Modelling lithosphere dynamics with robust rheological implementations: Towards 3D

2020 ◽  
Author(s):  
Thibault Duretz ◽  
René de Borst ◽  
Ludovic Räss
Keyword(s):  
Numerical Models ◽  
Three Dimensional ◽  
Two Dimensions ◽  
Strain Localisation ◽  
Lithospheric Deformation ◽  
Robust Solution ◽  
Solution Methods ◽  
Graphical Processing ◽  
Three Dimensional Models ◽  
Lithosphere Dynamics

<div>Reliable numerical models of lithospheric deformation require robust solution methods. The latter should account for a complex and realistic rheological model and should also provide convergent and reproducible results.</div><div>Here we present models of crustal-scale deformation that accurately capture the phenomenon of strain localisation in two-dimensions. The use of viscous regularisation yields convergent numerical results. We will compare linearisation methods (consistent tangent, effective viscosity) and discuss the implementation of rheological models (power-law viscous, hardening/softening laws). We will also present three-dimensional models of crustal-scale strain localisation that benefit from both the above-described methods and the computing power of graphical processing units (GPUs).</div>

scholarly journals Star Formation from Turbulent Fragmentation

2003 ◽  
Vol 208 ◽  
pp. 61-70
Author(s):  
Ralf S. Klessen
Keyword(s):  
Mass Spectrum ◽  
Star Formation ◽  
Numerical Models ◽  
Three Dimensional ◽  
Dynamical Evolution ◽  
Small Scale ◽  
Solar Mass ◽  
Low Efficiency ◽  
Three Dimensional Models ◽  
Log Normal

Star formation is intimately linked to the dynamical evolution of molecular clouds. Turbulent fragmentation determines where and when protostellar cores form, and how they contract and grow in mass via accretion from the surrounding cloud material. Using numerical models of self-gravitating supersonic turbulence, efficiency, spatial distribution and timescale of star formation in turbulent interstellar clouds are estimated. Turbulence that is not continuously replenished or that is driven on large scales leads to a rapid formation of stars in a clustered mode, whereas interstellar turbulence that carries most energy on small scales results in isolated star formation with low efficiency. The clump mass spectrum for models of pure hydrodynamic turbulence is steeper than the observed one, but gets close to it when gravity is included. The mass spectrum of dense cores is log-normal for decaying and large-wavelength turbulence, similar to the IMF, but is too flat in the case of small-scale turbulence. The three-dimensional models of molecular cloud fragmentation can be combined with dynamical pre-main sequence stellar evolution calculations to obtain a consistent description of all phases of the star formation process. First results are reported for a one solar mass protostar.

scholarly journals Three-dimensional model of the Rzeczka object (the Riese Complex, Sowie Range) as an enhancement of the comprehensive geotourism potential of an underground tourist route

2018 ◽  
Vol 55 ◽  
pp. 00015
Author(s):  
Katarzyna Kądziołka ◽  
Damian Kasza ◽  
Wojciech J. Milczarek
Keyword(s):  
Laser Scanning ◽  
Numerical Models ◽  
Three Dimensional ◽  
Point Clouds ◽  
Digital Data ◽  
Measurement Technology ◽  
Three Dimensional Model ◽  
Historic Areas ◽  
The Creation ◽  
Three Dimensional Models

The dynamic development of measurement technology based on the use of laser scanners allows for fast transfer of information, related to terrestrial data, to a virtual environment and enables the creation of three-dimensional models. Because of the growing demand for underground areas inventory, especially historic areas, the creation of 3D numerical models increases in popularity. It allows to increase the geotouristic potential of a particular area and to use solutions in support of the safety of tourists as well as the safety of area itself. The development of the terrestrial laser scanning technique is accompanied simultaneously by the development of means of digital data processing that was obtained in the form of point clouds. Those means use the commercial software as well as software available in the open source system. Both computing environments use algorithms enabling the processing of huge collections of points in automatized mode by using a number of open-access algorithms either freeware or dedicated. The methodology of numerical models development, described in this article, has been presented on the example of underground object “Rzeczka” (“Riese” Complex) located at the Sowie Range (SW Poland).

scholarly journals Numerical Study of the Biomechanical Behaviour of the Different Implantation Methods of the Reverse Shoulder Replacement

2019 ◽  
Vol 43 ◽  
pp. 54-66
Author(s):  
Salah Mebarki ◽  
Benaoumeur Aour ◽  
Malachanne Etienne ◽  
Franck Jourdan ◽  
Abdel Hakem Belaghit ◽  
...  
Keyword(s):  
Numerical Study ◽  
Numerical Models ◽  
Total Shoulder Arthroplasty ◽  
Three Dimensional ◽  
Shoulder Prosthesis ◽  
Three Dimensional Model ◽  
Biomechanical Behavior ◽  
Three Dimensional Models ◽  
Reverse Shoulder Replacement ◽  
Reverse Total Shoulder

