Application potential of cold neutron radiography in plant science research

Though comprehensive knowledge of water status and water flow are important prerequisites for plant in many aspects of modern plant science truly non-destructive methods for the in-situ study of water transport are rare. Advanced imaging methods such as Magnetic Resonance Imaging (MRI) or Cold Neutron Radiography (CNR) may be applied to fill this gap. In CNR strong interaction of cold neutrons with hydrogen provides a high contrast even for small amounts of water. The combination of CNR with the low-contrast tracer D2O allows the direct visualisation of water flow and the calculation of water flow rates in plants with a high resolution at the tissue level. Here, we give a general introduction into this method, describe their latest developments, report about studies applying neutron radiography in plant science and provide most recent results of our experiments in this field

Dynamic volume magnetic domain wall imaging in grain oriented electrical steel at power frequencies with accumulative high-frame rate neutron dark-field imaging

The 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. 20 nanometers, however, allows only for an indirect interpretation of the internal volume domain structures. Here we show how accumulative high-frame rate dynamic neutron dark-field imaging is able for the first time to visualize the dynamic of the volume magnetic domain structures in grain oriented electrical steel laminations at power frequencies. In particular we studied the volume domain structures with a spatial resolution of ∼100 μm and successfully quantified domain sizes, wall velocities, domain annihilation and its duration and domain wall multiplication in real time recordings at power frequencies of 10, 25 and 50 Hz with ±262.5 A/m and ±525 A/m (peak to peak) applied field

Applied neutron tomography in modern archaeology

The use of neutron tomography for archaeometric purposes is quite a new technique. The property of neutron to transmit easily large, dense samples is of great importance in modern archaeology. The three-dimensional visualisation of the inner structure of samples of archaeological interest helps to make suggestions about the technological process of manufacturing or reveals information about the origins of delivering of noble materials used in ancient masterpieces. Another application field in modern archaeology is the non-destructive inspection of the quality of specimen conservation where the neutron tomography allows visualization of impregnation solutions in wood or metal matrices. The high sensibility of neutrons to hydrogen makes it possible to detect organic remains in fossils. All of these advantages make the neutron tomography a unique technique for non-destructive investigation in archaeological sciences

Inner ear development in cetaceans

Cetaceans face the challenge of maintaining equilibrium underwater and obtaining sensory input within a dense, low-visibility medium. The cetacean ear represents a key innovation that marked their evolution from terrestrial artiodactyls to among the most fully aquatic mammals in existence. Using micro-CT and histological data, we document shape and size changes in the cetacean inner ear during ontogeny, and demonstrate that, as a proportion of gestation time, the cetacean inner ear is precocial in its growth compared with that of suid artiodactyls. Cetacean inner ears begin ossifying and reach near-adult shape as early as at 32% of the gestation period, and near-adult dimensions as early as at 27% newborn total length. Our earliest embryos with measurable inner ears (13% newborn length) exhibit a flattened cochlea (i.e. smaller distance from cochlear apex to round window) compared with later and adult stages. Inner ears of Sus scrofa have neither begun ossifying nor reached near-adult dimensions at 55% of the gestation period, but have an adult-like ratio of cochlear diameters to each other, suggesting an adult-like shape. The precocial development of the cetacean inner ear complements previous work demonstrating precocial development of other cetacean anatomical features such as the locomotor muscles to facilitate swimming at the moment of birth.The John Stanley Gardiner Studentship and Queens’ College provided financial support for this project. This research also received support from the SYNTHESYS Project (http://www.synthesys.info/), which is financed by European Community Research Infrastructure Action under the FP7 Integrating Activities Programme. The authors thank the editor and reviewers for their comments on the manuscript

Three-Dimensional Imaging of Magnetic Domains with Neutron Grating Interferometry

This paper gives a brief overview on3D imaging of magnetic domains with shearing grating neutron tomography. We investigated the three-dimensional distribution of magnetic domain walls in the bulk of a wedge-shaped FeSi single crystal. The width of the magnetic domains wasanalyzed at different locations within the crystal. Magnetic domains close to the tip of the wedge are much smaller than in the bulk. Furthermore, the three-dimensional shape of individual domains wasinvestigated. We discuss prospects and limitations of the applied measurement technique