Phase stability and oxygen transport properties of mixed ionic-electronic conducting oxides

The application of mixed ionic-electronic conducting oxides as oxygen separation membrane for the production of oxygen offers significant advantages over conventional cryogenic distillation. Perovskite- and fluorite-type oxides are promising candidates for such application. The research described in this thesis is mainly focused on i) crystal chemistry and phase stability of either Zr- or Nb-substituted Ba0.5Sr0.5Co0.8Fe0.2O3-¿ (BSCF), and those of the parent perovskite phase, and ii) oxygen surface exchange kinetics of selected perovskite- and fluorite-type oxides

Depressed clad hollow optical fiber with fundamental LP01 mode cut-off

We propose a depressed clad hollow optical fiber with fundamental (LP01) mode cut-off suitable for high power short-wavelength, especially three-level, fiber laser operation by introducing highly wavelength dependent losses at longer wavelengths. The cut-off characteristic of such fiber structure was investigated. A Yb-doped depressed clad hollow optical fiber laser generating 59.1W of output power at 1046nm with 86% of slope efficiency with respect to the absorbed pump power was realised by placing the LP01 mode cut-off at ~1100nm

Computational Analysis of the External Aerodynamics of the Unpowered X-57 Mod-III Aircraft

Investigations of the external aerodynamics of the unpowered X-57 Mod-III configuration using computational fluid dynamics are presented. Two different Reynolds-averaged Navier-Stokes flow solvers were used in the analysis: the STAR-CCM+ unstructured solver using polyhedral grid topology, and the Launch Ascent Vehicle Aerodynamics (LAVA) structured curvilinear flow solver using structured overset grid topology. A grid refinement study was conducted and suitable grid resolution was determined by examining the forces and moments of the aircraft. Code-to-code comparison shows that STAR-CCM+ and LAVA are in good agreement both in quantitative values and trends. The angle-of-attack sweep and sideslip-angle sweep were performed. Results indicate that lift coefficients have a sharp drop at stall. At high angle of attack, STAR-CCM+ and LAVA show different flow separation behavior possibly due to differences in the turbulence model. The sideslip-angle sweep results show constant pitching moment from 0 to 15, then a sharp increase between 15 and 20 sideslip angle

Anti-oxidant and anti-hypercholesterolemic activities of Wasabia japonica

The effects of Wasabia japonica (WJ) were investigated in vitro and in vivo for their anti-oxidant and anti-hypercholesterolemic activities. It was found that the aqueous extracts of WJ leaves (WJL) had strong scavenging activities towards 1,1-Diphenyl-2-picryhydrazyl (DPPH) and nitric oxide (NO) free radicals in cell free systems. WJL also inhibited NO production and the expressions of inducible NO synthase (iNOS) mRNA and enzyme protein, determined by Griess reactions, RT-PCR or Western blotting respectively in Lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages cells. The anti-hypercholesterolemic effects of WJ diet were investigated in hypercholesterolemia rats. Sprague-Dawley rats were divided into four groups and were fed with either normal diet (Group 1), or diet containing 1%(w/w) cholesterol (Groups 2, 3 and 4). After 4 weeks, Group 2 was changed to normal diet, Groups 3 and 4 were changed to the diet containing 5% WJ leaf and or 5% WJ root, respectively. 3 weeks after WJ diets, Serum HDL-cholesterol levels were significantly increased in WJ diet groups compared with the normal diet hypercholesterolemia rats. In contrast, the serum LDL-cholesterol levels and liver xanthine oxidase (XO) activity in WJ diet groups were significantly decreased. The results indicate that the WJ extracts have significant anti-oxidant activities, and the WJ diet exhibited anti-hypercholesterolemic action in high cholesterol diet rats, which was companied with modulations of cholesterol metabolism and decrease in liver XO activity

Unsupervised Holistic Image Generation from Key Local Patches

We introduce a new problem of generating an image based on a small number of key local patches without any geometric prior. In this work, key local patches are defined as informative regions of the target object or scene. This is a challenging problem since it requires generating realistic images and predicting locations of parts at the same time. We construct adversarial networks to tackle this problem. A generator network generates a fake image as well as a mask based on the encoder-decoder framework. On the other hand, a discriminator network aims to detect fake images. The network is trained with three losses to consider spatial, appearance, and adversarial information. The spatial loss determines whether the locations of predicted parts are correct. Input patches are restored in the output image without much modification due to the appearance loss. The adversarial loss ensures output images are realistic. The proposed network is trained without supervisory signals since no labels of key parts are required. Experimental results on six datasets demonstrate that the proposed algorithm performs favorably on challenging objects and scenes.Comment: 16 page

Bulk transport and oxygen surface exchange of the mixed ionic electronic conductor Ce1-xTbxO2-δ (x= 1⁄4, 0.1, 0.2, 0.5)

Bulk ionic and electronic transport properties and the rate of oxygen surface exchange of Tb-doped ceria have been evaluated as a function of Tb concentration, aiming to assess the potential use of the materials as high-temperature oxygen-transport membranes and oxygen reduction catalysts. The materials were synthesized by the co-precipitation method. Cobalt oxide (2 mol%) was added in order to improve sinterability and conductivity. The materials were studied by means of X-ray diffraction (XRD), temperatureprogrammed desorption (TPD), thermogravimetry (TG), DC-conductivity and UV-vis spectrophotometry. The results indicate that the extent of mixed ionic–electronic conductivity is a function of temperature and can be tuned by modifying the Tb- (and Co-doping) concentration. Low Tb-content materials (x ¼ 0.1 and 0.2) are predominant ionic conductors, but the materials with 50 mol% Tb show both p-type electronic and ionic conductivity. The enhanced electronic conduction in Ce0.5Tb0.5O2 d is associated with narrowing of the band gap upon doping ceria with Tb. In addition, the surface chemistry of the samples was investigated by means of X-ray photoelectron spectroscopy (XPS) and pulse isotopic exchange (PIE). The surface exchange rate is found to increase on increasing the level of Tb doping. The highest surface exchange rates in this study are found for materials doped with 50 mol% Tb

Electroweak phase transition in a nonminimal supersymmetric model

The Higgs potential of the minimal nonminimal supersymmetric standard model (MNMSSM) is investigated within the context of electroweak phase transition. We investigate the allowed parameter space yielding correct electroweak phase transitoin employing a high temperature approximation. We devote to phenomenological consequences for the Higgs sector of the MNMSSM for electron-positron colliders. It is observed that a future $e^+ e^-$ linear collider with $\sqrt{s} = 1000$ GeV will be able to test the model with regard to electroweak baryogenesis.Comment: 28 pages, 5 tables, 12 figure

Collaborative learning in multi-domain optical networks

This paper presents a collaborative learning framework for multi-domain optical networks to enable cognitive end-to-end networking while guaranteeing the autonomy of each administrative domain

Machine-Learning-Aided Bandwidth and Topology Reconfiguration for Optical Data Center Networks

We present an overview of the application of machine learning for traffic engineering and network optimization in optical data center networks. In particular, we discuss the application of supervised and unsupervised learning for bandwidth and topology reconfiguration