Despite the widespread use of reverse total shoulder arthroplasty, there is still a problem of conflict between the polyethylene cup of the prosthesis and the scapula, which over time causes the phenomenon of notching. In order to circumvent this problem correctly, several innovations have been proposed regard to the implementation method. In this context, the aim of this work is to study the biomechanical behavior of new implantation methods using different glenoid configurations in order to avoid the notching phenomenon between the cup and the scapula. The study was performed using virtual prototypes of the shoulder prosthesis assembly. Using CT scan images, three-dimensional models of shoulder bones were reconstructed. The implantation of the prosthesis in the three-dimensional model was performed in collaboration with an experienced surgeon from the Caduceus Clinic (Oran, Algeria). The numerical models were imported to finite element calculation software. After the validation of the numerical model using the literature results, we assessed the biomechanical behavior of four implantation methods under the same boundary conditions and abduction movements. From the obtained results, it was found that among the proposed methods, the BIO-SR lateralization method offers significant biomechanical advantages in terms of the forces applied to the glenoid during the abduction movement.

Comparison of Magnetic Field Parameters Obtained from 2D and 3D Finite Element Analysis for an Active Magnetic Bearing

2014 ◽  
Vol 214 ◽  
pp. 130-137 ◽  
Author(s):  
Dawid Wajnert
Keyword(s):  
Magnetic Field ◽  
Finite Element ◽  
Numerical Models ◽  
Three Dimensional ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Element Analysis ◽  
3 Dimensional ◽  
Three Dimensional Models ◽  
Magnetic Field Computation

The paper presents numerical modeling of 8-pole radial active magnetic bearing based on 2-dimensional and 3-dimensional magnetic field computation with nonlinear characteristic of magnetic material. In this work has been used numerical models based on finite element methods. In paper has been specified differences between two and three dimensional models. Results of numerical calculation have been verified by measurement of magnetic field distribution and inductances of windings.

scholarly journals A fault-tolerant non-Clifford gate for the surface code in two dimensions

2020 ◽  
Vol 6 (21) ◽  
pp. eaay4929 ◽  
Author(s):  
Benjamin J. Brown
Keyword(s):  
Fault Tolerant ◽  
Error Correcting Code ◽  
Three Dimensional ◽  
Logic Gates ◽  
Two Dimensions ◽  
Two Dimensional ◽  
Decoding Algorithms ◽  
Future Technology ◽  
Surface Code ◽  
Three Dimensional Models

Fault-tolerant logic gates will consume a large proportion of the resources of a two-dimensional quantum computing architecture. Here we show how to perform a fault-tolerant non-Clifford gate with the surface code; a quantum error-correcting code now under intensive development. This alleviates the need for distillation or higher-dimensional components to complete a universal gate set. The operation uses both local transversal gates and code deformations over a time that scales with the size of the qubit array. An important component of the gate is a just-in-time decoder. These decoding algorithms allow us to draw upon the advantages of three-dimensional models using only a two-dimensional array of live qubits. Our gate is completed using parity checks of weight no greater than four. We therefore expect it to be amenable with near-future technology. As the gate circumvents the need for magic-state distillation, it may reduce the resource overhead of surface-code quantum computation considerably.

scholarly journals Back calculation of the In den Arelen avalanche with RAMMS: interpretation of model results

2010 ◽  
Vol 51 (54) ◽  
pp. 161-168 ◽  
Author(s):  
Marc Christen ◽  
Perry Bartelt ◽  
Julia Kowalski
Keyword(s):  
Numerical Models ◽  
Three Dimensional ◽  
Dynamics Simulation ◽  
Model Specification ◽  
Hazard Mapping ◽  
Avalanche Dynamics ◽  
Solution Methods ◽  
Simulation Results ◽  
Dimensional Models ◽  
Friction Parameters

AbstractTwo- and three-dimensional avalanche dynamics models are being increasingly used in hazard-mitigation studies. These models can provide improved and more accurate results for hazard mapping than the simple one-dimensional models presently used in practice. However, two- and three-dimensional models generate an extensive amount of output data, making the interpretation of simulation results more difficult. To perform a simulation in three-dimensional terrain, numerical models require a digital elevation model, specification of avalanche release areas (spatial extent and volume), selection of solution methods, finding an adequate calculation resolution and, finally, the choice of friction parameters. In this paper, the importance and difficulty of correctly setting up and analysing the results of a numerical avalanche dynamics simulation is discussed. We apply the two-dimensional simulation program RAMMS to the 1968 extreme avalanche event In den Arelen. We show the effect of model input variations on simulation results and the dangers and complexities in their interpretation.

