scholarly journals Influence of temperature gradient on diffracted X-ray spectrum in quartz crystal

2016 ◽  
Vol 135 ◽  
pp. 012028
Author(s):  
A R Mkrtchyan ◽  
A P Potylitsyn ◽  
A V Vukolov ◽  
A I Novokshonov ◽  
A S Gogolev ◽  
...  
Keyword(s):  
Temperature Gradient ◽  
Quartz Crystal ◽  
Influence Of Temperature ◽  
X Ray

scholarly journals Focusing of hard X-ray beams in quartz crystal under the temperature gradient

2014 ◽  
Vol 70 (a1) ◽  
pp. C1137-C1137
Author(s):  
Vahan Kocharyan ◽  
Sargis Khlopuzyan ◽  
Poghos Grigoryan ◽  
Edik Baghdasaryan ◽  
Ruben Amiraghyan
Keyword(s):  
Temperature Gradient ◽  
Plane Wave ◽  
Quartz Crystal ◽  
Spectral Width ◽  
X Rays ◽  
Ultrasonic Vibrations ◽  
Diffraction Vector ◽  
Wave Fronts ◽  
X Ray ◽  
Focus Point

The research of the focusing and defocusing of the diffracted X-rays with different wave fronts in crystals under the influences of the temperature gradient and the ultrasonic vibrations is given in the works [1,2]. This work is dedicated experimentally investigation of Laue diffraction of the hard X-rays in quartz single crystals under the influence of the temperature gradient. It is shown that the reflected beams under the influence of the temperature gradient are focused. When the vector of the temperature gradient is anti parallel to the diffraction vector, in accordance to the increasing value of the temperature gradient the focus point continuously approaches the crystal. When the vector of the temperature gradient is parallel to the diffraction vector, in accordance with the increasing value of the temperature gradient the focus point continuously distances itself from the crystal, and at a certain value of the temperature gradient it becomes a plane wave. Parallel to the further increasing of the temperature gradient we see an imaginary focus, which continuously approaches the entry surface of the crystal. It is shown that by using a thicker single crystal it is possible to focus and pump a larger angular and spectral width of X-rays in the direction of diffraction.

Effect of the Temperature Gradient on the X-ray Diffraction Spectrum of a Quartz Crystal

2017 ◽  
Vol 11 (6) ◽  
pp. 1109-1112
Author(s):  
A. R. Mkrtchyan ◽  
A. P. Potylitsyn ◽  
A. V. Vukolov ◽  
A. I. Novokshonov ◽  
A. S. Gogolev ◽  
...  
Keyword(s):  
Temperature Gradient ◽  
Quartz Crystal ◽  
Diffraction Spectrum ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals Unbinding of Hyaluronan Accelerates the Enzymatic Activity of Bee Hyaluronidase

2011 ◽  
Vol 286 (41) ◽  
pp. 35699-35707 ◽  
Author(s):  
Attila Iliás ◽  
Károly Liliom ◽  
Brigitte Greiderer-Kleinlercher ◽  
Stephan Reitinger ◽  
Günter Lepperdinger
Keyword(s):  
Experimental Data ◽  
Quartz Crystal ◽  
Surface Loop ◽  
X Ray ◽  
Site Model ◽  
Substrate Interaction ◽  
Close Proximity ◽  
Binding Groove ◽  
The One ◽  
Best Fit

Hyaluronan (HA), a polymeric glycosaminoglycan ubiquitously present in higher animals, is hydrolyzed by hyaluronidases (HAases). Here, we used bee HAase as a model enzyme to study the HA-HAase interaction. Located in close proximity to the active center, a bulky surface loop, which appears to obstruct one end of the substrate binding groove, was found to be functionally involved in HA turnover. To better understand kinetic changes in substrate interaction, binding of high molecular weight HA to catalytically inactive HAase was monitored by means of quartz crystal microbalance technology. Replacement of the delimiting loop by a tetrapeptide interconnection increased the affinity for HA up to 100-fold, with a KD below 1 nm being the highest affinity among HA-binding proteins surveyed so far. The experimental data of HA-HAase interaction were further validated showing best fit to the theoretically proposed sequential two-site model. Besides the one, which had been shown previously in course of x-ray structure determination, a previously unrecognized binding site works in conjunction with an unbinding loop that facilitates liberation of hydrolyzed HA.

X-ray reflectivity study of the influence of temperature fluctuations on the density profile of thin liquid films

2004 ◽  
Vol 219 (4) ◽  
Author(s):  
Robert Fendt ◽  
Michael Sprung ◽  
Christian Gutt ◽  
Oliver Hermann Seeck ◽  
Metin Tolan
Keyword(s):  
Density Profile ◽  
Temperature Fluctuations ◽  
Liquid Films ◽  
Electron Density Profile ◽  
Thin Liquid Films ◽  
Inversion Method ◽  
Layered System ◽  
Small Temperature ◽  
Influence Of Temperature ◽  
X Ray

AbstractWe report on X-ray reflectivity experiments of thin liquid heptane films. The films were examined using X-ray reflectivity and modelled both as a layered system using the Parratt algorithm and using a ´phase guessing´ inversion method. Our results combined with simulations of films of shrinking thickness show that small temperature instabilities during the investigation can cause artifacts in the electron density profile. These can easily be mistaken for density os cillations near the interface as might be expected for liquid molecules near a hard wall.

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