Bias Estimation for Evaluation of ATC surveillance systems

This paper describes an off-line bias estimation and correction system for air traffic control related sensors, used in a newly developed Eurocontrol tool for the assessment of ATC surveillance systems. Current bias estimation algorithms are mainly focused in radar sensors, but the installation of new sensors (especially automatic dependent surveillance-broadcast and wide area multilateration) demands the extension of those procedures. In this paper bias estimation architecture is designed, based on error models for all those sensors. The error models described rely on the physics of the measurement process. The results of these bias estimation methods will be exemplified with simulated data

Detailed-level-accounting approach calculation of radiative properties of aluminium plasmas in a wide range of density and temperature

In this work it is accomplished a study of radiative properties of aluminium plasmas. It is analyzed the calculation of spectrally resolved and mean opacities both under NLTE and LTE approaches. Furthermore, the effect of the re-absorption of the radiation in these magnitudes is also examined. The calculations were performed into the detailed-levelaccounting approach including configuration interaction among the levels belonging to the same non-relativistic configuration

Determination of level populations and radiative properties of optically thin and thick carbon plasmas

In several research fields of current interest such as astrophysics or inertial fusion confinement the knowledge of the interactions between the photons and the plasma particles, i.e. plasma radiative properties, result essential. Thus, for example, the understanding of these plasmas requires properties such as emissivities and opacities both for hydro-simulations and diagnostics. Carbon is one of the most interesting elements under investigation, since it is likely to be a major plasma-facing wall component in ITER, and it plays a major role in inertial fusion scenarios. Also, some laser experiments have focused on the spectrally resolved emission from hydrocarbon systems. Therefore, radiative properties from carbon plasmas must be known and, as a consequence, the theoretical study of these plasmas is a subject of current interest and many efforts are headed. In particular, recent NLTE workshops have focused on comparisons of modelling calculations for specific cases that allow testing the models since there are very few experimental measurements for carbon plasmas. For these reasons it is interesting to characterize them in a wide range of plasma conditions. In a previous work we carried out an exhaustive study of optically thin carbon plasmas under steady state condition in a wide range of electron densities and temperatures given by (1-200) eV and (10 12 -10 22 ) cm -3 respectively [1], where CE, NLTE or LTE regimes are achieved. In this work we analyse the reabsorption radiation effects for homogeneous carbon plasmas in planar geometry by means of the escape factor formalism. We focus our attention on the average ionization and ionic populations as well as the multifrequential and mean opacity. All the calculations presented in this work were performed by using ABAKO code [1] which integrates the RAPCAL code [2] in order to calculate optical properties for a wide range of temperatures and electron number densitie

Analytical opacity formulas for low Z plasmas

The accurate computation of radiative opacities is basic in the ICF target physics analysis, in which the radiation is an important feature to determine in detail. For this reason, accurate analytical formulas for giving mean opacities versus temperature and density of the plasma seem to be a useful tool. In this work we analyse some analytical expressions found in the literature for the opacity low Z plasmas in a wide range of temperature and densities. The validity of these formulas for computing the opacity under NLTE conditions is investigated using the new code ABAKO

Academic Directors Facing Internet Addictions, Learning and Health Promotion

The result that is presented is expressed from a bibliographic review of works published during the last two years 2020-2022 and, through which it was possible to verify the relationships that are established between the work of the Academic Directors, before the latent challenge and visible that is the crossroads of Internet addictions, by university students, increased in the stage already overcome of social isolation imposed by Covid 19 but, with emphasis on the achievement of learning at this high educational level, its risks and consequent decreases in the attacks that occur as a result of procrastination. All associated with the addictive phenomenon, in a projection of health promotion that the current, humanistic, modern and developing university should not give up in any way, being precisely in this direction an unavoidable pillar of social development, which lies precisely in the high professional qualification. of the new generations committed to a prosperous and sustainable social change

Influence of carbonation on the chloride ion diffusion coefficient in fly ash concrete

