cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.5286/isis.e.rb1510007
title: Practical viscosifiers for supercritical CO2

description: This proposal explores headgroup-free, fluorocarbon-hydrocarbon hybrid compounds able toform viscous elongated aggregates in supercritical CO2 with the aim of improving theefficiency of enhanced oil recovery (EOR). Oil fields typically contain large quantities of metalions and seawater that can affect the morphology and stability of surfactant molecularaggregates, which in turn acts to reduce the effectiveness of CO2-EOR. This SANS study willprovide important information enabling the development of novel, EOR-oriented, CO2-thickeners which are independent of the ionic strength, nature of the metal ions present andquantity of water.
DOI: 10.5286/isis.e.rb1510016
title: Worm-like reversed micelles with a CO2-philic surfactant

description: Hydrotropes (Figure 3 A-C) are known viscosifying agents with surfactants in organic solvents1 and interestingly now in supercritical CO2 (scCO2)5. The mechanism is hydrotrope-induced micelle growth to generate worm-like reverse micelles (WLRMs) 1,3,5. This experiment is to develop new surfactant+hydrotrope (or phenol) gelator combinations which are not only organophilic, but are also at same time CO2-philic. These would be unique WLRM systems, able to viscosify/gelate both oils and scCO2.  In this initial phase organogelation will be studied, and these results will inform future studies with the same mixtures in scCO2 under high pressure conditions.  A new approach taken here is to combine hydrotropes and phenols with a known CO2-phillic surfactant (TC14, Figure 2), and for these three-component mixtures greater viscosity enhancements are expected than for hydrotropes alone.
DOI: 10.5286/isis.e.rb1510065
title: Investigation of the micellar aggregates in low molecular weight gelators

description: We have been investigating dipeptide-based low molecular weight gelators. Here, on lowering the pH from 12 to 4, a self-supporting gel is formed. Gels are formed by the sel-assembly of the gelators into one dimensional fibres. We have shown that mixtures of two gelators can form self-sorted fibres (where the two components do not mix) or mixed fibres. At high pH pre-gelation, the gelators form micellar aggregates. It is not clear whether mixtures form a single mixed micellar structure, or self-sorted micelles. Our hypothesis is that the micellar structure determines the fibre phase. Here, we will test this hypothesis. The results will allow us to more rationally design multi-component structures, which will enable architectures suitable for a range of exciting applications.
DOI: 10.5286/isis.e.rb1510231
title: Mapping the evolution of residual stresses across the interface between dissimilar metallic alloys  Phase 2

description: Spray forming is a flexible materials casting technique capable of producing high value added products in the form of round billets, clad rolls and composite tubes of high-alloyed materials including alloy systems that often cannot be manufactured by conventional casting methods. However, one of the key challenges associated with the spray forming of dissimilar materials is to achieve high integrity metallurgical bonding between the interface of the deposit and substrate material. The proposed research is to study quantitatively the key factors that govern interface adhesion integrity in dissimilar metallic alloys during spraying using neutron diffraction/strain mapping. Knowledge from this investigation will help to accelerate the collaborative research programme to develop high performance bi-metallic components targeted for the metallurgical, oil and off-shore renewable industries.
DOI: 10.5286/isis.e.rb1510269
title: Mercury sulphide dimorphism in liquids and glasses

description: A waste majority of crystals exists in several polymorphic forms in different domains of the P,T-diagram.  Liquids and glasses also exhibit polyamorphism and the question remains whether the liquid-liquid transformation appears to be a first-order phase transition.  The mercury thioarsenate glasses seem to show a different phenomenon: an instantaneous mercury sulphide dimorphism.  Our Raman spectroscopy measurements and DFT modelling first exhibit a hybrid Hg-S chain/As-S pyramidal network.  Nevertheless, the preliminary high-energy x-ray diffraction measurements suggest also the presence of Hg-S tetrahedra.  The proposed ND experiments on HgS-As2S3 liquids and glasses using GEM or SANDALS together with complementary HE-XRD experiments and EPSR/RMS modelling will greatly advance our understanding of these important functional materials and the exciting phenomenon of polyamorphism.
DOI: 10.5286/isis.e.rb1510341
title: Non-destructive investigation of pottery finds from Vörs-Máriaasszonysziget

