scholarly journals TOPOGRAPHIC CHANGES IN THE SURF ZONE PROFILE

1966 ◽  
Vol 1 (10) ◽  
pp. 30 ◽  
Author(s):  
Choule J. Sonu ◽  
Richard J. Russell
Keyword(s):  
North Carolina ◽  
Surf Zone ◽  
Three Dimensional ◽  
Vertical Plane ◽  
Normal Wave ◽  
Field Investigation ◽  
Dimensional Approach ◽  
Outer Banks ◽  
Plane Normal ◽  
The Waves

The conventional method of dealing with relationships between wave action and topographic response on a beach is to reduce the problem to a two-dimensional scheme that regards basic processes as taking place in a vertical plane normal to the shoreline. This scheme is valid only if the waves arrive at right angles to the shore and the nearshore contours are reasonably straight and parallel the beach. As these conditions are not realized in many cases another analytical method is necessary - one that recognizes effects of other than normal wave arrival and systematic patterns of diversification in nearshore topography. This study, based on a long period of field investigation on the Outer Banks, North Carolina, examines a three-dimensional approach. Observations from a long pier were used to explain nearshore topographic diversification and resulted in conclusions that were confirmed by subsequent field observation.

Three-dimensional flow due to a microcantilever oscillating near a wall: an unsteady slender-body analysis

2006 ◽  
Vol 462 (2067) ◽  
pp. 913-933 ◽  
Author(s):  
R.J Clarke ◽  
O.E Jensen ◽  
J Billingham ◽  
P.M Williams
Keyword(s):  
Three Dimensional ◽  
Vertical Plane ◽  
Circular Cross Section ◽  
Slender Body ◽  
Order Effects ◽  
End Effects ◽  
Dimensional Flow ◽  
Plane Normal ◽  
Two Dimensional Flow ◽  
Resistive Force Theory

We compute the drag on a slender rigid cylinder, of uniform circular cross-section, oscillating in a viscous fluid at small amplitude near a horizontal wall. The cylinder's axis lies at an angle α to the horizontal and the cylinder oscillates in a vertical plane normal to either the wall or its own axis. The flow is described using an unsteady slender-body approximation, which we treat both numerically and using an iterative scheme that extends resistive-force theory to account for the leading-order effects of unsteady inertia and the wall. When α is small, two independent screening mechanisms are identified which suppress end-effects and produce approximately two-dimensional flow along the majority of the cylinder; however, three-dimensional effects influence the drag at larger tilt angles.

scholarly journals A FIELD INVESTIGATION OF SAND TRANSPORT IN THE SURF ZONE

1968 ◽  
Vol 1 (11) ◽  
pp. 22 ◽  
Author(s):  
Edward B. Thornton
Keyword(s):  
Energy Flux ◽  
Particle Motion ◽  
Field Experiments ◽  
Surf Zone ◽  
Field Investigation ◽  
Energy Spectra ◽  
Sand Transport ◽  
Bed Load ◽  
Water Particle ◽  
The Waves

The distribution of bed-load sand transport normal to the beach has been measured m a series of field experiments conducted in the surf zone at Fernandma Beach, Florida. Simultaneous measurements were made of the waves and water particle motion at various locations in the surf zone. The energy flux of the waves was resolved Into Its longshore component from the measured directional and energy spectra. It Is found that the bed-load transport is related to the depth of water and longshore energy flux. Insight into the mechanics of sediment transport is obtained by comparing the wave and water particle motion energy spectra, which give a direct measure of the kinetic and potential energy, at various locations in the surf zone.

MULTISPECTRAL ELECTROMAGNETIC EXPLORATION FOR SULFIDES

Geophysics ◽  
1974 ◽  
Vol 39 (5) ◽  
pp. 666-682 ◽  
Author(s):  
S. H. Ward ◽  
D. F. Pridmore ◽  
L. Rijo ◽  
W. E. Glenn
Keyword(s):  
Tilt Angle ◽  
Three Dimensional ◽  
Vertical Plane ◽  
Major Axis ◽  
Test Site ◽  
Electromagnetic System ◽  
Plane Normal ◽  
Plane Passing ◽  
Comparison Of The Results ◽  
Phase Sensitive Detector

A 14 frequency electromagnetic system has been developed and applied to continuous sounding‐profiling over the two sulfide deposits of the Cavendish Test Site in Ontario, Canada. The tilt of the major axis, tilt angle, and the ratio of minor to major axis, ellipticity, of the ellipse of magnetic field polarization are measured over the frequency range 10.5 hz to 86,016 hz. A dual coil receiver employing a phase‐sensitive detector has been used to measure tilt angle and ellipticity with three transmitter configurations along a single traverse line of the Cavendish test site. These different transmitting coil configurations are referred to as horizontal coil, vertical axial coil, and vertical rotating coil. In the horizontal coil configuration, tilt angle and ellipticity are measured in the vertical plane passing through the axis of a horizontal transmitting coil. In the vertical axial coil configuration, tilt angle and ellipticity are measured in the vertical plane which passes through the axis of a vertical transmitting coil; the axis of the transmitting coil is oriented normal to the strike of the subsurface conductivity inhomogeneity. Finally, in the vertical rotating coil configuration, the transmitting coil is located along strike from the traverse over the conductivity inhomogeneity and rotated to contain each point of observation in turn; measurements of tilt angle and ellipticity are made in a vertical plane normal to the plane of the transmitting coil. The limitations of single‐body interpretation schemes are illustrated by the data. Recourse to calculation of scattering by two‐ and three‐dimensional complex environments will be required to provide any sort of full interpretation of these data from one simple Precambrian geologic setting. A comparison of the results for the three transmitting coil configurations indicates that the vertical axial coil configuration is least sensitive to overburden and host rock, while adequately responsive to concentrated and disseminated sulfides.

