The Experts below are selected from a list of 201 Experts worldwide ranked by ideXlab platform
Pete R. Jemian - One of the best experts on this subject based on the ideXlab platform.
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irena tool suite for modeling and analysis of Small Angle Scattering
Journal of Applied Crystallography, 2009Co-Authors: Jan Ilavsky, Pete R. JemianAbstract:Irena, a tool suite for analysis of both X-ray and neutron Small-Angle Scattering (SAS) data within the commercial Igor Pro application, brings together a comprehensive suite of tools useful for investigations in materials science, physics, chemistry, polymer science and other fields. In addition to Guinier and Porod fits, the suite combines a variety of advanced SAS data evaluation tools for the modeling of size distribution in the dilute limit using maximum entropy and other methods, dilute limit Small-Angle Scattering from multiple non-interacting populations of scatterers, the pair-distance distribution function, a unified fit, the Debye–Bueche model, the reflectivity (X-ray and neutron) using Parratt's formalism, and Small-Angle diffraction. There are also a number of support tools, such as a data import/export tool supporting a broad sampling of common data formats, a data modification tool, a presentation-quality graphics tool optimized for Small-Angle Scattering data, and a neutron and X-ray Scattering contrast calculator. These tools are brought together into one suite with consistent interfaces and functionality. The suite allows robust automated note recording and saving of parameters during export.
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Irena: tool suite for modeling and analysis of Small‐Angle Scattering
Journal of Applied Crystallography, 2009Co-Authors: Jan Ilavsky, Pete R. JemianAbstract:Irena, a tool suite for analysis of both X-ray and neutron Small-Angle Scattering (SAS) data within the commercial Igor Pro application, brings together a comprehensive suite of tools useful for investigations in materials science, physics, chemistry, polymer science and other fields. In addition to Guinier and Porod fits, the suite combines a variety of advanced SAS data evaluation tools for the modeling of size distribution in the dilute limit using maximum entropy and other methods, dilute limit Small-Angle Scattering from multiple non-interacting populations of scatterers, the pair-distance distribution function, a unified fit, the Debye–Bueche model, the reflectivity (X-ray and neutron) using Parratt's formalism, and Small-Angle diffraction. There are also a number of support tools, such as a data import/export tool supporting a broad sampling of common data formats, a data modification tool, a presentation-quality graphics tool optimized for Small-Angle Scattering data, and a neutron and X-ray Scattering contrast calculator. These tools are brought together into one suite with consistent interfaces and functionality. The suite allows robust automated note recording and saving of parameters during export.
Steen Hansen - One of the best experts on this subject based on the ideXlab platform.
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Quantification of the information in Small‐Angle Scattering data
Journal of Applied Crystallography, 2014Co-Authors: Martin Cramer Pedersen, Steen Hansen, Bo Markussen, Lise Arleth, Kell MortensenAbstract:Small-Angle X-ray and neutron Scattering have become increasingly popular owing to improvements in instrumentation and developments in data analysis, sample handling and sample preparation. For some time, it has been suggested that a more systematic approach to the quantification of the information content in Small-Angle Scattering data would allow for a more optimal experiment planning and a more reliable data analysis. In the present article, it is shown how ray-tracing techniques in combination with a statistically rigorous data analysis provide an appropriate platform for such a systematic quantification of the information content in Scattering data. As examples of applications, it is shown how the exposure time at different instrumental settings or contrast situations can be optimally prioritized in an experiment. Also, the gain in information by combining Small-Angle X-ray and neutron Scattering is assessed. While solution Small-Angle Scattering data of proteins and protein–lipid complexes are used as examples in the present case study, the approach is generalizable to a wide range of other samples and experimental techniques. The source code for the algorithms and ray-tracing components developed for this study has been made available on-line.
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estimation of chord length distributions from Small Angle Scattering using indirect fourier transformation
Journal of Applied Crystallography, 2003Co-Authors: Steen HansenAbstract:It is shown that it is possible to estimate the chord length distribution from Small-Angle Scattering data by indirect Fourier transformation. This is done for several examples of scatterers varying in structure from globular to elongated as well as scatterers consisting of separated parts. The presented examples suggest that the chord length distribution may give additional information about the scatterer. Therefore it may be relevant to consider estimation of the chord length distribution as an additional tool for analysis of Small-Angle Scattering data.
Jan Ilavsky - One of the best experts on this subject based on the ideXlab platform.
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irena tool suite for modeling and analysis of Small Angle Scattering
Journal of Applied Crystallography, 2009Co-Authors: Jan Ilavsky, Pete R. JemianAbstract:Irena, a tool suite for analysis of both X-ray and neutron Small-Angle Scattering (SAS) data within the commercial Igor Pro application, brings together a comprehensive suite of tools useful for investigations in materials science, physics, chemistry, polymer science and other fields. In addition to Guinier and Porod fits, the suite combines a variety of advanced SAS data evaluation tools for the modeling of size distribution in the dilute limit using maximum entropy and other methods, dilute limit Small-Angle Scattering from multiple non-interacting populations of scatterers, the pair-distance distribution function, a unified fit, the Debye–Bueche model, the reflectivity (X-ray and neutron) using Parratt's formalism, and Small-Angle diffraction. There are also a number of support tools, such as a data import/export tool supporting a broad sampling of common data formats, a data modification tool, a presentation-quality graphics tool optimized for Small-Angle Scattering data, and a neutron and X-ray Scattering contrast calculator. These tools are brought together into one suite with consistent interfaces and functionality. The suite allows robust automated note recording and saving of parameters during export.
