Search results for "Continuum"
showing 10 items of 477 documents
Semi-terminal continua in homogeneous spaces
2016
A semi-terminal continuum Y in a space X is defined by the condition that no two disjoint subcontinua of X intersect both Y and X-Y. Though numerous obvious examples of such continua can be found in arcs, trees and tree-like continua, these examples are related to the non-homogeneity of the space, and having semi-terminal continua in a homogeneous continuum is counter-intuitive. Recently, a large collection of homogeneous spaces with semi-terminal, non-terminal subcontinua has been found. This paper is devoted to studying these spaces and the general structure of homogeneous continua related to the presence of semi-terminal subcontinua.
Biomechanical analysis of Ascending Thoracic Aortic Aneurysm (ATAA)
2021
According to the reports of the World Health Organisation (WHO), cardiovascular diseases are the number one cause of death worldwide. Specifically, arterial disease and degeneration are the major reasons for cardiovascular death and disability. Because these diseases are dependent on the changes of the mechanical properties of the arterial wall, it is very important to know as much as possible about the structural composition of arteries. The human aorta is the biggest artery in the body and consists of three main parts, ascending aorta, aortic arch and descending aorta. The walls of the arteries consist of three layers, the intima, media and adventitia, where each of the layers has differe…
Upper Caraş River (Danube watershed) fish populations fragmentation – technical rehabilitation proposal
2017
Abstract We propose a technical solution for fish movement based on the flow of water over a spill threshold. Such barriers are common in the Danube system. The proposed system has a range of operating components which are easily detachable from the spill threshold, are resistant to corrosion and will not harm the fish. In fact, if designed to complement swimming abilities of target fish, it should provide adequate passage for both adults and juveniles. If implemented correctly, the design may offer a solution to help displaced fish recolonize upstream habitats.
Faint γ-ray sources at low redshift: the radio galaxy IC 1531
2018
We present amultiwavelength study of IC 1531 (z=0.02564), an extragalactic radio source associated with the γ -ray object 3FGL J0009.9-3206 and classified as a blazar of uncertain type in the Third Fermi-Large Area Telescope AGN catalog (3LAC). A core-jet structure, visible in radio and X-rays, is enclosed within a ~220 kpc wide radio structure. The morphology and spectral characteristics of the kiloparsec jet in radio and X-rays are typical of Fanaroff-Riley type I galaxies. The analysis of the radio data and optical spectrum and different diagnostic methods based on the optical, infrared, and γ -ray luminosities also support a classification as a low-power RG seen at moderate angles (θ = …
Absolute kinematics of radio source components in the complete S5 polar cap sample
2008
We report on the first wide-field, high-precision astrometric analysis of the 13 extragalactic radio sources of the complete S5 polar cap sample at 15.4 GHz. We describe new algorithms developed to enable the use of differenced phase delays in wide-field astrometric observations and discuss the impact of using differenced phase delays on the precision of the wide-field astrometric analysis. From this global fit, we obtained estimates of the relative source positions with precisions ranging from 14 to 200 μas at 15.4 GHz, depending on the angular separation of the sources (from ∼1.6 to ∼20.8 degrees). These precisions are ∼10 times higher than the achievable precisions using the phase-refere…
Gestalt/Gestalt Theory
2020
Gestalt is a concept introduced to solve the problems of unity, connection and order that objects manifest in experience. Philosophers trained at Franz Brentano’s teaching began to work on it to address epistemological and ontological questions about perception, cognition and the structure of objects. This work was seminal for Gestalt psychology, from the research of the Graz and Berlin Schools, carried on by Cesare Musatti, Fabio Metelli, Gaetano Kanizsa, Paolo Bozzi in Padua and Trieste, Albert Michotte and Paul Fraisse in Louvain, to that of Edgar Rubin and David Katz, but also of Karl Buhler, Egon Brunswik and Ludwig Kardos in Wien. Common is the tenet that the world looks as neither a …
23 GHz VLBI observations of SN 2008ax (Research Note)
2009
We report on phase-referenced 23 GHz Very-Long-Baseline-Interferometry (VLBI) observations of the type IIb supernova SN 2008ax, made with the Very Long Baseline Array (VLBA) on 2 April 2008 (33 days after explosion). These observations resulted in a marginal detection of the supernova. The total flux density recovered from our VLBI image is 0.8 ± 0.3 mJy (one standard deviation). As it appears, the structure may be interpreted as either a core-jet or a double source. However, the supernova structure could be somewhat confused with a possible close by noise peak. In such a case, the recovered flux density would decrease to 0.48 ± 0.12 mJy, compatible with the flux densities measured with the…
On the location of the supermassive black hole in CTA102
2015
Relativistic jets in active galactic nuclei represent one of the most powerful phenomena in the Universe. They form in the surroundings of the supermassive black holes as a by-product of accretion onto the central black hole in active galaxies. The flow in the jets propagates at velocities close to the speed of light. The distance between the first part of the jet that is visible in radio images (core) and the black hole is still a matter of debate. Only very-long-baseline interferometry observations resolve the innermost compact regions of the radio jet. Those can access the jet base, and combining data at different wavelenghts, address the physical parameters of the outflow from its emiss…
Self-Assembled Molecular Rafts at Liquid|Liquid Interfaces for Four-Electron Oxygen Reduction
2011
The self-assembly of the oppositely charged water-soluble porphyrins, cobalt tetramethylpyridinium porphyrin (CoTMPyP(4+)) and cobalt tetrasulphonatophenyl porphyrin (CoTPPS(4-)), at the interface with an organic solvent to form molecular "rafts", provides an excellent catalyst to perform the interfacial four-electron reduction of oxygen by lipophilic electron donors such as tetrathiafulvalene (TTF). The catalytic activity and selectivity of the self-assembled catalyst toward the four-electron pathway was found to be as good as that of the Pacman type cofacial cobalt porphyrins. The assembly has been characterized by UV-visible spectroscopy, Surface Second Harmonic Generation, and Scanning …
Octave Spanning Supercontinuum in Titanium Dioxide Waveguides
2018
International audience; We report on the experimental generation of an octave-spanning supercontinuum in a 2.2 cm-long titanium dioxide optical waveguide with two zero dispersion wavelengths. The resulting on-chip supercontinuum reaches the visible wavelength range as well as the mid-infrared region by using a femtosecond fiber laser pump at 1.64 µm.