Science.gov

Sample records for 3d dynamic rupture

  1. A support-operator method for 3-D rupture dynamics

    NASA Astrophysics Data System (ADS)

    Ely, Geoffrey P.; Day, Steven M.; Minster, Jean-Bernard

    2009-06-01

    We present a numerical method to simulate spontaneous shear crack propagation within a heterogeneous, 3-D, viscoelastic medium. Wave motions are computed on a logically rectangular hexahedral mesh, using the generalized finite-difference method of Support Operators (SOM). This approach enables modelling of non-planar surfaces and non-planar fault ruptures. Our implementation, the Support Operator Rupture Dynamics (SORD) code, is highly scalable, enabling large-scale, multiprocessors calculations. The fault surface is modelled by coupled double nodes, where rupture occurs as dictated by the local stress conditions and a frictional failure law. The method successfully performs test problems developed for the Southern California Earthquake Center (SCEC)/U.S. Geological Survey (USGS) dynamic earthquake rupture code validation exercise, showing good agreement with semi-analytical boundary integral method results. We undertake further dynamic rupture tests to quantify numerical errors introduced by shear deformations to the hexahedral mesh. We generate a family of meshes distorted by simple shearing, in the along-strike direction, up to a maximum of 73°. For SCEC/USGS validation problem number 3, grid-induced errors increase with mesh shear angle, with the logarithm of error approximately proportional to angle over the range tested. At 73°, rms misfits are about 10 per cent for peak slip rate, and 0.5 per cent for both rupture time and total slip, indicating that the method (which, up to now, we have applied mainly to near-vertical strike-slip faulting) is also capable of handling geometries appropriate to low-angle surface-rupturing thrust earthquakes. Additionally, we demonstrate non-planar rupture effects, by modifying the test geometry to include, respectively, cylindrical curvature and sharp kinks.

  2. 3-D dynamic rupture simulations by a finite volume method

    NASA Astrophysics Data System (ADS)

    Benjemaa, M.; Glinsky-Olivier, N.; Cruz-Atienza, V. M.; Virieux, J.

    2009-07-01

    Dynamic rupture of a 3-D spontaneous crack of arbitrary shape is investigated using a finite volume (FV) approach. The full domain is decomposed in tetrahedra whereas the surface, on which the rupture takes place, is discretized with triangles that are faces of tetrahedra. First of all, the elastodynamic equations are described into a pseudo-conservative form for an easy application of the FV discretization. Explicit boundary conditions are given using criteria based on the conservation of discrete energy through the crack surface. Using a stress-threshold criterion, these conditions specify fluxes through those triangles that have suffered rupture. On these broken surfaces, stress follows a linear slip-weakening law, although other friction laws can be implemented. For The Problem Version 3 of the dynamic-rupture code verification exercise conducted by the SCEC/USGS, numerical solutions on a planar fault exhibit a very high convergence rate and are in good agreement with the reference one provided by a finite difference (FD) technique. For a non-planar fault of parabolic shape, numerical solutions agree satisfactorily well with those obtained with a semi-analytical boundary integral method in terms of shear stress amplitudes, stopping phases arrival times and stress overshoots. Differences between solutions are attributed to the low-order interpolation of the FV approach, whose results are particularly sensitive to the mesh regularity (structured/unstructured). We expect this method, which is well adapted for multiprocessor parallel computing, to be competitive with others for solving large scale dynamic ruptures scenarios of seismic sources in the near future.

  3. Dynamic earthquake rupture simulations on nonplanar faults embedded in 3D geometrically complex, heterogeneous elastic solids

    NASA Astrophysics Data System (ADS)

    Duru, Kenneth; Dunham, Eric M.

    2016-01-01

    Dynamic propagation of shear ruptures on a frictional interface in an elastic solid is a useful idealization of natural earthquakes. The conditions relating discontinuities in particle velocities across fault zones and tractions acting on the fault are often expressed as nonlinear friction laws. The corresponding initial boundary value problems are both numerically and computationally challenging. In addition, seismic waves generated by earthquake ruptures must be propagated for many wavelengths away from the fault. Therefore, reliable and efficient numerical simulations require both provably stable and high order accurate numerical methods. We present a high order accurate finite difference method for: a) enforcing nonlinear friction laws, in a consistent and provably stable manner, suitable for efficient explicit time integration; b) dynamic propagation of earthquake ruptures along nonplanar faults; and c) accurate propagation of seismic waves in heterogeneous media with free surface topography. We solve the first order form of the 3D elastic wave equation on a boundary-conforming curvilinear mesh, in terms of particle velocities and stresses that are collocated in space and time, using summation-by-parts (SBP) finite difference operators in space. Boundary and interface conditions are imposed weakly using penalties. By deriving semi-discrete energy estimates analogous to the continuous energy estimates we prove numerical stability. The finite difference stencils used in this paper are sixth order accurate in the interior and third order accurate close to the boundaries. However, the method is applicable to any spatial operator with a diagonal norm satisfying the SBP property. Time stepping is performed with a 4th order accurate explicit low storage Runge-Kutta scheme, thus yielding a globally fourth order accurate method in both space and time. We show numerical simulations on band limited self-similar fractal faults revealing the complexity of rupture dynamics

  4. Dynamic earthquake rupture simulation on nonplanar faults embedded in 3D geometrically complex, heterogeneous Earth models

    NASA Astrophysics Data System (ADS)

    Duru, K.; Dunham, E. M.; Bydlon, S. A.; Radhakrishnan, H.

    2014-12-01

    Dynamic propagation of shear ruptures on a frictional interface is a useful idealization of a natural earthquake.The conditions relating slip rate and fault shear strength are often expressed as nonlinear friction laws.The corresponding initial boundary value problems are both numerically and computationally challenging.In addition, seismic waves generated by earthquake ruptures must be propagated, far away from fault zones, to seismic stations and remote areas.Therefore, reliable and efficient numerical simulations require both provably stable and high order accurate numerical methods.We present a numerical method for:a) enforcing nonlinear friction laws, in a consistent and provably stable manner, suitable for efficient explicit time integration;b) dynamic propagation of earthquake ruptures along rough faults; c) accurate propagation of seismic waves in heterogeneous media with free surface topography.We solve the first order form of the 3D elastic wave equation on a boundary-conforming curvilinear mesh, in terms of particle velocities and stresses that are collocated in space and time, using summation-by-parts finite differences in space. The finite difference stencils are 6th order accurate in the interior and 3rd order accurate close to the boundaries. Boundary and interface conditions are imposed weakly using penalties. By deriving semi-discrete energy estimates analogous to the continuous energy estimates we prove numerical stability. Time stepping is performed with a 4th order accurate explicit low storage Runge-Kutta scheme. We have performed extensive numerical experiments using a slip-weakening friction law on non-planar faults, including recent SCEC benchmark problems. We also show simulations on fractal faults revealing the complexity of rupture dynamics on rough faults. We are presently extending our method to rate-and-state friction laws and off-fault plasticity.

  5. 3D dynamic rupture with anelastic wave propagation using an hp-adaptive Discontinuous Galerkin method

    NASA Astrophysics Data System (ADS)

    Tago, J.; Cruz-Atienza, V. M.; Etienne, V.; Virieux, J.; Benjemaa, M.; Sanchez-Sesma, F. J.

    2010-12-01

    Simulating any realistic seismic scenario requires incorporating physical basis into the model. Considering both the dynamics of the rupture process and the anelastic attenuation of seismic waves is essential to this purpose and, therefore, we choose to extend the hp-adaptive Discontinuous Galerkin finite-element method to integrate these physical aspects. The 3D elastodynamic equations in an unstructured tetrahedral mesh are solved with a second-order time marching approach in a high-performance computing environment. The first extension incorporates the viscoelastic rheology so that the intrinsic attenuation of the medium is considered in terms of frequency dependent quality factors (Q). On the other hand, the extension related to dynamic rupture is integrated through explicit boundary conditions over the crack surface. For this visco-elastodynamic formulation, we introduce an original discrete scheme that preserves the optimal code performance of the elastodynamic equations. A set of relaxation mechanisms describes the behavior of a generalized Maxwell body. We approximate almost constant Q in a wide frequency range by selecting both suitable relaxation frequencies and anelastic coefficients characterizing these mechanisms. In order to do so, we solve an optimization problem which is critical to minimize the amount of relaxation mechanisms. Two strategies are explored: 1) a least squares method and 2) a genetic algorithm (GA). We found that the improvement provided by the heuristic GA method is negligible. Both optimization strategies yield Q values within the 5% of the target constant Q mechanism. Anelastic functions (i.e. memory variables) are introduced to efficiently evaluate the time convolution terms involved in the constitutive equations and thus to minimize the computational cost. The incorporation of anelastic functions implies new terms with ordinary differential equations in the mathematical formulation. We solve these equations using the same order

  6. 3D Dynamic Rupture Simulations Across Interacting Faults: the Mw7.0, 2010, Haiti Earthquake

    NASA Astrophysics Data System (ADS)

    Douilly, R.; Aochi, H.; Calais, E.; Freed, A. M.; Aagaard, B.

    2014-12-01

    The mechanisms controlling rupture propagation between fault segments during an earthquake are key to the hazard posed by fault systems. Rupture initiation on a fault segment sometimes transfers to a larger fault, resulting in a significant event (e.g.i, 2002 M7.9Denali and 2010 M7.1 Darfield earthquakes). In other cases rupture is constrained to the initial segment and does not transfer to nearby faults, resulting in events of moderate magnitude. This is the case of the 1989 M6.9 Loma Prieta and 2010 M7.0 Haiti earthquakes which initiated on reverse faults abutting against a major strike-slip plate boundary fault but did not propagate onto it. Here we investigatethe rupture dynamics of the Haiti earthquake, seeking to understand why rupture propagated across two segments of the Léogâne fault but did not propagate to the adjacenent Enriquillo Plantain Garden Fault, the major 200 km long plate boundary fault cutting through southern Haiti. We use a Finite Element Model to simulate the nucleation and propagation of rupture on the Léogâne fault, varying friction and background stress to determine the parameter set that best explains the observed earthquake sequence. The best-fit simulation is in remarkable agreement with several finite fault inversions and predicts ground displacement in very good agreement with geodetic and geological observations. The two slip patches inferred from finite-fault inversions are explained by the successive rupture of two fault segments oriented favorably with respect to the rupture propagation, while the geometry of the Enriquillo fault did not allow shear stress to reach failure. Although our simulation results replicate well the ground deformation consistent with the geodetic surface observation but convolving the ground motion with the soil amplification from the microzonation study will correctly account for the heterogeneity of the PGA throughout the rupture area.

  7. Dynamic earthquake rupture modelled with an unstructured 3-D spectral element method applied to the 2011 M9 Tohoku earthquake

    NASA Astrophysics Data System (ADS)

    Galvez, P.; Ampuero, J.-P.; Dalguer, L. A.; Somala, S. N.; Nissen-Meyer, T.

    2014-08-01

    An important goal of computational seismology is to simulate dynamic earthquake rupture and strong ground motion in realistic models that include crustal heterogeneities and complex fault geometries. To accomplish this, we incorporate dynamic rupture modelling capabilities in a spectral element solver on unstructured meshes, the 3-D open source code SPECFEM3D, and employ state-of-the-art software for the generation of unstructured meshes of hexahedral elements. These tools provide high flexibility in representing fault systems with complex geometries, including faults with branches and non-planar faults. The domain size is extended with progressive mesh coarsening to maintain an accurate resolution of the static field. Our implementation of dynamic rupture does not affect the parallel scalability of the code. We verify our implementation by comparing our results to those of two finite element codes on benchmark problems including branched faults. Finally, we present a preliminary dynamic rupture model of the 2011 Mw 9.0 Tohoku earthquake including a non-planar plate interface with heterogeneous frictional properties and initial stresses. Our simulation reproduces qualitatively the depth-dependent frequency content of the source and the large slip close to the trench observed for this earthquake.

  8. Dynamic rupture modeling of the 2011 M9 Tohoku earthquake with an unstructured 3D spectral element method

    NASA Astrophysics Data System (ADS)

    Galvez, P.; Ampuero, J. P.; Dalguer, L. A.; Nissen-Meyer, T.

    2011-12-01

    On March 11th 2011, a Mw 9 earthquake stroke Japan causing 28000 victims and triggering a devastating tsunami that caused severe damage along the Japanese coast. The exceptional amount of data recorded by this earthquake, with thousands of sensors located all over Japan, provides a great opportunity for seismologist and engineers to investigate in detail the rupture process in order to better understand the physics of this type of earthquakes and their associated effects, like tsunamis. Here we investigate, by means of dynamic rupture simulations, a plausible mechanism to explain key observations about the rupture process of the 2011 M9 Tohoku earthquake, including the spatial complementarity between high and low frequency aspects of slip (e.g, Simons et al, Science 2011, Meng et al, GRL 2011). To model the dynamic rupture of this event, we use a realistic non-planar fault geometry of the megathrust interface, using the unstructured 3D spectral element open source code SPECFEM3D-SESAME, in which we recently implemented the dynamic fault boundary conditions. This implementation follows the principles introduced by Ampuero (2002) and Kaneko et al. (2008) and involves encapsulated modules plugged into the code. Our current implementation provides the possibility of modeling dynamic rupture for multiple, non-planar faults governed by slip-weakening friction. We successfully verified the code in several SCEC benchmarks, including a 3D problem with branched faults, as well as modeling the rupture of subduction megathrust with a splay fault, finding results comparable to published results. Our first set of simulations is aimed at testing if the diversity of rupture phenomena during the 2011 M9 Tohoku earthquake (see Ampuero et al in this session) can be overall reproduced by assuming the most basic friction law, linear slip-weakening friction, but prescribing a spatially heterogeneous distribution of the critical slip weakening distance Dc and initial fault stresses. Our

  9. 3D Dynamic Rupture Simulation Across a Complex Fault System: the Mw7.0, 2010, Haiti Earthquake

    NASA Astrophysics Data System (ADS)

    Douilly, R.; Aochi, H.; Calais, E.; Freed, A. M.

    2013-12-01

    Earthquakes ruptures sometimes take place on a secondary fault and surprisingly do not activate an adjacent major one. The 1989 Loma Prieta earthquake is a classic case where rupture occurred on a blind thrust while the adjacent San Andreas Fault was not triggered during the process. Similar to Loma Prieta, the Mw7.0, January 12 2010, Haiti earthquake also ruptured a secondary blind thrust, the Léogâne fault, adjacent to the main plate boundary, the Enriquillo Plantain Garden Fault, which did not rupture during this event. Aftershock relocalizations delineate the Léogâne rupture with two north dipping segments with slightly different dip, where the easternmost segment had mostly dip-slip motion and the westernmost one had mostly strike-slip motion. In addition, an offshore south dipping structure inferred from the aftershocks to the west of the rupture zone coincides with the offshore Trois Baies reverse fault, a region of increase in Coulomb stress increase. In this study, we investigate the rupture dynamics of the Haiti earthquake in a complex fault system of multiple segments identified by the aftershock relocations. We suppose a background stress regime that is consistent with the type of motion of each fault and with the regional tectonic regime. We initiate a nucleation on the east segment of the Léogâne fault by defining a circular region with a 2 km radius where shear stress is slightly greater than the yield stress. By varying friction on faults and background stress, we find a range of plausible scenarios. In the absence of near-field seismic records of the event, we score the different models against the static deformation field derived from GPS and InSAR at the surface. All the plausible simulations show that the rupture propagates from the eastern to the western segment along the Léogâne fault, but not on the Enriquillo fault nor on the Trois Baies fault. The best-fit simulation shows a significant increase of shear stresses on the Trois Baies

  10. 3-D ground motion modeling for M7 dynamic rupture earthquake scenarios on the Wasatch fault, Utah

    NASA Astrophysics Data System (ADS)

    Roten, D.; Olsen, K. B.; Cruz Atienza, V. M.; Pechmann, J. C.; Magistrale, H. W.

    2009-12-01

    The Salt Lake City segment of the Wasatch fault (WFSLC), located on the eastern edge of the Salt Lake Basin (SLB), is capable of producing M7 earthquakes and represents a serious seismic hazard to Salt Lake City, Utah. We simulate a series of rupture scenarios on the WFSLC to quantify the ground motion expected from such M7 events and to assess the importance of amplification effects from basin focusing and source directivity. We use the newly revised Wasatch Front community velocity model for our simulations, which is tested by simulating records of three local Mw 3.3-3.7 earthquakes in the frequency band 0.5 to 1.0 Hz. The M7 earthquake scenarios make use of a detailed 3-D model geometry of the WFSLC that we developed based on geological observations. To obtain a suite of realistic source representations for M7 WFSLC simulations we perform spontaneous-rupture simulations on a planar 43 km by 23 km fault with the staggered-grid split-node finite-difference (FD) method. We estimate the initial distribution of shear stress using models that assume depth-dependent normal stress for a dipping, normal fault as well as simpler models which use constant (depth-independent) normal stress. The slip rate histories from the spontaneous rupture scenarios are projected onto the irregular dipping geometry of the WFSLC and used to simulate 0-1 Hz wave propagation in the SLB area using a 4th-order, staggered-grid visco-elastic FD method. We find that peak ground velocities tend to be larger on the low-velocity sediments on the hanging wall side of the fault than on outcropping rock on the footwall side, confirming results of previous studies on normal faulting earthquakes. The simulated ground motions reveal strong along-strike directivity effects for ruptures nucleating towards the ends of the WFSLC. The 0-1 Hz FD simulations are combined with local scattering operators to obtain broadband (0-10 Hz) synthetics and maps of average peak ground motions. Finally we use broadband

  11. 3D Dynamic Echocardiography with a Digitizer

    NASA Astrophysics Data System (ADS)

    Oshiro, Osamu; Matani, Ayumu; Chihara, Kunihiro

    1998-05-01

    In this paper,a three-dimensional (3D) dynamic ultrasound (US) imaging system,where a US brightness-mode (B-mode) imagetriggered with an R-wave of electrocardiogram (ECG)was obtained with an ultrasound diagnostic deviceand the location and orientation of the US probewere simultaneously measured with a 3D digitizer, is described.The obtained B-mode imagewas then projected onto a virtual 3D spacewith the proposed interpolation algorithm using a Gaussian operator.Furthermore, a 3D image was presented on a cathode ray tube (CRT)and stored in virtual reality modeling language (VRML).We performed an experimentto reconstruct a 3D heart image in systole using this system.The experimental results indicatethat the system enables the visualization ofthe 3D and internal structure of a heart viewed from any angleand has potential for use in dynamic imaging,intraoperative ultrasonography and tele-medicine.

  12. Static & Dynamic Response of 3D Solids

    1996-07-15

    NIKE3D is a large deformations 3D finite element code used to obtain the resulting displacements and stresses from multi-body static and dynamic structural thermo-mechanics problems with sliding interfaces. Many nonlinear and temperature dependent constitutive models are available.

  13. Quantification of Ground Motion Reductions by Fault Zone Plasticity with 3D Spontaneous Rupture Simulations

    NASA Astrophysics Data System (ADS)

    Roten, D.; Olsen, K. B.; Cui, Y.; Day, S. M.

    2015-12-01

    We explore the effects of fault zone nonlinearity on peak ground velocities (PGVs) by simulating a suite of surface rupturing earthquakes in a visco-plastic medium. Our simulations, performed with the AWP-ODC 3D finite difference code, cover magnitudes from 6.5 to 8.0, with several realizations of the stochastic stress drop for a given magnitude. We test three different models of rock strength, with friction angles and cohesions based on criteria which are frequently applied to fractured rock masses in civil engineering and mining. We use a minimum shear-wave velocity of 500 m/s and a maximum frequency of 1 Hz. In rupture scenarios with average stress drop (~3.5 MPa), plastic yielding reduces near-fault PGVs by 15 to 30% in pre-fractured, low-strength rock, but less than 1% in massive, high quality rock. These reductions are almost insensitive to the scenario earthquake magnitude. In the case of high stress drop (~7 MPa), however, plasticity reduces near-fault PGVs by 38 to 45% in rocks of low strength and by 5 to 15% in rocks of high strength. Because plasticity reduces slip rates and static slip near the surface, these effects can partially be captured by defining a shallow velocity-strengthening layer. We also perform a dynamic nonlinear simulation of a high stress drop M 7.8 earthquake rupturing the southern San Andreas fault along 250 km from Indio to Lake Hughes. With respect to the viscoelastic solution (a), nonlinearity in the fault damage zone and in near-surface deposits would reduce long-period (> 1 s) peak ground velocities in the Los Angeles basin by 15-50% (b), depending on the strength of crustal rocks and shallow sediments. These simulation results suggest that nonlinear effects may be relevant even at long periods, especially for earthquakes with high stress drop.

  14. Can 3D-CT angiography (3D-CTA) replace conventional catheter angiography in ruptured aneurysm surgery? Our experience with 162 cases.

    PubMed

    Matsumoto, Masato; Kasuya, Hiromichi; Sato, Taku; Endo, Yuji; Sakuma, Jun; Suzuki, Kyouichi; Sasaki, Tatsuya; Kodama, Namio

    2007-12-01

    In this communication, we studied whether 3D-CT angiography (3D CTA) gives us enough information for a safe operation without those from conventional catheter angiography (CCA) in patients with ruptured aneurysms. Between December 1996 and September 2005, we treated 162 consecutive patients with ruptured aneurysms in the acute stage based on 3D-CTA findings. One hundred sixty-two ruptured aneurysms, including 64 associated unruptured aneurysms, were detected using 3D-CTA. CCA was performed in nine (5.6%) of the 162 patients after 3D-CTA. They were four dissecting vertebral artery aneurysms, two basilar tip aneurysms, one basilar artery-superior cerebellar artery (BA-SCA), one previously clipped BA-SCA and one internal carotid-posterior communicating artery aneurysm. All ruptured aneurysms confirmed at surgery were treated successfully. The lack of information on CCA did not lead any neurological deficits or difficulties in the surgical procedure. 3D-CTA was of high diagnostic value compatible with CCA and yielded important information such as the configuration of the aneurysmal sac and neck, calcification in the aneurysmal wall, and the aneurysms' anatomic relation with adjacent vessels and bone structures. We suggest that 3D-CTA can replace CCA in the diagnosis of ruptured aneurysms and that most of ruptured aneurysms can be operated by using only 3D-CTA without CCA. PMID:18402288

  15. 3D dynamic roadmapping for abdominal catheterizations.

    PubMed

    Bender, Frederik; Groher, Martin; Khamene, Ali; Wein, Wolfgang; Heibel, Tim Hauke; Navab, Nassir

    2008-01-01

    Despite rapid advances in interventional imaging, the navigation of a guide wire through abdominal vasculature remains, not only for novice radiologists, a difficult task. Since this navigation is mostly based on 2D fluoroscopic image sequences from one view, the process is slowed down significantly due to missing depth information and patient motion. We propose a novel approach for 3D dynamic roadmapping in deformable regions by predicting the location of the guide wire tip in a 3D vessel model from the tip's 2D location, respiratory motion analysis, and view geometry. In a first step, the method compensates for the apparent respiratory motion in 2D space before backprojecting the 2D guide wire tip into three dimensional space, using a given projection matrix. To countervail the error connected to the projection parameters and the motion compensation, as well as the ambiguity caused by vessel deformation, we establish a statistical framework, which computes a reliable estimate of the guide wire tip location within the 3D vessel model. With this 2D-to-3D transfer, the navigation can be performed from arbitrary viewing angles, disconnected from the static perspective view of the fluoroscopic sequence. Tests on a realistic breathing phantom and on synthetic data with a known ground truth clearly reveal the superiority of our approach compared to naive methods for 3D roadmapping. The concepts and information presented in this paper are based on research and are not commercially available. PMID:18982662

  16. The effectiveness of 3D animations to enhance understanding of cranial cruciate ligament rupture.

    PubMed

    Clements, Dylan N; Broadhurst, Henry; Clarke, Stephen P; Farrell, Michael; Bennett, David; Mosley, John R; Mellanby, Richard J

    2013-01-01

    Cranial cruciate ligament (CCL) rupture is one of the most important orthopedic diseases taught to veterinary undergraduates. The complexity of the anatomy of the canine stifle joint combined with the plethora of different surgical interventions available for the treatment of the disease means that undergraduate veterinary students often have a poor understanding of the pathophysiology and treatment of CCL rupture. We designed, developed, and tested a three dimensional (3D) animation to illustrate the pertinent clinical anatomy of the stifle joint, the effects of CCL rupture, and the mechanisms by which different surgical techniques can stabilize the joint with CCL rupture. When compared with a non-animated 3D presentation, students' short-term retention of functional anatomy improved although they could not impart a better explanation of how different surgical techniques worked. More students found the animation useful than those who viewed a comparable non-animated 3D presentation. Multiple peer-review testing is required to maximize the usefulness of 3D animations during development. Free and open access to such tools should improve student learning and client understanding through wide-spread uptake and use. PMID:23475409

  17. INCORPORATING DYNAMIC 3D SIMULATION INTO PRA

    SciTech Connect

    Steven R Prescott; Curtis Smith

    2011-07-01

    provide superior results and insights. We also couple the state model with the dynamic 3D simulation analysis representing events (such as flooding) to determine which (if any) components fail. Not only does the simulation take into account any failed items from the state model, but any failures caused by the simulation are incorporated back into the state model and factored into the overall results. Using this method we incorporate accurate 3D simulation results, eliminate static-based PRA issues, and have time ordered failure information.

  18. Structural control on the Tohoku earthquake rupture process investigated by 3D FEM, tsunami and geodetic data

    PubMed Central

    Romano, F.; Trasatti, E.; Lorito, S.; Piromallo, C.; Piatanesi, A.; Ito, Y.; Zhao, D.; Hirata, K.; Lanucara, P.; Cocco, M.

    2014-01-01

    The 2011 Tohoku earthquake (Mw = 9.1) highlighted previously unobserved features for megathrust events, such as the large slip in a relatively limited area and the shallow rupture propagation. We use a Finite Element Model (FEM), taking into account the 3D geometrical and structural complexities up to the trench zone, and perform a joint inversion of tsunami and geodetic data to retrieve the earthquake slip distribution. We obtain a close spatial correlation between the main deep slip patch and the local seismic velocity anomalies, and large shallow slip extending also to the North coherently with a seismically observed low-frequency radiation. These observations suggest that the friction controlled the rupture, initially confining the deeper rupture and then driving its propagation up to the trench, where it spreads laterally. These findings are relevant to earthquake and tsunami hazard assessment because they may help to detect regions likely prone to rupture along the megathrust, and to constrain the probability of high slip near the trench. Our estimate of ~40 m slip value around the JFAST (Japan Trench Fast Drilling Project) drilling zone contributes to constrain the dynamic shear stress and friction coefficient of the fault obtained by temperature measurements to ~0.68 MPa and ~0.10, respectively. PMID:25005351

  19. Structural control on the Tohoku earthquake rupture process investigated by 3D FEM, tsunami and geodetic data.

    PubMed

    Romano, F; Trasatti, E; Lorito, S; Piromallo, C; Piatanesi, A; Ito, Y; Zhao, D; Hirata, K; Lanucara, P; Cocco, M

    2014-01-01

    The 2011 Tohoku earthquake (Mw = 9.1) highlighted previously unobserved features for megathrust events, such as the large slip in a relatively limited area and the shallow rupture propagation. We use a Finite Element Model (FEM), taking into account the 3D geometrical and structural complexities up to the trench zone, and perform a joint inversion of tsunami and geodetic data to retrieve the earthquake slip distribution. We obtain a close spatial correlation between the main deep slip patch and the local seismic velocity anomalies, and large shallow slip extending also to the North coherently with a seismically observed low-frequency radiation. These observations suggest that the friction controlled the rupture, initially confining the deeper rupture and then driving its propagation up to the trench, where it spreads laterally. These findings are relevant to earthquake and tsunami hazard assessment because they may help to detect regions likely prone to rupture along the megathrust, and to constrain the probability of high slip near the trench. Our estimate of ~40 m slip value around the JFAST (Japan Trench Fast Drilling Project) drilling zone contributes to constrain the dynamic shear stress and friction coefficient of the fault obtained by temperature measurements to ~0.68 MPa and ~0.10, respectively. PMID:25005351

  20. SORD: A New Rupture Dynamics Modeling Code

    NASA Astrophysics Data System (ADS)

    Ely, G.; Minster, B.; Day, S.

    2005-12-01

    We report on our progress in validating our rupture dynamics modeling code, capable of dealing with nonplanar faults and surface topography. The method uses a "mimetic" approach to model spontaneous rupture on a fault within a 3D isotropic anelastic solid, wherein the equations of motion are approximated with a second order Support-Operator method on a logically rectangular mesh. Grid cells are not required to be parallelepipeds, however, so that non-rectangular meshes can be supported to model complex regions. However, for areas in the mesh which are in fact rectangular, the code uses a streamlined version of the algorithm that takes advantage of the simplifications of the operators in such areas. The fault itself is modeled using a double node technique, and the rheology on the fault surface is modeled through a slip-weakening, frictional, internal boundary condition. The Support Operator Rupture Dynamics (SORD) code, was prototyped in MATLAB, and all algorithms have been validated against known (including analytical solutions, eg Kostrov, 1964) solutions or previously validated solutions. This validation effort is conducted in the context of the SCEC Dynamic Rupture model validation effort led by R. Archuleta and R. Harris. Absorbing boundaries at the model edges are handled using the perfectly matched layers method (PML) (Olsen & Marcinkovich, 2003). PML is shown to work extremely well on rectangular meshes. We show that our implementation is also effective on non-rectangular meshes under the restriction that the boundary be planar. For validation of the model we use a variety of test cases using two types of meshes: a rectangular mesh and skewed mesh. The skewed mesh amplifies any biases caused by the Support-Operator method on non-rectangular elements. Wave propagation and absorbing boundaries are tested with a spherical wave source. Rupture dynamics on a planar fault are tested against (1) a Kostrov analytical solution, (2) data from foam rubber scale models

  1. 3D imaging using projected dynamic fringes

    NASA Astrophysics Data System (ADS)

    Shaw, Michael M.; Atkinson, John T.; Harvey, David M.; Hobson, Clifford A.; Lalor, Michael J.

    1994-12-01

    An instrument capable of highly accurate, non-contact range measurement has been developed, which is based upon the principle of projected rotating fringes. More usually known as dynamic fringe projection, it is this technique which is exploited in the dynamic automated range transducer (DART). The intensity waveform seen at the target and sensed by the detector, contains all the information required to accurately determine the fringe order. This, in turn, allows the range to be evaluated by the substitution of the fringe order into a simple algebraic expression. Various techniques for the analysis of the received intensity signals from the surface of the target have been investigated. The accuracy to which the range can be determined ultimately depends upon the accuracy to which the fringe order can be evaluated from the received intensity waveform. It is extremely important to be able to closely determine the fractional fringe order value, to achieve any meaningful results. This paper describes a number of techniques which have been used to analyze the intensity waveform, and critically appraises their suitability in terms of accuracy and required speed of operation. This work also examines the development of this instrument for three-dimensional measurements based on single or two beam systems. Using CCD array detectors, a 3-D range map of the object's surface may be produced.

  2. Simulating coronal condensation dynamics in 3D

    NASA Astrophysics Data System (ADS)

    Moschou, S. P.; Keppens, R.; Xia, C.; Fang, X.

    2015-12-01

    We present numerical simulations in 3D settings where coronal rain phenomena take place in a magnetic configuration of a quadrupolar arcade system. Our simulation is a magnetohydrodynamic simulation including anisotropic thermal conduction, optically thin radiative losses, and parametrised heating as main thermodynamical features to construct a realistic arcade configuration from chromospheric to coronal heights. The plasma evaporation from chromospheric and transition region heights eventually causes localised runaway condensation events and we witness the formation of plasma blobs due to thermal instability, that evolve dynamically in the heated arcade part and move gradually downwards due to interchange type dynamics. Unlike earlier 2.5D simulations, in this case there is no large scale prominence formation observed, but a continuous coronal rain develops which shows clear indications of Rayleigh-Taylor or interchange instability, that causes the denser plasma located above the transition region to fall down, as the system moves towards a more stable state. Linear stability analysis is used in the non-linear regime for gaining insight and giving a prediction of the system's evolution. After the plasma blobs descend through interchange, they follow the magnetic field topology more closely in the lower coronal regions, where they are guided by the magnetic dips.

  3. Analysis of the rupture process of the 1995 Kobe earthquake using a 3D velocity structure

    NASA Astrophysics Data System (ADS)

    Guo, Yujia; Koketsu, Kazuki; Ohno, Taichi

    2013-12-01

    A notable feature of the 1995 Kobe (Hyogo-ken Nanbu) earthquake is that violent ground motions occurred in a narrow zone. Previous studies have shown that the origin of such motions can be explained by the 3D velocity structure in this zone. This indicates not only that the 3D velocity structure significantly affects strong ground motions, but also that we should consider its effects in order to determine accurately the rupture process of the earthquake. Therefore, we have performed a joint source inversion of strong-motion, geodetic, and teleseismic data, where 3D Green's functions were calculated for strong-motion and geodetic data in the Osaka basin. Our source model estimates the total seismic moment to be about 2.1 × 1019 N m and the maximum slip reaches 2.9 m near the hypocenter. Although the locations of large slips are similar to those reported by Yoshida et al. (1996), there are quantitative differences between our results and their results due to the differences between the 3D and 1D Green's functions. We have also confirmed that our source model realized a better fit to the strong motion observations, and a similar fit as Yoshida et al. (1996) to the observed static displacements.

  4. 3D Dynamic Earthquake Fracture Simulation (Test Case)

    NASA Astrophysics Data System (ADS)

    Korkusuz Öztürk, Yasemin; Meral Özel, Nurcan; Ando, Ryosuke

    2016-04-01

    A 3D dynamic earthquake fracture simulation is being developed for the fault structures which are non-planar to understand heterogeneous stress states in the Marmara Sea. Locating in a seismic gap, a large earthquake is expected in the center of the Sea of Marmara. Concerning the fact that more than 14 million inhabitants of İstanbul, located very closely to the Marmara Sea, the importance of the analysis of the Central Marmara Sea is extremely high. A few 3D dynamic earthquake fracture studies have been already done in the Sea of Marmara for pure right lateral strike-slip stress regimes (Oglesby and Mai, 2012; Aochi and Ulrich, 2015). In this study, a 3D dynamic earthquake fracture model with heterogeneous stress patches from the TPV5, a SCEC code validation case, is adapted. In this test model, the fault and the ground surfaces are gridded by a scalene triangulation technique using GMSH program. For a grid size changing between 0.616 km and 1.050 km the number of elements for the fault surface is 1984 and for the ground surface is 1216. When these results are compared with Kaneko's results for TPV5 from SPECFEM3D, reliable findings could be observed for the first 6.5 seconds (stations on the fault) although a stability problem is encountered after this time threshold. To solve this problem grid sizes are made smaller, so the number of elements increase 7986 for the fault surface and 4867 for the ground surface. On the other hand, computational problems arise in that case, since the computation time is directly proportional to the number of total elements and the required memory also increases with the square of that. Therefore, it is expected that this method can be adapted for less coarse grid cases, regarding the main difficulty coming from the necessity of an effective supercomputer and run time limitations. The main objective of this research is to obtain 3D dynamic earthquake rupture scenarios, concerning not only planar and non-planar faults but also

  5. Phase unwrapping in the dynamic 3D measurement

    NASA Astrophysics Data System (ADS)

    Su, Xianyu; Zhang, Qican

    2010-04-01

    In the dynamic 3D shape measurement phase distribution has 3D character, in which phase changes along x and y directions in space and also along t direction in time. 3D phase unwrapping plays a very important role in the dynamic 3D shape measurement. In the dynamic 3D shape measurement methods based on the structured illumination, Fourier transformation profilometry (FTP) is particularly fit for dynamic 3D measurement, because of only one fringe pattern needed and full field analysis. In this paper some 3D phase unwrapping techniques for dynamic 3D shape measurement mainly in our Lab. are presented and reviewed. The basic methods and algorithm design are introduced. The basic methods include direct 3D phase unwrapping, 3D diamond phase unwrapping, 3D phase unwrapping based on reliability ordering, 3D phase unwrapping based on marked fringe tracing. The advantage of the phase unwrapping based on reliability ordering is that the path of phase unwrapping is always along the direction from the pixel with higher reliability parameter value to the pixel with low reliability parameter value. Therefore, in the worse case the error is limited, if there is any, to local minimum areas.

  6. Rupture dynamics in model polymer systems.

    PubMed

    Borah, Rupam; Debnath, Pallavi

    2016-05-11

    In this paper we explore the rupture dynamics of a model polymer system to capture the microscopic mechanism during relative motion of surfaces at the single polymer level. Our model is similar to the model for friction introduced by Filippov, Klafter, and Urbakh [Filippov et al., Phys. Rev. Lett., 2004, 92, 135503]; but with an important generalization to a flexible transducer (modelled as a bead spring polymer) which is attached to a fixed rigid planar substrate by interconnecting bonds (modelled as harmonic springs), and pulled by a constant force FT. Bonds are allowed to rupture stochastically. The model is simulated, and the results for a certain set of parameters exhibit a sequential rupture mechanism resulting in rupture fronts. A mean field formalism is developed to study these rupture fronts and the possible propagating solutions for the coupled bead and bond dynamics, where the coupling excludes an exact analytical treatment. Numerical solutions to mean field equations are obtained by standard numerical techniques, and they agree well with the simulation results which show sequential rupture. Within a travelling wave formalism based on the Tanh method, we show that the velocity of the rupture front can be obtained in closed form. The derived expression for the rupture front velocity gives good agreement with the stochastic and mean field results, when the rupture is sequential, while propagating solutions for bead and bond dynamics are shown to agree under certain conditions. PMID:27087684

  7. 3D-dynamic representation of DNA sequences.

    PubMed

    Wąż, Piotr; Bielińska-Wąż, Dorota

    2014-03-01

    A new 3D graphical representation of DNA sequences is introduced. This representation is called 3D-dynamic representation. It is a generalization of the 2D-dynamic dynamic representation. The sequences are represented by sets of "material points" in the 3D space. The resulting 3D-dynamic graphs are treated as rigid bodies. The descriptors characterizing the graphs are analogous to the ones used in the classical dynamics. The classification diagrams derived from this representation are presented and discussed. Due to the third dimension, "the history of the graph" can be recognized graphically because the 3D-dynamic graph does not overlap with itself. Specific parts of the graphs correspond to specific parts of the sequence. This feature is essential for graphical comparisons of the sequences. Numerically, both 2D and 3D approaches are of high quality. In particular, a difference in a single base between two sequences can be identified and correctly described (one can identify which base) by both 2D and 3D methods. PMID:24567158

  8. DYNAMIC 3D QSAR TECHNIQUES: APPLICATIONS IN TOXICOLOGY

    EPA Science Inventory

    Two dynamic techniques recently developed to account for conformational flexibility of chemicals in 3D QSARs are presented. In addition to the impact of conformational flexibility of chemicals in 3D QSAR models, the applicability of various molecular descriptors is discussed. The...

  9. Dynamic 3D echocardiography in virtual reality

    PubMed Central

    van den Bosch, Annemien E; Koning, Anton HJ; Meijboom, Folkert J; McGhie, Jackie S; Simoons, Maarten L; van der Spek, Peter J; Bogers, Ad JJC

    2005-01-01

    Background This pilot study was performed to evaluate whether virtual reality is applicable for three-dimensional echocardiography and if three-dimensional echocardiographic 'holograms' have the potential to become a clinically useful tool. Methods Three-dimensional echocardiographic data sets from 2 normal subjects and from 4 patients with a mitral valve pathological condition were included in the study. The three-dimensional data sets were acquired with the Philips Sonos 7500 echo-system and transferred to the BARCO (Barco N.V., Kortrijk, Belgium) I-space. Ten independent observers assessed the 6 three-dimensional data sets with and without mitral valve pathology. After 10 minutes' instruction in the I-Space, all of the observers could use the virtual pointer that is necessary to create cut planes in the hologram. Results The 10 independent observers correctly assessed the normal and pathological mitral valve in the holograms (analysis time approximately 10 minutes). Conclusion this report shows that dynamic holographic imaging of three-dimensional echocardiographic data is feasible. However, the applicability and use-fullness of this technology in clinical practice is still limited. PMID:16375768

  10. Probabilistic Seismic Hazard Maps of Seattle, Washington, Including 3D Sedimentary Basin Effects and Rupture Directivity: Implications of 3D Random Velocity Variations (Invited)

    NASA Astrophysics Data System (ADS)

    Frankel, A. D.; Stephenson, W. J.; Carver, D.; Odum, J.; Williams, R. A.; Rhea, S.

    2010-12-01

    We have produced probabilistic seismic hazard maps of Seattle for 1 Hz spectral acceleration, using over five hundred 3D finite-difference simulations of earthquakes on the Seattle fault, Southern Whidbey Island fault, and Cascadia subduction zone, as well as for random deep and shallow earthquakes at various locations. The 3D velocity model was validated by modeling the observed waveforms for the 2001 M6.8 Nisqually earthquake and several smaller events in the region. At these longer periods (≥ 1 sec) that are especially important to the response of buildings of ten stories or higher, seismic waves are strongly influenced by sedimentary basins and rupture directivity. We are investigating how random spatial variations in the 3D velocity model affect the simulated ground motions for M6.7 earthquakes on the Seattle fault. A fractal random variation of shear-wave velocity with a Von Karman correlation function produces spatial variations of peak ground velocity with multiple scale lengths. We find that a 3D velocity model with a 10% standard deviation in shear-wave velocity in the top 1.5 km and 5% standard deviation from 1.5-10 km depth produces variations in peak ground velocities of as much as a factor of two, relative to the case with no random variations. The model with random variations generally reduces the peak ground velocity of the forward rupture directivity pulse for sites near the fault where basin-edge focusing of S-waves occurs. It also tends to reduce the peak velocity of localized areas where basin surface waves are focused. However, the medium with random variations also causes small-scale amplification of ground motions over distances of a few kilometers. We are also evaluating alternative methods of characterizing the aleatory uncertainty in the probabilistic hazard calculations.

  11. Dynamic 3D Visualization of Vocal Tract Shaping During Speech

    PubMed Central

    Zhu, Yinghua; Kim, Yoon-Chul; Proctor, Michael I.; Narayanan, Shrikanth S.; Nayak, Krishna S.

    2014-01-01

    Noninvasive imaging is widely used in speech research as a means to investigate the shaping and dynamics of the vocal tract during speech production. 3D dynamic MRI would be a major advance, as it would provide 3D dynamic visualization of the entire vocal tract. We present a novel method for the creation of 3D dynamic movies of vocal tract shaping based on the acquisition of 2D dynamic data from parallel slices and temporal alignment of the image sequences using audio information. Multiple sagittal 2D real-time movies with synchronized audio recordings are acquired for English vowel-consonant-vowel stimuli /ala/, /aɹa/, /asa/ and /aʃa/. Audio data are aligned using mel-frequency cepstral coefficients (MFCC) extracted from windowed intervals of the speech signal. Sagittal image sequences acquired from all slices are then aligned using dynamic time warping (DTW). The aligned image sequences enable dynamic 3D visualization by creating synthesized movies of the moving airway in the coronal planes, visualizing desired tissue surfaces and tube-shaped vocal tract airway after manual segmentation of targeted articulators and smoothing. The resulting volumes allow for dynamic 3D visualization of salient aspects of lingual articulation, including the formation of tongue grooves and sublingual cavities, with a temporal resolution of 78 ms. PMID:23204279

  12. Dynamic rupture activation of backthrust fault branching

    NASA Astrophysics Data System (ADS)

    Xu, Shiqing; Fukuyama, Eiichi; Ben-Zion, Yehuda; Ampuero, Jean-Paul

    2015-03-01

    We perform dynamic rupture simulations to investigate the possible reactivation of backthrust branches triggered by ruptures along a main thrust fault. Simulations with slip-weakening fault friction and uniform initial stress show that fast propagation speed or long propagation distance of the main rupture promotes reactivation of backthrust over a range of branch angles. The latter condition may occur separately from the former if rupture speed is limited by an increasing slip-weakening distance towards the junction direction. The results suggest a trade-off between the amplitude and duration of the dynamic stress near the main rupture front for backthrust reactivation. Termination of the main rupture by a barrier can provide enhanced loading amplitude and duration along a backthrust rooted near the barrier, facilitating its reactivation especially with a high frictional resistance. The free surface and depth-dependent initial stress can have several additional effects. The sign of the triggered motion along the backthrust can be reversed from thrust to normal if a deeply nucleated main rupture breaks the free surface, while it is preserved as thrust if the main rupture is terminated by a barrier at depth. The numerical results are discussed in relation to several recent megathrust earthquakes in Sumatra, Chile, and Japan, and related topics such as branch feedbacks to the main fault. The dynamic view on backthrust fault branching provided by the study fills a gap not covered by quasi-static models or observations. A specific examined case of antithetic fault branching may be useful for indicating a barrier-like behavior along the main fault.

  13. A 3-D perspective of dynamic behaviour of heterogeneous solids

    NASA Astrophysics Data System (ADS)

    Lu, Yong; Zhou, Rongxin

    2015-09-01

    The dynamic behaviour of concrete-like materials under high strain rates has been a subject of continuous scrutiny over the years. A prevailing explanation attributes much of the dynamic increase of strength, especially under compression, to the macroscopic inertia confinement. Studies conducted by the authors' group using meso-scale computational models suggest that the heterogeneity of the material composition, in particular the involvement of the aggregates, also plays a sensible part in the process of damage evolution and the increase of the bulk strength under high strain rates, and a detailed investigation into this effect would benefit if a realistic representation of the heterogeneity in 3D can be achieved. This paper presents some recent progress in the development of a 3-D meso-scale computational model incorporating randomly-shaped 3-D aggregate particles, including the general validation of the model, and application in the simulation of the dynamic response of concrete under high strain rate compression.

  14. An Evaluative Review of Simulated Dynamic Smart 3d Objects

    NASA Astrophysics Data System (ADS)

    Romeijn, H.; Sheth, F.; Pettit, C. J.

    2012-07-01

    Three-dimensional (3D) modelling of plants can be an asset for creating agricultural based visualisation products. The continuum of 3D plants models ranges from static to dynamic objects, also known as smart 3D objects. There is an increasing requirement for smarter simulated 3D objects that are attributed mathematically and/or from biological inputs. A systematic approach to plant simulation offers significant advantages to applications in agricultural research, particularly in simulating plant behaviour and the influences of external environmental factors. This approach of 3D plant object visualisation is primarily evident from the visualisation of plants using photographed billboarded images, to more advanced procedural models that come closer to simulating realistic virtual plants. However, few programs model physical reactions of plants to external factors and even fewer are able to grow plants based on mathematical and/or biological parameters. In this paper, we undertake an evaluation of plant-based object simulation programs currently available, with a focus upon the components and techniques involved in producing these objects. Through an analytical review process we consider the strengths and weaknesses of several program packages, the features and use of these programs and the possible opportunities in deploying these for creating smart 3D plant-based objects to support agricultural research and natural resource management. In creating smart 3D objects the model needs to be informed by both plant physiology and phenology. Expert knowledge will frame the parameters and procedures that will attribute the object and allow the simulation of dynamic virtual plants. Ultimately, biologically smart 3D virtual plants that react to changes within an environment could be an effective medium to visually represent landscapes and communicate land management scenarios and practices to planners and decision-makers.

  15. Dynamic rupture processes inferred from laboratory microearthquakes

    NASA Astrophysics Data System (ADS)

    Passelègue, François. X.; Schubnel, Alexandre; Nielsen, Stefan; Bhat, Harsha S.; Deldicque, Damien; Madariaga, Raúl

    2016-06-01

    We report macroscopic stick-slip events in saw-cut Westerly granite samples deformed under controlled upper crustal stress conditions in the laboratory. Experiments were conducted under triaxial loading (σ1>σ2=σ3) at confining pressures (σ3) ranging from 10 to 100 MPa. A high-frequency acoustic monitoring array recorded particle acceleration during macroscopic stick-slip events allowing us to estimate rupture speed. In addition, we record the stress drop dynamically and we show that the dynamic stress drop measured locally close to the fault plane is almost total in the breakdown zone (for normal stress >75 MPa), while the friction f recovers to values of f > 0.4 within only a few hundred microseconds. Enhanced dynamic weakening is observed to be linked to the melting of asperities which can be well explained by flash heating theory in agreement with our postmortem microstructural analysis. Relationships between initial state of stress, rupture velocities, stress drop, and energy budget suggest that at high normal stress (leading to supershear rupture velocities), the rupture processes are more dissipative. Our observations question the current dichotomy between the fracture energy and the frictional energy in terms of rupture processes. A power law scaling of the fracture energy with final slip is observed over 8 orders of magnitude in slip, from a few microns to tens of meters.

  16. Study of the tsunamigenic rupture process of the 2011 Tohoku earthquake using a 3D Finite Element Model

    NASA Astrophysics Data System (ADS)

    Romano, Fabrizio; Trasatti, Elisa; Lorito, Stefano; Piromallo, Claudia; Piatanesi, Alessio; Cocco, Massimo; Murphy, Shane; Tonini, Roberto; Volpe, Manuela; Brizuela, Beatriz

    2016-04-01

    The study of the 2011 Tohoku earthquake revealed some new aspects in the rupture process of a megathrust event. Indeed, despite its magnitude Mw 9.0, this earthquake was characterized by a spatially limited rupture area and, contrary to the common view that the shallow portion of the subduction interface mainly experiences aseismic slip, the seismic rupture propagated onto the Japan trench with very large slip (> 50 m). Starting from slip distributions obtained by joint inversion of tsunami and geodetic data, we discuss the sensitivity of the tsunami impact predictions to the complexity of the modelling strategy. We use numerical tools ranging from a homogeneous half-space dislocation model (considering only vertical sea-floor displacement and tsunami propagation in the linear shallow-water approximation) to the more complex 3D-FEM model (with heterogeneous elastic parameters derived from 3D seismic tomography), including horizontal displacement and non-hydrostatic dispersive tsunami modeling. This research is funded by the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 603839 (Project ASTARTE - Assessment, Strategy and Risk Reduction for Tsunamis in Europe)

  17. The Vibrational Dynamics of 3D HOCl Above Dissociation

    NASA Astrophysics Data System (ADS)

    Lin, Yi-Der; Reichl, Linda; Jung, Christof

    2015-03-01

    We have analyzed the vibrational dynamics of HOCl above dissociation using a 3D energy surface which governs the vibrational dynamics of HOCl above dissociation. The dynamics is dominated by an invariant manifold which is transversally unstable for small spacing between Cl and HO complex, and stable for large spacing. Above dissociation, the InM separates two mirror image periodic orbits, embedded in a large chaotic sea, that can hold a large number of quantum states. These periodic orbits have the capability of forming significant quasibound states of the molecule above dissociation. Welch Foundation.

  18. Zemmouri earthquake rupture zone (Mw 6.8, Algeria): Aftershocks sequence relocation and 3D velocity model

    NASA Astrophysics Data System (ADS)

    Ayadi, A.; Dorbath, C.; Ousadou, F.; Maouche, S.; Chikh, M.; Bounif, M. A.; Meghraoui, M.

    2008-09-01

    We analyze the aftershocks sequence of the Zemmouri thrust faulting earthquake (21 May 2003, Mw 6.8) located east of Algiers in the Tell Atlas. The seismic sequence located during ˜2 months following the mainshock is made of more than 1500 earthquakes and extends NE-SW along a ˜60-km fault rupture zone crossing the coastline. The earthquake relocation was performed using handpicked P and S phases located with the tomoDD in a detailed 3D velocity structure of the epicentral area. Contrasts between velocity patches seem to correlate with contacts between granitic-volcanic basement rocks and the sedimentary formation of the eastern Mitidja basin. The aftershock sequence exhibits at least three seismic clouds and a well-defined SE-dipping main fault geometry that reflects the complex rupture. The distribution of seismic events presents a clear contrast between a dense SW zone and a NE zone with scattered aftershocks. We observe that the mainshock locates between the SW and NE seismic zones; it also lies at the NNS-SSE contact that separates a basement block to the east and sedimentary formations to the west. The aftershock distribution also suggests fault bifurcation at the SW end of the fault rupture, with a 20-km-long ˜N 100° trending seismic cluster, with a vertical fault geometry parallel to the coastline juxtaposed. Another aftershock cloud may correspond to 75° SE dipping fault. The fault geometry and related SW branches may illustrate the interference between pre-existing fault structures and the SW rupture propagation. The rupture zone, related kinematics, and velocity contrasts obtained from the aftershocks distribution are in agreement with the coastal uplift and reflect the characteristics of an active zone controlled by convergent movements at a plate boundary.

  19. Dynamic Rupture Processes during Laboratory Earthquakes

    NASA Astrophysics Data System (ADS)

    Passelègue, F. X.; Schubnel, A.; Nielsen, S. B.; Bhat Suresh, H.; Madariaga, R. I.

    2014-12-01

    Since the proposal by Brace and Byerlee [1966] that the mechanism of stick-slip is similar to earthquakes, many experimental studies have been conducted in order to improve the understanding of rupture mechanics. Here, we report the results of macroscopic stick-slip events in saw-cut samples deformed under controlled upper crustal stress conditions in the laboratory. Experiments were conducted under triaxial laoding (σ1>σ2=σ3) at confining pressures ranging from 10 to 100 MPa. Usual a dual gain system, a high frequency monitoring array recorded the microseismicity during stick-slip sequences and the particle accelerations during macroscopic instabilities. While strain, stress and axial shortening were measured until 10 Hz sampling rate, we also recorded for the first time the dynamic stress changes during macroscopic rupture using dynamic strain gages located close to the fault plane (10 MHz sampling rate). We show that increasing the normal stress acting on the fault plane (i) increases the intensity of foreshock activity prior to the main rupture, (ii) increases the friction along the fault plane, (iii) increases the seismic slip, and (iv) induces the transition from sub-Rayleigh to supershear ruptures [Passelègue et al., 2013]. In addition, after demonstrating that our stick-slip instabilities exhibit a purely slip weakening behavior, we estimated the rupture processes parameters including the size of the breakdown zone (R), the slip-weakening distance (Dc), the energy rate (F) and the fracture energy (G). We compare our results with linear elastic fracture mechanics and previous experimental studies. Finally, the dynamic stress drop is almost complete at high normal stresses with dynamic friction drop ranging from 0.4 to 0.6. These results are consistent with the onset of melting, which was confirmed by our post mortem microstructural analysis (XRD, SEM, TEM). These results show that weakening mechanisms are activated after only 80 μm of slip, suggesting

  20. Vortex dynamics in ruptured and unruptured intracranial aneurysms

    NASA Astrophysics Data System (ADS)

    Trylesinski, Gabriel

    Intracranial aneurysms (IAs) are a potentially devastating pathological dilation of brain arteries that affect 1.5-5 % of the population. Causing around 500 000 deaths per year worldwide, their detection and treatment to prevent rupture is critical. Multiple recent studies have tried to find a hemodynamics predictor of aneurysm rupture, but concluded with distinct opposite trends using Wall Shear Stress (WSS) based parameters in different clinical datasets. Nevertheless, several research groups tend to converge for now on the fact that the flow patterns and flow dynamics of the ruptured aneurysms are complex and unstable. Following this idea, we investigated the vortex properties of both unruptured and ruptured cerebral aneurysms. A brief comparison of two Eulerian vortex visualization methods (Q-criterion and lambda 2 method) showed that these approaches gave similar results in our complex aneurysm geometries. We were then able to apply either one of them to a large dataset of 74 patient specific cases of intracranial aneurysms. Those real cases were obtained by 3D angiography, numerical reconstruction of the geometry, and then pulsatile CFD simulation before post-processing with the mentioned vortex visualization tools. First we tested the two Eulerian methods on a few cases to verify their implementation we made as well as compare them with each other. After that, the Q-criterion was selected as method of choice for its more obvious physical meaning (it shows the balance between two characteristics of the flow, its swirling and deformation). Using iso-surfaces of Q, we started by categorizing the patient-specific aneurysms based on the gross topology of the aneurysmal vortices. This approach being unfruitful, we found a new vortex-based characteristic property of ruptured aneurysms to stratify the rupture risk of IAs that we called the Wall-Kissing Vortices, or WKV. We observed that most ruptured aneurysms had a large amount of WKV, which appears to agree with

  1. 3-D Dynamic Behavior of Generalized Polar Wind

    NASA Astrophysics Data System (ADS)

    Barakat, A. R.; Schunk, R. W.; Demars, H. G.

    2003-12-01

    The dynamic behavior of the high-latitude plasma during a representative geomagnetic storm is investigated using a 3-D macroscopic particle-in-cell (mac-PIC) model. In this study, we simulate the behavior of a large number ( ˜100 to 1000) of plasma-filled geomagnetic flux tubes. Each flux tube extends from 1200 km to several Earth radii, includes ˜106 simulation particles, and is followed for ˜12 hours. The lower boundary conditions of the model are provided by a 3-D fluid-like model that extends down to 100 km. Several physical mechanisms are included such as wave-particle interactions, ion-ion collisions, low-altitude ion energization, and magnetospheric particles. The computing-intensive nature of the model requires the utilization of parallel programming techniques. We use a cluster of five nodes, with two (1.6 GHz) processors each, that is available at Utah State University, with the intention of transferring the code to a bigger facility in the future. A 3-D picture is assembled from the temporal evolution of the individual flux tubes by keeping track of their locations. This 3-D picture facilitates comparison with observations, such as radar and satellite measurements. The model and its preliminary results are presented.

  2. The SCEC-USGS Dynamic Earthquake Rupture Code Verification Exercise: Regular and Extreme Ground Motion

    NASA Astrophysics Data System (ADS)

    Harris, R.; Barall, M.; Archuleta, R. J.; Aagaard, B.; Ampuero, J. P.; Andrews, D. J.; Cruz-Atienza, V. M.; Dalguer Gudiel, L. A.; Day, S. M.; Duan, B.; Dunham, E. M.; Ely, G. P.; Gabriel, A. A.; Kaneko, Y.; Kase, Y.; Lapusta, N.; Ma, S.; Noda, H.; Oglesby, D. D.; Olsen, K. B.; Roten, D.; Song, S.

    2010-12-01

    We summarize recent progress by the SCEC-USGS Dynamic Rupture Code Verification Group, that examines if SCEC and USGS researchers’ spontaneous-rupture computer codes agree when computing benchmark scenarios for dynamic earthquake rupture. Our latest benchmarks are ‘regular’ dynamic ruptures on a vertical strike-slip fault and on a normal fault, at a range of resolutions, and, ‘extreme’ dynamic ruptures on a normal fault. The ‘extreme’ dynamic ruptures were designed as complete stress-drop, supershear ruptures that would be most likely to produce maximum possible ground motions. These simulated ruptures could be thought of as very unlikely, but still possible. Among the 2009 ‘extreme’ dynamic rupture benchmarks were those targeted to test two simplified versions of the Andrews et al. [BSSA, 2007] numerical simulations for hypothesized maximum-possible ground motion at a site near Yucca Mountain. To test the Andrews et al. methodology, we constructed a benchmark for a planar dipping normal-fault set in a medium where the off-fault response was designated to be elastic (TPV12), and another benchmark where the off-fault response was designated to be plastic (TPV13). Although most of our group’s previous benchmarks have concentrated on 3D solutions, both the TPV12 and TPV13 benchmarks were offered with both 2D and 3D options, partly because the Andrews et al. study was conducted in 2D, and partly because it is important to understand the differences and similarities among 2D and 3D rupture propagation and ground motion predictions. Seven researchers’ codes participated in the TPV12 2D benchmark test, seven participated in the TPV12 3D test, six participated in the TPV13 2D benchmark test, and four participated in the TPV13 3D test. Our findings were similar to those hypothesized in the Andrews et al. publication. At a proposed site for a nuclear waste repository, that was modeled to be 1-km from the fault, at 300 m depth, our 2D elastic benchmark

  3. Vortex dynamics in ruptured and unruptured intracranial aneurysms

    NASA Astrophysics Data System (ADS)

    Trylesinski, Gabriel; Varble, Nicole; Xiang, Jianping; Meng, Hui

    2013-11-01

    Intracranial aneurysms (IAs) are potentially devastating pathological dilations of arterial walls that affect 2-5% of the population. In our previous CFD study of 119 IAs, we found that ruptured aneurysms were correlated with complex flow pattern and statistically predictable by low wall shear stress and high oscillatory shear index. To understand flow mechanisms that drive the pathophysiology of aneurysm wall leading to either stabilization or growth and rupture, we aim at exploring vortex dynamics of aneurysmal flow and provide insight into the correlation between the previous predictive morphological parameters and wall hemodynamic metrics. We adopt the Q-criterion definition of coherent structures (CS) and analyze the CS dynamics in aneurysmal flows for both ruptured and unruptured IA cases. For the first time, we draw relevant biological conclusions concerning aneurysm flow mechanisms and pathophysiological outcome. In pulsatile simulations, the coherent structures are analyzed in these 119 patient-specific geometries obtained using 3D angiograms. The images were reconstructed and CFD were performed. Upon conclusion of this work, better understanding of flow patterns of unstable aneurysms may lead to improved clinical outcome.

  4. 3-D structure and dynamics of microtubule self-organization

    NASA Astrophysics Data System (ADS)

    Wang, Jing; Ou-Yang, H. Daniel

    2008-03-01

    Laser scanning confocal microscopy was used to study the dynamics of 3D assemblies spontaneously formed in microtubule (MT) solutions. Microtubule solutions prepared by mixing and incubating tubulin in the presence of GTP and Oregon Green conjugated taxol in PM buffer were placed in long, sub-millimeter thin glass cells by the capillary action. Within 24 hours, starting with a uniform distribution, microtubules were found to be gradually separated into a few large ``buckled'' bundles along the long direction, and in the middle plane, of the sample cell. A well-defined wavelength of the buckling sinusoids was around 510 μm. The cross section of these round bundles was approximately 40 μm in diameter and the lengths were several centimeters. Detailed analysis of the 3-D image within the bundles revealed that each bundle seemed to consist of loosely packed MTs. It appeared that MTs were phase separated resulting from attractive interactions between charged MT fibers. The ``buckling'' behavior could be the result of geometrical constraints of the repulsive cell walls and the repulsive interaction between bundles. Detailed 3-D observations of the dynamic evolution of MT assembly could provide insight to the mechanisms of cellular MT organization and phase separation of charged colloidal rods.

  5. Complex flow dynamics around 3D microbot prototypes.

    PubMed

    Martínez-Aranda, Sergio; Galindo-Rosales, Francisco J; Campo-Deaño, Laura

    2016-02-28

    A new experimental setup for the study of the complex flow dynamics around 3D microbot prototypes in a straight microchannel has been developed and assessed. The ultimate aim of this work is focused on the analysis of the morphology of different microbot prototypes to get a better insight into their efficiency when they swim through the main conduits of the human circulatory system. The setup consists of a fused silica straight microchannel with a 3D microbot prototype fastened in the center of the channel cross-section by an extremely thin support. Four different prototypes were considered: a cube, a sphere and two ellipsoids with aspect ratios of 1 : 2 and 1 : 4, respectively. Flow visualization and micro-particle image velocimetry (μPIV) measurements were performed using Newtonian and viscoelastic blood analogue fluids. An efficiency parameter, ℑ, to discriminate the prototypes in terms of flow disturbance has been proposed. PMID:26790959

  6. Dynamic Rupture Segmentation Along The Nankai Trough, Southwest Japan

    NASA Astrophysics Data System (ADS)

    Hok, S.; Fukuyama, E.; Hashimoto, C.

    2010-12-01

    In southwest Japan, large devastating earthquakes (Mw>8) occurred along the Nankai subduction zone every 100-200 years (e.g. Ando, 1975, Tectonophys.; Ishibashi, 2004, Ann. Geophys.). Historical records revealed the segmented nature of the 600 km long seismogenic zone, producing Nankai and Tonankai earthquakes to occur separately or jointly at each cycle. The intersegment zone which separates Nankai and Tonankai source areas, near the Kii Peninsula, should have some special physical properties. In this study, we investigate the dynamic linkage of the coseismic slips on the Nankai and Tonankai segments, by modeling the spontaneous rupture propagation on the subduction interface. To conduct a reliable modeling, the parameters’ lateral variations along the place interface are introduced by combining several geophysical observation data sets. First, we use a large-scale 3D geometry for the plate interface, inferred from seismicity; we also integrate the slip deficit distribution (Hashimoto et al., 2009, SSJ meeting) obtained by inversion of GPS data, to constrain the distribution of stress drop on the interface. This distribution is not uniform, and explains the 1st order asperities of the subduction zone: Hyuga, Nankai, Tonankai and Tokai areas appear clearly as loaded regions. In addition, a constitutive friction law is required to link fault slip and stress release. We compiled regional geophysical information relevant to the segmentation, to infer the distribution of the frictional parameters at seismogenic depths. We focused on areas where the rupture is known to have stopped. The barriers seem to be related to upper plate structure (Wells et al. 2003, JGR, Rosenau and Oncken 2009, JGR). Uplifted areas show common characteristics: end of seismogenic segments, underplating in the wedge, and higher density of the upper old wedge (granitic intrusions). Following above review, we introduced 3 barrier regions delimiting 2 asperity regions (Nankai and Tonankai

  7. Correlative Microscopy for 3D Structural Analysis of Dynamic Interactions

    PubMed Central

    Jun, Sangmi; Zhao, Gongpu; Ning, Jiying; Gibson, Gregory A.; Watkins, Simon C.; Zhang, Peijun

    2013-01-01

    Cryo-electron tomography (cryoET) allows 3D visualization of cellular structures at molecular resolution in a close-to-physiological state1. However, direct visualization of individual viral complexes in their host cellular environment with cryoET is challenging2, due to the infrequent and dynamic nature of viral entry, particularly in the case of HIV-1. While time-lapse live-cell imaging has yielded a great deal of information about many aspects of the life cycle of HIV-13-7, the resolution afforded by live-cell microscopy is limited (~ 200 nm). Our work was aimed at developing a correlation method that permits direct visualization of early events of HIV-1 infection by combining live-cell fluorescent light microscopy, cryo-fluorescent microscopy, and cryoET. In this manner, live-cell and cryo-fluorescent signals can be used to accurately guide the sampling in cryoET. Furthermore, structural information obtained from cryoET can be complemented with the dynamic functional data gained through live-cell imaging of fluorescent labeled target. In this video article, we provide detailed methods and protocols for structural investigation of HIV-1 and host-cell interactions using 3D correlative high-speed live-cell imaging and high-resolution cryoET structural analysis. HeLa cells infected with HIV-1 particles were characterized first by confocal live-cell microscopy, and the region containing the same viral particle was then analyzed by cryo-electron tomography for 3D structural details. The correlation between two sets of imaging data, optical imaging and electron imaging, was achieved using a home-built cryo-fluorescence light microscopy stage. The approach detailed here will be valuable, not only for study of virus-host cell interactions, but also for broader applications in cell biology, such as cell signaling, membrane receptor trafficking, and many other dynamic cellular processes. PMID:23852318

  8. 3D precision surface measurement by dynamic structured light

    NASA Astrophysics Data System (ADS)

    Franke, Ernest A.; Magee, Michael J.; Mitchell, Joseph N.; Rigney, Michael P.

    2004-02-01

    This paper describes a 3-D imaging technique developed as an internal research project at Southwest Research Institute. The technique is based on an extension of structured light methods in which a projected pattern of parallel lines is rotated over the surface to be measured. A sequence of images is captured and the surface elevation at any location can then be determined from measurements of the temporal pattern, at any point, without considering any other points on the surface. The paper describes techniques for system calibration and surface measurement based on the method of projected quadric shells. Algorithms were developed for image and signal analysis and computer programs were written to calibrate the system and to calculate 3-D coordinates of points on a measured surface. A prototype of the Dynamic Structured Light (DSL) 3-D imaging system was assembled and typical parts were measured. The design procedure was verified and used to implement several different configurations with different measurement volumes and measurement accuracy. A small-parts measurement accuracy of 32 micrometers (.0012") RMS was verified by measuring the surface of a precision-machined plane. Large aircraft control surfaces were measured with a prototype setup that provided .02" depth resolution over a 4" by 8" field of view. Measurement times are typically less than three minutes for 300,000 points. A patent application has been filed.

  9. Brittle dynamic damage due to earthquake rupture

    NASA Astrophysics Data System (ADS)

    Bhat, Harsha; Thomas, Marion

    2016-04-01

    The micromechanical damage mechanics formulated by Ashby and Sammis, 1990, and generalized by Deshpande and Evans 2008 has been extended to allow for a more generalized stress state and to incorporate an experimentally motivated new crack growth (damage evolution) law that is valid over a wide range of loading rates. This law is sensitive to both the crack tip stress field and its time derivative. Incorporating this feature produces additional strain-rate sensitivity in the constitutive response. The model is also experimentally verified by predicting the failure strength of Dionysus-Pentelicon marble over wide range of strain rates. We then implement this constitutive response to understand the role of dynamic brittle off-fault damage on earthquake ruptures. We show that off-fault damage plays an important role in asymmetry of rupture propagation and is a source of high-frequency ground motion in the near source region.

  10. Dynamic stress changes during earthquake rupture

    USGS Publications Warehouse

    Day, S.M.; Yu, G.; Wald, D.J.

    1998-01-01

    We assess two competing dynamic interpretations that have been proposed for the short slip durations characteristic of kinematic earthquake models derived by inversion of earthquake waveform and geodetic data. The first interpretation would require a fault constitutive relationship in which rapid dynamic restrengthening of the fault surface occurs after passage of the rupture front, a hypothesized mechanical behavior that has been referred to as "self-healing." The second interpretation would require sufficient spatial heterogeneity of stress drop to permit rapid equilibration of elastic stresses with the residual dynamic friction level, a condition we refer to as "geometrical constraint." These interpretations imply contrasting predictions for the time dependence of the fault-plane shear stresses. We compare these predictions with dynamic shear stress changes for the 1992 Landers (M 7.3), 1994 Northridge (M 6.7), and 1995 Kobe (M 6.9) earthquakes. Stress changes are computed from kinematic slip models of these earthquakes, using a finite-difference method. For each event, static stress drop is highly variable spatially, with high stress-drop patches embedded in a background of low, and largely negative, stress drop. The time histories of stress change show predominantly monotonic stress change after passage of the rupture front, settling to a residual level, without significant evidence for dynamic restrengthening. The stress change at the rupture front is usually gradual rather than abrupt, probably reflecting the limited resolution inherent in the underlying kinematic inversions. On the basis of this analysis, as well as recent similar results obtained independently for the Kobe and Morgan Hill earthquakes, we conclude that, at the present time, the self-healing hypothesis is unnecessary to explain earthquake kinematics.

  11. Coupling geodynamic earthquake cycles and dynamic ruptures

    NASA Astrophysics Data System (ADS)

    van Zelst, Iris; van Dinther, Ylona; Gabriel, Alice-Agnes; Heuret, Arnauld

    2016-04-01

    Studying the seismicity in a subduction zone and its effects on tsunamis requires diverse modelling methods that span spatial and temporal scales. Hundreds of years are necessary to build the stresses and strengths on a fault, while consequent earthquake rupture propagation is determined by both these initial fault conditions and the feedback of seismic waves over periods of seconds up to minutes. This dynamic rupture displaces the sea floor, thereby causing tsunamis. The aim of the ASCETE (Advanced Simulations of Coupled Earthquake and Tsunami Events) project is to study all these aspects and their interactions. Here, we present preliminary results of the first aspects in this modelling chain: the coupling of a seismo-thermo-mechanical (STM) code to the dynamic rupture model SeisSol. STM models of earthquake cycles have the advantage of solving multiple earthquake events in a self-consistent manner concerning stress, strength and geometry. However, the drawback of these models is that they often lack in spatial or temporal resolution and do not include wave propagation. In contrast, dynamic rupture models solve for frictional failure coupled to seismic wave propagation. We use the software package SeisSol (www.seissol.org) based on an ADER-DG discretization allowing high-order accuracy in space and time as well as flexible tetrahedral meshing. However, such simulations require assumptions on the initial fault stresses and strengths and its geometry, which are hard to constrain due to the lack of near-field observations and the complexity of coseismic conditions. By adapting the geometry as well as the stress and strength properties of the self-consistently developing non-finite fault zones from the geodynamic models as initial conditions for the dynamic rupture models, the advantages of both methods are exploited and modelling results may be compared. Our results show that a dynamic rupture can be triggered spontaneously and that the propagating rupture is

  12. Investigation on the key parameters of slip weakening law in dynamic rupture simulations

    NASA Astrophysics Data System (ADS)

    Liu, Q.; Zhang, H.; Chen, X.

    2008-12-01

    How the crack propagates on the fault plane when an earthquake happens is a fundamental problem in earthquake studies. To understand the dynamics of a spontaneously propagating crack various constitutive laws for friction, e.g., slip weakening, slip rate weakening, effective temperature and rate-and-state laws, which define the relationship between the instantaneous stress and slip (or slip rate) on the fault have been widely used in various rupture simulations. One crucial aspect of the variety of rupture models is to to quantify how the main parameters characterizing a certain law affect the rupture process. We chose the slip weakening law and then massively computed a large suite of dynamic rupture simulations on a rectangular fault embedded in 3-D isotropic homogeneous medium. The simulations included hundreds of different sets of parameters varying Dc, the critical slip weakening distance and Te the initial stress. All are spatially constant except in a rectangular asperity, where the rupture is triggered. With the same parameter set we used several different discretizations to avoid the numerical effects. Computationally we use the boundary integral method. We have also given definitions of rupture status: non-growth rupture, growth rupture, subshear rupture and supershear rupture. With all of the simulations we construct a phase-diagram on which different rupture states locate in different parameter-set zones (phase boundary lines with errors less than 0.1%) We find that (1) In the areas with smaller Dc, phase boundary lines seems to fit the ones Madariaga (1998) predicted using non- dimensionalized parameter κ, but not for the whole phase line. (2) When Dc reaches a particular size, none of the ruptures will propagate regardless of the value of the initial stress on the fault. (3) Some transitional states may occur where a rupture propagates only 2-4 times the initial asperity size and then stops spontaneously.

  13. Dynamical Systems Analysis of Fully 3D Ocean Features

    NASA Astrophysics Data System (ADS)

    Pratt, L. J.

    2011-12-01

    Dynamical systems analysis of transport and stirring processes has been developed most thoroughly for 2D flow fields. The calculation of manifolds, turnstile lobes, transport barriers, etc. based on observations of the ocean is most often conducted near the sea surface, whereas analyses at depth, usually carried out with model output, is normally confined to constant-z surfaces. At the meoscale and larger, ocean flows are quasi 2D, but smaller scale (submesoscale) motions, including mixed layer phenomena with significant vertical velocity, may be predominantly 3D. The zoology of hyperbolic trajectories becomes richer in such cases and their attendant manifolds are much more difficult to calculate. I will describe some of the basic geometrical features and corresponding Lagrangian Coherent Features expected to arise in upper ocean fronts, eddies, and Langmuir circulations. Traditional GFD models such as the rotating can flow may capture the important generic features. The dynamical systems approach is most helpful when these features are coherent and persistent and the implications and difficulties for this requirement in fully 3D flows will also be discussed.

  14. Seismic Hazard Maps for Seattle, Washington, Incorporating 3D Sedimentary Basin Effects, Nonlinear Site Response, and Rupture Directivity

    USGS Publications Warehouse

    Frankel, Arthur D.; Stephenson, William J.; Carver, David L.; Williams, Robert A.; Odum, Jack K.; Rhea, Susan

    2007-01-01

    This report presents probabilistic seismic hazard maps for Seattle, Washington, based on over 500 3D simulations of ground motions from scenario earthquakes. These maps include 3D sedimentary basin effects and rupture directivity. Nonlinear site response for soft-soil sites of fill and alluvium was also applied in the maps. The report describes the methodology for incorporating source and site dependent amplification factors into a probabilistic seismic hazard calculation. 3D simulations were conducted for the various earthquake sources that can affect Seattle: Seattle fault zone, Cascadia subduction zone, South Whidbey Island fault, and background shallow and deep earthquakes. The maps presented in this document used essentially the same set of faults and distributed-earthquake sources as in the 2002 national seismic hazard maps. The 3D velocity model utilized in the simulations was validated by modeling the amplitudes and waveforms of observed seismograms from five earthquakes in the region, including the 2001 M6.8 Nisqually earthquake. The probabilistic seismic hazard maps presented here depict 1 Hz response spectral accelerations with 10%, 5%, and 2% probabilities of exceedance in 50 years. The maps are based on determinations of seismic hazard for 7236 sites with a spacing of 280 m. The maps show that the most hazardous locations for this frequency band (around 1 Hz) are soft-soil sites (fill and alluvium) within the Seattle basin and along the inferred trace of the frontal fault of the Seattle fault zone. The next highest hazard is typically found for soft-soil sites in the Duwamish Valley south of the Seattle basin. In general, stiff-soil sites in the Seattle basin exhibit higher hazard than stiff-soil sites outside the basin. Sites with shallow bedrock outside the Seattle basin have the lowest estimated hazard for this frequency band.

  15. Dynamic deformable models for 3D MRI heart segmentation

    NASA Astrophysics Data System (ADS)

    Zhukov, Leonid; Bao, Zhaosheng; Gusikov, Igor; Wood, John; Breen, David E.

    2002-05-01

    Automated or semiautomated segmentation of medical images decreases interstudy variation, observer bias, and postprocessing time as well as providing clincally-relevant quantitative data. In this paper we present a new dynamic deformable modeling approach to 3D segmentation. It utilizes recently developed dynamic remeshing techniques and curvature estimation methods to produce high-quality meshes. The approach has been implemented in an interactive environment that allows a user to specify an initial model and identify key features in the data. These features act as hard constraints that the model must not pass through as it deforms. We have employed the method to perform semi-automatic segmentation of heart structures from cine MRI data.

  16. Distributed 3D Information Visualization - Towards Integration of the Dynamic 3D Graphics and Web Services

    NASA Astrophysics Data System (ADS)

    Vucinic, Dean; Deen, Danny; Oanta, Emil; Batarilo, Zvonimir; Lacor, Chris

    This paper focuses on visualization and manipulation of graphical content in distributed network environments. The developed graphical middleware and 3D desktop prototypes were specialized for situational awareness. This research was done in the LArge Scale COllaborative decision support Technology (LASCOT) project, which explored and combined software technologies to support human-centred decision support system for crisis management (earthquake, tsunami, flooding, airplane or oil-tanker incidents, chemical, radio-active or other pollutants spreading, etc.). The performed state-of-the-art review did not identify any publicly available large scale distributed application of this kind. Existing proprietary solutions rely on the conventional technologies and 2D representations. Our challenge was to apply the "latest" available technologies, such Java3D, X3D and SOAP, compatible with average computer graphics hardware. The selected technologies are integrated and we demonstrate: the flow of data, which originates from heterogeneous data sources; interoperability across different operating systems and 3D visual representations to enhance the end-users interactions.

