This work describes the implementation of polarized neutron imaging capabilities at the neutron and x-ray tomograph (NeXT) imaging station of the Institut Laue Langevin. This development enhances the capacity of this instrument to study advanced magnetic materials, which are crucial in a variety of engineering applications. Here, the feasibility of polarized neutron imaging at NeXT is demonstrated by visualizing the magnetic field generated by a simple bar magnet.
View Article and Find Full Text PDFIncreasingly, environmental research efforts seek to understand how the continuous input of microplastics into terrestrial environments alters soil physicochemical properties and affects plants and other soil biota. However, fundamental understanding is hampered by the destructive nature of current analytical techniques, which typically require the disruption of soil samples and often the removal of soil organic matter. This results in the irretrievable loss of essential information about soil microstructure and the spatial distribution of microplastic particles.
View Article and Find Full Text PDFThe Oak Ridge National Laboratory is planning to build the Second Target Station (STS) at the Spallation Neutron Source (SNS). STS will host a suite of novel instruments that complement the First Target Station's beamline capabilities by offering an increased flux for cold neutrons and a broader wavelength bandwidth. A novel neutron imaging beamline, named the Complex, Unique, and Powerful Imaging Instrument for Dynamics (CUPI2D), is among the first eight instruments that will be commissioned at STS as part of the construction project.
View Article and Find Full Text PDFA systematic study has been carried out to investigate the neutron transmission signal as a function of sample tem-per-ature. In particular, the experimentally de-ter-mined wavelength-dependent neutron attenuation spectra for a martensitic steel at tem-per-atures ranging from 21 to 700°C are com-pared with simulated data. A theoretical description that includes the Debye-Waller factor in order to describe the tem-per-ature influence on the neutron cross sections was im-plemented in the software and used for the simulations.
View Article and Find Full Text PDFHerein, the concept of constructing binder- and carbon additive-free organosulfur cathode was proved based on thiol-containing conducting polymer poly(4-(thiophene-3-yl) benzenethiol) (PTBT). The PTBT featured the polythiophene-structure main chain as a highly conducting framework and the benzenethiol side chain to copolymerize with sulfur and form a crosslinked organosulfur polymer (namely S/PTBT). Meanwhile, it could be in-situ deposited on the current collector by electro-polymerization, making it a binder-free and free-standing cathode for Li-S batteries.
View Article and Find Full Text PDFA large and increasing number of scientific domains pushes for high neutron imaging resolution achieved in reasonable times. Here we present the principle, design and performance of a detector based on infinity corrected optics combined with a crystalline GdGaO : Eu scintillator, which provides an isotropic sub-4 µm true resolution. The exposure times are only of a few minutes per image.
View Article and Find Full Text PDFThis article summarizes developments attained in oral vaccine formulations based on the encapsulation of antigen proteins inside porous silica matrices. These vaccine vehicles show great efficacy in protecting the proteins from the harsh acidic stomach medium, allowing the Peyer's patches in the small intestine to be reached and consequently enhancing immunity. Focusing on the pioneering research conducted at the Butantan Institute in Brazil, the optimization of the antigen encapsulation yield is reported, as well as their distribution inside the meso- and macroporous network of the porous silica.
View Article and Find Full Text PDFThe behaviour of subsurface-reservoir porous rocks is a central topic in the resource engineering industry and has relevant applications in hydrocarbon, water production, and CO2 sequestration. One of the key open issues is the effect of deformation on the hydraulic properties of the host rock and, specifically, in saturated environments. This paper presents a novel full-field data set describing the hydro-mechanical properties of porous geomaterials through in situ neutron and X-ray tomography.
View Article and Find Full Text PDFExtensive research is being conducted on magnesium (Mg) alloys for bone implant manufacturing, due to their biocompatibility, biodegradability and mechanical properties. Gadolinium (Gd) is among the most promising alloying elements for property control in Mg alloy implants; however, its toxicity is controversial. Investigating Gd behavior during implant corrosion is thus of utmost importance.
View Article and Find Full Text PDFThe neutron imaging instrument CONRAD was operated as a part of the user program of the research reactor BER-II at Helmholtz-Zentrum Berlin (HZB) from 2005 to 2020. The instrument was designed to use the neutron flux from the cold source of the reactor, transported by a curved neutron guide. The pure cold neutron spectrum provided a great advantage in the use of different neutron optical components such as focusing lenses and guides, solid-state polarizers, monochromators and phase gratings.
View Article and Find Full Text PDFRoot water uptake is an essential process for terrestrial plants that strongly affects the spatiotemporal distribution of water in vegetated soil. Fast neutron tomography is a recently established non-invasive imaging technique capable to capture the 3D architecture of root systems in situ and even allows for tracking of three-dimensional water flow in soil and roots. We present an in vivo analysis of local water uptake and transport by roots of soil-grown maize plants-for the first time measured in a three-dimensional time-resolved manner.
