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The icy moons of the solar system show several phenomena in their polar regions like active geysers or a thinner crust than at the equator, all of which might be related to a non-uniform heat transport in the underlying ocean of liquid water. We investigate the potential for local heat transport enhancement in these sub-glacial oceans by conducting direct numerical simulations of rotating Rayleigh-Bénard convection (RRBC) in spherical geometry at a water-like Prandtl number Pr=4.38, Rayleigh number Ra=106, and Rossby number ∞≥Ro≥0.03 (or in terms of the Ekman number ∞≥Ek≥6.28·10-5). We probe two ratios of inner to outer radius η=ri/ro=0.6 and η=0.8, which is closer to the presumed conditions on most icy moons, for different gravitational laws g(r)∝rγ. The simulations cover the full range from zero to rapid rotation close to where convection ceases, and therefore cross the rotation-affected regime of intermediate rotation rates with a potentially enhanced dimensionless heat transport Nu>Nunon–rot as known from planar RRBC.Although the global heat transport does not increase (Nuglobal≤Nunon–rot), we find an enhancement up to 28% at high latitudes around the poles (Nuhl>Nunon–rot), which is compensated by a reduced heat transport at low latitudes around the equator (Null

Funding Information: Open Access funding provided by University of Oulu including Oulu University Hospital. The research leading to these results received funding from the Horizon 2020 Program of the European Community under Grant Agreement no. 812580 (MSCA-ETN SULTAN) and Academy of Finland project “ACNF” (325276). R.H would like to thank the Academy of Finland for their financial support with the “BioMInt” (13324592) Postdoctoral Research Project. This research benefited from the RAMI- RawMatTERS Finland Infrastructure. Publisher Copyright: © 2022, The Author(s). Surface modifications of cellulose nanomaterials can be used to tailor their surface charge and hydrophilicity-hydrophobicity characteristics. Additionally, it can facilitate the selective interaction of nanocelluloses with other solid particles to further expand their applicability in different fields. For instance, cellulose nanocrystals (CNC) with amphiphilic features are potential green alternatives in mineral processing such as particle flotation. In the present study, aqueous, one- and two-step silylation of CNCs with amino and alkyl silanes was considered to create a novel bifunctionalized CNCs that contained both positively charged amino silane moieties and hydrophobic alkyl chains. Especially, the effects of reaction conditions and different reaction routes on the silylation were investigated, and the electric surface potential and hydrophobicity of CNCs were determined. The bifunctionalization conducted by the simultaneous addition of an amino silane and alkyl silane led to a high reaction efficiency, and the grafting amount was notably higher than that obtained with the sequential reactions with individual reagents. After the functionalization, the hydrophobicity of the CNCs was strongly altered, leading to water contact angles of up to 135° on CNC films. However, the silylation with amino silanes slightly affected the ζ-potential of the functionalized CNCs. Due to the relatively low ζ-potential, the interaction and orthokinetic attachment of CNCs onto quartz surfaces were insufficient, resulting in a limited flotation recovery in microflotation using a Hallimond tube.

Moderate rotation and moderate horizontal confinement similarly enhance the heat transport in Rayleigh–Bénard convection (RBC). Here, we systematically investigate how these two types of flow stabilization together affect the heat transport. We conduct direct numerical simulations of confined-rotating RBC in a cylindrical set-up at Prandtl number $\textit {Pr}=4.38$ , and various Rayleigh numbers $2\times 10^{8}\leqslant {\textit {Ra}}\leqslant 7\times 10^{9}$ . Within the parameter space of rotation (given as inverse Rossby number $0\leqslant {\textit {Ro}}^{-1}\leqslant 40$ ) and confinement (given as height-to-diameter aspect ratio $2\leqslant \varGamma ^{-1}\leqslant 32$ ), we observe three heat transport maxima. At lower $ {\textit {Ra}}$ , the combination of rotation and confinement can achieve larger heat transport than either rotation or confinement individually, whereas at higher $ {\textit {Ra}}$ , confinement alone is most effective in enhancing the heat transport. Further, we identify two effects enhancing the heat transport: (i) the ratio of kinetic and thermal boundary layer thicknesses controlling the efficiency of Ekman pumping, and (ii) the formation of a stable domain-spanning flow for an efficient vertical transport of the heat through the bulk. Their interfering efficiencies generate the multiple heat transport maxima.