Reconstruction of Objects from their Projections Using Orthogonal Functions

1973 ◽  
Vol 31 ◽  
pp. 268-269
Author(s):  
Elrnar Zeitler
Keyword(s):  
Unit Area ◽  
Three Dimensional ◽  
One Dimension ◽  
Spatial Density ◽  
Dimensional Representation ◽  
Orthogonal Functions ◽  
Object A ◽  
Plane Normal ◽  
Dimensional Object ◽  
Spatial Density Distribution

Considering any finite three-dimensional object, a “projection” is here defined as a two-dimensional representation of the object's mass per unit area on a plane normal to a given projection axis, here taken as they-axis. Since the object can be seen as being built from parallel, thin slices, the relation between object structure and its projection can be reduced by one dimension. It is assumed that an electron microscope equipped with a tilting stage records the projectionWhere the object has a spatial density distribution p(r,ϕ) within a limiting radius taken to be unity, and the stage is tilted by an angle 9 with respect to the x-axis of the recording plane.

Shifting perspectives: method, media and the complex image

1998 ◽  
Vol 10 (1-3) ◽  
pp. 100-108 ◽  
Author(s):  
Alicia Colson ◽  
Ross Parry
Keyword(s):  
Image Processing ◽  
Three Dimensional ◽  
Geographical Location ◽  
Spatial Relationship ◽  
Two Dimensional ◽  
Dimensional Approach ◽  
Complex Image ◽  
Cultural Resonance

This article argues that the analysis of a threedimensional image demanded a three-dimensional approach. The authors realise that discussions of images and image processing inveterately conceptualise representation as being flat, static, and finite. The authors recognise the need for a fresh acuteness to three-dimensionality as a meaningful – although problematic – element of visual sources. Two dramatically different examples are used to expose the shortcomings of an ingrained two-dimensional approach and to facilitate a demonstration of how modern (digital) techniques could sanction new historical/anthropological perspectives on subjects that have become all too familiar. Each example could not be more different in their temporal and geographical location, their cultural resonance, and their historiography. However, in both these visual spectacles meaning is polysemic. It is dependent upon the viewer's spatial relationship to the artifice as well as the spirito-intellectual viewer within the community. The authors postulate that the multi- faceted and multi-layered arrangement of meaning in a complex image could be assessed by working beyond the limitations of the two-dimensional methodological paradigm and by using methods and media that accommodated this type of interconnectivity and representation.

scholarly journals Development and Validation of Quasi-Eulerian Mean Three-Dimensional Equations of Motion Using the Generalized Lagrangian Mean Method

2021 ◽  
Vol 9 (1) ◽  
pp. 76
Author(s):  
Duoc Nguyen ◽  
Niels Jacobsen ◽  
Dano Roelvink
Keyword(s):  
Surface Waves ◽  
Deep Water ◽  
Surf Zone ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Breaking Waves ◽  
Successful Implementation ◽  
Random Waves ◽  
Mean Motion ◽  
Generalized Lagrangian

This study aims at developing a new set of equations of mean motion in the presence of surface waves, which is practically applicable from deep water to the coastal zone, estuaries, and outflow areas. The generalized Lagrangian mean (GLM) method is employed to derive a set of quasi-Eulerian mean three-dimensional equations of motion, where effects of the waves are included through source terms. The obtained equations are expressed to the second-order of wave amplitude. Whereas the classical Eulerian-mean equations of motion are only applicable below the wave trough, the new equations are valid until the mean water surface even in the presence of finite-amplitude surface waves. A two-dimensional numerical model (2DV model) is developed to validate the new set of equations of motion. The 2DV model passes the test of steady monochromatic waves propagating over a slope without dissipation (adiabatic condition). This is a primary test for equations of mean motion with a known analytical solution. In addition to this, experimental data for the interaction between random waves and a mean current in both non-breaking and breaking waves are employed to validate the 2DV model. As shown by this successful implementation and validation, the implementation of these equations in any 3D model code is straightforward and may be expected to provide consistent results from deep water to the surf zone, under both weak and strong ambient currents.

A three dimensional approach for quantifying resultant loading at the knee

The Knee ◽  
2017 ◽  
Vol 24 (1) ◽  
pp. 31-39 ◽  
Author(s):  
Ryan T. Lewinson ◽  
Chad P. Maag ◽  
Victor M.Y. Lun ◽  
J. Preston Wiley ◽  
Chirag Patel ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Dimensional Approach
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