"Barbs" for river bend bank protection: application of a three-dimensional numerical model

2007 ◽  
Vol 34 (9) ◽  
pp. 1087-1095 ◽  
Author(s):  
B Minor ◽  
C D Rennie ◽  
R D Townsend
Keyword(s):  
Sediment Transport ◽  
Numerical Model ◽  
Flow Field ◽  
Numerical Models ◽  
Laboratory Data ◽  
Three Dimensional ◽  
Channel Bend ◽  
Bank Protection ◽  
Three Dimensional Models ◽  
Movable Bed

A three-dimensional numerical model was used to examine the turbulent flow field and associated sediment transport due to a series of barbs (submerged groynes) in a channel bend. Model results were in good agreement with measured laboratory data and adequately simulated the important features of sediment transport. Statistical comparison of the predicted and measured equilibrium bed geometry found average regression coefficients of determination of 0.77 and 0.72 for the 90° and 135° channels, respectively. The predicted velocity data followed expected trends. The capability of a three-dimensional numerical model to simulate sediment transport through bend sections of a channel containing barbs was verified. This included the simulation of the effects of different arrangements of barb groups and an analysis of the data to determine the relation of the flow field to associated scour and deposition in a complex fluvial environment. These novel results are useful for improved analyses of the bank-protection capabilities of these structures and for the development and improvement of design guidelines.Key words: three-dimensional models, numerical models, movable bed models, channel bends, turbulence, secondary flow, scour, barbs, groynes.

Laser Scanning Confocal Microscopy and Three-Dimesnsional Reconstruction of the Mitotic Spindles of Unequally Dividing Embryonic Cells

1990 ◽  
Vol 48 (3) ◽  
pp. 166-167
Author(s):  
J. Holy ◽  
G. Schatten
Keyword(s):  
Confocal Microscopy ◽  
Mitotic Spindle ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Laser Scanning Confocal Microscopy ◽  
Two Dimensions ◽  
Embryonic Cells ◽  
Mitotic Spindles ◽  
Cleavage Division ◽  
Scanning Confocal Microscopy

One of the classic limitations of light microscopy has been the fact that three dimensional biological events could only be visualized in two dimensions. Recently, this shortcoming has been overcome by combining the technologies of laser scanning confocal microscopy (LSCM) and computer processing of microscopical data by volume rendering methods. We have employed these techniques to examine morphogenetic events characterizing early development of sea urchin embryos. Specifically, the fourth cleavage division was examined because it is at this point that the first morphological signs of cell differentiation appear, manifested in the production of macromeres and micromeres by unequally dividing vegetal blastomeres.The mitotic spindle within vegetal blastomeres undergoing unequal cleavage are highly polarized and develop specialized, flattened asters toward the micromere pole. In order to reconstruct the three-dimensional features of these spindles, both isolated spindles and intact, extracted embryos were fluorescently labeled with antibodies directed against either centrosomes or tubulin.

Plastic replicas as three-dimensional models of pulps

1975 ◽  
Vol 39 (8) ◽  
pp. 544-546
Author(s):  
HL Wakkerman ◽  
GS The ◽  
AJ Spanauf
Keyword(s):  
Three Dimensional ◽  
Dimensional Models ◽  
Three Dimensional Models

Validation of a Belt Model for Prediction of Hub Forces from a Rolling Tire4

2009 ◽  
Vol 37 (2) ◽  
pp. 62-102 ◽  
Author(s):  
C. Lecomte ◽  
W. R. Graham ◽  
D. J. O’Boy
Keyword(s):  
Internal Pressure ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Prediction Method ◽  
Analytical Models ◽  
Beam Model ◽  
Impedance Boundary ◽  
Bending Waves ◽  
Tire Rotation ◽  
Three Dimensional Models

Abstract An integrated model is under development which will be able to predict the interior noise due to the vibrations of a rolling tire structurally transmitted to the hub of a vehicle. Here, the tire belt model used as part of this prediction method is first briefly presented and discussed, and it is then compared to other models available in the literature. This component will be linked to the tread blocks through normal and tangential forces and to the sidewalls through impedance boundary conditions. The tire belt is modeled as an orthotropic cylindrical ring of negligible thickness with rotational effects, internal pressure, and prestresses included. The associated equations of motion are derived by a variational approach and are investigated for both unforced and forced motions. The model supports extensional and bending waves, which are believed to be the important features to correctly predict the hub forces in the midfrequency (50–500 Hz) range of interest. The predicted waves and forced responses of a benchmark structure are compared to the predictions of several alternative analytical models: two three dimensional models that can support multiple isotropic layers, one of these models include curvature and the other one is flat; a one-dimensional beam model which does not consider axial variations; and several shell models. Finally, the effects of internal pressure, prestress, curvature, and tire rotation on free waves are discussed.

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