Tidal activity in the meteor zone over Budrio, Italy

A brief survey is presented of the variations with time and height of atmospheric tides observed at Budrio (45 deg N, 12 deg E) in the wind field between 80 and 110 km altitude during the 1978 to 1982 year period. Variations of amplitude maxima mainly of the semidiurnal tide in the winter data of 1979 and 1980 show periodicities of a few days throughout the observing period. Upward propagation of tidal energy during a stratospheric warming in January 1982 is proposed to be inhibited because of instabilities in atmospheric conditions

Radar observations of the Leonid meteoroid stream in 2001

Results of the Leonid meteoroid stream observed in 2001 are presented. Data have been collected during November 13-23, 2001 by using a forward-scatter radar operating along the two long baselines of Bologna-Lecce (700 km) and Bologna-Modra (600 km). The profile of the reflection time shows a broad component on November 18 in the 00–12h UT time interval with maxima between 09:00h and 11:00h UT. About 90% of the reflection time was recorded at the two receiving stations of Lecce and Modra during the peak hour with an associated mass index of s = 1.72. The flux reached a value of 4.5 × 10−11 m−2 s−1 at the solar longitude 236◦ .09±0◦ .02 (November 18, 9h 30m UT) for echoes with duration T ≥ 1 s corresponding to a limiting mass of m � 10 −5 kg. For longer-duration (T ≥ 8 s) echoes, the main activity peak was found a hour later at the solar longitude 236◦ .13±0◦ .02 (November 18, 10h30m UT), similarly as reported by visual observations. The perspective of high levels of Leonid activity in 2002 is discussed

Approaching deterministic and probabilistic truth: a unified account

The basic problem of a theory of truth approximation is defining when a theory is \u201cclose to the truth\u201d about some relevant domain. Existing accounts of truthlikeness or verisimilitude address this problem, but are usually limited to the problem of approaching a \u201cdeterministic\u201d truth by means of deterministic theories.Ageneral theory of truth approximation, however, should arguably cover also cases where either the relevant theories, or \u201cthe truth\u201d, or both, are \u201cprobabilistic\u201d in nature. As a step forward in this direction, we first present a general characterization of both deterministic and probabilistic truth approximation; then, we introduce a new account of verisimilitude which provides a simple formal framework to deal with such issue in a unified way. The connections of our account with some other proposals in the literature are also briefly discussed

Supercritical carbon dioxide recovery system applied to cement industries

The paper addresses the potential heat-to-power application of supercritical CO2 (sCO2) plants to the cement industry, thereby reducing their electricity demand and improving energy efficiency. The research was conducted as part of the European project CO2OLHEAT (G.A. 101022831), which involves the installation of a 2 MW Waste-Heat-to-Power (WH2P) skid based on a sCO2 cycle in a cement plant, the first of its kind with a MW-scale power output. The paper summarizes technologies and processes employed in the Italian cement production sector, detecting where the waste heat can be successfully extracted to feed the recovery plant without compromising the industrial process. Moreover, the paper discusses the national cement market and explores the potential advantages and limitations of integrating sCO2 recovery plants within the national cement context, considering production and energy-related data. The final finding reveals the percentage of recoverable electricity per technological class for the cement production sector in Italy with a potential application of the sCO2 recovery plant, aiming at identifying the potential market penetration of the CO2OLHEAT installation

The orbit, structure and evolution of the Lyrid meteoroid stream

The orbit and structure of the Lyrid meteor stream based on photographic orbits available in the IAU Meteor database are investigated. Seventeen Lyrids were found in the database and the radiant and orbit of the stream were derived. In the stream three very distinct groups of orbits—short-period, longperiod and extreme (hyperbolic orbits), are separated. The mutual consistence of the groups is investigated by following the orbital evolution of individual meteors. The long-period group has the evolution almost identical with that of the parent comet C/1861 G1 Thatcher. The hyperbolic orbits are most probably the result of erroneous measurements

The Leonid meteor shower 1996-2002: Results from forward-scatter radio observations

Results from the observations of the Leonid meteor shower in 1996-2002 by the BLM (Bologna-Lecce-Modra) forward-scatter radio system for meteor observation carried out along two baselines, Bologna-Lecce (Italy)and Bologna-Modra (Slovakia), are presented and discussed. The activity curves of long-duration echoes (≥ 8 s)and their variations indicate multiple peak activity which are attributed to filamentary structure of the stream. The mass distribution exponents in the period of the shower maximum shows significant changes in individual years, with a high contribution of larger particles chiefly in 1998