The X-ray free-electron lasers that became available during the last decade, like the European XFEL (EuXFEL), place high demands on their instrumentation. Especially at low photon energies below $1\,\text{keV}$, detectors with high sensitivity, and consequently low noise and high quantum efficiency, are required to enable facility users to fully exploit the scientific potential of the photon source. A 1-Megapixel pnCCD detector with a $1024\times 1024$ pixel format has been installed and commissioned for imaging applications at the Nano-Sized Quantum System (NQS) station of the Small Quantum System (SQS) instrument at EuXFEL. The instrument is currently operating in the energy range between $0.5$ and $3\,\text{keV}$ and the NQS station is designed for investigations of the interaction of intense FEL pulses with clusters, nano-particles and small bio-molecules, by combining photo-ion and photo-electron spectroscopy with coherent diffraction imaging techniques. The core of the imaging detector is a pn-type charge coupled device (pnCCD) with a pixel pitch of $75\,\mu\text{m}\times 75\,\mu\text{m}$. Depending on the experimental scenario, the pnCCD enables imaging of single photons thanks to its very low electronic noise of $3$e$^-$ and high quantum efficiency. Here we present an overview on the EuXFEL pnCCD detector and the results from the commissioning and first user operation at the SQS experiment in June 2019. The detailed descriptions of the detector design and capabilities, its implementation at EuXFEL both mechanically and from the controls side as well as important data correction steps aim to provide useful background for users planning and analyzing experiments at EuXFEL and may serve as a benchmark for comparing and planning future endstations at other FELs., Comment: 10 pages, 10 figures, submitted to the Journal of Synchrotron Radiation

This article reports on energy-dispersive micro Laue (µLaue) diffraction of an individual gold nanowire that was mechanically deformed in three-point bending geometry using an atomic force microscope. The nanowire deformation was investigated by scanning the focused polychromatic X-ray beam along the nanowire and recording µLaue diffraction patterns using an energy-sensitive pnCCD detector that permits measurement of the angular positions of the Laue spots and the energies of the diffracted X-rays simultaneously., This article reports on energy-dispersive micro Laue (µLaue) diffraction of an individual gold nanowire that was mechanically deformed in three-point bending geometry using an atomic force microscope. The nanowire deformation was investigated by scanning the focused polychromatic X-ray beam along the nanowire and recording µLaue diffraction patterns using an energy-sensitive pnCCD detector that permits measurement of the angular positions of the Laue spots and the energies of the diffracted X-rays simultaneously. The plastic deformation of the nanowire was shown by a bending of up to 3.0 ± 0.1°, a torsion of up to 0.3 ± 0.1° and a maximum deformation depth of 80 ± 5 nm close to the position where the mechanical load was applied. In addition, extended Laue spots in the vicinity of one of the clamping points indicated the storage of geometrically necessary dislocations with a density of 7.5 × 1013 m−2. While µLaue diffraction with a non-energy-sensitive detector only gives access to the deviatoric strain, the energy sensitivity of the employed pnCCD offers absolute strain measurements with a resolution of 1%. Here, the residual strain after complete unloading of the nanowire amounted to maximum tensile and compressive strains of the order of +1.2 and −3%, which is comparable to the actual resolution limit. The combination of white-beam µLaue diffraction using an energy-sensitive pixel detector with nano-mechanical testing opens up new possibilities for the study of mechanical behavior at the nanoscale.

