The IR spectrum of triplet phenylnitrene. On the origin of didehydroazepine in low temperature matrices

1990 ◽  
Vol 112 (15) ◽  
pp. 5879-5881 ◽  
Author(s):  
James C. Hayes ◽  
Robert S. Sheridan
Keyword(s):  
Low Temperature ◽  
Ir Spectrum

CRYOGENIC GREASE LUBRICANTS FOR ROCKET AND SPACE TECHNOLOGY

2021 ◽  
pp. 31-41
Author(s):  
Andrey D. PLOTNIKOV ◽  
Aleksandr V. VODOLAZHSKIY ◽  
Natalya S. YAKUPOVA
Keyword(s):  
Chemical Composition ◽  
Low Temperature ◽  
Key Words ◽  
Ir Spectrum ◽  
Practical Relevance ◽  
Space Technology ◽  
Potential Evaporation ◽  
Testing Methods ◽  
Solidification Temperature ◽  
Temperature Characteristics

The paper represents requirements for cryogenic grease lubricants used in the rocket and space technology. Data on lubricants based on perfluoropolyether liquid FEN is provided. New lubricant testing methods enabling to analyze their chemical composition and low-temperature characteristics are proposed. Quoted are investigation results for the equivalents of previously used cryogenic lubricants NIKA, NIRA and «Ametist». A practical relevance of the paper has been proven by introduction of low-temperature lubricants «Sever» currently being used in rocket and space items, as well аs successful application of the developed lubricant incoming inspection procedures at RSC Energia. Key words: low-temperature lubricant, perfluoropolyether liquid FEN, viscosity, solidification temperature, IR spectrum, potential evaporation.

IR spectrum of H2SO4 species trapped in low temperature solid CO and in CO containing matrices

1998 ◽  
Vol 94 (16) ◽  
pp. 2277-2286 ◽  
Author(s):  
Aharon Givan ◽  
Lars A. Larsen ◽  
Aharon Loewenschuss ◽  
Claus J. Nielsen
Keyword(s):  
Low Temperature ◽  
Ir Spectrum

Adsorption of Bisphenol A from the Solution by β-Cyclodextrin Modified TiO2

2014 ◽  
Vol 665 ◽  
pp. 579-582 ◽  
Author(s):  
Li Guo ◽  
Ji Ping Yu ◽  
Xiao Li Li ◽  
Wen Ding
Keyword(s):  
Low Temperature ◽  
Ir Spectrum ◽  
Active Sites ◽  
Control Experiment ◽  
Process Analysis ◽  
Crosslinking Agent ◽  
X Ray Diffraction ◽  
X Ray ◽  
Modification Process ◽  
Enhanced Adsorption

TiO2nanoparticles were modified by β-cyclodextrin with crosslinking agent and characterized by X-ray diffraction (XRD) and infrared spectrum (IR spectrum). The X-ray diffraction examination showed that the crystal pattern of TiO2was not changed because of low-temperature during modification process. Analysis of IR spectrum showed that β-cyclodextrin was supported on surface of TiO2nanoparticles. The adsorption control experiment indicated β-cyclodextrin modification methods strongly enhanced adsorption capacity of TiO2for bisphenols A(BPA), because β-cyclodextrin which was on surface of nanoparticles increased the adsorption active sites of TiO2.

Low-temperature IR spectrum of ??-D-glucose and of its deuterated analog

1984 ◽  
Vol 40 (2) ◽  
pp. 173-178
Author(s):  
E. V. Korolik ◽  
N. V. Ivanova ◽  
V. V. Sivchik ◽  
T. E. Kolosova ◽  
R. G. Zhbankov
Keyword(s):  
Low Temperature ◽  
Ir Spectrum ◽  
Deuterated Analog

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.

Field ion microscopy

1988 ◽  
Vol 46 ◽  
pp. 434-435
Author(s):  
Gert Ehrlich
Keyword(s):  
Low Temperature ◽  
Sample Surface ◽  
Low Pressure ◽  
Radius Of Curvature ◽  
Field Ion Microscopy ◽  
Phosphor Screen ◽  
Ion Microscopy ◽  
Field Ion Microscope

The field ion microscope, devised by Erwin Muller in the 1950's, was the first instrument to depict the structure of surfaces in atomic detail. An FIM image of a (111) plane of tungsten (Fig.l) is typical of what can be done by this microscope: for this small plane, every atom, at a separation of 4.48Å from its neighbors in the plane, is revealed. The image of the plane is highly enlarged, as it is projected on a phosphor screen with a radius of curvature more than a million times that of the sample. Müller achieved the resolution necessary to reveal individual atoms by imaging with ions, accommodated to the object at a low temperature. The ions are created at the sample surface by ionization of an inert image gas (usually helium), present at a low pressure (< 1 mTorr). at fields on the order of 4V/Å.

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