scholarly journals A Feynman diagram description of the 2D-Raman-THz response of amorphous ice

2020 ◽  
Vol 153 (4) ◽  
pp. 044502
Author(s):  
David Sidler ◽  
Peter Hamm
Keyword(s):  
Feynman Diagram ◽  
Amorphous Ice

The structure of membranes and membrane proteins embedded in amorphous ice

1992 ◽  
Vol 50 (1) ◽  
pp. 432-433
Author(s):  
Uwe Lücken ◽  
Joachim Jäger
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Membrane Proteins ◽  
Phase Transition Temperature ◽  
Lipid Vesicles ◽  
Freezing Stress ◽  
Amorphous Ice ◽  
Different Temperatures ◽  
Band Pass ◽  
Lipid Polymorphism

TEM imaging of frozen-hydrated lipid vesicles has been done by several groups Thermotrophic and lyotrophic polymorphism has been reported. By using image processing, computer simulation and tilt experiments, we tried to learn about the influence of freezing-stress and defocus artifacts on the lipid polymorphism and fine structure of the bilayer profile. We show integrated membrane proteins do modulate the bilayer structure and the morphology of the vesicles.Phase transitions of DMPC vesicles were visualized after freezing under equilibrium conditions at different temperatures in a controlled-environment vitrification system. Below the main phase transition temperature of 24°C (Fig. 1), vesicles show a facetted appearance due to the quasicrystalline areas. A gradual increase in temperature leads to melting processes with different morphology in the bilayer profile. Far above the phase transition temperature the bilayer profile is still present. In the band-pass-filtered images (Fig. 2) no significant change in the width of the bilayer profile is visible.

A metal- coating Chamber for High-Resolution Cryo-SEM

1990 ◽  
Vol 48 (1) ◽  
pp. 418-419
Author(s):  
John G. Sheehan
Keyword(s):  
High Resolution ◽  
Colloidal Suspensions ◽  
Metal Coating ◽  
Colloidal Interactions ◽  
Amorphous Ice ◽  
High Vapor ◽  
Particulate Coatings ◽  
20 Nm ◽  
Film Nucleation ◽  
Coating Chamber

Improvements in particulate coatings for printable paper require understanding mechanisms of colloidal interactions in paper coating suspensions. One way to deduce colloidal interactions is to mage particle spacings and orientations at high resolution with cryo-SEM. Recent improvements in cryo-SEM technique have increased resolution enough to image particles in coating paints,vhich are sometimes smaller than 100 nm. In this report, a metal-coating chamber is described for preparation of colloidal suspensions for cryo-SEM at resolution down to 20 nm. It was found that etching is not necessary to achieve this resolution.A 120 K cryo-SEM sample will remain in an SEM for hours without noticeable condensation of imorphous ice. This is due to the high vapor pressure of vapor-condensed amorphous ice, measured by Kouchi. However, clean vacuum is required to coat samples with the thinnest possible continuous metal films which are required for high magnification SEM. Vapor contaminants, especially hrydrocarbons, are known to interfere with thin-film nucleation and growth so that more metal is needed to form continuous films, and resolution is decreased. That is why the metal-coating chamber in fig. 1 is designed for the cleanest possible vacuum. Feedthroughs for the manipulator md the shutter, which are operated during metal coating, are sealed with leak-proof stainless-steel Dellows. The transfer rod slides through a baseplate feedthrough that is double o-ring sealed.

Structure and dynamics of interface between forsterite glass and amorphous ice

2020 ◽  
Vol 760 ◽  
pp. 138028
Author(s):  
Ayane Kubo ◽  
Junya Nishizawa ◽  
Tomoko Ikeda-Fukazawa
Keyword(s):  
Amorphous Ice ◽  
Structure And Dynamics

scholarly journals Feynman diagrams and rooted maps

Open Physics ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 149-167 ◽  
Author(s):  
Andrea Prunotto ◽  
Wanda Maria Alberico ◽  
Piotr Czerski
Keyword(s):  
Single Particle ◽  
Feynman Diagram ◽  
Feynman Diagrams ◽  
Topological Properties ◽  
Many Body ◽  
Perturbative Order ◽  
Original Definition ◽  
Many Body Systems ◽  
Definition Of ◽  
Particle Propagator

Abstract The rooted maps theory, a branch of the theory of homology, is shown to be a powerful tool for investigating the topological properties of Feynman diagrams, related to the single particle propagator in the quantum many-body systems. The numerical correspondence between the number of this class of Feynman diagrams as a function of perturbative order and the number of rooted maps as a function of the number of edges is studied. A graphical procedure to associate Feynman diagrams and rooted maps is then stated. Finally, starting from rooted maps principles, an original definition of the genus of a Feynman diagram, which totally differs from the usual one, is given.

scholarly journals A general expression for symmetry factors of Feynman diagrams

2002 ◽  
Vol 80 (8) ◽  
pp. 847-854 ◽  
Author(s):  
C D Palmer ◽  
M E Carrington
Keyword(s):  
General Expression ◽  
Feynman Diagram ◽  
Simple Formula ◽  
Feynman Diagrams ◽  
Scalar Theory ◽  
Symmetry Factor

The calculation of the symmetry factor corresponding to a given Feynman diagram is well known to be a tedious problem. We have derived a simple formula for these symmetry factors. Our formula works for any diagram in scalar theory (ϕ3 and ϕ4 interactions), spinor QED, scalar QED, or QCD. PACS Nos.: 11.10-z, 11.15-q, 11.15Bt

From parallel to single crystallization kinetics in high-density amorphous ice

2013 ◽  
Vol 88 (17) ◽  
Author(s):  
Markus Seidl ◽  
Katrin Amann-Winkel ◽  
Philip H. Handle ◽  
Gerhard Zifferer ◽  
Thomas Loerting
Keyword(s):  
Crystallization Kinetics ◽  
High Density ◽  
Amorphous Ice

Amorphous ice still a puzzle

Nature ◽  
1987 ◽  
Vol 326 (6116) ◽  
pp. 823-823 ◽  
Author(s):  
John Maddox
Keyword(s):  
Amorphous Ice

Feynman-diagram approach in heavy-ion interactions

1967 ◽  
Vol 52 (2) ◽  
pp. 570-573 ◽  
Author(s):  
L. Taffara ◽  
V. Vanzani
Keyword(s):  
Feynman Diagram ◽  
Heavy Ion ◽  
Ion Interactions ◽  
Diagram Approach

Convergent Raman Features in High Density Amorphous Ice, Ice VII, and Ice VIII under Pressure

2011 ◽  
Vol 115 (14) ◽  
pp. 3756-3760 ◽  
Author(s):  
Yukihiro Yoshimura ◽  
Sarah T. Stewart ◽  
Maddury Somayazulu ◽  
Ho Kwang Mao ◽  
Russell J. Hemley
Keyword(s):  
High Density ◽  
Amorphous Ice

Vacuum ultraviolet photoelectric emission from amorphous ice

1978 ◽  
Vol 68 (4) ◽  
pp. 1997-1999 ◽  
Author(s):  
Bill Baron ◽  
Dale Hoover ◽  
Ferd Williams
Keyword(s):  
Vacuum Ultraviolet ◽  
Amorphous Ice ◽  
Photoelectric Emission
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