description: The present application focuses on the determination of possible differences in pottery production methods during the Neolithic Period . Samples of coarse grain temper (organic and inorganic, i.e., chaff, grog (=broken pottery) and rock fragments will be studied to relate to neutron tomography of the interiors of the sample. The pieces analyzed will be provided by the Hungarian National Museum, from Vörs-Máriaasszonysziget, a site which has special importance in the spreading of the "Neolithic package", i.e., notions on productive economy, pottery-making and other Neolithic crafts in the Central parts of Europe. This study will provide data at the low Q-range complementing TOF neutron diffraction and X-ray tomography data .
DOI: 10.5286/isis.e.rb1510371
title: Structural studies of Staufen1 in complex with Upf1, a crucial assembly in gene regulation

description: Gene expression is regulated during both the synthesis and the decay of mRNAs. Various pathways of cytoplasmic mRNA decay exist. These include ARE-mediated decay, miRNA-Mediated mRNA decay, Nonsense-Mediated mRNA decay (NMD), and the recently discovered Staufen-Mediated mRNA decay (SMD) (1). We want to understand the interplay of Staufen1 (Stau1), a dsRNA-binding protein, with a key mediator of mRNA decay, the Upf1 helicase, as they come together on an mRNA substrate. To do so, we will integrate small angle scattering, biophysical and biochemical analyses with electron microscopy studies. The proposed work will provide unique mechanistic insights into an important and medically relevant mechanism of gene expression regulation in humans.
DOI: 10.5286/isis.e.rb1510433
title: Using SERGIS to characterise monolayer buckling on the approach to collapse

description: Thin films just one or a few molecules thick can play an important role in controlling many important phenomena. This includes the lipid monolayers that coat the surface of our lungs or form the membrane at the surface of a bacteria and proteins and peptides stabilizing foams in food and drink applications. In this experiment we will use the special property of the neutron to precess like a gyroscope to probe the details of two such thin films when they are under compression. When compressed, such films have been observed first to wrinkle with a periodic wavelength and then to fold before collapse. The wrinkle wavelength is determined by the mechanical properties of the film, which in turn affects how stable the peptide layer stabilising a foam might be or how a bacterial membrane responds to the addition of peptide molecules.
DOI: 10.5286/isis.e.rb1510520
title: Investigation of ambient temperature polarity and magnetism in the ternary solid solution BiFe2/8Ti3/8Mg3/8O3  NdFeO3  BaTiO3

description: Pb-based materials such as PbZrxTi1-xO3 (PZT) are widely used as transducers, actuators and sensors in a range of modern technologies due to their excellent piezoelectric and ferroelectric properties. However, the toxicity of Pb raises serious environmental concerns and the application of these materials is to be limited by new legislation. It is therefore necessary to develop new Pb-free analogues to PZT, with Bi3+ compounds emerging as strong candidates due to the similar stereochemistry of the 6s2 Pb2+ and Bi3+ ions which gives rise to electrical polarisation. Our recent work using high-resolution diffraction data from HRPD has shown that Pb-free ferroelectrics based on BiFe2/8Mg3/8Ti3/8O3 (BTFM) can be modified by chemical substitution to substantially improve their ferroelectric properties.
DOI: 10.5286/isis.e.rb1520412
title: Chemical binding and effective temperature survey beyond the nuclear recoil resolution limit.

description: Differences in heavy metal nuclear momentum distributions (NMDs) in different metallic compounds due to chemical binding and effective temperature difference will most likely never be possible to be measured via conventional technique of recoil peak separation in neutron Compton scattering (NCS). However, in recent  years a new avenue has been explored in the electron volt spectroscopy at ISIS,  (n,gamma) absorption resonance Dopplerimetry (NRD). Following successful pilot work on caesium and iodine resonances, this proposal aims at extending the capability of NRD towards characterisation of compounds of a heavy resonant metal nucleus in the weak binding regime, tantalum (Ta), by comparing TaF3, TaCl3, TaN5O15  at T=10K, and TaH0.15 as a function of temperature.  Obtained results will be compared with ab initio predictions obtained from CASTEP code.
DOI: 10.5286/isis.e.rb1610053
title: The magnetic structure of an A- site and B-site ordered perovskite: CaCu3Fe2Os2O12

