Hypersonic test facility Patent

Hypersonic test facility for studying ablation in models under high pressure and high temperatur

Kinetic pathways of multi-phase surfactant systems

The relaxation following a temperature quench of two-phase (lamellar and sponge phase) and three-phase (lamellar, sponge and micellar phase) samples, has been studied in an SDS/octanol/brine system. In the three-phase case we have observed samples that are initially mainly sponge phase with lamellar and micellar phase on the top and bottom respectively. Upon decreasing temperature most of the volume of the sponge phase is replaced by lamellar phase. During the equilibriation we have observed three regimes of behaviour within the sponge phase: (i) disruption in the sponge texture, then (ii) after the sponge phase homogenises there is a lamellar nucleation regime and finally (iii) a bizarre plume connects the lamellar phase with the micellar phase. The relaxation of the two-phase sample proceeds instead in two stages. First lamellar drops nucleate in the sponge phase forming a onion `gel' structure. Over time the lamellar structure compacts while equilibriating into a two phase lamellar/sponge phase sample. We offer possible explanatioins for some of these observations in the context of a general theory for phase kinetics in systems with one fast and one slow variable.Comment: 1 textfile, 20 figures (jpg), to appear in PR

Controlled Thiol-ene Polymer Microsphere Production Using a Low-Frequency Acoustic Excitation Coaxial Flow Method

A novel technique for the production of thiol-ene microspheres using acoustic resonance and coaxial flow is reported. The method utilizes low-frequency acoustically driven mechanical perturbations to disrupt the flow of a thiol-ene liquid jet, resulting in small thiol-ene droplets that are photochemically polymerized to yield thiol-ene microspheres. Tuning of the frequency, amplitude, and monomer solution viscosity are critical parameters impacting the diameter of the microspheres produced. Characterization by optical microscopy, scanning electron microscopy, and dynamic light scattering reveal microspheres of diameters \u3c10 mu m, with narrow particle distributions. (C) 2016 Elsevier Ltd. All rights reserved

Historical-institutionalist perspectives on the development of the EU budget system

The EU budget has only recently started to feature in theories of European integration. Studies typically adopt a historical-institutionalist framework, exploring notions such as path dependency. They have, however, generally been rather aggregated, or coarse-grained, in their approach. The EU budget has thus been treated as a single entity rather than a series of inter-linked institutions. This paper seeks to address these lacunae by adopting a fine-grained approach. This enables us to emphasize the connections that exist between EU budgetary institutions, in both time and space. We show that the initial set of budgetary institutions was unable, over time, to achieve consistently their treaty-based objectives. In response, rather than reform these institutions at potentially high political cost, additional institutions were layered on top of the extant structures. We thus demonstrate how some EU budgetary institutions have remained unchanged, whilst others have been added or changed over time

Aortic Embolism in Cats: Prevalence, Surgical Treatment and Electrocardiography

Aortic embolism (caudal arterial thromboembolism) was diagnosed over a four-year-period in 14 out of 2,000 cats in a hospital clinic population (7/1,000). Including 35 cases reported in the literature, the average age of 50 cats with aortic embolism was 6-8 years (range one to 16 years). Of these, 37 were males and 13 were females. Endocarditis with thrombosis was the most frequently observed cause of aortic embolism, although aortic arteriosclerosis was reported in one cat. The clinical and pathological features of aortic embolism in five cats are described in this report. In electrocardiograms of four of these, arrhythmias or conduction disturbances were recorded. Intact emboli in the aorta and external iliac arteries were removed by abdominal aortic embolectomy in two cats within hours after the onset of posterior paralysis. Death resulted in one case from cardiac complications and in the other by euthanasia at the later date because of probably recurrent aortic embolism. In the other three cases, multiple sections of the aorta with the embolus in situ were examined, but no microscopic changes in the aortic wall were noted. Surgical removal of an aortic embolus is technically and economically feasible and is considered the treatment of choice when treatment is requested within hours after the onset of clinical signs. Although embolectomy can yield a good immediate result; the long range justification for such therapy requires further evaluation, since recurrent embolization may develop

