Search results for "basel"

Catching the radio flare in CTA 102

2013

We performed multifrequency multiepoch Very Long Baseline Array (VLBA) observations of the blazar CTA 102 during its 2006 radio flare, the strongest ever reported for this source. These observations provide an excellent opportunity to investigate the evolution of the physical properties of blazars, especially during these flaring events. We want to study the kinematic changes in the source during the strong radio outburst in April 2006 and test the assumption of a shock-shock interaction. This assumption is based on the analysis and modeling of the single-dish observations of CTA\,102 (Paper I). In this paper we study the kinematics of CTA 102 at several frequencies using VLBI observations.…

VLBA observations of a rare multiple quasar imaging event caused by refraction in the interstellar medium

2013

We report on the first detection of the theoretically-predicted rare phenomenon of multiple parsec-scale imaging of an active galactic nucleus induced by refractive effects due to localized foreground electron density enhancements, e.g., in an AU-scale plasma lens(es) in the ionized component of the Galactic interstellar medium. We detected multiple imaging in the low galactic latitude (b=-2 deg) quasar 2023+335 from the 15.4 GHz MOJAVE observations when the source was undergoing an ESE. While the parsec-scale jet of the source normally extends along PA -20 deg, in the 28 May 2009 and 23 July 2009 images a highly significant multi-component pattern of secondary images is stretched out nearl…

Discovery of off-axis jet structure of TeV blazar Mrk 501 with mm-VLBI

2016

Context. High-resolution millimeter wave very-long-baseline interferometry (mm-VLBI) is an ideal tool for probing the structure at the base of extragalactic jets in detail. The TeV blazar Mrk 501 is one of the best targets among BL Lac objects for studying the nature of off-axis jet structures because it shows different jet position angles at different scales. Aims. The aim of this study is to investigate the properties of the off-axis jet structure through high-resolution mm-VLBI images at the jet base and physical parameters such as kinematics, flux densities, and spectral indices. Methods. We performed Very Long Baseline Array (VLBA) observations over six epochs from 2012 February to 201…

The role of Kelvin-Helmholtz instability in the internal structure of relativistic outflows. The case of the jet in 3C 273

2006

Relativistic outflows represent one of the best-suited tools to probe the physics of AGN. Numerical modelling of internal structure of the relativistic outflows on parsec scales provides important clues about the conditions and dynamics of the material in the immediate vicinity of the central black holes in AGN. We investigate possible causes of the structural patterns and regularities observed in the parsec-scale jet of the well-known quasar 3C 273. We present here the results from a 3D relativistic hydrodynamics numerical simulation based on the parameters given for the jet by Lobanov & Zensus (2001), and one in which the effects of jet precession and the injection of discrete compone…

Pumps as turbines (PATs) in water distribution networks affected by intermittent service

2013

A hydraulic model was developed in order to evaluate the potential energy recovery from the use of centrifugal pumps as turbines (PATs) in a water distribution network characterized by the presence of private tanks. The model integrates the Global Gradient Algorithm (GGA), with a pressure-driven model that permits a more realistic representation of the influence on the network behaviour of the private tanks filling and emptying. The model was applied to a real case study: a District Metered Area in Palermo (Italy). Three different scenarios were analysed and compared with a baseline scenario (Scenario 0 – no PAT installed) to identify the system configuration with added PATs that permits th…

Space-VLBI phase-reference mapping and astrometry

2001

We present 5 GHz space-VLBI observations of the quasar pair B1342+662/B1342+663 that demonstrate the feasibility of phase-reference techniques using an antenna in space. The space-based data were taken by the satellite HALCA, of the space-VLBI mission VSOP. From residual (referenced) phases we derive an upper bound of 10 meters to the uncertainty of the spacecraft orbit reconstruction. An analysis of the phase-reference maps of the sources additionally suggests that the above mentioned uncertaintyis likely not larger than 3 meters. With errors of this magnitude, HALCA is a useful tool for astrometric studies of close pairs of radio sources.

Theoretical Old-Age Pension Benefits and Replacement Rates in the Baltic States: A Retrospective Simulation

2016

Abstract The author presents a comparative analysis of old-age pension systems in Estonia, Latvia and Lithuania using a method of retrospective simulation run on a self-developed model. The model baseline case is a person retiring in December 2014 after 40 years of service with nationwide average salary. Other cases include low and high-earners, funded schemes participants and simulations for modified notional capital valorisation formulae. Three study countries return very dissimilar results, which is caused by differences in their pension systems’ designs. Lack of non-contributory element (basic pension) in Latvia leads to a low degree of progressivity, with inexcusably low pensions to lo…

Baseline port surveys for invasive marine species in the Northeastern Baltic

2006

Marine ecosystems around the world are being transformed and degraded by non-indigenous species, which affect the structure and function of the ecosystem, causing major ecological and economic implications. Ships have been recognized as a major vector for the introduction of non-indigenous harmful organisms, carrying them in ballast water tanks and sediments. Activities to prevent and mitigate the impact of invasive alien species have to be based on cooperation. Financed by Phare Cross Border Co-operation Programme in the Baltic Sea Region (2005–2006) Latvia together with Estonia will focus on baseline port surveys for non-indigenous species in the north-eastern part of the Baltic Sea.

Procyclicality and loan pricing effects under Basel 2: a simulation exercise to assess the impact on Italian SMEs

2008

2013 ECONOMY MOMENTUM CHALLENGES FOR NEXT 10 YEARS

2013

Last 5 years of almost unprecedented financial market turmoil it s still generating comprehensive crisis theories, market paradigms and nevertheless unprecedented situations. The aim of this paper is to explain 2013 milestone momentum for new market rules and regulations implementation - Basel III. The expected immediate cushion factors as well the possible negative impact on financial markets is presented from financial institutions perspective. Finally, the paper seeks for an exploratory after 10 years scenario connected with imminent market evolution and tendencies.