scholarly journals BioSAXS on the SWING beamline at Synchrotron SOLEIL

2021 ◽  
Vol 54 (6) ◽  
Author(s):  
Aurélien Thureau ◽  
Pierre Roblin ◽  
Javier Pérez
Keyword(s):  
High Performance ◽  
State Of The Art ◽  
Spectroscopic Techniques ◽  
Fibre Optics ◽  
X Ray ◽  
X Ray Scattering ◽  
Independent Determination ◽  
Scientific Disciplines ◽  
Reduction Methods

Small-angle X-ray scattering (SAXS) of proteins in solution has become a key tool for biochemists and structural biologists, thanks especially to the availability of beamlines with high-throughput capabilities at synchrotron sources. Despite the large spectrum of scientific disciplines tackled on the SWING beamline since its opening in 2008, there has always been a strong commitment to offering state-of-the-art biological SAXS (BioSAXS) instrumentation and data reduction methods to the scientific community. The extremely reliable in-vacuum EigerX-4M detector allows collection of an unlimited number of frames without noise. A small beamstop including a diamond diode-based monitor enables measurements of the transmitted intensity with 0.1% precision as well as a q max/q min ratio as large as 140 at a single distance. The parasitic scattering has been strongly reduced by the installation of new hybrid blades. A new thermally controlled in-vacuum capillary holder including fibre-optics-based spectroscopic functionalities allows the simultaneous use of three spectroscopic techniques in addition to SAXS measurements. The addition of a second high-performance liquid chromatography (HPLC) circuit has virtually eliminated the waiting time associated with column equilibration. The easy in-line connection of a multi-angle light scattering spectrometer and a refractometer allows for an independent determination of the molecular mass and of the concentration of low-UV-absorption samples such as detergents and sugars, respectively. These instrumental improvements are combined with important software developments. The HPLC injection Agilent software is controlled by the SAXS beamline acquisition software, allowing a virtually unlimited series of automated SAXS measurements to be synchronized with the sample injections. All data-containing files and reports are automatically stored in the same folders, with names related to both the user and sample. In addition, all raw SAXS images are processed automatically on the fly, and the analysed data are stored in the ISPyB database and made accessible via a web page.

scholarly journals The Degree of Oxidation of Graphene Oxide

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 560
Author(s):  
Alexandra Carvalho ◽  
Mariana C. F. Costa ◽  
Valeria S. Marangoni ◽  
Pei Rou Ng ◽  
Thi Le Hang Nguyen ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Ab Initio ◽  
State Of The Art ◽  
High Accuracy ◽  
Precise Determination ◽  
Photoemission Spectroscopy ◽  
Pristine Graphene ◽  
X Ray ◽  
Degree Of Oxidation

We show that the degree of oxidation of graphene oxide (GO) can be obtained by using a combination of state-of-the-art ab initio computational modeling and X-ray photoemission spectroscopy (XPS). We show that the shift of the XPS C1s peak relative to pristine graphene, ΔEC1s, can be described with high accuracy by ΔEC1s=A(cO−cl)2+E0, where c0 is the oxygen concentration, A=52.3 eV, cl=0.122, and E0=1.22 eV. Our results demonstrate a precise determination of the oxygen content of GO samples.

Determination of the Growth Rate of Hydrothermally Synthesised ZnO2 Crystallites

2017 ◽  
Vol 50 ◽  
pp. 41-47 ◽  
Author(s):  
Martin Egblewogbe ◽  
Garu Gebreyesus ◽  
Samuel A. Atarah
Keyword(s):  
Growth Rate ◽  
Zinc Acetate Dihydrate ◽  
Hydrothermal Process ◽  
Growth Rate Constant ◽  
Acetate Dihydrate ◽  
X Ray ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Zinc Peroxide

Powders consisting of nanoparticles of zinc peroxide were prepared via a simple hydrothermal process using zinc acetate dihydrate and hydrogen peroxide precursors. The size of the crystallites was determined using x-ray powder diffraction. Over a period of 5 hours the crystallite radius increased from 4 nm – 9 nm at a temperature of 68 °C ± 5 °C, with growth rate constant of 0.23 nm3 min−1 calculated using the Lifshitz, Slyozov, and Wagner model. The powders were further characterised with High Resolution Transmission Electron Microscopy, Energy Dispersive X-ray analysis, and Small Angle X-ray Scattering, showing well-crystallised ZnO2 nanoparticles.

Diffuse X-ray scattering from tiny sample volumes

2005 ◽  
Vol 220 (12) ◽  
Author(s):  
Gene E. Ice ◽  
Rozaliya I. Barabash ◽  
Wenjun Liu
Keyword(s):  
Local Structure ◽  
Diffuse Scattering ◽  
High Performance ◽  
Sensitive Area ◽  
X Ray ◽  
X Ray Scattering ◽  
Defect Content ◽  
Ray Scattering

AbstractThe emergence of intense synchrotron X-ray sources, efficient focusing optics and high-performance X-ray sensitive area detectors allows for measurements of diffuse scattering from cubic micron-scale sample vol umes. Here we present an experiment that illustrates methods for studying the local structure and defect content of tiny sample volumes. In the experiment, an X-ray microbeam illuminating about ∼5 μm

Structure Determination of 3,5-Biscyclohexylidene-1,2,4-trithiolane / Structure Determination of 3,5-Biscyclohexylidene-1,2,4-trithiolane

