A. Kontogeorgos, P. Tsitsipis, C. Caroubalos, X. Moussas, P. Preka-Papadema, A. Hilaris, V. Petoussis, J.-L. Bougeret, C. E. Alissandrakis, G. Dumas, J. Polygiannakis
We present the improved solar radiospectrograph of the University of Athens operating at the Thermopylae Satellite Station. Observations now cover the frequency range from 20 to 650 MHz. The spectrograph has a 7-meter moving parabola feeding by a log-period antenna for 100 to 650MHz and a stationary inverted V fat dipole antenna for the 20 to 100 MHz. Two receivers are operating in parallel, one sweep frequency for the whole range (10 spectra/sec, 630 channels/spectrum) and one acousto-optical receiver for the range 270 to 450 MHz (100 spectra/sec, 128 channels/spectrum). The data...
TC4 Symposium 2004
· TC4
· 2004
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Patrick Boets, Leo Van Biesen
A model is proposed to describe the local connection between the capacitive and the inductive unbalance functions of two neighbouring twisted pairs. A realistic simulation of the unbalance functions indicates that the constant ratio of the inductive unbalance with respect to the capacitive unbalance is a workable model. Using this model, it is demonstrated that the calculation of the reflective coupling constant for the calculation of reflective crosstalk is possible when one has disposal of the widely used coupling constants to predict Near-End and Far-End crosstalk in case the line ends...
TC4 Symposium 2004
· TC4
· 2004
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Cristian Zet, Cristian Fosalau, Lars Westerberg, Reimar Spohr
Three algorithms for real-time digital pulse processing of fast detector signals (1 - 100 μs) are described and implemented through Field Programmable Gate Arrays (FPGAs). The signal from a PIN diode used as ion detector is amplified and digitized with a fast flash ADC at a rate of 10 MHz/s. Whenever a preset threshold is exceeded, an event is detected. The pulse maximum is determined using one of the three methods, characterized by decreasing response times and increasing the result confidence degree: (1) searching for the maximum, (2) integrating the signal and (3) looking for the...
TC4 Symposium 2004
· TC4
· 2004
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Valeriu David, Alexandru Salceanu, Mihai Cretu, Eduard Lunca
In this paper we present the results of electromagnetic field measurements near two RF transmitters: one in the medium wave domain and one in FM radio and television frequency range. The RF transmitters are situated at about 15 km distance from the town, but near them there are: tourist places; main roads; houses, where the public may be present. Using both a set of near field E & H probes and the adjustable dipole antennas, comparative measurements were made. Beside the instantaneous values of the fields, the maximum and average values for 1 minute observation period were determined.
TC4 Symposium 2004
· TC4
· 2004
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M.Bertocco, C.Narduzzi, E.Sieni, A.Sona
In this work, efficient techniques for the computation of the low frequency magnetic field due to the electrical circuit in buildings or industrial environment are discussed. Existing models used to compute the magnetic field caused by power lines are recalled at first. Then, an algorithm for the fast evaluation of the magnetic field due to electrical wires is proposed. It is based on the partitioning of the various sources into simpler magnetic sources: for each elementary magnetic source, some closed-form formulae are provided and combination rules are suggested in order to provide the...
TC4 Symposium 2004
· TC4
· 2004
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Janusz Zarębski, Krzysztof Górecki
This paper deals with the problem of measuring the thermal resistance of silicon p-n diodes. The values of this parameter given in the catalogues rarely correspond to the real conditions of device cooling, e.g. the diode operating on the heat-sink. Therefore, the value of the thermal resistance has to be obtained from measurements. In the paper a new comfortable method of the measurement of the thermal resistance of silicon p-n diodes, based on measurements of their d.c. current-voltage characteristic and the estimation of the model parameter values with the use of PARTS-software, is...
TC4 Symposium 2004
· TC4
· 2004
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Bolesław Dudojć
A connection of a new transmitter with measurement line while the system is working is a routine action under exploitation conditions. During this operation the transmitter is in a transient state. Usually, the properties of transmitters in the transient state are not defined by producers. In the paper, the results of the research of transient states of selected transmitters were presented. Basic features of current disturbances and their influence on the measurement line were discussed. Related suggestions for designers were proposed.
TC4 Symposium 2004
· TC4
· 2004
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José E. Manzoli, Celso Lemos, Luz C.G.A. Panzarini, Juliana S. Félix, Magali Monteiro
Diffusion coefficient is an important quantity that affects any migration process on food or nutritional systems. Special care has to be done to migration of undesirable substances from packaging into foods, if the diffusion is the only process involved in mass transfer. The Fick´s equation resolution permits to describe the kinetic of migration from polymer packaging into food or simulant, once it was given the correct contour and initial conditions. Another important quantity is the partition coefficient, which quantifies the relation between the final or equilibrium concentrations in...
MEFNM 2008 (TC24)
· TC24
· 2008
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Franco Pavese
This paper, starting from reviewing basic concepts, such as repeatability, reproducibility, accuracy, systematic error, true value, bias, Type A and B uncertainty components, as defined in international documents, shows that, currently, full consensus and a common understanding seems not be achieved yet. This fact reflects on the process of combining data, namely in chemistry.
MEFNM 2008 (TC24)
· TC24
· 2008
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Buzoianu Mirella
Reliable, traceable and comparable measurements provide the rational basis for evaluation of the quality of a result and the starting point for laboratory accreditation. Nowadays good measurements are essential not only for manufacturing, science and trade, they also underpin a wide range of aspects of the quality of live, from healthcare to sport. Starting from the role of the National Institute of Metrology (INM) in assuring the traceability of all measurements, regardless their end-use and level of accuracy, the paper depicts some aspects related to the present state-of-art in the field...
MEFNM 2008 (TC24)
· TC24
· 2008
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