1,721,274 research outputs found
Inhabiting simultaneous lives: analysing process of reversibilization of mobility practices in Italy
No full textThis chapter aims to study some emerging mobility practices in Italy and the consequences they have had on the use and configuration of spaces. A growing number of people live their lives across a vast space consisting of work, family, and friendship networks, and are travelling longer distances, in shorter periods of time, than ever before. This paper addresses the hypothesis that those transformations are modifying the relationships between people and territory, allowing people to live simultaneous lives, and increasing relationships within multiple territories. I will use biographies of highly mobile people as a tool to describe this process. Describing and analysing their mobility behaviours allow to show how people try to “catch ubiquity and simultaneity” (Ascher in Cahiers internationaux de sociologie. PUF, Paris, p. 53, 2005) in their everyday lives, highlighting how far those practices have transformed the relation between people and territory and the spaces of mobility. The first results presented here consist on the identification of three territorial profiles based on the geography of personal relationships and revealing how this geography interacts with a general transformation of everyday urban rhythm in the construction of simultaneous lives
Low-order CFD simulation of a ducted wind turbine in realistic hilly environments
No full textIt is common to place wind turbines over smooth hills to exploit the speed up effect resulting from the hill slope. On the other hand, another way to increase the power output of small turbines consists in the adoption of a diffuser. Therefore, it would be interesting to investigate the union of these two techniques, however, since the computing resources required by traditional fully 3D CFD simulations would be prohibitive, other less expensive approaches are needed. Using CFD, the performance of a 50kW wind turbine positioned on the top of a hill and equipped with a symmetrical convergent-divergent diffuser was predicted. To save computation time, the fluid dynamic interaction with the rotating blades is mimicked by adopting the momentum source low-order approach, that in our case is based on the Virtual Blade Model (VBM). The diffuser behavior has been analyzed for three hill profiles characterized by the same height but different shapes that are representative of realistic environments. The results show that the diffuser not only allows a general massive increase in power but also that its use is especially advantageous, compared to the bare turbine, in cases of flows made yawed by the slope of the hill or the geometry of the cliff. This happens because the converging section of the diffuser is able to realign the skewed flows normally to the turbine rotor. © 2024 IEEE
Tidal Farms: Optimising site-specific layouts by combining analytical methods and fluid dynamic simulations
No full textTidal energy is a promising source of renewable energy that countries should consider including in their energy mix. This paper presents a simple and efficient methodology for the analysis of tidal farms. Specifically, we have used a Mixed Integer Quadratic Programming (MIQP) model to optimise the farm layout using a discrete approach. The farm is made up of HATTs (Horizontal Axis Tidal Turbines). We compare the results obtained with a conventional discretisation based on literature assumptions to a site-specific adapted discretisation. The latter is obtained through 3D fluid dynamic simulations performed in series using the SHYFEM software, which is based on the Shallow Water equations. SHYFEM is an open-source marine circulation code and has been equipped with turbines parameterized by momentum source terms: this allows to reduce the computational effort while maintaining the accuracy of the turbine behaviour predictions thanks to the Blade-Element\Momentum (BEM) approach. In addition, the BEM approach allows interactions between devices to be captured, making the code well suited for farm applications. The results show a +6.7% increase in power production achieved by using the site-adapted discretisation for the optimisation process. © 2024 IEEE
Endocannabinoid signaling and epidermal differentiation
No full textEndocannabinoids represent a class of endogenous lipid mediators, that are involved in various biological processes, both centrally and peripherally. The prototype member of this group of compounds, anandamide, regulates cell growth, differentiation and death; this holds true also in the skin, that is the largest organ of the body constantly exposed to physical, chemical, bacterial and fungal challenges. The epidermis is a keratinized multistratified epithelium that functions as a barrier to protect the organism from dehydration, mechanical trauma, and microbial insults, and epidermal differentiation represents one of the best characterized mechanisms of cell specialization. In this review, we shall summarize current knowledge about the main members of the so-called "endocannabinoid system (ECS)", in order to put in a better perspective the manifold roles that they play in skin pathophysiology. In particular, we shall discuss some aspects of the molecular regulation by endocannabinoids of proliferation and terminal differentiation ("cornification") of mammalian epidermis, showing that ECS is finely regulated by, and can interfere with, the differentiation program. In addition, we shall review evidence demonstrating that disruption of this fine regulation might cause different skin diseases, such as acne, seborrhoea, allergic dermatitis, itch, psoriasis and hair follicle regression (catagen), making of ECS an attractive target for therapeutic intervention
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
A generalization of the orthogonal regression technique for life cycle inventory
No full textLife cycle assessment (LCA) is a method used to quantify the environmental impacts of a product, process, or service across its whole life cycle. One of the problems occurring when the system at hand involves processes delivering more than one valuable output is the apportionment of resource consumption and environmental burdens in the correct proportion amongst the products. The mathematical formulation of the problem is represented by the solution of an over-determined system of linear equations. The paper describes the application of an iterative algorithm for the implementation of least square regression to solve this over-determined system directly in its rectangular form. The applied algorithm dynamically passes from an Ordinary Least Squares (OLS) problem to the regression problems known as Total Least Squares (TLS) and Data Least Squares (DLS). The obtained results suggest further investigations. In particular, the so called constrained least squares method is identifed as an interesting development of the methodology
A Bladder Stone 28 Years After Burch Colposuspension
No full textAn 86-year-old lady was referred for a 3-cm bladder stone 28 years after Burch colposuspension. Cystoscopy showed a stone over a nonabsorbable suture, eroding from the right anterolateral bladder wall. The patient underwent a transurethral holmium laser lithotripsy and thulium laser removal of the eroded bladder wall. A high index of suspicion of suture erosion should always be present in case of de novo symptoms in women who underwent colposuspension, even in the long-term period
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