Laboratory measurements on molecules of astrophysical interest

Summary The infra-red absorption bands of a representative polycylic aromatic hydrocarbon (PAH) molecule, coronene, have been examined in the laboratory at various temperatures up to 240 °C. This paper is devoted to a systematic analysis of the temperature variations of the integrated band intensity. A tentative interpretation of the observed behaviour is given in terms of anharmonicity effects. These new laboratory results may be helpful in the context of the attribution of the ?unidentified? infra-red band to PAH molecules. In addition, for the first time thermal-emission spectra of three different PAHs recorded at 240 °C are presented. Paper presented at the V Cosmic Physics National Conference, S. Miniato, November 27–30, 1990.     

Integrated BVRIJHK photometry of galactic globular clusters

Summary We present preliminary BVRI photometric data of 22 galactic globular clusters of the Southern hemisphere. The observations were carried out at the ESO Observatory, during two observing runs in August 1988 (VRI) and March 1989 (BVRI). In both periods half of the total number of nights was used to perform near-infrared (JHK) photometry of the same clusters: the goal of this quasi-contemporary photometry was to obtain a homogeneus sample of galactic clusters photometric observations, on a wavelength range as wide as possible. Paper presented at the V Cosmic Physics National Conference, S. Miniato, November 27–30, 1990.     

Control system for small automatic telescopes (ATs)

Summary The present paper illustrates some aspects of particular significance which result from applied research in the field of small, medium-size and large telescopes, to implement a reliable technological system capable of handling in an autonomous manner remotely loaded astronomical observation program. Because of their specific applications, the automatic telescope (AT) must be highly reliable. In this case, the term reliability is intended in its widest sense, that is, as quality and continuity of service of all the component subsystems. The integration of engineering, information science, mechanics, and, of course, astrophysics expertise is of primary importance. Paper presented at the V Cosmic Physics National Conference, S. Miniato, November 27–30, 1990.     

Numerical simulation of astronomical observations with ISO-LWS

Summary The purpose of this work is the numerical simulation of the ISO-LWS spectrometer output with a computer code aiming at obtaining data similar as far as possible to those to be gained during the mission. With such data the processing and analysis programmes will be tested in order to assess the instrument capabilities and limits. As an example we have simulated the realization of a spectral and spatial map of the sky region with the outflow of L1551-IRS5. Paper presented at the 6th Cosmic Physics National Conference, Palermo, 3–7 November 1992.     

Periodic motion of a star inside an elliptical galaxy with a variable mass

Periodic solutions are constructed to the problem of a star’s motion inside a layered inhomogeneous rotating elliptical galaxy with a variable mass using the Lyapunov and the small parameter methods. The stability of periodic solutions in the Lyapunov sense is studied.     

Arguments in favour of physical reality of the peculiar (200÷300) Mpc scale in the distribution of the rich clusters of galaxies

Summary It is necessary to examine the significance of the recently discovered peak of spatial two-point correlation function determined for the rich Abel clusters. We discuss the different possibilities to do it and propose the programme of further observations.

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Riassunto è necessario esaminare il significato del picco recentemente scoperto della funzione di correlazione a due punti spaziale determinata per i cluster ricchi di Abell. Si discutono le diverse possibilità di farlo e si propone la programmazione di ulteriori osservazioni.

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Резюме Отмечается важность исследования недавно обнаруженного пика пространственной функции двух-точечной корреляции, определенной для больших Абеллевых кластеров. Мы обсуждаем различные возможности проведения исследований и предлагаем программу дальнейших наблюдений.

     

N -body simulations and dynamics of groups of galaxies

Summary Results of a set ofN-body simulations of groups of galaxies and their comparison with observations are reported. A preliminary analysis of the theoretical and observed velocity dispersion distributions indicates a basic discrepancy possibly related with projection effects and the presence of interlopers. Paper presented at the V Cosmic Physics National Conference, S. Miniato, November 27–30, 1990.     

A classicalN-body simulation of groups of galaxies

Summary Groups of galaxies are simulated by Monte Carlo technique. The mass distribution of the groups is assumed to follow a power law. Furthermore a linear relationship between mass and luminosity is considered. The calculated velocity dispersion is compared with the observational data and provides an estimate of the range in which the galaxy masses are distributed. It is shown, in this case, that the mass discrepancy can cover up two orders of magnitude, such as pointed out in the literature. The authors of this paper have agreed to not receive the proofs for correction. Supported by Conselho Nacional de Desenvolvimento Cientifico e Tecnológico, CNPq (Brasil).     