  17. Modeling tree crown dynamics with 3D partial differential equations.

    PubMed

    Beyer, Robert; Letort, Véronique; Cournède, Paul-Henry

    2014-01-01

    We characterize a tree's spatial foliage distribution by the local leaf area density. Considering this spatially continuous variable allows to describe the spatiotemporal evolution of the tree crown by means of 3D partial differential equations. These offer a framework to rigorously take locally and adaptively acting effects into account, notably the growth toward light. Biomass production through photosynthesis and the allocation to foliage and wood are readily included in this model framework. The system of equations stands out due to its inherent dynamic property of self-organization and spontaneous adaptation, generating complex behavior from even only a few parameters. The density-based approach yields spatially structured tree crowns without relying on detailed geometry. We present the methodological fundamentals of such a modeling approach and discuss further prospects and applications. PMID:25101095

  18. 3D Seismic Velocity Structure in the Rupture Area of the 2010 Maule Mw=8.8 Earthquake

    NASA Astrophysics Data System (ADS)

    Hicks, S. P.; Rietbrock, A.; Ryder, I. M.; Nippress, S.; Haberland, C. A.

    2011-12-01

    The 2010 Mw=8.8 Maule, Chile earthquake is one of the largest subduction zone earthquakes ever recorded. Up to now numerous co-seismic and some post-seismic slip models have been published based entirely on seismological, geodetic, or tsunami run-up heights, or combinations of these data. Most of these models use a simplified megathrust geometry derived mainly from global earthquake catalogues, and also simplified models of seismic parameters (e.g. shear modulus). By using arrival times for a vast number of aftershocks that have been recorded on a temporary seismic array, we present a new model for the slab geometry based on earthquake locations together with a new 3D seismic velocity model of the region, for both vp and vp/vs. We analyzed 3552 aftershocks that occurred between 18 March and 24 May 2011, recorded by the International Maule Aftershock Dataset (IMAD) seismic network. Event selection from a catalogue of automatically-determined events was based on 20 or more arrival times, from which at least 10 are S-wave observations. In total over 170,000 arrival times (~125,000 and 45,000 P and S wave arrival times respectively) are used for the tomographic reconstructions. Initially, events were relocated in a 2D velocity model based on a previously published model for the southern end of the rupture area (Haberland et al., 2009). Afterwards a staggered inversion scheme is implemented, starting with a 2D inversion followed by a coarse 3D and a subsequent fine 3D inversion. Based on our preliminary inversions we conclude that aftershock seismicity is mainly concentrated between 20 and 35 km depth along the subduction interface. A second band of seismicity between 40 and 50 km depth is also observed. Low seismic velocities and an increased vp/vs ratio characterize the marine forearc. The obtained velocity model will be discussed.

  19. Atomic-Resolution 3D Electron Microscopy with Dynamic Diffraction

    SciTech Connect

    O'Keefe, Michael A.; Downing, Kenneth H.; Wenk, Hans-Rudolf; Meisheng, Hu

    2005-02-15

    Achievement of atomic-resolution electron-beam tomography will allow determination of the three-dimensional structure of nanoparticles (and other suitable specimens) at atomic resolution. Three-dimensional reconstructions will yield ''section'' images that resolve atoms overlapped in normal electron microscope images (projections), resolving lighter atoms such as oxygen in the presence of heavier atoms, and atoms that lie on non-lattice sites such as those in non-periodic defect structures. Lower-resolution electron microscope tomography has been used to produce reconstructed 3D images of nanoparticles [1] but extension to atomic resolution is considered not to be straightforward. Accurate three-dimensional reconstruction from two-dimensional projections generally requires that intensity in the series of 2-D images be a monotonic function of the specimen structure (often specimen density, but in our case atomic potential). This condition is not satisfied in electron microscopy when specimens with strong periodicity are tilted close to zone-axis orientation and produce ''anomalous'' image contrast because of strong dynamic diffraction components. Atomic-resolution reconstructions from tilt series containing zone-axis images (with their contrast enhanced by strong dynamical scattering) can be distorted when the stronger zone-axis images overwhelm images obtained in other ''random'' orientations in which atoms do not line up in neat columns. The first demonstrations of 3-D reconstruction to atomic resolution used five zone-axis images from test specimens of staurolite consisting of a mix of light and heavy atoms [2,3]. Initial resolution was to the 1.6{angstrom} Scherzer limit of a JEOL-ARM1000. Later experiments used focal-series reconstruction from 5 to 10 images to produce staurolite images from the ARM1000 with resolution extended beyond the Scherzer limit to 1.38{angstrom} [4,5]. To obtain a representation of the three-dimensional structure, images were obtained

  20. Rupture Processes of the Mw8.3 Sea of Okhotsk Earthquake and Aftershock Sequences from 3-D Back Projection Imaging

    NASA Astrophysics Data System (ADS)

    Jian, P. R.; Hung, S. H.; Meng, L.

    2014-12-01

    On May 24, 2013, the largest deep earthquake ever recorded in history occurred on the southern tip of the Kamchatka Island, where the Pacific Plate subducts underneath the Okhotsk Plate. Previous 2D beamforming back projection (BP) of P- coda waves suggests the mainshock ruptured bilaterally along a horizontal fault plane determined by the global centroid moment tensor solution. On the other hand, the multiple point source inversion of P and SH waveforms argued that the earthquake comprises a sequence of 6 subevents not located on a single plane but actually distributed in a zone that extends 64 km horizontally and 35 km in depth. We then apply a three-dimensional MUSIC BP approach to resolve the rupture processes of the manishock and two large aftershocks (M6.7) with no a priori setup of preferential orientations of the planar rupture. The maximum pseudo-spectrum of high-frequency P wave in a sequence of time windows recorded by the densely-distributed stations from US and EU Array are used to image 3-D temporal and spatial rupture distribution. The resulting image confirms that the nearly N-S striking but two antiparallel rupture stages. The first subhorizontal rupture initially propagates toward the NNE direction, while at 18 s later it directs reversely to the SSW and concurrently shifts downward to 35 km deeper lasting for about 20 s. The rupture lengths in the first NNE-ward and second SSW-ward stage are about 30 km and 85 km; the estimated rupture velocities are 3 km/s and 4.25 km/s, respectively. Synthetic experiments are undertaken to assess the capability of the 3D MUSIC BP for the recovery of spatio-temporal rupture processes. Besides, high frequency BP images based on the EU-Array data show two M6.7 aftershocks are more likely to rupture on the vertical fault planes.

  1. A parallel algorithm for 3D dislocation dynamics

    NASA Astrophysics Data System (ADS)

    Wang, Zhiqiang; Ghoniem, Nasr; Swaminarayan, Sriram; LeSar, Richard

    2006-12-01

    Dislocation dynamics (DD), a discrete dynamic simulation method in which dislocations are the fundamental entities, is a powerful tool for investigation of plasticity, deformation and fracture of materials at the micron length scale. However, severe computational difficulties arising from complex, long-range interactions between these curvilinear line defects limit the application of DD in the study of large-scale plastic deformation. We present here the development of a parallel algorithm for accelerated computer simulations of DD. By representing dislocations as a 3D set of dislocation particles, we show here that the problem of an interacting ensemble of dislocations can be converted to a problem of a particle ensemble, interacting with a long-range force field. A grid using binary space partitioning is constructed to keep track of node connectivity across domains. We demonstrate the computational efficiency of the parallel micro-plasticity code and discuss how O(N) methods map naturally onto the parallel data structure. Finally, we present results from applications of the parallel code to deformation in single crystal fcc metals.

  2. A high-resolution 3D seismic velocity model of the 2010 Mw 8.8 Maule, Chile earthquake rupture zone using land & OBS networks

    NASA Astrophysics Data System (ADS)

    Hicks, S. P.; Rietbrock, A.; Ryder, I. M.; Miller, M.; Lee, C.

    2013-12-01

    Knowledge of seismic properties along a subduction megathrust can shed light on the composition and structure of rocks along the fault. By comparing seismic velocity structure with models of interseismic locking, co-seismic slip and afterslip, we can begin to understand how physical properties may affect fault dynamics throughout the subduction seismic cycle. The Maule earthquake, which hit the coast of central Chile in 2010, is the 6th largest earthquake ever recorded, rupturing a 500 x 80 km area of the Chilean megathrust. Published models demonstrate a complex bilateral rupture, with most co-seismic slip occurring to the north of the mainshock epicentre, although significant slip likely stopped short of the trench and the continental Moho. Here, we show a new high-resolution 3D velocity model (vp and vp/vs ratio) of the central Chilean margin Our velocity model is based on manually picked P- and S-wave arrival times from 670 aftershocks recorded by the International Maule Aftershock Deployment (IMAD) network. Seismic properties of the marine forearc are poorly understood in subduction zones, but by incorporating picks from two ocean-bottom seismometer (OBS) networks, we can resolve the velocity structure of the megathrust as far as the trench. In total, the catalogue used for the tomographic inversion yields a total of ~50,000 high quality P- and S-wave picks. We analyse the quality of our model by analysis of the resolution matrix and by testing characteristic models. The 3D velocity model shows the main structures associated within a subduction forearc: the marine forearc basin (vp < 6.0 km/s), continental mantle (vp > 7.5 km/s), and subducting oceanic crust (vp ~ 7.7 km/s). The plate interface is well defined by relocated aftershock seismicity. P-wave velocities along the megathrust range from 6.5 km/s beneath the marine forearc to 7.7 km/s at the intersection of the megathrust with the continental Moho. We infer several high vp anomalies within the South

  3. Dynamic rupture models of earthquakes on the Bartlett Springs Fault, Northern California

    USGS Publications Warehouse

    Lozos, Julian C.; Harris, Ruth A.; Murray, Jessica R.; Lienkaemper, James J.

    2015-01-01

    The Bartlett Springs Fault (BSF), the easternmost branch of the northern San Andreas Fault system, creeps along much of its length. Geodetic data for the BSF are sparse, and surface creep rates are generally poorly constrained. The two existing geodetic slip rate inversions resolve at least one locked patch within the creeping zones. We use the 3-D finite element code FaultMod to conduct dynamic rupture models based on both geodetic inversions, in order to determine the ability of rupture to propagate into the creeping regions, as well as to assess possible magnitudes for BSF ruptures. For both sets of models, we find that the distribution of aseismic creep limits the extent of coseismic rupture, due to the contrast in frictional properties between the locked and creeping regions.

  4. Dynamic rupture models of earthquakes on the Bartlett Springs Fault, Northern California

    NASA Astrophysics Data System (ADS)

    Lozos, Julian C.; Harris, Ruth A.; Murray, Jessica R.; Lienkaemper, James J.

    2015-06-01

    The Bartlett Springs Fault (BSF), the easternmost branch of the northern San Andreas Fault system, creeps along much of its length. Geodetic data for the BSF are sparse, and surface creep rates are generally poorly constrained. The two existing geodetic slip rate inversions resolve at least one locked patch within the creeping zones. We use the 3-D finite element code FaultMod to conduct dynamic rupture models based on both geodetic inversions, in order to determine the ability of rupture to propagate into the creeping regions, as well as to assess possible magnitudes for BSF ruptures. For both sets of models, we find that the distribution of aseismic creep limits the extent of coseismic rupture, due to the contrast in frictional properties between the locked and creeping regions.

  5. Dynamic 3D simulations of earthquakes on en echelon faults

    USGS Publications Warehouse

    Harris, R.A.; Day, S.M.

    1999-01-01

    One of the mysteries of earthquake mechanics is why earthquakes stop. This process determines the difference between small and devastating ruptures. One possibility is that fault geometry controls earthquake size. We test this hypothesis using a numerical algorithm that simulates spontaneous rupture propagation in a three-dimensional medium and apply our knowledge to two California fault zones. We find that the size difference between the 1934 and 1966 Parkfield, California, earthquakes may be the product of a stepover at the southern end of the 1934 earthquake and show how the 1992 Landers, California, earthquake followed physically reasonable expectations when it jumped across en echelon faults to become a large event. If there are no linking structures, such as transfer faults, then strike-slip earthquakes are unlikely to propagate through stepovers >5 km wide. Copyright 1999 by the American Geophysical Union.

  6. Extracellular Matrix Dynamics and Fetal Membrane Rupture

    PubMed Central

    Strauss,, Jerome F.

    2013-01-01

    The extracellular matrix (ECM) plays an important role in determining cell and organ function: (1) it is an organizing substrate that provides tissue tensile strength; (2) it anchors cells and influences cell morphology and function via interaction with cell surface receptors; and (3) it is a reservoir for growth factors. Alterations in the content and the composition of the ECM determine its physical and biological properties, including strength and susceptibility to degradation. The ECM components themselves also harbor cryptic matrikines, which when exposed by conformational change or proteolysis have potent effects on cell function, including stimulating the production of cytokines and matrix metalloproteinases (MMPs). Collectively, these properties of the ECM reflect a dynamic tissue component that influences both tissue form and function. This review illustrates how defects in ECM synthesis and metabolism and the physiological process of ECM turnover contribute to changes in the fetal membranes that precede normal parturition and contribute to the pathological events leading to preterm premature rupture of membranes (PPROM). PMID:22267536

  7. Extracellular matrix dynamics and fetal membrane rupture.

    PubMed

    Strauss, Jerome F

    2013-02-01

    The extracellular matrix (ECM) plays an important role in determining cell and organ function: (1) it is an organizing substrate that provides tissue tensile strength; (2) it anchors cells and influences cell morphology and function via interaction with cell surface receptors; and (3) it is a reservoir for growth factors. Alterations in the content and the composition of the ECM determine its physical and biological properties, including strength and susceptibility to degradation. The ECM components themselves also harbor cryptic matrikines, which when exposed by conformational change or proteolysis have potent effects on cell function, including stimulating the production of cytokines and matrix metalloproteinases (MMPs). Collectively, these properties of the ECM reflect a dynamic tissue component that influences both tissue form and function. This review illustrates how defects in ECM synthesis and metabolism and the physiological process of ECM turnover contribute to changes in the fetal membranes that precede normal parturition and contribute to the pathological events leading to preterm premature rupture of membranes (PPROM). PMID:22267536

  8. Dynamical Lorentz symmetry breaking in 3D and charge fractionalization

    SciTech Connect

    Charneski, B.; Gomes, M.; Silva, A. J. da; Mariz, T.; Nascimento, J. R.

    2009-03-15

    We analyze the breaking of Lorentz invariance in a 3D model of fermion fields self-coupled through four-fermion interactions. The low-energy limit of the theory contains various submodels which are similar to those used in the study of graphene or in the description of irrational charge fractionalization.

  9. Surgery for ruptured sinus of valsalva aneurysm into right ventricular outflow tract: role of intraoperative 2D and real time 3D transesophageal echocardiography.

    PubMed

    Gadhinglajkar, Shrinivas; Sreedhar, Rupa

    2010-08-01

    A major limitation of the 2D echocardiography during surgery for a complex cardiac lesion is its inability to provide an accurate spatial orientation of the structure. The real time 3D transesophageal echocardiography (RT-3D-TEE) technology available in Philips IE 33 ultrasound machine is relatively new to an operation suite. We evaluated its intraoperative utility in a patient, who was operated for repair of a ruptured sinus of Valsalva aneurysm (RSOVA) and closure of a supracristal ventricular septal defect. The VSD and RSOVA were visualized through different virtual windows in a more promising way on intraoperative RT-3D-TEE than on the 2D echocardiography. The acquired images could be virtually cropped and displayed in anatomical views to the operating surgeon for a clear orientation to the anatomy of the lesion. RT-3D-TEE is a potential intraoperative monitoring tool in surgeries for complex cardiac lesions. PMID:21050263

  10. DREAM3D simulations of inner-belt dynamics

    SciTech Connect

    Cunningham, Gregory Scott

    2015-05-26

    A 1973 paper by Lyons and Thorne explains the two-belt structure for electrons in the inner magnetosphere as a balance between inward radial diffusion and loss to the atmosphere, where the loss to the atmosphere is enabled by pitch-angle scattering from Coulomb and wave-particle interactions. In the 1973 paper, equilibrium solutions to a decoupled set of 1D radial diffusion equations, one for each value of the first invariant of motion, μ, were computed to produce the equilibrium two-belt structure. Each 1D radial diffusion equation incorporated an L-and μ-dependent `lifetime' due to the Coulomb and wave-particle interactions. This decoupling of the problem is appropriate under the assumption that radial diffusion is slow in comparison to pitch-angle scattering. However, for some values of μ and L the lifetime associated with pitch-angle scattering is comparable to the timescale associated with radial diffusion, suggesting that the true equilibrium solutions might reflect `coupled modes' involving pitch-angle scattering and radial diffusion and thus requiring a 3D diffusion model. In the work we show here, we have computed the equilibrium solutions using our 3D diffusion model, DREAM3D, that allows for such coupling. We find that the 3D equilibrium solutions are quite similar to the solutions shown in the 1973 paper when we use the same physical models for radial diffusion and pitch-angle scattering from hiss. However, we show that the equilibrium solutions are quite sensitive to various aspects of the physics model employed in the 1973 paper that can be improved, suggesting that additional work needs to be done to understand the two-belt structure.

  11. How Fault Geometry Affects Dynamic Rupture Models of Earthquakes in San Gorgonio Pass, CA

    NASA Astrophysics Data System (ADS)

    Tarnowski, J. M.; Oglesby, D. D.; Cooke, M. L.; Kyriakopoulos, C.

    2015-12-01

    We use 3D dynamic finite element models to investigate potential rupture paths of earthquakes propagating along faults in the western San Gorgonio Pass (SGP) region of California. The SGP is a structurally complex area along the southern California portion of the San Andreas fault system (SAF). It has long been suspected that this structural knot, which consists of the intersection of various non-planar strike-slip and thrust fault segments, may inhibit earthquake rupture propagation between the San Bernardino and Banning strands of the SAF. The above condition may limit the size of potential earthquakes in the region. Our focus is on the San Bernardino strand of the SAF and the San Gorgonio Pass Fault zone, where the fault connectivity is not well constrained. We use the finite element code FaultMod (Barall, 2009) to investigate how fault connectivity, nucleation location, and initial stresses influence rupture propagation and ground motion, including the likelihood of through-going rupture in this region. Preliminary models indicate that earthquakes that nucleate on the San Bernardino strand and propagate southward do not easily transfer rupture to the thrust faults of the San Gorgonio Pass fault zone. However, under certain assumptions, earthquakes that nucleate along the San Gorgonio Pass fault zone can transfer rupture to the San Bernardino strand.

  12. Ground-motion signature of dynamic ruptures on rough faults

    NASA Astrophysics Data System (ADS)

    Mai, P. Martin; Galis, Martin; Thingbaijam, Kiran K. S.; Vyas, Jagdish C.

    2016-04-01

    Natural earthquakes occur on faults characterized by large-scale segmentation and small-scale roughness. This multi-scale geometrical complexity controls the dynamic rupture process, and hence strongly affects the radiated seismic waves and near-field shaking. For a fault system with given segmentation, the question arises what are the conditions for producing large-magnitude multi-segment ruptures, as opposed to smaller single-segment events. Similarly, for variable degrees of roughness, ruptures may be arrested prematurely or may break the entire fault. In addition, fault roughness induces rupture incoherence that determines the level of high-frequency radiation. Using HPC-enabled dynamic-rupture simulations, we generate physically self-consistent rough-fault earthquake scenarios (M~6.8) and their associated near-source seismic radiation. Because these computations are too expensive to be conducted routinely for simulation-based seismic hazard assessment, we thrive to develop an effective pseudo-dynamic source characterization that produces (almost) the same ground-motion characteristics. Therefore, we examine how variable degrees of fault roughness affect rupture properties and the seismic wavefield, and develop a planar-fault kinematic source representation that emulates the observed dynamic behaviour. We propose an effective workflow for improved pseudo-dynamic source modelling that incorporates rough-fault effects and its associated high-frequency radiation in broadband ground-motion computation for simulation-based seismic hazard assessment.

  13. Towards coupled earthquake dynamic rupture and tsunami simulations: The 2011 Tohoku earthquake.

    NASA Astrophysics Data System (ADS)

    Galvez, Percy; van Dinther, Ylona

    2016-04-01

    The 2011 Mw9 Tohoku earthquake has been recorded with a vast GPS and seismic network given an unprecedented chance to seismologists to unveil complex rupture processes in a mega-thrust event. The seismic stations surrounding the Miyagi regions (MYGH013) show two clear distinct waveforms separated by 40 seconds suggesting two rupture fronts, possibly due to slip reactivation caused by frictional melting and thermal fluid pressurization effects. We created a 3D dynamic rupture model to reproduce this rupture reactivation pattern using SPECFEM3D (Galvez et al, 2014) based on a slip-weakening friction with sudden two sequential stress drops (Galvez et al, 2015) . Our model starts like a M7-8 earthquake breaking dimly the trench, then after 40 seconds a second rupture emerges close to the trench producing additional slip capable to fully break the trench and transforming the earthquake into a megathrust event. The seismograms agree roughly with seismic records along the coast of Japan. The resulting sea floor displacements are in agreement with 1Hz GPS displacements (GEONET). The simulated sea floor displacement reaches 8-10 meters of uplift close to the trench, which may be the cause of such a devastating tsunami followed by the Tohoku earthquake. To investigate the impact of such a huge uplift, we ran tsunami simulations with the slip reactivation model and plug the sea floor displacements into GeoClaw (Finite element code for tsunami simulations, George and LeVeque, 2006). Our recent results compare well with the water height at the tsunami DART buoys 21401, 21413, 21418 and 21419 and show the potential using fully dynamic rupture results for tsunami studies for earthquake-tsunami scenarios.

  14. Role of geometric complexities and off-fault damage in dynamic rupture propagation

    NASA Astrophysics Data System (ADS)

    Bhat, Harsha Suresh

    2007-12-01

    To analyze the effect of fault branches on dynamic rupture propagation we numerically simulated the observed dynamic slip transfer from the Denali to Totschunda faults during the Mw 7.9, November 3, 2002, Denali fault earthquake, Alaska and show that the theory and methodology of Poliakov et al. [2002] and Kame et al. [2003] is valid for the 2002 Denali fault event. To understand the effect of fault branch length on dynamic rupture propagation we analyze earthquake ruptures propagating along a straight "main" fault and encountering a finite-length branch fault. We show finite branches have the tendency of stopping or re-nucleating rupture on the main fault depending on their length in addition to the parameters singled out by Kame et al. [2003]. We also illustrate branch-related complexities in rupture velocity and slip evolution. We illustrate the effect of backward branches (branches at obtuse angle to the main fault with the same sense of slip as the main fault) and propose a mechanism of backward branching. As a field example we simulate numerically, using a two-dimensional elastodynamic boundary integral equation formulation incorporating slip-weakening rupture, the backward branching phenomenon observed during the Landers 1992 earthquake. To characterize the effect of supershear ruptures on off-fault materials we extend a model of a two-dimensional self-healing slip pulse, propagating dynamically in steady-state with slip-weakening failure criterion, to the supershear regime and show that there exists a non-attenuating stress field behind the Mach front which radiates high stresses arbitrarily far from the fault (practically this would be limited to distances comparable to the depth of the seismogenic zone). We apply this model to study damage features induced during the 2001 Kokoxili (Kunlun) event in Tibet. We also study the 3D effects of supershear ruptures by simulating bilateral ruptures on a finite-width vertical strike-slip fault breaking the surface

  15. The vibrational dynamics of 3D HOCl above dissociation

    SciTech Connect

    Lin, Yi-Der; Reichl, L. E.; Jung, Christof

    2015-03-28

    We explore the classical vibrational dynamics of the HOCl molecule for energies above the dissociation energy of the molecule. Above dissociation, we find that the classical dynamics is dominated by an invariant manifold which appears to stabilize two periodic orbits at energies significantly above the dissociation energy. These stable periodic orbits can hold a large number of quantum states and likely can support a significant quasibound state of the molecule, well above the dissociation energy. The classical dynamics and the lifetime of quantum states on the invariant manifold are determined.

  16. The vibrational dynamics of 3D HOCl above dissociation

    NASA Astrophysics Data System (ADS)

    Lin, Yi-Der; Reichl, L. E.; Jung, Christof

    2015-03-01

    We explore the classical vibrational dynamics of the HOCl molecule for energies above the dissociation energy of the molecule. Above dissociation, we find that the classical dynamics is dominated by an invariant manifold which appears to stabilize two periodic orbits at energies significantly above the dissociation energy. These stable periodic orbits can hold a large number of quantum states and likely can support a significant quasibound state of the molecule, well above the dissociation energy. The classical dynamics and the lifetime of quantum states on the invariant manifold are determined.

  17. Dynamic rupture in a damage-breakage rheology model

    NASA Astrophysics Data System (ADS)

    Lyakhovsky, Vladimir; Ben-Zion, Yehuda; Ilchev, Assen; Mendecki, Aleksander

    2016-05-01

    We present a thermodynamically-based formulation for modeling dynamic rupture processes in the brittle crust using a continuum damage-breakage rheology. The model combines aspects of a continuum viscoelastic damage framework for brittle solids with a continuum breakage mechanics for granular flow within dynamically generated slip zones. The formulation accounts for the density of distributed cracking and other internal flaws in damaged rocks with a scalar damage parameter, and addresses the grain size distribution of a granular phase in the slip zone with a breakage parameter. A dynamic brittle instability is associated with a critical level of damage in the solid, leading to loss of convexity of the solid strain energy, localization, and transition to a granular phase associated with lower energy level. The continuum damage-breakage rheology model treats the localization to a slip zone at the onset of dynamic rupture and post-failure recovery process as phase transitions between solid and granular states. The model generates sub- and super-shear rupture velocities and pulse-type ruptures seen also in frictional models, and additional important features such as strong dynamic changes of volumetric strain near the rupture front and diversity of nucleation mechanisms. The propagation of rupture front and slip accumulation at a point are correlated with sharp dynamic dilation followed by a gradual decay to a level associated with the final volumetric change associated with the granular phase transition in the slipping zone. The local brittle failure process associated with the solid-granular transition is expected to produce isotropic radiation in addition to the deviatoric terms. The framework significantly extends the ability to model brittle processes in complex geometrical structures and allows analyzing the roles of gouge thickness and other parameters on nucleation, rupture and radiation characteristics.

  18. Dynamic rupture in a damage-breakage rheology model

    NASA Astrophysics Data System (ADS)

    Lyakhovsky, Vladimir; Ben-Zion, Yehuda; Ilchev, Assen; Mendecki, Aleksander

    2016-08-01

    We present a thermodynamically based formulation for modelling dynamic rupture processes in the brittle crust using a continuum damage-breakage rheology. The model combines aspects of a continuum viscoelastic damage framework for brittle solids with a continuum breakage mechanics for granular flow within dynamically generated slip zones. The formulation accounts for the density of distributed cracking and other internal flaws in damaged rocks with a scalar damage parameter, and addresses the grain size distribution of a granular phase in the slip zone with a breakage parameter. A dynamic brittle instability is associated with a critical level of damage in the solid, leading to loss of convexity of the solid strain energy, localization and transition to a granular phase associated with lower energy level. The continuum damage-breakage rheology model treats the localization to a slip zone at the onset of dynamic rupture and post-failure recovery process as phase transitions between solid and granular states. The model generates sub- and supershear rupture velocities and pulse-type ruptures seen also in frictional models, and additional important features such as strong dynamic changes of volumetric strain near the rupture front and diversity of nucleation mechanisms. The propagation of rupture front and slip accumulation at a point are correlated with sharp dynamic dilation followed by a gradual decay to a level associated with the final volumetric change associated with the granular phase transition in the slipping zone. The local brittle failure process associated with the solid-granular transition is expected to produce isotropic radiation in addition to the deviatoric terms. The framework significantly extends the ability to model brittle processes in complex geometrical structures and allows analysing the roles of gouge thickness and other parameters on nucleation, rupture and radiation characteristics.

  19. First 3-D simulations of meteor plasma dynamics and turbulence

    NASA Astrophysics Data System (ADS)

    Oppenheim, Meers M.; Dimant, Yakov S.

    2015-02-01

    Millions of small but detectable meteors hit the Earth's atmosphere every second, creating trails of hot plasma that turbulently diffuse into the background atmosphere. For over 60 years, radars have detected meteor plasmas and used these signals to infer characteristics of the meteoroid population and upper atmosphere, but, despite the importance of meteor radar measurements, the complex processes by which these plasmas evolve have never been thoroughly explained or modeled. In this paper, we present the first fully 3-D simulations of meteor evolution, showing meteor plasmas developing instabilities, becoming turbulent, and inhomogeneously diffusing into the background ionosphere. These instabilities explain the characteristics and strength of many radar observations, in particular the high-resolution nonspecular echoes made by large radars. The simulations reveal how meteors create strong electric fields that dig out deep plasma channels along the Earth's magnetic fields. They also allow researchers to explore the impacts of the intense winds and wind shears, commonly found at these altitudes, on meteor plasma evolution. This study will allow the development of more sophisticated models of meteor radar signals, enabling the extraction of detailed information about the properties of meteoroid particles and the atmosphere.

  20. Quantifying cellular interaction dynamics in 3-D fluorescence microscopy data

    PubMed Central

    Klauschen, Frederick; Ishii, Masaru; Qi, Hai; Bajénoff, Marc; Egen, Jackson G.; Germain, Ronald N.; Meier-Schellersheim, Martin

    2012-01-01

    The wealth of information available from advanced fluorescence imaging techniques used to analyze biological processes with high spatial and temporal resolution calls for high-throughput image analysis methods. Here, we describe a fully automated approach to analyzing cellular interaction behavior in 3-D fluorescence microscopy images. As example application we present the analysis of drug-induced and S1P1-knock-out-related changes in bone-osteoclast interactions. Moreover, we apply our approach to images showing the spatial association of dendritic cells with the fibroblastic reticular cell network within lymph nodes and to microscopy data about T-B lymphocyte synapse formation. Such analyses that yield important information about the molecular mechanisms determining cellular interaction behavior would be very difficult to perform with approaches that rely on manual/semi-automated analyses. This protocol integrates adaptive threshold segmentation, object detection, adaptive color channel merging and neighborhood analysis and permits rapid, standardized, quantitative analysis and comparison of the relevant features in large data sets. PMID:19696749

  1. Intersonic and Supersonic ruptures in a model of dynamic rupture in a layered medium

    NASA Astrophysics Data System (ADS)

    Ma, X.; Elbanna, A. E.

    2014-12-01

    The velocity structure in the lithosphere is quite complex and is rarely homogeneous. Wave reflection, transmission, and diffraction from the boundaries of the different layers and inclusions are expected to lead to a rich dynamic response and significantly affect rupture propagation on embedded faults. Here, we report our work on modeling dynamic rupture in an elastic domain with an embedded soft (stiff) layer as a first step towards modeling rupture propagation in realistic velocity structures. We use the Finite Element method (Pylith) to simulate rupture on a 2D in-plane fault embedded in an elastic full space. The simulated domain is 30 km wide and 100km long. Absorbing boundary conditions are used around the edges of the domain to simulate an infinite extension in all directions. The fault operates under linear slip-weakening friction law. We initiate the rupture by artificially overstressing a localized region near the left edge of the fault. We consider embedded soft/stiff layers with 20% to 60% reduction/increase of wave velocity respectively. The embedded layers are placed at different distances from the fault surface. We observed that the existence of a soft layer significantly shortens the transition length to supershear propagation through the Burridge-Andrews mechanism. The higher the material contrast, the shorter the transition length to supershear propagation becomes. We also observe that supershear rupture could be generated at pretress values that are lower than what is theoretically predicted for a homogeneous medium. We find that the distance from the lower boundary of the soft layer to the fault surface has a stronger influence on the supershear transition length as opposed to the thickness of the soft layer. In the existence of an embedded stiffer layer we found that rupture could propagate faster than the fault zone P-wave speed. In this case, the propagating rupture generate two Mach cones; one is associated with the shear wave, and the

  2. Spectral Element Simulations of Rupture Dynamics along kinked faults

    NASA Astrophysics Data System (ADS)

    Vilotte, J.; Festa, G.; Madariaga, R.

    2005-12-01

    Numerical simulation of earthquake source dynamics provides key elements for ground-motion prediction and insights into the physics of dynamic rupture propagation. Faulting is controlled by non-linear frictional interactions and damage within the fault zone. Important features of the earthquakes dynamics, such as rupture velocity, arrest phase and high-frequency radiation are believed to be strongly influenced by the geometry of the faults (kinks, jogs and forks). Data analysis as well as kinematic inversions have pointed out potential links between super-shear and geometry, as in the case of the Denali and Izmit earthquakes. Finally, recent laboratory experiments of sub- and super-shear rupture propagation along kink interfaces have shed new lights on these phenomena. We present here spectral element simulations of the dynamic rupture propagation along kinked and curved fault interfaces, a problem that has been experimentally investigated by Rousseau and Rosakis (2003). Depending on the state of the initial stress, we numerically analyze the mechanics of the dynamical fault branching for sub- and super-shear rupture propagation. Special interest is devoted to source directivity effects and high frequency generation related to the branching process. Implications for strong motion analysis will be discussed. This work was supported by the SPICE - Research and Training project

  3. Rupture models with dynamically determined breakdown displacement

    USGS Publications Warehouse

    Andrews, D.J.

    2004-01-01

    The critical breakdown displacement, Dc, in which friction drops to its sliding value, can be made dependent on event size by specifying friction to be a function of variables other than slip. Two such friction laws are examined here. The first is designed to achieve accuracy and smoothness in discrete numerical calculations. Consistent resolution throughout an evolving rupture is achieved by specifying friction as a function of elapsed time after peak stress is reached. Such a time-weakening model produces Dc and fracture energy proportional to the square root of distance rupture has propagated in the case of uniform stress drop. The second friction law is more physically motivated. Energy loss in a damage zone outside the slip zone has the effect of increasing Dc and limiting peak slip velocity (Andrews, 1976). This article demonstrates a converse effect, that artificially limiting slip velocity on a fault in an elastic medium has a toughening effect, increasing fracture energy and Dc proportionally to rupture propagation distance in the case of uniform stress drop. Both the time-weakening and the velocity-toughening models can be used in calculations with heterogeneous stress drop.

  4. Dynamics of free subduction from 3-D boundary element modeling

    NASA Astrophysics Data System (ADS)

    Li, Zhong-Hai; Ribe, Neil M.

    2012-06-01

    In order better to understand the physical mechanisms underlying free subduction, we perform three-dimensional boundary-element numerical simulations of a dense fluid sheet with thickness h and viscosity η2 sinking in an `ambient mantle' with viscosity η1. The mantle layer is bounded above by a traction-free surface, and is either (1) infinitely deep or (2) underlain by a rigid boundary at a finite depth H + d, similar to the typical geometry used in laboratory experiments. Instantaneous solutions in configuration (1) show that the sheet's dimensionless `stiffness' S determines whether the slab's sinking speed is controlled by the viscosity of the ambient mantle (S < 1) or the viscosity of the sheet itself (S > 10). Time-dependent solutions with tracers in configuration (2) demonstrate a partial return flow around the leading edge of a retreating slab and return flow around its sides. The extra `edge drag' exerted by the flow around the sides causes transverse deformation of the slab, and makes the sinking speed of a 3-D slab up to 40% less than that of a 2-D slab. A systematic investigation of the slab's interaction with the bottom boundary as a function of η2/η1 and H/h delineates a rich regime diagram of different subduction modes (trench retreating, slab folding, trench advancing) and reveals a new `advancing-folding' mode in which slab folding is preceded by advancing trench motion. The solutions demonstrate that mode selection is controlled by the dip of the leading edge of the slab at the time when it first encounters the bottom boundary.

  5. Introducing a New 3D Dynamical Model for Barred Galaxies

    NASA Astrophysics Data System (ADS)

    Jung, Christof; Zotos, Euaggelos E.

    2015-11-01

    The regular or chaotic dynamics of an analytical realistic three dimensional model composed of a spherically symmetric central nucleus, a bar and a flat disk is investigated. For describing the properties of the bar, we introduce a new simple dynamical model and we explore the influence on the character of orbits of all the involved parameters of it, such as the mass and the scale length of the bar, the major semi-axis and the angular velocity of the bar, as well as the energy. Regions of phase space with ordered and chaotic motion are identified in dependence on these parameters and for breaking the rotational symmetry. First, we study in detail the dynamics in the invariant plane z = pz = 0 using the Poincaré map as a basic tool and then study the full three-dimensional case using the Smaller Alignment index method as principal tool for distinguishing between order and chaos. We also present strong evidence obtained through the numerical simulations that our new bar model can realistically describe the formation and the evolution of the observed twin spiral structure in barred galaxies.

  6. Rupture of a biomembrane under dynamic surface tension

    NASA Astrophysics Data System (ADS)

    Bicout, D. J.; Kats, E.

    2012-03-01

    How long will a fluid membrane vesicle stressed with a steady ramp of micropipette last before rupture? Or conversely, how high should the surface tension be to rupture such a membrane? To answer these challenging questions we developed a theoretical framework that allows for the description and reproduction of dynamic tension spectroscopy (DTS) observations. The kinetics of the membrane rupture under ramps of surface tension is described as a succession of an initial pore formation followed by the Brownian process of the pore radius crossing the time-dependent energy barrier. We present the formalism and a derive (formal) analytical expression of the survival probability describing the fate of the membrane under DTS conditions. Using numerical simulations for the membrane prepared in an initial state with a given distribution of times for pore nucleation, we study the membrane lifetime (or inverse of rupture rate) and distribution of membrane surface tension at rupture as a function of membrane characteristics like pore nucleation rate, the energy barrier to failure, and tension loading rate. It is found that simulations reproduce the main features of DTS experiments, particularly the pore nucleation and pore-size diffusion-controlled limits of membrane rupture dynamics. This approach can be adapted and applied to processes of permeation and pore opening in membranes (electroporation, membrane disruption by antimicrobial peptides, vesicle fusion).

  7. Dynamic rupture processes on two orthogonal but not conjugate fault segments

    NASA Astrophysics Data System (ADS)

    Kase, Y.; Aoi, S.

    2010-12-01

    The 2009 Suruga-bay, Japan, earthquake was supposed to rupture two orthogonal but not conjugate fault segments. The aftershock distribution consisting of two planes, which has the SE- and NE-dipping planes for the southern and northern source areas, respectively, and the hypocenter of the main shock was located at the SE-dipping plane (Aoi et al., 2010, Nature geoscience). The normal vectors of the two planes are almost orthogonal. Using the fault plane model that consists of the SE-dipping fault segment with a hypocenter and the NE-dipping fault segment connecting with the other segment at the point 5 km west of the hypocenter, Aoi et al. (2010) estimated the rupture process using the near-source strong-motion data. The estimated rake angles suggested that the SE-dipping fault segment had right-lateral strike slip, and that the NE-dipping segment had reverse slip. In this study, we investigate a physical possibility of coseismic slip on two orthogonal but not conjugate fault segments, using dynamic rupture simulations. The 3-D finite-difference method of Kase and Kuge (2001, GJI) is modified for an infinite medium. Varying the geometry of two faults and the maximum compressional stress axis, we calculate spontaneous rupture processes on segments, and examine whether a rupture propagating to the joint can jump to the second segment. Assuming coefficients of friction to be uniform on the two faults, we estimate the ranges of azimuth and plunge using rake angle on the first (SE-dipping) segment and stress condition on the second (NE-dipping) segment, respectively. Results of spontaneous rupture simulations show that a rupture triggered on the second segment successfully propagates only when strength excess is smaller and stress drop is larger on the second segment than the first segment. The conditions of the stress and dynamic parameters for successful rupture jump and propagation on the second segment are very limited. When the rupture extends on the both segments

  8. Cotranslational processing mechanisms: towards a dynamic 3D model.

    PubMed

    Giglione, Carmela; Fieulaine, Sonia; Meinnel, Thierry

    2009-08-01

    Recent major advances have been made in understanding how cotranslational events are achieved in the course of protein biosynthesis. Specifically, several studies have shed light into the dynamic process of how nascent chains emerging from the ribosome are supported by protein biogenesis factors to ensure both processing and folding mechanisms. To take into account the awareness that coordination is needed, a new 'concerted model' recently proposed simultaneous action of both processes on the ribosome. In the model, any emerging nascent chain is first encountered by the chaperone trigger factor (TF), which forms an open cradle underneath the ribosomal exit tunnel. This cradle serves as a passive router that channels the nascent chains to the first cotranslational event, the proteolysis event performed by the N-terminal methionine excision machinery. Although fascinating, this model clearly raises more questions than it answers. Does the data used to develop this model stand up to scrutiny and, if not, what are the alternative mechanisms that the data suggest? PMID:19647435

  9. High resolution earthquake source mechanisms in a subduction zone: 3-D waveform simulations of aftershocks from the 2010 Mw 8.8 Chile rupture

    NASA Astrophysics Data System (ADS)

    Hicks, Stephen; Rietbrock, Andreas

    2015-04-01

    The earthquake rupture process is extremely heterogeneous. For subduction zone earthquakes in particular, it is vital to understand how structural variations in the overriding plate and downgoing slab may control slip style. The large-scale 3-D geometry of subduction plate boundaries is rapidly becoming well understood (e.g. Hayes et al., 2012); however, the nature of slip style along any finer-scale structures remains elusive. Regional earthquake moment tensor (RMT) inversion can shed light on faulting mechanisms. However, many traditional regional moment tensor inversions use simplified (1-D) Earth models (e.g. Agurto et al., 2012; Hayes et al., 2013) that only use the lowest frequency parts of the waveform, which may mask source complexity. As a result, we may have to take care when making small-scale interpretations about the causative fault and its slip style. This situation is compounded further by strong lateral variations in subsurface geology, as well as poor station coverage for recording offshore subduction earthquakes. A formal assessment of the resolving capability of RMT inversions in subduction zones is challenging and the application of 3-D waveform simulation techniques in highly heterogeneous media is needed. We generate 3-D waveform simulations of aftershocks from a large earthquake that struck Chile in 2010. The Mw 8.8 Maule earthquake is the sixth largest earthquake ever recorded. Following the earthquake, there was an international deployment of seismic stations in the rupture area, making this one of the best observed aftershock sequences to date. We therefore have a unique opportunity to compare recorded waveforms with simulated waveforms for many earthquakes, shedding light on the effect of 3-D heterogeneity on source imaging. We perform forward simulations using the spectral element wave propagation code, SPEFEM3D (e.g. Komatitsch et al., 2010) for a set of moderate-sized aftershocks (Mw 4.0-5.5). A detailed knowledge of velocity structure

  10. 3D numerical simulations of vesicle and inextensible capsule dynamics

    NASA Astrophysics Data System (ADS)

    Farutin, Alexander; Biben, Thierry; Misbah, Chaouqi

    2014-10-01

    Vesicles are locally-inextensible fluid membranes, capsules are endowed with in-plane shear elasticity mimicking the cytoskeleton of red blood cells (RBCs), but are extensible, while RBCs are inextensible. We use boundary integral (BI) methods based on the Green function techniques to model and solve numerically their dynamics. We regularize the single layer integral by subtraction of exact identities for the terms involving the normal and the tangential components of the force. The stability and precision of BI calculation is enhanced by taking advantage of additional quadrature nodes located in vertices of an auxiliary mesh, constructed by a standard refinement procedure from the main mesh. We extend the partition of unity technique to boundary integral calculation on triangular meshes. The proposed algorithm offers the same treatment of near-singular integration regardless whether the source and the target points belong to the same surface or not. Bending forces are calculated by using expressions derived from differential geometry. Membrane incompressibility is handled by using two penalization parameters per suspended entity: one for deviation of the global area from prescribed value and another for the sum of squares of local strains defined on each vertex. Extensible or inextensible capsules, a model of RBC, are studied by storing the position in the reference configuration for each vertex. The elastic force is then calculated by direct variation of the elastic energy. Various nonequilibrium physical examples on vesicles and capsules will be presented and the convergence and precision tests highlighted. Overall, a good convergence is observed with numerical error inversely proportional to the number of vertices used for surface discretization, the highest order of convergence allowed by piece-wise linear interpolation of the surface.

  11. The 1999 Izmit, Turkey, earthquake: A 3D dynamic stress transfer model of intraearthquake triggering

    USGS Publications Warehouse

    Harris, R.A.; Dolan, J.F.; Hartleb, R.; Day, S.M.

    2002-01-01

    Before the August 1999 Izmit (Kocaeli), Turkey, earthquake, theoretical studies of earthquake ruptures and geological observations had provided estimates of how far an earthquake might jump to get to a neighboring fault. Both numerical simulations and geological observations suggested that 5 km might be the upper limit if there were no transfer faults. The Izmit earthquake appears to have followed these expectations. It did not jump across any step-over wider than 5 km and was instead stopped by a narrower step-over at its eastern end and possibly by a stress shadow caused by a historic large earthquake at its western end. Our 3D spontaneous rupture simulations of the 1999 Izmit earthquake provide two new insights: (1) the west- to east-striking fault segments of this part of the North Anatolian fault are oriented so as to be low-stress faults and (2) the easternmost segment involved in the August 1999 rupture may be dipping. An interesting feature of the Izmit earthquake is that a 5-km-long gap in surface rupture and an adjacent 25° restraining bend in the fault zone did not stop the earthquake. The latter observation is a warning that significant fault bends in strike-slip faults may not arrest future earthquakes.

  12. Coupling a geodynamic seismic cycling model to rupture dynamic simulations

    NASA Astrophysics Data System (ADS)

    Gabriel, Alice; van Dinther, Ylona

    2014-05-01

    The relevance and results of dynamic rupture scenarios are implicitly linked to the geometry and pre-existing stress and strength state on a fault. The absolute stresses stored along faults during interseismic periods, are largely unquantifiable. They are, however, pivotal in defining coseismic rupture styles, near-field ground motion, and macroscopic source properties (Gabriel et al., 2012). Obtaining these in a physically consistent manner requires seismic cycling models, which directly couple long-term deformation processes (over 1000 year periods), the self-consistent development of faults, and the resulting dynamic ruptures. One promising approach to study seismic cycling enables both the generation of spontaneous fault geometries and the development of thermo-mechanically consistent fault stresses. This seismo-thermo-mechanical model has been developed using a methodology similar to that employed to study long-term lithospheric deformation (van Dinther et al., 2013a,b, using I2ELVIS of Gerya and Yuen, 2007). We will innovatively include the absolute stress and strength values along physically consistent evolving non-finite fault zones (regions of strain accumulation) from the geodynamic model into dynamic rupture simulations as an initial condition. The dynamic rupture simulations will be performed using SeisSol, an arbitrary high-order derivative Discontinuous Galerkin (ADER-DG) scheme (Pelties et al., 2012). The dynamic rupture models are able to incorporate the large degree of fault geometry complexity arising in naturally evolving geodynamic models. We focus on subduction zone settings with and without a splay fault. Due to the novelty of the coupling, we first focus on methodological challenges, e.g. the synchronization of both methods regarding the nucleation of events, the localization of fault planes, and the incorporation of similar frictional constitutive relations. We then study the importance of physically consistent fault stress, strength, and

  13. 3D video-based deformation measurement of the pelvis bone under dynamic cyclic loading

    PubMed Central

    2011-01-01

    Background Dynamic three-dimensional (3D) deformation of the pelvic bones is a crucial factor in the successful design and longevity of complex orthopaedic oncological implants. The current solutions are often not very promising for the patient; thus it would be interesting to measure the dynamic 3D-deformation of the whole pelvic bone in order to get a more realistic dataset for a better implant design. Therefore we hypothesis if it would be possible to combine a material testing machine with a 3D video motion capturing system, used in clinical gait analysis, to measure the sub millimetre deformation of a whole pelvis specimen. Method A pelvis specimen was placed in a standing position on a material testing machine. Passive reflective markers, traceable by the 3D video motion capturing system, were fixed to the bony surface of the pelvis specimen. While applying a dynamic sinusoidal load the 3D-movement of the markers was recorded by the cameras and afterwards the 3D-deformation of the pelvis specimen was computed. The accuracy of the 3D-movement of the markers was verified with 3D-displacement curve with a step function using a manual driven 3D micro-motion-stage. Results The resulting accuracy of the measurement system depended on the number of cameras tracking a marker. The noise level for a marker seen by two cameras was during the stationary phase of the calibration procedure ± 0.036 mm, and ± 0.022 mm if tracked by 6 cameras. The detectable 3D-movement performed by the 3D-micro-motion-stage was smaller than the noise level of the 3D-video motion capturing system. Therefore the limiting factor of the setup was the noise level, which resulted in a measurement accuracy for the dynamic test setup of ± 0.036 mm. Conclusion This 3D test setup opens new possibilities in dynamic testing of wide range materials, like anatomical specimens, biomaterials, and its combinations. The resulting 3D-deformation dataset can be used for a better estimation of material

  14. Simulating Large-Scale Earthquake Dynamic Rupture Scenarios On Natural Fault Zones Using the ADER-DG Method

    NASA Astrophysics Data System (ADS)

    Gabriel, Alice; Pelties, Christian

    2014-05-01

    In this presentation we will demonstrate the benefits of using modern numerical methods to support physic-based ground motion modeling and research. For this purpose, we utilize SeisSol an arbitrary high-order derivative Discontinuous Galerkin (ADER-DG) scheme to solve the spontaneous rupture problem with high-order accuracy in space and time using three-dimensional unstructured tetrahedral meshes. We recently verified the method in various advanced test cases of the 'SCEC/USGS Dynamic Earthquake Rupture Code Verification Exercise' benchmark suite, including branching and dipping fault systems, heterogeneous background stresses, bi-material faults and rate-and-state friction constitutive formulations. Now, we study the dynamic rupture process using 3D meshes of fault systems constructed from geological and geophysical constraints, such as high-resolution topography, 3D velocity models and fault geometries. Our starting point is a large scale earthquake dynamic rupture scenario based on the 1994 Northridge blind thrust event in Southern California. Starting from this well documented and extensively studied event, we intend to understand the ground-motion, including the relevant high frequency content, generated from complex fault systems and its variation arising from various physical constraints. For example, our results imply that the Northridge fault geometry favors a pulse-like rupture behavior.

  15. Local 3D matrix microenvironment regulates cell migration through spatiotemporal dynamics of contractility-dependent adhesions.

    PubMed

    Doyle, Andrew D; Carvajal, Nicole; Jin, Albert; Matsumoto, Kazue; Yamada, Kenneth M

    2015-01-01

    The physical properties of two-dimensional (2D) extracellular matrices (ECMs) modulate cell adhesion dynamics and motility, but little is known about the roles of local microenvironmental differences in three-dimensional (3D) ECMs. Here we generate 3D collagen gels of varying matrix microarchitectures to characterize their regulation of 3D adhesion dynamics and cell migration. ECMs containing bundled fibrils demonstrate enhanced local adhesion-scale stiffness and increased adhesion stability through balanced ECM/adhesion coupling, whereas highly pliable reticular matrices promote adhesion retraction. 3D adhesion dynamics are locally regulated by ECM rigidity together with integrin/ECM association and myosin II contractility. Unlike 2D migration, abrogating contractility stalls 3D migration regardless of ECM pore size. We find force is not required for clustering of activated integrins on 3D native collagen fibrils. We propose that efficient 3D migration requires local balancing of contractility with ECM stiffness to stabilize adhesions, which facilitates the detachment of activated integrins from ECM fibrils. PMID:26548801

  16. Local 3D matrix microenvironment regulates cell migration through spatiotemporal dynamics of contractility-dependent adhesions

    PubMed Central

    Doyle, Andrew D.; Carvajal, Nicole; Jin, Albert; Matsumoto, Kazue; Yamada, Kenneth M.

    2015-01-01

    The physical properties of two-dimensional (2D) extracellular matrices (ECMs) modulate cell adhesion dynamics and motility, but little is known about the roles of local microenvironmental differences in three-dimensional (3D) ECMs. Here we generate 3D collagen gels of varying matrix microarchitectures to characterize their regulation of 3D adhesion dynamics and cell migration. ECMs containing bundled fibrils demonstrate enhanced local adhesion-scale stiffness and increased adhesion stability through balanced ECM/adhesion coupling, whereas highly pliable reticular matrices promote adhesion retraction. 3D adhesion dynamics are locally regulated by ECM rigidity together with integrin/ECM association and myosin II contractility. Unlike 2D migration, abrogating contractility stalls 3D migration regardless of ECM pore size. We find force is not required for clustering of activated integrins on 3D native collagen fibrils. We propose that efficient 3D migration requires local balancing of contractility with ECM stiffness to stabilize adhesions, which facilitates the detachment of activated integrins from ECM fibrils. PMID:26548801

  17. Local 3D matrix microenvironment regulates cell migration through spatiotemporal dynamics of contractility-dependent adhesions

    NASA Astrophysics Data System (ADS)

    Doyle, Andrew D.; Carvajal, Nicole; Jin, Albert; Matsumoto, Kazue; Yamada, Kenneth M.

    2015-11-01

    The physical properties of two-dimensional (2D) extracellular matrices (ECMs) modulate cell adhesion dynamics and motility, but little is known about the roles of local microenvironmental differences in three-dimensional (3D) ECMs. Here we generate 3D collagen gels of varying matrix microarchitectures to characterize their regulation of 3D adhesion dynamics and cell migration. ECMs containing bundled fibrils demonstrate enhanced local adhesion-scale stiffness and increased adhesion stability through balanced ECM/adhesion coupling, whereas highly pliable reticular matrices promote adhesion retraction. 3D adhesion dynamics are locally regulated by ECM rigidity together with integrin/ECM association and myosin II contractility. Unlike 2D migration, abrogating contractility stalls 3D migration regardless of ECM pore size. We find force is not required for clustering of activated integrins on 3D native collagen fibrils. We propose that efficient 3D migration requires local balancing of contractility with ECM stiffness to stabilize adhesions, which facilitates the detachment of activated integrins from ECM fibrils.

  18. Dynamic Rupture Benchmarking of the ADER-DG Method

    NASA Astrophysics Data System (ADS)

    Pelties, C.; Gabriel, A.

    2012-12-01

    We will verify the arbitrary high-order derivative Discontinuous Galerkin (ADER-DG) method in various test cases of the 'SCEC/USGS Dynamic Earthquake Rupture Code Verification Exercise' benchmark suite (Harris et al. 2009). The ADER-DG scheme is able to solve the spontaneous rupture problem with high-order accuracy in space and time on three-dimensional unstructured tetrahedral meshes. Strong mesh coarsening or refinement at areas of interest can be applied to keep the computational costs feasible. Moreover, the method does not generate spurious high-frequency contributions in the slip rate spectra and therefore does not require any artificial damping as demonstrated in previous presentations and publications (Pelties et al. 2010 and 2012). We will show that the mentioned features hold also for more advanced setups as e.g. a branching fault system, heterogeneous background stresses and bimaterial faults. The advanced geometrical flexibility combined with an enhanced accuracy will make the ADER-DG method a useful tool to study earthquake dynamics on complex fault systems in realistic rheologies. References: Harris, R.A., M. Barall, R. Archuleta, B. Aagaard, J.-P. Ampuero, H. Bhat, V. Cruz-Atienza, L. Dalguer, P. Dawson, S. Day, B. Duan, E. Dunham, G. Ely, Y. Kaneko, Y. Kase, N. Lapusta, Y. Liu, S. Ma, D. Oglesby, K. Olsen, A. Pitarka, S. Song, and E. Templeton, The SCEC/USGS Dynamic Earthquake Rupture Code Verification Exercise, Seismological Research Letters, vol. 80, no. 1, pages 119-126, 2009 Pelties, C., J. de la Puente, and M. Kaeser, Dynamic Rupture Modeling in Three Dimensions on Unstructured Meshes Using a Discontinuous Galerkin Method, AGU 2010 Fall Meeting, abstract #S21C-2068 Pelties, C., J. de la Puente, J.-P. Ampuero, G. Brietzke, and M. Kaeser, Three-Dimensional Dynamic Rupture Simulation with a High-order Discontinuous Galerkin Method on Unstructured Tetrahedral Meshes, JGR. - Solid Earth, VOL. 117, B02309, 2012

  19. Dynamic Rupture Benchmarking of the ADER-DG Method

    NASA Astrophysics Data System (ADS)

    Gabriel, Alice; Pelties, Christian

    2013-04-01

    We will verify the arbitrary high-order derivative Discontinuous Galerkin (ADER-DG) method in various test cases of the 'SCEC/USGS Dynamic Earthquake Rupture Code Verification Exercise' benchmark suite (Harris et al. 2009). The ADER-DG scheme is able to solve the spontaneous rupture problem with high-order accuracy in space and time on three-dimensional unstructured tetrahedral meshes. Strong mesh coarsening or refinement at areas of interest can be applied to keep the computational costs feasible. Moreover, the method does not generate spurious high-frequency contributions in the slip rate spectra and therefore does not require any artificial damping as demonstrated in previous presentations and publications (Pelties et al. 2010 and 2012). We will show that the mentioned features hold also for more advanced setups as e.g. a branching fault system, heterogeneous background stresses and bimaterial faults. The advanced geometrical flexibility combined with an enhanced accuracy will make the ADER-DG method a useful tool to study earthquake dynamics on complex fault systems in realistic rheologies. References: Harris, R.A., M. Barall, R. Archuleta, B. Aagaard, J.-P. Ampuero, H. Bhat, V. Cruz-Atienza, L. Dalguer, P. Dawson, S. Day, B. Duan, E. Dunham, G. Ely, Y. Kaneko, Y. Kase, N. Lapusta, Y. Liu, S. Ma, D. Oglesby, K. Olsen, A. Pitarka, S. Song, and E. Templeton, The SCEC/USGS Dynamic Earthquake Rupture Code Verification Exercise, Seismological Research Letters, vol. 80, no. 1, pages 119-126, 2009 Pelties, C., J. de la Puente, and M. Kaeser, Dynamic Rupture Modeling in Three Dimensions on Unstructured Meshes Using a Discontinuous Galerkin Method, AGU 2010 Fall Meeting, abstract #S21C-2068 Pelties, C., J. de la Puente, J.-P. Ampuero, G. Brietzke, and M. Kaeser, Three-Dimensional Dynamic Rupture Simulation with a High-order Discontinuous Galerkin Method on Unstructured Tetrahedral Meshes, JGR. - Solid Earth, VOL. 117, B02309, 2012

  20. Dynamic visual image modeling for 3D synthetic scenes in agricultural engineering

    NASA Astrophysics Data System (ADS)

    Gao, Li; Yan, Juntao; Li, Xiaobo; Ji, Yatai; Li, Xin

    The dynamic visual image modeling for 3D synthetic scenes by using dynamic multichannel binocular visual image based on the mobile self-organizing network. Technologies of 3D modeling synthetic scenes have been widely used in kinds of industries. The main purpose of this paper is to use multiple networks of dynamic visual monitors and sensors to observe an unattended area, to use the advantages of mobile network in rural areas for improving existing mobile network information service further and providing personalized information services. The goal of displaying is to provide perfect representation of synthetic scenes. Using low-power dynamic visual monitors and temperature/humidity sensor or GPS installed in the node equipment, monitoring data will be sent at scheduled time. Then through the mobile self-organizing network, 3D model is rebuilt by synthesizing the returned images. On this basis, we formalize a novel algorithm for multichannel binocular visual 3D images based on fast 3D modeling. Taking advantage of these low prices mobile, mobile self-organizing networks can get a large number of video from where is not suitable for human observation or unable to reach, and accurately synthetic 3D scene. This application will play a great role in promoting its application in agriculture.

  1. 3D velocity structure of the outer forearc of the Colombia-Ecuador subduction zone; implications for the 1958 megathrust earthquake rupture zone

    NASA Astrophysics Data System (ADS)

    Galve, A.; Charvis, P.; Garcia Cano, L.; Marcaillou, B.

    2013-12-01

    In 2005, we conducted an onshore-offshore 3D refraction and wide-angle reflection seismic experiment over the rupture zone of the 1958 subduction earthquake that occurred near the border between Colombia and Ecuador. This earthquake was part of a sequence of 3 large ruptures (1942, Mw=7.8; 1958, Mw=7.7; 1979, Mw=8.2), which successively broke from south to north the segments of the megathrust that had been ruptured in 1906 by a single, very large magnitude (8.8) earthquake. Using first arrival traveltime inversion, we constructed a well-defined Vp velocity model of the plate boundary and of the upper and lower plates, down to 25 km depth. The model reveals a 5-km thick, low velocity zone in the upper plate, located immediately above the interplate contact. Because similar low-velocity zones are commonly observed along margins made of oceanic or island-arc accreted terranes, we suggest that the low-velocity zone might result from the alteration and hydration of mafic and ultramafic rocks in the upper plate basement, rather than from hydrofracturing alone. Sediments underplated beneath the inner wedge might contribute to the low-velocity zone but it is unlikely that they are several kilometers thick. Nevertheless, fluids expelled by the compaction and dehydration of those underplated sediments possibly favor the alteration of the overlying rocks. The low-velocity zone is spatially coincident with the 1958 rupture area. Near the toe of the margin, the model shows a low velocity gradient in the outer wedge that we interpret as a zone of highly faulted and fractured rocks or of poorly consolidated sediments. This low velocity/low gradient region forms the oceanward limit of the rupture zones of both the 1958 and the 1979 earthquakes. We suggest that the two earthquake ruptures were arrested by the low velocity zone because its low rigidity contributed to dissipate most of the seismic energy and of the coseismic strain/stress. This might be the reason why the 1958

  2. Nonrigid registration and classification of the kidneys in 3D dynamic contrast enhanced (DCE) MR images

    NASA Astrophysics Data System (ADS)

    Yang, Xiaofeng; Ghafourian, Pegah; Sharma, Puneet; Salman, Khalil; Martin, Diego; Fei, Baowei

    2012-02-01

    We have applied image analysis methods in the assessment of human kidney perfusion based on 3D dynamic contrast-enhanced (DCE) MRI data. This approach consists of 3D non-rigid image registration of the kidneys and fuzzy C-mean classification of kidney tissues. The proposed registration method reduced motion artifacts in the dynamic images and improved the analysis of kidney compartments (cortex, medulla, and cavities). The dynamic intensity curves show the successive transition of the contrast agent through kidney compartments. The proposed method for motion correction and kidney compartment classification may be used to improve the validity and usefulness of further model-based pharmacokinetic analysis of kidney function.

  3. Parallel contact detection algorithm for transient solid dynamics simulations using PRONTO3D

    SciTech Connect

    Attaway, S.W.; Hendrickson, B.A.; Plimpton, S.J.

    1996-09-01

    An efficient, scalable, parallel algorithm for treating material surface contacts in solid mechanics finite element programs has been implemented in a modular way for MIMD parallel computers. The serial contact detection algorithm that was developed previously for the transient dynamics finite element code PRONTO3D has been extended for use in parallel computation by devising a dynamic (adaptive) processor load balancing scheme.

  4. Evolution, Interaction, and Intrinsic Properties of Dislocations in Intermetallics: Anisotropic 3D Dislocation Dynamics Approach

    SciTech Connect

    Qian Chen

    2008-08-18

    The generation, motion, and interaction of dislocations play key roles during the plastic deformation process of crystalline solids. 3D Dislocation Dynamics has been employed as a mesoscale simulation algorithm to investigate the collective and cooperative behavior of dislocations. Most current research on 3D Dislocation Dynamics is based on the solutions available in the framework of classical isotropic elasticity. However, due to some degree of elastic anisotropy in almost all crystalline solids, it is very necessary to extend 3D Dislocation Dynamics into anisotropic elasticity. In this study, first, the details of efficient and accurate incorporation of the fully anisotropic elasticity into 3D discrete Dislocation Dynamics by numerically evaluating the derivatives of Green's functions are described. Then the intrinsic properties of perfect dislocations, including their stability, their core properties and disassociation characteristics, in newly discovered rare earth-based intermetallics and in conventional intermetallics are investigated, within the framework of fully anisotropic elasticity supplemented with the atomistic information obtained from the ab initio calculations. Moreover, the evolution and interaction of dislocations in these intermetallics as well as the role of solute segregation are presented by utilizing fully anisotropic 3D dislocation dynamics. The results from this work clearly indicate the role and the importance of elastic anisotropy on the evolution of dislocation microstructures, the overall ductility and the hardening behavior in these systems.

  5. A 3D hp-Discontinuous Galerkin Method: Revisiting the M7.3 Landers Earthquake Dynamics

    NASA Astrophysics Data System (ADS)

    Tago, J.; Cruz-Atienza, V. M.; Virieux, J.; Etienne, V.; Sanchez-Sesma, F. J.

    2011-12-01

    Reliable dynamic source models should account of both fault geometry and heterogeneities in the surrounding medium. In this work we introduce a novel numerical method for modeling the dynamic rupture based on a 3D hp-Discontinuous Galerkin (DG) scheme. Our method is derived from the scheme proposed by Benjemaa et al. (2009), which is based on a Finite Volume (FV) approach. Migrating from such approach to the hp-Discontinuous Galerkin philosophy is somehow straightforward since the FV method can be seen as the DG method with its lowest order or approximation (i.e. P0 element). We present a novel approach for treating dynamic rupture boundary conditions using an hp-Discontinuous Galerkin method for unstructured tetrahedral meshes. Although the theory we have developed holds for fault elements with arbitrary order, we show that second order (P2) elements yield a very good convergence. Since the DG method does not impose continuity between elements, our strategy consists in the way we compute the fluxes across the fault elements. During rupture propagation, the fluxes in the elements where the shear traction overcomes the fault strength are such that continuity of every wavefield is imposed except for the tangential fault velocities, while in the unbroken elements tangential continuity is also imposed. Because the fault nodes of a given element are coupled through the Mass and Flux matrices, when a fault node breaks we impose the shear traction on that node and need to recompute the values throughout the rest, to avoid any violation of the friction law throughout the element. This procedure repeats itself iteratively following a predictor-corrector scheme for a given time step until the element solutions stabilize. We point out that our scheme for the fault fluxes in the case of P0 elements is exactly the same as the one proposed by Benjemaa et al. who compute them through energy balance considerations. To verify our mathematical and computational model we have solved

  6. 3D seismic velocity structure in the rupture area of the 2014 M8.2 Iquique earthquake in Northern Chile

    NASA Astrophysics Data System (ADS)

    Woollam, Jack; Fuenzallida, Amaya; Garth, Tom; Rietbrock, Andreas; Ruiz, Sergio; Tavera, Hernando

    2016-04-01

    Seismic velocity tomography is one of the key tools in Earth sciences to image the physical properties of the subsurface. In recent years significant advances have been made to image the Chilean subductions zone, especially in the area of the 2010 M8.8 Maule earthquake (e.g. Hicks et al., 2014), providing much needed physical constraints for earthquakes source inversions and rupture models. In 2014 the M8.2 Iquique earthquake struck the northern part of the Chilean subduction zone in close proximity to the Peruvian boarder. The pre- and aftershock sequence of this major earthquake was recorded by a densified seismological network in Northern Chile and Southern Peru, which provides an excellent data set to study in depth the 3D velocity structure along the subduction megathrust. Based on an automatic event catalogue of nearly 10,000 events spanning the time period March to May 2014 we selected approximately 450 events for a staggered 3D inversion approach. Events are selected to guarantee an even ray coverage through the inversion volume. We only select events with a minimum GAP of 200 to improve depth estimates and therefore increase resolution in the marine forearc. Additionally, we investigate secondary arrivals between the P- and S-wave arrival to improve depth location. Up to now we have processed about 450 events, from which about 150 with at least 30 P- and S-wave observations have been selected for the subsequent 3D tomography. Overall the data quality is very high, which allows arrival time estimates better than 0.05s on average. We will show results from the 1D, 2D, and preliminary 3D inversions and discuss the results together with the obtained seismicity distribution.

  7. First application of the 3D-MHB on dynamic compressive behavior of UHPC

    NASA Astrophysics Data System (ADS)

    Cadoni, Ezio; Dotta, Matteo; Forni, Daniele; Riganti, Gianmario; Albertini, Carlo

    2015-09-01

    In order to study the dynamic behaviour of material in confined conditions a new machine was conceived and called 3D-Modified Hopkinson Bar (3D-MHB). It is a Modified Hopkinson Bar apparatus designed to apply dynamic loading in materials having a tri-axial stress state. It consists of a pulse generator system (with pre-tensioned bar and brittle joint), 1 input bar, and 5 output bars. The first results obtained on Ultra High Performance Concrete in compression with three different mono-axial compression states are presented. The results show how the pre-stress states minimize the boundary condition and a more uniform response is obtained.

  8. 3D dynamic simulation of crack propagation in extracorporeal shock wave lithotripsy

    NASA Astrophysics Data System (ADS)

    Wijerathne, M. L. L.; Hori, Muneo; Sakaguchi, Hide; Oguni, Kenji

    2010-06-01

    Some experimental observations of Shock Wave Lithotripsy(SWL), which include 3D dynamic crack propagation, are simulated with the aim of reproducing fragmentation of kidney stones with SWL. Extracorporeal shock wave lithotripsy (ESWL) is the fragmentation of kidney stones by focusing an ultrasonic pressure pulse onto the stones. 3D models with fine discretization are used to accurately capture the high amplitude shear shock waves. For solving the resulting large scale dynamic crack propagation problem, PDS-FEM is used; it provides numerically efficient failure treatments. With a distributed memory parallel code of PDS-FEM, experimentally observed 3D photoelastic images of transient stress waves and crack patterns in cylindrical samples are successfully reproduced. The numerical crack patterns are in good agreement with the experimental ones, quantitatively. The results shows that the high amplitude shear waves induced in solid, by the lithotriptor generated shock wave, play a dominant role in stone fragmentation.

  9. Trans3D: a free tool for dynamical visualization of EEG activity transmission in the brain.

    PubMed

    Blinowski, Grzegorz; Kamiński, Maciej; Wawer, Dariusz

    2014-08-01

    The problem of functional connectivity in the brain is in the focus of attention nowadays, since it is crucial for understanding information processing in the brain. A large repertoire of measures of connectivity have been devised, some of them being capable of estimating time-varying directed connectivity. Hence, there is a need for a dedicated software tool for visualizing the propagation of electrical activity in the brain. To this aim, the Trans3D application was developed. It is an open access tool based on widely available libraries and supporting both Windows XP/Vista/7(™), Linux and Mac environments. Trans3D can create animations of activity propagation between electrodes/sensors, which can be placed by the user on the scalp/cortex of a 3D model of the head. Various interactive graphic functions for manipulating and visualizing components of the 3D model and input data are available. An application of the Trans3D tool has helped to elucidate the dynamics of the phenomena of information processing in motor and cognitive tasks, which otherwise would have been very difficult to observe. Trans3D is available at: http://www.eeg.pl/. PMID:24967953

  10. How Spatial Abilities and Dynamic Visualizations Interplay When Learning Functional Anatomy with 3D Anatomical Models

    ERIC Educational Resources Information Center

    Berney, Sandra; Bétrancourt, Mireille; Molinari, Gaëlle; Hoyek, Nady

    2015-01-01

    The emergence of dynamic visualizations of three-dimensional (3D) models in anatomy curricula may be an adequate solution for spatial difficulties encountered with traditional static learning, as they provide direct visualization of change throughout the viewpoints. However, little research has explored the interplay between learning material…

  11. Effect of Ductile Agents on the Dynamic Behavior of SiC3D Network Composites

    NASA Astrophysics Data System (ADS)

    Zhu, Jingbo; Wang, Yangwei; Wang, Fuchi; Fan, Qunbo

    2016-07-01

    Co-continuous SiC ceramic composites using pure aluminum, epoxy, and polyurethane (PU) as ductile agents were developed. The dynamic mechanical behavior and failure mechanisms were investigated experimentally using the split Hopkinson pressure bar (SHPB) method and computationally by finite element (FE) simulations. The results show that the SiC3D/Al composite has the best overall performance in comparison with SiC3D/epoxy and SiC3D/PU composites. FE simulations are generally consistent with experimental data. These simulations provide valuable help in predicting mechanical strength and in interpreting the experimental results and failure mechanisms. They may be combined with micrographs for fracture characterizations of the composites. We found that interactions between the SiC phase and ductile agents under dynamic compression in the SHPB method are complex, and that interfacial condition is an important parameter that determines the mechanical response of SiC3D composites with a characteristic interlocking structure during dynamic compression. However, the effect of the mechanical properties of ductile agents on dynamic behavior of the composites is a second consideration in the production of the composites.

  12. On the Dynamic Programming Approach for the 3D Navier-Stokes Equations

    SciTech Connect

    Manca, Luigi

    2008-06-15

    The dynamic programming approach for the control of a 3D flow governed by the stochastic Navier-Stokes equations for incompressible fluid in a bounded domain is studied. By a compactness argument, existence of solutions for the associated Hamilton-Jacobi-Bellman equation is proved. Finally, existence of an optimal control through the feedback formula and of an optimal state is discussed.

  13. Sketch on dynamic gesture tracking and analysis exploiting vision-based 3D interface

    NASA Astrophysics Data System (ADS)

    Woo, Woontack; Kim, Namgyu; Wong, Karen; Tadenuma, Makoto

    2000-12-01

    In this paper, we propose a vision-based 3D interface exploiting invisible 3D boxes, arranged in the personal space (i.e. reachable space by the body without traveling), which allows robust yet simple dynamic gesture tracking and analysis, without exploiting complicated sensor-based motion tracking systems. Vision-based gesture tracking and analysis is still a challenging problem, even though we have witnessed rapid advances in computer vision over the last few decades. The proposed framework consists of three main parts, i.e. (1) object segmentation without bluescreen and 3D box initialization with depth information, (2) movement tracking by observing how the body passes through the 3D boxes in the personal space and (3) movement feature extraction based on Laban's Effort theory and movement analysis by mapping features to meaningful symbols using time-delay neural networks. Obviously, exploiting depth information using multiview images improves the performance of gesture analysis by reducing the errors introduced by simple 2D interfaces In addition, the proposed box-based 3D interface lessens the difficulties in both tracking movement in 3D space and in extracting low-level features of the movement. Furthermore, the time-delay neural networks lessens the difficulties in movement analysis by training. Due to its simplicity and robustness, the framework will provide interactive systems, such as ATR I-cubed Tangible Music System or ATR Interactive Dance system, with improved quality of the 3D interface. The proposed simple framework also can be extended to other applications requiring dynamic gesture tracking and analysis on the fly.

  14. Modes of Dynamic Rupture Propagation and Rupture Front Speeds in Earthquake Models That Account for Dynamic Weakening Mechanisms

    NASA Astrophysics Data System (ADS)

    Lapusta, N.

    2005-12-01

    Laboratory experiments and theories of how fault materials respond suggest that the constitutive response of faults is far from simple. For slow slip rates, laboratory-derived rate and state friction formulations incorporate small, less than 10%, variations in frictional strength about a representative value which is the product of a typical slow-rate friction coefficient (0.6-0.7 for most rock surfaces and fault-like gouge) times the effective normal stress (which is comparable to overburden minus hydrostatic pore pressure, about 150 MPa at the representative seismic depth of 8 km). One could refer to this slow-rate frictional strength as (high) static fault strength. For fast sliding velocities and large slips, additional weakening mechanisms are activated that result in much lower frictional resistance during dynamic sliding. Hence we need to build earthquake models that would account for both high static strength and low dynamic strength of faults. At first, it seems that the combination of high static strength and low, near-zero, dynamic strength should create static stress drops that are large compared to 1-10 MPa static stress drops typically observed. However, Rice (AGU, 1994) and Lapusta and Rice (AGU, 2003, 2004) proposed a model that avoids that pitfall by incorporating small defect regions that nucleate ruptures while the average stress on the fault is still low compared to its static strength. By simulating earthquake sequences in the framework of a 2D depth-averaged elastic model of a faulted crustal plate, they showed that the fault would then operate with reasonable static stress drops, low shear stress, and low heat generation as follows: Earthquakes nucleate under low shear stress in a defect (weak) and then propagate into strong regions due to significant dynamic weakening. The simulations incorporated truly slow, tectonic-type loading of 35 mm/year and resolved all stages of the simulated earthquakes, including the nucleation process and

  15. Fault geometry, rupture dynamics and ground motion from potential earthquakes on the North Anatolian Fault under the Sea of Marmara

    NASA Astrophysics Data System (ADS)

    Oglesby, David D.; Mai, P. Martin

    2012-03-01

    Using the 3-D finite-element method, we develop dynamic spontaneous rupture models of earthquakes on the North Anatolian Fault system in the Sea of Marmara, Turkey, considering the geometrical complexity of the fault system in this region. We find that the earthquake size, rupture propagation pattern and ground motion all strongly depend on the interplay between the initial (static) regional pre-stress field and the dynamic stress field radiated by the propagating rupture. By testing several nucleation locations, we observe that those far from an oblique normal fault stepover segment (near Istanbul) lead to large through-going rupture on the entire fault system, whereas nucleation locations closer to the stepover segment tend to produce ruptures that die out in the stepover. However, this pattern can change drastically with only a 10° rotation of the regional stress field. Our simulations also reveal that while dynamic unclamping near fault bends can produce a new mode of supershear rupture propagation, this unclamping has a much smaller effect on the speed of the peak in slip velocity along the fault. Finally, we find that the complex fault geometry leads to a very complex and asymmetric pattern of near-fault ground motion, including greatly amplified ground motion on the insides of fault bends. The ground-motion pattern can change significantly with different hypocentres, even beyond the typical effects of directivity. The results of this study may have implications for seismic hazard in this region, for the dynamics and ground motion of geometrically complex faults, and for the interpretation of kinematic inverse rupture models.

  16. Dynamic scattering theory for dark-field electron holography of 3D strain fields.

    PubMed

    Lubk, Axel; Javon, Elsa; Cherkashin, Nikolay; Reboh, Shay; Gatel, Christophe; Hÿtch, Martin

    2014-01-01

    Dark-field electron holography maps strain in crystal lattices into reconstructed phases over large fields of view. Here we investigate the details of the lattice strain-reconstructed phase relationship by applying dynamic scattering theory both analytically and numerically. We develop efficient analytic linear projection rules for 3D strain fields, facilitating a straight-forward calculation of reconstructed phases from 3D strained materials. They are used in the following to quantify the influence of various experimental parameters like strain magnitude, specimen thickness, excitation error and surface relaxation. PMID:24012934

  17. Stereoscopic 3D Visual Discomfort Prediction: A Dynamic Accommodation and Vergence Interaction Model.

    PubMed

    Oh, Heeseok; Lee, Sanghoon; Bovik, Alan Conrad

    2016-02-01

    The human visual system perceives 3D depth following sensing via its binocular optical system, a series of massively parallel processing units, and a feedback system that controls the mechanical dynamics of eye movements and the crystalline lens. The process of accommodation (focusing of the crystalline lens) and binocular vergence is controlled simultaneously and symbiotically via cross-coupled communication between the two critical depth computation modalities. The output responses of these two subsystems, which are induced by oculomotor control, are used in the computation of a clear and stable cyclopean 3D image from the input stimuli. These subsystems operate in smooth synchronicity when one is viewing the natural world; however, conflicting responses can occur when viewing stereoscopic 3D (S3D) content on fixed displays, causing physiological discomfort. If such occurrences could be predicted, then they might also be avoided (by modifying the acquisition process) or ameliorated (by changing the relative scene depth). Toward this end, we have developed a dynamic accommodation and vergence interaction (DAVI) model that successfully predicts visual discomfort on S3D images. The DAVI model is based on the phasic and reflex responses of the fast fusional vergence mechanism. Quantitative models of accommodation and vergence mismatches are used to conduct visual discomfort prediction. Other 3D perceptual elements are included in the proposed method, including sharpness limits imposed by the depth of focus and fusion limits implied by Panum's fusional area. The DAVI predictor is created by training a support vector machine on features derived from the proposed model and on recorded subjective assessment results. The experimental results are shown to produce accurate predictions of experienced visual discomfort. PMID:26672036

  18. Dynamic rupture process of the great 1668 Anatolian earthquake

    NASA Astrophysics Data System (ADS)

    Kase, Yuko; Kondo, Hisao; Emre, Ömer

    2010-05-01

    The North Anatolian fault system (NAFS) gives us the well-preserved evidences of multi-segment earthquakes. During the 1939 Erzincan earthquake, surface ruptures extended along the Resadiye segment. The surface ruptures during the 1942 earthquake appeared on two segments, the eastern Niksar and the western Erbaa segments which are to the west of the Resadiye segment. On the other hand, paleoseismological evidences show that the 1668 earthquake was a single multi-segment earthquake including the Resadiye, Niksar, and Erbaa segments (Kondo et al., 2009). The fault geometry, however, does not make us imagine a single multi-segment occurring. The distance along strike and step-over width between the Resadiye and Niksar segments is 17 and 11 km, respectively. This fault discontinuity is much larger than the previously-known threshold of a multi-segment rupture, 5 km, shown in observations of historical earthquakes (Matsuda, 1990; Wesnousky, 2006) and numerical studies (Harris and Day, 1999; Kase and Kuge, 2001). In this study, we construct dynamic rupture models for the North Anatolian earthquakes based on seismological data of the 1939 and 1942 earthquakes and the present stress condition, and then we investigate possibility of a single multi-segment earthquake in agreement with the paleoseismological data of the 1668 earthquake. A fault model is assumed, based on the surface traces, hypocenter distribution and source mechanisms of the 20th century earthquakes on the NAFS. Using the source mechanism of the 1939 earthquake (McKenzie, 1972) and the stress inversion results along the NAFS (Bellier et al., 1997; Fuenzalida et al., 1997), we adopt a regional stress field that is resolved onto all fault segments. We perform preliminary simulations to determine a hydrostatic stress condition and coefficient of friction producing surface slip distribution consistent with the observed surface slips during the 1939 and 1942 earthquakes (Barka, 1996; Emre et al., 2009; Kondo et

  19. Prediction of Severe Eye Injuries in Automobile Accidents: Static and Dynamic Rupture Pressure of the Eye

    PubMed Central

    Kennedy, Eric A.; Voorhies, Katherine D.; Herring, Ian P.; Rath, Amber L.; Duma, Stefan M.

