53 research outputs found
Flying Qualities of Otto Lilienthal's Large Biplane
The paper describes full-scale balance tests, which have proven structural integrity and longitudinal static stability of an authentic replica of Otto Lilienthal's Large Biplane glider. In addition to that, the replica, built after patent drawings, photographs, and textual descriptions by the Otto-Lilienthal-Museum, was towed using a rope winch and finally flown downhill without rope or guide wires. The tests allow for the assessment of the aircraft's controllability and stability not only during steady flight, but also during takeoff, landing, and on the occasion of wind gusts. A brief description of the design parameters and applied methods is given along with force and moment data gained from balance measurements as well as the evaluation of a limited set of data acquired during flight, including speed, duration, and distances flown
Ăber die Flugeigenschaften von Otto Lilienthals groĂem Doppeldecker
Der Artikel beschreibt aerodynamische Messungen, die die strukturelle und die statische LĂ€ngsstabilitĂ€t eines authentischen Nachbaus von Otto Lilienthals groĂem Doppeldecker nachweisen. DarĂŒber hinaus wurde der nach Patentzeichnungen, Fotos und Textbeschreibungen vom Otto-Lilienthal-Museum gebaute Nachbau des historischen Gleiters mit einer Seilwinde geschleppt und schlieĂlich, ganz ohne Seile, bergab geflogen. Die Tests ermöglichen die Beurteilung der Steuerbarkeit und StabilitĂ€t des Flugzeugs nicht nur im stationĂ€ren Flug, sondern auch bei Start, Landung und bei Windböen. Eine kurze Beschreibung der Konstruktionsparameter und der angewandten Methoden wird ebenso beschrieben wie die Auswertungen Kraft- und Momentdaten, die aus Waagenmessungen gewonnen wurden. Dargestellt wird darĂŒber hinaus die Auswertung eines begrenzten Satzes von Daten, die wĂ€hrend des Fluges gewonnen wurden, einschlieĂlich Geschwindigkeit, Dauer und geflogene Distanzen
Flight testing Otto Lilienthal's experimental monoplane
Free flights and tethered flights were performed using an authentic replica of Otto Lilienthal's experimental monoplane, the "VorflĂŒgelapparat", achieving flight distances of more than 100m. The flight stability, controllability and performance of the design has been verified through balance measurements using a 1:5 scaled wind tunnel test
Flight Controls of Otto Lilienthal's Experimental Monoplane from 1895
In 1889, Otto Lilienthal published his book Birdflight as the Basis of Aviation, containing the first lift-versus-drag data of cambered wings and other important information required for human flight. In 1895, Lilienthal demonstrated his 12th aircraft design, a monoplane with a wing area of over 20 m2. Because of its wingspan of almost 9 m and wing chord length of 3 m, Lilienthalâs largest monoplane can only be used in light winds. Lilienthal applied for a patent on the same day. The patent claim was submitted for the front wing (VorflĂŒgel), a leading-edge flap used in a glider for this purpose for the first time. Because of the size of the apparatus, three profile rails were slid onto each wing instead of the usual two
Windkanal- und Flugversuche mit Otto Lilienthal's ExperimentiergerÀt von 1895
1895 patentierte, baute und flog Otto Lilienthal ein Forschungsflugzeug, das mit SteuerflĂ€chen ausgestattet war, die vom Piloten betĂ€tigt wurden. Es verfĂŒgte ĂŒber gummibandbetĂ€tigte Vorderkantenklappen fĂŒr die automatische Nicksteuerung, sowie ĂŒber Spoiler, FlĂŒgelverwindung und Ruder fĂŒr die Gier- und Rollsteuerung, die durch eine HĂŒftgabel betĂ€tigt wurden. FĂŒr die hier beschriebenen Untersuchungen wurden ein maĂstabsgetreuer Nachbau und ein 1:5 Modell gebaut. Alle Strukturmaterialien, die fĂŒr die Flugeigenschaften relevant sind, wurden mit groĂer Sorgfalt ausgewĂ€hlt. Das 1:5-Modell wurde in zwei verschiedenen WindkanĂ€len am Institut fĂŒr Aerodynamik und Strömungstechnik des Deutschen Zentrums fĂŒr Luft- und Raumfahrt (DLR) in Göttingen getestet. Der maĂstabsgetreue Nachbau wurde fĂŒr eine Reihe von Fesselflugtests auf den Outer Banks (NC) in Zusammenarbeit mit der Drachenflugschule Kitty Hawk Kites eingesetzt. Die Windkanaltests lieferten neue Erkenntnisse ĂŒber die Leistung, den Trimmzustand, die FlugstabilitĂ€t und die Steuerbarkeit. Nach der gĂ€ngigen Klassifizierung von Lilienthals Segelflugzeugen hat das "ExperimentiergerĂ€t" eine Spannweite von 8,8m und eine FlĂŒgelflĂ€che von 23m2. Lilienthal schrieb, dass diese gröĂeren Abmessungen im Vergleich zu seinen frĂŒheren EntwĂŒrfen zu besseren Leistungen bei niedrigen Windgeschwindigkeiten fĂŒhrten, aber zusĂ€tzliche Steuermittel erforderten, da seine Methode der Gewichtsverlagerung nur begrenzte Steuermöglichkeiten fĂŒr FlĂŒgelspannweiten von mehr als 7 m bot. Es wurden Windkanalmessungen und eine begrenzte Anzahl von Flugtests durchgefĂŒhrt, um zu untersuchen, ob die patentierte automatische Nicksteuerung und die SteuerflĂ€chen ausreichend waren, um das Flugzeug sicher zu steuern
Sex Differences in Cardiovascular Research: A Scientometric Analysis
Background
We sought to investigate sexâspecific differences in authorship of cardiovascular research over the past decade.
