and scaling relationships of extensional faults in carbonates

    Bastesen, Eivind; Braathen, Alvar


    Fault seal evaluations in carbonates are challenged by limited input data. Our analysis of 100 extensional faults in shallow-buried layered carbonate rocks aims to improve forecasting of fault core characteristics in these rocks. We have analyzed the spatial distribution of fault core elements described using a Fault Facies classification scheme; a method specifically developed for 3D fault description and quantification, with application in reservoir modelling. In modelling, the fault envelope is populated with fault facies originating from the host rock, the properties of which (e.g. dimensions, geometry, internal structure, petrophysical properties, and spatial distribution of structural elements) are defined by outcrop data. Empirical data sets were collected from outcrops of extensional faults in fine grained, micro-porosity carbonates from western Sinai (Egypt), Central Spitsbergen (Arctic Norway), and Central Oman (Adam Foothills) which all have experienced maximum burial of 2-3 kilometres and exhibit displacements ranging from 4 centimetres to 400 meters. Key observations include fault core thickness, intrinsic composition and geometry. The studied fault cores display several distinct fault facies and facies associations. Based on geometry, fault cores can be categorised as distributed or localized. Each can be further sub-divided according to the presence of shale smear, carbonate fault rocks and cement/secondary calcite layers. Fault core thickness in carbonate rocks may be controlled by several mechanisms: (1) Mechanical breakdown: Irregularities such as breached relays and asperities are broken down by progressive faulting and fracturing to eventually form a thicker fault rock layer. (2) Layer shearing: Accumulations of shale smear along the fault core. (3) Diagenesis; pressure solution, karstification and precipitation of secondary calcite in the core. Observed fault core thicknesses scatter over three orders of magnitude, with a D/T range of 1:1 to 1

  14. A comparison of boundary element and finite element methods for modeling axisymmetric polymeric drop deformation

    Hooper, Russell; Toose, E.M.; Macosko, Christopher W.; Derby, Jeffrey J.


    A modified boundary element method (BEM) and the DEVSS-G finite element method (FEM) are applied to model the deformation of a polymeric drop suspended in another fluid subjected to start-up uniaxial extensional flow. The effects of viscoelasticity, via the Oldroyd-B differential model, are

  15. New Constraints on Extensional Environments through Analysis of Teleseisms

    Eilon, Zachary Cohen

    We apply a variety of teleseismic methodologies to investigate the upper mantle structure in extensional environments. Using a body wave dataset collected from a regional deployment in the Woodlark Rift, Papua New Guinea, we image anisotropic velocity structure of a rapidly extending rift on the cusp of continental breakup. In the process, we develop a technique for azimuthal anisotropy tomography that is generally applicable to regions of relatively simple anisotropic structure. The Cascadia Initiative ocean bottom seismometer (OBS) deployment provides coverage of an entire oceanic plate in unprecedented detail; we measure attenuation and velocities of teleseisms to characterize the temperature and melt structure from ridge to trench. Our study of shear wave splitting reveals strong azimuthal anisotropy within the Woodlark Rift with fairly uniform fast directions parallel to extension. This observation differs markedly from other continental rifts and resembles the pattern seen at mid-ocean ridges. This phenomenon is best explained by extension-related strain causing preferential alignment of mantle olivine. We develop a simple relationship that links total extension to predicted splitting, and show that it explains the apparent dichotomy in rifts' anisotropy. Finite frequency tomography using a dataset of teleseismic P- and S-wave differential travel times reveals the upper mantle velocity structure of the Woodlark Rift. A well developed slow rift axis extending >250 km along strike from the adjacent seafloor spreading centers demonstrates the removal of mantle lithosphere prior to complete crustal breakup. We argue that the majority of this rift is melt-poor, in agreement with geochemical results. A large temperature gradient arises from the juxtaposition of upwelled axial asthenosphere with a previously unidentified cold structure north of the rift that hosts well located intermediate depth earthquakes. Localization of upper mantle extension is apparent from

  16. Strain Localization Within a Syn-Tectonic Pluton in a Back-Arc Extensional Context: the Naxos granodiorite (Cyclades, Greece)

    Bessiere, Eloïse; Rabillard, Aurélien; Arbaret, Laurent; Jolivet, Laurent; Augier, Romain; Menant, Armel


    Naxos Island is part of the central Cyclades (Aegean Sea, Greece) where a series of migmatite-cored metamorphic domes were exhumed below large-scale detachment systems during a Cenozoic back-arc extension. On Naxos, the Miocene exhumation history of the high-temperature metamorphic dome was notably achieved through two anastomosing and closely spaced top-to-the-north detachments belonging to the Naxos-Paros detachment system. According to previous contributions, the late exhumation stages were accompanied by the emplacement of a syn-kinematic I-type granodiorite that intruded a ductile-then-brittle detachment. Later the detachment migrated at the interface between the pluton and the metamorphic unit under ductile-to-brittle conditions. To clarify how extensional deformation was precisely distributed within the pluton, a multi-scale approach from field observations to laboratory investigations was undertaken. Through macro- to micro-structural observations, we show a continuous deformation history from magmatic to solid-state ductile/brittle conditions under an overall north-directed shearing deformation. The early magmatic or sub-solidus deformation is evidenced in a large part of the granodiorite, notably in its southern part where the original intrusive contact is still preserved. Solid-state deformation is recorded further north when approaching the detachment zone, highlighted by a thicker cataclastic zone and numerous pseudotachylite veins. From these field observations, we defined six strain facies, leading us to propose a qualitative strain map of the Naxos granodiorite. Based on field pictures and X-ray tomography of oriented samples collected along the strain gradient, we quantified the intensity of mineralogical fabrics in 2D and 3D. This step required the treatment of 600 rocks samples and pictures using SPO2003 (Shape Preferred Orientation) and Intercepts2003. Measured shape variations of the strain ellipsoid thus corroborate the large-scale strain

  17. The tectonic evolution of Southeast Asia through accretionary and extensional episodes since the Cretaceous

    Seton, M.; Zahirovic, S.; Müller, R.


    Although a number of tectonic reconstructions exist that document the development of the present-day complex assemblage of exotic terranes in Southeast Asia, very few describe the continuously evolving plate boundaries and the geodynamic driving forces in the region. We propose a plate motion model that attempts to reconcile evidence from both surface geology and the subsurface mantle structure, and implement continuously closing plate polygons using our open-source plate reconstruction software, GPlates, for the eastern Asian margin and eastern Tethyan domain since the Cretaceous. We link the change from a compressional to an extensional regime along eastern Asia in the Late Cretaceous as the likely opening of the Proto South China Sea in a back-arc setting to account for obducted ophiolite sections on Palawan that are Cretaceous in age, with a likely Miocene emplacement resulting from subduction of the Proto South China Sea crust. Such an interpretation is also consistent with the timing of accretionary episodes along northern Borneo and the upper mantle slab visible in P-wave seismic tomography models. The development of Sundaland is also intricately linked to the opening of the Proto South China Sea and the accretion of Gondwana-derived micro-continental blocks, including East Java and West Sulawesi, in the Cretaceous. Whether Sundaland behaved as a rigid cohesive block, or whether Borneo rotated and moved relative to Sundaland has been a matter of debate due to inconsistencies between paleomagnetic and structural data. Paleomagnetic results indicate significant rotations of Borneo that are accommodated by oroclinal bending without the need for bounding transform faults, which are not obvious in both seismic and potential field data. In the absence of preserved seafloor, we use geological evidence such as ophiolite emplacements, magmatic episodes, paleomagnetic constraints, structural reactivation and deformation as proxies to build a self-consistent plate

  18. Ductile strain rate recorded in the Symvolon syn-extensional plutonic body (Rhodope core complex, Greece)

    Cirrincione, Rosolino; Fazio, Eugenio; Ortolano, Gaetano; Fiannacca, Patrizia; Kern, Hartmut; Mengel, Kurt; Pezzino, Antonino; Punturo, Rosalda


    The present contribution deals with quantitative microstructural analysis, which was performed on granodiorites of the syn-tectonic Symvolon pluton (Punturo et al., 2014) at the south-western boundary of the Rhodope Core Complex (Greece). Our purpose is the quantification of ductile strain rate achieved across the pluton, by considering its cooling gradient from the centre to the periphery, using the combination of a paleopiezometer (Shimizu, 2008) and a quartz flow law (Hirth et al., 2001). Obtained results, associated with a detailed cooling history (Dinter et al., 1995), allowed us to reconstruct the joined cooling and strain gradient evolution of the pluton from its emplacement during early Miocene (ca. 700°C at 22 Ma) to its following cooling stage (ca. 500-300°C at 15 Ma). Shearing temperature values were constrained by means of a thermodynamic approach based on the recognition of syn-shear assemblages at incremental strain; to this aim, statistical handling of mineral chemistry X-Ray maps was carried out on microdomains detected at the tails of porphyroclasts. Results indicate that the strain/cooling gradients evolve "arm in arm" across the pluton, as also testified by the progressive development of mylonitic fabric over the magmatic microstructures approaching the host rock. References • Dinter, D. A., Macfarlane, A., Hames, W., Isachsen, C., Bowring, S., and Royden, L. (1995). U-Pb and 40Ar/39Ar geochronology of the Symvolon granodiorite: Implications for the thermal and structural evolution of the Rhodope metamorphic core complex, northeastern Greece. Tectonics, 14 (4), 886-908. • Shimizu, I. (2008). Theories and applicability of grain size piezometers: The role of dynamic recrystallization mechanisms. Journal of Structural Geology, 30 (7), 899-917. • Hirth, G., Teyssier, C., and Dunlap, J. W. (2001). An evaluation of quartzite flow laws based on comparisons between experimentally and naturally deformed rocks. International Journal of Earth

  19. Sedimentary response to tectonism in the extensional Chihuahua trough, Cretaceous of Southern North America

    Budhathoki, P.; Langford, R. P.; Pavlis, T. L.


    During the Jurassic and Cretaceous, the Chihuahua Trough formed an extensional basin, extending from the Gulf of Mexico to Southern Arizona, along the Present Border of the United States and Mexico. West of the Big Bend of Texas, Jurassic and Cretaceous sediments are less than 150 m thick, and in many areas are absent. The sedimentary package thickens to over 3km within the trough. The Albian Cox Sandstone is one of the most areally extensive formations and consists of interbedded fluvial coastal and shallow marine sandstones and shales. In this study area, shales (10-70 m) are thicker more than sandstone beds (2-10 m). This unit is overlain by Finlay formation, a fine crystalline gray limestone and underlain by Bluff Mesa formation, a fossiliferous shallow marine limestone. Cross-bedded, brown, fine to medium grained sandstone, interbedded with siltstone, shale and limestone are characteristic lithology of the Cox. The Indio Mountains of Trans-Pecos Texas offer an ideal location to study how this package accommodates the deformation associated with the subsiding Chihuahua trough. A continuous outcrop extends over 30 km oblique to the basin margin and thickens from approximately 375 m on the northern side to 437 m on the southern side of the 10 km section studied so far. One important mechanism is rotation of the strata into the basin, followed by truncation along sequence boundaries. The lower two sequence in the southern Indio mountains are rotated down to the basin relative to Finlay. The lowest sequences thicken from an erosional pinch out towards the South. Shale beds thicken within the rotated strata and accommodate some of the tilting. For example, Thickness of the shale bed varies from 18 m to 70 m within a 2 km distance. However, erosional truncation of the tilted strata accounts for most of the increases in thickness within sequences. The base of the formation has been rotated about 6 degrees south relative to the top of the formation. Another observed

  20. Contracture deformity

    Deformity - contracture ... Contracture can be caused by any of the following: Brain and nervous system disorders, such as cerebral ... Follow your health care provider's instructions for treating contracture at home. Treatments may include: Doing exercises and ...

  1. Modeling of dual cylinder wind-up extensional rheometers

    Yu, Kaijia; Marin, Jose; Jensen, Mette

    .L. Sentmanat, Rheol Acta, 43:657--669, 2004. [2] J.M.R. Marín, H.K.Rasmussen, J. Non-Newtonian Fluid Mech, 156 (3) , p. 177-188. [3] K.Y, J.M.R. Marín, H.K.Rasmussen, O.Hassager, J. Non-Newtonian Fluid Mech, 165 (1) , p. 14-23. [4] Y.Wang, P.Boukany, S.Wang, X.Wang, Physical Review Letters, 99, 237801 (2007...... a finite element technique based on a Lagrangian kinematics description of the 3D time-dependent flow of K-BKZ type fluids [2] is used to simulate extension flow of both cylindrical and strip shaped sample in the SER. Here the purpose is to discuss the potential deviations from ideal uni-axial deformation...

  2. Neotectonics and geomorphic evolution of the northwestern arm of the Yellowstone Tectonic Parabola: Controls on intra-cratonic extensional regimes, southwest Montana

    Ruleman, Chester A.; Larsen, Mort; Stickney, Michael C.


    The catastrophic Hebgen Lake earthquake of 18 August 1959 (MW 7.3) led many geoscientists to develop new methods to better understand active tectonics in extensional tectonic regimes that address seismic hazards. The Madison Range fault system and adjacent Hebgen Lake–Red Canyon fault system provide an intermountain active tectonic analog for regional analyses of extensional crustal deformation. The Madison Range fault system comprises fault zones (~100 km in length) that have multiple salients and embayments marked by preexisting structures exposed in the footwall. Quaternary tectonic activity rates differ along the length of the fault system, with less displacement to the north. Within the Hebgen Lake basin, the 1959 earthquake is the latest slip event in the Hebgen Lake–Red Canyon fault system and southern Madison Range fault system. Geomorphic and paleoseismic investigations indicate previous faulting events on both fault systems. Surficial geologic mapping and historic seismicity support a coseismic structural linkage between the Madison Range and Hebgen Lake–Red Canyon fault systems. On this trip, we will look at Quaternary surface ruptures that characterize prehistoric earthquake magnitudes. The one-day field trip begins and ends in Bozeman, and includes an overview of the active tectonics within the Madison Valley and Hebgen Lake basin, southwestern Montana. We will also review geologic evidence, which includes new geologic maps and geomorphic analyses that demonstrate preexisting structural controls on surface rupture patterns along the Madison Range and Hebgen Lake–Red Canyon fault systems.

  3. Transient shortening strain across an active extensional fault, Basin and Range Province, north-central Nevada, USA, based on geodetic and paleoseismologic data.

    Friedrich, A.; Wernicke, B.; Lee, J.; Sieh, K.


    The northern Basin and Range province is one of the largest continental extensional regions on earth. At 40 degrees N latitude, the province is 800 km wide and consists of 15 and 20 N-S striking normal faults. These faults accommodated mainly east-west directed extension of tens of kilometers since Mid-Miocene time and recent geodetic surveys show that extension is still active today at a rate of ~1.5 cm/yr across the province (e.g., Bennett et al. 2000; Thatcher et al. 1999). The distribution of this geodetically measurable strain accumulation within the province, however, contradicts geologic observations across some of the active normal faults. For example, coordinated geologic and geodetic measurements across the Crescent Valley fault (CVF), north-central Nevada, reveal a profound mismatch in deformation rates. Since 1996, the two ranges on either side of the CVF have been moving toward each other at ca. 2 mm/yr, indicating shortening. In contrast, new reconnaissance mapping and paleoseismological analyses along the CVF also indicate that this fault is one of the more active normal faults of the Basin and Range province. The 50 km long Cortez Mountains range front is characterized by relief of up to 1.3 km, steep (up to 36 degrees) triangular facets, and young (late Pleistocene to late Holocene) alluvial fans cut by normal fault scarps. Vertical displacement across the CVF is ca. 3 km; since 15 Ma the average long-term vertical displacement rate is ca. 0.2 mm/yr. Topographic profiling shows that fault scarps, 2-7 m high, are the result of a single rupture event and cut late Holocene alluvial fans. A trench across a faulted alluvial fan at Fourmile Canyon reveals a vertical displacement of 4.5 m distributed across two normal faults. 14C analyses on charcoal from a buried offset surface in the hanging wall of the trench and from the base of the overlying colluvial wedge tightly bracket the age of the most recent earthquake to between 2.8 +- 0.1 and 2.7 +- 0.1 ka

  4. Extensional orogenic collapse captured by strike-slip tectonics: Constraints from structural geology and Usbnd Pb geochronology of the Pinhel shear zone (Variscan orogen, Iberian Massif)

    Fernández, Rubén Díez; Pereira, Manuel Francisco


    The late Paleozoic collision between Gondwana and Laurussia resulted in the polyphase deformation and magmatism that characterizes the Iberian Massif of the Variscan orogen. In the Central Iberian Zone, initial continental thickening (D1; folding and thrusting) was followed by extensional orogenic collapse (D2) responsible for the exhumation of high-grade rocks coeval to the emplacement of granitoids. This study presents a tectonometamorphic analysis of the Trancoso-Pinhel region (Central Iberian Zone) to explain the processes in place during the transition from an extension-dominated state (D2) to a compression-dominated one (D3). We reveal the existence of low-dipping D2 extensional structures later affected by several pulses of subhorizontal shortening, each of them typified by upright folds and strike-slip shearing (D3, D4 and D5, as identified by superimposition of structures). The D2 Pinhel extensional shear zone separates a low-grade domain from an underlying high-grade domain, and it contributed to the thermal reequilibration of the orogen by facilitating heat advection from lower parts of the crust, crustal thinning, decompression melting, and magma intrusion. Progressive lessening of the gravitational disequilibrium carried out by this D2 shear zone led to a switch from subhorizontal extension to compression and the eventual cessation and capture of the Pinhel shear zone by strike-slip tectonics during renewed crustal shortening. High-grade domains of the Pinhel shear zone were folded together with low-grade domains to define the current upright folded structure of the Trancoso-Pinhel region, the D3 Tamames-Marofa-Sátão synform. New dating of syn-orogenic granitoids (SHRIMP Usbnd Pb zircon dating) intruding the Pinhel shear zone, together with the already published ages of early extensional fabrics constrain the functioning of this shear zone to ca. 331-311 Ma, with maximum tectonomagmatic activity at ca. 321-317 Ma. The capture and apparent cessation

  5. Bridging the Gap between Polymer Melts and Solutions in Extensional Rheology

    Huang, Qian; Hengeller, Ludovica; Alvarez, Nicolas J.


    and polymer melts. We compare the nonlinear extensional rheology of a series of polystyrene solutions with wide concentration range between 10% and 100% (melt) in order to determine the key missing physics that can account for dilution effects. All the solutions studied have the same number of entanglements...

  6. Extensional rheology of entangled polystyrene solutions suggests importance of nematic interactions

    Huang, Qian; Javier Alvarez, Nicolas; Matsumiya, Yumi

    polymer solutions in extensional flow. We prepared three polystyrene (PS) solutions with identical concentrations of the same PS sample (with the molecular weight M = 545k), but diluted with three different solvents, oligomeric styrene (OS) with M = 1k, 2k, and 4k. The three solutions have exactly...

  7. The dynamics of cylindrical samples in dual wind-up extensional rheometers

    Yu, Kaijia; Rasmussen, Henrik K.; Marín, Jose Manuel Román


    Numerical computations of the extension of circular cylindrical shaped samples in a dual wind-up drum rheometer of Sentmanat extensional rheometer type M. L. Sentmanat, Rheol. Acta 43, 657 (2004); R. Garritano and H. Berting, US Patent No. 7,096,728 (08/29/2006) are presented. These time-dependen...

  8. Interchain tube pressure effect in extensional flows of oligomer diluted nearly monodisperse polystyrene melts

    Rasmussen, Henrik K.; Huang, Qian


    We have derived a constitutive equation to explain the extensional dynamics of oligomer-diluted monodisperse polymers, if the length of the diluent has at least two Kuhn steps. These polymer systems have a flow dynamics which distinguish from pure monodisperse melts and solutions thereof, if the ...

  9. Monitoring the hydration of DNA self-assembled monolayers using an extensional nanomechanical resonator

    Cagliani, Alberto; Kosaka, Priscila; Tamayo, Javier;


    We have fabricated an ultrasensitive nanomechanical resonator based on the extensional vibration mode to weigh the adsorbed water on self-assembled monolayers of DNA as a function of the relative humidity. The water adsorption isotherms provide the number of adsorbed water molecules per nucleotid...

  10. Shear and Extensional Flow-Induced Particle Orientation in Polypropylene/Clay Nanocomposites

    Burghardt, Wesley; McCready, Erica


    Synchrotron-based in situ x-ray scattering is used to monitor the orientation of dispersed particles in molten polypropylene/clay nanocomposite melts during flow. Nanocomposite samples were prepared via twin screw extrusion processing, and the degree of clay exfoliation assessed in terms of the magnitude of the low frequency enhancement in viscoelasticity. In shear flow, an annular cone and plate flow cell is used which allows measurement of the degree and direction of particle orientation in the flow-gradient (1-2) plane. Samples were also studied in extensional flow, using an SER extensional flow fixture installed in a custom-built convection oven that provides x-ray access. In both shear and extensional flow, only a moderate degree of particle orientation is observed. Extensional flow studies are complicated by (i) the tendency of samples to fail at moderate Hency strain, and (ii) a heterogeneous initial distribution of particle orientation in the SER specimens, prepared by compression molding of extruded pellets of the nanocomposite.

  11. The missing link between the extensional dynamics of polymer melts and solutions

    Rasmussen, Henrik K.; Huang, Qian


    Based on extensional viscosities measured on narrow molecular weight distributed (NMMD) polystyrenes and polystyrene oligomer dilutions thereof, we discuss the relation between the flow physics of polymer solutions and melts. A polymer solution is here characterized as a dilution where the diluen...

  12. Extensional Basins in a Convergent Margin: Oligocene-Early Miocene Salar de Atacama and Calama basins, Central Andes

    Jordan, T. E.; Mpodozis, C.; Blanco, N.; Pananont, P.; Dávila, F.


    The Salar de Atacama Basin (SdAB) is the largest and most persistent sedimentary basin of northern Chile, accumulating nonmarine sediment from Cretaceous to modern times. Its northwestern neighbor, the Calama, was a Cenozoic basin. Although SdAB was in the backarc zone early in the Andean orogeny, both are now forearc basins. Others demonstrated that the basins overlie anomalously cold, strong, and dense crust and lithosphere. We focus on an extensional Oligocene basin stage. Interpretation of the basin-controlling faults is based on seismic reflection studies supported by field relations. The SdAB is limited to the west by the NNE-trending, steeply east-dipping, Paciencia Fault (PF). The PF experienced 5-7 km of down-to-the-east offset during the Oligocene-early Miocene. Syntectonic strata, an arid succession of siliciclastics and evaporites, are asymmetric, with thicknesses of 5000 m and abundant halite adjacent to the PF, and of 1000 m with fine detrital clastic strata 25 km farther east. Relations in conglomeratic growth strata that overlap the PF also demonstrate normal displacement during sediment accumulation. Seismic data reveal that a buried normal fault with 1-1.5 km down-to-the-east displacement limits the western margin of the Oligocene-Miocene Calama siliciclastic basin fill. Regionally, Oligocene-early Miocene margin-parallel strike-slip deformation dominated northwest of the basins, contributing sinistral offset (West Fissure Fault) to the northern segment of the long-lived Domeyko Fault System. The new SdAB and Calama data reveal that a 20,000 km2 domain of extensional basins existed within the dominantly strike-slip region. Even if PF and the fault in the Calama Basin were transtensional, the proportion of extension to strike-slip displacement is much greater in these basins than elsewhere in northern Chile. Further study is required to understand what combination of factors caused this kinematic distinction as well as delayed the onset of CVZ

  13. Deformation microstructures

    Hansen, N.; Huang, X.; Hughes, D.A.


    Microstructural characterization and modeling has shown that a variety of metals deformed by different thermomechanical processes follows a general path of grain subdivision, by dislocation boundaries and high angle boundaries. This subdivision has been observed to very small structural scales...... of the order of 10 nm, produced by deformation under large sliding loads. Limits to the evolution of microstructural parameters during monotonic loading have been investigated based on a characterization by transmission electron microscopy. Such limits have been observed at an equivalent strain of about 10...

  14. Haglund's Deformity

    ... to follow the surgeon’s instructions for postsurgical care. Prevention To help prevent a recurrence of Haglund’s deformity: wear appropriate shoes; avoid shoes with a rigid heel back use arch supports or orthotic devices perform stretching exercises to prevent the Achilles tendon from tightening ...

  15. Extensional Detachment faulting in melange rocks. Plurikilometres migration by W the External Zone (Cordillera Bética, Spain)

    Roldán, Francisco Javier; Azañon, Jose Miguel; Rodríguez, Jose; Mateos, Rosa Maria


    The synthesis and correlation of units carried out in the continuous geological map (Roldán et al., 2012), has revealed a fragmentation of the carbonate outcrops belong to the Subbetic Domain (García-Hernández et al., 1980). Subbetic NW verging thrust and fold axial traces have not lateral continuity and Jurassic carbonate outscrops appear as klippes on the olistotromic unit. These ductile structures that can be observed in the internal structure of these jurassic blocks are unrelated to the brittle-ductile deformation bands observed at the basal pelitic levels. Basal detachments are rooted in: a) the Olistostromic unit, a Upper Langhian-Lower Serravallian breccia constituted by gypsum-bearing clay and marls; b) Cretaceous-Tertiary marly sedimentary rocks (Rodríguez-Fernández, et al., 2013) . In both kind of rocks, cataclastic structures allows to infer a top-to-the WSW displacement. Paleostress measurements, made on these detachments levels, are compatible with a extensional regime (Roldán et al., 2012). At the same time, the analysis and interpretation of subsurface data (seismic surveys and borehole testing) shows that the Subbetic Domain (External Subbetic, Molina 1987) are affected by westward low-angle normal faults. A balanced cross-section, based on morphological and cartographic data in the area between Sierra de Cabra and Sierra de Alta Coloma (Valdepeñas de Jaén), shows plurikilometric displacements which has been produced during Late Serravallian-Early Tortonian times. References: García-Hernández, M., López-Garrido, A.C., Rivas, P., Sanz de Galdeano, C., Vera, J.A. (1980): Mesozoic paleogeographic evolution of the zones of the Betic Cordillera. Geol. Mijnb. 59 (2). 155-168. Molina, J.M. (1987). Análisis de facies del Mesozoico en el Subbético. Tesis Doctoral, Univ. Granada. 518 p. Rodríguez-Fernández, J., Roldán, F. J., Azañón, J.M. y García-Cortés, A. (2013). El colapso gravitacional del frente orogénico a lpino en el Dominio Subb

  16. A double-cycle lake basin formed in extensional to transtensional setting: The Paleogene Nanpu Sag, Bohai Bay Basin, China

    Zhang, Jianguo; Jiang, Zaixing; Gierlowski-Kordesch, Elizabeth; Xian, Benzhong; Li, Zhenpeng; Wang, Siqi; Wang, Xiabin


    It has been known that both extensional and transtensional tectonics commonly trigger a one-cycle evolution of lake sediments, but lake-cycle development co-controlled by extensional and transtensional tectonics still need identification. Here we report a double-cycle of lake sediments formed in extensional to transtensional phases in the Paleogene Nanpu Sag of the Bohai Bay Basin, China. The sag successively experienced five phases of lake-type evolution, characterized by: 1) overfilled, 2) balanced-fill, 3) overfilled, 4) balanced-fill, and 5) overfilled. Extensional tectonics was responsible for the opening of the basin and the initial creation of accommodation (1st through 3rd phase). Next, subsidence increased again through transtensional tectonics resulting in the creation of new accommodation (4th-5th phases). Investigations show this double-cycle lake-type evolution is also present in other lake-basins with similar tectonic settings (e.g., both extensional and transtensional tectonics). A different exploration and exploitation strategy should be devoted to the double-cycle evolution of lake basins controlled by extensional to transtensional tectonics in comparison to the single-cycle evolution in extensional or transtensional lake basins.

  17. The role of partial melting and extensional strain rates in the development of metamorphic core complexes

    Rey, P. F.; Teyssier, C.; Whitney, D. L.


    geothermal gradient (35 to 65 °C km - 1 ); material remains partially molten in the dome during ascent. At low strain rate (mm yr - 1 in the core complex region), the partially molten crust crystallizes at high pressure; this material is subsequently deformed in the solid-state along a cooler geothermal gradient (20 to 35 °C km - 1 ) during ascent. Therefore, the models predict distinct crystallization versus exhumation histories of migmatite cores as a function of extensional strain rates. The Shuswap metamorphic core complex (British Columbia, Canada) exemplifies a metamorphic core complex in which an asymmetric, detachment-controlled migmatite dome records rapid exhumation and cooling likely related to faster rates of extension. In contrast the Ruby Mountain-East Humboldt Ranges (Nevada, U.S.A.) exhibits characteristics associated with slower metamorphic core complexes.

  18. Long thickness-extensional waves in thin film bulk acoustic wave filters affected by interdigital electrodes.

    Liu, Jing; Du, Jianke; Wang, Ji; Yang, Jiashi


    We studied free vibrations of thin-film bulk acoustic wave filters with interdigital electrodes theoretically using the scalar differential equations by Tiersten and Stevens. The filters are made from AlN or ZnO films on Si substrates with ground and driving electrodes. They operate with thickness-extensional modes. The basic vibration characteristics including resonant frequencies and mode shapes were obtained. Their dependence on various geometric parameters was examined. It was found that for properly design filters there exist trapped modes whose vibrations are strong in regions with a driving electrode and decay away from the electrode edges. These trapped modes are essentially long plate thickness-extensional modes modulated by the electrode fingers. The number of trapped modes is sensitive to the geometric parameters.

  19. Prediction of cryogenic cavitation around hydrofoil by an extensional Schnerr-Sauer cavitation model

    Sun, T. Z.; Wei, Y. J.; Wang, C.


    Developing a robust computational strategy to address the rich physics characteristic involved in the thermodynamic effects on the cryogenic cavitation remains a challenging problem. The objective of this present study is to model the numerical methodology to simulate the cryogenic cavitation by implanting the thermodynamic effects to the Schnerr-Sauer cavitation model, and coupling the energy equation considered the latent heat. For this purpose, cavitating flows are investigated over a three dimensional hydrofoil in liquid hydrogen and nitrogen. Experimental measurements of pressure and temperature are utilized to validate the extensional Schnerr-Sauer cavitation model. Specifically, the further analysis of the cavitation solution with respect to the thermodynamic term is conducted. The results show that the extensional Schnerr-Sauer cavitation model predicts better accuracy to the quasi-steady cavitation over hydrofoil in the two cryogenic fluids.

  20. Recurring extensional and strike-slip tectonics after the Neoproterozoic collisional events in the southern Mantiqueira province

    Renato P. Almeida


    Full Text Available In Eastern South America, a series of fault-bounded sedimentary basins that crop out from Southern Uruguay to Southeastern Brazil were formed after the main collisional deformation of the Brasiliano Orogeny and record the tectonic events that affected the region from the Middle Ediacaran onwards. We address the problem of discerning the basin-forming tectonics from the later deformational events through paleostress analysis of more than 600 fault-slip data, mainly from the Camaquã Basin (Southern Brazil, sorted by stratigraphic level and cross-cutting relationships of superposed striations, and integrated with available stratigraphic and geochronological data. Our results show that the Camaquã Basin was formed by at least two distinct extensional events, and that rapid paleostress changes took place in the region a few tens of million years after the major collision (c.a. 630 Ma, probably due to the interplay between local active extensional tectonics and the distal effects of the continued amalgamation of plates and terranes at the margins of the still-forming Gondwana Plate. Preliminary paleostress data from the Castro Basin and published data from the Itajaí Basin suggest that these events had a regional nature.No Leste da América do Sul, um conjunto de bacias sedimentares que afloram do sul do Uruguai ao sudeste do Brasil formou-se após os eventos colisionais da Orogenia Brasiliana, registrando os eventos tectônicos que afetaram a região a partir do Mesoediacarano. O problema da distinção entre a tectônica formadora das bacias e os eventos deformacionais posteriores é aqui abordado através da análise de paleotensões de mais de 600 dados de falhas com estrias, obtidos principalmente na Bacia Camaquã (Sul do Brasil, que foram classificados por nível estratigráfico e relações de corte entre estrias sobrepostas, e intergrados a dados estratigráficos e geocronológicos disponíveis. Nossos resultados revelam que a Bacia Camaqu

  1. Induction of mammalian cell death by simple shear and extensional flows.

    Tanzeglock, Timm; Soos, Miroslav; Stephanopoulos, Gregory; Morbidelli, Massimo


    In this work we investigated whether the type of shear flow, to which cells are exposed, influences the initiation of cell death. It is shown that mammalian cells, indeed, distinguish between discrete types of flow and respond differently. Two flow devices were employed to impose accurate hydrodynamic flow fields: uniform steady simple shear flow and oscillating extensional flow. To distinguish between necrotic and apoptotic cell death, fluorescence activated cell sorting and the release of DNA in the culture supernatant was used. Results show that Chinese Hamster Ovaries and Human Embryonic Kidney cells will enter the apoptotic pathway when subjected to low levels of hydrodynamic stress (around 2.0 Pa) in oscillating, extensional flow. In contrast, necrotic death prevails when the cells are exposed to hydrodynamic stresses around 1.0 Pa in simple shear flow or around 500 Pa in extensional flow. These threshold values at which cells enter the respective death pathway should be avoided when culturing cells for recombinant protein production to enhance culture longevity and productivity.

  2. Extensional Tectonic Framework of Post High and Ultrahigh Pressure Metamorphism in Dabieshan, China


    The most prominent feature of the extensional tectonic framework of post high-pressure (HP) and ultrahigh-pressure (UHP) metamorphism in Dabieshan is the development of the multi-layered extension detachment zones surrounding the core of the Luotian dome, and the separation of the UHP, HP and epidote blueschist units by the detachment zones, which form the vertically stacking sheet-like slices of the HP and UHP metamorphic rocks. From the core outwards, exist the HP and UHP rock-barren Dabie complex, UHP unit, HP unit and epidote blueschist unit. The extension tectonics of post HP and UHP metamorphic event constrain the distribution and present configuration of the HP and UHP metamorphic rocks, and the extensional tectonic framework bears some similarities to the Cordillera metamorphic core complex. It is suggested that partial melting happened in the Dabie gneiss complex (DGC) and UHP unit contemporaneously with the extrusion of UHP metamorphic rocks into the lower-middle crust. The formation and emplacement of the migmatite and granites are the response to the change in thermal state, facilitating the transfer from the compressive regime to extensional regime in the crust. The large-scale crustal extension and uplift and the accompanying anatexis in Dabieshan are probably related to the delamination and magmatic underplating in the mantle and the lower crust.

  3. Pattern of seismic deformation in the Western Mediterranean

    S. Pondrelli


    Full Text Available The seismic deformation of the Western Mediterranean was studied with the aim of defining the strain pattern that characterizes the Africa-Eurasia plate boundary in this area. Within different sections along the boundary the cumulative moment tensor was computed over 90 years of seismological data. The results were compared with NUVELlA plate motion model and geodetic data. A stable agreement was found along Northern Africa to Sicily, where only Africa and Eurasia plates are involved. In this zone it is evident that changes in the strike of the boundary correspond to variations in the prevailing geometry of deformation, tectonic features and in the percentage of seismic with respect to total expected deformation. The geometry of deformation of periadriatic sections (Central to Southern Apennines, Eastern Alps and the Eastern Adriatic area agrees well with VLBI measurements and with regional geological features. Seismicity seems to account for low rates, from 3% to 31%, of total expected deformation. Only in the Sicily Strait, characterized by extensional to strike slip deformation, does the ratio reach a higher value (79%. If the amount of deformation deduced from seismicity seems low, because 90 years are probably not representative of the recurrence seismic cycle of the Western Mediterranean, the strain pattern we obtain from cumulative moment tensors is more representative of the kinematics of this area than global plate motion models and better identifies lower scale geodynamic features.

  4. Risk of shear failure and extensional failure around over-stressed excavations in brittle rock

    Nick Barton


    Full Text Available The authors investigate the failure modes surrounding over-stressed tunnels in rock. Three lines of investigation are employed: failure in over-stressed three-dimensional (3D models of tunnels bored under 3D stress, failure modes in two-dimensional (2D numerical simulations of 1000 m and 2000 m deep tunnels using FRACOD, both in intact rock and in rock masses with one or two joint sets, and finally, observations in TBM (tunnel boring machine tunnels in hard and medium hard massive rocks. The reason for ‘stress-induced’ failure to initiate, when the assumed maximum tangential stress is approximately (0.4–0.5σc (UCS, uniaxial compressive strength in massive rock, is now known to be due to exceedance of a critical extensional strain which is generated by a Poisson's ratio effect. However, because similar ‘stress/strength’ failure limits are found in mining, nuclear waste research excavations, and deep road tunnels in Norway, one is easily misled into thinking of compressive stress induced failure. Because of this, the empirical SRF (stress reduction factor in the Q-system is set to accelerate as the estimated ratio σθmax/σc >> 0.4. In mining, similar ‘stress/strength’ ratios are used to suggest depth of break-out. The reality behind the fracture initiation stress/strength ratio of ‘0.4’ is actually because of combinations of familiar tensile and compressive strength ratios (such as 10 with Poisson's ratio (say 0.25. We exceed the extensional strain limits and start to see acoustic emission (AE when tangential stress σθ ≈ 0.4σc, due to simple arithmetic. The combination of 2D theoretical FRACOD models and actual tunnelling suggests frequent initiation of failure by ‘stable’ extensional strain fracturing, but propagation in ‘unstable’ and therefore dynamic shearing. In the case of very deep tunnels (and 3D physical simulations, compressive stresses may be too high for extensional strain fracturing, and

  5. Eocene extensional exhumation of basement and arc rocks along southwesternmost Peru, Central Andes.

    Noury, Mélanie; Bernet, Matthias; Sempéré, Thierry


    The overthickened crust of the current Central Andes is commonly viewed as the result of tectonic shortening. However, in the present-day terrestrial forearc and arc of southwesternmost Peru, crustal thickness increases from 30 km along the coastline to >60 km below the active arc, whereas the upper crust exhibits little to no evidence of crustal shortening and, in constrast, many extensional features. How (and when) crustal overthickness was acquired in this region is thus little understood. Because crustal overthickening often results in extensional collapse and/or significant erosion, here we address this issue through a regional-scale study of exhumation using fission-track thermochronology. The limited fission-track data previously available in the area suggested that exhumation began during the Mesozoic. In this study, we present new apatite and zircon fission-track data obtained along the current terrestrial forearc of southwesternmost Peru. This relatively restricted area presents the interest of providing extensive outcrops of Precambrian to Ordovician basement and Early Jurassic to Late Cretaceous arc plutons. In order to compare the chronology of exhumation of these units, we performed extensive sampling for fission-track dating, as well as structural mapping. Our results indicate that the basement rocks and Jurassic plutons that crop out in the Arequipa region, where the crust is now >50 km-thick, experienced a rapid cooling through the 240-110°C temperature range between ~65 and ~35 Ma. This period of rapid exhumation coincided in time with the accumulation of terrestrial forearc deposits (the Lower Moquegua Group), that exhibit many syn-sedimentary extensional features and are bounded by conspicuous normal faults, specifically along the region where intense activity of the main arc between ~90 and ~60 Ma had led to voluminous magma emplacement. This close succession of (1) intense magmatic activity and (2) regional-scale exhumation associated with

  6. Uniaxial Extensional Behavior of A--B--A Thermoplastic Elastomers: Structure-Properties Relationship and Modeling

    Martinetti, Luca

    At service temperatures, A--B--A thermoplastic elastomers (TPEs) behave similarly to filled (and often entangled) B-rich rubbers since B block ends are anchored on rigid A domains. Therefore, their viscoelastic behavior is largely dictated by chain mobility of the B block rather than by microstructural order. Relating the small- and large-strain response of undiluted A--B--A triblocks to molecular parameters is a prerequisite for designing associated TPE-based systems that can meet the desired linear and nonlinear rheological criteria. This dissertation was aimed at connecting the chemical and topological structure of A--B--A TPEs with their viscoelastic properties, both in the linear and in the nonlinear regime. Since extensional deformations are relevant for the processing and often the end-use applications of thermoplastic elastomers, the behavior was investigated predominantly in uniaxial extension. The unperturbed size of polymer coils is one of the most fundamental properties in polymer physics, affecting both the thermodynamics of macromolecules and their viscoelastic properties. Literature results on poly(D,L-lactide) (PLA) unperturbed chain dimensions, plateau modulus, and critical molar mass for entanglement effect in viscosity were reviewed and discussed in the framework of the coil packing model. Self-consistency between experimental estimates of melt chain dimensions and viscoelastic properties was discussed, and the scaling behaviors predicted by the coil packing model were identified. Contrary to the widespread belief that amorphous polylactide must be intrinsically stiff, the coil packing model and accurate experimental measurements undoubtedly support the flexible nature of PLA. The apparent brittleness of PLA in mechanical testing was attributed to a potentially severe physical aging occurring at room temperature and to the limited extensibility of the PLA tube statistical segment. The linear viscoelastic response of A--B--A TPEs was first

  7. Probing hydrogen bond interactions in a shear thickening polysaccharide using nonlinear shear and extensional rheology.

    Jaishankar, Aditya; Wee, May; Matia-Merino, Lara; Goh, Kelvin K T; McKinley, Gareth H


    Mamaku gum is a polysaccharide extracted from the fronds of the black tree fern found in New Zealand. The cooked pith has traditionally been used for various medicinal purposes and as a food source by the Maori people of New Zealand. It has potential applications as a thickener in the food industry and as a palliative for patients with dysphagia. Studies on the shear rheology of Mamaku gum have revealed that the gum exhibits shear thickening at a critical shear rate due to a transition from intra- to inter-molecular chain interactions upon shear-induced chain elongation. In this paper, we demonstrate that these interactions are primarily due to hydrogen bonding. We perform extensional rheology on mixtures of Mamaku gum and urea (a known disruptor of hydrogen bonds) to quantify the nature of these interactions. Capillary Breakup Extensional Rheometry (CaBER) performed on the pure Mamaku gum solutions yield plateau values of the Trouton ratio as high as ∼10(4), showing that the viscoelasticity of the gum in uniaxial elongation is much higher than in shear. For all Mamaku concentrations tested, the extensional viscosity decreases upon increasing urea concentration. Furthermore, the relaxation time decreases exponentially with increasing urea concentration. This exponential relationship is independent of the Mamaku concentration, and is identical to the relationships between urea concentration and characteristic timescales measured in nonlinear shear rheology. We show using the sticky reptation model for polymers with multiple sticker groups along the backbone how such a relationship is consistent with a linear decrease in the free energy for hydrogen bond dissociation. We then demonstrate that a time-concentration superposition principle can be used to collapse the viscoelastic properties of the Mamaku-gum/urea mixtures. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Origin and role of fluids involved in the seismic cycle of extensional faults in carbonate rocks

    Smeraglia, Luca; Berra, Fabrizio; Billi, Andrea; Boschi, Chiara; Carminati, Eugenio; Doglioni, Carlo


    We examine the potentially-seismic right-lateral transtensional-extensional Tre Monti Fault (central Apennines, Italy) with structural and geochemical methods and develop a conceptual evolutionary model of extensional faulting with fluid involvement in shallow (≤3 km depth) faults in carbonate rocks. In the analysed fault zone, multiscale fault rock structures include injection veins, fluidized ultracataclasite layers, and crackle breccias, suggesting that the fault slipped seismically. We reconstructed the relative chronology of these structures through cross-cutting relationship and cathodoluminescence analyses. We then used C- and O-isotope data from different generations of fault-related mineralizations to show a shift from connate (marine-derived) to meteoric fluid circulation during exhumation from 3 to ≤1 km depths and concurrent fluid cooling from ∼68 to hydrological system, where prevalently connate fluids circulated within the fault zone at temperatures between 60° and 75 °C. During fault zone exhumation, at depths ≤1 km and temperatures hydrological circulation became open and meteoric-derived fluids progressively infiltrated and circulated within the fault zone. The role of these fluids during syn-exhumation seismic cycles of the Tre Monti Fault has been substantially passive along the whole fault zone, the fluids being passively redistributed at hydrostatic pressure following co-seismic dilatancy. Only the principal fault has been characterized, locally and transiently, by fluid overpressures. The presence of low-permeability clayey layers in the sedimentary sequence contributed to control the type of fluids infiltrating into the fault zone and possibly their transient overpressures. These results can foster the comprehension of seismic faulting at shallow depths in carbonate rocks of other fold-thrust belts involved in post-collisional seismogenic extensional tectonics.

  9. Deformation geometry and timing of theWupoer thrust belt in the NE Pamir and its tectonic implications

    Cheng, Xiaogan; Chen, Hanlin; Lin, Xiubin; Yang, Shufeng; Chen, Shenqiang; Zhang, Fenfen; Li, Kang; Liu, Zelin


    The Pamir region, located to the northwest of the Tibetan Plateau, provides important information that can aid the understanding of the plateau's tectonic evolution. Here we present new findings on the deformation geometry and timing of the Wupoer thrust belt at the northeastern margin of Pamir. Field investigations and interpretations of seismic profiles indicate that the eastern portion of the Wupoer thrust belt is dominated by an underlying foreland basin and an overlying piggy-back basin. A regional unconformity occurs between the Pliocene (N2) and the underlying Miocene (N1) or Paleogene (Pg) strata associated with two other local unconformities between Lower Pleistocene (Q1) and N2 and between Middle Pleistocene (Q2-4) and Q1 strata. Results of structural restorations suggest that compressional deformation was initiated during the latest Miocene to earliest Pliocene, contributing a total shortening magnitude of 48.6 km with a total shortening rate of 48.12%, most of which occurred in the period from the latest Miocene to earliest Pliocene. These results, combined with previous studies on the Kongur and Tarshkorgan extensional system, suggest an interesting picture of strong piedmont compressional thrusting activity concurrent with interorogen extensional rifting. Combining these results with previously published work on the lithospheric architecture of the Pamir, we propose that gravitational collapse drove the formation of simultaneous extensional and compressional structures with a weak, ductile middle crustal layer acting as a décollement along which both the extensional and compressional faults merged.

  10. Deformation geometry and timing of theWupoer thrust belt in the NE Pamir and its tectonic implications

    Cheng, Xiaogan; Chen, Hanlin; Lin, Xiubin; Yang, Shufeng; Chen, Shenqiang; Zhang, Fenfen; Li, Kang; Liu, Zelin


    The Pamir region, located to the northwest of the Tibetan Plateau, provides important information that can aid the understanding of the plateau's tectonic evolution. Here we present new findings on the deformation geometry and timing of the Wupoer thrust belt at the northeastern margin of Pamir. Field investigations and interpretations of seismic profiles indicate that the eastern portion of the Wupoer thrust belt is dominated by an underlying foreland basin and an overlying piggy-back basin. A regional unconformity occurs between the Pliocene (N2) and the underlying Miocene (N1) or Paleogene (Pg) strata associated with two other local unconformities between Lower Pleistocene (Q1) and N2 and between Middle Pleistocene (Q2-4) and Q1 strata. Results of structural restorations suggest that compressional deformation was initiated during the latest Miocene to earliest Pliocene, contributing a total shortening magnitude of 48.6 km with a total shortening rate of 48.12%, most of which occurred in the period from the latest Miocene to earliest Pliocene. These results, combined with previous studies on the Kongur and Tarshkorgan extensional system, suggest an interesting picture of strong piedmont compressional thrusting activity concurrent with interorogen extensional rifting. Combining these results with previously published work on the lithospheric architecture of the Pamir, we propose that gravitational collapse drove the formation of simultaneous extensional and compressional structures with a weak, ductile middle crustal layer acting as a décollement along which both the extensional and compressional faults merged.

  11. Extensional and Flexural Waves in a Thin-Walled Graphite/Epoxy Tube

    Prosser, William H.; Gorman, Michael R.; Dorighi, John


    Simulated acoustic emission signals were induced in a thin-walled graphite/epoxy tube by means of lead breaks (Hsu-Neilsen source). The tube is of similar material and layup to be used by NASA in fabricating the struts of Space Station Freedom. The resulting waveforms were detected by broad band ultrasonic transducers and digitized. Measurements of the velocities of the extensional and flexural modes were made for propagation directions along the tube axis (0 degrees), around the tube circumference (90 degrees) and at an angle of 45 degrees. These velocities were found to be in agreement with classical plate theory.

  12. An Extensional Characterization of Lambda-Lifting and Lambda-Dropping

    Danvy, Olivier


    Lambda-lifting and lambda-dropping respectively transform a block-structured functional program into recursive equations and vice versa. Lambda-lifting was developed in the early 80’s, whereas lambda-dropping is more recent. Both are split into an analysis and a transformation. Published work......, however, has only concentrated on the analysis parts. We focus here on the transformation parts and more precisely on their correctness, which appears never to have been proven. To this end, we define extensional versions of lambda-lifting and lambda-dropping and establish their correctness with respect...

  13. An Extensional Characterization of Lambda-Lifting and Lambda-Dropping

    Danvy, Olivier


    Lambda-lifting and lambda-dropping respectively transform a block-structured functional program into recursive equations and vice versa. Lambda-lifting was developed in the early 80’s, whereas lambda-dropping is more recent. Both are split into an analysis and a transformation. Published work......, however, has only concentrated on the analysis parts. We focus here on the transformation parts and more precisely on their correctness, which appears never to have been proven. To this end, we define extensional versions of lambda-lifting and lambda-dropping and establish their correctness with respect...

  14. Extensional basin evolution in the presence of small-scale convection

    Petersen, Kenni Dinesen; Nielsen, S.B.; Clausen, O.R.


    The plate model of Parsons & Sclater provides a generally accepted, quantitative framework for the thermal subsidence-evolution in extensional basins. It predicts an asymptotic evolution of the geotherm towards a steady state, featuring a constant lithospheric thickness and ceased subsidence...... a two-dimensional, numerical, thermo-mechanical model of the lithosphere and upper mantle to asses the effects of small-scale convection. Given a particular mantle rheology, our model features such convection, and, over time, the horizontally averaged geotherm converges towards a self-consistent, quasi...

  15. Tectono-stratigraphic evolution of an inverted extensional basin: the Cameros Basin (north of Spain)

    Omodeo Salè, Silvia; Guimerà, Joan; Mas, Ramón; Arribas, José


    The Cameros Basin is a part of the Mesozoic Iberian Rift. It is an extensional basin formed during the late Jurassic and early Cretaceous, in the Mesozoic Iberian Rift context, and it was inverted in the Cenozoic as a result of the Alpine contraction. This work aims to reconstruct the tectono-stratigraphic evolution of the basin during the Mesozoic, using new and revised field, geophysical and subsurface data. The construction of a basin-wide balanced section with partial restorations herein offers new insights into the geometry of the syn-rift deposits. Field data, seismic lines and oil well data were used to identify the main structures of the basin and the basin-forming mechanisms. Mapping and cross-sectional data indicate the marked thickness variation of the depositional sequences across the basin, suggesting that the extension of the depositional area varied during the syn-rift stage and that the depocentres migrated towards the north. From field observation and seismic line interpretation, an onlap of the depositional sequences to the north, over the marine Jurassic substratum, can be deduced. In the last few decades, the structure and geometry of the basin have been strongly debated. The structure and geometry of the basin infill reconstructed herein strongly support the interpretation of the Cameros Basin as an extensional-ramp synclinal basin formed on a blind south-dipping extensional ramp. The gradual hanging-wall displacement to the south shifted the depocentres to the north over time, thus increasing the basin in size northwards, with onlap geometry on the pre-rift substratum. The basin was inverted by means of a main thrust located in a detachment located in the Upper Triassic beds (Keuper), which branched in depth with the Mesozoic extensional fault flat. The reconstruction of the tectono-stratigraphic evolution of the Cameros Basin proposed herein represents a synthesis and an integration of previous studies of the structure and geometry of the

  16. Dynamics of Star Polymers in Fast Extensional Flow and Stress Relaxation

    Huang, Qian; Agostini, Serena; Hengeller, Ludovica


    We confirm the observation from Ianniruberto and Marrucci [ Macromolecules 2013, 46, 267-275 ] that entangled melts of branched polystyrenes behave like linear polystyrenes in the steady state of fast extensional flow, by measuring a linear, an asymmetric star, and a symmetric star polystyrene wi...... they relax in a similar way, most likely via arm retraction, at short time, but behave differently at long time due to both the length of the arm and the branch point. The terminal relaxation is described by a Doi and Edwards based model, i.e., considering pure orientational relaxation....

  17. Miocene extension and extensional folding in an anticlinal segment of the Black Mountains accommodation zone, Colorado River extensional corridor, southwestern United States

    Varga, Robert J.; Faulds, James E.; Snee, Lawrence W.; Harlan, Stephen S.; Bettison-Varga, Lori


    Recent studies demonstrate that rifts are characterized by linked tilt domains, each containing a consistent polarity of normal faults and stratal tilt directions, and that the transition between domains is typically through formation of accommodation zones and generally not through production of throughgoing transfer faults. The mid-Miocene Black Mountains accommodation zone of southern Nevada and western Arizona is a well-exposed example of an accommodation zone linking two regionally extensive and opposing tilt domains. In the southeastern part of this zone near Kingman, Arizona, east dipping normal faults of the Whipple tilt domain and west dipping normal faults of the Lake Mead domain coalesce across a relatively narrow region characterized by a series of linked, extensional folds. The geometry of these folds in this strike-parallel portion of the accommodation zone is dictated by the geometry of the interdigitating normal faults of opposed polarity. Synclines formed where normal faults of opposite polarity face away from each other whereas anticlines formed where the opposed normal faults face each other. Opposed normal faults with small overlaps produced short folds with axial trends at significant angles to regional strike directions, whereas large fault overlaps produce elongate folds parallel to faults. Analysis of faults shows that the folds are purely extensional and result from east/northeast stretching and fault-related tilting. The structural geometry of this portion of the accommodation zone mirrors that of the Black Mountains accommodation zone more regionally, with both transverse and strike-parallel antithetic segments. Normal faults of both tilt domains lose displacement and terminate within the accommodation zone northwest of Kingman, Arizona. However, isotopic dating of growth sequences and crosscutting relationships show that the initiation of the two fault systems in this area was not entirely synchronous and that west dipping faults of the

  18. 3D geometrical modelling of post-foliation deformations in metamorphic terrains (Syros, Cyclades, Greece)

    Philippon, Mélody; Le Carlier de Veslud, Christian; Gueydan, Frédéric; Brun, Jean-Pierre; Caumon, Guillaume


    Superposed to ductile syn-metamorphic deformations, post-foliation deformations affect metamorphic units during their exhumation. Understanding the role of such deformations in the structuration of metamorphic units is key for understanding the tectonic evolution of convergence zones. We characterize post-foliations deformations using 3D modelling which is a first-order tool to describe complex geological structures, but a challenging task where based only on surface data. We propose a modelling procedure that combines fast draft models (interpolation of orientation data), with more complex ones where the structural context is better understood (implicit modelling), allowing us to build a 3D geometrical model of Syros Island blueschists (Cyclades), based on field data. With our approach, the 3D model is able to capture the complex present-day geometry of the island, mainly controlled by the superposition of three types of post-metamorphic deformations affecting the original metamorphic pile: i) a top-to-South ramp-flat extensional system that dominates the overall island structure, ii) large-scale folding of the metamorphic units associated with ramp-flat extensional system, and iii) steeply-dipping normal faults trending dominantly NNW-SSE and EW. The 3D surfaces produced by this method match outcrop data, are geologically consistent, and provide reasonable estimates of geological structures in poorly constrained areas.

