Search results for " ZEN"
showing 6 items of 96 documents
Atmospheric radiative effects of an in-situ measured Saharan dust plume and the role of large particles
2007
This work will present aerosol size distributions measured in a Saharan dust plume between 0.9 and 12 km altitude during the ACE-2 campaign 1997. The distributions contain a significant fraction of large particles of diameters from 4 to 30 μm. Radiative transfer calculations have been performed using these data as input. Shortwave, longwave as well as total atmospheric radiative effects (AREs) of the dust plume are investigated over ocean and desert within the scope of sensitivity studies considering varied input parameters like solar zenith angle, scaled total dust optical depth, tropospheric standard aerosol profiles and particle complex refractive index. The results indicate that the lar…
Digital zenith camera for vertical deflection determination
2012
Recent accomplishments in advancement of accurate astrometric reference star catalogues, development of digital imaging technology, high accuracy tiltmeter technology, and geocentric coordinate availability provided by GNSS, have made possible accurate, fast and automated determination of vertical deflections using astrometric methods. Zenith cameras for this kind of measurements have been developed or are being developed by several research groups. The paper describes a research project by Institute of Geodesy and Geoinformation, intended to design a portable digital zenith camera for vertical deflection determination with 0.1” expected accuracy. Camera components are described, proposed d…
CLINICAL AND IMAGING FINDINGS OF RARE SYMPTOMATIC GIANT KILLIAN-JAMIESON DIVERTICULUM
2014
Learning objectives Background Findings and procedure details Conclusion Personal information References
Enhancing Metastability by Dissipation and Driving in an Asymmetric Bistable Quantum System.
2018
The stabilizing effect of quantum fluctuations on the escape process and the relaxation dynamics from a quantum metastable state are investigated. Specifically, the quantum dynamics of a multilevel bistable system coupled to a bosonic Ohmic thermal bath in strong dissipation regime is analyzed. The study is performed by a non-perturbative method based on the real-time path integral approach of the Feynman-Vernon influence functional. We consider a strongly asymmetric double well potential with and without a monochromatic external driving, and with an out-of-equilibrium initial condition. In the absence of driving we observe a nonmonotonic behavior of the escape time from the metastable regi…
Quando i recinti tracimeranno. Lo sprawl e le insulae dello ZEN 2
2008
Dal 1989 mi interesso al quartiere ZEN di Palermo, al quale ho dedicato la tesi di dottorato, alcuni articoli, una monografia, molte lezioni, diversi progetti e, ovviamente, moltissimi sopralluoghi. Sono trascorsi, quindi, circa venti anni dalla fase iniziale di studio e ho avuto modo, in questo periodo, di seguire quelle trasformazioni che, insieme al quartiere, hanno riguardato l’area più a nord della Piana dei Colli. Punti di vista privilegiati per seguire e comprendere tali mutamenti sono il Monte Pellegrino e la strada panoramica che, almeno per una parte, si srotola, come un nastro, lungo il fianco che limita ad est il parco de La Favorita. Da molti degli sguardi offerti dal monte, c…
Performance analysis of Latvian zenith camera
2018
Since finalizing of design in 2016, the digital zenith camera of the University of Latvia was involved in a number of test observations as well as field observations at about 70 different sites. The paper presents analysis of observation results, estimation of instrument’s performance and accuracy. Random and systematic error sources are outlined. Impact of anomalous refraction on vertical deflection determination is discussed. Results of adaptation of GAIA reference star catalog for astrometric data reduction are reported.