cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.25919/74r9-jx31
title: Parkes observations for project P960 semester 2023APRS_05

description: We aim to carry out receiver pointing and characterisation tests of Parkes receivers. Typically, these tests are carried out after the receiver package is installed, but time does not always allow for proper characterisation. Receivers for consideration include UWL, MARS and 13MM packages. In addition to cross-referencing C007 for flux calibration via pointing, we aim to conduct gain-elevation and system temperature experiments using the Moon, to ensure users of the Parkes Observatory have the most accurate information available for calibration purposes.
DOI: 10.25919/n4wb-hm33
title: Parkes observations for project P1101 semester 2023APRS_11

description: We propose to carry out fortnightly monitoring of a very active repeater, FRB~190520, with the Parkes UWL system. Our current observations show that FRB~190520 is not only the most active FRB that can be observed with Parkes, but also shows extreme rotation measure (RM) variations and unique behavior at 2 to 3 GHz frequency. This makes UWL the ideal instrument to carry out in-depth studies of this repeating FRB. With this program, we expect to detect a large sample of bursts from FRB~190520, and in collaboration with the FAST telescope, we will study the local environment, emission properties, fluence distributions, and polarisation properties over an extremely wide bandwidth with high sensitivity.
DOI: 10.25919/a6mk-yw35
title: Parkes observations for project P456 semester 2023APRS_14

description: The Parkes Pulsar Timing Array (PPTA) project has three primary goals: (a) detection of gravitational waves from astronomical sources, (b) establishment of a pulsar timescale, and (c) improvement of our understanding of Solar-system dynamics. We are now in an exciting regime where a signal detected in our (and other data sets) has the form expected for a gravitational wave background. We are therefore now attempting to confirm, or deny, this exciting result. With this proposal we aim to maintain our pre-eminent position in the field. Unlike most observing proposals, this is a continuing proposal for which the observations will continue to improve bounds on ultra-low-frequency gravitational waves until they are finally detected. Continued Parkes observations will remain valuable at least until the first stage of the SKA is able to improve on our sensitivity and observing cadence. Even after the gravitational wave background is detected we will want to continue observations in support of the nascent field of gravitational wave astronomy!
DOI: 10.15151/esrf-es-1303533505
title: Structural Biology of macromolecules and macromolecular complexes from India

description: Structural biology research groups located in India constitute the INDIA-BAG and will utilize MX, SAXS and CryoEM to study different biological macromolecules. The non-proprietary agreement signed between ESRF and the Regional Centre for Biotechnology (RCB), on behalf of the Department of Biotechnology (DBT) enables studies that provide fundamental insight regarding different biological processes . About 50 groups are part of this BAG and the allocated beamtime will be available for over 500 young researchers. A brief description of all the research groups is provided in the global summary. The ESRF-India partnership is supported by a grant provided by the DBT. Please note that a comprehensive annual report has to be sent to the DBT to obtain release of funds to pay ESRF membership dues. Consequently, all the structural biologists from India are grouped in a single BAG to enable smooth allocation of beamtime and monitoring of progress to collect the required statistics.
DOI: 10.15151/esrf-es-1336085277
title: NORWAY BAG

description: The fourteen PIs associated to this proposal represent the entire crystallography community in Norway and are affiliated to the major Norwegian universities. The research interests of the PIs and their collaborators revolves around topics linked to structural biology and material sciences. We apply for beam time for single- and multi-wavelength MX, Bio-SAXS and Cryo-EM, in support of our research projects funded e.g. by the Research Council of Norway and the ERC. Examples of research projects or topics are carbohydrate-active proteins of medical or bioeconomic relevance, inhibition of DNA repair enzymes, metalloprotein function and catalysis, regulation of cell-cycle processes, enzyme discovery, antibiotic resistance/drug-discovery and neurological diseases. Our overarching aim is to use bright synchrotron sources to produce high quality science.
DOI: 10.15151/esrf-es-1311038656
title: Probing nano-scale heterogeneities in metallic glasses