The idea of using ultrashort X-ray pulses to obtain images of single proteins frozen in time has fascinated and inspired many. It was one of the arguments for building X-ray free-electron lasers. According to theory1, the extremely intense pulses provide sufficient signal to dispense with using crystals as an amplifier, and the ultrashort pulse duration permits capturing the diffraction data before the sample inevitably explodes2. This was first demonstrated on biological samples a decade ago on the giant mimivirus3. Since then a large collaboration4has been pushing the limit of the smallest sample that can be imaged5,6. The ability to capture snapshots on the timescale of atomic vibrations, while keeping the sample at room temperature, may allow probing the entire conformational phase space of macromolecules. Here we show the first observation of an X-ray diffraction pattern from a single protein, that ofEscherichia coliGroEL which at 14 nm in diameter7is the smallest biological sample ever imaged by X-rays, and demonstrate that the concept of diffraction before destruction extends to single proteins. From the pattern, it is possible to determine the approximate orientation of the protein. Our experiment demonstrates the feasibility of ultrafast imaging of single proteins, opening the way to single-molecule time-resolved studies on the femtosecond timescale.

While the heat transfer and the flow dynamics in a cylindrical Rayleigh-Bénard (RB) cell are rather independent of the aspect ratio Γ (diameter/height) for large Γ, a small-Γ cell considerably stabilizes the flow and thus affects the heat transfer. Here, we first theoretically and numerically show that the critical Rayleigh number for the onset of convection at given Γ follows Ra_{c,Γ}∼Ra_{c,∞}(1+CΓ^{-2})^{2}, with C≲1.49 for Oberbeck-Boussinesq (OB) conditions. We then show that, in a broad aspect ratio range (1/32)≤Γ≤32, the rescaling Ra→Ra_{ℓ}≡Ra[Γ^{2}/(C+Γ^{2})]^{3/2} collapses various OB numerical and almost-OB experimental heat transport data Nu(Ra,Γ). Our findings predict the Γ dependence of the onset of the ultimate regime Ra_{u,Γ}∼[Γ^{2}/(C+Γ^{2})]^{-3/2} in the OB case. This prediction is consistent with almost-OB experimental results (which only exist for Γ=1, 1/2, and 1/3) for the transition in OB RB convection and explains why, in small-Γ cells, much larger Ra (namely, by a factor Γ^{-3}) must be achieved to observe the ultimate regime.

People living in long-term care facilities due to physical or mental impairments have few opportunities for self-determined activity. Virtual reality (VR) technologies offer a potential to expand individual experience through immersive presence in artificial environments, to activate mentally and to promote autonomy through the impact of self-efficacy. The overall goal of the Austrian project VR4Care was to research design basics for the development of a motivating, gender-sensitive, personalized and cost-effective VR technology to increase the activation and quality of life primarily of residents in inpatient long-term care. In the further development of VR for senior citizens, gender-specific differences were taken into account, such as gender-specific requirements for user interfaces, gender-specific preferences in interests with regard to content and different expectations of support when using the VR-based system.

Affective states play a prominent role in the context of human activation and motivation. Immersive VR-based presence provides opportunities to activate elderly people in the context of preferred leisure activities (Häussl et al., 2021) or to apply mindfulness interventions for their cognitive reserve (Paletta et al., 2021). The appropriate design of positively activating content is pivotal for appropriate changes in users’ affective states. The presented study provided insight into the potential of non-invasive VR-based eye tracking for automated estimation of affective state induced by video content, in an explorative pilot study with seven elderly persons living in a nursing home. The results indicate the feasibility of estimating mood change from typical eye movement features, such as, fixation duration and pupil diameter, as a promising future research topic.

Froth flotation is the most common process in the mining industry for the beneficiation of complex sulfide ores. For this purpose, thiol collectors (mostly xanthates) are typically used as flotation chemicals because of their efficacy. However, concerns for their effect on human health and negative impact on the environment increasingly urge for alternative candidates. Consequently, there are great ecological and economical interests to develop novel green chemicals from renewable resources to overcome the inherent environmental and health problems associated with traditional petroleum-derived mining chemicals. Cellulose, which is the most abundant natural polymer resource, represents a green alternative raw material to develop sustainable chemicals that could replace currently used synthetic additives. In the present work, we introduce a novel environmentally friendly and industrially feasible process to produce selective froth flotation chemicals. Therefore, the pulp fibers were disintegrated to cellulose nanoparticles and further functionalized with a silylation reaction in aqueous conditions. Two different functional groups were incorporated into the cellulose nanoparticles and subsequently investigated, namely a thiol-functional moiety, which has an affinity towards pyrite ore surfaces, or an amine-functional moiety, which has an affinity towards silica surfaces. Microflotation tests were carried out in a Hallimond tube to study the flotability of pure pyrite or quartz as a function of pH value, collector concentration, flotation time, and gas flow rate using the novel green nanoparticles, and their results were compared with commercial xanthate and amine chemicals. Keywords: cellulose nanoparticles, deep-eutectic solvent, silylation, ore beneficiation, froth flotation.

