Paracrystalline Structure of Glass-Like Carbons

2016 ◽  
Vol 7 (3) ◽  
pp. 355-363 ◽  
Author(s):  
Karolina Jurkiewicz ◽  
Stanisław Duber ◽  
Andrzej Burian
Keyword(s):  
Paracrystalline Structure

Analysis of crystallization behavior of Fe48Cr15Mo14Y2C15B6 bulk metallic glass by synchrotron radiation

2008 ◽  
Vol 23 (8) ◽  
pp. 2166-2173 ◽  
Author(s):  
T.A. Baser ◽  
M. Baricco ◽  
S. Enzo ◽  
G. Vaughan ◽  
A.R. Yavari
Keyword(s):  
Synchrotron Radiation ◽  
Structure Factor ◽  
Factor Model ◽  
Structure Evolution ◽  
Continuous Heating ◽  
Scanning Calorimetry ◽  
Crystallization Volume ◽  
Paracrystalline Structure ◽  
Diffraction Patterns ◽  
Average Lattice

The amorphous-to-crystalline transformation behavior of Fe48Cr15Mo14Y2C15B6 bulk metallic glasses was first investigated by high-temperature differential scanning calorimetry. Three events were detected with onset temperatures at 922, 975, and 1036 K, respectively. In situ synchrotron radiation x-ray diffraction patterns were collected during continuous heating and analyzed with the Rietveld approach. To describe simultaneously the amorphous fraction and crystallization products as a function of temperature, a paracrystalline structure-factor model was developed. It was included for quantitative evaluation of the amorphous phase, together with the structure factor of Cr23C6- and Fe3Mo3C-type phases observed during crystallization. Volume fractions of phases as well as lattice parameters, average lattice disorder, and crystallite size of the crystallized phases have been followed as a function of temperature. In this way, the structure evolution and thermal events have been closely inspected and accounted for by a crystallization mechanism.

Phase Structure of Acrylic Fibers Processed with Ionic Liquid as Solvent

2012 ◽  
Vol 560-561 ◽  
pp. 41-45 ◽  
Author(s):  
Xue Min Yin ◽  
Li Zhang ◽  
Xin Jun Zhu ◽  
Hua Ping Wang ◽  
Yu Mei Zhang
Keyword(s):  
Ionic Liquid ◽  
Phase Structure ◽  
Draw Ratio ◽  
High Viscosity ◽  
Wet Spinning ◽  
Ordered Structure ◽  
Strain Measurements ◽  
Initial Modulus ◽  
Paracrystalline Structure ◽  
Acrylic Fibers

The acrylic fibers were prepared by dry-jet wet spinning technology from polyacrylinitrile (PAN) /1-butyl-3-methylimidazolium chloride ([BMIM]Cl) solution for the investigation of phase structure changing with drawing in boiling water. The DMA, WAXD and stress-strain measurements were conducted. It is shown that only a single Tg was observed from DMA and the paracrystalline structure was shown from WAXD. Although the the crystallinity and orientation increased with increasing draw ratio, the high crystallinity of the pre-drawn fiber indicates that the ordered structure was formed in the pre-drawn fiber by the high pre-drawn ratio (3.5) during the dry-jet wet spinning from high-viscosity PAN/[BMIM]Cl solution. It is also found that the initial modulus, ultimate elongation and tenacity increased with the increase of draw ratio.

scholarly journals Tau protein becomes long and stiff upon phosphorylation: correlation between paracrystalline structure and degree of phosphorylation.

1989 ◽  
Vol 109 (4) ◽  
pp. 1643-1651 ◽  
Author(s):  
T Hagestedt ◽  
B Lichtenberg ◽  
H Wille ◽  
E M Mandelkow ◽  
E Mandelkow
Keyword(s):  
Alkaline Phosphatase ◽  
Structural Properties ◽  
Tau Protein ◽  
The State ◽  
Striking Feature ◽  
Protein Tau ◽  
Microtubule Associated Protein Tau ◽  
Paracrystalline Structure ◽  
High Degree

In a previous report we have shown that microtubule-associated protein tau can be induced to form paracrystals (Lichtenberg, B., E.-M. Mandelkow, T. Hagestedt, and E. Mandelkow. 1988. Nature [Lond.]. 334:359-362). A striking feature was the high degree of elasticity of the molecules. We now report that this property is related to the state of phosphorylation. When tau is dephosphorylated by alkaline phosphatase, it becomes shorter and more elastic; when it is phosphorylated by Ca++/calmodulin-dependent kinase, it becomes longer and stiffer. This may provide a model for the control of structural properties of tau-like molecules by phosphorylation.

Intranuclear elements in the Leydig cell of the snail Helix

1970 ◽  
Vol 48 (3) ◽  
pp. 614-615 ◽  
Author(s):  
A. S. M. Saleuddin
Keyword(s):  
Leydig Cell ◽  
Paracrystalline Structure

The presence of glycogen granules and a paracrystalline structure has been reported in the nucleus of the Leydig cell of Helix.

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