1,720,963 research outputs found
Thermodynamic modelling and simulation of geothermal power plants: case studies and environmental impact
Full text linkThe emissions associated with Geothermal power plant (GTPP) due to geothermal fluids represents a compelling challenge addressed in the last decades. The on-line measuring of pollutants generated by GTPP might result in a complicated task to handle. Simulation of GTPP has become an excellent tool to monitor and control the emission of pollutants. In the present work, the pollutant emissions of GTPP of Hellisheidi (Island), Chiusdino, and Castelnuovo (Italy) are modelled and developed with Unisim Design R480 using well understood thermodynamical models implemented in OLI. The presence of brine in the thermodynamical models has been taken into account. Carbon dioxide, methane, and hydrogen sulfide are the chemical pollutants considered for the process simulation. The AQ framework model in OLI is being used for binary mixtures and non-condensable gas. Furthermore, for liquid mixtures containing more than two components, the MSE-SRK Thermodynamic model is desirable depending on the original geothermal fluid source. The simulation process outcome agrees with experimental data for pressure between 30 and 100 bar within 5% deviation. A systematic study of the spatial distribution of the emissions has been made for the area surrounding the GTPP. Furthermore, an economic evaluation overview has been performed to highlight the equipment needed for maintenance and tool substitution
Modelling of Basic Oxygen Furnace Slag Treatment and Processing in Order to Evaluate Possibility of Their Reuse
No full textMetodo sperimentale per quantificare un flusso di gas fuggitivo mediante misure verticali di concentrazione
No full textLa tesi si basa su un lavoro sperimentale che ha visto la messa a punto di un nuovo sistema di rilevamento a distanza di metano aerodisperso tramite laser TDLAS ( Tunable Diode Laser Absorption Spectroscopy), una tecnologia a cammino aperto, che fornisce le concentrazioni medie del gas che si vuole rilevare ( in questa tesi CH4),misurando l'estinzione dell'intensità della radiazione laser a una data lunghezza d'onda, lungo un cammino ottico lineare che può arrivare fino a 30 metri. Il laser TDLAS è stato inserito su un mezzo aeromobile senza pilota (UAV) che ha effettuato le misure dall'alto e monitorare un'area d'interesse come la discarica. I test in campo hanno riguardato sia il monitoraggio di una reale dispersione di metano da una discarica nel grossetano sia la messa a punto del fenomeno con un tubo in plexiglas che avesse la funzione di un hot spot per la dispersione di metano in un campo aperto e isolato. La misura delle concentrazioni delle sostanze pericolose risulta importante sia per scopi di sorveglianza ambientale sia nel caso di dispersione da sorgente puntuale al fine di rilevare le perdite e di intervenire rapidamente per non mettere a rischio i lavoratori e la popolazione che soggiorna nelle vicinanze di una discarica o di un impianto chimico- petrolchimico. La tecnologia, nel suo complesso, risulta essere una assoluta innovazione nel settore del monitoraggio dell'atmosfera e di conseguenza si è sviluppato anche un metodo numerico applicabile a tale sperimentazione
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
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