    2004-01-01

    The purpose of this paper is to determine the static and dynamic rupture pressures of 20 human and 20 porcine eyes. This study found the static test results show an average rupture pressure for porcine eyes of 1.00 ± 0.18 MPa while the average rupture pressure for human eyes was 0.36 ± 0.20 MPa. For dynamic loading, the average porcine rupture pressure was 1.64 ± 0.32 MPa, and the average rupture pressure for human eyes was 0.91 ± 0.29 MPa. Significant differences are found between average rupture pressures from all four groups of tests (p = 0.01). A risk function has been developed and predicts a 50% risk of globe rupture at 1.02 MPa, 1.66 MPa, 0.35 MPa, and 0.90 MPa internal pressure for porcine static, porcine dynamic, human static, and human dynamic loading conditions, respectively. PMID:15319124

  20. Dynamic Rupture Simulations of 11 March 2011 Tohoku Earthquake

    NASA Astrophysics Data System (ADS)

    Kozdon, J. E.; Dunham, E. M.

    2012-12-01

    There is strong observational evidence that the 11 March 2011 Tohoku earthquake rupture reached the seafloor. This was unexpected because the shallow portion of the plate interface is believed to be frictionally stable and thus not capable of sustaining coseismic rupture. In order to explore this seeming inconsistency we have developed a two-dimensional dynamic rupture model of the Tohoku earthquake. The model uses a complex fault, seafloor, and material interface structure as derived from seismic surveys. We use a rate-and-state friction model with steady state shear strength depending logarithmically on slip velocity, i.e., there is no dynamic weakening in the model. The frictional parameters are depth dependent with the shallowest portions of the fault beneath the accretionary prism being velocity strengthening. The total normal stress on the fault is taken to be lithostatic and the pore pressure is hydrostatic until a maximum effective normal stress is reached (40 MPa in our preferred model) after which point the pore pressure follows the lithostatic gradient. We also account for poroelastic buffering of effective normal stress changes on the fault. The off-fault response is linear elastic. Using this model we find that large stress changes are dynamically transmitted to the shallowest portions of the fault by waves released by deep slip that are reflected off the seafloor. These stress changes are significant enough to drive the rupture through a velocity strengthening region that is tens of kilometers long. Rupture to the trench is therefore consistent with standard assumptions about depth-dependence of subduction zone properties, and does not require extreme dynamic weakening, shallow high stress drop asperities, or other exceptional processes. We also make direct comparisons with measured seafloor deformation and onshore 1-Hz GPS data from the Tohoku earthquake. Through these comparisons we are able to determine the sensitivity of these data to several

  1. Modeling the Dynamic Rupture Process of the 1987 Superstition Hills Earthquake

    NASA Astrophysics Data System (ADS)

    Liu, Q.; Archuleta, R. J.

    2012-12-01

    The Mw 6.6 Superstition Hill (SH) earthquake (Nov. 24, 1987) in southern California intrigues us in terms of its rupture dynamics. Kinematic source inversion results imply a complex event, which consisted of 3 subevents (Frankel & Wennerberg, 1989; Wald et al., 1990). All of the subevents seemed to initiate at the northwestern end of the SH fault where SH fault intersects with a conjugate Elmore Ranch (ER) fault. Moreover a Mw 6.2 earthquake and its aftershock sequence occurred on the Elmore Ranch fault within the 12 hours before the SH earthquake. Existing studies show that the distribution of seismicity correlates with the subsurface geology (Fuis et al. 1984). Based on comparison of the extent of each subevent with the fault trace, the fault geometry might make significant contribution to the dynamic process. The San-Jacinto (SJ) fault system certainly complicates the local stress field near SH fault by introducing several pairs of conjugate faults at various length scales in the region. A possible scenario of the Mw 6.6 event would be a sequence of seismic events on the conjugate ER fault perturbed the already complicated initial stress field on the non-planar SH fault and triggered the SH event. Using a finite element approach (Ma & Liu, 2006), we try to create a reasonable initial stress condition for the Mw 6.6 event and model its rupture process, incorporating complex fault geometry, 3D velocity structure and varying frictional properties (velocity weakening/strengthening) both along strike and dip. Recent results on SH fault's creeping behavior (e.g., Wei et al. 2009) also impose constraints on its frictional and rheological material properties, which is essential in the dynamic rupture modeling as well as the nucleation phase.

  2. Molecular dynamics simulations of lipid membranes with lateral force: rupture and dynamic properties.

    PubMed

    Xie, Jun Yu; Ding, Guang Hong; Karttunen, Mikko

    2014-03-01

    Membranes' response to lateral tension, and eventual rupture, remains poorly understood. In this study, pure dipalmitoylphosphatidylcholine (DPPC) lipid bilayers, under tension/pressure, were studied using molecular dynamics (MD) simulations. The irreversible membrane breakdown is demonstrated to depend on the amplitude of lateral tension, loading rate, and the size of the bilayer. In all of our simulations, -200bar lateral pressure was found to be enough to rupture lipid membrane regardless of the loading rate or the membrane size. Loading rate and membrane size had a significant impact on rupture. A variety of dynamic properties of lipid molecules, probability distribution of area per lipid particularly, have been determined, and found to be fundamental for describing membrane behavior in detail, thus providing the quantitative description for the requirement of membrane rupture. PMID:24374317

  3. Seismically Inferred Rupture Process of the 2011 Tohoku-Oki Earthquake by Using Data-Validated 3D and 2.5D Green's Tensor Waveforms

    NASA Astrophysics Data System (ADS)

    Okamoto, T.; Takenaka, H.; Hara, T.; Nakamura, T.; Aoki, T.

    2014-12-01

    We analyze "seismic" rupture process of the March 11, 2011 Tohoku-Oki earthquake (GCMT Mw9.1) by using a non-linear multi-time-window waveform inversion method. We incorporate the effect of the near-source laterally heterogeneous structure on the synthetic Green's tensor waveforms; otherwise the analysis may result in erroneous solutions [1]. To increase the resolution we use teleseismic and strong-motion seismograms jointly because the one-sided distribution of strong-motion station may cause reduced resolution near the trench axis [2]. We use a 2.5D FDM [3] for teleseismic P-waves and a full 3D FDM that incorporates topography, oceanic water layer, 3D heterogeneity and attenuation for strong-motions [4]. We apply multi-GPU acceleration by using the TSUBAME supercomputer in Tokyo Institute of Technology [5]. We "validated" the Green's tensor waveforms with a point-source moment tensor inversion analysis for a small (Mw5.8) shallow event: we confirm the observed waveforms are reproduced well with the synthetics.The inferred slip distribution using the 2.5D and 3D Green's functions has large slips (max. 37 m) near the hypocenter and small slips near the trench (figure). Also an isolated slip region is identified close to Fukushima prefecture. These features are similar to those obtained by our preliminary study [4]. The land-ward large slips and trench-ward small slips have also been reported by [2]. It is remarkable that we confirmed these features by using data-validated Green's functions. On the other hand very large slips are inferred close to the trench when we apply "1D" Green's functions that do not incorporate the lateral heterogeneity. Our result suggests the trench-ward large deformation that caused large tsunamis did not radiate strong seismic waves. Very slow slips (e.g., the tsunami earthquake), delayed slips and anelastic deformation are among the candidates of the physical processes of the deformation.[1] Okamoto and Takenaka, EPS, 61, e17-e20, 2009

  4. Dynamic 3D micropatterned cell co-cultures within photocurable and chemically degradable hydrogels

    PubMed Central

    Sugiura, Shinji; Cha, Jae Min; Yanagawa, Fumiki; Zorlutuna, Pinar; Bae, Hojae; Khademhosseini, Ali

    2014-01-01

    In this paper we report on the development of dynamically controlled 3D micropatterned cellular co-cultures within photocurable and chemically degradable hydrogels. Specifically, we generated dynamic co-cultures of micropatterned murine embryonic stem (mES) cells with human hepatocellular carcinoma (HepG2) cells within 3D hydrogels. HepG2 cells were used due to their ability to direct the differentiation of mES cells through secreted paracrine factors. To generate dynamic co-cultures, mES cells were first encapsulated within micropatterned photocurable poly(ethylene glycol) (PEG) hydrogels. These micropatterned cell-laden PEG hydrogels were subsequently surrounded by calcium alginate (Ca-Alg) hydrogels containing HepG2 cells. After 4 days, the co-culture step was halted by exposing the system to sodium citrate solution, which removed the alginate gels and the encapsulated HepG2 cells. The encapsulated mES cells were then maintained in the resulting cultures for 16 days and cardiac differentiation was analyzed. We observed that the mES cells that were exposed to HepG2 cells in the co-cultures, generated cells with higher expression of cardiac genes and proteins as well as increased spontaneous beating. Due to its ability to control the 3D microenvironment of cells in a spatially and temporally regulated manner the method presented in this study is useful for a range of cell culture applications related to tissue engineering and regenerative medicine. PMID:24170301

  5. Dynamical D4-D8 and D3-D7 branes in supergravity

    SciTech Connect

    Binetruy, Pierre; Sasaki, Misao; Uzawa, Kunihito

    2009-07-15

    We present a class of dynamical solutions for intersecting D4-D8 and D3-D7 brane systems in ten-dimensional type IIA and IIB supergravity. We discuss if these solutions can be recovered in lower-dimensional effective theories for the warped compactification of a general p-brane system. It is found that an effective p+1-dimensional description is not possible in general due to the entanglement of the transverse coordinates and the p+1-dimensional coordinates in the metric components. For the D4-D8 brane system, the dynamical solutions reduces to a static warped AdS{sub 6}xS{sup 4} geometry in a certain spacetime region. For the D3-D7 brane system, we find a dynamical solution whose metric form is similar to that of a D3-brane solution. The main difference is the existence of a nontrivial dilaton configuration in the D3-D7 solution. Then we discuss cosmology of these solutions. We find that they behave like a Kasner-type cosmological solution at {tau}{yields}{infinity}, while it reduces to a warped static solution at {tau}{yields}0, where {tau} is the cosmic time.

  6. Dynamical D4-D8 and D3-D7 branes in supergravity

    NASA Astrophysics Data System (ADS)

    Binetruy, Pierre; Sasaki, Misao; Uzawa, Kunihito

    2009-07-01

    We present a class of dynamical solutions for intersecting D4-D8 and D3-D7 brane systems in ten-dimensional type IIA and IIB supergravity. We discuss if these solutions can be recovered in lower-dimensional effective theories for the warped compactification of a general p-brane system. It is found that an effective p+1-dimensional description is not possible in general due to the entanglement of the transverse coordinates and the p+1-dimensional coordinates in the metric components. For the D4-D8 brane system, the dynamical solutions reduces to a static warped AdS6×S4 geometry in a certain spacetime region. For the D3-D7 brane system, we find a dynamical solution whose metric form is similar to that of a D3-brane solution. The main difference is the existence of a nontrivial dilaton configuration in the D3-D7 solution. Then we discuss cosmology of these solutions. We find that they behave like a Kasner-type cosmological solution at τ→∞, while it reduces to a warped static solution at τ→0, where τ is the cosmic time.

  7. RV functional imaging: 3-D echo-derived dynamic geometry and flow field simulations.

    PubMed

    Pasipoularides, Ares D; Shu, Ming; Womack, Michael S; Shah, Ashish; Von Ramm, Olaf; Glower, Donald D

    2003-01-01

    We describe a novel functional imaging approach for quantitative analysis of right ventricular (RV) blood flow patterns in specific experimental animals (or humans) using real-time, three-dimensional (3-D) echocardiography (RT3D). The method is independent of the digital imaging modality used. It comprises three parts. First, a semiautomated segmentation aided by intraluminal contrast medium locates the RV endocardial surface. Second, a geometric scheme for dynamic RV chamber reconstruction applies a time interpolation procedure to the RT3D data to quantify wall geometry and motion at 400 Hz. A volumetric prism method validated the dynamic geometric reconstruction against simultaneous sonomicrometric canine measurements. Finally, the RV endocardial border motion information is used for mesh generation on a computational fluid dynamics solver to simulate development of the early RV diastolic inflow field. Boundary conditions (tessellated endocardial surface nodal velocities) for the solver are directly derived from the endocardial geometry and motion information. The new functional imaging approach may yield important kinematic information on the distribution of instantaneous velocities in the RV diastolic flow field of specific normal or diseased hearts. PMID:12388220

  8. PRONTO3D users` instructions: A transient dynamic code for nonlinear structural analysis

    SciTech Connect

    Attaway, S.W.; Mello, F.J.; Heinstein, M.W.; Swegle, J.W.; Ratner, J.A.; Zadoks, R.I.

    1998-06-01

    This report provides an updated set of users` instructions for PRONTO3D. PRONTO3D is a three-dimensional, transient, solid dynamics code for analyzing large deformations of highly nonlinear materials subjected to extremely high strain rates. This Lagrangian finite element program uses an explicit time integration operator to integrate the equations of motion. Eight-node, uniform strain, hexahedral elements and four-node, quadrilateral, uniform strain shells are used in the finite element formulation. An adaptive time step control algorithm is used to improve stability and performance in plasticity problems. Hourglass distortions can be eliminated without disturbing the finite element solution using either the Flanagan-Belytschko hourglass control scheme or an assumed strain hourglass control scheme. All constitutive models in PRONTO3D are cast in an unrotated configuration defined using the rotation determined from the polar decomposition of the deformation gradient. A robust contact algorithm allows for the impact and interaction of deforming contact surfaces of quite general geometry. The Smooth Particle Hydrodynamics method has been embedded into PRONTO3D using the contact algorithm to couple it with the finite element method.

  9. A 3D GCL compatible cell-centered Lagrangian scheme for solving gas dynamics equations

    NASA Astrophysics Data System (ADS)

    Georges, Gabriel; Breil, Jérôme; Maire, Pierre-Henri

    2016-01-01

    Solving the gas dynamics equations under the Lagrangian formalism enables to simulate complex flows with strong shock waves. This formulation is well suited to the simulation of multi-material compressible fluid flows such as those encountered in the domain of High Energy Density Physics (HEDP). These types of flows are characterized by complex 3D structures such as hydrodynamic instabilities (Richtmyer-Meshkov, Rayleigh-Taylor, etc.). Recently, the 3D extension of different Lagrangian schemes has been proposed and appears to be challenging. More precisely, the definition of the cell geometry in the 3D space through the treatment of its non-planar faces and the limiting of a reconstructed field in 3D in the case of a second-order extension are of great interest. This paper proposes two new methods to solve these problems. A systematic and symmetric geometrical decomposition of polyhedral cells is presented. This method enables to define a discrete divergence operator leading to the respect of the Geometric Conservation Law (GCL). Moreover, a multi-dimensional minmod limiter is proposed. This new limiter constructs, from nodal gradients, a cell gradient which enables to ensure the monotonicity of the numerical solution even in presence of strong discontinuity. These new ingredients are employed into a cell-centered Lagrangian scheme. Robustness and accuracy are assessed against various representative test cases.

  10. Dynamic WIFI-Based Indoor Positioning in 3D Virtual World

    NASA Astrophysics Data System (ADS)

    Chan, S.; Sohn, G.; Wang, L.; Lee, W.

    2013-11-01

    A web-based system based on the 3DTown project was proposed using Google Earth plug-in that brings information from indoor positioning devices and real-time sensors into an integrated 3D indoor and outdoor virtual world to visualize the dynamics of urban life within the 3D context of a city. We addressed limitation of the 3DTown project with particular emphasis on video surveillance camera used for indoor tracking purposes. The proposed solution was to utilize wireless local area network (WLAN) WiFi as a replacement technology for localizing objects of interest due to the wide spread availability and large coverage area of WiFi in indoor building spaces. Indoor positioning was performed using WiFi without modifying existing building infrastructure or introducing additional access points (AP)s. A hybrid probabilistic approach was used for indoor positioning based on previously recorded WiFi fingerprint database in the Petrie Science and Engineering building at York University. In addition, we have developed a 3D building modeling module that allows for efficient reconstruction of outdoor building models to be integrated with indoor building models; a sensor module for receiving, distributing, and visualizing real-time sensor data; and a web-based visualization module for users to explore the dynamic urban life in a virtual world. In order to solve the problems in the implementation of the proposed system, we introduce approaches for integration of indoor building models with indoor positioning data, as well as real-time sensor information and visualization on the web-based system. In this paper we report the preliminary results of our prototype system, demonstrating the system's capability for implementing a dynamic 3D indoor and outdoor virtual world that is composed of discrete modules connected through pre-determined communication protocols.

  11. How spatial abilities and dynamic visualizations interplay when learning functional anatomy with 3D anatomical models.

    PubMed

    Berney, Sandra; Bétrancourt, Mireille; Molinari, Gaëlle; Hoyek, Nady

    2015-01-01

    The emergence of dynamic visualizations of three-dimensional (3D) models in anatomy curricula may be an adequate solution for spatial difficulties encountered with traditional static learning, as they provide direct visualization of change throughout the viewpoints. However, little research has explored the interplay between learning material presentation formats, spatial abilities, and anatomical tasks. First, to understand the cognitive challenges a novice learner would be faced with when first exposed to 3D anatomical content, a six-step cognitive task analysis was developed. Following this, an experimental study was conducted to explore how presentation formats (dynamic vs. static visualizations) support learning of functional anatomy, and affect subsequent anatomical tasks derived from the cognitive task analysis. A second aim was to investigate the interplay between spatial abilities (spatial visualization and spatial relation) and presentation formats when the functional anatomy of a 3D scapula and the associated shoulder flexion movement are learned. Findings showed no main effect of the presentation formats on performances, but revealed the predictive influence of spatial visualization and spatial relation abilities on performance. However, an interesting interaction between presentation formats and spatial relation ability for a specific anatomical task was found. This result highlighted the influence of presentation formats when spatial abilities are involved as well as the differentiated influence of spatial abilities on anatomical tasks. PMID:25689057

  12. Dynamics of tokamak plasma surface current in 3D ideal MHD model

    NASA Astrophysics Data System (ADS)

    Galkin, Sergei A.; Svidzinski, V. A.; Zakharov, L. E.

    2013-10-01

    Interest in the surface current which can arise on perturbed sharp plasma vacuum interface in tokamaks was recently generated by a few papers (see and references therein). In dangerous disruption events with plasma-touching-wall scenarios, the surface current can be shared with the wall leading to the strong, damaging forces acting on the wall A relatively simple analytic definition of δ-function surface current proportional to a jump of tangential component of magnetic field nevertheless leads to a complex computational problem on the moving plasma-vacuum interface, requiring the incorporation of non-linear 3D plasma dynamics even in one-fluid ideal MHD. The Disruption Simulation Code (DSC), which had recently been developed in a fully 3D toroidal geometry with adaptation to the moving plasma boundary, is an appropriate tool for accurate self-consistent δfunction surface current calculation. Progress on the DSC-3D development will be presented. Self-consistent surface current calculation under non-linear dynamics of low m kink mode and VDE will be discussed. Work is supported by the US DOE SBIR grant #DE-SC0004487.

  13. Temporal dynamics and developmental memory of 3D chromatin architecture at Hox gene loci

    PubMed Central

    Noordermeer, Daan; Leleu, Marion; Schorderet, Patrick; Joye, Elisabeth; Chabaud, Fabienne; Duboule, Denis

    2014-01-01

    Hox genes are essential regulators of embryonic development. Their step-wise transcriptional activation follows their genomic topology and the various states of activation are subsequently memorized into domains of progressively overlapping gene products. We have analyzed the 3D chromatin organization of Hox clusters during their early activation in vivo, using high-resolution circular chromosome conformation capture. Initially, Hox clusters are organized as single chromatin compartments containing all genes and bivalent chromatin marks. Transcriptional activation is associated with a dynamic bi-modal 3D organization, whereby the genes switch autonomously from an inactive to an active compartment. These local 3D dynamics occur within a framework of constitutive interactions within the surrounding Topological Associated Domains, indicating that this regulation process is mostly cluster intrinsic. The step-wise progression in time is fixed at various body levels and thus can account for the chromatin architectures previously described at a later stage for different anterior to posterior levels. DOI: http://dx.doi.org/10.7554/eLife.02557.001 PMID:24843030

  14. Using articulated scene models for dynamic 3d scene analysis in vista spaces

    NASA Astrophysics Data System (ADS)

    Beuter, Niklas; Swadzba, Agnes; Kummert, Franz; Wachsmuth, Sven

    2010-09-01

    In this paper we describe an efficient but detailed new approach to analyze complex dynamic scenes directly in 3D. The arising information is important for mobile robots to solve tasks in the area of household robotics. In our work a mobile robot builds an articulated scene model by observing the environment in the visual field or rather in the so-called vista space. The articulated scene model consists of essential knowledge about the static background, about autonomously moving entities like humans or robots and finally, in contrast to existing approaches, information about articulated parts. These parts describe movable objects like chairs, doors or other tangible entities, which could be moved by an agent. The combination of the static scene, the self-moving entities and the movable objects in one articulated scene model enhances the calculation of each single part. The reconstruction process for parts of the static scene benefits from removal of the dynamic parts and in turn, the moving parts can be extracted more easily through the knowledge about the background. In our experiments we show, that the system delivers simultaneously an accurate static background model, moving persons and movable objects. This information of the articulated scene model enables a mobile robot to detect and keep track of interaction partners, to navigate safely through the environment and finally, to strengthen the interaction with the user through the knowledge about the 3D articulated objects and 3D scene analysis. [Figure not available: see fulltext.

  15. Parallel implementation of 3D FFT with volumetric decomposition schemes for efficient molecular dynamics simulations

    NASA Astrophysics Data System (ADS)

    Jung, Jaewoon; Kobayashi, Chigusa; Imamura, Toshiyuki; Sugita, Yuji

    2016-03-01

    Three-dimensional Fast Fourier Transform (3D FFT) plays an important role in a wide variety of computer simulations and data analyses, including molecular dynamics (MD) simulations. In this study, we develop hybrid (MPI+OpenMP) parallelization schemes of 3D FFT based on two new volumetric decompositions, mainly for the particle mesh Ewald (PME) calculation in MD simulations. In one scheme, (1d_Alltoall), five all-to-all communications in one dimension are carried out, and in the other, (2d_Alltoall), one two-dimensional all-to-all communication is combined with two all-to-all communications in one dimension. 2d_Alltoall is similar to the conventional volumetric decomposition scheme. We performed benchmark tests of 3D FFT for the systems with different grid sizes using a large number of processors on the K computer in RIKEN AICS. The two schemes show comparable performances, and are better than existing 3D FFTs. The performances of 1d_Alltoall and 2d_Alltoall depend on the supercomputer network system and number of processors in each dimension. There is enough leeway for users to optimize performance for their conditions. In the PME method, short-range real-space interactions as well as long-range reciprocal-space interactions are calculated. Our volumetric decomposition schemes are particularly useful when used in conjunction with the recently developed midpoint cell method for short-range interactions, due to the same decompositions of real and reciprocal spaces. The 1d_Alltoall scheme of 3D FFT takes 4.7 ms to simulate one MD cycle for a virus system containing more than 1 million atoms using 32,768 cores on the K computer.

  16. Quantification of Dynamic Morphological Drug Responses in 3D Organotypic Cell Cultures by Automated Image Analysis

    PubMed Central

    Härmä, Ville; Schukov, Hannu-Pekka; Happonen, Antti; Ahonen, Ilmari; Virtanen, Johannes; Siitari, Harri; Åkerfelt, Malin; Lötjönen, Jyrki; Nees, Matthias

    2014-01-01

    Glandular epithelial cells differentiate into complex multicellular or acinar structures, when embedded in three-dimensional (3D) extracellular matrix. The spectrum of different multicellular morphologies formed in 3D is a sensitive indicator for the differentiation potential of normal, non-transformed cells compared to different stages of malignant progression. In addition, single cells or cell aggregates may actively invade the matrix, utilizing epithelial, mesenchymal or mixed modes of motility. Dynamic phenotypic changes involved in 3D tumor cell invasion are sensitive to specific small-molecule inhibitors that target the actin cytoskeleton. We have used a panel of inhibitors to demonstrate the power of automated image analysis as a phenotypic or morphometric readout in cell-based assays. We introduce a streamlined stand-alone software solution that supports large-scale high-content screens, based on complex and organotypic cultures. AMIDA (Automated Morphometric Image Data Analysis) allows quantitative measurements of large numbers of images and structures, with a multitude of different spheroid shapes, sizes, and textures. AMIDA supports an automated workflow, and can be combined with quality control and statistical tools for data interpretation and visualization. We have used a representative panel of 12 prostate and breast cancer lines that display a broad spectrum of different spheroid morphologies and modes of invasion, challenged by a library of 19 direct or indirect modulators of the actin cytoskeleton which induce systematic changes in spheroid morphology and differentiation versus invasion. These results were independently validated by 2D proliferation, apoptosis and cell motility assays. We identified three drugs that primarily attenuated the invasion and formation of invasive processes in 3D, without affecting proliferation or apoptosis. Two of these compounds block Rac signalling, one affects cellular cAMP/cGMP accumulation. Our approach supports

  17. Chaotic electroconvection near ion-selective membranes: investigation of transport dynamics from a 3D DNS

    NASA Astrophysics Data System (ADS)

    Druzgalski, Clara; Mani, Ali

    2014-11-01

    We have investigated the transport dynamics of an electrokinetic instability that occurs when ions are driven from bulk fluids to ion-selective membranes due to externally applied electric fields. This phenomenon is relevant to a wide range of electrochemical applications including electrodialysis for fresh water production. Using data from our 3D DNS, we show how electroconvective instability, arising from concentration polarization, results in a chaotic flow that significantly alters the net ion transport rate across the membrane surface. The 3D DNS results, which fully resolve the spatiotemporal scales including the electric double layers, enable visualization of instantaneous snapshots of current density directly on the membrane surface, as well as analysis of transport statistics such as concentration variance and fluctuating advective fluxes. Furthermore, we present a full spectral analysis revealing broadband spectra in both concentration and flow fields and deduce the key parameter controlling the range of contributing scales.

  18. Dynamic 3D imaging based on acousto-optic heterodyne fringe interferometry.

    PubMed

    Guan, Yingjian; Yin, Yongkai; Li, Ameng; Liu, Xiaoli; Peng, Xiang

    2014-06-15

    An acoustic-optics heterodyne fringe interferometry coupled with a three-camera system is developed for dynamic 3D imaging. In this system, first-order beams with a slight frequency difference diffracted from two acousto-optic deflectors (AODs) form a beat intensity fringe pattern. Setting the frequency of the trigger signal for the CCD cameras into four times the beat frequency, four-step phase-shifting fringe patterns can be obtained, and the wrapped phase map (WPM) can be calculated. Under the epipolar constraint among three cameras, the homologous points can be determined unambiguously with the assistant of a WPM; thus the 3D shape can be reconstructed while skipping the phase unwrapping step. Experimental results are presented to validate this approach. PMID:24978566

  19. User's manuals for DYNA3D and DYNAP: nonlinear dynamic analysis of solids in three dimensions

    SciTech Connect

    Hallquist, J.O.

    1981-07-01

    This report provides a user's manual for DYNA3D, an explicit three-dimensional finite element code for analyzing the large deformation dynamic response of inelastic solids. A contact-impact algorithm permits gaps and sliding along material interfaces. By a specialization of this algorithm, such interfaces can be rigidly tied to admit variable zoning without the need of transition regions. Spatial discretization is achieved by the use of 8-node solid elements, and the equations-of-motion are integrated by the central difference method. Post-processors for DYNA3D include GRAPE for plotting deformed shapes and stress contours and DYNAP for plotting time histories. A user's manual for DYNAP is also provided in this report.

  20. Radial electric field 3D modeling for wire arrays driving dynamic hohlraums on Z.

    SciTech Connect

    Mock, Raymond Cecil

    2007-06-01

    The anode-cathode structure of the Z-machine wire array results in a higher negative radial electric field (Er) on the wires near the cathode relative to the anode. The magnitude of this field has been shown to anti-correlate with the axial radiation top/bottom symmetry in the DH (Dynamic Hohlraum). Using 3D modeling, the structure of this field is revealed for different wire-array configurations and for progressive mechanical alterations, providing insight for minimizing the negative Er on the wire array in the anode-to-cathode region of the DH. Also, the 3D model is compared to Sasorov's approximation, which describes Er at the surface of the wire in terms of wire-array parameters.

  1. Blob Dynamics in 3D BOUT Simulations of Tokamak Edge Turbulence

    SciTech Connect

    Russell, D; D'Ippolito, D; Myra, J; Nevins, W; Xu, X

    2004-08-23

    Propagating filaments of enhanced plasma density, or blobs, observed in 3D numerical simulations of a diverted, neutral-fueled tokamak are studied. Fluctuations of vorticity, electrical potential {phi}, temperature T{sub e} and current density J{sub {parallel}} associated with the blobs have a dipole structure perpendicular to the magnetic field and propagate radially with large E {center_dot} B drift velocities (> 1 km/s). The simulation results are consistent with a 3D blob dynamics model that incorporates increased parallel plasma resistivity (from neutral cooling of the X-point region), blob disconnection from the divertor sheath, X-point closure of the current loops, and collisional physics to sustain the {phi}, T{sub e}, J{sub {parallel}} dipoles.

  2. Nonlinear dynamics of Airy-vortex 3D wave packets: emission of vortex light waves.

    PubMed

    Driben, Rodislav; Meier, Torsten

    2014-10-01

    The dynamics of 3D Airy-vortex wave packets is studied under the action of strong self-focusing Kerr nonlinearity. Emissions of nonlinear 3D waves out of the main wave packets with the topological charges were demonstrated. Because of the conservation of the total angular momentum, charges of the emitted waves are equal to those carried by the parental light structure. The rapid collapse imposes a severe limitation on the propagation of multidimensional waves in Kerr media. However, the structure of the Airy beam carrier allows the coupling of light from the leading, most intense peak into neighboring peaks and consequently strongly postpones the collapse. The dependence of the critical input amplitude for the appearance of a fast collapse on the beam width is studied for wave packets with zero and nonzero topological charges. Wave packets carrying angular momentum are found to be much more resistant to the rapid collapse. PMID:25360922

  3. Hand Gesture Spotting Based on 3D Dynamic Features Using Hidden Markov Models

    NASA Astrophysics Data System (ADS)

    Elmezain, Mahmoud; Al-Hamadi, Ayoub; Michaelis, Bernd

    In this paper, we propose an automatic system that handles hand gesture spotting and recognition simultaneously in stereo color image sequences without any time delay based on Hidden Markov Models (HMMs). Color and 3D depth map are used to segment hand regions. The hand trajectory will determine in further step using Mean-shift algorithm and Kalman filter to generate 3D dynamic features. Furthermore, k-means clustering algorithm is employed for the HMMs codewords. To spot meaningful gestures accurately, a non-gesture model is proposed, which provides confidence limit for the calculated likelihood by other gesture models. The confidence measures are used as an adaptive threshold for spotting meaningful gestures. Experimental results show that the proposed system can successfully recognize isolated gestures with 98.33% and meaningful gestures with 94.35% reliability for numbers (0-9).

  4. 3D kinematic and dynamic analysis of the front crawl tumble turn in elite male swimmers.

    PubMed

    Puel, F; Morlier, J; Avalos, M; Mesnard, M; Cid, M; Hellard, P

    2012-02-01

    The aim of this study was to identify kinematic and dynamic variables related to the best tumble turn times (3mRTT, the turn time from 3-m in to 3-m out, independent variable) in ten elite male swimmers using a three-dimensional (3D) underwater analysis protocol and the Lasso (least absolute shrinkage and selection operator) as statistical method. For each swimmer, the best-time turn was analyzed with five stationary and synchronized underwater cameras. The 3D reconstruction was performed using the Direct Linear Transformation algorithm. An underwater piezoelectric 3D force platform completed the set-up to compute dynamic variables. Data were smoothed by the Savitzky-Golay filtering method. Three variables were considered relevant in the best Lasso model (3mRTT=2.58-0.425 RD+0.204 VPe+0.0046 TD): the head-wall distance where rotation starts (RD), the horizontal speed at the force peak (VPe), and the 3D length of the path covered during the turn (TD). Furthermore, bivariate analysis showed that upper body (CUBei) and lower limb extension indexes at first contact (CLLei) were also linked to the turn time (r=-0.65 and p<0.05 for both variables). Thus the best turn times were associated with a long RD, slower VPe and reduced TD. By an early transverse rotation, male elite swimmers reach the wall with a slightly flexed posture that results in fast extension. These swimmers opt for a movement that is oriented forward and they focus on reducing the distance covered. PMID:22176710

  5. EB1-recruited microtubule +TIP complexes coordinate protrusion dynamics during 3D epithelial remodeling

    PubMed Central

    Gierke, Sarah; Wittmann, Torsten

    2012-01-01

    SUMMARY Background Epithelial remodeling, in which apical-basal polarized cells switch to a migratory phenotype, plays a central role in development and disease of multicellular organisms. Although dynamic microtubules (MTs) are required for directed migration on flat surfaces, how MT dynamics are controlled or contribute to epithelial remodeling in a more physiological three-dimensional (3D) environment is not understood. We use confocal live cell imaging to analyze MT function and dynamics during 3D epithelial morphogenesis and remodeling of polarized Madin-Darby canine kidney (MDCK) epithelial cells that undergo partial epithelial-to-mesenchymal transition (EMT) in response to hepatocyte growth factor (HGF). Results We find that HGF treatment increases MT growth rate before morphological changes are evident, and that large numbers of MTs grow into HGF-induced cell extensions independent of centrosome reorientation. Using lentivirus-mediated shRNA, we demonstrate that EB1, an adaptor protein that mediates recruitment of numerous other +TIP proteins to growing MT plus ends, is required for this HGF-induced MT reorganization. We further show that protrusion and adhesion dynamics are disorganized, and that vesicular trafficking to the tip of HGF-induced cell extensions is disrupted in EB1-depleted cells. Conclusions We conclude that EB1-mediated interactions with growing MTs are important to coordinate cell shape changes and directed migration into the surrounding extracellular matrix during epithelial remodeling in a physiological 3D environment. In contrast, EB1 is not required for the establishment or maintenance of apical-basal cell polarity, suggesting different functions of +TIPs and MTs in different types of cell polarity. PMID:22483942

  6. Using Dynamic Rupture Models to Explore Physical Controls on the 2011 Mw 9.0 Tohoku-Oki Earthquake Rupture

    NASA Astrophysics Data System (ADS)

    Duan, B.

    2011-12-01

    Seismic and geodetic recordings are routinely used to invert for kinematic source models of large earthquakes, which provide us with detailed images of slip distribution and rupture evolution on causative faults. To gain insight into physical conditions that allow a fault to slip and a rupture to propagate in the way they did, we can resort to dynamic source models that obey physical laws in continuum mechanics and rock friction. Published kinematic models of the 2011 Mw 9.0 Tohoku-Oki earthquake reveal several features of the rupture. These features include 1) high static stress drop with large amounts of slip in a small area, 2) a weak initial phase, down-dip rupture for the first 40 seconds, extensive shallow rupture during 60 to 70 seconds, and continuing deeper rupture lasting more than 100 seconds, and 3) systematically down-dip high-frequency radiation with respect to the hypocenter. In this study, we use spontaneous rupture models to explore what physical conditions, including the initial stress state and friction properties on the subducting fault, can reproduce these features, so that we can gain some physical insights into controls on this megathrust earthquake. Dynamic rupture simulations of this shallow dipping megathrust faulting at reasonable spatial and temporal resolutions require parallel computing on supercomputers. Our newly parallelized finite element method algorithm EQdyna allows us to simulate a large suite of spontaneous rupture models to examine the questions. In model setup, we use depth-dependence principal stresses and take into account variations in pore fluid pressure and frictional properties associated with subducted seafloor features such as seamounts. Our preliminary results suggest followings. First, a high strength and high stress drop patch (probably a subducted seamount or seamout chain) just above the hypocenter on the fault plane can delay up-dip rupture and result in a concentrated large slip area. Second, significantly

  7. Noninvasive Imaging of 3D Dynamics in Thickly Fluorescent Specimens Beyond the Diffraction Limit

    PubMed Central

    Gao, Liang; Shao, Lin; Higgins, Christopher D.; Poulton, John S.; Peifer, Mark; Davidson, Michael W.; Wu, Xufeng; Goldstein, Bob; Betzig, Eric

    2013-01-01

    SUMMARY Optical imaging of the dynamics of living specimens involves tradeoffs between spatial resolution, temporal resolution, and phototoxicity, made more difficult in three-dimensions. Here, however, we report that rapid 3D dynamics can be studied beyond the diffraction limit in thick or densely fluorescent living specimens over many time points by combining ultra-thin planar illumination produced by scanned Bessel beams with superresolution structured illumination microscopy. We demonstrate in vivo karyotyping of chromosomes during mitosis and identify different dynamics for the actin cytoskeleton at the dorsal and ventral surfaces of fibroblasts. Compared to spinning disk confocal microscopy, we demonstrate substantially reduced photodamage when imaging rapid morphological changes in D. discoideum cells, as well as improved contrast and resolution at depth within developing C. elegans embryos. Bessel beam structured plane illumination thus promises new insights into complex biological phenomena that require 4D subcellular spatiotemporal detail in either a single or multicellular context. PMID:23217717

  8. Quantification of Diaphragm Mechanics in Pompe Disease Using Dynamic 3D MRI

    PubMed Central

    Mogalle, Katja; Perez-Rovira, Adria; Ciet, Pierluigi; Wens, Stephan C. A.; van Doorn, Pieter A.; Tiddens, Harm A. W. M.; van der Ploeg, Ans T.; de Bruijne, Marleen

    2016-01-01

    Background Diaphragm weakness is the main reason for respiratory dysfunction in patients with Pompe disease, a progressive metabolic myopathy affecting respiratory and limb-girdle muscles. Since respiratory failure is the major cause of death among adult patients, early identification of respiratory muscle involvement is necessary to initiate treatment in time and possibly prevent irreversible damage. In this paper we investigate the suitability of dynamic MR imaging in combination with state-of-the-art image analysis methods to assess respiratory muscle weakness. Methods The proposed methodology relies on image registration and lung surface extraction to quantify lung kinematics during breathing. This allows for the extraction of geometry and motion features of the lung that characterize the independent contribution of the diaphragm and the thoracic muscles to the respiratory cycle. Results Results in 16 3D+t MRI scans (10 Pompe patients and 6 controls) of a slow expiratory maneuver show that kinematic analysis from dynamic 3D images reveals important additional information about diaphragm mechanics and respiratory muscle involvement when compared to conventional pulmonary function tests. Pompe patients with severely reduced pulmonary function showed severe diaphragm weakness presented by minimal motion of the diaphragm. In patients with moderately reduced pulmonary function, cranial displacement of posterior diaphragm parts was reduced and the diaphragm dome was oriented more horizontally at full inspiration compared to healthy controls. Conclusion Dynamic 3D MRI provides data for analyzing the contribution of both diaphragm and thoracic muscles independently. The proposed image analysis method has the potential to detect less severe diaphragm weakness and could thus be used to determine the optimal start of treatment in adult patients with Pompe disease in prospect of increased treatment response. PMID:27391236

  9. Signatures of topological phase transition in 3 d topological insulators from dynamical axion response

    NASA Astrophysics Data System (ADS)

    Makhfudz, Imam

    2016-04-01

    Axion electrodynamics, first proposed in the context of particle physics, manifests itself in condensed matter physics in the topological field theory description of 3 d topological insulators and gives rise to magnetoelectric effect, where applying magnetic (electric) field B (E ) induces polarization (magnetization) p (m ) . We use linear response theory to study the associated topological current using the Fu-Kane-Mele model of 3 d topological insulators in the presence of time-dependent uniform weak magnetic field. By computing the dynamical current susceptibility χij jpjp(ω ) , we discover from its static limit an `order parameter' of the topological phase transition between weak topological (or ordinary) insulator and strong topological insulator, found to be continuous. The χij jpjp(ω ) shows a sign-changing singularity at a critical frequency with suppressed strength in the topological insulating state. Our results can be verified in current noise experiment on 3 d TI candidate materials for the detection of such topological phase transition.

  10. Salinity effects on cracking morphology and dynamics in 3-D desiccating clays

    NASA Astrophysics Data System (ADS)

    DeCarlo, Keita F.; Shokri, Nima

    2014-04-01

    Saline conditions induce not only chemical but physical changes in swelling clays, and have a significant influence on the crack dynamics and morphology of desiccating clays. In this study, we used X-ray microtomography to experimentally investigate the effects of sodium chloride on the morphology and dynamics of desiccation cracks in three-dimensional mixtures of sand-bentonite slurry under varying rheological conditions. Rectangular glass containers were packed with slurries of different salt concentrations, with the top boundary exposed to air for evaporation. The growth and propagation of the cracking network that subsequently formed was visualized in 3-D at multiple intervals. The characterization of cracking and branching behavior shows a high extent of localized surficial crack networks at low salinity, with a transition to less extensive but more centralized crack networks with increased salinity. The observed behavior was described in the context of the physicochemical properties of the montmorillonite clay, where shifts from an "entangled" (large platelet spacing, small pore structure) to a "stacked" (small platelet spacing, open pore structure) network influence fluid distribution and thus extent of cracking and branching behavior. This is further corroborated by vertical profiles of water distribution, which shows localized desiccation fronts that shift to uniform desaturation with increasing salt concentration. Our results provide new insights regarding the formation, dynamics, and patterns of desiccation cracks formed during evaporation from 3-D saline clay structures, which will be useful in hydrological applications including water management, land surface evaporation, and subsurface contaminant transport.

  11. Semi-automatic segmentation for 3D motion analysis of the tongue with dynamic MRI.

    PubMed

    Lee, Junghoon; Woo, Jonghye; Xing, Fangxu; Murano, Emi Z; Stone, Maureen; Prince, Jerry L

    2014-12-01

    Dynamic MRI has been widely used to track the motion of the tongue and measure its internal deformation during speech and swallowing. Accurate segmentation of the tongue is a prerequisite step to define the target boundary and constrain the tracking to tissue points within the tongue. Segmentation of 2D slices or 3D volumes is challenging because of the large number of slices and time frames involved in the segmentation, as well as the incorporation of numerous local deformations that occur throughout the tongue during motion. In this paper, we propose a semi-automatic approach to segment 3D dynamic MRI of the tongue. The algorithm steps include seeding a few slices at one time frame, propagating seeds to the same slices at different time frames using deformable registration, and random walker segmentation based on these seed positions. This method was validated on the tongue of five normal subjects carrying out the same speech task with multi-slice 2D dynamic cine-MR images obtained at three orthogonal orientations and 26 time frames. The resulting semi-automatic segmentations of a total of 130 volumes showed an average dice similarity coefficient (DSC) score of 0.92 with less segmented volume variability between time frames than in manual segmentations. PMID:25155697

  12. An easy implementation of displacement calculations in 3D discrete dislocation dynamics codes

    NASA Astrophysics Data System (ADS)

    Fivel, Marc; Depres, Christophe

    2014-10-01

    Barnett's coordinate-free expression of the displacement field of a triangular loop in an isotropic media is revisited in a view to be implemented in 3D discrete dislocation dynamics codes. A general meshing procedure solving the problems of non-planar loops is presented. The method is user-friendly and can be used in numerical simulations since it gives the contribution of each dislocation segment to the global displacement field without defining the connectivity of closed loops. Easy to implement in parallel calculations, this method is successfully applied to large-scale simulations.

  13. Parallel 3-D particle-in-cell modelling of charged ultrarelativistic beam dynamics

    NASA Astrophysics Data System (ADS)

    Boronina, Marina A.; Vshivkov, Vitaly A.

    2015-12-01

    > ) in supercolliders. We use the 3-D set of Maxwell's equations for the electromagnetic fields, and the Vlasov equation for the distribution function of the beam particles. The model incorporates automatically the longitudinal effects, which can play a significant role in the cases of super-high densities. We present numerical results for the dynamics of two focused ultrarelativistic beams with a size ratio 10:1:100. The results demonstrate high efficiency of the proposed computational methods and algorithms, which are applicable to a variety of problems in relativistic plasma physics.

  14. Time resolved 3D momentum imaging of ultrafast dynamics by coherent VUV-XUV radiation.

    PubMed

    Sturm, F P; Wright, T W; Ray, D; Zalyubovskaya, I; Shivaram, N; Slaughter, D S; Ranitovic, P; Belkacem, A; Weber, Th

    2016-06-01

    We present a new experimental setup for measuring ultrafast nuclear and electron dynamics of molecules after photo-excitation and ionization. We combine a high flux femtosecond vacuum ultraviolet (VUV) and extreme ultraviolet (XUV) source with an internally cold molecular beam and a 3D momentum imaging particle spectrometer to measure electrons and ions in coincidence. We describe a variety of tools developed to perform pump-probe studies in the VUV-XUV spectrum and to modify and characterize the photon beam. First benchmark experiments are presented to demonstrate the capabilities of the system. PMID:27370429

  15. Simulation studies of defect textures and dynamics in 3-d cholesteric droplets

    NASA Astrophysics Data System (ADS)

    Gimenez-Pinto, Vianney; Lu, Shin-Ying; Selinger, Jonathan; Selinger, Robin

    2010-03-01

    We model defect texture evolution in droplets of cholesteric liquid crystals by solving for the dynamics of the nematic director field. In order to accommodate defects in the simulated texture, we use a finite difference formulation that is explicitly independent of sign reversal of the director at any position in the sample. Textures are visualized using either the Berreman 4x4 matrix method or by mapping free energy density. We study both planar and focal conic cholesteric textures in 3-d spherical and cylindrical droplets, with the goal to optimize device geometries for bistable display applications.

  16. Simulation studies of dynamics and defect textures in 3-d cholesteric droplets

    NASA Astrophysics Data System (ADS)

    Gimenez-Pinto, Vianney; Lu, Shin-Ying; Selinger, Jonathan; Selinger, Robin

    2010-04-01

    We model defect texture evolution in droplets of cholesteric liquid crystals by solving for the dynamics of the nematic director field. In order to accommodate defects in the simulated texture, we use a finite difference formulation that is explicitly independent of sign reversal of the director at any position in the sample. Textures are visualized using either the Berreman 4x4 matrix method or by mapping free energy density. We study both planar and focal conic cholesteric textures in 3-d spherical and cylindrical droplets, with the goal to optimize device geometries for bistable display applications.

  17. Dynamic Characteristics of a Model and Prototype for 3D-RC Structure

    NASA Astrophysics Data System (ADS)

    Moniuddin, Md. Khaja; Vasanthalakshmi, G.; Chethan, K.; Babu, R. Ramesh

    2016-06-01

    Infill walls provide durable and economical partitions that have relatively excellent thermal and sound insulation with high fire resistance. Monolithic infilled walls are provided within RC structures without being analyzed as a combination of concrete and brick elements, although in reality they act as a single unit during earthquakes. The performance of such structures during earthquakes has proved to be superior in comparison to bare frames in terms of stiffness, strength and energy dissipation. To know the dynamic characteristics of monolithic infill wall panels and masonry infill, modal, response spectrum and time history analyses have been carried out on a model and prototype of a 3D RC structure for a comparative study.

  18. Time resolved 3D momentum imaging of ultrafast dynamics by coherent VUV-XUV radiation

    NASA Astrophysics Data System (ADS)

    Sturm, F. P.; Wright, T. W.; Ray, D.; Zalyubovskaya, I.; Shivaram, N.; Slaughter, D. S.; Ranitovic, P.; Belkacem, A.; Weber, Th.

    2016-06-01

    We present a new experimental setup for measuring ultrafast nuclear and electron dynamics of molecules after photo-excitation and ionization. We combine a high flux femtosecond vacuum ultraviolet (VUV) and extreme ultraviolet (XUV) source with an internally cold molecular beam and a 3D momentum imaging particle spectrometer to measure electrons and ions in coincidence. We describe a variety of tools developed to perform pump-probe studies in the VUV-XUV spectrum and to modify and characterize the photon beam. First benchmark experiments are presented to demonstrate the capabilities of the system.

  19. Inversion for rupture properties based upon 3-D directivity effect and application to deep earthquakes in the Sea of Okhotsk region

    NASA Astrophysics Data System (ADS)

    Park, Sunyoung; Ishii, Miaki

    2015-11-01

    Rupture properties, such as rupture direction, length, propagation speed and source duration, provide important insights into earthquake mechanisms. One approach to estimate these properties is to investigate the body-wave duration that depends upon the relative location of the station with respect to the rupture direction. Under the assumption that the propagation is unilateral, the duration can be expressed as a function of the dip and azimuth of the rupture. Examination of duration measurements with respect to both the take-off angle and the azimuth is crucial to obtain robust estimates of rupture parameters, especially for nearly vertical rupture propagation. Moreover, limited data coverage, such as using only teleseismic data, can bias the source duration estimate for dipping ruptures, and this bias can map into estimates of other source properties such as rupture extent and rupture speed. Based upon this framework, we introduce an inversion scheme that uses the duration measurements to obtain four parameters: the source duration, a measure of the rupture extent and speed, and dip and azimuth of the rupture propagation. The method is applied to two deep-focus events in the Sea of Okhotsk region, an Mw 7.7 event that occurred on 2012 August 14 and an Mw 8.3 event from 2013 May 24. The source durations are 26 ± 1 and 37 ± 1 s, and rupture speeds are 49 ± 4 per cent and 26 ± 3 per cent of shear wave speed for the Mw 7.7 and 8.3 events, respectively. The azimuths of the two ruptures are parallel to the trench, but are in opposite directions. The dips of the Mw 7.7 and 8.3 events are constrained to be 48° ± 8° downdip and 19° ± 8° updip, respectively. The fit to the data is significantly poorer for the Mw 8.3 event than the Mw 7.7 event, suggesting that the unilateral rupture may not be a good assumption. The analysis is expanded into a multi-episode model, and a secondary episode is determined for the Mw 8.3 event in the southeast direction. The two

  20. Insights from 3D numerical simulations on the dynamics of the India-Asia collision zone

    NASA Astrophysics Data System (ADS)

    Pusok, A. E.; Kaus, B.; Popov, A.

    2013-12-01

    The dynamics of the India-Asia collision zone remains one of the most remarkable topics of the current research interest: the transition from subduction to collision and uplift, followed by the rise of the abnormally thick Tibetan plateau, and the deformation at its Eastern and Western syntaxes, are processes still not fully understood. Models that have addressed this topic include wholescale underthrusting of Indian lithospheric mantle under Tibet, distributed homogeneous shortening or the thin-sheet model, slip-line field model for lateral extrusion or lower crustal flow models for the exhumation of the Himalayan units and lateral spreading of the Tibetan plateau. Of these, the thin-sheet model has successfully illustrated some of the basic physics of continental collision and has the advantage of a 3D model being reduced to 2D, but one of its major shortcomings is that it cannot simultaneously represent channel flow and gravitational collapse of the mantle lithosphere, since these mechanisms require the lithosphere to interact with the underlying mantle, or to have a vertically non-homogeneous rheology. As a consequence, 3D models are emerging as powerful tools to understand the dynamics of coupled systems. However, because of yet recent developments and various complexities, the current 3D models simulating the dynamics of continent collision zones have relied on certain explicit assumptions, such as replacing part of the asthenosphere with various types of boundary conditions that mimic the effect of mantle flow, in order to focus on the lithospheric/crustal deformation. Here, we employ the parallel 3D code LaMEM (Lithosphere and Mantle Evolution Model), with a finite difference staggered grid solver, which is capable of simulating lithospheric deformation while simultaneously taking mantle flow and a free surface into account. We present qualitative results on lithospheric and upper-mantle scale simulations in which the Indian lithosphere is subducted and

  1. Rapid 3D dynamic arterial spin labeling with a sparse model-based image reconstruction.

    PubMed

    Zhao, Li; Fielden, Samuel W; Feng, Xue; Wintermark, Max; Mugler, John P; Meyer, Craig H

    2015-11-01

    Dynamic arterial spin labeling (ASL) MRI measures the perfusion bolus at multiple observation times and yields accurate estimates of cerebral blood flow in the presence of variations in arterial transit time. ASL has intrinsically low signal-to-noise ratio (SNR) and is sensitive to motion, so that extensive signal averaging is typically required, leading to long scan times for dynamic ASL. The goal of this study was to develop an accelerated dynamic ASL method with improved SNR and robustness to motion using a model-based image reconstruction that exploits the inherent sparsity of dynamic ASL data. The first component of this method is a single-shot 3D turbo spin echo spiral pulse sequence accelerated using a combination of parallel imaging and compressed sensing. This pulse sequence was then incorporated into a dynamic pseudo continuous ASL acquisition acquired at multiple observation times, and the resulting images were jointly reconstructed enforcing a model of potential perfusion time courses. Performance of the technique was verified using a numerical phantom and it was validated on normal volunteers on a 3-Tesla scanner. In simulation, a spatial sparsity constraint improved SNR and reduced estimation errors. Combined with a model-based sparsity constraint, the proposed method further improved SNR, reduced estimation error and suppressed motion artifacts. Experimentally, the proposed method resulted in significant improvements, with scan times as short as 20s per time point. These results suggest that the model-based image reconstruction enables rapid dynamic ASL with improved accuracy and robustness. PMID:26169322

  2. A 3D mechanistic model for brittle materials containing evolving flaw distributions under dynamic multiaxial loading

    NASA Astrophysics Data System (ADS)

    Hu, Guangli; Liu, Junwei; Graham-Brady, Lori; Ramesh, K. T.

    2015-05-01

    We present a validated fully 3D mechanism-based micromechanical constitutive model for brittle solids under dynamic multiaxial loading conditions. Flaw statistics are explicitly incorporated through a defect density, and evolving flaw distributions in both orientation and size. Interactions among cracks are modeled by means of a crack-matrix-effective-medium approach. A tensorial damage parameter is defined based upon the crack length and orientation development under local effective stress fields. At low confining stresses, the wing-cracking mechanism dominates, leading to the degradation of the modulus and peak strength of the material, whereas at high enough confining stresses, the cracking mechanism is completely shut-down and dislocation mechanisms become dominant. The model handles general multiaxial stress states, accounts for evolving internal variables in the form of evolving flaw size and orientation distributions, includes evolving anisotropic damage and irreversible damage strains in a thermodynamically consistent fashion, incorporates rate-dependence through the micromechanics, and includes dynamic bulking based on independent experimental data. Simulation results are discussed and compared with experimental results on one specific structural ceramic, aluminum nitride. We demonstrate that this 3D constitutive model is capable of capturing the general constitutive response of structural ceramics.

  3. Grounding line dynamics inferred from a 3D full-Stokes model solving the contact problem

    NASA Astrophysics Data System (ADS)

    Favier, Lionel; Gagliardini, Olivier; Durand, Gael; Zwinger, Thomas

    2010-05-01

    The mass balance of marine ice-sheets, such as the West Antarctic Ice Sheet, is mostly controlled by their grounding line dynamics. Most numerical models simulating marine ice-sheets involve simplifications and do not include all the stress gradients. First results obtained with a 3D full-Stokes model for the grounded ice-sheet / floating ice-shelf transition, using the finite-element code Elmer/Ice, are presented. The initial geometry, which takes into account a dome and a calving front, has been laterally extruded from a previously investigated 2D flowline geometry. The grounding line migration is computed by solving the contact problem between the ice and the rigid downward sloping bedrock, where a non linear friction law is applied in the two horizontal directions. The evolutions of the sea-air and sea-ice interfaces are determined by the solution of a local transport equation. The consistency between the 3D model and the analogous results of the flowline model is shown by comparing the results in the basic extruded case, with no normal flux through lateral boundaries. Thereafter, spatially non uniform perturbations are introduced, to simulate the grounding line dynamics under fully three-dimensional perturbations.

  4. Computational Analysis of the Transonic Dynamics Tunnel Using FUN3D

    NASA Technical Reports Server (NTRS)

    Chwalowski, Pawel; Quon, Eliot; Brynildsen, Scott E.

    2016-01-01

    This paper presents results from an exploratory two-year effort of applying Computational Fluid Dynamics (CFD) to analyze the empty-tunnel flow in the NASA Langley Research Center Transonic Dynamics Tunnel (TDT). The TDT is a continuous-flow, closed circuit, 16- x 16-foot slotted-test-section wind tunnel, with capabilities to use air or heavy gas as a working fluid. In this study, experimental data acquired in the empty tunnel using the R-134a test medium was used to calibrate the computational data. The experimental calibration data includes wall pressures, boundary-layer profiles, and the tunnel centerline Mach number profiles. Subsonic and supersonic flow regimes were considered, focusing on Mach 0.5, 0.7 and Mach 1.1 in the TDT test section. This study discusses the computational domain, boundary conditions, and initial conditions selected and the resulting steady-state analyses using NASA's FUN3D CFD software.

  5. 3D microscale laser dynamic forming: Multiscale modeling and experimental validation

    SciTech Connect

    Gao Huang; Cheng, Gary J.

    2011-05-15

    Microscale laser dynamic forming ({mu}LDF) shows great potential in fabricating robust and high-aspect-ratio metallic microcomponents. Experiments revealed that strain rate and sample size play important roles in determining the dynamic plasticity and final results of {mu}LDF. To further understand these effects, a multiscale modeling methodology is adopted to characterize the microscale dynamic plasticity considering the evolutions of nano-to-submicron dislocations avalanches under shock loading. In this methodology, 3D discrete dislocation dynamics simulations are implemented to derive the yield strength and the initial strain hardening dependence on size and strain rate. It is observed that there exist three dynamic stages during deformation process. The initial strain hardening rate in Stage II increases with strain rate. The mechanical threshold stress model, intrinsically equipped with strain-rate-dependent flow stress and initial hardening, is chosen and modified to incorporate size effect quantitatively. This scale-dependent model, implemented in abaqus/explicit, provides deformation depths and thickness variations in good agreement with experimental results in {mu}LDF.

  6. Population and Evolutionary Dynamics based on Predator-Prey Relationships in a 3D Physical Simulation.

    PubMed

    Ito, Takashi; Pilat, Marcin L; Suzuki, Reiji; Arita, Takaya

    2016-01-01

    Recent studies have reported that population dynamics and evolutionary dynamics, occurring at different time scales, can be affected by each other. Our purpose is to explore the interaction between population and evolutionary dynamics using an artificial life approach based on a 3D physically simulated environment in the context of predator-prey and morphology-behavior coevolution. The morphologies and behaviors of virtual prey creatures are evolved using a genetic algorithm based on the predation interactions between predators and prey. Both population sizes are also changed, depending on the fitness. We observe two types of cyclic behaviors, corresponding to short-term and long-term dynamics. The former can be interpreted as a simple population dynamics of Lotka-Volterra type. It is shown that the latter cycle is based on the interaction between the changes in the prey strategy against predators and the long-term change in both population sizes, resulting partly from a tradeoff between their defensive success and the cost of defense. PMID:26934093

  7. A grid-doubling finite-element technique for calculating dynamic three-dimensional spontaneous rupture on an earthquake fault

    USGS Publications Warehouse

    Barall, M.

    2009-01-01

    We present a new finite-element technique for calculating dynamic 3-D spontaneous rupture on an earthquake fault, which can reduce the required computational resources by a factor of six or more, without loss of accuracy. The grid-doubling technique employs small cells in a thin layer surrounding the fault. The remainder of the modelling volume is filled with larger cells, typically two or four times as large as the small cells. In the resulting non-conforming mesh, an interpolation method is used to join the thin layer of smaller cells to the volume of larger cells. Grid-doubling is effective because spontaneous rupture calculations typically require higher spatial resolution on and near the fault than elsewhere in the model volume. The technique can be applied to non-planar faults by morphing, or smoothly distorting, the entire mesh to produce the desired 3-D fault geometry. Using our FaultMod finite-element software, we have tested grid-doubling with both slip-weakening and rate-and-state friction laws, by running the SCEC/ USGS 3-D dynamic rupture benchmark problems. We have also applied it to a model of the Hayward fault, Northern California, which uses realistic fault geometry and rock properties. FaultMod implements fault slip using common nodes, which represent motion common to both sides of the fault, and differential nodes, which represent motion of one side of the fault relative to the other side. We describe how to modify the traction-at-split-nodes method to work with common and differential nodes, using an implicit time stepping algorithm. ?? Journal compilation ?? 2009 RAS.

  8. Surface 3D nanostructuring by tightly focused laser pulse: simulations by Lagrangian code and molecular dynamics

    NASA Astrophysics Data System (ADS)

    Inogamov, Nail A.; Zhakhovsky, Vasily V.

    2016-02-01

    There are many important applications in which the ultrashort diffraction-limited and therefore tightly focused laser pulses irradiates metal films mounted on dielectric substrate. Here we present the detailed picture of laser peeling and 3D structure formation of the thin (relative to a depth of a heat affected zone in the bulk targets) gold films on glass substrate. The underlying physics of such diffraction-limited laser peeling was not well understood previously. Our approach is based on a physical model which takes into consideration the new calculations of the two-temperature (2T) equation of state (2T EoS) and the two-temperature transport coefficients together with the coupling parameter between electron and ion subsystems. The usage of the 2T EoS and the kinetic coefficients is required because absorption of an ultrashort pulse with duration of 10-1000 fs excites electron subsystem of metal and transfers substance into the 2T state with hot electrons (typical electron temperatures 1-3 eV) and much colder ions. It is shown that formation of submicrometer-sized 3D structures is a result of the electron-ion energy transfer, melting, and delamination of film from substrate under combined action of electron and ion pressures, capillary deceleration of the delaminated liquid metal or semiconductor, and ultrafast freezing of molten material. We found that the freezing is going in non-equilibrium regime with strongly overcooled liquid phase. In this case the Stefan approximation is non-applicable because the solidification front speed is limited by the diffusion rate of atoms in the molten material. To solve the problem we have developed the 2T Lagrangian code including all this reach physics in. We also used the high-performance combined Monte- Carlo and molecular dynamics code for simulation of surface 3D nanostructuring at later times after completion of electron-ion relaxation.

  9. Making and Remaking Dynamic 3D Structures by Shining Light on Flat Liquid Crystalline Vitrimer Films without a Mold.

    PubMed

    Yang, Yang; Pei, Zhiqiang; Li, Zhen; Wei, Yen; Ji, Yan

    2016-02-24

    Making dynamic three-dimensional (3D) structures capable of reversible shape changes or locomotion purely out of dry polymers is very difficult. Meanwhile, no previous dynamic 3D structures can be remade into new configurations while being resilient to mechanical damages and low temperature. Here, we show that light-activated transesterification in carbon nanotube dispersed liquid crystalline vitrimers enables flexible design and easy building of dynamic 3D structures out of flat films upon irradiation of light without screws, glues, or molds. Shining light also enables dynamic 3D structures to be quickly modified on demand, restored from distortion, repaired if broken, in situ healed when microcrack appears, assembled for more sophisticated structures, reconfigured, and recycled after use. Furthermore, the fabrication, reconfiguration, actuation, reparation, and assembly as well as healing can be performed even at extremely low temperatures (e.g., -130 °C). PMID:26840838

  10. Coseismic temporal changes of slip direction: the effect of absolute stress on dynamic rupture

    USGS Publications Warehouse

    Guatteri, Mariagiovanna; Spudich, P.

    1998-01-01

    We investigate the dynamics of rupture at low-stress level. We show that one main difference between the dynamics of high- and low-stress events is the amount of coseismic temporal rake rotation occurring at given points on the fault. Curved stations on exposed fault surfaces and earthquake dislocation models derived from ground-motion inversion indicate that the slip direction may change with time at a pointon the fault during dynamic rupture. We use a 3D boundary integral method to model temporal rake variations during dynamic rupture propagation assuming a slip-weakening friction law and isotropic friction. The points at which the slip rotates most are characterized by an initial shear stress direction substantially different from the average stress direction over the fault plane. We show that for a given value of stress drop, the level of initial shear stress (i.e., the fractional stress drop) determines the amount of rotation in slip direction. We infer that seismic events that show evidence of temporal rake rorations are characterized by a low initial shear-stress level with spatially variable direction on the fault (possibly due to changes in fault surface geometry) and an almost complete stress drop. Our models motivate a new interpretation of curved and cross-cutting striations and put new constraints on their analysis. The initial rake is in general collinear with the initial stress at the hypocenter zone, supporting the assumptions made in stress-tensor inversion from first-motion analysis. At other points on the fualt, especially away from the hypocenter, the initial slip rake may not be collinear with the initial shear stress, contradicting a common assumption of structural geology. On the other hand, the later part of slip in our models is systematically more aligned withi the average stress direction than the early slip. Our modeling suggests that the length of the straight part of curved striations is usually an upper bound of the slip

  11. Observing molecular dynamics with time-resolved 3D momentum imaging

    NASA Astrophysics Data System (ADS)

    Sturm, F. P.; Wright, T.; Bocharova, I.; Ray, D.; Shivaram, N.; Cryan, J.; Belkacem, A.; Weber, T.; Dörner, R.

    2014-05-01

    Photo-excitation and ionization trigger rich dynamics in molecular systems which play a key role in many important processes in nature such as vision, photosynthesis or photoprotection. Observing those reactions in real-time without significantly disturbing the molecules by a strong electric field has been a great challenge. Recent experiments using Time-of-Flight and Velocity Map Imaging techniques have revealed important information on the dynamics of small molecular systems upon photo-excitation. We have developed an apparatus for time-resolved momentum imaging of electrons and ions in all three spatial dimensions that employs two-color femtosecond laser pulses in the vacuum and extreme ultraviolet (VUV, XUV) for probing molecular dynamics. Our COLTRIMS style reaction microscope can measure electrons and ions in coincidence and reconstruct the momenta of the reaction fragments in 3D. We use a high power 800 nm laser in a loose focusing geometry gas cell to efficinetly drive High Harmonic Generation. The resulting photon flux is sufficient to perform 2-photon pump-probe experiments using VUV and XUV pulses for both pump and probe. With this setup we investigate non-Born-Oppenheimer dynamics in small molecules such as C2H4 and CO2 on a femtosecond time scale. Supported by Chemical Sciences, Geosciences and Biosciences division of BES/DOE.

  12. Segmentation of Whole Cells and Cell Nuclei From 3-D Optical Microscope Images Using Dynamic Programming

    PubMed Central

    McCullough, Dean P.; Gudla, Prabhakar R.; Harris, Bradley S.; Collins, Jason A.; Meaburn, Karen J.; Nakaya, Masa-Aki; Yamaguchi, Terry P.; Misteli, Tom; Lockett, Stephen J.

    2009-01-01

    Communications between cells in large part drive tissue development and function, as well as disease-related processes such as tumorigenesis. Understanding the mechanistic bases of these processes necessitates quantifying specific molecules in adjacent cells or cell nuclei of intact tissue. However, a major restriction on such analyses is the lack of an efficient method that correctly segments each object (cell or nucleus) from 3-D images of an intact tissue specimen. We report a highly reliable and accurate semi-automatic algorithmic method for segmenting fluorescence-labeled cells or nuclei from 3-D tissue images. Segmentation begins with semi-automatic, 2-D object delineation in a user-selected plane, using dynamic programming (DP) to locate the border with an accumulated intensity per unit length greater that any other possible border around the same object. Then the two surfaces of the object in planes above and below the selected plane are found using an algorithm that combines DP and combinatorial searching. Following segmentation, any perceived errors can be interactively corrected. Segmentation accuracy is not significantly affected by intermittent labeling of object surfaces, diffuse surfaces, or spurious signals away from surfaces. The unique strength of the segmentation method was demonstrated on a variety of biological tissue samples where all cells, including irregularly shaped cells, were accurately segmented based on visual inspection. PMID:18450544

  13. Mutual information as a measure of image quality for 3D dynamic lung imaging with EIT

    PubMed Central

    Crabb, M G; Davidson, J L; Little, R; Wright, P; Morgan, A R; Miller, C A; Naish, J H; Parker, G J M; Kikinis, R; McCann, H; Lionheart, W R B

    2014-01-01

    We report on a pilot study of dynamic lung electrical impedance tomography (EIT) at the University of Manchester. Low-noise EIT data at 100 frames per second (fps) were obtained from healthy male subjects during controlled breathing, followed by magnetic resonance imaging (MRI) subsequently used for spatial validation of the EIT reconstruction. The torso surface in the MR image and electrode positions obtained using MRI fiducial markers informed the construction of a 3D finite element model extruded along the caudal-distal axis of the subject. Small changes in the boundary that occur during respiration were accounted for by incorporating the sensitivity with respect to boundary shape into a robust temporal difference reconstruction algorithm. EIT and MRI images were co-registered using the open source medical imaging software, 3D Slicer. A quantitative comparison of quality of different EIT reconstructions was achieved through calculation of the mutual information with a lung-segmented MR image. EIT reconstructions using a linear shape correction algorithm reduced boundary image artefacts, yielding better contrast of the lungs, and had 10% greater mutual information compared with a standard linear EIT reconstruction. PMID:24710978

  14. Description of patellar movement by 3D parameters obtained from dynamic CT acquisition

    NASA Astrophysics Data System (ADS)

    de Sá Rebelo, Marina; Moreno, Ramon Alfredo; Gobbi, Riccardo Gomes; Camanho, Gilberto Luis; de Ávila, Luiz Francisco Rodrigues; Demange, Marco Kawamura; Pecora, Jose Ricardo; Gutierrez, Marco Antonio

    2014-03-01

    The patellofemoral joint is critical in the biomechanics of the knee. The patellofemoral instability is one condition that generates pain, functional impairment and often requires surgery as part of orthopedic treatment. The analysis of the patellofemoral dynamics has been performed by several medical image modalities. The clinical parameters assessed are mainly based on 2D measurements, such as the patellar tilt angle and the lateral shift among others. Besides, the acquisition protocols are mostly performed with the leg laid static at fixed angles. The use of helical multi slice CT scanner can allow the capture and display of the joint's movement performed actively by the patient. However, the orthopedic applications of this scanner have not yet been standardized or widespread. In this work we present a method to evaluate the biomechanics of the patellofemoral joint during active contraction using multi slice CT images. This approach can greatly improve the analysis of patellar instability by displaying the physiology during muscle contraction. The movement was evaluated by computing its 3D displacements and rotations from different knee angles. The first processing step registered the images in both angles based on the femuŕs position. The transformation matrix of the patella from the images was then calculated, which provided the rotations and translations performed by the patella from its position in the first image to its position in the second image. Analysis of these parameters for all frames provided real 3D information about the patellar displacement.

  15. 3D Plasma Clusters: Analysis of dynamical evolution and individual particle interaction

    SciTech Connect

    Antonova, T.; Thomas, H. M.; Morfill, G. E.; Annaratone, B. M.

    2008-09-07

    3D plasma clusters (up to 100 particles) have been built inside small (32 mm{sup 3}) plasma volume in gravity. It has been estimated that the external confinement has a negligible influence on the processes inside the clusters. At such conditions the analysis of dynamical evolution and individual particle interactions have shown that the binary interaction among particles in addition to the repelling Coulomb force exhibits also an attractive part. The tendency of the systems to approach the state with minimum energy by rearranging particles inside has been detected. The measured 63 particles' cluster vibrations are in close agreement with vibrations of a drop with surface tension. This indicates that even a 63 particle cluster already exhibits properties normally associated with the cooperative regime.

  16. 3D Dynamic Finite Element Analysis of the Nonuniform Residual Stress in Ultrasonic Impact Treatment Process

    NASA Astrophysics Data System (ADS)

    Hu, Shengsun; Guo, Chaobo; Wang, Dongpo; Wang, Zhijiang

    2016-07-01

    The nonuniform distributions of the residual stress were simulated by a 3D finite element model to analyze the elastic-plastic dynamic ultrasonic impact treatment (UIT) process of multiple impacts on the 2024 aluminum alloy. The evolution of the stress during the impact process was discussed. The successive impacts during the UIT process improve the uniformity of the plastic deformation and decrease the maximum compressive residual stress beneath the former impact indentations. The influences of different controlled parameters, including the initial impact velocity, pin diameter, pin tip, device moving, and offset distances, on the residual stress distributions were analyzed. The influences of the controlled parameters on the residual stress distributions are apparent in the offset direction due to the different surface coverage in different directions. The influences can be used to understand the UIT process and to obtain the desired residual stress by optimizing the controlled parameters.

  17. Self-Consistent 3D Modeling of Electron Cloud Dynamics and Beam Response

    SciTech Connect

    Furman, Miguel; Furman, M.A.; Celata, C.M.; Kireeff-Covo, M.; Sonnad, K.G.; Vay, J.-L.; Venturini, M.; Cohen, R.; Friedman, A.; Grote, D.; Molvik, A.; Stoltz, P.

    2007-04-02

    We present recent advances in the modeling of beam electron-cloud dynamics, including surface effects such as secondary electron emission, gas desorption, etc, and volumetric effects such as ionization of residual gas and charge-exchange reactions. Simulations for the HCX facility with the code WARP/POSINST will be described and their validity demonstrated by benchmarks against measurements. The code models a wide range of physical processes and uses a number of novel techniques, including a large-timestep electron mover that smoothly interpolates between direct orbit calculation and guiding-center drift equations, and a new computational technique, based on a Lorentz transformation to a moving frame, that allows the cost of a fully 3D simulation to be reduced to that of a quasi-static approximation.

  18. Dynamic Implicit 3D Adaptive Mesh Refinement for Non-Equilibrium Radiation Diffusion

    SciTech Connect

    Philip, Bobby; Wang, Zhen; Berrill, Mark A; Rodriguez Rodriguez, Manuel; Pernice, Michael

    2014-01-01

    The time dependent non-equilibrium radiation diffusion equations are important for solving the transport of energy through radiation in optically thick regimes and find applications in several fields including astrophysics and inertial confinement fusion. The associated initial boundary value problems that are encountered exhibit a wide range of scales in space and time and are extremely challenging to solve. To efficiently and accurately simulate these systems we describe our research on combining techniques that will also find use more broadly for long term time integration of nonlinear multiphysics systems: implicit time integration for efficient long term time integration of stiff multiphysics systems, local control theory based step size control to minimize the required global number of time steps while controlling accuracy, dynamic 3D adaptive mesh refinement (AMR) to minimize memory and computational costs, Jacobian Free Newton Krylov methods on AMR grids for efficient nonlinear solution, and optimal multilevel preconditioner components that provide level independent linear solver convergence.

  19. The Quantum Dynamics of a Dilute Gas in a 3D BCC Optical Lattice

    NASA Astrophysics Data System (ADS)

    Reichl, Linda; Boretz, Yingyue

    2015-03-01

    The classical and quantum dynamics of a dilute gas of rubidium atoms, in a 3D body-centered cubic optical lattice, is studied for a range of polarizations of the laser beams forming the lattice. The relative polarization of the lasers determines the the structure of the potential energy seen by the rubidium atoms. If three pairs of in-phase mutually perpendicular laser beams, with the same wavelength, form the lattice, only a limited range of possible couplings can be realized in the lab. We have determined the band structure of the BCC optical lattice for all theoretically possible couplings, and find that the band structure for lattices realizable in the lab, differs significantly from that expected for a BCC crystal. As coupling is increased, the lattice becomes increasingly chaotic and it becomes possible to produce band structure that has qualitative similarity to a BCC. Welch Foundation

  20. 3D Reconstruction of Human Laryngeal Dynamics Based on Endoscopic High-Speed Recordings.

    PubMed

    Semmler, Marion; Kniesburges, Stefan; Birk, Veronika; Ziethe, Anke; Patel, Rita; Dollinger, Michael

    2016-07-01

    Standard laryngoscopic imaging techniques provide only limited two-dimensional insights into the vocal fold vibrations not taking the vertical component into account. However, previous experiments have shown a significant vertical component in the vibration of the vocal folds. We present a 3D reconstruction of the entire superior vocal fold surface from 2D high-speed videoendoscopy via stereo triangulation. In a typical camera-laser set-up the structured laser light pattern is projected on the vocal folds and captured at 4000 fps. The measuring device is suitable for in vivo application since the external dimensions of the miniaturized set-up barely exceed the size of a standard rigid laryngoscope. We provide a conservative estimate on the resulting resolution based on the hardware components and point out the possibilities and limitations of the miniaturized camera-laser set-up. In addition to the 3D vocal fold surface, we extended previous approaches with a G2-continuous model of the vocal fold edge. The clinical applicability was successfully established by the reconstruction of visual data acquired from 2D in vivo high-speed recordings of a female and a male subject. We present extracted dynamic parameters like maximum amplitude and velocity in the vertical direction. The additional vertical component reveals deeper insights into the vibratory dynamics of the vocal folds by means of a non-invasive method. The successful miniaturization allows for in vivo application giving access to the most realistic model available and hence enables a comprehensive understanding of the human phonation process. PMID:26829782

  1. Transforming 2d Cadastral Data Into a Dynamic Smart 3d Model

    NASA Astrophysics Data System (ADS)

    Tsiliakou, E.; Labropoulos, T.; Dimopoulou, E.

