1,720,956 research outputs found
The integration of BIPV Adaptive Flakes in the building envelope
No full textThe research presented within this paper deals with the design of an adaptive BIPV (Building Integrated PhotoVoltaic) façade system able to self-orientate the photovoltaic layer to improve the energy production. To reach this goal, thin film solar cells are coupled with a thin layer of hydromorphic material that responds to changes in environmental humidity by modifying its own curvature. The hydromorphic layer consists of two wooden slats assembled together and produced from different types of trunk cuts. The adaptive layer thus obtained can change its shape as a function of temperature and relative humidity outdoor conditions, thanks to the different expansion coefficients of the two materials. In the winter period, the flakes are designed to be almost vertical so that the solar cells can receive direct sunlight in a favourable way; in the summer season, instead, they naturally present high values of curvature, orienting the solar cells so as to maximize the production of photovoltaic energy. The paper, after outlining the main technological features of the system, illustrates the geometry optimization process and the results of the performed energy simulations. In addition, it shows how these BIPV flakes can be installed on a wood frame to create modular panels that can be used as façade cladding, sun-shading system and street furniture item (e.g. bus stop shelters)
Study of a BIPV adaptive system combining timber and photovoltaic technologies
No full textThe reduction in building energy consumption and CO2 emissions is one of the main goals in the nearly Zero Energy Buildings (nZEB) framework. In this regard, adaptive technologies and materials represent a constantly developing sector and source of innovation. Moreover, these systems are often aimed at collect and convert renewable energy (mainly solar) in order to cover as much as possible the building energy consumption.
In this context, the research goal has been the design of a BIPV (Building Integrated PhotoVoltaic) facade system able to change its curvature in relation to the external environmental conditions, orientating itself in order to optimize the energy production without the aid of any mechanical and electrical system. The following aspects have been considered: passive dynamism, lightness, weather resistance, easy maintenance, applicability on a large scale, easy integration in the building envelope, Life Cycle sustainability.
The adaptive layer consists of two wooden sheets, one active and one passive, joined together. The response of a hydromorphic material is a function of ΔMC’ (effective moisture content change), that is, the difference in the moisture content in the wood, which in turn depends on the air temperature and Relative Humidity (RH) and it varies in relation to the wood species. Moreover, this response is a function of the dimensional variations of the two wooden layers used to produce the composite self-adjusting flake. The variation in outdoor air RH activates the movement of the wooden flakes, that can therefore change their curvature thanks to the different expansion coefficients of the two wooden slats.
To evaluate the performance of the component, three shape configurations for the adaptive flakes have been assumed. For each hypothesis, the flakes have been modelled using the Rhinoceros 5 Software, according to the curvatures taken during the different months of the year. The Rhino models have been imported into Autodesk Ecotect Analysis to calculate the incident solar radiation and to study the self-shadowing effect in the various configurations (considering the climatic conditions of the city of Milano)
Studio, progettazione e modellazione di un sistema fotovoltaico innovativo integrato nell'involucro edilizio
No full textLAUREA MAGISTRALEIl presente elaborato ha come oggetto le soluzioni integrate involucro edilizio – sistemi impiantistici ad alte prestazioni per edifici a basso consumo e ha come obiettivo la progettazione di una soluzione di facciata in grado di sfruttare le fonti di energia rinnovabile che vinca i principali limiti della soluzioni esistenti e ne potenzi i punti di forza.
Il punto di partenza è stato l’analisi dello stato dell’arte in materia di Zero Energy Building al fine di individuare quali siano i criteri progettuali e le soluzioni tecniche adottate per ottenere edifici a bassissimo fabbisogno energetico.
Successivamente si investiga la attuale concezione di involucro edilizio e si analizzano, dal punto di vista tipologico, funzionale e prestazionale, le tipologie di involucro che contribuiscono al contenimento dei consumi energetici in modo attivo e passivo. La ricerca coinvolgerà soluzioni di facciata via via più innovative delle quali si mettono in evidenza i punti di forza e di debolezza.
