Low‐Temperature Observation of Oxygen‐17 NMR in H2O, D2O, and Eutectic Solutions

1964 ◽  
Vol 41 (11) ◽  
pp. 3405-3407 ◽  
Author(s):  
Sherman W. Rabideau ◽  
Jasper A. Jackson
Keyword(s):  
Low Temperature ◽  
Temperature Observation

Low-temperature observation of the softened C-H stretching vibrations of cyclohexane on Rh(111)

2009 ◽  
Vol 80 (19) ◽  
Author(s):  
Takanori Koitaya ◽  
Atsushi Beniya ◽  
Kozo Mukai ◽  
Shinya Yoshimoto ◽  
Jun Yoshinobu
Keyword(s):  
Low Temperature ◽  
Temperature Observation ◽  
Stretching Vibrations

Use of platinum shadowing and magnetron sputter coating in an Oxford Cryotrans system to increase low temperature resolution of biological samples in a Hitachi field-emission Scanning Electron Microscope

1993 ◽  
Vol 51 ◽  
pp. 122-123
Author(s):  
William P. Wergin ◽  
Eric F. Erbe ◽  
Alan Robins
Keyword(s):  
Electron Microscope ◽  
Low Temperature ◽  
Scanning Electron Microscope ◽  
Field Emission ◽  
High Vacuum ◽  
Water Ice ◽  
Temperature Observation ◽  
Sputter Coating ◽  
Magnetron Sputter ◽  
Scanning Electron

Previous studies in this laboratory have shown that the resolution of biological specimens could be increased at least two fold in a conventional as well as a field emission SEM by substituting high vacuum evaporation of Pt for standard sputter coating. Because the EMscope SP2000A Sputter Cryo System and the Oxford CT 1500 Cryotrans System, which were used in these experiments, employed standard sputter coating, Pt shadowing and C evaporation were carried out in a modified Denton DFE-3 freeze-etch module on a DV-503 high vacuum evaporator and the coated specimens were transferred to the cryostage (EMscope) or the prechamber (Oxford) of the cryosystem. Not only did this procedure require a high vacuum evaporator but as a result of a through air transfer into LN2, considerable contamination condensed on the surface of the specimen. Most of this contamination consisted of water ice that could be easily sublimed; however, other unidentifiable contaminants remained. To increase the versatility of the cryosystem, reduce surface contamination of the specimen and evaluate alternative coating procedures, Oxford Cryotrans Systems were equipped and tested with a Pt evaporator and a high resolution magnetron sputter head. Low temperature observation and evaluation of the coated specimens were performed in a Hitachi S4100 field emission scanning electron microscope.

Low-temperature observation of localized uranium-moments in dilute (, U)Al2 alloys

Physica B+C ◽  
1980 ◽  
Vol 102 (1-3) ◽  
pp. 321-325 ◽  
Author(s):  
W. Schlabitz ◽  
F. Steglich ◽  
C.D. Bredl ◽  
W. Franz
Keyword(s):  
Low Temperature ◽  
Temperature Observation

Exsolution and inversion in pigeonite from the Whin Sill, Northern England

1978 ◽  
Vol 36 (1) ◽  
pp. 474-475
Author(s):  
P.P.K. Smith
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Homogeneous Nucleation ◽  
Silicate Mineral ◽  
Antiphase Boundaries ◽  
Two Phase ◽  
Primitive Form ◽  
The Core ◽  
Nucleation Mechanisms ◽  
And Inversion

Grains of pigeonite, a calcium-poor silicate mineral of the pyroxene group, from the Whin Sill dolerite have been ion-thinned and examined by TEM. The pigeonite is strongly zoned chemically from the composition Wo8En64FS28 in the core to Wo13En34FS53 at the rim. Two phase transformations have occurred during the cooling of this pigeonite:- exsolution of augite, a more calcic pyroxene, and inversion of the pigeonite from the high- temperature C face-centred form to the low-temperature primitive form, with the formation of antiphase boundaries (APB's). Different sequences of these exsolution and inversion reactions, together with different nucleation mechanisms of the augite, have created three distinct microstructures depending on the position in the grain.In the core of the grains small platelets of augite about 0.02μm thick have farmed parallel to the (001) plane (Fig. 1). These are thought to have exsolved by homogeneous nucleation. Subsequently the inversion of the pigeonite has led to the creation of APB's.

Low temperature x-ray microanalysis of frozen-hydrated tobacco leaves

1984 ◽  
Vol 42 ◽  
pp. 284-285
Author(s):  
S. Edith Taylor ◽  
Patrick Echlin ◽  
May McKoon ◽  
Thomas L. Hayes
Keyword(s):  
Low Temperature ◽  
Lemna Minor ◽  
Root Tips ◽  
Tobacco Leaves ◽  
X Ray ◽  
Whole Cells ◽  
Carbon Coated ◽  
The Right ◽  
Beam Currents ◽  
The University

Low temperature x-ray microanalysis (LTXM) of solid biological materials has been documented for Lemna minor L. root tips. This discussion will be limited to a demonstration of LTXM for measuring relative elemental distributions of P,S,Cl and K species within whole cells of tobacco leaves.Mature Wisconsin-38 tobacco was grown in the greenhouse at the University of California, Berkeley and picked daily from the mid-stalk position (leaf #9). The tissue was excised from the right of the mid rib and rapidly frozen in liquid nitrogen slush. It was then placed into an Amray biochamber and maintained at 103K. Fracture faces of the tissue were prepared and carbon-coated in the biochamber. The prepared sample was transferred from the biochamber to the Amray 1000A SEM equipped with a cold stage to maintain low temperatures at 103K. Analyses were performed using a tungsten source with accelerating voltages of 17.5 to 20 KV and beam currents from 1-2nA.

Bulk standards for low-temperature biological x-ray microanalysis

1984 ◽  
Vol 42 ◽  
pp. 282-283
Author(s):  
P. Echlin ◽  
M. McKoon ◽  
E.S. Taylor ◽  
C.E. Thomas ◽  
K.L. Maloney ◽  
...  
Keyword(s):  
Phase Separation ◽  
Low Temperature ◽  
Analytical Method ◽  
Salt Solutions ◽  
Absolute Concentration ◽  
Cooling Process ◽  
X Ray ◽  
The Absolute ◽  
Analytical Procedures ◽  
Electrical Conductors

Although sections of frozen salt solutions have been used as standards for x-ray microanalysis, such solutions are less useful when analysed in the bulk form. They are poor thermal and electrical conductors and severe phase separation occurs during the cooling process. Following a suggestion by Whitecross et al we have made up a series of salt solutions containing a small amount of graphite to improve the sample conductivity. In addition, we have incorporated a polymer to ensure the formation of microcrystalline ice and a consequent homogenity of salt dispersion within the frozen matrix. The mixtures have been used to standardize the analytical procedures applied to frozen hydrated bulk specimens based on the peak/background analytical method and to measure the absolute concentration of elements in developing roots.

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