High-Resolution Nonhydrostatic Outfall Plume Modeling: Cross-Flow Validation

Intense vortical circulations, often organized in counterrotating vortex pairs, were detected in midcontinental cumulus congestus over southeast Wyoming in July 2003. The sampled clouds developed in dry environments and at cold temperatures, and were a few kilometers in depth and width. Observations were obtained with the Wyoming Cloud Radar from aboard the Wyoming King Air research aircraft. Dual-Doppler analyses of the data yielded high-resolution (30–45 m) depictions of the horizontal components of air motions across vigorously growing clouds. The vortices found in the horizontal cross sections are interpreted as components of the toroidal circulations in thermals when those are tilted because of the effect of ambient cross flow. This configuration also leads to a partial stabilization of the vertical trajectory of the updraft, by opposing the drag by the ambient wind. Additionally, dry air intrusions were seen to accompany these features when the vortices developed near the cloud outer boundaries; recirculation of hydrometeors occurred when the vortices were adjacent to in-cloud downdrafts. These features are also evident in the radar reflectivity patterns. In general, gradients of velocities and vorticity values in horizontal planes are comparable to those found in vertical planes.

Download Full-text

Correlation of Fabrication and Structural/Electronic Properties of Carbon Nanotubes Using TEM/EELS

Microscopy and Microanalysis ◽

10.1017/s1431927600033511 ◽

2000 ◽

Vol 6 (S2) ◽

pp. 204-205

Author(s):

B. W. Reed ◽

M. Sarikaya ◽

L. R. Dalton ◽

G. F. Bertsch

Keyword(s):

Carbon Nanotubes ◽

High Resolution ◽

Electronic Properties ◽

Research Effort ◽

Cross Flow ◽

Acid Reflux ◽

Growth Conditions ◽

Laser Vaporization ◽

Spectroscopic Techniques ◽

Cross Flow Filtration

Since their discovery, carbon nanotubes have been the focus of much research effort aimed at optimizing growth conditions, elucidating physical structure, and measuring electronic properties. Measurement methods have included high resolution techniques such as AFM, STM, TEM, and EELS, as well as surface and bulk spectroscopic techniques, such as XPS. Most investigations have been quite specific, centering on a small number of nanotubes formed under particular growth conditions and typically employing only one or two modes of analysis. Broader, more systematic studies are relatively rare, and it is the intent of the present work to help fill this gap. We combine results of high-resolution TEM imaging, electron diffraction, low-energy EELS, and carbon K-edge EELS to characterize a variety of nanotube samples, grown and annealed under various conditions.The Carbon Nanotubes (Cnts) Are Made By The Dual, Pulsed-Laser Vaporization Method, And Purified With A Process That Involves Nitric Acid Reflux, Washing/Centrifugation Cycles, Hollow-Fiber, And Cross-Flow Filtration.

Download Full-text

Observations of the spatial structure of interstellar hydrogen

Symposium - International Astronomical Union ◽

10.1017/s007418090010066x ◽

1967 ◽

Vol 31 ◽

pp. 45-46

Author(s):

Carl Heiles

Keyword(s):

High Resolution ◽

Spatial Structure ◽

Velocity Dispersion ◽

Temperature Variations

High-resolution 21-cm line observations in a region aroundlII= 120°,b11= +15°, have revealed four types of structure in the interstellar hydrogen: a smooth background, large sheets of density 2 atoms cm-3, clouds occurring mostly in groups, and ‘Cloudlets’ of a few solar masses and a few parsecs in size; the velocity dispersion in the Cloudlets is only 1 km/sec. Strong temperature variations in the gas are in evidence.

Download Full-text

Combining integrated systems-biology approaches with intervention-based experimental design provides a higher-resolution path forward for microbiome research

Behavioral and Brain Sciences ◽

10.1017/s0140525x18002911 ◽

2019 ◽

Vol 42 ◽

Author(s):

J. Alfredo Blakeley-Ruiz ◽

Carlee S. McClintock ◽

Ralph Lydic ◽

Helen A. Baghdoyan ◽

James J. Choo ◽

...

Keyword(s):

Systems Biology ◽

High Resolution ◽

Experimental Design ◽

Integrated Systems ◽

Microbiome Research ◽

Constructive Criticism

Abstract The Hooks et al. review of microbiota-gut-brain (MGB) literature provides a constructive criticism of the general approaches encompassing MGB research. This commentary extends their review by: (a) highlighting capabilities of advanced systems-biology “-omics” techniques for microbiome research and (b) recommending that combining these high-resolution techniques with intervention-based experimental design may be the path forward for future MGB research.

Download Full-text

Very High Resolution Analysis of the Dynamics of a Coronal Plasmoid

International Astronomical Union Colloquium ◽

10.1017/s0252921100026117 ◽

1994 ◽

Vol 144 ◽

pp. 593-596

Author(s):

O. Bouchard ◽

S. Koutchmy ◽

L. November ◽

J.-C. Vial ◽

J. B. Zirker

Keyword(s):

High Resolution ◽

Solar Eclipse ◽

Total Solar Eclipse ◽

Field Of View ◽

Small Field ◽

High Resolution Analysis ◽

Ccd Observations ◽

Resolution Analysis ◽

Very High ◽

Small Field Of View

AbstractWe present the results of the analysis of a movie taken over a small field of view in the intermediate corona at a spatial resolution of 0.5“, a temporal resolution of 1 s and a spectral passband of 7 nm. These CCD observations were made at the prime focus of the 3.6 m aperture CFHT telescope during the 1991 total solar eclipse.

