scholarly journals Closed-form ab initio solutions of geometric albedos and reflected light phase curves of exoplanets

2021 ◽  
Vol 5 (10) ◽  
pp. 1001-1008
Author(s):  
Kevin Heng ◽  
Brett M. Morris ◽  
Daniel Kitzmann
Keyword(s):  
Ab Initio ◽  
Closed Form ◽  
Light Phase ◽  
Reflected Light

The Negative π/2 Phase Shift of Total Reflect Light

2011 ◽  
Vol 254 ◽  
pp. 103-106
Author(s):  
Bing Liu ◽  
Li Xiang Chen ◽  
X. Sun ◽  
R.C. Dong ◽  
X.G. Jie ◽  
...  
Keyword(s):  
Phase Shift ◽  
Theoretical Analysis ◽  
Exponential Decay ◽  
Evanescent Wave ◽  
Wave Intensity ◽  
The Other ◽  
Light Phase ◽  
Reflected Light

Traveling light is totally reflected on boundary, the evanescent wave intensity exhibits exponential decay with distance from the boundary at which the wave was formed. In this paper, we do theoretical analysis of the total reflected light phase shift and power value of the evanescent wave was “disturbed” by the other objects. A marvelous optics phenomenon is the -π/2 phase shift of reflected light.

scholarly journals Reflected Light Phase Curves in the TESS Era

2019 ◽  
Vol 158 (2) ◽  
pp. 66 ◽  
Author(s):  
L. C. Mayorga ◽  
Natasha E. Batalha ◽  
Nikole K. Lewis ◽  
Mark S. Marley
Keyword(s):  
Light Phase ◽  
Reflected Light

Daily Analytical Problem Solving in Criminalistics with Rapid and Reliable Advanced Instrumentation - the Microscope

2001 ◽  
Vol 7 (S2) ◽  
pp. 468-469
Author(s):  
W. Moorehead
Keyword(s):  
Dna Analysis ◽  
Drug Analysis ◽  
Electromagnetic Spectrum ◽  
Light Phase ◽  
Analytical Scheme ◽  
Scientific Disciplines ◽  
Reflected Light ◽  
Fusion Methods ◽  
Scene Investigation ◽  
Engineering Psychology

Forensic science incorporates many different scientific disciplines: criminalistics, toxicology, pathology, entomology, engineering, psychology, accounting, etc. Criminalistics incorporates such diverse areas as crime scene investigation, sexual assault evidence, DNA analysis, firearms identification and comparison, drug analysis, impression evidence, and trace evidence.A variety of microscopes and microscopical techniques are used to answer “real world” questions about physical evidence in criminalistics. The microscopes most often used include stereo (dissecting), biological (brightfield), polarizing light, phase contrast, fluorescence, transmitted light comparison, reflected light comparison, and scanning electron. Additionally, detectors from different areas of the electromagnetic spectrum have been added to microscopes to enhance the information obtained from a specimen: infrared, visible-ultraviolet, and x-ray. to gather more information about the specimen with visible light microscopes, dispersion staining(1), contrast enhancement techniques(2) fusion methods(3), chemical staining(4), and micro-chemical tests(5,6) can be integrated into the analytical scheme.

scholarly journals EFFECT OF LONGITUDE-DEPENDENT CLOUD COVERAGE ON EXOPLANET VISIBLE WAVELENGTH REFLECTED-LIGHT PHASE CURVES

2015 ◽  
Vol 804 (2) ◽  
pp. 94 ◽  
Author(s):  
Matthew W. Webber ◽  
Nikole K. Lewis ◽  
Mark Marley ◽  
Caroline Morley ◽  
Jonathan J. Fortney ◽  
...  
Keyword(s):  
Light Phase ◽  
Cloud Coverage ◽  
Visible Wavelength ◽  
Reflected Light

scholarly journals On ab initio-based, free and closed-form expressions for gravitational waves

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Manuel Tiglio ◽  
Aarón Villanueva
Keyword(s):  
Artificial Intelligence ◽  
Ab Initio ◽  
Closed Form ◽  
Gravitational Waves ◽  
Large Scale ◽  
Interpolation Method ◽  
Ground Truth ◽  
Einstein Equations ◽  
Free Form ◽  
Reduced Basis

AbstractWe introduce a new approach for findinghigh accuracy, free and closed-form expressionsfor the gravitational waves emitted by binary black hole collisions fromab initio models. More precisely, our expressions are built from numerical surrogate models based on supercomputer simulations of the Einstein equations, which have been shown to be essentially indistinguishable from each other. Distinct aspects of our approach are that: (i) representations of the gravitational waves can beexplicitlywritten in a few lines, (ii) these representations are free-form yet still fast to search for and validate and (iii) there are no underlying physical approximations in the underlying model. The key strategy is combining techniques from Artificial Intelligence and Reduced Order Modeling for parameterized systems. Namely, symbolic regression through genetic programming combined with sparse representations in parameter space and the time domain using Reduced Basis and the Empirical Interpolation Method enabling fast free-form symbolic searches and large-scale a posteriori validations. As a proof of concept we present our results for the collision of two black holes, initially without spin, and with an initial separation corresponding to 25–31 gravitational wave cycles before merger. The minimum overlap, compared to ground truth solutions, is 99%. That is, 1% difference between our closed-form expressions and supercomputer simulations; this is considered for gravitational (GW) science more than the minimum required due to experimental numerical errors which otherwise dominate. This paper aims to contribute to the field of GWs in particular and Artificial Intelligence in general.