  19. Transient overshoot extensional rheology of long-chain branched polyethylenes: Experimental and numerical comparisons between filament stretching and cross-slot flow

    Hoyle, D.M.; Huang, Qian; Auhl, D.


    This work analyses the high-strain extensional behavior of long-chain branched polyethylenes, employing two novel extensional rheometer devices, the filament stretching rheometer and the cross-slot extensional rheometer. The filament stretching rheometer uses an active feedback loop to control...... the outflow centre line (named W-cusps). Using constitutive modeling of the observed transient overshoot in extension seen in the filament stretching rheometer and using finite element simulations we show that the overshoot explains the W-cusps seen in the cross-slot extensional rheometer, further confirming...

  20. Transient extensional viscosity of polymer melts in the filament stretching rheometer. A. Bach, H. Bastian, M.H. Wagner, H.K. Rasmussen and O. Hassager

    Rasmussen, Henrik Koblitz; Bach, Anders; Bastian, Heike


    In many polymer processing operations, the polymer molecules becomes highly elongated and the extensional viscosity becomes an inportant parameter in estimating properties during and after the process....

  1. Transient extensional viscosity of polymer melts in the filament stretching rheometer. A. Bach, H. Bastian, M.H. Wagner, H.K. Rasmussen and O. Hassager

    Rasmussen, Henrik Koblitz; Bach, Anders; Bastian, Heike


    In many polymer processing operations, the polymer molecules becomes highly elongated and the extensional viscosity becomes an inportant parameter in estimating properties during and after the process....

  2. Avalanches of coalescence events and local extensional flows--stabilisation or destabilisation due to surfactant.

    Gunes, Deniz Z; Clain, Xavier; Breton, Olivier; Mayor, Guy; Burbidge, Adam S


    From two-drop collision experiments, it is known that local extensional flow favors coalescence. Recently, Bremond et al. used microfluidic methods to evidence this point. Similarly, we used specific microfluidic geometries to impose sudden extensional flow, following drop collision under controlled conditions, and coalescence events were recorded with a high-speed camera. In this study we focus on the effect of surfactant on the coalescence, or stabilisation against it, between drops flowing apart due to either imposed external flow or capillary forces related to drop shape relaxation. Coalescence can be induced even when drops are initially separated by an intersticial lubricating film by far thicker than the critical thickness for rupturing under the action of Van der Waals forces. This is particularly relevant to avalanches of coalescence events, in flowing or even quiescent emulsions or foams. When non-ionic surfactant was used, it was observed that small concentrations apparently enhance coalescence in extension. But at higher concentrations it provides stabilisation through a specific mechanism of thread formation and rupture; the stabilisation mechanism can be complex.

  3. Dynamic Finite Element Analysis of Extensional-Torsional Coupled Vibration in Nonuniform Composite Beams

    Hashemi, Seyed M.; Roach, Andrew


    The application of a Dynamic Finite Element (DFE) technique to the extensional-torsional free vibration analysis of nonuniform composite beams, in the absence of flexural coupling, is presented. The proposed method is a fusion of the Galerkin weighted residual formulation and the Dynamic Stiffness Matrix (DSM) method, where the basis functions of approximation space are assumed to be the closed form solutions of the differential equations governing uncoupled extensional and torsional vibrations of the beam. The use of resulting dynamic trigonometric interpolation (shape) functions leads to a frequency dependent stiffness matrix, representing both mass and stiffness properties of the beam element. Assembly of the element matrices and the application of the boundary conditions then leads to a frequency dependent nonlinear eigenproblem, which is solved to evaluate the system natural frequencies and modes. Two illustrative examples of uniform and tapered cantilevered, Circumferentially Uniform Stiffness ( CUS), hollow, composite beams are presented. The influence of ply fibre-angle on the natural frequencies is also studied. The correctness of the theory and the superiority of the proposed DFE over the contrasting DSM and conventional FEM methods are confirmed by the published results and numerical checks. The discussion of results is followed by some concluding remarks.

  4. Reflection of drill-string extensional waves at the bit-rock contact.

    Poletto, Flavio; Malusa, Massimo


    Downward propagating extensional waves are partially reflected at the bit-rock contact. The evaluation of the reflection coefficient is important to obtain while drilling information about the acoustic properties of the formations. The scope of this work is to estimate the bit-rock reflection coefficient, assuming a flat drill bit in perfect contact with the formation. Using the low-frequency approximation, which holds when the wavelength is much larger than the lateral dimensions of the borehole, the drill-string is assumed to be a laterally free rod, and the formation an homogeneous and isotropic medium. This work shows that the reflection coefficient of the extensional waves depends, along with the elastic properties of the formation, on the ratio of the cross sections of the drill-string and borehole. The impedance of the drilled rock can be calculated from the measured reflection coefficient, which is related to the amplitude of waves produced in the string and in the formation by a working drill-bit.

  5. Structural evolution of fault zones in sandstone by multiple deformation mechanisms: Moab fault, southeast Utah

    Davatzes, N.C.; Eichhubl, P.; Aydin, A.


    Faults in sandstone are frequently composed of two classes of structures: (1) deformation bands and (2) joints and sheared joints. Whereas the former structures are associated with cataclastic deformation, the latter ones represent brittle fracturing, fragmentation, and brecciation. We investigated the distribution of these structures, their formation, and the underlying mechanical controls for their occurrence along the Moab normal fault in southeastern Utah through the use of structural mapping and numerical elastic boundary element modeling. We found that deformation bands occur everywhere along the fault, but with increased density in contractional relays. Joints and sheared joints only occur at intersections and extensional relays. In all locations , joints consistently overprint deformation bands. Localization of joints and sheared joints in extensional relays suggests that their distribution is controlled by local variations in stress state that are due to mechanical interaction between the fault segments. This interpretation is consistent with elastic boundary element models that predict a local reduction in mean stress and least compressive principal stress at intersections and extensional relays. The transition from deformation band to joint formation along these sections of the fault system likely resulted from the combined effects of changes in remote tectonic loading, burial depth, fluid pressure, and rock properties. In the case of the Moab fault, we conclude that the structural heterogeneity in the fault zone is systematically related to the geometric evolution of the fault, the local state of stress associated with fault slip , and the remote loading history. Because the type and distribution of structures affect fault permeability and strength, our results predict systematic variations in these parameters with fault evolution. ?? 2004 Geological Society of America.

  6. Seismic slip at the base of the seismogenic layer along the exhumed extensional Oligocene Trois Villes Fault (Western Italian Alps)

    Bistacchi, A.; Gatta, D.; Grizzetti, R.; Pennacchioni, G.


    The characterisation of fault rocks from exhumed faults is of paramount importance in fault and earthquake mechanics, since these rocks might provide constraints for models of seismic rupture initiation and propagation. The Trois Ville Fault is a major Oligocene extensional fault of the internal NW Alps, showing a cumulative displacement of c.a. 1 km evidenced by the offset boundary between Austroalpine gneisses (hangingwall) and Piedmont calcschists (footwall). Fault rocks consist of greenschist mylonitic gneiss (from an early stage), green indurated cataclasites, which constitute the 2-10 m thick core zone, and a thin (c.a. 10 cm) but extremely continuous layer of polycyclic pseudotachylytes which mark a strongly localised principal slipping zone. Pseudotachylytes lack distinctive features such as glass, microlites-spherulites, etc., but show a distinctive mineralogy of the melt-derived very fine-grained matrix, which is almost entirely constituted by monoclinic K-feldspar (low sanidine crystallised at ca. 990°C and partly ordered as far as 500- 700°C). This matrix is composed by very small crystals (0.5-5 μm), organised in aggregates and dendritic snowflake-like aggregates which might be explained by sintering or synneusis processes. The high crystallization T implies that pseudotachylytes derive from frictional melting of ultracataclasites (possibly incoherent, hence a fault gouge, at the time of deformation) near the brittle plastic transition (250- 300°C and 8-10 km). Hence, a new diagnostic criterion for frictional melting, based on crystallographic analysis, is introduced in this work. The melt mainly derived from phyllosilicates (muscovite and minor chlorite; Tmelt c.a. 750°C) and evidences of superheating may be envisaged (partial assimilation of albite and quartz; T > c.a. 1300°C). This points to a considerable seismic slip after the onset of frictional melting and to an efficient melting lubrication process in this kind of fault rocks

  7. Tectónica extensional triásica en el sector norte de la cuenca Cuyana: primeros datos cinemáticos Triassic extensional tectonics at the northern branch of the Cuyana basin (South Precordillera: First kinematic data

    María S. Japas


    . 35º- 40° obtenida en los afloramientos de la quebrada El Salto, se infiere en forma preliminar una importante componente sinestral durante la extensión en el tramo norte de la cuenca.Triassic clastic and volcanic rocks from the Precordillera were deposited in the Cuyana rift basin filling half-graben systems. Contractional/ transpressional Andean tectonics leads to the almost complete inversion of some portions of the basin which resulted in present-day isolated, structurally controlled outcrops of these Triassic rocks. In the Southern Precordillera both the degree of Neogene tectonic inversion and structural compexities are variable. At the regional scale, these variations in Andean deformation are related to first order anisotropies like the Cuyana basin borders and previous shear zones of Permian age (San Rafael orogenic phase. This paper focuses on the kinematic analysis done in the Cerro Manantial thrust sheet area (Cordón San Bartolo, central sector of the South Precordillera where tectonic inversion was not that strong and the influence of oblique strain zones is practically null. Four sets of extensional / transtensional faults were recognized affecting Triassic sedimentary rocks of the El Cielo Formation (Uspallata Group at the Quebrada El Salto. Fault displacements are of decimetric to metric scale. Mesoscopic kinematic indicators (en-échèlon tensional gashes, Riedel shear fractures, sigmoidal fractures were measured. Once Andean deformation was restored, a NNE direction for the Triassic extension was determined. Considering a northern branch of the Cuyana basin trending NNW (Az. 150° and oblique to the direction of extension (Az. 35-40°, a sinistral strike-slip component could be inferred for this portion of the basin.

  8. The role of crustal quartz in controlling Cordilleran deformation.

    Lowry, Anthony R; Pérez-Gussinyé, Marta


    Large-scale deformation of continents remains poorly understood more than 40 years after the plate tectonic revolution. Rock flow strength and mass density variations both contribute to stress, so both are certain to be important, but these depend (somewhat nebulously) on rock type, temperature and whether or not unbound water is present. Hence, it is unclear precisely how Earth material properties translate to continental deformation zones ranging from tens to thousands of kilometres in width, why deforming zones are sometimes interspersed with non-deforming blocks and why large earthquakes occasionally rupture in otherwise stable continental interiors. An important clue comes from observations that mountain belts and rift zones cyclically form at the same locations despite separation across vast gulfs of time (dubbed the Wilson tectonic cycle), accompanied by inversion of extensional basins and reactivation of faults and other structures formed in previous deformation events. Here we show that the abundance of crustal quartz, the weakest mineral in continental rocks, may strongly condition continental temperature and deformation. We use EarthScope seismic receiver functions, gravity and surface heat flow measurements to estimate thickness and seismic velocity ratio, v(P)/v(S), of continental crust in the western United States. The ratio v(P)/v(S) is relatively insensitive to temperature but very sensitive to quartz abundance. Our results demonstrate a surprising correlation of low crustal v(P)/v(S) with both higher lithospheric temperature and deformation of the Cordillera, the mountainous region of the western United States. The most plausible explanation for the relationship to temperature is a robust dynamical feedback, in which ductile strain first localizes in relatively weak, quartz-rich crust, and then initiates processes that promote advective warming, hydration and further weakening. The feedback mechanism proposed here would not only explain

  9. Early Permian extensional shearing of an Ordovician granite: The Saint-Eutrope "C/S-like" orthogneiss (Montagne Noire, French Massif Central)

    Pitra, Pavel; Poujol, Marc; Van Den Driessche, Jean; Poilvet, Jean-Charles; Paquette, Jean-Louis


    Dating the magmatic events in the Montagne Noire gneiss dome is a key point to arbitrate between the different interpretations of the Late Carboniferous-Early Permian tectonics in this southern part of the Variscan belt. The Saint-Eutrope orthogneiss crops out along the northern flank of the dome. We show that the protolith of this orthogneiss is an Ordovician granite dated at 455 ± 2 Ma (LA-ICP-MS U-Pb dating on zircon). This age is identical to that previously obtained on the augen orthogneiss of the southern flank, strongly suggesting that both orthogneiss occurrences have the same Ordovician protolith. The Saint-Eutrope orthogneiss experienced intense shearing along the Espinouse extensional detachment at ca. 295 Ma (LA-ICP-MS U-Pb-Th on monazite), an age close to that determined previously on mica by the 39Ar-40Ar method and contemporaneous with the emplacement age of the syntectonic Montalet granite farther to the west. This normal sense shearing reworked previous fabrics related to Variscan thrusting that can be still observed in the augen orthogneiss of the southern flank, and is responsible for the spectacular "C/S-like" pattern of the Saint-Eutrope orthogneiss. This work also shows that care is needed when dealing with C/S-type structures, since they can develop not only in syntectonic intrusions, but also in orthogneisses affected by an intense secondary deformation, at decreasing temperature.

  10. Derivation of deformation characteristics in fast-moving glaciers

    Herzfeld, Ute C.; Clarke, Garry K. C.; Mayer, Helmut; Greve, Ralf


    Crevasse patterns are the writings in a glacier's history book—the movement, strain and deformation frozen in ice. Therefore by analysis of crevasse patterns we can learn about the ice-dynamic processes which the glacier has experienced. Direct measurement of ice movement and deformation is time-consuming and costly, in particular for large glaciers; typically, observations are lacking when sudden changes occur. Analysis of crevasse patterns provides a means to reconstruct past and ongoing deformation processes mathematically. This is especially important for fast-moving ice. Ice movement and deformation are commonly described and analyzed using continuum mechanics and measurements of ice velocities or strain rates. Here, we present a different approach to the study of ice deformation based on principles of structural geology. Fast ice movement manifests itself in the occurrence of crevasses. Because crevasses remain after the deformation event and may be transported, overprinted or closed, their analysis based on aerial videography and photography or satellite data gives information on past deformation events and resulting strain states. In our treatment, we distinguish (A) continuously fast-moving glaciers and ice streams, and (B) surge-type glaciers, based on observations of two prototypes, Jakobshavns Isbræ, Greenland, for (A), and Bering Glacier, Alaska, during the 1993-1995 surge, for (B). Classes of ice-deformation types are derived from aerial images of ice surfaces using structural geology, i.e. structural glaciology. For each type, the deformation gradient matrix is formed. Relationships between invariants used in structural geology and continuum mechanics and the singular value decomposition are established and applied to ice-surface classification. Deformation during a surge is mostly one of the extensional deformation types. Continuously, or infinitesimally repeated, deformation acting in continuously fast-moving ice causes different typical

  11. A workflow for sub-/seismic structure and deformation quantification of 3-D reflection seismic data sets across different scales

    Krawczyk, C.M.; Lohr, T.; Oncken, O. [GFZ Potsdam (Germany); Tanner, D.C. [Goettingen Univ. (Germany). GZG; Endres, H. [RWTH Aachen (Germany)]|[TEEC, Isernhagen (Germany); Trappe, H.; Kukla, P. [TEEC, Isernhagen (Germany)


    The evolution of a sedimentary basin is mostly affected by deformation. Large-scale, subsurface deformation is typically identified by seismic data, sub-seismic small-scale fractures by well data. Between these two methods, we lack a deeper understanding of how deformation scales. We analysed a 3-D reflection seismic data set in the North German Basin, in order to determine the magnitude and distribution of deformation and its accumulation in space and time. A five-step approach is introduced for quantitative deformation and fracture prediction. An increased resolution of subtle tectonic lineaments is achieved by coherency processing, allowing to unravel the kinematics in the North German Basin from structural interpretation. Extensional events during basin initiation and later inversion are evident. 3-D retrodeformation shows major-strain magnitudes between 0-20% up to 1.3 km away from a fault trace, and variable deviations of associated extensional fractures. Good correlation of FMI data, strain distribution from retro-deformation and from geostatistic tools (see also Trappe et al., this volume) allows the validation of the results and makes the prediction of small-scale faults/fractures possible. The temporal component will be gained in the future by analogue models. The suggested workflow is applicable to reflection seismic surveys and yields in great detail both the tectonic history of a region as well as predictions for hydrocarbon plays or deep groundwater or geothermal reservoirs. (orig.)

  12. Extensional flow of nematic liquid crystal with an applied electric field



    Systematic asymptotic methods are used to formulate a model for the extensional flow of a thin sheet of nematic liquid crystal. With no external body forces applied, the model is found to be equivalent to the so-called Trouton model for Newtonian sheets (and fibres), albeit with a modified \\'Trouton ratio\\'. However, with a symmetry-breaking electric field gradient applied, behaviour deviates from the Newtonian case, and the sheet can undergo finite-time breakup if a suitable destabilizing field is applied. Some simple exact solutions are presented to illustrate the results in certain idealized limits, as well as sample numerical results to the full model equations. Copyright © Cambridge University Press 2013.

  13. Monitoring the hydration of DNA self-assembled monolayers using an extensional nanomechanical resonator.

    Cagliani, Alberto; Kosaka, Priscila; Tamayo, Javier; Davis, Zachary James


    We have fabricated an ultrasensitive nanomechanical resonator based on the extensional vibration mode to weigh the adsorbed water on self-assembled monolayers of DNA as a function of the relative humidity. The water adsorption isotherms provide the number of adsorbed water molecules per nucleotide for monolayers of single stranded (ss) DNA and after hybridization with the complementary DNA strand. Our results differ from previous data obtained with bulk samples, showing the genuine behavior of these self-assembled monolayers. The hybridization cannot be inferred from the water adsorption isotherms due to the low hybridization efficiency of these highly packed monolayers. Strikingly, we efficiently detect the hybridization by measuring the thermal desorption of water at constant relativity humidity. This finding adds a new nanomechanical tool for developing a label-free nucleic acid sensor based on the interaction between water and self-assembled monolayers of nucleic acids.

  14. Genetic model of hanging wall syncline and central dome in extensional fault

    刘德来; 丁贵明; 鲁兵


    Hanging wall syncline and central dome are special extension structures, developing over the hanging wall in an extensional ramp-flat fault. Under the condition that the flat is sub-horizontal, the hanging wall syncline is separated from the half graben by the central dome. And on the dome forms an erosional surface. Both sediments in the half graben and erosional surface on the top of the central dome extended over the dome and entered into the hanging wall syncline with extension going on. Meanwhile, those having entered were overlapped by new sedimentary layers in the hanging wall syncline, so that there is a together-threaded, diachronic unconformity to form in the same epoch stratum. The layers in the hanging wall syncline also have an attribute of migrating laterally and getting tilted with extension. There is no sedimentation on the central dome. But sediments, which came from the half graben, got thicker over the dome in extension.

  15. Carbonate sedimentation in an extensional active margin: Cretaceous history of the Haymana region, Pontides

    Okay, Aral I.; Altiner, Demir


    The Haymana region in Central Anatolia is located in the southern part of the Pontides close to the İzmir-Ankara suture. During the Cretaceous, the region formed part of the south-facing active margin of the Eurasia. The area preserves a nearly complete record of the Cretaceous system. Shallow marine carbonates of earliest Cretaceous age are overlain by a 700-m-thick Cretaceous sequence, dominated by deep marine limestones. Three unconformity-bounded pelagic carbonate sequences of Berriasian, Albian-Cenomanian and Turonian-Santonian ages are recognized: Each depositional sequence is preceded by a period of tilting and submarine erosion during the Berriasian, early Albian and late Cenomanian, which corresponds to phases of local extension in the active continental margin. Carbonate breccias mark the base of the sequences and each carbonate sequence steps down on older units. The deep marine carbonate deposition ended in the late Santonian followed by tilting, erosion and folding during the Campanian. Deposition of thick siliciclastic turbidites started in the late Campanian and continued into the Tertiary. Unlike most forearc basins, the Haymana region was a site of deep marine carbonate deposition until the Campanian. This was because the Pontide arc was extensional and the volcanic detritus was trapped in the intra-arc basins and did not reach the forearc or the trench. The extensional nature of the arc is also shown by the opening of the Black Sea as a backarc basin in the Turonian-Santonian. The carbonate sedimentation in an active margin is characterized by synsedimentary vertical displacements, which results in submarine erosion, carbonate breccias and in the lateral discontinuity of the sequences, and differs from blanket like carbonate deposition in the passive margins.

  16. Extensional Seismogenic Stress and Tectonic Movement on the Central Region of the Tibetan Plateau

    Jiren Xu


    Full Text Available Various earthquake fault types, mechanism solutions and stress fields, as well as GPS and geothermal data are analyzed for the study of the crustal movements on the Tibetan plateau and their tectonic implications. The results show that a lot of the normal faulting type-event concentrated at altitudes greater than 4000 m on the central Tibetan plateau. The altitudes concentrating normal faulting type-events can be zoned two parts: the western part, the Lhasa block, and the eastern part, the Qiangtang-Changdu region. The azimuths of T-axes are in a general E-W direction in the Lhasa block and NW-SE or NNW-SSE in the Qiangtang-Changdu region at the altitudes of the Tibetan plateau. The tensional stresses in E-W direction and NW-SE direction predominate normal faulting earthquake occurrence in the Lhasa block and the Qiangtang-Changdu region, respectively. The slipping displacements of the normal-faulting-type events have great components in near E-W direction and NW-SE direction in the Lhasa block and the Qiangtang-Changdu region, respectively. The extensions are probably an eastward or southeastward extensional motion, being mainly tectonic activity phenomena in the plateau altitudes. The extensional motions due to normal-fault earthquakes are important tectonic activity regimes on the high altitudes of the plateau. The easterly crustal extensions on the plateau are attributable to the gravitational collapse of the high plateau and eastward extrusion of hotter mantle materials beneath the eastern boundary of the plateau. Numbers of thrust-fault and strike-slip-fault earthquakes with strong compressive stress in a general NNE-SSW direction occur on the edges of the plateau.

  17. Analysis Method for Predicting Strain in Interior Beds and Sub-Resolution Faults from Area Balance Theory in Extensional Basins


    Extensional basins include mainly grabens and half grabens displaced along a lower detachment. Based on area balance theory, there is a linear relationship between a height of regional and the lower detachment h on the outside of the basin and "lost area S" from the regional in the basin. The pre-growth beds above lower detachment are of the same extensional displacement so that an "S-h diagram" can be used to determine the depth to lower detachment and to calculate the total extensional displacement of the beds above the lower detachment. The extensional displacement is dominated by the heave of various scale normal faults. The displacement of obvious faults can be immediately figured out from the measured bed-length. The requisite extension calculated by area balance is the layer-parallel strain, which could be accommodated by displacement on sub-resolution faults. Accordingly, the layer-parallel strain can help us predict the magnitude and distribution of sub-resolution faults on the basis of analysis of the structural style and rheological behavior.

  18. Deformations of crystal frameworks

    Borcea, Ciprian S


    We apply our deformation theory of periodic bar-and-joint frameworks to tetrahedral crystal structures. The deformation space is investigated in detail for frameworks modelled on quartz, cristobalite and tridymite.

  19. Deformed General Relativity

    Bojowald, Martin


    Deformed special relativity is embedded in deformed general relativity using the methods of canonical relativity and loop quantum gravity. Phase-space dependent deformations of symmetry algebras then appear, which in some regimes can be rewritten as non-linear Poincare algebras with momentum-dependent deformations of commutators between boosts and time translations. In contrast to deformed special relativity, the deformations are derived for generators with an unambiguous physical role, following from the relationship between canonical constraints of gravity with stress-energy components. The original deformation does not appear in momentum space and does not give rise to non-locality issues or problems with macroscopic objects. Contact with deformed special relativity may help to test loop quantum gravity or restrict its quantization ambiguities.

  20. New constraints on the timing of flexural deformation along the northern Australian margin: Implications for arc-continent collision and the development of the Timor Trough

    Saqab, Muhammad Mudasar; Bourget, Julien; Trotter, Julie; Keep, Myra


    Numerous extensional faults offset the passive margin strata of the northern Bonaparte Basin. This extensional deformation has been attributed to lithospheric flexure of the descending Australian Plate, in an overall convergence setting. Here we use an extensive 2D and 3D seismic dataset calibrated with well biostratigraphy and strontium (Sr) isotope age data to constrain the timing of deformation along the northern Australian margin during the Neogene. Analysis of fault throw and differential thickness variations give new insights on the propagation and slip history of the faults. Along-dip throw profiles exhibit 'D' shape distributions, skewed towards the top. Positive throw gradients above the throw maxima, coinciding with intervals of growth strata, indicate multiphase fault activity. Results indicate that post-rift extensional deformation initiated during the latest Miocene (ca. 6 Ma). The development of the modern Timor Trough (as a foreland basin) and Cartier Trough also commenced during this period. A second episode of increased tectonic activity occurred around the Pliocene-Quaternary boundary (ca. 3 Ma), and the deformation continued intermittently to the present-day. These new results are in agreement with the timing of initiation of collision between the Australian Plate and the Banda Arc and uplift of the Timor Island, recently derived from stratigraphic analysis in Timor. These regional tectonic events have profoundly affected the paleogeography of the Timor Sea and may explain major changes in oceanic circulation and climate during the Neogene.

  1. Death Valley turtlebacks: Mesozoic contractional structures overprinted by Cenozoic extension and metamorphism beneath syn-extensional plutons

    Pavlis, T. L.; Miller, M.; Serpa, L.


    The term turtleback was first coined to describe the curvilinear fault surfaces that produced a distinctive geomorphic form in the Black Mountains east of Death Valley, and although it was decades before their full significance was appreciated, they remain one of the most distinctive features of the extensional structure of the Death Valley region. Historically the interpretation of the features has varied markedly, and misconceptions about their character continue to abound, including descriptions in popular field guides for the area. It the 1990's, however, the full history of the systems began to be apparent from several key data: 1) the dating of the plutonic assemblage associated with the turtlebacks demonstrated that late Miocene, syn-extensional plutonism was fundamental to their formation; 2) the plutonic assemblage forms an intrusive sheet structurally above the turtlebacks, indicating a tie between much of the high grade metamorphism and Cenozoic plutonism; 3) a modern analog for the syn-extensional plutonism in the Black Mountains was recognized beneath Death Valley with the imaging of a mid-crustal magma body; 4) the Neogene structural history was worked out in the turtlebacks showing that folding of early-formed shear zones formed the turtleback anticlinoria but overprinting by brittle faults produced the final form as they cut obliquely across the older structure; and 5) the pre-extensional structural history was clarified, demonstrating that Mesozoic basement-involved thrust systems are present within the turtlebacks, but have been overprinted by the extensional system. An unresolved issue is the significance of Eocene U-Pb dates for pegmatites within the region, but presumably these relate somehow to the pre-extensional history. Miller and Pavlis (2005; E. Sci. Rev.) reviewed many features of the turtlebacks, and our working model for the region is that the turtlebacks originated as mid-crustal ductile-thrust systems within the Cordilleran fold

  2. Deformable Nanolaminate Optics

    Olivier, S S; Papavasiliou, A P; Barbee, T W; Miles, R R; Walton, C C; Cohn, M B; Chang, K


    We are developing a new class of deformable optic based on electrostatic actuation of nanolaminate foils. These foils are engineered at the atomic level to provide optimal opto-mechanical properties, including surface quality, strength and stiffness, for a wide range of deformable optics. We are combining these foils, developed at Lawrence Livermore National Laboratory (LLNL), with commercial metal processing techniques to produce prototype deformable optics with aperture sizes up to 10 cm and actuator spacing from 1 mm to 1 cm and with a range of surface deformation designed to be as much as 10 microns. The existing capability for producing nanolaminate foils at LLNL, coupled with the commercial metal processing techniques being used, enable the potential production of these deformable optics with aperture sizes of over 1 m, and much larger deformable optics could potentially be produced by tiling multiple deformable segments. In addition, based on the fabrication processes being used, deformable nanolaminate optics could potentially be produced with areal densities of less than 1 kg per square m for applications in which lightweight deformable optics are desirable, and deformable nanolaminate optics could potentially be fabricated with intrinsically curved surfaces, including aspheric shapes. We will describe the basic principles of these devices, and we will present details of the design, fabrication and characterization of the prototype deformable nanolaminate optics that have been developed to date. We will also discuss the possibilities for future work on scaling these devices to larger sizes and developing both devices with lower areal densities and devices with curved surfaces.

  3. 液晶高分子流体在拉伸流动中拉伸粘度的解析计算研究%Computational Analytical Approach to Extensional Viscosity of Liquid Crystalline Polymer in Extensional Flow



    The shearing extension is a main factor in the extrusion process of LC polymer melt. Using the constitutive equation of LCP-B for LC polymer melts and solutions, the influence of orientational motion on extensional viscosity is studied. The change curves of dimensionless extensional viscosity with relaxation time and shear rate have been obtained.%在液晶高分子熔液挤出过程中,剪切拉伸是主要考虑因素.用液晶高分子B模型本构方程,并考虑取向运动的影响得到拉伸粘度随松驰时间与拉伸率之间的变化关系和曲线.

  4. A constitutive analysis of the extensional flows of nearly monodisperse polyisoprene melts

    Rasmussen, Henrik K.


    Here two particular formulations [M.H. Wagner, S. Kheirandish, O. Hassager, Journal of Rheology 49 (6) (2005) 1317–1327; H.K. Rasmussen, Q. Huang, Rheologica Acta 53 (3) (2014) 199–208; G. Marrucci, G. Ianniruberto, Macromolecules 37 (10) (2004) 3934–3942] of the ‘interchain pressure’ [39......], incorporated into the molecular stress function method [M.H. Wagner, S. Kheirandish, O. Hassager, Journal of Rheology 49 (6) (2005) 1317–1327], are used to assess the extensional [J.K. Nielsen, O. Hassager, H.K Rasmussen, G.H. McKinley, Journal of Rheology 53 (6) (2009) 1327–1346; G. Liu, H. Sun, S. Rangou, K....... Ntetsikas, A. Avgeropoulos, S.-Q. Wang, Journal of Rheology 57 (1) (2013) 89–104] and shear viscosities [D. Auhl, J. Ramirez, A.E. Likhtman, P. Chambon, C. Fernyhough, Journal of Rheology 52 (3) (2008) 801–835] of narrow molecular weight distributed (NMMD) polyisoprene melts. These two formulations...

  5. Salt diapirs in the Dead Sea basin and their relationship to Quaternary extensional tectonics

    Al-Zoubi, A.; ten Brink, U.S.


    Regional extension of a brittle overburden and underlying salt causes differential loading that is thought to initiate the rise of reactive diapirs below and through regions of thin overburden. We present a modern example of a large salt diapir in the Dead Sea pull-apart basin, the Lisan diapir, which we believe was formed during the Quaternary due to basin transtension and subsidence. Using newly released seismic data that are correlated to several deep wells, we determine the size of the diapir to be 13 x 10 km. its maximum depth 7.2 km. and its roof 125 m below the surface. From seismic stratigraphy, we infer that the diapir started rising during the early to middle Pleistocene as this section of the basin underwater rapid subsidence and significant extension of the overburden. During the middle to late Pleistocene, the diapir pierced through the extensionally thinned overburden, as indicated by rim synclines, which attest to rapid salt withdrawal from the surrounding regions. Slight positive topography above the diapir and shallow folded horizons indicate that it is still rising intermittently. The smaller Sedom diapir, exposed along the western bounding fault of the basin is presently rising and forms a 200 m-high ridge. Its initiation is explained by localized E-W extension due monoclinal draping over the edge of a rapidly subsiding basin during the early to middle Pleistocene, and its continued rise by lateral squeezing due to continued rotation of the Amazyahu diagonal fault. ?? 2001 Elsevier Science Ltd. All rights reserved.

  6. Constraints for timing of extensional tectonics in the western margin of the Red Sea in Eritrea

    Ghebreab, Woldai; Carter, Andrew; Hurford, Anthony J.; Talbot, Christopher J.


    Recent work on asthenosphere-lithosphere coupling reinforces past observations that active and passive rifting models do not adequately describe real rifts. There remains insufficient knowledge of fundamental controls on rift architecture. In the actively extending Red Sea margin of eastern Eritrea, which lies at the Red Sea/Danakil-Gulf of Aden and the East African rift triple junction zone, the geometry and kinematics of extension are complex and poorly defined due to large data gaps. Extension and sea-floor spreading in both the Red Sea and Gulf of Aden have influenced the Neogene tectonic development of Eritrea but many of the structures have Pan-African origins and do not follow normal plate opening geometries. To constrain the rifting history in eastern Eritrea, apatite fission-track thermochronologic data were measured for 22 Pan-African rock samples. Results identify late Oligocene-early Miocene cooling coincident with extension and erosion along the conjugate margin in Yemen. A younger age group, confined to Mt Ghedem, relates to an episode of fault reactivation and dyke injection that began ˜10 Ma coincident with rotation of the nearby Danakil block. Initially this was driven by onset of sea-floor spreading in the Gulf of Aden and later, in the Pliocene, aided by northward rifting in the Afar depression concomitant with spreading in the Red Sea. These different processes highlight the complex linkage between different extensional events and rift architecture.

  7. Nonlinear flap-lag-extensional vibrations of rotating, pretwisted, preconed beams including Coriolis effects

    Subrahmanyam, K. B.; Kaza, K. R. V.


    The effects of pretwist, precone, setting angle, Coriolis forces and second degree geometric nonlinearities on the natural frequencies, steady state deflections and mode shapes of rotating, torsionally rigid, cantilevered beams were studied. The governing coupled equations of flap lag extensional motion are derived including the effects of large precone and retaining geometric nonlinearities up to second degree. The Galerkin method, with nonrotating normal modes, is used for the solution of both steady state nonlinear equations and linear perturbation equations. Parametric indicating the individual and collective effects of pretwist, precone, Coriolis forces and second degree geometric nonlinearities on the steady state deflection, natural frequencies and mode shapes of rotating blades are presented. It is indicated that the second degree geometric nonlinear terms, which vanish for zero precone, can produce frequency changes of engineering significance. Further confirmation of the validity of including those generated by MSC NASTRAN. It is indicated that the linear and nonlinear Coriolis effects must be included in analyzing thick blades. The Coriolis effects are significant on the first flatwise and the first edgewise modes.

  8. Mechanisms of Cenozoic deformation in the Bohai Basin, Northeast China: Physical modelling and discussions

    ZHOU; Jianxun; ZHOU; Jiansheng


    The Bohai Basin is a Cenozoic petroliferous extensional basin in China and has apparent geometrical and kinematic similarities with the other Meso-Cenozoic extensional basins located along the eastern margin of Eurasian Plate. However, the deformation mechanisms of the basin are still in dispute. Physcial modelling referring to the Huanghua Depression, located in the central part of the Bohai Basin was conducted employing four sets of planar sandbox experimental models with different extension directions. Only experimental results of the model with N-S extension show good structural similarity with the depression. The results also indicate that complex variations of fault strike in a rift basin are not necessarily the results of complex kinematic mechanisms or polyphase deformation. Based on comparison of experimental results with the actual structures and the good structural similarity between Huanghua Depression and the whole Bohai Basin, it is concluded that the Bohai Basin was formed by the N-S extension. The strike slip deformation along the NNE-trending border faults of the basin resulted from the N-S extension and played the role of lateral transformation for the N-S extension. In addition, according to the apparent geometrical and kinematic similarities among the Bohai Basin and other Meso-Cenozoic extensional basins located along the eastern margin of the Eurasian Plate, it is proposed that: (1) this "N-S extension" model provides a better kinematic interpretation for the formation of Bohai Basin and the other adjacent basins located along the eastern margin of the Eurasian Plate; and (2) the N-S extension was probably the effect of the "slab window" formed by the subduction of the nearly E-W trending oceanic ridge between the Kula and Pacific Plates. The "slab window" effect can also provide reasonable explanations for the phenomena that initial rifting ages of basins become progressively younger westwards along the eastern margin of the Eurasian Plate

  9. Synmagmatic deformation in the underplated igneous complex of the Ivrea-Verbano zone

    Quick, J.E.; Sinigoi, S.; Negrini, L.; Demarchi, G.; Mayer, A.


    The Ivrea-Verbano zone, northern Italy, contains an igneous complex up to 10km thick that is thought to have been intruded near the interface between the continental crust and mantle during the late Paleozoic. New data indicate that this complex is pervasively deformed and concentrically foliated. The presence of analogous features in ophiolitic gabbros suggests that emplacement of the Ivrea-Verbano zone plutonic rocks involved large-scale flow of crystal mush in a dynamic, and possibly extensional, tectonic environment. -from Authors

  10. Simple Model for the Deformation-Induced Relaxation of Glassy Polymers

    Fielding, S. M.; Larson, R. G.; Cates, M. E.


    Glassy polymers show “strain hardening”: at constant extensional load, their flow first accelerates, then arrests. Recent experiments have found this to be accompanied by a striking and unexplained dip in the segmental relaxation time. Here we explain such behavior by combining a minimal model of flow-induced liquefaction of a glass with a description of the stress carried by strained polymers, creating a nonfactorable interplay between aging and strain-induced rejuvenation. Under constant load, liquefaction of segmental motion permits strong flow that creates polymer-borne stress. This slows the deformation enough for the segmental modes to revitrify, causing strain hardening.

  11. Tectono-stratigraphic evolution through successive extensional events of the Anydros Basin, hosting Kolumbo volcanic field at the Aegean Sea, Greece

    Nomikou, P.; Hübscher, C.; Ruhnau, M.; Bejelou, K.


    The structural evolution of the South Aegean Sea is little explored due to the lack of marine seismic data. Our present day understanding is mainly based on some island outcrops and GPS measurements. In this study we discuss the rather incremental opening of the Anydros Basin in the Pliocene during six major tectonic pulses and the subsequent basin fill processes by interpreting seismic data and derived time isochore maps. Between the active pulses basin floor tilting persisted on a much lower rate. Seismic data illustrate the depositional processes in the emerging Anydros Basin. The observation of onlap fill strata, divergent reflection pattern, moat channels and contourite drifts imply that deposition was controlled by turbidity and contour currents as well as the tilting basin floor. The metamorphic Attico-Cycladic basement shows a rise that aligns along an NW-SE directed axis crossing Anydros island. This axis marks a structural change of the Santorini-Amorgos Ridge and thus represents a major structural boundary. Dip angles of NE-SW trending major faults, like the Santorini-Amorgos Fault, indicate normal faulting to be the superior mechanism forming the present horst and graben environment. Hence, the area is likely to be in a state of NW-SE directed extensional stresses forming the asymmetric graben structure of Anydros. Secondary fault clusters strike the same direction but show much steeper dip angles, possibly indicating strike-slip movement or resulting from deformational stresses along the hinge zones of the normal faults. The majority of the faults we discovered are located in the area of earthquake clusters, which is another indication of recent faulting. Ring faults around Kolumbo submarine volcano, result from caldera collapse and mark the diameter of the magma chamber approximately to 20 km.

  12. Non-linear Shear and Uniaxial Extensional Rheology of Polyether-Ester-Sulfonate Copolymer Ionomer Melts

    Shabbir, Aamir; Huang, Qian; P. Baeza, Guilhem


    (ethylene oxide) (PEO) along the backbone in the coionomer with poly ( tetramethylene glycol) PTMO, increases the maximum Hencky strain at fracture thus adding ductility to the brittle PTMO-Na ionomer. As a result, the coionomer deforms much more compared to PTMO-Na but both fracture eventually...... to formation of strong ionic aggre-gates. These ionomer melts exhibit viscoelastic properties similar to well-entangled melts with an extended rubbery plateau. To evaluate the effects of nonlinear deforma-tion, the rheology of these ionomers was investigated using uniaxial extension and shear. The measurements...

  13. Large-Scale Dextral Strike-Slip Movement and Associated Tectonic Deformation Along the Red-River Fault Zone

    Xiang Hongfa; Han Zhujun; Guo Shunmin; Zhang Wanxia; Chen Lichun


    Field investigation has revealed that the large-scale dextral strike-slip movement and the associated tectonic deformation along the Red River fault zone have the following features:geometrically, the Red River fault zone can be divided into three deformation regions, namely,the north, central and south regions. The north region lies on the eastern side of the Northwest Yunnan extensional taphrogenic belt, which is characterized by the 3 sets of rift-depression basins striking NNW, NNE and near N-S since the Pliocene time, and on its western side is the Lanping-Yunlong compressive deformation belt of the Paleogene to Neogene; the deformation in the central region is characterized by dextral strike-slip or shearing. The east Yunnan Miocene compressive deformation belt lies on the eastern side of the fault in the south, and the Tengtiaohe tensile fault depression belt is located on its west. In terms of tectonic geomorphology, the aforementioned deformation is represented by basin-range tectonics in the north, linear faulted valley-basins in the central part and compressive (or tensional) basins in the south. Among them, the great variance in elevation of the planation surfaces on both sides of the Cangshan-Erhai fault suggests prominent normal faulting along the Red River fault since the Pliocene. From the viewpoint of spatial-temporal evolution, the main active portion of the fault was the southern segment in the Paleogene-Miocene-Pliocene, which is represented by "tearing" from south to north. The main active portion of the fault has migrated to the northern segment since the Pliocene, especially in the late Quaternary, which is characterized by extensional slip from north to southeast. The size of the deformation region and the magnitude of deformation show that the eastern plate of the Red River fault has been an active plate of the relative movement of blocks.

  14. -Deformed nonlinear maps

    Ramaswamy Jaganathan; Sudeshna Sinha


    Motivated by studies on -deformed physical systems related to quantum group structures, and by the elements of Tsallis statistical mechanics, the concept of -deformed nonlinear maps is introduced. As a specific example, a -deformation procedure is applied to the logistic map. Compared to the canonical logistic map, the resulting family of -logistic maps is shown to have a wider spectrum of interesting behaviours, including the co-existence of attractors – a phenomenon rare in one-dimensional maps.

  15. Alar Rim Deformities.

    Totonchi, Ali; Guyuron, Bahman


    The alar rim plays an important role in nasal harmony. Alar rim flaws are common following the initial rhinoplasty. Classification of the deformities helps with diagnosis and successful surgical correction. Diagnosis of the deformity requires careful observation of the computerized or life-sized photographs. Techniques for treatment of these deformities can easily be learned with attention to detail. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Fluctuations as stochastic deformation

    Kazinski, P. O.


    A notion of stochastic deformation is introduced and the corresponding algebraic deformation procedure is developed. This procedure is analogous to the deformation of an algebra of observables like deformation quantization, but for an imaginary deformation parameter (the Planck constant). This method is demonstrated on diverse relativistic and nonrelativistic models with finite and infinite degrees of freedom. It is shown that under stochastic deformation the model of a nonrelativistic particle interacting with the electromagnetic field on a curved background passes into the stochastic model described by the Fokker-Planck equation with the diffusion tensor being the inverse metric tensor. The first stochastic correction to the Newton equations for this system is found. The Klein-Kramers equation is also derived as the stochastic deformation of a certain classical model. Relativistic generalizations of the Fokker-Planck and Klein-Kramers equations are obtained by applying the procedure of stochastic deformation to appropriate relativistic classical models. The analog of the Fokker-Planck equation associated with the stochastic Lorentz-Dirac equation is derived too. The stochastic deformation of the models of a free scalar field and an electromagnetic field is investigated. It turns out that in the latter case the obtained stochastic model describes a fluctuating electromagnetic field in a transparent medium.

  17. Deformed discrete symmetries

    Arzano, Michele; Kowalski-Glikman, Jerzy


    We construct discrete symmetry transformations for deformed relativistic kinematics based on group valued momenta. We focus on the specific example of κ-deformations of the Poincaré algebra with associated momenta living on (a sub-manifold of) de Sitter space. Our approach relies on the description of quantum states constructed from deformed kinematics and the observable charges associated with them. The results we present provide the first step towards the analysis of experimental bounds on the deformation parameter κ to be derived via precision measurements of discrete symmetries and CPT.

  18. Crustal deformation across the Southern Patagonian Icefield observed by GNSS

    Richter, A.; Ivins, E.; Lange, H.; Mendoza, L.; Schröder, L.; Hormaechea, J. L.; Casassa, G.; Marderwald, E.; Fritsche, M.; Perdomo, R.; Horwath, M.; Dietrich, R.


    Geodetic GNSS observations at 43 sites well distributed over the Southern Patagonian Icefield region yield site velocities with a mean accuracy of 1 mm/a and 6 mm/a for the horizontal and vertical components, respectively. These velocities are analyzed to reveal the magnitudes and patterns of vertical and horizontal present-day crustal deformation as well as their primary driving processes. The observed vertical velocities confirm a rapid uplift, with rates peaking at 41 mm/a, causally related to glacial-isostatic adjustment (GIA). They yield now an unambiguous preference between two competing GIA models. Remaining discrepancies between the preferred model and our observations point toward an effective upper mantle viscosity even lower than 1.6 ṡ1018 Pas and effects of lateral rheological heterogeneities. An analysis of the horizontal strain and strain-rate fields reveals some complex superposition, with compression dominating in the west and extension in the east. This deformation field suggests significant contributions from three processes: GIA, a western interseismic tectonic deformation field related to plate subduction, and an extensional strain-rate field related to active Patagonian slab window tectonics.

  19. The rift architecture and extensional tectonics of the South China Sea

    Cameselle, Alejandra L.; Ranero, César R.; Barckhausen, Udo; Franke, Dieter


    Non-volcanic rifted continental margins are classically described as the product of lithospheric stretching and breakup leading to mantle exhumation, and subsequent seafloor spreading. However, recent studies question this model and indicate a wider range of structural evolutions, that challenge the existing model (e.g. Australia-Antarctic Rift System (Direen et al. 2007, 2011); the Tyrrhenian basin (Prada et al., 2014) or the South China Sea (Cameselle et al. 2015)). Rifting in the South China Sea developed from a series of extensional events, from early Eocene to Late Oligocene, resulting in a V-shape oceanic basin affected by the occurrence of several spreading centers, ridges, transform faults and post-spreading volcanism. In recent years, this marginal basin - the largest in East Asia - has increasingly become one of the key sites for the study of rifting and continental break-up. Its relative small size - compared to many classic, Atlantic-type continental margin settings - allows to easily match conjugated rifted margins and its relative youth promotes the preservation of its original nature. To examine the rifting evolution of the South China Sea, we have reprocessed with modern algorithms multichannel seismic profiles acquired during Sonne49 and BGR84 cruises across the three major subbasins: NW, SW and East subbasins. State-of-the-art of processing techniques have been used to increase the signal to noise ratio, including Tau-P and Wiener predictive deconvolution, multiple attenuation by both radon filtering and wave-equation-based surface-related multiple elimination (SRME) and time migration. To complement seismic interpretation, available vintage multichannel seismic data have been reprocessed with a post-stack flow, including Wiener deconvolution, FK-filtering, space and time variant band-pass filter and time migration. The improving quality of the seismic images shows a range of features including post-rift and syn-rift sediments, the structure of

  20. Hydrothermal dolomitization of basinal deposits controlled by a synsedimentary fault system in Triassic extensional setting, Hungary

    Hips, Kinga; Haas, János; Győri, Orsolya


    Dolomitization of relatively thick carbonate successions occurs via an effective fluid circulation mechanism, since the replacement process requires a large amount of Mg-rich fluid interacting with the CaCO3 precursor. In the western end of the Neotethys, fault-controlled extensional basins developed during the Late Triassic spreading stage. In the Buda Hills and Danube-East blocks, distinct parts of silica and organic matter-rich slope and basinal deposits are dolomitized. Petrographic, geochemical, and fluid inclusion data distinguished two dolomite types: (1) finely to medium crystalline and (2) medium to coarsely crystalline. They commonly co-occur and show a gradual transition. Both exhibit breccia fabric under microscope. Dolomite texture reveals that the breccia fabric is not inherited from the precursor carbonates but was formed during the dolomitization process and under the influence of repeated seismic shocks. Dolomitization within the slope and basinal succession as well as within the breccia zones of the underlying basement block is interpreted as being related to fluid originated from the detachment zone and channelled along synsedimentary normal faults. The proposed conceptual model of dolomitization suggests that pervasive dolomitization occurred not only within and near the fault zones. Permeable beds have channelled the fluid towards the basin centre where the fluid was capable of partial dolomitization. The fluid inclusion data, compared with vitrinite reflectance and maturation data of organic matter, suggest that the ascending fluid was likely hydrothermal which cooled down via mixing with marine-derived pore fluid. Thermal gradient is considered as a potential driving force for fluid flow.

  1. Experimental characterization of breakage rate of colloidal aggregates in axisymmetric extensional flow.

    Saha, Debashish; Soos, Miroslav; Lüthi, Beat; Holzner, Markus; Liberzon, Alex; Babler, Matthaus U; Kinzelbach, Wolfgang


    Aggregates prepared under fully destabilized conditions by the action of Brownian motion were exposed to an extensional flow generated at the entrance of a sudden contraction. Two noninvasive techniques were used to monitor their breakup process [i.e. light scattering and three-dimensional (3D) particle tracking velocimetry (3D-PTV)]. While the first one can be used to measure the size and the morphology of formed fragments after the breakage event, the latter is capable of resolving trajectories of individual aggregates up to the breakage point as well as the trajectories of formed fragments. Furthermore, measured velocity gradients were used to determine the local hydrodynamic conditions at the breakage point. All this information was combined to experimentally determine for the first time the breakage rate of individual aggregates, given in the form of a size reduction rate K(R), as a function of the applied strain rate, as well as the properties of the formed fragments (i.e., the number of formed fragments and the size ratio between the largest fragment and the original aggregate). It was found that K(R) scales with the applied strain rate according to a power law with the slope being dependent on the initial fractal dimension only, while the obtained data indicates a linear dependency of K(R) with the initial aggregate size. Furthermore, the probability distribution function (PDF) of the number of formed fragments and the PDF of the size ratio between the largest fragment and the original aggregate indicate that breakage will result with high probability (75%) in the formation of two to three fragments with a rather asymmetric ratio of sizes of about 0.8. The obtained results are well in agreement with the results from the numerical simulations published in the literature.

  2. Tectonic and gravity extensional collapses in overpressured cohesive and frictional wedges

    Yuan, X. P.; Leroy, Y. M.; Maillot, B.


    Two modes of extensional collapse in a cohesive and frictional wedge of arbitrary topography, finite extent, and resting on an inclined weak décollement are examined by analytical means. The first mode consists of the gravitational collapse by the action of a half-graben, rooting on the décollement and pushing seaward the frontal part of the wedge. The second mode results from the tectonics extension at the back wall with a similar half-graben kinematics and the landward sliding of the rear part of the wedge. The predictions of the maximum strength theorem, equivalent to the kinematic approach of limit analysis and based on these two collapse mechanisms, not only match exactly the solutions of the critical Coulomb wedge theory, once properly amended, but generalizes them in several aspects: wedge of finite size, composed of cohesive material and of arbitrary topography. This generalization is advantageous to progress in our understanding of many laboratory experiments and field cases. For example, it is claimed from analytical results validated by experiments that the stability transition for a cohesive, triangular wedge occurs with the activation of the maximum length of the décollement. It is shown that the details of the topography, for the particular example of the Mejillones peninsula (North Chile) is, however, responsible for the selection of a short length-scale, dynamic instability corresponding to a frontal gravitational instability. A reasonable amount of cohesion is sufficient for the pressures proposed in the literature to correspond to a stability transition and not with a dynamically unstable state.

