scholarly journals Ultra-small-angle neutron scattering with azimuthal asymmetry

2016 ◽  
Vol 49 (3) ◽  
pp. 934-943 ◽  
Author(s):  
X. Gu ◽  
D. F. R. Mildner
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Incident Beam ◽  
Bedding Plane ◽  
Double Crystal ◽  
Thin Sections ◽  
Wide Range ◽  
Sans Data ◽  
Double Crystal Diffractometer

Small-angle neutron scattering (SANS) measurements from thin sections of rock samples such as shales demand as great a scattering vector range as possible because the pores cover a wide range of sizes. The limitation of the scattering vector range for pinhole SANS requires slit-smeared ultra-SANS (USANS) measurements that need to be converted to pinhole geometry. The desmearing algorithm is only successful for azimuthally symmetric data. Scattering from samples cut parallel to the plane of bedding is symmetric, exhibiting circular contours on a two-dimensional detector. Samples cut perpendicular to the bedding show elliptically dependent contours with the long axis corresponding to the normal to the bedding plane. A method is given for converting such asymmetric data collected on a double-crystal diffractometer for concatenation with the usual pinhole-geometry SANS data. The aspect ratio from the SANS data is used to modify the slit-smeared USANS data to produce quasi-symmetric contours. Rotation of the sample about the incident beam may result in symmetric data but cannot extract the same information as obtained from pinhole geometry.

Absolute Calibration of Small-Angle Neutron Scattering Data of a Double-Crystal Diffractometer

1997 ◽  
Vol 30 (5) ◽  
pp. 857-861 ◽  
Author(s):  
F. Carsughi ◽  
D. Bellmann ◽  
J. Kulda ◽  
M. Magnani ◽  
M. Stefanon
Keyword(s):  
Neutron Scattering ◽  
Cross Section ◽  
Cross Sections ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Scattering Data ◽  
Absolute Calibration ◽  
Double Crystal ◽  
Similar Materials ◽  
Double Crystal Diffractometer

Small-angle neutron scattering (SANS) experiments generally provide the absolute SANS cross sections and this allows quantitative results to be obtained; however, data collected at double-crystal diffractometers are frequently not normalized to absolute cross sections and they are used only for qualitative analysis. In point-geometry diffractometers, the normalization is done by comparing the scattered intensities to those of samples of known cross sections or by measuring the direct-beam intensity; in the double-crystal diffractometer, the incident flux information is contained in the rocking curve measured without a sample and this feature can therefore be used to normalize the scattered intensities to the SANS cross sections. A sample of thickness 1 mm of the Ni-based superalloy UDIMET 520 was analyzed at a double-crystal diffractometer; the SANS cross section obtained by the proposed procedure compares well with the SANS cross section found for similar materials by using conventional point-geometry diffractometers and calibrated by light water.

scholarly journals High-pressure small-angle neutron scattering studies of glucose isomerase conformation in solution

2009 ◽  
Vol 42 (3) ◽  
pp. 461-468 ◽  
Author(s):  
Ewa Banachowicz ◽  
Maciej Kozak ◽  
Adam Patkowski ◽  
Gerhard Meier ◽  
Joachim Kohlbrecher
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Electrostatic Interactions ◽  
Xylose Isomerase ◽  
Glucose Isomerase ◽  
Secondary Standard ◽  
High Structural Stability ◽  
Streptomyces Rubiginosus ◽  
Sans Data

Small-angle neutron scattering (SANS) of solutions of glucose/xylose isomerase fromStreptomyces rubiginosuswas measured as a function of pressure. It is shown that the structure of the enzyme in solution as seen by SANS is practically the same as that in the crystal and does not change with pressure up to 150 MPa. This reflects the unusually high structural stability of this material, which makes it extremely interesting to use as a secondary standard for pressure-dependent SANS experiments. This lack of pressure dependence of the SANS data also indicates that any possible change in hydration of the protein induced by pressure is not visible in the SANS curves. An appropriate correction procedure must be used for the SANS data in order to account for the distortion of the intensity curve due to hard-sphere and electrostatic interactions. After this correction, the isomerase can be readily used as a secondary standard for SANS measurements.

