1,720,968 research outputs found
Widening neuropsychoanalysis. Georg Northoff’s contribution to the dialogue between psychoanalysis and neuroscience
Full text linkLa possibilità di dialogo tra psicoanalisi e neuroscienze è proceduta tra diffidenze reciproche e rifiuti, essendo sempre più perseguita nel corso degli ultimi due decenni attraverso la creazione di una disciplina “cerniera”, la neuropsicoanalisi. Il tentativo di far incontrare queste due discipline è tuttavia ostacolato da una serie di questioni epistemologiche e metodologiche. Con questo lavoro si introduce alla proposta di Georg Northoff, neurofilosofo e psichiatra, per superare questi rischi in una nuova cornice ampliata della neuropsicoanalisi. Il presupposto epistemologico dell’autore evidenzia la necessità di passare da una visione neuroscientifica in terza persona a un punto di vista sperimentale in grado di contemplare i fenomeni in prima persona di cui si occupa tradizionalmente la psicoanalisi. In particolare, la strategia di ricerca concettuale e sperimentale di Northoff si sofferma su come l’analisi dei profili di attivazione temporale cerebrale dell’attività a riposo, “resting state” e in presenza di uno stimolo esterno consente di indagare sul piano della ricerca neuroscientifica il Sé, un costrutto centrale nel pensiero psicoanalitico e fenomenologico.The possibility of a dialogue between psychoanalysis and neuroscience though raising mutual wariness and rebuttals, has been more and more pursued in the recent years, in particular, through the creation of a linkage-discipline, which is, neuropsychoanalysis. The encounter between these two disciplines, however, is hindered by a series of episthemological and methodological issues. In this paper, the German psychiatrist and neurophilosopher, Georg Northoff’s proposal to overcome these risks within a new widened psychoanalytic framework is introduced. Northoff’s episthemological assumption urges to a passage from a third-person neuroscience to an experimental perspective able to account for the first-person phenomena traditionally dealt with by psychoanalysis. Specifically, Northoff emphasizes how the analyses of temporal profiles of neural activation of the brain the “resting state” and in the presence of an external stimulus allows to investigate at a neuro-scientific level the self, a central construct for psychoanalytic and psychopathological thinking
Investigation on low and high temperature fuel cell components and their evaluation in short stack configuration
Full text linkLa ricerca sulle celle a combustibile ad ossidi solidi (SOFC) ed a membrana ad elettrolita polimerico è attualmente indirizzata al miglioramento delle performance e della loro vita utile, così come alla riduzione dei costi. Tali aspetti sono importanti per rendere questi dispositivi più interessanti per il mercato, sia nelle applicazioni stazionarie che automotive.
Da questo punto di vista, per la tecnologia PEMFC sembra necessario un incremento della temperatura (da 80°C a 110-120°C, high temperature PEMFC o HT-PEMFC).
Ciò porterebbe ad una migliore resistenza alle impurezze di CO nel fuel, un migliore thermal and water management ed una migliore efficienza per la co-generazione.
Al contrario, la tecnologia SOFC va verso temperature intermedie (IT-SOFC); ciò permetterebbe una riduzione dei costi nello sviluppo di celle planari, grazie a processi di fabbricazione meno onerosi ed ad un incremento della stabilità.
Questi modi di estendere l'applicazione sono ben studiati per celle singole, ma il processo di scale-up verso dispositivi di potenza necessita di ulteriori specifici approfondimenti. Inoltre, tecnologie differenti necessitano di procedure di test differenti, adattate a specifici settori applicativi.
In questa tesi di Dottorato, sono stati testati dispositivi a celle a combustibile basati su tecnologia ad ossidi solidi od ad elettrolita polimerico per applicazioni specifiche. In particolare, sono stati studiati stack di fuel cells di potenza nominale pari ad 1kW, per verificare la possibilità dell'utilizzo di fuel cell per applicazioni di piccola taglia.
Attualmente, i dispositivi basati su HT-PEMFC stanno suscitando interesse per lo sviluppo delle celle a combustibile. Nonostante una profonda conoscenza delle proprietà dei materiali, la valutazione degli stessi a livello di stack è stata oggetto di un piccolo numero di studi. In questa attività di ricerca è stato approfondito proprio questo aspetto.
La tecnologia IT-SOFC è considerata adatta per applicazioni stazionarie e per la produzione di energia distribuita, poiché può usare combustibile poco costoso in processi elettrochimici ad elevata efficienza. Inoltre, per applicazioni relative ad utenze residenziali, i dispositivi studiati possono essere considerati come la base per lo sviluppo di un sistema turn-key e non come la versione downscaled per studi da laboratorio.
