317 research outputs found
You Can\u27t Park Your Elephant on Main Street, You Know
In lieu of an abstract, below is the essay\u27s first paragraph.
LAW: A person may not cross state lines with a duck atop his head. (Location: United States, Minnesota
Last Days of Northside
In lieu of an abstract, below is the essay\u27s first paragraph.
When I was seven years old, I was happy to be me. I went to grade school in Falconer, NY and my parents were actually told I was too chatty which was a far cry from when I was voted \u27The Quietest\u27 in high school. One report card even said, \u27Mikey is a good student but likes to chitchat too much.\u27 I just remember getting along with all the kids in school then; and since it was a small school, you knew everyone. Most, if not all, the kids lived within a few blocks of Northside Elementary. I lived close enough to trot my towheaded self to school every day
Functional Investigation of Geometrically Scaled Drive Components by X-in-the-Loop Testing with Scaled Prototypes
From Reality to Simulation – Using the C&C²-Approach to Support the Modelling of a Dynamic System
Frontloading in Aircraft Development Process by Integration of a new Validation Method
In product engineering Frontloading can be supported by the implementation of new methods in a product development process. In this contribution the integration of a new validation method called in an aircraft development process is presented. The requirements for the application of the validation method are discussed
Frühe funktionale Absicherung in der Antriebsstrangentwicklung – Ein Ansatz zur Einbindung von skalierten Teilsystemen durch physisch-virtuelle Leistungsskalierung = Early Functional Validation in Drivetrain Development: An Approach to Integrate Scaled Subsystems through Physical-Virtual Performance Scaling
Die Verkürzung der Entwicklungszeit und Reduzierung der Gesamtkosten durch die Vermeidung von späten Designänderungen wird in der Produktentwicklung immer relevanter. Im Rahmen dieser Forschungsarbeit wird ein Ansatz zur Unterstützung des Frontloading aufgezeigt und an einem Beispielsystem aus einem Akkubohrschrauber angewandt. An drei Untersuchungsbeispielen werden die Einsatzmöglichkeiten des Ansatzes zu skalierten Untersuchungen in der Produktentwicklung aufgezeigt und evaluiert.
Durch die Kopplung von unterschiedlichen Teilsystemen und dem zeitgleichen Betrieb in einem Antriebsstrangprüfstand (scaled-Components-in-the-Loop-Prüfstand) wird eine vorgezogene Absicherung unterstützt. Vorteile bietet eine vorgezogene Absicherung insbesondere für die Vorentwicklungsphasen, in denen noch keine vollständig funktionsfähigen Versuchs- bzw. Technologieträger zur Verfügung stehen, gleichzeitig jedoch eine frühe funktionale Absicherung mit Hardwarekomponenten gewünscht ist.
Das Frontloading in der Produktentwicklung wird damit unterstützt und gefördert. Die skalierten Untersuchungen werden in drei Experimenten am scaled-Componentsin-the-Loop-Prüfstand für einen Akkubohrschrauber durch exemplarische Anwendungen veranschaulicht. Es erfolgt die beispielhafte Umsetzung der Skalierung der Leistungsgrößen in einem XiL-Prüfstand zur Anpassung des Systemverhaltens an veränderte Prototypen.
Anhand von Experimenten an einem Antriebsstrangprüfstand werden Skalierungsfaktoren für die Anpassung der rotatorischen Leistungsgrößen zwischen miteinander verbundenen Systemen abgeleitet und verifiziert. Die Integration der skalierten Komponenten erfolgt auf einem XiL-Prüfstand über Koppelsysteme in das Gesamtsystem. Dadurch wird eine skalierte Komponentenprüfung unter Berücksichtigung des restlichen Systems ermöglicht. Basierend auf den abgeleiteten Skalierungsmodellen wird der Einfluss von Geometrievarianten auf das dynamische Verhalten einer Überlastkupplung eines Akkubohrschraubers untersucht. Durch den Einsatz des scaled-Components-in-the-Loop-Prüfstands und der abgeleiteten Skalierungsfaktoren können Gestaltvariationen bereits durch Einsatz eines Referenzsystems bewertet werden. Durch die Einbindung von physischen Komponenten und Teilsystemen aus Referenzprodukten und die Ableitung von Skalierungsfaktoren können frühe Untersuchungen skalierter Komponenten unter Berücksichtigung des Gesamtsystems durchgeführt werden. Die Forschungsarbeit beschreibt basierend auf den gezeigten Untersuchungen eine Validierungsmethode und stellt Möglichkeiten zur Integration der Methode in den Produktentwicklungsprozess vor
SPARC Collaboration: New Strategy for Storage Ring Physics at FAIR
SPARC collaboration at FAIR pursues the worldwide unique research program by
utilizing storage ring and trapping facilities for highly-charged heavy ions.