  3. Active faulting, 3-D geological architecture and Plio-Quaternary structural evolution of extensional basins in the central Apennine chain, Italy

    Gori, Stefano; Falcucci, Emanuela; Ladina, Chiara; Marzorati, Simone; Galadini, Fabrizio


    The general basin and range Apennine topographic characteristic is generally attributed to the presently active normal fault systems, whose long-term activity (throughout the Quaternary) is supposed to have been responsible for the creation of morphological/structural highs and lows. By coupling field geological survey and geophysical investigations, we reconstructed the 3-D geological model of an inner tectonic basin of the central Apennines, the Subequana Valley, bounded to the northeast by the southern segment of one of the major active and seismogenic normal faults of the Apennines, known as the Middle Aterno Valley-Subequana Valley fault system. Our analyses revealed that, since the late Pliocene, the basin evolved in a double half-graben configuration through a polyphase tectonic development. An early phase, Late Pliocene-Early Pleistocene in age, was controlled by the ENE-WSW-striking and SSE-dipping Avezzano-Bussi fault, that determined the formation of an early depocentre towards the N-NW. Subsequently, the main fault became the NW-SE-striking faults, which drove the formation during the Quaternary of a new fault-related depocentre towards the NE. By considering the available geological information, a similar structural evolution has likely involved three close tectonic basins aligned along the Avezzano-Bussi fault, namely the Fucino Basin, the Subequana Valley, and the Sulmona Basin, and it has been probably experienced by other tectonic basins of the chain. The present work therefore points out the role of pre-existing transverse tectonic structures, inherited by previous tectonic phases, in accommodating the ongoing tectonic deformation and, consequently, in influencing the structural characteristics of the major active normal faults. This has implications in terms of earthquake fault rupture propagation and segmentation. Lastly, the morpho-tectonic setting of the Apennine chain results from the superposition of deformation events whose geological

  4. Trench curvature and deformation of the subducting lithosphere

    Schettino, Antonio; Tassi, Luca


    The subduction of oceanic lithosphere is generally accompanied by downdip and lateral deformation. The downdip component of strain is associated with external forces that are applied to the slab during its sinking, namely the gravitational force and the mantle resistance to penetration. Here, we present theoretical arguments showing that a tectonic plate is also subject to a predictable amount of lateral deformation as a consequence of its bending along an arcuate trench zone, independently from the long-term physical processes that have determined the actual curvature of the subduction zone. In particular, we show that the state of lateral strain and the lateral strain rate of a subducting slab depend from geometric and kinematic parameters, such as trench curvature, dip function and subduction velocity. We also demonstrate that the relationship between the state of lateral strain in a subducting slab and the geometry of bending at the corresponding active margin implies a small component of lateral shortening at shallow depths, and may include large extensional lateral deformation at intermediate depths, whereas a state of lateral mechanical equilibrium can only represent a localized exception. Our formulation overcomes the flaws of the classic 'ping-pong ball' model for the bending of the lithosphere at subduction zones, which lead to severe discrepancies with the observed geometry and style of deformation of the modern subducting slabs. A study of the geometry and seismicity of eight modern subduction zones is performed, to assess the validity of the theoretical relationship between trench curvature, slab dip function, and lateral strain rate. The strain pattern within the eight present-day slabs, which is reconstructed through an analysis of Harvard CMT solutions, shows that tectonic plates cannot be considered as flexible-inextensible spherical caps, whereas the lateral intraslab deformation which is accommodated through seismic slip can be explained in terms

  5. Intracrystalline deformation of calcite

    de Bresser, Hans


    It is well established from observations on natural calcite tectonites that intracrystalline plastic mechanisms are important during the deformation of calcite rocks in nature. In this thesis, new data are presented on fundamental aspects of deformation behaviour of calcite under conditions where 'd

  6. Resurgent deformation quantisation

    Garay, Mauricio, E-mail: [Institut für Mathematik, FB 08 Physik, Mathematik und Informatik, Johannes Gutenberg-Universität, 55099 Mainz (Germany); Goursac, Axel de, E-mail: [Chargé de Recherche au F.R.S.-FNRS, IRMP, Université Catholique de Louvain, Chemin du Cyclotron, 2, B-1348 Louvain-la-Neuve (Belgium); Straten, Duco van, E-mail: [Institut für Mathematik, FB 08 Physik, Mathematik und Informatik, Johannes Gutenberg-Universität, 55099 Mainz (Germany)


    We construct a version of the complex Heisenberg algebra based on the idea of endless analytic continuation. The algebra would be large enough to capture quantum effects that escape ordinary formal deformation quantisation. -- Highlights: •We construct resurgent deformation quantisation. •We give integral formulæ. •We compute examples which show that hypergeometric functions appear naturally in quantum computations.

  7. Deformations of Superconformal Theories

    Cordova, Clay; Intriligator, Kenneth


    We classify possible supersymmetry-preserving relevant, marginal, and irrelevant deformations of unitary superconformal theories in $d \\geq 3$ dimensions. Our method only relies on symmetries and unitarity. Hence, the results are model independent and do not require a Lagrangian description. Two unifying themes emerge: first, many theories admit deformations that reside in multiplets together with conserved currents. Such deformations can lead to modifications of the supersymmetry algebra by central and non-central charges. Second, many theories with a sufficient amount of supersymmetry do not admit relevant or marginal deformations, and some admit neither. The classification is complicated by the fact that short superconformal multiplets display a rich variety of sporadic phenomena, including supersymmetric deformations that reside in the middle of a multiplet. We illustrate our results with examples in diverse dimensions. In particular, we explain how the classification of irrelevant supersymmetric deformat...

  8. Massey products and deformations

    Fuchs, D; Fuchs, Dmitry; Lang, Lynelle


    The classical deformation theory of Lie algebras involves different kinds of Massey products of cohomology classes. Even the condition of extendibility of an infinitesimal deformation to a formal one-parameter deformation of a Lie algebra involves Massey powers of two dimensional cohomology classes which are not powers in the usual definition of Massey products in the cohomology of a differential graded Lie algebra. In the case of deformations with other local bases, one deals with other, more specific Massey products. In the present work a construction of generalized Massey products is given, depending on an arbitrary graded commutative, associative algebra. In terms of these products, the above condition of extendibility is generalized to deformations with arbitrary local bases. Dually, a construction of generalized Massey products on the cohomology of a differential graded commutative associative algebra depends on a nilpotent graded Lie algebra. For example, the classical Massey products correspond to the...

  9. Deformation mechanisms in experimentally deformed Boom Clay

    Desbois, Guillaume; Schuck, Bernhard; Urai, Janos


    Bulk mechanical and transport properties of reference claystones for deep disposal of radioactive waste have been investigated since many years but little is known about microscale deformation mechanisms because accessing the relevant microstructure in these soft, very fine-grained, low permeable and low porous materials remains difficult. Recent development of ion beam polishing methods to prepare high quality damage free surfaces for scanning electron microscope (SEM) is opening new fields of microstructural investigation in claystones towards a better understanding of the deformation behavior transitional between rocks and soils. We present results of Boom Clay deformed in a triaxial cell in a consolidated - undrained test at a confining pressure of 0.375 MPa (i.e. close to natural value), with σ1 perpendicular to the bedding. Experiments stopped at 20 % strain. As a first approximation, the plasticity of the sample can be described by a Mohr-Coulomb type failure envelope with a coefficient of cohesion C = 0.117 MPa and an internal friction angle ϕ = 18.7°. After deformation test, the bulk sample shows a shear zone at an angle of about 35° from the vertical with an offset of about 5 mm. We used the "Lamipeel" method that allows producing a permanent absolutely plane and large size etched micro relief-replica in order to localize and to document the shear zone at the scale of the deformed core. High-resolution imaging of microstructures was mostly done by using the BIB-SEM method on key-regions identified after the "Lamipeel" method. Detailed BIB-SEM investigations of shear zones show the following: the boundaries between the shear zone and the host rock are sharp, clay aggregates and clastic grains are strongly reoriented parallel to the shear direction, and the porosity is significantly reduced in the shear zone and the grain size is smaller in the shear zone than in the host rock but there is no evidence for broken grains. Comparison of microstructures

  10. Wrinkling of extensional thin films through modified large deflection equations analytically and experimentally

    M.-H. R. Jen


    Full Text Available The stretch-induced wrinkling of thin films is solved through the modified von Kármán large deflection equations by first selecting the suitable deformation expressions that satisfy boundary conditions. Then, adopting the principle of minimum potential energy we obtain the deformations of simply supported rectangular thin films. The obtained significant deflections are nonlinearly elastic and of the lowest order of infinite solutions. The parameters of aspect ratio, the thickness and material of thin films are studied analytically and numerically. The highlighted results of wrinkle amplitude and load are in good agreement with experiments. The methodology also indicates the limit load impending plasticity and predicts the applied load precisely for each wrinkle. Further, it can be extended to the variety of multifunctional orthotropic and multi-layered thin films.

  11. 3D modelling of salt tectonics with a brittle overburden in an extensional regime

    Eichheimer, Philipp; Reuber, Georg; Kaus, Boris


    Most previous numerical models of salt tectonics only considered 2D cases or did not taken a brittle sedimentary overburden into account, both of which are likely to be important in nature. To get insights into the dynamics of diapiric rise of salt we here present time-dependent high resolution 3D models of salt tectonics in the presence of a brittle overburden and sedimentation. We focus on the internal deformation of an embedded anhydrite layer within a nonlinear viscous salt layer. As salt in nature tends to rise upwards to the surface along fault zones, the salt layer is overlain by a brittle overburden to simulate faulting. The resulting complex folding of the anhydrite layer obtained in our models is consistent with natural observations, e.g. Gorleben [1]. Regarding field examples we vary the shape of the anhydrite layer to understand different modes of deformation [2]. We test the effect of overburden rheology, extension and sedimentation rates on the 3D salt dome patterns and on its internal deformation. [1] O. Bornemann. Zur Geologie des Salzstocks Gorleben nach den Bohrergebnissen. Bundesamt für Strahlenschutz (1991). [2] Z. Chemia, H. Koyi, and H. Schmeling. Numerical modelling of rise and fall of a dense layer in salt diapirs. Geophysical Journal International 172.2 (2008): 798-816.

  12. The 2011-2012 Santorini unrest: Swarms of micro-seismicity, crustal deformation and magma pulses

    Saltogianni, Vasso; Stiros, Stathis; Newman, Andrew; Papazachos, Costas; Moschas, Fanis


    In 2011-2012 swarms of micro-seismicity were observed in Santorini caldera for the first probably time since its last eruption 60 years ago. This seismicity was along a major extensional lineament (Kammeni Line), in which all post-Minoan eruptions were confined and was characterized by extensional focal mechanisms. GPS observations provided evidence of a somewhat radial deformation, which was assigned to a spherical magma source ~4km deep in the north part of the caldera, about 2km away from the Kammeni Line. Because such a source cannot explain extensional seismicity observed along the Kammeni Line, we investigated alternative intrusion models. On the basis of seismicity and deformation rates, the unrest period was divided into five intervals each 3-6 months long. Then, using a new inversion method/software we modeled each interval separately for one or two sources. No solution was found possible for the fifth interval, while for the other four there was evidence of a shallow, relative small source at the north part of the caldera; this source tends to overshadow other deeper sources. During intervals of seismicity, the deeper source is identified inside or beneath the Kammeni Line and has the potential to produce the deviatoric stresses and explain the observed seismicity swarms. During the fourth interval, this source was found much smaller and at some distance from the Kammeni Line, in a position not permitting to trigger seismicity. The northern source seems to be systematically arrested by the upper most layers of sediments, as is also derived by marine geophysical surveys. The variability in space and time of intrusions in 2011-2012 is consistent with the hypothesis of composite pulses of magma from deeper sources.

  13. New constraints on the active tectonic deformation of the Aegean

    Nyst, M.; Thatcher, W.


    Site velocities from six separate Global Positioning System (GPS) networks comprising 374 stations have been referred to a single common Eurasia-fixed reference frame to map the velocity distribution over the entire Aegean. We use the GPS velocity field to identify deforming regions, rigid elements, and potential microplate boundaries, and build upon previous work by others to initially specify rigid elements in central Greece, the South Aegean, Anatolia, and the Sea of Marmara. We apply an iterative approach, tentatively defining microplate boundaries, determining best fit rigid rotations, examining misfit patterns, and revising the boundaries to achieve a better match between model and data. Short-term seismic cycle effects are minor contaminants of the data that we remove when necessary to isolate the long-term kinematics. We find that present day Aegean deformation is due to the relative motions of four microplates and straining in several isolated zones internal to them. The RMS misfit of model to data is about 2-sigma, very good when compared to the typical match between coseismic fault models and GPS data. The simplicity of the microplate description of the deformation and its good fit to the GPS data are surprising and were not anticipated by previous work, which had suggested either many rigid elements or broad deforming zones that comprise much of the Aegean region. The isolated deforming zones are also unexpected and cannot be explained by the kinematics of the microplate motions. Strain rates within internally deforming zones are extensional and range from 30 to 50 nanostrain/year (nstrain/year, 10-9/year), 1 to 2 orders of magnitude lower than rates observed across the major microplate boundaries. Lower strain rates may exist elsewhere withi the microplates but are only resolved in Anatolia, where extension of 13 ?? 4 nstrain/ year is required by the data. Our results suggest that despite the detailed complexity of active continental deformation

  14. The Spherical Deformation Model

    Hobolth, Asgar


    Miller et al. (1994) describe a model for representing spatial objects with no obvious landmarks. Each object is represented by a global translation and a normal deformation of a sphere. The normal deformation is defined via the orthonormal spherical-harmonic basis. In this paper we analyse...... the spherical deformation model in detail and describe how it may be used to summarize the shape of star-shaped three-dimensional objects with few parameters. It is of interest to make statistical inference about the three-dimensional shape parameters from continuous observations of the surface and from...

  15. Calcaneo-valgus deformity.

    Evans, D


    A discussion of the essential deformity in calcaneo-valgus feet develops a theme originally put forward in 1961 on the relapsed club foot (Evans 1961). Whereas in the normal foot the medial and lateral columns are about equal in length, in talipes equino-varus the lateral column is longer and in calcaneo-valgus shorter than the medial column. The suggestion is that in the treatment of both deformities the length of the columns be made equal. A method is described of treating calcaneo-valgus deformity by inserting cortical bone grafts taken from the tibia to elongate the anterior end of the calcaneus.

  16. Kinematics and dynamics of the Mesozoic orogeny and late-orogenic extensional collapse in the Sino-Mongolian border areas

    ZHENG; Yadong


    The Sino-Mongolian border areas underwent two important tectonic events during Mesozoic time after late Paleozoic orogeny: a late Triassic to earlier Jurassic contractional event that resulted in a large-scale south-vergent thrust during the orogeny and a late Jurassic-earlier Cretaceous extensional event in a north-south direction that formed a metamorphic core complex. The kinematic and dynamic analyses show that the thrust sheet moved southwards with a kinematic vorticity number of ca. -0.10 and sub-horizontal maximum compressive stress axis that belongs to a contraction-thickening shear. The upper plate of the late-orogenic detachment relatively moved in a 165°direction. The average kinematic vorticity in its earlier stage was 0.74 that belongs to simple shear dominated shearing and related to the maximum compressive stress axes dipping at ~66°, while the later average kinematic vorticity was ~0.55°that belongs to pure shear dominated shearing with sub-vertical maximum compressive stress axes. This suggests that the thrusting led to the crust thickened and the lower plate rocks that were originally located in the upper crust depressed through a brittle-ductile transition zone into the lower crust and became warmer. The heated rocks trended to uplift since their increasing volume and decreasing density while the loading of the upper-plate rocks increased due to the structural thickening. Under the combined effect of the loading and the thermal-uplifting, the ductile shear zone in between increased in its component of vertical pure shear. Once its pure-shear component exceeded its simple-shear one the ductile shear zone became an extension-thinned shear zone. This progressive transitional process reflects internal and essential temporal and spatial relationships: the extensional factor nucleated during the crust thickening by thrusting and increase of the extensional factor finally led to late-orogenic collapse.

  17. Extensional and compressional regime driven left-lateral shear in southwestern Anatolia (eastern Mediterranean): The Burdur-Fethiye Shear Zone

    Elitez, İrem; Yaltırak, Cenk; Aktuğ, Bahadır


    The tectonic framework of the eastern Mediterranean presented in this paper is based on an active subduction and small underwater hills/mountains on the oceanic crust moving toward the north. The Hellenic Arc, the Anaximander Mountains, the Rhodes and Finike basins, the compressional southern regions of the Western Taurides, and the extensional western Anatolian graben are the main interrelated tectonic structures that are shaped by the complex tectonic regimes. There are still heated debates regarding the structural properties and tectonic evolution of the southwestern Anatolia. GPS velocities and focal mechanisms of earthquakes demonstrate the absence of a single transform fault across the Burdur-Fethiye region; however, hundreds of small faults showing normal and left-lateral oblique slip indicate the presence of a regionally extensive shear zone in southwestern Turkey, which plays an important role in the eastern Mediterranean tectonics. The 300-km-long, 75-90-km-wide NE-SW-trending Burdur-Fethiye Shear Zone developed during the formation of Aegean back-arc extensional system and the thrusting of Western Taurides. Today, the left-lateral differential motion across the Burdur-Fethiye Shear Zone varies from 3 to 4 mm/yr in the north to 8-10 mm/yr in the south. This finding could be attributed to the fact that while the subduction of the African Plate is relatively fast beneath the western Anatolia at the Hellenic Trench, it is slow or locked beneath the Western Taurides. Therefore, the GPS vectors and their distributions on land indicate remarkable velocity differences and enable us to determine the left-lateral shear zone located between the extensional and compressional blocks. Furthermore, this active tectonic regime creates differences in topography. This study also demonstrates how deep structures, such as the continuation of the subduction transform edge propagator (STEP) fault between the Hellenic and Cyprus arcs in the continental area, can come into play


    Malinowski Gadja, Elzbieta


    La práctica común para la creación de repositorios de datos espaciales es el uso de archivos shape, los cuales no proporcionan características necesarias para el control de consistencia de los datos, la redundancia o el acceso concurrente, entre otros. Por otra parte, las extensiones espaciales de los sistemas de administración de bases de datos (SABD) facilitan el uso de los mecanismos de controles declarativos o dinámicos (disparadores), aplicados a datos convencionales y espaciales. Sin em...

  19. Tectónica extensional cretácica en la subcuenca de Oliete (Cordillera Ibérica central)


    The control of the extensional tectonics on the geometry of the Oliete Subbasin during Early Barremian-Basal Aptian (Early Cretaceous) is examinated. Both, the main NW-SE trending of the basin, its asymetrical geometry and the location of the depocenters was controlled by the reactivation of NW-SE and NE-SW Late Variscan faults, and the formation of new faults. We propose that the general geometry of the basin is controlled by a flexion in the cover, with some associated minor normal faults. ...

  20. Extensional flow behavior of aqueous guar gum derivative solutions by capillary breakup elongational rheometry (CaBER).

    Szopinski, Daniel; Handge, Ulrich A; Kulicke, Werner-Michael; Abetz, Volker; Luinstra, Gerrit A


    The extensional rheological properties of aqueous ionic carboxymethyl hydroxypropyl guar gum (CMHPG) and non-ionic hydroxypropyl guar gum (HPG) solutions between the semi-dilute solution state and the concentrated network solution state were investigated by capillary breakup elongational rheometry (CaBER). Carboxymethylated guar gum derivatives show an instable filament formation in deionized water. The ratio of elongational relaxation time λE over the shear relaxation time λS follows a power law of λE/λS∼(c · [η])(-2). The difference of the relaxation times in shear and elongation can be related to the loss of entanglements and superstructures in elongational flows at higher strains.

  1. Geodetic deformations in the Central-Southern Apennines (Italy) from repeated GPS surveys

    Serpelloni, E.; Baldi, P. [Bologna Univ., Bologna (Italy). Dipt. di Fisica; Pesci, A.; Riguzzi, F.; Anzidei, M.; Casula, G.; Galvani, A. [Istituto Nazionale di Geofisica e Vulcanologia, Rome (Italy)


    It was computed the horizontal strain rate field for a sector of the Central-Southern Apennines (Italy) from GPS data collected during yearly repeated campaigns performed from 1994 to 2000 on the GeoModAp (Geodynamic Modeling of the Appennines) geodetic network. Site velocities were obtained starting from the daily coordinates and covariance solutions, using a Kalman filter approach. The residual velocity field with respect to a Eurasian fixed reference frame shows two different prevalent motion trends, NE-ward for the the eastern sector of the network and NW-ward for the western one. The mean strain rate tensor, obtained from a least square inversion method, shows a significant extensional deformation (1.2 x 10{sup -}8 strain/yr) normal to the Apennine chain, in agreement with seismological and neotectonic data. On the basis of the network dimension, of about 250 km, this value gives a well constrained estimate of about 3.0 plus or minus 0.2 mm/yr of the extensional velocity oriented N55E, normal to the chain axis. The results show a transition of the strain rate field from about N-S compression in the Tyrrhenian side to about NE-SW extension toward the Adriatic, which depicts a more complex deformation pattern.

  2. Extremely deformable structures


    Recently, a new research stimulus has derived from the observation that soft structures, such as biological systems, but also rubber and gel, may work in a post critical regime, where elastic elements are subject to extreme deformations, though still exhibiting excellent mechanical performances. This is the realm of ‘extreme mechanics’, to which this book is addressed. The possibility of exploiting highly deformable structures opens new and unexpected technological possibilities. In particular, the challenge is the design of deformable and bi-stable mechanisms which can reach superior mechanical performances and can have a strong impact on several high-tech applications, including stretchable electronics, nanotube serpentines, deployable structures for aerospace engineering, cable deployment in the ocean, but also sensors and flexible actuators and vibration absorbers. Readers are introduced to a variety of interrelated topics involving the mechanics of extremely deformable structures, with emphasis on ...

  3. Switching deformation mode during natural faulting in Carrara marbles.

    Molli, Giancarlo


    A study on meso- and microstructural features of a high angle normal fault observed in the Alpi Apuane NW Tuscany (Italy) is presented to document switching in the deformation mode during different evolutionary stages of a fault zone growth in naturally deformed Carrara marble. The studied fault was formed at c.3 Km of depth and belongs to structures related to the most recent deformation history of the Alpi Apuane metamorphic core (from c.4 Ma until now, Fellin et al. 2007; Molli, 2008). On the basis of deformation mechanisms and their chronology interpreted from cross-cutting relationships, different stages of the fault zone evolution have been recognized. An early stage of deformation (stage 1) was associated with extensional and shear veins now observable in both hangingwall and footwall blocks as part of the deformation zone developed at decameter-scale. Geochemical data indicate vein-development in a locally closed system where a "stationary" fluid phase migrates over meter scale distances (Molli et al., in press). During stage 2, a localization of the deformation, possibly in precursory coarse grained calcite/quartz shear veins of stage 1, took place. During this second stage crystal-plastic deformation affected areas at the head and along the hanging wall rim of fractures accommodating fault tip distorsions in a way recalling the mode-II geometry of stable crack propagation (Atkinson, 1987; Vermilye and Scholtz, 1993; Kim et al., 2004). Following pervasive cataclasis (stage 3) characterizes a plurimeter-wide dilational jog between two non-parallel main slip surfaces with brecciation and far-derived fluids channelling leading to significant geochemical alteration of the fault rocks with respect to the protolith (Molli et al., in press). Cataclastic deformation produced a grain size refinement and a decimetric thick fault core asymmetrically bounded by the upper main slip surface. Deformation was then localized within ultracataclasite of the fault core where

  4. Deformations of singularities

    Stevens, Jan


    These notes deal with deformation theory of complex analytic singularities and related objects. The first part treats general theory. The central notion is that of versal deformation in several variants. The theory is developed both in an abstract way and in a concrete way suitable for computations. The second part deals with more specific problems, specially on curves and surfaces. Smoothings of singularities are the main concern. Examples are spread throughout the text.

  5. Diffeomorphic Statistical Deformation Models

    Hansen, Michael Sass; Hansen, Mads/Fogtman; Larsen, Rasmus


    In this paper we present a new method for constructing diffeomorphic statistical deformation models in arbitrary dimensional images with a nonlinear generative model and a linear parameter space. Our deformation model is a modified version of the diffeomorphic model introduced by Cootes et al. Th...... with ground truth in form of manual expert annotations, and compared to Cootes's model. We anticipate applications in unconstrained diffeomorphic synthesis of images, e.g. for tracking, segmentation, registration or classification purposes....

  6. Deformation in nanocrystalline metals

    Helena Van Swygenhoven; Julia R. Weertman


    It is now possible to synthesize polycrystalline metals made up of grains that average less than 100 nm in size. Such nanocrystalline metals contain a significant volume fraction of interfacial regions separated by nearly perfect crystals. The small sizes involved limit the conventional operation of dislocation sources and thus a fundamental question arises: how do these materials deform plastically? We review the current views on deformation mechanisms in nanocrystalline, face-centered cubic...

  7. The effect of bimineralic composition on extensional processes at lithospheric scale

    Jammes, Suzon; Lavier, Luc L.


    We investigate how lithospheric scale compositional heterogeneities affect kilometric scale deformation processes. To this end, we perform numerical experiments of lithospheric extension in which we vary the Moho temperature and the mineralic composition of the mantle and the crust. In both the crust and the mantle, we use an explicit bimineralic composition by randomly distributing two mineral phases in the materials. Comparison of our models to simulations using an implicit bimineralic composite (one average viscous flow laws for a two-phase aggregate) crust and mantle demonstrates that an explicit bimineralic composition assimilated to heterogeneities succeeds in explaining observations related to the formation of rifted margins such a: (1) the absence of a sharp deformation zone at the brittle ductile transition (BDT), (2) the initiation of the rifting process as a wide delocalized rift system with multiple normal faults dipping in both directions; (3) the development of anastomosing shear zones in the middle/lower crust and the upper lithospheric mantle similar to the crustal scale anastomosing patterns observed in the field or in seismic data; (4) the preservation of undeformed lenses of material leading to lithospheric scale boudinage structure and resulting in the formation of continental ribbons as observed along the Iberian-Newfoundland margin.

  8. 3-D palinspastic restoration of normal faults in the Inner Moray Firth: implications for extensional basin development

    Barr, David


    Balanced cross-section techniques, and the construction of a restored section, permit 2-dimensional palinspastic restorations to be made in both compressional and extensional terraines. In 3 dimensions, an equivalent restoration can be made by assuming conservation of bedding-plane area and considering the volume of a stratigraphic interval rather than its cross-sectional area. Extensional basins displaying upper crustal listric normal faulting are particularly amenable to this approach. Computerised 3-D restorations have been made of the Inner Moray Firth basin, offshore Scotland. This basin is not isostatically compensated, and was produced by 7-8% post-Triassic extension, of which 2.5-3% is post-Jurassic, above a detachment surface at 20-25 km depth, close to the base of the crust. Limited lower crustal thinning (and lithospheric stretching) has affected the eastern part of the basin, but this can account for no more than half of the measured upper crustal extension. Some of this shallow extension is probably coupled by low-angle faults or shear zones into major zones of lithospheric stretching such as the North Sea grabens, where it may help account for discrepancies between estimates of lithospheric thinning and upper crustal extension.

  9. Time interval between volcanism and burial metamorphism and rate of basin subsidence in a Cretaceous Andean extensional setting

    Aguirre, L.; Féraud, G.; Morata, D.; Vergara, M.; Robinson, D.


    40Ar/ 39Ar ages were obtained from basaltic flows belonging to a 9-km-thick sequence generated in an extensional ensialic setting of an arc/back-arc basin type during the Early Cretaceous and presently exposed along the Coastal Range of central Chile. The basalts have been affected by very low- to low-grade burial metamorphism, mostly under prehnite-pumpellyite facies. Age values obtained from primary (volcanic) and secondary (metamorphic) minerals permit to quantify the time interval between volcanism and burial metamorphism. A plateau age of 119±1.2 Ma from primary plagioclase represents the best estimation of the age of the volcanism, whereas adularia, in low-variance assemblages contained in amygdules, gave a plateau age of 93.1±0.3 Ma which is interpreted as the age of the metamorphism. Considering the P- T conditions estimated for this metamorphic event, the c. 25 Ma time interval between volcanic emplacement and prehnite-pumpellyite facies metamorphism, the rate of basin subsidence in this extensional geodynamic setting would be comprised in the interval 150-180 m/Ma.

  10. Structural analysis and deformation characteristics of the Yingba metamorphic core complex, northwestern margin of the North China craton, NE Asia

    Yin, Congyuan; Zhang, Bo; Han, Bao-Fu; Zhang, Jinjiang; Wang, Yang; Ai, Sheng


    The presence of the Yingba (Yinggete-Bagemaode) metamorphic core complex (MCC) is confirmed near the Sino-Mongolian border in China. We report its structural evolution and the rheological features of ductile shear zones within this complex. Three deformations (Ds, Dm, and Db) since the Late Jurassic are identified. Ds is characterized by ductile structures that resulted from early NW-oriented, low-angle, extensional ductile shearing. Dm is associated with partial melting and magmatic diapirism, which accelerated the formation of the dome-like geometry of the Yingba MCC. Synchronously with or slightly subsequently to Ds and Dm, the Yingba MCC was subjected to brittle, extensional faulting (Db), which was accompanied by the exhumation of the lower crust and the formation of supracrustal basins. The ductile shearing (Ds) developed under greenschist-to amphibolite-facies metamorphic conditions (400-650 °C), as indicated by microstructures in quartz and feldspar, quartz [c] axis fabrics, and two-feldspar geothermometry. The mean kinematic vorticity estimates of 48-62% show a pure shear-preferred flow during Ds. The Yingba MCC provides an excellent sample that recorded an intermediate to high temperature shearing, which also implies the widely extensional regime in northeastern Asia at that time.

  11. Deformation quantization of principal bundles

    Aschieri, Paolo


    We outline how Drinfeld twist deformation techniques can be applied to the deformation quantization of principal bundles into noncommutative principal bundles, and more in general to the deformation of Hopf-Galois extensions. First we twist deform the structure group in a quantum group, and this leads to a deformation of the fibers of the principal bundle. Next we twist deform a subgroup of the group of authomorphisms of the principal bundle, and this leads to a noncommutative base space. Considering both deformations we obtain noncommutative principal bundles with noncommutative fiber and base space as well.

  12. Research on extensional viscosity of liquid crystalline polymer%液晶高分子流体拉伸粘度的研究



    The relationship between the extensional viscosity and material parameters is studied through the analytical formulas of stress and extensional viscosity derived from the constitutive equation, boundary conditions and the equation of motion of co-rotational Oldroyd fluid B model. By using software MATLAB, the differential equations are solved and the curves of extensional viscosity with other parameters are drawn, and the influence of these parameters on the rheologic behavior is shown.These results qualitatively agree with the experimental results.%利用液晶高分子共转Oldroyd流体B模型,研究了拉伸粘度的变化规律.作出了拉伸粘度随其它参数变化曲线.结论与实验结果一致.

  13. Control of pre-Cenozoic extensional heterogeneities on the kinematics of Cenozoic shortening: Northwestern Argentina

    Pearson, D. M.; Kapp, P. A.; Reiners, P. W.; Gehrels, G. E.


    Results from regional-scale mapping and structural analysis, (U-Th)/He and U-Pb age dating of apatite and zircon, and a regional balanced cross section allow us to build upon the pre-existing geological framework for the retroarc of northwestern Argentina. Coupled with previous work in the region, our results suggest that the style, distribution, and kinematics of shortening in the Eastern Cordillera and Santa Bárbara tectonomorphic provinces of the thrust belt at this latitude (24-25°S) were strongly influenced by the architecture of a Mesozoic rift system. In contrast to the thin-skinned Subandean fold-thrust belt of southern Bolivia where structures are primarily W-dipping and propagated progressively eastward through time, reverse faults in northwestern Argentina are more variably oriented, steeply E-dipping, locally inverted structures that propagated in an overall eastward direction in a much more sporadic manner. The first major eastward propagation event at this latitude occurred at ~40 Ma and is expressed as Eocene (U-Th)/He apatite and zircon ages coincident with the western arm of the Cretaceous Salta rift system. Other workers also documented angular unconformities of this age in the western and eastern arms of the rift system. Up until ~10 Ma, deformation and exhumation were restricted to the western margin of the Cretaceous rift in the western Eastern Cordillera and eastern margin of the Puna plateau. This was followed by an ~75 km jump in the location of the thrust front toward the east to bypass the central portion of a horst block of the Cretaceous rift system, followed by subsequent initiation of new E-dipping reverse faults in a subsystem that propagated toward the west into this pre-existing structural high. During Pliocene time, deformation again migrated >100 km eastward to a Cretaceous syn-rift depocenter in the Santa Bárbara Ranges and was likely followed by additional westward propagation to the current location of deformation with the

  14. Pseudotachylytes and mirror-like surfaces from extensional faults in Alpine Corsica (France)

    Di Toro, G.; Prando, F.; Mazzoli, C.; Nestola, F.; Zorzi, F.; Pennacchioni, G.


    At present we cannot investigate several phenomena occurring during earthquake propagation by means of seismological methods, mainly because of source, path and attenuation effects that result in loss of information transported by seismic waves. The above limitation forces us to a complementary approach which involves field geology (investigation of ancient now exhumed seismogenic structures), deep drilling projects (investigation of active seismogenic structures), microstructural (investigation of natural fault zone rocks) and laboratory (experiments reproducing seismic deformation conditions) studies. Here we propose that, because of the eastward migration of the lithospheric extension in this area of the Mediterranean, the Oligocene-in-age normal faults now outcropping in Alpine Corsica are the exhumed analogues of the seismogenic structures now active at depth in the Italian Apennines. The investigated fault zones cut serpentinites, quartzites, marbles and calc-schists of the Schistes Lustrés Complex (peak metamorphism Late Cretaceous- Late Eocene). Microstructural (EDS-equipped field emission scanning electron microscope, optical microscope cathodoluminescence) and mineralogical (micro-Raman spectroscopy and X-Ray powder diffraction) studies conducted on rocks sampled from the normal faults, evidenced a sequence of seismic and inter-seismic deformation processes during exhumation. Pseudotachylyte (scars of ancient seismic ruptures) produced at 8-15 km depth were overprinted by carbonate-rich veins and eventually cut by mirror-like fault surfaces made by nano-grains (< 50 nm in size) of quartz. The above overprinting microstructural relationships suggest continuous seismicity aided by the ingression of CO2-rich fluids during exhumation. These relationships are consistent with those proposed between crustal-mantle degassing and ingression of CO2-rich fluids in the faults responsible for the actual seismicity in the Italian Apennines.

  15. Deformable Simplicial Complexes

    Misztal, Marek Krzysztof

    In this dissertation we present a novel method for deformable interface tracking in 2D and 3D|deformable simplicial complexes (DSC). Deformable interfaces are used in several applications, such as fluid simulation, image analysis, reconstruction or structural optimization. In the DSC method......, the interface (curve in 2D; surface in 3D) is represented explicitly as a piecewise linear curve or surface. However, the domain is also subject to discretization: triangulation in 2D; tetrahedralization in 3D. This way, the interface can be alternatively represented as a set of edges/triangles separating...... demonstrate those strengths in several applications. In particular, a novel, DSC-based fluid dynamics solver has been developed during the PhD project. A special feature of this solver is that due to the fact that DSC maintains an explicit interface representation, surface tension is more easily dealt with...

  16. Autogenous Deformation of Concrete

    Autogenous deformation of concrete can be defined as the free deformation of sealed concrete at a constant temperature. A number of observed problems with early age cracking of high-performance concretes can be attributed to this phenomenon. During the last 10 years , this has led to an increased...... focus on autogenous deformation both within concrete practice and concrete research. Since 1996 the interest has been significant enough to hold international, yearly conferences entirely devoted to this subject. The papers in this publication were presented at two consecutive half-day sessions...... at the American Concrete Institute’s Fall Convention in Phoenix, Arizona, October 29, 2002. All papers have been reviewed according to ACI rules. This publication, as well as the sessions, was sponsored by ACI committee 236, Material Science of Concrete. The 12 presentations from 8 different countries indicate...

  17. Autogenous Deformation of Concrete

    Autogenous deformation of concrete can be defined as the free deformation of sealed concrete at a constant temperature. A number of observed problems with early age cracking of high-performance concretes can be attributed to this phenomenon. During the last 10 years , this has led to an increased...... focus on autogenous deformation both within concrete practice and concrete research. Since 1996 the interest has been significant enough to hold international, yearly conferences entirely devoted to this subject. The papers in this publication were presented at two consecutive half-day sessions...... at the American Concrete Institute’s Fall Convention in Phoenix, Arizona, October 29, 2002. All papers have been reviewed according to ACI rules. This publication, as well as the sessions, was sponsored by ACI committee 236, Material Science of Concrete. The 12 presentations from 8 different countries indicate...

  18. Post-laminectomy deformities

    Fabiano Stumpf Lutz


    Full Text Available Objective: To present the deformities and evaluate the results of their treatment. Methods: Retrospective study of patients with deformity following surgical access to the spinal canal. Fifteen patients who met the inclusion criteria were included. Patients without complete data in medical records were excluded. Results: Fourteen patients underwent surgical treatment and one patient received conservative treatment with vest type TLSO. The average angle of kyphosis correction was 87° preoperatively to 38° postoperatively, while the associated scoliosis correction was 69° preoperatively to 23° postoperatively. Conclusions: The prevention of deformity should be emphasized to avoid laminectomy alone, while laminoplasty should be the procedure of choice for canal access in surgeries where there is no need for resection of the posterior elements.

  19. Deformation of C isotopes

    Kanada-Enyo, Y


    Systematic analysis of the deformations of proton and neutron densities in even-even C isotopes was done based on the method of antisymmetrized molecular dynamics. The $E2$ transition strength was discussed in relation to the deformation. We analyze the $B(E2;2^+_1\\to 0^+_1)$ in $^{16}$C, which has been recently measured to be abnormally small. The results suggest the difference of the deformations between proton and neutron densities in the neutron-rich C isotopes. It was found that stable proton structure in C isotopes plays an important role in the enhancement the neutron skin structure as well as in the systematics of $B(E2)$ in the neutron-rich C.

  20. Deformation in nanocrystalline metals

    Helena Van Swygenhoven


    Full Text Available It is now possible to synthesize polycrystalline metals made up of grains that average less than 100 nm in size. Such nanocrystalline metals contain a significant volume fraction of interfacial regions separated by nearly perfect crystals. The small sizes involved limit the conventional operation of dislocation sources and thus a fundamental question arises: how do these materials deform plastically? We review the current views on deformation mechanisms in nanocrystalline, face-centered cubic metals based on insights gained by atomistic computer simulations. These insights are discussed with reference to recent striking experimental observations that can be compared with predictions made by the simulations.

  1. Heat treatment deformations

    Bavaro, A. (Soliveri SpA, Caravaggio (Italy))


    Types and causes of heat treatement derived isotropic and anisotropic dilatancies in ferrous materials are reviewed. The concepts are developed in such a way as to allow extension to all materials exhibiting martensitic tempering behaviour. This paper intends to illustrate the basic processes of dimensional variations undergone by the materials under heat treatments. The parametric analysis includes an analysis of the interactions amongst the parameters themselves. The relative importance of each parameter is assessed in order to determine methods to attenuate deformation action. Simplified examples are offered to provide technicians explanations as to why specific deformations occur and indications on improved materials working techniques.

  2. Power-law Distribution of Normal Fault Displacement and Length and Estimation of Extensional Strain due to Normal Faults:A Case Study of the Sierra de San Miguelito,Mexico



    The Sierra de San Miguelito is a relatively uplifted area and is constituted by a large amount of silicic volcanic rocks with ages from middle to late Cenozoic. The normal faults of the Sierra de San Miguelito are Domino-style and nearly parallel. The cumulative length and displacement of the faults obey power-law distribution. The fractal dimension of the fault traces is -1.49. Using the multi-line one-dimensional sampling, the calculated exponent of cumulative fault displacements is -0.66. A cumulative curve combining measurements of all four sections yielded a slope of -0.63. The displacement-length plot shows a non-linear relationship and large dispersion of data. The large dispersion in the plot is mainly due to the fault linkage during faulting. An estimation of extensional strain due to the normal faults is ca. 0.1830.The bed extension strain is always less than or equal to the horizontal extension strain. The deformation in the Sierra de San Miguelito occurred near the surface, producing pervasive faults and many faults are too small to appear in maps and sections at common scales. The stretching produced by small faults reach ca. 33% of the total horizontal elongation.

  3. Positive inversion of extensional footwalls in the southern Serra do Espinhaço, Brazil - insights from sandbox laboratory experiments

    Caroline J.S. Gomes


    Full Text Available Analogue experiments were carried out to get insights into the processes governing positive inversion during the foreland propagating thrust tectonics in the southern Serra do Espinhaço, a Brasiliano/Panafrican foldthrust belt in southeast Brazil. In particular, model listric half-grabens were inverted by applying contractional displacement to the footwall blocks. We investigated two different inversion conditions in listric half-grabens: (i extensional and contractional detachments at the same level and (ii at different positions. The models revealed that the development of a forward-breaking thrust system occurs in the basin synrift deposits, by contractional translation of the extensional footwall block when the extensional and contractional master faults do not coincide. Our experiments show the tectonic imbrication between basement and synrift sequences which characterizes the southern Serra do Espinhaço, and support the location in the eastern mountain range domain of the Espinhaço rift master fault system, which is not exposed at the surface.Em experimentos de areia foi simulada a inversão positiva com o intuito de investigar os processos que governam a tectônica da Cordilheira do Espinhaço Meridional na borda sudeste do Cráton São Francisco. Analisou-se, em particular, a evolução progressiva de hemigrabens, com falha de borda lístrica, na qual o fechamento da bacia ocorreu através da translação do bloco do muro da falha mestra. Duas condições foram investigadas: (i os descolamentos distensivos e compressivos ocorrem na mesma cota e (ii os descolamentos situam-se em posições diferentes. Os modelos revelaram que um sistema de falhas de cavalgamento com estilo colapso da lapa se desenvolve no interior do depósito sinrift quando os descolamentos não coincidem. O imbricamento entre escamas do pré- e sinrift, nos modelos, permite esboçar uma analogia com a tectônica da porção sul da Cordilheira do Espinhaço e situar a

  4. Marginally Deformed Starobinsky Gravity

    Codello, A.; Joergensen, J.; Sannino, Francesco


    We show that quantum-induced marginal deformations of the Starobinsky gravitational action of the form $R^{2(1 -\\alpha)}$, with $R$ the Ricci scalar and $\\alpha$ a positive parameter, smaller than one half, can account for the recent experimental observations by BICEP2 of primordial tensor modes....

  5. Electrospinning of polyvinylidene difluoride with carbon nanotubes: synergistic effects of extensional force and interfacial interaction on crystalline structures.

    Huang, Shu; Yee, Wu Aik; Tjiu, Wuiwui Chauhari; Liu, Ye; Kotaki, Masaya; Boey, Yin Chiang Freddy; Ma, Jan; Liu, Tianxi; Lu, Xuehong


    Polyvinylidene difluoride (PVDF) solutions containing a very low concentration of single-walled carbon nanotubes (SWCNTs) and multiwalled carbon nanotubes (MWCNTs) of similar surface chemistry, respectively, were electrospun, and the nanofibers formed were collected using a modified rotating disk collector. The polymorphic behavior and crystal orientation of the nanofibers were studied using wide-angle X-ray diffraction and infrared spectroscopy, while the nanotube alignment and interfacial interactions in the nanofibers were probed by transmission electron microscopy and Raman spectroscopy. It is shown that the interfacial interaction between the SWCNTs and PVDF and the extensional force experienced by the nanofibers in the electrospinning and collection processes can work synergistically to induce highly oriented beta-form crystallites extensively. In contrast, the MWCNTs could not be well aligned along the nanofiber axis, which leads to a lower degree of crystal orientation.

  6. The effect of shear and extensional viscosities on atomization of Newtonian and non-Newtonian fluids in ultrasonic inhaler.

    Broniarz-Press, L; Sosnowski, T R; Matuszak, M; Ochowiak, M; Jabłczyńska, K


    The paper contains results of the experimental study on atomization process of aqueous solutions of glycerol and aqueous solutions of glycerol-polyacrylamide (Rokrysol WF1) in an ultrasonic inhaler. In experiments the different concentration aqueous solutions of glycerol and glycerol-polyacrylamide have been tested. The results have been obtained by the use of laser diffraction technique. The differences between characteristics of ultrasonic atomization for test liquids have been observed. The analysis of drop size histograms shows that the different sizes of drops have been formed during atomization process. The present study confirmed the previous reports which suggested that the drops size changes with the increase in viscosity of solution changes in spray characteristics were also observed. It has been shown that the shear and extensional viscosities affect the process of atomization.

  7. Monazite geochronology, magmatism, and extensional dynamics within the Menderes Massif, western Turkey

    Catlos, E J [University of Texas at Austin, Jackson School of Geosciences, Geological Science Department, 1 University Station C1100, Austin, TX 78712-0254 (United States); Baker, C B; Cemen, I [Oklahoma State University, School of Geology, 105 Noble Research Center, Stillwater, OK 74078 (United States); Sorensen, S S [Smithsonian Institution Museum of Natural History, PO Box 37012, MRC 119, Washington, DC, 20013-7012 (United States); Hancer, M [Pamukkale Universitesi, Muhendislik Fakultesi, Jeoloji Muh. Bolmu, Denizli, 20070 Turkey (Turkey)], E-mail:


    Geochemical and geochronological data were collected from S-type, peraluminous granites (Salihli and Turgutlu) that intrude a detachment that bounds the northern edge of the central Menderes Massif core complex (Aegean region, western Turkey). The granites may have been generated due to subduction of the Eastern Mediterranean floor along the Hellenic trench. In situ Th-Pb ion microprobe monazite ages from the rocks range from 21.7{+-}4.5 Ma to 9.6{+-}1.6 Ma ({+-}1{sigma}), which could record their exhumation history. Higher uncertainty in the ages is attributed to monazite common Pb, but the range is consistent with cathodoluminescence (CL) images that document complex textures within the granites. Salihli and Turgutlu granites share many similar characteristics, including multiple generations of plagioclase, plagioclase replacing K-feldspar and the development of myrmekite, evidence for fluid interaction, and multiple generations of microcracks. Ages reported here are similar to dates constraining extension reported elsewhere in the Aegean, but indicate additional complexities when linking movement within the Menderes Massif to large-scale geodynamic processes that created other metamorphic core complexes in the region. Difficulties exist in linking the ages obtained from the granites to specific tectonic events due to the presence of secondary alteration textures, generations of mineral growth and multiple episodes of deformation.

  8. Segmentation pattern and structural complexities in seismogenic extensional settings: The North Matese Fault System (Central Italy)

    Ferrarini, Federica; Boncio, Paolo; de Nardis, Rita; Pappone, Gerardo; Cesarano, Massimo; Aucelli, Pietro P. C.; Lavecchia, Giusy


    We investigated the northern slope of the Matese Mts. (Molise, Central Italy) with the aim of characterizing the N- to NE-dipping active normal fault system in the Bojano basin, a sector of primary importance from a seismic hazard perspective. We collected field data to define the geometry and segmentation pattern of two sub-systems (Patalecchia-Colle di Mezzo and Bojano-Campochiaro). New evidence of late Quaternary faulting was obtained by exploiting well log interpretations. Kinematic analysis revealed the interaction of pre-Quaternary inherited (mainly E-W-striking) and newly formed (NW-SE-striking) normal faults. Slip accommodation through linkage was clearly noted in the case of the Patalecchia-Colle di Mezzo sub-system. Detailed topographic profiles across the active fault segments provided post-LGM (15 ± 3 kyr) slip rates up to ∼2 mm/yr which agree with the high deformation rates based on different approaches in the literature. Finally, the instrumental seismicity analysis constrained the bottom of the seismogenic layer to depths of 13-14 km, and the gathered information allowed us to reconstruct the North Matese seismogenic source. Its 3D geometry and dimensions agree with both the dimension-magnitude relationships and macroseismic information available for the 1805 earthquake (Mw 6.6), the main historical earthquake to have struck the Bojano basin.

  9. Constraints on deformation of the Southern Andes since the Cretaceous from anisotropy of magnetic susceptibility

    Maffione, Marco; Hernandez-Moreno, Catalina; Ghiglione, Matias C.; Speranza, Fabio; van Hinsbergen, Douwe J. J.; Lodolo, Emanuele


    The southernmost segment of the Andean Cordillera underwent a complex deformation history characterized by alternation of contractional, extensional, and strike-slip tectonics. Key elements of southern Andean deformation that remain poorly constrained, include the origin of the orogenic bend known as the Patagonian Orocline (here renamed as Patagonian Arc), and the exhumation mechanism of an upper amphibolite facies metamorphic complex currently exposed in Cordillera Darwin. Here, we present results of anisotropy of magnetic susceptibility (AMS) from 22 sites in Upper Cretaceous to upper Eocene sedimentary rocks within the internal structural domain of the Magallanes fold-and-thrust belt in Tierra del Fuego (Argentina). AMS parameters from most sites reveal a weak tectonic overprint of the original magnetic fabric, which was likely acquired upon layer-parallel shortening soon after sedimentation. Magnetic lineation from 17 sites is interpreted to have formed during compressive tectonic phases associated to a continuous N-S contraction. Our data, combined with the existing AMS database from adjacent areas, show that the Early Cretaceous-late Oligocene tectonic phases in the Southern Andes yielded continuous contraction, variable from E-W in the Patagonian Andes to N-S in the Fuegian Andes, which defined a radial strain field. A direct implication is that the exhumation of the Cordillera Darwin metamorphic complex occurred under compressive, rather than extensional or strike-slip tectonics, as alternatively proposed. If we agree with recent works considering the curved Magallanes fold-and-thrust belt as a primary arc (i.e., no relative vertical-axis rotation of the limbs occurs during its formation), then other mechanisms different from oroclinal bending should be invoked to explain the documented radial strain field. We tentatively propose a kinematic model in which reactivation of variably oriented Jurassic faults at the South American continental margin controlled

  10. Deformed Algebras and Generalizations of Independence on Deformed Exponential Families

    Hiroshi Matsuzoe


    Full Text Available A deformed exponential family is a generalization of exponential families. Since the useful classes of power law tailed distributions are described by the deformed exponential families, they are important objects in the theory of complex systems. Though the deformed exponential families are defined by deformed exponential functions, these functions do not satisfy the law of exponents in general. The deformed algebras have been introduced based on the deformed exponential functions. In this paper, after summarizing such deformed algebraic structures, it is clarified how deformed algebras work on deformed exponential families. In fact, deformed algebras cause generalization of expectations. The three kinds of expectations for random variables are introduced in this paper, and it is discussed why these generalized expectations are natural from the viewpoint of information geometry. In addition, deformed algebras cause generalization of independences. Whereas it is difficult to check the well-definedness of deformed independence in general, the κ-independence is always well-defined on κ-exponential families. This is one of advantages of κ-exponential families in complex systems. Consequently, we can well generalize the maximum likelihood method for the κ-exponential family from the viewpoint of information geometry.

  11. Deformation of chlorite in naturally deformed low-grade rocks

    Bons, A.J.


    The intracrystalline deformation of chlorite in naturally deformed low-grade rocks was investigated with transmission electron microscopy (TEM). As in other phyllosilicates, the deformation of chlorite is dominated by the (001) slip plane. Slip along this plane is very easy through the generation an

  12. Left-lateral transtension along the Tierra Colorada deformation zone, northern margin of the Xolapa magmatic arc of southern Mexico

    Riller, U.; Ratschbacher, L.; Frisch, W.


    Structural analysis of steeply NNW-dipping tectonites along the northern margin of the Xolapa magmatic arc, southern Mexico, reveals progressive deformation involving ductile and brittle deformation mechanisms. Ductile deformation detached Cretaceous cover rocks from the Xolapa basement along a crustal-scale mylonite zone with normal fault geometry. Normal faults dissected the mylonite zone into blocks which rotated a minimum of 35° to the north. Stress tensors calculated from fault-striae data show subhorizontal, roughly N/S-trending principal extension. Deformation resulted from differential uplift of the Xolapa magmatic arc with respect to its northern hinterland (Mixteca terrane). The oblique normal fault geometry of the mylonites conforms with strike-slip and dip-slip movements along the faults. Left-lateral transtension commenced ductilely between 90 Ma (age of deformed cover rocks) and 34 Ma (U/Pb zircon age of an undeformed pluton cutting the mylonite zone) and continued brittlely into the late Tertiary (tilted Miocene volcanic rocks). We argue that deformation resulted from the interaction of a left-lateral strike-slip regime established during formation of the Caribbean, and an extensional collapse of the Xolapa magmatic arc resulting from a change in steady-state plate-boundary conditions in the early Tertiary.

  13. Postural deformities in Parkinson's disease

    Doherty, K.M.; Warrenburg, B.P.C. van de; Peralta, M.C.; Silveira-Moriyama, L.; Azulay, J.P.; Gershanik, O.S.; Bloem, B.R.


    Postural deformities are frequent and disabling complications of Parkinson's disease (PD) and atypical parkinsonism. These deformities include camptocormia, antecollis, Pisa syndrome, and scoliosis. Recognition of specific postural syndromes might have differential diagnostic value in patients prese

  14. Nonperturbative effects in deformation quantization

    Periwal, V


    The Cattaneo-Felder path integral form of the perturbative Kontsevich deformation quantization formula is used to explicitly demonstrate the existence of nonperturbative corrections to na\\"\\i ve deformation quantization.

  15. Kinematics of deformation across the Philippine Archipelago as observed from GPS campaign data

    Bacolcol, T.; Solidum, R., Jr.; Yu, S.; Phivolcs Gps Team


    More than 150 Global Positioning System (GPS) points across the Philippine archipelago have been installed by the Philippine Institute of Volcanology and Seismology (PHIVOLCS) and its collaborative partners. Results from the repeated GPS measurements conducted since 1996 up to the present on these points showed the following: (1) Based on uniform motion and velocity directions gathered from the GPS data, the Philippine Mobile Belt can generally be subdivided into three blocks: Central to Northern Luzon; Southern Luzon to Southern Visayas; Mindanao; (2) There is a significant internal deformation in the Philippine Mobile Belt as seen from variable velocities and azimuth directions relative to Eurasian plate. (3) Relative velocities across the Philippine Fault vary from 20 mm/yr to 29 mm/yr (vector azimuths from 322 deg to 4 deg) in Northern Luzon; 31.2 mm/yr to 53.3 mm/yr (300 deg to 310 deg) in Southern Luzon; 20.5 mm/yr to 25.1 mm/yr (305 deg to 347 deg) in Visayas and 14 mm/yr to 33 mm/yr (338 deg to 40 deg) in Mindanao. (4) There is an active extensional deformation (18 mm/yr) in Macolod Corridor while compressional deformation (24 mm/yr) exists between Southern Visayas and Mindanao. This reverse analogue of deformation is probably the result of the collision between Palawan and the Philippine Mobile Belt.