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Irena: tool suite for modeling and analysis of Small‐Angle Scattering
Journal of Applied Crystallography, 2009Co-Authors: Jan Ilavsky, Pete R. JemianAbstract:Irena, a tool suite for analysis of both X-ray and neutron Small-Angle Scattering (SAS) data within the commercial Igor Pro application, brings together a comprehensive suite of tools useful for investigations in materials science, physics, chemistry, polymer science and other fields. In addition to Guinier and Porod fits, the suite combines a variety of advanced SAS data evaluation tools for the modeling of size distribution in the dilute limit using maximum entropy and other methods, dilute limit Small-Angle Scattering from multiple non-interacting populations of scatterers, the pair-distance distribution function, a unified fit, the Debye–Bueche model, the reflectivity (X-ray and neutron) using Parratt's formalism, and Small-Angle diffraction. There are also a number of support tools, such as a data import/export tool supporting a broad sampling of common data formats, a data modification tool, a presentation-quality graphics tool optimized for Small-Angle Scattering data, and a neutron and X-ray Scattering contrast calculator. These tools are brought together into one suite with consistent interfaces and functionality. The suite allows robust automated note recording and saving of parameters during export.
A. Sequeira - One of the best experts on this subject based on the ideXlab platform.
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The inverse problem in multiple Small-Angle Scattering
Physica B-condensed Matter, 1997Co-Authors: S. Mazumder, B. Jayaswal, A. SequeiraAbstract:Abstract Small-Angle Scattering data from strong Scattering systems, like pores in structural ceramics and cements, cannot be analysed invoking single Scattering approximation (S. Mazumder and A. Sequeira, Pramana J. Phys. 38 (1992) 95) as specimen needed to replicate the bulk matrix in essential properties are too thick to validate the approximation. This paper deals with an algorithm to extract single Scattering profile from Small-Angle Scattering data affected by multiple Scattering. The algorithm can process the Scattering data and deduce single Scattering profile in absolute scale. A software package, SIMSAS, has been developed for executing this inversion step. This package can be used both to simulate and to analyse multiple Small-Angle Scattering data.
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Multiple Small-Angle Scattering from a Statistical Medium
Journal of Applied Crystallography, 1992Co-Authors: S. Mazumder, A. SequeiraAbstract:A generalized formalism on multiple Small-Angle Scattering is proposed to investigate the nature of the extractable structural information on inhomogeneities from the multiple-Scattering profile. It is found that the statistical nature of the medium can broaden as well as narrow the Scattering profile depending upon the characteristics of the medium. The nature and the extent of the effect of the various approximations on analysing the multiple-Scattering data are discussed.
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Multiple Small-Angle Scattering—A review
Pramana, 1992Co-Authors: S. Mazumder, A. SequeiraAbstract:Small-Angle Scattering (SAS) is a powerful experimental technique in condensed matter physics for studying structural features of inhomogeneities of colloidal dimensions. So far the technique has been largely exploited to study thin samples for which the single Scattering approximation, for the radiation-matrix interaction, holds good. The single Scattering approximation is invalid when the thickness of the sample exceeds the Scattering mean free path. This situation calls for a guideline to analyse the Scattering data having significant contribution from multiple Scattering. Since multiple Scattering broadens the Scattering profile, the beam broadening nature of multiple Scattering can also be exploited, by making the sample suitably thick, to study large size inhomogeneities which are otherwise inaccessible to a Small-Angle Scattering set up because of its resolution constraints. The present article presents a review and extension of the theoretical basis for analysing multiple Scattering data from the point of view of a recent formalism on multiple Small-Angle Scattering. The formalism is valid for both monodisperse and polydisperse Scattering media characterized by the presence of large size inhomogeneities in the matrix. It is shown that multiple Scattering from a polydisperse sample can be described by a system of coupled integrodifferential equation. However, multiple Scattering from a monodisperse sample can be described by a Fokker-Planck type of equation. These equations have been analysed with an emphasis laid on the nature of the structural information pertaining to the inhomogeneities which is extractable from the multiple Scattering profile. When the linear dimension of inhomogeneities becomes comparable to the Scattering mean free path of the radiation in the sample, the statistical nature of the medium becomes pronounced. The statistical nature of the medium modulates the Scattering profile. The modulation effect could be broadening or narrowing of the profile depending upon the nature of the inhomogeneities and their population distribution. The limiting regimes of validity and the implications of various approximations, frequently used to analyse the Scattering data, have been indicated.
