Rapid small-angle X-ray diffraction of a tonically contracting molluscan smooth muscle recorded with imaging plates

1989 ◽  
Vol 22 (1) ◽  
pp. 72-74 ◽  
Author(s):  
Y. Tajima ◽  
K. Okada ◽  
O. Yoshida ◽  
T. Seto ◽  
Y. Amemiya
Keyword(s):  
Small Angle ◽  
Structural Changes ◽  
High Sensitivity ◽  
Imaging Plate ◽  
Layer Line ◽  
X Ray Diffraction ◽  
Thin Filaments ◽  
X Ray ◽  
Area Detector ◽  
Diffraction Patterns

Small-angle X-ray diffraction patterns from the anterior byssus retractor muscles of Mytilus edulis contracting tonically in response to stimulation with acetylcholine were recorded in a 30 s exposure with synchrotron radiation and a high-sensitivity X-ray area detector called an imaging plate. The 190 Å layer line from the thin filaments increased in intensity with increase in tonic tension up to 6 x 104 kg m−2. Above this value, the layer-line intensity remained almost constant and comparable to that for a contracting skeletal muscle, indicating that the same structural changes of the thin filaments occur in both muscles.

scholarly journals Determination of crystal size distribution by two-dimensional X-ray diffraction

2014 ◽  
Vol 70 (a1) ◽  
pp. C1131-C1131
Author(s):  
Alejandro Rodriguez-Navarro ◽  
Krzysztof Kudłacz
Keyword(s):  
Size Distribution ◽  
Crystal Size ◽  
High Sensitivity ◽  
Crystal Size Distribution ◽  
Polycrystalline Materials ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Area Detector ◽  
Diffraction Patterns

Polycrystalline materials properties and behaviour are ultimately determined by their crystallinity, phase composition and microstructure (i.e., crystal size, preferential orientation). Two-dimensional (2D) diffraction patterns collected with an area detector (i.e., CDD), available in modern X-ray diffractometers, contain detailed information about all these important material characteristics. Furthermore, recent advances in detector technologies permits the collection of high resolution diffraction patterns in which the microstructure of the material can be directly imaged. If the size of beam relative to the crystal size in the sample is adequately choosen, the diffraction pattern produced will have spotty rings in which the spots are the diffracted images of individual grains. The resolution of the image is mainly dependent on the characteristics of the X-ray beam (i.e., diameter, angular divergence), which can be modulated by X-ray optics, sample to detector distance, the pixel size of the detector and the sharpness of the point spread function. From these patterns, the crystal size distribution of different crystalline phases present in the sample can be independently determined using specialized software capable of extracting and combining the information contained in these patterns. This technique is applicable to materials with crystal sizes ranging from submicron to mm sizes and is complementary to techniques based on peak profile analyses (i.e., Scherrer method) which are applicable only to nanocrystalline materials. Finally, given the high sensitivity of current detectors, crystal size evolution can be followed in real-time to study important transformation processes such as crystallization, annealing, etc. The use of 2D X-ray diffraction as applied to microstructure characterization will be illustrated through several examples.

Influence of Aging Time on the Structural Changes of Cassava Thermoplastic Starch

2012 ◽  
Vol 1372 ◽  
Author(s):  
José H. Mina ◽  
Alex Valadez ◽  
Pedro J. Herrera-Franco ◽  
Tanit Toledano
Keyword(s):  
Yield Stress ◽  
Amorphous Phase ◽  
Structural Changes ◽  
Thermoplastic Starch ◽  
X Ray Diffraction ◽  
X Ray ◽  
Second Stage ◽  
Diffraction Patterns ◽  
Type V ◽  
Stress Drops