La ricerca bibliografica si conclude con l’analisi delle principali tipologie di smart materials, in modo da avere una visione completa delle nuove tecnologie disponibili.
La quarta e ultima parte dell’elaborato oggetto di questa trattazione riguarda il processo progettuale che si basa sulla volontà di proporre un componente di facciata di nuova concezione la cui tecnologia si basi però su tecnologie impiantistiche con un know-how consolidato.
Partendo dunque dalla tecnologia del fotovoltaico, sapendo che il suo rendimento di produzione è influenzato dalla direzione dei raggi solari rispetto all’inclinazione della superficie di captazione, si vuole realizzare un pannello in grado di orientarsi in modo quanto più perpendicolare possibile ai raggi solari, sfruttando però un sistema di movimentazione che sia azionato da meccanismi naturali.
Per fare ciò vengono utilizzati gli hydromorphic materials, ossia un materiale composito, formato da due lamelle in legno ricavate da diverse tipologie di taglio del tronco e assemblate tra loro, che sfruttando i diversi coefficienti di dilatazione di questi due strati, è in grado di inflettersi in funzione della temperatura e dell’umidità relativa dell’ambiente esterno.
È così possibile realizzare un sistema di lamelle mobili che, in condizioni di elevata umidità relativa e bassa temperatura, ossia durante l’inverno, si distendono diventando quasi perpendicolari al suolo, in modo da captare al meglio i raggi con bassa declinazione. Al contrario, in condizioni di medio-bassa umidità relativa e temperatura medio-alta, ossia durante il periodo estivo, aumentano la loro curvatura, inclinandosi rispetto alla verticale e captando i raggi più perpendicolari al suolo.
Queste lamelle mobili vengono installate su supporti in legno per creare dei pannelli modulari che possono essere usati sia come rivestimento di facciata, sia come schermature solari, sia come arredo urbano.
Per caratterizzare il componente dal punto di vista prestazionale si calcola l’energia ottenibile durante un anno solare nelle varie configurazioni di curvatura delle lamelle, si verifica che la durabilità del legno non trattato sia tale da rendere la realizzazione del componente economicamente sostenibile e che il fabbisogno di energia e le emissioni di CO2 del processo produttivo siano tali da rendere la realizzazione del componente sostenibile anche a livello ambientale. Infine si conduce una stima dei tempi e dei costi di realizzazione.The aim of this paper is to investigate the worldwide scenario of buildings’ envelopes able to generate energy using renewable energy sources in order to design a solar panel with increased performances.
First of all there is a state-of-art review about Zero Energy Building to define the common features of the design strategies for the envelope and for the MEP to reduce energy consumptions to the smallest possible quantity.
Then the research focuses on an exhaustive technical review of the different types of building envelope components using active or passive energy efficient strategies to improve energy efficiency of buildings. In this part, both common envelope components and recent developments, like prototypes, are involved. In order to have a complete point of view about new technologies, smart materials are also investigated.
The last part of the paper is about the design process whose target is a sustainable, self-moving (without electric devices), high-performance solar panel.
To reach these goals, solar cells are installed on sheets of hydromorphic materials, i.e. natural materials which respond to changes in environmental humidity by modifying their curvature. So in the winter period, when humidity is high and the hydromorphic sheets have low values of curvature, solar cells are almost vertical and they can receive sunlight in a proper way since the solar elevation angle is low. Otherwise in the summer period, when humidity is lower and the hydromorphic sheets have high values of curvature, solar cells can receive sunlight in a proper way since the solar elevation angle is high.
These cells and sheets are installed on a wood frame to create modular panels used as a façade cladding system, as sun-shades or as street furniture.
To characterize the component from a performances point of view, the following check-list is verified:
•Analysis of the energy production during a year in every configuration of curvature
•Service life of wood in outdoor applications
•Carbon footprint and embodied energy of the life cycle of every material used
•Cost analysis
•Production time analysi
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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