Simple way of introducing the optical theorem for non-spherical particles

In case of non-spherical particles, by considering the elements of the amplitude matrix J, the form of the optical theorem for the cross-section is obtained in a general way which is faster than how is shown in usual textbooks. It takes into account polarization of incident radiation. Polarized radiation scattered in the forward direction by a thin layer of the medium is added to the incident plane wave. Interference leads to the optical theorem. Dichroism can be avoided by considering two modes of polarization, which can be defined from the elements of the J matrix. In this paper: upper-case bold symbols denote vectors or matrices; lower-case bold symbols denote unit vectors

Multiple scattering measurements in laboratory and foggy atmosphere

Multiple scattering affects propagation of light beams in turbid media. Backscattering or forward scattering based measurements of atmospheric parameters are influenced by this effect. Although largely studied theoretically, the effect needs measurements in control of situations due to the large variety of situations of practical importance. The results of laboratory measurements pertaining to the transmission of a collimated light beam (Helium-Neon souce, 10 mW) through suspensions of latex spheres in water are presented and a comparison was made with the predictions of calculation in a foggy atmosphere will also be presented

Nuove e vecchie periferie popolari. Una ricerca etnografica in due aree di edilizia residenziale pubblica

Public housing suburbs are often an important element in reshaping the social and spatial geography of the city. This article is based on the study of two areas of public housing in Livorno: an historical and a more recent one. In Livorno social housing has led the urban development and the concentration of homogeneous groups of inhabitants. We report some results of an ethnographic research reconstructing how the spatial separation interacts with social relations of inhabitants of physically and socially peripheral areas. This kind of so called weak suburbs, despite possible trajectories of change, present complex patterns of problems. Attention has also been paid to the way concepts of neighborhood, suburb and community are merged in different combinations in the two areas, highlighting the «neighborhood effect», segregation, and encapsulation forms

Lungo il cammino delle merci. Un’indagine sulle condizioni di lavoro nel settore della logistica

The logistic sector in Italy has been subject to a wave of strikes and trade union actions in recent years, particularly in the Pianura Padana area.  Although, the protests have been documented, the analysis of working conditions are rare. Not enough consideration has been given, furthermore, to the concept of “labour exploitation” in this specific sector. In this paper, we will present an empirical research carried out in the area of Florence, through in–depth interviews with three kinds of workers:  truckers, couriers and warehouse workers. The research analyses the working conditions of the interviewees and demonstrates how a model of labour exploitation has emerged in this sector, transversal to the three compartments analyse

A note on the testing of a Monte Carlo procedure for evaluating multiple-scattering effects on lidar returns from clouds

A Monte Carlo code for calculating lidar returns from clouds in regime of multiple scattering is tested, by comparing its results pertaining to second order of scattering with those obtained by using an analytic formula developed in a completely different way. For obtaining second order of scattering all the essential parts of the Monte Carlo code are employed. Thus the very good agreement between the results of the two procedures, which have been found in a series of different situations of scattering media, has to be considered as a positive test of the Monte Carlo code reliability

Nuove e vecchie periferie popolari. Una ricerca etnografica in due aree di edilizia residenziale pubblica

Public housing suburbs are often an important element in reshaping the social and spatial geography of the city. This article is based on the study of two areas of public housing in Livorno: an historical and a more recent one. In Livorno social housing has led the urban development and the concentration of homogeneous groups of inhabitants. We report some results of an ethnographic research reconstructing how the spatial separation interacts with social relations of inhabitants of physically and socially peripheral areas. This kind of so called weak suburbs, despite possible trajectories of change, present complex patterns of problems. Attention has also been paid to the way concepts of neighborhood, suburb and community are merged in different combinations in the two areas, highlighting the «neighborhood effect», segregation, and encapsulation forms