Comparing the performance of hyperbolic and circular rod quadrupole mass spectrometers with applied higher order auxiliary excitation

This work applies higher order auxiliary excitation techniques to two types of quadrupole mass spectrometers (QMSs): commercial systems and spaceborne instruments. The operational settings of a circular rod geometry commercial system and an engineering test-bed for a hyperbolic rod geometry spaceborne instrument were matched, with the relative performance of each sensor characterized with and without applied excitation using isotopic measurements of Kr+. Each instrument was operated at the limit of the test electronics to determine the effect of auxiliary excitation on extending instrument capabilities. For the circular rod sensor, with applied excitation, a doubling of the mass resolution at 1% of peak transmission resulted from the elimination of the low-mass side peak tail typical of such rod geometries. The mass peak stability and ion rejection efficiency were also increased by factors of 2 and 10, respectively, with voltage scan lines passing through the center of stability islands formed from auxiliary excitation. Auxiliary excitation also resulted in factors of 6 and 2 in peak stability and ion rejection efficiency, respectively, for the hyperbolic rod sensor. These results not only have significant implications for the use of circular rod quadrupoles with applied excitation as a suitable replacement for traditional hyperbolic rod sensors, but also for extending the capabilities of existing hyperbolic rod QMSs for the next generation of spaceborne instruments and low-mass commercial systems.

The influence of different osteosynthesis configurations with locking compression plates (LCP) on stability and fracture healing after an oblique 45° angle osteotomy

Background Locking compression plates are used in various configurations with lack of detailed information on consequent bone healing. Study design In this in vivo study in sheep 5 different applications of locking compression plate (LCP) were tested using a 45° oblique osteotomy simulating simple fracture pattern. 60 Swiss Alpine sheep where assigned to 5 different groups with 12 sheep each (Group 1: interfragmentary lag screw and an LCP fixed with standard cortex screws as neutralisation plate; Group 2: interfragmentary lag screw and LCP with locking head screws; Group 3: compression plate technique (hybrid construct); Group 4: internal fixator without fracture gap; Group 5: internal fixator with 3 mm gap at the osteotomy site). One half of each group (6 sheep) was monitored for 6 weeks, and the other half (6 sheep) where followed for 12 weeks. Methods X-rays at 3, 6, 9 and 12 weeks were performed to monitor the healing process. After sacrifice operated tibiae were tested biomechanically for nondestructive torsion and compared to the tibia of the healthy opposite side. After testing specimens were processed for microradiography, histology, histomorphometry and assessment of calcium deposition by fluorescence microscopy. Results In all groups bone healing occurred without complications. Stiffness in biomechanical testing showed a tendency for higher values in G2 but results were not statistically significant. Values for G5 were significantly lower after 6 weeks, but after 12 weeks values had improved to comparable results. For all groups, except G3, stiffness values improved between 6 and 12 weeks. Histomorphometrical data demonstrate endosteal callus to be more marked in G2 at 6 weeks. Discussion and conclusion All five configurations resulted in undisturbed bone healing and are considered safe for clinical application.

Das enthüllte Preußenthum oder Deutschlands Zukunft unter Preußischer Oberherrschaft, unter welcher Gestalt sie auch eintrete : Mit besonderer Rücksicht auf die Preußische Circular-Note vom 23. Januar 1849

Boberach: Die preußische Zirkularnote für einen Engeren Bund ist ein Meisterstück der Diplomatie, aber Preußen und seinem König ist nicht zu trauen, sie würden nur ein preußisches Kaisertum mit preußischer Bürokratie aufrichten. Das preußische Großmachtstreben würde sofort die kleineren Einzelstaaten bedrohen. - Wentzke: Die Note an und für sich ist ein diplomatisches Meisterstück, indem sie die Notwendigkeit des österreichischen Kaiserstaates für Deutschland und die Ehrlichkeit der preußischen Politik hervorhebt. Leider aber hat die Vergangenheit Preußens, seine Großmachtsgelüste, zu tiefen Anlaß zum Mißtrauen gegeben. Dazu hat die Heuchelei der Reaktion unter Friedrich Wilhelm IV. den Höhepunkt erreicht. Wird Preußens König deutscher Kaiser, so wird er zunächst die kleineren Staaten vernichten und durch seine Bureaukratie das preußische Kaisertum aufrichten

Detection efficiency of microchannel plates for e(-) and pi(-) in the momentum range from 17.5 to 345 MeV/c

High-energy e(-) and pi(-) were measured by the multichannel plate (MCP) detector at the PiM1 beam line of the High Intensity Proton Accelerator Facilities located at the Paul Scherrer Institute, Villigen, Switzerland. The measurements provide the absolute detection efficiencies for these particles: 5.8% +/- 0.5% for electrons in the beam momenta range 17.5-300 MeV/c and 6.0% +/- 1.3% for pions in the beam momenta range 172-345 MeV/c. The pulse height distribution determined from the measurements is close to an exponential function with negative exponent, indicating that the particles penetrated the MCP material before producing the signal somewhere inside the channel. Low charge extraction and nominal gains of the MCP detector observed in this study are consistent with the proposed mechanism of the signal formation by penetrating radiation. A very similar MCP ion detector will be used in the Neutral Ion Mass (NIM) spectrometer designed for the JUICE mission of European Space Agency (ESA) to the Jupiter system, to perform measurements of the chemical composition of the Galilean moon exospheres. The detection efficiency for penetrating radiation determined in the present studies is important for the optimisation of the radiation shielding of the NIM detector against the high-rate and high-energy electrons trapped in Jupiter's magnetic field. Furthermore, the current studies indicate that MCP detectors can be useful to measure high-energy particle beams at high temporal resolution. (C) 2015 AIP Publishing LLC.

Circular Nº 1

Primera circular de las XXI Jornadas de Cátedra y Carreras de Educación Especial de las Universidades Nacionales (RUEDES) y XV Jornadas Nacionales de la Red de Estudiantes de Cátedras y Carreras de Educación Especial (RECCEE). Se desarrollarán el 6,7 y 8 de septiembre de 2012 en la Facultad de Humanidades y Ciencias Sociales de la Universidad Nacional de la Patagonia San Juan Bosco (Comodoro Rivadavia, Chubut, Argentina). El tema de estas Jornadas es "las relaciones entre la educación común y especial. Dilemas de una construcción socio-educativa".

Córdoba en pedazos : habitar/circular en contextos sociosegregados

La ciudad de Córdoba se ha ido constituyendo como ciudad turística/ciudad espectáculo, a través de un “embellecimiento estratégico" que la vuelve extraña a sus propios habitantes, especialmente a los de clases subalternas. Las presentes reflexiones abordan las experiencias de habitar/desplazarse por la ciudad de estos sujetos durante la última década. Partimos de una breve referencia a la forma sociohabitacional ciudad barrio como respuesta de vivienda social generada por el Gobierno Provincial que impactó fuertemente en la experiencia de los “beneficiarios" como en el perfil de la ciudad. Desde una perspectiva metodológica en clave benjaminiana orientada a “pensar en/a partir de imágenes", presentamos algunas escenas expresivas de los modos de habitar, percibir y sentirse en la ciudad, algunas imágenes que condensan ciertos estados de sentir que manifiestan los pobladores -mediante la palabra pero también mediante la forma de apropiación de la vivienda y del barrio observada-. Ponemos en juego estas imágenes con otras, producto de una encuesta realizada en las ciudades barrio. Buscamos así reconstruir algunos de los fragmentos de la urbe cordobesa tal como es vivida, pedazos que abarcan el mero espacio de la casa, y trayectos fuertemente segregados por clase.