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Contains fulltext : 117019.pdf (publisher's version ) (Open Access)

We have investigated the properties of interfaces between LaAlO3 films grown on SrTiO3 substrates singly terminated by TiO2. We used RF sputtering in a high-pressure oxygen atmosphere. The films are smooth, with flat surfaces. Transmission electron microscopy shows sharp and continuous interfaces with some slight intermixing. The elemental ratio of La to Al, measured by the energy dispersive X-ray technique, is found to be 1.07. Importantly, we find these interfaces to be non-conducting, indicating that the sputtered interface is not electronically reconstructed in the way reported for films grown by pulsed laser deposition because of the different interplays among stoichiometry, mixing, and oxygen vacancies., QN/Quantum Nanoscience, Applied Sciences

We show ferromagnetic properties of hydrogen-functionalized epitaxial graphene on SiC. Ferromagnetism in such a material is not directly evident as it is inherently composed of only nonmagnetic constituents. Our results nevertheless show strong ferromagnetism with a saturation of 0.9µ B /hexagon projected area, which cannot be explained by simple magnetic impurities. The ferromagnetism is unique to hydrogenated epitaxial graphene on SiC, where interactions with the interfacial buffer layer play a crucial role. We argue that the origin of the observed ferromagnetism is governed by electron correlation effects of the narrow Si dangling bond states in the buffer layer exchange coupled to localized states in the hydrogenated graphene layer. This forms a quasi-three-dimensional ferromagnet with a Curie temperature higher than 300 K.

Background: Clinical decision support (CDS) for electronic prescribing systems (computerized physician order entry) should help prescribers in the safe and rational use of medicines. However, the best ways to alert users to unsafe or irrational prescribing are uncertain. Specifically, CDS systems may generate too many alerts, producing unwelcome distractions for prescribers, or too few alerts running the risk of overlooking possible harms. Obtaining the right balance of alerting to adequately improve patient safety should be a priority. Methods: A workshop funded through the European Regional Development Fund was convened by the University Hospitals Birmingham NHS Foundation Trust to assess current knowledge on alerts in CDS and to reach a consensus on a future research agenda on this topic. Leading European researchers in CDS and alerts in electronic prescribing systems were invited to the workshop. Results: We identified important knowledge gaps and suggest research priorities including (1) the need to determine the optimal sensitivity and specificity of alerts; (2) whether adaptation to the environment or characteristics of the user may improve alerts; and (3) whether modifying the timing and number of alerts will lead to improvements. We have also discussed the challenges and benefits of using naturalistic or experimental studies in the evaluation of alerts and suggested appropriate outc Conclusions: We have identified critical problems in CDS, which should help to guide priorities in research to evaluate alerts. It is hoped that this will spark the next generation of novel research from which practical steps can be taken to implement changes to CDS systems that will ultimately reduce alert fatigue and improve the design of future systems.

A large number of former unaccompanied minors in the Netherlands leave for unknown destinations during the asylum procedure or after being rejected. In this contribution the authors provide answers to the question how undocumented (former) unaccompanied minors provide for their iving and housing. The study is based on interviews with 118 former undocumented unaccompanied minors who were recruited through the personal networks of the researchers and through contacts with representatives of (private) organizations who support the youngsters. The undocumented minors are excluded from formal employment as well as provisions of the welfare state. By far the largest group of the undocumented (former) unaccompanied minors has never been involved in criminal activities and only one third of them work in the informal economy. The sectors in which these youngsters perform informal work vary from cleaning and construction to catering and personal services. The work is characterized by uncertain working hours. There are often few hours available and the work often takes place on call. The pay is meagre and few respondents can survive exclusively on their earnings. The undocumented (former) unaccompanied minors are mainly supported by friends and private organizations for their living and housing. It is because of this support that the youngsters do not roam the streets and can continue their illegal stay in the Netherlands. The strong orientation of the youngsters towards a lawful residence in the Netherlands causes them to fear the risks of arrest while working, so they rather settle for the limited support of private organizations and friends. The support of private organizations and the focus of the youngsters towards a lawful stay thus constitute a buffer against exploitation.

