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Single-stage AC/DC dual inductor BCM current-fed push-pull for HB-LED lighting applications
No full textA single-stage, AC/DC driver for High Brightness Light-Emitting Diodes (HB-LED) with galvanic isolation is presented in this paper. The driver is based on a Dual Inductor Current-fed Push-Pull (DICPP) converter with each inductor operating in Boundary Conduction Mode (BCM). The interleaving between the two inductors makes possible for the converter to reduce the high input current ripple of a BCM. Moreover, it is fully compliant with IEC 1000-3-2 Class C, and it is also able to achieve high Power Factor (PF). Moreover, the low component count, simplicity and overall outstanding characteristics make this topology suitable for medium power range HB-LED drivers in low cost applications. Finally, the proposed topology has been tested on a 90W prototype for the full range of the US single-phase line voltage, feeding several strings of HB-LED, with an output voltage of 48V at full load. The prototype achieves a maximum efficiency of 92% with 0.99 power factor, 8% THD at full load and guarantees good quality light.This work has been supported by the Spanish Government under Project MINECO-13-DPI2013-47176-C2-2-R and the Principality of Asturias under the grants “Severo Ochoa” BP14-140 and BP14-85 and by the Project FC-15-GRUPIN14-143 and by European Regional Development Fund (ERDF) grant
Unusual flexibility of mesophase pitch-derived carbon materials: An approach to the synthesis of graphene
No full textStructural flexibility in a petroleum pitch-derived carbon material has been indirectly evaluated using X-ray diffraction (XRD), immersion calorimetry and inelastic neutron scattering (INS) measurements. Exposure of the carbon material to an organic solvent (e.g., n-nonane) gives rise to a large internal rearrangement, associated with a drastic re-ordering of the graphitic microdomains. These structural changes are also associated with a high flexibility of the internal porous network, as observed by inelastic neutron scattering measurements. The internal rearrangement and the structural flexibility could be responsible for the excellent performance of this kind of activated carbons in a wide variety of adsorption processes. Last but not least, the structural characteristics of these carbon materials composed of graphitic microdomains has been used to synthesize graphene “egg-like” flakes following a simple procedure based on exfoliation with organic solvents.UK Science and Technology Facilities Council for the provision of beam time on the TOSCA spectrometer (Project RB1410624) and financial support from the European Commission under the 7th Framework Programme through the “Research Infrastructures” action of the “Capacities” Programme (NMI3-II Grant number 283883). J.S.A. acknowledge financial support from MINECO Projects: MAT2013-45008-p and CONCERT Project – NASEMS (PCIN-2013-057) and from Generalitat Valenciana (PROMETEO2009/002). Financial support from Principado de Asturias-PCTI (Severo Ochoa pre-doctoral grant of A.M. Pérez-Mas
Biology and population genetics of Arvicola scherman cantabriae (Rodentia, Arvicolinae)
No full textThe montane water vole Arvicola scherman occurs in mountainous areas of Europe, living in underground burrow systems located in grasslands and fruit orchards.
This species feeds on the root system of plants, including fruit trees. Specifically, the
subspecies A. scherman cantabriae is nowadays one of the main causes of economical
loss in apple orchards of Asturias (northwestern Spain). An official control program in
Spain considers all sustainable phytosanitary measures that can reduce population
growth of this species. Since the pest condition of A. scherman depends on its biology
and ecology, a deep knowledge of these aspects is needed to set up specific and suitable
control strategies. Thus, the aim of this research is to obtain essential information on the
reproductive biology and population genetics of this species in the agricultural
landscape of Asturias.
More than 800 individuals of A. scherman cantabriae were gathered in apple
orchards located at low altitude in Villaviciosa and Nava municipalities during two
annual cycles (from February 2011 to January 2013). Sexual characteristics, body
measurements and relative age class of each specimen were recorded. Body condition of
females, which indicates energy provision, and the number of embryos of each one were
also wrote down. Skeletal muscle samples of 137 specimens from ten demes were used
to conduct a microsatellite-based analysis (12 microsatellite loci). These orchards are
placed in a landscape conformed by a mosaic of small and different land-use plots,
which was assessed in a vector based geographic information system and it was focused
on soil-occupancy categories.
