1,720,984 research outputs found
Geothermal Potential Evaluation for Northern Chile and Suggestions for New Energy Plans
Full text linkChile is a country rich in natural resources, and it is the world’s largest producer and exporter of copper. Mining is the main industry and is an essential part of the Chilean economy, but the country has limited indigenous fossil fuels—over 90% of the country’s fossil fuels must be imported. The electricity market in Chile comprises two main independent systems: the Northern Interconnected Power Grid (SING) and the Central Interconnected Power Grid (SIC). Currently, the primary Chilean energy source is imported fossil fuels, whereas hydropower represents the main indigenous source. Other renewables such as wind, solar, biomass and geothermics are as yet poorly developed. Specifically, geothermal energy has not been exploited in Chile, but among all renewables it has the greatest potential. The transition from thermal power plants to renewable energy power plants is an important target for the Chilean Government in order to reduce dependence on imported fossil fuels. In this framework, the proposed study presents an evaluation of the geothermal potential for northern Chile in terms of power generation. The El Tatio, Surire, Puchuldiza, Orriputunco-Olca and Apacheta geothermal fields are considered for the analysis. The estimated electrical power is approximately 1300 MWe, and the energy supply is 10,200 GWh/year. This means that more than 30% of the SING energy could be provided from geothermal energy, reducing the dependence on imported fossil fuels, saving 8 Mton/year of CO2 and supplying the mining industry, which is Chile’s primary energy user
Enrichment in Heavy Metal (HM) and Rare Earth Element (REE) in Fluvial Placer Deposits: Case Study of Zambesi River (Mozambique)
No full textMozambique has a huge mineral potential that is largely untapped. Tantalum-niobium, other rare metals, gold and semiprecious stones are abundant. Deposits of heavy mineral sands and a wide range of industrial minerals comprise a few of the mineral wealth in Mozambique that are under development. One of the most interesting zones of Mozambique is definitely the Zambezi River, where the placers deposits are rich in HM and REE. For this reason, ENEA in 2013 has performed an extensive multidisciplinary research along the Lower Zambezi, in cooperation with the Minas Rio Bravo Company (Mozambique). The aim of the research is to
verify the REE and heavy metal abundances by measuring geochemical and mineralogical characteristics of the sediments from the bottom of the Zambezi, in the area between Tete and Tambara cities. The analyses were carried out at the Department of Physics and Earth Science of Ferrara University by X-ray fluorescence analysis, X-ray diffraction analysis and pycnometer method. The result of XRD shows that the main minerals are quartz and feldspar. Unfortunately, the XRD peak of the main mineral phases covers up the others. However, chemical analyses reveal high presence of Iron and Titanium oxides and trace elements, as Cesium, Chromium and Lanthanum, suitable for industrial mining purposes. Furthermore, the data of density are comparable to the detecting phases found with XRD. The goal of the survey is to determinate the economic value of the Zambezi sediments for industrial minerals sector. Secondly, the results are important to improve the geochemical and mineralogical knowledge of this zone.Published216-2211TR. Studi per le GeorisorseN/A or not JC
The Unconventional Geothermal Resources: Features and Current Uses
No full textThe geotliernml systems can be distinguished as conventional and unconventional resources. The conventional geothermal systems are composed o essential elements, such as a heat source, a reservoi with a geotherrrial fluid and a caprock. The heat source can be a magmatic chamber or volcanic bodies which are both generally located in areas north crustal thinning and mantle uprising phenomena. In the last two decades, non-conventional geothermal systems, such as enhanced geothermal systems, magma systems with supercritical fluids and geopressured systems have been also explored. This chapter provides a description of the above mentioned unconventional geothermal systems. The chapter is divided in three main paragraphs, starting from the enhanced geothermal systems to conclude with the geopressures systems. Geological features, case studies and current uses of each one are highlighted.rth the resumed systems. The final part of the chapter has been dedicated to a special case study relative to production of geothermal energy with co-produced resources.Published1TR. Studi per le Georisors
The Unconventional Geothermal Resources: Features and Current Uses
No full textThe geotliernml systems can be distinguished as conventional and unconventional resources. The conventional geothermal systems are composed o essential elements, such as a heat source, a reservoi with a geotherrrial fluid and a caprock. The heat source can be a magmatic chamber or volcanic bodies which are both generally located in areas north crustal thinning and mantle uprising phenomena. In the last two decades, non-conventional geothermal systems, such as enhanced geothermal systems, magma systems with supercritical fluids and geopressured systems have been also explored. This chapter provides a description of the above mentioned unconventional geothermal systems. The chapter is divided in three main paragraphs, starting from the enhanced geothermal systems to conclude with the geopressures systems. Geological features, case studies and current uses of each one are highlighted.rth the resumed systems. The final part of the chapter has been dedicated to a special case study relative to production of geothermal energy with co-produced resources.Published1TR. Studi per le Georisors
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
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