scholarly journals A Recipe to Obtain Lidar Polarisation Calibration Parameters G, H and K

2020 ◽  
Vol 237 ◽  
pp. 05002
Author(s):  
Joelle Buxmann ◽  
Martin Osborne ◽  
George Georgoussis ◽  
Volker Freudenthaler
Keyword(s):  
Rotation Angle ◽  
Atmospheric Conditions ◽  
Depolarisation Ratio ◽  
Aerosol Classification ◽  
Linear Polarisation ◽  
Calibration Parameters

The accuracy of the polarisation calibration is of prime importance for aerosol classification using lidars. We present a detailed description how to obtain the calibration parameters introduced in 2016 [1] accounting for various effects of non-ideal optics, lasers and atmospheric conditions. We find that crucial parameters such as the rotation angle of the plane of polarisation of the Laser (RotL) as well as the degree of linear polarisation (DOLP) influence the volume linear depolarisation ratio significantly.

Structure and migration of planar defects in crystals observed in atomic scale

1978 ◽  
Vol 36 (1) ◽  
pp. 284-285 ◽  
Author(s):  
H. Hashimoto ◽  
Y. Sugimoto ◽  
Y. Takai ◽  
H. Endoh
Keyword(s):  
Electron Microscope ◽  
Rotation Angle ◽  
Crystal Surface ◽  
Electron Gun ◽  
Atomic Scale ◽  
Present Observation ◽  
Twist Boundary ◽  
Optical Magnification ◽  
Zinc Crystal ◽  
And Migration

As was demonstrated by the present authors that atomic structure of simple crystal can be photographed by the conventional 100 kV electron microscope adjusted at “aberration free focus (AFF)” condition. In order to operate the microscope at AFF condition effectively, highly stabilized electron beams with small energy spread and small beam divergence are necessary. In the present observation, a 120 kV electron microscope with LaB6 electron gun was used. The most of the images were taken with the direct electron optical magnification of 1.3 million times and then magnified photographically.1. Twist boundary of ZnSFig. 1 is the image of wurtzite single crystal with twist boundary grown on the surface of zinc crystal by the reaction of sulphur vapour of 1540 Torr at 500°C. Crystal surface is parallel to (00.1) plane and electron beam is incident along the axis normal to the crystal surface. In the twist boundary there is a dislocation net work between two perfect crystals with a certain rotation angle.

Selective Corrosion of brazed joint between BNi-2 filler metal and stainless steel 316

1996 ◽  
Vol 54 ◽  
pp. 218-219
Author(s):  
H. S. Kim ◽  
R. U. Lee
Keyword(s):  
Stainless Steel ◽  
Filler Metal ◽  
Surface Preparation ◽  
Optical Microscope ◽  
Heating Element ◽  
Incomplete Fusion ◽  
Atmospheric Conditions ◽  
Leak Test ◽  
High Temperature Side ◽  
Inconel 600

A heating element/electrical conduit assembly used in the Orbiter Maneuvering System failed a leak test during a routine refurbishment inspection. The conduit, approximately 100 mm in length and 12 mm in diameter, was fabricated from two tubes and braze-joined with a sleeve. The tube on the high temperature side (heating element side) and the sleeve were made of Inconel 600 and the other tube was stainless steel (SS) 316. For the filler metal, a Ni-Cr-B brazing alloy per AWS BNi-2, was used. A Helium leak test spotted the leak located at the joint between the sleeve and SS 316 tubing. This joint was dissected, mounted in a plastic mold, polished, and examined with an optical microscope. Debonding of the brazed surfaces was noticed, more pronounced toward the sleeve end which was exposed to uncontrolled atmospheric conditions intermittently. Initially, lack of wetting was suspected, presumably caused by inadequate surface preparation or incomplete fusion of the filler metal. However, this postulation was later discarded based upon the following observations: (1) The angle of wetting between the fillet and tube was small, an indication of adequate wetting, (2) the fillet did not exhibit a globular microstructure which would be an indication of insufficient melting of the filler metal, and (3) debonding was intermittent toward the midsection of the sleeve.

Recent Progress In High-Resolution Shadowing For Biological Transmission Electron Microscopy

1990 ◽  
Vol 48 (1) ◽  
pp. 510-511 ◽  
Author(s):  
Heinz Gross ◽  
Katarina Krusche ◽  
Peter Tittmann
Keyword(s):  
Heavy Metal ◽  
High Resolution ◽  
Freeze Drying ◽  
Atmospheric Conditions ◽  
Vacuum Equipment ◽  
Transmission Electron ◽  
Gas Atmosphere ◽  
Gas Molecules ◽  
Residual Gas ◽  
Backing Layer

Freeze-drying followed by heavy metal shadowing is a long established and straight forward approach to routinely study the structure of dehydrated macromolecules. Very thin specimens such as isolated membranes or single macromolecules are directly adsorbed on C-coated grids. After rapid freezing the grids are transferred into a suitable vacuum equipment for freeze-drying and heavy metal shadowing.To improve the resolution power of shadowing films we introduced shadowing at very low specimen temperature (−250°C). To routinely do that without the danger of contamination we developed in collaboration with Balzers an UHV (p≤10-9 mbar) machine (BAF500K, Fig.2). It should be mentioned here that at −250°C the specimen surface acts as effective cryopump for practically all impinging residual gas molecules from the residual gas atmosphere.Common high resolution shadowing films (Pt/C, Ta/W) have to be protected from alterations due to air contact by a relatively thick C-backing layer, when transferred via atmospheric conditions into the TEM. Such an additional C-coat contributes disturbingly to the contrast at high resolution.

Musculoskeletal disorder risk associated with auto rotation angle during an assembly task

2009 ◽  
Author(s):  
Sue A. Ferguson ◽  
William S. Marras ◽  
W. Gary Allread ◽  
Gregory G. Knapik ◽  
Kimberly A. Vandlen ◽  
...  
Keyword(s):  
Musculoskeletal Disorder ◽  
Rotation Angle ◽  
Assembly Task ◽  
Disorder Risk

MUELLER ALLOY 3140

Alloy Digest ◽  
1983 ◽  
Vol 32 (1) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Tensile Properties ◽  
Copper Alloy ◽  
Heat Treating ◽  
Lead Content ◽  
Atmospheric Conditions ◽  
Excellent Corrosion Resistance ◽  
High Copper ◽  
Screw Machine

Abstract MUELLER Alloy 3140 is a high-copper alloy with moderate strength, a rich bronze color and excellent corrosion resistance. Its lead content gives it excellent machinability which makes it suitable for screw-machine applications. Its uses include many screw-machine products, decorative hardware, pickling crates and parts to resist severe atmospheric conditions. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Cu-451. Producer or source: Mueller Brass Company.

Choose you own scientific experiment: Triggering debris flows and flash floods

2016 ◽  
Author(s):  
Thea Turkington
Keyword(s):  
Debris Flows ◽  
Flash Floods ◽  
The Other ◽  
Background Information ◽  
Atmospheric Conditions ◽  
Scientific Experiment

Landslides and flash floods result in many fatalities around the globe. Understanding what triggers these events is therefore vital, although how to approach this problem is not straight forward. After background information for the experiment and some guidelines, two options are presented to learn more about the triggers of debris flows: (A) using rainfall or (B) the atmospheric conditions. You can then choose the option that appears more useful and interesting to you (you can always go back and read the other experiment afterwards). The article then ends with a reflection on the results.

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