ABSTRACTIn this work the change in the structural properties of cassava (manihot sculenta Crantz) thermoplastic starch (TPS) under controlled environment (humidity and temperature) was studied. Fourier Transform Infrared spectroscopy (FTIR) and X-ray diffraction (XRD) results showed an evident increasing in the amorphous phase of the TPS regarding the native starch. There was a relative decrease of the band at 1047 cm-1 associated to crystalline structure of starch compared to the amorphous peak at 1022 cm-1. The X-ray diffraction patterns confirmed the increment of the amorphous phase in the TPS samples. Likewise the X-ray diffraction patterns shows evidence of residual type C crystallinity and the formation of a new crystalline phase type VH due to the orientation induced in plasticization process. In first stage of conditioning the tensile yield stress drops from 7.5 drops to 0.5 MPa and the break strain increases 1000%. At the same time it seems that the crystallinity of the samples increases as was evidenced by the gradually increasing of the FTIR band at 1047 cm-1. In a second stage, the yield stress increases, the break strain drops and the crystallinity continue growing steadily. These findings suggest that coexist two phenomena simultaneously in the samples. A phenomenon of re-crystallization (retrogradation) that tends to make the material more stiff and a process of plasticization that tends to softening it. It seems that the latter mechanism predominates in the first stage, at short times, and the former in the second stage, at older times.

A model-independent maximum-entropy method for the inversion of small-angle X-ray diffraction patterns

1999 ◽  
Vol 32 (6) ◽  
pp. 1069-1083 ◽  
Author(s):  
J. A. Elliott ◽  
S. Hanna
Keyword(s):  
Maximum Entropy ◽  
Small Angle ◽  
Disordered Systems ◽  
Maximum Entropy Method ◽  
Structural Model ◽  
Entropy Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Model Independent ◽  
Diffraction Patterns

A model-independent maximum-entropy method is presented which will produce a structural model from small-angle X-ray diffraction data of disordered systems using no other prior information. In this respect, it differs from conventional maximum-entropy methods which assume the form of scattering entitiesa priori. The method is demonstrated using a number of different simulated diffraction patterns, and applied to real data obtained from perfluorinated ionomer membranes, in particular Nafion™, and a liquid crystalline copolymer of 1,4-oxybenzoate and 2,6-oxynaphthoate (B–N).

An X-Ray Small-Angle Scattering Instrument

1967 ◽  
Vol 11 ◽  
pp. 332-338 ◽  
Author(s):  
Donald M. Koffman
Keyword(s):  
Small Angle ◽  
Scintillation Counter ◽  
Small Angle Scattering ◽  
High Angular Resolution ◽  
X Ray Diffraction ◽  
Multiple Diffraction ◽  
Double Crystal ◽  
X Ray ◽  
Angle Scattering ◽  
Diffraction Patterns

AbstractAn X-ray small-angle scattering instrument is described which is used for recording X-ray diffraction patterns or small-angle X-ray scattering curves in an angular region very close to the direct beam. The measurement of X-ray intensity is accomplished with standard geiger or scintillation counter techniques. The instrument is designed for use with a spot-focus or vertical-line X-ray source, In essence, it is a multiple-reflection double-crystal diffractometer, based on a concept developed by Bonse and Hart, employing two grooved perfect germanium crystals arranged in the parallel position. Multiple diffraction from these crystals produces a monochromated X-ray beam which can be several millimeters wide while still exhibiting extremely high angular resolution. As a result, effective sample volumes can be employed with maximum volume-to-thickness ratios. The principal features of the instrument are discussed with emphasis on the advantages of this device over those employing complex slit systems and film-re cording techniques, Data are presented to illustrate the operation, intensity, and resolution of the unit.

scholarly journals Hierarchical architecture of spider attachment setae reconstructed from scanning nanofocus X-ray diffraction data

2019 ◽  
Vol 16 (150) ◽  
pp. 20180692 ◽  
Author(s):  
Clemens F. Schaber ◽  
Silja Flenner ◽  
Anja Glisovic ◽  
Igor Krasnov ◽  
Martin Rosenthal ◽  
...  
Keyword(s):  
Small Angle ◽  
Adhesive Contact ◽  
Quantitative Information ◽  
Hair Shaft ◽  
Hierarchical Architecture ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dry Adhesion ◽  
Angle Scattering ◽  
Diffraction Patterns