The main focus is laid on the exploration of the physics at strong, ultra-short
electromagnetic fields including the fundamental interactions between electrons
and heavy nuclei as well as on the experiments at the border between nuclear
and atomic physics. Very recently SPARC worked out a realization scheme for
experiments with highly-charged heavy-ions at relativistic energies in the
High-Energy Storage Ring HESR and at very low-energies at the CRYRING coupled
to the present ESR. Both facilities provide unprecedented physics opportunities
already at the very early stage of FAIR operation. The installation of CRYRING,
dedicated Low-energy Storage Ring (LSR) for FLAIR, may even enable a much
earlier realisation of the physics program of FLAIR with slow anti-protons.Comment: IX International Workshop on "APPLICATION OF LASERS AND STORAGE
DEVICES IN ATOMIC NUCLEI RESEARCH", Recent Achievements and Future Prospects,
May 13 - 16, 2013, Pozna\'n, Polan
Hybrid apparatus for Bose-Einstein condensation and cavity quantum electrodynamics: Single atom detection in quantum degenerate gases
We present and characterize an experimental system in which we achieve the
integration of an ultrahigh finesse optical cavity with a Bose-Einstein
condensate (BEC). The conceptually novel design of the apparatus for the
production of BECs features nested vacuum chambers and an in-vacuo magnetic
transport configuration. It grants large scale spatial access to the BEC for
samples and probes via a modular and exchangeable "science platform". We are
able to produce \87Rb condensates of five million atoms and to output couple
continuous atom lasers. The cavity is mounted on the science platform on top of
a vibration isolation system. The optical cavity works in the strong coupling
regime of cavity quantum electrodynamics and serves as a quantum optical
detector for single atoms. This system enables us to study atom optics on a
single particle level and to further develop the field of quantum atom optics.
We describe the technological modules and the operation of the combined BEC
cavity apparatus. Its performance is characterized by single atom detection
measurements for thermal and quantum degenerate atomic beams. The atom laser
provides a fast and controllable supply of atoms coupling with the cavity mode
and allows for an efficient study of atom field interactions in the strong
coupling regime. Moreover, the high detection efficiency for quantum degenerate
atoms distinguishes the cavity as a sensitive and weakly invasive probe for
cold atomic clouds
The effect of cryotherapy on the vascular regeneration following closed soft tissue trauma
INTRODUCTION Icing (cryotherapy) is being widely used for the treatment of closed soft tissue trauma (CSTT), such as those resulting from sport injuries. It is believed that cryotherapy induces vasoconstriction and through this mechanism reduces inflammation [1]. However, the impact of this technique on the healing of impaired vasculature and muscle injuries following trauma remains controversial. Recent evidence suggests that the muscle regeneration is delayed after cryotherapy [2]. Consequently, we aimed to investigate the effect of cryotherapy on the vascular morphology following CSTT using an experimental model in rats by contrast-enhanced micro-CT imaging. METHODS Fifty four rats were divided into three main groups: control (no injury, n=6), sham (CSTT but no icing treatment, n=24) and icing (CSTT, treated with one session of ice block massaged directly on the injured muscle for 20 minutes, n=24). The CSTT was induced to the left thigh (Biceps Femoris) of anaesthetised rats (Male, Wistar) to create a standardized and reproducible vascular and muscle injury using an impact device [3]. Following trauma, animals were euthanized after 1, 3, 7, and 28 days healing time (n=6 for each time point). For a three-dimensional vascular morphological assessment, the blood vessels of euthanised rats were flushed with heparinised saline and then perfused with a radio-opaque contrast agent (Microfil, MV 122, Flowtech, USA) using an infusion pump. Both hind-limbs were dissected, and then the injured and non-injured limbs were imaged using a micro-CT scanner (µCT 40, Scanco Medical, Switzerland) and total volume of the perfused blood vessels (TVV) was calculated. More detailed morphological parameters such as vessel volume (VV), diameter (VD), spacing (VSp), number (VN) and connectivity (VConn) were quantified through high resolution (6 µm), micro-CT-scanned biopsy samples (diameter: 8mm) taken directly from the region of the injured muscles. The biopsies were then analysed histologically to confirm the results derived from contrast-enhanced micro-CT imaging. RESULTS AND DISCUSSION The TVV was significantly higher in the injured legs compared to the non-injured legs at day 1 and 7 in the sham group and at day 28 in both sham and icing groups. The biopsies from the injured legs of the icing group showed a significant reduction in VV, VN, VD, VConn and an increase in VSp compared to those in the sham and control groups at days 1, 3 and 7, post injury. While the injured legs of the sham group exhibited a decrease in VN and VConn 28 days post trauma, indicating a return to the original values prior to trauma, these parameters had increased in the icing group (Figure 1). Also, at day 1 post injury, VV and VD of the injured legs were significantly higher in the sham group compared to the icing group, which may be attributed to the effect of vasoconstriction induced by icing. Further histomorphological evaluation of day 1 post injury, indicated that although cryotherapy significantly reduced the injury size and influx of inflammatory cells, including macrophages and neutrophils, a delay in vascular and muscle fiber regeneration was found at later time points confirming other reports from the literature [2]. CONCLUSIONS We have demonstrated using micro-CT imaging that the vascular morphology changes after CSTT, and that its recovery is affected by therapeutic modalities such as icing. This may be useful for the development of future clinical monitoring, diagnosis and treatment of CSTT. While icing reduces the swelling after trauma, our results suggest that it may delay the recovery of the vasculature in the injured tissue
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