scholarly journals THE FINE STRUCTURE OF SILK FIBROIN

1967 ◽  
Vol 32 (2) ◽  
pp. 289-295 ◽  
Author(s):  
M. G. Dobb ◽  
R. D. B. Fraser ◽  
T. P. Macrae
Keyword(s):  
Fine Structure ◽  
Silk Fibroin ◽  
Crystalline Material ◽  
Fiber Axis ◽  
X Ray Diffraction ◽  
Silk Fibers ◽  
X Ray ◽  
Considerable Length ◽  
Bombyx Mori Silk ◽  
Lateral Extent

The fine structure of Bombyx mori silk fibroin was investigated by electron microscopy and X-ray diffraction techniques. Examination of silk fibers fragmented with ultrasonic radiation and negatively stained revealed the presence of ribbon-like filaments of well-defined lateral dimensions. Analysis of the breadths of the equatorial reflections in the X-ray diffraction pattern of fibroin yielded similar dimensions for the lateral extent of the crystallites. It is concluded that the crystalline material in B. mori silk fibroin is in the form of ribbon-like filaments of considerable length parallel to the fiber axis and of lateral dimensions approximately 20 x 60 A.

scholarly journals Влияние температуры термомеханической обработки на гетерогенную структуру углеродного волокна

2019 ◽  
Vol 89 (12) ◽  
pp. 1862
Author(s):  
В.А. Тюменцев ◽  
А.Г. Фазлитдинова ◽  
С.А. Подкопаев
Keyword(s):  
Fine Structure ◽  
Thermomechanical Treatment ◽  
Carbon Fibers ◽  
Fiber Material ◽  
Coherent Scattering ◽  
Component Composition ◽  
Fiber Axis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Increasing Temperature

The change in the fine structure of carbon fibers with increasing temperature of thermomechanical treatment was studied by X-ray diffraction analysis. It is shown that the fiber material is heterogeneous, its component composition is determined by the modes of thermomechanical treatment, and also depends on the angle of the orientation of the coherent scattering regions relative to the fiber axis

scholarly journals The Fine Structure and Biosynthesis of Silk Fibroin

1952 ◽  
Vol 5 (3) ◽  
pp. 366 ◽  
Author(s):  
EH Mercer
Keyword(s):  
Fine Structure ◽  
Silk Fibroin ◽  
Microscopic Examination ◽  
Electron Microscopic Examination ◽  
Fibre Axis ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
X Ray

Electron microscopic examination of fibrillar fragments produced by the enzymic disintegration of silk fibroin suggests the existence of fine microfibrils about 100 A in diameter extended parallel to the length of the fibre axis. The microfibrils are similar in width to the crystalline micelles deduced from X-ray diffraction.

scholarly journals Fabrication of Silk Resin with High Bending Properties by Hot-Pressing and Subsequent Hot-Rolling

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2716
Author(s):  
Hoang Anh Tuan ◽  
Shinji Hirai ◽  
Shota Inoue ◽  
Alharbi A. H. Mohammed ◽  
Shota Akioka ◽  
...  
Keyword(s):  
Hot Rolling ◽  
Hot Pressing ◽  
Bending Strength ◽  
Decomposition Temperature ◽  
Attenuated Total Reflectance ◽  
X Ray Diffraction ◽  
Bending Properties ◽  
X Ray ◽  
Bombyx Mori Silk ◽  
Increased Strength

This research reports the processability and mechanical properties of silk resins prepared by hot-pressing followed by hot-rolling and then analyzes their thermal and structural properties. The results show that regenerated silk (RS) resins are better suited for hot-rolling than Eri and Bombyx mori silk resins (untreated silk). When hot-rolling at 160 °C with a 50% of reduction ratio, maximum bending strength and Young’s modulus of RS resin reaches 192 MPa and 10.2 GPa, respectively, after pretreatment by immersion in 40 vol% ethanol, and 229 MPa and 12.5 GPa, respectively, after pretreatment by immersion in boiling water. Increased strength of the material is attributed to the increased content of aggregated strands and intramolecular linking of β sheets (attenuated total reflectance Fourier-transform infrared spectroscopy) and higher crystallinity (X-ray diffraction analysis). After hot-pressing and hot-rolling, RS resins have a stable decomposition temperature (297 °C).

Extended X-ray absorption fine-structure analysis of vacuum-deposited amorphous germanium

1989 ◽  
Vol 67 (4) ◽  
pp. 358-364 ◽  
Author(s):  
G. W. Johnson ◽  
D. E. Brodie ◽  
E. D. Crozier
Keyword(s):  
Fine Structure ◽  
Amorphous Materials ◽  
Amorphous Material ◽  
Amorphous Structure ◽  
Low Energy ◽  
X Ray Diffraction ◽  
Two Phase ◽  
Edge Structure ◽  
X Ray ◽  
Low Energy Electrons

In this study, thin films of germanium have been vacuum deposited in four regimes. Care was taken to prepare reproducible films, which required that the partial pressure of water be below 10−8 Torr during deposition (1 Torr = 133.3 Pa). First, films deposited onto substrates held during deposition at a temperature Ts that is below 473 K are amorphous. Once annealed above 423 K, their electrical conductivity and optical band gap are independent of deposition temperature and rate, and of whether or not low-energy electron irradiation of the substrate is used during deposition. This suggests that a well-defined and reproducible structure is being prepared. Second, a "precrystallization regime" is obtained when Ts is between 473 and 513 K. Extended X-ray adsorption fine-structure and X-ray diffraction confirm that this regime is a two-phase mixture of amorphous material and crystallites. Third, films deposited with Ts near 513 K, while using low-energy electrons to bombard the substrate, are amorphous, but these films have different electrical and optical properties from the films m the first regime. From this, we infer that a second well-defined amorphous structure exists. Fourth, films deposited with Ts above 513 K are polycrystalline. Extended X-ray adsorption fine-structure and X-ray adsorption near-edge structure could not distinguish between the two amorphous materials in the first and third regimes.

Differentiation of biological hydroxyapatite compounds by infrared spectroscopy, x-ray diffraction and extended x-ray absorption fine structure

2001 ◽  
Vol 90 (12) ◽  
pp. 6440-6446 ◽  
Author(s):  
E. Chassot ◽  
H. Oudadesse ◽  
J. Irigaray ◽  
E. Curis ◽  
S. Bénazeth ◽  
...  
Keyword(s):  
Fine Structure ◽  
Infrared Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Absorption Fine ◽  
X Ray Absorption

The Application of X-Ray Diffraction to Medical Problems

1959 ◽  
Vol 3 ◽  
pp. 349-364
Author(s):  
Jonathan Parsons
Keyword(s):  
Kidney Stones ◽  
Crystalline Material ◽  
Routine Analysis ◽  
X Ray Diffraction ◽  
Medical Problems ◽  
Thorium Dioxide ◽  
X Ray

AbstractThe use of the X-ray diffraction Debye-Scherrer powder technique for the identification of crystalline material often found in pathologic tissue is discussed. Cases cited include: heart calcification, lung silicosis, thorium dioxide in liver and spleen, and granulomas of the skin and pericardium. The routine analysis of kidney stones using powder cameras as well as an X-ray diffractometer will be described.

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