Questa tesi di Dottorato include considerazioni per applicazioni sia stazionarie che automotive, analizzando stack di fuel cells di potenza sufficiente per essere considerati come proof-of-concept. In altre parole, la potenza è sufficiente per studiare i principali fenomeni che appaiono in stack di dimensioni superiori orientate ad applicazioni pratiche.
L'intera attività può essere suddivisa in due parti:
1) test di short stack HT-PEMFC per la valutazione delle performance in condizioni tipiche del settore automovtive (corrente, temperatura, umidificazione, pressione) e per individuare il punto di lavoro ottimale;
2) test di stack IT-SOFC in gas naturale per valutare la perdita di prestazioni per fenomeni legati a cicli redox che possono avvenire durante l'uso reale.
Tecniche di diagnosi, come il metodo di interruzione di corrente e la spettrocopia d'impedenza hanno completato lo studio fornendo informazioni circa l'ottimizzazione dell'assemblaggio degli stack.
La sperimentazione è stata interamente condotta in laboratorio, per controllare in maniera accurata le variabili di processo; nonostante ciò, le prestazioni ottenute sono comunque utili per applicazioni concrete, una volta che siano state definite condizioni di lavoro appropriate come compromesso tra prestazioni e costi.Research activities on solid oxide (SOFC) or polymer electrolyte membrane
(PEMFC) fuel cells are currently focused on performance and lifetime
enhancement as well as costs reduction. These aspects are relevant to make such
systems more attractive for the market, both for stationary and automotive
applications.
From this point of view, an increase of temperature (from 80°C to 110-120°C)
appears necessary for PEMFC technology (high temperature PEMFC, or HTPEMFC).
This would allow more resistance to CO contaminants in the fuel, better
thermal and water management and a better efficiency for co-generation.
On the contrary, SOFC technology is moving towards intermediate
temperature (IT-SOFC); this would allow cost reduction while developing planar
cells, due to less critical construction processes and an increase of stability.
These ways to enhance the fuel cells applications are well studied for single
cell but the scale-up process to significant power production devices needs specific
investigations. Moreover, different technologies need different field test
procedures, tailored on the specific application sectors.
In this Ph.D. thesis, fuel cell devices exploiting either solid oxide or polymer
electrolyte technologies, were tested for specific applications. In particular, 1kW
fuel cell stacks were tested in order to verify the possibility of fuel cell use in small
size applications.
Nowadays, HT-PEMFC devices are creating lot of interest for FC technology
development. Anyway, despite a deep knowledge of material properties, the
assessment of the new materials at stack level have undergone only few studies. In
this research activity this aspect was investigated.
Moreover, IT-SOFC technology is considered valuable for stationary
applications and distributed energy production, using cheap fuels and a highly
efficient electrochemical process. Nevertheless, for residential energy consumption, the studied SOFC device can be considered not as a downscaled
device for laboratory study, but as the base to develop a complete system.
This Ph.D. thesis involves considerations for both stationary and automotive
applications, by analysing fuel cells stack with a size large enough to be
considered a proof-of-concept. In other words, the size appears sufficient to
investigate main phenomena visible in larger stack oriented to real world
applications.
The whole activity can be divided in two lines:
1) tests of HT-PEMFC short stacks that were carried out to evaluate their
performance in typical automotive working conditions (current, temperature,
humidification, pressure) and to establish an optimal operating point.
2) tests of IT-SOFC stacks in natural gas, in order to evaluate performance
decay and its response to detrimental effects due to thermal and redox cycles that
can appear in "out of laboratory" usage.
Diagnostic analysis such as current interrupt method and electrochemical
impedance spectroscopy completed the study by supplying information about the
optimization of stack assembling procedure.