    2013-08-01

    3D property registration has become an imperative need in order to optimally reflect all complex cases of the multilayer reality of property rights and restrictions, revealing their vertical component. This paper refers to the potentials and multiple applications of 3D cadastral systems and explores the current state-of-the art, especially the available software with which 3D visualization can be achieved. Within this context, the Hellenic Cadastre's current state is investigated, in particular its data modeling frame. Presenting the methodologies and specifications addressing the registration of 3D properties, the operating cadastral system's shortcomings and merits are pointed out. Nonetheless, current technological advances as well as the availability of sophisticated software packages (proprietary or open source) call for 3D modeling. In order to register and visualize the complex reality in 3D, Esri's CityEngine modeling software has been used, which is specialized in the generation of 3D urban environments, transforming 2D GIS Data into Smart 3D City Models. The application of the 3D model concerns the Campus of the National Technical University of Athens, in which a complex ownership status is established along with approved special zoning regulations. The 3D model was built using different parameters based on input data, derived from cadastral and urban planning datasets, as well as legal documents and architectural plans. The process resulted in a final 3D model, optimally describing the cadastral situation and built environment and proved to be a good practice example of 3D visualization.

  2. A Unified Simulation Framework for Megathrust Rupture Dynamics and Tsunamis

    NASA Astrophysics Data System (ADS)

    Dunham, E. M.; Lotto, G. C.; Kozdon, J. E.

    2014-12-01

    Many earthquakes, including megathrust events in subduction zones, occur offshore. In addition to seismic waves, such earthquakes also generate tsunamis. We present a methodology for simultaneously investigating earthquake rupture dynamics and tsunamigenesis, based on solution of the elastic and acoustic wave equations, in the solid and fluid portions of the domain, respectively. Surface gravity waves or tsunamis emerge naturally in such a description when gravitational restoring forces are properly taken into account. In our approach, we adopt an Eulerian description of the ocean and within it solve for particle velocities and the perturbation in pressure, Δp, about an initial hydrostatic state. The key step is enforcing the traction-free boundary condition on the moving ocean surface. We linearize this boundary condition, in order to apply it on the initial surface, and express it as Δp-ρgη=0, where -ρg is the initial hydrostatic gradient in pressure and η is the sea surface uplift (obtained, to first order, by integrating vertical particle velocity on the initial ocean surface). We show that this is the only place one needs to account for gravity. Additional terms in the momentum balance and linearized equation of state describing advection of pressure and density gradients can be included to study internal gravity waves within the ocean, but these can be safely neglected for problems of interest to us. We present a range of simulations employing this new methodology. These include test problems used to verify the accuracy of the method for modeling seismic, ocean acoustic, and tsunami waves, as well as more detailed models of megathrust ruptures. Our present work is focused on tsunami generation in models with variable bathymetry, where previous studies have raised questions regarding how horizontal displacement of a sloping seafloor excites tsunamis. Our approach rigorously accounts for time-dependent seafloor motion, horizontal momentum transfer, and

  3. Rupture Dynamics Simulations Along Subduction Zones: Bimaterial Interfaces and Free Surface Interaction

    NASA Astrophysics Data System (ADS)

    Scala, A.; Vilotte, J. P.; Festa, G.

    2015-12-01

    Largest earthquakes occur along subduction zones, where normal and tangential stress coupling drives the earthquake rupture due to the geometry of the subduction interface between dissimilar materials and the interaction with waves reflected from free surface as the rupture propagates toward the trench. We numerically investigate these effects in the context of dynamic rupture simulations. We revisit the problem of in-plane interface rupture propagation between dissimilar elastic media, in the case of slip-weakening friction, by performing a numerical study using the Spectral Element Method with a non-smooth contact formulation. For classical slip-weakening friction, the problem is ill posed due to a missing length or time scale in the response of the frictional shear stress to dynamic normal stress perturbations. We first perform a parametric study of the regularization formulation proposed by Rubin and Ampuero (2007). We show that the dynamic regularization, driven by local slip rate does not allow for a proper modeling of the asymptotic rupture propagation. We propose a new regularization approach based on the non-local length scale, associated to the actual size of the process zone. Numerical results are shown to be consistent with mathematical modeling of dynamic interface rupture propagation with a process zone ahead of the rupture front. The numerical study is extended to inclined ruptures intersecting a free surface at different angles. We investigate interaction between rupture propagation and stress changes induced by waves reflected from the free surface, in the generation of large interface slip, transient healing and opening effects. Finally, preliminary in-plane dynamic simulations of the 2011 Tohoku earthquake, incorporating the along-dip structure and geometry of the subduction interface, are presented enlightening the role of the geometry of the bi-material interface and of the free surface in the rupture propagation and radiation.

  4. Numerical simulations of large earthquakes: Dynamic rupture propagation on heterogeneous faults

    USGS Publications Warehouse

    Harris, R.A.

    2004-01-01

    Our current conceptions of earthquake rupture dynamics, especially for large earthquakes, require knowledge of the geometry of the faults involved in the rupture, the material properties of the rocks surrounding the faults, the initial state of stress on the faults, and a constitutive formulation that determines when the faults can slip. In numerical simulations each of these factors appears to play a significant role in rupture propagation, at the kilometer length scale. Observational evidence of the earth indicates that at least the first three of the elements, geometry, material, and stress, can vary over many scale dimensions. Future research on earthquake rupture dynamics needs to consider at which length scales these features are significant in affecting rupture propagation. ?? Birkha??user Verlag, Basel, 2004.

  5. Using 3D dynamic models to reproduce X-ray properties of colliding wind binaries

    NASA Astrophysics Data System (ADS)

    Russell, Christopher Michael Post

    Colliding wind binaries (CWBs) are unique laboratories for X-ray astrophysics. The two massive stars contained in these systems have powerful radiatively driven stellar winds, and the conversion of their kinetic energy to heat (up to 108 K) at the wind-wind collision region generates hard thermal X-rays (up to 10 keV). Rich data sets exist of several multi-year-period systems, as well as key observations of shorter period systems, and detailed models are required to disentangle the phase-locked emission and absorption processes in these systems. To interpret these X-ray light curves and spectra, this dissertation models the wind-wind interaction of CWBs using 3D smoothed particle hydrodynamics (SPH), and solves the 3D formal solution of radiative transfer to synthesize the model X-ray properties, allowing direct comparison with the colliding-wind X-ray spectra observed by, e.g., RXTE and XMM. The multi-year-period, highly eccentric CWBs we examine are eta Carinae and WR140. For the commonly inferred primary mass loss rate of ˜10 -3 Msun/yr, eta Carinae's 3D model reproduces quite well the 2-10 keV RXTE light curve, hardness ratio, and dynamic spectra in absolute units. This agreement includes the ˜3 month X-ray minimum associated with the 1998.0 and 2003.5 periastron passages, which we find to occur as the primary wind encroaches into the secondary wind's acceleration region. This modeling provides further evidence that the observer is mainly viewing the system through the secondary's shock cone, and suggests that periastron occurs ~1 month after the onset of the X-ray minimum. The model RXTE observables of WR140 match the data well in absolute units, although the decrease in model X-rays around periastron is less than observed. There is very good agreement between the observed XMM spectrum taken on the rise before periastron and the model. We also model two short-period CWBs, HD150136, which has a wind-star collision, and delta Orionis A, the closest eclipsing

  6. Slip reactivation during the 2011 Tohoku earthquake: Dynamic rupture and ground motion simulations

    NASA Astrophysics Data System (ADS)

    Galvez, P.; Dalguer, L. A.

    2013-12-01

    The 2011 Mw9 Tohoku earthquake generated such as vast geophysical data that allows studying with an unprecedented resolution the spatial-temporal evolution of the rupture process of a mega thrust event. Joint source inversion of teleseismic, near-source strong motion and coseismic geodetic data , e.g [Lee et. al, 2011], reveal an evidence of slip reactivation process at areas of very large slip. The slip of snapshots of this source model shows that after about 40 seconds the big patch above to the hypocenter experienced an additional push of the slip (reactivation) towards the trench. These two possible repeating slip exhibited by source inversions can create two waveform envelops well distinguished in the ground motion pattern. In fact seismograms of the KiK-Net Japanese network contained this pattern. For instance a seismic station around Miyagi (MYGH10) has two main wavefronts separated between them by 40 seconds. A possible physical mechanism to explain the slip reactivation could be a thermal pressurization process occurring in the fault zone. In fact, Kanamori & Heaton, (2000) proposed that for large earthquakes frictional melting and fluid pressurization can play a key role of the rupture dynamics of giant earthquakes. If fluid exists in a fault zone, an increase of temperature can rise up the pore pressure enough to significantly reduce the frictional strength. Therefore, during a large earthquake the areas of big slip persuading strong thermal pressurization may result in a second drop of the frictional strength after reaching a certain value of slip. Following this principle, we adopt for slip weakening friction law and prescribe a certain maximum slip after which the friction coefficient linearly drops down again. The implementation of this friction law has been done in the latest unstructured spectral element code SPECFEM3D, Peter et. al. (2012). The non-planar subduction interface has been taken into account and place on it a big asperity patch inside

  7. Holographic display system for dynamic synthesis of 3D light fields with increased space bandwidth product.

    PubMed

    Agour, Mostafa; Falldorf, Claas; Bergmann, Ralf B

    2016-06-27

    We present a new method for the generation of a dynamic wave field with high space bandwidth product (SBP). The dynamic wave field is generated from several wave fields diffracted by a display which comprises multiple spatial light modulators (SLMs) each having a comparably low SBP. In contrast to similar approaches in stereoscopy, we describe how the independently generated wave fields can be coherently superposed. A major benefit of the scheme is that the display system may be extended to provide an even larger display. A compact experimental configuration which is composed of four phase-only SLMs to realize the coherent combination of independent wave fields is presented. Effects of important technical parameters of the display system on the wave field generated across the observation plane are investigated. These effects include, e.g., the tilt of the individual SLM and the gap between the active areas of multiple SLMs. As an example of application, holographic reconstruction of a 3D object with parallax effects is demonstrated. PMID:27410593

  8. 3D Global Braginskii Simulations of Plasma Dynamics and Turbulence in LAPD

    NASA Astrophysics Data System (ADS)

    Fisher, Dustin; Rogers, Barrett

    2013-10-01

    3D global two-fluid simulations are presented in an ongoing effort to identify and understand the plasma dynamics in the Large Plasma Device (LAPD) at UCLA's Basic Science Facility. Modeling is done using a modified version of the Global Braginskii Solver (GBS) that models the plasma from source to edge region on a field-aligned grid using a finite difference method and 4th order Runge-Kutta time stepping. Progress has been made to account for the thermionic cathode emission of fast electrons at the source, the axial dependence of the plasma source, and biasing the front and side walls. Along with trying to understand the effect sheath's and neutrals have in setting the plasma potential, work is being done to model the biasable limiter recently used by colleagues at UCLA to better understand flow shear and particle transport in the LAPD. Comparisons of the zero bias case are presented along with analysis of the growth and dynamics of turbulent structures (such as drift waves) seen in the simulations. Supported through CICART under the auspices of the DOE's EPSCoR Grant No. DE-FG02-10ER46372.

  9. A Real-time, 3D Musculoskeletal Model for Dynamic Simulation of Arm Movements

    PubMed Central

    Chadwick, Edward K.; Blana, Dimitra; van den Bogert, Antonie J.; Kirsch, Robert F.

    2010-01-01

    Neuroprostheses can be used to restore movement of the upper limb in individuals with high-level spinal cord injury. Development and evaluation of command and control schemes for such devices typically requires real-time, “patient-in-the-loop” experimentation. A real-time, three-dimensional, musculoskeletal model of the upper limb has been developed for use in a simulation environment to allow such testing to be carried out non-invasively. The model provides real-time feedback of human arm dynamics that can be displayed to the user in a virtual reality environment. The model has a three degree-of-freedom gleno-humeral joint as well as elbow flexion/extension and pronation/supination, and contains 22 muscles of the shoulder and elbow divided into multiple elements. The model is able to run in real time on modest desktop hardware and demonstrates that a large-scale, 3D model can be made to run in real time. This is a prerequisite for a real-time, whole arm model that will form part of a dynamic arm simulator for use in the development, testing and user training of neural prosthesis systems. PMID:19272926

  10. A digital holography set-up for 3D vortex flow dynamics

    NASA Astrophysics Data System (ADS)

    Lebon, Benoît; Perret, Gaële; Coëtmellec, Sébastien; Godard, Gilles; Gréhan, Gérard; Lebrun, Denis; Brossard, Jérôme

    2016-06-01

    In the present paper, a digital in-line holography (DIH) set-up, with a converging beam, is used to take three-dimensional (3D) velocity measurements of vortices. The vortices are formed periodically at the edges of a submerged horizontal plate submitted to regular waves. They take the form of vortex filaments that extend from side to side of the channel. They undergo strongly three-dimensional instability mechanisms that remain very complicated to characterize experimentally. The experiments are performed in a 10 × 0.3 × 0.3 m3 wave flume. The DIH set-up is performed using a modulated laser diode emitting at the wavelength of 640 nm and a lensless CCD camera. The beam crosses the channel side to side. To reveal the flow dynamics, 30-μm hydrogen bubbles are generated at the edge of the plate to serve as tracers. Their locations are recorded on the holograms multiple times to access the dynamics of the flow. This method leads to an accuracy in the order of 100 μm on the axial location. Those measurements have been validated with stereo-PIV measurements. A very good agreement is found on time-averaged velocity fields between the two techniques.

  11. Real-time automated 3D sensing, detection, and recognition of dynamic biological micro-organic events

    NASA Astrophysics Data System (ADS)

    Javidi, Bahram; Yeom, Seokwon; Moon, Inkyu; Daneshpanah, Mehdi

    2006-05-01

    In this paper, we present an overview of three-dimensional (3D) optical imaging techniques for real-time automated sensing, visualization, and recognition of dynamic biological microorganisms. Real time sensing and 3D reconstruction of the dynamic biological microscopic objects can be performed by single-exposure on-line (SEOL) digital holographic microscopy. A coherent 3D microscope-based interferometer is constructed to record digital holograms of dynamic micro biological events. Complex amplitude 3D images of the biological microorganisms are computationally reconstructed at different depths by digital signal processing. Bayesian segmentation algorithms are applied to identify regions of interest for further processing. A number of pattern recognition approaches are addressed to identify and recognize the microorganisms. One uses 3D morphology of the microorganisms by analyzing 3D geometrical shapes which is composed of magnitude and phase. Segmentation, feature extraction, graph matching, feature selection, and training and decision rules are used to recognize the biological microorganisms. In a different approach, 3D technique is used that are tolerant to the varying shapes of the non-rigid biological microorganisms. After segmentation, a number of sampling patches are arbitrarily extracted from the complex amplitudes of the reconstructed 3D biological microorganism. These patches are processed using a number of cost functions and statistical inference theory for the equality of means and equality of variances between the sampling segments. Also, we discuss the possibility of employing computational integral imaging for 3D sensing, visualization, and recognition of biological microorganisms illuminated under incoherent light. Experimental results with several biological microorganisms are presented to illustrate detection, segmentation, and identification of micro biological events.

  12. Transition Of Dynamic Rupture Modes And Macroscopic Source Properties In Elastic And Plastic Media

    NASA Astrophysics Data System (ADS)

    Gabriel, A. A.; Ampuero, J. P.; Mai, P. M.; Dalguer Gudiel, L. A.

    2010-12-01

    Seismic inversions of earthquakes show dominantly pulse-like behavior, i.e. the fault heals shortly after the rupture front has passed leading to short rise times. In numerical simulations with strong velocity-weakening friction, pulse-like ruptures occur under certain initial conditions. However, a complete picture of the dynamics of rupture pulses remains elusive: what controls their rupture speed and their rise time? We apply the 2D spectral element method (SEM2DPACK of Ampuero, 2008) to model spontaneous rupture under strong velocity-and-state-dependent friction in a 2D in-plane model with and without Coulomb off-fault plasticity. Depending on initial stresses and nucleation procedure, the generated ruptures approach distinct regimes of stable self-similar behavior: decaying, steady-state and growing pulse-like, crack-like and super-shear ruptures, bounded by sensitive transitional zones. The asymptotic behavior of these self-similar areas is independent of the initial parameters, unlike the transient approach to that asymptotic solution. We characterize these general rupture modes as a function of background shear stress, angle of maximum compressive initial stress and nucleation procedure in elastic and plastic media. Interestingly, the pulse-crack transition is involving a re-activation of the former healed rupture due to gradual stress build-up near the hypocenter. The introduction of off-fault inelasticity quantitatively shifts the conditions to obtain each rupture mode. Furthermore, the considerable amount of induced off-fault energy dissipation alters macroscopic source properties, e.g. leads to slower rupture velocities, lower peak slip rates and lower shear stress levels on the fault compared to the elastic case. Our simulations provide quantitative relations between off-fault energy dissipation, seismic moment rate and the speed of rupture and healing fronts. These relations provide a self-consistent theoretical framework for the study of the

  13. 3D airflow dynamics over transverse ridges Mpekweni, South Africa: implications for dune field migration behaviour

    NASA Astrophysics Data System (ADS)

    Jackson, Derek; Cooper, Andrew; Green, Andrew; Beyers, Meiring; Wiles, Errol; Benallack, Keegan

    2016-04-01

    Un-vegetated dune fields provide excellent opportunities to examine airflow dynamics over various types and scales of dune landforms. The three dimensional surface over which lower boundary layers travel, help adjust surface airflow and consequently the aeolian response of the dunes themselves. The use of computational fluid dynamic (CFD) modelling in recent studies now enables investigation of the 3D behaviour of airflow over complex terrain, providing new insights into heterogeneous surface flow and aeolian response of dune surfaces on a large (dunefield) scale. Using a largely un-vegetated coastal dune field site at Mpekweni, Eastern Cape, South Africa, a detailed (0.1m gridded) terrestrial laser scanning survey was conducted to create a high resolution topographical surface. Using local wind flow measurements and local met station records as input, CFD modelling was performed for a number of scenarios involving variable direction and magnitude to examine surface flow patterns across multiple dune forms. Near surface acceleration, expansion and separation of airflow inducing convergence and divergence (steering) of flow velocity streamlines are investigated. Flow acceleration over dune crests/brink lines is a key parameter in driving dune migration and slip face dynamics. Dune aspect ratio (height to length) is also important in determining the degree of crestal flow acceleration, with an increase in flow associated with increasing aspect ratios. Variations in dune height appear to be the most important parameter in driving general flow acceleration. The results from the study provide new insights into dune migration behaviour at this site as well as surface flow behaviour across multiple dune configurations and length scales within un-vegetated dune fields.

  14. 3D Dynamics of Freshwater Lenses in the Near-Surface Layer of the Tropical Ocean

    NASA Astrophysics Data System (ADS)

    Soloviev, Alexander; Dean, Cayla

    2015-04-01

    Convective rains in the Intertropical Convergence Zone (ITCZ) produce lenses of freshened water on the ocean surface. These lenses are localized in space and typically involve both salinity and temperature anomalies. Due to significant density anomalies, strong pressure gradients develop, which result in lateral spreading of freshwater lenses in a form resembling gravity currents. Gravity currents inherently involve three-dimensional dynamics. As a type of organized structure, gravity currents in the upper layer of the ocean may also interact with, and be shaped by, the ambient oceanic environment and atmospheric conditions. Among the important factors are the background stratification, wind stress, wind/wave mixing and spatially coherent organized motions in the near-surface layer of the ocean. Under certain conditions, a resonant interaction between a propagating freshwater lens and internal waves in the underlying pycnocline (e.g., barrier layer) may develop, whereas interaction with wind stress may produce an asymmetry in the freshwater lens and associated mixing. These two types of interactions working in concert may explain the series of sharp frontal interfaces, which have been observed in association with freshwater lenses during TOGA COARE. In this work, we have conducted a series of numerical experiments using computational fluid dynamics tools. These numerical simulations were designed to elucidate the relationship between vertical mixing and horizontal advection of salinity under various environmental conditions and potential impact on the Aquarius and SMOS satellite image formation. Available near-surface data from field experiments served as a guidance for numerical simulations. The results of this study indicate that 3D dynamics of freshwater lenses are essential within a certain range of wind/wave conditions and the freshwater influx in the surface layer of the ocean.

  15. Seismological evidence and dynamic model of reverse rupture propagation during the 2010 M7.2 El Mayor Cucapah earthquake

    NASA Astrophysics Data System (ADS)

    Meng, L.; Ampuero, J. P.; Page, M. T.; Hudnut, K. W.

    2011-12-01

    The 2010 El Mayor-Cucapah earthquake has produced some unique observations that exemplify the complexity of rupture dynamics. An eyewitness located near the fault when the rupture broke reported signatures of reverse surface rupture (rupture towards the South at a location North from the hypocenter). We report here on seismological evidence of this phenomenon and present dynamic rupture simulations that illustrate a possible mechanism. Reverse rupture propagation is not admissible in traditional source inversions, because of restrictive assumptions about the rupture kinematics adopted to reduce the non-uniqueness of the inverse problem. In contrast, source imaging by back-projection of dense array data is free from such assumptions. Recently, we have enhanced the array back-projection technique to achieve higher resolution on rupture evolution. We have also extended this approach to recordings at regional distance, despite the complexity of the regional Pn waveforms. We imaged the source of the El Mayor-Cucapah earthquake by back-projecting Pn waves recorded by the SIEDCAR array in New Mexico. Our analysis reveals a segment with reverse rupture propagation consistent with the eyewitness reports. Our simulations of dynamic earthquake rupture show that reverse rupture propagation can be caused by delayed rupture of a strong fault region with a negative along-strike gradient of strength excess. In this scenario the rupture front tunnels through (or surrounds) the strong area, then starts breaking the opposite, weaker end of the strong patch, inducing a reverse rupture front.

  16. Toward a 3D dynamic model of a faulty duplex ball bearing

    NASA Astrophysics Data System (ADS)

    Kogan, Gideon; Klein, Renata; Kushnirsky, Alex; Bortman, Jacob

    2015-03-01

    Bearings are vital components for safe and proper operation of machinery. Increasing efficiency of bearing diagnostics usually requires training of health and usage monitoring systems via expensive and time-consuming ground calibration tests. The main goal of this research, therefore, is to improve bearing dynamics modeling tools in order to reduce the time and budget needed to implement the health and usage monitoring approach. The proposed three-dimensional ball bearing dynamic model is based on the classic dynamic and kinematic equations. Interactions between the bodies are simulated using non-linear springs combined with dampers described by Hertz-type contact relation. The force friction is simulated using the hyperbolic-tangent function. The model allows simulation of a wide range of mechanical faults. It is validated by comparison to known bearing behavior and to experimental results. The model results are verified by demonstrating numerical convergence. The model results for the two cases of single and duplex angular ball bearings with axial deformation in the outer ring are presented. The qualitative investigation provides insight into bearing dynamics, the sensitivity study generalizes the qualitative findings for similar cases, and the comparison to the test results validates model reliability. The article demonstrates the variety of the cases that the 3D bearing model can simulate and the findings to which it may lead. The research allowed the identification of new patterns generated by single and duplex bearings with axially deformed outer race. It also enlightened the difference between single and duplex bearing manifestation. In the current research the dynamic model enabled better understanding of the physical behavior of the faulted bearings. Therefore, it is expected that the modeling approach has the potential to simplify and improve the development process of diagnostic algorithms. • A deformed outer race of a single axially loaded bearing is

  17. QUANTIFYING UNCERTAINTIES IN GROUND MOTION SIMULATIONS FOR SCENARIO EARTHQUAKES ON THE HAYWARD-RODGERS CREEK FAULT SYSTEM USING THE USGS 3D VELOCITY MODEL AND REALISTIC PSEUDODYNAMIC RUPTURE MODELS

    SciTech Connect

    Rodgers, A; Xie, X

    2008-01-09

    This project seeks to compute ground motions for large (M>6.5) scenario earthquakes on the Hayward Fault using realistic pseudodynamic ruptures, the USGS three-dimensional (3D) velocity model and anelastic finite difference simulations on parallel computers. We will attempt to bound ground motions by performing simulations with suites of stochastic rupture models for a given scenario on a given fault segment. The outcome of this effort will provide the average, spread and range of ground motions that can be expected from likely large earthquake scenarios. The resulting ground motions will be based on first-principles calculations and include the effects of slip heterogeneity, fault geometry and directivity, however, they will be band-limited to relatively low-frequency (< 1 Hz).

  18. Additively Manufactured Device for Dynamic Culture of Large Arrays of 3D Tissue Engineered Constructs.

    PubMed

    Costa, Pedro F; Hutmacher, Dietmar W; Theodoropoulos, Christina; Gomes, Manuela E; Reis, Rui L; Vaquette, Cédryck

    2015-04-22

    The ability to test large arrays of cell and biomaterial combinations in 3D environments is still rather limited in the context of tissue engineering and regenerative medicine. This limitation can be generally addressed by employing highly automated and reproducible methodologies. This study reports on the development of a highly versatile and upscalable method based on additive manufacturing for the fabrication of arrays of scaffolds, which are enclosed into individualized perfusion chambers. Devices containing eight scaffolds and their corresponding bioreactor chambers are simultaneously fabricated utilizing a dual extrusion additive manufacturing system. To demonstrate the versatility of the concept, the scaffolds, while enclosed into the device, are subsequently surface-coated with a biomimetic calcium phosphate layer by perfusion with simulated body fluid solution. 96 scaffolds are simultaneously seeded and cultured with human osteoblasts under highly controlled bidirectional perfusion dynamic conditions over 4 weeks. Both coated and noncoated resulting scaffolds show homogeneous cell distribution and high cell viability throughout the 4 weeks culture period and CaP-coated scaffolds result in a significantly increased cell number. The methodology developed in this work exemplifies the applicability of additive manufacturing as a tool for further automation of studies in the field of tissue engineering and regenerative medicine. PMID:25721231

  19. Integration of Libration Point Orbit Dynamics into a Universal 3-D Autonomous Formation Flying Algorithm

    NASA Technical Reports Server (NTRS)

    Folta, David; Bauer, Frank H. (Technical Monitor)

    2001-01-01

    The autonomous formation flying control algorithm developed by the Goddard Space Flight Center (GSFC) for the New Millennium Program (NMP) Earth Observing-1 (EO-1) mission is investigated for applicability to libration point orbit formations. In the EO-1 formation-flying algorithm, control is accomplished via linearization about a reference transfer orbit with a state transition matrix (STM) computed from state inputs. The effect of libration point orbit dynamics on this algorithm architecture is explored via computation of STMs using the flight proven code, a monodromy matrix developed from a N-body model of a libration orbit, and a standard STM developed from the gravitational and coriolis effects as measured at the libration point. A comparison of formation flying Delta-Vs calculated from these methods is made to a standard linear quadratic regulator (LQR) method. The universal 3-D approach is optimal in the sense that it can be accommodated as an open-loop or closed-loop control using only state information.

  20. Foot roll-over evaluation based on 3D dynamic foot scan.

    PubMed

    Samson, William; Van Hamme, Angèle; Sanchez, Stéphane; Chèze, Laurence; Van Sint Jan, Serge; Feipel, Véronique

    2014-01-01

    Foot roll-over is commonly analyzed to evaluate gait pathologies. The current study utilized a dynamic foot scanner (DFS) to analyze foot roll-over. The right feet of ten healthy subjects were assessed during gait trials with a DFS system integrated into a walkway. A foot sole picture was computed by vertically projecting points from the 3D foot shape which were lower than a threshold height of 15 mm. A 'height' value of these projected points was determined; corresponding to the initial vertical coordinates prior to projection. Similar to pedobarographic analysis, the foot sole picture was segmented into anatomical regions of interest (ROIs) to process mean height (average of height data by ROI) and projected surface (area of the projected foot sole by ROI). Results showed that these variables evolved differently to plantar pressure data previously reported in the literature, mainly due to the specificity of each physical quantity (millimeters vs Pascals). Compared to plantar pressure data arising from surface contact by the foot, the current method takes into account the whole plantar aspect of the foot, including the parts that do not make contact with the support surface. The current approach using height data could contribute to a better understanding of specific aspects of foot motion during walking, such as plantar arch height and the windlass mechanism. Results of this study show the underlying method is reliable. Further investigation is required to validate the DFS measurements within a clinical context, prior to implementation into clinical practice. PMID:24119779

  1. Monitoring an eruption fissure in 3D: video recording, particle image velocimetry and dynamics

    NASA Astrophysics Data System (ADS)

    Witt, Tanja; Walter, Thomas R.

    2015-04-01

    The processes during an eruption are very complex. To get a better understanding several parameters are measured. One of the measured parameters is the velocity of particles and patterns, as ash and emitted magma, and of the volcano itself. The resulting velocity field provides insights into the dynamics of a vent. Here we test our algorithm for 3 dimensional velocity fields on videos of the second fissure eruption of Bárdarbunga 2014. There we acquired videos from lava fountains of the main fissure with 2 high speed cameras with small angles between the cameras. Additionally we test the algorithm on videos from the geyser Strokkur, where we had 3 cameras and larger angles between the cameras. The velocity is calculated by a correlation in the Fourier space of contiguous images. Considering that we only have the velocity field of the surface smaller angles result in a better resolution of the existing velocity field in the near field. For general movements also larger angles can be useful, e.g. to get the direction, height and velocity of eruption clouds. In summary, it can be stated that 3D velocimetry can be used for several application and with different setup due to the application.

  2. Dynamic implicit 3D adaptive mesh refinement for non-equilibrium radiation diffusion

    SciTech Connect

    B. Philip; Z. Wang; M.A. Berrill; M. Birke; M. Pernice

    2014-04-01

    The time dependent non-equilibrium radiation diffusion equations are important for solving the transport of energy through radiation in optically thick regimes and find applications in several fields including astrophysics and inertial confinement fusion. The associated initial boundary value problems that are encountered often exhibit a wide range of scales in space and time and are extremely challenging to solve. To efficiently and accurately simulate these systems we describe our research on combining techniques that will also find use more broadly for long term time integration of nonlinear multi-physics systems: implicit time integration for efficient long term time integration of stiff multi-physics systems, local control theory based step size control to minimize the required global number of time steps while controlling accuracy, dynamic 3D adaptive mesh refinement (AMR) to minimize memory and computational costs, Jacobian Free Newton–Krylov methods on AMR grids for efficient nonlinear solution, and optimal multilevel preconditioner components that provide level independent solver convergence.

  3. A 3D Parallel Beam Dynamics Code for Modeling High Brightness Beams in Photoinjectors

    SciTech Connect

    Qiang, Ji; Lidia, S.; Ryne, R.D.; Limborg, C.; /SLAC

    2006-02-13

    In this paper we report on IMPACT-T, a 3D beam dynamics code for modeling high brightness beams in photoinjectors and rf linacs. IMPACT-T is one of the few codes used in the photoinjector community that has a parallel implementation, making it very useful for high statistics simulations of beam halos and beam diagnostics. It has a comprehensive set of beamline elements, and furthermore allows arbitrary overlap of their fields. It is unique in its use of space-charge solvers based on an integrated Green function to efficiently and accurately treat beams with large aspect ratio, and a shifted Green function to efficiently treat image charge effects of a cathode. It is also unique in its inclusion of energy binning in the space-charge calculation to model beams with large energy spread. Together, all these features make IMPACT-T a powerful and versatile tool for modeling beams in photoinjectors and other systems. In this paper we describe the code features and present results of IMPACT-T simulations of the LCLS photoinjectors. We also include a comparison of IMPACT-T and PARMELA results.

  4. A 3d Parallel Beam Dynamics Code for Modeling High BrightnessBeams in Photoinjectors

    SciTech Connect

    Qiang, J.; Lidia, S.; Ryne, R.; Limborg, C.

    2005-05-16

    In this paper we report on IMPACT-T, a 3D beam dynamics code for modeling high brightness beams in photoinjectors and rf linacs. IMPACT-T is one of the few codes used in the photoinjector community that has a parallel implementation, making it very useful for high statistics simulations of beam halos and beam diagnostics. It has a comprehensive set of beamline elements, and furthermore allows arbitrary overlap of their fields. It is unique in its use of space-charge solvers based on an integrated Green function to efficiently and accurately treat beams with large aspect ratio, and a shifted Green function to efficiently treat image charge effects of a cathode. It is also unique in its inclusion of energy binning in the space-charge calculation to model beams with large energy spread. Together, all these features make IMPACT-T a powerful and versatile tool for modeling beams in photoinjectors and other systems. In this paper we describe the code features and present results of IMPACT-T simulations of the LCLS photoinjectors. We also include a comparison of IMPACT-T and PARMELA results.

  5. Dynamic coupling between fluid flow and vein growth in fractures: a 3D numerical model

    NASA Astrophysics Data System (ADS)

    Schwarz, J.-O.; Enzmann, F.

    2012-04-01

    Fluid flow is one of the main mass transport mechanisms in the Earth's crust and abundant mineral vein networks are important indicators for fluid flow and fluid rock interaction. These systems are dynamic and part of the so called RTM processes (reaction-transport-mechanics). Understanding of mineral vein systems requires coupling of these processes. Here we present a conceptional model for dynamic vein growth of syntaxial, posttectonic veins generated by advective fluid flow and show first results of a numerical model for this scenario. Vein generation requires three processes to occur: (i) fracture generation by mechanical stress e.g. hydro-fracturing, (ii) flow of a supersaturated fluid on that fracture and (iii) crystallization of phase(s) on or in the fracture. 3D synthetic fractures are generated with the SynFrac code (Ogilvie, et al. 2006). Subsequently solutions of the Navier-Stokes equation for this fracture are computed by a computational fluid dynamics code called GeoDict (Wiegmann 2007). Transport (advective and diffusive) of chemical species to growth sites in the fracture and vein growth are computed by a self-written MATLAB script. The numerical model discretizes the wall rock and fracture geometry by volumetric pixels (voxels). Based on this representation, the model computes the three basic functions for vein generation: (a) nucleation, (b) fluid flow with transport of chemical species and (c) growth. The following conditions were chosen for these three modules. Nucleation is heterogeneous and occurs instantaneously at the wall rock/fracture interface. Advective and diffusive flow of a supersaturated fluid and related transport of chemical species occurs according to the computed fluid flow field by GeoDict. Concentration of chemical species at the inflow is constant, representing external fluid buffering. Changes/decrease in the concentration of chemical species occurs only due to vein growth. Growth of nuclei is limited either by transport of

  6. A Quantitative Analysis of Aqueous Nanofilm Rupture by Molecular Dynamic Simulation

    SciTech Connect

    Peng, Tiefeng; Nguyen, Anh V.; Peng, Hong; Dang, Liem X.

    2012-01-26

    In this study, we used molecular dynamic (MD) simulations of the rupture process for a water film to define and determine the critical rupture time (CRT). This new approach could be an important method for authentically defining and determining the rupture point of a water film and associated phenomena. We were able to generically predict the CRT and the critical thickness of the water film. Then, we studied the effect of ions on the film rupture process. Our results showed that addition of sodium chloride did not significantly affect on the stability of the water film. Results from MD simulations, when compared with results from experimental measurements, can provide insights into the film rupture process.

  7. Stylolite shape, roughness growth dynamics and related burial history: a 3D analysis.

    NASA Astrophysics Data System (ADS)

    Beaudoin, Nicolas; Koehn, Daniel

    2016-04-01

    Stylolites are dissolution features that develop under applied pressure and during chemical compaction. Stylolites are common in sedimentary basin, altering the chemistry and physical properties of rocks, as well as the small- to large-scale hydrological system. This contribution follows recent finding about the self-affine roughness growth properties leading to a fractal, stitch-like shape of stylolites. 3D surface scanning and X-ray computed microtomography imaging have been carried out onto numerous stylolites from the southern Permian Zechstein basin (Germany) and from the Umbria Marches fold-and-thrust belts (Italy). In these two environments stylolites have been sorted following a recent advanced classification of stylolite based on the shape and growth dynamics. This classification consists in four classes (rectangular layer type, seismogram pinning type suture/sharp peak type and simple wave-like type) and we aim to characterize the roughness properties for each of these classes. A fractal analysis has been conducted accordingly using Fourier transform and Correlation function signal analysis over roughness surfaces. These fractal analyses have been used to reconstruct the maximum burial depth recorded by each stylolite. The reconstruction of burial depths at the same place but regarding all stylolite classes returns and maximum depth evolution. This dataset is thus used 1- to understand the links between the roughness growth dynamics of stylolites and their final shape and 2- to establish a relationship linking the shape of roughness to the maximum burial depth recorded. We hope results and interpretation reported can push the community to consider stylolite as an efficient tool and reliable way to appraise burial history in sedimentary basins.

  8. Self-healing slip pulses in dynamic rupture models due to velocity-dependent strength

    USGS Publications Warehouse

    Beeler, N.M.; Tullis, T.E.

    1996-01-01

    Seismological observations of short slip duration on faults (short rise time on seismograms) during earthquakes are not consistent with conventional crack models of dynamic rupture and fault slip. In these models, the leading edge of rupture stops only when a strong region is encountered, and slip at an interior point ceases only when waves from the stopped edge of slip propagate back to that point. In contrast, some seismological evidence suggests that the duration of slip is too short for waves to propagate from the nearest edge of the ruptured surface, perhaps even if the distance used is an asperity size instead of the entire rupture dimension. What controls slip duration, if not dimensions of the fault or of asperities? In this study, dynamic earthquake rupture and slip are represented by a propagating shear crack. For all propagating shear cracks, slip velocity is highest near the rupture front, and at a small distance behind the rupture front, the slip velocity decreases. As pointed out by Heaton (1990), if the crack obeys a negative slip-rate-dependent strength relation, the lower slip velocity behind the rupture front will lead to strengthening that further reduces the velocity, and under certain circumstances, healing of slip can occur. The boundary element method of Hamano (1974) is used in a program adapted from Andrews (1985) for numerical simulations of mode II rupture with two different velocity-dependent strength functions. For the first function, after a slip-weakening displacement, the crack follows an exponential velocity-weakening relation. The characteristic velocity V0 of the exponential determines the magnitude of the velocity-dependence at dynamic velocities. The velocity-dependence at high velocity is essentially zero when V0 is small and the resulting slip velocity distribution is similar to slip weakening. If V0 is larger, rupture propagation initially resembles slip-weakening, but spontaneous healing occurs behind the rupture front. The

  9. Compartment modeling anslysis of C-11 flumazenil kinetics in human brain using dynamic 2D and 3D PET

    SciTech Connect

    Choi, Y.; Simpson, N.; Townsend, D.W.

    1994-05-01

    We examined the feasibility of compartment modeling analysis and the numerical accuracy of model parameters of radioligand delivery and binding in the brain using 2D and 3D PET. Two subjects were injected with C-11 flumazenil (FMZ) i.v., and imaged over the brain with a dynamic sequence of 6x20 s, 2x30 s, 4x90 s, 4x180 s, 2x300 s, 2x600 s, and 2x1200 s frames. Different scatter correction methods were applied to the 3D data: No scatter correction (NOC), dual-energy window subtraction (DEW) and convolution-subtraction (CON). The kinetic data for regions listed below were fitted to a 2-compartment, 2-parameter model. Both 2D and 3D results are similar and within the expected range. The 3D %SE was less than 2D despite the smaller dose. The effect of the scatter in 3D parameter estimates appears to be small. These preliminary data indicate temporally sufficient kinetic data can be acquired in 3D mode to perform compartmental analysis of C-11 FMZ. Improved sensitivity in 3D may allow more accurate receptor characterization especially in small structures or in low specific binding areas.

  10. The SCEC-USGS Dynamic Earthquake Rupture Code Verification Exercise - Recent Progress

    NASA Astrophysics Data System (ADS)

    Harris, R.

    2012-12-01

    We summarize recent progress by the SCEC-USGS Dynamic Rupture Code Verification Group, that examines if SCEC and USGS researchers' spontaneous-rupture computer codes agree when computing benchmark scenarios of dynamically propagating earthquake rupture. Our latest benchmarks have involved dynamic rupture propagating on planar vertical strike-slip faults with heterogeneous initial stress conditions and cases of dynamic rupture on branching vertical strike-slip faults. The heterogeneous initial stress cases produced good agreement among the codes and we are confident that this was a successful endeavor. The branching fault cases will be a focus of continued study because those results were not as successful as hoped. We are examining the reasons for this mismatch of the branching fault benchmark results, and have a number of ideas to explore. Our next benchmark exercises will continue with dynamic rupture on branching vertical strike-slip faults, until we obtain good matches among the code results. We will also investigate another fault geometry, the case of a stepover in a vertical strike-slip fault.

  11. A novel time dependent gamma evaluation function for dynamic 2D and 3D dose distributions.

    PubMed

    Podesta, Mark; Persoon, Lucas C G G; Verhaegen, Frank

    2014-10-21

    Modern external beam radiotherapy requires detailed verification and quality assurance so that confidence can be placed on both the delivery of a single treatment fraction and on the consistency of delivery throughout the treatment course. To verify dose distributions, a comparison between prediction and measurement must be made. Comparisons between two dose distributions are commonly performed using a Gamma evaluation which is a calculation of two quantities on a pixel by pixel basis; the dose difference, and the distance to agreement. By providing acceptance criteria (e.g. 3%, 3 mm), the function will find the most appropriate match within its two degrees of freedom. For complex dynamic treatments such as IMRT or VMAT it is important to verify the dose delivery in a time dependent manner and so a gamma evaluation that includes a degree of freedom in the time domain via a third parameter, time to agreement, is presented here. A C++ (mex) based gamma function was created that could be run on either CPU and GPU computing platforms that would allow a degree of freedom in the time domain. Simple test cases were created in both 2D and 3D comprising of simple geometrical shapes with well-defined boundaries varying over time. Changes of varying magnitude in either space or time were introduced and repeated gamma analyses were performed varying the criteria. A clinical VMAT case was also included, artificial air bubbles of varying size were introduced to a patient geometry, along with shifts of varying magnitude in treatment time. For all test cases where errors in distance, dose or time were introduced, the time dependent gamma evaluation could accurately highlight the errors.The time dependent gamma function presented here allows time to be included as a degree of freedom in gamma evaluations. The function allows for 2D and 3D data sets which are varying over time to be compared using appropriate criteria without penalising minor offsets of subsequent radiation fields

  12. Characterizing interstate vibrational coherent dynamics of surface adsorbed catalysts by fourth-order 3D SFG spectroscopy

    NASA Astrophysics Data System (ADS)

    Li, Yingmin; Wang, Jiaxi; Clark, Melissa L.; Kubiak, Clifford P.; Xiong, Wei

    2016-04-01

    We report the first fourth-order 3D SFG spectroscopy of a monolayer of the catalyst Re(diCN-bpy)(CO)3Cl on a gold surface. Besides measuring the vibrational coherences of single vibrational modes, the fourth-order 3D SFG spectrum also measures the dynamics of interstate coherences and vibrational coherences states between two vibrational modes. By comparing the 3D SFG to the corresponding 2D and third-order 3D IR spectroscopy of the same molecules in solution, we found that the interstate coherences exist in both liquid and surface systems, suggesting that the interstate coherence is not disrupted by surface interactions. However, by analyzing the 3D spectral lineshape, we found that the interstate coherences also experience non-negligible homogenous dephasing dynamics that originate from surface interactions. This unique ability of determining interstate vibrational coherence dynamics of the molecular monolayer can help in understanding of how energy flows within surface catalysts and other molecular monolayers.

  13. Dynamics and materials physics of fault rupture and glacial processes

    NASA Astrophysics Data System (ADS)

    Platt, John Daniel

    This thesis focuses on two main topics, the physics governing how faults rapidly weaken during an earthquake and the thermal and mechanical structure of ice stream shear margins. The common theme linking these two projects is the desire to understand how the complicated interactions between stress and temperature control deformation and failure. All of the problems in this thesis are attacked using a combination of analytic and numerical methods, and the interplay between these two approaches provides a powerful way to understand the different physical balances that dominate in different regimes. We also use aspects of materials science to understand how the often complicated rheologies are controlled by underlying physical phenomena such as melting, phase transitions, diffusion, and dislocation motion. With regards to fault mechanics, we begin by showing how co-seismic weakening mechanisms driven by elevated pore fluid pressures lead to micron-scale strain localization during an earthquake. We solve for the localized zone thickness for a range of fault temperatures, test these predictions using numerical simulations, and show how the onset of localization accelerates fault weakening. Next we present the first solutions to account for thermal decomposition reactions during a dynamic rupture, showing that the activation of thermal decomposition may lead to a larger slip duration and total slip. Finally we present a new set of experiments studying flash heating of serpentinite, highlighting the dependence of friction on normal stress and the presence of gouge, and producing the first model to explain the hysteresis commonly observed in flash heating experiments. With regards to ice stream shear margins, we begin by extending the work of Perol and Rice [2011] to study the formation of temperate ice in shear margins, and quantify the total melt that may be generated within the shear margins. We conclude by investigating how the presence of such a channel alters the

  14. The 3-D dynamics of slab break-off and implications for continental collision zones

    NASA Astrophysics Data System (ADS)

    van Hunen, Jeroen; Allen, Mark

    2010-05-01

    Some of the world best studied mountain ranges are a result of continental collision, such as the Himalayas, Zagros mountains, and the Alps. Continental collision forms the last stage of the closure of an oceanic basin, and leads to the slow-down or complete cessation of the subduction process. Previously subducted slab material will experience a period of thermal warming (Gerya et al., 2004) and/or a larger tensile stress, and will eventually weaken, yield and sink into the mantle. This process has potentially important implications for the thermal and stress regime of the overlying convergence zone, and has been held responsible for various phenomena such as late-stage magmatism (Davies and von Blanckenburg, 1995) and surface uplift or depression (van der Meulen et al., 1998, Buiter et al., 2002). Even though the collision process itself is relatively short-lived compared to the preceding oceanic subduction, its remnants are often preserved, and probably provide a valuable window into the plate tectonic process during the Proterozoic and perhaps the Archaean (e.g. Calvert et al., 1995). The three-dimensional nature of this break-off process has previously been discussed with conceptual models. E.g. slab break-off has been suggested to propagate laterally through an advancing tear (Wortel and Spakman, 2000). In this study we present 3D numerical results of the evolution of slab break-off. We focus on the development and evolution of a laterally migrating slab tear, and present results on the sensitivity of this process to the geometry of the closing oceanic basin, the tensile stresses in and the rheological properties of the slab, and the thermal state of the surrounding mantle. By comparing our numerical results to previously published analogue results (Regard et al., 2004) and various tomographic, structural, and magmatic observations of well-studied subduction collision systems, we are able to extract valuable insights in to the dynamics and strength of

  15. 3D Visualization of "Frozen" Dynamic Magma Chambers in the Duluth Complex, Northeastern Minnesota

    NASA Astrophysics Data System (ADS)

    Peterson, D. M.; Hauck, S. A.

    2005-12-01

    The Mesoproterozoic Duluth Complex and associated intrusions of the Midcontinent Rift in northeastern Minnesota constitute one of the largest, semi-continuous, mafic intrusive complexes in the world, second only to the Bushveld Complex of South Africa. These rocks cover an arcuate area of over 5,000 square kilometers and give rise to two strong gravity anomalies (+50 & +70 mgal) that imply intrusive roots to more than 13 km depth. The geometry of three large mafic intrusions within the Duluth Complex have been modeled by the integration of field mapping and drill hole data with maps of gravity and magnetic anomalies. The igneous bodies include the South Kawishiwi, Partridge River, and Bald Eagle intrusions that collectively outcrop over an area of > 800 square kilometers. The South Kawishiwi and Partridge River intrusions host several billion tons of low-grade Cu-Ni-PGE mineralization near their base, while the geophysical expressions of the Bald Eagle intrusion have the same shape and dimensions as the "bulls eye" pattern of low velocity seismic reflection anomalies along the East Pacific Rise. These anomalies are interpreted to define regions of melt concentrations, i.e., active magma chambers. This suggests that the funnel-shaped Bald Eagle intrusion could be an example of a "frozen" dynamic magma chamber. In support of this analogy we note that the magmatic systems of intracontinental rifts, mid-ocean ridges, extensional regimes in back-arc environments, and ophiolites have a common characteristic: the emplacement of magma in extensional environments, and the common products in all four are varieties of layered intrusions, dikes and sills, and overlying volcanic rocks. 3D visualization of these intrusions is integral to the understanding of the Duluth Complex magmatic system and associated mineralization, and can be used as a proxy for study of similar systems, such as the Antarctic Ferrar dolerites, worldwide.

  16. Slip reactivation model for the 2011 Mw9 Tohoku earthquake: Dynamic rupture, sea floor displacements and tsunami simulations.

    NASA Astrophysics Data System (ADS)

    Galvez, P.; Dalguer, L. A.; Rahnema, K.; Bader, M.

    2014-12-01

    The 2011 Mw9 Tohoku earthquake has been recorded with a vast GPS and seismic network given unprecedented chance to seismologists to unveil complex rupture processes in a mega-thrust event. In fact more than one thousand near field strong-motion stations across Japan (K-Net and Kik-Net) revealed complex ground motion patterns attributed to the source effects, allowing to capture detailed information of the rupture process. The seismic stations surrounding the Miyagi regions (MYGH013) show two clear distinct waveforms separated by 40 seconds. This observation is consistent with the kinematic source model obtained from the inversion of strong motion data performed by Lee's et al (2011). In this model two rupture fronts separated by 40 seconds emanate close to the hypocenter and propagate towards the trench. This feature is clearly observed by stacking the slip-rate snapshots on fault points aligned in the EW direction passing through the hypocenter (Gabriel et al, 2012), suggesting slip reactivation during the main event. A repeating slip on large earthquakes may occur due to frictional melting and thermal fluid pressurization effects. Kanamori & Heaton (2002) argued that during faulting of large earthquakes the temperature rises high enough creating melting and further reduction of friction coefficient. We created a 3D dynamic rupture model to reproduce this slip reactivation pattern using SPECFEM3D (Galvez et al, 2014) based on a slip-weakening friction with sudden two sequential stress drops . Our model starts like a M7-8 earthquake breaking dimly the trench, then after 40 seconds a second rupture emerges close to the trench producing additional slip capable to fully break the trench and transforming the earthquake into a megathrust event. The resulting sea floor displacements are in agreement with 1Hz GPS displacements (GEONET). The seismograms agree roughly with seismic records along the coast of Japan.The simulated sea floor displacement reaches 8-10 meters of

  17. How the venetian blind percept emerges from the laminar cortical dynamics of 3D vision.

    PubMed

    Cao, Yongqiang; Grossberg, Stephen

    2014-01-01

    The 3D LAMINART model of 3D vision and figure-ground perception is used to explain and simulate a key example of the Venetian blind effect and to show how it is related to other well-known perceptual phenomena such as Panum's limiting case. The model proposes how lateral geniculate nucleus (LGN) and hierarchically organized laminar circuits in cortical areas V1, V2, and V4 interact to control processes of 3D boundary formation and surface filling-in that simulate many properties of 3D vision percepts, notably consciously seen surface percepts, which are predicted to arise when filled-in surface representations are integrated into surface-shroud resonances between visual and parietal cortex. Interactions between layers 4, 3B, and 2/3 in V1 and V2 carry out stereopsis and 3D boundary formation. Both binocular and monocular information combine to form 3D boundary and surface representations. Surface contour surface-to-boundary feedback from V2 thin stripes to V2 pale stripes combines computationally complementary boundary and surface formation properties, leading to a single consistent percept, while also eliminating redundant 3D boundaries, and triggering figure-ground perception. False binocular boundary matches are eliminated by Gestalt grouping properties during boundary formation. In particular, a disparity filter, which helps to solve the Correspondence Problem by eliminating false matches, is predicted to be realized as part of the boundary grouping process in layer 2/3 of cortical area V2. The model has been used to simulate the consciously seen 3D surface percepts in 18 psychophysical experiments. These percepts include the Venetian blind effect, Panum's limiting case, contrast variations of dichoptic masking and the correspondence problem, the effect of interocular contrast differences on stereoacuity, stereopsis with polarity-reversed stereograms, da Vinci stereopsis, and perceptual closure. These model mechanisms have also simulated properties of 3D neon

  18. How the venetian blind percept emerges from the laminar cortical dynamics of 3D vision

    PubMed Central

    Cao, Yongqiang; Grossberg, Stephen

    2014-01-01

    The 3D LAMINART model of 3D vision and figure-ground perception is used to explain and simulate a key example of the Venetian blind effect and to show how it is related to other well-known perceptual phenomena such as Panum's limiting case. The model proposes how lateral geniculate nucleus (LGN) and hierarchically organized laminar circuits in cortical areas V1, V2, and V4 interact to control processes of 3D boundary formation and surface filling-in that simulate many properties of 3D vision percepts, notably consciously seen surface percepts, which are predicted to arise when filled-in surface representations are integrated into surface-shroud resonances between visual and parietal cortex. Interactions between layers 4, 3B, and 2/3 in V1 and V2 carry out stereopsis and 3D boundary formation. Both binocular and monocular information combine to form 3D boundary and surface representations. Surface contour surface-to-boundary feedback from V2 thin stripes to V2 pale stripes combines computationally complementary boundary and surface formation properties, leading to a single consistent percept, while also eliminating redundant 3D boundaries, and triggering figure-ground perception. False binocular boundary matches are eliminated by Gestalt grouping properties during boundary formation. In particular, a disparity filter, which helps to solve the Correspondence Problem by eliminating false matches, is predicted to be realized as part of the boundary grouping process in layer 2/3 of cortical area V2. The model has been used to simulate the consciously seen 3D surface percepts in 18 psychophysical experiments. These percepts include the Venetian blind effect, Panum's limiting case, contrast variations of dichoptic masking and the correspondence problem, the effect of interocular contrast differences on stereoacuity, stereopsis with polarity-reversed stereograms, da Vinci stereopsis, and perceptual closure. These model mechanisms have also simulated properties of 3D neon

  19. On the Rupture Dynamics of Shallow Dip-Slip Faulting in a Stratified Medium

    NASA Astrophysics Data System (ADS)

    Uenishi, Koji

    2015-04-01

    One significant feature of a shallow dip-slip earthquake is the broken symmetry of seismic motion in the proximity of the rupturing fault plane. In general, the strong motion is much larger on the hanging wall than on the footwall, but the mechanics behind this asymmetry has not been wholly understood yet. Therefore, in this contribution, based on finite difference calculations and dynamic photoelasticity, we try to deepen our understanding on the rupture dynamics of a shallow dip-slip fault plane numerically as well as experimentally. In our two-dimensional crack-like rupture models, a flat vertical or inclined fault plane is prepared in a monolithic (first model) or stratified (second model) linear elastic medium. In the basic first model, as predicted numerically by Uenishi and Madariaga (Eos 2005), the primary fault rupture approaching the horizontal free surface may induce four Rayleigh-type waves, two Rayleigh waves propagating along the free surface to the far field and the other two interface waves travelling back downwards along the ruptured fault plane. In the case of the inclined fault plane, the interaction of the interface and Rayleigh waves may generate a strong shear wave (corner wave) and cause stronger disturbances in the hanging wall. The corner wave may exist only when the fault plane is asymmetrically inclined. On the contrary, in the second model, symmetry of seismic motion may be broken even in geometrically symmetric cases if the secondary rupture is allowed at an interface between geological layers. For instance, if primary vertical fault rupture propagates from depth and interferes with a horizontal interface obeying a tensile fracture criterion, the interface segments on which the primary fault rupture produces dynamic compression (in the relatively rising hanging wall) may remain unbroken and only some interface segments in the subsiding footwall may be fractured in tension. That is, in the hanging wall, the dynamic disturbances in the

  20. 3D-seismic observations of Late Pleistocene glacial dynamics on the central West Greenland margin

    NASA Astrophysics Data System (ADS)

    Hofmann, Julia; Knutz, Paul; Cofaigh, Colm Ó.

    2016-04-01

    Fast-flowing ice streams and outlet glaciers exert a major control on glacial discharge from contemporary and palaeo ice sheets. Improving our understanding of the extent and dynamic behaviour of these palaeo-ice streams is therefore crucial for predictions of the response of ice sheets to present and future climate warming and the associated implications for global sea level. This poster presents results from two 3D-seismic surveys located on the shelf adjoining the Disko Bay trough-mouth fan (TMF), one of the largest glacial outlet systems in Greenland. Located at the seaward terminus of the c. 370 km long cross-shelf Disko Trough, the Disko Bay TMF was generated by highly efficient subglacial sediment delivery onto the continental slopes during repeated ice-stream advances. A variety of submarine glacial landform assemblages are recognised on the seabed reflecting past ice-stream activity presumably related to glacial-interglacial cycles. The 3D-seismic volumes cover the shallow banks located north and south of the Disko Trough. The focus of this study is the seabed and the uppermost stratigraphic interval associated with the Late Stage of TMF development, presumably covering the late Pleistocene (Hofmann et al., submitted). Seabed morphologies include multiple sets of ridges up to 20 m high that extend in NW-SE direction for c. 30 km, and cross-cutting curvilinear furrows with maximum lengths of c. 9 km and average depths of c. 4.5 m. Back-stepping, arcuate scarps facing NW define the shelf break on the northern survey, comprising average widths of c. 4.5 km and incision depths of c. 27.5 m. The large transverse ridge features on the southern survey are likely ice-marginal and are interpreted as terminal moraine ridges recording the existence of a shelf-edge terminating, grounded Late Weichselian ice sheet. The furrows, most prominent on the outer shelf adjoining the shallow banks and partly incising the moraine ridges, are interpreted as iceberg ploughmarks

  1. 3D time-lapse analysis of Rab11/FIP5 complex: spatiotemporal dynamics during apical lumen formation.

    PubMed

    Mangan, Anthony; Prekeris, Rytis

    2015-01-01

    Fluorescent imaging of fixed cells grown in two-dimensional (2D) cultures is one of the most widely used techniques for observing protein localization and distribution within cells. Although this technique can also be applied to polarized epithelial cells that form three-dimensional (3D) cysts when grown in a Matrigel matrix suspension, there are still significant limitations in imaging cells fixed at a particular point in time. Here, we describe the use of 3D time-lapse imaging of live cells to observe the dynamics of apical membrane initiation site (AMIS) formation and lumen expansion in polarized epithelial cells. PMID:25800842

  2. Nonuniformity of the constitutive law parameters for shear rupture and quasistatic nucleation to dynamic rupture: a physical model of earthquake generation processes.

    PubMed Central

    Ohnaka, M

    1996-01-01

    Based on the recent high-resolution laboratory experiments on propagating shear rupture, the constitutive law that governs shear rupture processes is discussed in view of the physical principles and constraints, and a specific constitutive law is proposed for shear rupture. It is demonstrated that nonuniform distributions of the constitutive law parameters on the fault are necessary for creating the nucleation process, which consists of two phases: (i) a stable, quasistatic phase, and (ii) the subsequent accelerating phase. Physical models of the breakdown zone and the nucleation zone are presented for shear rupture in the brittle regime. The constitutive law for shear rupture explicitly includes a scaling parameter Dc that enables one to give a common interpretation to both small scale rupture in the laboratory and large scale rupture as earthquake source in the Earth. Both the breakdown zone size Xc and the nucleation zone size L are prescribed and scaled by Dc, which in turn is prescribed by a characteristic length lambda c representing geometrical irregularities of the fault. The models presented here make it possible to understand the earthquake generation process from nucleation to unstable, dynamic rupture propagation in terms of physics. Since the nucleation process itself is an immediate earthquake precursor, deep understanding of the nucleation process in terms of physics is crucial for the short-term (or immediate) earthquake prediction. PMID:11607667

  3. Spontaneous Rupture of Pyometra Causing Peritonitis in Elderly Female Diagnosed on Dynamic Transvaginal Ultrasound.

    PubMed

    Malvadkar, Sharad M; Malvadkar, Madhuri S; Domkundwar, Shilpa V; Mohd, Shariq

    2016-01-01

    Pyometra is collection of pus within the uterine cavity and is usually associated with underlying gynaecological malignancy or other benign causes. Spontaneous rupture of pyometra is a rare complication. We report a case of a 65-year-old female who presented with acute abdomen and was diagnosed with a ruptured uterus secondary to pyometra and consequent peritonitis on dynamic transvaginal sonography (TVS) which was later confirmed on contrast enhanced computed tomography (CECT). An emergency laparotomy was performed and about 800 cc of pus was drained from the peritoneal cavity. A rent was found in the anterior uterine wall and hence hysterectomy was performed. Histopathology revealed mixed inflammatory cell infiltrate with no evidence of malignancy. There are only 31 cases of ruptured pyometra reported till date, most of which were definitively diagnosed only on laparotomy. In only two of these cases the preoperative diagnosis was made on CECT. We report this case, as the correct and definitive diagnosis was made preoperatively on dynamic TVS. To our knowledge, this is the first case report revealing spontaneous ruptured pyometra being diagnosed preoperatively on dynamic TVS. This report is aimed at giving emphasis on the use of simple dynamic TVS for accurate diagnosis of rare spontaneous ruptured pyometra causing peritonitis. PMID:26989549

  4. Spontaneous Rupture of Pyometra Causing Peritonitis in Elderly Female Diagnosed on Dynamic Transvaginal Ultrasound

    PubMed Central

    Malvadkar, Sharad M.; Malvadkar, Madhuri S.; Domkundwar, Shilpa V.; Mohd, Shariq

    2016-01-01

    Pyometra is collection of pus within the uterine cavity and is usually associated with underlying gynaecological malignancy or other benign causes. Spontaneous rupture of pyometra is a rare complication. We report a case of a 65-year-old female who presented with acute abdomen and was diagnosed with a ruptured uterus secondary to pyometra and consequent peritonitis on dynamic transvaginal sonography (TVS) which was later confirmed on contrast enhanced computed tomography (CECT). An emergency laparotomy was performed and about 800 cc of pus was drained from the peritoneal cavity. A rent was found in the anterior uterine wall and hence hysterectomy was performed. Histopathology revealed mixed inflammatory cell infiltrate with no evidence of malignancy. There are only 31 cases of ruptured pyometra reported till date, most of which were definitively diagnosed only on laparotomy. In only two of these cases the preoperative diagnosis was made on CECT. We report this case, as the correct and definitive diagnosis was made preoperatively on dynamic TVS. To our knowledge, this is the first case report revealing spontaneous ruptured pyometra being diagnosed preoperatively on dynamic TVS. This report is aimed at giving emphasis on the use of simple dynamic TVS for accurate diagnosis of rare spontaneous ruptured pyometra causing peritonitis. PMID:26989549

  5. Graph-Based Compression of Dynamic 3D Point Cloud Sequences.

    PubMed

    Thanou, Dorina; Chou, Philip A; Frossard, Pascal

    2016-04-01

    This paper addresses the problem of compression of 3D point cloud sequences that are characterized by moving 3D positions and color attributes. As temporally successive point cloud frames share some similarities, motion estimation is key to effective compression of these sequences. It, however, remains a challenging problem as the point cloud frames have varying numbers of points without explicit correspondence information. We represent the time-varying geometry of these sequences with a set of graphs, and consider 3D positions and color attributes of the point clouds as signals on the vertices of the graphs. We then cast motion estimation as a feature-matching problem between successive graphs. The motion is estimated on a sparse set of representative vertices using new spectral graph wavelet descriptors. A dense motion field is eventually interpolated by solving a graph-based regularization problem. The estimated motion is finally used for removing the temporal redundancy in the predictive coding of the 3D positions and the color characteristics of the point cloud sequences. Experimental results demonstrate that our method is able to accurately estimate the motion between consecutive frames. Moreover, motion estimation is shown to bring a significant improvement in terms of the overall compression performance of the sequence. To the best of our knowledge, this is the first paper that exploits both the spatial correlation inside each frame (through the graph) and the temporal correlation between the frames (through the motion estimation) to compress the color and the geometry of 3D point cloud sequences in an efficient way. PMID:26891486

  6. Earthquake recurrence and rupture dynamics of Himalayan Frontal Thrust, India.

    PubMed

    Kumar, S; Wesnousky, S G; Rockwell, T K; Ragona, D; Thakur, V C; Seitz, G G

    2001-12-14

    The Black Mango fault is a structural discontinuity that transforms motion between two segments of the active Himalayan Frontal Thrust (HFT) in northwestern India. The Black Mango fault displays evidence of two large surface rupture earthquakes during the past 650 years, subsequent to 1294 A.D. and 1423 A.D., and possibly another rupture at about 260 A.D. Displacement during the last two earthquakes was at minimum 4.6 meters and 2.4 to 4.0 meters, respectively, and possibly larger for the 260 A.D. event. Abandoned terraces of the adjacent Markanda River record uplift due to slip on the underlying HFT of 4.8 +/- 0.9 millimeters per year or greater since the mid-Holocene. The uplift rate is equivalent to rates of fault slip and crustal shortening of 9.6(-3.5)(+7.0) millimeters per year and 8.4(-3.6)(+7.3) millimeters per year, respectively, when it is assumed that the HFT dips 30 degrees +/- 10 degrees. PMID:11729266

  7. Earthquake Recurrence and Rupture Dynamics of Himalayan Frontal Thrust, India

    NASA Astrophysics Data System (ADS)

    Kumar, Senthil; Wesnousky, Steven G.; Rockwell, Thomas K.; Ragona, Daniel; Thakur, Vikram C.; Seitz, Gordon G.

    2001-12-01

    The Black Mango fault is a structural discontinuity that transforms motion between two segments of the active Himalayan Frontal Thrust (HFT) in northwestern India. The Black Mango fault displays evidence of two large surface rupture earthquakes during the past 650 years, subsequent to 1294 A.D. and 1423 A.D., and possibly another rupture at about 260 A.D. Displacement during the last two earthquakes was at minimum 4.6 meters and 2.4 to 4.0 meters, respectively, and possibly larger for the 260 A.D. event. Abandoned terraces of the adjacent Markanda River record uplift due to slip on the underlying HFT of 4.8 +/- 0.9 millimeters per year or greater since the mid-Holocene. The uplift rate is equivalent to rates of fault slip and crustal shortening of 9.6-3.5+7.0 millimeters per year and 8.4-3.6+7.3 millimeters per year, respectively, when it is assumed that the HFT dips 30° +/- 10°.

  8. Large scale dynamic rupture scenario of the 2004 Sumatra-Andaman megathrust earthquake

    NASA Astrophysics Data System (ADS)

    Ulrich, Thomas; Madden, Elizabeth H.; Wollherr, Stephanie; Gabriel, Alice A.

    2016-04-01

    The Great Sumatra-Andaman earthquake of 26 December 2004 is one of the strongest and most devastating earthquakes in recent history. Most of the damage and the ~230,000 fatalities were caused by the tsunami generated by the Mw 9.1-9.3 event. Various finite-source models of the earthquake have been proposed, but poor near-field observational coverage has led to distinct differences in source characterization. Even the fault dip angle and depth extent are subject to debate. We present a physically realistic dynamic rupture scenario of the earthquake using state-of-the-art numerical methods and seismotectonic data. Due to the lack of near-field observations, our setup is constrained by the overall characteristics of the rupture, including the magnitude, propagation speed, and extent along strike. In addition, we incorporate the detailed geometry of the subducting fault using Slab1.0 to the south and aftershock locations to the north, combined with high-resolution topography and bathymetry data.The possibility of inhomogeneous background stress, resulting from the curved shape of the slab along strike and the large fault dimensions, is discussed. The possible activation of thrust faults splaying off the megathrust in the vicinity of the hypocenter is also investigated. Dynamic simulation of this 1300 to 1500 km rupture is a computational and geophysical challenge. In addition to capturing the large-scale rupture, the simulation must resolve the process zone at the rupture tip, whose characteristic length is comparable to smaller earthquakes and which shrinks with propagation distance. Thus, the fault must be finely discretised. Moreover, previously published inversions agree on a rupture duration of ~8 to 10 minutes, suggesting an overall slow rupture speed. Hence, both long temporal scales and large spatial dimensions must be captured. We use SeisSol, a software package based on an ADER-DG scheme solving the spontaneous dynamic earthquake rupture problem with high

  9. User's manual for PELE3D: a computer code for three-dimensional incompressible fluid dynamics

    SciTech Connect

    McMaster, W H

    1982-05-07

    The PELE3D code is a three-dimensional semi-implicit Eulerian hydrodynamics computer program for the solution of incompressible fluid flow coupled to a structure. The fluid and coupling algorithms have been adapted from the previously developed two-dimensional code PELE-IC. The PELE3D code is written in both plane and cylindrical coordinates. The coupling algorithm is general enough to handle a variety of structural shapes. The free surface algorithm is able to accommodate a top surface and several independent bubbles. The code is in a developmental status since all the intended options have not been fully implemented and tested. Development of this code ended in 1980 upon termination of the contract with the Nuclear Regulatory Commission.

  10. Versatile, Immersive, Creative and Dynamic Virtual 3-D Healthcare Learning Environments: A Review of the Literature

    PubMed Central

    2008-01-01

    The author provides a critical overview of three-dimensional (3-D) virtual worlds and “serious gaming” that are currently being developed and used in healthcare professional education and medicine. The relevance of this e-learning innovation for teaching students and professionals is debatable and variables influencing adoption, such as increased knowledge, self-directed learning, and peer collaboration, by academics, healthcare professionals, and business executives are examined while looking at various Web 2.0/3.0 applications. There is a need for more empirical research in order to unearth the pedagogical outcomes and advantages associated with this e-learning technology. A brief description of Roger’s Diffusion of Innovations Theory and Siemens’ Connectivism Theory for today’s learners is presented as potential underlying pedagogical tenets to support the use of virtual 3-D learning environments in higher education and healthcare. PMID:18762473

  11. Versatile, immersive, creative and dynamic virtual 3-D healthcare learning environments: a review of the literature.

    PubMed

    Hansen, Margaret M

    2008-01-01

    The author provides a critical overview of three-dimensional (3-D) virtual worlds and "serious gaming" that are currently being developed and used in healthcare professional education and medicine. The relevance of this e-learning innovation for teaching students and professionals is debatable and variables influencing adoption, such as increased knowledge, self-directed learning, and peer collaboration, by academics, healthcare professionals, and business executives are examined while looking at various Web 2.0/3.0 applications. There is a need for more empirical research in order to unearth the pedagogical outcomes and advantages associated with this e-learning technology. A brief description of Roger's Diffusion of Innovations Theory and Siemens' Connectivism Theory for today's learners is presented as potential underlying pedagogical tenets to support the use of virtual 3-D learning environments in higher education and healthcare. PMID:18762473

  12. Implications of Style-of-Faulting and Loading Characteristics on the Dynamic Rupture Process

    NASA Astrophysics Data System (ADS)

    Dalguer, L. A.; Mai, M.

    2008-12-01

    Assuming that shear failure on pre-existing faults of shallow earthquakes is governed by Coulomb friction, the mode of faulting and the loading history in compressional and extensional tectonic regimes play an important role in determining the absolute value of frictional strength (e.g. Sibson, 1991) and the initial stress on the fault prior to rupture. Considering for example a fault system under confining pressure equivalent to the gravitational load, then the tectonic loading in a compressional regime accumulates shear stress on the fault while simultaneously frictional strength is expected to increase due to increasing normal stress. In contrast, the loading in an extensional regime results in a reduction of the shear strength due to decreasing normal stress. In this case, the resulting strength of the fault would not be able to maintain large shear stresses because the normal stress at shallow depth is limited to the gravitational loading. We examine the implications of these loading regimes for the dynamic rupture process by developing a variety of dynamic models on thrust, normal and vertical strike-slip faults. For each class of model we combine stochastic irregularities in initial stress, compatible with seismological observations and findings from previous dynamic rupture simulations, with the external tectonic loading. Due to the nature of the fault systems described above, the normal stress is depth dependent, consequently the frictional strength (static and dynamic sliding strength) is also depth dependent. Our tectonic loading scheme generates uniformly increasing shear stress on the fault plane until a nucleation criterion is met (Ripperger et al 2007). Assuming that the fault rupture is governed by linear slip-weakening friction, we perform spontaneous dynamic rupture simulations to examine the rupture complexity and specific characteristics of these classes of models.

  13. Motion field estimation for a dynamic scene using a 3D LiDAR.

    PubMed

    Li, Qingquan; Zhang, Liang; Mao, Qingzhou; Zou, Qin; Zhang, Pin; Feng, Shaojun; Ochieng, Washington

    2014-01-01

    This paper proposes a novel motion field estimation method based on a 3D light detection and ranging (LiDAR) sensor for motion sensing for intelligent driverless vehicles and active collision avoidance systems. Unlike multiple target tracking methods, which estimate the motion state of detected targets, such as cars and pedestrians, motion field estimation regards the whole scene as a motion field in which each little element has its own motion state. Compared to multiple target tracking, segmentation errors and data association errors have much less significance in motion field estimation, making it more accurate and robust. This paper presents an intact 3D LiDAR-based motion field estimation method, including pre-processing, a theoretical framework for the motion field estimation problem and practical solutions. The 3D LiDAR measurements are first projected to small-scale polar grids, and then, after data association and Kalman filtering, the motion state of every moving grid is estimated. To reduce computing time, a fast data association algorithm is proposed. Furthermore, considering the spatial correlation of motion among neighboring grids, a novel spatial-smoothing algorithm is also presented to optimize the motion field. The experimental results using several data sets captured in different cities indicate that the proposed motion field estimation is able to run in real-time and performs robustly and effectively. PMID:25207868

  14. 3D dynamics of hydrous thermal-chemical plumes in subduction zones

    NASA Astrophysics Data System (ADS)

    Zhu, G.; Gerya, T.; Yuen, D.; Connolly, J. A. D.

    2009-04-01

    Mantle wedges are identified as sites of intense thermal convection and thermal-chemical Rayleigh-Taylor instabilities ("cold plumes") controlling distribution and intensity of magmatic activity in subduction zones. To investigate 3D hydrous partially molten cold plumes forming in the mantle wedge in response to slab dehydration, we perform 3D petrological-thermomechanical numerical simulations of the intraoceanic one-sided subduction with spontaneously bending retreating slab characterized by weak hydrated upper interface. I3ELVIS code is used which is developed based on multigrid approach combined with marker-in-cell method with conservative finite-difference schemes. We investigated regional 800 km wide and 200 km deep 3D subduction models with variable 200 to 800 km lateral dimension along the trench using uniform numerical staggered grid with 405x101x101 nodal points and up to 50 million markers. Our results show three patterns (roll(sheet)-, zig-zag- and finger-like) of Rayleigh-Taylor instabilities can develop above the subducting slab, which are controlled by effective viscosity of partially molten rocks. Spatial and temporal periodicity of plumes correlate well with that of volcanic activity in natural intraoceanic arcs such as Japan. High laterally variable surface heat flow predicted in the arc region in response to thermal-chemical plumes activity is also consistent with natural observations.

  15. Motion Field Estimation for a Dynamic Scene Using a 3D LiDAR

    PubMed Central

    Li, Qingquan; Zhang, Liang; Mao, Qingzhou; Zou, Qin; Zhang, Pin; Feng, Shaojun; Ochieng, Washington

    2014-01-01

    This paper proposes a novel motion field estimation method based on a 3D light detection and ranging (LiDAR) sensor for motion sensing for intelligent driverless vehicles and active collision avoidance systems. Unlike multiple target tracking methods, which estimate the motion state of detected targets, such as cars and pedestrians, motion field estimation regards the whole scene as a motion field in which each little element has its own motion state. Compared to multiple target tracking, segmentation errors and data association errors have much less significance in motion field estimation, making it more accurate and robust. This paper presents an intact 3D LiDAR-based motion field estimation method, including pre-processing, a theoretical framework for the motion field estimation problem and practical solutions. The 3D LiDAR measurements are first projected to small-scale polar grids, and then, after data association and Kalman filtering, the motion state of every moving grid is estimated. To reduce computing time, a fast data association algorithm is proposed. Furthermore, considering the spatial correlation of motion among neighboring grids, a novel spatial-smoothing algorithm is also presented to optimize the motion field. The experimental results using several data sets captured in different cities indicate that the proposed motion field estimation is able to run in real-time and performs robustly and effectively. PMID:25207868

  16. Scaling of the rupture dynamics of polymer chains pulled at one end at a constant rate.

    PubMed

    Fugmann, S; Sokolov, I M

    2009-02-01

    We consider the rupture dynamics of a homopolymer chain pulled at one end at a constant loading rate r . Compared to single bond breaking, the existence of the chain introduces two aspects into rupture dynamics: The non-Markovian aspect in the barrier crossing and the slow down of the force propagation to the breakable bond. The relative impact of both these processes is investigated, and the second one was found to be the most important at moderate loading rates. The most probable rupture force is found to decrease with the number of bonds as f{max} proportional, variant-[ln(const N/r)]2/3 and finally to approach a saturation value independent on N . All of our analytical findings are confirmed by extensive numerical simulations. PMID:19391768

  17. Biologic response of inguinal hernia prosthetics: a comparative study of conventional static meshes versus 3D dynamic implants.

    PubMed

    Amato, Giuseppe; Romano, Giorgio; Agrusa, Antonino; Marasa, Salvatore; Cocorullo, Gianfranco; Gulotta, Gaspare; Goetze, Thorsten; Puleio, Roberto

    2015-01-01

    Despite improvements in prosthetics and surgical techniques, the rate of complications following inguinal hernia repair remains high. Among these, discomfort and chronic pain have become a source of increasing concern among surgeons. Poor quality of tissue ingrowth, such as thin scar plates or shrinking scars-typical results with conventional static implants and plugs-may contribute to these adverse events. Recently, a new type of 3D dynamically responsive implant was introduced to the market. This device, designed to be placed fixation-free, seems to induce ingrowth of viable and structured tissue instead of regressive fibrotic scarring. To elucidate the differences in biologic response between the conventional static meshes and this 3D dynamically responsive implant, a histological comparison was planned. The aim of this study was to determine the quality of tissue incorporation in both types of implants excised after short, medium, and long periods post-implantation. The results showed large differences in the biologic responses between the two implant types. Histologically, the 3D dynamic implant showed development of tissue elements more similar to natural abdominal wall structures, such as the ingrowth of loose and well-hydrated connective tissue, well-formed vascular structures, elastic fibers, and mature nerves, with negligible or absent inflammatory response. All these characteristics were completely absent in the conventional static implants, where a persistent inflammatory reaction was associated with thin, hardened, and shrunken fibrotic scar formation. Consequently, as herniation is a degenerative process, the 3D dynamic implants, which induce regeneration of the typical groin components, seem to address its pathogenesis. PMID:25626584

  18. Role of viscoelastic rheologies on heterogeneous stress fields in dynamic rupture models.

    NASA Astrophysics Data System (ADS)

    Radiguet, Mathilde; Kammer, David S.; Molinari, Jean-François

    2014-05-01

    Understanding how past ruptures will affect the propagation of the following ruptures, and how stress heterogeneities develop on faults are fundamental to a better comprehension of earthquake behavior. In that sense, numerical simulations provide a useful tool to study slip dynamics. In this study, we show, using dynamic rupture simulations, the importance of viscoelastic rheologies on the persistence of heterogeneous stress states along a frictional interface. The modeled set-up is a system used in laboratory friction experiments [Rubinstein et al., 2007; Ben-David et al. 2010]. Using a finite-element code, we model two 2D blocks of viscoelastic material (PMMA), with a slip-weakening friction law at the interface between the two solids. The system is loaded from the side of the upper block, resulting in a sequence of precursory slip events, which initiate at the trailing edge and stop before propagating over the entire interface. Their length increases with increasing loading, and high stress concentrations are generated at the tip of each arrested rupture. We analyze the evolution of these stress concentrations when the following slip events take place. We show that due to the viscous properties of the bulk material, the stress concentrations created by the arrest of precursory slip are not erased by the propagation of the following rupture, but reappear with the relaxation of the material, with a smaller amplitude. The amplitude of the stress concentrations follows an exponential decrease rate with successive rupture, which is controlled by by the material properties, and in particular by the ratio of the viscous over instantaneous Young's moduli. We extend this analysis by using rheological parameters relevant for rocks. Our results highlight the importance of viscous relaxation mechanisms in the persistence of heterogeneous stress states along a frictional interface. This study also provides a mechanism to explain how previous slip history will influence the

  19. Dynamic Assessment of Fibroblast Mechanical Activity during Rac-induced Cell Spreading in 3-D Culture

    PubMed Central

    Petroll, W. Matthew; Ma, Lisha; Kim, Areum; Ly, Linda; Vishwanath, Mridula

    2009-01-01

    The goal of this study was to determine the morphological and sub-cellular mechanical effects of Rac activation on fibroblasts within 3-D collagen matrices. Corneal fibroblasts were plated at low density inside 100 μm thick fibrillar collagen matrices and cultured for 1 to 2 days in serum-free media. Time-lapse imaging was then performed using Nomarski DIC. After an acclimation period, perfusion was switched to media containing PDGF. In some experiments, Y-27632 or blebbistatin were used to inhibit Rho-kinase (ROCK) or myosin II, respectively. PDGF activated Rac and induced cell spreading, which resulted in an increase in cell length, cell area, and the number of pseudopodial processes. Tractional forces were generated by extending pseudopodia, as indicated by centripetal displacement and realignment of collagen fibrils. Interestingly, the pattern of pseudopodial extension and local collagen fibril realignment was highly dependent upon the initial orientation of fibrils at the leading edge. Following ROCK or myosin II inhibition, significant ECM relaxation was observed, but small displacements of collagen fibrils continued to be detected at the tips of pseudopodia. Taken together, the data suggests that during Rac-induced cell spreading within 3-D matrices, there is a shift in the distribution of forces from the center to the periphery of corneal fibroblasts. ROCK mediates the generation of large myosin II-based tractional forces during cell spreading within 3-D collagen matrices, however residual forces can be generated at the tips of extending pseudopodia that are both ROCK and myosin II-independent. PMID:18452153

  20. Dynamic Analysis of 2D Electromagnetic Resonant Optical Scanner Using 3D Finite Element Method

    NASA Astrophysics Data System (ADS)

    Hirata, Katsuhiro; Hong, Sara; Maeda, Kengo

    The optical scanner is a scanning device in which a laser beam is reflected by a mirror that can be rotated or oscillated. In this paper, we propose a new 2D electromagnetic resonant optical scanner that employs electromagnets and leaf springs. Torque characteristics and resonance characteristics of the scanner are analyzed using the 3D finite element method. The validity of the analysis is shown by comparing the characteristics inferred from the analysis with the characteristics of the prototype. Further, 2D resonance is investigated by introducing a superimposed-frequency current in a single coil.

