A suspicious dark lesion in a boy.

The presence of history of hyperpigmented crust in a patient with a history of adequate hygiene is typical of terra firma\u2010forme dermatosis. The treatment is the rubbing of the skin with isopropyl alcohol (removal of the hyperpigmented brown crust, confirming the diagnosis). Physicians should be aware because early diagnosis avoid unnecessary treatment

Fast 4D imaging of fluid flow in rock by high‐speed neutron tomography

High‐speed neutron tomographies (1‐min acquisition) have been acquired during water invasion into air‐filled samples of both intact and deformed (ex situ) Vosges sandstone. Three‐dimensional volume images have been processed to detect and track the evolution of the waterfront and to calculate full‐field measurement of its speed of advance. The flow process correlates well with known rock properties and is especially sensitive to the distribution of the altered properties associated with observed localized deformation, which is independently characterized by Digital Volume Correlation of X‐ray tomographies acquired before and after the mechanical test. The successful results presented herein open the possibility of in situ analysis of the local evolution of hydraulic properties of rocks due to mechanical deformation

Characterization of the recovery of mechanical properties of ion-implanted diamond after thermal annealing

Due to their outstanding mechanical properties, diamond and diamond-like materials find significant technological applications ranging from well-established industrial fields (cutting tools, coatings, etc.) to more advanced mechanical devices as micro- and nano-electromechanical systems. The use of energetic ions is a powerful and versatile tool to fabricate three-dimensional micro-mechanical structures. In this context, it is of paramount importance to have an accurate knowledge of the effects of ion-induced structural damage on the mechanical properties of this material, firstly to predict potential undesired side-effects of the ion implantation process, and possibly to tailor the desired mechanical properties of the fabricated devices. We present an Atomic Force Microscopy (AFM) characterization of free-standing cantilevers in single-crystal diamond obtained by a FIB-assisted lift-off technique, which allows a determination of the Young's modulus of the diamond crystal after the MeV ion irradiation process concurrent to the fabrication of the microstructures, and subsequent thermal annealing. The AFM measurements were performed with the beam-bending technique and show that the thermal annealing process allows for an effective recovery of the mechanical properties of the pristine crystal.Comment: 15 pages, 5 figure

Characterisation of single phase fluid flow heterogeneity due to localised deformation in a porous rock using rapid neutron tomography

The 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. The use of high performance neutron imaging facilities such as CONRAD 2 Helmholtz Zentrum Berlin allows the tracking of the fluid front in saturated samples, making use of the differential neutron contrast between normal water and heavy water. To quantify the local hydro mechanical coupling, we applied a number of existing image analysis algorithms and developed an array of bespoke methods to track the water front and calculate the 3D speed maps. The experimental campaign performed revealed that the pressure driven flow speed decreases, in saturated samples, in the presence of pre existing low porosity heterogeneities and compactant shear bands. Furthermore, the observed complex mechanical behaviour of the samples and the associated fluid flow highlight the necessity for 3D imaging and analysi

Editors’ choice—4D neutron and X-ray tomography studies of high energy density primary batteries: Part II. multi-modal microscopy of LiSOCl2 cells

The ability to track electrode degradation, both spatially and temporally, is fundamental to understand performance loss during operation of lithium batteries. X-ray computed tomography can be used to follow structural and morphological changes in electrodes; however, the direct detection of electrochemical processes related to metallic lithium is difficult due to the low sensitivity to the element. In this work, 4-dimensional neutron computed tomography, which shows high contrast for lithium, is used to directly quantify the lithium diffusion process in spirally wound Li/SOCl$_{2}$ primary cells. The neutron dataset enables the quantification of the lithium transport from the anode and the accumulation inside the SOCl$_{2}$ cathode to be locally resolved. Complementarity between the collected neutron and X-ray computed tomographies is shown and by applying both methods in concert we have observed lithium diffusion blocking by the LiCl protection layer and identified all cell components which are difficult to distinguish using one of the methods alone