scholarly journals On the Occurrence of Clathrate Hydrates in Extreme Conditions: Dissociation Pressures and Occupancies at Cryogenic Temperatures with Application to Planetary Systems

2020 ◽  
Vol 1 (3) ◽  
pp. 80
Author(s):  
Hideki Tanaka ◽  
Takuma Yagasaki ◽  
Masakazu Matsumoto
Keyword(s):  
Planetary Systems ◽  
Clathrate Hydrates ◽  
Extreme Conditions ◽  
Cryogenic Temperatures ◽  
Dissociation Pressures

scholarly journals Spatial distribution of air molecules within individual clathrate hydrates in polar ice sheets

2000 ◽  
Vol 31 ◽  
pp. 252-256 ◽  
Author(s):  
Tomoko Ikeda ◽  
Andrey N. Salamatin ◽  
Vladimir Ya. Lipenkov ◽  
Shinji Mae ◽  
Takeo Hondoh
Keyword(s):  
Spatial Distribution ◽  
Ice Cores ◽  
Clathrate Hydrate ◽  
Clathrate Hydrates ◽  
Diffusive Mass Transfer ◽  
Polar Ice Sheets ◽  
Hydrate Crystal ◽  
Diffusion Rates ◽  
The Difference ◽  
Dissociation Pressures

AbstractWe measured the N2/O2 ratios in clathrate hydrate crystals from Vostok Antarctic ice cores using Raman spectroscopy in order to investigate the spatial distribution of air molecules within a crystal. The results showed that the pattern of the spatial distribution of air molecules in clathrate hydrate depends on the crystal. Some clathrate hydrates have inhomogeneous distributions of the N2/O2 ratio within the crystals, while others are practically homogeneous. The spatial distribution of air molecules within an individual clathrate hydrate changes with time due to three processes: (1) the initial selective enclathration caused by the difference between the dissociation pressures of pure N2- and O2–clathrate hydrates, (2) the diffusive mass transfer of air molecules from surrounding air bubbles through the ice matrix, and (3) diffusion of air molecules in the clathrate hydrate crystal. The dissociation pressures and the diffusion rates of air molecules in ice and clathrate hydrate strongly depend on temperature. Therefore, it is concluded that the pattern of the spatial distribution of air molecules in clathrate hydrate is mainly determined by the depth at which they formed and the temperature in the ice sheet.

scholarly journals Ammonia clathrate hydrates as new solid phases for Titan, Enceladus, and other planetary systems

2012 ◽  
Vol 109 (37) ◽  
pp. 14785-14790 ◽  
Author(s):  
K. Shin ◽  
R. Kumar ◽  
K. A. Udachin ◽  
S. Alavi ◽  
J. A. Ripmeester
Keyword(s):  
Planetary Systems ◽  
Clathrate Hydrates ◽  
Solid Phases

Cryogenic atomic force microscopy

1991 ◽  
Vol 49 ◽  
pp. 54-55
Author(s):  
K. A. Fisher ◽  
M. G. L. Gustafsson ◽  
M. B. Shattuck ◽  
J. Clarke
Keyword(s):  
Room Temperature ◽  
Rapid Freezing ◽  
Cryogenic Temperatures ◽  
Soft Or ◽  
Electrically Conductive ◽  
Force Microscopy ◽  
Flexible Molecules ◽  
Advantages And Disadvantages ◽  
Atomic Force ◽  
Chemical Perturbation

The atomic force microscope (AFM) is capable of imaging electrically conductive and non-conductive surfaces at atomic resolution. When used to image biological samples, however, lateral resolution is often limited to nanometer levels, due primarily to AFM tip/sample interactions. Several approaches to immobilize and stabilize soft or flexible molecules for AFM have been examined, notably, tethering coating, and freezing. Although each approach has its advantages and disadvantages, rapid freezing techniques have the special advantage of avoiding chemical perturbation, and minimizing physical disruption of the sample. Scanning with an AFM at cryogenic temperatures has the potential to image frozen biomolecules at high resolution. We have constructed a force microscope capable of operating immersed in liquid n-pentane and have tested its performance at room temperature with carbon and metal-coated samples, and at 143° K with uncoated ferritin and purple membrane (PM).

38. The Attenuation of Hearing Protectors in Extreme Conditions

2002 ◽  
Author(s):  
E. Toppila ◽  
J. Starck ◽  
I. Pyykkö
Keyword(s):  
Extreme Conditions ◽  
Hearing Protectors

From Dust to Life

2017 ◽  
Author(s):  
John Chambers ◽  
Jacqueline Mitton
Keyword(s):  
Solar System ◽  
Extrasolar Planets ◽  
Planetary Systems ◽  
History Of Astronomy ◽  
Human Origins ◽  
History Of ◽  
The Subject ◽  
Emergence Of Life

The birth and evolution of our solar system is a tantalizing mystery that may one day provide answers to the question of human origins. This book tells the remarkable story of how the celestial objects that make up the solar system arose from common beginnings billions of years ago, and how scientists and philosophers have sought to unravel this mystery down through the centuries, piecing together the clues that enabled them to deduce the solar system's layout, its age, and the most likely way it formed. Drawing on the history of astronomy and the latest findings in astrophysics and the planetary sciences, the book offers the most up-to-date and authoritative treatment of the subject available. It examines how the evolving universe set the stage for the appearance of our Sun, and how the nebulous cloud of gas and dust that accompanied the young Sun eventually became the planets, comets, moons, and asteroids that exist today. It explores how each of the planets acquired its unique characteristics, why some are rocky and others gaseous, and why one planet in particular—our Earth—provided an almost perfect haven for the emergence of life. The book takes readers to the very frontiers of modern research, engaging with the latest controversies and debates. It reveals how ongoing discoveries of far-distant extrasolar planets and planetary systems are transforming our understanding of our own solar system's astonishing history and its possible fate.

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