  16. Nanoscale deformation mechanisms in bone.

    Gupta, Himadri S; Wagermaier, Wolfgang; Zickler, Gerald A; Raz-Ben Aroush, D; Funari, Sérgio S; Roschger, Paul; Wagner, H Daniel; Fratzl, Peter


    Deformation mechanisms in bone matrix at the nanoscale control its exceptional mechanical properties, but the detailed nature of these processes is as yet unknown. In situ tensile testing with synchrotron X-ray scattering allowed us to study directly and quantitatively the deformation mechanisms at the nanometer level. We find that bone deformation is not homogeneous but distributed between a tensile deformation of the fibrils and a shearing in the interfibrillar matrix between them.

  17. Effects of permeability fields on fluid, heat, and oxygen isotope transport in extensional detachment systems

    Gottardi, RaphaëL.; Kao, Po-Hao; Saar, Martin O.; Teyssier, Christian


    Field studies of Cordilleran metamorphic core complexes indicate that meteoric fluids permeated the upper crust down to the detachment shear zone and interacted with highly deformed and recrystallized (mylonitic) rocks. The presence of fluids in the brittle/ductile transition zone is recorded in the oxygen and hydrogen stable isotope compositions of the mylonites and may play an important role in the thermomechanical evolution of the detachment shear zone. Geochemical data show that fluid flow in the brittle upper crust is primarily controlled by the large-scale fault-zone architecture. We conduct continuum-scale (i.e., large-scale, partial bounce-back) lattice-Boltzman fluid, heat, and oxygen isotope transport simulations of an idealized cross section of a metamorphic core complex. The simulations investigate the effects of crust and fault permeability fields as well as buoyancy-driven flow on two-way coupled fluid and heat transfer and resultant exchange of oxygen isotopes between meteoric fluid and rock. Results show that fluid migration to middle to lower crustal levels is fault controlled and depends primarily on the permeability contrast between the fault zone and the crustal rocks. High fault/crust permeability ratios lead to channelized flow in the fault and shear zones, while lower ratios allow leakage of the fluids from the fault into the crust. Buoyancy affects mainly flow patterns (more upward directed) and, to a lesser extent, temperature distributions (disturbance of the geothermal field by ~25°C). Channelized fluid flow in the shear zone leads to strong vertical and horizontal thermal gradients, comparable to field observations. The oxygen isotope results show δ18O depletion concentrated along the fault and shear zones, similar to field data.

  18. Cosmetic and Functional Nasal Deformities

    ... nasal complaints. Nasal deformity can be categorized as “cosmetic” or “functional.” Cosmetic deformity of the nose results in a less ... taste , nose bleeds and/or recurrent sinusitis . A cosmetic or functional nasal deformity may occur secondary to ...

  19. Current deformation in Central Afar and triple junction kinematics deduced from GPS and InSAR measurements

    Doubre, Cécile; Déprez, Aline; Masson, Frédéric; Socquet, Anne; Lewi, Elias; Grandin, Raphaël; Nercessian, Alexandre; Ulrich, Patrice; De Chabalier, Jean-Bernard; Saad, Ibrahim; Abayazid, Ahmadine; Peltzer, Gilles; Delorme, Arthur; Calais, Eric; Wright, Tim


    Kinematics of divergent boundaries and Rift-Rift-Rift junctions are classically studied using long-term geodetic observations. Since significant magma-related displacements are expected, short-term deformation provides important constraints on the crustal mechanisms involved both in active rifting and in transfer of extensional deformation between spreading axes. Using InSAR and GPS data, we analyse the surface deformation in the whole Central Afar region in detail, focusing on both the extensional deformation across the Quaternary magmato-tectonic rift segments, and on the zones of deformation transfer between active segments and spreading axes. The largest deformation occurs across the two recently activated Asal-Ghoubbet (AG) and Manda Hararo-Dabbahu (MH-D) magmato-tectonic segments with very high strain rates, whereas the other Quaternary active segments do not concentrate any large strain, suggesting that these rifts are either sealed during interdyking periods or not mature enough to remain a plate boundary. Outside of these segments, the GPS horizontal velocity field shows a regular gradient following a clockwise rotation of the displacements from the Southeast to the East of Afar, with respect to Nubia. Very few shallow creeping structures can be identified as well in the InSAR data. However, using these data together with the strain rate tensor and the rotations rates deduced from GPS baselines, the present-day strain field over Central Afar is consistent with the main tectonic structures, and therefore with the long-term deformation. We investigate the current kinematics of the triple junction included in our GPS data set by building simple block models. The deformation in Central Afar can be described by adding a central microblock evolving separately from the three surrounding plates. In this model, the northern block boundary corresponds to a deep EW-trending trans-tensional dislocation, locked from the surface to 10-13 km and joining at depth the

  20. [Babies with cranial deformity].

    Feijen, Michelle M W; Claessens, Edith A W M Habets; Dovens, Anke J Leenders; Vles, Johannes S; van der Hulst, Rene R W J


    Plagiocephaly was diagnosed in a baby aged 4 months and brachycephaly in a baby aged 5 months. Positional or deformational plagio- or brachycephaly is characterized by changes in shape and symmetry of the cranial vault. Treatment options are conservative and may include physiotherapy and helmet therapy. During the last two decades the incidence of positional plagiocephaly has increased in the Netherlands. This increase is due to the recommendation that babies be laid on their backs in order to reduce the risk of sudden infant death syndrome. We suggest the following: in cases of positional preference of the infant, referral to a physiotherapist is indicated. In cases of unacceptable deformity of the cranium at the age 5 months, moulding helmet therapy is a possible treatment option.

  1. Deformation twinning in monazite

    Hay, R.S.; Marshall, D.B


    Polycrystalline monazite (LaPO{sub 4}) was deformed at room temperature by a spherical indenter. Deformation twins were identified by TEM in 70 grains. Five twin planes were found: (100) was by far the most common; (001) and (120) were less common; (122-bar)was rare, and kinks in (120) twins were identified as irrational '(483)' twin planes. The twinning modes on these planes were inferred from the expression of twinning shear at free surfaces, predictions of classical deformation twinning theory, and various considerations of twin morphology and crystal structure. Atomic shuffle calculations that allow formation of either a glide plane or a mirror plane at the twin interface were used to analyze twin modes. The inferred twin modes all have small atomic shuffles. For (001) twins, the smallest shuffles were obtained with a glide plane at the interface, with displacement vector R=((1)/(2))[010]. The results do not uniquely define a twin mode on (100), leaving open the possibility of more than one mode operating on this plane. Factors that may determine the operative deformation twinning modes are discussed. Crystal structure considerations suggest that the relative abundance of twinning modes may correlate with low shear modulus on the twin plane in the direction of twinning shear, and with a possible low-energy interface structure consisting of a layer of xenotime of one half-unit-cell thickness that could form at (100) and (001) twins. The three most common twins have low strains to low {sigma} coincidence site lattices (CSLs)

  2. Localization of plastic deformation

    Rice, J R


    The localization of plastic deformation into a shear band is discussed as an instability of plastic flow and a precursor to rupture. Experimental observations are reviewed, a general theoretical framework is presented, and specific calculations of critical conditions are carried out for a variety of material models. The interplay between features of inelastic constitutive description, especially deviations from normality and vertex-like yielding, and the onset of localization is emphasized.

  3. Sprengels deformity: anaesthesia management.

    Dave S


    Full Text Available A 28 years old lady presented with Sprengels deformity and hemivertebrae for Fothergills surgery. Clinically there were no anomalies of the nervous, renal or the cardiovascular systems. She had a short neck and score on modified Mallapati test was grade 2. She was successfully anaesthetised using injection Propofol as a total intravenous anaesthetic agent after adequate premedication with injection Midazolam and injection Pentazocine. Patient had an uneventful intraoperative and postoperative course.

  4. Nanoscale Deformable Optics

    Strauss, Karl F.; Sheldon, Douglas J.


    Several missions and instruments in the conceptual design phase rely on the technique of interferometry to create detectable fringe patterns. The intimate emplacement of reflective material upon electron device cells based upon chalcogenide material technology permits high-speed, predictable deformation of the reflective surface to a subnanometer or finer resolution with a very high degree of accuracy. In this innovation, a layer of reflective material is deposited upon a wafer containing (perhaps in the millions) chalcogenic memory cells with the reflective material becoming the front surface of a mirror and the chalcogenic material becoming a means of selectively deforming the mirror by the application of heat to the chalcogenic material. By doing so, the mirror surface can deform anywhere from nil to nanometers in spots the size of a modern day memory cell, thereby permitting realtime tuning of mirror focus and reflectivity to mitigate aberrations caused elsewhere in the optical system. Modern foundry methods permit the design and manufacture of individual memory cells having an area of or equal to the Feature (F) size of the design (assume 65 nm). Fabrication rules and restraints generally require the instantiation of one memory cell to another no closer than 1.5 F, or, for this innovation, 90 nm from its neighbor in any direction. Chalcogenide is a semiconducting glass compound consisting of a combination of chalcogen ions, the ratios of which vary according to properties desired. It has been shown that the application of heat to cells of chalcogenic material cause a large alteration in resistance to the range of 4 orders of magnitude. It is this effect upon which chalcogenidebased commercial memories rely. Upon removal of the heat source, the chalcogenide rapidly cools and remains frozen in the excited state. It has also been shown that the chalcogenide expands in volume because of the applied heat, meaning that the coefficient of expansion of chalcogenic

  5. q-变形的Hom-Leibniz中心扩张%Hom-Leibniz Central Extension on the q -Deformed Witt Algebra

    程永胜; 梁宏伟


    This paper investigates a new realization, the central extensional and the second cohomology group of the q -deformed Witt algebra. Finally it proves that the centralextensions of the q -deformed Witt algebra in the category of Horn-Lie algebra and in the category of Horn-Leibniz algebra coincide with each other.%给出Witt代数的q-变形的一个新的实现,并研究了它的中心扩张和第二上同调群.最后证明了Witt代数的q-变形的Hom-Leibniz中心扩张在Hom-Lie代数范畴内和Hom-Leibniz代数范畴内是一致的.

  6. Quantizing Earth surface deformations

    C. O. Bowin


    Full Text Available The global analysis of Bowin (2010 used the global 14 absolute Euler pole set (62 Myr history from Gripp and Gordon (1990 and demonstrated that plate tectonics conserves angular momentum. We herein extend that analysis using the more detailed Bird (2003 52 present-day Euler pole set (relative to a fixed Pacific plate for the Earth's surface, after conversion to absolute Euler poles. Additionally, new analytical results now provide new details on upper mantle mass anomalies in the outer 200 km of the Earth, as well as an initial quantizing of surface deformations.

  7. Space Deformations, Surface Deformations and the Opportunities In-Between

    Daniel Cohen-Or


    In recent years we have witnessed a large interest in surface deformation techniques. This has been a reaction that can be attributed to the ability to develop techniques which are detail-preserving. Space deformation techniques, on the other hand, received less attention, but nevertheless they have many advantages over surface-based techniques. This paper explores the potential of these two approaches to deformation and discusses the opportunities that the fusion of the two may lead to.

  8. Vibration of prolate spheroidal shells with shear deformation and rotatory inertia: Axisymmetric case

    Hayek, Sabih I.; Boisvert, Jeffrey E.


    This paper presents the derivation of the equations for nonaxisymmetric motion of prolate spheroidal shells of constant thickness. The equations include the effect of distributed mechanical surface forces and moments. The shell theory used in this derivation includes three displacements and two thickness shear rotations. Thus, the effects of membrane, bending, shear deformation, and rotatory inertia are included in this theory. The resulting five coupled partial differential equations are self-adjoint and positive definite. The frequency-wave-number spectrum has five branches, two acoustic and three optical branches representing flexural, extensional, torsional, and two thickness shear. For the case of axisymmetric motion, these were computed for various spheroidal shell eccentricities and thickness-to-length ratios for a large number of modes. The axisymmetric dynamic response for damped shells of various eccentricities and thicknesses under point and ring surface forces are presented.

  9. Brittle–viscous deformation of vein quartz under fluid-rich low greenschist facies conditions

    H. J. Kjøll


    Full Text Available A coarse grained, statically crystallized quartz vein, embedded in a phyllonitic matrix, was studied by EBSD and optical microscopy to gain insights into the processes of strain localization in quartz deformed under low-grade conditions, broadly coincident with the frictional–viscous transition. The vein is from a high strain zone at the front of the Porsa Imbricate Stack in the Paleoproterozoic Repparfjord Tectonic Window in northern Norway. The vein was deformed under lower greenschist facies conditions during deformation along a large out-of-sequence phyllonitic thrust of Caledonian age. The host phyllonite formed at the expense of metabasalt wherein feldspar broke down to form interconnected layers of fine, synkinematic phyllosilicates. In the mechanically weak framework of the phyllonite, the studied quartz vein acted as a relatively rigid body deforming mainly by coaxial strain. Viscous deformation was initially accommodated by basal ⟨a⟩ slip of quartz during the development of a mesoscopic pervasive extensional crenulation cleavage. Under the prevailing boundary conditions, however, dislocation glide-accommodated deformation of quartz resulted inefficient and led to dislocation tangling and strain hardening of the vein. In response to hardening, to the progressive increase of fluid pressure and the increasing competence contrast between the vein and the weak foliated host phyllonite, quartz crystals began to deform frictionally along specific, optimally oriented lattice planes, creating microgouges along microfractures. These were, however, rapidly sealed by nucleation of new grains as transiently over pressured fluids penetrated the deforming system. The new nucleated grains grew initially by solution-precipitation and later by grain boundary migration. Due to the random initial orientation of the vein crystals, strain was accommodated differently in the individual crystals, leading to the development of remarkably different

  10. Formation and subdivision of deformation structures during plastic deformation

    Jakobsen, B.; Poulsen, H.F.; Lienert, U.;


    During plastic deformation of metals and alloys, dislocations arrange in ordered patterns. How and when these self-organization processes take place have remained elusive, because in situ observations have not been feasible. We present an x-ray diffraction method that provided data on the dynamics...... of individual, deeply embedded dislocation structures. During tensile deformation of pure copper, dislocation-free regions were identified. They showed an unexpected intermittent dynamics, for example, appearing and disappearing with proceeding deformation and even displaying transient splitting behavior....... Insight into these processes is relevant for an understanding of the strength and work-hardening of deformed materials....

  11. The influence of inherited extensional structures on the tectonic evolution of an intracratonic chain: the example of the Western Pyrenees

    Velasque, P. C.; Ducasse, L.; Muller, J.; Scholten, R.


    A geotraverse, constructed on the basis of surface and subsurface data across the Basque-Béarnais portion of the Pyrenees, east of the Pamplona fault, reveals, from north to south, the existence of three major tectono-sedimentary units: the North Pyrenean Zone (NPZ), the Central Zone (CZ) and the Axial Zone (AZ). These zones are characterized both by the type and age of their sediments and volcanics, and by the style of their Cretaceous synsedimentary structures. Paleogeographically, they correspond to a Cretaceous platform (AZ), margin (CZ) and basin (NPZ), separated by zones of normal faults. During Alpine convergence, the Cretaceous fault system was to varying degrees reactivated in the reverse sense. The NPZ grades into the CZ without any significant hiatus. By contrast, the CZ is separated from the AZ by a major southward overthrust, the Orly-Lakhoura overthrust, which shows up as the most important fault in the cross-section. Its subsurface continuation is constrained by regional microseismicity and other seismic data. All these data lead us to consider the Orhy-Lakhoura overthrust as the surface evidence of the Alpine crustal underthrust of Iberia below the European continental domain. Restoration of the cross-section suggests that this Alpine underthrust follows a previous crustal discontinuity linked to the Cretaceous extensional episode.

  12. Extensional flow of low-viscosity fluids in capillary bridges formed by pulsed surface acoustic wave jetting

    Bhattacharjee, P K; McDonnell, A G; Prabhakar, R; Yeo, L Y; Friend, J, E-mail: [MicroNanophysics Research Laboratory, Department of Mechanical and Aerospace Engineering, Monash University, Melbourne, VIC 3800 (Australia); Melbourne Centre for Nanofabrication, Melbourne, VIC 3800 (Australia)


    Forming capillary bridges of low-viscosity ({approx}<10 mPa s) fluids is difficult, making the study of their capillary-thinning behavior and the measurement of the fluid's extensional viscosity difficult as well. Current techniques require some time to form a liquid bridge from the stretching of a droplet. Rapidly stretching a liquid bridge using these methods can cause its breakup if the viscosity is too low. Stretching more slowly allows the bridge to thin and break up before a suitable bridge geometry can be established to provide reliable and accurate rheological data. Using a pulsed surface acoustic wave to eject a jet from a sessile droplet, a capillary bridge may be formed in about 7.5 ms, about seven times quicker than current methods. With this approach, capillary bridges may be formed from Newtonian and non-Newtonian fluids having much lower viscosities-water, 0.04% by weight solution of high-molecular-weight (7 MDa) polystyrene in dioctyl phthalate and 0.25% fibrinogen solution in demineralized water, for example. Details of the relatively simple system used to achieve these results are provided, as are experimental results indicating deviations from a Newtonian response by the low-viscosity non-Newtonian fluids used in our study.

  13. Extensional flow of low-viscosity fluids in capillary bridges formed by pulsed surface acoustic wave jetting

    Bhattacharjee, P. K.; McDonnell, A. G.; Prabhakar, R.; Yeo, L. Y.; Friend, J.


    Forming capillary bridges of low-viscosity (lsim10 mPa s) fluids is difficult, making the study of their capillary-thinning behavior and the measurement of the fluid's extensional viscosity difficult as well. Current techniques require some time to form a liquid bridge from the stretching of a droplet. Rapidly stretching a liquid bridge using these methods can cause its breakup if the viscosity is too low. Stretching more slowly allows the bridge to thin and break up before a suitable bridge geometry can be established to provide reliable and accurate rheological data. Using a pulsed surface acoustic wave to eject a jet from a sessile droplet, a capillary bridge may be formed in about 7.5 ms, about seven times quicker than current methods. With this approach, capillary bridges may be formed from Newtonian and non-Newtonian fluids having much lower viscosities—water, 0.04% by weight solution of high-molecular-weight (7 MDa) polystyrene in dioctyl phthalate and 0.25% fibrinogen solution in demineralized water, for example. Details of the relatively simple system used to achieve these results are provided, as are experimental results indicating deviations from a Newtonian response by the low-viscosity non-Newtonian fluids used in our study.

  14. Extensional Flow of a Polystyrene Boger Fluid Through a 4:1:4 Axisymmetric Contraction/Expansion

    Rothstein, Jonathan P.; McKinley, Gareth H.


    The creeping flow of a dilute (0.025 wt%) monodisperse polystyrene/polystyrene Boger fluid through a 4:1:4 axisymmetric contraction/expansion is experimentally observed for a wide range of Deborah numbers. Pressure drop measurements across the orifice plate show a large extra pressure drop that increases monotonically with Deborah number above the value observed for a similar Newtonian fluid at the same flow rate. This enhancement in the dimensionless pressure drop is not associated with the onset of a flow instability, yet it is not predicted by existing steady-state or transient numerical computations with simple dumbbell models. It is conjectured that this extra pressure drop is the result of an additional dissipative contribution to the polymeric stress arising from a stress-conformation hysteresis in the strong non-homogeneous extensional flow near the contraction plane. Such a hysteresis has been independently measured and computed in recent studies of homogeneous transient uniaxial stretching of PS/PS Boger fluids. Flow visualization and velocity field measurements using digital particle image velocimetry (DPIV) show large upstream growth of the corner vortex with increasing Deborah number. At large Deborah numbers, the onset of an elastic instability is observed, first locally as small amplitude fluctuations in the pressure measurements, and then globally as an azimuthal precessing of the upstream corner vortex accompanied by periodic oscillations in the pressure drop across the orifice.

  15. Three-port impedance model of a piezoelectric bar element: Application to generation and damping of extensional waves

    Jansson, A.; Lundberg, B.


    A straight bar element containing piezoelectric members is viewed as a linear system with one electrical and two mechanical ports where it can interact with external electrical and mechanical devices through voltage, current, forces and velocities. A generalized force vector, with one voltage and two forces as elements, is expressed as the product of an impedance matrix and a generalized velocity vector, with one current and two velocities, as elements. Due to symmetry and reciprocity, this matrix is defined by four of its nine elements. Two applications are considered for a piezoelectric bar element (PBE) that constitutes a part of a long elastic or viscoelastic bar, viz. generation and damping of extensional waves in the bar. In the first, the PBE is driven by a given input voltage or by the output voltage from a linear power amplifier. In the second, the PBE supplies an output voltage to an external load. In numerical simulations carried out for a specific laminated PBE, an elastic bar, a serial RL load and a bell-shaped incident wave, the highest fraction of wave energy dissipated was 8.1%. This is much less than the 50% achievable for a harmonic wave under condition of electrical impedance matching.

  16. Rotary deformity in degenerative spondylolisthesis

    Kang, Sung Gwon; Kim, Jeong; Kho, Hyen Sim; Yun, Sung Su; Oh, Jae Hee; Byen, Ju Nam; Kim, Young Chul [Chosun University College of Medicine, Gwangju (Korea, Republic of)


    We studied to determine whether the degenerative spondylolisthesis has rotary deformity in addition to forward displacement. We have made analysis of difference of rotary deformity between the 31 study groups of symptomatic degenerative spondylolisthesis and 31 control groups without any symptom, statistically. We also reviewed CT findings in 15 study groups. The mean rotary deformity in study groups was 6.1 degree(the standard deviation is 5.20), and the mean rotary deformity in control groups was 2.52 degree(the standard deviation is 2.16)(p < 0.01). The rotary deformity can be accompanied with degenerative spondylolisthesis. We may consider the rotary deformity as a cause of symptomatic degenerative spondylolisthesis in case that any other cause is not detected.

  17. Deformation analysis: The Fredericton approach

    Vrečko, Anja; Ambrožič, Tomaž


    In this article, the Fredericton approach to deformation analysis is presented. It is possible to use several deformation models to determine the differences between the geodetic observations or between the coordinates of points in geodetic network in more epochs. The most appropriate deformation model has been chosen based on statistical testing and available information about dynamics at the area of interest. First, a theoretical background of the approach ...

  18. Deformable paper origami optoelectronic devices

    He, Jr-Hau


    Deformable optoelectronic devices are provided, including photodetectors, photodiodes, and photovoltaic cells. The devices can be made on a variety of paper substrates, and can include a plurality of fold segments in the paper substrate creating a deformable pattern. Thin electrode layers and semiconductor nanowire layers can be attached to the substrate, creating the optoelectronic device. The devices can be highly deformable, e.g. capable of undergoing strains of 500% or more, bending angles of 25° or more, and/or twist angles of 270° or more. Methods of making the deformable optoelectronic devices and methods of using, e.g. as a photodetector, are also provided.

  19. Viscosidade extensional e em cisalhamento de suspensões acidificadas de amido de amaranto e caseinato de sódio Extensional and shear viscosity of acidified amaranth starch-sodium caseinate suspensions

    Angela Maria Gozzo


    Full Text Available Foram avaliadas as viscosidades extensional e em cisalhamento de suspensões acidificadas de amido de amaranto-caseinato de sódio. Sistemas mistos de amido de amaranto-caseinato de sódio acidificados com glucona-delta-lactona (GDL foram estudados por ensaios reológicos em compressão biaxial e cisalhamento. Os efeitos da velocidade de acidificação (lenta e rápida e pH final (neutro e no ponto isoelétrico da caseína foram avaliados considerando as interações entre os biopolímeros e sua consequente influência nos parâmetros reológicos. Todas as amostras apresentaram comportamento pseudoplástico, no entanto, a adição de caseinato de sódio nas suspensões de amido, em pH neutro, promoveu um efeito negativo sobre a viscosidade aparente. Amostras acidificadas apresentaram um aumento na complexidade do sistema devido à formação da rede de amido e caseína, observando que a força necessária para o escoamento foi sempre maior para as amostras contendo concentrações maiores de caseinato. Isso mostra que a agregação e gelificação da proteína promovidas pela acidificação, impediram a microsseparação de fases. Esta rede foi mais forte em sistemas gelificados lentamente, devido à formação de uma rede de proteína mais organizada. Apesar da técnica de compressão biaxial imperfeita ser limitada para avaliação de determinados sistemas, neste estudo, mostrou ser um modo prático e eficiente de se mensurar o comportamento reológico.Extensional and shear viscosity of acidified amaranth starch-sodium caseinate suspensions were evaluated. Mixed systems of amaranth starch-sodium caseinate acidified with glucone-delta-lactone (GDL were studied using rheological measurements under biaxial compression and shear. The effects of the acidification rate (slow and fast and final pH (neutral and isoelectric point of casein were evaluated considering the interactions between biopolymers and their influence on the rheological parameters

  20. Forceful Emplacement of Granitic Plutons in an Extensional Tectonic Setting: Syn-kinematic Plutons in the Yagan-Onch Hayrhan Metamorphic Core Complex

    王涛; 郑亚东; 李天兵; 高永军; 马铭波


    It is generally considered that granitic plutons are forcefully emplaced in a compressional setting and permissively emplaced in an extensional setting. This paper, however, shows that syn-kinematic (extensional) elliptic granitic plutons in the Yagan-Onch Hayrhan metamorphic core complex (MCC) have relatively strong forceful emplacement, which are indicated by (1) concentric distribution of the rock units, (2) a strain pattern with strong strains on the margins and low strains at the centre of a pluton, and particularly (3) syn-emplacement shortening of the host rocks within the aureole. The strain analysis for the host rocks shows that the host-rock ductile shortening, I.e. Forceful emplacement, provides about 16?24% of the emplacement space for the present plutons. All these suggest that forceful emplacement occurs not only in a compressional tectonic setting, but also in an extensional setting. This study further demonstrates the significance of the multiple emplacement of granitic plutons and provides new information about the causality between granitic magmatism and the formation of the MCC and its dynamics.

  1. Positive inversion of extensional footwalls in the southern Serra do Espinhaço, Brazil--insights from sandbox laboratory experiments.

    Gomes, Caroline J S; Martins-Neto, Marcelo A; Ribeiro, Valéria E


    Analogue experiments were carried out to get insights into the processes governing positive inversion during the foreland propagating thrust tectonics in the southern Serra do Espinhaço, a Brasiliano/Panafrican foldthrust belt in southeast Brazil. In particular, model listric half-grabens were inverted by applying contractional displacement to the footwall blocks. We investigated two different inversion conditions in listric half-grabens: (i) extensional and contractional detachments at the same level and (ii) at different positions. The models revealed that the development of a forward-breaking thrust system occurs in the basin synrift deposits, by contractional translation of the extensional footwall block when the extensional and contractional master faults do not coincide. Our experiments show the tectonic imbrication between basement and synrift sequences which characterizes the southern Serra do Espinhaço, and support the location in the eastern mountain range domain of the Espinhaço rift master fault system, which is not exposed at the surface.

  2. Correlation between distribution and shape of VMS deposits and regional deformation patterns, Skellefte district, northern Sweden

    Bauer, Tobias E.; Skyttä, Pietari; Hermansson, Tobias; Allen, Rodney L.; Weihed, Pär


    The Skellefte district in northern Sweden is host to abundant volcanogenic massive sulphide (VMS) deposits comprising pyritic, massive, semi-massive and disseminated Zn-Cu-Au ± Pb ores surrounded by disseminated pyrite and with or without stockwork mineralisation. The VMS deposits are associated with Palaeoproterozoic upper crustal extension (D1) that resulted in the development of normal faults and related transfer faults. The VMS ores formed as sub-seafloor replacement in both felsic volcaniclastic and sedimentary rocks and partly as exhalative deposits within the uppermost part of the volcanic stratigraphy. Subsequently, the district was subjected to deformation (D2) during crustal shortening. Comparing the distribution of VMS deposits with the regional fault pattern reveals a close spatial relationship of VMS deposits to the faults that formed during crustal extension (D1) utilising the syn-extensional faults as fluid conduits. Analysing the shape and orientation of VMS ore bodies shows how their deformation pattern mimics those of the hosting structures and results from the overprinting D2 deformation. Furthermore, regional structural transitions are imitated in the deformation patterns of the ore bodies. Plotting the aspect ratios of VMS ore bodies and the comparison with undeformed equivalents in the Hokuroko district, Japan allow an estimation of apparent strain and show correlation with the D2 deformation intensity of the certain structural domains. A comparison of the size of VMS deposits with their location shows that the smallest deposits are not related to known high-strain zones and the largest deposits are associated with regional-scale high-strain zones. The comparison of distribution and size with the pattern of high-strain zones provides an important tool for regional-scale mineral exploration in the Skellefte district, whereas the analysis of ore body shape and orientation can aid near-mine exploration activities.

  3. Permanent deformation of asphalt mixes

    Muraya, P.M.


    This dissertation describes the results of a research that was conducted on the permanent deformation of asphalt mixtures. Central to this research was the separate characterization of the contribution of the aggregate skeleton and the bituminous mortar towards resistance to permanent deformation. T

  4. Deformation of the ABJM Theory

    Faizal, Mir


    In this paper we analyse the ABJM theory on deformed spacetime. We show that this theory reduces to a deformed super-Yang-Mills theory when one of the scalar superfields is given a non-vanishing vacuum expectation value. Our analyse is done in N=1 superspace formulism.

  5. Fraktalnist deformational relief polycrystalline aluminum

    М.В. Карускевич


    Full Text Available  The possibility of the fractal geometry method application for the analisys of surface deformation structures under cyclic loading is presented.It is shown, that deformation relief of the alclad aluminium alloyes meets the criteria of the fractality. For the fractal demention estimation the method of  “box-counting”can be applied.

  6. Metastable vacua and geometric deformations

    Amariti, A; Girardello, L; Mariotti, A


    We study the geometric interpretation of metastable vacua for systems of D3 branes at non isolated toric deformable singularities. Using the L^{aba} examples, we investigate the relations between the field theoretic susy breaking and restoration and the complex deformations of the CY singularities.

  7. Extensional Lower Cretaceous volcanism in the Coastal Range (29°20'-30°S), Chile: geochemistry and petrogenesis

    Morata, D.; Aguirre, L.


    Lower Cretaceous volcanism in the Coastal Range (29°20'-30°S) of Chile is mainly represented by highly porphyritic (20-30% phenocrysts) lavas with unzoned Ca-rich plagioclase (An 57-54Ab 40-42Or 3-4), clinopyroxene (Wo 40En 43Fs 17), magnetite, and minor idiomorphic, altered olivines. Geochemically, these lavas are characterized by a relative homogeneity with high Al 2O 3 and low MgO contents, and classified as high-K to shoshonitic basaltic andesites to andesites generated in an intra-arc extensional setting due to oblique subduction. Their isotopic geochemistry is characterized by highly homogeneous low initial Sr ratios (( 87Sr/ 86Sr) 0˜0.7036) and positive ɛNd values ( ɛNd=+2.9 to +4.7 ( 143Nd/ 144Nd) 0˜0.5127) that are very different from those proposed as representative of 'Andean-type' magmatism. A non-Andean modern setting dominated by subduction associated with intra-arc extension is proposed. On a ( 87Sr/ 86Sr) 0 versus ɛNd diagram, these lavas fit a model mixing curve for which the end members are Pacific MORB and Jurassic plutonic rocks from the Coastal Range. Coeval granitoids from the Coastal Range and lavas from the High Andes plot on the same field. Isotopically depleted mafic magmas could be metasomatized by the subducted sediments, which would increase their LILE content, and then partially contaminated by Jurassic plutonic rocks. The genesis of this magmatism may be related to a global low-spreading rate of 5 cm yr -1 in the southeast Pacific during 125-110 Ma.

  8. Deformation of Man Made Objects

    Ibrahim, Mohamed


    We introduce a framework for 3D object deformation with primary focus on man-made objects. Our framework enables a user to deform a model while preserving its defining characteristics. Moreover, our framework enables a user to set constraints on a model to keep its most significant features intact after the deformation process. Our framework supports a semi-automatic constraint setting environment, where some constraints could be automatically set by the framework while others are left for the user to specify. Our framework has several advantages over some state of the art deformation techniques in that it enables a user to add new features to the deformed model while keeping its general look similar to the input model. In addition, our framework enables the rotation and extrusion of different parts of a model.

  9. Making Deformable Template Models Operational

    Fisker, Rune


    Deformable template models are a very popular and powerful tool within the field of image processing and computer vision. This thesis treats this type of models extensively with special focus on handling their common difficulties, i.e. model parameter selection, initialization and optimization...... published during the Ph.D. project. To put these articles into the general context of deformable template models and to pass on an overview of the deformable template model literature, the thesis starts with a compact survey of the deformable template model literature with special focus on representation....... A proper handling of the common difficulties is essential for making the models operational by a non-expert user, which is a requirement for intensifying and commercializing the use of deformable template models. The thesis is organized as a collection of the most important articles, which has been...

  10. Exhumation of the Deylaman fault trend and its effects on the deformation style of the western Alborz belt in Iran

    Hakimi Asiabar, Saeid; Bagheriyan, Siyamak


    The Alborz range in northern Iran stretches along the southern coast of the Caspian Sea and finally runs northeast and merges into the Pamir mountains in Afghanistan. Alborz mountain belt is a doubly vergent orogen formed along the northern edge of the Iranian plateau in response to the closure of the Neo-Tethys ocean and continental collision between Arabia and Eurasia. The south Caspian depression—the Alborz basin of Mesozoic age (with W-E trend) in northern Iran—inverted in response to the Arabia-Eurasia collision. Pre-existing extensional faults of the south Caspian-Alborz system preferentially reactivated as contractional faults because of tectonic inversion. These contractional structures tend to run parallel to the trends of pre-existing extensional faults and acquire W and WNW-ESE orientations across the previous accommodation zones that were imposed by the reactivation of adjacent extensional faults with different directions. The NNE to N dipping faults show evidences of reactivation. The Deylaman fault is one of the important faults of western Alborz in Iran and is an example of inversion tectonic style of deformation in the western Alborz mountain range. The Deylaman fault, with an E-W trend, contains three discontinuous fault segments in the area under investigation. These fault segments have evidence of oblique right-lateral reverse motion and links eastward to the dextral Kandavan thrust. The importance of this fault is due to its effect on sedimentation of several rock units from the Jurassic to Neogene in western Alborz; the rock facies on each side of this fault are very different and illustrate different parts of tectonic history.

  11. Towards the determination of deformation rates - pinch-and-swell structures as a natural and simulated paleo-strain rate gage

    Peters, Max; Poulet, Thomas; Karrech, Ali; Regenauer-Lieb, Klaus; Herwegh, Marco


    Layered rocks deformed under viscous deformation conditions frequently show boudinage, a phenomenon that results from differences in effective viscosity between the involved layers. In the case of continuous necking of a mechanically stiffer layer embedded in a weaker matrix, symmetric boudins are interpreted as the result of dominant visco-plastic deformation (Goscombe et al., 2004). However, information on the physical conditions, material properties and deformation processes are yet unknown. Natural samples deformed under low-grade (Trelatively high extensional strains. REFERENCES Austin, N. and Evans, B. (2007). Paleowattmeters: A scaling relation for dynamically recrystallized grain size. Geology, 35. Goscombe, B.D., Passchier, C.W. and Hand, M. (2004). Boudinage classification: End-member boudin types and modified boudin structures, Journal of Structural Geology, 26. Herwegh, M., Poulet, T., Karrech, A. and Regenauer-Lieb, K. (in press). From transient to steady state deformation and grain size: A thermodynamic approach using elasto-visco-plastic numerical modeling. Journal of Geophysical Research. Karrech, A., Regenauer-Lieb, K. and Poulet, T. (2011a). A Damaged visco-plasticity model for pressure and temperature sensitive geomaterials. Journal of Engineering Science 49. Regenauer-Lieb, K. and Yuen, D. (2004). Positive feedback of interacting ductile faults from coupling of equation of state, rheology and thermal-mechanics. Physics of the Earth and Planetary Interiors, 142. Schmalholz, S.M. and Maeder, X. (2012). Pinch-and-swell structure and shear zones in viscoplastic layers. Journal of Structural Geology, 34.

  12. Supersymmetric q-deformed quantum mechanics

    Traikia, M. H.; Mebarki, N. [Laboratoire de Physique Mathematique et Subatomique, Mentouri University, Constantine (Algeria)


    A supersymmetric q-deformed quantum mechanics is studied in the weak deformation approximation of the Weyl-Heisenberg algebra. The corresponding supersymmetric q-deformed hamiltonians and charges are constructed explicitly.

  13. Involvement of valgus hindfoot deformity in hallux valgus deformity in rheumatoid arthritis.

    Yamada, Shutaro; Hirao, Makoto; Tsuboi, Hideki; Akita, Shosuke; Matsushita, Masato; Ohshima, Shiro; Saeki, Yukihiko; Hashimoto, Jun


    The involvement of valgus hindfoot deformity in hallux valgus deformity was confirmed in a rheumatoid arthritis case with a destructive valgus hindfoot deformity. Correction of severe valgus, calcaneal lateral offset, and pronated foot deformity instantly normalized hallux valgus deformities postoperatively. Thus, careful hindfoot status evaluation is important when assessing forefoot deformity, including hallux valgus, in rheumatoid arthritis cases.

  14. Inelastic deformation in crystalline rocks

    Rahmani, H.; Borja, R. I.


    The elasto-plastic behavior of crystalline rocks, such as evaporites, igneous rocks, or metamorphic rocks, is highly dependent on the behavior of their individual crystals. Previous studies indicate that crystal plasticity can be one of the dominant micro mechanisms in the plastic deformation of crystal aggregates. Deformation bands and pore collapse are examples of plastic deformation in crystalline rocks. In these cases twinning within the grains illustrate plastic deformation of crystal lattice. Crystal plasticity is governed by the plastic deformation along potential slip systems of crystals. Linear dependency of the crystal slip systems causes singularity in the system of equations solving for the plastic slip of each slip system. As a result, taking the micro-structure properties into account, while studying the overall behavior of crystalline materials, is quite challenging. To model the plastic deformation of single crystals we use the so called `ultimate algorithm' by Borja and Wren (1993) implemented in a 3D finite element framework to solve boundary value problems. The major advantage of this model is that it avoids the singularity problem by solving for the plastic slip explicitly in sub steps over which the stress strain relationship is linear. Comparing the results of the examples to available models such as Von Mises we show the significance of considering the micro-structure of crystals in modeling the overall elasto-plastic deformation of crystal aggregates.

  15. Perceptual transparency from image deformation.

    Kawabe, Takahiro; Maruya, Kazushi; Nishida, Shin'ya


    Human vision has a remarkable ability to perceive two layers at the same retinal locations, a transparent layer in front of a background surface. Critical image cues to perceptual transparency, studied extensively in the past, are changes in luminance or color that could be caused by light absorptions and reflections by the front layer, but such image changes may not be clearly visible when the front layer consists of a pure transparent material such as water. Our daily experiences with transparent materials of this kind suggest that an alternative potential cue of visual transparency is image deformations of a background pattern caused by light refraction. Although previous studies have indicated that these image deformations, at least static ones, play little role in perceptual transparency, here we show that dynamic image deformations of the background pattern, which could be produced by light refraction on a moving liquid's surface, can produce a vivid impression of a transparent liquid layer without the aid of any other visual cues as to the presence of a transparent layer. Furthermore, a transparent liquid layer perceptually emerges even from a randomly generated dynamic image deformation as long as it is similar to real liquid deformations in its spatiotemporal frequency profile. Our findings indicate that the brain can perceptually infer the presence of "invisible" transparent liquids by analyzing the spatiotemporal structure of dynamic image deformation, for which it uses a relatively simple computation that does not require high-level knowledge about the detailed physics of liquid deformation.

  16. Deforming tachyon kinks and tachyon potentials

    Afonso, V. I.; Bazeia, D.; Brito, F. A.


    In this paper we investigate deformation of tachyon potentials and tachyon kink solutions. We consider the deformation of a DBI type action with gauge and tachyon fields living on D1-brane and D3-brane world-volume. We deform tachyon potentials to get other consistent tachyon potentials by using properly a deformation function depending on the gauge field components. Resolutions of singular tachyon kinks via deformation and applications of deformed tachyon potentials to scalar cosmology scena...

  17. Recent Contractile Deformation in the Forearc of Southern Peru: A Geomorphologic Analysis And 10Be Surface Exposure Ages

    Hall, S.; Farber, D. L.; Audin, L.; Finkel, R.


    . Cosmogenic 10Be surface exposure ages from a set of three distinct abandoned terraces in the Pampa Cabeza de Vaca region yield ages ranging from ~35-550ky and incision rates of ~0.04-0.09mm/yr. Thus, the contractile deformation within this region has been active for at least the last 500ky and is plausibly presently active. The documentation of recent contractile deformation within the forearc of southern Peru stylistically contrasts with previously held view active deformation in this region is dominated by extensional topographic collapse. Moreover, active shortening within the Peruvian forearc bears on our models of how the Altiplano plateau is currently being maintained along the western margin. Indeed, by identifying and quantifying active deformation within the Peruvian forearc, we can begin to address the potential links between surface processes related to climate and active tectonics, and the dynamics of the lithosphere.

  18. Microstructural investigations on carbonate fault core rocks in active extensional fault zones from the central Apennines (Italy)

    Cortinovis, Silvia; Balsamo, Fabrizio; Storti, Fabrizio


    The study of the microstructural and petrophysical evolution of cataclasites and gouges has a fundamental impact on both hydraulic and frictional properties of fault zones. In the last decades, growing attention has been payed to the characterization of carbonate fault core rocks due to the nucleation and propagation of coseismic ruptures in carbonate successions (e.g., Umbria-Marche 1997, L'Aquila 2009, Amatrice 2016 earthquakes in Central Apennines, Italy). Among several physical parameters, grain size and shape in fault core rocks are expected to control the way of sliding along the slip surfaces in active fault zones, thus influencing the propagation of coseismic ruptures during earthquakes. Nevertheless, the role of grain size and shape distribution evolution in controlling the weakening or strengthening behavior in seismogenic fault zones is still not fully understood also because a comprehensive database from natural fault cores is still missing. In this contribution, we present a preliminary study of seismogenic extensional fault zones in Central Apennines by combining detailed filed mapping with grain size and microstructural analysis of fault core rocks. Field mapping was aimed to describe the structural architecture of fault systems and the along-strike fault rock distribution and fracturing variations. In the laboratory we used a Malvern Mastersizer 3000 granulometer to obtain a precise grain size characterization of loose fault rocks combined with sieving for coarser size classes. In addition, we employed image analysis on thin sections to quantify the grain shape and size in cemented fault core rocks. The studied fault zones consist of an up to 5-10 m-thick fault core where most of slip is accommodated, surrounded by a tens-of-meters wide fractured damage zone. Fault core rocks consist of (1) loose to partially cemented breccias characterized by different grain size (from several cm up to mm) and variable grain shape (from very angular to sub

  19. Evolution of an Interbasin Mountain-Block Extensional Accommodation Zone Within the Central Colorado Rio Grande Rift, USA

    Minor, S. A.; Caine, J. S.; Fridrich, C.; Hudson, M. R.


    Our understanding of extensional strain transfer and accommodation in continental rifts has grown considerably, but few studied transfer zones exhibit high internal topographic and structural relief. In the Rio Grande rift of Colorado the WNW-trending northern tip of the Sangre de Cristo Range separates the opposite-tilted Upper Arkansas River (UAR) and San Luis half grabens. We have investigated the development and role of faults flanking this "Poncha" intrarift mountain block in transferring extension between rift basins, mountain block surface uplift, and landscape evolution. The topographically rugged Poncha block consists of Proterozoic metamorphic and plutonic rocks overlain on its west and southwest flanks by 34.5-33-Ma volcanic rocks and alluvial deposits of the Mio-Pliocene Dry Union Formation. Similar Dry Union sediments underlie a moderately elevated, strongly dissected older piedmont along the northern front of the mountain block. All of these units are tilted 10-35º to the W and SW. A WNW-trending, right-stepping fault system > 25 km in length separates the piedmont and UAR basin from the steep northern Poncha mountain front. Slip measurements along this fault system, cutting deposits as young as ~200 ka, indicate dextral-normal oblique movement. The NNW-striking, down-to-E southern Sawatch range-front fault system forms the western terminus of the Poncha block where it juxtaposes Dry Union deposits against Sawatch Proterozoic basement rocks. Gently tilted proximal diamicton and alluvial deposits on the downthrown blocks of both range-front faults likely mark Plio-Pleistocene(?) mountain block uplift. Arrays of NNW- to WNW-striking faults cutting volcanic and Dry Union units on the flanks of the Poncha block commonly have normal-oblique slip, with greater tendency for dextral strike-slip components on WNW-striking faults. Preliminary paleomagnetic data from the volcanic rocks detect no significant vertical-axis rotation that accompanied oblique

  20. The transition between shortening and extensional regimes in central Mexico recorded in the tourmaline veins of the Comanja Granite

    Angeles-Moreno, Edgar; Nieto-Samaniego, Angel Francisco; Ruiz-González, Francisco Jesús; Levresse, Gilles; Alaniz-Alvarez, Susana Alicia; Olmos Moya, María de Jesús Paulina; Xu, Shunshan; Miranda-Avilés, Raúl


    In central Mexico, there is a major angular unconformity separating two lithologic groups. Below the unconformity, the rocks display shortening deformation structures produced by the Laramide orogeny, overprinting those shortening structures there are normal faults related to the Cenozoic Basin and Range tectonics. Above the unconformity, the rocks are affected only by the Basin and Range tectonics, displaying mainly normal faults and in minor amount, lateral-oblique faults. We analyzed the Comanja Granite in the Sierra de Guanajuato, it is a large pluton that contains tourmaline veins. The Granite lacks of the shortening structures that pervasively affected the Mesozoic host-rocks; for this reason, we infer that the granite was formed after the main shortening event. We determined that the emplacement of the Comanja Granite took place between 51.0 ± 0.3 Ma and 49.5 ± 0.8 Ma, and that the tourmaline veins of the granite were formed at ∼51.0 Ma. At the microscopic scale, the tourmaline veins contain three kinds of tourmaline, called T1, T2, and T3, according to the order of their formation. The T1 tourmalines are brown colored and appear affected by brittle-ductile (D1) and brittle (D2) deformations. The cataclasites formed during D2 overprinted the brittle-ductile structures of D1, indicating the transition from deeper to shallower levels. In contrast, T2 and T3 tourmalines were not involved in those deformations. At the outcrop scale, we identified two slickensides in the tourmaline veins. The older, related to D1, is strike-slip with a small thrust component and the younger, related to D2, is normal with oblique components. The T1 tourmalines (which are deformed) were formed before the lateral-thrust faulting, whereas the T2 and T3 tourmalines, which are not deformed, were deposited after the faulting occurred in the veins. Our interpretation is that T1 tourmalines were deposited in the later phases of the Comanja Granite emplacement, with the minimum

  1. Shape Deformations in Atomic Nuclei

    Hamamoto, Ikuko


    The ground states of some nuclei are described by densities and mean fields that are spherical, while others are deformed. The existence of non-spherical shape in nuclei represents a spontaneous symmetry breaking.

  2. Plastic Deformation of Metal Surfaces

    Hansen, Niels; Zhang, Xiaodan; Huang, Xiaoxu


    parameters by TEM and EBSD and apply strength-structural relationships established for the bulk metal deformed to high strains. This technique has been applied to steel deformed by high energy shot peening and a calculated stress gradient at or near the surface has been successfully validated by hardness......Plastic deformation of metal surfaces by sliding and abrasion between moving parts can be detrimental. However, when the plastic deformation is controlled for example by applying different peening techniques hard surfaces can be produced which can increase the fracture resistance and fatigue life...... of metal components. An optimization of processes and material parameters must be based on a quantification of stress and strain gradients at the surface and in near surface layer where the structural scale can reach few tens of nanometers. For such fine structures it is suggested to quantify structural...

  3. Deformed two center shell model

    Gherghescu, R A


    A highly specialized two-center shell model has been developed accounting for the splitting of a deformed parent nucleus into two ellipsoidaly deformed fragments. The potential is based on deformed oscillator wells in direct correspondance with the shape change of the nuclear system. For the first time a potential responsible for the necking part between the fragments is introduced on potential theory basis. As a direct consequence, spin-orbit {\\bf ls} and {\\bf l$^2$} operators are calculated as shape dependent. Level scheme evolution along the fission path for pairs of ellipsoidaly deformed fragments is calculated. The Strutinsky method yields the shell corrections for different mass asymmetries from the superheavy nucleus $^{306}$122 and $^{252}$Cf all along the splitting process.

  4. ROCK DEFORMATION. Final Progress Report



    The Gordon Research Conference (GRC) on ROCK DEFORMATION was held at II Ciocco from 5/19/02 thru 5/24/02. Emphasis was placed on current unpublished research and discussion of the future target areas in this field.

  5. Non-linear elastic deformations

    Ogden, R W


    Classic in the field covers application of theory of finite elasticity to solution of boundary-value problems, analysis of mechanical properties of solid materials capable of large elastic deformations. Problems. References.

  6. Deformed Calabi-Yau Completions

    Keller, Bernhard


    We define and investigate deformed n-Calabi-Yau completions of homologically smooth differential graded (=dg) categories. Important examples are: deformed preprojective algebras of connected non Dynkin quivers, Ginzburg dg algebras associated to quivers with potentials and dg categories associated to the category of coherent sheaves on the canonical bundle of a smooth variety. We show that deformed Calabi-Yau completions do have the Calabi-Yau property and that their construction is compatible with derived equivalences and with localizations. In particular, Ginzburg dg algebras have the Calabi-Yau property. We show that deformed 3-Calabi-Yau completions of algebras of global dimension at most 2 are quasi-isomorphic to Ginzburg dg algebras and apply this to the study of cluster-tilted algebras and to the construction of derived equivalences associated to mutations of quivers with potentials. In the appendix, Michel Van den Bergh uses non commutative differential geometry to give an alternative proof of the fac...

  7. Nonlinear Deformable-body Dynamics

    Luo, Albert C J


    "Nonlinear Deformable-body Dynamics" mainly consists in a mathematical treatise of approximate theories for thin deformable bodies, including cables, beams, rods, webs, membranes, plates, and shells. The intent of the book is to stimulate more research in the area of nonlinear deformable-body dynamics not only because of the unsolved theoretical puzzles it presents but also because of its wide spectrum of applications. For instance, the theories for soft webs and rod-reinforced soft structures can be applied to biomechanics for DNA and living tissues, and the nonlinear theory of deformable bodies, based on the Kirchhoff assumptions, is a special case discussed. This book can serve as a reference work for researchers and a textbook for senior and postgraduate students in physics, mathematics, engineering and biophysics. Dr. Albert C.J. Luo is a Professor of Mechanical Engineering at Southern Illinois University, Edwardsville, IL, USA. Professor Luo is an internationally recognized scientist in the field of non...

  8. Bilateral cleft lip nasal deformity

    Singh Arun; Nandini R.


    Bilateral cleft lip nose deformity is a multi-factorial and complex deformity which tends to aggravate with growth of the child, if not attended surgically. The goals of primary bilateral cleft lip nose surgery are, closure of the nasal floor and sill, lengthening of the columella, repositioning of the alar base, achieving nasal tip projection, repositioning of the lower lateral cartilages, and reorienting the nares from horizontal to oblique position. The multiplicity of procedures in the li...

  9. Symmetries in Connection Preserving Deformations

    Christopher M. Ormerod


    Full Text Available e wish to show that the root lattice of Bäcklund transformations of the q-analogue of the third and fourth Painlevé equations, which is of type (A_2+A_1^{(1}, may be expressed as a quotient of the lattice of connection preserving deformations. Furthermore, we will show various directions in the lattice of connection preserving deformations present equivalent evolution equations under suitable transformations. These transformations correspond to the Dynkin diagram automorphisms.

  10. Properties of deformed Λ hypernuclei

    ZHOU Xian-Rong


    The properties of Be and B isotopes and the corresponding Λ hypernuclei are studied by using a deformed Skyrme Hartree-Fock approach with realistic nucleonic Skyrme forces, pairing correlations, and a microscopically determined lambda-nucleon interaction based on Brueckner-Hartree-Fock calculations of hypernuclear matter. The results suggest that the core nuclei and the corresponding hypernuclei have similar deformations with the same sign.

  11. Shortening in the upper plate of the Buckskin-Rawhide extensional detachment fault, southwestern U.S., and implications for stress conditions during extension

    Spencer, Jon E.; Reynolds, Stephen J.; Scott, Robert J.; Richard, Stephen M.


    Detailed geologic mapping in the Buckskin, Rawhide, and Artillery Mountains in western Arizona identified numerous folds in Oligocene-Miocene strata above the Buckskin-Rawhide extensional detachment fault. The folds are above or adjacent to the Harcuvar metamorphic core complex, which was uplifted and exposed by top-northeast normal faulting and penetrative shearing at 27-9 Ma. Strata deposited during extension were folded, and the folds are truncated by the detachment fault, demonstrating that folding occurred during the period of extensional faulting. Fold axes are approximately perpendicular to regional extension direction. In two of the four areas of folding described here, alluvial-fan deposits derived partially from lower plate mylonitic rocks are the stratigraphically highest folded strata. Folding could have occurred above low-angle normal faults with curved or ramp-flat geometries, but fold abundance, large size, high degree of closure, and steep northeastward dips of the northeast limbs of anticlines lead us to consider the possibility that at least some folds reflect local shortening in the same direction as regional extension. Application of critical-taper theory to an extensional wedge with very low basal friction indicates that wedge shortening would be expected if the wedge developed a sufficient surface slope that was downhill away from the wedge tip. Such a slope could have developed late during extension either because core-complex uplift tilted the wedge away from the core complex or because alluvial fans shed off the core complex produced such a slope. In either case, wedge shortening would promote core-complex denudation.

  12. Timing and Style of Deformation in the Floresta Massif, Axial Eastern Cordillera, Colombia

    Saylor, J.; Stockli, D. F.; Mora, A.


