In situ TiB2 particles with polyhedral or near-spherical morphology with more high-index crystal planes exposed were prepared by controlling the addition amount of Sc in commercial pure aluminum matrix. As the content of Sc increased, TiB2 morphology transformed from hexagonal platelets to polyhedral or near-spherical morphology with a decrease in particle size. In the present paper, a simple method to prepare near-spherical in situ TiB2 particles in Al matrix was explored and it was found that the reinforcement distribution was improved significantly. The different growth mechanism of TiB2 particles in Al and Al–Sc systems was discussed. The key reason for the morphology evolution was that the Sc was preferentially adsorbed on ${\bf \left\{ {1{\bf \overline{2}}12} \right\}}$, ${\bf \left\{ {11\overline{2}0} \right\}}$, and ${\bf \left\{ {10\overline{1}1} \right\}}$ which would inhibit the growth of these faces effectively and retain a lower-energy state of the polyhedral or quasispherical TiB2 particles in Al–Sc systems.

On April 3, 2015, the ICSID tribunal in Venoklim Holding B. V. v. Bolivarian Republic of Venezuela issued the first public decision to consider the effect of a state’s denunciation of the ICSID Convention (Convention). The tribunal decided that Venezuela’s denunciation on January 24, 2012, did not preclude jurisdiction over a claim submitted in the period after notification of the denunciation but before its effective date. Yet the tribunal also held that Venezuela’s domestic statute was insufficient as an autonomous offer of consent to ICSID arbitration, and that the conjunction of the statute with an investment treaty did not confer such consent where the conditions in the statute were not fulfilled. The award was notable too because of the majority’s holding that the tribunal lacked jurisdiction owing to the Venezuelan nationality of the underlying beneficial owners of the Dutch corporation that was the claimant in the ICSID arbitration. The Tribunal held that, because the claimant was effectively owned by Venezuelan nationals, the requirement of foreign ownership or control was not satisfied for the purposes of the applicable Venezuelan investment statute and the ICSID Convention.

Recently, the research team synthesized some scandium- and titanium-based oxide compounds, in order to analyze their thermoluminescent (TL) response [1-2]. The oxides mixture Sc2TiO5:Eu2Ti2O7:Sc2O3 was synthesized in equilibrium phase by solid state reaction at 1100 °C / 48 h. The structural characterization was performed by XRD and SEM. The TL properties of this oxide mixture were examined after exposing it to gamma radiation from a 60Co source. The glow curve showed two main glow peaks at 151 °C and 260 °C, yet the curve shape looks quite complex, revealing that it is composed by overlapped individual TL peaks, which was confirmed with the Tstop preheat method performed [3]. The linear dose-response between 150 to 600 Gy was obtained, followed by a slow saturation stage. The intensity of the glow curves increases as the radiation dose increases, and their maxima remain at the same temperature values, which indicates that the TL phenomenon follows first-order kinetics [4]. After ten irradiation-TL readout cycles at 500 Gy, good stability (SD 2.02 %) between TL integrated response and the exposure dose was found. It is concluded that Sc2TiO5:Eu2Ti2O7:Sc2O3 is a promising material to use as high-dose dosimeter.

The combination of the molecular beam epitaxy growth method with the in-situ reflection high energy electron diffraction measurements currently offers unprecedented control of crystalline growth materials. We present here a stoichiometric study of MnxSc(1-x) [x = 0, 0.03, 0.05, 0.15, 0.25, 0.35, and 0.50] thin films grown on MgO(001) substrates with this growth method. Reflection high energy electron diffraction and atomic force microscopy measurements reveal alloy behavior for all of our samples. In addition, we found that samples Mn0.10Sc0.90 and Mn0.50Sc0.50 display surface self-assembled nanowires with a length/width ratio of ~ 800 – 2000.

Using a combination of retrograde horseradish peroxidase (HRP) labelling, silver staining, and electron microscopy, we have assessed the relationship between retinal ganglion cell soma size and axon diameter in the adult ferret (Mustela putorius furo). Retinal ganglion cells were labelled following injections of HRP into the lateral geniculate nucleus (LGN), superior colliculus (SC), or LGN+SC. The soma size distributions following LGN, SC, or LGN+SC injections were all unimodal showing considerable overlap between different cell classes. This was confirmed for alpha cells, identified on the basis of dendritic filling or from neurofibrillar-stained retinae. Analysis of the soma size and axon diameters of a population of heavily labelled retinal ganglion cells showed a significant correlation between the two. However, the overall distribution of intraretinal axon diameter was bimodal with an extended tail. Analysis of the ganglion cell distributions in the adult ferret indicates that beta cells comprise about 50.5–55%, gamma 42.5–47%, and alpha 2.5% of the ganglion cell population. This implies that the proportion of gamma, beta, alpha cells in both cat and ferret retina is highly conserved despite differences in visual specialization in the two species.

Degradation of current gain for ion implanted 4H-SiC bipolar junction transistor is described. The influence of bandgap-narrowing to the collector and base currents of the transistor was investigated using ISE-TCAD simulator. Simulated results show good agreement with the measured results, which show that the common emitter current gain of 3.9 is obtained at a maximum base concentration of 2×1017/cm3 and a maximum emitter concentration of 4×1019/cm3 for ion implanted 4H-SiC BJTs.