Alleenstaande minderjarige vreemdelingen (amv’s) die uitgeprocedeerd raken, krijgen voorzieningen van de overheid totdat zij kunnen worden uitgezet óf tot de dag dat zij 18 jaar worden. Op dat moment worden zij geacht, net als andere afgewezen asielzoekers, zelfstandig Nederland te verlaten. Het grote aantal jonge asielzoekers dat echter met onbekende bestemming vanuit de asielprocedure of vanuit de opvang verdwijnt, roept de vraag op wat er met hen gebeurt. Hoe voorzien de illegaal verblijvende (voormalige) amv’s in hun levensonderhoud en huisvesting, welke contacten hebben zij met anderen en de overheid en hoe en waar zien zij hun toekomstig verblijf? Deze en andere vragen komen uitgebreid aan de orde in dit boek dat handelt over de levensomstandigheden van jongeren die op moment van binnenkomst in Nederland vreemdeling, alleenstaand en minderjarig waren en die thans onrechtmatig in Nederland verblijven of hebben verbleven. Op basis van uitgebreide gesprekken met 118 jongeren wordt een indringend beeld geschetst van hun situatie en verwachtingen over de toekomst.

We report on measurements of supercurrents through the half-metallic ferromagnet CrO2 grown on hexagonal Al2O3 (sapphire). The current was observed to flow over a distance of 700 nm between two superconducting amorphous Mo70Ge30 electrodes which were deposited on the CrO2 film. The critical current Ic increases as function of decreasing temperature. Upon applying an in-plane magnetic field, Ic goes through a maximum at the rather high field of 80 mT. We believe this to be a long-range proximity effect in the ferromagnet, carried by odd-frequency pairing correlations., Kavli Institute of Nanoscience, Applied Sciences

IN every problem in which it is asked to investigate a locus, be this on a straight line or on a curve, one arrives at an equation determining an arbitrarily chosen point on the required locus [1.1] if one considers as known and determinate two unknown and indeterminate line segments enclosing a given or chosen angle [1.2]. If in this equation (after reduction to its simplest form) neither of the two unknown quantities has been raised to the second or a higher power – that is, if they do not occur multiplied by themselves nor by each other – then the required locus will be a straight line. But if one of these unknown quantities has been raised to the second power but the other not and if this other one has not been multiplied by itself nor by the first one, then the required locus will be a parabola.

The first mention of the problem that would later become known as Pappus’s problem can be found in the introduction to the Conica (I, 1) by Apollonius. There he writes that Euclid had insufficiently worked out the problem of the locus in the case of three or four lines and that the results of Euclid were not even that good. Apollonius refers to the work of Euclid on conics, which is now lost. He attributes the shortcomings of Euclid to the unavailability of two relevant fundamental theorems that Apollonius himself found and proved. We will see further on which theorems these are.

1.1

1.1 The second part of Jan de Witt´s Elementa Curvarum Linearum is the essence of the whole work. The first part was merely a necessary preparation to Liber Secundus, which is referred to in the correspondence and in Part I as the tractatus (or compositio) locorum planorum et solidorum. This last text was delivered to Van Schooten at the beginning of 1658. In a letter to Jan de Witt dated 8 February 1658, Van Schooten expressed his great appreciation for this work and promised to study it carefully and to help in any way he could with the preparation for publication.

In this summary the theorems and their corollaries (corollaria) are restated in our modern notation, without proofs. The essence of the statements, however, has been preserved. For the proofs we refer to the text, the translation, and the notes. This summary aims only at giving a global survey of the contents of the book. For an overview of the structure of Liber Secundus and the method followed by Jan de Witt, we refer the reader to the Introduction, Section 1.10.

The magnetic-flux distribution in a bilayer ring consisting of superconducting Nb and ferromagnetic amorphous Gd19 Ni81 is studied at low temperature by magneto-optical imaging. The ring is macroscopic with an outer diameter of 500 μm and an inner diameter of 300 μm. Below the superconducting transition and with a small magnetic field applied along the ring axis, we observe a field enhancement at the inner edge and a field reduction at the outer edge, opposite to what is observed for a bare superconducting ring. With help from numerical simulations we show this to be due to an in-plane rotation of the magnetization of the Gd19 Ni81 layer toward the radial direction, under the influence of shielding currents in the superconductor. In the superconductor, the resulting stray field of the magnetic layer is in the same direction as the field due to the superconducting shielding currents. As a consequence, these shielding currents are reduced. Alternatively, for a fixed critical current, the superconductor will be able to withstand a larger external field if coated by the magnetic material; it is hardened by it. © 2009 The American Physical Society.