Local order in aqueous solutions of rare gases and the role of the solute concentration: a computer simulation study with a polarizable potential

Aqueous solutions of rare gases are studied by computer simulation employing a polarizable potential for both water and solutes. The use of a polarizable potential allows to study the systems from ambient to supercritical conditions for water. In particular the effects of increasing the concentration and the size of the apolar solutes are considered in an extended range of temperatures. By comparing the results at increasing temperature it appears clearly the change of behaviour from the tendency to demix at ambient conditions to a regime of complete solubility in the supercritical region. In this respect the role of the hydrogen bond network of water is evidenced.Comment: Accepted for publication in Molecular Physics 2004. 19 pages, 10 figure

The Aw-Rascle traffic model with locally constrained flow

We consider solutions of the Aw-Rascle model for traffic flow fulfilling a constraint on the flux at $x=0$. Two different kinds of solutions are proposed: at $x=0$ the first one conserves both the number of vehicles and the generalized momentum, while the second one conserves only the number of cars. We study the invariant domains for these solutions and we compare the two Riemann solvers in terms of total variation of relevant quantities. Finally we construct ad hoc finite volume numerical schemes to compute these solutions.Comment: 24 page

The parallelism between galaxy clusters and early-type galaxies: I. The light and mass profiles

We have analyzed the parallelism between the properties of galaxy clusters and early-type galaxies (ETGs) by looking at the similarity between their light profiles. We find that the equivalent luminosity profiles of all these systems in the \vfilt\ band, once normalized to the effective radius \re\ and shifted in surface brightness, can be fitted by the S\'ersic's law \Sers\ and superposed with a small scatter ($\le0.3$ mag). By grouping objects in different classes of luminosity, the average profile of each class slightly deviates from the other only in the inner and outer regions (outside $0.1\leq r/R_e\leq 3$), but the range of values of $n$ remains ample for the members of each class, indicating that objects with similar luminosity have quite different shapes. The "Illustris" simulation reproduces quite well the luminosity profiles of ETGs, with the exception of in the inner and outer regions where feedback from supernovae and active galactic nuclei, wet and dry mergers, are at work. The total mass and luminosity of galaxy clusters as well as their light profiles are not well reproduced. By exploiting simulations we have followed the variation of the effective half-light and half-mass radius of ETGs up to $z=0.8$, noting that progenitors are not necessarily smaller in size than current objects. We have also analyzed the projected dark+baryonic and dark-only mass profiles discovering that after a normalization to the half-mass radius, they can be well superposed and fitted by the S\'ersic's law.Comment: 25 pages, 19 figure

Immigrant women’s entrepreneurship: is there a development model in Italy?

The aim of this paper is to verify if there is a typical enterprise model for the development of immigrant female entrepreneurship in Italy. Based on the literature on the subject, however, it is useful to ask the following research question: “can membership in a national and international network facilitate the development of immigrant female entrepreneurship operating in Italy”? The survey was carried out by submitting a questionnaire to a sample of immigrant women entrepreneurs in the textile and clothing sector based in Italy. The choice fell on this specific economic segment because it represents the third largest sector for the number of female immigrant entrepreneurs (2.271 units) which amounts to 16% of the total number of entrepreneurs operating in the same sector. The percentage of respondents was 35%, with 795 completed questionnaires. The structure of the questionnaire reflects the need to examine the personal features of female entrepreneurs, the organizational aspects and the style of leadership, the task environment in which the enterprise works and the main possible benefits, or obstacles, they might obtain, or face. In addition to the objective of enlarging the literature regarding the management and governance of businesses run by women entrepreneurs, that is quite limited to date, this paper is a contribution to the analysis of a possible development model of women entrepreneurs

