Multiscale structural analysis of nacre-like HAp-based composites using small-angle X-ray scattering tensor tomography

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Designing humidity-driven actuators with rapid, programmable motion remains challenging due to limited responsiveness and poor mechanical integrity in conventional materials. Here, we demonstrate a strategy that transforms one-dimensional (1D) cellulose nanofibers (CNFs) into mechanically robust two-dimensional films through premodification, which simultaneously directs the controlled growth of covalent organic frameworks (COFs) to produce tunable, moisture-responsive surfaces. Fourier transform infrared sp

The hierarchical structure of cortical bone plays a key role in its mechanical performance and in the development of fragility fractures such as those occurring in the femoral neck. While bone structure has been extensively studied at the macro- and microscale, increasing evidence suggests that nanostructural features also contribute to mechanical performance and may be relevant for understanding age- and disease-related changes such as osteoporosis. This thesis aims to improve the multiscale structural cha

The human femoral neck is particularly vulnerable to fracture, with failure most often initiating in the superior region. While age-related microstructural changes such as cortical thinning and increased porosity are well established, the contribution of material properties at the lamellar and mineralised collagen fibril (MCF) levels remains poorly understood. Here, regional differences in nanostructural properties of cortical bone from 78 femoral necks obtained from 44 donors aged 54–96 are investigated us

Transient receptor potential melastatin 4 (TRPM4) is a Ca 2+ −activated cation channel whose pharmacology is shaped by its molecular environment. It remains poorly understood how temperature and membrane context influence inhibitor recognition. Here we combine cryo−electron microscopy of membrane-derived vesicles and detergent−solubilized TRPM4 to investigate lipid−associated architecture and binding of the potent anthranilic anilide inhibitor PBA. We find that membrane vesicles preserve a native−like paral

Stereoisomers of C 13 Cl 2 exhibiting helical orbitals around a ring of carbon atoms were synthesized by atom manipulation on NaCl surfaces. We resolved the enantiomeric geometries of the singlet states by atomic force microscopy and mapped their helical orbital densities by scanning tunnelling microscopy. A π-orbital basis of the helical, non-planar singlets that twists by 90° in one circulation is consistent with a half-Möbius topology. In such a topology, the π-orbital basis changes sign with respect to

Recent advances in lasers and electron optics technology have allowed transmission electron microscopes to achieve high spatial and temporal resolution, making them capable of tracking atoms, charges and spin motions down to the attosecond and nanometre scales. This Primer discusses the most common and practical experimental implementation of time-resolved transmission electron microscopy and the stroboscopic mode for evaluating ultrafast reversible dynamics. An in-depth discussion of photo-induced near-fie

In this workshop resource, different numerical models associated with structural systems are provided using the COMPAS FEA1 package.

Single-layer MoS2 is a newly emerging two-dimensional semiconductor with a potentially wide range of applications in the fields of nanoelectronics and energy harvesting. The fact that it can be exfoliated down to single-layer thickness, makes MoS2 interesting both for practical applications and for fundamental research, where the structure and crystalline order of ultrathin MoS2 will have a strong influence on electronic, mechanical and other properties. Here, we report on the transmission electron microsco

Flash memories based on nanoparticles (NPs) offer an attractive alternative for performance enhancement and size downscaling of non-volatile memory cells. In these devices, Coulomb blockade and quantized charging effects can be exploited at room temperature for a limited number of addressed NPs [1]. A successful exploitation of these nanoscale effects requires not only knowledge of the NPs properties (size, nature, structure and location) but also a sound understanding of the charge trapping phenomena that

Solid Oxide Fuel Cells (SOFC) are an efficient energy technology for converting different types of fuels to electricity and heat. An important material limitation, especially for (planar) Ni-based anode supported cells, is their redox stability. The nickel volume change between its metallic and oxide state is destroying the thin electrolyte. Thereby it is crucial to understand mechanisms of nickel reduction, oxidation and coarsening in this system. Reduction parameters are also important from an electrochem

Time-resolved x-ray absorption fine structure (XAFS) spectroscopy with picosecond temporal resolution is a new method to observe electronic and geometric structures of short-lived reaction intermediates. It combines an intense femtosecond laser source synchronized to the x-ray pulses delivered into the microXAS beamline of the Swiss Light Source (SLS). We present key experiments on charge transfer reactions as well as spin-crossover processes in coordination chemistry compounds next to solvation dynamics st

Electron energy-loss near-edge structure data for the N K and the Cr L 2,3 edges of CrN and Cr2N have been acquired in order to distinguish between these chromium nitride modifications. The N K edge spectra of these compounds have been modelled using both band structure and multiple scattering methods. We compare the results of these calculations with the experimental edges which have been recorded using a conventional transmission electron microscope (TEM) as well as a monochromated TEM (Wien filter).

