We describe the outcome of a large international interlaboratory study of the measurement of particle number concentration of colloidal nanoparticles, project 10 of the technical working area 34, "Nanoparticle Populations" of the Versailles Project on Advanced Materials and Standards (VAMAS). A total of 50 laboratories delivered results for the number concentration of 30 nm gold colloidal nanoparticles measured using particle tracking analysis (PTA), single particle inductively coupled plasma mass spectrometry (spICP-MS), ultraviolet-visible (UV-Vis) light spectroscopy, centrifugal liquid sedimentation (CLS) and small angle X-ray scattering (SAXS). The study provides quantitative data to evaluate the repeatability of these methods and their reproducibility in the measurement of number concentration of model nanoparticle systems following a common measurement protocol. We find that the population-averaging methods of SAXS, CLS and UV-Vis have high measurement repeatability and reproducibility, with between-labs variability of 2.6%, 11% and 1.4% respectively. However, results may be significantly biased for reasons including inaccurate material properties whose values are used to compute the number concentration. Particle-counting method results are less reproducibile than population-averaging methods, with measured between-labs variability of 68% and 46% for PTA and spICP-MS respectively. This study provides the stakeholder community with important comparative data to underpin measurement reproducibility and method validation for number concentration of nanoparticles.

Low volume samples, high throughput capabilities and easily reconfigurable instrument parameters for biological small angle x-ray scattering have previously been reserved for measurements at state-of-the-art synchrotron beamlines.With the introduction of the presented new dedicated solution SAXS instrument, Xenocs is not only moving the sample handling technology previously only seen at synchrotrons into the home lab, but also providing it and the instrument itself with a level of automation that empower users at any skill level to obtain the best data for their particular sample without compromise.The high throughput nature of the instrument and the ability to automatically mix sample components shortly before measurements facilitates the study of biomolecular kinetics that was previously not possible in an automated fashion on a lab source SAXS instrument.This level of automation allows for automatic screening in time resolved studies in the minutes to hours scale, and greatly increases productivity.The instrument has been developed to be a truly easy to use workhorse for samples in solution.By integrating computer vision technology, sample volumes down to 5 uL are possible and the in-line UV/VIS absorption measurements facilitate concentration estimation on the exposed sample.Automated sample loading, sample cell cleaning and drying is done with a high precision pipetting robot that also ensures gentle transport from the 2x96 well tray sample containers to the sample cell.No compromise is made on data quality as the detector is fully in vacuum, ensuring the lowest possible background.Furthermore, using a motorized detector stage and motorized scatterless slits, the sample to detector distance and flux can be automatically optimized to fit a large variety of protein complex sizes.Data reduction and analysis can also be automated and done using the open source software RAW that also includes integration and compatibility with the advanced software suite ATSAS from the EMBL.This new and unique instrument is the latest offering to the quickly growing biological SAXS community and lowers the complexity for researchers that want an easy to use yet powerful SAXS system for their lab.

Successful developments of applications in synchrotron beamlines have led to an increase need for high quality laboratory equipments. We will present the latest features and results with the Xeuss SAXS/WAXS equipment from Xenocs on low concentration protein solutions. A new generation of scatterless collimation with variable resolution opens the door to unprecedented ratios of primary beam intensity to background and to measurements on weakly scattering samples.

Complementing structural data obtained by X-ray diffraction with optical spectroscopic techniques has become a growing interest in structural biology.In-situ spectroscopy can reveal the nature of chemical species that remain ambiguous in the electron density maps.Here we present some of the results obtained by the use of the on-axis micro-spectrophotometer developed at beamline X10SA of the Swiss Light Source [1].The on-axis geometry of the micro-spectrophotometer is perfect for studying radiation damage and/or the X-ray induced phenomena.Photo-reduction of the copper centers in Copper nitrite reductase from Achromobacter cycloclastes has been monitored using UV-Vis absorption spectroscopy.A 'low-dose' data set with the Cu centers still oxidized has been collected and the structure has been validated by spectroscopy.Raman spectroscopy under resonant conditions (in the Soret absorption band), has been carried out on two different hemoproteins: myoglobin from horse heart and cytochrome c' from Alcaligenes xylosoxidans by the use of laser probes at either 405 or 413 nm.In both cases vibrational spectroscopy results complement the active site picture provided by X-ray diffraction.Non-resonant Raman experiments, with an excitation wavelength in the near infra red domain (785 nm), have been successfully performed on horse heart insulin and hen egg-white lysozyme.For these two proteins, the disulfide bond breakage due to X-ray exposure has been followed by the decreasing intensity of the S-S stretch band.