description: We propose to study nano-scale density inhomogeneities in metallic glasses (MGs) and how they relate to the stability and mechanical properties of the glasses, using nano-tomography at ID16A. Recent studies have shown that density inhomogeneities on the length scale of 200nm and above, and up to 20% in magnitude, can exist in melt-quenched MGs. However, it is unknown how these density inhomogeneities relate to the preparation method and thermal history of the MGs. Phase-contrast X-ray tomography at ID16A is well suited to answer this question thanks to its capability to detect low-level electron density fluctuations. The results are relevant to both the physical nature of the glass transition and industrial applications based on the mechanical properties of MGs.
DOI: 10.15151/esrf-es-1310741300
title: Towards TR-SSX with Protein Photoreceptors at ID29

description: We aim to explore new opportunities at ESRF beamline ID29 to investigate the reaction dynamics of proteins. For this we will investigate protein photoreceptors such as the Stigmatella aurantiaca bacteriophytochrome 2 (SaBphP2) on time-scales from 10 μs to 10 s. Phytochromes are light regulated enzymes where both light perception and enzymatic activity reside on the same polypeptide chain. The light signal is transduced from a central chromophore through about 150 Å to the enzymatic domain. The long term goal is to observe signal transduction and enzyme regulation in real time by using time-resolved, synchrotron based, serial X-ray crystallography (TR-SSX).
DOI: 10.15151/esrf-es-1310739394
title: Characterizing the microstructure and gas transport properties of electrospun Gas Diffusion Layers for Proton Exchange Membrane Fuel Cells u

description: We investigate the impact of controlled microstructure of electrospun Gas Diffusion Layer (GDL) samples for PEMFC using X-Ray nanotomography at ID16B beamline of ESRF. The samples are made of carbon nanofibers and are produced through the innovative method of electrospinning. This method allows modifying structural parameters of the electrospun GDL : fiber size and orientation, pore size distribution, thickness. We use the acquired 3D structures to determine monophasic and biphasic gas transport properties such as porosity, permeability, diffusion, tortuosity, capillary pressure, relative permeability. Calculations are run on GeoDict software. Thus we apply a numerical method on representative structures. The final objective is to gain insights into how the controlled microstructure affects gas transport properties and water intrusion in the GDL. The information obtained from this study will provide valuable knowledge for the development of more efficient GDL in fuel cells.
DOI: 10.15151/esrf-es-1310739485
title: Early-stage aggregation of thermo-sensitive chitosan hydrogels: study of the transition from a polymer solution to an attractive colloidal g

description: Aqueous solutions of chitosan and phosphate salts are highly attractive biomaterials to deliver and encapsulate cell populations, as they are liquid at neutral pH and room temperature and form hydrogels at body temperature. Here, we aim to study the early stages of gelation which have been hitherto little investigated. Preliminary results show that microscopic chitosan-rich aggregates first emerge and form a colloidal suspension that later aggregates to form a colloidal gel. Using time-resolved SAXS and XPCS, we will systematically explore the formation of microscopic structures during gelation as a function of chitosan concentration. We aim to decipher the physical mechanism controlling the formation of these colloidal-like chitosan particles, as well as their attractive interactions. This holds the keys to understanding the microscopic origin of the final microstructural properties of these gels, and will help us defining formulation guidelines to improve cell-hydrogel interactions.
DOI: 10.15151/esrf-es-1323886503
title: Unveiling the phosphate adsorption sites in a series of Zr-based MOFs by in situ HR-PXRD

description: The P-compounds, which contaminate fresh waters, lead to severe environmental problems. The study of specifically designed adsorbents for their efficient capture is mandatory. This experiment is meant to get structural understanding of phosphate adsorption in three different Zr-based MOFs, which have been successfully used to remove phosphate from water solutions. UiO-66 [Zr6O4(OH)4(C8H4O4)6], NU-1000 [Zr6(μ3-OH)8(–OH)8(TBAPy)2] and MOF-808 [Zr6O4(OH)4(BTC)2(HCOO)6] show different connectivity: 12-/8-/6- connected ones recpectively. HR-PXRD data at 298 K on different phosphate loaded samples [activated and moisture saturated] will allow us to unveil for the first time the host-guest interactions and to clarify the MOF connectivity and defects role, while rebuilding the adsorption curve. This experiment will allow a deeper understanding on the (PO4)3- capture and recovery process, opening the way to the design and synthesis of improved, new generation adsorbents.
DOI: 10.15151/esrf-es-1310463467
title: Low-temperature chemical structure of the isostructural quantum multiferroics Cs2Cu2Mo3O12 and Rb2Cu2Mo3O12.