WFPC2 LRF Imaging of Emission Line Nebulae in 3CR Radio Galaxies

We present HST/WFPC2 Linear Ramp Filter images of high surface brightness emission lines (either [OII], [OIII], or H-alpha+[NII]) in 80 3CR radio sources. We overlay the emission line images on high resolution VLA radio images (eight of which are new reductions of archival data) in order to examine the spatial relationship between the optical and radio emission. We confirm that the radio and optical emission line structures are consistent with weak alignment at low redshift (z < 0.6) except in the Compact Steep Spectrum (CSS) radio galaxies where both the radio source and the emission line nebulae are on galactic scales and strong alignment is seen at all redshifts. There are weak trends for the aligned emission line nebulae to be more luminous, and for the emission line nebula size to increase with redshift and/or radio power. The combination of these results suggests that there is a limited but real capacity for the radio source to influence the properties of the emission line nebulae at these low redshifts (z < 0.6). Our results are consistent with previous suggestions that both mechanical and radiant energy are responsible for generating alignment between the radio source and emission line gas.Comment: 80 pages, 54 figures. Accepted for publication in ApJ

EPR identification of defects responsible for thermoluminescence in Cu-doped lithium tetraborate (Li2B4O7) crystals

Electron paramagnetic resonance (EPR) is used to identify the electron and hole traps responsible for thermoluminescence (TL) peaks occurring near 100 and 200 ◦C in copper-doped lithium tetraborate (Li2B4O7) crystals. As-grown crystals have Cu+ and Cu2+ ions substituting for lithium and have Cu+ ions at interstitial sites. All of the substitutional Cu2+ ions in the as-grown crystals have an adjacent lithium vacancy and give rise to a distinct EPR spectrum. Exposure to ionizing radiation at room temperature produces a second and different Cu2+ EPR spectrum when a hole is trapped by substitutional Cu+ ions that have no nearby defects. These two Cu2+ trapped-hole centers are referred to as Cu2+-VLi and Cu2+active, respectively. Also during the irradiation, two trapped-electron centers in the form of interstitial Cu0 atoms are produced when interstitial Cu+ ions trap electrons. They are observed with EPR and are labeled Cu0A and Cu0B. When an irradiated crystal is warmed from 25 to 150 ◦C, the Cu2+active centers have a partial decay step that correlates with the TL peak near 100 ◦C. The concentrations of Cu0A and Cu0B centers, however, increase as the crystal is heated through this range. As the crystal is futher warmed between 150 and 250 ◦C, the EPR signals from the Cu2+active hole centers and Cu0A and Cu0B electron centers decay simultaneously. This decay step correlates with the intense TL peak near 200 ◦C

Dust emission from a parsec-scale structure in the Seyfert 1 nucleus of NGC 4151

We report mid-IR interferometric measurements with \sim 10 mas resolution, which resolve the warm (T = 285 +25 / -50 K) thermal emission at the center of NGC 4151. Using pairs of VLT 8.2 m telescopes with MIDI and by comparing the data to a Gaussian model, we determined the diameter of the dust emission region, albeit only along one position angle, to be 2.0 +/- 0.4 pc (FWHM). This is the first size and temperature estimate for the nuclear warm dust distribution in a Seyfert 1 galaxy. The parameters found are comparable to those in Seyfert 2 galaxies, thus providing direct support for the unified model. Using simple analytic temperature distributions, we find that the mid-infrared emission is probably not the smooth continuation of the hot nuclear source that is marginally resolved with K band interferometry. We also detected weak excess emission around 10.5 micron in our shorter baseline observation, possibly indicating that silicate emission is extended to the parsec scale.Comment: 5 pages, 4 figures, accepted for publication in The Astrophysical Journal Letter