475 research outputs found
Subsequential tightness for branching random walk in random environment
We consider branching random walk in random environment (BRWRE) and prove the
existence of deterministic subsequences along which their maximum, centered at
its mean, is tight. This partially answers an open question in
arXiv:1711.00852. The method of proof adapts an argument developed by Dekking
and Host for branching random walks with bounded increments. The question of
tightness without the need for subsequences remains open.Comment: 15 page
Ein Verfahren zur Optimierung der Faserverläufe in Verbundwerkstoffen durch Minimierung der Schubspannungen nach Vorbildern der Natur
Energy spectrum, density of states and optical transitions in strongly biased narrow-gap quantum wells
We study theoretically the effect of an electric field on the electron states
and far-infrared optical properties in narrow-gap lead salt quantum wells. The
electron states are described by a two-band Hamiltonian. An application of a
strong electric field across the well allows the control of the energy gap
between the two-dimensional (2D) states in a wide range. A sufficiently strong
electric field transforms the narrow-gap quantum well to a nearly gapless 2D
system, whose electron energy spectrum is described by linear dispersion
relations \epsilon_{\sigma} (k) ~\pm (k-k_{\sigma}), where k_{\sigma} are the
field-dependent 2D momenta corresponding to the minimum energy gaps for the
states with spin numbers \sigma. Due to the field-induced shift of the 2D
subband extrema away from k=0 the density of states has inverse-square-root
divergencies at the edges. This property may result in a considerable increase
of the magnitude of the optical absorption and in the efficiency of the
electrooptical effect.Comment: Text 18 pages in Latex/Revtex format, 7 Postscript figure
Monitoring of Pentoxifylline Thermal Behavior by Novel Simultaneous Laboratory Small and Wide X-Ray Scattering (SWAXS) and Differential Scanning Calorimetry (DSC)
Influence of Fatigue and Anticipation on Knee Kinematics and Kinetics during a Jump-cut Maneuver
BACKGROUND AND PURPOSE: Injuries to the anterior cruciate ligament (ACL) are common among athletes, particularly females. This research aims to reconcile the anticipated and unanticipated movement pattern of jumping and cutting with fatigue for both genders. The research will compare lower extremity biomechanics of a jump-cut after a sports specific fatigue protocol, intending to examine movement patterns which may predispose the subject to ACL injury. METHODS: Twenty healthy subjects were studied (24.9±3.3yrs), including 10 females. A 3D electromagnetic system measured knee kinematics and kinetics during jump-cut tasks. The jump-cut task included anticipated (A) and unanticipated (UA) trials to both directions. For the UA trials, the subject was unaware of the cutting direction until initiation of the task. The fatigue protocol consisted of jumping, sprinting, step-ups, and agility. Subjects completed the jump-cut task again in a fatigued state. A repeated measures ANOVA was used to analyze peak and mean angles, moments and ground reaction forces (GRF), with post-hoc Tukey tests for significant findings between factors (gender, pre/post-fatigue, A/UA). RESULTS: Significant main effects were found for gender and IR/ER and ADD/ABD peak and/or mean angles, and ADD/ABD moments; pre and post-fatigue and IR/ER, EXT/FLEX, and ADD/ABD peak and/or mean angles, and ADD/ABD moments; A/UA conditions and IR/ER and ADD/ABD peak and/or mean angles. Significant interactions existed for gender and A/UA for EXT moment and for pre/post-fatigue and A/UA for EXT moment, IR moment and IR/ER angles.
CONCLUSION: Subjects demonstrated significant changes in knee kinematics and kinetics. Fatigue and A/UA states influenced knee movement patterns in variable ways, which may indicate an attempt to safely land and cut. Additionally, females demonstrated biomechanics that may increase their risk for ACL injury relative to males. Gender, fatigue, and A/UA conditions had an impact on one another and should be considered when designing sports training programs to reduce risky movement patterns
Geschichtsvermittlung im TV
Diese Arbeit behandelt das Thema ‚Geschichtsvermittlung im öffentlich-rechtlichen Fernsehen‘. Sie beschäftigt sich mit der Art, dem Umfang und der Aufbereitung von Geschichtsthemen im öffentlich-rechtlichen Fernsehen. Dabei wurde ein Vergleich zwischen Österreich, Deutschland und der Schweiz angestrebt. Die österreichischen TV-Programme ORF 1 und ORF 2, die deutschen Programme Das Erste und das ZDF so wie die Schweizer Sender SF 1 und SF 2 stellen dabei die Untersuchungseinheiten dar. Die Medienunternehmen die dahinter stehen, sind öffentlich-rechtliche Anstalten, die einem gesetzlichen Programmauftrag Folge leisten müssen.