description: The dielectric response of the frustrated, quasi-1D quantum magnet Cs2Cu2Mo3O12 shows two components: a critical divergence at the quantum critical point, and an unusual relaxation at ultra-low temperatures. This feature is in complete agreement with a model of Debye relaxation of electric dipoles mediated by soft magnons, in a newly discovered multiferroic relaxation process. In contrast, the isostructural system Rb2Cu2Mo3O12 only shows the critical contribution. It is suspected that a reduction of lattice symmetry in Rb2Cu2Mo3O12 at low temperatures is responsible for the origin of the fundamentally distinct behavior. Therefore, determining the correct space groups at low temperatures of both materials is indispensable to understanding the origin of this exotic form of relaxation. Single crystal and powder diffraction will be combined to refine the chemical structures down to the lowest accessible temperature of 5 K.
DOI: 10.15151/esrf-es-1310465157
title: Tracking the emergence and persistence of abnormal grain growth in aluminum

description: A polycrystal manifests abnormal grain growth (AGG) when a subset of grains grows rapidly into an environment of largely stagnant matrix grains. If allowed to proceed to completion, the final microstructure can be orders of magnitude coarser than in the initial state. AGG is far from a rare occurrence, but its underlying mechanism(s) continue to confound researchers—the primary problem being a lack of time-resolved experimental data revealing the migration of abnormal/matrix interfaces in 3D. Evidence suggests that local inhomogeneities in the distribution of crystallographic orientations as well as second-phase pinning particles play a decisive role in determining where in a specimen AGG occurs and how fast. By combining DCT + PCT scans, performed between sequential anneals of a commercial-grade aluminum alloy, we gain access to both distributions in 4D, which promises to deliver a robust experimental basis for resolving some of the open questions surrounding the phenomenon of AGG.
DOI: 10.15151/esrf-es-1310465158
title: What makes chalky teeth crumble? - Towards scanning high-resolution 3D-XRD

description: Molar incisor hypomineralization (MIH) is a worldwide growing developmental dental condition in paediatric dentistry with a prevalence of up to 44 %. MIH-teeth are highly prone to fracture and caries as hardness, elasticity, and acidic resistance of the enamel barrier are deteriorated. It is unclear why the mechanical properties with respect to the mineral phases are so significantly compromised. Sound enamel exhibits high stiffness and hardness. The drastic difference indicates structural changes in MIH. In this experiment we aim to target the orientation of hydroxyapatite (HAP) crystallites in MIH-affected enamel in comparison to sound enamel with high-resolution scanning 3D-XRD. This experiment will reveal the hidden HAP crystallite orientation distribution in real 3D volume and provide information on the degree of mis-orientation in MIH-enamel on the nano-scale, eventually, shedding light on the disturbed amelogenesis process in MIH.
DOI: 10.15151/esrf-es-1310466365
title: Time lapse In situ observation of crack growth in 3D mechanical metamaterials

description: We can make extremely fine architected metamaterials comprising millions of cells offering an almost limitless degree of freedom in optimizing material architecture. Recently, we made a ground-breaking discovery: 3D architected solids can exhibit remarkable damage tolerance violating the classical Griffith ideas of brittle fracture due to the inherent discreteness of the microstructure. Preliminary observations from in-situ fracture experiments in lab-based X-ray CT have shed initial light on this finding but the resolution and scan time preclude detailed study. It is now necessary to use a synchrotron facility to monitor the progress of fully embedded cracks in 3D as a function of loading and crack growth. The results, combined with numerical calculations, will lead to a revision of classical fracture mechanics to include architected metamaterials, enabling us to learn how to optimize the design lattice mechanical metamaterials for crack resistance.
DOI: 10.15151/esrf-es-1310194783
title: Origins of hearing and sensory capabilities in early amniotes

description: The origins of terrestrial sensory capabilities in vertebrates are a source of major unanswered questions in evolutionary biology. This gap in understanding can be addressed by investigating the neural anatomy of early members of Amniota, the group of four-legged vertebrates that conquered land. Here we propose to scan the skulls of four extinct early amniote species (comprising 9 specimens) from the Permian of South Africa. With these scans we will be able to reconstruct their brain endocasts, cranial nerves, and inner ear, enabling an evolutionary understanding of the sensory capabilities in these important fossil species.
DOI: 10.15151/esrf-es-1310196237
title: Strain release versus recrystallization in magnetoelectric arrays of embedded ferrite nanostructures

