Planar Doppler velocimetry in a large-scale facility

AIAA Journal ◽  
2000 ◽  
Vol 38 ◽  
pp. 1010-1024 ◽  
Author(s):  
A. D. Mosedale ◽  
G. S. Elliott ◽  
C. D. Carter ◽  
T. J. Beutner
2019 ◽  
Vol 70 ◽  
pp. 101660 ◽  
Author(s):  
Tomoaki Kyoden ◽  
Shunsuke Akiguchi ◽  
Tomoki Tajiri ◽  
Tsugunobu Andoh ◽  
Noriyuki Furuichi ◽  
...  

AIAA Journal ◽  
2000 ◽  
Vol 38 (6) ◽  
pp. 1010-1024 ◽  
Author(s):  
A. D. Mosedale ◽  
G. S. Elliott ◽  
C. D. Carter ◽  
T. J. Beutner

This is an experimental study of laminar pulsating flow that passes through separation and is led to a separated region. Detailed information is obtained on all interconnected regions, namely, the approaching attached laminar boundary layer, the immediate neighbourhood of separation, the separated shear layer, the large-scale vortical region of the wake and the outer inviscid flow. The approaching flow is pulsated with frequencies that include the natural frequencies of the wake. Flow visualizations are contrasted with instantaneous and averaged digital data obtained via laser-Doppler velocimetry and hot-wire anemometry. The interaction of the disturbing and natural frequencies is studied. Results are com pared with recent theoretical advances. It is found that the amplitude of the imposed disturbance grows sharply in the neighbourhood of separation.


1999 ◽  
Vol 173 ◽  
pp. 243-248
Author(s):  
D. Kubáček ◽  
A. Galád ◽  
A. Pravda

AbstractUnusual short-period comet 29P/Schwassmann-Wachmann 1 inspired many observers to explain its unpredictable outbursts. In this paper large scale structures and features from the inner part of the coma in time periods around outbursts are studied. CCD images were taken at Whipple Observatory, Mt. Hopkins, in 1989 and at Astronomical Observatory, Modra, from 1995 to 1998. Photographic plates of the comet were taken at Harvard College Observatory, Oak Ridge, from 1974 to 1982. The latter were digitized at first to apply the same techniques of image processing for optimizing the visibility of features in the coma during outbursts. Outbursts and coma structures show various shapes.


1994 ◽  
Vol 144 ◽  
pp. 29-33
Author(s):  
P. Ambrož

AbstractThe large-scale coronal structures observed during the sporadically visible solar eclipses were compared with the numerically extrapolated field-line structures of coronal magnetic field. A characteristic relationship between the observed structures of coronal plasma and the magnetic field line configurations was determined. The long-term evolution of large scale coronal structures inferred from photospheric magnetic observations in the course of 11- and 22-year solar cycles is described.Some known parameters, such as the source surface radius, or coronal rotation rate are discussed and actually interpreted. A relation between the large-scale photospheric magnetic field evolution and the coronal structure rearrangement is demonstrated.


2000 ◽  
Vol 179 ◽  
pp. 205-208
Author(s):  
Pavel Ambrož ◽  
Alfred Schroll

AbstractPrecise measurements of heliographic position of solar filaments were used for determination of the proper motion of solar filaments on the time-scale of days. The filaments have a tendency to make a shaking or waving of the external structure and to make a general movement of whole filament body, coinciding with the transport of the magnetic flux in the photosphere. The velocity scatter of individual measured points is about one order higher than the accuracy of measurements.


Author(s):  
Simon Thomas

Trends in the technology development of very large scale integrated circuits (VLSI) have been in the direction of higher density of components with smaller dimensions. The scaling down of device dimensions has been not only laterally but also in depth. Such efforts in miniaturization bring with them new developments in materials and processing. Successful implementation of these efforts is, to a large extent, dependent on the proper understanding of the material properties, process technologies and reliability issues, through adequate analytical studies. The analytical instrumentation technology has, fortunately, kept pace with the basic requirements of devices with lateral dimensions in the micron/ submicron range and depths of the order of nonometers. Often, newer analytical techniques have emerged or the more conventional techniques have been adapted to meet the more stringent requirements. As such, a variety of analytical techniques are available today to aid an analyst in the efforts of VLSI process evaluation. Generally such analytical efforts are divided into the characterization of materials, evaluation of processing steps and the analysis of failures.


Author(s):  
V. C. Kannan ◽  
A. K. Singh ◽  
R. B. Irwin ◽  
S. Chittipeddi ◽  
F. D. Nkansah ◽  
...  

Titanium nitride (TiN) films have historically been used as diffusion barrier between silicon and aluminum, as an adhesion layer for tungsten deposition and as an interconnect material etc. Recently, the role of TiN films as contact barriers in very large scale silicon integrated circuits (VLSI) has been extensively studied. TiN films have resistivities on the order of 20μ Ω-cm which is much lower than that of titanium (nearly 66μ Ω-cm). Deposited TiN films show resistivities which vary from 20 to 100μ Ω-cm depending upon the type of deposition and process conditions. TiNx is known to have a NaCl type crystal structure for a wide range of compositions. Change in color from metallic luster to gold reflects the stabilization of the TiNx (FCC) phase over the close packed Ti(N) hexagonal phase. It was found that TiN (1:1) ideal composition with the FCC (NaCl-type) structure gives the best electrical property.


Sign in / Sign up

Export Citation Format

Share Document