When sitting and walking, the feet of wandering spiders reversibly attach to many surfaces without the use of gluey secretions. Responsible for the spiders' dry adhesion are the hairy attachment pads that are built of specially shaped cuticular hairs (setae) equipped with approximately 1 µm wide and 20 nm thick plate-like contact elements (spatulae) facing the substrate. Using synchrotron-based scanning nanofocus X-ray diffraction methods, combining wide-angle X-ray diffraction/scattering and small-angle X-ray scattering, allowed substantial quantitative information to be gained about the structure and materials of these fibrous adhesive structures with 200 nm resolution. The fibre diffraction patterns showed the crystalline chitin chains oriented along the long axis of the attachment setae and increased intensity of the chitin signal dorsally within the seta shaft. The small-angle scattering signals clearly indicated an angular shift by approximately 80° of the microtrich structures that branch off the bulk hair shaft and end as the adhesive contact elements in the tip region of the seta. The results reveal the specific structural arrangement and distribution of the chitin fibres within the attachment hair's cuticle preventing material failure by tensile reinforcement and proper distribution of stresses that arise upon attachment and detachment.

scholarly journals A simple model for dynamic small-angle X-ray diffraction in colloidal crystals

2007 ◽  
Vol 40 (1) ◽  
pp. 144-150 ◽  
Author(s):  
Alex G. F. de Beer ◽  
Andrei V. Petukhov
Keyword(s):  
Simple Model ◽  
Small Angle ◽  
Colloidal Crystals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns

A simple model is presented that allows calculation of the small-angle X-ray diffraction patterns of perfect colloidal crystals. The model is based on the Wentzel–Kramers–Brillouin approximation and permits a straightforward evaluation of multibeam interactions. Results are illustrated by several examples.

Oriented Crystallization of Amides on Collagen with Modification of the Collagen Lattice

1963 ◽  
Vol 7 ◽  
pp. 252-255 ◽  
Author(s):  
E. H. Shaw
Keyword(s):  
Carbonyl Group ◽  
Collagen Fiber ◽  
Saturated Solution ◽  
Fiber Axis ◽  
Layer Line ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns ◽  
Collagen Layer ◽  
Rat Tail

AbstractRat tail tendons were fixed in 4% formaldehyde at 250 g tension, soaked in nearly saturated solution of the amides involved, and dried while still under tension. X-ray diffraction patterns, taken with rotation around the collagen fiber axis, showed well-defined layer lines of the amide and usually substantial expansion of the collagen equatorial spacing.The layer lines on collagen, in two cases on abnormal or polymorphic axes, are clustered around the number 4.86 ± 0.33 Å, or a figure twice this, implying the presence of a repeating hydro gen-bond accepting group such as the carbonyl group at this interval. The prominent collagen layer line at 9.4 Å is approximately double this interval.

Education program for controversial defect of recent X-ray instrument termed as a simultaneous small angle X-ray scattering and wide angle X-ray diffraction measuring instrument

2018 ◽  
Vol 90 (6) ◽  
pp. 969-987
Author(s):  
Masaru Matsuo ◽  
Yuezhen Bin
Keyword(s):  
Small Angle ◽  
Diffraction Peak ◽  
Bragg Angle ◽  
Imaging Plate ◽  
Wide Angle ◽  
Measuring Instrument ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

Abstract Simultaneous rotations of sample and X-ray detected counter are needed to evaluate orientation distribution of crystallites and amorphous chains oriented predominantly parallel to the film surface in addition to exact diffraction peak profiles obtained without the complicated intensity corrections. The rotation mode is known as “θ–2θ scanning” system (θ: film, 2θ: counter). The system has been mainly used in research and development institutes. However, such instruments are not produced at present. Recently, small angle X-ray scattering (SAXS) and wide angle X-ray diffraction (WAXD) intensities have been measured by using X-ray beam generated along one direction. The brand name of the instrument is “a simultaneous SAXS and WAXD measuring instrument”. The X-ray beam generated by the instrument has surely high luminance providing high degree resolution of peak profiles by diffraction and/or scattering. The sample stage and detector, however, are fixed, since the intensities for SAXS and WAXD are obtained by the digital display of the number of X-ray photons detected on the imaging plate. Such optical system contains controversial defect on evaluating orientation of crystal planes parallel to the surface of films prepared by T-die and inflation methods as well as the exact profile. The imaging plate cannot detect the diffraction intensity from the crystal planes existing in the angle range between incident beam and Bragg angle associated with the diffraction peak position of the individual crystal planes.

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