scholarly journals Stratigraphic and structural characterization of the OU-1 area at the former George Air Force Base, Adelanto, Southern California

2001 ◽  
Author(s):  
R.D. Catchings ◽  
G. Gandhok ◽  
M.R. Goldman
Keyword(s):  
Air Force ◽  
Structural Characterization ◽  
Southern California ◽  
Air Force Base

Characterization of Shock Wave–Endwall Boundary Layer Interactions in a Transonic Compressor Rotor

1988 ◽  
Vol 110 (3) ◽  
pp. 386-392 ◽  
Author(s):  
D. C. Rabe ◽  
A. J. Wennerstrom ◽  
W. F. O’Brien
Keyword(s):  
Boundary Layer ◽  
Shock Wave ◽  
Air Force ◽  
Leading Edge ◽  
Transonic Compressor ◽  
Laser Measurements ◽  
Compressor Rotor ◽  
Boundary Layer Interaction ◽  
Air Force Base

The passage shock wave–endwall boundary layer interaction in a transonic compressor was investigated with a laser transit anemometer. The transonic compressor used in this investigation was developed by the General Electric Company under contract to the Air Force. The compressor testing was conducted in the Compressor Research Facility at Wright-Patterson Air Force Base, OH. Laser measurements were made in two blade passages at seven axial locations from 10 percent of the axial blade chord in front of the leading edge to 30 percent of the axial blade chord into the blade passage. At three of these axial locations, laser traverses were taken at different radial immersions. A total of 27 different locations were traversed circumferentially. The measurements reveal that the endwall boundary layer in this region is separated from the core flow by what appears to be a shear layer where the passage shock wave and all ordered flow seem to end abruptly.

Investigations of magnetic field disturbances at an air force base compass calibration hardstand

Geophysics ◽  
1993 ◽  
Vol 58 (3) ◽  
pp. 434-440 ◽  
Author(s):  
Dwain K. Butler ◽  
Thomas B. Kean
Keyword(s):  
Magnetic Field ◽  
Air Force ◽  
Concrete Aggregate ◽  
Large Bulk ◽  
The Status ◽  
Bulk Magnetic Susceptibility ◽  
Compass Calibration ◽  
Air Force Base ◽  
The Magnetic Field

Investigations were conducted to determine the nature and cause of magnetic field disturbances at the calibration hardstand (compass rose) at an air force base. The disturbances have prevented the normal and routine use of the hardstand since its construction in the mid-1950s, with heightened concern over the problem every 10–12 years. The investigations included the characterization of the horizontal, vertical, and temporal variation of the total magnetic field strength both on and off the hardstand. On the hardstand, the field varies by as much as 1,000 nT over 10 m horizontally and by as much as 600 nT over 2.5 m vertically. Also, on the hardstand, the magnetic field varies extremely erratically with time by 50–60 nT over periods of a few seconds. Off the hardstand, the magnetic field is extremely stable, and varies by less than 10 nT over 10 m horizontally, 2.5 m vertically, and over periods of 10–15 min. The magnetic field “stabilizes” at distances less than 10 m horizontally from the edge of the hardstand. Both on and off the hardstand, the magnetic field variations are independent of the status (on or off) of a nearby instrument landing system (ILS) (approach radar). The results of the magnetic field characterization indicate that the cause of the problem is the hardstand itself. The hardstand concrete was found to have a large bulk magnetic susceptibility, and the concrete aggregate has a permanent magnetization sufficiently large to visibly deflect a compass needle; these factors, coupled with a correlation with the 11-year solar cycle, suffice to explain the magnetic “disturbances” at the hardstand.

New ultrastructural findings about Borrelia burgdorferi by cryofixation, negative staining, thin sectioning and scanning techniques

1990 ◽  
Vol 48 (3) ◽  
pp. 582-583
Author(s):  
S. F. Hayes ◽  
M. D. Corwin ◽  
T. G. Schwan ◽  
D. W. Dorward ◽  
W. Burgdorfer
Keyword(s):  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Structural Characterization ◽  
Negative Staining ◽  
Low Speed ◽  
Thin Sectioning ◽  
Ultrastructural Findings

Characterization of Borrelia burgdorferi strains by means of negative staining EM has become an integral part of many studies related to the biology of the Lyme disease organism. However, relying solely upon negative staining to compare new isolates with prototype B31 or other borreliae is often unsatisfactory. To obtain more satisfactory results, we have relied upon a correlative approach encompassing a variety EM techniques, i.e., scanning for topographical features and cryotomy, negative staining and thin sectioning to provide a more complete structural characterization of B. burgdorferi.For characterization, isolates of B. burgdorferi were cultured in BSK II media from which they were removed by low speed centrifugation. The sedimented borrelia were carefully resuspended in stabilizing buffer so as to preserve their features for scanning and negative staining. Alternatively, others were prepared for conventional thin sectioning and for cryotomy using modified procedures. For thin sectioning, the fixative described by Ito, et al.

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