View Article and Find Full Text PDFThe temporally and spatially resolved tracking of lithium intercalation and electrode degradation processes are crucial for detecting and understanding performance losses during the operation of lithium-batteries. Here, high-throughput X-ray computed tomography has enabled the identification of mechanical degradation processes in a commercial Li/MnO primary battery and the indirect tracking of lithium diffusion; furthermore, complementary neutron computed tomography has identified the direct lithium diffusion process and the electrode wetting by the electrolyte. Virtual electrode unrolling techniques provide a deeper view inside the electrode layers and are used to detect minor fluctuations which are difficult to observe using conventional three dimensional rendering tools.
View Article and Find Full Text PDFIn various kinds of radiography, deficient transmission imaging may occur due to backlighting inside the detector itself arising from light or radiation scattering. The related intensity mismatches barely disturb the high resolution contrast, but its long range nature results in reduced attenuation levels which are often disregarded. Based on X-ray observations and an empirical formalism, a procedure is developed for a first order correction of detector backlighting.
View Article and Find Full Text PDFHere, we report on a new record in the acquisition time for fast neutron tomography. With an optimized imaging setup, it was possible to acquire single radiographic projection images with 10 ms and full tomographies with 155 projections images and a physical spatial resolution of 200 µm within 1.5 s.
View Article and Find Full Text PDFWe herein report on using a compact and low cost scintillator-camera based neutron detection system for quantitative time-of-flight imaging applications. While powerful pulsed neutron sources emerge and enable unprecedented scientific achievements, one bottleneck is the availability of suitable detectors that provide high count- and high frame- rate capabilities. For imaging applications the achievable spatial resolution/pixel size is obviously another key characteristic.
View Article and Find Full Text PDFOperando laboratory X-ray radiographies were carried out for imaging of two different silver-based gas diffusion electrodes containing an electroconductive Ni mesh structure, one gas diffusion electrode composed of 95 wt.% Ag and 5 wt.% polytetrafluoroethylene and one composed of 97 wt.
View Article and Find Full Text PDFInnovative solutions have been designed to meet the global demand for energy and environmental sustainability, such as enhanced hydrocarbon recovery and geo-sequestration of CO. These processes involve the movement of immiscible fluids through permeable rocks, which is affected by the interfacial properties of rocks at the pore scale. Overcoming major challenges in these processes relies on a deeper understanding about the fundamental factors that control the rock wettability.
View Article and Find Full Text PDFDeveloping a technology that enables oral vaccines to work efficiently remains a considerable effort since a number of difficulties must be addressed. The key objective being to ensure the safe passage through the harsh conditions within the gastrointestinal tract, promoting delivery that induces enhanced immune response. In the particular case of hepatitis B, the oral formulation in the nanostructured silica SBA-15 is a viable approach.
View Article and Find Full Text PDFThe polarized neutron imaging technique provides a non-invasive method of characterizing localized magnetic fields inside superconductors. However, complete understanding of the magnetic field distribution has yet to be realized experimentally due to the complexity of the interaction between neutron polarization and magnetic field. In this article, we show that a well-defined and controlled magnetic field through the neutron path contributes to simplify the data analysis and makes future quantitative polarized neutron imaging possible.
View Article and Find Full Text PDFMost epiphytic bromeliads, especially those in the genus Tillandsia, lack functional roots and rely on the absorption of water and nutrients by large, multicellular trichomes on the epidermal surfaces of leaves and stems. Another important function of these structures is the spread of water over the epidermal surface by capillary action between trichome "wings" and epidermal surface. Although critical for the ultimate absorption by these plants, understanding of this function of trichomes is primarily based on light microscope observations.
View Article and Find Full Text PDFGorgonopsia is one of the major clades of non-mammalian synapsids, and includes an array of large-bodied carnivores that were the top terrestrial predators of the late Permian. Most research on the clade has focused on these largest members; small-bodied gorgonopsians are relatively little-studied. Here, we redescribe a small gorgonopsian skull (MB.
View Article and Find Full Text PDFThe mobility of magnetic domains forms the link between the basic physical properties of a magnetic material and its global characteristics such as permeability and saturation field. Most commonly, surface domain structure are studied using magneto-optical Kerr microscopy. The limited information depth of approx.
View Article and Find Full Text PDFThe internal microstructure of a silicon electrode in a lithium ion battery was visualized by operando synchrotron X-ray radioscopy during battery cycling. The silicon particles were found to change their sizes upon lithiation and delithiation and the changes could be quantified. It was found that volume change of a particle is related to its initial size and is also largely determined by the changing surrounding electron-conductive network and internal interface chemical environment (e.
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