The transformation of Spirals into S0 galaxies in the cluster environment

We discuss the observational evidences of the morphological transformation of Spirals into S0 galaxies in the cluster environment exploiting two big databases of galaxy clusters: WINGS (0.04 < z < 0.07) and EDisCS (0.4 < z < 0.8). The most important results are: 1) the average number of S0 galaxies in clusters is almost a factor of $\sim 3 - 4$ larger today than at redshift $z \sim 1$; 2) the fraction of S0's to Spirals increases on average by a factor $\sim$ 2 every Gyr; 3) the average rate of transformation for Spirals (not considering the infall of new galaxies from the cosmic web) is: $\sim$ 5 Sp into S0's per Gyr and $\sim$ 2 Sp into E's per Gyr; 4) there are evidences that the interstellar gas of Spirals is stripped by an hot intergalactic medium; 5) there are also indirect hints that major/minor merging events have played a role in the transformation of Spiral galaxies. In particular, we show that: 1) the ratio between the number of S0's and Spirals (NS0/NSp) in the WINGS clusters is correlated with their X-ray luminosity $L_X$ ; 2) that the brightest and massive S0's are always close to the cluster center; 3) that the mean Sersic index of S0's is always larger than that of Spirals (and lower than E's) for galaxy stellar masses above $10^9.5$ Msun; 4) that the number of E's in clusters cannot be constant; 5) that the largest difference between the mean mass of S0's and E's with respect to Spirals is observed in clusters with low velocity dispersion. Finally, by comparing the properties of the various morphological types for galaxies in clusters and in the field, we find that the most significant effect of the environment is the stripping of the outer galaxy regions, resulting in a systematic difference in effective radius and Sersic index.Comment: 38 pages, 20 figure

Development perspectives of relational capital in women-led firms

The purpose of the paper is to analyze the strategic role of relational capital for the achievement of sustainable development in Italian micro and small tourist businesses run by women. The paper focuses on the tourism enterprises because that sector constitute 10 % of the Italian GDP. The qualitative research methodology that has been used is that of case study research (Yin, 2009). Such process consisted in a survey with an ad-hoc questionnaire developed to analyze the distinctive features of a woman-owned micro and small enterprise that can be identified with the CAOS model (Paoloni, 2011). The paper applies the CAOS model examining the personal characteristics of the female entrepreneur (C); the environment in which the in SMEs operates (A); organizational and managerial aspects (O); and the motivations for manage a new business (S). This model is able to link these factors and classify different types of connections, it is possible to identify the kind of existing relations. The paper intends to help address a gap in the existing literature regarding the management and governance of tourism firms run by women. The paper can contribute to improving the competitiveness Italian enterprises studying how women entrepreneurs manage her business

Model assisted approaches to complex survey sampling from finite populations using Bayesian Networks

A class of estimators based on the dependency structure of a multivariate variable of interest and the survey design is defined. The dependency structure is the one described by the Bayesian networks. This class allows ratio type estimators as a subclass identified by a particular dependency structure. It will be shown by a Monte Carlo simulation how the adoption of the estimator corresponding to the population structure is more efficient than the others. It will also be underlined how this class adapts to the problem of integration of information from two surveys through probability updating system of the Bayesian networks.Graphical models, probability update, survey design

Paradata and Bayesian networks: a tool for monitoring and troubleshooting the data production process

The problem of monitoring and managing the data production process by means of process flow indicators is presented in a decision theory framework. Here it is shown how to represent and solve the decision problem via influence diagrams, i.e. Bayesian network supporting decisions. An illustrative example is provided.Expected utility, graphical models, probability update,

Empowering Rural Citizen Journalism Via Web 2.0 Technologies

Once acquainted with the modern information and communication tools made available with the advent of the Internet, five Brazilian rural communities participating in a pilot project to develop a self-sustaining telecenter model, engaged in citizen journalism using inexpensive digital video cameras. Community members used Web 2.0 collaborative tools to post short videos on the telecenter portal. The 95 video blogs published between September 2006 and May 2008 recorded various aspects of community life,including religious celebrations,oral history arts and crafts traditions,folklore,and envirnmental concerns. This study evaluates the impact of video blogging in these communities