The incorporation of fly ash (FA) in cementitious matrices has been frequently used in order to make the matrix more resistant to the action of chlorides. On the other hand, it is known that Ca(OH)2 existing in the matrix is consumed by the pozzolanic reactions, which makes easier the carbonation front advance. Given that the chloride ingress and carbonation are the two main causes of degradation in reinforced concrete, we speculate about the behaviour of FA concrete when the structure is submitted simultaneously to chlorides and carbonation. This work studied the influence of carbonation on the chloride migration coefficient in FA concrete. For this, specimens with 0% and 40% replacement of cement CEM I 42.5R by FA were casted with water/binder 0.55 and 0.50 respectively. After 90 days of curing period, half of samples were subjected to accelerated carbonation (20ºC ,55%RH and 4%CO2) for 1, 2 and 3 months. The other half was protected with plastic film during the same period. Non-steady-state migration tests, according to LNEC E463 (Portuguese specification), were performed with specimens subjected to both experimental conditions. The results show that, for these conditions, the carbonation has a direct influence on chloride diffusion coefficient, increasing it. For FA concrete samples this effect is more evident. In these cases, the carbonated samples studied showed a diffusion coefficient up to two times higher than noncarbonated ones. The increase in large capillary pores, caused by carbonation, can be responsible for the increase of chloride penetration into concrete subjected to combined actio

Multifrequential and mean opacity calculation of carbon plasmas in a wide range of density and temperature

The purpose of this work is to calculate the multifrequential and mean opacity of optically thin carbon plasmas in a wide range of density and temperature, where corona equilibrium, local thermodynamic equilibrium and non-local thermodynamic equilibrium regimes are present

Low-latitude equinoctial spread-F occurrence at different longitude sectors under low solar activity

We present the results of a comparative study of spread-F signatures over five low-latitude sites: Chiangmai (CGM; 18.8° N, 98.9° E, mag. Lat. 8.8° N), Thailand; Tanjungsari (TNJ; 6.9° S, 107.6° E, mag. Lat. 16.9° S), Indonesia; Palmas (PAL; 10.2° S, 311.8° E, mag. Lat. 0.9° S) and São José Dos Campos (SJC; 23.2° S, 314.1° E, mag. Lat. 14.0° S), Brazil; and Tucumán (TUC; 26.9° S, 294.6° E, mag. Lat. 16.8° S), Argentina. The investigation was based on simultaneous ionograms recorded by an FMCW (frequency-modulated continuous-wave) at CGM, an IPS-71 (digital ionosonde from KEL aerospace) at TNJ, a CADI (Canadian Advanced Digital Ionosonde) at PAL and SJC, and an AIS-INGV (Advanced Ionospheric Sounder – Istituto Nazionale di Geofisica e Vulcanologia) at TUC, during the equinoctial periods March–April (R12 = 2.0 and R12 = 2.2) and September–October (R12 = 6.1 and R12 = 7.0) 2009, for very low solar activity. Spread-F signatures were categorized into two types: the range spread-F (RSF) and the frequency spread-F (FSF). The study confirms that the dynamics and the physical processes responsible for these phenomena are actually complicated. In fact, the features that arise from the investigation are different, depending on both the longitude sector and on the hemisphere. For instance, TUC, under the southern crest of the ionospheric equatorial ionization anomaly (EIA), shows a predominance of RSF signatures, while both SJC, under the southern crest of EIA but in a different longitude sector, and CGM, under the northern crest of EIA, show a predominance of FSF signatures. Moreover, the spread-F occurrence over the longitude sector that includes CGM and TNJ is significantly lower than the spread-F occurrence over the longitude sector of PAL, SJC, and TUC.Fil: Pezzopane, M.. Istituto Nazionale Di Geofisica E Vulcanologia; Italia;Fil: Zuccheretti, E.. Istituto Nazionale Di Geofisica E Vulcanologia; Italia;Fil: Abadi, P.. Indonesian National Institute of Aeronautics and Space. Space Science Center. Division of Ionosphere and Telecommunication; Indonesia;Fil: de Abreu, A. J.. Universidade do Vale do Paraíba; Brazil;Fil: de Jesus, R.. Universidade do Vale do Paraíba; Brazil;Fil: Fagundes, P. R.. Universidade do Vale do Paraíba; Brazil;Fil: Supnithi, P.. King Mongkut’s Institute of Technology Ladkrabang . Faculty of Engineering; Tailandia;Fil: Rungraengwajiake, S.. King Mongkut’s Institute of Technology Ladkrabang . Faculty of Engineering; Tailandia;Fil: Nagatsuma, T.. National Institute of Information and Communications Technology. Space Weather and Environment Informatics Laboratory; Japón;Fil: Tsugawa, T.. National Institute of Information and Communications Technology. Space Weather and Environment Informatics Laboratory; Japón;Fil: Cabrera, Miguel Angel. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Física. Laboratorio de Ionosfera; Argentina; Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Electricidad, Electrónica y Computación. Laboratorio de Telecomunicaciones; Argentina; Universidad Tecnológica Nacional. Facultad Regional Tucumán. Centro de Investigación de Atmósfera Superior y Radiopropagación; Argentina;Fil: Ezquer, Rodolfo Gerardo. Universidad Tecnológica Nacional. Facultad Regional Tucumán. Centro de Investigación de Atmósfera Superior y Radiopropagación; Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina; Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Física. Laboratorio de Ionosfera; Argentina