Doping effect of nano TiO 2 has been the main concern of material scientists in the field of photocatalyst and dyesensitized solar cell (DSC).The electronic states of doped surface and interface, without regard to the sort of interface including solid/solid and solid/liquid, are very different from the bulk states.For example, Si doping on TiO 2 bulk almost brings minor changes of the main energy level structure near conduction band and valence band.However, when Si is doped on the surface, new doping levels appear in middle position between the conduction band edge and valence band edge.This means that the surface doping of Si will seriously change the electric and optical properties of TiO 2 having high surface area such as nano particle and mesoporous film, although the bulk doping doesn't show any effect.The doping elements in this calculation involved a series of transient metals, IV family group and some light metals.Here, main discussion will be concentrated on the electric properties in association with DSC.

Page s131 on protein size, secondary structure and overall conformation will be presented.The characterization of the solution structure and oligomerization state of the Arabidopsis gamma subunit is novel and important contribution to studies on Gproteins providing insights also for the mammalian proteins [1]

caused by thermal cycling like elastic and plastic deformation of film and substrate, recrystallisation, phase transformation, annealing of defects [1,2].The purpose of this contribution is to present a new complex hightemperature X-ray diffraction (XRD) approach which can be used to in-situ characterize structural changes occurring in thin film structures during thermal cycling.The novelty of the approach resides in the characterization of a free standing thin film-substrate composite which can bend freely in the high-temperature chamber (DHS900, Anton Paar GmbH).This gives an opportunity to characterize the substrate curvature by measuring substrate symmetrical reflections at different sample positions [3].In this way, the macroscopic stress imposed on the film can be correlated with other structural parameters like elastic strain, size of coherently diffracting domains, point defect density.The approach provides thus an opportunity to perform a complex thermo-mechanical and structural characterization of films.By comparing measured stress and strains, absolute magnitude of temperature dependent X-ray and mechanical elastic constants can be determined.In the case of multilayered coatings, a comparison of the macroscopic stresses imposed on the whole film composite with the elastic strain behaviour of individual sublayers can be used to study thermo-mechanical effects in complex thin films structures.The new approach was applied to a variety of thin film systems e.g.TiN, CrN/Cr, Al, Cu, CrN on Si(100) measured using laboratory and synchrotron sources (BESSY and Hasylab) in the temperature range -100 to 550°C [4].In the case metal thin films with the thickness down to 50 nm, the approach was used to determine flow stresses which exceed 800 MPa in Al.Moreover, first high-temperature X-ray elastic constants of textured Cu, Al and TiN thin films were evaluated.In the case of hard CrN films with an average crystallite size of about 10 nm deposited on Si(100) and steel, the new approach allowed for the calculation of exact XECs and quantify intrinsic and extrinsic stresses.Also other examples of high-temperature XRD analysis of thin films will be provided.

Distributed electron cyclotron resonance (DECR) plasma sputtering was used for depositing W/Si multilayers for x-rya optics. The argon plasma used in the sputtering process was excited by the DECR method. The DECR argon plasma diffusing the middle of the deposition chamber was characterized with a Langmuir probe. The ionization rate was found to be 7 X 10-4. This allowed us to sputter W and Si with a large range of target bias values at low pressures. Deposited single layers and W/Si multilayers were characterized with grazing incidence x-ray reflectometry. As an illustration of the capabilities, data is shown for a W/Si multilayer with period d equals 3.0 nm and an interface roughness (sigma) < 0.47 nm.

Multilayer-based X-ray optical components call for structures made of smooth and uniform layers with an abrupt interface as well as a high thickness repeatability over many layers. A wide bandpass high energy x-ray reflector illustrates this extreme case where one needs an in-depth graded period multilayer with several hundreds of layers [1]. Thus, in situ characterization techniques are essential to detect thickness fluctuations and are moreover very helpful to optimize the layers. This is the purpose of the two different methods described: grazing X-ray reflectance and optical ellipsometry.

Until recently, the use of reflective optics at short wavelengths was limited by the low critical angles of minor materials. Single coating mirrors are impractical for energies above ~ 40 keV, because the approximate relation E[keV]· ·θ [mrad] ≤ √ 80 · Z, (where θ is the incidence angle and Z is the atomic number of the mirror material) must be fulfilled. For neutrons the use of graded d-spacing multilayers, so-called supermirrors, has helped to considerably increase the usable angles and has facilitated the construction of flux concentrators at energies where single coatings do not perform well1,2,3. We have previously reported on supermirrors for high energy x-rays4,5. For energies above 40 keV and away from absorption edges, supermirrors show significant reflectivity out to E[keV]· θ[mrad] ≤ 6.2·103/dmin[Å], where dmin is the minimum period of the supermirror. In this summary we describe the first focusing of a high energy polychromatic x-ray beam with a W/Si supermirror.