1,721,018 research outputs found
Senegalese Migrtants in Italy: Beyond the Assimilation/Transnationalism Divide
No full textThe article is subdivided into three parts. The first
provides readers with an overview of contemporary Senegalese “culture of migration” and explores how it translates into the Italian experience of West African immigration. In the second part, drawing on our and other colleagues’ empirical work, we discuss the diversification of Senegalese strategies to enter Italian public space and to strengthen transnational connections with the context of origin. In the final part, we take into account the experiences of the “second generation” and the engagement with projects facilitating the return of the elderly. We conclude by urging researchers to go beyond the assimilation versus transnationalism dichotomy to enhance our understanding of West African transnational migration into Southern Europe
Imagining greener pastures? Shifting perceptions of Europe and mobility in Senegalese society
Full text linkOver the past few years, the European crisis and the EU enforcement and
externalization of border control have shaped how Europe and migration are
perceived in Africa. Areas of out-migration, such as Senegal, are not only experiencing
changes in mobility patterns but also a social diversification in the
way in which «Europe» is viewed and talked about. While several studies have
underlined transformations occurring over time amongst Senegalese migrants
in Europe, less attention has been paid to analysing their migration decisionmaking
practices through a diachronic perspective. Drawing on ethnographic
research carried out in Senegal and Italy between the mid-1990s and the first
decade of the 2000s, this paper aims to explore how imaginaries and narratives
of migration and destination countries are formed. Taking into account
the interconnections of global and local dynamics, the paper discusses shifting
perceptions of Europe and mobility in Senegal, highlighting how imaginaries
of «elsewhere» are ambivalent and historically grounde
Experimental investigation on the acoustic behaviour of a small tractor cabin
No full textThe quality and acoustic comfort of agricultural tractor cabins are nowadays highly valued by the market. For this reason, tractor manufacturers are more and more interested in improving the behaviour of their vehicles also from an acoustics point of view. A tractor cabin is an unusual environment, with a space mainly developed in the vertical direction, characterised by a relatively small volume of air and surrounded by windows, which can be considered as large reflecting surfaces. This feature causes strong standing waves that, when coupled with an acoustic source, can generate high sound pressure levels resulting in reduced comfort for the driver. This paper investigates, through measurements and simulations, the low frequency acoustic behaviour of a small tractor cabin. The technique adopted for the measurements is based on a multiple transfer function analysis. Measured frequency response functions are processed for the cabin's acoustic mode parameters. The results of the experiments are validated through a finite-element model allowing the reconstruction of the sound pressure contours inside the volume and further analyses
Development of an Exhaust System for Agricultural Tractors
No full textThe main sources of sound emitted by vehicles are the engine and the rolling noise produced by the tires. In case agricultural tractors are considered, the engine and the transmission are responsible of the main emissions since they often work in the fields on soft ground at low speeds. This work focuses on the combined acoustic and mechanical development of a new exhaust system for an existing agricultural tractor, with the aim of providing a product with improved acoustic performances and a neater design. The host vehicle is equipped with a 300 hp diesel engine which can be particularly noisy at low rpm, with a further constraint being the “under the bonnet” available volume to fit the system into. The existing exhaust system is the baseline for the engineering process. The acoustic design is carried out by a 1D simulation software based on an electro-acoustic analogy, while the design modelling is performed by using Solidworks® 3D CAD. After the design stage a prototype has been manufactured and tested at the MWL/KTH laboratory. The engineering process gave the product a cleaner design and allowed to identify feasible solutions ensuring increased sound attenuation performances
Dynamical and structural analysis of a Bronze Age war chariot
No full textThe introduction of two-wheel chariots, pulled by horses, was a key technological
innovation in the Bronze Age. Archaeological evidences, found in Northern Africa, Europe and
Asia, allowed identifying various chariot typologies and understanding their main features.
However, many questions about the function of single pieces and the behavior of the vehicles
are still open. In a previous work, a war chariot wheel, found in northern Italy and known as the
“Mercurago wheel”, was studied with an engineering approach. In this paper, the whole vehicle,
to which the wheel was hypothesized to belong, was studied. In particular, two chariot
typologies, differing mainly for the axle position, were analyzed. The stiffness of the various
chariot parts were characterized by means of static finite element analyses. These data were
subsequently used as input parameters in running multibody dynamics simulations. Finite
element dynamical simulations were carried out as well. The analyses results allowed
determining the crucial effect of some parts, particularly the cockpit floor, in favoring the
passenger stability in dangerous conditions, such as bumping. The effect of the axle position on
the passenger and wheel trajectory were evaluated as well
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Modelling of a 15-kW Electric Utility Vehicle and Range Assessment through Driving Cycle Analysis Based on GPS Experimental Data
No full textThe electrification of utility vehicles represents a promising solution to reduce the emissions in the urban context. Differently from traditional vehicles, they operate intermittently and generally follow routine driving cycles. In this paper, we model a 15-kW electric utility vehicle, adopting a backward-looking approach, widely used in literature to estimate the range of electric cars. The model requires a limited number of data, either supplied by the vehicle manufacturer or found in literature, as in case of the induction motor/generator efficiency and of the battery Peukert coefficient. The model can be used to assess the possibility of the vehicle to complete an assigned mission, as well as to optimize the vehicle's design and architecture. The model is validated on GPS data obtained through an experimental campaign where the electric utility vehicle was driven to depletion considering different routes, including the effect of slopes. A satisfactory correspondence with the experimental data was observed with maximum difference in the simulated average energy consumption lower than about 8%. Results of the simulations show that the range of the electric utility vehicle is about 110 km on urban flat cycle while it significantly reduces when slopes are included in portions of the routes
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