Pregnant females and young specimens were detected over the whole year,
which mean that A. scherman cantabriae showed a continuous breeding pattern during
the study period. Intra-annual changes in body mass and size of sexual organs of males
did not affect significantly reproduction at a population scale. Thus, primary demands
of these voles seem to be properly fulfilled during the whole year and hence energy
budgets can be destined to cop continuous reproduction. To our knowledge, no other A.
scherman population shows regularly this reproductive pattern. Females were able to
produce a high number of litters per year (7.30) although litter size was relatively
moderate (embryos/female: first year: 3.87; second year: 3.63). Each female was able to
produce 28.25 pups per year. The reproductive potential showed by Cantabrian voles is,to our knowledge, the highest one reported to date for this species; probably because the
breeding season does not entail a critical factor in this area. A positive correlation
between litter size and the body condition of the mother was observed. Therefore, the
body condition of females seems to be one of the main factors involved in the variation
of the reproductive potential in A. scherman cantabriae.
These studied demes showed relatively low level of genetic diversity (HE =
0.621; HO = 0.601; AR = 4.42) probably due to both the inbreeding and genetic drift
effects. Significant genetic differentiation appeared among demes, which revealed a
strong pattern of significant isolation-by-distance both for Euclidean distances (r =
0.790) and effective distances (r = 0.780). The spatial autocorrelation analysis detected
four genetic clusters or populations in this study area (120 km2). Thus, this mosaic of
different land-use plots decreases connectivity among suitable habitats even at local
scale, in which A. scherman populations mainly depend on birth and death rates. An
estuary and a four-lane road did not suppose a barrier for gene flow of this species. Less
seasonal environment and highly patched landscape would suggest that this species does
not show well marked multiannual fluctuations of density at large scale in this area.
Control strategies for A. scherman cantabriae at a regional scale can be
discarded. The monitoring of each population, or management unit, will be essential to
know the population dynamic and to establish coordinated control strategies. Preserving
and promoting this patchy landscape would favour the presence of predators and
hamper dispersion of this species. A continuous population control throughout the year would be advisable, using sustainable methods, such as traps, the installation of barriers and/or coordinated manipulation of habitat.Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA
Synthesis of Functionalized Cyclopentene Derivatives from Vinyldiazo Compounds and Vinylazides through Sequential Copper-Promoted [3+2] Cycloaddition/Azide Rearrangement
No full textThe reaction of vinylazides with alkenyldiazo compounds in the presence of [Cu(CH3CN)4][BF4] provided cyclopentene derivatives retaining the azide functionality. This process would involve a sequence comprising: 1) decomposition of the diazo component with generation of a copper alkenylcarbene species; 2) stepwise regioselective [3+2] cycloaddition; 3) allylic azide rearrangement. A broad range of substrates is compatible with this protocol. We have also shown that azide-containing cycloadducts can be efficiently converted to the corresponding amine and triazole derivatives
Conventos femeninos y reforma: la implantación de la Observancia en los monasterios de la Orden de Predicadores en Castilla durante el siglo XV. Zamora y Toro
Get PDFESPAÑOL: A través de la presente contribución, pretendemos realizar una aproximación a las características que definieron la primera etapa del fenómeno reformista dentro del ámbito femenino dominicano castellano, prestando especial atención a las comunidades radicadas en los núcleos urbanos de Zamora y Toro. Algunas cuestiones como el posible origen de la reforma observante, la delimitación de los impulsores del proceso, así como las aplicaciones prácticas del mismo serán abordadas a lo largo de este trabajo. / ENGLISH: In this paper, we want to carry out an approximation to the characteristics that defined the first
period of the reformist phenomenon that concerned to the female Dominican convents in Castile, paying special attention to the convents located in Zamora and Toro. Some questions like the possible origin of the Observant reform, the identification of the authors of the process and
the practical applications of it will be discussed throughout this study
Las Clarisas de Pamplona: vinculaciones sociales y proyección patrimonial (1228-1331)
Get PDFESPAÑOL: La fundación del monasterio femenino de Clarisas de Santa Engracia de Pamplona, que tradicionalmente
se data en 1228, fue al parecer promovido y tutelado por un grupo de familias burguesas del núcleo franco de San Saturnino o San Cernin. Estos linajes, prestigiados económica y socialmente en la urbe, facilitaron la viabilidad patrimonial del convento, al tiempo que dispensaron algunas de las vocaciones para su comunidad; comportamientos que también evidencian los documentos en relación a la mediana nobleza. Asimismo, una atenta lectura de las primeras operaciones en relación al asentamiento de estas sorores, indica que quizá detrás de todo este