    The Floresta Massif is one of the largest exposures of Paleozoic and Pre-Cambrian rocks in the Eastern Cordillera. Estimates for the age of onset of shortening-related deformation in the Eastern Cordillera range from late Cretaceous to late Miocene (e.g., Hoorn et al., 1995; Bayona et al., 2008; Parra et al., 2009). The massif is typically interpreted as being exhumed along a high-angle reverse fault (the Soapaga fault) that reactivated Mesozoic extensional structures (e.g., Kammer and Sanchez, 2006). We examined these dual linked issued with new zircon U/Th-He (ZHe) data, new geological mapping and previously published apatite fission track (AFT) data from the Floresta Massif and the associated footwall strata. Previously, an overturned Paleozoic - Cretaceous sequence was mapped emplaced on Tertiary strata along the Soapaga fault. However, new geologic mapping identifies two previously unrecognized thrusts which place, from west to east, Paleozoic strata on Jurassic strata (Fault 3), Jurassic strata on Cretaceous strata (Fault 2) and Cretaceous strata on Tertiary strata (along the previously identified Fault 1). These results are confirmed by AFT and ZHe data. ZHe ages show no resetting in the Tertiary footwall strata, but show partial resetting in the Cretaceous strata and full resetting in the Jurassic and Paleozoic strata. Similarly, AFT data show older ages in the Cretaceous strata than in the Jurassic or Paleozoic strata. Fully reset ZHe ages from Jurassic strata show that exhumation of the Floresta Massif was ongoing by at least the early Oligocene (~ 30 Ma). However, this deformation post-dates an older episode of deformation associated with partially reset ZHe ages in the Cretaceous strata. Based on a decrease in lag time in detrital ZHe data, we infer that the earlier episode of deformation occurred in the mid - late Eocene (45 - 35 Ma).

  13. Lithospheric deformation in the Canadian Appalachians: evidence from shear wave splitting

    Gilligan, Amy; Bastow, Ian D.; Watson, Emma; Darbyshire, Fiona A.; Levin, Vadim; Menke, William; Lane, Victoria; Hawthorn, David; Boyce, Alistair; Liddell, Mitchell V.; Petrescu, Laura


    Plate-scale deformation is expected to impart seismic anisotropic fabrics on the lithosphere. Determination of the fast shear wave orientation (φ) and the delay time between the fast and slow split shear waves (δt) via SKS splitting can help place spatial and temporal constraints on lithospheric deformation. The Canadian Appalachians experienced multiple episodes of deformation during the Phanerozoic: accretionary collisions during the Palaeozoic prior to the collision between Laurentia and Gondwana, and rifting related to the Mesozoic opening of the North Atlantic. However, the extent to which extensional events have overprinted older orogenic trends is uncertain. We address this issue through measurements of seismic anisotropy beneath the Canadian Appalachians, computing shear wave splitting parameters (φ, δt) for new and existing seismic stations in Nova Scotia and New Brunswick. Average δt values of 1.2 s, relatively short length scale (≥100 km) splitting parameter variations, and a lack of correlation with absolute plate motion direction and mantle flow models, demonstrate that fossil lithospheric anisotropic fabrics dominate our results. Most fast directions parallel Appalachian orogenic trends observed at the surface, while δt values point towards coherent deformation of the crust and mantle lithosphere. Mesozoic rifting had minimal impact on our study area, except locally within the Bay of Fundy and in southern Nova Scotia, where fast directions are subparallel to the opening direction of Mesozoic rifting; associated δt values of >1 s require an anisotropic layer that spans both the crust and mantle, meaning the formation of the Bay of Fundy was not merely a thin-skinned tectonic event.

  14. April 7, 2009, Mw 5.5 aftershock of the L'Aquila earthquake: seismogenic fault geometry and its implication for the central Apennines active extensional tectonics (Italy).

    Adinolfi, Guido Maria; Lavecchia, Giusy; De Matteis, Raffaella; Nardis Rita, De; Francesco, Brozzetti; Federica, Ferrarini; Zollo, Aldo


    On April 6, 2009 (at 01:32 UTC) a Mw 6.3 earthquake hit the town of L'Aquila (central Italy) and surrounding villages causing fatalities and severe damage in the area. After few days, a nearly 40-km-long extensional fault system was activated generating both northward and southward seismicity migration along the NW-SE trending sector of central Apennines. During the intense aftershocks sequence, different sesmogenic sources with a distinct geometry, size and the degree of involvement were reactivated. Among the relevant aftershocks with Mw 5.0 to 5.5, the largest one occurred on April 7 (at 17:47 UTC), 9 km SE-ward of the mainshock involving a source seated at much greater depths (~14 km). Despite the enormous number of studies of the 2009 L'Aquila earthquake, mainly focused on the various geological and seismological aspects of the main Paganica source, the April 7 strongest aftershock (Mw 5.5) has not yet been deeply investigated. Consistent geometric and kinematic correlations between the geological and seismological data about this seismogenic source are missing. There are still open questions concerning its unresolved geometry and the unknown style of the central Apennines structure activated at greater depths during the 2009 L'Aquila seismic sequence. Furthermore, some authors (Lavecchia et al., 2012) have supposed that the April 7, 2009 aftershock (Mw 5.5) occurred onto an high dip segment (~50°) of an east-dipping extensional basal detachment with a potential surface expression outcropping in the area of the eastern Sabina-Simbruini Mts. In this work we propose a seismological analysis of the April 7, 2009 aftershock (Mw 5.5) rupture process. In order to define the unresolved source geometry, we computed the focal mechanism through the time domain, moment tensor full waveform inversion (Dreger and Helmberger, 1993). Also, we estimated the apparent source time functions (ASTFs) by deconvolution of the impulse response of the medium from the recorded data

  15. Decollement controls on pro versus retro wedge deformation in mountain belts

    Grool, Arjan; Huismans, Ritske S.; Ford, Mary


    Doubly vergent orogens have a pro-wedge (lower plate) and a retro-wedge (upper plate). Most shortening is accommodated on the pro-wedge while retro-wedge shortening is typically limited. For example, the Eastern Pyrenees have experienced about 145 km of convergence, of which about 125 km (86%) was accommodated in the pro-wedge and about 20 km (14%) in the retro-wedge. Strain partitioning between pro- and retro-wedge is influenced by several factors, some of which have been identified in past work: Extensional inheritance and syn-orogenic sedimentation can help to increase the percentage of total shortening accommodated in the retro-wedge while erosion promotes pro-wedge shortening. We use high-resolution 2D numerical models to investigate factors that control pro- versus retro-wedge shortening. For a total convergence similar to the Eastern Pyrenees, our models predict that variations in extensional inheritance and syn-orogenic sedimentation will result in a maximum of 10% of total shortening being accommodated in the retro-wedge. Here, we investigate the role of 1) the rheology and 2) distribution of a decollement layer. Our models show that: 1) Decollement rheology has a first order control on strain distribution between the pro- and the retro-wedge. After 145 km of total convergence, a model with a weak frictional (φ=2, shale-like) decollement will only accommodate 9% of total shortening in the retro-wedge. In contrast in models with a weak viscous (μ=1018, salt-like) decollement retro-wedge shortening amounts to 18% and a stronger, but still weak, viscous decollement (μ=1019) leads to 21%. 2) Décollement distribution influences the timing of the first outward propagation of thick-skinned deformation in the retro-wedge. In the Eastern Pyrenees, thick-skinned deformation propagated out into the retro-wedge within 145 km of total convergence. In models with a decollement on both sides of the orogen this only occurred after 240 km. If, as in the Eastern

  16. Analysis of Mining Terrain Deformation Characteristics with Deformation Information System

    Blachowski, Jan; Milczarek, Wojciech; Grzempowski, Piotr


    Mapping and prediction of mining related deformations of the earth surface is an important measure for minimising threat to surface infrastructure, human population, the environment and safety of the mining operation itself arising from underground extraction of useful minerals. The number of methods and techniques used for monitoring and analysis of mining terrain deformations is wide and increasing with the development of geographical information technologies. These include for example: terrestrial geodetic measurements, global positioning systems, remote sensing, spatial interpolation, finite element method modelling, GIS based modelling, geological modelling, empirical modelling using the Knothe theory, artificial neural networks, fuzzy logic calculations and other. The aim of this paper is to introduce the concept of an integrated Deformation Information System (DIS) developed in geographic information systems environment for analysis and modelling of various spatial data related to mining activity and demonstrate its applications for mapping and visualising, as well as identifying possible mining terrain deformation areas with various spatial modelling methods. The DIS concept is based on connected modules that include: the spatial database - the core of the system, the spatial data collection module formed by: terrestrial, satellite and remote sensing measurements of the ground changes, the spatial data mining module for data discovery and extraction, the geological modelling module, the spatial data modeling module with data processing algorithms for spatio-temporal analysis and mapping of mining deformations and their characteristics (e.g. deformation parameters: tilt, curvature and horizontal strain), the multivariate spatial data classification module and the visualization module allowing two-dimensional interactive and static mapping and three-dimensional visualizations of mining ground characteristics. The Systems's functionality has been presented on

  17. Preferred orientation in experimentally deformed stishovite: implications for deformation mechanisms

    Kaercher, P. M.; Zepeda-Alarcon, E.; Prakapenka, V.; Kanitpanyacharoen, W.; Smith, J.; Sinogeikin, S. V.; Wenk, H. R.


    The crystal structure of the high pressure SiO2 polymorph stishovite has been studied in detail, yet little is known about its deformation mechanisms. Information about how stishovite deforms under stress is important for understanding subduction of quartz-bearing crustal rocks into the mantle. Particularly, stishovite is elastically anisotropic and thus development of crystallographic preferred orientation (CPO) during deformation may contribute to seismic anomalies in the mantle. We converted a natural sample of flint to stishovite in a laser heated diamond anvil cell and compressed the stishovite aggregate up to 38 GPa. Diffraction patterns were collected in situ in radial geometry at the Advanced Light Source (ALS) and the Advanced Photon Source (APS) to examine development of CPO during deformation. We find that (001) poles preferentially align with the compression direction and infer deformation mechanisms leading to the observed CPO with visco-plastic self consistent (VPSC) polycrystal plasticity models. Our results show pyramidal and basal slip are most likely active at high pressure and ambient temperature, in agreement with transmission electron microscopy (TEM) studies of rutile (TiO2) and paratellurite (TeO2), which are isostructural to stishovite. Conversely other TEM studies of stishovite done at higher temperature suggest dominant prismatic slip. This indicates that a variety of slip systems may be active in stishovite, depending on conditions. As a result, stishovite's contribution to the seismic signature in the mantle may vary as a function of pressure and temperature and thus depth.

  18. Rheological Behaviour and Microstructures of Natural Gypsum Experimentally Deformed in Simple Shear

    Barberini, V.; Burlini, L.; Rutter, E. H.; Dapiaggi, M.


    Gypsum is an important mineral of evaporitic rocks. Evaporites, interlayered within sedimentary sequences, play an important role in localizing the deformation especially in thrust tectonics (Apennines, Zagros, Gulf of Mexico, etc.) since are generally weaker than the other rocks; in some cases the deformation is accompanied by seismicity as in the Northern Apennines extensional systems. In order to determine the rheological and microstructural evolution of gypsum with strain, a set of experiments was performed on natural gypsum samples from Volterra (Tuscany, Italy). Experimental deformation tests were performed at confining pressures up to 300 MPa, at temperatures up to 130° C and at strain rates ranging between 6x10-4 and 5x10-6 s-1. In order to reach high shear strain values, we deformed gypsum specimens using both the torsion technique in the Paterson apparatus at ETH Zurich (up to γ = 5) and the sawcut-type assembly at 35° in a Heard-type apparatus at Manchester University (up to γ = 1.2). All samples have been studied by optical microscopy, to investigate the evolution of the microstructure with strain, and by XRD analysis, to determine whether and to what extent gypsum dehydrated during deformation. In torsion, the shear stress increased with the strain rate and decreased with the temperature. In general a peak stress was reached at γ between 0.5 and 1 (at higher temperatures is reached sooner). After the peak, a various amount of weakening occurred, and mechanical 'steady state' conditions were never reached. Weakening was up to 30-40%. Most of the times the jacket failure ended prematurely the experiment. The microstructure evolved from a deformation microstructure, where grains changed shape according to the bulk strain imposed, into a recrystallization microstructure, where grains were more aequant. Grain boundary migration recrystallization was very effective in resetting the microstructure after γ of 1 or 2. In the samples deformed using saw

  19. Paleogene-early miocene deformations of Bukulja-Venčac crystalline (Vardar zone, Serbia

    Marović Milun


    Full Text Available Low-grade metamorphic rocks of the crystalline of Mts. Bukulja and Venčac, which are integral parts of the Vardar Zone, are of Late Cretaceous age. From the Middle Paleogene to the beginning of the Miocene, they were subjected to three phases of intensive deformations. In the first phase, during the Middle Paleogene, these rocks were subjected to intense shortening (approximately in the E-W direction, regional metamorphism and deformations in the ductile and brittle domains, when first-generation folds with NNE-SSW striking fold hinges were formed. In the second phase, during the Late Oligocene and up to the Early Miocene, extensional unroofing and exhumation of the crystalline occurred, which was followed by intrusion of the granitoid of Bukulja and refolding of the previously formed folds in a simple brachial form of Bukulja and Venčac with an ESE-WNW striking B-axis. The third phase was expressed in the Early lowermost Miocene (before the Ottnanghian, under conditions of NE-SW compression and NW-SE tension. It was characterized by wrench-tectonic activity, particularly by dextral movements along NNW-SSE striking faults.

  20. Modelling deformation rates in the western Gulf of Corinth: rheological constraints

    Cianetti, S.; Tinti, E.; Giunchi, C.; Cocco, M.


    The Gulf of Corinth is one of the most active extensional regions in the Mediterranean area characterized by a high rate of seismicity. However, there are still open questions concerning the role and the geometry of the numerous active faults bordering the basin, as well as the mechanisms governing the seismicity. In this paper, we use a 2-D plane strain finite element analysis to constrain the upper crust rheology by modelling the available deformation data (GPS and geomorphology). We consider a SSW-NNE cross-section of the rift cutting the main active normal faults (Aigion, West Eliki and Off-Shore faults). The models run for 650 Kyr assuming an elasto-viscoplastic rheology and 1.3 cmyr-1 horizontal extension as boundary condition (resulting from GPS data). We model the horizontal and vertical deformation rates and the accumulation of plastic strain at depth, and we compare them with GPS data, with long term uplift rates inferred from geomorphology and with the distribution of seismicity, respectively. Our modelling results demonstrate that dislocation on high-angle normal faults in a plastic crustal layer plays a key role in explaining the extremely localized strain within the Gulf of Corinth. Conversely, the contribution of structures such as the antithetic Trizonia fault or the buried hypothetical subhorizontal discontinuity are not necessary to model observed data.

  1. Present-day crustal deformation along the El Salvador Fault Zone from ZFESNet GPS network

    Staller, Alejandra; Martínez-Díaz, José Jesús; Benito, Belén; Alonso-Henar, Jorge; Hernández, Douglas; Hernández-Rey, Román; Díaz, Manuel


    This paper presents the results and conclusions obtained from new GPS data compiled along the El Salvador Fault Zone (ESFZ). We calculated a GPS-derived horizontal velocity field representing the present-day crustal deformation rates in the ESFZ based on the analysis of 30 GPS campaign stations of the ZFESNet network, measured over a 4.5 year period from 2007 to 2012. The velocity field and subsequent strain rate analysis clearly indicate dextral strike-slip tectonics with extensional component throughout the ESFZ. Our results suggest that the boundary between the Salvadoran forearc and Caribbean blocks is a deformation zone which varies along the fault zone. We estimate that the movement between the two blocks is at least ~ 12 mm yr- 1. From west to east, this movement is variably distributed between faults or segments of the ESFZ. We propose a kinematic model with three main blocks; the Western, Central and Eastern blocks delimited by major faults. For the first time, we were able to provide a quantitative measure of the present-day horizontal geodetic slip rate of the main segments of ESFZ, ranging from ~ 2 mm yr- 1 in the east segment to ~ 8 mm yr- 1, in the west and central segments. This study contributes new kinematic and slip rate data that should be used to update and improve the seismic hazard assessments in northern Central America.

  2. Superposed deformation straddling the continental-oceanic transition in deep-water Angola

    Cramez, C. [TotalFina Elf Exploration and Production, Paris La Defense (France); Jackson, M.P.A. [Texas Univ., Austin, TX (United States). Bureau of Economic Geology


    The Angolan margin is the type area for raft tectonics. New seismic data reveal the contractional buffer for this thin-skinned extension. A 200-km-long composite section from the Lower Congo Basin and Kwanza Basin illustrates a complex history of superposed deformation caused by: (1) progradation of the margin; and (2) episodic Tertiary epeirogenic uplift. Late Cretaceous tectonics was driven by a gentle slope created by thermal subsidence; extensional rafting took place updip, contractional thrusting and buckling downdip; some distal folds were possibly unroofed to form massive salt walls. Oligocene deformation was triggered by gentle kinking of the Atlantic Hinge Zone as the shelf and coastal plain rose by 2 or 3 km; relative uplift stripped Paleogene cover off the shelf, provided space for Miocene progradation, and steepened the continental slope, triggering more extension and buckling. In the Neogene, a subsalt half graben was inverted or reactivated, creating keystone faults that may have controlled the Congo Canyon; a thrust duplex of seaward-displaced salt jacked up the former abyssal plain, creating a plateau of salt 3-4 km thick on the present lower slope. The Angola Escarpment may be the toe of the Angola thrust nappe, in which a largely Cretaceous roof of gently buckled strata, was transported seawards above the thickened salt by up to {approx}20 km. (author)

  3. Syn-extensional plutonism and peak metamorphism in the albion-raft river-grouse creek metamorphic core complex

    Strickland, A.; Miller, E.L.; Wooden, J.L.; Kozdon, R.; Valley, J.W.


    The Cassia plutonic complex (CPC) is a group of variably deformed, Oligocene granitic plutons exposed in the lower plate of the Albion-Raft River- Grouse Creek (ARG) metamorphic core complex of Idaho and Utah. The plutons range from granodiorite to garnet-bearing, leucogranite, and during intrusion, sillimanite- grade peak metamorphism and ductile attenuation occurred in the country rocks and normal-sense, amphibolite-grade deformation took place along the Middle Mountain shear zone. U-Pb zircon geochronology from three variably deformed plutons exposed in the lower plate of the ARG metamorphic core complex revealed that each zircon is comprised of inherited cores (dominantly late Archean) and Oligocene igneous overgrowths. Within each pluton, a spread of concordant ages from the Oligocene zircon overgrowths is interpreted as zircon recycling within a long-lived magmatic system. The plutons of the CPC have very low negative whole rock ??Nd values of -26 to -35, and initial Sr values of 0.714 to 0.718, consistent with an ancient, crustal source. Oxygen isotope ratios of the Oligocene zircon overgrowths from the CPC have an average ??18O value of 5.40 ?? 0.63 permil (2SD, n = 65) with a slight trend towards higher ??18O values through time. The ??18O values of the inherited cores of the zircons are more variable at 5.93 ?? 1.51 permil (2SD, n = 29). Therefore, we interpret the plutons of the CPC as derived, at least in part, from melting Archean crust based on the isotope geochemistry. In situ partial melting of the exposed Archean basement that was intruded by the Oligocene plutons of the CPC is excluded as the source for the CPC based on field relationships, age and geochemistry. Correlations between Ti and Hf concentrations in zircons from the CPC suggest that the magmatic system may have become hotter (higher Ti concentration in zircon) and less evolved (lower Hf in zircon concentration) through time. Therefore, the CPC represents prolonged or episodic magmatism

  4. Bilateral cleft lip nasal deformity

    Singh Arun


    Full Text Available Bilateral cleft lip nose deformity is a multi-factorial and complex deformity which tends to aggravate with growth of the child, if not attended surgically. The goals of primary bilateral cleft lip nose surgery are, closure of the nasal floor and sill, lengthening of the columella, repositioning of the alar base, achieving nasal tip projection, repositioning of the lower lateral cartilages, and reorienting the nares from horizontal to oblique position. The multiplicity of procedures in the literature for correction of this deformity alludes to the fact that no single procedure is entirely effective. The timing for surgical intervention and its extent varies considerably. Early surgery on cartilage may adversely affect growth and development; at the same time, allowing the cartilage to grow in an abnormal position and contributing to aggravation of deformity. Some surgeons advocate correction of deformity at an early age. However, others like the cartilages to grow and mature before going in for surgery. With peer pressure also becoming an important consideration during the teens, the current trend is towards early intervention. There is no unanimity in the extent of nasal dissection to be done at the time of primary lip repair. While many perform limited nasal dissection for the fear of growth retardation, others opt for full cartilage correction at the time of primary surgery itself. The value of naso-alveolar moulding (NAM too is not universally accepted and has now more opponents than proponents. Also most centres in the developing world have neither the personnel nor the facilities for the same. The secondary cleft nasal deformity is variable and is affected by the extent of the original abnormality, any prior surgeries performed and alteration due to nasal growth. This article reviews the currently popular methods for correction of nasal deformity associated with bilateral cleft lip, it′s management both at the time of cleft lip repair

  5. Deformation of second and third quantization

    Faizal, Mir


    In this paper, we will deform the second and third quantized theories by deforming the canonical commutation relations in such a way that they become consistent with the generalized uncertainty principle. Thus, we will first deform the second quantized commutator and obtain a deformed version of the Wheeler-DeWitt equation. Then we will further deform the third quantized theory by deforming the third quantized canonical commutation relation. This way we will obtain a deformed version of the third quantized theory for the multiverse.

  6. Deformation of Second and Third Quantization

    Faizal, Mir


    In this paper, we will deform the second and third quantized theories by deforming the canonical commutation relations in such a way that they become consistent with the generalized uncertainty principle. Thus, we will first deform the second quantized commutator and obtain a deformed version of the Wheeler-DeWitt equation. Then we will further deform the third quantized theory by deforming the third quantized canonical commutation relation. This way we will obtain a deformed version of the third quantized theory for the multiverse.

  7. Time-slice maps showing age, distribution, and style of deformation in Alaska north of 60° N.

    Moore, Thomas E.; Box, Stephen E.


    The structural architecture of Alaska is the product of a complex history of tectonism that occurred along the Cordilleran and Arctic margins of North America through interactions with ancient and modern ocean plates and with continental elements derived from Laurentia, Siberia, and Baltica. To unravel the tectonic history of Alaska, we constructed maps showing the age, distribution, structural style, and kinematics of contractional and penetrative extensional deformation in Alaska north of latitude 60° N. at a scale of 1:5,000,000. These maps use the Geologic Map of the Arctic (Harrison and others, 2011) as a base map and follow the guidelines in the Tectonic Map of the Arctic project (Petrov and others, 2013) for construction, including use of the International Commission on Stratigraphy time scale (Cohen and others, 2013) divided into 20 time intervals. We find evidence for deformation in 14 of the 20 time intervals and present maps showing the known or probable extent of deformation for each time interval. Maps and descriptions of deformational style, age constraints, kinematics, and information sources for each deformational episode are discussed in the text and are reported in tabular form. This report also contains maps showing the lithologies and structural geology of Alaska, a terrane map, and the distribution of tectonically important units including post-tectonic sedimentary basins, accretionary complexes, ophiolites, metamorphic rocks.These new maps show that most deformational belts in Alaska are relatively young features, having developed during the late Mesozoic and Cenozoic. The oldest episode of deformation recognized anywhere in Alaska is found in the basement of the Farewell terrane (~1.75 Ga). Paleozoic and early Mesozoic deformational events, including Devonian deformation in the Arctic Alaska terrane, Pennsylvanian deformation in the Alexander terrane, Permian deformation in the Yukon Composite (Klondike orogeny) and Farewell terranes (Browns

  8. Thrust-related, diapiric, and extensional doming in a frontal orogenic wedge: example of the Montagne Noire, Southern French Hercynian Belt

    Soula, Jean-Claude; Debat, Pierre; Brusset, Stéphane; Bessière, Gilbert; Christophoul, Frédéric; Déramond, Joachim


    The Montagne Noire, which is situated at the toe of the orogenic wedge of the French Massif Central South European Variscides, appears to be a well-suited area for studying the origin and evolution of middle to upper crustal domes adjacent to foreland basins. The data reported in the present paper show that the Montagne Noire dome is a particular type of basement-involved frontal culmination in an orogenic wedge and foreland basin system. This frontal culmination is characterized by a syn-contractional HT decompression recorded by clockwise PTt paths and widespread strata overturning in thrust and fold structures, which controlled the sedimentation in the adjacent foreland basin. These unusual characteristics are interpreted to be a result of the succession of thrusting, diapirism and extensional collapse. Antiformal stacking of syn-metamorphic thrust sheets controlled the first stages of the foreland basin development. Diapirism was essentially responsible for the HT decompression and widespread strata overturning. Extensional doming was a result of late- to post-metamorphic collapse acting on the pre-existing high-amplitude dome. Diapirism and associated isothermal decompression metamorphism, which constitute the essential difference between the Montagne Noire and 'ordinary' frontal ridges in orogenic wedges, were probably enhanced by a local partial melting of the upper to middle crust. It is suggested that the occurrence of these phenomena in front of an orogenic wedge was related to local over-thickening due to the superposition of an upper crustal antiformal stack on top of a lower crustal ramp anticline.

  9. Numerical analysis of the rheology of polymeric liquid crystals. 2nd Report. Shear and extensional flow behavior; Kobunshi ekisho no Rheology no suchi kaiseki. 2. Sendan shinchoryu tokusei

    Chono, S.; Tsuji, T. [Kochi Institute of Technology, Kochi (Japan)


    The Doi equations have been directly computed for shear and extensional flow without closure approximations. An extension is imposed on the shear flow plane. It is well-known that for simple shear flow there are three orientation regimes, depending on the magnitude of shear rate; rotational (tumbling), oscillatory (wagging), and stationary (aligning) orientation behaviors. When we add an extension to simple shear flow, the time period of tumbling is increased, while the order parameter in the regime is almost unchanged. In the wagging regime, however, both the time period and the order parameter are increased. Transitions from the tumbling and wagging regimes to the aligning regime are induced when more than a certain magnitude of extension is imposed on a system. An extension has also an effect to make the first normal stress difference positive. Furthermore, motion of individual molecules has been analyzed by integrating the Langevin equation. It is found that the aligning state in shear and extensional flow is due to an approximately stationary behavior of individual molecules, while the aligning state in simple shear flow is an apparently stationary behavior of a group of many rotational molecules. (author)

  10. Mixing of discontinuously deforming media

    Smith, L. D.; Rudman, M.; Lester, D. R.; Metcalfe, G.


    Mixing of materials is fundamental to many natural phenomena and engineering applications. The presence of discontinuous deformations—such as shear banding or wall slip—creates new mechanisms for mixing and transport beyond those predicted by classical dynamical systems theory. Here, we show how a novel mixing mechanism combining stretching with cutting and shuffling yields exponential mixing rates, quantified by a positive Lyapunov exponent, an impossibility for systems with cutting and shuffling alone or bounded systems with stretching alone, and demonstrate it in a fluid flow. While dynamical systems theory provides a framework for understanding mixing in smoothly deforming media, a theory of discontinuous mixing is yet to be fully developed. New methods are needed to systematize, explain, and extrapolate measurements on systems with discontinuous deformations. Here, we investigate "webs" of Lagrangian discontinuities and show that they provide a template for the overall transport dynamics. Considering slip deformations as the asymptotic limit of increasingly localised smooth shear, we also demonstrate exactly how some of the new structures introduced by discontinuous deformations are analogous to structures in smoothly deforming systems.

  11. Studies of Quaternary deformation zones through geomorphic and geophysical evidence: A case in the Precordillera Sur, Central Andes of Argentina

    Terrizzano, Carla M.; Fazzito, Sabrina Y.; Cortés, José M.; Rapalini, Augusto E.


    At the northern sector of the Precordillera Sur (31° 50'-32° 40' SL/68° 45'-69° 20' WL), Central Andes of Argentina, NW-trending sinistral transpressive shear zones at different scales, product of the Late Cenozoic Andean deformation, are recognized. The most significant of them is the 120 km long Barreal-Las Peñas Belt and within it, a small-scale (7 km long) Quaternary sinistral transpressive shear zone, called Los Avestruces, has been detected from geomorphological and geophysical analysis (32° SL/69° 21 WL). Geophysical techniques were applied to better characterize the shallow structure and kinematics of some representative structures in this shear zone. In particular, the use of tomography of electrical resistivity methods allowed characterizing the subsurface geometry of some areas of interest, enabling the recognition of Quaternary layers against their original slope, the geometry of the reverse fault which uplifted the Pleistocene deposits of one of the highs, the geometry of a likely previous extensional fault reactivated and inverted during the Quaternary as well as the presence of a reverse blind fault, which has uplifted the Quaternary deposits of the Los Avestruces bog. The location of the above mentioned shear zones coincides with the northern branch of the NW-trending extensional Triassic Cuyana basin. Thus, their presence appears to be related to Andean reactivation of older (Triassic), mainly NW-trending, structures. In the northern area of the Precordillera Sur, as well as in other places of the world here discussed, these kinds of paleotectonic oblique features play a major role in defining the geometry and kinematics of Late Cenozoic deformation.

  12. The Characteristics of Intra-continental Deformation and Hydrocarbon Distribution Controlled by the Himalayan Tectonic Movements in China

    JIA, Chengzao

    Based on previous studies and the latest insights from recent petroleum exploration programs, we propose that the characteristics of intra-continental deformation and its distribution, caused by the Himalayan tectonic movements, are controlled by basement framework formed by a collage of microcratons and lithotectonic terranes and dynamic factors such as the Indian/Eurasia collision and subduction of the Pacific plate. The evolution of Himalayan tectonic movements can be resolved by three principal dynamic mechanisms: (1) the uplift of Tibetan Plateau, (2) the coupling of orogenic belts and basins surrounding the Tibetan Plateau, and (3) extensional tectonics in eastern China. The tectonic framework and deformation that resulted from the Himalayan tectonic movements are mainly embodied in four tectonic domains: (1) the uplifted regions of the Tibetan Plateau, (2) the basin-and-range coupling of peripheral Tibetan Plateau, (3) stable regions, and (4) regions of active rifting along the western circum-Pacific margin. Sedimentary basins formed during the Himalayan tectonic movements, can be assorted into three categories: (1) rift basins due to extensional tectonics in east China, such as Bohai Bay Basin and Songliao Basin; (2) basins in central China, controlled by eastward compression of the Tibetan Plateau, which are characteristic of thrusting of basin margin and uplift-denudation in basins; (3) basins in west China such as the Tarim, Junggar and Qaidam Basins, which are associated with north-directed compression and exhibit thrust movements and flexural subsidence along basin margins. Their structural style is that of basin-and-range type. We conclude that Himalayan tectonic movements may have controlled the late hydrocarbon accumulation in China.

  13. The TR method: A new graphical method that uses the slip preference of the faults to separate heterogeneous fault-slip data in extensional and compressional stress regimes

    Tranos, Markos


    The new graphical TR method uses the slip preference (SP) of the faults to separate heterogeneous fault-slip data. This SP is described in detail and several examples of the application of the TR method are presented. For this purpose, synthetic fault-slip data driven by various extensional and compressional stress regimes whose greatest principal stress axis (σ1) or least principal stress axis (σ3) always remains in vertical or horizontal position respectively as in Andersonian stress states have been considered. Their SP is given through a simple graphical manner and the aid of the Win-Tensor stress inversion software. The extensional stress regimes that have been examined are the radial extension (RE), radial-pure extension (RE-PE), pure extension (PE), pure extension-transtension (PE-TRN) and transtension (TRN), whereas the compressional stress regimes are the radial compression (RC), radial-pure compression (RC-PC), pure compression (PC), pure compression-transpression (PC-TRP) and transpression (TRP). A necessary condition for the TR method that is the faults dipping towards the certain horizontal principal stress axis of the driving stress regime are dip-slip faults, either normal or reverse ones, is satisfied for all extensional and compressional stress regimes respectively. The trend of the horizontal least or greatest principal stress axis of the driving extensional or compressional stress regime respectively can be directly defined by the trend of the T-axes of the normal faults or the P-axes of the reverse faults respectively. Taking into account a coefficient of friction no smaller than 0.6, the reactivated extensional faults in the crust dip at angles higher than about 40°, and the increase of the stress ratio and/or the fault dip angle results in the increase of the slip deviation from the normal activation. In turn, in the compressional stress regimes, the dip angle and SP of the activated faults suggest the distinction of the compressional

  14. Plate boundary deformation in North Iceland during 1992–2009 revealed by InSAR time-series analysis and GPS

    Metzger, Sabrina


    In North Iceland, extensional plate motion is accommodated by the Northern Volcanic Zone, a set of en-echelon volcanic systems, and the Tjörnes Fracture Zone, a transform offset in the mid-Atlantic Ridge consisting of two parallel transform lineaments. The southern lineament, the Húsavík–Flatey fault, is a 100 km-long right-lateral strike slip fault that has not ruptured for more than 140 years and poses a significant seismic hazard to Húsavík, a fishing town located by the fault, and to other coastal communities. We present results of InSAR time-series analysis data spanning almost two decades (1992–2009) that show extensional and interseismic deformation within the Northern Volcanic Zone and the on-shore part of the Tjörnes Fracture Zone. The results also exhibit transient inflation at Theistareykir volcano, deflation at Krafla central volcano and a broad uplift north of Krafla. The current plate extension is not uniform across the Northern Volcanic Zone, but concentrated at the western fissures of the Theistareykir volcanic system and the outermost fissures of the Krafla fissure swarm. We combine a back-slip plate boundary model with a set of point pressure sources representing volcanic changes to describe the current extensional plate boundary deformation and update the previous estimations of the locking depth and slip rate of the Húsavík–Flatey fault that were based on GPS data alone. Using different combinations of input data, we find that the Húsavík–Flatey fault has a locking depth of 6–10 km and, with a slip rate of 6–9 mm/yr, is accommodating about a third of the full transform motion. We furthermore show that while the InSAR data provide important constraints on the volcanic deformation within the NVZ, they do not significantly improve the model parameter estimation for the HFF, as the dense GPS network appears to better capture the deformation across the fault.

  15. Mixing of discontinuously deforming media

    Smith, Lachlan D; Lester, Daniel R; Metcalfe, Guy


    Mixing of materials is fundamental to many natural phenomena and engineering applications. The presence of discontinuous deformations - such as shear banding or wall slip - creates new mechanisms for mixing and transport beyond those predicted by classical dynamical systems theory. Here we show how a novel mixing mechanism combining stretching with cutting and shuffling yields exponential mixing rates, quantified by a positive Lyapunov exponent, an impossibility for systems with cutting and shuffling alone or bounded systems with stretching alone, and demonstrate it in a fluid flow. While dynamical systems theory provides a framework for understanding mixing in smoothly deforming media, a theory of discontinuous mixing is yet to be fully developed. New methods are needed to systematize, explain and extrapolate measurements on systems with discontinuous deformations. Here we investigate 'webs' of Lagrangian discontinuities and show that they provide a template for the overall transport dynamics. Considering sl...

  16. Shock metamorphism of deformed quartz

    Gratz, Andrew J.; Christie, John; Tyburczy, James; Ahrens, Thomas; Pongratz, Peter


    The effect produced by shock loading (to peak pressures of 12 and 24) on deformed synthetic quartz containing a dislocation and abundant bubbles and small inclusions was investigated, and the relationships between preexisting dislocation density shock lamellae in the target material were examined. The resultant material was found to be inhomogeneously deformed and extremely fractured. Results of TEM examinations indicate that no change in dislocation density was caused by shock loading except in regions containing shock lamellae, where the dislocation density was lowered. The shock-induced defects tend to nucleate on and be controlled by preexisting stress concentrators; shock lamellae, glassy veins, and most curviplanar defects form in tension, presumably during release. An extremely mobile silica fluid is formed and injected into fractures during release, which forcibly removes crystalline fragments from vein walls. It is concluded that shock deformation in quartz is dominated by fracture and melting.

  17. Finite Deformation of Magnetoelastic Film

    Barham, Matthew Ian [Univ. of California, Berkeley, CA (United States)


    A nonlinear two-dimensional theory is developed for thin magnetoelastic lms capable of large deformations. This is derived directly from three-dimensional theory. Signi cant simpli cations emerge in the descent from three dimensions to two, permitting the self eld generated by the body to be computed a posteriori. The model is specialized to isotropic elastomers with two material models. First weak magnetization is investigated leading to a free energy where magnetization and deformation are un-coupled. The second closely couples the magnetization and deformation. Numerical solutions are obtained to equilibrium boundary-value problems in which the membrane is subjected to lateral pressure and an applied magnetic eld. An instability is inferred and investigated for the weak magnetization material model.

  18. On deformations of triangulated models

    De Deken, Olivier


    This paper is the first part of a project aimed at understanding deformations of triangulated categories, and more precisely their dg and A infinity models, and applying the resulting theory to the models occurring in the Homological Mirror Symmetry setup. In this first paper, we focus on models of derived and related categories, based upon the classical construction of twisted objects over a dg or $A_{\\infty}$-algebra. For a Hochschild 2 cocycle on such a model, we describe a corresponding "curvature compensating" deformation which can be entirely understood within the framework of twisted objects. We unravel the construction in the specific cases of derived A infinity and abelian categories, homotopy categories, and categories of graded free qdg-modules. We identify a purity condition on our models which ensures that the structure of the model is preserved under deformation. This condition is typically fulfilled for homotopy categories, but not for unbounded derived categories.

  19. Deformation Rates in the Snake River Plain and Adjacent Basin and Range Regions Based on GPS Measurements

    Payne, S. J.; McCaffrey, R.; King, R. W.; Kattenhorn, S. A.


    We estimate horizontal velocities for 405 sites using Global Positioning System (GPS) phase data collected from 1994 to 2010 within the Northern Basin and Range Province, U.S.A. The velocities reveal a slowly-deforming region within the Snake River Plain in Idaho and Owyhee-Oregon Plateau in Oregon separated from the actively extending adjacent Basin and Range regions by shear. Our results show a NE-oriented extensional strain rate of 5.6 ± 0.7 nanostrain/yr in the Centennial Tectonic Belt and an ~E-oriented extensional strain rate of 3.5 ± 0.2 nanostrain/yr in the Great Basin. These extensional rates contrast with the very low strain rate within the 125 km x 650 km region of the Snake River Plain and Owyhee-Oregon Plateau which is not distinguishable from zero (-0.1 ± 0.4 x nanostrain/yr). Inversions of Snake River Plain velocities with dike-opening models indicate that rapid extension by dike intrusion in volcanic rift zones, as previously hypothesized, is not currently occurring. GPS data also disclose that rapid extension in the surrounding regions adjacent to the slowly-deforming region of the Snake River Plain drives shear between them. We estimate right-lateral shear with slip rates of 0.3-1.5 mm/yr along the northwestern boundary adjacent to the Centennial Tectonic Belt and left-lateral oblique extension with slip rates of 0.5-1.5 mm/yr along the southeastern boundary adjacent to the Intermountain Seismic Belt. The fastest lateral shearing evident in the GPS occurs near the Yellowstone Plateau where earthquakes with right-lateral strike-slip focal mechanisms are within a NE-trending zone of seismicity. The regional velocity gradients are best fit by nearby poles of rotation for the Centennial Tectonic Belt, Snake River Plain, Owyhee-Oregon Plateau, and eastern Oregon, indicating that clockwise rotation is not locally driven by Yellowstone hotspot volcanism, but instead by extension to the south across the Wasatch fault possibly due to gravitational

  20. Deformable mirror with thermal actuators.

    Vdovin, Gleb; Loktev, Mikhail


    Low-cost adaptive optics is applied in lasers, scientific instrumentation, ultrafast sciences, and ophthalmology. These applications demand that the deformable mirrors used be simple, inexpensive, reliable, and efficient. We report a novel type of ultralow-cost deformable mirror with thermal actuators. The device has a response time of ~5 s , an actuator stroke of ~6mum , and temporal stability of ~lambda/10 rms in the visible range and can be used for correction of rather large aberrations with slow-changing amplitude.

  1. Computing layouts with deformable templates

    Peng, Chihan


    In this paper, we tackle the problem of tiling a domain with a set of deformable templates. A valid solution to this problem completely covers the domain with templates such that the templates do not overlap. We generalize existing specialized solutions and formulate a general layout problem by modeling important constraints and admissible template deformations. Our main idea is to break the layout algorithm into two steps: a discrete step to lay out the approximate template positions and a continuous step to refine the template shapes. Our approach is suitable for a large class of applications, including floorplans, urban layouts, and arts and design. Copyright © ACM.

  2. Cavity coalescence in superplastic deformation

    Stowell, M.J.; Livesey, D.W.; Ridley, N.


    An analysis of the probability distribution function of particles randomly dispersed in a solid has been applied to cavitation during superplastic deformation and a method of predicting cavity coalescence developed. Cavity size distribution data were obtained from two microduplex nickel-silver alloys deformed superplastically to various extents at elevated temperature, and compared to theoretical predictions. Excellent agreement occurred for small void sizes but the model underestimated the number of voids in the largest size groups. It is argued that the discrepancy results from a combination of effects due to non-random cavity distributions and to enhanced growth rates and incomplete spheroidization of the largest cavities.

  3. Fourth order deformed general relativity

    Cuttell, Peter D


    Whenever the condition of anomaly freedom is imposed within the framework of effective approaches to loop quantum cosmology, one seems to conclude that a deformation of general covariance is required. Here, starting from a general deformation we regain an effective gravitational Lagrangian including terms up to fourth order in extrinsic curvature. We subsequently constrain the form of the corrections, and then investigate the conditions for the occurrence of a big bounce and the realisation of an inflationary era, in the presence of a perfect fluid or scalar field.

  4. Deforming baryons into confining strings

    Hartnoll, S A; Hartnoll, Sean A.; Portugues, Ruben


    We find explicit probe D3-brane solutions in the infrared of the Maldacena-Nunez background. The solutions describe deformed baryon vertices: q external quarks are separated in spacetime from the remaining N-q. As the separation is taken to infinity we recover known solutions describing infinite confining strings in ${\\mathcal{N}}=1$ gauge theory. We present results for the mass of finite confining strings as a function of length. We also find probe D2-brane solutions in a confining type IIA geometry, the reduction of a G_2 holonomy M theory background. The interpretation of these solutions as deformed baryons/confining strings is not as straightforward.

  5. Coseismic Pit Crater, Normal Fault, and Extensional Fissure Formation in Unconsolidated Sediment and Basalt in Northern Iceland

    Ferrill, D. A.; Wyrick, D. Y.; Smart, K. J.


    Two rifting-related seismic events in 1975 and 1978 along the Mid-Atlantic Ridge near the northern coast of Iceland produced an array of surface deformation features in Holocene basalt flows and overlying unconsolidated sediments. New field mapping and aerial photograph interpretation is coupled with analysis of maps of seismic activity and level-line survey results to constrain the timing, style, and magnitude of this deformation. Fault scarps and fissures in basalts can be traced laterally down a gentle northward dip projecting into unconsolidated braided stream deposits, providing an impressive view of the deformation style in the two contrasting mechanical layers. We report on detailed field mapping of two of these laterally traceable structures conducted in the summer of 2008 and analysis of a suite of aerial photographs from 1958 to 1998. Map-scale structures in the basalts with little or no sedimentary cover include (i) fault scarps, (ii) fissures, and (iii) locally-developed gentle dip away from the related normal fault. Dilation of faults and extension fractures in the basalt has led to rock toppling and rock fall causing widening of fissures. Wedging of toppled rock blocks at the tops of fissures has locally produced keystone arches and bridges across the tops of open fissures. Different stages in the progression of fissure formation and collapse, including (i) fissure, (ii) widened fissure with cavern, (iii) localized collapse pit, and (iv) elongate collapsed fissure, can be observed over along-strike distances of 10's of meters. Where unconsolidated sand and gravel deposits >3 m thick cover the basalts (200 m to the north along strike) structural geomorphologic features are dominated by (i) grabens, (ii) pit craters, and (iii) elongate troughs. Graben-bounding normal faults cutting the sedimentary cover in many cases have displacements >1 m. Pit craters have cone to bowl shapes, commonly occur within grabens, and have depths up to 2.8 m. The mapped

  6. Deformations of the Almheiri-Polchinski model

    Kyono, Hideki; Okumura, Suguru; Yoshida, Kentaroh


    We study deformations of the Almheiri-Polchinski (AP) model by employing the Yang-Baxter deformation technique. The general deformed AdS2 metric becomes a solution of a deformed AP model. In particular, the dilaton potential is deformed from a simple quadratic form to a hyperbolic function-type potential similarly to integrable deformations. A specific solution is a deformed black hole solution. Because the deformation makes the spacetime structure around the boundary change drastically and a new naked singularity appears, the holographic interpretation is far from trivial. The Hawking temperature is the same as the undeformed case but the Bekenstein-Hawking entropy is modified due to the deformation. This entropy can also be reproduced by evaluating the renormalized stress tensor with an appropriate counter-term on the regularized screen close to the singularity.

  7. Space-based monitoring of ground deformation

    Nobakht Ersi, Fereydoun; Safari, Abdolreza; Gamse, Sonja


    Ground deformation monitoring is valuable to understanding of the behaviour of natural phenomena. Space-Based measurement systems such as Global Positioning System are useful tools for continuous monitoring of ground deformation. Ground deformation analysis based on space geodetic techniques have provided a new, more accurate, and reliable source of information for geodetic positioning which is used to detect deformations of the Ground surface. This type of studies using displacement fields derived from repeated measurments of space-based geodetic networks indicates how crucial role the space geodetic methods play in geodynamics. The main scope of this contribution is to monitor of ground deformation by obtained measurements from GPS sites. We present ground deformation analysis in three steps: a global congruency test on daily coordinates of permanent GPS stations to specify in which epochs deformations occur, the localization of the deformed GPS sites and the determination of deformations.

  8. Effect of extensional cyclic strain on the mechanical and physico-mechanical properties of PVC-NBR/graphite composites


    Full Text Available The variation of electrical resistivity as will as the mechanical properties of PVC (polyvinylchloride-NBR (acrylonitrile butadiene rubber based conductive composites filled with different concentrations of graphite were studied. These samples were studied as function of the constant deformation fatigue test. When the specimen was subjected to a large number of rapidly repeating strain cycles, and different strain amplitudes, the conductivity, σ(T, shows an initial rapid fall followed by dynamic equilibrium. Increasing the number of cycles and strain amplitudes, the conductivity remains almost constant over the temperature range 30–140°C. The equilibrium state between destruction and reconstruction of graphite particles has been detected for all strains of certain values of strain cycles (1000, 2000, 3000, and 4000 cycles for 30% strain amplitude. A preliminary study was done to optimize the possibility to use Conductive Polymer Composites (CPC as a strain sensor and to evaluate its performance by an intrinsic physico-mechanical modification measurement. The electromechanical characterization was performed to demonstrate the adaptability and the correct functioning of the sensor as a strain gauge on the fabric. The coefficient of strain sensitivity (K was measured for 50 phr graphite/PVCNBR vulcanized at 3000 number of strain cycles and 30% strain amplitude. There was a broad maximum of K, with a peak value of 82, which was much higher, compared to conventional wire resistors. A slight hysteresis was observed at unloading due to plasticity of the matrix. A good correlation exists between mechanical and electrical response to the strain sensitivity. Mechanical reinforcement was in accordance with the Quemada equation [1] and Guth model [2] attested to good particle-matrix adhesion. It was found that the viscous component of deformation gradually disappeared and the hardening occurred with increasing strain cycles. The modulus, fracture

  9. Deformation-induced silica redistribution in banded iron formation, Hamersley Province, Australia

    Egglseder, Mathias S.; Cruden, Alexander R.; Tomkins, Andrew G.; Wilson, Christopher J. L.


    -precipitation creep, providing a possible explanation for the destruction of primary features. We show that different generations of chert alternate on a micro-scale, suggesting that the role of deformation has been underestimated in many aspects of BIF research. The discovery of dissolution-precipitation creep in low-grade metamorphic BIF provides a potential link between the physical and chemical processes that occur within these rocks after deposition. In the Hamersley Province, dissolution-precipitation creep was active from the compaction or diagenesis stage and probably operated during all major extensional and compressional deformation events. We also suggest that chert layers without CPO record the least overprint by diagenesis, and as the most pristine form of BIF should be targeted for future paleo-environmental research.

  10. Pacific plate slab pull and intraplate deformation in the early Cenozoic

    Butterworth, N. P.; Müller, R. D.; Quevedo, L.; O'Connor, J. M.; Hoernle, K.; Morra, G.


    Large tectonic plates are known to be susceptible to internal deformation, leading to a~range of phenomena including intraplate volcanism. However, the space and time dependence of intraplate deformation and its relationship with changing plate boundary configurations, subducting slab geometries, and absolute plate motion is poorly understood. We utilise a buoyancy-driven Stokes flow solver, BEM-Earth, to investigate the contribution of subducting slabs through time on Pacific plate motion and plate-scale deformation, and how this is linked to intraplate volcanism. We produce a series of geodynamic models from 62 to 42 Ma in which the plates are driven by the attached subducting slabs and mantle drag/suction forces. We compare our modelled intraplate deformation history with those types of intraplate volcanism that lack a clear age progression. Our models suggest that changes in Cenozoic subduction zone topology caused intraplate deformation to trigger volcanism along several linear seafloor structures, mostly by reactivation of existing seamount chains, but occasionally creating new volcanic chains on crust weakened by fracture zones and extinct ridges. Around 55 Ma, subduction of the Pacific-Izanagi ridge reconfigured the major tectonic forces acting on the plate by replacing ridge push with slab pull along its northwestern perimeter, causing lithospheric extension along pre-existing weaknesses. Large-scale deformation observed in the models coincides with the seamount chains of Hawaii, Louisville, Tokelau and Gilbert during our modelled time period of 62 to 42 Ma. We suggest that extensional stresses between 72 and 52 Ma are the likely cause of large parts of the formation of the Gilbert chain and that localised extension between 62 and 42 Ma could cause late-stage volcanism along the Musicians volcanic ridges. Our models demonstrate that early Cenozoic changes in Pacific plate driving forces only cause relatively minor changes in Pacific absolute plate motion

  11. Pacific Plate slab pull and intraplate deformation in the early Cenozoic

    N. P. Butterworth


    Full Text Available Large tectonic plates are known to be susceptible to internal deformation, leading to a range of phenomena including intraplate volcanism. However, the space and time dependence of intraplate deformation and its relationship with changing plate boundary configurations, subducting slab geometries, and absolute plate motion is poorly understood. We utilise a buoyancy driven Stokes flow solver, BEM-Earth, to investigate the contribution of subducting slabs through time on Pacific Plate motion and plate-scale deformation, and how this is linked to intraplate volcanism. We produce a series of geodynamic models from 62 to 42 Ma in which the plates are driven by the attached subducting slabs and mantle drag/suction forces. We compare our modelled intraplate deformation history with those types of intraplate volcanism that lack a clear age progression. Our models suggest that changes in Cenozoic subduction zone topology caused intraplate deformation to trigger volcanism along several linear seafloor structures, mostly by reactivation of existing seamount chains, but occasionally creating new volcanic chains on crust weakened by fracture zones and extinct ridges. Around 55 Ma subduction of the Pacific-Izanagi ridge reconfigured the major tectonic forces acting on the plate by replacing ridge push with slab pull along its north-western perimeter, causing lithospheric extension along pre-existing weaknesses. Large scale deformation observed in the models coincides with the seamount chains of Hawaii, Louisville, Tokelau, and Gilbert during our modelled time period of 62 to 42 Ma. We suggest that extensional stresses between 72 and 52 Ma are the likely cause of large parts of the formation of the Gilbert chain and that localised extension between 62 and 42 Ma could cause late-stage volcanism along the Musicians Volcanic Ridges. Our models demonstrate that early Cenozoic changes in Pacific plate driving forces only cause relatively minor changes in Pacific

  12. Pacific plate slab pull and intraplate deformation in the early Cenozoic

    N. P. Butterworth


    Full Text Available Large tectonic plates are known to be susceptible to internal deformation, leading to a~range of phenomena including intraplate volcanism. However, the space and time dependence of intraplate deformation and its relationship with changing plate boundary configurations, subducting slab geometries, and absolute plate motion is poorly understood. We utilise a buoyancy-driven Stokes flow solver, BEM-Earth, to investigate the contribution of subducting slabs through time on Pacific plate motion and plate-scale deformation, and how this is linked to intraplate volcanism. We produce a series of geodynamic models from 62 to 42 Ma in which the plates are driven by the attached subducting slabs and mantle drag/suction forces. We compare our modelled intraplate deformation history with those types of intraplate volcanism that lack a clear age progression. Our models suggest that changes in Cenozoic subduction zone topology caused intraplate deformation to trigger volcanism along several linear seafloor structures, mostly by reactivation of existing seamount chains, but occasionally creating new volcanic chains on crust weakened by fracture zones and extinct ridges. Around 55 Ma, subduction of the Pacific-Izanagi ridge reconfigured the major tectonic forces acting on the plate by replacing ridge push with slab pull along its northwestern perimeter, causing lithospheric extension along pre-existing weaknesses. Large-scale deformation observed in the models coincides with the seamount chains of Hawaii, Louisville, Tokelau and Gilbert during our modelled time period of 62 to 42 Ma. We suggest that extensional stresses between 72 and 52 Ma are the likely cause of large parts of the formation of the Gilbert chain and that localised extension between 62 and 42 Ma could cause late-stage volcanism along the Musicians volcanic ridges. Our models demonstrate that early Cenozoic changes in Pacific plate driving forces only cause relatively minor changes in Pacific

  13. Crustal deformation and surface kinematics after the 2010 earthquakes in Latin America

    Sánchez, L.; Drewes, H.


