1,721,049 research outputs found
Wireless Sensor for Monitoring of Individual PV Modules
No full textThe paper deals with a module-level monitoring and diagnostic system consisting in wireless self-powered sensors installed on individual PV modules and performing real-time measurements of operating voltage and current, open-circuit voltage, and short-circuit current. A disconnection system assures that the PV sensor does not affect the behavior of the string during the measurement phase and allows many benefits like the automatic detection of bypass events. An experimental campaign is performed to prove the reliability and usefulness of the sensor for monitoring of PV plants. The capability to detect faults and to accurately localize malfunctioning modules in a PV string is highlighted
A Power MOS Based Circuit for Controlling the Hot Spot Temperature in Photovoltaic Modules
No full textLocalized overtemperature (hot spot) is universally recognized as the main cause of unexpected failure and reliability issues in photovoltaic plants. In fact, the hot spot temperature can be so high to permanently injury the solar panel. Right now, the only countermeasure adopted by solar panel manufacturers is to group solar cells in shorter strings, so that the allowed electrical power in each group is low enough to keep the overtemperature within safe limits. In this paper, a bypass circuit able of controlling power dissipation by modulating the current flowing through the affected solar cell, up to, if applicable, completely cancelling such current. This latter is deviated through a parallel bypass diode (as in standard solar panels), whose possible over heating is in turn prevented by the proper sharing of the current. The correct operation of the circuit is evidenced by means of experiments showing the capability to regulate the overtemperature from zero to the hot spot
Cuffie neonatali rinvenute nella "Tomba Tartini" nella chiesa di S. Caterina in Padova: studio dei materiali
No full textStudio cristallochimico di reperti ossei e di un anello rinvenuti nella tomba di Giuseppe Tartini (1692-1770) nella chiesa di S. Caterina in Padova
No full textAutomatic edge identification for accurate analysis of thermographic images of solar panels
No full textThis paper proposes a segmentation method to analyze thermographic images of large solar fields with the aim to identify the borders of photovoltaic modules. This kind of analysis allows to correctly attribute possible faults, revealed by thermography, to a well specified solar panel. Moreover, the knowledge of the specific model of solar panel allows to bring the analysis to the single solar cell. This latter feature can help to eliminate some false positive that the mere observation of hot spots might produce
Crystal-chemical study of Remains found in the tomb of Giuseppe Tartini (1692-1770).
No full textWe describe a crystal-chemical investigation on extremely altered skeletal material and a greatly altered ring found in the tomb of the musician and composer Giuseppe Tartini. X-ray powder diffraction and electron probe microanalysis show the presence of brushite and a small amount of hydroxyapatite in the skeletal remains. The brass ring is composed of an inner core part of cuprite (Cu2O) surrounded by parascholzite (CaZn2(PO4)2??2H2O in the outer part. This indicates that Tartini's body underwent chemical attack by a strong acid, probably sulphuric acid, as an intentional technique of mortuary hygiene in the second half of the 18th century
Indagini sulle reliquie attribuite a "San Luca Evangelista", Basilica di Santa Giustina in Padova: studi cristallochimici, isotopici e datazione mediante 14C dei reperti ossei
No full textIl lavoro espone i risultati degli studi cristallochimici e isotopici condotti sulle ossa dello scheletro conservate nell'abbazia benedettina di Santa Giustina a Padova, che una tradizione medievale attribuisce a San Luca evangelista. Sono state utilizzate metodologie analitiche precise e poco distruttive al fine di garantire la massima integrità dei reperti in studio (microscopia ottica ed elettronica) diffrattometria e spettrometria dei raggi X, spettrometria di massa per gli isotopi del piombo e del carbonio). E' stato caratterizzato il tessuto osseo del femore, tale tessuto appare fortemente alterato dai processi di alterazione microbica ed è interessato da evidenti processi di ricristallizzazione. Sono state studiate le incrostazioni della superficie esterna delle ossa del bacino, prodotte da una intensa quanto rapida aggrossione del piombo della bara durante il processo di decomposizione cadaverica. Vengono poste in relazione cronologica scheletro e cassa e ricostruiti alcuni eventi della storia post-deposizionale della salma, documentando inoppugnabilmente che la attuale cassa è quella originaria. Le analisi del radiocarbonio 14C, condotte in due diversi laboratori (Tucson e Oxford) forniscono datazioni tra loro congruenti entro i limiti dell'errore. In funzione del diverso grado di confidenza vengono definiti gli intervalli temporali dal II al IV secolo A.D.(1σ) e dalla seconda metà del I all'inizio del V secolo A.D. (2σ). Una analoga datazione, condotta su frammenti del teschio attribuita all'evangelista Luca conservato in vativcano, evidenzia come tale reliquia. databile al V-VI secolo non possa essere correlato allo scheletro padovano
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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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