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A formalism on multiple Small-Angle Scattering
Physica B: Condensed Matter, 1991Co-Authors: S. Mazumder, A. SequeiraAbstract:Abstract The present paper reports on a formalism of multiple Small-Angle Scattering (SAS) with a view to examining the nature of the multiple Scattering profile, the nature of the extractable information from the multiple SAS experiment, and the effect of the statistical nature of the medium on multiple Scattering profile.
S. Mazumder - One of the best experts on this subject based on the ideXlab platform.
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Characterization of porous materials by Small-Angle Scattering
Pramana, 2004Co-Authors: S. Mazumder, D. Sen, A.k. PatraAbstract:Characterization of porous materials by Small-Angle Scattering has been extensively pursued for several years now as the pores are often of mesoscopic size and compatible with the length scale accessible by the technique using both neutrons and X-rays as probing radiation. With the availability of ultra Small-Angle Scattering instruments, one can investigate porous materials in the sub-micron length scale. Because of the increased accessible length scale vis-a-vis the multiple Scattering effect, conventional data analysis procedures based on single Scattering approximation quite often fail. The limitation of conventional data analysis procedures is also pronounced in the case of thick samples and long wavelength of the probing radiation. Effect of multiple Scattering is manifested by broadening the Scattering profile. Sample thickness for some technologically important materials is often significantly high, as the experimental samples have to replicate all its essential properties in the bulk material. Larger wavelength of the probing radiation is used in some cases to access large length scale and also to minimize the effect of double Bragg reflections.
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The inverse problem in multiple Small-Angle Scattering
Physica B-condensed Matter, 1997Co-Authors: S. Mazumder, B. Jayaswal, A. SequeiraAbstract:Abstract Small-Angle Scattering data from strong Scattering systems, like pores in structural ceramics and cements, cannot be analysed invoking single Scattering approximation (S. Mazumder and A. Sequeira, Pramana J. Phys. 38 (1992) 95) as specimen needed to replicate the bulk matrix in essential properties are too thick to validate the approximation. This paper deals with an algorithm to extract single Scattering profile from Small-Angle Scattering data affected by multiple Scattering. The algorithm can process the Scattering data and deduce single Scattering profile in absolute scale. A software package, SIMSAS, has been developed for executing this inversion step. This package can be used both to simulate and to analyse multiple Small-Angle Scattering data.
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Multiple Small-Angle Scattering. A probe for large inhomogeneities
Journal De Physique Iv, 1993Co-Authors: S. MazumderAbstract:in conventional Small-Angle Scattering technique, multiple Scattering is consideted to be of nuisence value and one looks for a correction factor to eliminate its effect. But it is possible to expand the scope of Small-Angle Scattering beyond its conventional limit if multiple Scattering is suitably exploited. This paper intends to illustrate this point
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Multiple Small-Angle Scattering from a Statistical Medium
Journal of Applied Crystallography, 1992Co-Authors: S. Mazumder, A. SequeiraAbstract:A generalized formalism on multiple Small-Angle Scattering is proposed to investigate the nature of the extractable structural information on inhomogeneities from the multiple-Scattering profile. It is found that the statistical nature of the medium can broaden as well as narrow the Scattering profile depending upon the characteristics of the medium. The nature and the extent of the effect of the various approximations on analysing the multiple-Scattering data are discussed.
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Multiple Small-Angle Scattering—A review
Pramana, 1992Co-Authors: S. Mazumder, A. SequeiraAbstract:Small-Angle Scattering (SAS) is a powerful experimental technique in condensed matter physics for studying structural features of inhomogeneities of colloidal dimensions. So far the technique has been largely exploited to study thin samples for which the single Scattering approximation, for the radiation-matrix interaction, holds good. The single Scattering approximation is invalid when the thickness of the sample exceeds the Scattering mean free path. This situation calls for a guideline to analyse the Scattering data having significant contribution from multiple Scattering. Since multiple Scattering broadens the Scattering profile, the beam broadening nature of multiple Scattering can also be exploited, by making the sample suitably thick, to study large size inhomogeneities which are otherwise inaccessible to a Small-Angle Scattering set up because of its resolution constraints. The present article presents a review and extension of the theoretical basis for analysing multiple Scattering data from the point of view of a recent formalism on multiple Small-Angle Scattering. The formalism is valid for both monodisperse and polydisperse Scattering media characterized by the presence of large size inhomogeneities in the matrix. It is shown that multiple Scattering from a polydisperse sample can be described by a system of coupled integrodifferential equation. However, multiple Scattering from a monodisperse sample can be described by a Fokker-Planck type of equation. These equations have been analysed with an emphasis laid on the nature of the structural information pertaining to the inhomogeneities which is extractable from the multiple Scattering profile. When the linear dimension of inhomogeneities becomes comparable to the Scattering mean free path of the radiation in the sample, the statistical nature of the medium becomes pronounced. The statistical nature of the medium modulates the Scattering profile. The modulation effect could be broadening or narrowing of the profile depending upon the nature of the inhomogeneities and their population distribution. The limiting regimes of validity and the implications of various approximations, frequently used to analyse the Scattering data, have been indicated.
