Experimental evidence for fast cluster formation of chain oxygen vacancies in YBa2Cu3O7-d being at the origin of the fishtail anomaly

We report on three different and complementary measurements, namely magnetisation measurements, positron annihilation spectroscopy and NMR measurements, which give evidence that the formation of oxygen vacancy clusters is on the origin of the fishtail anomaly in YBa2Cu3O7-d. While in the case of YBa2Cu3O7.0 the anomaly is intrinsically absent, it can be suppressed in the optimally doped state where vacancies are present. We therefore conclude that the single vacancies or point defects can not be responsible for this anomaly but that clusters of oxygen vacancies are on its origin.Comment: 10 pages, 4 figures, submitted to PR

The development and technology transfer of software engineering technology at NASA. Johnson Space Center

The United State's big space projects of the next decades, such as Space Station and the Human Exploration Initiative, will need the development of many millions of lines of mission critical software. NASA-Johnson (JSC) is identifying and developing some of the Computer Aided Software Engineering (CASE) technology that NASA will need to build these future software systems. The goal is to improve the quality and the productivity of large software development projects. New trends are outlined in CASE technology and how the Software Technology Branch (STB) at JSC is endeavoring to provide some of these CASE solutions for NASA is described. Key software technology components include knowledge-based systems, software reusability, user interface technology, reengineering environments, management systems for the software development process, software cost models, repository technology, and open, integrated CASE environment frameworks. The paper presents the status and long-term expectations for CASE products. The STB's Reengineering Application Project (REAP), Advanced Software Development Workstation (ASDW) project, and software development cost model (COSTMODL) project are then discussed. Some of the general difficulties of technology transfer are introduced, and a process developed by STB for CASE technology insertion is described

Vaskulärer Zugang in der Kindernotfallanästhesie

Zusammenfassung: Zum Thema des schwierigen intervenösen Zugangs bei pädiatrischen Notfallsituationen existieren erstaunlich wenige Angaben in der Literatur. "Wie machen es die Anderen?" war die Motivationsgrundlage für eine Umfrage bei in Kinderanästhesie erfahrenen Anästhesisten. Insgesamt 89Fragebögen wurden an die Leiter der Weiterbildungsstätten für Anästhesie in der Schweiz und an alle Mitglieder der Schweizerischen Gesellschaft für Kinderanästhesie verschickt. Anhand von 2Fallbeispielen (FallA: nicht nüchternes Kleinkind mit einer Radiusfraktur, FallB: Säugling mit hohem Ileus) wurde das weitere Vorgehen nach 2-3 erfolglosen peripheren Punktionsversuchen erfragt. Die Beantwortung ergab, dass die meisten der Befragten in beiden Situationen zunächst weitere periphere Venenpunktionen vornehmen werden. Falls diese Versuche erfolglos bleiben, wird beim Kleinkind mit der Radiusfraktur eine intramuskuläre oder inhalative Anästhesieeinleitung befürwortet. Bei dem Säugling mit Ileus wird versucht, für die Anästhesieeinleitung einen intraossären oder zentralvenösen Zugang (V.femoralis) zu legen. Aufgrund der Resultate der Umfrage und einer Literaturrecherche wird eine Prioritätenliste zu den wichtigsten vaskulären Zugängen und alternativen Anästhesieeinleitungsmethoden in der pädiatrischen Notfallsituation vorgeschlage

Counseling the Military Population: The Factor of Prior Military Exposure for Counselors-in-Training

Counselors must learn to ethically work with all cultures. This article explores how both counselors-in-training with prior military culture exposure and those with none can be trained to effectively counsel individuals from this culture. Additionally, the article highlights strategies for counselor educators on how to meet both groups’ learning needs

Observation of a Triangular to Square Flux Lattice Phase Transition in YBCO

We have used the technique of small-angle neutron scattering to observe magnetic flux lines directly in an YBCO single crystal at fields higher than previously reported. For field directions close to perpendicular to the CuO2 planes, we find that the flux lattice structure changes smoothly from a distorted triangular co-ordination to nearly perfectly square as the magnetic induction approaches 11 T. The orientation of the square flux lattice is as expected from recent d-wave theories, but is 45 deg from that recently observed in LSCO

Counseling the Military Population: The Factor of Prior Military Exposure for Counselors-in-Training

Counselors must learn to ethically work with all cultures. This article explores how both counselors-in-training with prior military culture exposure and those with none can be trained to effectively counsel individuals from this culture. Additionally, the article highlights strategies for counselor educators on how to meet both groups’ learning needs

High magnetic field studies of the Vortex Lattice structure in YBa2Cu3O7

We report on small angle neutron scattering measurements of the vortex lattice in twin-free YBa2Cu3O7, extending the previously investigated maximum field of 11~T up to 16.7~T with the field applied parallel to the c axis. This is the first microscopic study of vortex matter in this region of the superconducting phase. We find the high field VL displays a rhombic structure, with a field-dependent coordination that passes through a square configuration, and which does not lock-in to a field-independent structure. The VL pinning reduces with increasing temperature, but is seen to affect the VL correlation length even above the irreversibility temperature of the lattice structure. At high field and temperature we observe a melting transition, which appears to be first order, with no detectable signal from a vortex liquid above the transition

The Gaussian formula and spherical aberration of the static and moving curved mirrors from Fermat's principle

The Gaussian formula and spherical aberrations of the static and relativistic curved mirrors are analyzed using the optical path length (OPL) and Fermat's principle. The geometrical figures generated by the rotation of conic sections about their symmetry axes are considered for the shapes of the mirrors. By comparing the results in static and relativistic cases, it is shown that the focal lengths and the spherical aberration relations of the relativistic mirrors obey the Lorentz contraction. Further analysis of the spherical aberrations for both static and relativistic cases have resulted in the information about the limits for the paraxial approximation, as well as for the minimum speed of the systems to reduce the spherical aberrations.Comment: 15 pages, 7 figures, uses iopart. Major revisions on the physical interpretations of the results. Accepted for publication in J. Op

Shape-Driven Interpolation With Discontinuous Kernels: Error Analysis, Edge Extraction, and Applications in Magnetic Particle Imaging

Accurate interpolation and approximation techniques for functions with discontinuities are key tools in many applications, such as medical imaging. In this paper, we study a radial basis function type of method for scattered data interpolation that incorporates discontinuities via a variable scaling function. For the construction of the discontinuous basis of kernel functions, information on the edges of the interpolated function is necessary. We characterize the native space spanned by these kernel functions and study error bounds in terms of the fill distance of the node set. To extract the location of the discontinuities, we use a segmentation method based on a classification algorithm from machine learning. The results of the conducted numerical experiments are in line with the theoretically derived convergence rates in case that the discontinuities are a priori known. Further, an application to interpolation in magnetic particle imaging shows that the presented method is very promising in order to obtain edge-preserving image reconstructions in which ringing artifacts are reduced