Methods and Results
All 387 463 cardiovascular publications between 2010 and 2019 were retrieved from Web of Science. Articles increased from 19 960 to 29 604 articles per year (P>0.001). The number of articles written by female first authors increased by 76.3% (6434â11 343 articles) and by 35.0% for male first authors (13 526â18 261) (P<0.001). The first author was more likely to be a female author in articles with female last authors. The median impact factor (IF) for articles by female first authors was lower (2.46 [interquartile range, 7 1.11â4.03] versus 2.51 [interquartile range, 1.17â4.10]; P<0.001). Female authorship articles reached the highest IF in North America (average IF, 3.7), with the lowest in Africa (average IF, 1.8).
Conclusions
Publications in cardiovascular research have increased over the past decade, particularly by female authors. Female researchers are cited less often compared with their male peers. The IF remains lower for articles by female researchers
First Measurement of the Ru(p,)Rh Cross Section for the p-Process with a Storage Ring
This work presents a direct measurement of the Ru()Rh cross section via a novel technique using a storage ring,
which opens opportunities for reaction measurements on unstable nuclei. A
proof-of-principle experiment was performed at the storage ring ESR at GSI in
Darmstadt, where circulating Ru ions interacted repeatedly with a
hydrogen target. The Ru()Rh cross section between 9
and 11 MeV has been determined using two independent normalization methods. As
key ingredients in Hauser-Feshbach calculations, the -ray strength
function as well as the level density model can be pinned down with the
measured () cross section. Furthermore, the proton optical potential
can be optimized after the uncertainties from the -ray strength
function and the level density have been removed. As a result, a constrained
Ru()Rh reaction rate over a wide temperature range is
recommended for -process network calculations.Comment: 10 pages, 7 figs, Accepted for publication at PR
Measurements of proton-induced reactions on ruthenium-96 in the ESR at GSI
8th International Conference on Nuclear Physics at Storage Rings Stori11, October 9-14, 2011 Laboratori Nazionale di Frascati, Italy.
Storage rings offer the possibility of measuring proton- and alpha-induced reactions in inverse kinematics. The combination of this approachwith a radioactive beamfacility allows, in principle, the determination of the respective cross sections for radioactive isotopes. Such data are highly desired for a better understanding of astrophysical nucleosynthesis processes like the p-process. A pioneering experiment has been performed at the Experimental Storage Ring (ESR) at GSI using a stable 96Ru beam at 9-11 AMeV and a hydrogen target. Monte-Carlo simulations of the experiment were made using the Geant4 code. In these simulations, the experimental setup is described in detail and all reaction channels can be investigated. Based on the Geant4 simulations, a prediction of the shape of different spectral components can be performed. A comparison of simulated predictions with the experimental results shows a good agreement and allows the extraction of the cross section
Systemic Maternal Inflammation and Neonatal Hyperoxia Induces Remodeling and Left Ventricular Dysfunction in Mice
The impact of the neonatal environment on the development of adult cardiovascular disease is poorly understood. Systemic maternal inflammation is linked to growth retardation, preterm birth, and maturation deficits in the developing fetus. Often preterm or small-for-gestational age infants require medical interventions such as oxygen therapy. The long-term pathological consequences of medical interventions on an immature physiology remain unknown. In the present study, we hypothesized that systemic maternal inflammation and neonatal hyperoxia exposure compromise cardiac structure, resulting in LV dysfunction during adulthood.Pregnant C3H/HeN mice were injected on embryonic day 16 (E16) with LPS (80 ”g/kg; i.p.) or saline. Offspring were placed in room air (RA) or 85% O(2) for 14 days and subsequently maintained in RA. Cardiac echocardiography, cardiomyocyte contractility, and molecular analyses were performed. Echocardiography revealed persistent lower left ventricular fractional shortening with greater left ventricular end systolic diameter at 8 weeks in LPS/O(2) than in saline/RA mice. Isolated cardiomyocytes from LPS/O(2) mice had slower rates of contraction and relaxation, and a slower return to baseline length than cardiomyocytes isolated from saline/RA controls. α-/ÎČ-MHC ratio was increased and Connexin-43 levels decreased in LPS/O(2) mice at 8 weeks. Nox4 was reduced between day 3 and 14 and capillary density was lower at 8 weeks of life in LPS/O(2) mice.These results demonstrate that systemic maternal inflammation combined with neonatal hyperoxia exposure induces alterations in cardiac structure and function leading to cardiac failure in adulthood and supports the importance of the intrauterine and neonatal milieu on adult health
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