Im ersten Teil der Arbeit wurden die ‚Mediatisierung von Geschichte‘, die ‚Kulturelle Prägung von Geschichte‘ und ‚Theoretische Ansätze der Geschichtsvermittlung‘ anhand einer Literaturstudie behandelt.
Um die im allgemeinen Teil erläuterten und zusammengefassten theoretischen Erkenntnisse zu ergänzen, wurden im empirischen Teil dieser Arbeit öffentlich-rechtliche Fernsehsender inhaltsanalytisch auf ihr Geschichtsangebot hin verglichen. Als empirisches Instrument dient die Programmanalyse. Der Ergebnisteil beinhaltet im ersten Punkt die Analyseobjekte. In diesem Zusammenhang wurden die Rundfunksysteme in Österreich, Deutschland und der Schweiz vorgestellt und ihre Merkmale, Aufbau, sowie Rechte und Pflichten der selbigen dargelegt. Darauf folgt eine dreigliedrige Auswertung der Programmanalyse. Diese besteht aus der Beantwortung von generellen Fragen über die Geschichtsvermittlung im deutschsprachigen öffentlich-rechtlichen Fernsehen, der Darstellung von länderspezifischen Besonderheiten in der Geschichtsvermittlung sowie einem Resümee. Besonderes Augenmerk liegt dabei auf den Darbietungsformen, der Themenwahl und dem historischen Zeitbezug von geschichtlichen Themen.
Da es im Sinne des gesetzlichen Programmauftrags ist, geschichtliche Ereignisse für die Öffentlichkeit auch im Fernsehen aufzubereiten, habe ich im Rahmen dieser Arbeit versucht, eine Einschätzung zu treffen, inwiefern die öffentlich-rechtlichen Fernsehsender in Österreich, Deutschland und der Schweiz diesem Auftrag nachkommen.The master thesis ‚Geschichtsvermittlung im TV: Ein quantitativer Vergleich der Angebotsseiten im österreichischen, deutschen und Schweizer öffentlich-rechtlichen Fernsehen‘ deals with history on german-speaking television. By an empirical analysis of the TV-programme, there should be determined the character, the type and the style of history in public broadcasting. The subjects of this quantitative research are six public broadcasting transmitters. ORF 1 and ORF 2 are the Austrian ones, ARD and ZDF the German ones and SF 1 and SF 2 the Suisse ones.
Public broadcasting transmitters have to abide by a compulsory appointment for there tv-programme. The tv-programme has to be, for example informative, sustentative and educational.
This thesis also describes the specifics of the broadcasting network in Austria, Germany and Switzerland, including the responsibilities, the rights and the duties of the broadcasting companies.
Within the empiric programme-analysis I tried to find out about general subject about the history-tv in german-speaking broadcasting and about national specifics in history-tv.
The programme-analysis turns it's attention on the type of historical tv-programme, the theme of the historical tv-show
Synthesis of indium nanoparticles at ambient temperature; simultaneous phase transfer and ripening
The synthesis of size-monodispersed indium nanoparticles via an innovative simultaneous phase transfer and ripening method is reported. The formation of nanoparticles occurs in a one-step process instead of well-known two-step phase transfer approaches. The synthesis involves the reduction of InCl3 with LiBH4 at ambient temperature and although the reduction occurs at room temperature, fine indium nanoparticles, with a mean diameter of 6.4 ± 0.4 nm, were obtained directly in non-polar n-dodecane. The direct synthesis of indium nanoparticles in n-dodecane facilitates their fast formation and enhances their size-monodispersity. In addition, the nanoparticles were highly stable for more than 2 months. The nanoparticles were characterised by dynamic light scattering (DLS), small angle X-ray scattering (SAXS), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS) and Fourier transform infrared (FT-IR) spectroscopy to determine their morphology, structure and phase purity
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