In the search for more sustainable alternatives to the chemical reagents currently used in froth flotation, the present work offers further insights into the behavior of functionalized cellulose nanocrystals as mineral hydrophobization agents. The study corroborates that hexylamine cellulose nanocrystals (HACs) are an efficient collector for the flotation of quartz and also identifies some particular characteristics as a result of their colloidal nature, as opposed to the water-soluble reagents conventionally used. To investigate the individual and collective effects of the frother and HACs on the attachment of particles and air bubbles, an automated contact timer apparatus was used. This induction timer measures particle-bubble attachment probabilities (Patt) without the influence of macroscopic factors present in typical flotation experiments. This allowed the study of the combined influence of nanocellulose and frother concentration on Patt for the first time. While HACs readily adsorb on quartz modifying its wettability, the presence of a frother leads to a drastic reduction in Patt up to 70%. The improved recovery of quartz in flotation cells might thus be attributed to froth stabilization by HACs, perhaps acting as a Pickering foam stabilizer. Among the main findings, a tendency of HACs to form mineral agglomerates was identified and further explained using the extended DLVO theory in combination with measured adsorption rates in a quartz crystal microbalance. Therefore, this study distinguishes for the first time the antagonistic effect of frothers on Patt and their synergies with HACs on the stabilization of orthokinetic froths through the hydrophobization mechanism unlike those of typical water-soluble collectors.

Insufficient tailoring of individual needs of nursing home residents can lead to standardized (leisure) activities. Virtual Reality (VR) provides the potential to offer a multimodal experience of individualized activities to residents. The aim of the VR4Care study is to explore attitudes, knowledge, and expectations regarding the use of VR glasses for (leisure) activities in female residents living in rural nursing homes. A mixed method approach in two phases (phase 1: interviews with a complementary standardized questionnaire; phase 2: measurement of affective states) was used. In total, 20 participants were interviewed regarding nine categories. The results show that the most described VR-scenarios for (leisure) activities include arts and crafts (e.g., sewing and knitting), followed by gardening (e.g., farmhouse garden), washing and ironing clothes and dancing (e.g., Austrian folk dances). This study serves as an important basis for scenario development and for testing the use of biosensor measurements in phase 2.

Detectors with high energy and position resolution over a wide energy range are required for space telescopes in high energy astrophysics missions. By combining a low noise fully depleted pnCCD detector with a columnar CsI(Tl) scintillator, an energy dispersive spatially resolving detector can be realized with high quantum efficiency in the range from below 0.5 keV to above 150 keV. The detector is exposed to the photon source such that the X-rays first traverse the 450 μm sensitive pnCCD. If they are stopped through the photoelectric effect in the silicon detector, Fano-noiselimited energy resolution is achieved. This is true for X-rays from a few hundred eV up to approximately 15 keV. Above this energy the probability that the photon penetrates the pnCCD and converts in the CsI(Tl) scintillator is becoming higher. Due to the high atomic number of Cs (Z=55) and I (Z=53) hard X-rays are stopped efficiently in a 0.7 mm thick CsI(Tl) scintillator for photon energies up to 150 keV. The light from the scintillator is recorded with the same backilluminated pnCCD. For X-rays from a 57Co source with an energy of 122 keV and 136 keV we achieve an energy resolution of 0.7% (FWHM=850 eV) for the direct conversion in the silicon while the energy resolution for the conversion in the CsI(Tl) is 10% (12 keV). We have performed a knife-edge experiment at 122 keV and achieved a position precision of 27 μm at that energy. Monte Carlo simulations were showing similar, fully compatible results. In case the X-rays are converted directly in the silicon the position precision is better than 10 μm. This is close to the theoretical limit of the spatial resolution in such a system, which is given by the length of the tracks of the secondary electrons in the ionizing process in silicon and CsI. Spectra, images and the results of the GEANT4 simulations will be shown.