The ventral lateral geniculate nucleus (vLGN), the pretectal nuclear complex (PNC) and the superior colliculus (SC) are structures that all receive retinal input. All three structures are important relay stations of the subcortical visual system. They are strongly connected with each other and involved in circadian and/or visuomotor processes. However, the information transferred along these pathways is unknown and their possible functions are, therefore, not well understood. Here, we characterized multiple pathways between the vLGN, the PNC, and the SC electrophysiologically and anatomically in an in vitro study using acute rat brain slices. Using orthodromic and antidromic electrical stimulation, we first characterized vLGN neurons that receive pretectal input and those that project to the PNC. Morphological reconstructions of cells labeled after patch clamp recordings identified these neurons as geniculo-tectal neurons and as medium-sized multipolar neurons. We identified inhibitory connections in both pathways and we could show that inhibitory postsynaptic currents (IPSCs) evoked from the PNC in vLGN neurons are mediated only by GABAA receptors, while IPSCs evoked in PNC neurons by vLGN stimulation are either mediated by both, GABAA and GABAC receptors or by a GABA receptor with mixed GABAA and GABAC receptor-like pharmacology. Finally, retrograde double labeling experiments with two different fluorescent dextran amines indicated that pretectal neurons which project to the ipsilateral vLGN also project to the ipsilateral SC.

Polycrystalline transparent Yb:Sc2O3 ceramics were obtained in the best conditions by a solid-state reaction route using high purity Sc2O3 and Yb2O3 powders with TEOS as a sintering aid. The as-prepared powders containing various ytterbium content were characterized by BET measurements, XRD and FEG-SEM. The sintering behaviour of the powders was investigated by dilatometry. The sintered materials microstructures were observed by FEG-SEM. EPMA allowed to characterize the repartition of the dopant Yb3+ in the Sc2O3 matrix.

Commercial scandium oxide doped thermionic cathodes have demonstrated current densities over 100 A/cm2. In order to understand the effect of Sc- and Ba- oxides on the emissivity of these cathodes we have imaged thin films of scandium oxide and barium oxide on tungsten foils using photoelectron emission microscopy and thermionic emission microscopy. Arrays of 100 um × 100 um squares of scandium and 25 um × 25 um squares of barium, 200 nm thick, were sputter deposited onto 50 um thick sheets of tungsten foil. Imaging squares of different sizes gives an unequivocal identification of each material and a completely consistent comparison of each material and cathode structure under identical conditions in one image.

The metal squares oxidize in air before imaging. Each sample was heated in situ in a Bauer-Telieps style LEEM/PEEM used primarily in the ThEEM mode. The barium oxide squares emit below 875 K, and diffuse over the scandium below 875 K. Thermionic emission from scandium oxide squares is observed at temperatures significantly larger than 875 K. Failure of the barium oxide film cathode is through barium desorption. AES spectra show that the Sc does not desorb.

While the origin of reduced emission temperature is commonly believed to be a result of a low work function monolayer of Ba and Sc oxides, in our study, the benefits of a combined Ba/Sc cathode are present in a thick (multi-layer), layered structure of barium oxide on top of a thick scandium oxide layer.

We seek to explain 1) the effectiveness of substituting Sc with Dy, Er, Y and 2) the loss of properties when Sc is replaced with Yb, Gd and Sm [1]. For a preliminary insight into the stability of structures we utilize the concept of Atomic Environment Type (AET) as pertaining to trialuminides. Electronic density functional total energy calculations at zero temperature are performed to obtain the enthalpy of mixing of quasi-binary Al-Sc-X structures. Estimates of the entropy are used to compute the stability regions of Al3Sc1-αXα L12 phase. We show that Sc is completely miscible with X=Dy, Er, Y and that there is a miscibility gap for X=Yb, Gd and Sm at temperatures near the aging temperature of Al-Sc alloys.

Sc-doped ZnO thin films were deposited on Corning 1737 glasses by using RF magnetron co-sputtering system with Sc2O3 and ZnO targets. Different sputtering powers of Sc2O3 target and post annealing of 550°C for 2 hr were investigated to understand the effect on microstructural, optical and electrical properties of Sc-doped ZnO thin films. From X-ray diffraction (XRD) results, the Sc-doped films have (002) preferred orientation. Cross-sectional scanning electron microscope (SEM) show that the Sc-doped ZnO thin films have columnar structure before and after annealing procedure. Atomic force microscopy (AFM) surface measurement also shows that the surface roughness of the films was smoother when the Sc2O3 sputtering power increased. The optical transmission of as deposited Sc-doped films in the visible region all exceeded 80%, and increased about 3% after samples annealed. Electrical resistivity measurement reveals that the as-deposited Sc-doped ZnO thin films had lowest resistivity of 0.97 Ω cm when the Sc2O3 sputtering power was 125W. After annealing the lowest resistivity decreased to 9.85 × 10−2 Ω cm in which 200W of the Sc2O3 sputtering power was applied.

Epitaxial ScxGa1-xN films of low Sc concentration (x = 0.08 ± 0.01) were deposited on MOCVD-grown GaN films (using an Al2O3 substrate) at 800°C using molecular beam epitaxy employing ammonia as a reactive nitrogen source (NH3-MBE). The strain-free lattice parameters of the films were determined using a method based on high-resolution X-ray diffraction (HRXRD) in conjunction with an in-situ elastic tester. It is found that the c:a lattice parameter ratio increases slightly and that the Poisson’s ratio decreases with increasing Sc concentration. The crystalline quality and long-range ordering of the ScxGa1-xN films (as indicated by HRXRD peak intensities and full width at half maximum values) is improved considerably relative to the GaN template. Our results indicate that threading dislocations do not propagate effectively into the ScxGa1-xN films and that these may therefore potentially find application as dislocation blocking layers in GaN-based optoelectronic devices.