    Strong earthquakes cause large changes in the station positions and velocities of the geodetic reference stations; i.e., the global ITRF (International Terrestrial Reference Frame) and its regional densifications like SIRGAS (Sistema de Referencia Geocéntrico para Las Américas) in Latin America and the Caribbean. To ensure the long-term stability of the geodetic reference frames, the transformation of station positions between different epochs requires the computation of reliable continuous surface deformation (or velocity) models. This paper presents the computation of a new continental continuous crustal deformation model for Latin America and the Caribbean inferred from GNSS (GPS + GLONASS) measurements gained after the strong earthquakes occurred in 2010 in Chile and Mexico. It is based on a multi-year velocity solution for a network of 456 continuously operating GNSS stations and covering a five years period from March 14, 2010 to April 11, 2015. This new deformation model, called VEMOS2015 (Velocity Model for SIRGAS 2015), is computed using the least square collocation (LSC) approach with empirically determined covariance functions. The result is summarised as follows: While the effects of the Baja California earthquake can be considered as local, the effects of the Maule earthquake changed the surface kinematics of a large area (between the latitudes 30°S-45°S from the Pacific to the Atlantic coasts). Before the Maule earthquake, the strain rate field in this area showed a strong west-east compression with maximum rates of about 0.40 μstrain/a between latitudes 38°S and 44°S. In accordance, the deformation vectors were roughly parallel to the plate subduction direction and their magnitudes decreased with the distance from the subduction front. After the earthquake, the largest compression (0.25 μstrain/a) occurs between the latitudes 37°S and 40°S with a N30°E direction. The maximum extensional strain rate (0.20-0.35 μstrain/a) is observed in the

  14. Fault-induced deformation in a poorly consolidated, siliciclastic growth basin: A study from the Devonian in Norway

    Braathen, A.; Osmundsen, P. T.; Hauso, H.; Semshaug, S.; Fredman, N.; Buckley, S. J.


    The extensional Berge fault (Devonian Kvamshesten Basin, West Norway) displays 430 m of syntectonic stratigraphy with fluvial sandstones and red fines exposed in a hanging wall growth section. The fault consists of three linked strands, where the offset diminishes and tips out stratigraphically upwards. Folds in the growth basin include a rollover and drag fold that record cumulative deformation during the main phases of fault slip, and a monocline that records the death and burial of the fault. Deformation styles in both the subbasin fill and the fault core indicate that the sediments were unconsolidated to poorly lithified during deformation. The upward-narrowing fault core consists of indurated breccias derived from footwall conglomerates, and mainly laminated fault gouge of subbasin affinity. Towards the hanging wall there is a mixed layer of sandstone lenses enclosed in fault gouge; this unit is variably sheared. In the damage zone deeper in the subbasin, truncating-style small-scale tabular shear bands show a general increase in frequency towards the fault, with abundant peaks in frequency next to the fault core. Smearing-style shear bands are merely encountered near the master fault. In the upper monocline realm, an overall broad zone of deformation reveals a moderate frequency of shear bands, characterized by clear distinctions between variably deformed layers. Some tabular dilation structures are found locally as layer-confined strain throughout the basin. We reason that the mixed layer is a product of fluid mobilization in/along the fault core. Fluid induced weakening combined with differential compaction would augment aseismic creep, as advocated for the creation of the smearing shear bands. We discuss a conceptual model in which damage zones grow by repeated rejuvenation and expand during propagation events, advocating that a distinctive damage zone becomes better expressed with increasing faulting events and depth (consolidation) in a growth basin.

  15. Deformation and orientation statistics of neutrally buoyant sub-Kolmogorov ellipsoidal droplets in turbulent Taylor-Couette flow

    Spandan, Vamsi; Lohse, Detlef; Verzicco, Roberto


    The influence of the underlying flow topology on the shape and size of sub-Kolmogorov droplets dispersed in a turbulent flow is of considerable interest in many industrial and scientific applications. In this work we study the deformation and orientation statistics of sub-Kolmogorov droplets dispersed into a turbulent Taylor-Couette flow. Along with Direct Numerical Simulations (DNS) of the carrier phase and Lagrangian tracking of the dispersed droplets, we solve a phenomenological equation proposed by Maffettone and Minale (\\emph{J. Fluid Mech.} 78, 227-241 (1998)) to track the shape evolution and orientation of approximately $10^5$ ellipsoidal droplets. By varying the capillary number $Ca$ and viscosity ratio $\\hat \\mu$ of the droplets we find that the droplets deform more with increasing capillary number $Ca$ and this effect is more pronounced in the boundary layer regions. This indicates that along with a capillary number effect there is also a strong correlation between spatial position and degree of deformation of the droplet. Regardless of the capillary number $Ca$, the major-axis of the ellipsoids tends to align with the stream-wise direction and the extensional strain rate eigen direction in the boundary layer region while the distribution is highly isotropic in the bulk. When the viscosity ratio between the droplet and the carrier fluid is increased we find that there is no preferential stretched axis which is due to the increased influence of rotation over stretching and relaxation. Droplets in high viscosity ratio systems are thus less deformed and oblate (disk-like) as compared to highly deformed prolate (cigar-like) droplets in low viscosity ratio systems.

  16. Deformable Models for Eye Tracking

    Vester-Christensen, Martin; Leimberg, Denis; Ersbøll, Bjarne Kjær;


    A deformable template method for eye tracking on full face images is presented. The strengths of the method are that it is fast and retains accuracy independently of the resolution. We compare the me\\$\\backslash\\$-thod with a state of the art active contour approach, showing that the heuristic...

  17. Spatiotemporal deformations of reflectionless potentials

    Horsley, S. A. R.; Longhi, S.


    Reflectionless potentials for classical or matter waves represent an important class of scatteringless systems encountered in different areas of physics. Here we mathematically demonstrate that there is a family of non-Hermitian potentials that, in contrast to their Hermitian counterparts, remain reflectionless even when deformed in space or time. These are the profiles that satisfy the spatial Kramers-Kronig relations. We start by considering scattering of matter waves for the Schrödinger equation with an external field, where a moving potential is observed in the Kramers-Henneberger reference frame. We then generalize this result to the case of electromagnetic waves, by considering a slab of reflectionless material that both is scaled and has its center displaced as an arbitrary function of position. We analytically and numerically demonstrate that the backscattering from these profiles remains zero, even for extreme deformations. Our results indicate the supremacy of non-Hermitian Kramers-Kronig potentials over reflectionless Hermitian potentials in keeping their reflectionless property under deformation and could find applications to, e.g., reflectionless optical coatings of highly deformed surfaces based on perfect absorption.

  18. Bethe ansatz and Isomonodromic deformations

    Talalaev, D


    We study symmetries of the Bethe equations for the Gaudin model appeared naturally in the framework of the geometric Langlands correspondence under the name of Hecke operators and under the name of Schlesinger transformations in the theory of isomonodromic deformations, and particularly in the theory of Painlev\\'e transcendents.

  19. Pre-Lie Deformation Theory

    Dotsenko, V.; Shadrin, S.; Vallette, B.


    In this paper, we develop the deformation theory controlled by pre-Lie algebras; the main tool is a new integration theory for preLie algebras. The main field of application lies in homotopy algebra structures over a Koszul operad; in this case, we provide a homotopical description of the associated

  20. Highly deformable nanofilaments in flow

    Pawłowska, S.


    Experimental analysis of hydrogel nanofilaments conveyed by flow is conducted to help in understanding physical phenomena responsible for transport properties and shape deformations of long bio-objects, like DNA or proteins. Investigated hydrogel nanofilaments exhibit typical macromolecules-like behavior, as spontaneous conformational changes and cross-flow migration. Results of the experiments indicate critical role of thermal fluctuations behavior of single filaments.

  1. Tectono-sedimentary evolution of an extensional basin revealed by a combined photo-geological and field-mapping approach. The Montefalco Basin (Northern Apennines, Italy)

    Bucci, Francesco; Mirabella, Francesco; Santangelo, Michele; Cardinali, Mauro; Guzzetti, Fausto


    Active extensional basins are important since their sedimentary infills and bounding tectonic structures provide: i) sinks with preservation potential for sedimentary and fossil records of past changes in climate and sediment/water supply, ii) information on the growth, activity, decay and death of normal faults, iii) vast economic reserves of hydrocarbons, water and minerals. Unfortunately, quaternary extensional basins, especially if located in humid and temperate climate environments, are often characterized by extensively cultivated areas, homogeneous terrains and quite flat morphologies. Furthermore, they commonly host human settlements, together with roads, economic and industrial infrastructures, with a consequent limited availability of good outcrops. Such a limitation can (often severely) hamper an adequate mapping of the sedimentary infill. Therefore alternative methodological approaches (such as aerial photographs interpretation, API) are needed to integrate heterogeneous and incomplete datasets. This contribution presents an updated photo-geological map of a Quaternary extensional basin in Central Italy, the Montefalco Basin. This basin developed in a continental environment characterized by clayey-sandy lacustrine and fluvial sequences (late Pliocene - early Pleistocene) underlying more recent coarse grained deposits related to alluvial fan environment (early-to-late Pleistocene) and younger palustrine deposits (late Pleistocene). Since the late Pleistocene, regional uplift and local tectonics led to the end of deposition in the Montefalco basin, which experienced a diffuse incision and the modification of the drainage network, in response to the W-to-E migration of active faulting and tectonic subsidence. The new photo-geological map represents an important improvement compared to the existing data, since it provides unprecedented and spatially distributed information on the geometry of the continental deposits and on the tectonic structures affecting

  2. From detachment to transtensional faulting: A model for the Lake Mead extensional domain based on new ages and correlation of subbasins

    Beard, L.; Umhoefer, P. J.; Martin, K. L.; Blythe, N.


    New studies of selected basins in the Miocene extensional belt of the northern Lake Mead domain suggest a new model for the early extensional history of the region (lower Horse Spring Formation and correlative strata). Critical data are from (i) Longwell Ridges area west of Overton Arm and within the Lake Mead fault system, (ii) Salt Spring Wash basin in the hanging wall of the South Virgin-White Hills detachment (SVWHD) fault, and (iii) previously studied subbasins of the south Virgin Mountains in the Gold Butte step-over region. The basins and faulting patterns suggest two stages of basin development related to two distinct faulting episodes, an early period of detachment faulting followed by a switch to faulting mainly along the Lake Mead transtensional fault system while detachment faulting waned. Apatite fission track ages suggest the footwall block of the SVWHD was cooling at 18-17 Ma, but the only evidence for basin deposition at that time is in the Gold Butte step-over where slow rates of sedimentation and facies patterns make faulting on the north side of the Gold Butte block ambiguous. The first basin stage was ca. 16.5 to 15.5 Ma, during which there was slow to moderate faulting and subsidence in a basin along the SVWHD and north of Gold Butte block in the Gold Butte step-over basin; the step- over basin had complex fluvial and lacustrine facies and was synchronous with landslides and debris flows in front of the SVWHD. At ca. 15.5-14.5 Ma, there was a [dramatic] increase in sedimentation rate related to formation of the Gold Butte fault, a change from lacustrine to widespread fluvial, playa, and local landslide facies in the step-over basin, and the peak of exhumation and faulting rates on the SVWHD. The simple step-over basin broke up into numerous subbasins [at[ as initial faults of the Lake Mead fault system formed. From 14.5 to 14.0 Ma, there was completion of a major change from dominantly detachment faulting to dominantly transtensional faulting

  3. Vertical tectonic deformation associated with the San Andreas fault zone offshore of San Francisco, California

    Ryan, H. F.; Parsons, T.; Sliter, R. W.


    A new fault map of the shelf offshore of San Francisco, California shows that faulting occurs as a distributed shear zone that involves many fault strands with the principal displacement taken up by the San Andreas fault and the eastern strand of the San Gregorio fault zone. Structures associated with the offshore faulting show compressive deformation near where the San Andreas fault goes offshore, but deformation becomes extensional several km to the north off of the Golden Gate. Our new fault map serves as the basis for a 3-D finite element model that shows that the block between the San Andreas and San Gregorio fault zone is subsiding at a long-term rate of about 0.2-0.3 mm/yr, with the maximum subsidence occurring northwest of the Golden Gate in the area of a mapped transtensional basin. Although the long-term rates of vertical displacement primarily show subsidence, the model of coseismic deformation associated with the 1906 San Francisco earthquake indicates that uplift on the order of 10-15 cm occurred in the block northeast of the San Andreas fault. Since 1906, 5-6 cm of regional subsidence has occurred in that block. One implication of our model is that the transfer of slip from the San Andreas fault to a fault 5 km to the east, the Golden Gate fault, is not required for the area offshore of San Francisco to be in extension. This has implications for both the deposition of thick Pliocene-Pleistocene sediments (the Merced Formation) observed east of the San Andreas fault, and the age of the Peninsula segment of the San Andreas fault.

  4. Deformation and degradation of polymers in ultra-high-pressure liquid chromatography.

    Uliyanchenko, Elena; van der Wal, Sjoerd; Schoenmakers, Peter J


    Ultra-high-pressure liquid chromatography (UHPLC) using columns packed with sub-2 μm particles has great potential for separations of many types of complex samples, including polymers. However, the application of UHPLC for the analysis of polymers meets some fundamental obstacles. Small particles and narrow bore tubing in combination with high pressures generate significant shear and extensional forces in UHPLC systems, which may affect polymer chains. At high stress conditions flexible macromolecules may become extended and eventually the chemical bonds in the molecules can break. Deformation and degradation of macromolecules will affect the peak retention and the peak shape in the chromatogram, which may cause errors in the obtained results (e.g. the calculated molecular-weight distributions). In the present work we explored the limitations of UHPLC for the analysis of polymers. Degradation and deformation of macromolecules were studied by collecting and re-injecting polymer peaks and by off-line two-dimensional liquid chromatography. Polystyrene standards with molecular weight of 4 MDa and larger were found to degrade at UHPLC conditions. However, for most polymers degradation could be avoided by using low linear velocities. No degradation of 3-MDa PS (and smaller) was observed at linear velocities up to 7 mm/s. The column frits were implicated as the main sources of polymer degradation. The extent of degradation was found to depend on the type of the column and on the column history. At high flow rates degradation was observed without a column being installed. We demonstrated that polymer deformation preceded degradation. Stretched polymers eluted from the column in slalom chromatography mode (elution order opposite to that in SEC or HDC). Under certain conditions we observed co-elution of large and small PS molecules though a convolution of slalom chromatography and hydrodynamic chromatography.

  5. Brittle-viscous deformation of vein quartz under fluid-rich low greenschist facies conditions

    Jørgen Kjøll, Hans; Viola, Giulio; Menegon, Luca; Sørensen, Bjørn


    A coarse grained, statically crystallized quartz vein with a random CPO, embedded in a phyllonitic matrix, was studied by optical microscopy, SEM imaging and EBSD to gain insights into the processes of strain localization in quartz deformed under low greenschist facies conditions at the frictional-viscous transition. The vein is located in a high strain zone at the front of an imbricate stack of Caledonian age along the northwesternmost edge of the Repparfjord Tectonic Window in northern Norway. The vein was deformed within the Nussirjavrri Fault Zone (NFZ), an out-of-sequence thrust with a phyllonitic core characterized by a ramp-flat-ramp geometry, NNW plunging stretching lineations and top-to-the SSE thrusting kinematics. Deformation conditions are typical of the frictional-viscous transition. The phyllonitic core formed at the expense of metabasalt wherein feldspar broke down to form interconnected layers of fine, synkinematic phyllosilicates. In the mechanically weak framework of the phyllonite, the studied quartz vein acted as a relatively rigid body deforming mainly by coaxial strain. Viscous deformation, related to the development of a mesoscopic pervasive extensional crenulation cleavage, was accommodated within the vein initially by basal slip of suitably oriented quartz crystals, which produced e.g. undulose extinction, extinction bands and bulging grain boundaries. In the case of misoriented quartz crystals, however, glide-accommodated dislocation creep resulted soon inefficient and led to localized dislocation tangling and strain hardening. In response to 1) hardening, 2) progressive increase of fluid pressure within the actively deforming vein and 3) increasing competence contrast between the vein and the surrounding weak, foliated phyllonitic fault core, quartz crystals began to deform frictionally along specific lattice planes oriented optimally with respect to the imposed stress field. Microfaulting generated small volumes of gouge along

  6. Thorax deformity, joint hypermobility, and anxiety disorders.

    Gulsun, Murat; Yilmaz, Mehmet B; Pinar, Murat; Tonbul, Murat; Celik, Cemil; Ozdemir, Barbaros; Dumlu, Kemal; Erbas, Mevlut


    To evaluate the association between thorax deformities, panic disorder, and joint hypermobility The study includes 52 males diagnosed with thorax deformity, and 40 healthy male controls without thorax deformity, in Tatvan Bitlis and Isparta, Turkey. The study was carried out from 2004 to 2006. The teleradiographic and thoracic lateral images of the subjects were evaluated to obtain the Beighton scores; subjects' psychiatric conditions were evaluated using the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-1), and the Hamilton Anxiety Scale (HAM-A) was applied in order to determine the anxiety levels. Both the subjects and controls were compared in sociodemographic, anxiety levels, and joint mobility levels. In addition, males with joint hypermobility and thorax deformity were compared to the group with thorax deformity without joint hypermobility. A significant difference in HAM-A scores was found between the groups with thorax deformity and without. In addition, 21 subjects with thorax deformity met the joint hypermobility criteria in the group with thorax deformity, and 7 subjects without thorax deformity met the joint hypermobility criteria in the group without thorax deformity, according to Beighton scoring. The Beighton scores of the subjects with thorax deformity were significantly different from those of the group without deformity. Additionally, anxiety scores of the males with thorax deformity and joint hypermobility were found higher than males with thorax deformity without joint hypermobility. Anxiety disorders, particularly panic disorder, have a significantly higher distribution in male subjects with thorax deformity compared to the healthy control group. In addition, the anxiety level of males with thorax deformity and joint hypermobility is higher than males with thorax deformity without joint hypermobility.

  7. Fluid flow in extensional detachments determined from stable isotope analyses: Application to Kettle dome detachment, Washington, USA

    Quilichini, A.; Teyssier, C.; Mulch, A.; Nachlas, W.


    In detachment systems that border metamorphic core complexes fluids convect from the surface to the detachment along faults and fractures in the brittle crust that serve as zones of recharge and discharge. This buoyancy-driven fluid flow is controlled by a high heat flow at the base of the system, beneath the detachment, where heat is advected by crustal thinning and magma intrusions. This hydrothermal convective flow is focused in the detachment for the duration of activity of the detachment and at relatively high temperature (300-500°C), resulting in very significant fluid-rock interaction and isotopic exchange. Studies of detachments in the North American Cordilleran core complexes suggest that meteoric fluids permeate detachment zones, as recorded by the deuterium composition of hydrous phases such as white mica, biotite, and amphibole. Quantifying fluid flux in detachments is a challenge because permeability of ductilely deforming rocks is poorly understood. The approach we are using focuses on oxygen and hydrogen isotopes in quartzite (+ minor mica) sections of detachments, complemented by high-precision chemical analyses of mica to understand their growth history and recrystallization process. The initial fluid isotopic composition is approximated using the deuterium composition of mica at a particular temperature that is given by oxygen isotopes in quartz-mica pairs. The more fluid interact with the quartzite, the larger the expected shift in oxygen isotope value. The Eocene Kettle Dome detachment in the North American Cordillera provides a continuous section of ~200 m thick quartzite mylonite where this methodology is applied. High-resolution sampling (up to 5 m) complements the initial sampling that was performed every 10 m in this section (Mulch et al., 2006, Tectonics, TC4001). Based on mica deuterium values, the fluid that participated in mica crystallization was meteoric in origin (~110 per mil). Interaction of this fluid with the quartz mylonite

  8. Highly deformable bones: unusual deformation mechanisms of seahorse armor.

    Porter, Michael M; Novitskaya, Ekaterina; Castro-Ceseña, Ana Bertha; Meyers, Marc A; McKittrick, Joanna


    Multifunctional materials and devices found in nature serve as inspiration for advanced synthetic materials, structures and robotics. Here, we elucidate the architecture and unusual deformation mechanisms of seahorse tails that provide prehension as well as protection against predators. The seahorse tail is composed of subdermal bony plates arranged in articulating ring-like segments that overlap for controlled ventral bending and twisting. The bony plates are highly deformable materials designed to slide past one another and buckle when compressed. This complex plate and segment motion, along with the unique hardness distribution and structural hierarchy of each plate, provide seahorses with joint flexibility while shielding them against impact and crushing. Mimicking seahorse armor may lead to novel bio-inspired technologies, such as flexible armor, fracture-resistant structures or prehensile robotics.

  9. Prediction of deformity in spinal tuberculosis

    Jutte, Paul; Wuite, Sander; The, Bertram; van Altena, Richard; Veldhuizen, Albert


    Tuberculosis of the spine may cause kyphosis, which may in turn cause late paraplegia, respiratory compromise, and unsightly deformity. Surgical correction therefore may be considered for large or progressive deformities. We retrospectively analyzed clinical and radiographic parameters to predict th

  10. Depositional architecture of a mixed travertine-terrigenous system in a fault-controlled continental extensional basin (Messinian, Southern Tuscany, Central Italy)

    Croci, Andrea; Della Porta, Giovanna; Capezzuoli, Enrico


    The extensional Neogene Albegna Basin (Southern Tuscany, Italy) includes several thermogene travertine units dating from the Miocene to Holocene time. During the late Miocene (Messinian), a continental fault-controlled basin (of nearly 500-km2 width) was filled by precipitated travertine and detrital terrigenous strata, characterized by a wedge-shaped geometry that thinned northward, with a maximum thickness of nearly 70 m. This mixed travertine-terrigenous succession was investigated in terms of lithofacies types, depositional environment and architecture and the variety of precipitated travertine fabrics. Deposited as beds with thickness ranging from centimetres to a few decimetres, carbonates include nine travertine facies types: F1) clotted peloidal micrite and microsparite boundstone, F2) raft rudstone/floatstone, F3) sub-rounded radial coated grain grainstone, F4) coated gas bubble boundstone, F5) crystalline dendrite cementstone, F6) laminated boundstone, F7) coated reed boundstone and rudstone, F8) peloidal skeletal grainstone and F9) calci-mudstone and microsparstone. Beds of terrigenous deposits with thickness varying from a decimetre to > 10 m include five lithofacies: F10) breccia, F11) conglomerate, F12) massive sandstone, F13) laminated sandstone and F14) claystone. The succession recorded the following three phases of evolution of the depositional setting: 1) At the base, a northward-thinning thermogene travertine terraced slope (Phase I, travertine slope lithofacies association, F1-F6) developed close to the extensional fault system, placed southward with respect to the travertine deposition. 2) In Phase II, the accumulation of travertines was interrupted by the deposition of colluvial fan deposits with a thickness of several metres (colluvial fan lithofacies association, F10 and F12), which consisted of massive breccias, adjacent to the alluvial plain lithofacies association (F11-F14) including massive claystone and sandstone and channelized

  11. 非良基集合的外延公理%The Axioms of Extensionality of Non-Well-Founded Sets

    李娜; 杜文静


    In recent years, since non-well-founded sets have important applications in artifi-cial intelligence, cognitive science and philosophy, there has been a furry of interest in them. How to judge the identity of two objects is the fundamental question in set theory. How-ever, contrary to well founded sets, it is difficult to find the fundamental elements of non-well-founded sets. Thus the ordinary axiom of extensionality can not determine the equality of two non-well-founded sets, for example, the two sets x = {x} and y = {y}. In order to find a criterion to determine the equality of sets involving non-well-founded sets, we need something stronger than the ordinary axiom of extensionality. According to the four non-well-founded axioms (AFA, SAFA, FAFA, and BAFA) introduced by Aczel, we deduce four criteria for equality of non-well-founded sets. Furthermore, we illustrate how to use our criteria to determine the equality for two given non-well-founded sets by examples, so such problem of equality be-tween "circular sets" has been solved. In addition, we also account for that the four criteria are the extensions of the ordinary axiom of extensionality, not replacement of it. To this end, in this paper we first present some basic definitions and results of sets and graph; secondly, we discuss the four set universes A, S, F, and B determined respectively by four non-well-founded axioms AFA, SAFA, FAFA, and BAFA; lastly, we study the extension of the ordinary axiom of extensionality.%近年来,由于非良基集合在人工智能、认知科学及哲学等领域都有很重要的应用,它的研究越来越受到人们的关注.判断两个对象的同一性是集合论中最基本的问题,然而,与良基集合不同的是,非良基集合难以找到其最基本的组成成分,这样通常的外延公理就无法判断两个非良基集合(例如x={x}和y={y})相等.为了找到判断两个非良基集合相等的标准,我们必须强化

  12. Geochemical Relationships between Middle- to Upper-Crustal Exposures of the Alisitos Oceanic Arc (Baja California, Mexico): An Outstanding Field Analog to Active Extensional Oceanic Arcs

    Morris, R.; DeBari, S. M.; Busby, C.; Medynski, S.


    The southern volcano-bounded basin of the Rosario segment of the Cretaceous Alisitos oceanic arc provides outstanding 3-D exposures of an extensional arc, where crustal generation processes are recorded in the upper-crustal volcanic units and underlying middle-crustal plutonic rocks. Geochemical linkages between exposed crustal levels provide an analog for extensional arc systems such as the Izu-Bonin-Mariana (IBM) Arc. Upper-crustal units comprise a 3-5 km thick volcanic-volcaniclastic stratigraphy with hypabyssal intrusions. Deep-seated plutonic rocks intrude these units over a transition of overlap. The most mafic compositions occur in upper-crustal hypabyssal units, and as amphibole cumulates in the plutonic rocks ( 51% SiO2). The most felsic compositions occur in welded ignimbrites and a tonalite pluton ( 71% SiO2). All units are low K with flat REE patterns, and show LILE enrichment and HFSE depletion. Trace element ratios show limited variation throughout the crustal section. Zr/Y and Nb/Y ratios are similar to the Izu active ( 3 Ma to present) zone of extension immediately behind the arc front, suggesting comparable mantle melt % during extension. Th/Zr ratios are more enriched in Alisitos compared to Izu, suggesting greater subducted sediment input. The Alisitos crustal section shows a limited range in ɛNd (5.7-7.1), but a wider range in 87Sr/86Sr (0.7035-0.7055) and 206Pb/204Pb (18.12-19.12); the latter is likely alteration effects. Arc magmas were derived from a subduction-modified MORB mantle source, less depleted than Izu arc front and less enriched than the rear arc, but is a good match with the zone of extension that lies between. Differentiation occurred in a closed system (i.e., fractional crystallization/self-melting with back mixing), producing the entire crustal section in <3 Ma.

  13. Extensional and Colisional Magmatic Records in the Apiaí Terrane, South-Southeastern Brazil: Integration of Geochronological U-Pb Zircon Ages

    Oswaldo Siga Junior


    Full Text Available The aim of this work is the presentation of a synthesis of available geochronological data for the basement inliers andmetavolcano-sedimentary sequences which occur in the southern part of the Apiaí Terrane, south-southeastern Brazil.These data, especially those obtained during the last decade, have made substantial modifi cations to the tectonic scenarioof south-southeastern Brazil with the recognition of the presence of extensional basins (continental rifts with magmatismand sedimentation at the late Paleoproterozoic (1790 - 1750 Ma and of the Mesoproterozoic (1600 - 1450 Ma. Theseprocesses started at the late Paleoproterozoic in the Betara, Perau and Apiai Mirim Nuclei, and the basins became widerduring the Mesoproterozoic with the deposition of the Betara, Perau, Votuverava and Água Clara metavolcano-sedimentarysequences. A different pattern is found for the Itaicoca Sequence which occupies the northern part of the Apiaí Terrain.Here two rock associations of different ages are found. The fi rst is a metamorphosed carbonate platform association withsubalkaline, tholeiitic metabasic rocks with minimum deposition ages at the end of the Mesoproterozoic or beginning of theNeoproterozoic (Itaiacoca Sequence; 1030 - 900 Ma, while the second mainly contains metapsammites and metavolcanicrocks including ultrapotassic trachytes deposited during the Cryogenian-Ediacaran transition between 645 and 628 Ma(Abapã Sequence. It is then proposed that the present scenario of the Apiaí Terrane be representative of the distincttectono-sedimentary histories, refl ecting a polycyclic evolution. In the Mesoproterozoic, stable conditions prevailed, withthe deposition of the majority of the sequences (Lajeado, Água Clara, Betara, Perau, Votuverava in a passive margincontext, succeded by a Tonian extensional phase (deposition of the Itaiacoca Sequence. In the Ediacaran the region wastransformed into an unstable active margin, with the predominance of magmatic

  14. Estrategias de gestión del valor de marca de las cabeceras de prensa españolas a través de sus extensiones digitales



    Full Text Available Las marcas periodísticas encuentran en las plataformas digitales una gran oportunidad de mantener y aumentar el valor que tienen. Solo una minoría de empresas informativas tradicionales ha desarrollado estrategias de gestión de ese valor. Cuando las extensiones digitales no son coherentes con las marcas madre, pueden diluir su imagen y acabar siendo contraproducentes. Este artículo explora hasta qué punto las marcas de prensa utilizan sus extensiones digitales para aumentar su valor y cómo comunican su marca a través de ellas. La metodología escogida para ello es el análisis de contenidos de las ediciones online y de los perfiles en redes sociales de las 44 cabeceras más leídas en España. Los resultados indican que esas marcas no han explotado aún todo el potencial que las plataformas online tienen para ganar valor. Realizan solo una comunicación parcial de sí mismas y no han llevado a cabo algunas de las acciones que se consideran prioritarias en la gestión estratégica de la marca, tales como la definición de la identidad y la concreción de la misión. La discusión de los resultados permite proponer algunas estrategias de creación de valor de marca en las empresas informativas.

  15. Paleomagnetic and Anisotropy of Magnetic Susceptibility (AMS analyses of the Plio-Pleistocene extensional Todi basin, Central Italy

    L. Alfonsi


    Full Text Available In the last few years paleomagnetic investigations within the Apennine chain have revealed that the area is characterized by a complex pattern of deformation, not linkable to a simple and homogeneous process. In order to estimate the amount, sense and timing of vertical axis rotations within the Central Apennines, Neogene continental basins have been investigated for paleomagnetic studies. The paleomagnetic results obtained in the Plio-Pleistocene Todi basin showed that the Upper Pliocene-Lower Pleistocene evolution, associated with major dip-slip tectonics, has not involved vertical axis rotation since that time. The Anisotropy of Magnetic Susceptibility analysis (AMS, carried out on the same samples treated for paleomagnetic determination, revealed the presence of two groups of specimens characterized by different magnetic lineation directions. One direction trends NE-SW and is parallel to the orientation of the regional extension stress typical of the area. This direction is observed throughout the northern basin. The other, restricted to the southern basin, trends N-S and shows no links with the tectonic, hydrological-sedimentary conditions of the area. The results of the AMS analysis will be presented and discussed in the light of the rock magnetic results and the tectonic framework of the area.

  16. Protein transfer to membranes upon shape deformation

    Sagis, L.M.C.; Bijl, E.; Antono, L.; Ruijter, de N.C.A.; Valenberg, van H.J.F.


    Red blood cells, milk fat droplets, or liposomes all have interfaces consisting of lipid membranes. These particles show significant shape deformations as a result of flow. Here we show that these shape deformations can induce adsorption of proteins to the membrane. Red blood cell deformability is a

  17. Airborne Repeat Pass Interferometry for Deformation Measurements

    Groot, J.; Otten, M.; Halsema, E. van


    In ground engineering the need for deformation measurements is urgent. SAR interferometry can be used to measure small (sub-wavelength) deformations. An experiment to investigate this for dike deformations was set up, using the C-band SAR system PHARUS (PHased ARray Universal SAR). This paper descri

  18. Variational approach and deformed derivatives

    Weberszpil, J.; Helayël-Neto, J. A.


    Recently, we have demonstrated that there exists a possible relationship between q-deformed algebras in two different contexts of Statistical Mechanics, namely, the Tsallis' framework and the Kaniadakis' scenario, with a local form of fractional-derivative operators for fractal media, the so-called Hausdorff derivatives, mapped into a continuous medium with a fractal measure. Here, in this paper, we present an extension of the traditional calculus of variations for systems containing deformed-derivatives embedded into the Lagrangian and the Lagrangian densities for classical and field systems. The results extend the classical Euler-Lagrange equations and the Hamiltonian formalism. The resulting dynamical equations seem to be compatible with those found in the literature, specially with mass-dependent and with nonlinear equations for systems in classical and quantum mechanics. Examples are presented to illustrate applications of the formulation. Also, the conserved ​Noether current is worked out.

  19. Variational Approach and Deformed Derivatives

    Weberszpil, José


    Recently, we have demonstrated that there exists a possible relationship between q-deformed algebras in two different contexts of Statistical Mechanics, namely, the Tsallis' framework and the Kaniadakis' scenario, with a local form of fractional-derivative operators for fractal media, the so-called Hausdorff derivatives, mapped into a continuous medium with a fractal measure. Here, in this paper, we present an extension of the traditional calculus of variations for systems containing deformed-derivatives embedded into the Lagrangian and the Lagrangian densities for classical and field systems. The results extend the classical Euler-Lagrange equations and the Hamiltonian formalism. The resulting dynamical equations seem to be compatible with those found in the literature, specially with mass-dependent and with nonlinear equations for systems in classical and quantum mechanics. Examples are presented to illustrate applications of the formulation. Also, the conserved Nether current, are worked out.

  20. Molecular deformation mechanisms in polyethylene

    Coutry, S


    adjacent labelled stems is significantly larger when the DPE guest is a copolymer molecule. Our comparative studies on various types of polyethylene lead to the conclusion that their deformation behaviour under drawing has the same basis, with additional effects imputed to the presence of tie-molecules and branches. Three major points were identified in this thesis. The changes produced by drawing imply (1) the crystallisation of some of the amorphous polymer and the subsequent orientation of the newly formed crystals, (2) the re-orientation of the crystalline ribbons and (3) the beginning of crystallite break-up. However, additional effects were observed for the high molecular weight linear sample and the copolymer sample and were attributed, respectively, to the presence of tie-molecules and of branches. It was concluded that both the tie-molecules and the branches are restricting the molecular movement during deformation, and that the branches may be acting as 'anchors'. This work is concerned with details...

  1. Deformation quantization and Nambu mechanics

    Dito, G; Sternheimer, D; Takhtajan, L A; Dito, Giuseppe; Flato, Moshe; Sternheimer, Daniel; Takhtajan, Leon


    Starting from deformation quantization (star-products), the quantization problem of Nambu Mechanics is investigated. After considering some impossibilities and pushing some analogies with field quantization, a solution to the quantization problem is presented in what we call the Zariski quantization of fields (observables, functions, in this case polynomials). This quantization is based on the factorization over {\\Bbb R} of polynomials in several real variables. We quantize the algebra of fields generated by the polynomials by defining a deformation of this algebra which is Abelian, associative and distributive. This procedure is then adapted to derivatives (needed for the Nambu brackets), which ensures the validity of the Fundamental Identity of Nambu Mechanics also at the quantum level. Our construction is in fact more general than the particular case considered here: it can be utilized for quite general defining identities and for much more general star-products.

  2. Deformation of noncommutative quantum mechanics

    Jiang, Jian-Jian; Chowdhury, S. Hasibul Hassan


    In this paper, the Lie group GNC α , β , γ , of which the kinematical symmetry group GNC of noncommutative quantum mechanics (NCQM) is a special case due to fixed nonzero α, β, and γ, is three-parameter deformation quantized using the method suggested by Ballesteros and Musso [J. Phys. A: Math. Theor. 46, 195203 (2013)]. A certain family of QUE algebras, corresponding to GNC α , β , γ with two of the deformation parameters approaching zero, is found to be in agreement with the existing results of the literature on quantum Heisenberg group. Finally, we dualize the underlying QUE algebra to obtain an expression for the underlying star-product between smooth functions on GNC α , β , γ .

  3. Deformations of extremal toric manifolds

    Rollin, Yann


    Let $X$ be a compact toric extremal K\\"ahler manifold. Using the work of Sz\\'ekelyhidi, we provide a simple criterion on the fan describing $X$ to ensure the existence of complex deformations of $X$ that carry extremal metrics. As an example, we find new CSC metrics on 4-points blow-ups of $\\C\\P^1\\times\\C\\P^1$.

  4. Spinal deformities in tall girls.

    Skogland, L B; Steen, H; Trygstad, O


    In a prospective study, 62 girls who consulted the paediatric department because of tall stature were examined for spinal deformities. Thirteen cases of scoliosis measuring 10 degrees or more were found. Eighteen girls had a thoracic kyphosis of more than 40 degrees and 11 had additional vertebral abnormalities indicating Scheuermann's disease. The incidence of scoliosis and Scheuermann's disease was much higher in our material than normal.

  5. Constructal Hypothesis for Mechanical Deformation

    Atanu Chatterjee


    Full Text Available Mild Steel specimen, when subjected to tensile forces shows considerable plastic deformation before fracture. A cross-section of the fractured specimen has the familiar cup – cone form and shows traces of a three – dimensional parabolic geometry. The morphing of the steel specimen from a volume to a point as a spontaneous, entropy producing or energy dispersing process is analysed using the Constructal law.

  6. Deformation Driven Alloying and Transformation


    Rolling, Acta Materiala (08 2014) Zhe Wang , John H Perepezko, David Larson, David Reinhard. Mixing Behaviors in Cu/Ni and Ni/V Multilayers Cold Rolling, Journal of Alloys and Compounds (07 2014) Zhe Wang , John H. Perepezko. Deformation-Induced Nanoscale Mixing Reactions in Cu/Ni...FTE Equivalent: Total Number: Discipline Zhe Wang 0.50 0.50 1 Names of Post Doctorates Names of Faculty Supported Names of Under Graduate students

  7. Integrable Deformations of T -Dual σ Models

    Borsato, Riccardo; Wulff, Linus


    We present a method to deform (generically non-Abelian) T duals of two-dimensional σ models, which preserves classical integrability. The deformed models are identified by a linear operator ω on the dualized subalgebra, which satisfies the 2-cocycle condition. We prove that the so-called homogeneous Yang-Baxter deformations are equivalent, via a field redefinition, to our deformed models when ω is invertible. We explain the details for deformations of T duals of principal chiral models, and present the corresponding generalization to the case of supercoset models.

  8. Stochastic deformation of a thermodynamic symplectic structure

    Kazinski, P. O.


    A stochastic deformation of a thermodynamic symplectic structure is studied. The stochastic deformation is analogous to the deformation of an algebra of observables such as deformation quantization, but for an imaginary deformation parameter (the Planck constant). Gauge symmetries of thermodynamics and corresponding stochastic mechanics, which describes fluctuations of a thermodynamic system, are revealed and gauge fields are introduced. A physical interpretation to the gauge transformations and gauge fields is given. An application of the formalism to a description of systems with distributed parameters in a local thermodynamic equilibrium is considered.

  9. Loop-deformed Poincar\\'e algebra

    Mielczarek, Jakub


    In this essay we present evidence suggesting that loop quantum gravity leads to deformation of the local Poincar\\'e algebra within the limit of high energies. This deformation is a consequence of quantum modification of effective off-shell hypersurface deformation algebra. Surprisingly, the form of deformation suggests that the signature of space-time changes from Lorentzian to Euclidean at large curvatures. We construct particular realization of the loop-deformed Poincar\\'e algebra and find that it can be related to curved momentum space, which indicates the relationship with recently introduced notion of relative locality. The presented findings open a new way of testing loop quantum gravity effects.

  10. Quantification and validation of soft tissue deformation

    Mosbech, Thomas Hammershaimb; Ersbøll, Bjarne Kjær; Christensen, Lars Bager


    markers are easy to distinguish from the surrounding soft tissue in 3D computed tomography images. By tracking corresponding markers using methods from point-based registration, we are able to accurately quantify the magnitude and propagation of the induced deformation. The deformation is parameterised......We present a model for soft tissue deformation derived empirically from 10 pig carcases. The carcasses are subjected to deformation from a known single source of pressure located at the skin surface, and the deformation is quantified by means of steel markers injected into the tissue. The steel...

  11. Occurrence of oral deformities in larval anurans

    Drake, D.L.; Altig, R.; Grace, J.B.; Walls, S.C.


    We quantified deformities in the marginal papillae, tooth rows, and jaw sheaths of tadpoles from 13 population samples representing three families and 11 sites in the southeastern United States. Oral deformities were observed in all samples and in 13.5-98% of the specimens per sample. Batrachochytrium dendrobatidis (chytrid) infections were detected in three samples. There was high variability among samples in the pattern and number of discovered deformities. Pairwise associations between oral structures containing deformities were nonrandom for several populations, especially those with B. dendrobatidis infections or high total numbers of deformities. Comparisons of deformities among samples using multivariate analyses revealed that tadpole samples grouped together by family. Analyses of ordination indicated that three variables, the number of deformities, the number of significant associations among deformity types within populations, and whether populations were infected with B. dendrobatidis, were significantly correlated with the pattern of deformities. Our data indicate that the incidence of oral deformities can be high in natural populations and that phylogeny and B. dendrobatidis infection exert a strong influence on the occurrence and type of oral deformities in tadpoles. ?? by the American Society of Ichthyologists and Herperologists.

  12. Helium release during shale deformation: Experimental validation

    Bauer, Stephen J.; Gardner, W. Payton; Heath, Jason E.


    This work describes initial experimental results of helium tracer release monitoring during deformation of shale. Naturally occurring radiogenic 4He is present in high concentration in most shales. During rock deformation, accumulated helium could be released as fractures are created and new transport pathways are created. We present the results of an experimental study in which confined reservoir shale samples, cored parallel and perpendicular to bedding, which were initially saturated with helium to simulate reservoir conditions, are subjected to triaxial compressive deformation. During the deformation experiment, differential stress, axial, and radial strains are systematically tracked. Release of helium is dynamically measured using a helium mass spectrometer leak detector. Helium released during deformation is observable at the laboratory scale and the release is tightly coupled to the shale deformation. These first measurements of dynamic helium release from rocks undergoing deformation show that helium provides information on the evolution of microstructure as a function of changes in stress and strain.

  13. Long-term and seasonal ground deformation in the Santa Clara Valley, California, revealed by multi decadal InSAR time series

    Chaussard, E.; Burgmann, R.; Shirzaei, M.; Baker, B.


    The Santa Clara Valley, California, is a shallow basin located between the San Andreas and Hayward-Calaveras fault zones. The Valley is known to experience land subsidence and uplift related to groundwater extraction and recharge. We use Small Baseline (SB) Interferometric Synthetic Aperture Radar (InSAR) time series to precisely map time-dependent ground deformation at the scale of the basin, relying on data sets from 4 satellites (ERS1, ERS2, Envisat, and ALOS1) to cover a twenty-year time period (1992-2012). The ground deformation map produced provides constraints on the lateral distribution of water-bearing units in the valley, information that is critical to effectively manage groundwater resources, and on the areas more likely to experience subsidence related ground deformation or flooding. Multi-year and seasonal time-series reveal different ground deformation patterns. Long-term uplift at few millimeters per year dominates east of the Silver Creek fault (SCF) and likely relates to the poroelastic response of the confined aquifer to recovery of groundwater levels since the 1960s. In contrast seasonal uplift and subsidence in winter and summer, respectively, dominate west of the SCF, near San Jose. We compare the InSAR derived deformation to precipitation and well data to explain this seasonal variability. The differential subsidence across the SCF indicates that the fault partitions the shallow confined aquifer and was likely active since the deposition of these Holocene sediments. Relying on the multiple viewing geometries from the different spacecraft we isolate a narrow band of horizontal deformation in the immediate vicinity of the SCF. This zone of high extensional strain is due to the localized differential subsidence and is likely to experience fissuring.

  14. Leukocyte deformability: finite element modeling of large viscoelastic deformation.

    Dong, C; Skalak, R


    An axisymmetric deformation of a viscoelastic sphere bounded by a prestressed elastic thin shell in response to external pressure is studied by a finite element method. The research is motivated by the need for understanding the passive behavior of human leukocytes (white blood cells) and interpreting extensive experimental data in terms of the mechanical properties. The cell at rest is modeled as a sphere consisting of a cortical prestressed shell with incompressible Maxwell fluid interior. A large-strain deformation theory is developed based on the proposed model. General non-linear, large strain constitutive relations for the cortical shell are derived by neglecting the bending stiffness. A representation of the constitutive equations in the form of an integral of strain history for the incompressible Maxwell interior is used in the formulation of numerical scheme. A finite element program is developed, in which a sliding boundary condition is imposed on all contact surfaces. The mathematical model developed is applied to evaluate experimental data of pipette tests and observations of blood flow.

  15. Transient deformation of karst aquifers due to seasonal and multiyear groundwater variations observed by GPS in southern Apennines (Italy)

    Silverii, Francesca; D'Agostino, Nicola; Métois, Marianne; Fiorillo, Francesco; Ventafridda, Gerardo


    We present GPS, hydrological, and GRACE (Gravity Recovery and Climate Experiment) observations in southern Apennines (Italy) pointing to a previously unnoticed response of the solid Earth to hydrological processes. Transient patterns in GPS horizontal time series near to large karst aquifers are controlled by seasonal and interannual phases of groundwater recharge/discharge of karst aquifers, modulating the extensional ˜3 mm/yr strain within the tectonically active Apennines. We suggest that transient signals are produced, below the saturation level of the aquifers and above a poorly constrained depth in the shallow crust, by time-dependent opening of subvertical, fluid-filled, conductive fractures. We ascribe this process to the immature karstification and intense tectonic fracturing, favoring slow groundwater circulation, and to multiyear variations of the water table elevation, influenced by variable seasonal recharge. The vertical component displays seasonal and multiyear signals more homogeneously distributed in space and closely correlated with estimates of total water storage from GRACE, reflecting the elastic response of the lithosphere to variations of surface water loads. The different sensitivities of vertical and horizontal components to the hydrologically induced deformation processes allow us to spatially and temporally resolve the different phases of the water cycle, from maximum hydrological loading at the surface to maximum hydrostatic pressure beneath karst aquifers. Finally, we suggest that transient deformation signals in the geodetic series of the Apennines are correlated to large-scale climatic patterns (Northern Atlantic Oscillation) through their influence on precipitation variability and trends at the regional scale.

  16. Propagating Atlantic rifts and Pacific slabs battle it out in the Arctic: A summary of extensional provinces in the Alaskan-Russian Arctic

    Miller, E. L.; Dumitru, T.; Brumley, K.; Gottlieb, E.; Meisling, K.; Akinin, V.


    Relevant data are compiled and synthesized across Arctic Alaska and Russia with the goal of establishing spatial and temporal connections between rifting in the Eurasia and Amerasia basins of the Arctic Ocean and extension within the circum-Arctic landmasses. Although timing, direction and magnitude of continental extension are still poorly known, geochronologic and thermochronologic studies have proven to be an excellent means of bracketing extension-related tilting, uplift and denudation (e.g. Brooks Range, Seward Peninsula, Lisburne Hills and Wrangel Island). The south flank of the Brooks Range, Seward Peninsula, Bering Strait, Chukotka and Wrangel Island all underwent large magnitude N-S extension that regionally overlaps in age with the intrusion of 120-90 Ma plutons and the formation of deep marine basins in Alaska. This widespread extension is traditionally attributed to paleo-Pacific slab rollback following Jura-Cretaceous (~160-140?Ma) convergence and shortening. Westward across Chukotka, extensional (and strike-slip?) structures were also coeval with ~120-90 Ma magmatism, but are more poorly documented. By contrast, extensional structures west of longitude 175° in Chukotka (and offshore Siberian Shelf) appear to have developed in response to E-W, rather than N-S extension. The South Annui Zone and its inferred continuation to the Siberian Islands appears to separate (by ~1300 km) similar sequences with identical source regions, suggesting right-lateral transform or accommodation of E-W to WNW-ESE extension to the north. Its motion was likely over by the ~88-90 Ma eruption of the Okhotsk-Chukotka volcanic belt, linked to the reconfiguration of paleo-Pacific subduction. Large ~E-W trending shelfal basins in the Bering Strait region formed in latest Cretaceous (?) to early Tertiary (N. and S. Chukchi, Hope, Norton, Anadyr and St. Matthew basins). In Siberia, N-S trending extensional structures of the Laptev Sea are related to southward propagation of Gakkel

  17. Gradient Domain Mesh Deformation - A Survey

    Wei-Wei Xu; Kun Zhou


    This survey reviews the recent development of gradient domain mesh deformation method. Different to other deformation methods, the gradient domain deformation method is a surface-based, variational optimization method. It directly encodes the geometric details in differential coordinates, which are also called Laplacian coordinates in literature. By preserving the Laplacian coordinates, the mesh details can be well preserved during deformation. Due to the locality of the Laplacian coordinates, the variational optimization problem can be casted into a sparse linear system. Fast sparse linear solver can be adopted to generate deformation result interactively, or even in real-time. The nonlinear nature of gradient domain mesh deformation leads to the development of two categories of deformation methods: linearization methods and nonlinear optimization methods. Basically, the linearization methods only need to solve the linear least-squares system once. They are fast, easy to understand and control, while the deformation result might be suboptimal. Nonlinear optimization methods can reach optimal solution of deformation energy function by iterative updating. Since the computation of nonlinear methods is expensive, reduced deformable models should be adopted to achieve interactive performance. The nonlinear optimization methods avoid the user burden to input transformation at deformation handles, and they can be extended to incorporate various nonlinear constraints, like volume constraint, skeleton constraint, and so on. We review representative methods and related approaches of each category comparatively and hope to help the user understand the motivation behind the algorithms. Finally, we discuss the relation between physical simulation and gradient domain mesh deformation to reveal why it can achieve physically plausible deformation result.

  18. Plate boundary deformation at the latitude of the Salton Trough - northern Gulf of California (Invited)

    Stock, J. M.


    Along the Pacific-North America plate boundary zone, the segment including the southern San Andreas fault to Salton Trough and northern Gulf of California basins has been transtensional throughout its evolution, based on Pacific-North America displacement vectors calculated from the global plate circuit (900 × 20 km at N54°W since 20 Ma; 460 × 20 km at N48°W since 11 Ma). Nevertheless, active seismicity and focal mechanisms show a broad zone of plate boundary deformation within which the inferred stress regime varies locally (Yang & Hauksson 2013 GJI), and fault patterns in some regions suggest ongoing tectonic rotation. Similar behavior is inferred to have occurred in this zone over most of its history. Crustal structure in this region is constrained by surface geology, geophysical experiments (e.g., the 2011 Salton Seismic Imaging Project (SSIP), USGS Imperial Valley 1979, PACE), and interdisciplinary marine and onland studies in Mexico (e.g., NARS-Baja, Cortes, and surveys by PEMEX). Magnetic data (e.g., EMAG-2) aids in the recognition of large-scale crustal provinces and fault boundaries in regions lacking detailed geophysical surveys. Consideration of existing constraints on crustal thickness and architecture, and fault and basin evolution suggests that to reconcile geological deformation with plate motion history, the following additional factors need to be taken into account. 1) Plate boundary displacement via interacting systems of rotating blocks, coeval with slip on steep strike slip faults, and possibly related to slip on low angle extensional faults (e.g, Axen & Fletcher 1998 IGR) may be typical prior to the onset of seafloor spreading. This fault style may have accommodated up to 150 km of plate motion in the Mexican Continental Borderland and north of the Vizcaino Peninsula, likely between 12 and 15 Ma, as well as explaining younger rotations adjacent to the Gulf of California and current deformation southwest of the Salton Sea. 2) Geophysical

  19. A two-dimensional deformable phantom for quantitatively verifying deformation algorithms

    Kirby, Neil; Chuang, Cynthia; Pouliot, Jean [Department of Radiation Oncology, University of California San Francisco, San Francisco, California 94143-1708 (United States)


    Purpose: The incorporation of deformable image registration into the treatment planning process is rapidly advancing. For this reason, the methods used to verify the underlying deformation algorithms must evolve equally fast. This manuscript proposes a two-dimensional deformable phantom, which can objectively verify the accuracy of deformation algorithms, as the next step for improving these techniques. Methods: The phantom represents a single plane of the anatomy for a head and neck patient. Inflation of a balloon catheter inside the phantom simulates tumor growth. CT and camera images of the phantom are acquired before and after its deformation. Nonradiopaque markers reside on the surface of the deformable anatomy and are visible through an acrylic plate, which enables an optical camera to measure their positions; thus, establishing the ground-truth deformation. This measured deformation is directly compared to the predictions of deformation algorithms, using several similarity metrics. The ratio of the number of points with more than a 3 mm deformation error over the number that are deformed by more than 3 mm is used for an error metric to evaluate algorithm accuracy. Results: An optical method of characterizing deformation has been successfully demonstrated. For the tests of this method, the balloon catheter deforms 32 out of the 54 surface markers by more than 3 mm. Different deformation errors result from the different similarity metrics. The most accurate deformation predictions had an error of 75%. Conclusions: The results presented here demonstrate the utility of the phantom for objectively verifying deformation algorithms and determining which is the most accurate. They also indicate that the phantom would benefit from more electron density heterogeneity. The reduction of the deformable anatomy to a two-dimensional system allows for the use of nonradiopaque markers, which do not influence deformation algorithms. This is the fundamental advantage of this

  20. Deformation-specific and deformation-invariant visual object recognition: pose vs identity recognition of people and deforming objects

    Tristan J Webb


    Full Text Available When we see a human sitting down, standing up, or walking, we can recognise one of these poses independently of the individual, or we can recognise the individual person, independently of the pose. The same issues arise for deforming objects. For example, if we see a flag deformed by the wind, either blowing out or hanging languidly, we can usually recognise the flag, independently of its deformation; or we can recognise the deformation independently of the identity of the flag. We hypothesize that these types of recognition can be implemented by the primate visual system using temporo-spatial continuity as objects transform as a learning principle. In particular, we hypothesize that pose or deformation can be learned under conditions in which large numbers of different people are successively seen in the same pose, or objects in the same deformation. We also hypothesize that person-specific representations that are independent of pose, and object-specific representations that are independent of deformation and view, could be built, when individual people or objects are observed successively transforming from one pose or deformation and view to another. These hypotheses were tested in a simulation of the ventral visual system, VisNet, that uses temporal continuity, implemented in a synaptic learning rule with a short-term memory trace of previous neuronal activity, to learn invariant representations. It was found that depending on the statistics of the visual input, either pose-specific or deformation-specific representations could be built that were invariant with respect to individual and view; or that identity-specific representations could be built that were invariant with respect to pose or deformation and view. We propose that this is how pose-specific and pose-invariant, and deformation-specific and deformation-invariant, perceptual representations are built in the brain.