Investigation on the chirality of positrons from22Na decay and their asymmetrical interactions with D-, L- and DL-alanines

Summary An investigation on the chirality of the positrons from²²Na and on their asymmetrical interactions with D-, L-, and DL-alanines was carried out. By using nuclear gamma-spectroscopy, the asymmetrical interaction was proved to be induced with a distinguishably asymmetrical effect.

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Riassunto è stata studiata l'interazione di positroni polarizzati con aminoacidi, D- L- e DL-alanine. Mediante misure di spettrometria nucleare gamma, si dimostra che l'interazione è asimmetrica e l'entità di tale effetto asimmetrico viene quantificata.

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Резюме Исследуются киральнсоть позитронов из распада²²Na и их асимметричные взаимодействия с D-, L- и DL-аланинами. Используя ядерную гаммаспектроскопию, доказывается, что асимметричное взаимодействие индуцирует асимметричный зффект.

     

ISO spectroscopy: the study of active galaxies

Summary Infrared spectroscopy can greatly help in the understanding of the active galaxies phenomena, having the advantage over optical and UV spectroscopy of penetrating those nuclei heavily obscured by absorbing dust. The standard photoionization code CLOUDY by Ferland has been used to predict the intensities of the infrared ionic fine-structure lines. Examples of line ratio diagrams are presented which constrain the two main free parameters of the models (gas density and ionization parameter), and separate line emission in the different regions of active galaxies (Seyfert and LINER type nuclei, coronal emission region, starbursts). Moreover, some line ratio diagrams can disentangle emission-line components from shock excited and photodissociated gas. Finally we show that the observations of these infrared lines will be possible in the near future with the ISO (Infrared Space Observatory) spectrometers. Paper presented at the V Cosmic Physics National Conference, S. Miniato, November 27–30, 1990.     

Energy balance of a climatized building: Comparison between simulation and experiment

Summary The heating energy required for the winter climatization of a small apartment has been measured; it results in good agreement with the figures obtained by a recently reported simulation procedure. The comparison with the usually adopted calculation code, which was taken as basis from the Italian standards, is discussed.

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Riassunto è stata misurata l'energia necessaria a garantire, nel periodo invernale, il mantenimento di una data temperatura all'interno di un piccolo appartamento; si è confrontato il risultato cosí ottenuto con quello previsto mediante un programma di simulatzione recentemente descritto. Si discute il confronto tra questi risultati e le previsioni delle procedure di calcolo usualmente adottate, su cui si basa, ad esempio, la normativa italiana per questo settore.

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Резюме Измеряется величина тепловой энергии, необходимой в зимний период для небольшой квартиры. Результаты хорошо согласуются с данными, полученными недавно с помощяю программы моделирования. Проводится сравнение полученных результатов с предсказаниями обычно применяемых вычислений, которые базируются на Итальянских стандартах.

     

Solution of the unanimity rule on exponential, uniform and scalefree networks: A simple model for biodiversity collapse in foodwebs

We solve the Unanimity Rule on networks with exponential, uniform and scalefree degree distributions. In particular we arrive at equations relating the asymptotic number of nodes in one of two states to the initial fraction of nodes in this state. The solutions for exponential and uniform networks are exact, the analytical approximation for the scalefree case is in perfect agreement with simulation results. We use these solutions to provide a theoretical understanding for biodiversity loss in experimental data of foodwebs, which is available for the three network types discussed. The model allows in principle to estimate the critical value of species that have to be removed from the system to induce a complete diversity collapse.     

Mössbauer and ERS evidence of hemocromes in neoplastic pathologies

Summary Red blood cells collected from patients with leukaemia and breast cancer have been investigated with M?ssbauer spectroscopy. A component not usually present in red cells has been analysed. The M?ssbauer parameters, also supported by electron spin resonance measurements, suggest that they can be assigned to a hemocrome. This work was supported by Ministero Pubblica Istruzione and Italian National Research Council.     