A numerical model analysis of the tidal flows in the Bay of Algeciras, Strait of Gibraltar

A numerical model has been applied to study the tidal flows of the Bay of Algeciras in the eastern part of the Strait of Gibraltar, focusing on the M-2 semidiurnal constituent. The numerical model was satisfactorily validated against a comprehensive set of observations collected in the bay in the year 2011 and the model outputs were used for a detailed analysis of the local tidal circulation. The M-2 net (vertically integrated) transport across the mouth of the bay has an amplitude of 2.7 x 10(-3) Sv, while that of the sea surface signal is of similar to 30 cm and is in quadrature with this flow. However, the vertically integrated flow is the result of a pronounced baroclinic structure consisting of an upper (S 37.5) layers, whose associated transports are one order of magnitude higher. This reveals a noticeable internal tide that is characterized by an inward (to the head of the bay) propagation and a likely quarter-wave resonance. During the rising tide, Atlantic water from the strait comes in and produces the thickening of the upper (Atlantic) layer in the bay, while Mediterranean water of the lower layer is pushed out to join the Mediterranean water stream that is flowing to the west along the Strait of Gibraltar. During the falling tide, Atlantic water flows out of the bay and incorporates to the eastward flow in the strait. In this tidal phase, Mediterranean water flows into the bay. Therefore, Atlantic and Mediterranean waters accumulate in the bay during the rising and falling tide, respectively. This pattern is opposite to that observed in the strait, where the Mediterranean layer thickens during the rising tide and becomes thinner during the falling tide. This suggests that the internal tide in the bay is basically determined by the baroclinic forcing at its mouth imposed by the baroclinic tide of the Strait of Gibralta

Analysis of microscopic magnitudes of radiative blast waves launched in xenon clusters with collisional-radiative steady-state simulations

Radiative shock waves play a pivotal role in the transport energy into the stellar medium. This fact has led to many efforts to scale the astrophysical phenomena to accessible laboratory conditions and their study has been highlighted as an area requiring further experimental investigations. Low density material with high atomic mass is suitable to achieve radiative regime, and, therefore, low density xenon gas is commonly used for the medium in which the radiative shocks such as radiative blast waves propagate. In this work, by means of collisional-radiative steady-state calculations, a characterization and an analysis of microscopic magnitudes of laboratory blast waves launched in xenon clusters are made. Thus, for example, the average ionization, the charge state distribution, the cooling time or photon mean free paths are studied. Furthermore, for a particular experiment, the effects of the self-absorption and self-emission in the specific intensity emitted by the shock front and that is going through the radiative precursor are investigated. Finally, for that experiment, since the electron temperature is not measured experimentally, an estimation of this magnitude is made both for the shock shell and the radiative precursor