Design of non-singular two-dimensional layered cloaks mapped from small areas

2016 ◽  
Author(s):  
Fabio J. F. Goncalves ◽  
Elson J. Silva ◽  
Renato C. Mesquita
Keyword(s):  
Two Dimensional ◽  
Small Areas

Maximum Crest Heights Over an Area and the Air Gap Problem

2006 ◽  
Author(s):  
George Z. Forristall
Keyword(s):  
Numerical Simulations ◽  
Single Point ◽  
Ocean Waves ◽  
The Other ◽  
Wave Crest ◽  
Two Dimensional ◽  
Extreme Wave ◽  
Small Areas ◽  
Dimensional Version ◽  
Crest Height

Ocean waves are dispersive and directionally spread, changing size and shape as they propagate. Therefore the maximum crest height over an area in a given length of time will be larger than the maximum crest at a single point. Extreme crest heights are usually calculated from single point statistics, but the designer of a platform is really interested in the probability of a wave crest reaching any part of the deck area. Statistics for the maximum crest over an area have been developed using a combination of analytic theory and numerical simulations. The resulting crest heights are significantly higher than given by point statistics even for relatively small areas. On the other hand, only a small fraction of the deck may be inundated. That fraction can be estimated by a applying a two dimensional version of the NewWave method that finds the most probable shape of an extreme wave.

Supersonic Nozzle Design

1946 ◽  
Vol 13 (4) ◽  
pp. A265-A270 ◽  
Author(s):  
A. E. Puckett
Keyword(s):  
Flow Field ◽  
Method Of Characteristics ◽  
Supersonic Nozzle ◽  
Approximate Solutions ◽  
Two Dimensional ◽  
Nozzle Design ◽  
Small Areas ◽  
Engineering Problems ◽  
Two Dimensional Flow ◽  
Flow Changes

Abstract A two-dimensional flow field in which the velocity is everywhere supersonic can always be represented approximately by a number of small adjacent quadrilateral flow fields in each of which the velocity and pressure are constant. These quadrilaterals must be separated by lines representing waves in the flow; changes in velocity and pressure through any wave can be computed. By increasing the number of small areas into which the complete flow field is divided, the accuracy of this approximate solutions may be increased without limit. This constitutes the “method of characteristics” solution, which has been known for many years. This method may be applied to the graphical computation of flow in a supersonic nozzle, with the particular aim of producing uniform supersonic flow at the end of the nozzle. It is pointed out that such a computation is essentially simple and rapid, and its essential features are presented in a form which, it is hoped, may be easily applied to engineering problems.

Design of Non-Singular Two-Dimensional Layered Cloaks Mapped from Small Areas

2017 ◽  
pp. 1-1 ◽  
Author(s):  
Fabio J. F. Goncalves ◽  
Elson J. Silva ◽  
Renato C. Mesquita
Keyword(s):  
Two Dimensional ◽  
Small Areas

Two Dimensional Transient Analysis of Temperature Distribution in a Solid Irradiated by a Gaussian Laser Source

Volume 1 ◽  
2004 ◽  
Author(s):  
Nicola Bianco ◽  
Oronzio Manca ◽  
Sergio Nardini
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Laser Source ◽  
Thermal Gradients ◽  
Two Dimensional ◽  
Gaussian Laser Beam ◽  
Steady State Condition ◽  
Small Areas ◽  
Variable Heat

The use of localized heat source, such as lasers and electron beams, in many manufacturing processes has received a lot of attention in last years. This is due to their versatility and to the possibility to concentrate high powers over small areas. In this paper the transient two dimensional thermal field in a solid irradiated by a moving Gaussian laser beam has been numerically analyzed. The numerical simulation allows for both surface heat losses, convective and radiative, and variable thermophysical properties. Three cases are considered: one is related to an adiabatic workpiece, the other two to a diabatic workpiece with a constant or variable heat transfer coefficient on the upper and lower surfaces. Results show that a local quasi-steady state condition is reached after a time that is much larger when the solid is adiabatic than the cases with constant or variable heat transfer coefficient. Thermal gradients along the depth decrease as z and x coordinates increase.

Spectrophotometric measurements of objective-prism spectra

1966 ◽  
Vol 24 ◽  
pp. 118-119
Author(s):  
Th. Schmidt-Kaler
Keyword(s):  
Progress Report ◽  
Two Dimensional ◽  
Objective Prism ◽  
Made In

I should like to give you a very condensed progress report on some spectrophotometric measurements of objective-prism spectra made in collaboration with H. Leicher at Bonn. The procedure used is almost completely automatic. The measurements are made with the help of a semi-automatic fully digitized registering microphotometer constructed by Hög-Hamburg. The reductions are carried out with the aid of a number of interconnected programmes written for the computer IBM 7090, beginning with the output of the photometer in the form of punched cards and ending with the printing-out of the final two-dimensional classifications.

