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A Comparison Between the LCA of a PEMFC and an MCFC Systems for the Production of Electric Energy, and Traditional Energy Conversion Systems
No full textThis paper investigates the environmental impact of electric energy generation by using a PEMFC and an MCFC system. Fuel cells are considered to be ultra-clean energy conversion devices, since pollutants emissions during operation have a very low concentration, compared to those of traditional energy systems. In order to understand the real environmental impact of fuel cells, this is not enough and it is necessary to study their "cradle-to- grave" life, starting from the construction phase, to the operational life and eventually to its disposal. In fact, it is not really correct to say that fuel cells are almost zero-emission systems, because they produce not-negligible emissions during manufacturing and to produce hydrogen. The method used in this paper is the Life Cycle Assessment (LCA), which has been calculated with the software SimaPro 5.0. The functional unit chosen in this study is the production of 1 kWh of electric energy by a PEMFC and an MCFC. Thanks to this approach, the critical process related to the production of energy by the previous fuel cell systems, (i.e. the production of hydrogen by natural gas steam reforming), has been determined. After a separated LCA of the PEMFC and the MCFC, a comparison was made between the two systems, considering the environmental impact of electric energy generation. Finally, the production of electric energy by a PEMFC and an MCFC systems is compared to that by conventional energy conversion system
A Comparison Between Life Cycle Assessment Of An MCFC System, An LFG – MCFC System, And Traditional Energy Conversion Systems
No full textThe present work aims at evaluating the environmental impact caused by fuel cell systems in the production of electric energy. The very low pollutant emission levels in fuel cells makes them an attractive alternative in ultra clean energy conversion systems. Actually, to truly understand the environmental impact related to fuel cells, it is necessary to study their “cradle-to-grave” life, from the construction phase, during the conversion of primary fuel into hydrogen, to its disposal. The tool used in this analysis is the Life Cycle Assessment approach; in particular the environmental impact of a fuel cell system has been simulated through the software SimaPro 5.0. Thanks to this approach, once the critical process regarding the production of energy by fuel cell system, (i.e. the production of hydrogen by natural gas steam reforming), has been determined, an analysis of the use of landfill gas as a renewable source to produce hydrogen was done. Finally, the production of electric energy by fuel cell systems was compared to that by some conventional energy conversion systems. A second comparison was done between the Molten Carbonate Fuel Cell (MCFC) fuelled by landfill gas and natural gas
Life cycle assessment of a reflective foil material and comparison with other solutions for thermal insulation of buildings
No full textIn the last twenty years, the exploitation of non-renewable resources and the effects of their applications on environment and human health were considered central topics in political and scientific debate on European and worldwide scale. This kind of resources have been used in different sectors, as energy systems, technological research, but also in private/public buildings and production of consumer goods, involving significantly domestic and ordinary life of every human being. Studies about the effect of this exploitation carried out discouraging results, in terms of climate changes and energy sustenance; this determined a progressive approach process to a new concept of development, able to couple the qualitative standard of modern life with the respect of planet and its inhabitants. Starting from this reflection, scientific community moved towards research on alternative resources and developed a new way to conceive planning process and technical innovations, in order to exploit renewable energies and recycled materials, promote energy savings and reduce environmental pollution. In this context the present paper aims at evaluating benefits relating to different solutions of thermal insulation in building envelope. In fact a high grade of insulation ensures better comfort conditions in inner spaces, reducing energy consumptions due to heating and cooling conditioning. The paper presents the results of a detailed Life Cycle Assessment (LCA) of the reflective foil ISOLIVING, conceived and produced by an Italian company. The Life Cycle Assessment methodology allows to consider all stages of the life cycle, from the extraction of raw materials to the product’s disposal, in an optics “from cradle to grave.” In particular, the study takes into account the production phase of the reflective foil ISOLIVING, the installation phase, the transport of all components to the production site and also the end of life scenario of the material. The possibility to collect many detailed information about the production phase adds value to the study. The analysis is carried out according to UNI EN ISO 14040 and UNI EN ISO 14044, which regulate the LCA procedure. The LCA modeling was performed using SimaPro software application. The results of the analysis allow to make an important comparison concerning the environmental performances, between the reflective foil ISOLIVING and other types of insulating materials
Studio di fattibilità tecnico economico di un impianto di condizionamento a pompa di calore geotermico e confronto con modello di calcolo attraverso il software di simulazione TRNSYS
No full textFeasibility study to realize an anaerobc digester fed with vegetables matrices in central Italy
Full text linkIn the present paper we have analysed the possibility to realize an anaerobic digester in a bio-Energy Park located in Città della Pieve, a small town in Central Italy. The use of anaerobic digesters is quite common in Europe for reducing the environmental impact of manure in a co-digestion procedure with vegetables materials. In addition, for several areas of Central Italy there is the need to find alternative productions to improve farmer's incomes, as traditional cropping systems are loosing convenience. An interesting alternative seems to be cultivation of energy crops because of the favourable conditions of the electric energy market. We are suggesting a low input cropping system to be implemented in areas where low input food/feed crops are no more profitable. In particular our case-study is an example based on the use of a forage legume, alfalfa (Medicago sativa L.), together with other crops, like sorghum, to realize small-size bio-digesters plants. Alfalfa: is a highly sustainable crop as it is able to fix nitrogen and therefore it does not require this fertilization with the consequence of avoiding underground water pollution. Moreover alfalfa residual products are nitrogen rich thus improving soil structure and fertility more than popular graminaceous energy crops such as corn. Beside, alfalfa mostly does not need irrigation in the typical Central Italy environment, all these traits make it one of the species with the lowest energy needs for growing. The aims of this feasibility study are: i) optimization of plant materials feeding the bio-digester, ii) typology of bio-digester, iii) size of bio-digester in relation with land availability for growing energetic cultures, iv) the utilization of bio-gas produced by bio-digester plant to produce electric and thermal energy using cogeneration engines, vi) disposal of waste-water produced according to regional and national laws. The final aim of this study is to verify the possibility to develop an alternative economical use of marginal soils in relatively dry areas of Central Italy that would be replicable in other European areas with a similar climatic situation
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
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