  1. 3D and 4D Simulations of the Dynamics of the Radiation Belts using VERB code

    NASA Astrophysics Data System (ADS)

    Shprits, Yuri; Kellerman, Adam; Drozdov, Alexander; Orlova, Ksenia

    2015-04-01

    Modeling and understanding of ring current and higher energy radiation belts has been a grand challenge since the beginning of the space age. In this study we show long term simulations with a 3D VERB code of modeling the radiation belts with boundary conditions derived from observations around geosynchronous orbit. We also present 4D VERB simulations that include convective transport, radial diffusion, pitch angle scattering and local acceleration. We show that while lower energy radial transport is dominated by the convection and higher energy transport is dominated by the diffusive radial transport. We also show there exists an intermediate range of energies for electrons for which both processes work simultaneously.

  2. Dynamic rupture simulation with an experimentally-determined friction law leads to slip-pulse propagation

    NASA Astrophysics Data System (ADS)

    Liao, Z.; Chang, J. C.; Reches, Z.

    2013-12-01

    We simulate the dynamic rupture along a vertical, strike-slip fault in an elastic half-space. The fault has frictional properties that were determined in high-velocity, rotary shear apparatus Sierra-White granite. The experimental fault was abruptly loaded by a massive flywheel, which is assumed to simulate the loading of a fault patch during an earthquake, and termed Earthquake-Like-Slip Event (ELSE) (Chang et al., 2012). The experiments revealed systematic alteration between slip-weakening and slip-strengthening (Fig. 1A), and were considered as proxies of fault-patch behavior during earthquakes of M = 4-8. We used the friction-distance relations of these experiments to form an empirical slip-dependent friction model, ELSE-model (Fig. 1B). For the dynamic rupture simulation, we used the program of Ampuero (2002) (2D spectral boundary integral elements) designed for anti-plane (mode III) shear fracturing. To compare with published works, the calculations used a crust with mechanical properties and stress state of Version 3 benchmark of SCEC (Harris et al., 2004). The calculations with a fault of ELSE-model friction revealed: (1) Rupture propagation in a slip-pulse style with slip cessation behind the pulse; (2) Systematic decrease of slip distance away from the nucleation zone; and (3) Spontaneous arrest of the dynamic rupture without a barrier. These features suggest a rupture of a self-healing slip-pulse mode (Fig. 1C), in contrast to rupturing of a fault with linear slip-weakening friction (Fig. 1B) (Rojas et al., 2008) in crack-like mode and no spontaneous arrest. We deduce that the slip-pulse in our simulation results from the fast recovery of shear strength as observed in ELSE experiments, and argue that incorporating this experimentally-based friction model to rupture modeling produces realistic propagation style of earthquake rupture. Figure 1 Fault patch behavior during an earthquake. (A) Experimental evolution of frictional stress, slip velocity, and

  3. Optimization of a 3D Dynamic Culturing System for In Vitro Modeling of Frontotemporal Neurodegeneration-Relevant Pathologic Features.

    PubMed

    Tunesi, Marta; Fusco, Federica; Fiordaliso, Fabio; Corbelli, Alessandro; Biella, Gloria; Raimondi, Manuela T

    2016-01-01

    Frontotemporal lobar degeneration (FTLD) is a severe neurodegenerative disorder that is diagnosed with increasing frequency in clinical setting. Currently, no therapy is available and in addition the molecular basis of the disease are far from being elucidated. Consequently, it is of pivotal importance to develop reliable and cost-effective in vitro models for basic research purposes and drug screening. To this respect, recent results in the field of Alzheimer's disease have suggested that a tridimensional (3D) environment is an added value to better model key pathologic features of the disease. Here, we have tried to add complexity to the 3D cell culturing concept by using a microfluidic bioreactor, where cells are cultured under a continuous flow of medium, thus mimicking the interstitial fluid movement that actually perfuses the body tissues, including the brain. We have implemented this model using a neuronal-like cell line (SH-SY5Y), a widely exploited cell model for neurodegenerative disorders that shows some basic features relevant for FTLD modeling, such as the release of the FTLD-related protein progranulin (PRGN) in specific vesicles (exosomes). We have efficiently seeded the cells on 3D scaffolds, optimized a disease-relevant oxidative stress experiment (by targeting mitochondrial function that is one of the possible FTLD-involved pathological mechanisms) and evaluated cell metabolic activity in dynamic culture in comparison to static conditions, finding that SH-SY5Y cells cultured in 3D scaffold are susceptible to the oxidative damage triggered by a mitochondrial-targeting toxin (6-OHDA) and that the same cells cultured in dynamic conditions kept their basic capacity to secrete PRGN in exosomes once recovered from the bioreactor and plated in standard 2D conditions. We think that a further improvement of our microfluidic system may help in providing a full device where assessing basic FTLD-related features (including PRGN dynamic secretion) that may be

  4. WARP3D-Release 10.8: Dynamic Nonlinear Analysis of Solids using a Preconditioned Conjugate Gradient Software Architecture

    NASA Technical Reports Server (NTRS)

    Koppenhoefer, Kyle C.; Gullerud, Arne S.; Ruggieri, Claudio; Dodds, Robert H., Jr.; Healy, Brian E.

    1998-01-01

    This report describes theoretical background material and commands necessary to use the WARP3D finite element code. WARP3D is under continuing development as a research code for the solution of very large-scale, 3-D solid models subjected to static and dynamic loads. Specific features in the code oriented toward the investigation of ductile fracture in metals include a robust finite strain formulation, a general J-integral computation facility (with inertia, face loading), an element extinction facility to model crack growth, nonlinear material models including viscoplastic effects, and the Gurson-Tver-gaard dilatant plasticity model for void growth. The nonlinear, dynamic equilibrium equations are solved using an incremental-iterative, implicit formulation with full Newton iterations to eliminate residual nodal forces. The history integration of the nonlinear equations of motion is accomplished with Newmarks Beta method. A central feature of WARP3D involves the use of a linear-preconditioned conjugate gradient (LPCG) solver implemented in an element-by-element format to replace a conventional direct linear equation solver. This software architecture dramatically reduces both the memory requirements and CPU time for very large, nonlinear solid models since formation of the assembled (dynamic) stiffness matrix is avoided. Analyses thus exhibit the numerical stability for large time (load) steps provided by the implicit formulation coupled with the low memory requirements characteristic of an explicit code. In addition to the much lower memory requirements of the LPCG solver, the CPU time required for solution of the linear equations during each Newton iteration is generally one-half or less of the CPU time required for a traditional direct solver. All other computational aspects of the code (element stiffnesses, element strains, stress updating, element internal forces) are implemented in the element-by- element, blocked architecture. This greatly improves

  5. Mapping dynamic mechanical remodeling in 3D tumor models via particle tracking microrheology

    NASA Astrophysics Data System (ADS)

    Jones, Dustin P.; Hanna, William; Celli, Jonathan P.

    2015-03-01

    Particle tracking microrheology (PTM) has recently been employed as a non-destructive way to longitudinally track physical changes in 3D pancreatic tumor co-culture models concomitant with tumor growth and invasion into the extracellular matrix (ECM). While the primary goal of PTM is to quantify local viscoelasticity via the Generalized Stokes-Einstein Relation (GSER), a more simplified way of describing local tissue mechanics lies in the tabulation and subsequent visualization of the spread of probe displacements in a given field of view. Proper analysis of this largely untapped byproduct of standard PTM has the potential to yield valuable insight into the structure and integrity of the ECM. Here, we use clustering algorithms in R to analyze the trajectories of probes in 3D pancreatic tumor/fibroblast co-culture models in an attempt to differentiate between probes that are effectively constrained by the ECM and/or contractile traction forces, and those that exhibit uninhibited mobility in local water-filled pores. We also discuss the potential pitfalls of this method. Accurately and reproducibly quantifying the boundary between these two categories of probe behavior could result in an effective method for measuring the average pore size in a given region of ECM. Such a tool could prove useful for studying stromal depletion, physical impedance to drug delivery, and degradation due to cellular invasion.

  6. Lattice Boltzmann simulation of dynamics of plunge and pitch of 3D flexible wing

    NASA Astrophysics Data System (ADS)

    Qi, Dewei; Shyy, Wei

    2008-11-01

    The method of lattice Boltzmann (LB) simulation has been used to simulate fluid structures and motion of a flexible insect wing in a 3D space. In the method, a beam has been discretized into a chain of rigid segments. Each segment is connected through ball and socket joints at its ends. One segment may be bent and twisted with its neighboring segment. A constraint force is applied to each joint to ensure the solid structure moving as a whole flexible elastic body.We have demonstrated that the LB method is suitable for modeling of aerodynamics of insects flight at low Reynolds numbers. First, a simulation of plunging and pitching of a rigid wing is performed at Re=75 in a 2D space and the results of lift forces and flow structures are in excellent agreement with the previous results. Second, plunging and pitching of a flexible wing in span-wise direction is simulated at Re=136 in a 3D space. We found that when twisting elasticity is large enough the twisting angle could be controlled at a level of smaller than 0.2 degree. It is shown that as bending and twisting elasticity is large enough, the motion of flexible wing approaches that of a rigid membrane wing. The simulation results show that the optimization of flexibility in span-wise direction will benefit thrust and an intermediate level is favorable. The results are consistent with experimental finding.

  7. Using 3D dynamic cartography and hydrological modelling for linear streamflow mapping

    NASA Astrophysics Data System (ADS)

    Drogue, G.; Pfister, L.; Leviandier, T.; Humbert, J.; Hoffmann, L.; El Idrissi, A.; Iffly, J.-F.

    2002-10-01

    This paper presents a regionalization methodology and an original representation of the downstream variation of daily streamflow using a conceptual rainfall-runoff model (HRM) and the 3D visualization tools of the GIS ArcView. The regionalization of the parameters of the HRM model was obtained by fitting simultaneously the runoff series from five sub-basins of the Alzette river basin (Grand-Duchy of Luxembourg) according to the permeability of geological formations. After validating the transposability of the regional parameter values on five test basins, streamflow series were simulated with the model at ungauged sites in one medium size geologically contrasted test basin and interpolated assuming a linear increase of streamflow between modelling points. 3D spatio-temporal cartography of mean annual and high raw and specific discharges are illustrated. During a severe flooding, the propagation of the flood waves in the different parts of the stream network shows an important contribution of sub-basins lying on impervious geological formations (direct runoff) compared with those including permeable geological formations which have a more contrasted hydrological response. The effect of spatial variability of rainfall is clearly perceptible.

  8. Persistent and automatic intraoperative 3D digitization of surfaces under dynamic magnifications of an operating microscope

    PubMed Central

    Kumar, Ankur N.; Miga, Michael I.; Pheiffer, Thomas S.; Chambless, Lola B.; Thompson, Reid C.; Dawant, Benoit M.

    2014-01-01

    One of the major challenges impeding advancement in image-guided surgical (IGS) systems is the soft-tissue deformation during surgical procedures. These deformations reduce the utility of the patient’s preoperative images and may produce inaccuracies in the application of preoperative surgical plans. Solutions to compensate for the tissue deformations include the acquisition of intraoperative tomographic images of the whole organ for direct displacement measurement and techniques that combines intraoperative organ surface measurements with computational biomechanical models to predict subsurface displacements. The later solution has the advantage of being less expensive and amenable to surgical workflow. Several modalities such as textured laser scanners, conoscopic holography, and stereo-pair cameras have been proposed for the intraoperative 3D estimation of organ surfaces to drive patient-specific biomechanical models for the intraoperative update of preoperative images. Though each modality has its respective advantages and disadvantages, stereo-pair camera approaches used within a standard operating microscope is the focus of this article. A new method that permits the automatic and near real-time estimation of 3D surfaces (at 1Hz) under varying magnifications of the operating microscope is proposed. This method has been evaluated on a CAD phantom object and on full-length neurosurgery video sequences (~1 hour) acquired intraoperatively by the proposed stereovision system. To the best of our knowledge, this type of validation study on full-length brain tumor surgery videos has not been done before. The method for estimating the unknown magnification factor of the operating microscope achieves accuracy within 0.02 of the theoretical value on a CAD phantom and within 0.06 on 4 clinical videos of the entire brain tumor surgery. When compared to a laser range scanner, the proposed method for reconstructing 3D surfaces intraoperatively achieves root mean square

  9. Persistent and automatic intraoperative 3D digitization of surfaces under dynamic magnifications of an operating microscope.

    PubMed

    Kumar, Ankur N; Miga, Michael I; Pheiffer, Thomas S; Chambless, Lola B; Thompson, Reid C; Dawant, Benoit M

    2015-01-01

    One of the major challenges impeding advancement in image-guided surgical (IGS) systems is the soft-tissue deformation during surgical procedures. These deformations reduce the utility of the patient's preoperative images and may produce inaccuracies in the application of preoperative surgical plans. Solutions to compensate for the tissue deformations include the acquisition of intraoperative tomographic images of the whole organ for direct displacement measurement and techniques that combines intraoperative organ surface measurements with computational biomechanical models to predict subsurface displacements. The later solution has the advantage of being less expensive and amenable to surgical workflow. Several modalities such as textured laser scanners, conoscopic holography, and stereo-pair cameras have been proposed for the intraoperative 3D estimation of organ surfaces to drive patient-specific biomechanical models for the intraoperative update of preoperative images. Though each modality has its respective advantages and disadvantages, stereo-pair camera approaches used within a standard operating microscope is the focus of this article. A new method that permits the automatic and near real-time estimation of 3D surfaces (at 1 Hz) under varying magnifications of the operating microscope is proposed. This method has been evaluated on a CAD phantom object and on full-length neurosurgery video sequences (∼1 h) acquired intraoperatively by the proposed stereovision system. To the best of our knowledge, this type of validation study on full-length brain tumor surgery videos has not been done before. The method for estimating the unknown magnification factor of the operating microscope achieves accuracy within 0.02 of the theoretical value on a CAD phantom and within 0.06 on 4 clinical videos of the entire brain tumor surgery. When compared to a laser range scanner, the proposed method for reconstructing 3D surfaces intraoperatively achieves root mean square

  10. A microfluidic model to study fluid dynamics of mucus plug rupture in small lung airways

    PubMed Central

    Hu, Yingying; Bian, Shiyao; Grotberg, John; Filoche, Marcel; White, Joshua; Takayama, Shuichi; Grotberg, James B.

    2015-01-01

    Fluid dynamics of mucus plug rupture is important to understand mucus clearance in lung airways and potential effects of mucus plug rupture on epithelial cells at lung airway walls. We established a microfluidic model to study mucus plug rupture in a collapsed airway of the 12th generation. Mucus plugs were simulated using Carbopol 940 (C940) gels at concentrations of 0.15%, 0.2%, 0.25%, and 0.3%, which have non-Newtonian properties close to healthy and diseased lung mucus. The airway was modeled with a polydimethylsiloxane microfluidic channel. Plug motion was driven by pressurized air. Global strain rates and shear stress were defined to quantitatively describe plug deformation and rupture. Results show that a plug needs to overcome yield stress before deformation and rupture. The plug takes relatively long time to yield at the high Bingham number. Plug length shortening is the more significant deformation than shearing at gel concentration higher than 0.15%. Although strain rates increase dramatically at rupture, the transient shear stress drops due to the shear-thinning effect of the C940 gels. Dimensionless time-averaged shear stress, Txy, linearly increases from 3.7 to 5.6 times the Bingham number as the Bingham number varies from 0.018 to 0.1. The dimensionless time-averaged shear rate simply equals to Txy/2. In dimension, shear stress magnitude is about one order lower than the pressure drop, and one order higher than yield stress. Mucus with high yield stress leads to high shear stress, and therefore would be more likely to cause epithelial cell damage. Crackling sounds produced with plug rupture might be more detectable for gels with higher concentration. PMID:26392827

  11. Fully 3D Multiple Beam Dynamics Processes Simulation for the Fermilab Tevatron

    SciTech Connect

    Stern, E.; Amundson, J.; Spentzouris, P; Valishev, A.; /Fermilab

    2010-06-01

    The Fermilab Tevatron has been, until 2010, the premier high-energy physics collider in the world. The data collected over the last decade by high-energy physics experiments running at the Tevatron have been analyzed to make important measurements in fundamental areas such as B meson masses and flavor oscillation, searches for the Higgs boson, and supersymmetry. Collecting these data at the limits of detectability has required the Tevatron to operate reliably at high beam intensities to maximize the number of collisions to analyze. This impressive achievement has been assisted by the use of HPC resources and software provided through the SciDAC program. This paper describes the enhancements to the BeamBeam3d code to realistically simulate the Tevatron, the validation of these simulations, and the improvement in equipment reliability and personal safety achieved with the aid of simulations.

  12. Dynamic complex optical fields for optical manipulation, 3D microscopy, and photostimulation of neurotransmitters

    NASA Astrophysics Data System (ADS)

    Daria, Vincent R.; Stricker, Christian; Bekkers, John; Redman, Steve; Bachor, Hans

    2010-08-01

    We demonstrate a multi-functional system capable of multiple-site two-photon excitation of photo-sensitive compounds as well as transfer of optical mechanical properties on an array of mesoscopic particles. We use holographic projection of a single Ti:Sapphire laser operating in femtosecond pulse mode to show that the projected three-dimensional light patterns have sufficient spatiotemporal photon density for multi-site two-photon excitation of biological fluorescent markers and caged neurotransmitters. Using the same laser operating in continuous-wave mode, we can use the same light patterns for non-invasive transfer of both linear and orbital angular momentum on a variety of mesoscopic particles. The system also incorporates high-speed scanning using acousto-optic modulators to rapidly render 3D images of neuron samples via two-photon microscopy.

  13. Tidal dynamics of the Terminos Lagoon, Mexico: observations and 3D numerical modelling

    NASA Astrophysics Data System (ADS)

    Contreras Ruiz Esparza, Adolfo; Douillet, Pascal; Zavala-Hidalgo, Jorge

    2014-09-01

    The tidal circulation patterns in the Terminos Lagoon were studied based on the analysis of 1 year of measurements and numerical simulations using a baroclinic 3D hydrodynamic model, the MARS3D. A gauging network was installed consisting of six self-recording pressure-temperature sensors, a tide gauge station and two current profilers, with pressure and temperature sensors moored in the main lagoon inlets. Model simulations were validated against current and sea level observations and were used to analyse the circulation patterns caused by the tidal forcing. The numerical model was forced with eight harmonic components, four diurnal ( K 1, O 1, P 1, Q 1) and four semi-diurnal ( M 2, S 2, N 2, K 2), extracted from the TPX0.7 database. The tidal patterns in the study area vary from mixed, mainly diurnal in the two main inlets of the lagoon, to diurnal in its interior. The tidal residual circulation inside the lagoon is dominated by a cyclonic gyre. The results indicate a net flux from the southwest Ciudad del Carmen inlet (CdC) towards the northeast Puerto Real inlet (PtR) along the southern side of the lagoon and the opposite in the northern side. The results indicate two areas of strong currents in the vicinity of the inlets and weak currents inside the lagoon. The area of strong currents in the vicinity of the CdC inlet is larger than that observed in the PtR inlet. Nevertheless, the current analysis indicates that the highest current speeds, which can reach a magnitude of 1.9 m s-1, occurred in PtR. A further analysis of the tide distortion in the inlets revealed that both passages are ebb dominated.

  14. Fault steps and the dynamic rupture process: 2-D numerical simulations of a spontaneously propagating shear fracture

    NASA Astrophysics Data System (ADS)

    Harris, Ruth A.; Archuleta, Ralph J.; Day, Steven M.

    1991-05-01

    Fault steps may have controlled the sizes of the 1966 Parkfield, 1968 Borrego Mountain, 1979 Imperial Valley, 1979 Coyote Lake and the 1987 Superstition Hills earthquakes. This project investigates the effect of fault steps of various geometries on the dynamic rupture process. We have used a finite difference code to simulate spontaneous rupture propagation in two dimensions. We employ a slip-weakening fracture criterion as the condition for rupture propagation and examine how rupture on one plane initiates rupture on parallel fault planes. The geometry of the two parallel fault planes allows for stepover widths of 0.5 to 10.0 km and overlaps of -5 to 5 km. Our results demonstrate that the spontaneous rupture on the first fault segment continues to propagate onto the second fault segment for a range of geometries for both compressional and dilational fault steps. A major difference between the compressional and dilational cases is, that a dilational step requires a longer time delay between the rupture front reaching the end of the first fault segment and initiating rupture on the second segment. Therefore our dynamic study implies that a compressional step will be jumped quickly, whereas a dilational step will cause a time delay leading to a lower apparent rupture velocity. We also find that the rupture is capable of jumping a wider dilational step than compressional step.

  15. Fault steps and the dynamic rupture process: 2-D numerical simulations of a spontaneously propagating shear fracture

    SciTech Connect

    Harris, R.A.; Archuleta, R.J. ); Day, S.M. )

    1991-05-01

    Fault steps may have controlled the sizes of the 1966 Parkfield, 1968 Borrego Mountain, 1979 Imperial Valley, 1979 Coyote Lake and the 1987 Superstition Hills earthquakes. This project investigates the effect of fault steps of various geometries on the dynamic rupture process. The authors have used a finite difference code to simulate spontaneous rupture propagation in two dimensions. They employ a slip-weakening fracture criterion as the condition for rupture propagation and examine how rupture on one plane initiates rupture on parallel fault planes. The geometry of the two parallel fault planes allows for stepover widths of 0.5 to 10.0 m and overlaps of {minus}5 to 5 km. Results demonstrate that the spontaneous rupture on the first fault segment continues to propagate onto the second fault segment for a range of geometries for both compressional and dilational fault steps. A major difference between the compressional and dilational cases is that a dilational step requires a longer time delay between the rupture front reaching the end of the first fault segment and initiating rupture on the second segment. Therefore this dynamic study implies that a compressional step will be jumped quickly, whereas a dilational step will cause a time delay leading to a lower apparent rupture velocity. The authors also find that the rupture is capable of jumping a wider dilational step than compressional step.

  16. 3D quasi-dynamic modeling of earthquake cycles of the great Tohoku-oki earthquake by considering high-speed friction and thermal pressurization

    NASA Astrophysics Data System (ADS)

    Shibazaki, B.; Tsutsumi, A.; Shimamoto, T.; Noda, H.

    2012-12-01

    Some observational studies [e.g. Hasegawa et al., 2011] suggested that the 2011 great Tohoku-oki Earthquake (Mw 9.0) released roughly all of the accumulated elastic strain on the plate interface owing to considerable weakening of the fault. Recent studies show that considerable weakening can occur at a high slip velocity because of thermal pressurization or thermal weakening processes [Noda and Lapusta, 2010; Di Toro et al., 2011]. Tsutsumi et al. [2011] examined the frictional properties of clay-rich fault materials under water-saturated conditions and found that velocity weakening or strengthening occurs at intermediate slip velocities and that dramatic weakening occurs at high slip velocities. This dramatic weakening at higher slip velocities is caused by pore-fluid pressurization via frictional heating or gouge weakening. In the present study, we investigate the generation mechanism of megathrust earthquakes along the Japan trench by performing 3D quasi-dynamic modeling with high-speed friction or thermal pressurization. We propose a rate- and state-dependent friction law with two state variables that exhibit weak velocity weakening or strengthening with a small critical displacement at low to intermediate velocities, but a strong velocity weakening with a large critical displacement at high slip velocities [Shibazaki et al., 2011]. We use this friction law for 3D quasi-dynamic modeling of a cycle of the great Tohoku-oki earthquake. We set several asperities where velocity weakening occurs at low to intermediate slip velocities. Outside of the asperities, velocity strengthening occurs at low to intermediate slip velocities. At high slip velocities, strong velocity weakening occurs both within and outside of the asperities. The rupture of asperities occurs at intervals of several tens of years, whereas megathrust events occur at much longer intervals (several hundred years). Megathrust slips occur even in regions where velocity strengthening occurs at low to

  17. A synthetic GMPE based on deterministic simulated ground motion data obtained from dynamic rupture models

    NASA Astrophysics Data System (ADS)

    Dalguer, L. A.; Baumann, C.; Cauzzi, C.

    2013-12-01

    Empirical ground motion prediction in the very near-field and for large magnitudes is often based on extrapolation of ground motion prediction equations (GMPEs) outside the range where they are well constrained by recorded data. With empirical GMPEs it is also difficult to capture source-dominated ground motion patterns, such as the effects of velocity pulses induced by subshear and supershear rupture directivity, buried and surface-rupturing, hanging-wall and foot-wall, weak shallow layers, complex geometry faults and stress drop. A way to cope at least in part with these shortcomings is to augment the calibration datasets with synthetic ground motions. To this aim, physics-based dynamic rupture models - where the physical bases involved in the fault rupture are explicitly considered - appear to be a suitable approach to produce synthetic ground motions. In this contribution, we first perform an assessment of a database of synthetic ground motions generated by a suite of dynamic rupture simulations to verify compatibility of the peak ground amplitudes with current GMPEs. The synthetic data-set is composed by 360 earthquake scenarios with moment magnitudes in the range of 5.5-7, for three mechanisms of faulting (reverse, normal and strike-slip) and for both buried faults and surface rupturing faults. Second, we parameterise the synthetic dataset through a GMPE. For this purpose, we identify the basic functional forms by analyzing the variation of the synthetic peak ground motions and spectral ordinates as a function of different explanatory variables related to the earthquake source characteristics, in order to account for some of the source effects listed above. We argue that this study provides basic guidelines for the developments of future GMPEs including data from physics-based numerical simulations.

  18. TRACE 3-D documentation

    SciTech Connect

    Crandall, K.R.

    1987-08-01

    TRACE 3-D is an interactive beam-dynamics program that calculates the envelopes of a bunched beam, including linear space-charge forces, through a user-defined transport system. TRACE 3-D provides an immediate graphics display of the envelopes and the phase-space ellipses and allows nine types of beam-matching options. This report describes the beam-dynamics calculations and gives detailed instruction for using the code. Several examples are described in detail.

  19. Seismological asperities from the point of view of dynamic rupture modeling: the 2007 Mw6.6 Chuetsu-Oki, Japan, earthquake

    NASA Astrophysics Data System (ADS)

    Aochi, Hideo; Yoshimi, Masayuki

    2016-03-01

    We study the ground motion simulations based on three finite-source models for the 2007 Mw6.6 Niigata Chuetsu-oki, Japan, earthquake in order to discuss the performance of the input ground motion estimations for the near-field seismic hazard analysis. The three models include a kinematic source inverted from the regional accelerations, a dynamic source on a planar fault with three asperities inferred from the very-near-field ground motion particle motions, and another dynamic source model with conjugate fault segments. The ground motions are calculated for an available 3D geological model using a finite-difference method. For the comparison, we apply a goodness-of-fit score to the ground motion parameters at different stations, including the nearest one that is almost directly above the ruptured fault segments. The dynamic rupture models show good performance. We find that seismologically inferred earthquake asperities on a single fault plane can be expressed with two conjugate segments. The rupture transfer from one segment to another can generate a significant radiation; this could be interpreted as an asperity projected onto a single fault plane. This example illustrates the importance of the fault geometry that has to be taken into account when estimating the very-near-field ground motion.

  20. A 3-D adaptive mesh refinement algorithm for multimaterial gas dynamics

    SciTech Connect

    Puckett, E.G. ); Saltzman, J.S. )

    1991-08-12

    Adaptive Mesh Refinement (AMR) in conjunction with high order upwind finite difference methods has been used effectively on a variety of problems. In this paper we discuss an implementation of an AMR finite difference method that solves the equations of gas dynamics with two material species in three dimensions. An equation for the evolution of volume fractions augments the gas dynamics system. The material interface is preserved and tracked from the volume fractions using a piecewise linear reconstruction technique. 14 refs., 4 figs.

  1. Insight into the physics of rupture: Dynamic triggering seismicity

    NASA Astrophysics Data System (ADS)

    Gonzalez-Huizar, Hector

    2009-12-01

    Seismic waves can trigger earthquakes and tremor at large distances from the causable event. Dynamic triggering occurs when the surface waves from large earthquakes change the stresses conditions on previously overstressed faults, promoting failure. To understand the causative stresses and environments behind dynamic triggering, we model the change in the stress field that the passing of Rayleigh and Love waves cause on a fault plane of arbitrary orientation relative to the direction of propagation of the waves, and apply a Coulomb failure criterion to calculate the potential of these stress changes to trigger seismicity. We apply our model to three different study regions and compare with observations. In the first case, we compare our model results with data from dynamically triggered earthquakes in the Australian Bowen Basin, Our data analysis shows that for this region, surface waves arriving at 45 degrees from the average local stress field are the most likely to trigger local seismicity. This agrees with our observations. In the second study case, we show how the same model can be applied to dynamic triggering of Non-volcanic tremor (NVT). Our modeling predicts the potential of a seismic wave to trigger slip on a fault plane promoting NVT. We search for tremor in the Central Range in Taiwan triggered by surfaces waves and compare the observations with our modeling. In the last study case, we present our modeling of the dynamic stress that triggered two events in Utah, one triggered by the 1992 Landers earthquake and the other by the 2002 Denali Fault earthquake. We show how dynamic stress modeling can be used to discriminate between the two axial planes of a first motion focal mechanism of a dynamically triggered event.

  2. Dynamic 3-D chemical agent cloud mapping using a sensor constellation deployed on mobile platforms

    NASA Astrophysics Data System (ADS)

    Cosofret, Bogdan R.; Konno, Daisei; Rossi, David; Marinelli, William J.; Seem, Pete

    2014-05-01

    The need for standoff detection technology to provide early Chem-Bio (CB) threat warning is well documented. Much of the information obtained by a single passive sensor is limited to bearing and angular extent of the threat cloud. In order to obtain absolute geo-location, range to threat, 3-D extent and detailed composition of the chemical threat, fusion of information from multiple passive sensors is needed. A capability that provides on-the-move chemical cloud characterization is key to the development of real-time Battlespace Awareness. We have developed, implemented and tested algorithms and hardware to perform the fusion of information obtained from two mobile LWIR passive hyperspectral sensors. The implementation of the capability is driven by current Nuclear, Biological and Chemical Reconnaissance Vehicle operational tactics and represents a mission focused alternative of the already demonstrated 5-sensor static Range Test Validation System (RTVS).1 The new capability consists of hardware for sensor pointing and attitude information which is made available for streaming and aggregation as part of the data fusion process for threat characterization. Cloud information is generated using 2-sensor data ingested into a suite of triangulation and tomographic reconstruction algorithms. The approaches are amenable to using a limited number of viewing projections and unfavorable sensor geometries resulting from mobile operation. In this paper we describe the system architecture and present an analysis of results obtained during the initial testing of the system at Dugway Proving Ground during BioWeek 2013.

  3. Ultrasensitive detection of 3D cerebral microvascular network dynamics in vivo

    PubMed Central

    Pan, Yingtian; You, Jiang; Volkow, Nora D.; Park, Ki; Du, Congwu

    2014-01-01

    Despite widespread applications of multiphoton microscopy in microcirculation, its small field of view and inability to instantaneously quantify cerebral blood flow velocity (CBFv) in vascular networks limit its utility in investigating the heterogeneous responses to brain stimulations. Optical Doppler tomography (ODT) provides 3D images of CBFv networks, but it suffers poor sensitivity for measuring capillary flows. Here we report a new method, contrast-enhanced ODT with intralipid that significantly improves quantitative CBFv imaging of capillary networks by obviating the errors from long latency between flowing red blood cells (low hematocrit ~20% in capillaries). This enhanced sensitivity allowed us to measure the ultraslow microcirculation surrounding a brain tumor and the abnormal ingrowth of capillary flows in the tumor as well as in ischemia triggered by chronic cocaine in the mouse brain that could not be detected by regular ODT. It also enabled significantly enhanced sensitivity for quantifying the heterogeneous CBFv responses of vascular networks to acute cocaine. Inasmuch as intralipids are widely used for parenteral nutrition the intralipid contrast method has translational potential for clinical applications. PMID:25192654

  4. Cation Exchange in Dynamic 3D Porous Magnets: Improvement of the Physical Properties.

    PubMed

    Grancha, Thais; Acosta, Alvaro; Cano, Joan; Ferrando-Soria, Jesús; Seoane, Beatriz; Gascon, Jorge; Pasán, Jorge; Armentano, Donatella; Pardo, Emilio

    2015-11-16

    We report two novel three-dimensional porous coordination polymers (PCPs) of formulas Li4{Mn4[Cu2(Me3mpba)2]3}·68H2O (2) and K4{Mn4[Cu2(Me3mpba)2]3}·69H2O (3) obtained-via alkali cation exchange in a single-crystal to single-crystal process-from the earlier reported anionic manganese(II)-copper(II) PCP of formula Na4{Mn4[Cu2(Me3mpba)2]3}·60H2O (1) [Me3mpba(4-) = N,N'-2,4,6-trimethyl-1,3-phenylenebis(oxamate)]. This postsynthetic process succeeds where the direct synthesis in solution from the corresponding building blocks fails and affords significantly more robust PCPs with enhanced magnetic properties [long-range 3D magnetic ordering temperatures for the dehydrated phases (1'-3') of 2.0 (1'), 12.0 (2'), and 20.0 K (3')]. Changes in the adsorptive properties upon postsynthetic exchange suggest that the nature, electrostatic properties, mobility, and location of the cations within the framework are crucial for the enhanced structural stability. Overall, these results further confirm the potential of postsynthetic methods (including cation exchange) to obtain PCPs with novel or enhanced physical properties while maintaining unaltered their open-framework structures. PMID:26492551

  5. Intersegmental dynamics of 3D upper arm and forearm longitudinal axis rotations during baseball pitching.

    PubMed

    Naito, Kozo; Takagi, Hiroyasu; Yamada, Norimasa; Hashimoto, Shinichi; Maruyama, Takeo

    2014-12-01

    The shoulder internal rotation (IR) and forearm pronation (PR) are important elements for baseball pitching, however, how rapid rotations of IR and PR are produced by muscular torques and inter-segmental forces is not clear. The aim of this study is to clarify how IR and PR angular velocities are maximized, depending on muscular torque and interactive torque effects, and gain a detailed knowledge about inter-segmental interaction within a multi-joint linked chain. The throwing movements of eight collegiate baseball pitchers were recorded by a motion capture system, and induced-acceleration analysis was used to assess the respective contributions of the muscular (MUS) and interactive torques associated with gyroscopic moment (GYR), and Coriolis (COR) and centrifugal forces (CEN) to maximum angular velocities of IR (MIRV) and PR (MPRV). The results showed that the contribution of MUS account for 98.0% of MIRV, while that contribution to MPRV was indicated as negative (-48.1%). It was shown that MPRV depends primarily on the interactive torques associated with GYR and CEN, but the effects of GYR, COR and CEN on MIRV are negligible. In conclusion, rapid PR motion during pitching is created by passive-effect, and is likely a natural movement which arises from 3D throwing movement. Applying the current analysis to IR and PR motions is helpful in providing the implications for improving performance and considering conditioning methods for pitchers. PMID:25303496

  6. A Dynamic 3D Graphical Representation for RNA Structure Analysis and Its Application in Non-Coding RNA Classification

    PubMed Central

    Dong, Xiaoqing; Fang, Yiliang; Wang, Kejing; Zhu, Lijuan; Wang, Ke; Huang, Tao

    2016-01-01

    With the development of new technologies in transcriptome and epigenetics, RNAs have been identified to play more and more important roles in life processes. Consequently, various methods have been proposed to assess the biological functions of RNAs and thus classify them functionally, among which comparative study of RNA structures is perhaps the most important one. To measure the structural similarity of RNAs and classify them, we propose a novel three dimensional (3D) graphical representation of RNA secondary structure, in which an RNA secondary structure is first transformed into a characteristic sequence based on chemical property of nucleic acids; a dynamic 3D graph is then constructed for the characteristic sequence; and lastly a numerical characterization of the 3D graph is used to represent the RNA secondary structure. We tested our algorithm on three datasets: (1) Dataset I consisting of nine RNA secondary structures of viruses, (2) Dataset II consisting of complex RNA secondary structures including pseudo-knots, and (3) Dataset III consisting of 18 non-coding RNA families. We also compare our method with other nine existing methods using Dataset II and III. The results demonstrate that our method is better than other methods in similarity measurement and classification of RNA secondary structures. PMID:27213271

  7. 3-D parallel program for numerical calculation of gas dynamics problems with heat conductivity on distributed memory computational systems (CS)

    SciTech Connect

    Sofronov, I.D.; Voronin, B.L.; Butnev, O.I.

    1997-12-31

    The aim of the work performed is to develop a 3D parallel program for numerical calculation of gas dynamics problem with heat conductivity on distributed memory computational systems (CS), satisfying the condition of numerical result independence from the number of processors involved. Two basically different approaches to the structure of massive parallel computations have been developed. The first approach uses the 3D data matrix decomposition reconstructed at temporal cycle and is a development of parallelization algorithms for multiprocessor CS with shareable memory. The second approach is based on using a 3D data matrix decomposition not reconstructed during a temporal cycle. The program was developed on 8-processor CS MP-3 made in VNIIEF and was adapted to a massive parallel CS Meiko-2 in LLNL by joint efforts of VNIIEF and LLNL staffs. A large number of numerical experiments has been carried out with different number of processors up to 256 and the efficiency of parallelization has been evaluated in dependence on processor number and their parameters.

  8. A Dynamic 3D Graphical Representation for RNA Structure Analysis and Its Application in Non-Coding RNA Classification.

    PubMed

    Zhang, Yi; Huang, Haiyun; Dong, Xiaoqing; Fang, Yiliang; Wang, Kejing; Zhu, Lijuan; Wang, Ke; Huang, Tao; Yang, Jialiang

    2016-01-01

    With the development of new technologies in transcriptome and epigenetics, RNAs have been identified to play more and more important roles in life processes. Consequently, various methods have been proposed to assess the biological functions of RNAs and thus classify them functionally, among which comparative study of RNA structures is perhaps the most important one. To measure the structural similarity of RNAs and classify them, we propose a novel three dimensional (3D) graphical representation of RNA secondary structure, in which an RNA secondary structure is first transformed into a characteristic sequence based on chemical property of nucleic acids; a dynamic 3D graph is then constructed for the characteristic sequence; and lastly a numerical characterization of the 3D graph is used to represent the RNA secondary structure. We tested our algorithm on three datasets: (1) Dataset I consisting of nine RNA secondary structures of viruses, (2) Dataset II consisting of complex RNA secondary structures including pseudo-knots, and (3) Dataset III consisting of 18 non-coding RNA families. We also compare our method with other nine existing methods using Dataset II and III. The results demonstrate that our method is better than other methods in similarity measurement and classification of RNA secondary structures. PMID:27213271

  9. Using 3D infrared imaging to calibrate and refine computational fluid dynamic modeling for large computer and data centers

    NASA Astrophysics Data System (ADS)

    Stockton, Gregory R.

    2011-05-01

    Over the last 10 years, very large government, military, and commercial computer and data center operators have spent millions of dollars trying to optimally cool data centers as each rack has begun to consume as much as 10 times more power than just a few years ago. In fact, the maximum amount of data computation in a computer center is becoming limited by the amount of available power, space and cooling capacity at some data centers. Tens of millions of dollars and megawatts of power are being annually spent to keep data centers cool. The cooling and air flows dynamically change away from any predicted 3-D computational fluid dynamic modeling during construction and as time goes by, and the efficiency and effectiveness of the actual cooling rapidly departs even farther from predicted models. By using 3-D infrared (IR) thermal mapping and other techniques to calibrate and refine the computational fluid dynamic modeling and make appropriate corrections and repairs, the required power for data centers can be dramatically reduced which reduces costs and also improves reliability.

  10. Dynamics of 3D Timoshenko gyroelastic beams with large attitude changes for the gyros

    NASA Astrophysics Data System (ADS)

    Hassanpour, Soroosh; Heppler, G. R.

    2016-01-01

    This work is concerned with the theoretical development of dynamic equations for undamped gyroelastic beams which are dynamic systems with continuous inertia, elasticity, and gyricity. Assuming unrestricted or large attitude changes for the axes of the gyros and utilizing generalized Hooke's law, Duleau torsion theory, and Timoshenko bending theory, the energy expressions and equations of motion for the gyroelastic beams in three-dimensional space are derived. The so-obtained comprehensive gyroelastic beam model is compared against earlier gyroelastic beam models developed using Euler-Bernoulli beam models and is used to study the dynamics of gyroelastic beams through numerical examples. It is shown that there are significant differences between the developed unrestricted Timoshenko gyroelastic beam model and the previously derived zero-order restricted Euler-Bernoulli gyroelastic beam models. These differences are more pronounced in the short beam and transverse gyricity cases.

  11. Beam dynamics study of RFQ for CADS with a 3D space-charge-effect

    NASA Astrophysics Data System (ADS)

    Li, Chao; Zhang, Zhi-Lei; Qi, Xin; Xu, Xian-Bo; He, Yuan; Yang, Lei

    2014-03-01

    The ADS (accelerator driven subcritical system) project was proposed by the Chinese Academy of Sciences. The initial proton beams delivered from an electron cyclotron resonance ion source can be effectively accelerated by 162.5 MHz 4.2 m long room temperature radio-frequency-quadrupoles (RFQ) operating in CW mode. To test the feasibility of this physical design, a new Fortran code for RFQ beam dynamics study, which is space charge dominated, was developed. This program is based on Particle-In-Cell (PIC) technique in the time domain. Using the RFQ structure designed for the CADS project, the beam dynamics behavior is performed. The well-known simulation code TRACK is used for benchmarks. The results given by these two codes show good agreements. Numerical techniques as well as the results of beam dynamics studies are presented in this paper.

  12. Dynamic Rupture Modeling in Three Dimensions on Unstructured Meshes Using a Discontinuous Galerkin Method

    NASA Astrophysics Data System (ADS)

    Pelties, C.; Käser, M.

    2010-12-01

    We will present recent developments concerning the extensions of the ADER-DG method to solve three dimensional dynamic rupture problems on unstructured tetrahedral meshes. The simulation of earthquake rupture dynamics and seismic wave propagation using a discontinuous Galerkin (DG) method in 2D was recently presented by J. de la Puente et al. (2009). A considerable feature of this study regarding spontaneous rupture problems was the combination of the DG scheme and a time integration method using Arbitrarily high-order DERivatives (ADER) to provide high accuracy in space and time with the discretization on unstructured meshes. In the resulting discrete velocity-stress formulation of the elastic wave equations variables are naturally discontinuous at the interfaces between elements. The so-called Riemann problem can then be solved to obtain well defined values of the variables at the discontinuity itself. This is in particular valid for the fault at which a certain friction law has to be evaluated. Hence, the fault’s geometry is honored by the computational mesh. This way, complex fault planes can be modeled adequately with small elements while fast mesh coarsening is possible with increasing distance from the fault. Due to the strict locality of the scheme using only direct neighbor communication, excellent parallel behavior can be observed. A further advantage of the scheme is that it avoids spurious high-frequency contributions in the slip rate spectra and therefore does not require artificial Kelvin-Voigt damping or filtering of synthetic seismograms. In order to test the accuracy of the ADER-DG method the Southern California Earthquake Center (SCEC) benchmark for spontaneous rupture simulations was employed. Reference: J. de la Puente, J.-P. Ampuero, and M. Käser (2009), Dynamic rupture modeling on unstructured meshes using a discontinuous Galerkin method, JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 114, B10302, doi:10.1029/2008JB006271

  13. Nucleation and Arrest of Dynamic Fault Rupture on a Pressurized Fault

    NASA Astrophysics Data System (ADS)

    Garagash, D.; Germanovich, L. N.

    2010-12-01

    Locally elevated pore pressure is a viable mechanism for reduction of fault strength and earthquake triggering. Possible sources of elevated pressure near faults that are associated with induced or triggered seismicity include (1) deep fluid injection into the crust (e.g., Healy et al, Science 1968); (2) fault-valve systems (inter-seismically impermeable fault transecting the suprahydrostatic pressure gradient, Sibson, Tectonophysics 1992); (3) metamorphic dehydration in thrust and normal fault systems. Although the mechanics of fault reactivation due to the pore pressure perturbation is generally well understood, there is a considerable lack of understanding of (1) the condition(s) under which the reactivation of fault slip leads to the nucleation of dynamic (earthquake) rupture; and (2) what is the extent of the dynamic rupture propagation before it is arrested (what separates micro-seismic events from earthquakes)? We address these questions by analyzing nucleation and possible arrest of the dynamic slip on a pressurized fault in the otherwise uniform background stress field. Evolving, locally-peaked pore pressure profile is generated by along-the-fault diffusion from a fluid source characterized by either a constant overpressure or constant flow rate. As a result, frictional strength of the fault, given by the product of the local normal effective stress and slip-weakening friction coefficient, reduces below the background stress within the pressurized region, which is expanding with time. This causes a shear crack, which growth is initially moderated by the pressure diffusion and, thus, quasi-static. The slip-weakening nature of friction suggests that the quasi-static growth may become eventually unstable, for example, leading to the nucleation of dynamic rupture. We extend the approach of Uenishi and Rice (JGR, 2003) to develop a solution for the extent of the nucleation patch and the time to the nucleation. A similar approach has been independently used by

  14. Constraining the Absolute Orientation of eta Carinae's Binary Orbit: A 3-D Dynamical Model for the Broad [Fe III] Emission

    NASA Technical Reports Server (NTRS)

    Madura, T. I.; Gull, T. R.; Owocki, S. P.; Groh, J. H.; Okazaki, A. T.; Russell, C. M. P.

    2011-01-01

    We present a three-dimensional (3-D) dynamical model for the broad [Fe III] emission observed in Eta Carinae using the Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS). This model is based on full 3-D Smoothed Particle Hydrodynamics (SPH) simulations of Eta Car's binary colliding winds. Radiative transfer codes are used to generate synthetic spectro-images of [Fe III] emission line structures at various observed orbital phases and STIS slit position angles (PAs). Through a parameter study that varies the orbital inclination i, the PA(theta) that the orbital plane projection of the line-of-sight makes with the apastron side of the semi-major axis, and the PA on the sky of the orbital axis, we are able, for the first time, to tightly constrain the absolute 3-D orientation of the binary orbit. To simultaneously reproduce the blue-shifted emission arcs observed at orbital phase 0.976, STIS slit PA = +38deg, and the temporal variations in emission seen at negative slit PAs, the binary needs to have an i approx. = 130deg to 145deg, Theta approx. = -15deg to +30deg, and an orbital axis projected on the sky at a P A approx. = 302deg to 327deg east of north. This represents a system with an orbital axis that is closely aligned with the inferred polar axis of the Homunculus nebula, in 3-D. The companion star, Eta(sub B), thus orbits clockwise on the sky and is on the observer's side of the system at apastron. This orientation has important implications for theories for the formation of the Homunculus and helps lay the groundwork for orbital modeling to determine the stellar masses.

  15. 3D Dynamics of Oblique Rift Systems: Fault Evolution from Rift to Break-up

    NASA Astrophysics Data System (ADS)

    Brune, S.

    2014-12-01

    Rift evolution and passive margin formation has been thoroughly investigated using conceptual and numerical models in two dimensions. However, the 2D assumption that the extension direction is perpendicular to the rift trend is often invalid. In fact, the majority of rift systems that lead to continental break-up during the last 150 My involved moderate to high rift obliquity. Yet, the degree to which oblique lithospheric extension affects first-order rift and passive margin properties like surface stress pattern, fault azimuths, and basin geometry, is still not entirely clear. This contribution provides insight in crustal stress patterns and fault orientations by applying a 3D numerical rift model to oblique extensional settings. The presented forward experiments cover the whole spectrum of oblique extension (i.e. rift-orthogonal extension, low obliquity, high obliquity, strike-slip deformation) from initial deformation to breakup. They are conducted using an elasto-visco-plastic finite element model and involve crustal and mantle layers accounting for self-consistent necking of the lithosphere. Even though the model setup is very simple (horizontally layered, no inherited faults), its evolution exhibits a variety of fault orientations that are solely caused by the interaction of far-field stresses with rift-intrinsic buoyancy and strength. Depending on rift obliquity, these orientations involve rift-parallel, extension-orthogonal, and intermediate normal fault directions as well as strike-slip faults. Allowing new insights on fault patterns of the proximal and distal margins, the model shows that individual fault populations are activated in a characteristic multi-phase evolution driven by lateral density variations of the evolving rift system. Model results are in very good agreement with inferences from the well-studied Gulf of Aden and provide testable predictions for other rifts and passive margins worldwide.

  16. 3D Case Studies of Monitoring Dynamic Structural Tests using Long Exposure Imagery

    NASA Astrophysics Data System (ADS)

    McCarthy, D. M. J.; Chandler, J. H.; Palmeri, A.

    2014-06-01

    Structural health monitoring uses non-destructive testing programmes to detect long-term degradation phenomena in civil engineering structures. Structural testing may also be carried out to assess a structure's integrity following a potentially damaging event. Such investigations are increasingly carried out with vibration techniques, in which the structural response to artificial or natural excitations is recorded and analysed from a number of monitoring locations. Photogrammetry is of particular interest here since a very high number of monitoring locations can be measured using just a few images. To achieve the necessary imaging frequency to capture the vibration, it has been necessary to reduce the image resolution at the cost of spatial measurement accuracy. Even specialist sensors are limited by a compromise between sensor resolution and imaging frequency. To alleviate this compromise, a different approach has been developed and is described in this paper. Instead of using high-speed imaging to capture the instantaneous position at each epoch, long-exposure images are instead used, in which the localised image of the object becomes blurred. The approach has been extended to create 3D displacement vectors for each target point via multiple camera locations, which allows the simultaneous detection of transverse and torsional mode shapes. The proposed approach is frequency invariant allowing monitoring of higher modal frequencies irrespective of a sampling frequency. Since there is no requirement for imaging frequency, a higher image resolution is possible for the most accurate spatial measurement. The results of a small scale laboratory test using off-the-shelf consumer cameras are demonstrated. A larger experiment also demonstrates the scalability of the approach.

  17. Scale-Dependent Friction and Damage Interface law: implications for effective earthquake rupture dynamics and radiation

    NASA Astrophysics Data System (ADS)

    Festa, Gaetano; Vilotte, Jean-Pierre; Raous, Michel; Henninger, Carole

    2010-05-01

    Propagation and radiation of an earthquake rupture is commonly considered as a friction dominated process on fault surfaces. Friction laws, such as the slip weakening and the rate-and-state laws are widely used in the modeling of the earthquake rupture process. These laws prescribe the traction evolution versus slip, slip rate and potentially other internal variables. They introduce a finite cohesive length scale over which the fracture energy is released. However faults are finite-width interfaces with complex internal structures, characterized by highly damaged zones embedding a very thin principal slip interface where most of the dynamic slip localizes. Even though the rupture process is generally investigated at wavelengths larger than the fault zone thickness, which should justify a formulation based upon surface energy, a consistent homogeneization, a very challenging problem, is still missing. Such homogeneization is however be required to derive the consistent form of an effective interface law, as well as the appropriate physical variables and length scales, to correctly describe the coarse-grained dissipation resulting from surface and volumetric contributions at the scale of the fault zone. In this study, we investigate a scale-dependent law, introduced by Raous et al. (1999) in the context of adhesive material interfaces, that takes into account the transition between a damage dominated and a friction dominated state. Such a phase-field formalism describes this transition through an order parameter. We first compare this law to standard slip weakening friction law in terms of the rupture nucleation. The problem is analyzed through the representation of the solution of the quasi-static elastic problem onto the Chebyshev polynomial basis, generalizing the Uenishi-Rice solution. The nucleation solutions, at the onset of instability, are then introduced as initial conditions for the study of the dynamic rupture propagation, in the case of in-plane rupture

  18. Dynamic fault rupture model of the 2008 Iwate-Miyagi Nairiku earthquake, Japan; Role of rupture velocity changes on extreme ground motions

    NASA Astrophysics Data System (ADS)

    Pulido Hernandez, N. E.; Dalguer Gudiel, L. A.; Aoi, S.

    2009-12-01

    The Iwate-Miyagi Nairiku earthquake, a reverse earthquake occurred in the southern Iwate prefecture Japan (2008/6/14), produced the largest peak ground acceleration recorded to date (4g) (Aoi et al. 2008), at the West Ichinoseki (IWTH25), KiK-net strong motion station of NIED. This station which is equipped with surface and borehole accelerometers (GL-260), also recorded very high peak accelerations up to 1g at the borehole level, despite being located in a rock site. From comparison of spectrograms of the observed surface and borehole records at IWTH25, Pulido et. al (2008) identified two high frequency (HF) ground motion events located at 4.5s and 6.3s originating at the source, which likely derived in the extreme observed accelerations of 3.9g and 3.5g at IWTH25. In order to understand the generation mechanism of these HF events we performed a dynamic fault rupture model of the Iwate-Miyagi Nairiku earthquake by using the Support Operator Rupture Dynamics (SORD) code, (Ely et al., 2009). SORD solves the elastodynamic equation using a generalized finite difference method that can utilize meshes of arbitrary structure and is capable of handling geometries appropriate to thrust earthquakes. Our spontaneous dynamic rupture model of the Iwate-Miyagi Nairiku earthquake is governed by the simple slip weakening friction law. The dynamic parameters, stress drop, strength excess and critical slip weakening distance are estimated following the procedure described in Pulido and Dalguer (2009) [PD09]. These parameters develop earthquake rupture consistent with the final slip obtained by kinematic source inversion of near source strong ground motion recordings. The dislocation model of this earthquake is characterized by a patch of large slip located ~7 km south of the hypocenter (Suzuki et al. 2009). Our results for the calculation of stress drop follow a similar pattern. Using the rupture times obtained from the dynamic model of the Iwate-Miyagi Nairiku earthquake we

  19. A method of improving the dynamic response of 3D force/torque sensors

    NASA Astrophysics Data System (ADS)

    Osypiuk, Rafał; Piskorowski, Jacek; Kubus, Daniel

    2016-02-01

    In the paper attention is drawn to adverse dynamic properties of filters implemented in commercial measurement systems, force/torque sensors, which are increasingly used in industrial robotics. To remedy the problem, it has been proposed to employ a time-variant filter with appropriately modulated parameters, owing to which it is possible to suppress the amplitude of the transient response and, at the same time, to increase the pulsation of damped oscillations; this results in the improvement of dynamic properties in terms of reducing the duration of transients. This property plays a key role in force control and in the fundamental problem of the robot establishing contact with rigid environment. The parametric filters have been verified experimentally and compared with filters available for force/torque sensors manufactured by JR3. The obtained results clearly indicate the advantages of the proposed solution, which may be an interesting alternative to the classic methods of filtration.

  20. Variable Quality Compression of Fluid Dynamical Data Sets Using a 3D DCT Technique

    NASA Astrophysics Data System (ADS)

    Loddoch, A.; Schmalzl, J.

    2005-12-01

    In this work we present a data compression scheme that is especially suited for the compression of data sets resulting from computational fluid dynamics (CFD). By adopting the concept of the JPEG compression standard and extending the approach of Schmalzl (Schmalzl, J. Using standard image compression algorithms to store data from computational fluid dynamics. Computers and Geosciences, 29, 10211031, 2003) we employ a three-dimensional discrete cosine transform of the data. The resulting frequency components are rearranged, quantized and finally stored using Huffman-encoding and standard variable length integer codes. The compression ratio and also the introduced loss of accuracy can be adjusted by means of two compression parameters to give the desired compression profile. Using the proposed technique compression ratios of more than 60:1 are possible with an mean error of the compressed data of less than 0.1%.

  1. Optimization of a 3D Dynamic Culturing System for In Vitro Modeling of Frontotemporal Neurodegeneration-Relevant Pathologic Features

    PubMed Central

    Tunesi, Marta; Fusco, Federica; Fiordaliso, Fabio; Corbelli, Alessandro; Biella, Gloria; Raimondi, Manuela T.

    2016-01-01

    Frontotemporal lobar degeneration (FTLD) is a severe neurodegenerative disorder that is diagnosed with increasing frequency in clinical setting. Currently, no therapy is available and in addition the molecular basis of the disease are far from being elucidated. Consequently, it is of pivotal importance to develop reliable and cost-effective in vitro models for basic research purposes and drug screening. To this respect, recent results in the field of Alzheimer’s disease have suggested that a tridimensional (3D) environment is an added value to better model key pathologic features of the disease. Here, we have tried to add complexity to the 3D cell culturing concept by using a microfluidic bioreactor, where cells are cultured under a continuous flow of medium, thus mimicking the interstitial fluid movement that actually perfuses the body tissues, including the brain. We have implemented this model using a neuronal-like cell line (SH-SY5Y), a widely exploited cell model for neurodegenerative disorders that shows some basic features relevant for FTLD modeling, such as the release of the FTLD-related protein progranulin (PRGN) in specific vesicles (exosomes). We have efficiently seeded the cells on 3D scaffolds, optimized a disease-relevant oxidative stress experiment (by targeting mitochondrial function that is one of the possible FTLD-involved pathological mechanisms) and evaluated cell metabolic activity in dynamic culture in comparison to static conditions, finding that SH-SY5Y cells cultured in 3D scaffold are susceptible to the oxidative damage triggered by a mitochondrial-targeting toxin (6-OHDA) and that the same cells cultured in dynamic conditions kept their basic capacity to secrete PRGN in exosomes once recovered from the bioreactor and plated in standard 2D conditions. We think that a further improvement of our microfluidic system may help in providing a full device where assessing basic FTLD-related features (including PRGN dynamic secretion) that may

  2. Non-linear dynamic analysis of ancient masonry structures by 3D rigid block models

    NASA Astrophysics Data System (ADS)

    Orduña, Agustin; Ayala, A. Gustavo

    2015-12-01

    This work presents a formulation for non-linear dynamic analysis of unreinforced masonry structures using rigid block models. This procedure is akin to the distinct element family of methods, nevertheless, we assume that small displacements occur and, therefore, the formulation does not involve the search for new contacts between blocks. This proposal is also related to the rigid element method, although, in this case we use full three-dimensional models and a more robust interface formulation.

  3. 3D Dynamics of Magnetopause Reconnection Using Hall-MHD Global Simulations

    NASA Astrophysics Data System (ADS)

    Maynard, K.; Germaschewski, K.; Raeder, J.; Bhattacharjee, A.

    2011-12-01

    Magnetic reconnection at Earth's magnetopause and in the magnetotail is of crucial importance for the dynamics of the global magnetosphere and space weather. Even though the plasma conditions in the magnetosphere are largely in the collisionless regime, most of the existing research using global computational models employ single-fluid magnetohydrodynamics (MHD) with artificial resistivity. Studies of reconnection in simplified, two-dimensional geometries have established that two-fluid and kinetic effects can dramatically alter dynamics and reconnection rates when compared with single-fluid models. These enhanced models also introduce particular signatures, for example a quadrupolar out-of-plane magnetic field component that has already been observed in space by satellite measurements. However, results from simplified geometries cannot be translated directly to the dynamics of three-dimensional magnetospheric reconnection. For instance, magnetic flux originating from the solar wind and arriving at the magnetopause can either reconnect or be advected around the magnetosphere. In this study, we use a new version of the OpenGGCM code that incorporates the Hall term in a Generalized Ohm's Law to study magnetopause reconnection under synthetic solar wind conditions and investigate how reconnection rates and dynamics of flux transfer events depend on the strength of the Hall term. The OpenGGCM, a global model of Earth's magnetosphere, has recently been ported to exploit modern computing architectures like the Cell processor and SIMD capabilities of conventional processors using an automatic code generator. These enhancements provide us with the performance needed to include the computationally expensive Hall physics.

  4. Numerical simulation of 3D unsteady flow in a rotating pump by dynamic mesh technique

    NASA Astrophysics Data System (ADS)

    Huang, S.; Guo, J.; Yang, F. X.

    2013-12-01

    In this paper, the numerical simulation of unsteady flow for three kinds of typical rotating pumps, roots blower, roto-jet pump and centrifugal pump, were performed using the three-dimensional Dynamic Mesh technique. In the unsteady simulation, all the computational domains, as stationary, were set in one inertial reference frame. The motions of the solid boundaries were defined by the Profile file in FLUENT commercial code, in which the rotational orientation and speed of the rotors were specified. Three methods (Spring-based Smoothing, Dynamic Layering and Local Re-meshing) were used to achieve mesh deformation and re-meshing. The unsteady solutions of flow field and pressure distribution were solved. After a start-up stage, the flow parameters exhibit time-periodic behaviour corresponding to blade passing frequency of rotor. This work shows that Dynamic Mesh technique could achieve numerical simulation of three-dimensional unsteady flow field in various kinds of rotating pumps and have a strong versatility and broad application prospects.

  5. Numerical Modeling of 3-D Dynamics of Ultrasound Contrast Agent Microbubbles Using the Boundary Integral Method

    NASA Astrophysics Data System (ADS)

    Calvisi, Michael; Manmi, Kawa; Wang, Qianxi

    2014-11-01

    Ultrasound contrast agents (UCAs) are microbubbles stabilized with a shell typically of lipid, polymer, or protein and are emerging as a unique tool for noninvasive therapies ranging from gene delivery to tumor ablation. The nonspherical dynamics of contrast agents are thought to play an important role in both diagnostic and therapeutic applications, for example, causing the emission of subharmonic frequency components and enhancing the uptake of therapeutic agents across cell membranes and tissue interfaces. A three-dimensional model for nonspherical contrast agent dynamics based on the boundary integral method is presented. The effects of the encapsulating shell are approximated by adapting Hoff's model for thin-shell, spherical contrast agents to the nonspherical case. A high-quality mesh of the bubble surface is maintained by implementing a hybrid approach of the Lagrangian method and elastic mesh technique. Numerical analyses for the dynamics of UCAs in an infinite liquid and near a rigid wall are performed in parameter regimes of clinical relevance. The results show that the presence of a coating significantly reduces the oscillation amplitude and period, increases the ultrasound pressure amplitude required to incite jetting, and reduces the jet width and velocity.

  6. Haptic perception of force magnitude and its relation to postural arm dynamics in 3D

    PubMed Central

    van Beek, Femke E.; Bergmann Tiest, Wouter M.; Mugge, Winfred; Kappers, Astrid M. L.

    2015-01-01

    In a previous study, we found the perception of force magnitude to be anisotropic in the horizontal plane. In the current study, we investigated this anisotropy in three dimensional space. In addition, we tested our previous hypothesis that the perceptual anisotropy was directly related to anisotropies in arm dynamics. In experiment 1, static force magnitude perception was studied using a free magnitude estimation paradigm. This experiment revealed a significant and consistent anisotropy in force magnitude perception, with forces exerted perpendicular to the line between hand and shoulder being perceived as 50% larger than forces exerted along this line. In experiment 2, postural arm dynamics were measured using stochastic position perturbations exerted by a haptic device and quantified through system identification. By fitting a mass-damper-spring model to the data, the stiffness, damping and inertia parameters could be characterized in all the directions in which perception was also measured. These results show that none of the arm dynamics parameters were oriented either exactly perpendicular or parallel to the perceptual anisotropy. This means that endpoint stiffness, damping or inertia alone cannot explain the consistent anisotropy in force magnitude perception. PMID:26643041

  7. Virgo Cluster and field dwarf ellipticals in 3D - II. Internal dynamics points to tidal harassment?

    NASA Astrophysics Data System (ADS)

    Ryś, A.; van de Ven, G.; Falcón-Barroso, J.

    2014-03-01

    We present the dynamical analysis of a sample of 12 dwarf elliptical (dE) galaxies for which we have obtained SAURON large-scale two-dimensional spectroscopic data. We construct Jeans axisymmetric models and obtain total dynamical masses enclosed within one effective radius. We use the obtained values to show that the validity of the dynamical scaling relations of massive early-type galaxies can be extended to these low-mass systems, except that dEs seem to contain relatively larger fraction of dark matter in their inner parts. We then demonstrate that dE galaxies have lower angular momenta than the present-day analogues of their presumed late-type progenitors, and we show that dE circular velocity curves are steeper than the rotation curves of galaxies with equal and up to an order of magnitude higher luminosity. This requires a transformation mechanism that is not only able to lower the angular momentum but also one that needs to account for increased stellar concentration. Additionally, we match the dark matter fraction of our galaxies to their location in the Virgo Cluster and see that galaxies in the cluster outskirts tend to have a higher dark-to-stellar matter ratio. Transformation due to tidal harassment is able to explain all of the above, unless the dE progenitors were already compact and had lower angular momenta at higher redshifts.

  8. Measuring dynamic cell–material interactions and remodeling during 3D human mesenchymal stem cell migration in hydrogels

    PubMed Central

    Schultz, Kelly M.; Kyburz, Kyle A.; Anseth, Kristi S.

    2015-01-01

    Biomaterials that mimic aspects of the extracellular matrix by presenting a 3D microenvironment that cells can locally degrade and remodel are finding increased applications as wound-healing matrices, tissue engineering scaffolds, and even substrates for stem cell expansion. In vivo, cells do not simply reside in a static microenvironment, but instead, they dynamically reengineer their surroundings. For example, cells secrete proteases that degrade extracellular components, attach to the matrix through adhesive sites, and can exert traction forces on the local matrix, causing its spatial reorganization. Although biomaterials scaffolds provide initially well-defined microenvironments for 3D culture of cells, less is known about the changes that occur over time, especially local matrix remodeling that can play an integral role in directing cell behavior. Here, we use microrheology as a quantitative tool to characterize dynamic cellular remodeling of peptide-functionalized poly(ethylene glycol) (PEG) hydrogels that degrade in response to cell-secreted matrix metalloproteinases (MMPs). This technique allows measurement of spatial changes in material properties during migration of encapsulated cells and has a sensitivity that identifies regions where cells simply adhere to the matrix, as well as the extent of local cell remodeling of the material through MMP-mediated degradation. Collectively, these microrheological measurements provide insight into microscopic, cellular manipulation of the pericellular region that gives rise to macroscopic tracks created in scaffolds by migrating cells. This quantitative and predictable information should benefit the design of improved biomaterial scaffolds for medically relevant applications. PMID:26150508

  9. Dynamically Self-consistent Simulations of the 3D Gravity and Magnetic Fields to be Measured by Juno at Jupiter

    NASA Astrophysics Data System (ADS)

    Glatzmaier, G.

    2013-12-01

    In 2016 NASA's Juno spacecraft will begin making high fidelity gravity and magnetic measurements near the surface of Jupiter that will provide clues to Jupiter's internal structure and dynamics. To prepare for the interpretation of these data, we are producing 3D dynamo simulations that self-consistently solve for the gravity and magnetic fields throughout the interior and exterior of our simulated gas giant. Knowing the trajectories of the 34 11-day polar orbits Juno will make around Jupiter as Jupiter rotates, we calculate the three components of the gravity and magnetic fields that Juno would measure as a function of time for two different simulated giant planet dynamos: one having latitudinally banded zonal winds that exist only in a shallow surface layer and one with banded zonal winds that extend deep below the surface. The different dynamo solutions are obtained by making different specifications for poorly known quantities, like the amplitude and radial dependence of the effective viscous diffusivity within Jupiter. By identifying fundamental differences in the 3D data that Juno would collect for these two scenarios, we will provide a dynamically self-consistent test for inferring the structure and amplitude of the zonal winds in Jupiter's interior. For example, a latitudinally banded pattern of magnetic field measured by Juno would suggest that strong zonal winds extend well below the surface to where the electrical conductivity is high enough for the generation of Jupiter's magnetic field.

  10. Seasonal dynamics and stoichiometry of the planktonic community in the NW Mediterranean Sea: a 3D modeling approach

    NASA Astrophysics Data System (ADS)

    Alekseenko, Elena; Raybaud, Virginie; Espinasse, Boris; Carlotti, François; Queguiner, Bernard; Thouvenin, Bénédicte; Garreau, Pierre; Baklouti, Melika

    2014-01-01

    The 3D hydrodynamic Model for Applications at Regional Scale (MARS3D) was coupled with a biogeochemical model developed with the Ecological Modular Mechanistic Modelling (Eco3M) numerical tool. The three-dimensional coupled model was applied to the NW Mediterranean Sea to study the dynamics of the key biogeochemical processes in the area in relation with hydrodynamic constraints. In particular, we focused on the temporal and spatial variability of intracellular contents of living and non-living compartments. The conceptual scheme of the biogeochemical model accounts for the complex food web of the NW Mediterranean Sea (34 state variables), using flexible plankton stoichiometry. We used mechanistic formulations to describe most of the biogeochemical processes involved in the dynamics of marine pelagic ecosystems. Simulations covered the period from September 1, 2009 to January 31, 2011 (17 months), which enabled comparison of model outputs with situ measurements made during two oceanographic cruises in the region (Costeau-4: April 27-May 2, 2010 and Costeau-6: January 23-January 27, 2011).

  11. 3D Dynamics of Magnetic Flux Ropes Across Scales: Solar Eruptions and Sun-Earth Plasma Coupling

    NASA Astrophysics Data System (ADS)

    Chen, James

    2012-10-01

    Central to the understanding of the eruptive phenomena on the Sun and their impact on the terrestrial plasma environment is the dynamics of coronal mass ejections (CMEs)---a 3D magnetic flux rope configuration---and the evolution of their magnetic fields. I will discuss the basic physics of CME eruption and solar flare energy release in the context of the analytic erupting flux rope model of CMEs. In this ideal MHD model, a CME is treated as a 3D flux rope with its two stationary footpoints anchored in the Sun. The model structure is non-axisymmetric and embedded in a model corona/solar wind. The initial flux rope is driven out of equilibrium by ``injection'' of poloidal flux and propagates under the Lorentz hoop force from the Sun to 1 AU, across a wide range of spatial and temporal scales. Comparisons of the model results and recent STEREO observations show that the solutions that best fit the observed CME position-time data (to within 1-2% of data) also correctly replicate the temporal profiles of associated flare X-ray emissions (GOES data) and the in situ magnetic field and plasma data of the CME ejecta at 1 AU where such data are available (e.g., ACE and STEREO/IMPAXCT/PLASTIC data), providing a unified basis of understanding CME dynamics and flare energetics.

  12. Complex scenes and situations visualization in hierarchical learning algorithm with dynamic 3D NeoAxis engine

    NASA Astrophysics Data System (ADS)

    Graham, James; Ternovskiy, Igor V.

    2013-06-01

    We applied a two stage unsupervised hierarchical learning system to model complex dynamic surveillance and cyber space monitoring systems using a non-commercial version of the NeoAxis visualization software. The hierarchical scene learning and recognition approach is based on hierarchical expectation maximization, and was linked to a 3D graphics engine for validation of learning and classification results and understanding the human - autonomous system relationship. Scene recognition is performed by taking synthetically generated data and feeding it to a dynamic logic algorithm. The algorithm performs hierarchical recognition of the scene by first examining the features of the objects to determine which objects are present, and then determines the scene based on the objects present. This paper presents a framework within which low level data linked to higher-level visualization can provide support to a human operator and be evaluated in a detailed and systematic way.

  13. Progress in the Peeling-Ballooning Model of ELMs: Numerical Studies of 3D Nonlinear ELM Dynamics

    SciTech Connect

    Snyder, P B; Wilson, H R; Xu, X Q

    2004-12-13

    Nonlinear simulations with the 3D electromagnetic two-fluid BOUT code are employed to study the dynamics of edge localized modes (ELMs) driven by intermediate wavelength peeling-ballooning modes. It is found that the early behavior of the modes is similar to expectations from linear, ideal peeling-ballooning mode theory, with the modes growing linearly at a fraction of the Alfven frequency. In the non-linear phase, the modes grow explosively, forming a number of extended filaments which propagate rapidly from the outer closed flux region into the open flux region toward the outer wall. Similarities to non-linear linear ballooning theory, as well as additional complexities are observed. Comparison to observations reveals a number of similarities. Implications of the simulations and proposals for the dynamics of the full ELM crash are discussed.

  14. PROGRESS IN THE PEELING-BALLOONING MODEL OF ELMS: NUMERICAL STUDIES OF 3D NONLINEAR ELM DYNAMICS

    SciTech Connect

    SNYDER,P.B; WILSON,H.R; XU,X.Q

    2004-11-01

    Nonlinear simulations with the 3D electromagnetic two-fluid BOUT code are employed to study the dynamics of edge localized modes (ELMs) driven by intermediate wavelength peeling-ballooning modes. It is found that the early behavior of the modes is similar to expectations from linear, ideal peeling-ballooning mode theory, with the modes growing linearly at a fraction of the Alfven frequency. In the nonlinear phase, the modes grow explosively, forming a number of extended filaments which propagate rapidly from the outer closed flux region into the open flux region toward the outboard wall. Similarities to non-linear ballooning theory, as well as additional complexities are observed. Comparison to observations reveals a number of similarities. Implications of the simulations and proposals for the dynamics of the full ELM crash are discussed.

  15. Creep rupture of fiber bundles: A molecular dynamics investigation

    NASA Astrophysics Data System (ADS)

    Linga, G.; Ballone, P.; Hansen, Alex

    2015-08-01

    The creep deformation and eventual breaking of polymeric samples under a constant tensile load F is investigated by molecular dynamics based on a particle representation of the fiber bundle model. The results of the virtual testing of fibrous samples consisting of 40 000 particles arranged on Nc=400 chains reproduce characteristic stages seen in the experimental investigations of creep in polymeric materials. A logarithmic plot of the bundle lifetime τ versus load F displays a marked curvature, ruling out a simple power-law dependence of τ on F . A power law τ ˜F-4 , however, is recovered at high load. We discuss the role of reversible bond breaking and formation on the eventual fate of the sample and simulate a different type of creep testing, imposing a constant stress rate on the sample up to its breaking point. Our simulations, relying on a coarse-grained representation of the polymer structure, introduce new features into the standard fiber bundle model, such as real-time dynamics, inertia, and entropy, and open the way to more detailed models, aiming at material science aspects of polymeric fibers, investigated within a sound statistical mechanics framework.

  16. Dynamic 3D shape of the plantar surface of the foot using coded structured light: a technical report

    PubMed Central

    2014-01-01

    Background The foot provides a crucial contribution to the balance and stability of the musculoskeletal system, and accurate foot measurements are important in applications such as designing custom insoles/footwear. With better understanding of the dynamic behavior of the foot, dynamic foot reconstruction techniques are surfacing as useful ways to properly measure the shape of the foot. This paper presents a novel design and implementation of a structured-light prototype system providing dense three dimensional (3D) measurements of the foot in motion. The input to the system is a video sequence of a foot during a single step; the output is a 3D reconstruction of the plantar surface of the foot for each frame of the input. Methods Engineering and clinical tests were carried out to test the accuracy and repeatability of the system. Accuracy experiments involved imaging a planar surface from different orientations and elevations and measuring the fitting errors of the data to a plane. Repeatability experiments were done using reconstructions from 27 different subjects, where for each one both right and left feet were reconstructed in static and dynamic conditions over two different days. Results The static accuracy of the system was found to be 0.3 mm with planar test objects. In tests with real feet, the system proved repeatable, with reconstruction differences between trials one week apart averaging 2.4 mm (static case) and 2.8 mm (dynamic case). Conclusion The results obtained in the experiments show positive accuracy and repeatability results when compared to current literature. The design also shows to be superior to the systems available in the literature in several factors. Further studies need to be done to quantify the reliability of the system in clinical environments. PMID:24456711

  17. MERIDIONAL CIRCULATION DYNAMICS FROM 3D MAGNETOHYDRODYNAMIC GLOBAL SIMULATIONS OF SOLAR CONVECTION

    SciTech Connect

    Passos, Dário; Charbonneau, Paul; Miesch, Mark

    2015-02-10

    The form of solar meridional circulation is a very important ingredient for mean field flux transport dynamo models. However, a shroud of mystery still surrounds this large-scale flow, given that its measurement using current helioseismic techniques is challenging. In this work, we use results from three-dimensional global simulations of solar convection to infer the dynamical behavior of the established meridional circulation. We make a direct comparison between the meridional circulation that arises in these simulations and the latest observations. Based on our results, we argue that there should be an equatorward flow at the base of the convection zone at mid-latitudes, below the current maximum depth helioseismic measures can probe (0.75 R{sub ⊙}). We also provide physical arguments to justify this behavior. The simulations indicate that the meridional circulation undergoes substantial changes in morphology as the magnetic cycle unfolds. We close by discussing the importance of these dynamical changes for current methods of observation which involve long averaging periods of helioseismic data. Also noteworthy is the fact that these topological changes indicate a rich interaction between magnetic fields and plasma flows, which challenges the ubiquitous kinematic approach used in the vast majority of mean field dynamo simulations.