The whole experimental activities were carried out in laboratory, to
accurately control the process variables; nevertheless, the recorded performances
are anyway meaningful with respect to real world applications, once defined
tailored working conditions by a good compromise between performances and
costs
Life cycle energy and environmental impacts of a solid oxide fuel cell micro-CHP system for residential application
No full textFuel cells are considered one of the key technologies to reach the ambitious European goal of a low carbon economy, by reducing CO2 emissions and limiting the production of other pollutants. The manuscript presents an assessment of the life cycle energy and environmental performances of a solid oxide fuel cell system for household applications using primary data from the manufacturing phase and experimental data for the start-up and operation phases. The Life Cycle Assessment methodology is applied, based on a functional unit of 1 MJ of exergy and includes the life cycle steps from the raw materials extraction to the maintenance. The results show a particular relevance of the operation stage on the impacts (about 98% of cumulative energy demand and more than 63% of about half of the examined environmental impacts), mainly due to the fuel supply and, focusing on climate change, to the CO2 emissions during the conversion of chemical energy into electricity. Manufacturing step is the main responsible of the remaining half of the impacts, with a contribution higher than 38%, mainly imputable to the stacks production. For almost half of the examined impact, a contribution of 20–30% is caused by the maintenance step, with a relevant contribution of the stacks and DC/DC booster substitutions. The analysis highlights that eco-design solutions of the assessed system can be traced in the improvement of the energy system efficiency and reduction of emissions during the operation, and in the increase of the durability of the system components, thus reducing the number of their substitutions. The results of a sensitivity analysis on the selection of the functional unit also clarified the importance of the recovery of the thermal energy generated by the fuel cells, in order to avoid concurrent energy generation from conventional sources
Toward a Digital Twin of a Solid Oxide Fuel Cell Microcogenerator: Data-Driven Modelling
Full text linkSolid oxide fuel cells (SOFC) could facilitate the green energy transition as they can produce high-temperature heat and electricity while emitting only water when supplied with hydrogen. Additionally, when operated with natural gas, these systems demonstrate higher thermoelectric efficiency compared to traditional microturbines or alternative engines. Within this context, although digitalisation has facilitated the acquisition of extensive data for precise modelling and optimal management of fuel cells, there remains a significant gap in developing digital twins that effectively achieve these objectives in real-world applications. Existing research predominantly focuses on the use of machine learning algorithms to predict the degradation of fuel cell components and to optimally design and theoretically operate these systems. In light of this, the presented study focuses on developing digital twin-oriented models that predict the efficiency of a commercial gas-fed solid oxide fuel cell under various operational conditions. This study uses data gathered from an experimental setup, which was employed to train various machine learning models, including artificial neural networks, random forests, and gradient boosting regressors. Preliminary findings demonstrate that the random forest model excels, achieving an R2 score exceeding 0.98 and a mean squared error of 0.14 in estimating electric efficiency. These outcomes could validate the potential of machine learning algorithms to support fuel cell integration into energy management systems capable of improving efficiency, pushing the transition towards sustainable energy solutions
A New Geographic Information System (GIS) Tool for Hydrogen Value Chain Planning Optimization: Application to Italian Highways
Full text linkOptimizing the hydrogen value chain is essential to ensure hydrogen market uptake in replacing traditional fossil fuel energy and to achieve energy system decarbonization in the next years. The design of new plants and infrastructures will be the first step. However, wrong decisions would result in temporal, economic losses and, in the worst case, failures. Because huge investments are expected, decision makers have to be assisted for its success. Because no tools are available for the optimum design and geographical location of power to gas (P2G) and power to hydrogen (P2H) plants, the geographic information system (GIS) and mathematical optimization approaches were combined into a new tool developed by CNR-ITAE and the University of Bologna in the SuperP2G project, aiming to support the interested stakeholders in the investigation and selection of the optimum size, location, and operations of P2H and P2G industrial plants while minimizing the levelized cost of hydrogen (LCOH). In the present study, the tool has been applied to hydrogen mobility, specifically to investigate the conversion of the existing refuelling stations on Italian highways to hydrogen refuelling stations (HRSs). Middle-term (2030) and long-term (2050) scenarios were investigated. In 2030, a potential demand of between 7000 and 10,000 tons/year was estimated in Italy, increasing to between 32,600 and 72,500 tons/year in 2050. The optimum P2H plant configuration to supply the HRS was calculated in different scenarios. Despite the optimization, even if the levelized cost of hydrogen (LCOH) reduces from 7.0-7.5 euro/kg in 2030 to 5.6-6.2 euro/kg in 2050, the results demonstrate that the replacement of the traditional fuels, i.e., gasoline, diesel, and liquefied petroleum gases (LPGs), will be disadvantaged without incentives or any other economic supporting schemes
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
Thermal integration of a SOFC power generator and a Na-NiCl2 battery for CHP domestic application
Full text linkIn this study the integration of a Solid Oxide Fuel Cell (SOFC) prime mover and a high temperature electrochemical Sodium Nickel Chloride (SNC) battery as storage has been investigated. The aim is to fulfil a domestic user energy demand and to reduce the primary energy consumption in comparison with a reference conventional scenario, thereby, to enhance the total efficiency in a Î1⁄4-CHP (Combined Heat and Power) application on a yearly basis. A realistic operational sequence of the SOFC-battery integration has been calculated using simple logic conditions. Both thermal and electric integration have been considered, where the innovative thermal integration has been proposed in order to exploit the SOFC residual heat for the battery stand-by feeding. The key advantage of this system architecture is that the SOFC is operated without major load variations close to constant load, resulting in longer lifetime and thus reducing total costs of operation. The thermal integration provides additional advantages, as calculated in this study. Eventually, a comparison with alternative Î1⁄4-CHP technologies has been carried out, highlighting the potential of the system based on the SOFC. Benefits are mainly shown in terms of primary energy savings and admissible costs
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