1980 ◽  
Vol 35 (8) ◽  
pp. 1015-1018 ◽  
Author(s):  
Werner Winter ◽  
Hanspeter Bühl ◽  
Herbert Meier
Keyword(s):  
General Formula ◽  
Structure Determination ◽  
Title Compound ◽  
Direct Methods ◽  
Spectroscopic Techniques ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
Final Structure

Abstract Fragmentation of 1,2,3-thiadiazoles (1) leads to the compounds 5 - 8 with an increasing proportion of sulphur. Numerous structural possibilities exist for the products 7 with the general formula (R2C2)2S3. The number of proposals can be reduced by spectroscopic techniques, but the final structure determination is accomplished by an X-ray analysis of the title compound 7a. 7a crystallizes in the space group P21/c (Z = 4) with cell parameters of a = 9.714(1), b = 16.188(8), c = 9.149(2) Å and β = 98.93(1)°. The structure is solved by direct methods and refined to R = 0.053 with 1955 diffractometer data (I ≥ 2σ(I)). The trithiolane ring has a puckered conformation and the whole molecule shows nearly perfect C2-symmetry, which is not required crystallographically.

scholarly journals Interpretation of the X-Ray Spectra of Solar Active Regions

1975 ◽  
Vol 68 ◽  
pp. 73-100 ◽  
Author(s):  
Arthur B. C. Walker
Keyword(s):  
Transition Region ◽  
Rate Constant ◽  
Active Regions ◽  
Temperature Structure ◽  
Spectroscopic Techniques ◽  
Density Structure ◽  
Coronal Temperature ◽  
X Ray ◽  
Euv Spectrum

This paper presents a review of recent analytical studies of the coronal X-ray spectrum below 25 Å. The techniques used to compute the theoretical coronal spectrum, and the currently available atomic rate constant data are reviewed first. Spectroscopic techniques which have been proposed for the determination of coronal temperature and density structure, and the results derived from their application to coronal spectra are also reviewed.A number of coronal models based on X-ray observations have been developed recently, and the coronal temperature structure and composition predicted by these models is discussed, and compared with models of the corona and transition region derived from studies of the solar EUV spectrum.

scholarly journals ASAXS study of CaF2nanoparticles embedded in a silicate glass matrix

2014 ◽  
Vol 47 (1) ◽  
pp. 60-66 ◽  
Author(s):  
Armin Hoell ◽  
Zoltan Varga ◽  
Vikram Singh Raghuwanshi ◽  
Michael Krumrey ◽  
Christian Bocker ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Spatial Distribution ◽  
Glass Matrix ◽  
Structural Parameters ◽  
Pixel Detector ◽  
Oxyfluoride Glass ◽  
X Ray ◽  
X Ray Scattering ◽  
Silicate Glass Matrix

The formation and growth of nanosized CaF2crystallites by heat treatment of an oxyfluoride glass of composition 7.65Na2O–7.69K2O–10.58CaO–12.5CaF2–5.77Al2O3–55.8SiO2(wt%) was investigated using anomalous small-angle X-ray scattering (ASAXS). A recently developed vacuum version of the hybrid pixel detector Pilatus 1M was used for the ASAXS measurements below the CaK-edge of 4038 eV down to 3800 eV. ASAXS investigation allows the determination of structural parameters such as size and size distribution of nanoparticles and characterizes the spatial distribution of the resonant element, Ca. The method reveals quantitatively that the growing CaF2crystallites are surrounded by a shell of lower electron density. This depletion shell of growing thickness hinders and finally limits the growth of CaF2crystallites. Moreover, in samples that were annealed for 10 h and more, additional very small heterogeneities (1.6 nm diameter) were found.

scholarly journals Size and Concentration Determination of Colloidal Nanocrystals by Small-Angle X-Ray Scattering

2018 ◽  
Author(s):  
Jorick Maes ◽  
Nicolo Castro ◽  
Kim De Nolf ◽  
Willem Walravens ◽  
Benjamin Abécassis ◽  
...  
Keyword(s):  
Band Gap ◽  
Small Angle ◽  
Accurate Determination ◽  
Band Gap Energy ◽  
Colloidal Nanocrystals ◽  
X Ray ◽  
Absolute Scale ◽  
X Ray Scattering ◽  
Ray Scattering

<div> <div> <div> <p>The accurate determination of the dimensions of a nano-object is paramount to the de- velopment of nanoscience and technology. Here, we provide procedures for sizing quasi- spherical colloidal nanocrystals (NCs) by means of small-angle x-ray scattering (SAXS). Using PbS NCs as a model system, the protocols outline the extraction of the net NC SAXS pattern by background correction and address the calibration of scattered x-ray intensity to an absolute scale. Different data analysis methods are compared, and we show that they yield nearly identical estimates of the NC diameter in the case of a NC ensemble with a monodisperse and monomodal size distribution. Extending the analysis to PbSe, CdSe </p> </div> </div> <div> <div> <p>and CdS NCs, we provide SAXS calibrated sizing curves, which relate the NC diameter and the NC band-gap energy as determined using absorbance spectroscopy. In compari- son with sizing curves calibrated by means of transmission electron microscopy (TEM), we systematically find that SAXS calibration assigns a larger diameter than TEM calibration to NCs with a given band gap. We attribute this difference to the difficulty of accurately sizing small objects in TEM images. To close, we demonstrate that NC concentrations can be directly extracted from SAXS patterns normalized to an absolute scale, and we show that SAXS-based concentrations agree with concentration estimates based on absorption spectroscopy.</p></div></div></div>

Sign in / Sign up

Export Citation Format

Share Document