The pseudo-spectral form of the sea level equation (SLE) requires the approximation of a radially-symmetric visco-elastic Earth. Thus, the resulting predictions of sea level change (SLC) and glacial isostatic adjustment (GIA) often ignore lateral variations in the Earth structure. Here, we assess the capabilities of a Multiple 1D Earth Approach (M1DEA) applied to large-scale ice load components with different Earth structures to account for these variations. In this approach the total SLC and GIA responses result from the superposition of individual responses from each load component, each computed globally assuming locally-appropriate 1D Earth structures. We apply the M1DEA to three separate regions (East Antarctica, West Antarctica, and outside Antarctica) to analyze uplift rates for a range of Earth structures and different ice loads at various distances. We find that the uplift response is mostly sensitive to the local Earth structure, which supports the usefulness of the M1DEA. However, stresses transmitted across rheological boundaries (e.g., producing peripheral bulges) present challenges for the M1DEA, but can be minimized under two conditions: (1) If the considered time period of ice loading for each component is consistent with the relaxation time of the local Earth structure. (2) If the load components can be subdivided according to the scale of the lateral variations in Earth structure. Overall, our results indicate that M1DEA could be a computationally much cheaper alternative to 3D finite element models, but further work is needed to quantify the relative accuracy of both methods for different resolutions, loads, and Earth structure variations.

Nowadays, humankind undergoes intensive efforts to minimize the environmental pollution worldwide. One main challenge is the reduction of chemicals based on mineral oil and petroleum by the employment of sustainable and environment-friendly alternatives. A promising candidate is cellulose, which is a green, sustainable and abundant polymer. Cellulose can be treated physically and chemically to obtain tailored properties, which enable the employment of cellulose in industrial processes, such as flotation. Nonetheless, the structure of cellulose, which differs substantially from conventional flotation reagents, leads to different behaviour in ore dressing and in subsequent particle-bubble attachment. Therefore, the interactions between cellulose and the minerals under different conditions is investigated using the Derjaguin-Landau, Verwey-Overbeek (DLVO) theory, comprising van-der-Waals and electrostatic interactions, and the results are put in context with flotation recoveries using a single gas capillary Hallimond tube. The results obtained indicate that van-der-Waals interactions are dominant at very close distances and electrostatic interactions at distances of several nanometres between cellulose and the minerals. Accordingly, this study illuminates that the occurrence of physisorption phenomena between cellulose and the minerals and efficient particle-bubble attachment depend on electrostatic interactions between them.

Microstructure of austenitic-ferritic duplex stainless steel loaded in the Very High Cycle Fatigue regime was investigated using microbeam energy-dispersive X-ray Laue diffraction. Scanning electron microscopy analysis of the surface shows that damage in the form of fatigue cracks is initiated at grain boundaries assisted by slip bands observed in austenite grains. Energy-dispersive X-ray Laue diffraction was then used to scan a damaged area containing both a fatigue crack and slip bands, in order to measure the changes in microstructure. Results from the X-ray data from the austenite grain indicates slip activation of the most favored slip system tilted by 45° with respect to the external loading direction, dividing the grain into two regions on either side of the slip band. In the ferrite phase, in front of the crack, variations in the angle and energy spectra of the diffraction peaks indicate the presence of lattice curvature and a strain gradient. In regions around the crack, diffraction peaks spatially split into several sub-peaks indicating the presence of fine granular areas separated by polarized dislocation walls. Possible reasons for the observed structural evolution are discussed and the advantages of using energy-dispersive X-ray Laue diffraction in fatigue damage analysis are illustrated.

