Using Bayesian Model Selection to Advise Neutron Reflectometry Analysis from Langmuir-Blodgett Monolayers

10.26434/chemrxiv.10028978 ◽

2019 ◽

Author(s):

Andrew McCluskey ◽

Tom Arnold ◽

Joshaniel F. K. Cooper ◽

Tim Snow

Keyword(s):

Experimental Data ◽

Soft Matter ◽

General Framework ◽

Neutron Reflectometry ◽

Analytical Models ◽

Colloid Interface ◽

X Ray ◽

Langmuir Blodgett ◽

Generic Framework

The analysis of neutron and X-ray reflectometry data is important for the study of interfacial soft matter structures. However, there is still substantial discussion regarding the analytical models<br>that should be used to rationalise relflectometry data. In this work, we outline a robust and generic framework for the determination of the evidence for a particular model given experimental data, by<br>applying Bayesian logic. We apply this framework to the study of Langmuir-Blodgett monolayers by considering three possible analytical models from a recently published investigation [Campbell et al., J. Colloid Interface Sci, 2018, 531, 98]. From this, we can determine which model has the most evidence given the experimental data, and show the effect that different isotopic contrasts of neutron reflectometry will have on this. We believe that this general framework could become an important component of neutron and X-ray reflectometry data analysis, and hope others more regularly consider the relative evidence for their analytical models.<br>

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EVALUATION OF THE STRESSED DEFORMED STATE OF MAIN GAS PIPELINES RUNNING IN PERMANENTLY FROZEN GROUNDS

Kontrol Diagnostika ◽

10.14489/td.2020.12.pp.058-063 ◽

2020 ◽

pp. 58-63

Author(s):

M. M. Sidorov ◽

N. I. Golikov ◽

R. P. Tihonov

Keyword(s):

Experimental Data ◽

Calculated Data ◽

Gas Pipeline ◽

Loss Of Stability ◽

Portable Equipment ◽

Ray Method ◽

X Ray ◽

Deformed State ◽

Pipeline Monitoring

The work evaluates the stress deformed state of the section of the interfield gas collecting main, running in permanently frozen grounds. The object of research is a section of a pipeline with an arched discharge formed as a result of loss of stability as a result of thermal erosion of permanently frozen grounds to disturbance of the vegetation cover. The determination of stresses was carried out by the X-ray method using portable equipment. The experimental data were analyzed with the calculated. The calculated data were obtained by measuring the spatial position of the gas pipeline section. The obtained values of the acting stresses and the estimates of the critical indicators of the gas pipeline monitoring section made it possible to reasonably estimate the stress state. The methodology for determining the acting stresses of pipelines using portable X-ray equipment can be successfully applied to estimate the stressed-deformed state of pipeline systems running in the zone of permafrost.

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Variance and centroid optimization in X-ray powder diffraction analysis

Powder Diffraction ◽

10.1017/s0885715600017899 ◽

1993 ◽

Vol 8 (2) ◽

pp. 89-97 ◽

Cited By ~ 9

Author(s):

G. Berti

Keyword(s):

Experimental Data ◽

Constrained Optimization ◽

Diffraction Analysis ◽

Powder Diffraction ◽

Instrumental Effects ◽

Line Profiles ◽

X Ray ◽

Visualization In Scientific Computing ◽

Diffraction Effects

Line profiles of a powder diffraction pattern and the aberrations which affect the centroid and the variances of the peaks have been analyzed using the visualization in scientific computing (ViSC) systems. The constrained optimization of those aberrations has been derived from the theory developed by Wilson (1963). It allows the determination of systematic instrumental effects and gives indication of other diffraction effects related to the samples. The CuKβradiation was used to process the experimental data directly as it is comprised of only one single wavelength.

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Determination of nanostructure of liposomes containing two model drugs by X-ray scattering from a synchrotron source

Journal of Synchrotron Radiation ◽

10.1107/s0909049513020074 ◽

2013 ◽

Vol 20 (5) ◽

pp. 721-728 ◽

Cited By ~ 8

Author(s):

Alexandr Nasedkin ◽

Jan Davidsson ◽

Mont Kumpugdee-Vollrath

Keyword(s):

Experimental Data ◽

Small Angle ◽

Structural Parameters ◽

Water Layer ◽

Synchrotron Source ◽

X Ray ◽

X Ray Scattering ◽

Extract Information ◽

Ray Scattering

Small-angle X-ray scattering has been employed to study how the introduction of paracetamol and acetylsalicylic acid into a liposome bilayer system affects the system's nanostructure. An X-ray scattering model, developed for multilamellar liposome systems [Pabstet al.(2000),Phys. Rev. E,62, 4000–4009], has been used to fit the experimental data and to extract information on how structural parameters, such as the number and thickness of the bilayers of the liposomes, thickness of the water layer in between the bilayers, size and volume of the head and tail groups, are affected by the drugs and their concentration. Even though the experimental data reveal a complicated picture of the drug–bilayer interaction, they clearly show a correlation between nanostructure, drug and concentration in some aspects. The localization of the drugs in the bilayers is discussed.

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Determination of the opening load for a growing fatigue crack: evaluation of experimental data reduction techniques and analytical models

Fatigue & Fracture of Engineering Materials & Structures ◽

10.1046/j.1460-2695.2002.00439.x ◽

2002 ◽

Vol 25 (1) ◽

pp. 17-26 ◽

Cited By ~ 12

Author(s):

R. S. Blandford ◽

S. R. Daniewicz ◽

J. D. Skinner

Keyword(s):

Experimental Data ◽

Fatigue Crack ◽

Data Reduction ◽

Analytical Models ◽

Reduction Techniques ◽

Opening Load

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Structure Determination of Ho2PdSi3

Acta Crystallographica Section A Foundations and Advances ◽

10.1107/s2053273314097757 ◽

2014 ◽

Vol 70 (a1) ◽

pp. C224-C224

Author(s):

Melanie Nentwich ◽

Matthias Zschornak ◽

Carsten Richter ◽

Dmitri Novikov ◽

Dirk Meyer

Keyword(s):

Crystal Structure ◽

Experimental Data ◽

Local Environment ◽

Ray Method ◽

X Ray ◽

Metal Silicides ◽

Wide Range ◽

Site Selective ◽

Palladium Silicide

Holmium-Palladium-Silicide Ho2PdSi3 is a member of rare earth-transition metal silicides exhibiting a wide range of interesting magnetic and electrical properties like multiple transition temperatues. The crystal structure results from HoSi2 by substitution of Si by Pd which is ordering commensurably with a 2 × 2 × 8 superstructure confirmed by a previous XRD and a Diffraction Anomalous Fine Structure (DAFS) measurement of the super structure reflection 1/2 1/2 3/8. DAFS is a X-ray method combining the advantages of absorption and diffraction and hence offers the possibility of element and site selective studies. Thus, it was feasible to probe the local environment of Ho and Pd separately. In the following, we will present a comparison of several structure proposals of Ho2PdSi3 with experimental data from beamline E2 and BW1 of the former synchrotron DORIS III at DESY/HASYLAB.

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