description: Recently, double perovskites have attracted enormous attention. Now, we have successfully synthesized a quadruple perovskite compound which shows not only one but, both, A-site and B-site ordering within the ABO3 perovskite structure. Interestingly, the introduction of magnetic ions both at the A and B sites in CaCu3Fe2Os2O12 increases the ferromagnetic transition to roughly 580 K. In order to clarify the magnetic structure of this new compound we propose to perform powder neutron diffraction experiments using the WISH diffractometer. Unfortunately, a very elaborate high pressure synthesis route is needed to synthesize this new material. Therefore, only tiny amounts of sample mass can be obtained after each synthesis process using high pressure cells. Hence, we ask for 5 days of beamtime for measuring the magnetic structure of the new quadruple perovskite material in CaCu3Fe2Os2O12.
DOI: 10.5286/isis.e.rb1610335
title: Spin Frustration in a Novel Molecular FeIII_7 Propeller

description: The hepta-nuclear Fe(III) title compound Fe7 exhibits a unique antiferromagnetic exchange topology reminiscent of a three-bladed propeller, giving rise to spin frustration, also suggested by the observed unprecedented Mössbauer spectra. However, both the magnetic and Mössbauer responses could not yet be explained beyond simplistic phenomenological models. We here suggest to study the low-energy spin excitations in Fe7 by inelastic neutron scattering to facilitate a proper magnetic modelling of the system. From numerical simulations and fits to the magnetization curves we expect a spin transition at ca. 0.8 meV and a further spin transition in the range of 0.3 to 2 meV, which we want to observe in this experiment. The IRIS spectrometer is very well suited for this energy range.
DOI: 10.5286/isis.e.rb1610381
title: Determination of crystal field spectrum in terbium gallium garnet.

description: Magnetic frustration is the phenomenon resulting from inability to satisfy all magnetic interactions present in a system. It has drawn lots of attention as it is the source of exotic behavior of many magnetic materials. Although it has been thoroughly studied in various groups of compounds, not much of an effort was put in its examination in half-garnet lattice family and especially terbium gallium garnet(Tb3Ga5O12). TGG is a promising candidate for a host of magnetically frustrated spin liquid regime. However, its existencein it has never been confirmed. Defining a crystal field scheme is a crucial, initial step in investigation of any rare earth based magnet and inelastic neutron scattering is the most reliable method of doing this. We propose a combined study at LET and MARI instruments aiming at observation  of Tb3+ ions' full crystal field spectrum in terbium gallium garnet.
DOI: 10.5286/isis.e.rb1620135
title: Structural determination of SMA-lipid particles in solution

description: The development of styrene-maleic acid lipid particles (SMALP) is opening the door to better understanding the nature of membrane proteins, these particles have been well characterised with non-atomistic techniques. However, the protein-free system is still not completely understood atomistically, with information such as the polymer conformation and the lipid arrangement still unknown. The ability of NIMROD to give atomic resolution on this organised system would allow the atomistic structure to be understood. Due to the large size of the system, we plan to use a pre-existing all-atom model as a starting point for the ESPR analysis, to assist in more rapidly determine the experimental solution structure. By comparing SMALPs formed using two different polymers we aim to understand polymer effects on encapsulated lipids which may impact properties of proteins supported in the nanodiscs.
DOI: 10.5286/isis.e.rb1620298
title: The phase diagram of the spin-density-wave metamagnet Sr3Ru2O7

description: Sr3Ru2O7 is an unusual layered oxide metamagnetic metal. It has been know for some time that the application of a large magnetic field (~8 T) perpendicular to the RuO2 planes induces a new "A" phase at low temperatures (T&lt;1.5K). The A  phase has thermodynamic and electronic transport anomalies which define its boundaries.  It also has anisotropic electronic properties. We have recently used WISH to identify the A phase as spin density wave (SDW) order and discover a neighbouring "B" phase at slightly higher field. Here we propose to: (i) map out the temperature/field phase boundary of the B phase (which is difficult by other techniques); (ii) determine whether electronic anomalies for magnetic  fields applied within the RuO2 planes also correspond to SDW order.
DOI: 10.5286/isis.e.rb1620422
title: Membrane-stacking properties of myelin proteins

