1,720,977 research outputs found
Investigation on a bio-composite material as acoustic absorber and thermal insulation
Get PDFIn order to limit the anthropic emissions of CO2, research is currently investigating new materials for the building sector. The main purpose is the reduction in the embodied energy consumption, especially in the residential sector, and consequently the limitation of the direct and indirect utilization of fossil fuels, for the indoor heating, cooling, and ventilation services. Indeed, the residential sector is affected by a high energy demand, thus the choice of improved materials is fundamental to improve the sustainability. All phases: construction, building life, and dismantling are impacting in terms of resource and energy consumption, both associated with the emissions of pollutants in the atmosphere. The aim of this experimental research is to study the thermal insulation and the acoustic absorption of a material composed by natural lime, water, and shives from sativa hemp, a variety of hemp usable for industrial applications. In order to assess the main characteristics of this material, some specimens have been made according to required shapes and sizes to test them in specific machines. The results obtained from the tests are compared with the values of similar lime-based materials already available on the market. The comparison shows how, in certain aspects, the lime and hemp shives materials represent a concrete alternative to conventional materials. This completely natural material would like to achieve thermal and acoustic comfort in indoor environments
A Review on Wind Power Simulation Models
Get PDFWind energy has emerged as a prominent source of renewable energy due to its sustainability and low environmental impact. Efficient utilization of wind resources requires accurate prediction and modeling of wind behavior. This paper presents an overview of the most commonly adopted mathematical models employed in simulating the electrical power production of renewable wind generators. In addition, some indication of the best application is provided for each category of simulation model
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Grid Stability Improvement Using Synthetic Inertia by Battery Energy Storage Systems in Small Islands
No full textIn this paper, the synthetic inertia need of the small island of Pantelleria in the Mediterranean Sea is assessed. Firstly, the optimal renewable energy mix able to minimize the Levelized Cost of Energy for the generation system of the island is evaluated, considering the yearly load demand and the characteristics of the local natural resources. The optimal energy mix introduces in the island a quota of power generation with static power converters interfaced to the grid that could jeopardize the security of the system if not suitably controlled. Therefore, the inherent inertial response of the diesel generators of the system is calculated hour by hour for each month of one year, considering the new schedule of the generators for various cases characterized by different percentages of production from the optimum renewable energy mix. Finally, the rated power and capacity of a battery energy storage system is calculated in order to compensate the reduction of the inertial response in the power system thanks to a suitable synthetic inertia control. The calculation is done by considering the maximum allowed frequency nadir in case of a disturbance. For each scenario, the maximum disturbance is also assessed with and without synthetic inertia. The results are compared with those obtained in a previous study on the same island where batteries were used for different purposes
Preliminary EER Analysis for Sizing HVAC Rooftop Units
Get PDFIn daily life, a lot of time is spent inside the confined environments, for example: children in school spend between 6 and 8 hours a day, in the work environment 8 hours a day, in restaurants a few hours, and finally the rest of the time is spent at home. The environment, given the hours spent within it, must provide quality and comfort to the occupants. Indoor environmental quality is referred to as “Indoor Environmental Quality (IEQ)” and is defined as the set of environmental conditions within buildings that can affect the well-being, health, and productivity of the people residing in the
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Evaluation of the Potential Environmental Impacts from an Offshore Wind Energy Farm in the Mediterranean Sea
Get PDFFollowing the desire to reduce the energy dependence from fossil fuels, plants supplied by renewable energy sources are spreading worldwide. Among the current technologies, a new frontier is represented by offshore wind energy, thanks to the possibility to increase the capacity factor, and consequently the income from the investment, and at the same time overcome the problem of finding places without environmental constrictions. In this context, some new projects are currently under investigation in Italy, proposing the installation of floating wind farms, due to the deep seabed. For this reason, this manuscript evaluates the potential impacts related to the construction of a new big offshore wind farm, located in the Mediterranean Sea. The LCA methodology is applied to the case study
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