Three-Dimensional Magnetic Model with Classical Spins of High Dimensionality

1969 ◽  
Vol 183 (2) ◽  
pp. 562-566 ◽  
Author(s):  
Eugene Helfand
Keyword(s):  
Three Dimensional ◽  
High Dimensionality ◽  
Magnetic Model

Earthquakes and Plutons in the Midcontinent - Evidence From the Bloomfield Pluton, New Madrid Rift Complex

1987 ◽  
Vol 58 (2) ◽  
pp. 41-52 ◽  
Author(s):  
D. N. Ravat ◽  
L. W. Braile ◽  
W. J. Hinze
Keyword(s):  
Country Rock ◽  
Three Dimensional ◽  
The Body ◽  
Seismic Zone ◽  
Gravity And Magnetic ◽  
Magnetic Model ◽  
Dimensional Gravity ◽  
Constant Distance ◽  
Gravity And Magnetic Anomaly ◽  
New Madrid

Abstract A three-dimensional gravity and magnetic model of the Bloomfield Pluton near New Madrid, Missouri, has been generated that provides an excellent match to the observed gravity and magnetic anomaly maps. Although this modeling is inherently non-unique, the steep gradients on the flanks of the anomalies constrain the causative body to a relatively shallow depth (≈2 km) and define the outline of the steep-sided (near-vertical) pluton. Comparison of the configuration of the Bloomfield Pluton with concentrated microearthquake seismicity in part of the New Madrid Seismic Zone indicates that earthquakes in the northern part of the zone occur primarily on the southeastern side of the pluton at about 10 km from the edge of the body. Based on the location of hypocenters and earthquake focal mechanisms, there is no evidence that stress concentration associated with the mass excess of the pluton is the cause of earthquakes near the pluton. The seismicity may be along zones of weakness independent of the pluton. Among other explanations investigated to explain the constant distance of earthquakes from the pluton, we favor the possibility of a zone of rigidity contrast caused by the thermal metamorphism of the country rock associated with the pluton intrusion. We have estimated increased temperatures of the country rock using an instantaneous intrusion model. Maximum anomalous country rock temperatures of greater than 100°C dominated the region within 10 km of the pluton edge. This ‘thermally metamorphosed’ aureole may provide sufficient homogeneity in the upper crust to localize anomalous stresses away from the margin and along the most favorable zones of weakness, thus influencing the locations of earthquakes.

Magnetic models of the Moyie anticline, Purcell anticlinorium, southeastern Canadian Cordillera

2015 ◽  
Vol 52 (6) ◽  
pp. 368-385 ◽  
Author(s):  
Michael D. Thomas
Keyword(s):  
3D Model ◽  
Three Dimensional ◽  
Structural Data ◽  
High Density ◽  
Data Modelling ◽  
Near Surface ◽  
Reflection Seismic ◽  
The Core ◽  
Magnetic Model ◽  
Drill Holes

Two-dimensional magnetic models of the Moyie anticline contribute to an independent project targeting development of a regional three-dimensional (3D) model of much of the Purcell anticlinorium by compensating for shortcomings in reflection seismic signatures and distributions of drill holes and surface structural data. Modelling has focused on prominent anomalies related to relatively strong magnetizations within the Creston Formation and Moyie sills. Models of the western flank of the anticline indicate the Creston Formation forms the bulk of a westward-thickening, wedge-shaped sedimentary package whose west-dipping layers are truncated by a steeply west-dipping Moyie fault, truncating also Moyie sills on the opposite side. Near-surface dips of the fault range from 54° to 87°. Stratigraphic comparisons across the fault indicate minimum reverse dip displacements ranging from 5.6 to 8.5 km. The eastern flank of the Moyie anticline is modelled consistently as a monoclinal, eastward-dipping stratigraphic package comprising mainly Lower Aldridge Formation (with intruded Moyie sills) through Kitchener Formation, in general accord with geological models. One magnetic model, however, shows stratigraphy disrupted by shallow thrust faults, above which a series of near-vertical blocks is modelled. The Yahk River syncline is modelled as a symmetrical fold having an axial depth of 4.2 km to the top of the Upper Aldridge Formation. Collectively, the models outline a broad domal pattern of Moyie sills in the core of the anticline to 12 km depth, supporting a proposal that a gravity high correlating with the Moyie anticline relates to high-density Moyie sills at relatively shallow depths, rather than deeper high-density basement.

scholarly journals Bayesian Random Tomography of Particle Systems

2021 ◽  
Vol 8 ◽  
Author(s):  
Nima Vakili ◽  
Michael Habeck
Keyword(s):  
Monte Carlo ◽  
Three Dimensional ◽  
Sampling Strategy ◽  
Particle Systems ◽  
High Dimensionality ◽  
Monte Carlo Algorithms ◽  
Posterior Sampling ◽  
Imaging Science ◽  
Speed Up ◽  
Projection Images

Random tomography is a common problem in imaging science and refers to the task of reconstructing a three-dimensional volume from two-dimensional projection images acquired in unknown random directions. We present a Bayesian approach to random tomography. At the center of our approach is a meshless representation of the unknown volume as a mixture of spherical Gaussians. Each Gaussian can be interpreted as a particle such that the unknown volume is represented by a particle cloud. The particle representation allows us to speed up the computation of projection images and to represent a large variety of structures accurately and efficiently. We develop Markov chain Monte Carlo algorithms to infer the particle positions as well as the unknown orientations. Posterior sampling is challenging due to the high dimensionality and multimodality of the posterior distribution. We tackle these challenges by using Hamiltonian Monte Carlo and a global rotational sampling strategy. We test the approach on various simulated and real datasets.