Download Full-text

FeXIV Line Emission Polarization of the July 11, 1991 Solar Corona

International Astronomical Union Colloquium ◽

10.1017/s0252921100026002 ◽

1994 ◽

Vol 144 ◽

pp. 541-547

Author(s):

J. Sýkora ◽

J. Rybák ◽

P. Ambrož

Keyword(s):

High Resolution ◽

Solar Corona ◽

Emission Line ◽

Solar Eclipse ◽

White Light ◽

Preliminary Analysis ◽

Line Emission ◽

Total Solar Eclipse ◽

Degree Of Polarization ◽

High Resolution Images

AbstractHigh resolution images, obtained during July 11, 1991 total solar eclipse, allowed us to estimate the degree of solar corona polarization in the light of FeXIV 530.3 nm emission line and in the white light, as well. Very preliminary analysis reveals remarkable differences in the degree of polarization for both sets of data, particularly as for level of polarization and its distribution around the Sun’s limb.

Download Full-text

Microcalorimeters for X-Ray Spectroscopy

International Astronomical Union Colloquium ◽

10.1017/s0252921100107365 ◽

1988 ◽

Vol 102 ◽

pp. 41

Author(s):

E. Silver ◽

C. Hailey ◽

S. Labov ◽

N. Madden ◽

D. Landis ◽

...

Keyword(s):

High Resolution ◽

High Efficiency ◽

Thermal Response ◽

Low Noise ◽

High Resolution Spectroscopy ◽

Superconducting Transition ◽

Sapphire Substrates ◽

Laboratory Plasmas ◽

Adiabatic Demagnetization ◽

Theoretical Predictions

The merits of microcalorimetry below 1°K for high resolution spectroscopy has become widely recognized on theoretical grounds. By combining the high efficiency, broadband spectral sensitivity of traditional photoelectric detectors with the high resolution capabilities characteristic of dispersive spectrometers, the microcalorimeter could potentially revolutionize spectroscopic measurements of astrophysical and laboratory plasmas. In actuality, however, the performance of prototype instruments has fallen short of theoretical predictions and practical detectors are still unavailable for use as laboratory and space-based instruments. These issues are currently being addressed by the new collaborative initiative between LLNL, LBL, U.C.I., U.C.B., and U.C.D.. Microcalorimeters of various types are being developed and tested at temperatures of 1.4, 0.3, and 0.1°K. These include monolithic devices made from NTD Germanium and composite configurations using sapphire substrates with temperature sensors fabricated from NTD Germanium, evaporative films of Germanium-Gold alloy, or material with superconducting transition edges. A new approache to low noise pulse counting electronics has been developed that allows the ultimate speed of the device to be determined solely by the detector thermal response and geometry. Our laboratory studies of the thermal and resistive properties of these and other candidate materials should enable us to characterize the pulse shape and subsequently predict the ultimate performance. We are building a compact adiabatic demagnetization refrigerator for conveniently reaching 0.1°K in the laboratory and for use in future satellite-borne missions. A description of this instrument together with results from our most recent experiments will be presented.

Download Full-text

Radiation Damage, Contrast and Statistics in High Resolution Biological Electron Microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100068291 ◽

1970 ◽

Vol 28 ◽

pp. 260-261

Author(s):

Robert M. Glaeser

Keyword(s):

High Resolution ◽

Particle Flux ◽

Unit Area ◽

Signal To Noise ◽

Resolution Image ◽

High Resolution Image ◽

Pass Through ◽

Counting Statistics ◽

The Relationship ◽

Picture Element

It is well known that a large flux of electrons must pass through a specimen in order to obtain a high resolution image while a smaller particle flux is satisfactory for a low resolution image. The minimum particle flux that is required depends upon the contrast in the image and the signal-to-noise (S/N) ratio at which the data are considered acceptable. For a given S/N associated with statistical fluxtuations, the relationship between contrast and “counting statistics” is s131_eqn1, where C = contrast; r2 is the area of a picture element corresponding to the resolution, r; N is the number of electrons incident per unit area of the specimen; f is the fraction of electrons that contribute to formation of the image, relative to the total number of electrons incident upon the object.

Download Full-text

Light Optical Diffraction Studies of Macromolecular Ultrastructure

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010006828x ◽

1970 ◽

Vol 28 ◽

pp. 258-259

Author(s):

Glen B. Haydon

Keyword(s):

High Resolution ◽

Diffraction Analysis ◽

Diffraction Pattern ◽

Electron Micrographs ◽

Optical Diffraction ◽

Electron Micrograph ◽

Its Analysis ◽

Resolution Electron ◽

Diffraction Patterns

Analysis of light optical diffraction patterns produced by electron micrographs can easily lead to much nonsense. Such diffraction patterns are referred to as optical transforms and are compared with transforms produced by a variety of mathematical manipulations. In the use of light optical diffraction patterns to study periodicities in macromolecular ultrastructures, a number of potential pitfalls have been rediscovered. The limitations apply to the formation of the electron micrograph as well as its analysis.(1) The high resolution electron micrograph is itself a complex diffraction pattern resulting from the specimen, its stain, and its supporting substrate. Cowley and Moodie (Proc. Phys. Soc. B, LXX 497, 1957) demonstrated changing image patterns with changes in focus. Similar defocus images have been subjected to further light optical diffraction analysis.

Download Full-text