  1. Revealing Hidden Deformation Sources in New Zealand: a Novel Inversion of GPS Data for Non-Prescriptive Physics-Based Surface Forces and High-Precision Strain Rates

    Dimitrova, L. L.; Haines, A. J.; Wallace, L. M.; Williams, C. A.


    Monitoring strain accumulation in active deformation zones is vital for studying and preparing for earthquake hazards. New Zealand straddles the complicated boundary between the obliquely converging Australian and Pacific plates. The motion is accommodated largely along the Alpine Fault in the south, through the Marlborough fault system and onto the Hikurangi trench in the north. In addition, a significant component of the motion is distributed on smaller, poorly characterized faults. Dimitrova et al. (2012) showed that the vertical derivatives of horizontal stress (VDoHS) rates are a substantially higher resolution expression of subsurface sources of ongoing deformation than the GPS velocities or GPS derived strain rates. We expand this method to solve the horizontal force balance equations for the VDoHS in 2-D to obtain the highest possible resolution picture of the surface deformation pattern in New Zealand. We invert GPS data from campaign GPS observations spanning from 1995 to 2012 for the VDoHS that best fit the GPS velocities, without prescribing sources or zones of deformation, while fully accounting for the physics of the problem. Using the VDoHS rates we identify (1) areas of deformation due to well-known active faults, (2) areas of poorly characterized deformation, e.g. deformation along faults without slip rate information mapped from palaeo-seismicity, (3) areas of previously unknown deformation, potentially on hidden faults, and (4) areas undergoing post-seismic deformation. The VDoHS are integrated to produce the highest resolution to-date maps of strain rates. We identify an area of extensional areal strain between the Alpine fault and the Main Divide of the central Southern Alps indicating possible gravitational collapse of the Southern Alps. Relationships between the VDoHS and strain rates allow us to calculate the variation in fault slip rate and locking depth for the identified faults, and we show selected results for the Alpine Fault and the

  2. Geodetic deformation Across the Central Apennines from GPS Data in the time span 1999-2003

    F. Loddo


    Full Text Available Abstract During the time span 1999-2003 was set up and repeatedly surveyed a not permanent GPS network located across one of the highest seismic areas of the central Apennines (Italy. The Central Apennine Geodetic Network (CA-GeoNet, extends across Umbria, Abruzzo, Marche and Lazio regions, in an area of ?180x130 km, from Tyrrhenian to the Adriatic sea. It consists in 125 GPS stations distributed at 3-5 km average grid and includes 7 permanent GPS stations operated by the Italian Space Agency (ASI and the Istituto Nazionale di Geofisica and Vulcanologia (INGV. With the aim to estimate the active strain rate across this part of the chain, the GPS sites have been located on the main geological units of the area and across the typical basin and range structures, related with the main seismogenic faults. In this paper we show the network and the first results obtained for a subset of 23 stations that have been occupied at least during three repeated campaigns, in the time span 1999-2003. Data analysis, performed by Bernese 4.2 software, shows an extensional rate normal to the chain, in agreement with geological and seismic data. The strain rates in the inner chain are ranging from 12x10-9±11yr-1 to 16x10-9±11yr-1 and from -14x10-9±11yr-1 to -3x10-9±11yr-1. This result provides an improved estimation of the ongoing deformation of this area with respect to previous studies and is in agreement with the style of deformation inferred from seismicity and with the features of the main seismogenic sources from recent geological and seismological investigations.

  3. Deformable Registration of Digital Images

    管伟光; 解林; 等


    is paper proposes a novel elastic model and presents a deformable registration method based on the model.The method registers images without the need to extract reatures from the images,and therefore works directly on grey-level images.A new similarity metric is given on which the formation of external forces is based.The registration method,taking the coarse-to-fine strategy,constructs external forces in larger scales for the first few iterations to rely more on global evidence,and ther in smaller scales for later iterations to allow local refinements.The stiffness of the elastic body decreases as the process proceeds.To make it widely applicable,the method is not restricted to any type of transformation.The variations between images are thought as general free-form deformations.Because the elastic model designed is linearized,it can be solved very efficiently with high accuracy.The method has been successfully tested on MRI images.It will certainly find other uses such as matching time-varying sequences of pictures for motion analysis,fitting templates into images for non-rigid object recognition,matching stereo images for shape recovery,etc.

  4. Physics of Deformed Special Relativity

    Girelli, F; Girelli, Florian; Livine, Etera R.


    In many different ways, Deformed Special Relativity (DSR) has been argued to provide an effective limit of quantum gravity in almost-flat regime. Unfortunately DSR is up to now plagued by many conceptual problems (in particular how it describes macroscopic objects) which forbids a definitive physical interpretation and clear predictions. Here we propose a consistent framework to interpret DSR. We extend the principle of relativity: the same way that Special Relativity showed us that the definition of a reference frame requires to specify its speed, we show that DSR implies that we must also take into account its mass. We further advocate a 5-dimensional point of view on DSR physics and the extension of the kinematical symmetry from the Poincare group to the Poincare-de Sitter group (ISO(4,1)). This leads us to introduce the concept of a pentamomentum and to take into account the renormalization of the DSR deformation parameter kappa. This allows the resolution of the "soccer ball problem" (definition of many-...

  5. Effect of body deformability on microswimming

    Pande, Jayant; Krüger, Timm; Harting, Jens; Smith, Ana-Sunčana


    In this work we consider the following question: given a mechanical microswimming mechanism, does increased deformability of the swimmer body hinder or promote the swimming? To answer this we run immersed boundary lattice Boltzmann simulations of a microswimmer comprised of three vesicular beads connected by springs and increase systematically the deformability of the beads. We impose the forces driving the motion and allow the swimming stroke to emerge on its own. The simulations show that both `deformability-enhanced' and `deformability-hindered' regimes of microswimming exist. To understand the occurrence of these regimes, we assume a model where the amplitudes of the surface oscillations of the beads in the swimmer are much smaller than the other length scales. This results in only the driving frequency mode of the surface deformations contributing to the velocity. The theory predicts that the dominant elasticity of the swimming mechanism dictates the deformability-based regime in which the swimming occur...

  6. Deformation Models Tracking, Animation and Applications

    Torres, Arnau; Gómez, Javier


    The computational modelling of deformations has been actively studied for the last thirty years. This is mainly due to its large range of applications that include computer animation, medical imaging, shape estimation, face deformation as well as other parts of the human body, and object tracking. In addition, these advances have been supported by the evolution of computer processing capabilities, enabling realism in a more sophisticated way. This book encompasses relevant works of expert researchers in the field of deformation models and their applications.  The book is divided into two main parts. The first part presents recent object deformation techniques from the point of view of computer graphics and computer animation. The second part of this book presents six works that study deformations from a computer vision point of view with a common characteristic: deformations are applied in real world applications. The primary audience for this work are researchers from different multidisciplinary fields, s...

  7. Deformations of three-dimensional metrics

    Pugliese, Daniela; Stornaiolo, Cosimo


    We examine three-dimensional metric deformations based on a tetrad transformation through the action the matrices of scalar field. We describe by this approach to deformation the results obtained by Coll et al. (Gen. Relativ. Gravit. 34:269, 2002), where it is stated that any three-dimensional metric was locally obtained as a deformation of a constant curvature metric parameterized by a 2-form. To this aim, we construct the corresponding deforming matrices and provide their classification according to the properties of the scalar and of the vector used in Coll et al. (Gen Relativ Gravit 34:269, 2002) to deform the initial metric. The resulting causal structure of the deformed geometries is examined, too. Finally we apply our results to a spherically symmetric three geometry and to a space sector of Kerr metric.

  8. Deformable mirrors development program at ESO

    Stroebele, Stefan; Vernet, Elise; Brinkmann, Martin; Jakob, Gerd; Lilley, Paul; Casali, Mark; Madec, Pierre-Yves; Kasper, Markus


    Over the last decade, adaptive optics has become essential in different fields of research including medicine and industrial applications. With this new need, the market of deformable mirrors has expanded a lot allowing new technologies and actuation principles to be developed. Several E-ELT instruments have identified the need for post focal deformable mirrors but with the increasing size of the telescopes the requirements on the deformable mirrors become more demanding. A simple scaling up of existing technologies from few hundred actuators to thousands of actuators will not be sufficient to satisfy the future needs of ESO. To bridge the gap between available deformable mirrors and the future needs for the E-ELT, ESO started a development program for deformable mirror technologies. The requirements and the path to get the deformable mirrors for post focal adaptive optics systems for the E-ELT is presented.

  9. Structural, Ams and Paleomagnetic Data On Plio-pleistocene Sedimentary Basins In Eastern Sicily: Deformative Pattern In A Back Arc, Foredeep To Foreland System

    Cifelli, F.; Mattei, M.; Rossetti, F.; Hirt, A. M.; Funiciello, R.

    We present results from an integrated structural, anisotropy of magnetic susceptibility (AMS), and paleomagnetic study on Plio-Pleistocene sedimentary basins in Eastern Sicily. These basins belong to three main tectonic domains, from north to south: the Tyrrhenian extensional hinterland domain, the Quaternary compressional foredeep do- main, and the Hyblean foreland domain. We sampled 310 oriented cylindrical samples from 23 sites in selected areas from the different tectonic domains. The AMS is typical for weakly deformed sediments, with a magnetic foliation sub-parallel to the bedding plane, and a well-defined magnetic lineation. The orientation of the magnetic lineation is controlled by the main tectonic deformation in the basins, where it is always par- allel to the extensional direction obtained by fault-slip and joint analyses. Structural and AMS data define a transition from NW-SE extension in the Tyrrhenian hinter- land domain, to E-W compression in the Catania foredeep domain, to E-W extension Hyblean foreland domain, respectively. The latter is mainly controlled by Quaternary activity of the Malta escarpment. Reliable paleomagnetic results have been obtained in 12 out of 23 sampled sites, since most of the Pliocene sites are poor recorders of the earth's magnetic field. A positive fold test indicates that the characteristic remanence directions are primary, and that no significant rotations occurred in any of the studied basins since the middle Pleistocene. These data allow us to define an upper limit to the large rotations about vertical axes that have been found in Calabria and in regions of Sicily.

  10. 3D geodetic monitoring slope deformations

    Weiss Gabriel


    Full Text Available For plenty of slope failures that can be found in Slovakia is necessary and very important their geodetic monitoring (because of their activity, reactivisations, checks. The paper gives new methodologies for these works, using 3D terrestrial survey technologies for measurements in convenient deformation networks. The design of an optimal type of deformation model for various kinds of landslides and their exact processing with an efficient testing procedure to determine the kinematics of the slope deformations are presented too.

  11. Smooth Crossed Products of Rieffel's Deformations

    Neshveyev, Sergey


    Assume is a Fréchet algebra equipped with a smooth isometric action of a vector group V, and consider Rieffel's deformation of . We construct an explicit isomorphism between the smooth crossed products and . When combined with the Elliott-Natsume-Nest isomorphism, this immediately implies that the periodic cyclic cohomology is invariant under deformation. Specializing to the case of smooth subalgebras of C*-algebras, we also get a simple proof of equivalence of Rieffel's and Kasprzak's approaches to deformation.

  12. Deformation effects in Giant Monopole Resonance

    Kvasil, J; Repko, A; Bozik, D; Kleinig, W; Reinhard, P -G


    The isoscalar giant monopole resonance (GMR) in Samarium isotopes (from spherical $^{144}$Sm to deformed $^{148-154}$Sm) is investigated within the Skyrme random-phase-approximation (RPA) for a variety of Skyrme forces. The exact RPA and its separable version (SRPA) are used for spherical and deformed nuclei, respectively. The quadrupole deformation is shown to yield two effects: the GMR broadens and attains a two-peak structure due to the coupling with the quadrupole giant resonance.

  13. Integrable Deformations of the XXZ Spin Chain

    Beisert, Niklas; de Leeuw, Marius; Loebbert, Florian


    We consider integrable deformations of the XXZ spin chain for periodic and open boundary conditions. In particular, we classify all long-range deformations and study their impact on the spectrum. As compared to the XXX case, we have the z-spin at our disposal, which induces two additional deformations: the short-range magnetic twist and a new long-range momentum-dependent twist.

  14. Deformed self-dual magnetic monopoles

    Bazeia, D. [Departamento de Física, Universidade Federal da Paraíba, 58051-900, João Pessoa, Paraíba (Brazil); Departamento de Física, Universidade Federal de Campina Grande, 58109-970, Campina Grande (Brazil); Casana, R.; Ferreira, M.M. [Departamento de Física, Universidade Federal do Maranhão, 65085-580, São Luís, Maranhão (Brazil); Hora, E. da, E-mail: [Departamento de Física, Universidade Federal do Maranhão, 65085-580, São Luís, Maranhão (Brazil); Coordenadoria do Curso Interdisciplinar em Ciência e Tecnologia, Universidade Federal do Maranhão, 65080-805, São Luís, Maranhão (Brazil); Losano, L. [Departamento de Física, Universidade Federal da Paraíba, 58051-900, João Pessoa, Paraíba (Brazil); Departamento de Física, Universidade Federal de Campina Grande, 58109-970, Campina Grande (Brazil)


    We develop a deformation method for attaining new magnetic monopole analytical solutions consistent with generalized Yang–Mills–Higgs model introduced recently. The new solutions fulfill the usual radially symmetric ansatz and the boundary conditions suitable to assure finite energy configurations. We verify our prescription by studying some particular cases involving both exactly and partially analytical initial configurations whose deformation leads to new analytic BPS monopoles. The results show consistency among the models, the deformation procedure and the profile of the new solutions.

  15. Deformed self-dual magnetic monopoles

    Bazeia, D; Ferreira, M M; da Hora, E; Losano, L


    We develop a deformation method for attaining new magnetic monopole analytical solutions consistent with generalized Yang-Mills-Higgs model introduced recently. The new solutions fulfill the usual radially symmetric ansatz and the boundary conditions suitable to assure finite energy configurations. We verify our prescription by studying some particular cases involving both exactly and partially analytical initial configurations whose deformation leads to new analytic BPS monopoles. The results show consistency among the models, the deformation procedure and the profile of the new solutions.

  16. Deformed self-dual magnetic monopoles

    Bazeia, D.; Casana, R.; Ferreira, M. M.; da Hora, E.; Losano, L.


    We develop a deformation method for attaining new magnetic monopole analytical solutions consistent with generalized Yang-Mills-Higgs model introduced recently. The new solutions fulfill the usual radially symmetric ansatz and the boundary conditions suitable to assure finite energy configurations. We verify our prescription by studying some particular cases involving both exactly and partially analytical initial configurations whose deformation leads to new analytic BPS monopoles. The results show consistency among the models, the deformation procedure and the profile of the new solutions.

  17. Deformation Twinning During Nanoindentation of Nanocrystalline Ta

    Wang, Y. M.; Hodge, A. M.; Biener, J.; Hamza, A.V.; Barnes, D E; Liu, Kai; Nieh, T. G.


    The deformation mechanism of body-centered cubic (bcc) nanocrystalline tantalum with grain sizes of 10–30 nm is investigated by nanoindentation, scanning electron microscopy and high-resolution transmission electron microscopy. In a deviation from molecular dynamics simulations and existing experimental observations on other bcc nanocrystalline metals, the plastic deformation of nanocrystalline Ta during nanoindentation is controlled by deformation twinning. The observation of multiple twin i...

  18. Self-adjointness of deformed unbounded operators

    Much, Albert [Instituto de Ciencias Nucleares, UNAM, México D.F. 04510 (Mexico)


    We consider deformations of unbounded operators by using the novel construction tool of warped convolutions. By using the Kato-Rellich theorem, we show that unbounded self-adjoint deformed operators are self-adjoint if they satisfy a certain condition. This condition proves itself to be necessary for the oscillatory integral to be well-defined. Moreover, different proofs are given for self-adjointness of deformed unbounded operators in the context of quantum mechanics and quantum field theory.

  19. Post-collisional deformation of the Anatolides and motion of the Arabian indenter: A paleomagnetic analysis

    Piper, J [Geomagnetism Laboratory, Department of Earth and Ocean Sciences, University of Liverpool, Liverpool, L69 7ZE (United Kingdom); Tatar, O; Gursoy, H; Mesci, B L; Kocbulut, F [Department of Geology, Cumhuriyet University, 58140 Sivas (Turkey); Huang, B [Palaeomagnetism and Geochronology Laboratory, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing (China)], E-mail:


    Neotectonic era is refuted. Instead, deformation has been distributed and differential as the collage has adapted to changing tectonic regimes. Crustal extrusion to the west and south has expanded the curvature of the Tauride Arc and combined with retreat of the Hellenic Arc to produce the extensional horst and graben province in western Turkey. A challenge of present work is to resolve the temporal framework of tectonic rotation. Evidence from the Cappadocian volcanic province and Sivas Basin in central Anatolia indicates that rotation has been concentrated within the last 2-3 million years of the neotectonic era and therefore correlates with establishment of the intracontinental transform framework. Thus we recognise two phases to the evolution of this sector of the orogen: the first embraces crustal thickening and uplift with initiation defined specifically by transition from marine to terrestrial deposition in the Serravallian at {approx}12 Ma, and the second embraces crustal extrusion to the west motivated by continuing northward movement of Arabia and roll back on the Hellenic Arc since late Pliocene times. Latitudinal motions detected by paleomagnetism are close to confidence limits and consistent with small northward motion of the Anatolides since Eocene times including up to a few hundred km of closure linked to crustal thickening since the demise of NeoTethys. The driving motion from the Arabian indenter can be partially resolved from the widespread basaltic volcanism that occurred along the periphery of the Arabian Shield at 12-18 Ma during final stages of collision along the Bitlis Suture. This defines CCW rotation of 13-21{sup 0} with respect to Eurasia. An average CCW rotation of 0.9{sup 0}/Myr since closure of the Bitlis Suture in mid-Miocene times is unlikely to have been uniform because it has been linked to three adjoining interactions namely episodic opening of the Red Sea, a transition from crustal thickening to tectonic escape in the Anatolian collage and

  20. Learning a hierarchical deformable template for rapid deformable object parsing.

    Zhu, Long Leo; Chen, Yuanhao; Yuille, Alan


    In this paper, we address the tasks of detecting, segmenting, parsing, and matching deformable objects. We use a novel probabilistic object model that we call a hierarchical deformable template (HDT). The HDT represents the object by state variables defined over a hierarchy (with typically five levels). The hierarchy is built recursively by composing elementary structures to form more complex structures. A probability distribution--a parameterized exponential model--is defined over the hierarchy to quantify the variability in shape and appearance of the object at multiple scales. To perform inference--to estimate the most probable states of the hierarchy for an input image--we use a bottom-up algorithm called compositional inference. This algorithm is an approximate version of dynamic programming where approximations are made (e.g., pruning) to ensure that the algorithm is fast while maintaining high performance. We adapt the structure-perceptron algorithm to estimate the parameters of the HDT in a discriminative manner (simultaneously estimating the appearance and shape parameters). More precisely, we specify an exponential distribution for the HDT using a dictionary of potentials, which capture the appearance and shape cues. This dictionary can be large and so does not require handcrafting the potentials. Instead, structure-perceptron assigns weights to the potentials so that less important potentials receive small weights (this is like a "soft" form of feature selection). Finally, we provide experimental evaluation of HDTs on different visual tasks, including detection, segmentation, matching (alignment), and parsing. We show that HDTs achieve state-of-the-art performance for these different tasks when evaluated on data sets with groundtruth (and when compared to alternative algorithms, which are typically specialized to each task).

  1. Metric Gauge Fields in Deformed Special Relativity

    Cardone, F; Petrucci, A


    We show that, in the framework of Deformed Special Relativity (DSR), namely a (four-dimensional) generalization of the (local) space-time struc- ture based on an energy-dependent "deformation" of the usual Minkowski geometry, two kinds of gauge symmetries arise, whose spaces either coin- cide with the deformed Minkowski space or are just internal spaces to it. This is why we named them "metric gauge theories". In the case of the internal gauge ?elds, they are a consequence of the deformed Minkowski space (DMS) possessing the structure of a generalized Lagrange space. Such a geometrical structure allows one to de?ne curvature and torsion in the DMS.

  2. Rigidity Constraints for Large Mesh Deformation

    Yong Zhao; Xin-Guo Liu; Qun-Sheng Peng; Hu-Jun Bao


    It is a challenging problem of surface-based deformation to avoid apparent volumetric distortions around largely deformed areas. In this paper, we propose a new rigidity constraint for gradient domain mesh deformation to address this problem. Intuitively the proposed constraint can be regarded as several small cubes defined by the mesh vertices through mean value coordinates. The user interactively specifies the cubes in the regions which are prone to volumetric distortions, and the rigidity constraints could make the mesh behave like a solid object during deformation. The experimental results demonstrate that our constraint is intuitive, easy to use and very effective.

  3. Origami-enabled deformable silicon solar cells

    Tang, Rui; Huang, Hai; Liang, Hanshuang; Liang, Mengbing [School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85287 (United States); Tu, Hongen; Xu, Yong [Electrical and Computer Engineering, Wayne State University, 5050 Anthony Wayne Dr., Detroit, Michigan 48202 (United States); Song, Zeming; Jiang, Hanqing, E-mail: [School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, Arizona 85287 (United States); Yu, Hongyu, E-mail: [School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85287 (United States); School of Earth and Space Exploration, Arizona State University, Tempe, Arizona 85287 (United States)


    Deformable electronics have found various applications and elastomeric materials have been widely used to reach flexibility and stretchability. In this Letter, we report an alternative approach to enable deformability through origami. In this approach, the deformability is achieved through folding and unfolding at the creases while the functional devices do not experience strain. We have demonstrated an example of origami-enabled silicon solar cells and showed that this solar cell can reach up to 644% areal compactness while maintaining reasonable good performance upon cyclic folding/unfolding. This approach opens an alternative direction of producing flexible, stretchable, and deformable electronics.

  4. A new interpretation of deformation rates in the Snake River Plain and adjacent basin and range regions based on GPS measurements

    Payne, S. J.; McCaffrey, R.; King, R. W.; Kattenhorn, S. A.


    Within the Northern Basin and Range Province, USA, we estimate horizontal velocities for 405 sites using Global Positioning System (GPS) phase data collected from 1994 to 2010. The velocities, together with geologic, volcanic, and earthquake data, reveal a slowly deforming region within the Snake River Plain in Idaho and Owyhee-Oregon Plateau in Oregon separated from the actively extending adjacent Basin and Range regions by shear. Our results show a NE-oriented extensional strain rate of 5.6 ± 0.7 × 10-9 yr-1 in the Centennial Tectonic Belt and an ˜E-oriented extensional strain rate of 3.5 ± 0.2 × 10-9 yr-1 in the Great Basin. These extensional rates contrast with the very low strain rate within the 125 km × 650 km region of the Snake River Plain and Owyhee-Oregon Plateau, which is indistinguishable from zero (-0.1 ± 0.4 × 10-9 yr-1). Inversions of the velocities with dyke-opening models indicate that rapid extension by dyke intrusion in volcanic rift zones, as previously hypothesized, is not currently occurring in the Snake River Plain. This slow internal deformation, in contrast to the rapidly extending adjacent Basin and Range regions, indicates shear along the boundaries of the Snake River Plain. We estimate right-lateral shear with slip rates of 0.3-1.4 mm yr-1 along the northwestern boundary adjacent to the Centennial Tectonic Belt and left-lateral oblique extension with slip rates of 0.5-1.5 mm yr-1 along the southeastern boundary adjacent to the Intermountain Seismic Belt. The fastest lateral shearing evident in the GPS occurs near the Yellowstone Plateau where strike-slip focal mechanisms and faults with observed strike-slip components of motion are documented. The regional velocity gradients are best fit by nearby poles of rotation for the Centennial Tectonic Belt, Snake River Plain, Owyhee-Oregon Plateau, and eastern Oregon, indicating that clockwise rotation is not locally driven by Yellowstone hotspot volcanism, but instead by extension to the

  5. Structure and provenance of Late Cretaceous-Miocene sediments located near the NE Dinarides margin: Inferences from kinematics of orogenic building and subsequent extensional collapse

    Stojadinovic, Uros; Matenco, Liviu; Andriessen, Paul; Toljić, Marinko; Rundić, Ljupko; Ducea, Mihai N.


    The NE part of the Dinarides Mountain chain, located near their junction with the Carpatho-Balkanides, is an area where sedimentary basins associated with the Neotethys subduction and collision are still exposed. We performed a provenance study, based on detrital fission track thermochronology combined with zircon Usbnd Pb magmatic geochronology, and existing studies of kinematics and exhumation. Our study shows rapid sedimentation in the trench and forearc basin overlying the upper European tectonic plate. A number of latest Cretaceous-Early Paleocene igneous provenance ages show a dominant magmatic source area, derived from a Late Cretaceous subduction-related arc. This arc shed short time lag sediments in the forearc and the trench system, possibly associated with focused exhumation in the Serbo-Macedonian margin. This was followed by burial of the trench sediments and a novel stage of Middle-Late Eocene exhumation driven by continued continental collision that had larger effects than previously thought. The collision was followed by Late Oligocene-Miocene exhumation of the former lower Adriatic plate along extensional detachments that reactivated the inherited collisional contact along the entire Dinarides margin. This event re-distributed sediments at short distances in the neighboring Miocene basins. Our study demonstrates that the Dinarides orogenic system is characterized by short lag times between exhumation and re-deposition, whereas the upper tectonic plate is significantly exhumed only during the final stages of collision. Such an exhumation pattern is not directly obvious from observing the overall geometry of the orogen.

  6. Oven controlled N++ [1 0 0] length-extensional mode silicon resonator with frequency stability of 1 ppm over industrial temperature range

    You, Weilong; Pei, Binbin; Sun, Ke; Zhang, Lei; Yang, Heng; Li, Xinxin


    This paper presents an oven controlled N++ [1 0 0] length-extensional mode silicon resonator, with a lookup-table based control algorithm. The temperature coefficient of resonant frequency (TCF) of the N++ doped resonator is nonlinear, and there is a turnover temperature point at which the TCF is equal to zero. The resonator is maintained at the turnover point by Joule heating; this temperature is a little higher than the upper limit of the industrial temperature range. It is demonstrated that the control algorithm based on the thermoresistor on the substrate and the lookup table for heating voltage versus chip temperature is sufficiently accurate to achieve a frequency stability of  ±0.5 ppm over the industrial temperature range. Because only two leads are required for electrical heating and piezoresistive sensing, the power required for heating of this resonator can be potentially lower than that of the oscillators with closed-loop oven control algorithm. It is also shown that the phase noise can be suppressed at the turnover temperature because of the very low value of the TCF, which justifies the usage of the heating voltage as the excitation voltage of the Wheatstone half-bridge.

  7. Extensional flow convecting a reactant undergoing a first order homogeneous reaction and diffusional mass transfer from a sphere at low to intermediate Peclet and Damkohler numbers

    Shah, N. Y.; Reed, X. B., Jr.


    Forced convective diffusion-reaction is considered for viscous axisymmetric extensional convecting velocity in the neighborhood of a sphere. For Peclet numbers in the range 0.1 less than or equal to Pe less than or equal to 500 and for Damkohler numbers increasing with increasing Pe but in the overall range 0.02 less than or equal to Da less than or equal to 10, average and local Sherwood numbers have been computed. By introducing the eigenfunction expansion c(r, Theta) = Sum of c(n)(r)P(n)(cos Theta) into the forced convective diffusion equation for the concentration of a chemical species undergoing a first order homogeneous reaction and by using properties of the Legendre functions Pn(cos Theta), the variable coefficient PDE can be reduced to a system of N + 1 second order ODEs for the radial functions c(sub n)(r), n = 0, 1, 2,..., N. The adaptive grid algorithm of Pereyra and Lentini can be used to solve the corresponding 2(N + 1) first order differential equations as a two-point boundary value problem on 1 less than or equal to r less than or equal to r(sub infinity). Convergence of the expansion for a specific value of N can thus be established and provides 'spectral' behavior as well as the full concentration field c(r, Theta).

  8. Area balance and strain in an extensional fault system: Strategies for improved oil recovery in fractured chalk, Gilbertown Field, southwestern Alabama. Annual report, March 1996--March 1997

    Pashin, J.C.; Raymond, D.E.; Rindsberg, A.K.; Alabi, G.G.; Groshong, R.H.


    Gilbertown Field is the oldest oil field in Alabama and produces oil from chalk of the Upper Cretaceous Selma Group and from sandstone of the Eutaw Formation along the southern margin of the Gilbertown fault system. Most of the field has been in primary recovery since establishment, but production has declined to marginally economic levels. This investigation applies advanced geologic concepts designed to aid implementation of improved recovery programs. The Gilbertown fault system is detached at the base of Jurassic salt. The fault system began forming as a half graben and evolved in to a full graben by the Late Cretaceous. Conventional trapping mechanisms are effective in Eutaw sandstone, whereas oil in Selma chalk is trapped in faults and fault-related fractures. Burial modeling establishes that the subsidence history of the Gilbertown area is typical of extensional basins and includes a major component of sediment loading and compaction. Surface mapping and fracture analysis indicate that faults offset strata as young as Miocene and that joints may be related to regional uplift postdating fault movement. Preliminary balanced structural models of the Gilbertown fault system indicate that synsedimentary growth factors need to be incorporated into the basic equations of area balance to model strain and predict fractures in Selma and Eutaw reservoirs.

  9. Advantages of formulating an evolution equation directly for elastic distortional deformation in finite deformation plasticity

    Rubin, M. B.; Cardiff, P.


    Simo (Comput Methods Appl Mech Eng 66:199-219, 1988) proposed an evolution equation for elastic deformation together with a constitutive equation for inelastic deformation rate in plasticity. The numerical algorithm (Simo in Comput Methods Appl Mech Eng 68:1-31, 1988) for determining elastic distortional deformation was simple. However, the proposed inelastic deformation rate caused plastic compaction. The corrected formulation (Simo in Comput Methods Appl Mech Eng 99:61-112, 1992) preserves isochoric plasticity but the numerical integration algorithm is complicated and needs special methods for calculation of the exponential map of a tensor. Alternatively, an evolution equation for elastic distortional deformation can be proposed directly with a simplified constitutive equation for inelastic distortional deformation rate. This has the advantage that the physics of inelastic distortional deformation is separated from that of dilatation. The example of finite deformation J2 plasticity with linear isotropic hardening is used to demonstrate the simplicity of the numerical algorithm.


    Kelemen, Peter


    Topics covered include: Failure At High Confining Pressure; Fluid-assisted Slip, Earthquakes & Fracture; Reaction-driven Cracking; Fluid Transport, Deformation And Reaction; Localized Fluid Transport And Deformation; Earthquake Mechanisms; Subduction Zone Dynamics And Crustal Growth.

  11. Individual Grain Orientation and Heterogeneous Deformation in Cold-deformed Interstitial-Free Sheet Steel


    The cold rolling deformation textural evolution of an interstitial-free (IF) steel sheet is investigated by experiment and simulation. The microstructure of the IF steel is observed by transmission electron microscopy (TEM). The relationship between the deformation behavior of individual grain and the grain orientation are connected by Taylor factor M. The results show that the grains with higher Taylor factor are deformed slighter than those with lower ones. By considering the heterogeneous deformation, the texture simulation result can be greatly improved.

  12. The Hot Deformation Activation Energy of 7050 Aluminum Alloy under Three Different Deformation Modes

    Deli Sang; Ruidong Fu; Yijun Li


    In this study, the hot deformation activation energy values of 7050-T7451 aluminum alloy, calculated with two different methods under three deformation modes, were compared. The results showed that the hot deformation activation energy values obtained with the classical constitutive equation are nearly equivalent under the hot tensile, compression, and shear-compression deformation modes. Average values exhibited an obvious increase when calculated with the modified constitutive equation beca...

  13. Deformation patterns on Kythnos, Western Cyclades; ongoing work

    Rice, A. Hugh N.; Grasemann, Bernhard


    Kythnos lies between Kea and Serifos in the Western Cyclades; on the former island, top-SSW directed D2 extensional deformation has essentially fully overprinted the top-SW HP D1 deformation whilst, on the latter, the D2 reworking is restricted to a very narrow zone directly underlying the West Cycladic Detachment System. Kythnos shows an intermediate degree of reworking, with a gradual change in stretching lineation orientation from dominantly SW-directed in the north of the island to SSW-directed in the south, where the Western Cycladic Detachment System is exposed, although the gradient in lineation directions is neither smooth nor perfect. Further, at a single outcrop, in both domains, there is a tendency (but not a rule) for stretching directions within pelitic rocks (which are parallel to contemporary crenulations) to have a more southerly azimuth than that observed in quartz-rich rocks, both metasedimentary and concordant/discordant veins. The opposite has not been observed. The map of de Smeth (1975) shows two marble horizons; a lower blue-grey marble (BGM) with minor amounts of muscovite/quartz and an upper yellow-brown marble (YBM) with large amounts of muscovite/quartz; these are separated by pelites. On the east side of southern Kythnos, the BGM is thick (perhaps > 10 m in places) and is clearly overlain by pelitic schists and then the YBM, the last forming the structurally highest part of the central-southern part of the island. However, NE of Aghios Dimitrios, (S. Kythnos) good exposures clearly show that the BGM thins from west to east and eventually, at the west coast NW of Ag. Dimitrios, it becomes a thin layer of carbonate within yellow quartz mylonites; essentially it is YBM, although de Smeth mapped this still as BGM. Some 3.5 km further north, however, de Smeth mapped exactly the same high-strain lithology as YBM. This band of high strain rocks (YBM) crops-out intermittently along the west side of the island and is likely a continuation of the

  14. Swimming near a deformable interface

    Dias, Marcelo; Powers, Thomas


    It is a known fact that swimmers behave differently near deformable soft tissues than when near a rigid surface. Motivated by this class of problems, we investigate swimming microorganisms near flexible walls. We calculate the speed of a n infinitely long swimmer near an interface between two viscous fluids. Part of the calculation of the speed is the calculation of the shape of the free boundary. The swimming speed is controlled by the competition between surface and viscous effects, where two limits are observed. When the surface tension vanishes, we get Taylor's result for a swimmer with no walls. When the surface tension is infinite, the problem is like that of a swimmer near a rigid wall.

  15. Deformation of Linked Polymer Coils

    董朝霞; 李明远; 吴肇亮; 林梅钦


    Linked polymer solution (LPS) is defined as the solution of linked polymer coils (LPCs) dispersed in water, composed of low concentration partially hydrolyzed polyacrylamide (HPAM) and aluminum citrate (crosslinker). In the work, the conformational changes of LPCs under different conditions were investigated by the methods of membrane filtering under low pressure, dynamic light scattering and core flooding experiments. The results showed that in some conditions the LPCs could be compressed mechanically to 1/158.5 of their original volume because of relatively lower HPAM cross-linking. The hydration property of LPCs was similar to that of normal polymer coils. The deformation of LPCs was more restricted than that of ordinary polymer coils under the flow shear stress or the shift of hydration equilibrium caused in the variation of the electrolyte concentration which is responsible for the effective plugging in the throats of porous media when LPCs are used for deep diverting.

  16. κ-deformed Fourier transform

    Scarfone, A. M.


    We present a new formulation of Fourier transform in the picture of the κ-algebra derived in the framework of the κ-generalized statistical mechanics. The κ-Fourier transform is obtained from a κ-Fourier series recently introduced by Scarfone (2013). The kernel of this transform, that reduces to the usual exponential phase in the κ → 0 limit, is composed by a κ-deformed phase and a damping factor that gives a wavelet-like behaviour. We show that the κ-Fourier transform is isomorph to the standard Fourier transform through a changing of time and frequency variables. Nevertheless, the new formalism is useful to study, according to Fourier analysis, those functions defined in the realm of the κ-algebra. As a relevant application, we discuss the central limit theorem for the κ-sum of n-iterate statistically independent random variables.

  17. Plastic deformation of nanocrystalline nickel


    A high-resolution electron microscopy study has uncovered the plastic behavior of accommodating large strains in nanocrystalline (NC) Ni subject to cold rolling at liquid nitrogen temperature. The activation of grain-boundary-mediated-plasticity is evidenced in NC-Ni, including twinning and formation of stacking fault via partial dislocation slips from the grain boundary. The formation and storage of 60? full dislocations are observed inside NC-grains. The grain/twin boundaries act as the barriers of dislocation slips, leading to dislocation pile-up, severe lattice distortion, and formation of sub-grain boundary. The vicinity of grain/twin boundary is where defects preferentially accumulate and likely the favorable place for onset of plastic deformation. The present results indicate the heterogeneous and multiple natures of accommodating plastic strains in NC-grains.

  18. Plastic deformation of nanocrystalline nickel

    WU XiaoLei


    A high-resolution electron microscopy study has uncovered the plastic behavior of accommodating large strains in nanocrystalline(NC)Ni subject to cold rolling at liquid nitrogen temperature.The acti vation of grain-boundary-mediated-plasticity is evidenced in NC-Ni,including twinning and formation of stacking fault via partial dislocation slips from the grain boundary.The formation and storage of 60° full dislocations are observed inside NC-grains.The grain/twin boundaries act as the barriers of dislocation slips,leading to dislocation pile-up,severe lattice distortion,and formation of sub-grain boundary.The vicinity of grain/twin boundary is where defects preferentially accumulate and likely the favorable place for onset of plastic deformation.The present results indicate the heterogeneous and multiple natures of accommodating plastic strains in NC-grains.

  19. Challenges of β-deformation

    Morozov, A. Yu.


    We briefly review problems arising in the study of the beta deformation, which turns out to be the most difficult element in a number of modern problems: the deviation of β from unity is connected with the "exit from the free-fermion point" in two-dimensional conformal theories, from the symmetric graviphoton field with ∈2 = -∈1 in instanton sums in four-dimensional supersymmetric Yang-Mills theories, with the transition from matrix models to beta ensembles, from HOMFLY polynomials to superpolynomials in the Chern-Simons theory, from quantum groups to elliptic and hyperbolic algebras, and so on. We mainly attend to issues related to the Alday-Gaiotto-Tachikawa correspondence and its possible generalizations.

  20. Deformation in the continental lithosphere

    The Physical Properties of Earth Materials Committee, a technical committee of AGU's Tectonophysics Section, is organizing a dinner/colloquium as part of the Fall Meeting in San Francisco, Calif. This event will be held Monday, December 3rd, in the Gold Rush Room of the Holiday Inn Golden Gateway Hotel at 1500 Van Ness St. There will be a no-host bar from 6:30 to 7:30 P.M., followed by dinner from 7:30 to 8:30 P.M. Paul Tapponnier will deliver the after-dinner talk, “Large-Scale Deformation Mechanisms in the Continental Lithosphere: Where Do We Stand?” It will start at 8:30 P.M. and a business meeting will follow at 9:30 P.M.

  1. Style and rate of quaternary deformation of the Hosgri Fault Zone, offshore south-central coastal California

    Hanson, Kathryn L.; Lettis, William R.; McLaren, Marcia; Savage, William U.; Hall, N. Timothy; Keller, Mararget A.


    The Hosgri Fault Zone is the southernmost component of a complex system of right-slip faults in south-central coastal California that includes the San Gregorio, Sur, and San Simeon Faults. We have characterized the contemporary style of faulting along the zone on the basis of an integrated analysis of a broad spectrum of data, including shallow high-resolution and deep penetration seismic reflection data; geologic and geomorphic data along the Hosgri and San Simeon Fault Zones and the intervening San Simeon/Hosgri pull-apart basin; the distribution and nature of near-coast seismicity; regional tectonic kinematics; and comparison of the Hosgri Fault Zone with worldwide strike-slip, oblique-slip, and reverse-slip fault zones. These data show that the modern Hosgri Fault Zone is a convergent right-slip (transpressional) fault having a late Quaternary slip rate of 1 to 3 mm/yr. Evidence supporting predominantly strike-slip deformation includes (1) a long, narrow, linear zone of faulting and associated deformation; (2) the presence of asymmetric flower structures; (3) kinematically consistent localized extensional and compressional deformation at releasing and restraining bends or steps, respectively, in the fault zone; (4) changes in the sense and magnitude of vertical separation both along trend of the fault zone and vertically within the fault zone; (5) strike-slip focal mechanisms along the fault trace; (6) a distribution of seismicity that delineates a high-angle fault extending through the seismogenic crust; (7) high ratios of lateral to vertical slip along the fault zone; and (8) the separation by the fault of two tectonic domains (offshore Santa Maria Basin, onshore Los Osos domain) that are undergoing contrasting styles of deformation and orientations of crustal shortening. The convergent component of slip is evidenced by the deformation of the early-late Pliocene unconformity. In characterizing the style of faulting along the Hosgri Fault Zone, we assessed

  2. Cyclic Plastic Deformation and Welding Simulation

    Ten Horn, C.H.L.J.


    One of the concerns of a fitness for purpose analysis is the quantification of the relevant material properties. It is known from experiments that the mechanical properties of a material can change due to a monotonic plastic deformation or a cyclic plastic deformation. For a fitness for purpose anal

  3. Structural refinement and coarsening in deformed metals

    Hansen, N.; Huang, X.; Xing, Q.


    The microstructural refinement by plastic deformation is analysed in terms of key parameters, the spacing between and the misorientation angle across the boundaries subdividing the structure. Coarsening of such structures by annealing is also characterised. For both deformed and annealed structur...

  4. Einstein-Riemann Gravity on Deformed Spaces

    Julius Wess


    Full Text Available A differential calculus, differential geometry and the E-R Gravity theory are studied on noncommutative spaces. Noncommutativity is formulated in the star product formalism. The basis for the gravity theory is the infinitesimal algebra of diffeomorphisms. Considering the corresponding Hopf algebra we find that the deformed gravity is based on a deformation of the Hopf algebra.

  5. Initialization and Optimation of Deformable Models

    Jensen, Rune Fisker; Carstensen, Jens Michael; Madsen, Kaj


    The deformable model literature has in general been very focused on the formulation and development of new models or the solution of a specific application. Teh final and crucial steps of initialization and optimazation of the deformable model, needed for making inference, have received very little...

  6. Cyclic Shearing Deformation Behavior of Saturated Clays


    The apparatus for static and dynamic universal triaxial and torsional shear soil testing is employed to perform stress-controlled cyclic single-direction torsional shear tests and two-direction coupled shear tests under unconsolidated-undrained conditions. Through a series of tests on saturated clay, the effects of initial shear stress and stress reversal on the clay's strain-stress behavior are examined, and the behavior of pore water pressure is studied. The experimental results indicate that the patterns of stress-strain relations are distinctly influenced by the initial shear stress in the cyclic single-direction shear tests. When the initial shear stress is large and no stress reversal occurs, the predominant deformation behavior is characterized by an accumulative effect. When the initial shear stress is zero and symmetrical cyclic stress occurs, the predominant deformation behavior is characterized by a cyclic effect. The pore water pressure fluctuates around the confining pressure with the increase of cycle number. It seems that the fluctuating amplitude increases with the increase of the cyclic stress. But a buildup of pore water pressure does not occur. The deformations of clay samples under the complex initial and the cyclic coupled stress conditions include the normal deviatoric deformation and horizontal shear deformation, the average deformation and cyclic deformation. A general strain failure criterion taking into account these deformations is recommended and is proved more stable and suitable compared to the strain failure criteria currently used.

  7. Deformation Wave Hardening of Metallic Materials

    A.V. Kirichek


    Full Text Available The article deals with the machine parts hardening by means of deformation waves generated by the impact system with a waveguide as an intermediary member. The conditions for the efficient use of impact energy for elastoplastic deformation of the processed material and creation of the deep hardened surface layer.

  8. Deformed metals - structure, recrystallisation and strength

    Hansen, Niels; Juul Jensen, Dorte


    It is shown how new discoveries and advanced experimental techniques in the last 25 years have led to paradigm shifts in the analysis of deformation and annealing structures of metals and in the way the strength of deformed samples is related to structural parameters. This is described in three...... sections: structural evolution by grain subdivision, recovery and recrystallisation and strength-structure relationships....

  9. Deformation of cylindrical shells under thermal shock

    Aptukov, V.N. (Institut Mekhaniki Sploshnykh Sred, Perm (USSR))


    The deformation and fracture behavior of cylindrical shells under conditions of a nonsymmetric thermal shock is investigated numerically using a two-dimensional formulation. In particular, attention is given to the effect of the shell thickness on the deformation and fracture characteristics. Some computational difficulties associated with the solution of problems of this type are examined. 16 refs.

  10. On the deformation analysis of point fields

    Velsink, H.


    A new approach to determine a multi-point deformation of the earth’s surface or objects upon it, represented by point fields measured in two epochs, is presented. The problem of determining, which points have been deformed, is not approached by testing point-by-point, but by formulating alternative

  11. Bimodules and branes in deformation quantization

    Calaque, Damien; Ferrario, Andrea; Rossi, Carlo A


    We prove a version of Kontsevich's formality theorem for two subspaces (branes) of a vector space $X$. The result implies in particular that the Kontsevich deformation quantizations of $\\mathrm{S}(X^*)$ and $\\wedge(X)$ associated with a quadratic Poisson structure are Koszul dual. This answers an open question in Shoikhet's recent paper on Koszul duality in deformation quantization.

  12. Acquired nasal deformities in fighter pilots.

    Schreinemakers, Joyce R C; van Amerongen, Pieter; Kon, Moshe


    Fighter pilots may develop slowly progressive deformities of their noses during their flying careers. The spectrum of deformities that may be acquired ranges from soft tissue to osseous changes. The main cause is the varying pressure exerted by the oxygen mask on the skin and bony pyramid of the nose during flying.

  13. On parameter estimation in deformable models

    Fisker, Rune; Carstensen, Jens Michael


    Deformable templates have been intensively studied in image analysis through the last decade, but despite its significance the estimation of model parameters has received little attention. We present a method for supervised and unsupervised model parameter estimation using a general Bayesian...... method is based on a modified version of the EM algorithm. Experimental results for a deformable template used for textile inspection are presented...

  14. [Longitudinal stent deformation during bifurcation lesion treatment].

    Mami, Z; Monsegu, J


    Longitudinal stent deformation is defined as a compression of stent length after its implantation. It's a rare complication but dangerous seen with several stents. We reported a case of longitudinal stent deformation during bifurcation lesion treatment with a Promus Element(®) and we perform a short review of this complication.

  15. Complementary energy principle for large elastic deformation

    GAO; Yuchen


    Using the "base forces" as the fundamental unknowns to determine the state of an elastic system, the complementary energy principle for large elastic deformation is constructed for the conjugate quantities being displacement gradients, which possesses exactly the same form as that of classical linear elasticity. It is revealed that the complementary energy contains deformation part and rotation part.

  16. Variscan Collisional Magmatism and Deformation In The Viseu Area (northern Central Portugal) - Constraints From U-pb Geochronology of Granitoids

    Azevedo, M. R.; Aguado, B. V.; Scaltegger, U.; Nolan, J.; Martins, M. R.; Medina, J.

    The Viseu area is located in the innermost zone of the Iberian Variscan Fold Belt (the Central Iberian Zone). It consists of abundant post-thickening, collision related grani- toids intruded into upper and middle crustal levels. The ascent of granite magmas took place after an extensional tectonic event (D2) and is coeval with D3 dextral and sinis- tral crustal-scale transcurrent shear zones. In the northern part of the area, the presence of a well preserved Upper Carboniferous tectonic basin filled with deformed conti- nental clastic sediments, bounded by contemporaneously exhumed deep crustal rocks and intruded by late-tectonic granites documents an episode of extension involving basin subsidence, uplift and erosion of the basement and granite magmatism in a post- thickening, but syn-convergent scenario. Convergence is manifested by strike-slip tec- tonics and basin inversion. According to structural criteria, the Variscan granitoids can be subdivided into two major groups: (1) syn-D3 granitoids including two dif- ferent petrological associations, highly peraluminous leucogranite and granodiorite- monzogranite intrusions and (2) late-D3 granitoids comprising slightly metaluminous to peraluminous granodiorites and monzogranites. Four plutons representing the syn- D3 leucogranites (Junqueira) and monzogranites (Maceira and Casal Vasco) and the late-D3 biotite granites (Cota) yielded U-Pb zircon + monazite or monazite ages of 310 Ma, 311 Ma, 311 Ma and 306 Ma, respectively. This points to a synchronous emplacement of the different syn-D3 plutons shortly followed by the intrusion of the late-D3 granites and suggests that the Upper Carboniferous plutonism occurred within a short time span of ca. 5 myr. Stratigraphic markers show that the oldest continental sediments in the Carboniferous basin are Westphalian whilst field relationships in- dicate that the deformation occurred prior to the intrusion of the late-D3 granitoids. Precise U-Pb geochronology proves that basin

  17. The VENICE Project : A GPS Network to Monitor the Deformation of Western Provence and Eastern Languedoc (Southern France)

    Masson, F.; Collard, P.; Chéry, J.; Ritz, J.-F.; Doerflinger, E.; Bellier, O.; Chardon, D.; Flouzat, M.


    The present-day tectonic activity of the Western Provence - Eastern Languedoc region is demonstrated by moderate seismicity (magnitudes of 5-6.5 and recurrence periods of several tens of thousands of years for the strongest events) and sparse geological and geomorphological observations of recent deformation. It probably results from the convergence between Africa and Europe which proceeds at a rate of ~0.6 cm/year around the Western Mediterranean region. It includes E-trending fold and thrust belts (Mont-Ventoux, Luberon, Costes, Trévaresse) and NNE-trending left-lateral strike-slip faults (Moyenne Durance, Nîmes and possibly Cévennes). Regional stress field determined from inversion of earthquake focal mechanisms suggests a drastic change in the stress regime from West to East. It is extensional with an E-trending s3 axis in the western zone, along the Rhône Valley, while it is compressional in the eastern part, with an about N- to NNE-trending s1. However the present-day kinematics of the deformation in the region are still largely unknown. GPS measurements provide unique data sets for assessing crustal deformation in regions of low strain rates. In 2001, we started the implementation of a network of 15 GPS stations measured each six months during a period of 2-3 weeks (VENICE - Ventoux/Nîmes/Cévennes - semipermanent network). We are complementing this network by stations implemented around the Trevaresse ridge, reactivated by the 1909 Lambesc (M=6) earthquake. The network is designed to surround most of the faults and to be able to record co-seismic displacement in case of low magnitude earthquakes (magnitude 5-5.5). We will present the objectives of the VENICE project, the GPS networks and the first results quantifying the quality of the data by a careful study of the repeatability.

  18. Some deformations of U[sl(2)] and their representations

    Ky, N A


    Some one- and two-parametric deformations of U[sl(2)] and their representations are considered. Interestingly, a newly introduced two-parametric deformation admits a class of infinite - dimensional representations which have no classical (non-deformed) and one-parametric deformation analogues, even at generic deformation parameters.

  19. The deformed uncertainty relation and the corresponding beam quality factor

    Li, K; Wang, S M; Li, Kang; Zhao, Dao Mu; Wang, Shao Min


    By using the theory of deformed quantum mechanics, we study the deformed light beam theoretically. The deformed beam quality factor M_q^2 is given explicitly under the case of deformed light in coherent state. When the deformation parameter q being a root of unity, the beam quality factor M_q^2 \\leq 1.

  20. Large deformations of a soft porous material

    MacMinn, Christopher W; Wettlaufer, John S


    Compressing a porous material will decrease the volume of pore space, driving fluid out. Similarly, injecting fluid into a porous material can drive mechanical deformation, distorting the solid skeleton. This poromechanical coupling has applications ranging from cell and tissue mechanics to geomechanics and hydrogeology. The classical theory of linear poroelasticity captures this coupling by combining Darcy's law with linear elasticity and then further linearizing in the strain. This is a good model for very small deformations, but it becomes increasingly inappropriate as deformations grow larger, and moderate to large deformations are common in the context of phenomena such as swelling or damage, or for materials that are extremely soft. Here, we first review a rigorous Eulerian framework for large-deformation poromechanics. We then compare the predictions of linear poroelasticity with those of fully nonlinear poromechanics in the context of two uniaxial model problems: Fluid outflow driven by an applied mec...

  1. (120) and (122-bar) monazite deformation twins

    Hay, R.S


    Unusual features of (120) and (122-bar) deformation twins in monazite (monoclinic LaPO{sub 4}) are described and analyzed. These features are kinks and other irregularities in (120) twins, and V-shaped indentations on (120) and (122-bar) twin planes. Twinning shear analysis suggests that the kinks are a type II deformation twin mode with shear direction ({eta}{sub 1}) of [21-bar0]. This complements previous analysis based on atom shuffling considerations. Shear strain compatibility requires extensive plastic deformation in the kink. The V-shaped indentations may be analogous to similar structures in b.c.c metal deformation twins. Deformation mechanisms that may be associated with these structures are discussed.

  2. Deformation Measurements of Smart Aerodynamic Surfaces

    Fleming, Gary A.; Burner, Alpheus


    Video Model Deformation (VMD) and Projection Moire Interferometry (PMI) were used to acquire wind tunnel model deformation measurements of the Northrop Grumman-built Smart Wing tested in the NASA Langley Transonic Dynamics Tunnel. The F18-E/F planform Smart Wing was outfitted with embedded shape memory alloys to actuate a seamless trailing edge aileron and flap, and an embedded torque tube to generate wing twist. The VMD system was used to obtain highly accurate deformation measurements at three spanwise locations along the main body of the wing, and at spanwise locations on the flap and aileron. The PMI system was used to obtain full-field wing shape and deformation measurements over the entire wing lower surface. Although less accurate than the VMD system, the PMI system revealed deformations occurring between VMD target rows indistinguishable by VMD. This paper presents the VMD and PMI techniques and discusses their application in the Smart Wing test.