Triple Isotopic Substitution Method in Small-Angle Neutron Scattering: Application to Some Problems of Structural Biology

1997 ◽  
Vol 30 (5) ◽  
pp. 787-791 ◽  
Author(s):  
I. N. Serdyuk ◽  
G. Zaccaï
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Structural Data ◽  
Necessary Condition ◽  
Isotopic Substitution ◽  
Deuterium Label ◽  
Geometrical Properties ◽  
Wide Range ◽  
Structural Methods

The triple isotopic substitution (TIS) method is based on the analysis of a scattering curve which is the difference between the scattering of two solutions containing appropriately deuterium-labelled particles. A necessary condition for the application of the method is that the two solutions are identical in all respects except for the extent of the deuterium label. Such an experimental scheme has allowed a number of unique physical experiments to be performed, the main ones being: (1) elimination of the contribution of the interparticle interference; (2) addition of both small- and large-sized foreign particles to those studied without distortions of the structural data; (3) highlighting of individual (quite small) regions in the molecules; (4) suppression of the dimerization contribution to the scattering curve. The application of this method is of special interest for studying the mutual three-dimensional disposition of individual small regions of molecules (3D mapping) and for investigating the geometrical properties of the surfaces of globular proteins. It is evident that TIS has a wide range of experimental possibilities, demonstrating that small-angle neutron scattering is one of the most informative structural methods for low resolution.

A Study of Tio2 Aerogels Pore and Ramified Structure by Small-Angle Neutron Scattering

1994 ◽  
Vol 376 ◽  
Author(s):  
Zhu Zhu ◽  
Min Lin ◽  
Geula Dagan ◽  
Micha Tomkiewicz
Keyword(s):  
Titanium Dioxide ◽  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Gas Adsorption ◽  
Scattering Data ◽  
Morphological Parameters ◽  
Nitrogen Gas ◽  
Light Density ◽  
Sans Data

ABSTRACTThe microstructral characteristics of titanium dioxide aerogels were studied by Small Angle Neutron Scattering (SANS). A variety of models were used to extract the morphological parameters from the SANS data. The evaluation of scattering data was found to be consistent with nitrogen gas adsorption and TEM measurements of a model of aerogel consisting of a light density matrix in which meso- and macro-pores are embedded.

Phase Separation In Blends of Polystyrene and Poly (P-METHYLSTYRENE) Using Thermal Analysis And Small-Angle Neutron Scattering

1993 ◽  
Vol 321 ◽  
Author(s):  
A. Xenopoulos ◽  
J. D. Londono ◽  
G. D. Wígnall ◽  
B. Wunderlich
Keyword(s):  
Thermal Analysis ◽  
Phase Separation ◽  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Small Difference ◽  
Glass Transitions ◽  
Scanning Calorimetry ◽  
Reliable Detection ◽  
Sans Data

ABSTRACTDifferential scanning calorimetry (DSC) was used to study blends of polystyrene (PS) and poly (p-Methylstyrene) (PpmS). The presence of two glass transitions on heating after quenching was interpreted as evidence of phase separation at the temperature of the liquid before quenching. The small difference between the glass transitions of the homopolymers in the PS/PpmS system of “13 K limits the reliable detection of double glass transitions for blends to concentrations between 30 and 70%. The results of the DSC technique are supported by comparison with small angle neutron scattering (SANS) data.

scholarly journals A novel methodology to study nanoporous alumina by small-angle neutron scattering

2019 ◽  
Vol 52 (4) ◽  
pp. 745-754 ◽  
Author(s):  
Anastasia Christoulaki ◽  
Alexis Chennevière ◽  
Isabelle Grillo ◽  
Lionel Porcar ◽  
Emmanuelle Dubois ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Condensed Matter ◽  
Quantitative Information ◽  
Sem Analysis ◽  
Experimental Conditions ◽  
Fitting Method ◽  
Hexagonal Arrangement ◽  
Sans Data

Nanoporous anodic aluminium oxide (AAO) membranes are promising host systems for confinement of condensed matter. Characterizing their structure and composition is thus of primary importance for studying the behavior of confined objects. Here a novel methodology to extract quantitative information on the structure and composition of well defined AAO membranes by combining small-angle neutron scattering (SANS) measurements and scanning electron microscopy (SEM) imaging is reported. In particular, (i) information about the pore hexagonal arrangement is extracted from SEM analysis, (ii) the best SANS experimental conditions to perform reliable measurements are determined and (iii) a detailed fitting method is proposed, in which the probed length in the fitting model is a critical parameter related to the longitudinal pore ordering. Finally, to validate this strategy, it is applied to characterize AAOs prepared under different conditions and it is shown that the experimental SANS data can be fully reproduced by a core/shell model, indicating the existence of a contaminated shell. This original approach, based on a detailed and complete description of the SANS data, can be applied to a variety of confining media and will allow the further investigation of condensed matter under confinement.

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