  18. 3D dislocation dynamics: stress-strain behavior and hardening mechanisms in FCC and BCC metals

    SciTech Connect

    Hirth, J P; Rhee, M; Zhib, H M; de la Rubia, T D

    1999-02-19

    A dislocation dynamics (DD) model for plastic deformation, connecting the macroscopic mechanical properties to basic physical laws governing dislocation mobility and related interaction mechanisms, has been under development. In this model there is a set of critical reactions that determine the overall results of the simulations, such as the stress-strain curve. These reactions are, annihilation, formation of jogs, junctions, and dipoles, and cross-slip. In this paper we discuss these reactions and the manner in which they influence the simulated stress- strain behavior in fcc and bcc metals. In particular, we examine the formation (zipping) and strength of dipoles and junctions, and effect of jogs, using the dislocation dynamics model. We show that the strengths (unzipping) of these reactions for various configurations can be determined by direct evaluation of the elastic interactions. Next, we investigate the phenomenon of hardening in metals subjected to cascade damage dislocations. The microstructure investigated consists of small dislocation loops decorating the mobile dislocations. Preliminary results reveal that these loops act as hardening agents, trapping the dislocations and resulting in increased hardening.

  19. High dynamic range image acquisition method for 3D solder paste measurement

    NASA Astrophysics Data System (ADS)

    Li, Xiaohui; Sun, Changku; Wang, Peng; Xu, Yixin

    2013-12-01

    In the solder paste inspection measurement system which is based on the structured light vision technology, the local oversaturation will emerge because of the reflection coefficient when the laser light project on PCB surface. As this, a high dynamic imaging acquisition system for the solder paste inspection research is researched to reduce the local oversaturation and misjudge. The Reflective liquid crystal on silicon has the merit that it can adjust the reflectance of the Incident light per-pixel. According to this merit, the high dynamic imaging acquisition system based on liquid crystal on silicon (LCoS) was built which using the high-resolution LCoS and CCD image sensor. The optical system was constructed by the imaging lens, the relay lens, the Polarizing Beam Splitter (PBS), and the hardware system was consist of ARM development board, video generic board, MCU and HX7809 according to the electrical characteristics of LCoS. Tests show that the system could reduce the phenomenon of image oversaturation and improve the quality of image.

  20. Dwarf ellipticals in the eye of SAURON: dynamical & stellar population analysis in 3D

    NASA Astrophysics Data System (ADS)

    Ryś, Agnieszka; Falcón-Barroso, Jesús; van de Ven, Glenn; Koleva, Mina

    2015-02-01

    We present the dynamical and stellar population analysis of 12 dwarf elliptical galaxies (dEs) observed using the SAURON IFU (WHT, La Palma). We demonstrate that dEs have lower angular momenta than their presumed late-type progenitors and we show that dE circular velocity curves are steeper than the rotation curves of galaxies with equal and up to an order of magnitude higher luminosity. Transformation due to tidal harassment is able to explain all of the above, unless the dE progenitors were already compact and had lower angular momenta at higher redshifts. We then look at the star formation histories (SFHs) of our galaxies and find that for the majority of them star formation activity was either still strong at a few Gyr of age or they experienced a secondary burst of star formation roughly at that time. This latter possibility would be in agreement with the scenario where tidal harassment drives the remaining gas inwards and induces a secondary star formation episode. Finally, one of our galaxies appears to be composed exclusively of an old population (>~12 Gyr). Combining this with our earlier dynamical results, we conclude that it either was ram-pressure stripped early on in its evolution in a group environment and subsequently tidally heated (which lowered its angular momentum and increased compactness), or that it evolved in situ in the cluster's central parts, compact enough to avoid tidal disruption.

  1. Solving the dynamic rupture problem with different numerical approaches and constitutive laws

    USGS Publications Warehouse

    Bizzarri, A.; Cocco, M.; Andrews, D.J.; Boschi, Enzo

    2001-01-01

    We study the dynamic initiation, propagation and arrest of a 2-D in-plane shear rupture by solving the elastodynamic equation by using both a boundary integral equation method and a finite difference approach. For both methods we adopt different constitutive laws: a slip-weakening (SW) law, with constant weakening rate, and rate- and state-dependent friction laws (Dieterich-Ruina). Our numerical procedures allow the use of heterogeneous distributions of constitutive parameters along the fault for both formulations. We first compare the two solution methods with an SW law, emphasizing the required stability conditions to achieve a good resolution of the cohesive zone and to avoid artificial complexity in the solutions. Our modelling results show that the two methods provide very similar time histories of dynamic source parameters. We point out that, if a careful control of resolution and stability is performed, the two methods yield identical solutions. We have also compared the rupture evolution resulting from an SW and a rate- and state-dependent friction law. This comparison shows that despite the different constitutive formulations, a similar behaviour is simulated during the rupture propagation and arrest. We also observe a crack tip bifurcation and a jump in rupture velocity (approaching the P-wave speed) with the Dieterich-Ruina (DR) law. The rupture arrest at a barrier (high strength zone) and the barrier-healing mechanism are also reproduced by this law. However, this constitutive formulation allows the simulation of a more general and complex variety of rupture behaviours. By assuming different heterogeneous distributions of the initial constitutive parameters, we are able to model a barrier-healing as well as a self-healing process. This result suggests that if the heterogeneity of the constitutive parameters is taken into account, the different healing mechanisms can be simulated. We also study the nucleation phase duration Tn, defined as the time

  2. Depth-kymography: high-speed calibrated 3D imaging of human vocal fold vibration dynamics

    NASA Astrophysics Data System (ADS)

    George, Nibu A.; de Mul, Frits F. M.; Qiu, Qingjun; Rakhorst, Gerhard; Schutte, Harm K.

    2008-05-01

    We designed and developed a laser line-triangulation endoscope compatible with any standard high-speed camera for a complete three-dimensional profiling of human vocal fold vibration dynamics. With this novel device we are able to measure absolute values of vertical and horizontal vibration amplitudes, length and width of vocal folds as well as the opening and closing velocities from a single in vivo measurement. We have studied, for the first time, the generation and propagation of mucosal waves by locating the position of its maximum vertical position and the propagation velocity. Precise knowledge about the absolute dimensions of human vocal folds and their vibration parameters has significant importance in clinical diagnosis and treatment as well as in fundamental research in voice. The new device can be used to investigate different kinds of pathological conditions including periodic or aperiodic vibrations. Consequently, the new device has significant importance in investigating vocal fold paralysis and in phonosurgical applications.

  3. A 3D model for α Gem AB: orbits and dynamics

    NASA Astrophysics Data System (ADS)

    Docobo, José A.; Andrade, Manuel; Campo, Pedro P.; Ling, Josefina F.

    2016-01-01

    The well-known multiple star system, Castor, and particularly, the [(Aa, Ab), (Ba, Bb)] subsystem, was studied in detail. After a rigorous analysis of the quality controls, a new solution for the visual orbit yielded new values for the different physical and orbital parameters of the system. In addition, a comprehensive investigation of the orbital configuration of the quadruple system allowed us to provide both accurate individual masses and orbital inclinations of the spectroscopic subcomponents, as well as a new value of its orbital parallax. Finally, by means of a numerical analysis of the long-term dynamics, we obtained the most probable values of the nodal angles of the two spectroscopic subsystems for the first time.

  4. Dynamical electron compressibility in the 3D topological insulator Bi2Se3

    NASA Astrophysics Data System (ADS)

    Inhofer, Andreas; Assaf, Badih; Wilmart, Quentin; Veyrat, Louis; Nowka, Christian; Dufouleur, Joseph; Giraud, Romain; Hampel, Silke; Buechner, Bernd; Fève, Gwendal; Berroir, Jean-Marc; Placais, Bernard

    Measurements of the quantum capacitance cq, related to the electron compressibility χ =cq /e2 is a sensitive tool to probe the density of states. In a topological insulator (TI) the situation is enriched by the coexistence and the interplay of topologically protected surface states and massive bulk carriers. We investigate top-gate metal-oxyde-TI capacitors using Bi2Se3 thin crystals at GHz frequencies. These measurements provide insight into the compressibillity of such a two electron-fluid system. Furthermore, the dynamical response yields information about electron scattering properties in TIs. More specifically, in our measurements we track simultaneously the conductivity σ and the compressibility as a function of a DC-gate voltage. Using the Einstein relation σ =cq D , we have access to the gate dependence of the electron diffusion constant D (Vg) , a signature of the peculiar scattering mechanisms in TIs.

  5. MORPHOLOGY AND DYNAMICS OF SOLAR PROMINENCES FROM 3D MHD SIMULATIONS

    SciTech Connect

    Terradas, J.; Soler, R.; Oliver, R.; Ballester, J. L.; Luna, M.

    2015-01-20

    In this paper we present a numerical study of the time evolution of solar prominences embedded in sheared magnetic arcades. The prominence is represented by a density enhancement in a background-stratified atmosphere and is connected to the photosphere through the magnetic field. By solving the ideal magnetohydrodynamic equations in three dimensions, we study the dynamics for a range of parameters representative of real prominences. Depending on the parameters considered, we find prominences that are suspended above the photosphere, i.e., detached prominences, but also configurations resembling curtain or hedgerow prominences whose material continuously connects to the photosphere. The plasma-β is an important parameter that determines the shape of the structure. In many cases magnetic Rayleigh-Taylor instabilities and oscillatory phenomena develop. Fingers and plumes are generated, affecting the whole prominence body and producing vertical structures in an essentially horizontal magnetic field. However, magnetic shear is able to reduce or even to suppress this instability.

  6. A parallel dynamic load balancing algorithm for 3-D adaptive unstructured grids

    NASA Technical Reports Server (NTRS)

    Vidwans, A.; Kallinderis, Y.; Venkatakrishnan, V.

    1993-01-01

    Adaptive local grid refinement and coarsening results in unequal distribution of workload among the processors of a parallel system. A novel method for balancing the load in cases of dynamically changing tetrahedral grids is developed. The approach employs local exchange of cells among processors in order to redistribute the load equally. An important part of the load balancing algorithm is the method employed by a processor to determine which cells within its subdomain are to be exchanged. Two such methods are presented and compared. The strategy for load balancing is based on the Divide-and-Conquer approach which leads to an efficient parallel algorithm. This method is implemented on a distributed-memory MIMD system.

  7. Micronozzles: 3D numerical structural and gas dynamics modeling, fabrication, and preliminary experimental results

    NASA Astrophysics Data System (ADS)

    Borovkov, Alexei I.; Pyatishev, Evgenij N.; Lurie, Mihail S.; Korshunov, Andrey V.; Akulshin, Y. D.; Dolganov, A. G.; Sabadash, V. O.

    2001-02-01

    The tiny engines, founded on the principle of reactive thrust, are one of most perspective actuators developed by modern micromechanics. These engines can be applied for such apparent problems, as orientation and stabilization of small space objects, but also as local or distributed reactive thrust of new phylum of aerospace objects, for control of boundary layer of flying objects and in series of converting power devices of different purposes. Distinctive features of jet tiny engines are profitability (very large thrust-to-weight ratio) and high (milliseconds) response, which makes them to irreplaceable elements in control systems and, specially, in distributed power generations. These features are provided the minimum sizes, high pressure in working chambers and hypersonic velocity of propulsive jet. Topologically micronozzles are designed as the flat batch devices (3 layers as minimum). The lower and upper layers make flat walls of the nozzle and mainly influence on strength properties of the device. The mean layer reshapes geometry and determines gas dynamic characteristic of the nozzle. A special problem is the opening-up of the combustion-mixture, which is not esteemed in this work. It is necessary to allow for effect of considerable local stresses arising at the expense of static and dynamic loading at design of the jet tiny engines. Thermal gas dynamic processes in the chamber and nozzle determine the values and nature of these stresses, which are hardly studied for the microdevices. The priority is mathematical and experimental simulation of these processes. The most suitable object for initial phase of experimental simulation is the 'cold' engine. The demanded chamber static pressure is formed by external compressed air. In Laboratory of Microtechnology and MicroElectroMechanical Systems a number of such tiny engines with different shapes of the chamber's and the nozzles' surfaces were designed, made and tested. The engines were produced from photosensing

  8. Micronozzles: 3D numerical structural and gas dynamics modeling, fabrication, and preliminary experimental results

    NASA Astrophysics Data System (ADS)

    Borovkov, Alexei I.; Pyatishev, Evgenij N.; Lurie, Mihail S.; Korshunov, Andrey V.; Akulshin, Y. D.; Dolganov, A. G.; Sabadash, V. O.

    2000-02-01

    The tiny engines, founded on the principle of reactive thrust, are one of most perspective actuators developed by modern micromechanics. These engines can be applied for such apparent problems, as orientation and stabilization of small space objects, but also as local or distributed reactive thrust of new phylum of aerospace objects, for control of boundary layer of flying objects and in series of converting power devices of different purposes. Distinctive features of jet tiny engines are profitability (very large thrust-to-weight ratio) and high (milliseconds) response, which makes them to irreplaceable elements in control systems and, specially, in distributed power generations. These features are provided the minimum sizes, high pressure in working chambers and hypersonic velocity of propulsive jet. Topologically micronozzles are designed as the flat batch devices (3 layers as minimum). The lower and upper layers make flat walls of the nozzle and mainly influence on strength properties of the device. The mean layer reshapes geometry and determines gas dynamic characteristic of the nozzle. A special problem is the opening-up of the combustion-mixture, which is not esteemed in this work. It is necessary to allow for effect of considerable local stresses arising at the expense of static and dynamic loading at design of the jet tiny engines. Thermal gas dynamic processes in the chamber and nozzle determine the values and nature of these stresses, which are hardly studied for the microdevices. The priority is mathematical and experimental simulation of these processes. The most suitable object for initial phase of experimental simulation is the 'cold' engine. The demanded chamber static pressure is formed by external compressed air. In Laboratory of Microtechnology and MicroElectroMechanical Systems a number of such tiny engines with different shapes of the chamber's and the nozzles' surfaces were designed, made and tested. The engines were produced from photosensing

  9. Modeling Dynamic Source Rupture with Slip Reactivation and Near-Source Ground Motion of the 2012 Mw 9.0 Tohoku earthquake

    NASA Astrophysics Data System (ADS)

    Galvez, P.; Dalguer, L. A.; Ampuero, J. P.

    2012-12-01

    The compilation of seismological, geodetic, bathymetric and tsunami observations as well as source inversion and back-projection studies of the 2011 Mw 9.0 Tohoku earthquake show that this earthquake is mainly characterized by three main features: 1) unusual large slip over 50m; 2) complex rupture patterns with multiple rupture fronts and slip reactivation; 3) distinct depth dependent frequency radiation patterns, in which the shallower part of the fault dominate the low frequency radiation and the deep part dominates the high frequency radiation. Earthquakes with extremely large slip can result from fault melting, pressurization, lubrication or other thermal weakening mechanisms that reduces further the frictional strength to lower levels. Kanamori and Heaton (2000) proposed a friction model in which frictional strength drops initially to certain value, but then at large slips there is a second drop of the frictional strength. We use Kanamori and Heaton's friction model to investigate the features mentioned above in a simple spontaneous dynamic rupture asperity model governed by slip weakening friction. The model is composed of large asperity patches of radius between 30 to 50 km in the intermediate and shallower part, and small patches of asperities at the bottom of the fault to account for the strong high frequency radiation. The very shallow part of the fault is considered as a stable zone that operates during rupture with an enhanced energy absorption mechanism. We model this zone by assuming negative stress drop and large critical slip distance. In our first attempt, we assume a planar fault using a 3D finite difference code, in which we reproduced the main three features mentioned above: rupture initiates propagating toward east and north. After around 40 sec of rupture initiation, the second drop of the frictional strength in the main asperity produces strong slip reactivation capable to break the free-surface with large slip. This slip reactivation also

  10. A molecular dynamics implementation of the 3D Mercedes-Benz water model

    NASA Astrophysics Data System (ADS)

    Hynninen, T.; Dias, C. L.; Mkrtchyan, A.; Heinonen, V.; Karttunen, M.; Foster, A. S.; Ala-Nissila, T.

    2012-02-01

    The three-dimensional Mercedes-Benz model was recently introduced to account for the structural and thermodynamic properties of water. It treats water molecules as point-like particles with four dangling bonds in tetrahedral coordination, representing H-bonds of water. Its conceptual simplicity renders the model attractive in studies where complex behaviors emerge from H-bond interactions in water, e.g., the hydrophobic effect. A molecular dynamics (MD) implementation of the model is non-trivial and we outline here the mathematical framework of its force-field. Useful routines written in modern Fortran are also provided. This open source code is free and can easily be modified to account for different physical context. The provided code allows both serial and MPI-parallelized execution. Program summaryProgram title: CASHEW (Coarse Approach Simulator for Hydrogen-bonding Effects in Water) Catalogue identifier: AEKM_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEKM_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 20 501 No. of bytes in distributed program, including test data, etc.: 551 044 Distribution format: tar.gz Programming language: Fortran 90 Computer: Program has been tested on desktop workstations and a Cray XT4/XT5 supercomputer. Operating system: Linux, Unix, OS X Has the code been vectorized or parallelized?: The code has been parallelized using MPI. RAM: Depends on size of system, about 5 MB for 1500 molecules. Classification: 7.7 External routines: A random number generator, Mersenne Twister ( http://www.math.sci.hiroshima-u.ac.jp/m-mat/MT/VERSIONS/FORTRAN/mt95.f90), is used. A copy of the code is included in the distribution. Nature of problem: Molecular dynamics simulation of a new geometric water model. Solution method: New force-field for

  11. Separation efficiency of a hydrodynamic separator using a 3D computational fluid dynamics multiscale approach.

    PubMed

    Schmitt, Vivien; Dufresne, Matthieu; Vazquez, Jose; Fischer, Martin; Morin, Antoine

    2014-01-01

    The aim of this study is to investigate the use of computational fluid dynamics (CFD) to predict the solid separation efficiency of a hydrodynamic separator. The numerical difficulty concerns the discretization of the geometry to simulate both the global behavior and the local phenomena that occur near the screen. In this context, a CFD multiscale approach was used: a global model (at the scale of the device) is used to observe the hydrodynamic behavior within the device; a local model (portion of the screen) is used to determine the local phenomena that occur near the screen. The Eulerian-Lagrangian approach was used to model the particle trajectories in both models. The global model shows the influence of the particles' characteristics on the trapping efficiency. A high density favors the sedimentation. In contrast, particles with small densities (1,040 kg/m(3)) are steered by the hydrodynamic behavior and can potentially be trapped by the separator. The use of the local model allows us to observe the particle trajectories near the screen. A comparison between two types of screens (perforated plate vs expanded metal) highlights the turbulent effects created by the shape of the screen. PMID:24622557

  12. 3D Study of the Morphology and Dynamics of Zeolite Nucleation.

    PubMed

    Melinte, Georgian; Georgieva, Veselina; Springuel-Huet, Marie-Anne; Nossov, Andreï; Ersen, Ovidiu; Guenneau, Flavien; Gedeon, Antoine; Palčić, Ana; Bozhilov, Krassimir N; Pham-Huu, Cuong; Qiu, Shilun; Mintova, Svetlana; Valtchev, Valentin

    2015-12-01

    The principle aspects and constraints of the dynamics and kinetics of zeolite nucleation in hydrogel systems are analyzed on the basis of a model Na-rich aluminosilicate system. A detailed time-series EMT-type zeolite crystallization study in the model hydrogel system was performed to elucidate the topological and temporal aspects of zeolite nucleation. A comprehensive set of analytical tools and methods was employed to analyze the gel evolution and complement the primary methods of transmission electron microscopy (TEM) and nuclear magnetic resonance (NMR) spectroscopy. TEM tomography reveals that the initial gel particles exhibit a core-shell structure. Zeolite nucleation is topologically limited to this shell structure and the kinetics of nucleation is controlled by the shell integrity. The induction period extends to the moment when the shell is consumed and the bulk solution can react with the core of the gel particles. These new findings, in particular the importance of the gel particle shell in zeolite nucleation, can be used to control the growth process and properties of zeolites formed in hydrogels. PMID:26503177

  13. Parallel phase-shifting digital holography and its application to high-speed 3D imaging of dynamic object

    NASA Astrophysics Data System (ADS)

    Awatsuji, Yasuhiro; Xia, Peng; Wang, Yexin; Matoba, Osamu

    2016-03-01

    Digital holography is a technique of 3D measurement of object. The technique uses an image sensor to record the interference fringe image containing the complex amplitude of object, and numerically reconstructs the complex amplitude by computer. Parallel phase-shifting digital holography is capable of accurate 3D measurement of dynamic object. This is because this technique can reconstruct the complex amplitude of object, on which the undesired images are not superimposed, form a single hologram. The undesired images are the non-diffraction wave and the conjugate image which are associated with holography. In parallel phase-shifting digital holography, a hologram, whose phase of the reference wave is spatially and periodically shifted every other pixel, is recorded to obtain complex amplitude of object by single-shot exposure. The recorded hologram is decomposed into multiple holograms required for phase-shifting digital holography. The complex amplitude of the object is free from the undesired images is reconstructed from the multiple holograms. To validate parallel phase-shifting digital holography, a high-speed parallel phase-shifting digital holography system was constructed. The system consists of a Mach-Zehnder interferometer, a continuous-wave laser, and a high-speed polarization imaging camera. Phase motion picture of dynamic air flow sprayed from a nozzle was recorded at 180,000 frames per second (FPS) have been recorded by the system. Also phase motion picture of dynamic air induced by discharge between two electrodes has been recorded at 1,000,000 FPS, when high voltage was applied between the electrodes.

  14. Characteristics of Ground Motions from Large-Scale Dynamic Rupture Simulations

    NASA Astrophysics Data System (ADS)

    Shi, Z.; Day, S. M.

    2012-12-01

    We investigate the characteristics of ground motions generated using an all-physics-based deterministic approach. The rupture events are simulated as dynamic ruptures along rough faults using large-scale three-dimensional models. The fault roughness assumed in our study follows self-similar fractal distribution with the roughness wavelength scales spanning three orders of magnitude from ~10^2 m to ~10^5 m. Frictional sliding on the fault is governed by a rate- and-state friction with strongly rate-weakening property and the inelastic yielding of the off-fault bulk material is subject to Drucker-Prager viscoplasticity. Our simulation results show that the fault roughness promotes the development of self-healing rupture pulses and causes loss of rupture coherence. The resulting rupture irregularity lead to ground motions of considerable complexity. Ground accelerations that show extensive high-frequency oscillations exhibit a rich variety of phases and near-flat power spectra between a few tenths of one Hz to slightly less than 10 Hz. The patterns of fault-parallel, fault-normal, vertical and geometric-mean PGAs all show considerable level of variability that appears to be quantitatively similar to that found in earthquake strong motion records. We also computed the orientation-independent RotD50 response spectra of the ground accelerations for representative periods from 0.1 to 3.0 seconds. Compared to the Ground Motion Prediction Equations for the Next Generation Attenuation project (Power et al., 2008), these RotD50 response spectra are highly consistent with those empirical estimates, within the epistemic uncertainty, giving credence to the usefulness of our approach. Our study will contribute to the better understanding of the theoretical aspects of ground motion and hopefully provide useful guidance for the future development of the seismic risk analysis in practice.

  15. Nonlinear dynamics of the 3D FMS and Alfven wave beams propagating in plasma of ionosphere and magnetosphere

    NASA Astrophysics Data System (ADS)

    Belashov, Vasily

    We study the formation, structure, stability and dynamics of the multidimensional soliton-like beam structures forming on the low-frequency branch of oscillation in the ionospheric and magnetospheric plasma for cases when beta=4pinT/B(2) <<1 and beta>1. In first case with the conditions omegadynamics under conditions {k_{x}}(2) >>{k_{yz}}(2,) v_{x}$<3D Belashov-Karpman (BK) equation [1] for magnetic field h=B_{wave}/B with due account of the high order dispersive correction defined by values of plasma parameters and the angle Theta=(B,k) [2]. In another case the dynamics of the finite-amplitude Alfvén waves propagating in the ionosphere and magnetosphere near-to-parallel to the field B is described by the 3D derivative nonlinear Schrödinger (3-DNLS) equation for the magnetic field of the wave h=(B_{y}+iB_{z})/2B/1-beta/ [3]. To study the stability of multidimensional solitons in both cases we use the method developed in [2] and investigated the Hamiltonian bounding with its deformation conserving momentum by solving the corresponding variation problem. To study evolution of solitons and their collision dynamics the proper equations were being integrated numerically using the codes specially developed and described in detail in [3]. As a result, we have obtained that in both cases for a single solitons on a level with wave spreading and collapse the formation of multidimensional solitons can be observed. These results may be interpreted in terms of self-focusing phenomenon for the FMS and Alfvén waves’ beam as stationary beam formation, scattering and self-focusing of wave beam. The soliton collisions on a level with known elastic interaction can lead to formation of complex structures including the multisoliton bound states. For all cases the problem of multidimensional soliton dynamics in the ionospheric and

  16. Static and dynamic fatigue behavior of topology designed and conventional 3D printed bioresorbable PCL cervical interbody fusion devices.

    PubMed

    Knutsen, Ashleen R; Borkowski, Sean L; Ebramzadeh, Edward; Flanagan, Colleen L; Hollister, Scott J; Sangiorgio, Sophia N

    2015-09-01

    Recently, as an alternative to metal spinal fusion cages, 3D printed bioresorbable materials have been explored; however, the static and fatigue properties of these novel cages are not well known. Unfortunately, current ASTM testing standards used to determine these properties were designed prior to the advent of bioresorbable materials for cages. Therefore, the applicability of these standards for bioresorbable materials is unknown. In this study, an image-based topology and a conventional 3D printed bioresorbable poly(ε)-caprolactone (PCL) cervical cage design were tested in compression, compression-shear, and torsion, to establish their static and fatigue properties. Difficulties were in fact identified in establishing failure criteria and in particular determining compressive failure load. Given these limitations, under static loads, both designs withstood loads of over 650 N in compression, 395 N in compression-shear, and 0.25 Nm in torsion, prior to yielding. Under dynamic testing, both designs withstood 5 million (5M) cycles of compression at 125% of their respective yield forces. Geometry significantly affected both the static and fatigue properties of the cages. The measured compressive yield loads fall within the reported physiological ranges; consequently, these PCL bioresorbable cages would likely require supplemental fixation. Most importantly, supplemental testing methods may be necessary beyond the current ASTM standards, to provide more accurate and reliable results, ultimately improving preclinical evaluation of these devices. PMID:26072198

  17. Static and Dynamic Fatigue Behavior of Topology Designed and Conventional 3D Printed Bioresorbable PCL Cervical Interbody Fusion Devices

    PubMed Central

    Knutsen, Ashleen R.; Borkowski, Sean L.; Ebramzadeh, Edward; Flanagan, Colleen L.; Hollister, Scott J.; Sangiorgio, Sophia N.

    2015-01-01

    Recently, as an alternative to metal spinal fusion cages, 3D printed bioresorbable materials have been explored; however, the static and fatigue properties of these novel cages are not well known. Unfortunately, current ASTM testing standards used to determine these properties were designed prior to the advent of bioresorbable materials for cages. Therefore, the applicability of these standards for bioresorbable materials is unknown. In this study, an image-based topology and a conventional 3D printed bioresorbable poly(ε)-caprolactone (PCL) cervical cage design were tested in compression, compression-shear, and torsion, to establish their static and fatigue properties. Difficulties were in fact identified in establishing failure criteria and in particular determining compressive failure load. Given these limitations, under static loads, both designs withstood loads of over 650N in compression, 395N in compression-shear, and 0.25Nm in torsion, prior to yielding. Under dynamic testing, both designs withstood 5 million (5M) cycles of compression at 125% of their respective yield forces. Geometry significantly affected both the static and fatigue properties of the cages. The measured compressive yield loads fall within the reported physiological ranges; consequently, these PCL bioresorbable cages would likely require supplemental fixation. Most importantly, supplemental testing methods may be necessary beyond the current ASTM standards, to provide more accurate and reliable results, ultimately improving preclinical evaluation of these devices. PMID:26072198

  18. Constraining the absolute orientation of η Carinae's binary orbit: a 3D dynamical model for the broad [Fe III] emission

    NASA Astrophysics Data System (ADS)

    Madura, T. I.; Gull, T. R.; Owocki, S. P.; Groh, J. H.; Okazaki, A. T.; Russell, C. M. P.

