General Vacuum Techniques

2002 ◽  
Author(s):  
Jack H. Singleton
Keyword(s):  
General Vacuum

General vacuum solution for Brans-Dicke-Bianchi type V

1991 ◽  
Vol 23 (9) ◽  
pp. 1007-1010 ◽  
Author(s):  
Enrique Guzmán
Keyword(s):  
Bianchi Type ◽  
Vacuum Solution ◽  
General Vacuum ◽  
Type V ◽  
Bianchi Type V

I. General vacuum science and engineering

Vacuum ◽  
1966 ◽  
Vol 16 (7) ◽  
pp. 404
Keyword(s):  
Science And Engineering ◽  
General Vacuum

scholarly journals OSCILLATING INSTANTONS AS HOMOGENEOUS TUNNELING CHANNELS

2013 ◽  
Vol 28 (18) ◽  
pp. 1350082 ◽  
Author(s):  
BUM-HOON LEE ◽  
WONWOO LEE ◽  
DONG-HAN YEOM
Keyword(s):  
Scalar Field ◽  
Local Minimum ◽  
Local Maximum ◽  
Einstein Gravity ◽  
Scale Factor ◽  
The Other ◽  
Vacuum Decay ◽  
General Vacuum

In this paper, we study Einstein gravity with a minimally coupled scalar field accompanied with a potential, assuming an O(4) symmetric metric ansatz. We call an Euclidean instanton is to be an oscillating instanton, if there exists a point where the derivative of the scale factor and the scalar field vanish at the same time. Then, we can prove that the oscillating instanton can be analytically continued, both as inhomogeneous and homogeneous tunneling channels. Here, we especially focus on the possibility of a homogeneous tunneling channel. For the existence of such an instanton, we have to assume three things: (1) there should be a local maximum and the curvature of the maximum should be sufficiently large, (2) there should be a local minimum and (3) the other side of the potential should have a sufficiently deeper vacuum. Then, we can show that there exists a number of oscillating instanton solutions and their probabilities are higher compared to the Hawking–Moss instantons. We also check the possibility when the oscillating instantons are comparable with the Coleman–de Luccia channels. Thus, for a general vacuum decay problem, we should not ignore the oscillating instanton channels.

scholarly journals Notes On Vacuum Techniques For Microscopists

2001 ◽  
Vol 9 (3) ◽  
pp. 16-19
Author(s):  
Scott D. Walck
Keyword(s):  
Electron Microscope ◽  
The Internet ◽  
General Vacuum

This article was originally written to respond to a discussion on the Microscopy Listserver found on the Internet concerning backfilling an electron microscope with nitrogen versus laboratory air. It was expanded to include general vacuum comments, suggestions, and techniques that could be of possible value to the working microscopist.

Some restrictions on algebraically general vacuum metrics

1975 ◽  
Vol 16 (4) ◽  
pp. 1008-1010 ◽  
Author(s):  
Carl H. Brans
Keyword(s):  
Vacuum Metrics ◽  
General Vacuum

scholarly journals Squeezed primordial bispectrum from a general vacuum state

2013 ◽  
Vol 30 (9) ◽  
pp. 095005 ◽  
Author(s):  
Jinn-Ouk Gong ◽  
Misao Sasaki
Keyword(s):  
Vacuum State ◽  
General Vacuum

scholarly journals Deconstructing Frame-Dragging

Universe ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 27
Author(s):  
Luis Herrera
Keyword(s):  
Frame Dragging ◽  
Physical Picture ◽  
General Vacuum ◽  
Stationary Spacetimes ◽  
Physical Quantities

The vorticity of world-lines of observers associated with the rotation of a massive body was reported by Lense and Thirring more than a century ago. In their example, the frame-dragging effect induced by the vorticity is directly (explicitly) related to the rotation of the source. However, in many other cases, it is not so, and the origin of vorticity remains obscure and difficult to identify. Accordingly, in order to unravel this issue, and looking for the ultimate origin of vorticity associated to frame-dragging, we analyze in this manuscript very different scenarios where the frame-dragging effect is present. Specifically, we consider general vacuum stationary spacetimes, general electro-vacuum spacetimes, radiating electro-vacuum spacetimes, and Bondi–Sachs radiating spacetimes. We identify the physical quantities present in all these cases, which determine the vorticity and may legitimately be considered as responsible for the frame-dragging. Doing so, we provide a comprehensive, physical picture of frame-dragging. Some observational consequences of our results are discussed.

scholarly journals Stability and recovery issues concerning chondroitin sulfate disaccharide analysis

2021 ◽  
Author(s):  
Gábor Tóth ◽  
Domonkos Pál ◽  
Károly Vékey ◽  
László Drahos ◽  
Lilla Turiák
Keyword(s):  
Sample Preparation ◽  
Chondroitin Sulfate ◽  
Solvent Exchange ◽  
Biological Functions ◽  
Solvent Content ◽  
General Vacuum ◽  
Long Time ◽  
Analytical Issue ◽  
The Stability ◽  
Sulfate Species

AbstractChondroitin sulfate (CS) is a widely studied class of glycosaminoglycans, responsible for diverse biological functions. Structural analysis of CS is generally based on disaccharide analysis. Sample preparation is a key analytical issue in this case. However, a detailed study on the stability and recovery of CS-derived species has been lacking so far. We have found that for solvent exchange, in general, vacuum evaporation (SpeedVac) is much preferable than lyophilization. Moreover, in the case of aqueous solutions, higher recovery was experienced than in solutions with high organic solvent content. Storage of the resulting disaccharide mixture in typical HPLC injection solvents is also critical; decomposition starts after 12 h at 4 °C; therefore, the mixtures should not be kept in the sample tray of an automatic injector for a long time. The study, therefore, lays down suggestions on proper sample preparation and measurement conditions for biologically derived chondroitin sulfate species.

I. General vacuum science and engineering

Vacuum ◽  
1978 ◽  
Vol 28 (3) ◽  
pp. 153 ◽  
Keyword(s):  
Science And Engineering ◽  
General Vacuum
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