description: Artificial multiferroic heterostructures are of high interest in many fields especially for their expected high industrial impact. We undertook a long-term project aiming at determining the coupling phenomena between the strain state, magnetic properties and ferroelectric properties in multiferroic composites made of embedded MFe2O4 ferrites (MFO, M = Co, Ni, Mn and Fe) in prototypical epitaxial BaTiO3 (001) (BTO) layers. Recrystallization by air annealing of the micron sized platelets is required to obtain long range magnetic and ferroelectric orderings which does not lead to intermixing because spinels and perovskites are phase separation systems. Importantly, multiferroicity may be lost when the interface lattice clamping is released, a compromise in annealing temperature needs thus to be found. We intend here to determine the local strain release within embedded platelets upon recrystallization by scanning X-ray microdiffraction.
DOI: 10.15151/esrf-es-1310196841
title: Oxybarometry constrains through multivalent cation XANES study on primitive achondrite spinels

description: Our purpose is to measure Ti, V, Cr and Fe valences in chromites in a set of olivine-rich primitive achondrite meteorites, namely brachinites and ungrouped achondrites with brachinite affinity, to obtain fO2 estimations. Spinel is a common accessory phase in terrestrial, lunar, martian and asteroidal ultramafic rocks. Moreover, being one of the first phases to crystallize from basaltic magmas and allowing the incorporation of many multivalent cations, it can provide insights on the pristine source composition and fO2 degree. Both brachinites and brachinite-like ungrouped achondrites represent oxidized meteorite groups and their genetic relationship remains still unknown. Although both groups share many similarities, textural and compositional features allow to infer about a different origin for their parent body(ies). A large and complete fO2 dataset could shed a new light on their genetic relationships and improve our knowledge about pristine parent body (ies) composition(s).
DOI: 10.15151/esrf-es-1309937286
title: Fate of ancient metallic deposits in a steel-making valley. Impact of dam opening on Zn and Fe speciation

description: In the Orne River, industrial residues were dumped during decades, stored under river waters. With the dam opening, the contaminated banks suffer oxidation, sunlight. The modification of hydrology also enhanced the erosion of bottom parts of the river banks (increase of water velocity), and increased the amplitude of water table oscillations. Using XAS experiments at Fe and Zn edge, we aim at following the mineralogical evolution of these ancient industrial deposits in order to assess the mobility of contaminants such as Zn.
DOI: 10.15151/esrf-es-1309937122
title: Connecting two-dimensional magnetic pyrazine-based networks with redox-active ligands

description: Expanding on our previous efforts and interest towards developing multidimensional magnetic systems, our current project aims to construct 3D magnetic networks through reactions between 2D magnetic networks and the pre-synthesized radical-based precursor: Na+(tpn)●-(THF) (tpn = terephthalonitrile). This radical ligand is expected to intercalate between these layered structures and bridge metal nodes of these 2D metal-organic frameworks in three dimensions with porosity, and to introduce additional magnetic coupling between layers and paramagnetic tpn●- linkers.In this project, it is expected that the beamline experiments at ID12, including XANES and XMCD for a series of compounds, will be used to assign the oxidation states and local magnetic moment of the Cr site and determine its chemical environment. At BM01, the HR-PXRD is critical to study the temperature dependence of the structure of these unprecedented materials.
DOI: 10.15151/esrf-es-1309937704
title: Unraveling the structural, electronic and magnetic interplay in A2FeIrO6 double perovskites (A = Ba, Sr, Ca) at high pressure

description: The double perovskites A2BB’O6 with 3d and 5d transition metals in B and B’ sites have unique electronic and magnetic properties due to high crystal fields and strong spin-orbit coupling. These samples can be used as hard magnets or in spintronics applications. Our objective is to unravel the interplay between the structural, electronic, and magnetic properties at high pressures, for the first time. At ambient conditions, it is known that structural distortions originate magnetic and electronic transitions simply by changing the ionic radius of A cation. Therefore, the application of high pressure will enable us to discover emerging electronic and magnetic modifications. We propose to study A2FeIrO6 (A = Ba, Sr, Ca) by using x-ray absorption spectroscopy up to 80 GPa, the only technique that allows to study simultaneously the local structure, crystal fields, and the spin-orbit coupling.
DOI: 10.15151/esrf-es-1309938879
title: VISUALIZATION OF CALCIUM-TRANSPORT REGULATORY MECHANISMS