Introductory paper

1966 ◽  
Vol 24 ◽  
pp. 3-5
Author(s):  
W. W. Morgan
Keyword(s):  
Line Intensity ◽  
Classification Scheme ◽  
Two Dimensional ◽  
Spectral Classification ◽  
Dimensional Array ◽  
Rr Lyrae ◽  
Metallic Line ◽  
Introductory Paper ◽  
Parameter Varying ◽  
Definition Of

1. The definition of “normal” stars in spectral classification changes with time; at the time of the publication of theYerkes Spectral Atlasthe term “normal” was applied to stars whose spectra could be fitted smoothly into a two-dimensional array. Thus, at that time, weak-lined spectra (RR Lyrae and HD 140283) would have been considered peculiar. At the present time we would tend to classify such spectra as “normal”—in a more complicated classification scheme which would have a parameter varying with metallic-line intensity within a specific spectral subdivision.

A one-dimensional self-gravitating stellar gas

1966 ◽  
Vol 25 ◽  
pp. 46-48 ◽  
Author(s):  
M. Lecar
Keyword(s):  
Gravitational Field ◽  
Phase Space ◽  
Motion Picture ◽  
Space Distribution ◽  
Two Dimensional ◽  
One Dimensional ◽  
Phase Space Distribution ◽  
Dimensional Phase Space ◽  
The Mean

“Dynamical mixing”, i.e. relaxation of a stellar phase space distribution through interaction with the mean gravitational field, is numerically investigated for a one-dimensional self-gravitating stellar gas. Qualitative results are presented in the form of a motion picture of the flow of phase points (representing homogeneous slabs of stars) in two-dimensional phase space.

Analysis of the 9th November 1990 flare

2000 ◽  
Vol 179 ◽  
pp. 229-232
Author(s):  
Anita Joshi ◽  
Wahab Uddin
Keyword(s):  
Image Processing ◽  
Two Dimensional ◽  
Temporal Behaviour ◽  
Contour Maps ◽  
Dimensional Measurements ◽  
Processing Software ◽  
Image Processing Software

AbstractIn this paper we present complete two-dimensional measurements of the observed brightness of the 9th November 1990Hαflare, using a PDS microdensitometer scanner and image processing software MIDAS. The resulting isophotal contour maps, were used to describe morphological-cum-temporal behaviour of the flare and also the kernels of the flare. Correlation of theHαflare with SXR and MW radiations were also studied.

Electron Diffraction of Wet Biological Membranes

1974 ◽  
Vol 32 ◽  
pp. 158-159
Author(s):  
S.W. Hui ◽  
D.F. Parsons
Keyword(s):  
Electron Diffraction ◽  
Data Collection ◽  
Biological Membranes ◽  
Small Areas ◽  
Electron Diffraction Technique ◽  
Electron Microscopes ◽  
Collection Time ◽  
Camera Length

The development of the hydration stages for electron microscopes has opened up the application of electron diffraction in the study of biological membranes. Membrane specimen can now be observed without the artifacts introduced during drying, fixation and staining. The advantages of the electron diffraction technique, such as the abilities to observe small areas and thin specimens, to image and to screen impurities, to vary the camera length, and to reduce data collection time are fully utilized. Here we report our pioneering work in this area.

High Resolution Microscopy of Multi-Layered Biological Crystals

1982 ◽  
Vol 40 ◽  
pp. 80-83
Author(s):  
H.A. Cohen ◽  
T.W. Jeng ◽  
W. Chiu
Keyword(s):  
High Resolution ◽  
Low Dose ◽  
Three Dimensional ◽  
Data Interpretation ◽  
Two Dimensional ◽  
Biological Objects ◽  
Density Maps ◽  
Density Map ◽  
Complex Crystal ◽  
High Resolution Microscopy

This tutorial will discuss the methodology of low dose electron diffraction and imaging of crystalline biological objects, the problems of data interpretation for two-dimensional projected density maps of glucose embedded protein crystals, the factors to be considered in combining tilt data from three-dimensional crystals, and finally, the prospects of achieving a high resolution three-dimensional density map of a biological crystal. This methodology will be illustrated using two proteins under investigation in our laboratory, the T4 DNA helix destabilizing protein gp32*I and the crotoxin complex crystal.

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