    2012-03-01

    We present a three-dimensional (3D) dynamical model for the broad [Fe III] emission observed in η Carinae using the Hubble Space Telescope/Space Telescope Imaging Spectrograph (STIS). This model is based on full 3D smoothed particle hydrodynamics simulations of η Car's binary colliding winds. Radiative transfer codes are used to generate synthetic spectroimages of [Fe III] emission-line structures at various observed orbital phases and STIS slit position angles (PAs). Through a parameter study that varies the orbital inclination i, the PA θ that the orbital plane projection of the line of sight makes with the apastron side of the semimajor axis and the PA on the sky of the orbital axis, we are able, for the first time, to tightly constrain the absolute 3D orientation of the binary orbit. To simultaneously reproduce the blueshifted emission arcs observed at orbital phase 0.976, STIS slit PA =+38° and the temporal variations in emission seen at negative slit PAs, the binary needs to have an i≈ 130° to 145°, θ≈-15° to +30° and an orbital axis projected on the sky at a PA ≈ 302° to 327° east of north. This represents a system with an orbital axis that is closely aligned with the inferred polar axis of the Homunculus nebula, in 3D. The companion star, ηB, thus orbits clockwise on the sky and is on the observer's side of the system at apastron. This orientation has important implications for theories for the formation of the Homunculus and helps lay the groundwork for orbital modelling to determine the stellar masses. Footnotes<label>1</label>Low- and high-ionization refer here to atomic species with ionizations potentials (IPs) below and above the IP of hydrogen, 13.6 eV.<label>2</label>Measured in degrees from north to east.<label>3</label>θ is the same as the angle φ defined in fig. 3 of O08.<label>4</label>The outer edge looks circular only because this marks the edge of the spherical computational domain of the SPH simulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PPCF...55j5005W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PPCF...55j5005W"><span id="translatedtitle">Characterization of <span class="hlt">3</span><span class="hlt">D</span> filament <span class="hlt">dynamics</span> in a MAST SOL flux tube geometry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Walkden, N. R.; Dudson, B. D.; Fishpool, G.</p> <p>2013-10-01</p> <p>Non-linear simulations of filament propagation in a realistic MAST SOL flux tube geometry using the BOUT++ fluid modelling framework show an isolation of the <span class="hlt">dynamics</span> of the filament in the divertor region from the midplane region due to three features of the magnetic geometry; the variation of magnetic curvature along the field line, the expansion of the flux tube and strong magnetic shear. Of the three effects, the latter two lead to a midplane ballooning feature of the filament, whilst the former leads to a ballooning around the X-points. In simulations containing all three effects the filament is observed to balloon at the midplane, suggesting that the role of curvature variation is sub-dominant to the flux expansion and magnetic shear. The magnitudes of these effects are all strongest near the X-point which leads to the formation of parallel density gradients. The filaments simulated, which represent filaments in MAST, are identified as resistive ballooning, meaning that their motion is inertially limited, not sheath limited. Parallel density gradients can drive the filament towards a Boltzmann response when the collisionalityof the plasma is low. The results here show that the formation of parallel density gradients is a natural and inevitable consequence of a realistic magnetic geometry and therefore the transition to the Boltzmann response is a consequence of the use of realistic magnetic geometry and does not require initializing specifically varying background profiles as in slab simulations. The filaments studied here are stable to the linear resistive drift-wave instability but are subject to the non-linear effects associated with the Boltzmann response, particularly Boltzmann spinning. The Boltzmann response causes the filament to spin on an axis. In later stages of its evolution a non-linear turbulent state develops where the vorticity evolves into a turbulent eddy field on the same length scale as the parallel current. The transition from interchange</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002RScI...73..459L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002RScI...73..459L"><span id="translatedtitle">An experimental method to <span class="hlt">dynamically</span> test pressure sensors using a <span class="hlt">rupture</span> disk</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Hanying; Miller, Don W.; Talnagi, Joseph W.</p> <p>2002-02-01</p> <p>The response time of a pressure sensor is required when it is used in control systems and in some measurement applications. It is often difficult to measure the response time of a pressure sensor since it is difficult to obtain changes in fluid pressure sufficient to characterize the sensor <span class="hlt">dynamic</span> response. In this article we describe a relatively simple system for measuring or validating the response time of pressure sensors with fast <span class="hlt">dynamic</span> response. The system consists of two chambers isolated by a graphite <span class="hlt">rupture</span> disk, a device that fully and rapidly opens at a known <span class="hlt">rupture</span> or break pressure. A pressure transient in the second chamber is initiated by slowly increasing the pressure in the first chamber until reaching the nominal break pressure of the <span class="hlt">rupture</span> disk. Performance of the system was validated by comparing the rise time predicted by a theoretical model with the rise time of the pressure transient measured by a piezoelectric pressure transducer. The method was evaluated by comparing the response to the pressure transient of an optical based pressure transducer with the response of the reference piezoelectric pressure transducer. The time constant of the tested fiber optic pressure sensor was found using the method presented in this article to be 0.488 ms, which is close to the time constant of 0.455 ms measured by a comparison method.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ISPArXL15...51A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ISPArXL15...51A"><span id="translatedtitle">Using Parameters of <span class="hlt">Dynamic</span> Pulse Function for <span class="hlt">3</span><span class="hlt">d</span> Modeling in LOD3 Based on Random Textures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alizadehashrafi, B.</p> <p>2015-12-01</p> <p>The pulse function (PF) is a technique based on procedural preprocessing system to generate a computerized virtual photo of the façade with in a fixed size square(Alizadehashrafi et al., 2009, Musliman et al., 2010). <span class="hlt">Dynamic</span> Pulse Function (DPF) is an enhanced version of PF which can create the final photo, proportional to real geometry. This can avoid distortion while projecting the computerized photo on the generated <span class="hlt">3</span><span class="hlt">D</span> model(Alizadehashrafi and Rahman, 2013). The challenging issue that might be handled for having <span class="hlt">3</span><span class="hlt">D</span> model in LoD3 rather than LOD2, is the final aim that have been achieved in this paper. In the technique based DPF the geometries of the windows and doors are saved in an XML file schema which does not have any connections with the <span class="hlt">3</span><span class="hlt">D</span> model in LoD2 and CityGML format. In this research the parameters of <span class="hlt">Dynamic</span> Pulse Functions are utilized via Ruby programming language in SketchUp Trimble to generate (exact position and deepness) the windows and doors automatically in LoD3 based on the same concept of DPF. The advantage of this technique is automatic generation of huge number of similar geometries e.g. windows by utilizing parameters of DPF along with defining entities and window layers. In case of converting the SKP file to CityGML via FME software or CityGML plugins the <span class="hlt">3</span><span class="hlt">D</span> model contains the semantic database about the entities and window layers which can connect the CityGML to MySQL(Alizadehashrafi and Baig, 2014). The concept behind DPF, is to use logical operations to project the texture on the background image which is <span class="hlt">dynamically</span> proportional to real geometry. The process of projection is based on two vertical and horizontal <span class="hlt">dynamic</span> pulses starting from upper-left corner of the background wall in down and right directions respectively based on image coordinate system. The logical one/zero on the intersections of two vertical and horizontal <span class="hlt">dynamic</span> pulses projects/does not project the texture on the background image. It is possible to define</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015ISPArXL15...51A&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015ISPArXL15...51A&link_type=ABSTRACT"><span id="translatedtitle">Using Parameters of <span class="hlt">Dynamic</span> Pulse Function for <span class="hlt">3</span><span class="hlt">d</span> Modeling in LOD3 Based on Random Textures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alizadehashrafi, B.</p> <p>2015-12-01</p> <p>The pulse function (PF) is a technique based on procedural preprocessing system to generate a computerized virtual photo of the façade with in a fixed size square(Alizadehashrafi et al., 2009, Musliman et al., 2010). <span class="hlt">Dynamic</span> Pulse Function (DPF) is an enhanced version of PF which can create the final photo, proportional to real geometry. This can avoid distortion while projecting the computerized photo on the generated <span class="hlt">3</span><span class="hlt">D</span> model(Alizadehashrafi and Rahman, 2013). The challenging issue that might be handled for having <span class="hlt">3</span><span class="hlt">D</span> model in LoD3 rather than LOD2, is the final aim that have been achieved in this paper. In the technique based DPF the geometries of the windows and doors are saved in an XML file schema which does not have any connections with the <span class="hlt">3</span><span class="hlt">D</span> model in LoD2 and CityGML format. In this research the parameters of <span class="hlt">Dynamic</span> Pulse Functions are utilized via Ruby programming language in SketchUp Trimble to generate (exact position and deepness) the windows and doors automatically in LoD3 based on the same concept of DPF. The advantage of this technique is automatic generation of huge number of similar geometries e.g. windows by utilizing parameters of DPF along with defining entities and window layers. In case of converting the SKP file to CityGML via FME software or CityGML plugins the <span class="hlt">3</span><span class="hlt">D</span> model contains the semantic database about the entities and window layers which can connect the CityGML to MySQL(Alizadehashrafi and Baig, 2014). The concept behind DPF, is to use logical operations to project the texture on the background image which is <span class="hlt">dynamically</span> proportional to real geometry. The process of projection is based on two vertical and horizontal <span class="hlt">dynamic</span> pulses starting from upper-left corner of the background wall in down and right directions respectively based on image coordinate system. The logical one/zero on the intersections of two vertical and horizontal <span class="hlt">dynamic</span> pulses projects/does not project the texture on the background image. It is possible to define</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ASPC..504..179P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ASPC..504..179P"><span id="translatedtitle">New Insights about Meridional Circulation <span class="hlt">Dynamics</span> from <span class="hlt">3</span><span class="hlt">D</span> MHD Global Simulations of Solar Convection and Dynamo Action</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Passos, D.; Charbonneau, P.; Miesch, M. S.</p> <p>2016-04-01</p> <p>The solar meridional circulation is a "slow", large scale flow that transports magnetic field and plasma throughout the convection zone in the (r,θ) plane and plays a crucial role in controlling the magnetic cycle solutions presented by flux transport dynamo models. Observations indicate that this flow speed varies in anti-phase with the solar cycle at the solar surface. A possible explanation for the source of this variation is based on the fact that inflows into active regions alter the global surface pattern of the meridional circulation. In this work we examine the meridional circulation profile that emerges from a <span class="hlt">3</span><span class="hlt">D</span> global simulation of the solar convection zone, and its associated <span class="hlt">dynamics</span>. We find that at the bottom of the convection zone, in the region where the toroidal magnetic field accumulates, the meridional circulation is highly modulated through the action of a magnetic torques and thus provides evidence for a new mechanism to explain the observed cyclic variations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JMPSo..63..491V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JMPSo..63..491V"><span id="translatedtitle">Modelling crystal plasticity by <span class="hlt">3</span><span class="hlt">D</span> dislocation <span class="hlt">dynamics</span> and the finite element method: The Discrete-Continuous Model revisited</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vattré, A.; Devincre, B.; Feyel, F.; Gatti, R.; Groh, S.; Jamond, O.; Roos, A.</p> <p>2014-02-01</p> <p>A unified model coupling <span class="hlt">3</span><span class="hlt">D</span> dislocation <span class="hlt">dynamics</span> (DD) simulations with the finite element (FE) method is revisited. The so-called Discrete-Continuous Model (DCM) aims to predict plastic flow at the (sub-)micron length scale of materials with complex boundary conditions. The evolution of the dislocation microstructure and the short-range dislocation-dislocation interactions are calculated with a DD code. The long-range mechanical fields due to the dislocations are calculated by a FE code, taking into account the boundary conditions. The coupling procedure is based on eigenstrain theory, and the precise manner in which the plastic slip, i.e. the dislocation glide as calculated by the DD code, is transferred to the integration points of the FE mesh is described in full detail. Several test cases are presented, and the DCM is applied to plastic flow in a single-crystal Nickel-based superalloy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014APS..DFD.F1065D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014APS..DFD.F1065D"><span id="translatedtitle">Non-linear <span class="hlt">dynamics</span> of viscous bilayers subjected to an electric field: <span class="hlt">3</span><span class="hlt">D</span> phase field simulations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dritselis, Christos; Karapetsas, George; Bontozoglou, Vasilis</p> <p>2014-11-01</p> <p>The scope of this work is to investigate the non-linear <span class="hlt">dynamics</span> of the electro-hydrodynamic instability of a bilayer of immiscible liquids. We consider the case of two viscous films which is separated from the top electrode by air. We assume that the liquids are perfect dielectrics and consider the case of both flat and patterned electrodes. We develop a computational model using the diffuse interface method and carry out <span class="hlt">3</span><span class="hlt">D</span> numerical simulations fully accounting for the flow and electric field in all phases. We perform a parametric study and investigate the influence of the electric properties of fluids, applied voltage and various geometrical characteristics of the mask. The authors acknowledge the support by the General Secretariat of Research and Technology of Greece under the action ``Supporting Postdoctoral Researchers'' (Grant Number PE8/906), co-funded by the European Social Fund and National Resources.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.6466P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.6466P"><span id="translatedtitle">The effect of rheological approximations on the <span class="hlt">dynamics</span> and topography in <span class="hlt">3</span><span class="hlt">D</span> subduction-collision models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pusok, Adina E.; Kaus, Boris J. P.; Popov, Anton A.</p> <p>2016-04-01</p> <p>Most of the major mountain belts and orogenic plateaus are found within the overlying plate of active or fossil subduction and/or collision zones. Moreover, they evolve differently from one another as the result of specific combinations of surface and mantle processes. These differences arise for several reasons, such as different rheological properties, different amounts of regional isostatic compensation, and different mechanisms by which forces are applied to the convergent plates. Previous <span class="hlt">3</span><span class="hlt">D</span> geodynamic models of subduction/collision processes have used various rheological approximations, making numerical results difficult to compare, since there is no clear image on the extent of these approximations on the <span class="hlt">dynamics</span>. Here, we employ the code LaMEM to perform high-resolution long-term <span class="hlt">3</span><span class="hlt">D</span> simulations of subduction/continental collision in an integrated lithospheric and upper-mantle scale model. We test the effect of rheological approximations on mantle and lithosphere <span class="hlt">dynamics</span> in a geometrically simplified model setup that resembles a tectonic map of the India-Asia collision zone. We use the "sticky-air" approach to allow for the development of topography and the <span class="hlt">dynamics</span> of subduction and collision is entirely driven by slab-pull (i.e. "free subduction"). The models exhibit a wide range of behaviours depending on the rheological law employed: from linear to temperature-dependent visco-elasto-plastic rheology that takes into account both diffusion and dislocation creep. For example, we find that slab <span class="hlt">dynamics</span> varies drastically between end member models: in viscous approximations, slab detachment is slow following a viscous thinning, while for a non-linear visco-elasto-plastic rheology, slab detachment is relatively fast, inducing strong mantle flow in the slab window. We also examine the stress states in the subducting and overriding plates and topography evolution in the upper plate, and we discuss the implications on lithosphere <span class="hlt">dynamics</span> at convergent margins</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.S23A2118N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.S23A2118N"><span id="translatedtitle"><span class="hlt">Rupture</span> propagation patterns of deep low-frequency earthquakes depending on source structure and frictional property: numerical analysis based on <span class="hlt">dynamic</span> model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nakata, R.; Ando, R.; Hori, T.; Ide, S.</p> <p>2010-12-01</p> <p>Deep nonvolcanic tremor and low-frequency earthquakes (LFEs) occurred along the subduction zones in southwest Japan and Cascadia are explained as shear slips on the plate interface [Ide et al., 2007a], and are considered as <span class="hlt">ruptures</span> of relatively unstable patches within the region where slow slip event (SSE) occurs [Ito et al., 2007]. The tremor sources migrate with the velocity of about 10 km/day along strike [Obara, 2002], and 100 km/hour along dip [Shelly et al., 2007]. Further, the moment rate spectra of the LFEs have a tendency that decay at the inverse proportional to the frequency [Ide et al., 2007b]. To explain these anisotropies of migration speed and spectral property, Ando et al. [2010] proposed a <span class="hlt">dynamic</span> model that unstable patches <span class="hlt">rupture</span> by passing stress pulse of SSE over the patches. The aim of this study is to investigate the frictional properties and detailed structure of LFE source to explain the spectral characteristics and moment rate function based on their model. The LFE source model comprises clustered unstable patches. To model the source process, which radiates seismic waves, we employed the <span class="hlt">dynamic</span> boundary integral equation method [Ando and Yamashita, 2007] in a <span class="hlt">3</span><span class="hlt">D</span> full space with a triangular mesh [Tada, 2006]. Within these clusters, some fluctuations are added so that the locations and sizes of their constituent patches follow a Gaussian distribution. We present physical quantities in nondimensionalized form. In this study, we modeled an LFE source with many small patches or large several patches distributed in dense or sparse. For each patch distributions, we calculated <span class="hlt">rupture</span> propagation with various values of the patch viscosity, background viscosity, and background frictional strength. In the simulations, both passive and spontaneous <span class="hlt">ruptures</span> appear depending on the viscosity, frictional strength, and patch distribution. The former is caused by the assumed stress pulse and the latter is by interaction between the patches and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.6088P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.6088P"><span id="translatedtitle">Comparing the effects of rheology on the <span class="hlt">dynamics</span> and topography of <span class="hlt">3</span><span class="hlt">D</span> subduction-collision models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pusok, Adina E.; Kaus, Boris; Popov, Anton</p> <p>2015-04-01</p> <p>Most of the major mountain belts and orogenic plateaus are found within the overlying plate of active or fossil subduction and/or collision zones. It is well known that they evolve differently from one another as the result of specific combinations of surface and mantle processes. The differences among the structures and evolutions of mountain belts arise for several reasons, such as different strengths of materials, different amounts of regional isostatic compensation, and different mechanisms by which forces are applied to the convergence plates. All these possible controlling factors can change with space and time. Of all the mountain belts and orogenic plateaus, the most striking example is the India-Asia collision zone, which gave rise to the Himalayas and the Tibetan Plateau, the largest region of elevated topography and anomalously thick crust on Earth. Understanding the formation and evolution of such a highly elevated region has been the focus of many tectonic and numerical models. While some of these models (i.e. thin sheet model) have successfully illustrated some of the basic physics of continental collision, none can simultaneously represent active processes such as subduction, underthrusting, channel flow or extrusion, for which fully <span class="hlt">3</span><span class="hlt">D</span> models are required. Here, we employed the <span class="hlt">3</span><span class="hlt">D</span> code LaMEM to investigate the role that subduction, continental collision and indentation play on lithosphere <span class="hlt">dynamics</span> at convergent margins, and the implications they have for the Asian tectonics. Our model setup resembles a simplified tectonic map of the India-Asia collision zone and we performed long-term <span class="hlt">3</span><span class="hlt">D</span> simulations to analyse the <span class="hlt">dynamics</span> and the conditions under which large topographic plateaus, such as the Tibetan Plateau can form in an integrated lithospheric and upper-mantle scale model. Results of models with linear viscous rheologies show different modes between the oceanic subduction side (continuous subduction, trench retreat and slab roll-back) and the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013AGUFM.H32G..04H&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013AGUFM.H32G..04H&link_type=ABSTRACT"><span id="translatedtitle">The SCEC-USGS <span class="hlt">Dynamic</span> Earthquake <span class="hlt">Rupture</span> Code Verification Exercise - Recent Progress</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Harris, R.</p> <p>2013-12-01</p> <p>I summarize recent progress by the SCEC-USGS <span class="hlt">Dynamic</span> <span class="hlt">Rupture</span> Code Verification Group, that examines if the results produced by researchers' earthquake simulation codes agree with each other when computing benchmark scenarios of <span class="hlt">dynamically</span> propagating earthquake <span class="hlt">ruptures</span>. To date we have tested the codes against benchmarks that incorporate a range of features, including a single planar vertical fault, a single planar dipping fault, slip-weakening, rate-state, and thermal pressurization friction, elastic and plastic off-fault behavior, complete stress drops that lead to supershear <span class="hlt">rupture</span> velocities and extreme ground motion, and, heterogeneous initial stresses. Our most recent benchmarks have involved complexities in fault geometry, with computationally simulated earthquakes spontaneously propagating on parallel non-co-planar vertical strike-slip faults and on branching vertical strike-slip faults. The parallel strike-slip fault case has been discussed in the published literature over the past decades, from both observational and theoretical perspectives, and the results are sometimes used in hazard estimates for multi-fault earthquake <span class="hlt">ruptures</span>. The branching fault case has been a focus of study due to its potential application to a number of geologically hazardous settings. Group members used their individual computer codes and achieved satisfactory agreement among the codes' results for both sets of these recent benchmarks, the parallel faults and the branched faults. Our next benchmark exercise will continue on the theme of complex fault geometry and investigate the case of a geometrical asperity on an otherwise planar fault. We also plan to work on developing suitable quantitative metrics for our code comparisons. For more information about our group and our work, please see our website and our group's overview papers, Harris et al., Seismological Research Letters, 2009, and Harris et al., Seismological Research Letters, 2011.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMOS51B1991D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMOS51B1991D"><span id="translatedtitle"><span class="hlt">3</span><span class="hlt">D</span> <span class="hlt">Dynamics</span> of the Near-Surface Layer of the Ocean in the Presence of Freshwater Influx</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dean, C.; Soloviev, A.</p> <p>2015-12-01</p> <p>Freshwater inflow due to convective rains or river runoff produces lenses of freshened water in the near surface layer of the ocean. These lenses are localized in space and typically involve both salinity and temperature anomalies. Due to significant density anomalies, strong pressure gradients develop, which result in lateral spreading of freshwater lenses in a form resembling gravity currents. Gravity currents inherently involve three-dimensional <span class="hlt">dynamics</span>. The gravity current head can include the Kelvin-Helmholtz billows with vertical density inversions. In this work, we have conducted a series of numerical experiments using computational fluid <span class="hlt">dynamics</span> tools. These numerical simulations were designed to elucidate the relationship between vertical mixing and horizontal advection of salinity under various environmental conditions and potential impact on the pollution transport including oil spills. The near-surface data from the field experiments in the Gulf of Mexico during the SCOPE experiment were available for validation of numerical simulations. In particular, we observed a freshwater layer within a few-meter depth range and, in some cases, a density inversion at the edge of the freshwater lens, which is consistent with the results of numerical simulations. In conclusion, we discuss applicability of these results to the interpretation of Aquarius and SMOS sea surface salinity satellite measurements. The results of this study indicate that <span class="hlt">3</span><span class="hlt">D</span> <span class="hlt">dynamics</span> of the near-surface layer of the ocean are essential in the presence of freshwater inflow.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26972111','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26972111"><span id="translatedtitle">Single Molecule <span class="hlt">3</span><span class="hlt">D</span> Orientation in Time and Space: A 6D <span class="hlt">Dynamic</span> Study on Fluorescently Labeled Lipid Membranes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Börner, Richard; Ehrlich, Nicky; Hohlbein, Johannes; Hübner, Christian G</p> <p>2016-05-01</p> <p>Interactions between single molecules profoundly depend on their mutual three-dimensional orientation. Recently, we demonstrated a technique that allows for orientation determination of single dipole emitters using a polarization-resolved distribution of fluorescence into several detection channels. As the method is based on the detection of single photons, it additionally allows for performing fluorescence correlation spectroscopy (FCS) as well as <span class="hlt">dynamical</span> anisotropy measurements thereby providing access to fast orientational <span class="hlt">dynamics</span> down to the nanosecond time scale. The <span class="hlt">3</span><span class="hlt">D</span> orientation is particularly interesting in non-isotropic environments such as lipid membranes, which are of great importance in biology. We used giant unilamellar vesicles (GUVs) labeled with fluorescent dyes down to a single molecule concentration as a model system for both, assessing the robustness of the orientation determination at different timescales and quantifying the associated errors. The vesicles provide a well-defined spherical surface, such that the use of fluorescent lipid dyes (DiO) allows to establish a a wide range of dipole orientations experimentally. To complement our experimental data, we performed Monte Carlo simulations of the rotational <span class="hlt">dynamics</span> of dipoles incorporated into lipid membranes. Our study offers a comprehensive view on the dye orientation behavior in a lipid membrane with high spatiotemporal resolution representing a six-dimensional fluorescence detection approach. PMID:26972111</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.1182P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.1182P"><span id="translatedtitle">The ADER-DG method for seismic wave propagation and earthquake <span class="hlt">rupture</span> <span class="hlt">dynamics</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pelties, Christian; Gabriel, Alice; Ampuero, Jean-Paul; de la Puente, Josep; Käser, Martin</p> <p>2013-04-01</p> <p>We will present the Arbitrary high-order DERivatives Discontinuous Galerkin (ADER-DG) method for solving the combined elastodynamic wave propagation and <span class="hlt">dynamic</span> <span class="hlt">rupture</span> problem. The ADER-DG method enables high-order accuracy in space and time while being implemented on unstructured tetrahedral meshes. A tetrahedral element discretization provides rapid and automatized mesh generation as well as geometrical flexibility. Features as mesh coarsening and local time stepping schemes can be applied to reduce computational efforts without introducing numerical artifacts. The method is well suited for parallelization and large scale high-performance computing since only directly neighboring elements exchange information via numerical fluxes. The concept of fluxes is a key ingredient of the numerical scheme as it governs the numerical dispersion and diffusion properties and allows to accommodate for boundary conditions, empirical friction laws of <span class="hlt">dynamic</span> <span class="hlt">rupture</span> processes, or the combination of different element types and non-conforming mesh transitions. After introducing fault <span class="hlt">dynamics</span> into the ADER-DG framework, we will demonstrate its specific advantages in benchmarking test scenarios provided by the SCEC/USGS Spontaneous <span class="hlt">Rupture</span> Code Verification Exercise. An important result of the benchmark is that the ADER-DG method avoids spurious high-frequency contributions in the slip rate spectra and therefore does not require artificial Kelvin-Voigt damping, filtering or other modifications of the produced synthetic seismograms. To demonstrate the capabilities of the proposed scheme we simulate an earthquake scenario, inspired by the 1992 Landers earthquake, that includes branching and curved fault segments. Furthermore, topography is respected in the discretized model to capture the surface waves correctly. The advanced geometrical flexibility combined with an enhanced accuracy will make the ADER-DG method a useful tool to study earthquake <span class="hlt">dynamics</span> on complex fault systems in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4607938','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4607938"><span id="translatedtitle">Effects of Stretching Speed on Mechanical <span class="hlt">Rupture</span> of Phospholipid/Cholesterol Bilayers: Molecular <span class="hlt">Dynamics</span> Simulation</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Shigematsu, Taiki; Koshiyama, Kenichiro; Wada, Shigeo</p> <p>2015-01-01</p> <p><span class="hlt">Rupture</span> of biological cell membrane under mechanical stresses is critical for cell viability. It is triggered by local rearrangements of membrane molecules. We investigated the effects of stretching speed on mechanical <span class="hlt">rupture</span> of phospholipid/cholesterol bilayers using unsteady molecular <span class="hlt">dynamics</span> simulations. We focused on pore formation, the trigger of <span class="hlt">rupture</span>, in a 40 mol% cholesterol-including bilayer. The unsteady stretching was modeled by proportional and temporal scaling of atom positions at stretching speeds from 0.025 to 30 m/s. The effects of the stretching speed on the critical areal strain, where the pore forms, is composed of two regimes. At low speeds (<1.0 m/s), the critical areal strain is insensitive to speed, whereas it significantly increases at higher speeds. Also, the strain is larger than that of a pure bilayer, regardless of the stretching speeds, which qualitatively agrees with available experimental data. Transient recovery of the cholesterol and phospholipid molecular orientations was evident at lower speeds, suggesting the formation of a stretch-induced interdigitated gel-like phase. However, this recovery was not confirmed at higher speeds or for the pure bilayer. The different responses of the molecular orientations may help explain the two regimes for the effect of stretching speed on pore formation. PMID:26471872</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.S43C2245Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.S43C2245Z"><span id="translatedtitle">Investigating the reliability of kinematic source inversion with <span class="hlt">dynamic</span> <span class="hlt">rupture</span> models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Y.; Song, S.; Dalguer, L. A.; Clinton, J. F.</p> <p>2011-12-01</p> <p>An essential element of understanding the earthquake source processes is obtaining a reliable source model via geophysical data inversion. However, the epistemic uncertainties in the kinematic source inversion produce a variety of source model estimates for any given event. Thus, as done in the Source Inversion Validation (SIV) project, it is important to validate our inversion methods with synthetic data by testing forward Green's function calculation and comparing various inversion methods. Spontaneous <span class="hlt">dynamic</span> <span class="hlt">rupture</span> modeling, which incorporates the conservation laws of continuum mechanics and the constitutive behavior of rocks under frictional sliding, is capable of producing physically self-consistent kinematic description of the fault and its associated seismic wave propagation resulting in ground motions on the surface. Here we develop accurate <span class="hlt">dynamic</span> <span class="hlt">rupture</span> simulation of a vertical strike slip fault. Our source model is composed of well-defined asperities (patches of large stress drop) and we assume that fault <span class="hlt">rupture</span> is governed by the linear slip weakening friction model. The resulting near-source ground motions dominated by low frequency (up to 1Hz) are used for testing our inversion method. We performed various inversion tests and compared estimated solutions with true solutions obtained by the forward <span class="hlt">dynamic</span> <span class="hlt">rupture</span> modeling. Our preliminary results show that estimated model spaces could be significantly perturbed, depending on data and modeling schemes used in the inversion, not only in terms of spatial distribution of model parameters, but also in terms of their auto- and cross-correlation structure. The Bayesian approach in source inversion is becoming increasingly popular because of the recent common availability of high performance computing capabilities. We adopted the Bayesian approach in our source inversion test, so that we can more effectively analyze the uncertainty of estimated models and also implement physically guided regularization</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..18..605D&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..18..605D&link_type=ABSTRACT"><span id="translatedtitle">Revealing plot scale heterogeneity in soil moisture <span class="hlt">dynamics</span> under contrasting vegetation assemblages using <span class="hlt">3</span><span class="hlt">D</span> electrical resistivity tomography (ERT) surveys</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dick, Jonathan; Tetzlaff, Doerthe; Bradford, John; Soulsby, Chris</p> <p>2016-04-01</p> <p>Soil moisture is a fundamental component of the water cycle that influences many hydrological processes, such as flooding, solute transport, biogeochemical processes, and land-atmosphere interactions. The relationship between vegetation and soil moisture is complex and reciprocal. Soil moisture may affect vegetation distribution due to its function as the primary source of water, in turn the structure of vegetation canopies regulate water partitioning into interception, throughfall and steam flow. Such spatial differences in inputs, together with complex patterns of water uptake from distributed root networks can create marked heterogeneity in soil moisture <span class="hlt">dynamics</span> at small scales. Traditional methods of monitoring soil moisture have revolved around limited point measurements, but improved geophysical techniques have facilitated a trend towards more spatially distributed measurements to help understand this heterogeneity. Here, we present a study using <span class="hlt">3</span><span class="hlt">D</span> ERT surveys in a 3.2km upland catchment in the Scottish Highlands where increasing afforestation (for climate change adaptation, biofuels and conservation) has the potential to increase interception losses and reduce soil moisture storage. The study combined <span class="hlt">3</span><span class="hlt">D</span> surveys, traditional point measurements and laboratory analysis of soil cores to assess the plot scale soil moisture <span class="hlt">dynamics</span> in podzolic soils under forest stands of 15m high Scots pine (Pinus sylvestris) and adjacent non-forest plots dominated by heather (Calluna vulgaris) shrubs (<0.5m high). These dominant species are typical of forest and non-forest vegetation communities the Scottish Highlands. Results showed differences in the soil moisture <span class="hlt">dynamics</span> under the different vegetation types, with heterogeneous patterns in the forested site mainly correlated with canopy cover and mirroring interception losses. Temporal variability in the forested site was greater, probably due to the interception, and increased evapotranspiration losses relative to the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009AGUFMNG41B1188A&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009AGUFMNG41B1188A&link_type=ABSTRACT"><span id="translatedtitle">Vertical Scan (V-SCAN) for <span class="hlt">3</span>-<span class="hlt">D</span> Grid Adaptive Mesh Refinement for an atmospheric Model <span class="hlt">Dynamical</span> Core</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Andronova, N. G.; Vandenberg, D.; Oehmke, R.; Stout, Q. F.; Penner, J. E.</p> <p>2009-12-01</p> <p>One of the major building blocks of a rigorous representation of cloud evolution in global atmospheric models is a parallel adaptive grid MPI-based communication library (an Adaptive Blocks for Locally Cartesian Topologies library -- ABLCarT), which manages the block-structured data layout, handles ghost cell updates among neighboring blocks and splits a block as refinements occur. The library has several modules that provide a layer of abstraction for adaptive refinement: blocks, which contain individual cells of user data; shells - the global geometry for the problem, including a sphere, reduced sphere, and now a <span class="hlt">3</span><span class="hlt">D</span> sphere; a load balancer for placement of blocks onto processors; and a communication support layer which encapsulates all data movement. A major performance concern with adaptive mesh refinement is how to represent calculations that have need to be sequenced in a particular order in a direction, such as calculating integrals along a specific path (e.g. atmospheric pressure or geopotential in the vertical dimension). This concern is compounded if the blocks have varying levels of refinement, or are scattered across different processors, as can be the case in parallel computing. In this paper we describe an implementation in ABLCarT of a vertical scan operation, which allows computing along vertical paths in the correct order across blocks transparent to their resolution and processor location. We test this functionality on a 2D and a <span class="hlt">3</span><span class="hlt">D</span> advection problem, which tests the performance of the model’s <span class="hlt">dynamics</span> (transport) and physics (sources and sinks) for different model resolutions needed for inclusion of cloud formation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4718466','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4718466"><span id="translatedtitle">Exploration of Novel Inhibitors for Bruton’s Tyrosine Kinase by <span class="hlt">3</span><span class="hlt">D</span> QSAR Modeling and Molecular <span class="hlt">Dynamics</span> Simulation</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Choi, Light; Woo Lee, Keun</p> <p>2016-01-01</p> <p>Bruton’s tyrosine kinase (BTK) is a cytoplasmic, non-receptor tyrosine kinase which is expressed in most of the hematopoietic cells and plays an important role in many cellular signaling pathways. B cell malignancies are dependent on BCR signaling, thus making BTK an efficient therapeutic target. Over the last few years, significant efforts have been made in order to develop BTK inhibitors to treat B-cell malignancies, and autoimmunity or allergy/hypersensitivity but limited success has been achieved. Here in this study, <span class="hlt">3</span><span class="hlt">D</span> QSAR pharmacophore models were generated for Btk based on known IC50 values and experimental energy scores with extensive validations. The five features pharmacophore model, Hypo1, includes one hydrogen bond acceptor lipid, one hydrogen bond donor, and three hydrophobic features, which has the highest correlation coefficient (0.98), cost difference (112.87), and low RMS (1.68). It was further validated by the Fisher’s randomization method and test set. The well validated Hypo1 was used as a <span class="hlt">3</span><span class="hlt">D</span> query to search novel Btk inhibitors with different chemical scaffold using high throughput virtual screening technique. The screened compounds were further sorted by applying ADMET properties, Lipinski’s rule of five and molecular docking studies to refine the retrieved hits. Furthermore, molecular <span class="hlt">dynamic</span> simulation was employed to study the stability of docked conformation and to investigate the binding interactions in detail. Several important hydrogen bonds with Btk were revealed, which includes the gatekeeper residues Glu475 and Met 477 at the hinge region. Overall, this study suggests that the proposed hits may be more effective inhibitors for cancer and autoimmune therapy. PMID:26784025</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..MARJ25004R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..MARJ25004R"><span id="translatedtitle">Large Scale <span class="hlt">3</span>-<span class="hlt">D</span> Dislocation <span class="hlt">Dynamics</span> and Atomistic Simulations of Flow and Strain-Hardening Behavior of Metallic Micropillars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rao, Satish</p> <p>2015-03-01</p> <p>Experimental studies show strong strengthening effects for micrometer-scale FCC as well as two-phase superalloy crystals, even at high initial dislocation densities. This talk shows results from large-scale <span class="hlt">3</span>-<span class="hlt">D</span> discrete dislocation simulations (DDS) used to explicitly model the deformation behavior of FCC Ni (flow stress and strain-hardening) as well as superalloy microcrystals for diameters ranging from 1 - 20 microns. The work shows that two size-sensitive athermal hardening processes, beyond forest and precipitation hardening, are sufficient to develop the dimensional scaling of the flow stress, stochastic stress variation, flow intermittency and, high initial strain-hardening rates, similar to experimental observations for various materials. In addition, <span class="hlt">3</span><span class="hlt">D</span> dislocation <span class="hlt">dynamics</span> simulations are used to investigate strain-hardening characteristics and dislocation microstructure evolution with strain in large 20 micron size Ni microcrystals (bulk-like) under three different loading axes: 111, 001 and 110. Three different multi-slip loading axes, < 111 > , < 001 > and < 110 > , are explored for shear strains of ~0.03 and final dislocation densities of ~1013/m2. The orientation dependence of initial strain hardening rates and dislocation microstructure evolution with strain are discussed. The simulated strain hardening results are compared with experimental data under similar loading conditions from bulk single-crystal Ni. Finally, atomistic simulation results on the operation of single arm sources in Ni bipillars with a large angle grain boundary is discussed. The atomistic simulation results are compared with experimental mechanical behavior data on Cu bipillars with a similar large angle grain boundary. This work was supported by AFOSR (Dr. David Stargel), and by a grant of computer time from the DOD High Performance Computing Modernization Program, at the Aeronautical Systems Center/Major Shared Resource Center.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014GMD.....7....1T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014GMD.....7....1T"><span id="translatedtitle">RIMBAY - a multi-approximation <span class="hlt">3</span><span class="hlt">D</span> ice-<span class="hlt">dynamics</span> model for comprehensive applications: model description and examples</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thoma, M.; Grosfeld, K.; Barbi, D.; Determann, J.; Goeller, S.; Mayer, C.; Pattyn, F.</p> <p>2014-01-01</p> <p>Glaciers and ice caps exhibit currently the largest cryospheric contributions to sea level rise. Modelling the <span class="hlt">dynamics</span> and mass balance of the major ice sheets is therefore an important issue to investigate the current state and the future response of the cryosphere in response to changing environmental conditions, namely global warming. This requires a powerful, easy-to-use, versatile multi-approximation ice <span class="hlt">dynamics</span> model. Based on the well-known and established ice sheet model of Pattyn (2003) we develop the modular multi-approximation thermomechanic ice model RIMBAY, in which we improve the original version in several aspects like a shallow ice-shallow shelf coupler and a full <span class="hlt">3</span><span class="hlt">D</span>-grounding-line migration scheme based on Schoof's (2007) heuristic analytical approach. We summarise the full Stokes equations and several approximations implemented within this model and we describe the different numerical discretisations. The results are cross-validated against previous publications dealing with ice modelling, and some additional artificial set-ups demonstrate the robustness of the different solvers and their internal coupling. RIMBAY is designed for an easy adaption to new scientific issues. Hence, we demonstrate in very different set-ups the applicability and functionality of RIMBAY in Earth system science in general and ice modelling in particular.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhFl...25k2111U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhFl...25k2111U"><span id="translatedtitle"><span class="hlt">Dynamics</span> of a pre-lens tear film after a blink: Model, evolution, and <span class="hlt">rupture</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Usha, R.; Anjalaiah, Sanyasiraju, Y. V. S. S.</p> <p>2013-11-01</p> <p>A mathematical model is developed to investigate the <span class="hlt">dynamics</span> and <span class="hlt">rupture</span> of a pre-lens tear film on a contact lens. The contact lens is modeled as a saturated porous medium of constant, finite thickness and is described by the Darcy-Brinkman equations with stress-jump condition at the interface. The model incorporates the influence of capillarity, gravitational drainage, contact lens properties such as the permeability, the porosity, and the thickness of the contact lens on the evolution and <span class="hlt">rupture</span> of a pre-lens tear film, when the eyelid has opened after a blink. Two models are derived for the evolution of a pre-lens tear film thickness using lubrication theory and are solved numerically; the first uses shear-free surface condition and the second, the tangentially immobile free surface condition. The results reveal that life span of a pre-lens tear film is longer on a thinner contact lens for all values of permeability and porosity parameter considered. An increase in permeability of contact lens, porosity or stress-jump parameter increases the rate of thinning of the film and advances the <span class="hlt">rupture</span> time. The viscous-viscous interaction between the porous contact lens and the pre-lens tear film increases the resistance offered by the frictional forces to the rate of thinning of pre-lens tear film. This slows down the thinning process and hence delays the <span class="hlt">rupture</span> of the film as compared to that predicted by the models of Nong and Anderson [SIAM. J. Appl. Math. 70, 2771-2795 (2010)] derived in the framework of Darcy model.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMDI31A2198K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMDI31A2198K"><span id="translatedtitle">Earthquake <span class="hlt">Rupture</span> <span class="hlt">Dynamics</span> using Adaptive Mesh Refinement and High-Order Accurate Numerical Methods</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kozdon, J. E.; Wilcox, L.</p> <p>2013-12-01</p> <p>Our goal is to develop scalable and adaptive (spatial and temporal) numerical methods for coupled, multiphysics problems using high-order accurate numerical methods. To do so, we are developing an opensource, parallel library known as bfam (available at http://bfam.in). The first application to be developed on top of bfam is an earthquake <span class="hlt">rupture</span> <span class="hlt">dynamics</span> solver using high-order discontinuous Galerkin methods and summation-by-parts finite difference methods. In earthquake <span class="hlt">rupture</span> <span class="hlt">dynamics</span>, wave propagation in the Earth's crust is coupled to frictional sliding on fault interfaces. This coupling is two-way, required the simultaneous simulation of both processes. The use of laboratory-measured friction parameters requires near-fault resolution that is 4-5 orders of magnitude higher than that needed to resolve the frequencies of interest in the volume. This, along with earlier simulations using a low-order, finite volume based adaptive mesh refinement framework, suggest that adaptive mesh refinement is ideally suited for this problem. The use of high-order methods is motivated by the high level of resolution required off the fault in earlier the low-order finite volume simulations; we believe this need for resolution is a result of the excessive numerical dissipation of low-order methods. In bfam spatial adaptivity is handled using the p4est library and temporal adaptivity will be accomplished through local time stepping. In this presentation we will present the guiding principles behind the library as well as verification of code against the Southern California Earthquake Center <span class="hlt">dynamic</span> <span class="hlt">rupture</span> code validation test problems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUFM.S43A1066T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUFM.S43A1066T"><span id="translatedtitle">Finite Element Simulations of <span class="hlt">Dynamic</span> Shear <span class="hlt">Rupture</span> Experiments and Path Selection Along Branched Faults</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Templeton, E. L.; Baudet, A.; Bhat, H. S.; Dmowska, R.; Rice, J. R.; Rosakis, A. J.; Rousseau, C. E.</p> <p>2005-12-01</p> <p>The study of <span class="hlt">dynamically</span> propagating shear cracks along geometrically complex paths is important to understanding the mechanics of earthquakes. Recent laboratory fracture studies of Rousseau and Rosakis examined a branched configuration, analogous to their study of <span class="hlt">rupture</span> along a bent fault path [Rousseau and Rosakis, JGR, 2003], to enhance understanding of the behavior of a shear <span class="hlt">rupture</span> approaching the intersection of two paths. Whereas crack motion along a simple bent path is readily explained by means of the energy available to sustain the propagating crack, or through a crack tip stress field criterion, the behavior of multiple paths displays more intricate variations featuring the inability of the crack to extend along secondary paths situated at shallow angles with respect to the initial direction of propagation. Secondary paths located at larger angles, on the extensional side, generally promote simultaneous extension along both paths beyond the junction, in contrast to preferred motion along the straight path, which is favored when secondary paths are situated on the compressional side. The experiments involve impact loading of thin plates of Homalite-100, a photoelastic polymer, which are cut along branched paths and weakly glued back together everywhere except along a starter notch near the impact site. High-speed photography of isochromatic fringe patterns (lines of constant difference between in-plane principal stresses) characterized the transient deformation field associated with the impact and <span class="hlt">rupture</span> propagation. We adapted the ABAQUS/Explicit <span class="hlt">dynamic</span> finite element program to analyze the propagation of shear cracks along such branched weakened paths. Two configurations for weakened paths, branches at 35° to the compressional side and the extensional side, were analyzed. We implemented a linear slip-weakening failure model as a user-defined constitutive relation within the ABAQUS program, where weakening could be included in either or both of (1</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/11295278','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/11295278"><span id="translatedtitle"><span class="hlt">Dynamics</span> of bubble oscillation in constrained media and mechanisms of vessel <span class="hlt">rupture</span> in SWL.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhong, P; Zhou, Y; Zhu, S</p> <p>2001-01-01</p> <p><span class="hlt">Rupture</span> of small blood vessels is a primary feature of the vascular injury associated with shock-wave lithotripsy (SWL) and cavitation has been implicated as a potential mechanism. To understand more precisely the underlying mechanical cause of the injury, the <span class="hlt">dynamics</span> of SWL-induced bubble <span class="hlt">dynamics</span> in constrained media were investigated. Silicone tubing and regenerated cellulose hollow fibers of various inner diameters (0.2 to 1.5 mm) were used to fabricate vessel phantoms, which were placed in a test chamber filled with castor oil so that cavitation outside the phantom could be suppressed. Degassed water seeded with 0.2% Albunex contrast agent was circulated inside the vessel phantom, and intraluminal bubble <span class="hlt">dynamics</span> during SWL were examined by high-speed shadowgraph imaging and passive cavitation detection via a 20-MHz focused transducer. It was observed that, in contrast to the typical large and prolonged expansion and violent inertial collapse of SWL-induced bubbles in a free field, the expansion of the bubbles inside the vessel phantom was significantly constrained, leading to asymmetric elongation of the bubbles along the vessel axis and, presumably, much weakened collapse. The severity of the constraint is vessel-size dependent, and increases dramatically when the inner diameter of the vessel becomes smaller than 300 microm. Conversely, the rapid, large intraluminal expansion of the bubbles causes a significant dilation of the vessel wall, leading to consistent <span class="hlt">rupture</span> of the hollow fibers (i.d. = 200 microm) after less than 20 pulses of shock wave exposure in a XL-1 lithotripter. The <span class="hlt">rupture</span> is dose-dependent, and varies with the spatial location of the vessel phantom in the lithotripter field. Further, when the large intraluminal bubble expansion was suppressed by inversion of the lithotripter pressure waveform, <span class="hlt">rupture</span> of the hollow fiber could be avoided even after 100 shocks. Theoretical calculation of SWL-induced bubble <span class="hlt">dynamics</span> in blood confirms that</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002AGUFMNG21B0941C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002AGUFMNG21B0941C"><span id="translatedtitle"><span class="hlt">Dynamic</span> <span class="hlt">Rupture</span> Simulation of Bending Faults With a Finite Difference Approach</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cruz-Atienza, V. M.; Virieux, J.; Operto, S.</p> <p>2002-12-01</p> <p>Many questions about physical parameters governing the <span class="hlt">rupture</span> propagation of earthquakes seem to find their answers within realistic <span class="hlt">dynamic</span> considerations. Sophisticated constitutive relations based in laboratory experiments have lead to a better understanding of <span class="hlt">rupture</span> evolution from its very beginning to its arrest. On the other hand, large amount of field observations as well as recent numerical simulations have also demonstrated the importance, in <span class="hlt">rupture</span> growing, of considering more reasonable geological settings (e.g., bending and step-over fault geometries; heterogeneous surrounding media). So far, despite the development of powerful numerical tools, there still exist some numerical considerations that overstep their possibilities. Authors have solved the <span class="hlt">dynamic</span> problem by applying the boundary integral equations method (BIEM) in order to explore the influence of fault geometry. This can be possible because of the fact that only the <span class="hlt">rupture</span> path must be discretized, reducing the impact of numerical discretization. However, the BIEM needs the analytical solution of Green functions that can only be computed for a homogeneous space. Up to date, no interaction with heterogeneous structures can be taken in to account. In contrast, finite difference (FD) approaches have been widely used. In this case, due to the specific discretization of the elastodynamic equations through the entire domain, and the azimuthal anisotropy intrinsic to differential operators, only planar faults have been considered and numerical artefacts have to be carefully checked. In this work, we have used a recently proposed four-order staggered grid finite difference scheme to model in-plane (mode II) <span class="hlt">dynamic</span> shear fracturing propagation with any pre-established geometry. In contrast with the classical 2-D staggered grid elementary cell in which all the elastic fields are defined in different positions (except the normal stresses), the stencil used here consider the velocity and stress</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3276601','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3276601"><span id="translatedtitle">Gender Dimorphic ACL Strain In Response to Combined <span class="hlt">Dynamic</span> <span class="hlt">3</span><span class="hlt">D</span> Knee Joint Loading: Implications for ACL Injury Risk</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Mizuno, Kiyonori; Andrish, Jack T.; van den Bogert, Antonie J.; McLean, Scott G.</p> <p>2009-01-01</p> <p>While gender-based differences in knee joint anatomies/laxities are well documented, the potential for them to precipitate gender-dimorphic ACL loading and resultant injury risk has not been considered. To this end, we generated gender-specific models of ACL strain as a function of any six degrees of freedom (6DOF) knee joint load state via a combined cadaveric and analytical approach. Continuously varying joint forces and torques were applied to five male and five female cadaveric specimens and recorded along with synchronous knee flexion and ACL strain data. All data (~10,000 samples) were submitted to specimen-specific regression analyses, affording ACL strain predictions as a function of the combined 6 DOF knee loads. Following individual model verifications, generalized gender-specific models were generated and subjected to 6 DOF external load scenarios consistent with both a clinical examination and a <span class="hlt">dynamic</span> sports maneuver. The ensuing model-based strain predictions were subsequently examined for gender-based discrepancies. Male and female specimen specific models predicted ACL strain within 0.51% ± 0.10% and 0.52% ± 0.07% of the measured data respectively, and explained more than 75% of the associated variance in each case. Predicted female ACL strains were also significantly larger than respective male values for both of simulated 6 DOF load scenarios. Outcomes suggest that the female ACL will <span class="hlt">rupture</span> in response to comparatively smaller external load applications. Future work must address the underlying anatomical/laxity contributions to knee joint mechanical and resultant ACL loading, ultimately affording prevention strategies that may cater to individual joint vulnerabilities. PMID:19464897</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AGUFM.S41A0947T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AGUFM.S41A0947T"><span id="translatedtitle">Finite Element Modeling of <span class="hlt">Dynamic</span> Shear <span class="hlt">Rupture</span> Experiments Along Non-Planar Faults</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Templeton, E. L.; Baudet, A.; Bhat, H. S.; Rice, J. R.</p> <p>2004-12-01</p> <p>The study of <span class="hlt">dynamically</span> propagating shear cracks along weak paths like faults is of great interest for the study of earthquakes. We adapted the ABAQUS/Explicit <span class="hlt">dynamic</span> finite element program to analyze the nucleation and propagation of shear cracks along a non-planar, kinked, weak path corresponding to the one that was used in recent laboratory fracture studies by Rousseau and Rosakis [JGR, 2003]. Their experiments involved impact loading of thin plates of Homalite-100, a photoelastically sensitive brittle polymer, which had been cut along a kinked path and then weakly glued back together everywhere except along a starter notch near the impact site. Under different conditions, propagation speeds were observed in both the sub-Rayleigh and intersonic (supershear) regimes. Strain gage recordings and high speed photography of isochromatic lines (lines of constant difference between the in-plane principal strains) provided characterization of the transient deformation fields associated with the impact and fracture propagation. For the finite element analyses, we implemented a slip-weakening failure model through an option in the ABAQUS program allowing user defined constitutive relations. The analyses of impact loading and of <span class="hlt">rupture</span> nucleation and propagation were then carried out in the 2D framework of plane stress. In a first set of studies of nucleation and propagation of <span class="hlt">rupture</span> along a straight fault, we determined after some trial and error an appropriate CFL number, and examined different element types and layouts, finding that the most acceptable results were obtained for low order elements. We used constant strain triangles, arrayed in groups of four to effectively form four-sided elements with corner nodes and one internal node. The studies also showed that to obtain representations of slip rate and shear stress near the propagating <span class="hlt">rupture</span> tip that were relatively free from numerical oscillations, it was necessary to have element side lengths of order Ro/50</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/18023735','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/18023735"><span id="translatedtitle">Delaunay-Object-<span class="hlt">Dynamics</span>: cell mechanics with a <span class="hlt">3</span><span class="hlt">D</span> kinetic and <span class="hlt">dynamic</span> weighted Delaunay-triangulation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Meyer-Hermann, Michael</p> <p>2008-01-01</p> <p>Mathematical methods in Biology are of increasing relevance for understanding the control and the <span class="hlt">dynamics</span> of biological systems with medical relevance. In particular, agent-based methods turn more and more important because of fast increasing computational power which makes even large systems accessible. An overview of different mathematical methods used in Theoretical Biology is provided and a novel agent-based method for cell mechanics based on Delaunay-triangulations and Voronoi-tessellations is explained in more detail: The Delaunay-Object-<span class="hlt">Dynamics</span> method. It is claimed that the model combines physically realistic cell mechanics with a reasonable computational load. The power of the approach is illustrated with two examples, avascular tumor growth and genesis of lymphoid tissue in a cell-flow equilibrium. PMID:18023735</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PhDT.......104H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PhDT.......104H"><span id="translatedtitle">Multi-fluid <span class="hlt">Dynamics</span> for Supersonic Jet-and-Crossflows and Liquid Plug <span class="hlt">Rupture</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hassan, Ezeldin A.</p> <p></p> <p>Multi-fluid <span class="hlt">dynamics</span> simulations require appropriate numerical treatments based on the main flow characteristics, such as flow speed, turbulence, thermodynamic state, and time and length scales. In this thesis, two distinct problems are investigated: supersonic jet and crossflow interactions; and liquid plug propagation and <span class="hlt">rupture</span> in an airway. Gaseous non-reactive ethylene jet and air crossflow simulation represents essential physics for fuel injection in SCRAMJET engines. The regime is highly unsteady, involving shocks, turbulent mixing, and large-scale vortical structures. An eddy-viscosity-based multi-scale turbulence model is proposed to resolve turbulent structures consistent with grid resolution and turbulence length scales. Predictions of the time-averaged fuel concentration from the multi-scale model is improved over Reynolds-averaged Navier-Stokes models originally derived from stationary flow. The response to the multi-scale model alone is, however, limited, in cases where the vortical structures are small and scattered thus requiring prohibitively expensive grids in order to resolve the flow field accurately. Statistical information related to turbulent fluctuations is utilized to estimate an effective turbulent Schmidt number, which is shown to be highly varying in space. Accordingly, an adaptive turbulent Schmidt number approach is proposed, by allowing the resolved field to adaptively influence the value of turbulent Schmidt number in the multi-scale turbulence model. The proposed model estimates a time-averaged turbulent Schmidt number adapted to the computed flowfield, instead of the constant value common to the eddy-viscosity-based Navier-Stokes models. This approach is assessed using a grid-refinement study for the normal injection case, and tested with 30 degree injection, showing improved results over the constant turbulent Schmidt model both in mean and variance of fuel concentration predictions. For the incompressible liquid plug propagation</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24057004','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24057004"><span id="translatedtitle"><span class="hlt">3</span><span class="hlt">D</span> lacunarity in multifractal analysis of breast tumor lesions in <span class="hlt">dynamic</span> contrast-enhanced magnetic resonance imaging.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Soares, Filipe; Janela, Filipe; Pereira, Manuela; Seabra, João; Freire, Mário M</p> <p>2013-11-01</p> <p><span class="hlt">Dynamic</span> contrast-enhanced magnetic resonance (DCE-MR) of the breast is especially robust for the diagnosis of cancer in high-risk women due to its high sensitivity. Its specificity may be, however, compromised since several benign masses take up contrast agent as malignant lesions do. In this paper, we propose a novel method of <span class="hlt">3</span><span class="hlt">D</span> multifractal analysis to characterize the spatial complexity (spatial arrangement of texture) of breast tumors at multiple scales. Self-similar properties are extracted from the estimation of the multifractal scaling exponent for each clinical case, using lacunarity as the multifractal measure. These properties include several descriptors of the multifractal spectra reflecting the morphology and internal spatial structure of the enhanced lesions relatively to normal tissue. The results suggest that the combined multifractal characteristics can be effective to distinguish benign and malignant findings, judged by the performance of the support vector machine classification method evaluated by receiver operating characteristics with an area under the curve of 0.96. In addition, this paper confirms the presence of multifractality in DCE-MR volumes of the breast, whereby multiple degrees of self-similarity prevail at multiple scales. The proposed feature extraction and classification method have the potential to complement the interpretation of the radiologists and supply a computer-aided diagnosis system. PMID:24057004</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013APS..MARY28014L&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013APS..MARY28014L&link_type=ABSTRACT"><span id="translatedtitle">Use of magnetic micro-cantilevers to study the <span class="hlt">dynamics</span> of <span class="hlt">3</span><span class="hlt">D</span> engineered smooth muscle constructs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Alan; Zhao, Ruogang; Copeland, Craig; Chen, Christopher; Reich, Daniel</p> <p>2013-03-01</p> <p>The normal and pathological response of arterial tissue to mechanical stimulus sheds important light on such conditions as atherosclerosis and hypertension. While most previous methods of determining the biomechanical properties of arteries have relied on excised tissue, we have devised a system that enables the growth and in situ application of forces to arrays of stable suspended microtissues consisting of arterial smooth muscle cells (SMCs). Briefly, this magnetic microtissue tester system consists of arrays of pairs of elastomeric magnetically actuated micro-cantilevers between which SMC-infused <span class="hlt">3</span><span class="hlt">D</span> collagen gels self-assemble and remodel into aligned microtissue constructs. These devices allow us to simultaneously apply force and track stress-strain relationships of multiple microtissues per substrate. We have studied the dilatory capacity and subsequent response of the tissues and find that the resulting stress-strain curves show viscoelastic behavior as well as a linear <span class="hlt">dynamic</span> recovery. These results provide a foundation for elucidating the mechanical behavior of this novel model system as well as further experiments that simulate pathological conditions. Supported in part by NIH grant HL090747.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26615711','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26615711"><span id="translatedtitle">The <span class="hlt">3</span><span class="hlt">D</span> pore structure and fluid <span class="hlt">dynamics</span> simulation of macroporous monoliths: High permeability due to alternating channel width.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jungreuthmayer, Christian; Steppert, Petra; Sekot, Gerhard; Zankel, Armin; Reingruber, Herbert; Zanghellini, Jürgen; Jungbauer, Alois</p> <p>2015-12-18</p> <p>Polymethacrylate-based monoliths have excellent flow properties. Flow in the wide channel interconnected with narrow channels is theoretically assumed to account for favorable permeability. Monoliths were cut into 898 slices in 50nm distances and visualized by serial block face scanning electron microscopy (SBEM). A <span class="hlt">3</span><span class="hlt">D</span> structure was reconstructed and used for the calculation of flow profiles within the monolith and for calculation of pressure drop and permeability by computational fluid <span class="hlt">dynamics</span> (CFD). The calculated and measured permeabilities showed good agreement. Small channels clearly flowed into wide and wide into small channels in a repetitive manner which supported the hypothesis describing the favorable flow properties of these materials. This alternating property is also reflected in the streamline velocity which fluctuated. These findings were corroborated by artificial monoliths which were composed of regular (interconnected) cells where narrow cells followed wide cells. In the real monolith and the artificial monoliths with interconnected flow channels similar velocity fluctuations could be observed. A two phase flow simulation showed a lateral velocity component, which may contribute to the transport of molecules to the monolith wall. Our study showed that the interconnection of small and wide pores is responsible for the excellent pressure flow properties. This study is also a guide for further design of continuous porous materials to achieve good flow properties. PMID:26615711</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/19363807','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/19363807"><span id="translatedtitle">A new <span class="hlt">dynamic</span> <span class="hlt">3</span><span class="hlt">D</span> virtual methodology for teaching the mechanics of atrial septation as seen in the human heart.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schleich, Jean-Marc; Dillenseger, Jean-Louis; Houyel, Lucile; Almange, Claude; Anderson, Robert H</p> <p>2009-01-01</p> <p>Learning embryology remains difficult, since it requires understanding of many complex phenomena. The temporal evolution of developmental events has classically been illustrated using cartoons, which create difficulty in linking spatial and temporal aspects, such correlation being the keystone of descriptive embryology. We synthesized the bibliographic data from recent studies of atrial septal development. On the basis of this synthesis, consensus on the stages of atrial septation as seen in the human heart has been reached by a group of experts in cardiac embryology and pediatric cardiology. This has permitted the preparation of three-dimensional (<span class="hlt">3</span><span class="hlt">D</span>) computer graphic objects for the anatomical components involved in the different stages of normal human atrial septation. We have provided a virtual guide to the process of normal atrial septation, the animation providing an appreciation of the temporal and morphologic events necessary to separate the systemic and pulmonary venous returns. We have shown that our animations of normal human atrial septation increase significantly the teaching of the complex developmental processes involved, and provide a new <span class="hlt">dynamic</span> for the process of learning. PMID:19363807</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007SPIE.6511E..2GT&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007SPIE.6511E..2GT&link_type=ABSTRACT"><span id="translatedtitle">Comparative study of diverse model building strategies for <span class="hlt">3</span><span class="hlt">D</span>-ASM segmentation of <span class="hlt">dynamic</span> gated SPECT data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tobon-Gomez, C.; Butakoff, C.; Ordas, S.; Aguade, S.; Frangi, A. F.</p> <p>2007-03-01</p> <p>Over the course of the last two decades, myocardial perfusion with Single Photon Emission Computed Tomography (SPECT) has emerged as an established and well-validated method for assessing myocardial ischemia, viability, and function. Gated-SPECT imaging integrates traditional perfusion information along with global left ventricular function. Despite of these advantages, inherent limitations of SPECT imaging yield a challenging segmentation problem, since an error of only one voxel along the chamber surface may generate a huge difference in volume calculation. In previous works we implemented a <span class="hlt">3</span>-<span class="hlt">D</span> statistical model-based algorithm for Left Ventricle (LV) segmentation of in <span class="hlt">dynamic</span> perfusion SPECT studies. The present work evaluates the relevance of training a different Active Shape Model (ASM) for each frame of the gated SPECT imaging acquisition in terms of their subsequent segmentation accuracy. Models are subsequently employed to segment the LV cavity of gated SPECT studies of a virtual population. The evaluation is accomplished by comparing point-to-surface (P2S) and volume errors, both against a proper Gold Standard. The dataset comprised 40 voxel phantoms (NCAT, Johns Hopkins, University of of North Carolina). Monte-Carlo simulations were generated with SIMIND (Lund University) and reconstructed to tomographic slices with ASPIRE (University of Michigan).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..1811125U&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..1811125U&link_type=ABSTRACT"><span id="translatedtitle">High-Speed Observations of <span class="hlt">Dynamic</span> Fracture Propagation in Solids and Their Implications in Earthquake <span class="hlt">Rupture</span> <span class="hlt">Dynamics</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Uenishi, Koji</p> <p>2016-04-01</p> <p>This contribution outlines our experimental observations of seismicity-related fast fracture (<span class="hlt">rupture</span>) propagation in solids utilising high-speed analog and digital photography (maximum frame rate 1,000,000 frames per second) over the last two decades. <span class="hlt">Dynamic</span> fracture may be triggered or initiated in the monolithic or layered seismic models by detonation of micro explosives, a projectile launched by a gun, laser pulses and electric discharge impulses, etc. First, we have investigated strike-slip <span class="hlt">rupture</span> along planes of weakness in transparent photoelastic (birefringent) materials at a laboratory scale and shown (at that time) extraordinarily fast <span class="hlt">rupture</span> propagation in a bi-material system and its possible effect on the generation of large strong motion in the limited narrow areas in the Kobe region on the occasion of the 1995 Hyogo-ken Nanbu, Japan, earthquake (Uenishi Ph.D. thesis 1997, Uenishi et al. BSSA 1999). In this series of experiments, we have also modelled shallow dip-slip earthquakes and indicated a possible origin of the asymmetric ground motion in the hanging and foot-walls. In the photoelastic photographs, we have found the unique <span class="hlt">dynamic</span> wave interaction and generation of specific shear and interface waves numerically predicted by Uenishi and Madariaga (Eos 2005), and considered as a case study the seismic motion associated with the 2014 Nagano-ken Hokubu (Kamishiro Fault), Japan, dip-slip earthquake (Uenishi EFA 2015). Second, we have experimentally shown that even in a monolithic material, <span class="hlt">rupture</span> speed may exceed the local shear wave speed if we employ hyperelasically behaving materials like natural rubber (balloons) (Uenishi Eos 2006, Uenishi ICF 2009, Uenishi Trans. JSME A 2012) but fracture in typical monolithic thin fluid films (e.g. soap bubbles, which may be treated as a solid material) propagates at an ordinary subsonic (sub-Rayleigh) speed (Uenishi et al. SSJ 2006). More recent investigation handling three-dimensional <span class="hlt">rupture</span> propagation</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1810136S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1810136S"><span id="translatedtitle">Modelling of river plume <span class="hlt">dynamics</span> in Öre estuary (Baltic Sea) with Telemac-<span class="hlt">3</span><span class="hlt">D</span> hydrodynamic model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sokolov, Alexander</p> <p>2016-04-01</p> <p>The main property of river plumes is their buoyancy, fresh water discharged by rivers is less dense than the receiving, saline waters. To study the processes of plume formation in case of river discharge into a brackish estuary where salinity is low (3.5 - 5 psu) a three dimensional hydrodynamic model was applied to the Öre estuary in the Baltic Sea. This estuary is a small fjord-like bay in the north part of the Baltic Sea. Size of the bay is about 8 by 8 km with maximum depth of 35 metres. River Öre has a small average freshwater discharge of 35 m3/s. But in spring during snowmelt the discharge can be many times higher. For example, in April 2015 the discharge increased from 8 m3/s to 160 m3/s in 18 days. To study river plume <span class="hlt">dynamics</span> a finite element based three dimensional baroclinic model TELEMAC - <span class="hlt">3</span><span class="hlt">D</span> is used. The TELEMAC modelling suite is developed by the National Laboratory of Hydraulics and Environment (LNHE) of Electricité de France (EDF). Modelling domain was approximated by an unstructured mesh with element size varies from 50 to 500 m. In vertical direction a sigma-coordinate with 20 layers was used. Open sea boundary conditions were obtained from the Baltic Sea model HIROMB-BOOS using COPERNICUS marine environment monitoring service. Comparison of modelling results with observations obtained by BONUS COCOA project's field campaign in Öre estuary in 2015 shows that the model plausible simulate river plume <span class="hlt">dynamics</span>. Modelling of age of freshwater is also discussed. This work resulted from the BONUS COCOA project was supported by BONUS (Art 185), funded jointly by the EU and the Swedish Research Council Formas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.4163E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.4163E"><span id="translatedtitle">Assessing pyroclastic density current <span class="hlt">dynamics</span> and hazard of Plinian events at Campi Flegrei (Italy) by using <span class="hlt">3</span><span class="hlt">D</span> numerical simulations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Esposti Ongaro, T.; Neri, A.; Todesco, M.</p> <p>2012-04-01</p> <p>Campi Flegrei is a densely populated widespread caldera located near the city of Naples. Current evaluation of volcanic hazard include the probable generation of pyroclastic density currents (PDC) produced by explosive events of variable size and uncertain vent location. In this study we investigate the <span class="hlt">dynamics</span> and hazard of PDC produced by the partial collapse of the volcanic column by using the <span class="hlt">3</span><span class="hlt">D</span> transient multiphase flow model PDAC (Esposti Ongaro et al., Parallel Computing, 2007). The model allows to describe the temporal and spatial evolution of the stratified PDC by accounting for the multiparticle nature of the flow and the complex topography of the caldera. Employed eruptive intensity and pyroclast properties are representative of magmatic phases of the Agnano Monte Spina (AMS, 4100 BP) Plinian eruption, the largest explosive event of the last cycle of activity of the caldera. Eruptive centers are supposed to be located in the north-eastern part of the caldera, the area with the largest number of past vents. Several simulations were performed considering different collapsing regimes, flow conditions at the source and vent locations. Results illustrate the complex <span class="hlt">dynamics</span> of flow propagation in the caldera settings and quantify the associated hazards. Fountain instabilities, recycling of collapsed material into the jet caused by the caldera walls, triggering of thermals and co-ignimbrite clouds by topographic reliefs, flow decoupling between dense and dilute streams, and generation of backflows are some of the processes simulated. The areas invaded by the PDC result affected by the inner topography of the caldera and therefore largely influenced by the assumed location of the vent. PDC result mostly confined by the outer caldera rims although they appear able to overcome Posillipo Hill and affect the eastern portions of the city of Naples. Comparisons with reconstructions of the AMS event are also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.3373A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.3373A"><span id="translatedtitle">Probabilistic approach for earthquake scenarios in the Marmara region from <span class="hlt">dynamic</span> <span class="hlt">rupture</span> simulations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Aochi, Hideo</p> <p>2014-05-01</p> <p>The Marmara region (Turkey) along the North Anatolian fault is known as a high potential of large earthquakes in the next decades. For the purpose of seismic hazard/risk evaluation, kinematic and <span class="hlt">dynamic</span> source models have been proposed (e.g. Oglesby and Mai, GJI, 2012). In general, the simulated earthquake scenarios depend on the hypothesis and cannot be verified before the expected earthquake. We then introduce a probabilistic insight to give the initial/boundary conditions to statistically analyze the simulated scenarios. We prepare different fault geometry models, tectonic loading and hypocenter locations. We keep the same framework of the simulation procedure as the <span class="hlt">dynamic</span> <span class="hlt">rupture</span> process of the adjacent 1999 Izmit earthquake (Aochi and Madariaga, BSSA, 2003), as the previous models were able to reproduce the seismological/geodetic aspects of the event. Irregularities in fault geometry play a significant role to control the <span class="hlt">rupture</span> progress, and a relatively large change in geometry may work as barriers. The variety of the simulate earthquake scenarios should be useful for estimating the variety of the expected ground motion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015Nanos...7.7674B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015Nanos...7.7674B"><span id="translatedtitle"><span class="hlt">Dynamic</span> effects in friction and adhesion through cooperative <span class="hlt">rupture</span> and formation of supramolecular bonds</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Blass, Johanna; Albrecht, Marcel; Bozna, Bianca L.; Wenz, Gerhard; Bennewitz, Roland</p> <p>2015-04-01</p> <p>We introduce a molecular toolkit for studying the <span class="hlt">dynamics</span> in friction and adhesion from the single molecule level to effects of multivalency. As experimental model system we use supramolecular bonds established by the inclusion of ditopic adamantane connector molecules into two surface-bound cyclodextrin molecules, attached to a tip of an atomic force microscope (AFM) and to a flat silicon surface. The <span class="hlt">rupture</span> force of a single bond does not depend on the pulling rate, indicating that the fast complexation kinetics of adamantane and cyclodextrin are probed in thermal equilibrium. In contrast, the pull-off force for a group of supramolecular bonds depends on the unloading rate revealing a non-equilibrium situation, an effect discussed as the combined action of multivalency and cantilever inertia effects. Friction forces exhibit a stick-slip characteristic which is explained by the cooperative <span class="hlt">rupture</span> of groups of host-guest bonds and their rebinding. No dependence of friction on the sliding velocity has been observed in the accessible range of velocities due to fast rebinding and the negligible delay of cantilever response in AFM lateral force measurements.We introduce a molecular toolkit for studying the <span class="hlt">dynamics</span> in friction and adhesion from the single molecule level to effects of multivalency. As experimental model system we use supramolecular bonds established by the inclusion of ditopic adamantane connector molecules into two surface-bound cyclodextrin molecules, attached to a tip of an atomic force microscope (AFM) and to a flat silicon surface. The <span class="hlt">rupture</span> force of a single bond does not depend on the pulling rate, indicating that the fast complexation kinetics of adamantane and cyclodextrin are probed in thermal equilibrium. In contrast, the pull-off force for a group of supramolecular bonds depends on the unloading rate revealing a non-equilibrium situation, an effect discussed as the combined action of multivalency and cantilever inertia effects. Friction</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.T43A2638K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.T43A2638K"><span id="translatedtitle">Development of an extended BIEM and its application to the analysis of earthquake <span class="hlt">dynamic</span> <span class="hlt">rupture</span> interacting with a medium interface</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kusakabe, T.; Kame, N.</p> <p>2013-12-01</p> <p>An extended boundary integral equation method (XBIEM) has been recently proposed for the analysis of <span class="hlt">dynamic</span> crack growth (=<span class="hlt">dynamic</span> earthquake <span class="hlt">rupture</span> model) in an inhomogeneous medium consisting of homogeneous sub-regions. Originally XBIEM is applicable to non-planar geometry of cracks and medium interfaces, but it has been demonstrated only for a simple planar crack along a bimaterial interface. Here we developed a code to analyse non-planar <span class="hlt">rupture</span> with non-planar interfaces in a mode III problem, and applied it to a <span class="hlt">dynamic</span> <span class="hlt">rupture</span> problem across a planar bimaterial interface to investigate the effect of medium inhomogeneity. For this purpose, we firstly derived all the displacement and displacement velocity kernels in a unified analytic discretized form, in addition to the stress kernels already derived, necessary for versatile geometry of boundaries (i.e., cracks and interfaces) and checked all the kernel components in the simulation of wave propagation across a non-planar interface cutting a homogeneous medium. Then we validated our code in a wave reflection-transmission problem across a planar bimaterial interface. Secondly, in order to realize the analysis of <span class="hlt">dynamic</span> <span class="hlt">rupture</span> crossing a bimaterial interface we introduced a new implicit time-stepping scheme for instantaneously interacting boundary elements on the crack and medium interface. Such interactions only appear in the crack's crossing the interface. Otherwise we can use the explicit scheme as employed for BIEM in a homogeneous medium. We validated our numerical code for the crack growth in a homogeneous medium cut with a planar interface and found that our new scheme worked well. Finally, we tackled <span class="hlt">dynamic</span> <span class="hlt">rupture</span> propagation on a planar fault embedded normal to the planar interface of a bimaterial. Spontaneous <span class="hlt">rupture</span> was allowed not only on the planar main fault but also on the interfacial fault and it is controlled by different slip-weakening laws on each of them: each peak strength is</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JGRB..119.1251J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JGRB..119.1251J"><span id="translatedtitle">Predicting fault damage zones by modeling <span class="hlt">dynamic</span> <span class="hlt">rupture</span> propagation and comparison with field observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Johri, Madhur; Dunham, Eric M.; Zoback, Mark D.; Fang, Zijun</p> <p>2014-02-01</p> <p>We use a two-dimensional plane strain <span class="hlt">dynamic</span> <span class="hlt">rupture</span> model with strongly rate-weakening friction and off-fault Drucker-Prager plasticity to model damage zones associated with buried second-order thrust faults observed in the SSC reservoir. The modeling of <span class="hlt">ruptures</span> propagating as self-sustaining pulses is performed in the framework of continuum plasticity where the plasticity formulation includes both deviatoric and volumetric plastic strains. The material deforming inelastically due to stress perturbations generated by the propagating <span class="hlt">rupture</span> is assumed to be the damage zone associated with the fault. Dilatant plastic strains are converted into a fracture population by assuming that the dilatant plastic strain is manifested in the form of fractures. The cumulative effect of multiple slip events is considered by superposition of the plastic strain field obtained from individual slip events. The relative number of various magnitude slip events is chosen so as to honor the Gutenberg-Richter law. Results show that the decay of fracture density (F) with distance (r) from the fault can be described by a power law F = F0r- n. The fault constant F0 represents the fracture density at unit distance from the fault. The decay rate (n) in fracture density is approximately 0.85 close to the fault and increases to ~1.4 at larger distances (>10 m). Modeled damage zones are approximately 60-100 m wide. These attributes are similar to those observed in the SSC reservoir using wellbore image logs and those reported in outcrop studies. Considering fault roughness affects local damage zone characteristics, these characteristics are similar to those modeled around planar faults at a scale (~10 m) that affects bulk fluid-flow properties.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JCoPh.273..548T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JCoPh.273..548T"><span id="translatedtitle">An overset grid method for integration of fully <span class="hlt">3</span><span class="hlt">D</span> fluid <span class="hlt">dynamics</span> and geophysics fluid <span class="hlt">dynamics</span> models to simulate multiphysics coastal ocean flows</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tang, H. S.; Qu, K.; Wu, X. G.</p> <p>2014-09-01</p> <p>It is now becoming important to develop our capabilities to simulate coastal ocean flows involved with distinct physical phenomena occurring at a vast range of spatial and temporal scales. This paper presents a hybrid modeling system for such simulation. The system consists of a fully three dimensional (<span class="hlt">3</span><span class="hlt">D</span>) fluid <span class="hlt">dynamics</span> model and a geophysical fluid <span class="hlt">dynamics</span> model, which couple with each other in two-way and march in time simultaneously. Particularly, in the hybrid system, the solver for incompressible flow on overset meshes (SIFOM) resolves fully <span class="hlt">3</span><span class="hlt">D</span> small-scale local flow phenomena, while the unstructured grid finite volume coastal ocean model (FVCOM) captures large-scale background flows. The integration of the two models are realized via domain decomposition implemented with an overset grid method. Numerical experiments on performance of the system in resolving flow patterns and solution convergence rate show that the SIFOM-FVCOM system works as intended, and its solutions compare reasonably with data obtained with measurements and other computational approaches. Its unparalleled capabilities to predict multiphysics and multiscale phenomena with high-fidelity are demonstrated by three typical applications that are beyond the reach of other currently existing models. It is anticipated that the SIFOM-FVCOM system will serve as a new platform to study many emerging coastal ocean problems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.2576Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.2576Y"><span id="translatedtitle"><span class="hlt">3</span><span class="hlt">D</span> numerical modeling of subduction <span class="hlt">dynamics</span>: plate stagnation and segmentation, and crustal advection in the mantle transition zone</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yoshida, M.; Tajima, F.</p> <p>2012-04-01</p> <p>Water content in the mantle transition zone (MTZ) has been broadly debated in the Earth science community as a key issue for plate <span class="hlt">dynamics</span> [e.g., Bercovici and Karato, 2003]. In this study, a systematic series of three-dimensional (<span class="hlt">3</span><span class="hlt">D</span>) numerical simulation are performed in an attempt to verify two hypotheses for plate subduction with effects of deep water transport: (1) the small-scale behavior of subducted oceanic plate in the MTZ; and (2) the role of subducted crust in the MTZ. These hypotheses are postulated based on the seismic observations characterized by large-scale flattened high velocity anomalies (i.e., stagnant slabs) in the MTZ and discontinuity depth variations. The proposed model states that under wet conditions the subducted plate main body of peridotite (olivine rich) is abutted by subducted crustal materials (majorite rich) at the base of the MTZ. The computational domain of mantle convection is confined to <span class="hlt">3</span><span class="hlt">D</span> regional spherical-shell geometry with a thickness of 1000 km and a lateral extent of 10° × 30° in the latitudinal and longitudinal directions. A semi-<span class="hlt">dynamic</span> model of subduction zone [Morishige et al., 2010] is applied to let the highly viscous, cold oceanic plate subduct. Weak (low-viscosity) fault zones (WFZs), which presumably correspond to the fault boundaries of large subduction earthquakes, are imposed on the top part of subducting plates. The phase transitions of olivine to wadsleyite and ringwoodite to perovskite+magnesiowüstite with Clapeyron slopes under both "dry" and "wet" conditions are considered based on recent high pressure experiments [e.g., Ohtani and Litasov, 2006]. Another recent experiment provides new evidence for lower-viscosity (weaker strength) of garnet-rich zones than the olivine dominant mantle under wet conditions [Katayama and Karato, 2008]. According to this, the effect of viscosity reduction of oceanic crust is considered under wet condition in the MTZ. Results show that there is a substantial difference</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFM.V13B0667B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFM.V13B0667B"><span id="translatedtitle">Geographic Variations in Hotspot Geochemistry Caused by <span class="hlt">3</span><span class="hlt">D</span> <span class="hlt">Dynamics</span> and Melting of a Heterogeneous Mantle Plume</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bianco, T. A.; Ito, G.; van Hunen, J.; Ballmer, M.; Mahoney, J. J.</p> <p>2006-12-01</p> <p>Spatial variations in magma geochemistry among hotspot volcanoes hold clues to the <span class="hlt">dynamics</span> and composition of the mantle feeding hotspot volcanism. We use a <span class="hlt">3</span><span class="hlt">D</span> geodynamic model of plume-lithosphere interaction to explore the causes of spatial patterns of magmatic volumes and compositions at intraplate hotspots. This study focuses on coupling between upper mantle flow, heat transfer, and melting of a heterogeneous (veined) plume. We assume multiple lithologies have different solidi, trace-element, and isotope composition. We use the Cartesian finite-element code, CITCOM, (Zhong and Watts, 2002) to simulate mantle convection with the extended Boussinesq approximation in a volume of upper mantle 400 km in thickness. A parameterized melting model is used to simulate melting of materials with different water contents (Katz et al., 2003). Melt depletion (F) for each lithology is calculated at finite element nodes as a function of temperature, pressure, and water content and is advected using particle tracers. We quantify the response of the geographic pattern of the volume and composition of magmas to different lithospheric thicknesses, and plume temperatures and viscosities, which together control the melting rates and sizes of the melting zones for the different lithologies. In the case of two-lithologies, preliminary results of a sluggishly convecting plume rising beneath thick lithosphere (60-100 km) predict that the melting zone of the least refractory "lithology 1" is wider than that of the more refractory "lithology 2". This leads to the prediction that on the surface, the isotope signature of lithology 1 is most prominent at the leading edge (i.e., upwind edge of plate motion) of the hotspot, whereas the isotope signature of lithology 2 is strongest at the hotspot center. This pattern will likely change for plumes convecting more vigorously or thinner lithosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26727249','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26727249"><span id="translatedtitle">A Diffusion-Based and <span class="hlt">Dynamic</span> <span class="hlt">3</span><span class="hlt">D</span>-Printed Device That Enables Parallel in Vitro Pharmacokinetic Profiling of Molecules.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lockwood, Sarah Y; Meisel, Jayda E; Monsma, Frederick J; Spence, Dana M</p> <p>2016-02-01</p> <p>The process of bringing a drug to market involves many steps, including the preclinical stage, where various properties of the drug candidate molecule are determined. These properties, which include drug absorption, distribution, metabolism, and excretion, are often displayed in a pharmacokinetic (PK) profile. While PK profiles are determined in animal models, in vitro systems that model in vivo processes are available, although each possesses shortcomings. Here, we present a <span class="hlt">3</span><span class="hlt">D</span>-printed, diffusion-based, and <span class="hlt">dynamic</span> in vitro PK device. The device contains six flow channels, each with integrated porous membrane-based insert wells. The pores of these membranes enable drugs to freely diffuse back and forth between the flow channels and the inserts, thus enabling both loading and clearance portions of a standard PK curve to be generated. The device is designed to work with 96-well plate technology and consumes single-digit milliliter volumes to generate multiple PK profiles, simultaneously. Generation of PK profiles by use of the device was initially performed with fluorescein as a test molecule. Effects of such parameters as flow rate, loading time, volume in the insert well, and initial concentration of the test molecule were investigated. A prediction model was generated from this data, enabling the user to predict the concentration of the test molecule at any point along the PK profile within a coefficient of variation of ∼ 5%. Depletion of the analyte from the well was characterized and was determined to follow first-order rate kinetics, indicated by statistically equivalent (p > 0.05) depletion half-lives that were independent of the starting concentration. A PK curve for an approved antibiotic, levofloxacin, was generated to show utility beyond the fluorescein test molecule. PMID:26727249</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6082054','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6082054"><span id="translatedtitle">Analysis of the <span class="hlt">dynamic</span> response of a double <span class="hlt">rupture</span> disc assembly to simulated sodium-water reaction pressure pulses</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Leonard, J.R.</p> <p>1980-03-01</p> <p>A series of double <span class="hlt">rupture</span> disc experiments were conducted in 1979 to evaluate the <span class="hlt">dynamic</span> response characteristics of this pressure relief apparatus. The tests were performed in a facility with water simulating sodium and rising pressure pulses representative of the pressure increase resulting from a water/steam leak from a steam generator into sodium in the intermediate heat transport system of a breeder reactor power plant. Maximum source pressures ranged in magnitude from 50 psi to 800 psi. <span class="hlt">Dynamic</span> response characteristics of each of the two <span class="hlt">rupture</span> discs were similar to those observed in larger scale sodium-water experiments conducted in the Series I and Series II Large Leak Test Program at the Energy Technology Engineering Center. The SRI double <span class="hlt">rupture</span> disc <span class="hlt">dynamic</span> behavior was found to be consistent and amendable to modelling in the TRANSWRAP II computer code. A series of correlations which represent <span class="hlt">rupture</span> disc buckling parameters were developed for use in the TRANSWRAP II code. The semi-empirical modeling of the <span class="hlt">rupture</span> discs in the TRANSWRAP II code showed very good agreement with the experimental results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70041794','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70041794"><span id="translatedtitle">Inelastic off-fault response and three-dimensional <span class="hlt">dynamics</span> of earthquake <span class="hlt">rupture</span> on a strike-slip fault</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Andrews, D.J.; Ma, Shuo</p> <p>2010-01-01</p> <p>Large <span class="hlt">dynamic</span> stress off the fault incurs an inelastic response and energy loss, which contributes to the fracture energy, limiting the <span class="hlt">rupture</span> and slip velocity. Using an explicit finite element method, we model three-dimensional <span class="hlt">dynamic</span> <span class="hlt">ruptures</span> on a vertical strike-slip fault in a homogeneous half-space. The material is subjected to a pressure-dependent Drucker-Prager yield criterion. Initial stresses in the medium increase linearly with depth. Our simulations show that the inelastic response is confined narrowly to the fault at depth. There the inelastic strain is induced by large <span class="hlt">dynamic</span> stresses associated with the <span class="hlt">rupture</span> front that overcome the effect of the high confining pressure. The inelastic zone increases in size as it nears the surface. For material with low cohesion (~5 MPa) the inelastic zone broadens dramatically near the surface, forming a "flowerlike" structure. The near-surface inelastic strain occurs in both the extensional and the compressional regimes of the fault, induced by seismic waves ahead of the <span class="hlt">rupture</span> front under a low confining pressure. When cohesion is large (~10 MPa), the inelastic strain is significantly reduced near the surface and confined mostly to depth. Cohesion, however, affects the inelastic zone at depth less significantly. The induced shear microcracks show diverse orientations near the surface, owing to the low confining pressure, but exhibit mostly horizontal slip at depth. The inferred <span class="hlt">rupture</span>-induced anisotropy at depth has the fast wave direction along the direction of the maximum compressive stress.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25833225','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25833225"><span id="translatedtitle"><span class="hlt">Dynamic</span> effects in friction and adhesion through cooperative <span class="hlt">rupture</span> and formation of supramolecular bonds.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Blass, Johanna; Albrecht, Marcel; Bozna, Bianca L; Wenz, Gerhard; Bennewitz, Roland</p> <p>2015-05-01</p> <p>We introduce a molecular toolkit for studying the <span class="hlt">dynamics</span> in friction and adhesion from the single molecule level to effects of multivalency. As experimental model system we use supramolecular bonds established by the inclusion of ditopic adamantane connector molecules into two surface-bound cyclodextrin molecules, attached to a tip of an atomic force microscope (AFM) and to a flat silicon surface. The <span class="hlt">rupture</span> force of a single bond does not depend on the pulling rate, indicating that the fast complexation kinetics of adamantane and cyclodextrin are probed in thermal equilibrium. In contrast, the pull-off force for a group of supramolecular bonds depends on the unloading rate revealing a non-equilibrium situation, an effect discussed as the combined action of multivalency and cantilever inertia effects. Friction forces exhibit a stick-slip characteristic which is explained by the cooperative <span class="hlt">rupture</span> of groups of host-guest bonds and their rebinding. No dependence of friction on the sliding velocity has been observed in the accessible range of velocities due to fast rebinding and the negligible delay of cantilever response in AFM lateral force measurements. PMID:25833225</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009JGRB..114.8304T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009JGRB..114.8304T"><span id="translatedtitle">Finite element simulations of <span class="hlt">dynamic</span> shear <span class="hlt">rupture</span> experiments and <span class="hlt">dynamic</span> path selection along kinked and branched faults</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Templeton, Elizabeth L.; Baudet, AuréLie; Bhat, Harsha S.; Dmowska, Renata; Rice, James R.; Rosakis, Ares J.; Rousseau, Carl-Ernst</p> <p>2009-08-01</p> <p>We analyze the nucleation and propagation of shear cracks along nonplanar, kinked, and branched fault paths corresponding to the configurations used in recent laboratory fracture studies by Rousseau and Rosakis (2003, 2009). The aim is to reproduce numerically those shear <span class="hlt">rupture</span> experiments and from that provide an insight into processes which are active when a crack, initially propagating in mode II along a straight path, interacts with a bend in the fault or a branching junction. The experiments involved impact loading of thin Homalite-100 (a photoelastic polymer) plates, which had been cut along bent or branched paths and weakly glued back together everywhere except along a starter notch near the impact site. Strain gage recordings and high-speed photography of isochromatic lines provided characterization of the transient deformation fields associated with the impact and fracture propagation. We found that <span class="hlt">dynamic</span> explicit 2-D plane-stress finite element analyses with a simple linear slip-weakening description of cohesive and frictional strength of the bonded interfaces can reproduce the qualitative <span class="hlt">rupture</span> behavior past the bend and branch junctions in most cases and reproduce the principal features revealed by the photographs of <span class="hlt">dynamic</span> isochromatic line patterns. The presence of a kink or branch can cause an abrupt change in <span class="hlt">rupture</span> propagation velocity. Additionally, the finite element results allow comparison between total slip accumulated along the main and inclined fault segments. We found that slip along inclined faults can be substantially less than slip along the main fault, and the amount depends on the branch angle and kink or branch configuration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRB..120.1108D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRB..120.1108D"><span id="translatedtitle">Three-dimensional <span class="hlt">dynamic</span> <span class="hlt">rupture</span> simulations across interacting faults: The Mw7.0, 2010, Haiti earthquake</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Douilly, R.; Aochi, H.; Calais, E.; Freed, A. M.</p> <p>2015-02-01</p> <p>The mechanisms controlling <span class="hlt">rupture</span> propagation between fault segments during a large earthquake are key to the hazard posed by fault systems. <span class="hlt">Rupture</span> initiation on a smaller fault sometimes transfers to a larger fault, resulting in a significant event (e.g., 2002 M7.9 Denali USA and 2010 M7.1 Darfield New Zealand earthquakes). In other cases <span class="hlt">rupture</span> is constrained to the initial fault and does not transfer to nearby faults, resulting in events of more moderate magnitude. This was the case of the 1989 M6.9 Loma Prieta and 2010 M7.0 Haiti earthquakes which initiated on reverse faults abutting against a major strike-slip plate boundary fault but did not propagate onto it. Here we investigate the <span class="hlt">rupture</span> <span class="hlt">dynamics</span> of the Haiti earthquake, seeking to understand why <span class="hlt">rupture</span> propagated across two segments of the Léogâne fault but did not propagate to the adjacent Enriquillo Plantain Garden Fault, the major 200 km long plate boundary fault cutting through southern Haiti. We use a finite element model to simulate propagation of <span class="hlt">rupture</span> on the Léogâne fault, varying friction and background stress to determine the parameter set that best explains the observed earthquake sequence, in particular, the ground displacement. The two slip patches inferred from finite fault inversions are explained by the successive <span class="hlt">rupture</span> of two fault segments oriented favorably with respect to the <span class="hlt">rupture</span> propagation, while the geometry of the Enriquillo fault did not allow shear stress to reach failure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9783E..1YD','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9783E..1YD"><span id="translatedtitle">Method for dose-reduced <span class="hlt">3</span><span class="hlt">D</span> catheter tracking on a scanning-beam digital x-ray system using <span class="hlt">dynamic</span> electronic collimation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dunkerley, David A. P.; Funk, Tobias; Speidel, Michael A.</p> <p>2016-03-01</p> <p>Scanning-beam digital x-ray (SBDX) is an inverse geometry x-ray fluoroscopy system capable of tomosynthesis-based <span class="hlt">3</span><span class="hlt">D</span> catheter tracking. This work proposes a method of dose-reduced <span class="hlt">3</span><span class="hlt">D</span> tracking using <span class="hlt">dynamic</span> electronic collimation (DEC) of the SBDX scanning x-ray tube. Positions in the 2D focal spot array are selectively activated to create a regionof- interest (ROI) x-ray field around the tracked catheter. The ROI position is updated for each frame based on a motion vector calculated from the two most recent <span class="hlt">3</span><span class="hlt">D</span> tracking results. The technique was evaluated with SBDX data acquired as a catheter tip inside a chest phantom was pulled along a <span class="hlt">3</span><span class="hlt">D</span> trajectory. DEC scans were retrospectively generated from the detector images stored for each focal spot position. DEC imaging of a catheter tip in a volume measuring 11.4 cm across at isocenter required 340 active focal spots per frame, versus 4473 spots in full-FOV mode. The dose-area-product (DAP) and peak skin dose (PSD) for DEC versus full field-of-view (FOV) scanning were calculated using an SBDX Monte Carlo simulation code. DAP was reduced to 7.4% to 8.4% of the full-FOV value, consistent with the relative number of active focal spots (7.6%). For image sequences with a moving catheter, PSD was 33.6% to 34.8% of the full-FOV value. The root-mean-squared-deviation between DEC-based <span class="hlt">3</span><span class="hlt">D</span> tracking coordinates and full-FOV <span class="hlt">3</span><span class="hlt">D</span> tracking coordinates was less than 0.1 mm. The <span class="hlt">3</span><span class="hlt">D</span> distance between the tracked tip and the sheath centerline averaged 0.75 mm. <span class="hlt">Dynamic</span> electronic collimation can reduce dose with minimal change in tracking performance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUFM.S32B..07L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUFM.S32B..07L"><span id="translatedtitle">Testing Friction Laws by Comparing Simulation Results With Experiments of Spontaneous <span class="hlt">Dynamic</span> <span class="hlt">Rupture</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lu, X.; Lapusta, N.; Rosakis, A. J.</p> <p>2005-12-01</p> <p> and experimental measurements comes from different <span class="hlt">rupture</span> initiation mechanisms. Andrews introduces an initial crack into his model, with the slip and stress distribution appropriate for the critical static crack, and then he increases the shear stress slightly to start the <span class="hlt">dynamic</span> <span class="hlt">rupture</span>. Since the critical crack size depends on the loading, Andrews effectively uses different initial crack lengths, in dimensional terms, for different loading. However, in the experiments, the size of the exploding wire and the explosion strength are the same for different values of compressive load P, and hence, for decreasing P, the size of the explosion becomes a progressively smaller fraction of the critical crack size. This feature is accounted for in our simulations. We plan to do more modeling and experiments to quantify the actual triggering mechanism. We will report on our current attempts to model the transition using experimentally and theoretically based Dieterich-Ruina rate and state friction law with Prakash-Clifton modification for variable normal stress and additional <span class="hlt">dynamic</span> weakening due to flash heating. In the future, we plan to use these simulations to find experimentally realizable setups that, in simulations, produce different results for the enhanced rate and state friction law and the linear slip-weakening law.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUFM.S43A1058T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUFM.S43A1058T"><span id="translatedtitle">The Scaling of the Slip Weakening Distance (Dc) With Final Slip During <span class="hlt">Dynamic</span> Earthquake <span class="hlt">Rupture</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tinti, E.; Fukuyama, E.; Cocco, M.; Piatanesi, A.</p> <p>2005-12-01</p> <p>Several numerical approaches have been recently proposed to retrieve the evolution of <span class="hlt">dynamic</span> traction during the earthquake propagation on extended faults. Although many studies have shown that the shear traction evolution as a function of time and/or slip may be complex, they all reveal an evident <span class="hlt">dynamic</span> weakening behavior during faulting. The main <span class="hlt">dynamic</span> parameters describing traction evolution are: the yield stress, the residual kinetic stress level and the characteristic slip weakening distance Dc. Recent investigations on real data yield the estimate of large Dc values on the fault plane and a correlation between Dc and the final slip. In this study, we focus our attention on the characteristic slip weakening distance Dc and on its variability on the fault plane. Different physical mechanisms have been proposed to explain the origin of Dc, some of them consider this parameter as a scale dependent quantity. We have computed the <span class="hlt">rupture</span> history from several spontaneous <span class="hlt">dynamic</span> models imposing a slip weakening law with prescribed Dc distributions on the fault plane. These synthetic models provide the slip velocity evolution during the earthquake <span class="hlt">rupture</span>. We have therefore generated a set of slip velocity models by fitting the "true" slip velocity time histories with an analytical source time function. To this goal we use the Yoffe function [Tinti et al. 2005], which is <span class="hlt">dynamically</span> consistent and allows a flexible parameterization. We use these slip velocity histories as a boundary condition on the fault plane to compute the traction evolution. We estimate the Dc values from the traction versus slip curves. We therefore compare the inferred Dc values with those of the original <span class="hlt">dynamic</span> models and we found that the Dc estimates are very sensitive to the adopted slip velocity function. Despite the problem of resolution that limits the estimate of Dc from kinematic earthquake models and the tradeoff that exists between Dc and strength excess, we show that to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.T51D2495V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.T51D2495V"><span id="translatedtitle">Scale dependency of fracture energy and estimates thereof via <span class="hlt">dynamic</span> <span class="hlt">rupture</span> solutions with strong thermal weakening</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Viesca, R. C.; Garagash, D.</p> <p>2013-12-01</p> <p>Seismological estimates of fracture energy show a scaling with the total slip of an earthquake [e.g., Abercrombie and Rice, GJI 2005]. Potential sources for this scale dependency are coseismic fault strength reductions that continue with increasing slip or an increasing amount of off-fault inelastic deformation with <span class="hlt">dynamic</span> <span class="hlt">rupture</span> propagation [e.g., Andrews, JGR 2005; Rice, JGR 2006]. Here, we investigate the former mechanism by solving for the slip dependence of fracture energy at the crack tip of a <span class="hlt">dynamically</span> propagating <span class="hlt">rupture</span> in which weakening takes place by strong reductions of friction via flash heating of asperity contacts and thermal pressurization of pore fluid leading to reductions in effective normal stress. Laboratory measurements of small characteristic slip evolution distances for friction (~10 μm at low slip rates of μm-mm/s, possibly up to 1 mm for slip rates near 0.1 m/s) [e.g., Marone and Kilgore, Nature 1993; Kohli et al., JGR 2011] imply that flash weakening of friction occurs at small slips before any significant thermal pressurization and may thus have a negligible contribution to the total fracture energy [Brantut and Rice, GRL 2011; Garagash, AGU 2011]. The subsequent manner of weakening under thermal pressurization (the dominant contributor to fracture energy) spans a range of behavior from the deformation of a finite-thickness shear zone in which diffusion is negligible (i.e., undrained-adiabatic) to that in which large-scale diffusion obscures the existence of a thin shear zone and thermal pressurization effectively occurs by the heating of slip on a plane. Separating the contribution of flash heating, the <span class="hlt">dynamic</span> <span class="hlt">rupture</span> solutions reduce to a problem with a single parameter, which is the ratio of the undrained-adiabatic slip-weakening distance (δc) to the characteristic slip-on-a-plane slip-weakening distance (L*). However, for any value of the parameter, there are two end-member scalings of the fracture energy: for small slip</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120014938','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120014938"><span id="translatedtitle">Development, Verification and Use of Gust Modeling in the NASA Computational Fluid <span class="hlt">Dynamics</span> Code FUN<span class="hlt">3</span><span class="hlt">D</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bartels, Robert E.</p> <p>2012-01-01</p> <p>This paper presents the implementation of gust modeling capability in the CFD code FUN<span class="hlt">3</span><span class="hlt">D</span>. The gust capability is verified by computing the response of an airfoil to a sharp edged gust. This result is compared with the theoretical result. The present simulations will be compared with other CFD gust simulations. This paper also serves as a users manual for FUN<span class="hlt">3</span><span class="hlt">D</span> gust analyses using a variety of gust profiles. Finally, the development of an Auto-Regressive Moving-Average (ARMA) reduced order gust model using a gust with a Gaussian profile in the FUN<span class="hlt">3</span><span class="hlt">D</span> code is presented. ARMA simulated results of a sequence of one-minus-cosine gusts is shown to compare well with the same gust profile computed with FUN<span class="hlt">3</span><span class="hlt">D</span>. Proper Orthogonal Decomposition (POD) is combined with the ARMA modeling technique to predict the time varying pressure coefficient increment distribution due to a novel gust profile. The aeroelastic response of a pitch/plunge airfoil to a gust environment is computed with a reduced order model, and compared with a direct simulation of the system in the FUN<span class="hlt">3</span><span class="hlt">D</span> code. The two results are found to agree very well.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6705941','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6705941"><span id="translatedtitle">NIKE<span class="hlt">3</span><span class="hlt">D</span>: an implicit, finite-deformation, finite element code for analyzing the static and <span class="hlt">dynamic</span> response of three-dimensional solids</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hallquist, J.O.</p> <p>1981-01-01</p> <p>A user's manual is provided for NIKE<span class="hlt">3</span><span class="hlt">D</span>, a fully implicit three-dimensional finite element code for analyzing the large deformation static and <span class="hlt">dynamic</span> response of inelastic solids. A contact-impact algorithm permits gaps and sliding along material interfaces. By a specialization of this algorithm, such interfaces can be rigidly tied to admit variable zoning without the need of transition regions. Spatial discretization is achieved by the use of 8-node constant pressure solid elements. Bandwidth minimization is optional. Post-processors for NIKE<span class="hlt">3</span><span class="hlt">D</span> include GRAPE for plotting deformed shapes and stress contours and DYNAP for plotting time histories.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013DPS....4551005M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013DPS....4551005M"><span id="translatedtitle">Gas Accretion by Giant Planets: <span class="hlt">3</span><span class="hlt">D</span> Simulations of Gap Opening and <span class="hlt">Dynamics</span> of the Circumplanetary Disk</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Morbidelli, Alessandro; Szulagyi, J.; Crida, A.; Tanigawa, T.; Lega, E.; Masset, F.; Bitsch, B.