description: Myelin is the multilamellar structure that ensheaths axons and accelerates nervous impulses in the nervous system. The fine structure of myelin remains to be further characterized on the biomolecular scale. There are many myelin proteins that contribute to myelin membrane stacking and are involved in demyelinating diseases. We propose an experiment at the INTER neutron reflectometer, where the properties of these proteins can be investigated on supported stacked lipid bilayers. The proteins and their properties have already been characterized in biomimetic systems at SURF, ISIS and D17, ILL, and now we wish to continue this at INTER. This helps us understand the ultrastructure of myelin from a structural and functional aspect. In this proposal we ask for 6 days of beamtime to carry out measurements involving three abundant myelin proteins in various lipid environments and contrasts.
DOI: 10.5286/isis.e.rb1620454
title: Formation of Ho2Ge2O7 Pyrochlore at High Temperature and Pressure

description: When synthesised at high pressure and temperature, holmium germanate adopts the pyrochlorestructure. Because of its geometry, materials with this structure often have exotic and interestingmagnetic properties. Normally, the pyrochlore structure is only stable when the two metals arerelatively similar in size, which is not the case for Ho and Ge. This explains why extremeconditions are required to make it. In this experiment we will use the Pearl diffractometer to followthe conversion of a mixture of the simple component oxides to the pyrochlore as we increasetemperature and pressure. We have also recently made a sample of holmium germanate in adifferent crystal structure and hope to use this as a precursor phase that can be converted to thepyrochlore at lower temperature or pressure than the simple oxide approach.
DOI: 10.5286/isis.e.rb1700059
title: Probing the viability of water-in-CO2 microemulsions with Headgroup-free amphiphiles

description: Recent SANS studies of an unusual headgroup-free surfactant (Nohead FC6-HC4) produced data that implied the formation of W/CO2 microemulsions (MEs) at a particular pressure (P) and temperature (T). However, at other P and T conditions, or for compounds having different tail lengths, SANS data suggested the formation of either hydrated aggregates (without aqueous cores) or no aggregate formation. With the compound Nohead FC6-HC4 having unusual surfactant architecture, the apparent stabilisation of W/CO2 MEs is a surprising find with a significant potential impact in colloid and interface chemistry. This proposal aims to find an answer to the question Can CO2-philic compounds without a headgroup really stabilize W/CO2 MEs, and if so, how do they work? This study explores W/CO2 ME formation using headgroup-free compounds of various structures over a range of experimental conditions.
DOI: 10.5286/isis.e.rb1710085
title: New Lifshits magnetic liquid phase in a non-centrosymmetric compound Mn3RhSi

description: Recently, new phase with Lifshits invariant of incommensurability is reported as a solitonic spin-liquid state above the magnetically ordered phase on Fe1-yTe. It cannot not be expressed by Gintzburg-Landau phae transition theory due to the Lifshits invariant. The term can be expected in a material with incommensurability or chiral magnet with Dzyaloshinsky-Moriya (DM) interaction. So far, the new phase of Fe1-yTe is only one example for the new liquid phase, where magnetic ordered moments persist even in the paramagnetic phase. Recently, we have found another candidate of a new liquid phase with Lifshits invariant. That is a chiral magnet of Mn3RhSi with the DM interaction in a non-centrosymmetric crystal structure. Wed like to reveal the magnetic liquid state by muSR.
DOI: 10.5286/isis.e.rb1710105
title: The origin of ultra-low thermal conductivity in the thermal barrier material La2Zr2O7

description: Thermal barrier materials are used in modern turbines to enable them to run above the melting temperature of the turbine blades. However, to go to higher temperatures (and higher efficiencies) we need new barrier materials with lower thermal conductivities. La2Zr2O7 is one such material however the origin of its low thermal conductivity is unknown. We propose to use the MERLIN spectrometer to determine the origin of the low thermal conductivity and identify the individual vibrations responsible for heat transfer. This will enable us to devise new ways to reduce the thermal conductivity both in La2Zr2O7 and other barrier materials.
DOI: 10.5286/isis.e.rb1710113
title: Effect of electron doping on the magnetic dynamics of the d^4 Mott insulator Ca2RuO4