The fundamental formation of the three phase contact in flotation is an intensively and controversially discussed phenomenon and the contact angle method is usually employed to characterise the wettability of solid surfaces. A more recent technique to explore the hydrophobicity of solid particulate phases is inverse gas chromatography (iGC) which is used to quantify the wettability of solid surfaces through thermodynamic parameters. In this article, the recently introduced net free energy of interaction between particles and bubbles immersed in water ΔGpwb is derived from the surface free energy analysis and its correlation to the flotability of solid phases is evaluated. At the same time, a more detailed analysis on the action of flotation reagents is presented performing iGC measurements under dry and flotation experiments under aqueous conditions. In general, flotation reagents have to satisfy required features to adsorb selectively, render the solid surface wetting property sufficiently, and comply current regulations concerning the preservation of the environment. Consequently, many conventional reagents are increasingly subjected to restrictions. One potential alternative candidate is nanocellulose due to the versatile chemical composition and functionality. The synthesis of cellulose nanocrystals (CNCs) includes different mechanical and chemical modification routes to lower the crystal sizes and integrate specific functional groups and organic components into the cellulose structure. This study is concentrated on the investigation of aminated CNCs for the flotation of quartz in comparison to conventional reagents. The employment of CNCs as a renewable and sustainable alternative to conventional chemicals is challenging due to the more complex structure of cellulose crystals and leads to new perspectives regarding the action of flotation reagents at the interface of a mineral under dry and wet environments.

Wood chip plastic composites (WCPC) with high mechanical properties were produced by combining long pine wood strands with formaldehyde-free binder systems. The obtained novel bio-based lightweight materials compensate major disadvantages of commonly used oriented strand board (OSB). WCPC are load- and application-optimized, non-toxic, with zero-waste and cost-efficient. Suitable binder systems and production process options for WCPC were selected. The behavior of strands when pressurized was investigated to specify the limit of the compression pressure, that did not cause damage of the wood cell walls. Specimens were produced with an experimental mold using thermoplastic as well as thermosetting binder systems and resin injection as well as hot compression molding techniques. Mechanical properties of WCPC were determined and compared with the properties of conventional wood-based materials.

By simultaneously measuring changes in energy and reflection angle of Laue spots with respect to a reference position, it is possible to measure all lattice parameters of a unit cell and calculate the full strain/stress tensors in a single-shot experiment with high spatial resolution., The full strain and stress tensor determination in a triaxially stressed single crystal using X-ray diffraction requires a series of lattice spacing measurements at different crystal orientations. This can be achieved using a tunable X-ray source. This article reports on a novel experimental procedure for single-shot full strain tensor determination using polychromatic synchrotron radiation with an energy range from 5 to 23 keV. Microbeam X-ray Laue diffraction patterns were collected from a copper micro-bending beam along the central axis (centroid of the cross section). Taking advantage of a two-dimensional energy-dispersive X-ray detector (pnCCD), the position and energy of the collected Laue spots were measured for multiple positions on the sample, allowing the measurement of variations in the local microstructure. At the same time, both the deviatoric and hydrostatic components of the elastic strain and stress tensors were calculated.

In fundamental flotation studies often the contact angle with water is used to describe wettability of a mineral surface and it is correlated with flotability. A more fundamental parameter however is the specific surface free energy related to the contact angle via Young’s equation. Inverse gas chromatography (iGC) has recently been proven to be a suitable method to determine specific surface free energy components and their distributions of particulate surfaces. In this study the pure minerals quartz (SiO2), fluoro-apatite (Ca5[F,(PO4)3]), and magnetite (Fe3O4) are examined for flotabilities and surface energy component distributions considering different methods of sample treatment and the effect of the collectors sodium oleate and dodecyl ammonium acetate. The parameter of specific net free energy of interaction between bubbles and particles immersed in water ΔGpwb resulting from the complex surface energy analyses is introduced and used to evaluate the hydrophobicity of the mineral surface in correlation to microflotation recoveries. The results lead to the hypothesis that only small fractions of the surface and their change of wettability by flotation reagent adsorption will inherently define the flotability of minerals. Consequently, the main purpose of the amphiphilic collector molecules seems to be the reduction of high specific surface free energies of small fractions of the surface that lead to a strong attraction between particle surface sites and water molecules rather than the hydrophobization of the entire mineral surface, a new paradigm in flotation science.