Confocal laser microscopy of impregnated central nervous system tissue

1988 ◽  
Vol 46 ◽  
pp. 94-95
Author(s):  
J.N. Turner ◽  
M. Siemens ◽  
D. Szarowski ◽  
D.N. Collins
Keyword(s):  
Electron Microscopy ◽  
Central Nervous System ◽  
Nervous System ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Confocal Laser ◽  
High Contrast ◽  
Central Nervous System Tissue ◽  
Tissue Samples ◽  
Reflected Light

A classic preparation of central nervous system tissue (CNS) is the Golgi procedure popularized by Cajal. The method is partially specific as only a few cells are impregnated with silver chromate usualy after osmium post fixation. Samples are observable by light (LM) or electron microscopy (EM). However, the impregnation is often so dense that structures are masked in EM, and the osmium background may be undesirable in LM. Gold toning is used for a subtle but high contrast EM preparation, and osmium can be omitted for LM. We are investigating these preparations as part of a study to develop correlative LM and EM (particularly HVEM) methodologies in neurobiology. Confocal light microscopy is particularly useful as the impregnated cells have extensive three-dimensional structure in tissue samples from one to several hundred micrometers thick. Boyde has observed similar preparations in the tandem scanning reflected light microscope (TSRLM).

Ab initio band theory approach to electron energy loss near edge structures

1988 ◽  
Vol 46 ◽  
pp. 506-507
Author(s):  
Xudong Weng ◽  
O.F. Sankey ◽  
Peter Rez
Keyword(s):  
Ab Initio ◽  
Local Density ◽  
Interpolation Method ◽  
Atomic Orbital ◽  
Plane Waves ◽  
Large Set ◽  
Theory Approach ◽  
Band Theory ◽  
Atomic Orbitals ◽  
Pseudopotential Calculations

Single electron band structure techniques have been applied successfully to the interpretation of the near edge structures of metals and other materials. Among various band theories, the linear combination of atomic orbital (LCAO) method is especially simple and interpretable. The commonly used empirical LCAO method is mainly an interpolation method, where the energies and wave functions of atomic orbitals are adjusted in order to fit experimental or more accurately determined electron states. To achieve better accuracy, the size of calculation has to be expanded, for example, to include excited states and more-distant-neighboring atoms. This tends to sacrifice the simplicity and interpretability of the method.In this paper. we adopt an ab initio scheme which incorporates the conceptual advantage of the LCAO method with the accuracy of ab initio pseudopotential calculations. The so called pscudo-atomic-orbitals (PAO's), computed from a free atom within the local-density approximation and the pseudopotential approximation, are used as the basis of expansion, replacing the usually very large set of plane waves in the conventional pseudopotential method. These PAO's however, do not consist of a rigorously complete set of orthonormal states.

Some early history of replica techniques for electron microscopy

1992 ◽  
Vol 50 (2) ◽  
pp. 1076-1077
Author(s):  
Robert M. Fisher
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Optical Microscope ◽  
Early History ◽  
Bulk Materials ◽  
Thin Sections ◽  
Transmission Electron ◽  
Reflected Light ◽  
History Of ◽  
Electron Microscopes

By 1940, a half dozen or so commercial or home-built transmission electron microscopes were in use for studies of the ultrastructure of matter. These operated at 30-60 kV and most pioneering microscopists were preoccupied with their search for electron transparent substrates to support dispersions of particulates or bacteria for TEM examination and did not contemplate studies of bulk materials. Metallurgist H. Mahl and other physical scientists, accustomed to examining etched, deformed or machined specimens by reflected light in the optical microscope, were also highly motivated to capitalize on the superior resolution of the electron microscope. Mahl originated several methods of preparing thin oxide or lacquer impressions of surfaces that were transparent in his 50 kV TEM. The utility of replication was recognized immediately and many variations on the theme, including two-step negative-positive replicas, soon appeared. Intense development of replica techniques slowed after 1955 but important advances still occur. The availability of 100 kV instruments, advent of thin film methods for metals and ceramics and microtoming of thin sections for biological specimens largely eliminated any need to resort to replicas.

Tandem scanning reflected light microscopy: How it works and applications

1986 ◽  
Vol 44 ◽  
pp. 84-87
Author(s):  
Alan Boyde ◽  
Milan Hadravský ◽  
Mojmír Petran ◽  
Timothy F. Watson ◽  
Sheila J. Jones ◽  
...  
Keyword(s):  
Light Microscopy ◽  
Focal Plane ◽  
Central Symmetry ◽  
Single Line ◽  
Scanning Microscope ◽  
Reflected Light ◽  
Illuminating Light ◽  
Illuminating Beam

The principles of tandem scanning reflected light microscopy and the design of recent instruments are fully described elsewhere and here only briefly. The illuminating light is intercepted by a rotating aperture disc which lies in the intermediate focal plane of a standard LM objective. This device provides an array of separate scanning beams which light up corresponding patches in the plane of focus more intensely than out of focus layers. Reflected light from these patches is imaged on to a matching array of apertures on the opposite side of the same aperture disc and which are scanning in the focal plane of the eyepiece. An arrangement of mirrors converts the central symmetry of the disc into congruency, so that the array of apertures which chop the illuminating beam is identical with the array on the observation side. Thus both illumination and “detection” are scanned in tandem, giving rise to the name Tandem Scanning Microscope (TSM). The apertures are arranged on Archimedean spirals: each opposed pair scans a single line in the image.

An ab initio study of Se-reacted GaAs(0 0 1) surfaces

1998 ◽  
Vol 184-185 (1-2) ◽  
pp. 80-84 ◽  
Author(s):  
W Faschinger
Keyword(s):  
Ab Initio ◽  
Ab Initio Study
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