  3. Hot deformation behavior of FGH96 superalloys

    Jiantao Liu; Guoquan Liu; Benfu Hu; Yuepeng Song; Ziran Qin; Yiwen Zhang


    The hot deformation behavior of FGH96 superalloys at 1070-1170℃ and 5×10-4-2×10-1 s-1 were investigated by means of the isothermal compression tests at a Gleeble-1500 thermal mechanical simulator. The results show that dynamic recovery acts as the main softening mechanism below 2×10-3 s-1, whereas dynamic recrystallization acts as the main softening mechanism above 2×10-3 s-1during deformation; the temperature increase caused by the deformation and the corresponding softening stress is negligible; the thermal-mechanical constitutive model to describe the hot deformation behavior is given, and the value of the apparent deformation activation energy (Qdef) is determined to be 354.93 kJ/mol.

  4. M-theory and Deformation Quantization

    Minic, D


    We discuss deformation quantization of the covariant, light-cone and conformal gauge-fixed p-brane actions (p>1) which are closely related to the structure of the classical and quantum Nambu brackets. It is known that deformation quantization of the Nambu bracket is not of the usual Moyal type. Yet the Nambu bracket can be quantized using the Zariski deformation quantization (discovered by Dito, Flato, Sternheimer and Takhtajan) which is based on factorization of polynomials in several real variables. We discuss a particular application of the Zariski deformed quantization in M-theory by considering the problem of a covariant formulation of Matrix theory. We propose that the problem of a covariant formulation of Matrix theory can be solved using the formalism of Zariski deformed quantization of the triple Nambu bracket.

  5. Transpression / transtension: a model for micro- to macro-scale deformation

    Sanderson, David J.


    Transpression and transtension were terms introduces by Harland (1971) to define deformation that involves both transcurrent (strike-slip) movement along a zone and compression or extension across it. Sanderson & Marchini (1984) produced a strain model for transpression, and the concept has subsequently been applied in a variety of tectonic settings over a wide range of scales. Transpression is modelled by the simultaneous application of a transcurrent shear and horizontal shortening orthogonal to a block, with no lateral stretch. Sanderson & Marchini originally used two parameters α (the vertical elongation) and γ (the shear strain on the zone boundary) to define the deformation within the block. For constant volume deformation, the shortening across the zone is simply β = α-1, but volume change (Δ) is easily incorporated in the models, where α β = (1+Δ). One may also specify transpression in terms of the strain rates (δɛsgγ) and the direction (A) and amount (S) of convergence/divergence, where tan A = δγ / δɛ. The transpressional model has a number of important implications, which include: It generally leads to triaxial deformation, hence is intrinsically 3-dimensional, e.g. flattening strains characterise transpressional zones, whereas constrictional strains result from transtension. It represents a spectrum of strain states, providing a useful way of classifying deformational styles between generalised compressional, strike-slip and extensional regimes. The vorticity axis will be normal to the shear direction (vertical) and does not need to be parallel to the intermediate principle stain axis. At a convergence angle of A ≡70.5O the incremental and finite strain axes may be differently oriented and this may produce situations where structures may appear to develop in unusual orientations with respect to the finite strain fabrics Both the compressional and shear components contribute to the stretch Sn normal to the zone, where Sn = (α2 + γ2

  6. From vein precipitates to deformation and fluid rock interaction within a SSZ: Insights from the Izu-Bonin-Mariana fore arc

    Micheuz, Peter; Quandt, Dennis; Kurz, Walter


    International Ocean Discovery Program (IODP) expeditions 352 and 351 drilled through oceanic crust of the Philippine Sea plate. The two study areas are located near the outer Izu-Bonin-Mariana (IBM) fore arc and in the Amami Sankaku Basin. The primary objective was to improve our understanding of supra-subduction zones (SSZ) and the process of subduction initiation. The recovered drill cores during IODP expedition 352 represent approximately 50 Ma old fore arc basalts (FAB) and boninites revealing an entire volcanic sequence of a SSZ. Expedition 351 drilled FAB like oceanic crust similar in age to the FABs of expedition 352. In this study we present data on vein microstructures, geochemical data and isotopic signatures of vein precipitates to give new insights into fluid flow and precipitation processes and deformation within the Izu-Bonin fore arc. Veins formed predominantly as a consequence of hydrofracturing resulting in the occurrence of branched vein systems and brecciated samples. Along these hydrofractures the amount of altered host rock fragments varies and locally alters the host rock completely to zeolites and carbonates. Subordinately extensional veins released after the formation of the host rocks. Cross-cutting relationships of different vein types point to multiple fracturing events subsequently filled with minerals originating from a fluid with isotopic seawater signature. Based on vein precipitates, their morphology and their growth patterns four vein types have been defined. Major vein components are (Mg-) calcite and various zeolites determined by Raman spectra and electron microprobe analyses. Zeolites result from alteration of volcanic glass during interaction with a seawaterlike fluid. Type I veins which are characterized by micritic infill represent neptunian dykes. They predominantly occur in the upper levels of drill cores being the result of an initial volume change subsequently to crystallization of the host rocks. Type II veins are

  7. The properties of Q-deformed hyperbolic and trigonometric functions in quantum deformation

    Deta, U. A., E-mail:, E-mail: [Department of Physics, the State University of Surabaya (Unesa), Jl. Ketintang, Surabaya 60231 (Indonesia); Suparmi [Departmet of Physics, Sebelas Maret University, Jl. Ir. Sutami 36A Kentingan, Surakarta 57126 (Indonesia)


    Quantum deformation has been studied due to its relation with applications in nuclear physics, conformal field theory, and statistical-quantum theory. The q-deformation of hyperbolic function was introduced by Arai. The application of q-deformed functions has been widely used in quantum mechanics. The properties of this two kinds of system explained in this paper including their derivative. The graph of q-deformed functions presented using Matlab. The special case is given for modified Poschl-Teller plus q-deformed Scarf II trigonometry potentials.

  8. Large Deformations of a Soft Porous Material

    MacMinn, Christopher W.; Dufresne, Eric R.; Wettlaufer, John S.


    Compressing a porous material will decrease the volume of the pore space, driving fluid out. Similarly, injecting fluid into a porous material can expand the pore space, distorting the solid skeleton. This poromechanical coupling has applications ranging from cell and tissue mechanics to geomechanics and hydrogeology. The classical theory of linear poroelasticity captures this coupling by combining Darcy's law with Terzaghi's effective stress and linear elasticity in a linearized kinematic framework. Linear poroelasticity is a good model for very small deformations, but it becomes increasingly inappropriate for moderate to large deformations, which are common in the context of phenomena such as swelling and damage, and for soft materials such as gels and tissues. The well-known theory of large-deformation poroelasticity combines Darcy's law with Terzaghi's effective stress and nonlinear elasticity in a rigorous kinematic framework. This theory has been used extensively in biomechanics to model large elastic deformations in soft tissues and in geomechanics to model large elastoplastic deformations in soils. Here, we first provide an overview and discussion of this theory with an emphasis on the physics of poromechanical coupling. We present the large-deformation theory in an Eulerian framework to minimize the mathematical complexity, and we show how this nonlinear theory simplifies to linear poroelasticity under the assumption of small strain. We then compare the predictions of linear poroelasticity with those of large-deformation poroelasticity in the context of two uniaxial model problems: fluid outflow driven by an applied mechanical load (the consolidation problem) and compression driven by a steady fluid throughflow. We explore the steady and dynamical errors associated with the linear model in both situations, as well as the impact of introducing a deformation-dependent permeability. We show that the error in linear poroelasticity is due primarily to kinematic

  9. An On-Chip RBC Deformability Checker Significantly Improves Velocity-Deformation Correlation

    Chia-Hung Dylan Tsai


    Full Text Available An on-chip deformability checker is proposed to improve the velocity–deformation correlation for red blood cell (RBC evaluation. RBC deformability has been found related to human diseases, and can be evaluated based on RBC velocity through a microfluidic constriction as in conventional approaches. The correlation between transit velocity and amount of deformation provides statistical information of RBC deformability. However, such correlations are usually only moderate, or even weak, in practical evaluations due to limited range of RBC deformation. To solve this issue, we implemented three constrictions of different width in the proposed checker, so that three different deformation regions can be applied to RBCs. By considering cell responses from the three regions as a whole, we practically extend the range of cell deformation in the evaluation, and could resolve the issue about the limited range of RBC deformation. RBCs from five volunteer subjects were tested using the proposed checker. The results show that the correlation between cell deformation and transit velocity is significantly improved by the proposed deformability checker. The absolute values of the correlation coefficients are increased from an average of 0.54 to 0.92. The effects of cell size, shape and orientation to the evaluation are discussed according to the experimental results. The proposed checker is expected to be useful for RBC evaluation in medical practices.

  10. GPS measurements of deformation near the Rio Grande rift: Evidence for variations in the rate of extension

    Murray, M. H.; Murray, K. D.; Sheehan, A. F.; Nerem, R. S.; van Wijk, J.; Axen, G. J.


    We use data from 215 continuous GPS stations, including 26 stations installed in 2006-2007 as part of a collaborative EarthScope experiment, to investigate how deformation is distributed near the Rio Grande rift (RGR) in New Mexico (NM) and Colorado (CO), USA. Our previous analysis, using data from 2006-2010, found nearly uniform 1.2±0.2 nanostrain/yr (nɛ/yr) east-west extensional strain rate along 5 profiles spanning a ~1000 km region (Berglund et al., 2012). We have included data from 1996-2015, and more formally account for correlated noise in the time series, which reduces horizontal velocity uncertainties to ~0.06 mm/yr. Strain rate along the profiles across the RGR increases from 0.55±0.06 nɛ/yr in southern NM to as much as 1.05±0.06 nɛ/yr in southern CO before dropping to ~0 nɛ/yr, within error, in northern CO. In all 5 east-west profiles across the RGR, strain rate is higher along the profiles west of the fault-defined rift zone than it is to the east—an increase to 1.65±0.1 nɛ/yr in southern CO, for example. Results from Euler pole analysis of sites within the Colorado Plateau relative to stable North America are consistent with significant internal deformation within the plateau, and using a subset of sites, we infer an Euler pole located in northern Utah that is roughly consistent with geologically derived estimates of a Miocene clockwise rotation (Chapin and Cather, 1994). A 2-dimensional strain rate field shows little evidence for higher extensional rates directly across the surface faults bounding the RGR, but does suggest a higher concentration along the Jemez lineament, which is a linear series of the youngest volcanic activity in NM located primarily at the SE edge of the Colorado Plateau. Two zones of possible contraction exist north and south of the Jemez lineament, which may reflect uplift from the NE section of the Jemez lineament due to upper mantle buoyancy.

  11. Petrogenesis of Neoarchean metavolcanic rocks in Changyukou, Northwestern Hebei: Implications for the transition stage from a compressional to an extensional regime for the North China Craton

    Liou, Peng; Shan, Houxiang; Liu, Fu; Guo, Jinghui


    fractional crystallization of basaltic andesites (high-Al basalts) and andesites. Mixing of magmas at various stages along the fractionation course of basaltic andesites (high-Al basalts) toward rhyolites promotes the trend of the calc-alkaline series. To reconcile the 2.55 to 2.5 Ga TTGs derived from overthickened crust, the 2.51 to 2.50 Ga calc-alkaline volcanic rocks derived from thickened crust, tholeiitic basalts representing low pressure and an extensional tectonic setting, 2493 Ma leucosyenogranites derived from overthickened crust, 2437 Ma biotite-monzogranites derived from slightly thinner crust than leucosyenogranites but still thickened, as well as the clockwise hybrid ITD and IBC P-T paths of the HP granulites and widespread extension and rifting setting within the NCC from 2300 Ma, we propose a model of an evolving subduction process. Among them, the composition of the 2.5 Ga Changyukou volcanic rocks and potassic granites as well as the clockwise hybrid ITD and IBC P-T paths of the HP granulites may reveal that the tectonic setting in Northwest Hebei was in a transition stage from a subduction-related compressional regime to an extensional regime related to plate rollback.

  12. Innovative tidal notch detection using TLS and fuzzy logic: Implications for palaeo-shorelines from compressional (Crete) and extensional (Gulf of Corinth) tectonic settings

    Schneiderwind, S.; Boulton, S. J.; Papanikolaou, I.; Reicherter, K.


    useful for the identification of palaeo-shorelines in extensional tectonic environments where coseismic footwall uplift (only 1/2 to 1/4 of net slip per event) is unlikely to raise an entire notch above the tidal range.

  13. High precision analysis of an embryonic extensional fault-related fold using 3D orthorectified virtual outcrops: The viewpoint importance in structural geology

    Tavani, Stefano; Corradetti, Amerigo; Billi, Andrea


    Image-based 3D modeling has recently opened the way to the use of virtual outcrop models in geology. An intriguing application of this method involves the production of orthorectified images of outcrops using almost any user-defined point of view, so that photorealistic cross-sections suitable for numerous geological purposes and measurements can be easily generated. These purposes include the accurate quantitative analysis of fault-fold relationships starting from imperfectly oriented and partly inaccessible real outcrops. We applied the method of image-based 3D modeling and orthorectification to a case study from the northern Apennines, Italy, where an incipient extensional fault affecting well-layered limestones is exposed on a 10-m-high barely accessible cliff. Through a few simple steps, we constructed a high-quality image-based 3D model of the outcrop. In the model, we made a series of measurements including fault and bedding attitudes, which allowed us to derive the bedding-fault intersection direction. We then used this direction as viewpoint to obtain a distortion-free photorealistic cross-section, on which we measured bed dips and thicknesses as well as fault stratigraphic separations. These measurements allowed us to identify a slight difference (i.e. only 0.5°) between the hangingwall and footwall cutoff angles. We show that the hangingwall strain required to compensate the upward-decreasing displacement of the fault was accommodated by this 0.5° rotation (i.e. folding) and coeval 0.8% thickening of strata in the hangingwall relatively to footwall strata. This evidence is consistent with trishear fault-propagation folding. Our results emphasize the viewpoint importance in structural geology and therefore the potential of using orthorectified virtual outcrops.

  14. The development of miocene extensional and short-lived basin in the Andean broken foreland: The Conglomerado Los Patos, Northwestern Argentina

    del Papa, Cecilia E.; Petrinovic, Ivan A.


    The Conglomerado Los Patos is a coarse-grained clastic unit that crops out irregularly in the San Antonio de los Cobres Valley in the Puna, Northwestern Argentina. It covers different units of the Cretaceous-Paleogene Salta Group by means of an angular unconformity and, in turn, is overlaid in angular unconformity by the Viscachayoc Ignimbrite (13 ± 0.3 Ma) or by late Miocene tuffs. Three lithofacies have been identified in the Corte Blanco locality; 1) Bouldery matrix-supported conglomerate (Gmm); 2) Clast-supported conglomerate (Gch) and 3) Imbricated clast-supported conglomerate (Gci). The stratigraphic pattern displays a general fining upward trend. The sedimentary facies association suggests gravitational flow processes and sedimentation in alluvial fan settings, from proximal to medial fan positions, together with a slope decrease upsection. Provenance studies reveal sediments sourced from Precambrian to Ordovician units located to the southwest, except for volcanic clasts in the Gmm facies that shows U/Pb age of 14.5 ± 0.5 Ma. This new age represents the maximum depositional age for the Conglomerado Los Patos, and it documents that deposition took place simultaneously during a period of increased tectonic and volcanic activity in the area. The structural analysis of the San Antonio de los Cobres Valley and the available thermochronological ages, indicate active N-S main thrusts and NW-SE transpressive and locally normal faults during the middle Miocene. In this context, we interpret the Conglomerado Los Patos to represent sedimentation in a small, extensional and short-lived basin associated with the compressional Andean setting.

  15. Mapping the nature of mantle domains in Western and Central Europe based on clinopyroxene and spinel chemistry: Evidence for mantle modification during an extensional cycle

    Picazo, S.; Müntener, O.; Manatschal, G.; Bauville, A.; Karner, G.; Johnson, C.


    Systematic differences in mineral composition of mantle peridotites are observed in ophiolites and peridotitic bodies from the Alpine Tethys, the Pyrenean domain, the Dinarides and Hellenides, and the Iberia-Newfoundland rifted margins. These differences can be understood in the context of the evolution of rifted margins and allow the identification of 3 major mantle domains: an inherited domain, a refertilized domain and a depleted domain. Most clinopyroxene from the inherited domain equilibrated in the spinel peridotite field and are too enriched in Na2O and Al2O3 to be residues of syn-rift melting. Clinopyroxene from the refertilized domain partially equilibrated with plagioclase and display lower Na2O and Al2O3, and elevated Cr2O3 contents. The refertilized domain is a hybrid zone, which locally preserves remnants from the inherited domain and overlapping chemical compositions. Depleted domains with clinopyroxene similar to abyssal peridotites are rare and Nd-isotopic studies indicate that they represent ancient periods of melting unrelated to the opening of the Jurassic and Cretaceous oceanic basins of the Alpine Tethys and southern North Atlantic. In many studied sections of mantle rocks in exposed ophiolites a systematic spatial distribution of the different domains with respect to the evolution of rifted margins can be identified. This new approach integrates observations from exposed and drilled mantle rocks and proposes that the mantle lithosphere evolved and was modified during an extensional cycle from post-orogenic collapse through several periods of rifting to seafloor spreading. The defined chemical and petrological characteristics of mantle domains based on clinopyroxene and spinel compositions are compiled on present-day and paleogeographic maps of Western and Central Europe. These maps show that the observed distribution of mantle domains are linked to processes related to late post-Variscan extension, rift evolution and refertilization associated

  16. Capillary Deformations of Bendable Films

    Schroll, R. D.


    We address the partial wetting of liquid drops on ultrathin solid sheets resting on a deformable foundation. Considering the membrane limit of sheets that can relax compression through wrinkling at negligible energetic cost, we revisit the classical theory for the contact of liquid drops on solids. Our calculations and experiments show that the liquid-solid-vapor contact angle is modified from the Young angle, even though the elastic bulk modulus (E) of the sheet is so large that the ratio between the surface tension γ and E is of molecular size. This finding indicates a new elastocapillary phenomenon that stems from the high bendability of very thin elastic sheets rather than from material softness. We also show that the size of the wrinkle pattern that emerges in the sheet is fully predictable, thus resolving a puzzle in modeling "drop-on-a-floating-sheet" experiments and enabling a quantitative, calibration-free use of this setup for the metrology of ultrathin films. © 2013 American Physical Society.

  17. Weak associativity and deformation quantization

    V.G. Kupriyanov


    Full Text Available Non-commutativity and non-associativity are quite natural in string theory. For open strings it appears due to the presence of non-vanishing background two-form in the world volume of Dirichlet brane, while in closed string theory the flux compactifications with non-vanishing three-form also lead to non-geometric backgrounds. In this paper, working in the framework of deformation quantization, we study the violation of associativity imposing the condition that the associator of three elements should vanish whenever each two of them are equal. The corresponding star products are called alternative and satisfy important for physical applications properties like the Moufang identities, alternative identities, Artin's theorem, etc. The condition of alternativity is invariant under the gauge transformations, just like it happens in the associative case. The price to pay is the restriction on the non-associative algebra which can be represented by the alternative star product, it should satisfy the Malcev identity. The example of nontrivial Malcev algebra is the algebra of imaginary octonions. For this case we construct an explicit expression of the non-associative and alternative star product. We also discuss the quantization of Malcev–Poisson algebras of general form, study its properties and provide the lower order expression for the alternative star product. To conclude we define the integration on the algebra of the alternative star products and show that the integrated associator vanishes.

  18. Weak associativity and deformation quantization

    Kupriyanov, V G


    Non-commutativity is quite natural in string theory. For open strings it appears due to the presence of non-vanishing background two-form in the world volume of Dirichlet brane, while in closed string theory the flux compactifications with non-vanishing three-form also lead to non-commutativity. Except for some specific cases, like the constant $B$-field in open strings, the string coordinates are not only non-commutative, but also non-associative. It manifests the non-geometric nature of the consistent string vacua. The aim of this paper is to study the mathematical tools necessary to deal with non-associativity in physics. Working in the framework of deformation quantization we admit non-associative star products, but keep the violation of associativity under control. We require that the star associator of three functions should vanish whenever each two of them are iqual. Such a star product is called alternative. This condition imposes the restriction on non-associative algebras, the star commutator should...

  19. Mass-deformed Brane Tilings

    Bianchi, Massimo; Hanany, Amihay; Morales, Jose Francisco; Pacifici, Daniel Ricci; Seong, Rak-Kyeong


    We study renormalization group flows among N=1 SCFTs realized on the worldvolume of D3-branes probing toric Calabi-Yau singularities, thus admitting a brane tiling description. The flows are triggered by masses for adjoint or vector-like pairs of bifundamentals and are generalizations of the Klebanov-Witten construction of the N=1 theory for the conifold starting from the N=2 theory for the C^2/Z_2 orbifold. In order to preserve the toric condition pairs of masses with opposite signs have to be switched on. We offer a geometric interpretation of the flows as complex deformations of the Calabi-Yau singularity preserving the toric condition. For orbifolds, we support this interpretation by an explicit string amplitude computation of the gauge invariant mass terms generated by imaginary self-dual 3-form fluxes in the twisted sector. In agreement with the holographic a-theorem, the volume of the Sasaki-Einstein 5-base of the Calabi-Yau cone always increases along the flow.

  20. Mathematical textbook of deformable neuroanatomies.

    Miller, M I; Christensen, G E; Amit, Y; Grenander, U


    Mathematical techniques are presented for the transformation of digital anatomical textbooks from the ideal to the individual, allowing for the representation of the variabilities manifest in normal human anatomies. The ideal textbook is constructed on a fixed coordinate system to contain all of the information currently available about the physical properties of neuroanatomies. This information is obtained via sensor probes such as magnetic resonance, as well as computed axial and emission tomography, along with symbolic information such as white- and gray-matter tracts, nuclei, etc. Human variability associated with individuals is accommodated by defining probabilistic transformations on the textbook coordinate system, the transformations forming mathematical translation groups of high dimension. The ideal is applied to the individual patient by finding the transformation which is consistent with physical properties of deformable elastic solids and which brings the coordinate system of the textbook to that of the patient. Registration, segmentation, and fusion all result automatically because the textbook carries symbolic values as well as multisensor features.

  1. Deformed soft matter under constraints

    Bertrand, Martin

    In the last few decades, an increasing number of physicists specialized in soft matter, including polymers, have turned their attention to biologically relevant materials. The properties of various molecules and fibres, such as DNA, RNA, proteins, and filaments of all sorts, are studied to better understand their behaviours and functions. Self-assembled biological membranes, or lipid bilayers, are also the focus of much attention as many life processes depend on these. Small lipid bilayers vesicles dubbed liposomes are also frequently used in the pharmaceutical and cosmetic industries. In this thesis, work is presented on both the elastic properties of polymers and the response of lipid bilayer vesicles to extrusion in narrow-channels. These two areas of research may seem disconnected but they both concern deformed soft materials. The thesis contains four articles: the first presenting a fundamental study of the entropic elasticity of circular chains; the second, a simple universal description of the effect of sequence on the elasticity of linear polymers such as DNA; the third, a model of the symmetric thermophoretic stretch of a nano-confined polymer; the fourth, a model that predicts the final sizes of vesicles obtained by pressure extrusion. These articles are preceded by an extensive introduction that covers all of the essential concepts and theories necessary to understand the work that has been done.

  2. Kinematics of SW Anatolia implications on crustal deformation above slab tear

    Özkaptan, Murat; Koç, Ayten; Lefebvre, Côme; Gülyüz, Erhan; Uzel, Bora; Kaymakci, Nuretdin; Langereis, Cornelis G.; Özacar, Arda A.; Sözbilir, Hasan


    measurements are also consistent with earthquake focal mechanisms suggesting active extension in the region. Thus, the FBFZ is characterized at the surface mainly by extension unlike previously proposed transcurrent deformation. We think, the FBFZ may represent a deep structure that formed at the ancient northern track of the STEP fault that reflected to the surface as a wide extensional zone displaying counter-clockwise rigid body rotation since late Miocene possibly due to fast Aegean slab retreat towards south. This research is supported byTubitak-Turkish National Science Foundation Grant Number 111Y239.

  3. Infinitesimal deformations of a formal symplectic groupoid

    Karabegov, Alexander


    Given a formal symplectic groupoid $G$ over a Poisson manifold $(M, \\pi_0)$, we define a new object, an infinitesimal deformation of $G$, which can be thought of as a formal symplectic groupoid over the manifold $M$ equipped with an infinitesimal deformation $\\pi_0 + \\varepsilon \\pi_1$ of the Poisson bivector field $\\pi_0$. The source and target mappings of a deformation of $G$ are deformations of the source and target mappings of $G$. To any pair of natural star products $(\\ast, \\tilde\\ast)$ having the same formal symplectic groupoid $G$ we relate an infinitesimal deformation of $G$. We call it the deformation groupoid of the pair $(\\ast, \\tilde\\ast)$. We give explicit formulas for the source and target mappings of the deformation groupoid of a pair of star products with separation of variables on a Kaehler- Poisson manifold. Finally, we give an algorithm for calculating the principal symbols of the components of the logarithm of a formal Berezin transform of a star product with separation of variables. This...

  4. Craniofacial neurofibromatosis: treatment of the midface deformity.

    Singhal, Dhruv; Chen, Yi-Chieh; Tsai, Yueh-Ju; Yu, Chung-Chih; Chen, Hung Chang; Chen, Yu-Ray; Chen, Philip Kuo-Ting


    Craniofacial Neurofibromatosis is a benign but devastating disease. While the most common location of facial involvement is the orbito-temporal region, patients often present with significant mid-face deformities. We reviewed our experience with Craniofacial Neurofibromatosis from June 1981 to June 2011 and included patients with midface soft tissue deformities defined as gross alteration of nasal or upper lip symmetry. Data reviewed included the medical records and photobank. Over 30 years, 52 patients presented to and underwent surgical management for Craniofacial Neurofibromatosis at the Chang Gung Craniofacial Center. 23 patients (43%) demonstrated gross mid-facial deformities at initial evaluation. 55% of patients with lip deformities and 28% of patients with nasal deformities demonstrated no direct tumour involvement. The respective deformity was solely due to secondary gravitational effects from neurofibromas of the cheek subunit. Primary tumour infiltration of the nasal and/or labial subunits was treated with excision followed by various methods of reconstruction including lower lateral cartilage repositioning, forehead flaps, free flaps, and/or oral commissure suspension. Soft tissue deformities of the midface are very common in patients with Craniofacial Neurofibromatosis and profoundly affect overall aesthetic outcomes. Distinguishing primary from secondary involvement of the midface assists in surgical decision making. Copyright © 2013 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  5. From labyrinthine aplasia to otocyst deformity

    Giesemann, Anja Maria; Goetz, Friedrich; Lanfermann, Heinrich [Hannover Medical School, Department of Diagnostic and Interventional Neuroradiology, Hannover (Germany); Neuburger, Juergen; Lenarz, Thomas [Hannover Medical School, Department of Otorhinolaryngology, Hannover (Germany)


    Inner ear malformations (IEMs) are rare and it is unusual to encounter the rarest of them, namely labyrinthine aplasia (LA) and otocyst deformity. They do, however, provide useful pointers as to the early embryonic development of the ear. LA is characterised as a complete absence of inner ear structures. While some common findings do emerge, a clear definition of the otocyst deformity does not exist. It is often confused with the common cavity first described by Edward Cock. Our purpose was to radiologically characterise LA and otocyst deformity. Retrospective analysis of CT and MRI data from four patients with LA or otocyst deformity. Middle and inner ear findings were categorised by two neuroradiologists. The bony carotid canal was found to be absent in all patients. Posterior located cystic structures were found in association with LA and otocyst deformity. In the most severe cases, only soft tissue was present at the medial border of the middle ear cavity. The individuals with otocyst deformity also had hypoplasia of the petrous apex bone. These cases demonstrate gradual changes in the two most severe IEMs. Clarification of terms was necessary and, based on these findings, we propose defining otocyst deformity as a cystic structure in place of the inner ear, with the cochlea, IAC and carotid canal absent. This condition needs to be differentiated from the common cavity described by Edward Cook. A clear definition of inner ear malformations is essential if outcomes following cochlear implantation are to be compared. (orig.)



    Full Text Available ABSTRACT Objective: Selective dorsal rhizotomy (SDR used for spasticity treatment could worsen or develop spinal deformities. Our goal is to describe spinal deformities seen in patients with cerebral palsy (CP after being treated by SDR. Methods: Retrospective study of patients operated on (SDR between January/1999 and June/2012. Inclusion criteria: spinal Rx before SDR surgery, spinography, and assessment at follow-up. We evaluated several factors emphasizing level and type of SDR approach, spinal deformity and its treatment, final Risser, and follow-up duration. Results: We found 7 patients (6 males: mean age at SDR 7.56 years (4.08-11.16. Mean follow-up: 6.64 years (2.16-13, final age: 14.32 years (7.5-19. No patient had previous deformity. GMFCS: 2 patients level IV, 2 level III, 3 level II. Initial walking status: 2 community walkers, 2 household walkers, 2 functional walkers, 1 not ambulant, at the follow-up, 3 patients improved, and 4 kept their status. We found 4 TL/L laminotomies, 2 L/LS laminectomies, and 1 thoracic laminectomy. Six spinal deformities were observed: 2 sagittal, 3 mixed, and 1 scoliosis. There was no association among the type of deformity, final gait status, topographic type, GMFCS, age, or SDR approach. Three patients had surgery indication for spinal deformity at skeletal maturity, while those patients with smaller deformities were still immature (Risser 0 to 2/3 although with progressive curves. Conclusions: After SDR, patients should be periodically evaluated until they reach Risser 5. The development of a deformity does not compromise functional results but adds morbidity because it may require surgical treatment.

  7. Procedure selection for the flexible adult acquired flatfoot deformity.

    Hentges, Matthew J; Moore, Kyle R; Catanzariti, Alan R; Derner, Richard


    Adult acquired flatfoot represents a spectrum of deformities affecting the foot and the ankle. The flexible, or nonfixed, deformity must be treated appropriately to decrease the morbidity that accompanies the fixed flatfoot deformity or when deformity occurs in the ankle joint. A comprehensive approach must be taken, including addressing equinus deformity, hindfoot valgus, forefoot supinatus, and medial column instability. A combination of osteotomies, limited arthrodesis, and medial column stabilization procedures are required to completely address the deformity.

  8. Preliminary results on the deformation rates of the Malatya Fault (Malatya-Ovacık Fault Zone, Turkey)

    Sançar, Taylan; Zabcı, Cengiz; Akçar, Naki; Karabacak, Volkan; Yazıcı, Müge; Akyüz, Hüsnü Serdar; Öztüfekçi Önal, Ayten; Ivy-Ochs, Susan; Christl, Marcus; Vockenhuber, Christof


    The complex tectonic architecture of the eastern Mediterranean is mainly shaped by the interaction between the Eurasian, African, Arabian plates and smaller Anatolian Scholle. Ongoing post-collisional convergence between Eurasian and Arabian plates causes; (1) the westward motion of the Anatolia and and (2) the formation of four neo-tectonic provinces in Turkey: (a) East Anatolian Province of Shortening (b) North Anatolian Province (c) Central Anatolian "Ova" Province (d) West Anatolian Extensional Province. The Central "Ova" Province, which defines a region between the Aegean extensional regime in the west, the North Anatolian Shear Zone (NASZ) in the north and the East Anatolian Shear Zone (EASZ) in the east, is deformed internally by a series of NW-striking dextral and NE-striking sinistral strike-slip faults. The Malatya-Ovacık Fault Zone (MOFZ) is one the sinistral faults of the "Ova" province, located close to its eastern boundary. In order to understand not only the spatio-temporal behaviour of the MOFZ, but also its role in the internal deformation of the Anatolian Scholle we started to study the southern section, the Malatya Fault (MF), of this strike-slip fault zone in the framework of the TÜBITAK project no. 114Y580. The scope of the study is to calculate (a) the horizontal geologic slip rate, (b) the uplift rate, and (c) the cumulative displacement of the Malatya Fault (MF) that constitute the southwest part of MOFZ. Offset streams between 20-1700 m, pressure ridges, hot springs and small pull-apart basin formations are clear geological and geomorphological evidences for fault geometry along the MF. Among them the ~1700 m offset of the Tohma River (TR) presents unique site to understand deformational characteristics of the MF. Three levels of strath terraces (T1 to T3) identified along the both flanks of the TR by analyses of aerial photos and the field observations. The spatial distribution of these terraces are well-constrained by using the high

  9. Mixed brittle-plastic deformation behaviour in a slate belt. Examples from the High-Ardenne slate belt (Belgium, Germany)

    Sintubin, Manuel; van Baelen, Hervé; van Noten, Koen; Muchez, Philippe


    In the High-Ardenne slate belt, part of the Rhenohercynian external fold-and-thrust belt at the northern extremity of the Late Palaeozoic Variscan orogen (Belgium, Germany, France), particular quartz vein occurrences can be observed in predominantly fine-grained siliciclastic metasediments. Detailed structural, petrographical and geochemical studies has revealed that these vein occurrences can be related to a mixed brittle-plastic deformation behaviour in a low-grade metamorphic mid-crustal environment. The first type of quartz veins are bedding-perpendicular, lens-shaped extension veins that are confined to the sandstone layers within the multilayer sequence. Fluid inclusion studies demonstrate high fluid pressures suggesting that the individual sandstone bodies acted as isolated high-pressure compartments in an overpressured basin. Hydraulic fracturing occurred during the tectonic inversion (from extension to compression) in the earliest stages of the Variscan orogeny. The vein fill shows a blocky character indicating crystal growth in open cavities. Both the typical lens shape of the veins and the subsequent cuspate-lobate folding of the bed interfaces in between the quartz veins suggest plastic deformation of cohesionless fluid-filled fissures. Metamorphic grade of the host rock and fluid temperature and pressure clearly indicates mid-crustal conditions below the brittle-plastic transition. This first type of quartz veins exemplifies mixed brittle-plastic deformation behaviour, possibly related to a transient deepening of the brittle-plastic transition. This is in contrast with contemporaneous bedding-perpendicular crack-seal veins observed in higher - upper-crustal - structural levels in the slate belt, reflecting pure brittle deformation behaviour. The second type are discordant quartz veins confined to extensional low-angle detachment shear zones. These very irregular veins transect a pre-existing pervasive cleavage fabric. They show no matching walls and

  10. Spinal Deformity Associated with Chiari Malformation.

    Kelly, Michael P; Guillaume, Tenner J; Lenke, Lawrence G


    Despite the frequency of Chiari-associated spinal deformities, this disease process remains poorly understood. Syringomyelia is often present; however, this is not necessary and scoliosis has been described in the absence of a syrinx. Decompression of the hindbrain is often recommended. In young patients (<10 years old) and/or those with small coronal Cobb measurements (<40°), decompression of the hindbrain may lead to resolution of the spinal deformity. Spinal fusion is reserved for those curves that progress to deformities greater than 50°. Further research is needed to understand the underlying pathophysiology to improve prognostication and treatment of this patient population.

  11. On the thermocapillary motion of deformable droplets

    Berejnov, V V


    In studies on Marangoni type motion of particles the surface tension is often approximated as a linear function of temperature. For deformable particles in a linear external temperature gradient far from the reference point this approximation yields a negative surface tension which is physically unrealistic. It is shown that H.Zhou and R.H.Davis J. Colloid Interface Sci., n.181,60,1996 presented calculation where the leading deformable drop moved into a region of negative surface tension. With respect numerical studies the restriction of the migration of two deformable drops is given in terms of the drift time.

  12. Cubic wavefunction deformation of compressed atoms

    Portela, Pedro Calvo


    We hypothesize that in a non-metallic crystalline structure under extreme pressures, atomic wavefunctions deform to adopt a reduced rotational symmetry consistent with minimizing interstitial space in the crystal. We exemplify with a simple numeric variational calculation that yields the energy cost of this deformation for Helium to 25%. Balancing this with the free energy gained by tighter packing we obtain the pressures required to effect such deformation. The consequent modification of the structure suggests a decrease in the resistance to tangential stress, and an associated decrease of the crystal's shear modulus. The atomic form factor is also modified. We also compare with neutron matter in the interior of compact stars.

  13. String theory of the Omega deformation

    Hellerman, Simeon; Reffert, Susanne


    In this article, we want to turn on real masses for the fields in the effective low energy gauge theory describing the motion of a stack of D2-branes. We do so by placing the D2-branes into the T-dual of a fluxbrane background. We furthermore show that the fluxbrane background is the string theory realization of an Omega-deformation of flat space in the directions transverse to the branes where the deformation parameters satisfy epsilon_1 = - epsilon_2. This Omega-deformation therefore serves to give real masses to the chiral fields of the gauge theory.

  14. Deformation of vanadium and niobium during hydrogenation

    Geld, P.V.; Kats, M.IA.; Spivak, L.V.


    The deformation behavior of polycrystalline vanadium and niobium during hydrogenation is investigated experimentally using a torsional pendulum to load 0.5-mm-diameter, 80-mm-long wire specimens. It is found that under conditions of isothermal hydrogenation, the macrodeformation of the V and Nb specimens is determined by the contributions of the following two components: deformation due to changes in the shear modulus of the system metal-hydrogen and deformation due to the oriented growth of the hydride phase in an applied stress field. 9 references.

  15. Atomistic deformation mechanisms in twinned copper nanospheres.

    Bian, Jianjun; Niu, Xinrui; Zhang, Hao; Wang, Gangfeng


    In the present study, we perform molecular dynamic simulations to investigate the compression response and atomistic deformation mechanisms of twinned nanospheres. The relationship between load and compression depth is calculated for various twin spacing and loading directions. Then, the overall elastic properties and the underlying plastic deformation mechanisms are illuminated. Twin boundaries (TBs) act as obstacles to dislocation motion and lead to strengthening. As the loading direction varies, the plastic deformation transfers from dislocations intersecting with TBs, slipping parallel to TBs, and then to being restrained by TBs. The strengthening of TBs depends strongly on the twin spacing.

  16. Deformation mechanisms of plasticized starch materials.

    Mikus, P-Y; Alix, S; Soulestin, J; Lacrampe, M F; Krawczak, P; Coqueret, X; Dole, P


    The aim of this paper is to understand the influence of plasticizer and plasticizer amount on the mechanical and deformation behaviors of plasticized starch. Glycerol, sorbitol and mannitol have been used as plasticizers. After extrusion of the various samples, dynamic mechanical analyses and video-controlled tensile tests have been performed. It was found that the nature of plasticizer, its amount as well as the aging of the material has an impact on the involved deformation mechanism. The variations of volume deformation could be explained by an antiplasticization effect (low plasticizer amount), a phase-separation phenomenon (excess of plasticizer) and/or by the retrogradation of starch.

  17. Research on monitoring system for slope deformation

    LIU Xiao-sheng; ZHANG Xue-zhuang; WANG Ai-gong


    The monitoring system for slope deformation which bases on Leica (TCA series)was researched and developed. This system consists of electronic total stations, high precision thermometer, digital barometer, photoelectric frequency adjustor and other related instruments and data collection and processing software. The system can monitor a series of targets automatically to obtain accurate data of distance at predetermined time, besides,it can timely display targets' coordinates and deformation value, velocity, etc. in graph as well. To compare of the results of different monitoring time, we can find the problems of mine slope deformation rapidly and accurately.

  18. On deformation theory of quantum vertex algebras

    Grosse, H; Grosse, Harald; Schlesinger, Karl-Georg


    We study an algebraic deformation problem which captures the data of the general deformation problem for a quantum vertex algebra. We derive a system of coupled equations which is the counterpart of the Maurer-Cartan equation on the usual Hochschild complex of an assocative algebra. We show that this system of equations results from an action principle. This might be the starting point for a perturbative treatment of the deformation problem of quantum vertex algebras. Our action generalizes the action of the Kodaira-Spencer theory of gravity and might therefore also be of relevance for applications in string theory.

  19. Peterson's Deformations of Higher Dimensional Quadrics

    Dinca, Ion I.


    We provide the first explicit examples of deformations of higher dimensional quadrics: a straightforward generalization of Peterson's explicit 1-dimensional family of deformations in C3 of 2-dimensional general quadrics with common conjugate system given by the spherical coordinates on the complex sphere S2 ⊂ C3 to an explicit (n-1)-dimensional family of deformations in C2n-1 of n-dimensional general quadrics with common conjugate system given by the spherical coordinates on the complex sphere Sn ⊂ Cn+1 and non-degenerate joined second fundamental forms. It is then proven that this family is maximal.

  20. Liquid Droplets on a Highly Deformable Membrane

    Schulman, Rafael D.; Dalnoki-Veress, Kari


    We examine the deformation produced by microdroplets atop thin elastomeric and glassy free-standing films. Because of the Laplace pressure, the droplets deform the elastic membrane thereby forming a bulge. Thus, two angles define the droplet or membrane geometry: the angles the deformed bulge and the liquid surface make with the film. These angles are measured as a function of the film tension, and are in excellent agreement with a force balance at the contact line. Finally, we find that if the membrane has an anisotropic tension, the droplets are no longer spherical but become elongated along the direction of high tension.

  1. Liquid Droplets on a Highly Deformable Membrane

    Schulman, Rafael; Dalnoki-Veress, Kari


    We present measurements of the deformation produced by micro-droplets atop thin elastomeric and glassy free-standing films. Due to the Laplace pressure, the droplets deform the elastic membrane thereby forming a bulge. Thus, there are two angles that define the droplet/membrane geometry: the angle the liquid surface makes with the film and the angle the deformed bulge makes with the film. The contact line geometry is well captured by a Neumann construction which includes contributions from interfacial and mechanical tensions. Finally, we show that a droplet atop a film with biaxial tension assumes an equilibrium shape which is elongated along the axis of high tension.

  2. Adsorption-Induced Deformation of Mesoporous Solids

    Gor, Gennady Yu


    The Derjaguin - Broekhoff - de Boer theory of capillary condensation is employed to describe deformation of mesoporous solids in the course of adsorption-desorption hysteretic cycles. We suggest a thermodynamic model, which relates the mechanical stress induced by adsorbed phase with the adsorption isotherm. Analytical expressions are derived for the dependence of the solvation pressure on the vapor pressure. The proposed method provides a semi-quantitative description of non-monotonic hysteretic deformation during capillary condensation without invoking any adjustable parameters. The method is showcased drawing on the examples of literature experimental data on adsorption deformation of porous glass and SBA-15 silica.

  3. Deformations of GR and BH thermodynamics

    Krasnov, Kirill


    In four space-time dimensions General Relativity can be non-trivially deformed. Deformed theories continue to describe two propagating degrees of freedom, as GR. We study Euclidean black hole thermodynamics in these deformations. We use the recently developed formulation that works with SO(3) connections as well as certain matrices M of auxiliary fields. We show that the black hole entropy is given by one quarter of the horizon area as measured by the Lie algebra valued two-form MF, where F is the connection curvature. This coincides with the horizon area as measured by the metric only for the case of General Relativity.

  4. Optical tweezer for probing erythrocyte membrane deformability

    Khan, Manas; Sood, A K; 10.1063/1.3272269


    We report that the average rotation speed of optically trapped crenated erythrocytes is direct signature of their membrane deformability. When placed in hypertonic buffer, discocytic erythrocytes are subjected to crenation. The deformation of cells brings in chirality and asymmetry in shape that make them rotate under the scattering force of a linearly polarized optical trap. A change in the deformability of the erythrocytes, due to any internal or environmental factor, affects the rotation speed of the trapped crenated cells. Here we show how the increment in erythrocyte membrane rigidity with adsorption of $Ca^{++}$ ions can be exhibited through this approach.

  5. Numerical modelling of stresses and deformations in casting processes

    Hattel, Jesper Henri


    Keywords: Stresses and deformations, casting, governing equations, thermal strain, control volume method......Keywords: Stresses and deformations, casting, governing equations, thermal strain, control volume method...

  6. Numerical modelling of stresses and deformations in casting processes

    Hattel, Jesper Henri


    Keywords: Stresses and deformations, casting, governing equations, thermal strain, control volume method......Keywords: Stresses and deformations, casting, governing equations, thermal strain, control volume method...

  7. Crustal deformation across the Southern Patagonian Icefield: GNSS observations and GIA models

    Mendoza, Luciano; Richter, Andreas; Marderwald, Eric; Hormaechea, José Luis; Ivins, Erik; Perdomo, Raúl; Lange, Heiner; Schröder, Ludwig; Dietrich, Reinhard


    We present the geodetic observation and geodynamic interpretation of crustal deformation rates in a network of 43 GNSS sites covering the region of the Southern Patagonian Icefield (Argentina and Chile). Repeated and semi-permanent GNSS observations initiated in 1996 yield 3D site velocities within a terrestrial reference frame with mean accuracies of 1 mm/a and 6 mm/a for the horizontal and vertical components, respectively. These site velocities are interpreted with regard to the magnitude, patterns and primary driving processes of vertical and horizontal present-day crustal deformation (Richter et al. 2016). The vertical site velocities document a rapid uplift causally related to glacial-isostatic adjustment (GIA) reaching 4 cm/a. They yield now an unambiguous preference between two competing regional GIA models (Lange et al. 2014). Remaining discrepancies between the preferred model and our observations point toward an exceptionally low effective upper mantle viscosity and effects of lateral rheological heterogeneities. The extension and geometry of our network allow, for the first time, also a detailed analysis of the horizontal velocity components. An analysis of the horizontal strain-rate field reveals a complex composite, with compression dominating in the west and extension in the east. The observed velocities suggest significant contributions from three processes: GIA, a western interseismic tectonic deformation field related to plate subduction, and an extensional strain-rate field related to active Patagonian slab window tectonics. They document a dual interaction between the peculiar tectonic situation and the visco-elastic response to ice-load changes: First, a mechanical superposition of the characteristic patterns of each of the three processes, which results in the complex superposition of horizontal deformation revealed by our strain analysis. And second, the lateral differentiation of the glacial-isostatic response imposed by the three

  8. Deformation Behavior of Nanoporous Metals

    Biener, J; Hodge, A M; Hamza, A V


    of free surfaces can no longer be neglected. As the material becomes more and more constraint by the presence of free surfaces, length scale effects on plasticity become more and more important and bulk properties can no longer be used to describe the material properties. Even the elastic properties may be affected as the reduced coordination of surface atoms and the concomitant redistribution of electrons may soften or stiffen the material. If, and to what extend, such length scale effects control the mechanical behavior of nanoporous materials depends strongly on the material and the characteristic length scale associated with its plastic deformation. For example, ductile materials such as metals which deform via dislocation-mediated processes can be expected to exhibit pronounced length scale effects in the sub-micron regime where free surfaces start to constrain efficient dislocation multiplication. In this chapter we will limit our discussion to our own area of expertise which is the mechanical behavior of nanoporous open-cell gold foams as a typical example of nanoporous metal foams. Throughout this chapter we will review our current understanding of the mechanical properties of nanoporous open-cell foams including both experimental and theoretical studies.

  9. Extensional structures in anisotropic rocks

    Platt, J.P.; Vissers, R.L.M.


    A distinct class of structures can form as a result of extension along a plane of anisotropy (foliation). The effect of the foliation is to decrease the ductility of the material in this orientation so that brittle fractures or shear-bands develop. Foliation boudinage is caused by brittle failure; e

  10. Driver ASICs for Advanced Deformable Mirrors Project

    National Aeronautics and Space Administration — The program leverages on our extensive expertise in developing high-performance driver ASICs for deformable mirror systems and seeks to expand the capacities of the...

  11. High Resolution Silicon Deformable Mirrors Project

    National Aeronautics and Space Administration — This proposal describes a plan to build a prototype small stroke, high precision deformable mirror suitable for space-based operation in systems for high-resolution...

  12. Zika Linked to Deformed Limbs in Newborns

    ... page: Zika Linked to Deformed Limbs in Newborns Cause isn' ... 2016 TUESDAY, Aug. 9, 2016 (HealthDay News) -- The Zika virus has already been linked to serious birth ...

  13. High Resolution Silicon Deformable Mirrors Project

    National Aeronautics and Space Administration — In this proposal we describe a plan to build a deformable mirror suitable for space-based operation in systems for high-resolution imaging. The prototype DM will be...

  14. True or false GPS-derived deformations?

    Riguzzi, F.; Pietrantonio, G.; Anzidei, M. [Istituto Nazionale di Geofisica e Vulcanologia, Rome (Italy); Crespi, M. [Rome Univ. La Sapienza, Rome (Italy). Dipartimento di Idraulica, Trasporti e Strade


    In this paper it was focused on the question whether GPS networks born with cartographic aims can be safely used in crustal deformation control. It was carried out a test on a network of five vertices located in the Rome district, comparing two data sets, the first coming from the adjustment of the survey carried out in 1994 in the frame of the IGM95 project, the second coming from the surveys carried out in 1996 and 1999 by the Department of Hydraulics, Transport Systems and Roads of La Sapienza University of Rome. The analysis shows how the detection of crustal deformation becomes extremely critical in absence of significant seismicity or when deformation events are limited. In other words, it is possible to find false deformations due to residual systematic effects affecting the coordinate estimates.

  15. Noncommutative principal bundles through twist deformation

    Aschieri, Paolo; Pagani, Chiara; Schenkel, Alexander


    We construct noncommutative principal bundles deforming principal bundles with a Drinfeld twist (2-cocycle). If the twist is associated with the structure group then we have a deformation of the fibers. If the twist is associated with the automorphism group of the principal bundle, then we obtain noncommutative deformations of the base space as well. Combining the two twist deformations we obtain noncommutative principal bundles with both noncommutative fibers and base space. More in general, the natural isomorphisms proving the equivalence of a closed monoidal category of modules and its twist related one are used to obtain new Hopf-Galois extensions as twists of Hopf-Galois extensions. A sheaf approach is also considered, and examples presented.

  16. Deformation Crossover: from nano to meso scale

    Cheng, Sheng [ORNL; Stoica, Alexandru Dan [ORNL; Wang, Xun-Li [ORNL; Liu, Chain T [ORNL; Horton Jr, Joe A [ORNL; Brown, Donald [Los Alamos National Laboratory (LANL); Clausen, B [Los Alamos National Laboratory (LANL); Liaw, Peter K [University of Tennessee, Knoxville (UTK)


    By investigating intergranular strains using in-situ high-energy x-ray and neutron diffraction, we demonstrate significantly different deformation behavior from previously observed in nanocrystalline and ultrafine-grained Ni. Little intergranular strain or texture change was found in nanocrystalline Ni indicating a grain boundary mediated deformation mechanism. A remarkable intergranular strain build-up was observed in ultrafine-grained Ni, which was attributed to dislocation activities, but the unusual angular dependence of intergranular strains gave evidence of stress relaxation by deformation twinning, as confirmed by TEM observations. From the intergranular strain evolution and the texture change, clear evidence of deformation crossovers is presented in Ni with grain sizes from nano to meso scale.

  17. Crustal deformation in northern Central America

    Cáceres, Diego; Monterroso, David; Tavakoli, Behrooz


    Evaluation of the seismic moment tensor for earthquakes on plate boundary is a standard procedure to determine the relative velocity of plates, which controls the seismic deformation rate predicted from the slip on a single fault. The moment tensor is also decomposed into an isotropic and a deviatoric part to discover the relationship between the average strain rate and the relative velocity between two plates. We utilize this procedure to estimate the rates of deformation in northern Central America where plate boundaries are seismically well defined. Four different tectonic environments are considered for modelling of the plate motions. The deformation rates obtained here compare well with those predicted from the plate motions models and are in good agreement with actual observations. Deformation rates on faults are increasingly being used to estimate earthquake recurrence from information on fault slip rate and more on how we can incorporate our current understanding into seismic hazard analyses.

  18. Driver ASICs for Advanced Deformable Mirrors Project

    National Aeronautics and Space Administration — The overall goal of the SBIR program is to develop a new Application Specified Integrated Circuit (ASIC) driver to be used in driver electronics of a deformable...

  19. Deformed and twisted black holes with NUTs

    Krtous, Pavel; Frolov, Valeri P; Kolar, Ivan


    We construct a new class of vacuum black hole solutions whose geometry is deformed and twisted by the presence of NUT charges. The solutions are obtained by `unspinning' the general Kerr-NUT-(A)dS spacetimes, effectively switching off some of their rotation parameters. The resulting geometry has a structure of warped space with the Kerr-like Lorentzian part warped to a Euclidean metric of deformed and/or twisted sphere, with the deformation and twist characterized by the `Euclidean NUT' parameters. In the absence of NUTs, the solution reduces to a well known Kerr-(A)dS black hole with several rotations switched off. New geometries inherit the original symmetry of the Kerr-NUT-(A)dS family, namely, they possess the full Killing tower of hidden and explicit symmetries. As expected, for vanishing NUT, twist, and deformation parameters, the symmetry is further enlarged.

  20. Nuclear deformation effects in the cluster radioactivity

    Misicu, S. [Department of Theoretical Physics, NINPE-HH, Bucharest-Magurele (Romania); Protopopescu, D. [Frank Laboratory of Neutron Physics, JINR, Dubna (Russian Federation)


    We investigate the influence of the nuclear deformation on the decay rates of some cluster emission processes. The interaction between the daughter and the cluster is given by a double folding potential including quadrupole and hexadecapole deformed densities of both fragments. The nuclear part of the nucleus-nucleus interaction is density dependent and at small distances a repulsive core in the potential will occur. In the frame of the WKB-approximation the assault frequency of the cluster will depend on the geometric properties of the potential pocket whereas the penetrability will be sensitive to changes in the barrier location. The results obtained in this paper point out that various combinations of cluster and daughter deformations may account for the measured values of the decay rate. The decay rates are however more sensitive to the changes in the daughter deformation due to the large mass asymmetry of the process. (author) 10 refs, 6 figs, 1 tab