description: Adenosine triphosphate (ATP) drives many critical cellular processes. We will use laser-induced release from a caged, inactive form of ATP followed by short X-ray pulses at the dedicated time-resolved X-ray solution scattering (TR-XSS) beamline ID09 at ESRF-EBS to study protein conformational change in real time. We aim to track how domain movements and kinetics in a bacterial calcium-transporting P-type ATPase (LMCA1) are regulated by lipid chemistry and pH levels. Lipids modulate membrane protein function, but the connection between lipid chemistry and reaction cycle kinetics and dynamics is not well understood. Survival of pathogenic bacteria under basic conditions depends critically on Ca2+ transport. Therefore, structural and kinetic mapping of pH-dependent LMCA1 dynamics can potentially provide clues to better understand the structural basis of infection processes. Overall, the results will provide better understanding of lipid- and pH-induced regulation of calcium transport.
DOI: 10.15151/esrf-es-1309940534
title: High-performance LiNi0.8Mn0.1Co0.1O2 cathode by nanoscale cerium (III) coating via atomic layer deposition

description: Layered lithium nickel manganese cobalt oxide (LiNi0.8Co0.1Mn0.1O2, NMC811) is one of the most promising positive electrode material due to its high capacity, low cost, and low toxicity (Li T, 2020). However, the structural instability of NMC at the charge/discharge process seriously restricts the battery performance and decreases its lifetime. To improve that, a thin protective coating by the ALD (Atomic Layer Deposition) can be used on the electrode for stabilizing the NMC811 batteries at high voltage. Synchrotron-based X-ray absorption spectroscopy (XAS) analysis will give further understanding of the local and environmental changes around the Ni, Mn, and Co of electrode materials (pristine and coated), the goal of this experiment is to perform in-situ XAS on organometallic (Ce3+) and CeO2 coated along with the pristine NMC811 electrodes in fresh and aged assembled coin cells to understand the exact role and behavior of the coating in the host NMC structure during cycling.
DOI: 10.15151/esrf-es-1309940970
title: A Phonon Study of the Charge Density Wave/Superconductor 2H-TaS2

description: The proposed experiment is an inelastic x-ray scattering study to map the temperature dependence of the phonon dispersion in the transition metal dichalcogenide (TMD) 2H-TaS2. 2H-TaS2 has been shown to form a charge density wave (CDW) below ~76 K. Here, we want to observe the collapse of the phonon as the CDW is formed, at the CDW q vector (0.341, 0, 0)a*. 2H-TaS2 has also been shown to be superconducting below ~1 K, with a strong crystallographic anisotropy. As seen in other TMD materials, the superconducting state could be heavily affected by the CDW state, specifically, the anisotropy. Therefore, studying the nature of the CDW state can give us information about both the CDW state as well as the superconducting state.
DOI: 10.15151/esrf-es-1309942137
title: XAS Study of inversion and time-reversal symmetry breaking in KTaO3 based 2D-electron gases

description: Recently, the novel oxide 2D-electron gases (2DEGs) discovered interfaces between quantum paraelectric KTaO3 and band insulating oxides attracted wide-spread interest due to the interplay between the large spin-orbit coupling of Ta-5d states and the superconductivity. Very surprisingly, these 2DEGs show very weak superconductivity at the (001) interface (Tc&lt;50 mK), but robust Tc of 2.2K and 1.1 K at the (111) and (110) interfaces, respectively. Here, we propose polarization dependent Ta-NIII (Ta 4p-&gt;5d) [4] and O-K (O 1s-&gt;2p) [5] edges x-ray absorption spectroscopy (XAS) to establish the Ta-5d crystal-field symmetry and t2g splitting, and their relationship with the ground states in the 2DEGs formed at the (001), (110) and (111) interfaces between KTO, non-magnetic (LaAlO3, AlOx) and ferromagnetic (EuO) overlayers. In EuO/KTO 2DEGs, we will also study magnetic correlation between Eu and Ta magnetic moments, by Eu-M4,5, Ta-NIII, and O-K edges x-ray magnetic circular dichroism (XMCD).