Influence of annealing parameters on the ferromagnetic properties of optimally passivated (Ga,Mn)As epilayers

The influence of annealing parameters - temperature and time - on the magnetic properties of As-capped (Ga,Mn)As epitaxial thin films have been investigated. The dependence of the transition temperature (Tc) on annealing time marks out two regions. The Tc peak behavior, characteristic of the first region, is more pronounced for thick samples, while for the second (`saturated') region the effect of the annealing time is more pronounced for thin samples. A right choice of the passivation medium, growth conditions along with optimal annealing parameters routinely yield Tc-values of ~ 150 K and above, regardless of the thickness of the epilayers.Comment: 5 pages, 3 figure

Equal Access to Make Emergency Calls: A Case for Equal Rights for Deaf Citizens in Norway and Sweden

It is stipulated that deaf citizens have equal right to use social services as other citizens. One social service is the access to make an emergency call. Deaf citizens who cannot hear and use a signed language to communicate have to make emergency calls in another way rather than relying on listening and speaking via a telephone. However, the possible ways to call are not the same for deaf citizens in all countries. This commentary shows that there are options dedicated for deaf citizens to make emergency alarms in both Norway and Sweden: via telephone typewriters, Short Message Service, and Video Relay Service, although the design of the respective options differs between the countries. However, it is argued that deaf citizens in Norway do not have equal access to make emergency alarms as other citizens in Norway, whereas the situation for deaf citizens in Sweden may be seen as equal compared to other citizens in Sweden, although there still are limitations

Fan geeks

In the Spring of 2001, the short documentary Fan Geeks was filmed. Fan Geeks explores The X-files fan community, showing the fans in context to the friendships and activities that express television as being part of their lives. Using film to document fans' micro-situations, Fan Geeks allows for audience analysis in context of popular and industrial texts. The written portion of Fan Geeks explores the work of previous fan research, a comprehensive discussion of the making of Fan Geeks, and conclusions that assist in the continuation of a television audience discourse

Interface characterization of Co2MnGe/Rh2CuSn Heusler multilayers

All-Heusler multilayer structures have been investigated by means of high kinetic x-ray photoelectron spectroscopy and x-ray magnetic circular dichroism, aiming to address the amount of disorder and interface diffusion induced by annealing of the multilayer structure. The studied multilayers consist of ferromagnetic Co$_2$MnGe and non-magnetic Rh$_2$CuSn layers with varying thicknesses. We find that diffusion begins already at comparably low temperatures between 200 $^{\circ}$C and 250 $^{\circ}$C, where Mn appears to be most prone to diffusion. We also find evidence for a 4 {\AA} thick magnetically dead layer that, together with the identified interlayer diffusion, are likely reasons for the small magnetoresistance found for current-perpendicular-to-plane giant magneto-resistance devices based on this all-Heusler system

Observation of the out-of-plane magnetization in a mesoscopic ferromagnetic structure superjacent to a superconductor

The geometry of magnetic flux penetration in a high temperature superconductor at a buried interface was imaged using element-specific x-ray excited luminescence. We performed low temperature observation of the flux penetration in YBa2Cu3O7–δ (YBCO) at a buried interface by imaging of the perpendicular magnetization component in square Permalloy (Py) mesostructures patterned superjacent to a YBCO film. Element specific imaging below the critical temperature of YBCO reveals a cross-like geometry of the perpendicular magnetization component which is decorated by regions of alternating out-of-plane magnetization at the edges of the patterned Py structures. The cross structure can be attributed to the geometry of flux penetration originating from the superconductor and is reproduced using micromagnetic simulations. Our experimental method opens up possibilities for the investigation of flux penetration in superconductors at the nanoscale

Particulate plutonium released from the Fukushima Daiichi meltdowns

Traces of Pu have been detected in material released from the Fukushima Daiichi Nuclear Power Plant (FDNPP) in March of 2011; however, to date the physical and chemical form of the Pu have remained unknown. Here we report the discovery of particulate Pu associated with cesium-rich microparticles (CsMPs) that formed in and were released from the reactors during the FDNPP meltdowns. The Cs-pollucite-based CsMP contained discrete U(IV)O2 nanoparticles,Peer reviewe

Vadose-Zone Alteration of Metaschoepite and Ceramic UO2 in Savannah River Site Field Lysimeters

Uranium dioxide (UO2) and metaschoepite (UO3•nH2O) particles have been identified as contaminants at nuclear sites. Understanding their behavior and impact is crucial for safe management of radioactively contaminated land and to fully understand U biogeochemistry. The Savannah River Site (SRS) (South Carolina, USA), is one such contaminated site, following historical releases of U-containing wastes to the vadose zone. Here, we present an insight into the behavior of these two particle types under dynamic conditions representative of the SRS, using field lysimeters (15 cm D x 72 cm L). Discrete horizons containing the different particle types were placed at two depths in each lysimeter (25 cm and 50 cm) and exposed to ambient rainfall for 1 year, with an aim of understanding the impact of dynamic, shallow subsurface conditions on U particle behavior and U migration. The dissolution and migration of U from the particle sources and the speciation of U throughout the lysimeters was assessed after 1 year using a combination of sediment digests, sequential extractions, and bulk and μ-focus X-ray spectroscopy. In the UO2 lysimeter, oxidative dissolution of UO2 and subsequent migration of U was observed over 1–2 cm in the direction of waterflow and against it. Sequential extractions of the UO2 sources suggest they were significantly altered over 1 year. The metaschoepite particles also showed significant dissolution with marginally enhanced U migration (several cm) from the sources. However, in both particle systems the released U was quantitively retained in sediment as a range of different U(IV) and U(VI) phases, and no detectable U was measured in the lysimeter effluent. The study provides a useful insight into U particle behavior in representative, real-world conditions relevant to the SRS, and highlights limited U migration from particle sources due to secondary reactions with vadose zone sediments over 1 year.Peer reviewe

Lees and Moonshine: Remembering Richard III, 1485-1635

Published version of article deposited in accordance with Sherpa Romeo guidelines. © University of Chicago Press, 2010publication-status: AcceptedNot long after Shakespeare’s birth (1564) the last witnesses to the reign of Richard III (1483-85) would have reached the end of their lives. Richard III (c. 1592) occupies a distinctive historical moment in relation to its subject – a period after the extinction of living memory, but still within the horizon of communicative memory, the period in which stories and recollections may be transmitted across multiple generations. This essay explores how memories and “postmemories” of Richard’s reign were preserved, transmitted and transformed over the course of the sixteenth century and into the seventeenth. Whilst reflecting the powerful influence of emerging contexts including the Reformation and, ultimately, Shakespeare’s play, these memories remained distinct from and sometimes at odds with textual history. They survived because they offered their bearers a resource for interpreting and resisting the predicaments of the present, from the problem of tyranny to the legacies of the Reformation