Froth flotation is a widely used process for the beneficiation of complex sulphide ores. Thiol collectors (mostly xanthates) are usually effective collectors for sulphide minerals but may have a low selectivity between different sulphide minerals when associated in complex sulphide ores. Additionally, a concern is their suggested harmfulness on human health and impact on the environment. In this study, a green sustainable reagent, butyl-amine cellulose (BAC), was synthesized from hardwood kraft pulp, a renewable abundant resource, for the selective separation of chalcopyrite and sphalerite. The performance evaluation was made using samples of two ores containing chalcopyrite and sphalerite, one was from Panasqueira mine (Portugal) and the other with a different mineral association (from the massive sulphide deposits of the Iberian Pyrite Belt). The study demonstrated that when chalcopyrite is associated with sphalerite, BAC is selective for chalcopyrite, i.e., it is a collector for this mineral and not for sphalerite. The recovery of chalcopyrite in the floated product was a function of interaction between BAC concentration and pulp pH. The study showed that the novel cellulose-based collector had a better performance than the reagents used in the industrial flotation of Panasqueira ore.

The lattice parameters and unit-cell orientation of an SrLaAlO4crystal have been determined by means of energy-dispersive X-ray Laue diffraction (EDLD) using a pnCCD detector coupled to a columnar structure CsI(Tl) scintillator in the energy range between 40 and 130 keV. By exploiting the high quantum efficiency (QE) achieved by this combined detection system for hard X-rays, a large number of Bragg reflections could be recorded by the relatively small detector area, allowing accurate and fast determination of the lattice parameters and the moduli of the structure factors. The experiment was performed on the energy-dispersive diffraction (EDDI) beamline at the BESSY II synchrotron using a pnCCD detector with 128 × 128 pixels. Since the energies and positions of the Laue peaks can be recorded simultaneously by the pnCCD system, the tetragonal structure of the investigated specimen was determined without any prior information. The unit-cell parameters and the angles between the lattice vectors were evaluated with an accuracy of better than 0.7%, while the structure-factor moduli of the reflections were determined with a mean deviation of 2.5% relative to the theoretical values.

Fluctuation X-ray scattering (FXS) is an emerging experimental technique in which solution scattering data are collected using X-ray exposures below rotational diffusion times, resulting in angularly anisotropic X-ray snapshots that provide several orders of magnitude more information than traditional solution scattering data. Such experiments can be performed using the ultrashort X-ray pulses provided by a free-electron laser source, allowing one to collect a large number of diffraction patterns in a relatively short time. Here, we describe a test data set for FXS, obtained at the Linac Coherent Light Source, consisting of close to 100 000 multi-particle diffraction patterns originating from approximately 50 to 200 Paramecium Bursaria Chlorella virus particles per snapshot. In addition to the raw data, a selection of high-quality pre-processed diffraction patterns and a reference SAXS profile are provided.

The time required for the attachment (tatt) between solid particles and bubbles in an aqueous phase is known to reflect the interfacial characteristics of the three-phase system. Although plenty of research has been performed on the use of induction timers to measure tatt, the derivation of quantitative parameters to determine the wettability of microparticles has not been reported so far. Indeed, the use of induction timers has been limited to the estimation of relative floatability of specific systems. Consequently, the objective of this work is to develop a sound methodology to overcome the current limitations of induction timers. In order to provide an adequate method for wettability characterisation, the present work offers a critical analysis on assumptions and experimental procedures previously reported in the literature regarding contact timers. The arbitrary definition of contact times at 50% bubble-particle attachment probability and the negligence of particle-bubble distance during attachment events are of particular concern. Using the novel Automated Contact Timer Apparatus (ACTA), it was found that, for a proper assessment of attachment due to interfacial forces, attachment probabilities should be measured within a zone of non-compressive attachment (NCA). In the absence of compression, only particles with a meaningful hydrophobic character present high attachment probabilities. It is also experimentally demonstrated that the probability of attachment as a function of contact time depends on the final distance between particles and bubbles. Using the right values of particle-bubble attachment probability, a method to deduce three-phase contact angles from induction timer experiments is proposed for the first time. The similarities between contact angles calculated from attachment timer results (i.e, 51° and 88°) and those of analogous flat surfaces with the sessile drop method (i.e, 49° and 78°) prove the applicability and high potential of this methodology to study the wettability of microparticles.