description: Oxides containing heavy transition-metal ions with four d electrons (d^4) surrounded by an octahedron of oxygen ions have recently been predicted to display a novel type of magnetic order called excitonic magnetism. The conditions required for this state are that the atomic spin-orbit coupling is comparable in strength to the magnetic coupling between neighbouring ions. A recent theoretical study predicted that excitonic magnetism can be found in Ca2RuO4, and that as a result the inter-site interactions are strongly modified by electron doping. We aim to investigate this prediction by comparing the spin dynamics of Ca2RuO4 with that of compounds doped with 5% of La and Pr. The spectrum of spin excitations is sensitive to the sign and magnitude of the inter-site coupling and also to the strength of the spin-orbit coupling, so by identifying changes in these we will test the predictions.
DOI: 10.5286/isis.e.rb1710139
title: Higher resolution inspection of the hydrocarbon pool connected with the methanol-to-gasoline reaction over ZSM-5

description: The reaction of methanol to form hydrocarbons over zeolite catalysts is an important option for conversion of natural gas or coal to liquid fuels.  We have shown previously via beamtime on the MERLIN spectrometer that INS can observe the hydrocarbon species present in the pores of a working commercial catalyst.  MERLIN was selected for this role because it provided access to vibrational transitions &gt;2000 cm-1.  However, it is a challenging task to discern the molecular identity of the retained hydrocarbon species in the MERLIN spectra, due to the restricted resolution of this instrument.  To address this constraint, we wish to use the recently up-graded TOSCA spectrometer, which possesses superior resolution in the diagnostically important fingerprint region of the spectrum (1600-400 cm-1).
DOI: 10.5286/isis.e.rb1710290
title: Investigation of the translocation potential of therapeutic macromolecules into cell-derived exosomes

description: Exosomes are released by cells are responsible for cell-cell communication of macromolecules and the development of disease such as cancer.  These nanoparticles are loaded with biologically active macromolecules, such interfering RNA and message RNA that mediate effects on the recipient cell.  The discovery that Anthrax toxin can delivers toxins to neighbouring cells using exosome biogenesis has afforded an opportunity to develop a novel strategy for the investigation of this important pathological process, and to investigate a manufacturing process for the development of therapeutic exosomes for the treatment of common diseases using macromolecular therapies.  We propose to investigate the ability of this toxin based system to package cell-derived exosomes with therapeutic macromolecules using neutron reflectometry to chart the translocation of these molecules in to the exosome.
DOI: 10.5286/isis.e.rb1710457
title: Geometrical frustration induced quantum phase transition in single crystal of CeRh0.9Pd0.1Sn: A Muon Spin relaxation/rotation study

description: -The quasi-kagome Kondo lattice CeRhSn exhibits quantum criticality induced by geometrical frustration. Divergent Grüneisen ratios provide evidence for a zero-field QCP. The thermal expansion, which only displays quantum critical behavior along a-axis and not along the c-axis, indicates that geometrical frustration induced QCP due to the presence of quasi-kagome layers in ab-plane in this system. Our recently heat-capacity study on CeRh1-xPdxSn (x=0 to 0.8) alloys reveals enhanced and clear sign of QCP/NFL behavior in x=0.1, but long range magnetic transitions for x ≥ 0.2. Here we proposed to carry out muon-spin rotation and relaxation measurements on single crystals of x=0.1 along muon beam parallel to c-axis and also perpendicular to c-axis. The proposed muon study will through light on the origin of QCP/NFL behavior in x=0.1 sample. We have been given beam time on MERLIN/GEM.
DOI: 10.5286/isis.e.rb1710501
title: Low-Dimensional Quantum Magnetism in a Molecular Framework

description: The exotic physics of low-dimensional quantum magnets has recently been highlighted by the award of a Nobel Prize to Duncan Haldane. We have identified the molecular framework material Cu(SCN)2 as a promising candidate for quantum-disordered magnetism. This material does not order magnetically down to 2 K, despite large magnetic interactions (~120 K), indicating strong effects of quantum mechanics, frustration, and/or dimensionality. We propose to measure high-resolution neutron-diffraction data on Cu(SCN)2 to obtain: (1) an unambiguous crystal-structure solution (2) the build-up of spin correlations in the paramagnetic regime, as probed by magnetic diffuse scattering and (3) the nature of magnetic order at the lowest temperatures (0.05 K). These measurements are important to reveal the potential of molecular framework materials to behave as model quantum magnets.
DOI: 10.5286/isis.e.rb1000102
title: 1000102
DOI: 10.5286/isis.e.rb1500025
title: Twinning in bcc Ti