scholarly journals Derivation and analysis of coupled PDEs on manifolds with high dimensionality gap arising from topological model reduction

2019 ◽  
Vol 53 (6) ◽  
pp. 2047-2080 ◽  
Author(s):  
Federica Laurino ◽  
Paolo Zunino
Keyword(s):  
Partial Differential Equations ◽  
Differential Equations ◽  
Model Reduction ◽  
Three Dimensional ◽  
Multiscale Methods ◽  
High Dimensionality ◽  
Topological Model ◽  
Modeling Error ◽  
Partial Differential ◽  
Coupled Partial Differential Equations

Multiscale methods based on coupled partial differential equations defined on bulk and embedded manifolds are still poorly explored from the theoretical standpoint, although they are successfully used in applications, such as microcirculation and flow in perforated subsurface reservoirs. This work aims at shedding light on some theoretical aspects of a multiscale method consisting of coupled partial differential equations defined on one-dimensional domains embedded into three-dimensional ones. Mathematical issues arise because the dimensionality gap between the bulk and the inclusions is larger than one, that is the high dimensionality gap case. First, we show that such model derives from a system of fully three-dimensional equations, by the application of a topological model reduction approach. Secondly, we rigorously analyze the problem, showing that the averaging operators applied for the model reduction introduce a regularization effect that resolves the issues due to the singularity of solutions and to the ill-posedness of restriction operators. Then, we exploit the structure of the model reduction technique to analyze the modeling error. This study confirms that for infinitesimally small inclusions, the modeling error vanishes. Finally, we discretize the problem by means of the finite element method and we analyze the approximation and the model error by means of numerical experiments.

scholarly journals Plurigon: three dimensional visualization and classification of high-dimensionality data

2013 ◽  
Vol 4 ◽  
Author(s):  
Bronwen Martin ◽  
Hongyu Chen ◽  
Caitlin M. Daimon ◽  
Wayne Chadwick ◽  
Sana Siddiqui ◽  
...  
Keyword(s):  
Three Dimensional ◽  
High Dimensionality

The orbit of Pluto over a long interval of time

1966 ◽  
Vol 25 ◽  
pp. 227-229 ◽  
Author(s):  
D. Brouwer
Keyword(s):  
Periodic Orbit ◽  
Numerical Integration ◽  
Restricted Problem ◽  
Three Dimensional ◽  
The Third ◽  
Circular Restricted Problem ◽  
Resonance Relation

The paper presents a summary of the results obtained by C. J. Cohen and E. C. Hubbard, who established by numerical integration that a resonance relation exists between the orbits of Neptune and Pluto. The problem may be explored further by approximating the motion of Pluto by that of a particle with negligible mass in the three-dimensional (circular) restricted problem. The mass of Pluto and the eccentricity of Neptune's orbit are ignored in this approximation. Significant features of the problem appear to be the presence of two critical arguments and the possibility that the orbit may be related to a periodic orbit of the third kind.

Conformation of Ribosomes from Escherichia Coli

1974 ◽  
Vol 32 ◽  
pp. 210-211
Author(s):  
M. Boublik ◽  
W. Hellmann ◽  
F. Jenkins
Keyword(s):  
Binding Sites ◽  
Ribosomal Proteins ◽  
Fluorescent Dyes ◽  
Protein Biosynthesis ◽  
Three Dimensional ◽  
Spatial Arrangement ◽  
Dimensional Structure ◽  
Complete Understanding ◽  
And Function

The present knowledge of the three-dimensional structure of ribosomes is far too limited to enable a complete understanding of the various roles which ribosomes play in protein biosynthesis. The spatial arrangement of proteins and ribonuclec acids in ribosomes can be analysed in many ways. Determination of binding sites for individual proteins on ribonuclec acid and locations of the mutual positions of proteins on the ribosome using labeling with fluorescent dyes, cross-linking reagents, neutron-diffraction or antibodies against ribosomal proteins seem to be most successful approaches. Structure and function of ribosomes can be correlated be depleting the complete ribosomes of some proteins to the functionally inactive core and by subsequent partial reconstitution in order to regain active ribosomal particles.

Ultrastructural Investigations of the Contractile Filaments of Amoebae

1974 ◽  
Vol 32 ◽  
pp. 188-189
Author(s):  
P.L. Moore
Keyword(s):  
Cytoplasmic Streaming ◽  
Three Dimensional ◽  
Freeze Fracture ◽  
Amoeboid Movement ◽  
Different Types ◽  
Chemical Conditions ◽  
Complete Interpretation

Previous freeze fracture results on the intact giant, amoeba Chaos carolinensis indicated the presence of a fibrillar arrangement of filaments within the cytoplasm. A complete interpretation of the three dimensional ultrastructure of these structures, and their possible role in amoeboid movement was not possible, since comparable results could not be obtained with conventional fixation of intact amoebae. Progress in interpreting the freeze fracture images of amoebae required a more thorough understanding of the different types of filaments present in amoebae, and of the ways in which they could be organized while remaining functional.The recent development of a calcium sensitive, demembranated, amoeboid model of Chaos carolinensis has made it possible to achieve a better understanding of such functional arrangements of amoeboid filaments. In these models the motility of demembranated cytoplasm can be controlled in vitro, and the chemical conditions necessary for contractility, and cytoplasmic streaming can be investigated. It is clear from these studies that “fibrils” exist in amoeboid models, and that they are capable of contracting along their length under conditions similar to those which cause contraction in vertebrate muscles.

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