We present a setup which allows the measurement of time-resolved x-ray absorption spectra with picosecond temporal resoln. on liq. samples at the Advanced Light Source at Lawrence Berkeley National Labs. The temporal resoln. is limited by the pulse width of the synchrotron source. We characterize the different sources of noise that limit the expt. and present a single-pulse detection scheme. [on SciFinder (R)]

Innovative surface imaging techniques allowing parallel magnetic and topographical microscopy with nanometer scale spatial resolution are developed in this project. Nanometer scale magnetosensitive devices on Atomic Force Microscopy (AFM) tips will be studied and fabricated, allowing quantitative and noninvasive magnetic field imaging with spatial resolution better than 100 nm and magnetic field resolution better than 100 mT/Hz. Such performance will allow one to perform magnetic microscopy studies, which a

The ferroelectric transition of bulk strontium titanate is suppressed by a combination of two effects: (1) the structural changes produced by the antiferrodistortive transition at T-a =105 K and (2) the quantum fluctuations. The structural changes are strongly perturbed within antiphase domain boundaries , and this in such a manner that a ferroelectric transition should occur in boundaries containing the tetragonal c-axis at T-c similar to 35 to 40 K. This provides a possible explanation for a number of ano

A series of polyquasicrystalline ingots with the nominal composition Al63.6Cu24.0Fe12.4 has been prepared by conventional drop casting and subsequent annealing at 1088 K for 24 h. Compression specimens prepared from the different ingots have been deformed at temperatures ranging from 750 to 1050 K. The details of the structure and microstructure of the as-cast, annealed and deformed materials have been investigated by optical, scanning and transmission electron microscopy. Whatever their initial structure (

We report on improved structural, crystallographic and electrical properties of epitaxial NdBa2Cu3O7-delta (NBCO) films grown on SrTiO3 by 'off-axis' pulsed laser deposition (PLD). Transport and XRD studies show that the c-axis-oriented epitaxial films, with critical temperatures of 90-92 K, are mono phase and single-crystalline. Furthermore, very smooth, almost outgrowth-free surfaces and crystal coherences of up to 0.8 mum (to our knowledge the best value ever reported for high-T-c films) were obtained.

We tested a new soft-x-ray transmission spectromiscropy technique on the Aladdin storage ring at the Wisconsin Synchrotron Radiation Center. Transmitted x rays were converted with a photocathode into photoelectrons, which were subsequently electron-optically processed by an x-ray secondary electron-emission microscope producing submicron-resolution images. Test images demonstrated the excellent contrast due to the chemical differences between silicon features and a silicon nitride substrate. We also obtaine

The feasibility of using the LEEM technique in neurobiology was tested with experiments on a rat cerebellar granule cell culture. A series of good-quality images, showing fine details such as axons and dendrites of the neuron network, demonstrate that the test was successful.

Core-level photoemission peaks taken on several insulators with spatial resolution of 30-300 mu m rigidly shift in energy from place to place, most likely because of local charging effects. Such phenomena can affect the linewidth and the general lineshape of conventional, spatially integrated spectra even when a flood gun is used, which is one of the standard remedies against charging. This may require a critical revision of photoemission linewidths and lineshapes for many past experiments on insulators.

Multiscale structural analysis of nacre-like HAp-based composites using small-angle X-ray scattering tensor tomography

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Programmable Humidity Actuators Enabled by Precise Interfacial Control of COF Nanostructures on Nanocellulose

Hierarchical Imaging and Mechanical Characterization of Cortical Bone

Combination of 3D and 2D small and wide angle X-ray scattering imaging reveals diminished bone quality in the superior human femoral neck cortex

Temperature-dependent ligand relocation reveals plasticity of TRPM4 inhibition

A molecule with half-Möbius topology

Laser-driven Ultrafast Transmission Electron Microscopy

FE Numerical Models for COMPAS FEA1 using OpenSees

Ripples and Layers in Ultrathin MoS2 Membranes

Charging dynamics of localized 2D layers of Si nanocrystals embedded into SiO2 by stencil masked ultra low energy ion implantation process

Reduction and Oxidation Study of Anode Supported Solid Oxide Fuel Cell

Ultrafast x-ray spectroscopy for structural dynamics studies in chemistry and biology

Electron energy loss-near edge structure as a fingerprint for identifying chromium nitrides

A setup for ultrafast time-resolved x-ray absorption spectroscopy

Bismuth Hall Sensors on Plastic Cantilevers

Low-T ferroelectricity in antiphase domain boundaries of SrTiO3

Mechanical behaviour versus structure of Al63.6Cu24.0Fe12.4

Improved structural properties and crystal coherence of superconducting NdBa2Cu3O7-delta films grown by pulsed laser ablation

An electron imaging approach to soft-x-ray transmission spectromicroscopy

Low-Energy-Electron Microscopy (Leem) Imaging of a Neuron Network

Spatially Localized Energy Shifts in the Photoemission Spectroscopy of Insulators