Applications of laser for ceramic alloying on metallic surfaces

Summary Ceramic and metallic materials were alloyed and cladded on a C40 steel by means of a CO₂ laser heat source. The main objectives of the research were to obtain a surface modification of the C40 steel in order to increase its wear resistance and to develop a repeatable coating process of potential industrial application. In the following sections, the laser coating process (including experimental equipment and working parameters) and the most important metallurgical results are described.     

Statistical mechanics of money: how saving propensity affects its distribution

We consider a simple model of a closed economic system where the total money is conserved and the number of economic agents is fixed. Analogous to statistical systems in equilibrium, money and the average money per economic agent are equivalent to energy and temperature, respectively. We investigate the effect of the saving propensity of the agents on the stationary or equilibrium probability distribution of money. When the agents do not save, the equilibrium money distribution becomes the usual Gibb's distribution, characteristic of non-interacting agents. However with saving, even for individual self-interest, the dynamics becomes cooperative and the resulting asymmetric Gaussian-like stationary distribution acquires global ordering properties. Intriguing singularities are observed in the stationary money distribution in the market, as functions of the marginal saving propensity of the agents. Received 2 May 2000     

Effect of electron correlation on positronium formation in positron-helium scattering

A three-parameter correlated wave function for the helium ground state is used to study the scattering reaction , where Ps stands for positronium atom. An exact analytical expression is constructed for the first Born scattering amplitude for Ps formation from helium. Based on this numerical results are presented for both differential and total cross-sections. It is demonstrated that the inner electronic correlation of the target atom plays a crucial role in explaining the discrepency between theory and experiment. Received: 9 April 1998 / Revised: 29 September 1998 / Accepted: 19 October 1998     

Quantum heat engines, the second law and Maxwell's daemon

We introduce a class of quantum heat engines which consists of two-energy-eigenstate systems, the simplest of quantum mechanical systems, undergoing quantum adiabatic processes and energy exchanges with heat baths, respectively, at different stages of a cycle. Armed with this class of heat engines and some interpretation of heat transferred and work performed at the quantum level, we are able to clarify some important aspects of the second law of thermodynamics. In particular, it is not sufficient to have the heat source hotter than the sink, but there must be a minimum temperature difference between the hotter source and the cooler sink before any work can be extracted through the engines. The size of this minimum temperature difference is dictated by that of the energy gaps of the quantum engines involved. Our new quantum heat engines also offer a practical way, as an alternative to Szilard's engine, to physically realise Maxwell's daemon. Inspired and motivated by the Rabi oscillations, we further introduce some modifications to the quantum heat engines with single-mode cavities in order to, while respecting the second law, extract more work from the heat baths than is otherwise possible in thermal equilibria. Some of the results above are also generalisable to quantum heat engines of an infinite number of energy levels including 1-D simple harmonic oscillators and 1-D infinite square wells, or even special cases of continuous spectra.     

Statistical mechanics of money

In a closed economic system, money is conserved. Thus, by analogy with energy, the equilibrium probability distribution of money must follow the exponential Boltzmann-Gibbs law characterized by an effective temperature equal to the average amount of money per economic agent. We demonstrate how the Boltzmann-Gibbs distribution emerges in computer simulations of economic models. Then we consider a thermal machine, in which the difference of temperatures allows one to extract a monetary profit. We also discuss the role of debt, and models with broken time-reversal symmetry for which the Boltzmann-Gibbs law does not hold. The instantaneous distribution of money among the agents of a system should not be confused with the distribution of wealth. The latter also includes material wealth, which is not conserved, and thus may have a different (e.g. power-law) distribution. Received 22 June 2000     

The relativistic statistical theory and Kaniadakis entropy: an approach through a molecular chaos hypothesis

We have investigated the proof of the H theorem within a manifestly covariant approach by considering the relativistic statistical theory developed in [G. Kaniadakis, Phys. Rev. E 66, 056125 (2002); G. Kaniadakis, Phys. Rev. E 72, 036108 (2005)]. As it happens in the nonrelativistic limit, the molecular chaos hypothesis is slightly extended within the Kaniadakis formalism. It is shown that the collisional equilibrium states (null entropy source term) are described by a κ power law generalization of the exponential Juttner distribution, e.g., , with θ=α(x)+β_μp^μ, where α(x) is a scalar, β_μ is a four-vector, and p^μ is the four-momentum. As a simple example, we calculate the relativistic κ power law for a dilute charged gas under the action of an electromagnetic field F^μν. All standard results are readly recovered in the particular limit κ→0.