</p> <p>2013-10-01</p> <p>What sets the terminal mass of a giant planet once the latter enters into a runaway gas-accretion phase? The formation of a gap around the planet's orbit may be an answer, provided that the gap is wide and deep enough. A wide-spread idea is that this happens if the viscosity in the circumstellar disk is small, i.e. if planets form in the "dead zone". With <span class="hlt">3</span><span class="hlt">D</span> hydrodynamical simulations we study the formation of a gap in details. We find an interesting 4-step meridional loop in the gas <span class="hlt">dynamics</span>: (1) the gas flows into the gap at the top layer of the disk; (2) then it falls towards the disk's midplane; (3) the planet keeps the gap open by pushing this infalling gas back into the disk; (4) the gas rises back to the disk's surface, which closes the loop. The gas flow in this loop is governed by the viscous timescale at the surface of the disk. It is generally accepted that the surface layer of the disk is MRI-active and viscous, even if a dead zone is present near the midplane. Thus, there should always be enough gas flowing into the gap for a Jupiter-mass planet to accrete at a fast rate, in absence of other regulation mechanisms. However, only a very small portion of the gas flowing into the gap is directly accreted by the planet. Most of the gas falling towards the planet forms a circumplanetary disk (CPD), due to angular momentum conservation. If the CPD is MRI-inactive, as suggested by Turner et al. (2010) and Fujii et al. (2011), it can act as a bottle-neck for planet accretion. We find that the main mechanism that allows the CPD to lose angular momentum is the torque exerted by the star via a spiral density wave. We compute that this promotes the accretion of 0.025% of the mass of the CPD per year, for a Jupiter mass planet at 5.2 AU, independent of viscosity. By balancing the pressure of the vertical inflow with that internal to the CPD, we estimate that the CPD should contain less than 1% of the planet's mass. This leads to a mass-doubling timescale for Jupiter</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16..162B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16..162B"><span id="translatedtitle"><span class="hlt">3</span><span class="hlt">D</span> multidisciplinary numerical model of polychlorinated biphenyl <span class="hlt">dynamics</span> on the Black Sea north-western shelf</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bagaiev, Andrii; Ivanov, Vitaliy</p> <p>2014-05-01</p> <p>The Black Sea north-western shelf plays a key role in economics of the developing countries such as Ukraine due to food supply, invaluable recreational potential and variety of the relevant maritime shipping routes. On the other hand, a shallow flat shelf is mostly affected by anthropogenic pollution, eutrophication, hypoxia and harmful algae blooms. The research is focused on modeling the transport and transformation of PCBs (PolyChlorinated Biphenyls) because they are exceedingly toxic and highly resistant to degradation, hence cumulatively affect marine ecosystems. Being lipophilic compounds, PCBs demonstrate the distinguishing sorption/desorption activity taking part in the biogeochemical fluxes via the organic matter particles and sediments. In the framework of the research, the coastal in-situ data on PCB concentration in the water column and sediments are processed, visualized and analyzed. It is concluded that the main sources of PCBs are related to the Danube discharge and resuspension from the shallow-water sediments. Developed <span class="hlt">3</span><span class="hlt">D</span> numerical model is aimed at simulation of PCB contamination of the water column and sediment. The model integrates the full physics hydrodynamic block as well as modules, which describe detritus transport and transformation and PCB <span class="hlt">dynamics</span>. Three state variables are simulated in PCB transport module: concentration in solute, on the settling particles of detritus and in the top layer of sediments. PCB adsorption/desorption on detritus; the reversible PCB fluxes at the water-sediment boundary; destruction of detritus are taken into consideration. Formalization of PCB deposition/resuspension in the sediments is adapted from Van Rijn's model of the suspended sediment transport. The model was spun up to reconstruct the short term scenario of the instantaneous PCB release from the St. George Arm of Danube. It has been shown that PCB transport on sinking detritus represents the natural buffer mechanism damping the spreading PCB</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1989JSP....56..939Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1989JSP....56..939Z"><span id="translatedtitle">A fast vectorized multispin coding algorithm for <span class="hlt">3</span><span class="hlt">D</span> Monte Carlo simulations using Kawasaki spin-exchange <span class="hlt">dynamics</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, M. Q.</p> <p>1989-09-01</p> <p>A new Monte Carlo algorithm for <span class="hlt">3</span><span class="hlt">D</span> Kawasaki spin-exchange simulations and its implementation on a CDC CYBER 205 is presented. This approach is applicable to lattices with sizes between 4×4×4 and 256×L2×L3 ((L2+2)(L3+4)/4⩽65535) and periodic boundary conditions. It is adjustable to various kinetic models in which the total magnetization is conserved. Maximum speed on 10 million steps per second can be reached for <span class="hlt">3</span>-<span class="hlt">D</span> Ising model with Metropolis rate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25875190','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25875190"><span id="translatedtitle">Multi-camera and structured-light vision system (MSVS) for <span class="hlt">dynamic</span> high-accuracy <span class="hlt">3</span><span class="hlt">D</span> measurements of railway tunnels.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhan, Dong; Yu, Long; Xiao, Jian; Chen, Tanglong</p> <p>2015-01-01</p> <p>Railway tunnel <span class="hlt">3</span><span class="hlt">D</span> clearance inspection is critical to guaranteeing railway operation safety. However, it is a challenge to inspect railway tunnel <span class="hlt">3</span><span class="hlt">D</span> clearance using a vision system, because both the spatial range and field of view (FOV) of such measurements are quite large. This paper summarizes our work on <span class="hlt">dynamic</span> railway tunnel <span class="hlt">3</span><span class="hlt">D</span> clearance inspection based on a multi-camera and structured-light vision system (MSVS). First, the configuration of the MSVS is described. Then, the global calibration for the MSVS is discussed in detail. The onboard vision system is mounted on a dedicated vehicle and is expected to suffer from multiple degrees of freedom vibrations brought about by the running vehicle. Any small vibration can result in substantial measurement errors. In order to overcome this problem, a vehicle motion deviation rectifying method is investigated. Experiments using the vision inspection system are conducted with satisfactory online measurement results. PMID:25875190</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.T22B..08S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.T22B..08S"><span id="translatedtitle">Numerical Models of Slow Slip and <span class="hlt">Dynamic</span> <span class="hlt">Rupture</span> Including Dilatant Stabilization and Thermal Pressurization</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Segall, P.; Bradley, A. M.</p> <p>2009-12-01</p> <p>Seismic and geodetic observations indicate that slow-slip events (SSE) occur down-dip of locked megathrusts, in areas of high pore-pressure, p. We suggest that at low effective stress (σ -p) dilatancy stabilizes rate-weakening faults, whereas at higher (σ -p) thermal pressurization overwhelms dilatancy leading to <span class="hlt">dynamic</span> slip. 2D simulations include rate-state (slip-law) friction with Linker-Dieterich normal stress effect, Segall-Rice dilatancy linked to state evolution, and heat and pore-fluid flow normal to the fault. The fault is loaded by down-dip slip at v∞ . We discretize the fault normal direction with log spacing, and employ explicit-implicit time integration to improve speed and accuracy. The governing equations involve numerous physical parameters, but relatively few non-dimensional groups. Ep={ɛ h}/ [2 {β (σ - p∞)}√ {{v{∞ }}/ {chyd}dc] and ET=({f_0Λ }/{2ρ cp})√ {{chydd_c v∞}}/{cth}2 represent dilatancy and shear heating efficiency, respectively. For a nominal set of parameters (given below), spatially uniform properties, and σ -p=1MPa, (Ep = 1.5 × 10-3, ET = 3 × 10-5), we find a series of propagating SSE, that are stabilized by dilatancy-induced drops in p at the <span class="hlt">rupture</span> tips. For a broad range of parameters we observe slow-slip events driven by down-dip slip, with negative stress drop, as well as faster (but quasi-static) events that relax the accumulated stress. At 10 MPa effective stress, the models exhibit both SSE and <span class="hlt">dynamic</span> <span class="hlt">ruptures</span>. Following <span class="hlt">dynamic</span> stress drops, a sequence of slow slip events is driven from the down-dip end of the fault, with generally increasing maximum slip-speeds. We also consider spatially variable (σ -p), ranging from 2 MPa down-dip to 10 MPa up-dip (with arctangent distribution such that 80% of the variation occurs across 20% of the fault), and uniform material properties. The models exhibit both SSE and <span class="hlt">dynamic</span> events. Following a <span class="hlt">dynamic</span> <span class="hlt">rupture</span> there are initially no slow events, and the</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70026263','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70026263"><span id="translatedtitle"><span class="hlt">Dynamic</span> <span class="hlt">rupture</span> modeling of the transition from thrust to strike-slip motion in the 2002 Denali fault earthquake, Alaska</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Aagaard, B.T.; Anderson, G.; Hudnut, K.W.</p> <p>2004-01-01</p> <p>We use three-dimensional <span class="hlt">dynamic</span> (spontaneous) <span class="hlt">rupture</span> models to investigate the nearly simultaneous <span class="hlt">ruptures</span> of the Susitna Glacier thrust fault and the Denali strike-slip fault. With the 1957 Mw 8.3 Gobi-Altay, Mongolia, earthquake as the only other well-documented case of significant, nearly simultaneous <span class="hlt">rupture</span> of both thrust and strike-slip faults, this feature of the 2002 Denali fault earthquake provides a unique opportunity to investigate the mechanisms responsible for development of these large, complex events. We find that the geometry of the faults and the orientation of the regional stress field caused slip on the Susitna Glacier fault to load the Denali fault. Several different stress orientations with oblique right-lateral motion on the Susitna Glacier fault replicate the triggering of <span class="hlt">rupture</span> on the Denali fault about 10 sec after the <span class="hlt">rupture</span> nucleates on the Susitna Glacier fault. However, generating slip directions compatible with measured surface offsets and kinematic source inversions requires perturbing the stress orientation from that determined with focal mechanisms of regional events. Adjusting the vertical component of the principal stress tensor for the regional stress field so that it is more consistent with a mixture of strike-slip and reverse faulting significantly improves the fit of the slip-rake angles to the data. Rotating the maximum horizontal compressive stress direction westward appears to improve the fit even further.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.S21B4431A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.S21B4431A"><span id="translatedtitle">New Efficient <span class="hlt">Dynamic</span> <span class="hlt">3</span>-<span class="hlt">D</span> Boundary Integral Equation Method and Application to Non-Planar Fault Geometry Dipping in Elastic Half Space</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ando, R.</p> <p>2014-12-01</p> <p>The boundary integral equation method formulated in the real space and time domain (BIEM-ST) has been used as a powerful tool to analyze the earthquake <span class="hlt">rupture</span> <span class="hlt">dynamics</span> on non-planar faults. Generally, BIEM is more accurate than volumetric methods such as the finite difference method and the finite difference method. With the recent development of the high performance computing environment, the earthquake <span class="hlt">rupture</span> simulation studies have been conducted considering three dimensional realistic fault geometry models. However, the utility of BIEM-ST has been limited due to its heavy computational demanding increased depending on square of time steps (N2), which was needed to evaluate the historic integration. While BIEM can be efficient with the spectral domain formulation, the applications of such a method are limited to planar fault cases. In this study, we propose a new method to reduce the calculation time of BIEM-ST to linear of time step (N) without degrading the accuracy in the 3 dimensional modeling space. We extends the method proposed earlier for the case of the 2 dimensional framework, applying the asymptotic expressions of the elasto-<span class="hlt">dynamic</span> Green's functions. This method uses the physical nature of the stress Green's function as dividing the causality cone according to the distances from the wave-fronts. The scalability of this method is shown on the parallel computing environment of the distributed memory. We demonstrate the applicability to analyses of subduction earthquake cases, suffering long time from the numerical limitations of previously available BIEMs. We analyze the <span class="hlt">dynamic</span> <span class="hlt">rupture</span> processes on dipping reverse faults embed in a three dimensional elastic half space.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005SPIE.5852..796S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005SPIE.5852..796S"><span id="translatedtitle">A stroboscopic structured illumination system used in <span class="hlt">dynamic</span> <span class="hlt">3</span><span class="hlt">D</span> visualization of high-speed motion object</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Su, Xianyu; Zhang, Qican; Li, Yong; Xiang, Liqun; Cao, Yiping; Chen, Wenjing</p> <p>2005-04-01</p> <p>A stroboscopic structured illumination system, which can be used in measurement for <span class="hlt">3</span><span class="hlt">D</span> shape and deformation of high-speed motion object, is proposed and verified by experiments. The system, present in this paper, can automatically detect the position of high-speed moving object and synchronously control the flash of LED to project a structured optical field onto surface of motion object and the shoot of imaging system to acquire an image of deformed fringe pattern, also can create a signal, set artificially through software, to synchronously control the LED and imaging system to do their job. We experiment on a civil electric fan, successful acquire a serial of instantaneous, sharp and clear images of rotation blade and reconstruct its <span class="hlt">3</span><span class="hlt">D</span> shapes in difference revolutions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70041801','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70041801"><span id="translatedtitle">Testing long-period ground-motion simulations of scenario earthquakes using the Mw 7.2 El Mayor-Cucapah mainshock: Evaluation of finite-fault <span class="hlt">rupture</span> characterization and <span class="hlt">3</span><span class="hlt">D</span> seismic velocity models</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Graves, Robert W.; Aagaard, Brad T.</p> <p>2011-01-01</p> <p>Using a suite of five hypothetical finite-fault <span class="hlt">rupture</span> models, we test the ability of long-period (T>2.0 s) ground-motion simulations of scenario earthquakes to produce waveforms throughout southern California consistent with those recorded during the 4 April 2010 Mw 7.2 El Mayor-Cucapah earthquake. The hypothetical <span class="hlt">ruptures</span> are generated using the methodology proposed by Graves and Pitarka (2010) and require, as inputs, only a general description of the fault location and geometry, event magnitude, and hypocenter, as would be done for a scenario event. For each <span class="hlt">rupture</span> model, two Southern California Earthquake Center three-dimensional community seismic velocity models (CVM-4m and CVM-H62) are used, resulting in a total of 10 ground-motion simulations, which we compare with recorded ground motions. While the details of the motions vary across the simulations, the median levels match the observed peak ground velocities reasonably well, with the standard deviation of the residuals generally within 50% of the median. Simulations with the CVM-4m model yield somewhat lower variance than those with the CVM-H62 model. Both models tend to overpredict motions in the San Diego region and underpredict motions in the Mojave desert. Within the greater Los Angeles basin, the CVM-4m model generally matches the level of observed motions, whereas the CVM-H62 model tends to overpredict the motions, particularly in the southern portion of the basin. The variance in the peak velocity residuals is lowest for a <span class="hlt">rupture</span> that has significant shallow slip (<5 km depth), whereas the variance in the residuals is greatest for <span class="hlt">ruptures</span> with large asperities below 10 km depth. Overall, these results are encouraging and provide confidence in the predictive capabilities of the simulation methodology, while also suggesting some regions in which the seismic velocity models may need improvement.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013APS..DFD.A9005O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013APS..DFD.A9005O"><span id="translatedtitle">Linear and nonlinear instability and ligament <span class="hlt">dynamics</span> in <span class="hlt">3</span><span class="hlt">D</span> laminar two-layer liquid/liquid flows</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ó Náraigh, Lennon; Valluri, Prashant; Scott, David; Bethune, Iain; Spelt, Peter</p> <p>2013-11-01</p> <p>We consider the linear and nonlinear stability of two-phase density-matched but viscosity contrasted fluids subject to laminar Poiseuille flow in a channel, paying particular attention to the formation of three-dimensional waves. The Orr-Sommerfeld-Squire analysis is used along with DNS of the <span class="hlt">3</span><span class="hlt">D</span> two-phase Navier-Stokes equations using our newly launched TPLS Solver (http://edin.ac/10cRKzS). For the parameter regimes considered, we demonstrate the existence of two distinct mechanisms whereby <span class="hlt">3</span><span class="hlt">D</span> waves enter the system, and dominate at late time. There exists a direct route, whereby <span class="hlt">3</span><span class="hlt">D</span> waves are amplified by the standard linear mechanism; for certain parameter classes, such waves grow at a rate less than but comparable to that of most-dangerous two-dimensional mode. Additionally, there is a weakly nonlinear route, whereby a purely spanwise wave couples to a streamwise mode and grows exponentially. We demonstrate these mechanisms in isolation and in concert. Consideration is also given to the ultimate state of these waves: persistent three-dimensional nonlinear waves are stretched and distorted by the base flow, thereby producing regimes of ligaments, ``sheets,'' or ``interfacial turbulence.'' HECToR RAP/dCSE Project e174, HPC-Europa 2.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014E%26ES...22c2030Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014E%26ES...22c2030Z"><span id="translatedtitle"><span class="hlt">Dynamic</span> characteristics of a pump-turbine during hydraulic transients of a model pumped-storage system: <span class="hlt">3</span><span class="hlt">D</span> CFD simulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, X. X.; Cheng, Y. G.; Xia, L. S.; Yang, J. D.</p> <p>2014-03-01</p> <p>The runaway process in a model pumped-storage system was simulated for analyzing the <span class="hlt">dynamic</span> characteristics of a pump-turbine. The simulation was adopted by coupling 1D (One Dimensional) pipeline MOC (Method of Characteristics) equations with a <span class="hlt">3</span><span class="hlt">D</span> (Three Dimensional) pump-turbine CFD (Computational Fluid <span class="hlt">Dynamics</span>) model, in which the water hammer wave in the <span class="hlt">3</span><span class="hlt">D</span> zone was defined by giving a pressure dependent density. We found from the results that the <span class="hlt">dynamic</span> performances of the pump-turbine do not coincide with the static operating points, especially in the S-shaped characteristics region, where the <span class="hlt">dynamic</span> trajectories follow ring-shaped curves. Specifically, the transient operating points with the same Q11 and M11 in different moving directions of the <span class="hlt">dynamic</span> trajectories give different n11. The main reason of this phenomenon is that the transient flow patterns inside the pump-turbine are influenced by the ones in the previous time step, which leads to different flow patterns between the points with the same Q11 and M11 in different moving directions of the <span class="hlt">dynamic</span> trajectories.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PApGe.172.1243X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PApGe.172.1243X"><span id="translatedtitle"><span class="hlt">Dynamic</span> <span class="hlt">Ruptures</span> on a Frictional Interface with Off-Fault Brittle Damage: Feedback Mechanisms and Effects on Slip and Near-Fault Motion</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xu, Shiqing; Ben-Zion, Yehuda; Ampuero, Jean-Paul; Lyakhovsky, Vladimir</p> <p>2015-05-01</p> <p>The spontaneous generation of brittle rock damage near and behind the tip of a propagating <span class="hlt">rupture</span> can produce <span class="hlt">dynamic</span> feedback mechanisms that modify significantly the <span class="hlt">rupture</span> properties, seismic radiation, and generated fault zone structure. In this work, we study such feedback mechanisms for single <span class="hlt">rupture</span> events and their consequences for earthquake physics and various possible observations. This is done through numerical simulations of in-plane <span class="hlt">dynamic</span> <span class="hlt">ruptures</span> on a frictional fault with bulk behavior governed by a brittle damage rheology that incorporates reduction of elastic moduli in off-fault yielding regions. The model simulations produce several features that modify key properties of the <span class="hlt">ruptures</span>, local wave propagation, and fault zone damage. These include (1) <span class="hlt">dynamic</span> generation of near-fault regions with lower elastic properties, (2) <span class="hlt">dynamic</span> changes of normal stress on the fault, (3) <span class="hlt">rupture</span> transition from crack-like to a detached pulse, (4) emergence of a <span class="hlt">rupture</span> mode consisting of a train of pulses, (5) quasi-periodic modulation of slip rate on the fault, and (6) asymmetric near-fault ground motion with higher amplitude and longer duration on the side with reduced elastic moduli. The results can have significant implications to multiple topics ranging from <span class="hlt">rupture</span> directivity and local amplification of seismic motion to near-fault tremor-like signals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PApGe.tmp..162X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PApGe.tmp..162X"><span id="translatedtitle"><span class="hlt">Dynamic</span> <span class="hlt">Ruptures</span> on a Frictional Interface with Off-Fault Brittle Damage: Feedback Mechanisms and Effects on Slip and Near-Fault Motion</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xu, Shiqing; Ben-Zion, Yehuda; Ampuero, Jean-Paul; Lyakhovsky, Vladimir</p> <p>2014-09-01</p> <p>The spontaneous generation of brittle rock damage near and behind the tip of a propagating <span class="hlt">rupture</span> can produce <span class="hlt">dynamic</span> feedback mechanisms that modify significantly the <span class="hlt">rupture</span> properties, seismic radiation, and generated fault zone structure. In this work, we study such feedback mechanisms for single <span class="hlt">rupture</span> events and their consequences for earthquake physics and various possible observations. This is done through numerical simulations of in-plane <span class="hlt">dynamic</span> <span class="hlt">ruptures</span> on a frictional fault with bulk behavior governed by a brittle damage rheology that incorporates reduction of elastic moduli in off-fault yielding regions. The model simulations produce several features that modify key properties of the <span class="hlt">ruptures</span>, local wave propagation, and fault zone damage. These include (1) <span class="hlt">dynamic</span> generation of near-fault regions with lower elastic properties, (2) <span class="hlt">dynamic</span> changes of normal stress on the fault, (3) <span class="hlt">rupture</span> transition from crack-like to a detached pulse, (4) emergence of a <span class="hlt">rupture</span> mode consisting of a train of pulses, (5) quasi-periodic modulation of slip rate on the fault, and (6) asymmetric near-fault ground motion with higher amplitude and longer duration on the side with reduced elastic moduli. The results can have significant implications to multiple topics ranging from <span class="hlt">rupture</span> directivity and local amplification of seismic motion to near-fault tremor-like signals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015MNRAS.453..287M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015MNRAS.453..287M"><span id="translatedtitle">The <span class="hlt">dynamics</span> of neutrino-driven supernova explosions after shock revival in 2D and <span class="hlt">3</span><span class="hlt">D</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Müller, B.</p> <p>2015-10-01</p> <p>We study the growth of the explosion energy after shock revival in neutrino-driven explosions in two and three dimensions (2D/<span class="hlt">3</span><span class="hlt">D</span>) using multi-group neutrino hydrodynamics simulations of an 11.2 M⊙ star. The <span class="hlt">3</span><span class="hlt">D</span> model shows a faster and steadier growth of the explosion energy and already shows signs of subsiding accretion after one second. By contrast, the growth of the explosion energy in 2D is unsteady, and accretion lasts for several seconds as confirmed by additional long-time simulations of stars of similar masses. Appreciable explosion energies can still be reached, albeit at the expense of rather high neutron star masses. In 2D, the binding energy at the gain radius is larger because the strong excitation of downward-propagating g modes removes energy from the freshly accreted material in the downflows. Consequently, the mass outflow rate is considerably lower in 2D than in <span class="hlt">3</span><span class="hlt">D</span>. This is only partially compensated by additional heating by outward-propagating acoustic waves in 2D. Moreover, the mass outflow rate in 2D is reduced because much of the neutrino energy deposition occurs in downflows or bubbles confined by secondary shocks without driving outflows. Episodic constriction of outflows and vertical mixing of colder shocked material and hot, neutrino-heated ejecta due to Rayleigh-Taylor instability further hamper the growth of the explosion energy in 2D. Further simulations will be necessary to determine whether these effects are generic over a wider range of supernova progenitors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22459649','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22459649"><span id="translatedtitle">High-dose radiotherapy in inoperable nonsmall cell lung cancer: comparison of volumetric modulated arc therapy, <span class="hlt">dynamic</span> IMRT and <span class="hlt">3</span><span class="hlt">D</span> conformal radiotherapy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bree, Ingrid de; van Hinsberg, Mariëlle G E; van Veelen, Lieneke R</p> <p>2012-01-01</p> <p>Conformal <span class="hlt">3</span><span class="hlt">D</span> radiotherapy (<span class="hlt">3</span><span class="hlt">D</span>-CRT) combined with chemotherapy for inoperable non-small cell lung cancer (NSCLC) to the preferable high dose is often not achievable because of dose-limiting organs. This reduces the probability of regional tumor control. Therefore, the surplus value of using intensity-modulated radiation therapy (IMRT) techniques, specifically volumetric modulated arc therapy (RapidArc [RA]) and <span class="hlt">dynamic</span> IMRT (d-IMRT) has been investigated. RA and d-IMRT plans were compared with <span class="hlt">3</span><span class="hlt">D</span>-CRT treatment plans for 20 patients eligible for concurrent high-dose chemoradiotherapy, in whom a dose of 60 Gy was not achievable. Comparison of dose delivery in the target volume and organs at risk was carried out by evaluating <span class="hlt">3</span><span class="hlt">D</span> dose distributions and dose-volume histograms. Quality of the dose distribution was assessed using the inhomogeneity and conformity index. For most patients, a higher dose to the target volume can be delivered using RA or d-IMRT; in 15% of the patients a dose ≥60 Gy was possible. Both IMRT techniques result in a better conformity of the dose (p < 0.001). There are no significant differences in homogeneity of dose in the target volume. IMRT techniques for NSCLC patients allow higher dose to the target volume, thus improving regional tumor control. PMID:22459649</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19900013774','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19900013774"><span id="translatedtitle">PLOT<span class="hlt">3</span><span class="hlt">D</span> user's manual</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Walatka, Pamela P.; Buning, Pieter G.; Pierce, Larry; Elson, Patricia A.</p> <p>1990-01-01</p> <p>PLOT<span class="hlt">3</span><span class="hlt">D</span> is a computer graphics program designed to visualize the grids and solutions of computational fluid <span class="hlt">dynamics</span>. Seventy-four functions are available. Versions are available for many systems. PLOT<span class="hlt">3</span><span class="hlt">D</span> can handle multiple grids with a million or more grid points, and can produce varieties of model renderings, such as wireframe or flat shaded. Output from PLOT<span class="hlt">3</span><span class="hlt">D</span> can be used in animation programs. The first part of this manual is a tutorial that takes the reader, keystroke by keystroke, through a PLOT<span class="hlt">3</span><span class="hlt">D</span> session. The second part of the manual contains reference chapters, including the helpfile, data file formats, advice on changing PLOT<span class="hlt">3</span><span class="hlt">D</span>, and sample command files.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22263870','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22263870"><span id="translatedtitle">CQL<span class="hlt">3</span><span class="hlt">D</span>-Hybrid-FOW modeling of the temporal <span class="hlt">dynamics</span> of NSTX NBI+HHFW discharges</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Harvey, R. W.; Petrov, Yu. V.; Liu, D.; Heidbrink, W. W.; Taylor, G.; Bonoli, P. T.</p> <p>2014-02-12</p> <p>The CQL<span class="hlt">3</span><span class="hlt">D</span> Fokker-Planck code[1] has been upgraded to include physics of finite-orbit-width (FOW) guiding-center orbits[2,3], as compared with the previous zero-orbit-width (ZOW) model, and a recent first-order orbit calculation[2]. The Fast Ion Diagnostic FIDA[4,5] signal resulting from neutral beam (NBI) and high harmonic fast wave (HHFW) RF power injected into the NSTX spherical tokamak can now be modeled quite accurately, using ion distributions from the CQL<span class="hlt">3</span><span class="hlt">D</span>-Hybrid-FOW code, a rapidly executing variant that includes FOW+gyro-orbit losses to the plasma edge, FOW effects on NBI injection and HHFW diffusion, but does not include neoclassical radial diffusion. Accurate simulation of prompt fast ion (FI) losses is a key feature of the marked modeling improvement relative to previous ZOW results. By comparing NBI-only and NBI+HHFW shots, independent confirmation of the usual 35% edge loss of HHFW in NSTX is obtained. Further, HHFW prompt losses from the plasma core are shown to be 3X as large (>25%) as the NBI-only case. The modulated NBI and time-dependent background plasma variations and charge exchange losses of fast ions are accounted for, and the temporal neutron variation is in approximate agreement with NSTX observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012SPIE.8320E..09P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012SPIE.8320E..09P"><span id="translatedtitle"><span class="hlt">Dynamic</span> shape modeling of the mitral valve from real-time <span class="hlt">3</span><span class="hlt">D</span> ultrasound images using continuous medial representation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pouch, Alison M.; Yushkevich, Paul A.; Jackson, Benjamin M.; Gorman, Joseph H., III; Gorman, Robert C.; Sehgal, Chandra M.</p> <p>2012-03-01</p> <p>Purpose: Patient-specific shape analysis of the mitral valve from real-time <span class="hlt">3</span><span class="hlt">D</span> ultrasound (rt-3DUS) has broad application to the assessment and surgical treatment of mitral valve disease. Our goal is to demonstrate that continuous medial representation (cm-rep) is an accurate valve shape representation that can be used for statistical shape modeling over the cardiac cycle from rt-3DUS images. Methods: Transesophageal rt-3DUS data acquired from 15 subjects with a range of mitral valve pathology were analyzed. User-initialized segmentation with level sets and symmetric diffeomorphic normalization delineated the mitral leaflets at each time point in the rt-3DUS data series. A deformable cm-rep was fitted to each segmented image of the mitral leaflets in the time series, producing a 4D parametric representation of valve shape in a single cardiac cycle. Model fitting accuracy was evaluated by the Dice overlap, and shape interpolation and principal component analysis (PCA) of 4D valve shape were performed. Results: Of the 289 <span class="hlt">3</span><span class="hlt">D</span> images analyzed, the average Dice overlap between each fitted cm-rep and its target segmentation was 0.880+/-0.018 (max=0.912, min=0.819). The results of PCA represented variability in valve morphology and localized leaflet thickness across subjects. Conclusion: Deformable medial modeling accurately captures valve geometry in rt-3DUS images over the entire cardiac cycle and enables statistical shape analysis of the mitral valve.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015NatSR...512175C&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015NatSR...512175C&link_type=ABSTRACT"><span id="translatedtitle">High-Throughput Cancer Cell Sphere Formation for Characterizing the Efficacy of Photo <span class="hlt">Dynamic</span> Therapy in <span class="hlt">3</span><span class="hlt">D</span> Cell Cultures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Yu-Chih; Lou, Xia; Zhang, Zhixiong; Ingram, Patrick; Yoon, Euisik</p> <p>2015-07-01</p> <p>Photodynamic therapy (PDT), wherein light sensitive non-toxic agents are locally and selectively activated using light, has emerged as an appealing alternative to traditional cancer chemotherapy. Yet to date, PDT efficacy has been mostly characterized using 2D cultures. Compared to 2D cultures, <span class="hlt">3</span><span class="hlt">D</span> sphere culture generates unique spatial distributions of nutrients and oxygen for the cells that better mimics the in-vivo conditions. Using a novel polyHEMA (non-adherent polymer) fabrication process, we developed a microfluidic sphere formation platform that can (1) generate 1,024 uniform (size variation <10%) cancer spheres within a 2 cm by 2 cm core area, (2) culture spheres for more than 2 weeks, and (3) allow the retrieval of spheres. Using the presented platform, we have successfully characterized the different responses in 2D and <span class="hlt">3</span><span class="hlt">D</span> cell culture to PDT. Furthermore, we investigated the treatment resistance effect in cancer cells induced by tumor associated fibroblasts (CAF). Although the CAFs can enhance the resistance to traditional chemotherapy agents, no significant difference in PDT was observed. The preliminary results suggest that the PDT can be an attractive alternative cancer therapy, which is less affected by the therapeutic resistance induced by cancer associated cells.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26153550','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26153550"><span id="translatedtitle">High-Throughput Cancer Cell Sphere Formation for Characterizing the Efficacy of Photo <span class="hlt">Dynamic</span> Therapy in <span class="hlt">3</span><span class="hlt">D</span> Cell Cultures.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chen, Yu-Chih; Lou, Xia; Zhang, Zhixiong; Ingram, Patrick; Yoon, Euisik</p> <p>2015-01-01</p> <p>Photodynamic therapy (PDT), wherein light sensitive non-toxic agents are locally and selectively activated using light, has emerged as an appealing alternative to traditional cancer chemotherapy. Yet to date, PDT efficacy has been mostly characterized using 2D cultures. Compared to 2D cultures, <span class="hlt">3</span><span class="hlt">D</span> sphere culture generates unique spatial distributions of nutrients and oxygen for the cells that better mimics the in-vivo conditions. Using a novel polyHEMA (non-adherent polymer) fabrication process, we developed a microfluidic sphere formation platform that can (1) generate 1,024 uniform (size variation <10%) cancer spheres within a 2 cm by 2 cm core area, (2) culture spheres for more than 2 weeks, and (3) allow the retrieval of spheres. Using the presented platform, we have successfully characterized the different responses in 2D and <span class="hlt">3</span><span class="hlt">D</span> cell culture to PDT. Furthermore, we investigated the treatment resistance effect in cancer cells induced by tumor associated fibroblasts (CAF). Although the CAFs can enhance the resistance to traditional chemotherapy agents, no significant difference in PDT was observed. The preliminary results suggest that the PDT can be an attractive alternative cancer therapy, which is less affected by the therapeutic resistance induced by cancer associated cells. PMID:26153550</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19950017291','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950017291"><span id="translatedtitle">Development of the <span class="hlt">dynamic</span> motion simulator of <span class="hlt">3</span><span class="hlt">D</span> micro-gravity with a combined passive/active suspension system</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Yoshida, Kazuya; Hirose, Shigeo; Ogawa, Tadashi</p> <p>1994-01-01</p> <p>The establishment of those in-orbit operations like 'Rendez-Vous/Docking' and 'Manipulator Berthing' with the assistance of robotics or autonomous control technology, is essential for the near future space programs. In order to study the control methods, develop the flight models, and verify how the system works, we need a tool or a testbed which enables us to simulate mechanically the micro-gravity environment. There have been many attempts to develop the micro-gravity testbeds, but once the simulation goes into the docking and berthing operation that involves mechanical contacts among multi bodies, the requirement becomes critical. A group at the Tokyo Institute of Technology has proposed a method that can simulate the <span class="hlt">3</span><span class="hlt">D</span> micro-gravity producing a smooth response to the impact phenomena with relatively simple apparatus. Recently the group carried out basic experiments successfully using a prototype hardware model of the testbed. This paper will present our idea of the <span class="hlt">3</span><span class="hlt">D</span> micro-gravity simulator and report the results of our initial experiments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4495468','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4495468"><span id="translatedtitle">High-Throughput Cancer Cell Sphere Formation for Characterizing the Efficacy of Photo <span class="hlt">Dynamic</span> Therapy in <span class="hlt">3</span><span class="hlt">D</span> Cell Cultures</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chen, Yu-Chih; Lou, Xia; Zhang, Zhixiong; Ingram, Patrick; Yoon, Euisik</p> <p>2015-01-01</p> <p>Photodynamic therapy (PDT), wherein light sensitive non-toxic agents are locally and selectively activated using light, has emerged as an appealing alternative to traditional cancer chemotherapy. Yet to date, PDT efficacy has been mostly characterized using 2D cultures. Compared to 2D cultures, <span class="hlt">3</span><span class="hlt">D</span> sphere culture generates unique spatial distributions of nutrients and oxygen for the cells that better mimics the in-vivo conditions. Using a novel polyHEMA (non-adherent polymer) fabrication process, we developed a microfluidic sphere formation platform that can (1) generate 1,024 uniform (size variation <10%) cancer spheres within a 2 cm by 2 cm core area, (2) culture spheres for more than 2 weeks, and (3) allow the retrieval of spheres. Using the presented platform, we have successfully characterized the different responses in 2D and <span class="hlt">3</span><span class="hlt">D</span> cell culture to PDT. Furthermore, we investigated the treatment resistance effect in cancer cells induced by tumor associated fibroblasts (CAF). Although the CAFs can enhance the resistance to traditional chemotherapy agents, no significant difference in PDT was observed. The preliminary results suggest that the PDT can be an attractive alternative cancer therapy, which is less affected by the therapeutic resistance induced by cancer associated cells. PMID:26153550</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4201771','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4201771"><span id="translatedtitle">Clinical examples of <span class="hlt">3</span><span class="hlt">D</span> dose distribution reconstruction, based on the actual MLC leaves movement, for <span class="hlt">dynamic</span> treatment techniques</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Osewski, Wojciech; Dolla, Łukasz; Radwan, Michał; Szlag, Marta; Rutkowski, Roman; Smolińska, Barbara; Ślosarek, Krzysztof</p> <p>2014-01-01</p> <p>Aim To present practical examples of our new algorithm for reconstruction of <span class="hlt">3</span><span class="hlt">D</span> dose distribution, based on the actual MLC leaf movement. Background DynaLog and RTplan files were used by DDcon software to prepare a new RTplan file for dose distribution reconstruction. Materials and methods Four different clinically relevant scenarios were used to assess the feasibility of the proposed new approach: (1) Reconstruction of whole treatment sessions for prostate cancer; (2) Reconstruction of IMRT verification treatment plan; (3) Dose reconstruction in breast cancer; (4) Reconstruction of interrupted arc and complementary plan for an interrupted VMAT treatment session of prostate cancer. The applied reconstruction method was validated by comparing reconstructed and measured fluence maps. For all statistical analysis, the U Mann–Whitney test was used. Results In the first two and the fourth cases, there were no statistically significant differences between the planned and reconstructed dose distribution (p = 0.910, p = 0.975, p = 0.893, respectively). In the third case the differences were statistically significant (p = 0.015). Treatment plan had to be reconstructed. Conclusion Developed dose distribution reconstruction algorithm presents a very useful QA tool. It provides means for <span class="hlt">3</span><span class="hlt">D</span> dose distribution verification in patient volume and allows to evaluate the influence of actual MLC leaf motion on the dose distribution. PMID:25337416</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUFM.S51F..04A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUFM.S51F..04A"><span id="translatedtitle"><span class="hlt">Rupture</span> Paths in Kappa-Maps: Quantitative Insights on Heterogeneous Earthquake <span class="hlt">Ruptures</span> From Energy Arguments.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ampuero, J.; Ripperger, J.; Mai, M.</p> <p>2005-12-01</p> <p>Earthquake <span class="hlt">rupture</span> is a notoriously complex process, at all observable scales. Although heterogeneities of strength and initial stress contribute to this <span class="hlt">rupture</span> complexity, a systematic approach to quantify their effect has not yet been attempted. For instance, little is known about the relation between the final size of an earthquake and the statistical properties of initial strength excess fields. Canonical cases of <span class="hlt">dynamic</span> <span class="hlt">rupture</span> (e.g. uniform initial stress and friction properties), can be characterized by two non-dimensional numbers: the S-parameter (ratio of strength excess to stress drop) and the Kappa-parameter (ratio of static energy release rate to fracture energy, Madariaga and Olsen, 2000). The latter was introduced as a global parameter, involving the fault depth or asperity size as the fundamental scale. However, because faults contain heterogeneities at all scales it is not clear how a single scale-length may be relevant to define Kappa. We define here a scale-dependent Kappa-map, based on classical energy concepts in fracture mechanics. In 2D these maps can be defined exactly, and their efficient computation is implemented as a series of FFT-convolutions, by scaled analytical filters related to stress intensity factor weight functions. For given heterogeneous stress drop and fracture energy, such Kappa-maps are useful to predict nucleation properties and final moment, as we illustrate through increasingly complex examples complemented by <span class="hlt">dynamic</span> <span class="hlt">rupture</span> simulations. Other properties that can be derived from the 2D Kappa-maps, with additional assumptions, include radiated energy and <span class="hlt">rupture</span> directivity. In <span class="hlt">3</span><span class="hlt">D</span>, the shape of the <span class="hlt">rupture</span> front is unknown a priori and the energy release rate G might be non-uniform along the front. We therefore propose an approximate definition of Kappa in which G is estimated on circular patches. Comparisons with <span class="hlt">3</span><span class="hlt">D</span> <span class="hlt">dynamic</span> <span class="hlt">rupture</span> simulations on highly heterogeneous initial stress fields show that the final moment can</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016E%26PSL.442...93M&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016E%26PSL.442...93M&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">3</span><span class="hlt">D</span> numerical modeling of mantle flow, crustal <span class="hlt">dynamics</span> and magma genesis associated with slab roll-back and tearing: The eastern Mediterranean case</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Menant, Armel; Sternai, Pietro; Jolivet, Laurent; Guillou-Frottier, Laurent; Gerya, Taras</p> <p>2016-05-01</p> <p>Interactions between subduction <span class="hlt">dynamics</span> and magma genesis have been intensely investigated, resulting in several conceptual models derived from geological, geochemical and geophysical data. To provide physico-chemical constraints on these conceptual models, self-consistent numerical simulations containing testable thermo-mechanical parameters are required, especially considering the three-dimensional (<span class="hlt">3</span><span class="hlt">D</span>) natural complexity of subduction systems. Here, we use a <span class="hlt">3</span><span class="hlt">D</span> high-resolution petrological and thermo-mechanical numerical model to quantify the relative contribution of oceanic and continental subduction/collision, slab roll-back and tearing to magma genesis and transport processes. Our modeling results suggest that the space and time distribution and composition of magmas in the overriding plate is controlled by the <span class="hlt">3</span><span class="hlt">D</span> slab <span class="hlt">dynamics</span> and related asthenospheric flow. Moreover, the decrease of the bulk lithospheric strength induced by mantle- and crust-derived magmas promotes the propagation of strike-slip and extensional fault zones through the overriding crust as response to slab roll-back and continental collision. Reduction of the lithosphere/asthenosphere rheological contrast by lithospheric weakening also favors the transmission of velocities from the flowing mantle to the crust. Similarities between our modeling results and the late Cenozoic tectonic and magmatic evolution across the eastern Mediterranean region suggest an efficient control of mantle flow on the magmatic activity in this region, which in turn promotes lithospheric deformation by mantle drag via melt-induced weakening effects.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFM.S13D..05L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.S13D..05L"><span id="translatedtitle">Variability of Slip Behavior in Simulations of <span class="hlt">Dynamic</span> <span class="hlt">Rupture</span> Interaction With Stronger Fault Patches Over Long-Term Deformation Histories</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lapusta, N.; Liu, Y.</p> <p>2007-12-01</p> <p>Heterogeneity in fault properties can have significant effect on <span class="hlt">dynamic</span> <span class="hlt">rupture</span> propagation and aseismic slip. It is often assumed that a fixed heterogeneity would have similar effect on fault slip throughout the slip history. We investigate <span class="hlt">dynamic</span> <span class="hlt">rupture</span> interaction with a fault patch of higher normal stress over several earthquake cycles in a three-dimensional model. We find that the influence of the heterogeneity on <span class="hlt">dynamic</span> events has significant variation and depends on prior slip history. We consider a planar strike-slip fault governed by rate and state friction and driven by slow tectonic loading on deeper extension of the fault. The 30 km by 12 km velocity-weakening region, which is potentially seismogenic, is surrounded by steady-state velocity-strengthening region. The normal stress is constant over the fault, except in a circular patch of 2 km in diameter located in the seismogenic region, where normal stress is higher than on the rest of the fault. Our simulations employ the methodology developed by Lapusta and Liu (AGU, 2006), which is able to resolve both <span class="hlt">dynamic</span> and quasi-static stages of spontaneous slip accumulation in a single computational procedure. The initial shear stress is constant on the fault, except in a small area where it is higher and where the first large <span class="hlt">dynamic</span> event initiates. For patches with 20%, 40%, 60% higher normal stress, the first event has significant <span class="hlt">dynamic</span> interaction with the patch, creating a <span class="hlt">rupture</span> speed decrease followed by a supershear burst and larger slip around the patch. Hence, in the first event, the patch acts as a seismic asperity. For the case of 100% higher stress, the <span class="hlt">rupture</span> is not able to break the patch in the first event. In subsequent <span class="hlt">dynamic</span> events, the behavior depends on the strength of heterogeneity. For the patch with 20% higher normal stress, <span class="hlt">dynamic</span> <span class="hlt">rupture</span> in subsequent events propagates through the patch without any noticeable perturbation in <span class="hlt">rupture</span> speed or slip. In particular</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.nlm.nih.gov/medlineplus/ency/article/001038.htm','NIH-MEDLINEPLUS'); return false;" href="https://www.nlm.nih.gov/medlineplus/ency/article/001038.htm"><span id="translatedtitle"><span class="hlt">Ruptured</span> eardrum</span></a></p> <p><a target="_blank" href="http://medlineplus.gov/">MedlinePlus</a></p> <p></p> <p></p> <p>Tympanic membrane perforation; Eardrum - <span class="hlt">ruptured</span> or perforated; Perforated eardrum ... Buttaravoli P, Leffler SM. Perforated tympanic membrane (<span class="hlt">ruptured</span> eardrum). ... PA: Mosby Elsevier; 2012:chap 37. Kerschner JE. Otitis ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.S43B2788G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.S43B2788G"><span id="translatedtitle">Hybrid broadband Ground Motion simulation based on a <span class="hlt">dynamic</span> <span class="hlt">rupture</span> model of the 2011 Mw 9.0 Tohoku earthquake.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Galvez, P.; Somerville, P.; Bayless, J.; Dalguer, L. A.</p> <p>2015-12-01</p> <p>The <span class="hlt">rupture</span> process of the 2011 Tohoku earthquake exhibits depth-dependent variations in the frequency content of seismic radiation from the plate interface. This depth-varying <span class="hlt">rupture</span> property has also been observed in other subduction zones (Lay et al, 2012). During the Tohoku earthquake, the shallow region radiated coherent low frequency seismic waves whereas the deeper region radiated high frequency waves. Several kinematic inversions (Suzuki et al, 2011; Lee et al, 2011; Bletery et al, 2014; Minson et al, 2014) detected seismic waves below 0.1 Hz coming from the shallow depths that produced slip larger than 40-50 meters close to the trench. Using empirical green functions, Asano & Iwata (2012), Kurahashi and Irikura (2011) and others detected regions of strong ground motion radiation at frequencies up to 10Hz located mainly at the bottom of the plate interface. A recent <span class="hlt">dynamic</span> model that embodies this depth-dependent radiation using physical models has been developed by Galvez et al (2014, 2015). In this model the <span class="hlt">rupture</span> process is modeled using a linear weakening friction law with slip reactivation on the shallow region of the plate interface (Galvez et al, 2015). This model reproduces the multiple seismic wave fronts recorded on the Kik-net seismic network along the Japanese coast up to 0.1 Hz as well as the GPS displacements. In the deep region, the <span class="hlt">rupture</span> sequence is consistent with the sequence of the strong ground motion generation areas (SMGAs) that radiate high frequency ground motion at the bottom of the plate interface (Kurahashi and Irikura, 2013). It remains challenging to perform ground motions fully coupled with a <span class="hlt">dynamic</span> <span class="hlt">rupture</span> up to 10 Hz for a megathrust event. Therefore, to generate high frequency ground motions, we make use of the stochastic approach of Graves and Pitarka (2010) but add to the source spectrum the slip rate function of the <span class="hlt">dynamic</span> model. In this hybrid-<span class="hlt">dynamic</span> approach, the slip rate function is windowed with Gaussian</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015Sci...347.1446G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015Sci...347.1446G"><span id="translatedtitle"><span class="hlt">Dynamic</span> DNA devices and assemblies formed by shape-complementary, non-base pairing <span class="hlt">3</span><span class="hlt">D</span> components</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gerling, Thomas; Wagenbauer, Klaus F.; Neuner, Andrea M.; Dietz, Hendrik</p> <p>2015-03-01</p> <p>We demonstrate that discrete three-dimensional (<span class="hlt">3</span><span class="hlt">D</span>) DNA components can specifically self-assemble in solution on the basis of shape-complementarity and without base pairing. Using this principle, we produced homo- and heteromultimeric objects, including micrometer-scale one- and two-stranded filaments and lattices, as well as reconfigurable devices, including an actuator, a switchable gear, an unfoldable nanobook, and a nanorobot. These multidomain assemblies were stabilized via short-ranged nucleobase stacking bonds that compete against electrostatic repulsion between the components’ interfaces. Using imaging by electron microscopy, ensemble and single-molecule fluorescence resonance energy transfer spectroscopy, and electrophoretic mobility analysis, we show that the balance between attractive and repulsive interactions, and thus the conformation of the assemblies, may be finely controlled by global parameters such as cation concentration or temperature and by an allosteric mechanism based on strand-displacement reactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25814577','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25814577"><span id="translatedtitle"><span class="hlt">Dynamic</span> DNA devices and assemblies formed by shape-complementary, non-base pairing <span class="hlt">3</span><span class="hlt">D</span> components.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gerling, Thomas; Wagenbauer, Klaus F; Neuner, Andrea M; Dietz, Hendrik</p> <p>2015-03-27</p> <p>We demonstrate that discrete three-dimensional (<span class="hlt">3</span><span class="hlt">D</span>) DNA components can specifically self-assemble in solution on the basis of shape-complementarity and without base pairing. Using this principle, we produced homo- and heteromultimeric objects, including micrometer-scale one- and two-stranded filaments and lattices, as well as reconfigurable devices, including an actuator, a switchable gear, an unfoldable nanobook, and a nanorobot. These multidomain assemblies were stabilized via short-ranged nucleobase stacking bonds that compete against electrostatic repulsion between the components' interfaces. Using imaging by electron microscopy, ensemble and single-molecule fluorescence resonance energy transfer spectroscopy, and electrophoretic mobility analysis, we show that the balance between attractive and repulsive interactions, and thus the conformation of the assemblies, may be finely controlled by global parameters such as cation concentration or temperature and by an allosteric mechanism based on strand-displacement reactions. PMID:25814577</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013SPIE.8615E..1BA&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013SPIE.8615E..1BA&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Dynamic</span> analysis of angiogenesis in transgenic zebrafish embryos using a <span class="hlt">3</span><span class="hlt">D</span> multilayer chip-based technology</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Akagi, Jin; Zhu, Feng; Hall, Chris J.; Khoshmanesh, Khashayar; Kalantar-Zadeh, Kourosh; Mitchell, Arnan; Crosier, Kathryn E.; Crosier, Philip S.; Wlodkowic, Donald</p> <p>2013-03-01</p> <p>Transgenic zebrafish (Danio rerio) models of human diseases have recently emerged as innovative experimental systems in drug discovery and molecular pathology. None of the currently available technologies, however, allow for automated immobilization and treatment of large numbers of spatially encoded transgenic embryos during real-time developmental analysis. This work describes the proof-of-concept design and validation of an integrated <span class="hlt">3</span><span class="hlt">D</span> microfluidic chip-based system fabricated directly in the poly(methyl methacrylate) transparent thermoplastic using infrared laser micromachining. At its core, the device utilizes an array of <span class="hlt">3</span><span class="hlt">D</span> micro-mechanical traps to actively capture and immobilize single embryos using a low-pressure suction. It also features built-in piezoelectric microdiaphragm pumps, embryo trapping suction manifold, drug delivery manifold and optically transparent indium tin oxide (ITO) heating element to provide optimal temperature during embryo development. Furthermore, we present design of the proof-of-concept off-chip electronic interface equipped with robotic servo actuator driven stage, innovative servomotor-actuated pinch valves and miniaturized fluorescent USB microscope. Our results show that the innovative device has 100% embryo trapping efficiency while supporting normal embryo development for up to 72 hours in a confined microfluidic environment. We also present data that this microfluidic system can be readily applied to kinetic analysis of a panel of investigational anti-angiogenic agents in transgenic zebrafish Tg(fli1a:EGFP) line. The optical transparency and embryo immobilization allow for convenient visualization of developing vasculature patterns in response to drug treatment without the need for specimen re-positioning. The integrated electronic interfaces bring the Lab-on-a-Chip systems a step closer to realization of complete analytical automation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22216000','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22216000"><span id="translatedtitle">Combined <span class="hlt">3</span><span class="hlt">D</span>-QSAR, molecular docking and molecular <span class="hlt">dynamics</span> study on thyroid hormone activity of hydroxylated polybrominated diphenyl ethers to thyroid receptors β</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Li, Xiaolin; Ye, Li; Wang, Xiaoxiang; Wang, Xinzhou; Liu, Hongling; Zhu, Yongliang; Yu, Hongxia</p> <p>2012-12-15</p> <p>Several recent reports suggested that hydroxylated polybrominated diphenyl ethers (HO-PBDEs) may disturb thyroid hormone homeostasis. To illuminate the structural features for thyroid hormone activity of HO-PBDEs and the binding mode between HO-PBDEs and thyroid hormone receptor (TR), the hormone activity of a series of HO-PBDEs to thyroid receptors β was studied based on the combination of <span class="hlt">3</span><span class="hlt">D</span>-QSAR, molecular docking, and molecular <span class="hlt">dynamics</span> (MD) methods. The ligand- and receptor-based <span class="hlt">3</span><span class="hlt">D</span>-QSAR models were obtained using Comparative Molecular Similarity Index Analysis (CoMSIA) method. The optimum CoMSIA model with region focusing yielded satisfactory statistical results: leave-one-out cross-validation correlation coefficient (q{sup 2}) was 0.571 and non-cross-validation correlation coefficient (r{sup 2}) was 0.951. Furthermore, the results of internal validation such as bootstrapping, leave-many-out cross-validation, and progressive scrambling as well as external validation indicated the rationality and good predictive ability of the best model. In addition, molecular docking elucidated the conformations of compounds and key amino acid residues at the docking pocket, MD simulation further determined the binding process and validated the rationality of docking results. -- Highlights: ► The thyroid hormone activities of HO-PBDEs were studied by <span class="hlt">3</span><span class="hlt">D</span>-QSAR. ► The binding modes between HO-PBDEs and TRβ were explored. ► <span class="hlt">3</span><span class="hlt">D</span>-QSAR, molecular docking, and molecular <span class="hlt">dynamics</span> (MD) methods were performed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.S52C..08W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.S52C..08W"><span id="translatedtitle">Deterministic High-Frequency Ground Motion Using <span class="hlt">Dynamic</span> <span class="hlt">Rupture</span> Along Rough Faults, Small-Scale Media Heterogeneities, and Frequency-Dependent Attenuation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Withers, K.; Olsen, K. B.; Day, S. M.</p> <p>2013-12-01</p> <p>The accuracy of earthquake source descriptions is a major limitation in high-frequency (~>1 Hz) deterministic ground motion prediction, which is critical for performance-based design by building engineers. We address this issue by an attempt to quantify the contributions to high-frequency ground motion from both small-scale fault geometry and media complexity and perform validation against recent Next Generation Attenuation (NGA) relations. Specifically, we use ground motion synthetics using <span class="hlt">dynamic</span> <span class="hlt">rupture</span> propagation along a rough fault imbedded in a velocity structure with small-scale heterogeneities described by a statistical model (Shi and Day, 2013). Here, the assumed fault roughness follows a self-similar fractal distribution with wavelength scales spanning three orders of magnitude from ~10^2 m to ~10^5 m. The <span class="hlt">rupture</span> irregularity caused by fault roughness generates high-frequency accelerations with near-flat power spectra up to almost 10 Hz. We then use the moment-rate time histories from the <span class="hlt">dynamic</span> <span class="hlt">rupture</span> simulation as a kinematic source to extend the ground motions out to farther distances (35 km+) from the fault with a highly scalable fourth-order staggered-grid finite difference method (AWP-ODC). The latter wave propagation simulations use a characteristic 1D rock model with and without small-scale heterogeneities. We find that our simulations are within one inter-event standard deviation of the median up to 10 Hz as given by recent NGA relations. Furthermore, small-scale heterogeneities tend to increase the elastic spectral accelerations at the higher frequencies. To address the effects of small-scale fault and media complexity it is important to model anelastic attenuation as accurately as possible. In the bandwidth below about 1 Hz, observations show that a frequency-independent Q relationship is appropriate. This has been modeled in many simulations with good accuracy using the coarse-grained approach of Day (1998) for a <span class="hlt">3</span><span class="hlt">D</span> anelastic medium, and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24746017','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24746017"><span id="translatedtitle">A multiscale 0-D/<span class="hlt">3</span>-<span class="hlt">D</span> approach to patient-specific adaptation of a cerebral autoregulation model for computational fluid <span class="hlt">dynamics</span> studies of cardiopulmonary bypass.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Neidlin, Michael; Steinseifer, Ulrich; Kaufmann, Tim A S</p> <p>2014-06-01</p> <p>Neurological complication often occurs during cardiopulmonary bypass (CPB). One of the main causes is hypoperfusion of the cerebral tissue affected by the position of the cannula tip and diminished cerebral autoregulation (CA). Recently, a lumped parameter approach could describe the baroreflex, one of the main mechanisms of cerebral autoregulation, in a computational fluid <span class="hlt">dynamics</span> (CFD) study of CPB. However, the cerebral blood flow (CBF) was overestimated and the physiological meaning of the variables and their impact on the model was unknown. In this study, we use a 0-D control circuit representation of the Baroreflex mechanism, to assess the parameters with respect to their physiological meaning and their influence on CBF. Afterwards the parameters are transferred to <span class="hlt">3</span><span class="hlt">D</span>-CFD and the static and <span class="hlt">dynamic</span> behavior of cerebral autoregulation is investigated. The parameters of the baroreflex mechanism can reproduce normotensive, hypertensive and impaired autoregulation behavior. Further on, the proposed model can mimic the effects of anesthetic agents and other factors controlling <span class="hlt">dynamic</span> CA. The CFD simulations deliver similar results of static and <span class="hlt">dynamic</span> CBF as the 0-D control circuit. This study shows the feasibility of a multiscale 0-D/<span class="hlt">3</span>-<span class="hlt">D</span> approach to include patient-specific cerebral autoregulation into CFD studies. PMID:24746017</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011ISPAr3816W.483P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011ISPAr3816W.483P"><span id="translatedtitle">Europeana and <span class="hlt">3</span><span class="hlt">D</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pletinckx, D.</p> <p>2011-09-01</p> <p>The current <span class="hlt">3</span><span class="hlt">D</span> hype creates a lot of interest in <span class="hlt">3</span><span class="hlt">D</span>. People go to <span class="hlt">3</span><span class="hlt">D</span> movies, but are we ready to use <span class="hlt">3</span><span class="hlt">D</span> in our homes, in our offices, in our communication? Are we ready to deliver real <span class="hlt">3</span><span class="hlt">D</span> to a general public and use interactive <span class="hlt">3</span><span class="hlt">D</span> in a meaningful way to enjoy, learn, communicate? The CARARE project is realising this for the moment in the domain of monuments and archaeology, so that real <span class="hlt">3</span><span class="hlt">D</span> of archaeological sites and European monuments will be available to the general public by 2012. There are several aspects to this endeavour. First of all is the technical aspect of flawlessly delivering <span class="hlt">3</span><span class="hlt">D</span> content over all platforms and operating systems, without installing software. We have currently a working solution in PDF, but HTML5 will probably be the future. Secondly, there is still little knowledge on how to create <span class="hlt">3</span><span class="hlt">D</span> learning objects, <span class="hlt">3</span><span class="hlt">D</span> tourist information or <span class="hlt">3</span><span class="hlt">D</span> scholarly communication. We are still in a prototype phase when it comes to integrate <span class="hlt">3</span><span class="hlt">D</span> objects in physical or virtual museums. Nevertheless, Europeana has a tremendous potential as a multi-facetted virtual museum. Finally, <span class="hlt">3</span><span class="hlt">D</span> has a large potential to act as a hub of information, linking to related 2D imagery, texts, video, sound. We describe how to create such rich, explorable <span class="hlt">3</span><span class="hlt">D</span> objects that can be used intuitively by the generic Europeana user and what metadata is needed to support the semantic linking.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2994415','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2994415"><span id="translatedtitle"><span class="hlt">3</span><span class="hlt">D</span> Surgical Simulation</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Cevidanes, Lucia; Tucker, Scott; Styner, Martin; Kim, Hyungmin; Chapuis, Jonas; Reyes, Mauricio; Proffit, William; Turvey, Timothy; Jaskolka, Michael</p> <p>2009-01-01</p> <p>This paper discusses the development of methods for computer-aided jaw surgery. Computer-aided jaw surgery allows us to incorporate the high level of precision necessary for transferring virtual plans into the operating room. We also present a complete computer-aided surgery (CAS) system developed in close collaboration with surgeons. Surgery planning and simulation include construction of <span class="hlt">3</span><span class="hlt">D</span> surface models from Cone-beam CT (CBCT), <span class="hlt">dynamic</span> cephalometry, semi-automatic mirroring, interactive cutting of bone and bony segment repositioning. A virtual setup can be used to manufacture positioning splints for intra-operative guidance. The system provides further intra-operative assistance with the help of a computer display showing jaw positions and <span class="hlt">3</span><span class="hlt">D</span> positioning guides updated in real-time during the surgical procedure. The CAS system aids in dealing with complex cases with benefits for the patient, with surgical practice, and for orthodontic finishing. Advanced software tools for diagnosis and treatment planning allow preparation of detailed operative plans, osteotomy repositioning, bone reconstructions, surgical resident training and assessing the difficulties of the surgical procedures prior to the surgery. CAS has the potential to make the elaboration of the surgical plan a more flexible process, increase the level of detail and accuracy of the plan, yield higher operative precision and control, and enhance documentation of cases. Supported by NIDCR DE017727, and DE018962 PMID:20816308</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016A%26A...587A..12W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016A%26A...587A..12W"><span id="translatedtitle">Near-infrared spectro-interferometry of Mira variables and comparisons to 1D <span class="hlt">dynamic</span> model atmospheres and <span class="hlt">3</span><span class="hlt">D</span> convection simulations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wittkowski, M.; Chiavassa, A.; Freytag, B.; Scholz, M.; Höfner, S.; Karovicova, I.; Whitelock, P. A.</p> <p>2016-03-01</p> <p>Aims: We aim at comparing spectro-interferometric observations of Mira variable asymptotic giant branch (AGB) stars with the latest 1D <span class="hlt">dynamic</span> model atmospheres based on self-excited pulsation models (CODEX models) and with <span class="hlt">3</span><span class="hlt">D</span> <span class="hlt">dynamic</span> model atmospheres including pulsation and convection (CO5BOLD models) to better understand the processes that extend the molecular atmosphere to radii where dust can form. Methods: We obtained a total of 20 near-infrared K-band spectro-interferometric snapshot observations of the Mira variables o Cet, R Leo, R Aqr, X Hya, W Vel, and R Cnc with a spectral resolution of about 1500. We compared observed flux and visibility spectra with predictions by CODEX 1D <span class="hlt">dynamic</span> model atmospheres and with azimuthally averaged intensities based on CO5BOLD <span class="hlt">3</span><span class="hlt">D</span> <span class="hlt">dynamic</span> model atmospheres. Results: Our visibility data confirm the presence of spatially extended molecular atmospheres located above the continuum radii with large-scale inhomogeneities or clumps that contribute a few percent of the total flux. The detailed structure of the inhomogeneities or clumps show a variability on time scales of 3 months and above. Both modeling attempts provided satisfactory fits to our data. In particular, they are both consistent with the observed decrease in the visibility function at molecular bands of water vapor and CO, indicating a spatially extended molecular atmosphere. Observational variability phases are mostly consistent with those of the best-fit CODEX models, except for near-maximum phases, where data are better described by near-minimum models. Rosseland angular diameters derived from the model fits are broadly consistent between those based on the 1D and the <span class="hlt">3</span><span class="hlt">D</span> models and with earlier observations. We derived fundamental parameters including absolute radii, effective temperatures, and luminosities for our sources. Conclusions: Our results provide a first observational support for theoretical results that shocks induced by convection and pulsation in the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.S53B4503C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.S53B4503C"><span id="translatedtitle"><span class="hlt">Dynamic</span> Source Inversion of an Intraslab Earthquake: a Slow and Inefficient <span class="hlt">Rupture</span> with Large Stress Drop and Radiated Energy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cruz-Atienza, V. M.; Diaz-Mojica, J.; Madariaga, R. I.; Singh, S. K.; Tago Pacheco, J.; Iglesias, A.</p> <p>2014-12-01</p> <p>We introduce a method for imaging the earthquake source <span class="hlt">dynamics</span> through the inversion of ground motion records based on a parallel genetic algorithm. The source model follows an elliptical patch approach and uses the staggered-grid split-node method to model the earthquake <span class="hlt">dynamics</span>. A statistical analysis is used to estimate uncertainties in both inverted and derived source parameters. Synthetic inversion tests reveal that the <span class="hlt">rupture</span> speed (Vr), the <span class="hlt">rupture</span> area and the stress drop (Δτ) are determined within an error of ~30%, ~12% and ~10%, respectively. In contrast, derived parameters such as the radiated energy (Er), the radiation efficiency (η) and the fracture energy (G) have larger uncertainties, around ~70%, ~40% and ~25%, respectively. We applied the method to the Mw6.5 intermediate-depth (62 km) normal-faulting earthquake of December 11, 2011 in Guerrero, Mexico (Diaz-Mojica et al., JGR, 2014). Inferred values of Δτ = 29.2±6.2 MPa and η = 0.26±0.1 are significantly higher and lower, respectively, than those of typical subduction thrust events. Fracture energy is large, so that more than 73% of the available potential energy for the <span class="hlt">dynamic</span> process of faulting was deposited in the focal region (i.e., G = (14.4±3.5)x1014J), producing a slow <span class="hlt">rupture</span> process (Vr/Vs = 0.47±0.09) despite the relatively-high energy radiation (Er = (0.54±0.31)x1015 J) and energy-moment ratio (Er/M0 = 5.7x10-5). It is interesting to point out that such a slow and inefficient <span class="hlt">rupture</span> along with the large stress drop in a small focal region are features also observed in the 1994 deep Bolivian earthquake.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19940002506&hterms=Tools+physicists&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DTools%2Bphysicists','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19940002506&hterms=Tools+physicists&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DTools%2Bphysicists"><span id="translatedtitle">PLOT<span class="hlt">3</span><span class="hlt">D</span>/AMES, APOLLO UNIX VERSION USING GMR<span class="hlt">3</span><span class="hlt">D</span> (WITH TURB<span class="hlt">3</span><span class="hlt">D</span>)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Buning, P.</p> <p>1994-01-01</p> <p>PLOT<span class="hlt">3</span><span class="hlt">D</span> is an interactive graphics program designed to help scientists visualize computational fluid <span class="hlt">dynamics</span> (CFD) grids and solutions. Today, supercomputers and CFD algorithms can provide scientists with simulations of such highly complex phenomena that obtaining an understanding of the simulations has become a major problem. Tools which help the scientist visualize the simulations can be of tremendous aid. PLOT<span class="hlt">3</span><span class="hlt">D</span>/AMES offers more functions and features, and has been adapted for more types of computers than any other CFD graphics program. Version 3.6b+ is supported for five computers and graphic libraries. Using PLOT<span class="hlt">3</span><span class="hlt">D</span>, CFD physicists can view their computational models from any angle, observing the physics of problems and the quality of solutions. As an aid in designing aircraft, for example, PLOT<span class="hlt">3</span><span class="hlt">D</span>'s interactive computer graphics can show vortices, temperature, reverse flow, pressure, and dozens of other characteristics of air flow during flight. As critical areas become obvious, they can easily be studied more closely using a finer grid. PLOT<span class="hlt">3</span><span class="hlt">D</span> is part of a computational fluid <span class="hlt">dynamics</span> software cycle. First, a program such as 3DGRAPE (ARC-12620) helps the scientist generate computational grids to model an object and its surrounding space. Once the grids have been designed and parameters such as the angle of attack, Mach number, and Reynolds number have been specified, a "flow-solver" program such as INS<span class="hlt">3</span><span class="hlt">D</span> (ARC-11794 or COS-10019) solves the system of equations governing fluid flow, usually on a supercomputer. Grids sometimes have as many as two million points, and the "flow-solver" produces a solution file which contains density, x- y- and z-momentum, and stagnation energy for each grid point. With such a solution file and a grid file containing up to 50 grids as input, PLOT<span class="hlt">3</span><span class="hlt">D</span> can calculate and graphically display any one of 74 functions, including shock waves, surface pressure, velocity vectors, and particle traces. PLOT<span class="hlt">3</span><span class="hlt">D</span>'s 74 functions are organized into</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19940002508&hterms=Tools+physicists&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DTools%2Bphysicists','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19940002508&hterms=Tools+physicists&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DTools%2Bphysicists"><span id="translatedtitle">PLOT<span class="hlt">3</span><span class="hlt">D</span>/AMES, APOLLO UNIX VERSION USING GMR<span class="hlt">3</span><span class="hlt">D</span> (WITHOUT TURB<span class="hlt">3</span><span class="hlt">D</span>)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Buning, P.</p> <p>1994-01-01</p> <p>PLOT<span class="hlt">3</span><span class="hlt">D</span> is an interactive graphics program designed to help scientists visualize computational fluid <span class="hlt">dynamics</span> (CFD) grids and solutions. Today, supercomputers and CFD algorithms can provide scientists with simulations of such highly complex phenomena that obtaining an understanding of the simulations has become a major problem. Tools which help the scientist visualize the simulations can be of tremendous aid. PLOT<span class="hlt">3</span><span class="hlt">D</span>/AMES offers more functions and features, and has been adapted for more types of computers than any other CFD graphics program. Version 3.6b+ is supported for five computers and graphic libraries. Using PLOT<span class="hlt">3</span><span class="hlt">D</span>, CFD physicists can view their computational models from any angle, observing the physics of problems and the quality of solutions. As an aid in designing aircraft, for example, PLOT<span class="hlt">3</span><span class="hlt">D</span>'s interactive computer graphics can show vortices, temperature, reverse flow, pressure, and dozens of other characteristics of air flow during flight. As critical areas become obvious, they can easily be studied more closely using a finer grid. PLOT<span class="hlt">3</span><span class="hlt">D</span> is part of a computational fluid <span class="hlt">dynamics</span> software cycle. First, a program such as 3DGRAPE (ARC-12620) helps the scientist generate computational grids to model an object and its surrounding space. Once the grids have been designed and parameters such as the angle of attack, Mach number, and Reynolds number have been specified, a "flow-solver" program such as INS<span class="hlt">3</span><span class="hlt">D</span> (ARC-11794 or COS-10019) solves the system of equations governing fluid flow, usually on a supercomputer. Grids sometimes have as many as two million points, and the "flow-solver" produces a solution file which contains density, x- y- and z-momentum, and stagnation energy for each grid point. With such a solution file and a grid file containing up to 50 grids as input, PLOT<span class="hlt">3</span><span class="hlt">D</span> can calculate and graphically display any one of 74 functions, including shock waves, surface pressure, velocity vectors, and particle traces. PLOT<span class="hlt">3</span><span class="hlt">D</span>'s 74 functions are organized into</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015EGUGA..1711726W&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015EGUGA..1711726W&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Dynamic</span> <span class="hlt">rupture</span> simulations on complex fault zone structures with off-fault plasticity using the ADER-DG method</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wollherr, Stephanie; Gabriel, Alice-Agnes; Igel, Heiner</p> <p>2015-04-01</p> <p>In <span class="hlt">dynamic</span> <span class="hlt">rupture</span> models, high stress concentrations at <span class="hlt">rupture</span> fronts have to to be accommodated by off-fault inelastic processes such as plastic deformation. As presented in (Roten et al., 2014), incorporating plastic yielding can significantly reduce earlier predictions of ground motions in the Los Angeles Basin. Further, an inelastic response of materials surrounding a fault potentially has a strong impact on surface displacement and is therefore a key aspect in understanding the triggering of tsunamis through floor uplifting. We present an implementation of off-fault-plasticity and its verification for the software package SeisSol, an arbitrary high-order derivative discontinuous Galerkin (ADER-DG) method. The software recently reached multi-petaflop/s performance on some of the largest supercomputers worldwide and was a Gordon Bell prize finalist application in 2014 (Heinecke et al., 2014). For the nonelastic calculations we impose a Drucker-Prager yield criterion in shear stress with a viscous regularization following (Andrews, 2005). It permits the smooth relaxation of high stress concentrations induced in the <span class="hlt">dynamic</span> <span class="hlt">rupture</span> process. We verify the implementation by comparison to the SCEC/USGS Spontaneous <span class="hlt">Rupture</span> Code Verification Benchmarks. The results of test problem TPV13 with a 60-degree dipping normal fault show that SeisSol is in good accordance with other codes. Additionally we aim to explore the numerical characteristics of the off-fault plasticity implementation by performing convergence tests for the 2D code. The ADER-DG method is especially suited for complex geometries by using unstructured tetrahedral meshes. Local adaptation of the mesh resolution enables a fine sampling of the cohesive zone on the fault while simultaneously satisfying the dispersion requirements of wave propagation away from the fault. In this context we will investigate the influence of off-fault-plasticity on geometrically complex fault zone structures like subduction</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.T53E..01R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.T53E..01R"><span id="translatedtitle">Role of visco-elastic rheologies in the persistence of heterogeneous stress distributions in <span class="hlt">dynamic</span> <span class="hlt">rupture</span> models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Radiguet, M.; Kammer, D. S.; Molinari, J.</p> <p>2013-12-01</p> <p>Understanding how past <span class="hlt">ruptures</span> will affect the propagation of the following <span class="hlt">ruptures</span> is fundamental to a better comprehension of earthquake behavior. In that sense, numerical simulations provide a useful tool to study the <span class="hlt">dynamics</span> of slip. In this study, we model a setup similar to laboratory friction experiments [Rubinstein et al., 2007; Ben-David et al. 2010], consisting of a 2D block of viscoelastic material in contact with a rigid body, with slip-weakening friction at the interface. As in the experiments, the block is loaded from the side, which results in a high concentration of shear stresses close to one edge, where slip will initiate. We observe a sequence of precursory slip, which initiate at shear levels well below the global static friction threshold. These precursory slip stop before propagating over the entire interface, and their length increase with increasing loading. High stress concentrations are generated at the tip of the arrested <span class="hlt">rupture</span>. We analyze the evolution of these stress concentrations when the following slip events take place. Due to the viscous properties of the material, the stress concentrations created by the arrest of precursory slip are not erased by the propagation of the following <span class="hlt">rupture</span>, but reappear with the relaxation of the material, with a smaller amplitude. This leads to perturbation in the <span class="hlt">rupture</span> velocities, with accelerations of the front at the location of these stress concentrations. The amplitude of the stress concentrations follows an exponential decrease rate with successive <span class="hlt">ruptures</span>. We show that this decrease rate is controlled by the material properties, in particular the ratio of the viscous over instantaneous Young's moduli. Our formulation gives a good agreement to the behavior observed in the simulations, and implies that about five slip fronts are necessary to erase all stress concentrations. These results highlight the importance of viscous relaxation mechanisms in the persistence of heterogeneous</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5232433','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5232433"><span id="translatedtitle"><span class="hlt">3</span><span class="hlt">D</span> field harmonics</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Caspi, S.; Helm, M.; Laslett, L.J.</p> <p>1991-03-30</p> <p>We have developed an harmonic representation for the three dimensional field components within the windings of accelerator magnets. The form by which the field is presented is suitable for interfacing with other codes that make use of the <span class="hlt">3</span><span class="hlt">D</span> field components (particle tracking and stability). The field components can be calculated with high precision and reduced cup time at any location (r,{theta},z) inside the magnet bore. The same conductor geometry which is used to simulate line currents is also used in CAD with modifications more readily available. It is our hope that the format used here for magnetic fields can be used not only as a means of delivering fields but also as a way by which beam <span class="hlt">dynamics</span> can suggest correction to the conductor geometry. 5 refs., 70 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23362119','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23362119"><span id="translatedtitle"><span class="hlt">Dynamic</span> perfusion bioreactor system for <span class="hlt">3</span><span class="hlt">D</span> culture of rat bone marrow mesenchymal stem cells on nanohydroxyapatite/polyamide 66 scaffold in vitro.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Qian, Xu; Yuan, Fang; Zhimin, Zhu; Anchun, Mo</p> <p>2013-08-01</p> <p>The aim of the study was to investigate the biocompatibility and osteogenic effectiveness of the porous nanohydroxyapatite/polyamide 66 (n-HA/PA66) scaffold material that was cultured with the rat bone marrow mesenchymal stem cells (rBMSCs), under the static culture condition and the <span class="hlt">dynamic</span> perfusion culture condition in vitro, and to investigate whether the <span class="hlt">3</span><span class="hlt">D</span> perfusion culture condition was better in provoking proliferation of rBMSCs than the <span class="hlt">3</span><span class="hlt">D</span> static culture condition. The Methyl thiazolyl tetrazolium (MTT) assay, alkaline phosphatase (ALP) activity assay, Osteocalcin (OCN) assay and scanning electron microscope (SEM) were used to observe the proliferation and differentiation of rBMSCs. The samples were respectively harvested at 1st, 3rd, 7th, 14th, and 21st days and effect comparisons were made between the two of the culture conditions. The results showed that values of MTT, ALP, and OCN were increased continuously and revealed a significant difference between the two culture conditions (p < 0.05). On the 14th day, SEM revealed calcified nodules 2-8 μm in diameter in the lamellar structure. Under the static culture condition, the pores were covered with the cells looking like a piece of blanket, but under the perfusion culture condition the cells were observed to have a <span class="hlt">3</span><span class="hlt">D</span> lamellar structure. In conclusion, the porous n-HA/PA66 scaffold material can be used as a good candidate material for the bone scaffold construction in the tissue engineering because of its excellent <span class="hlt">3</span><span class="hlt">D</span> structure, which can greatly improve the proliferation and differentiation of rBMSCs and make them proliferate and osteogenesis even better under the perfusion culture condition. PMID:23362119</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3753321','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3753321"><span id="translatedtitle">Ex-Vivo <span class="hlt">Dynamic</span> <span class="hlt">3</span>-<span class="hlt">D</span> Culture of Human Tissues in the RCCS™ Bioreactor Allows the Study of Multiple Myeloma Biology and Response to Therapy</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ponzoni, Maurilio; Belloni, Daniela; Berenzi, Angiola; Girlanda, Stefania; Caligaris-Cappio, Federico; Mazzoleni, Giovanna; Ferrero, Elisabetta</p> <p>2013-01-01</p> <p>Three-dimensional (<span class="hlt">3</span>-<span class="hlt">D</span>) culture models are emerging as invaluable tools in tumor biology, since they reproduce tissue-specific structural features and cell-cell interactions more accurately than conventional 2-D cultures. Multiple Myeloma, which depends on myeloma cell-Bone Marrow microenvironment interactions for development and response to drugs, may particularly benefit from such an approach. An innovative <span class="hlt">3</span>-<span class="hlt">D</span> <span class="hlt">dynamic</span> culture model based on the use of the RCCS™ Bioreactor was developed to allow long-term culture of myeloma tissue explants. This model was first validated with normal and pathological explants, then applied to tissues from myeloma patients. In all cases, histological examination demonstrated maintenance of viable myeloma cells inside their native microenvironment, with an overall well preserved histo-architecture including bone lamellae and vessels. This system was then successfully applied to evaluate the cytotoxic effects exerted by the proteasome inhibitor Bortezomib not only on myeloma cells but also on angiogenic vessels. Moreover, as surrogate markers of specialized functions expressed by myeloma cells and microenvironment, β2 microglobulin, VEGF and Angiopoietin-2 levels, as well as Matrix Metalloproteases activity, were evaluated in supernatants from <span class="hlt">3</span><span class="hlt">D</span> cultures and their levels reflected the effects of Bortezomib treatment. Notably, determination of β2 microglobulin levels in supernatants from Bortezomib-treated samples and in patients'sera following Bortezomib-based therapies disclosed an overall concordance in the response to the drug ex vivo and in vivo. Our findings indicate, as a proof of principle, that <span class="hlt">3</span>-<span class="hlt">D</span>, RCCS™ bioreactor-based culture of tissue explants can be exploited for studying myeloma biology and for a pre-clinical approach to patient-targeted therapy. PMID:23990965</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4711029','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4711029"><span id="translatedtitle">Velocity Measurement in Carotid Artery: Quantitative Comparison of Time-Resolved <span class="hlt">3</span><span class="hlt">D</span> Phase-Contrast MRI and Image-based Computational Fluid <span class="hlt">Dynamics</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Sarrami-Foroushani, Ali; Nasr Esfahany, Mohsen; Nasiraei Moghaddam, Abbas; Saligheh Rad, Hamidreza; Firouznia, Kavous; Shakiba, Madjid; Ghanaati, Hossein; Wilkinson, Iain David; Frangi, Alejandro Federico</p> <p>2015-01-01</p> <p>Background: Understanding hemodynamic environment in vessels is important for realizing the mechanisms leading to vascular pathologies. Objectives: Three-dimensional velocity vector field in carotid bifurcation is visualized using TR <span class="hlt">3</span><span class="hlt">D</span> phase-contrast magnetic resonance imaging (TR <span class="hlt">3</span><span class="hlt">D</span> PC MRI) and computational fluid <span class="hlt">dynamics</span> (CFD). This study aimed to present a qualitative and quantitative comparison of the velocity vector field obtained by each technique. Subjects and Methods: MR imaging was performed on a 30-year old male normal subject. TR <span class="hlt">3</span><span class="hlt">D</span> PC MRI was performed on a 3 T scanner to measure velocity in carotid bifurcation. <span class="hlt">3</span><span class="hlt">D</span> anatomical model for CFD was created using images obtained from time-of-flight MR angiography. Velocity vector field in carotid bifurcation was predicted using CFD and PC MRI techniques. A statistical analysis was performed to assess the agreement between the two methods. Results: Although the main flow patterns were the same for the both techniques, CFD showed a greater resolution in mapping the secondary and circulating flows. Overall root mean square (RMS) errors for all the corresponding data points in PC MRI and CFD were 14.27% in peak systole and 12.91% in end diastole relative to maximum velocity measured at each cardiac phase. Bland-Altman plots showed a very good agreement between the two techniques. However, this study was not aimed to validate any of methods, instead, the consistency was assessed to accentuate the similarities and differences between Time-resolved PC MRI and CFD. Conclusion: Both techniques provided quantitatively consistent results of in vivo velocity vector fields in right internal carotid artery (RCA). PC MRI represented a good estimation of main flow patterns inside the vasculature, which seems to be acceptable for clinical use. However, limitations of each technique should be considered while interpreting results. PMID:26793288</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.H43J..03N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.H43J..03N"><span id="translatedtitle">The Role of Water Subsidy on Vegetation <span class="hlt">Dynamics</span> in a Semiarid Grassland Catchment: Comparison between Field Measurements and <span class="hlt">3</span>-<span class="hlt">D</span> Ecohydrological Modeling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Niu, G.; Troch, P. A.; Paniconi, C.; Scott, R. L.; Durcik, M.; Zeng, X.; Huxman, T. E.; Goodrich, D. C.</p> <p>2010-12-01</p> <p>In water-limited regions, water and carbon fluxes are strongly controlled by soil water availability, which may be highly variable even at very small spatial scales (e.g., meters) due to variations in slope, aspect, soils, and vegetation conditions, as well as water redistribution along hillslopes. This paper examines key factors controlling soil water availability for plant growth and surface CO2 fluxes in a small semi-arid experimental watershed (7.92 ha) in southeastern Arizona, using a land surface model (LSM) coupled with a three-dimensional (<span class="hlt">3</span>-<span class="hlt">D</span>) process-based hydrological model. The LSM accounts for surface energy, water, and carbon exchanges between the land surface and the atmosphere, while the hydrological model accounts for <span class="hlt">3</span>-<span class="hlt">D</span> subsurface flow in variably saturated porous media and surface flow propagation over hillslopes and in stream channel networks. The coupled model, with minor calibration, simulated the observed surface energy, water, and CO2 fluxes well. The model mirrored the interannual variability of CO2 fluxes without accounting for the transition from native to exotic bunchgrasses that occurred at this site during the observation period, suggesting that water availability exerts a stronger control on the ecosystem <span class="hlt">dynamics</span> than changes in species. Results from <span class="hlt">3</span>-<span class="hlt">D</span> coupled model experiments with different lateral saturated hydraulic conductivities demonstrated that the model with smaller conductivities improved the simulation of evapotranspiration (ET) and CO2 fluxes, suggesting that lateral subsurface flow was very weak. Experiments with the one-dimensional LSM, which does not explicitly consider either surface or subsurface lateral flows, produced lower-than-observed ET and CO2 fluxes during drought years and in dry-down periods. However, in the <span class="hlt">3</span>-<span class="hlt">D</span> simulations, the wetter soils in lowland areas along stream channels, mainly induced by lateral overland flow and re-infiltration, provides plants with favorable conditions to produce more</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003sf2a.conf..101P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003sf2a.conf..101P"><span id="translatedtitle"><span class="hlt">3</span><span class="hlt">D</span> Structures & <span class="hlt">dynamic</span> of the solar corona: inputs from stereovision technics and joigned Ground Based and Space Observatories for the development of Space Weather</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Portier-Fozzani, F.; Stereo/Secchi Team At Mpae</p> <p></p> <p>While taking into account the difficulties encountered by <span class="hlt">3</span><span class="hlt">D</span> imaging specialists with usual objects over the last 20 years, we derived appropriate stereoscopic methods that we could use for the very specific case of the solar corona. Tomographic methods which should be better for such optically thin EUV lines need lots of different quasi-simultaneous viewpoints which is not possible. Usual objects reconstructed by stereovision are mainly optical thick objects such as lands, buildings, planes, tanks with variable external luminosity. Directlty applied, classical algorithms give at least big uncertainties due to the light emission integration along the line of sight. Also structures extractions and maching between images are very difficult to derived. Epipolar geometry has to be determined before all other steps and decomposing each image in wavelet spatial frequencies with Multiscale Vision Model for example, improves a lot the extract/match step. Results of such automatization of the method are presented in the paper. Another shorter method is to derive some <span class="hlt">3</span><span class="hlt">D</span> parameters with an 'a priori geometry' shape of the object observed. It has been used for loops studies. For an emerging active region loops, twist variations together with the expansion have been measured with consequences on the helicity. With such method, sigmoids evolution can be also described. When we limit the <span class="hlt">3</span><span class="hlt">D</span> study for some structures (such as filaments forming CMEs) to the calculation of the plane of expansion or the degree of twist, some evolution can be partly described from SOHO in the space weather context, which would be even better described when STEREO would take simultaneous images at different angle to take into account more the <span class="hlt">dynamic</span> of the solar corona with less evolution necessary assumption. The two methods will be mixed in the future with the philosophy of computer learning in <span class="hlt">3</span><span class="hlt">D</span> image processing for automatic space weather alerts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.U33A..04A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.U33A..04A"><span id="translatedtitle">Salient Features of the 2015 Gorkha, Nepal Earthquake in Relation to Earthquake Cycle and <span class="hlt">Dynamic</span> <span class="hlt">Rupture</span> Models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ampuero, J. P.; Meng, L.; Hough, S. E.; Martin, S. S.; Asimaki, D.</p> <p>2015-12-01</p> <p>Two salient features of the 2015 Gorkha, Nepal, earthquake provide new opportunities to evaluate models of earthquake cycle and <span class="hlt">dynamic</span> <span class="hlt">rupture</span>. The Gorkha earthquake broke only partially across the seismogenic depth of the Main Himalayan Thrust: its slip was confined in a narrow depth range near the bottom of the locked zone. As indicated by the belt of background seismicity and decades of geodetic monitoring, this is an area of stress concentration induced by deep fault creep. Previous conceptual models attribute such intermediate-size events to rheological segmentation along-dip, including a fault segment with intermediate rheology in between the stable and unstable slip segments. We will present results from earthquake cycle models that, in contrast, highlight the role of stress loading concentration, rather than frictional segmentation. These models produce "super-cycles" comprising recurrent characteristic events interspersed by deep, smaller non-characteristic events of overall increasing magnitude. Because the non-characteristic events are an intrinsic component of the earthquake super-cycle, the notion of Coulomb triggering or time-advance of the "big one" is ill-defined. The high-frequency (HF) ground motions produced in Kathmandu by the Gorkha earthquake were weaker than expected for such a magnitude and such close distance to the <span class="hlt">rupture</span>, as attested by strong motion recordings and by macroseismic data. Static slip reached close to Kathmandu but had a long rise time, consistent with control by the along-dip extent of the <span class="hlt">rupture</span>. Moreover, the HF (1 Hz) radiation sources, imaged by teleseismic back-projection of multiple dense arrays calibrated by aftershock data, was deep and far from Kathmandu. We argue that HF <span class="hlt">rupture</span> imaging provided a better predictor of shaking intensity than finite source inversion. The deep location of HF radiation can be attributed to <span class="hlt">rupture</span> over heterogeneous initial stresses left by the background seismic activity</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3597536','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3597536"><span id="translatedtitle">Spatial Pattern <span class="hlt">Dynamics</span> of <span class="hlt">3</span><span class="hlt">D</span> Stem Cell Loss of Pluripotency via Rules-Based Computational Modeling</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>White, Douglas E.; Kinney, Melissa A.; McDevitt, Todd C.; Kemp, Melissa L.</p> <p>2013-01-01</p> <p> powerful tool to predict stem cell behavior under a number of culture conditions that emulate characteristics of <span class="hlt">3</span><span class="hlt">D</span> stem cell niches. PMID:23516345</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Zheng+Zheng&pg=4&id=EJ970878','ERIC'); return false;" href="http://eric.ed.gov/?q=Zheng+Zheng&pg=4&id=EJ970878"><span id="translatedtitle">Caring in the <span class="hlt">Dynamics</span> of Design and Languaging: Exploring Second Language Learning in <span class="hlt">3</span><span class="hlt">D</span> Virtual Spaces</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Zheng, Dongping</p> <p>2012-01-01</p> <p>This study provides concrete evidence of ecological, dialogical views of languaging within the <span class="hlt">dynamics</span> of coordination and cooperation in a virtual world. Beginning level second language learners of Chinese engaged in cooperative activities designed to provide them opportunities to refine linguistic actions by way of caring for others, for the…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/543001','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/543001"><span id="translatedtitle">Wavefront construction in <span class="hlt">3</span>-<span class="hlt">D</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chilcoat, S.R. Hildebrand, S.T.</p> <p>1995-12-31</p> <p>Travel time computation in inhomogeneous media is essential for pre-stack Kirchhoff imaging in areas such as the sub-salt province in the Gulf of Mexico. The 2D algorithm published by Vinje, et al, has been extended to <span class="hlt">3</span><span class="hlt">D</span> to compute wavefronts in complicated inhomogeneous media. The <span class="hlt">3</span><span class="hlt">D</span> wavefront construction algorithm provides many advantages over conventional ray tracing and other methods of computing travel times in <span class="hlt">3</span><span class="hlt">D</span>. The algorithm <span class="hlt">dynamically</span> maintains a reasonably consistent ray density without making a priori guesses at the number of rays to shoot. The determination of caustics in <span class="hlt">3</span><span class="hlt">D</span> is a straight forward geometric procedure. The wavefront algorithm also enables the computation of multi-valued travel time surfaces.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020054405','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020054405"><span id="translatedtitle"><span class="hlt">3</span><span class="hlt">D</span> Flow Visualization Using Texture Advection</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kao, David; Zhang, Bing; Kim, Kwansik; Pang, Alex; Moran, Pat (Technical Monitor)</p> <p>2001-01-01</p> <p>Texture advection is an effective tool for animating and investigating 2D flows. In this paper, we discuss how this technique can be extended to <span class="hlt">3</span><span class="hlt">D</span> flows. In particular, we examine the use of <span class="hlt">3</span><span class="hlt">D</span> and 4D textures on <span class="hlt">3</span><span class="hlt">D</span> synthetic and computational fluid <span class="hlt">dynamics</span> flow fields.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JHEP...04..140C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JHEP...04..140C"><span id="translatedtitle"><span class="hlt">3</span><span class="hlt">d</span>-<span class="hlt">3</span><span class="hlt">d</span> correspondence revisited</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chung, Hee-Joong; Dimofte, Tudor; Gukov, Sergei; Sułkowski, Piotr</p> <p>2016-04-01</p> <p>In fivebrane compactifications on 3-manifolds, we point out the importance of all flat connections in the proper definition of the effective <span class="hlt">3</span><span class="hlt">d</span> {N}=2 theory. The Lagrangians of some theories with the desired properties can be constructed with the help of homological knot invariants that categorify colored Jones polynomials. Higgsing the full <span class="hlt">3</span><span class="hlt">d</span> theories constructed this way recovers theories found previously by Dimofte-Gaiotto-Gukov. We also consider the cutting and gluing of 3-manifolds along smooth boundaries and the role played by all flat connections in this operation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21148873','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21148873"><span id="translatedtitle">Second-Order Inelastic <span class="hlt">Dynamic</span> Analysis of <span class="hlt">3</span><span class="hlt">D</span> Semi-Rigid Steel Frames Under Earthquake Loads with Three Components</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ozakgul, Kadir</p> <p>2008-07-08</p> <p>In this study, it has been presented an algorithm for second-order elastoplastic <span class="hlt">dynamic</span> time-history analysis of three dimensional frames that have steel members with semirigid joints. The proposed analysis accounts for material, geometric and connection nonlinearities. Material nonlinearity have been modeled by the Ramberg-Osgood relation. While the geometric nonlinearity caused by axial force has been described by the use of the geometric stiffness matrix, the nonlinearity caused by the interaction between the axial force and bending moment has been also described by the use of the stability functions. The independent hardening model has been used to describe the nonlinear behaviour of semi-rigid connections. <span class="hlt">Dynamic</span> equation of motion has been solved by Newmark's constant acceleration method in time history domain.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015OptLE..74...47P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015OptLE..74...47P"><span id="translatedtitle"><span class="hlt">3</span><span class="hlt">D</span> transient multiphase model for keyhole, vapor plume, and weld pool <span class="hlt">dynamics</span> in laser welding including the ambient pressure effect</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pang, Shengyong; Chen, Xin; Zhou, Jianxin; Shao, Xinyu; Wang, Chunming</p> <p>2015-11-01</p> <p>The physical process of deep penetration laser welding involves complex, self-consistent multiphase keyhole, metallic vapor plume, and weld pool <span class="hlt">dynamics</span>. Currently, efforts are still needed to understand these multiphase <span class="hlt">dynamics</span>. In this paper, a novel <span class="hlt">3</span><span class="hlt">D</span> transient multiphase model capable of describing a self-consistent keyhole, metallic vapor plume in the keyhole, and weld pool <span class="hlt">dynamics</span> in deep penetration fiber laser welding is proposed. Major physical factors of the welding process, such as recoil pressure, surface tension, Marangoni shear stress, Fresnel absorptions mechanisms, heat transfer, and fluid flow in weld pool, keyhole free surface evolutions and solid-liquid-vapor three phase transformations are coupling considered. The effect of ambient pressure in laser welding is rigorously treated using an improved recoil pressure model. The predicated weld bead dimensions, transient keyhole instability, weld pool <span class="hlt">dynamics</span>, and vapor plume <span class="hlt">dynamics</span> are compared with experimental and literature results, and good agreements are obtained. The predicted results are investigated by not considering the effects of the ambient pressure. It is found that by not considering the effects of ambient pressure, the average keyhole wall temperature is underestimated about 500 K; besides, the average speed of metallic vapor will be significantly overestimated. The ambient pressure is an essential physical factor for a comprehensive understanding the <span class="hlt">dynamics</span> of deep penetration laser welding.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24026004','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24026004"><span id="translatedtitle">Duality between the <span class="hlt">dynamics</span> of line-like brushes of point defects in 2D and strings in <span class="hlt">3</span><span class="hlt">D</span> in liquid crystals.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Digal, Sanatan; Ray, Rajarshi; Saumia, P S; Srivastava, Ajit M</p> <p>2013-10-01</p> <p>We analyze the <span class="hlt">dynamics</span> of dark brushes connecting point vortices of strength ±1 formed in the isotropic-nematic phase transition of a thin layer of nematic liquid crystals, using a crossed polarizer set up. The evolution of the brushes is seen to be remarkably similar to the evolution of line defects in a three-dimensional nematic liquid crystal system. Even phenomena like the intercommutativity of strings are routinely observed in the <span class="hlt">dynamics</span> of brushes. We test the hypothesis of a duality between the two systems by determining exponents for the coarsening of total brush length with time as well as shrinking of the size of an isolated loop. Our results show scaling behavior for the brush length as well as the loop size with corresponding exponents in good agreement with the <span class="hlt">3</span><span class="hlt">D</span> case of string defects. PMID:24026004</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015PhFl...27b2104W&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015PhFl...27b2104W&link_type=ABSTRACT"><span id="translatedtitle">Numerical modeling of the <span class="hlt">3</span><span class="hlt">D</span> <span class="hlt">dynamics</span> of ultrasound contrast agent microbubbles using the boundary integral method</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Qianxi; Manmi, Kawa; Calvisi, Michael L.</p> <p>2015-02-01</p> <p>Ultrasound contrast agents (UCAs) are microbubbles stabilized with a shell typically of lipid, polymer, or protein and are emerging as a unique tool for noninvasive therapies ranging from gene delivery to tumor ablation. While various models have been developed to describe the spherical oscillations of contrast agents, the treatment of nonspherical behavior has received less attention. However, the nonspherical <span class="hlt">dynamics</span> of contrast agents are thought to play an important role in therapeutic applications, for example, enhancing the uptake of therapeutic agents across cell membranes and tissue interfaces, and causing tissue ablation. In this paper, a model for nonspherical contrast agent <span class="hlt">dynamics</span> based on the boundary integral method is described. The effects of the encapsulating shell are approximated by adapting Hoff's model for thin-shell, spherical contrast agents. A high-quality mesh of the bubble surface is maintained by implementing a hybrid approach of the Lagrangian method and elastic mesh technique. The numerical model agrees well with a modified Rayleigh-Plesset equation for encapsulated spherical bubbles. Numerical analyses of the <span class="hlt">dynamics</span> of UCAs in an infinite liquid and near a rigid wall are performed in parameter regimes of clinical relevance. The oscillation amplitude and period decrease significantly due to the coating. A bubble jet forms when the amplitude of ultrasound is sufficiently large, as occurs for bubbles without a coating; however, the threshold amplitude required to incite jetting increases due to the coating. When a UCA is near a rigid boundary subject to acoustic forcing, the jet is directed towards the wall if the acoustic wave propagates perpendicular to the boundary. When the acoustic wave propagates parallel to the rigid boundary, the jet direction has components both along the wave direction and towards the boundary that depend mainly on the dimensionless standoff distance of the bubble from the boundary. In all cases, the jet</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015PhDT.......213G&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015PhDT.......213G&link_type=ABSTRACT"><span id="translatedtitle">Study of <span class="hlt">3</span>-<span class="hlt">D</span> <span class="hlt">Dynamic</span> Roughness Effects on Flow Over a NACA 0012 Airfoil Using Large Eddy Simulations at Low Reynolds Numbers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guda, Venkata Subba Sai Satish</p> <p></p> <p>There have been several advancements in the aerospace industry in areas of design such as aerodynamics, designs, controls and propulsion; all aimed at one common goal i.e. increasing efficiency --range and scope of operation with lesser fuel consumption. Several methods of flow control have been tried. Some were successful, some failed and many were termed as impractical. The low Reynolds number regime of 104 - 105 is a very interesting range. Flow physics in this range are quite different than those of higher Reynolds number range. Mid and high altitude UAV's, MAV's, sailplanes, jet engine fan blades, inboard helicopter rotor blades and wind turbine rotors are some of the aerodynamic applications that fall in this range. The current study deals with using <span class="hlt">dynamic</span> roughness as a means of flow control over a NACA 0012 airfoil at low Reynolds numbers. <span class="hlt">Dynamic</span> <span class="hlt">3</span>-<span class="hlt">D</span> surface roughness elements on an airfoil placed near the leading edge aim at increasing the efficiency by suppressing the effects of leading edge separation like leading edge stall by delaying or totally eliminating flow separation. A numerical study of the above method has been carried out by means of a Large Eddy Simulation, a mathematical model for turbulence in Computational Fluid <span class="hlt">Dynamics</span>, owing to the highly unsteady nature of the flow. A user defined function has been developed for the <span class="hlt">3</span>-<span class="hlt">D</span> <span class="hlt">dynamic</span> roughness element motion. Results from simulations have been compared to those from experimental PIV data. Large eddy simulations have relatively well captured the leading edge stall. For the clean cases, i.e. with the DR not actuated, the LES was able to reproduce experimental results in a reasonable fashion. However DR simulation results show that it fails to reattach the flow and suppress flow separation compared to experiments. Several novel techniques of grid design and hump creation are introduced through this study.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1613669S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1613669S"><span id="translatedtitle">Contemporary surface <span class="hlt">ruptures</span> in the zone of the Baikal-Mondy fault (Baikal rift system): <span class="hlt">dynamics</span> of formation and origin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sankov, Vladimir; Sankov, Aleksei; Lebedeva, Marina; Ashurkov, Sergey; Parfeevets, Anna</p> <p>2014-05-01</p> <p>.08.2008, Mw = 6.3), the epicenter of which was located near the southern tip of the Baikal basin. The existence of centimeter level deformations is confirmed using of differential SAR interferometry method. A pair of images taken with an interval of 2 years highlighted the linear zone of active deformation in the centimeter level. The length of the structure is about 4 kilometers. The offset along the Line-of-Sight (LOS) direction is from 18 to 42 mm, which corresponds to the vertical displacement of 22 to 50 mm, or a horizontal displacement of 32 to 74 mm (Lebedeva et al., 2013). Along with the described <span class="hlt">ruptures</span> we discovered normal faults with an amplitude greater than 2 m, which can be traced along the submeridional local watershed. The length of the normal faults reaches 800 m. The morphology and position of these faults can be attributed to their sackung structures. We conclude that the detected current surface <span class="hlt">ruptures</span> have complex origins and develop under the influence of endogenous (tectonic) and exogenous forces. They founded along NE trending ancient tectonic structures within wide strike-slip zone and main direction of opening corresponds to the direction of extension of paleo- and present-day stress field. According to the <span class="hlt">dynamics</span> of <span class="hlt">ruptures</span> opening, the main phase of their formation is connected with stage of Kultuk earthquake preparation. As for geodetic data the block is stretched in all directions, it can be assumed that, by analogy with closely spaced sacking</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22299645','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22299645"><span id="translatedtitle"><span class="hlt">Dynamic</span> topology and flux rope evolution during non-linear tearing of <span class="hlt">3</span><span class="hlt">D</span> null point current sheets</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wyper, P. F. Pontin, D. I.</p> <p>2014-10-15</p> <p>In this work, the <span class="hlt">dynamic</span> magnetic field within a tearing-unstable three-dimensional current sheet about a magnetic null point is described in detail. We focus on the evolution of the magnetic null points and flux ropes that are formed during the tearing process. Generally, we find that both magnetic structures are created prolifically within the layer and are non-trivially related. We examine how nulls are created and annihilated during bifurcation processes, and describe how they evolve within the current layer. The type of null bifurcation first observed is associated with the formation of pairs of flux ropes within the current layer. We also find that new nulls form within these flux ropes, both following internal reconnection and as adjacent flux ropes interact. The flux ropes exhibit a complex evolution, driven by a combination of ideal kinking and their interaction with the outflow jets from the main layer. The finite size of the unstable layer also allows us to consider the wider effects of flux rope generation. We find that the unstable current layer acts as a source of torsional magnetohydrodynamic waves and <span class="hlt">dynamic</span> braiding of magnetic fields. The implications of these results to several areas of heliophysics are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRB..121.4446W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRB..121.4446W"><span id="translatedtitle">Earthquake <span class="hlt">rupture</span> extents and coseismic slips promoted by damaged fault zones</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Weng, Huihui; Yang, Hongfeng; Zhang, Zhenguo; Chen, Xiaofei</p> <p>2016-06-01</p> <p>Here we investigate the effects of damage fault zones on <span class="hlt">rupture</span> propagation by conducting a series of <span class="hlt">3</span>-<span class="hlt">D</span> <span class="hlt">dynamic</span> <span class="hlt">rupture</span> simulations on a planar vertical strike-slip fault. We find that damage fault zones can promote <span class="hlt">rupture</span> extent and increase earthquake potency. The waves reflected from the bottom of shallow damage fault zones can increase shear stress on the fault and thus promote <span class="hlt">rupture</span> propagation. In addition, the promotional effects increase with the width and depth extent of damage fault zones. The overall effects of the waves reflected from the fault-parallel side boundaries of damage fault zones are unfavorable for <span class="hlt">rupture</span> propagation. Therefore, <span class="hlt">rupture</span> propagation is promoted with the increased width of fault zones due to geometrical spreading effects. Moreover, nonground-breaking <span class="hlt">ruptures</span> may reach the ground surface with the effects of damage fault zones. Furthermore, along-strike segmented fault zones as suggested by observations could also promote <span class="hlt">ruptures</span> and may lead to preferred <span class="hlt">rupture</span> directions if epicenters are close to fault zones. The effects of damage fault zones on <span class="hlt">rupture</span> propagation hold important implications on assessing earthquake risk.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016Tectp.682...85L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016Tectp.682...85L"><span id="translatedtitle">Thermobarometry of metamorphosed pseudotachylyte and associated mylonite: Constraints on <span class="hlt">dynamic</span> Co-seismic <span class="hlt">rupture</span> depth attending Caledonian extension, North Norway</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Leib, S. E.; Moecher, D. P.; Steltenpohl, M. G.; Andresen, Arild</p> <p>2016-07-01</p> <p>The exhumed post-Caledonian Eidsfjord and Fiskfjord extensional shear zones of northern Norway exhibit evidence of coseismic <span class="hlt">rupture</span> propagating into the ductile crust as evidenced by the presence of mylonitic and metamorphosed pseudotachylyte. Geothermobarometric calculations on garnet-bearing mineral assemblages in mylonitic gneisses associated with mylonitic pseudotachylyte and in metamorphosed pseudotachylyte permit determination of the depth and ambient temperature of seismogenic low-angle ductile extension. Average pressures from Eidsfjord (570 ± 115 MPa at ca. 650 °C) and Fiskfjord (1120 ± 220 MPa at ca. 650 °C) correspond to faulting depths of 21 ± 4 km and 41 ± 9 km, respectively. The Fiskfjord results agree with previous thermobarometric calculations on mylonitic Cpx + Grt-bearing pseudotachylyte at Fiskfjord. The calculated depths are 5-25 km below the depth of the standard seismogenic zone. These results demonstrate that low angle normal faults may cut through a large portion of continental crust. This occurrence of mylonitic pseudotachylyte in an extensional crustal setting is most easily explained by <span class="hlt">dynamic</span> downward <span class="hlt">rupture</span> into the ductile regime and/or unusually high shear stresses to account for coseismic <span class="hlt">rupture</span> at such depths, implying a direct connection with a seismogenic normal fault in the upper crust.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AGUFM.S33C..04F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AGUFM.S33C..04F"><span id="translatedtitle"><span class="hlt">Dynamic</span> <span class="hlt">Rupture</span> Propagation on a Branched Fault System: The 1891 Nobi, Japan, Earthquake (M8.0)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fukuyama, E.; Mikumo, T.</p> <p>2004-12-01</p> <p>The 1891 Nobi earthquake was the largest intraplate earthquake that occurred in recent 200 years in Japan. Although it occurred more than 100 years ago, there are several photographs with geological descriptions (Koto, 1893, J. Coll. Sci. Imp. Univ. Tokyo) as well as the fault offsets some of which still remain on the surface. We constructed the fault model based on Mikumo and Ando (1975, J. Phys. Earth), who used the field survey results of the fault traces by Matsuda (1974, Spec. Rep. Earthq. Res. Inst.). The fault model consists of 5 subfaults, three of which form the curved northwesten segment and the rest two are for the branched faults. We take into account the static stress distribution, referring to the results by Mikumo and Fukuyama (2004, AGU Fall Meeting). Concerning the hypocenter location, there are two possibilities: the northern end (Mikumo and Ando, 1975) and the southern edge of the northern subfaults (Muramatu et al., 2003). If we considered