esfuerzo fundacional estuvo la cátedra episcopal, interesada en regular y encauzar en el área extramural de Pamplona una nueva comunidad de vida religiosa. / ENGLISH: The foundation of the Franciscan Clarist monastery of Saint Engratia of Pamplona, traditionally dated 1228, was apparently promoted by a group of bourgeois families from the Frankish borough
of Saint Saturnine. These families, of high economic and social standing, secured the patrimonial feasibility of the convent, as well as bestowed several vocations to the community. Similar tendencies may also be observed in documents related to middle nobility. A thorough reading of the first operations related to the settlement of these nuns suggests that the bishopric may have been behind this foundational effort, motivated by the wish to regulate and guide the new religious community outside Pamplona’s city walls
Overlapping Networks. Beguins, Franciscans, and Poor Clares at the Crossroads of a Shared Spirituality
Get PDFDuring the last quarter of the thirteenth century, the Order of Saint Francis underwent a crucial period in the definition of its own identity, while, at the same time, lay communities of men and women were already sensitised both to the idea of spiritual poverty and to the Joachite prophecies
announcing the advent of a new era of illumination. In the case of southern France, the influence of Spiritual Franciscans at the beginning of the fourteenth century was undeniable, so much so that their extreme pauperistic discourse and their apocalyptic expectations pervaded
lay society, resulting in the Beguin movement of Languedoc that would ultimately be persecuted as heretic. It is a fact that the region was also crowded with Clarissan convents, but, apparently, Spiritual Franciscans and Poor Clares remained within independent spiritual spheres. The goal
of this paper is to outline the diaspora of the Beguins of Languedoc and the persecuted Spiritual Franciscans in order to search for the confluence between them and the female rigorist branch that shared their same spiritual roots, that is, the Order of Saint Clare
La struttura sociale nelle necropoli longobarde italiane: una lettura archeologica
Get PDFITALIANO: Negli ultimi vent’anni, anche in Italia sono state riportate alla luce intere grandi necropoli in area aperta, ora analizzabili anche in termini comparativi. Nel contributo si ricavano alcune tendenze circa lo sviluppo topografico dei sepolcreti e la struttura sociale
che ne regola l’organizzazione, nonché la composizione della comunità dei vivi.
Si assiste alla compresenza di modelli differenziati di organizzazione e utilizzo degli spazi funerari, comunque incentrati in genere su gruppi familiari allargati. Di questi si valuta la composizione e il grado di differenziazione sociale, che può variare fra un sepolcreto
e l’altro. I legami parentali in qualche caso potrebbero essere indiziati dalla trasmissione di qualche manufatto carico di valenza simbolica.
Sembra di riconoscere casi di mobilità individuale: in particolare fra le donne per esogamia. Anche l’esclusività sociale, o piuttosto l’esclusione o almeno lo scarso interesse all’ostentazione e alla negoziazione sociale sono riflessi nelle pratiche funerarie. / ENGLISH: Over the last 20 years in Italy large, complete cemeteries in open areas have been brought to light, which lend themselves to comparative studies. The paper discusses certain tendencies concerning the topographic extension of these graveyards and the social structure that determined their organization, as well as the composition of the communities they represent.
Different models of organization and uses of burial areas are found to coexist, generally based on extended family groups. The composition and degree of social differentiation of these– which may vary between one graveyard and another – is evaluated; in some cases family ties are indicated by the presence of certain objects with strong symbolic significance. Probable cases of social mobility may be detected, in particular regarding female exogamy. Social exclusiveness, or an absence or low level of interest
in social ostentation and negotiation, are reflected in certain funerary practices
A proposito dei 40 anni di "Archeologia medievale" in Italia
No full textITALIANO: Il testo presenta alcuni dei principali interventi editi nel recente numero di "Archeologia medievale" dedicato ai 40 anni della rivista. Alla luce del contributo dato dall’archeologia medievale italiana al progresso degli studi storici e alle metodologie di ricerca archeologica, l’autore discute alcuni punti-chiave utili a conservare il tasso di innovazione della disciplina. / ENGLISH: "On forty years of 'Archeologia medievale' in Italy": This article makes a review of some of the key interventions published in the recent issue of "Archeologia medievale" dedicated to the fortieth anniversary of the magazine. In the light of the contribution made by Italian medieval archaeology to the progress of historical studies and archaeological research methodologies, the author discusses some key points for preserving the rate of innovation of the discipline
Concili "nazionali" e sotterranee rivoluzioni. Agde 506, Orléans 511, Épaone 517
No full textITALIANO: Il saggio cerca di mettere a fuoco alcuni aspetti del modo in cui i concili funzionano da sostanza catalizzatrice dei processi di trasformazione politica, sociale e culturale nel passaggio dalla realtà gallo-romana ai cosiddetti regni romano-barbarici. Punti di riferimento dell’analisi sono i primi tre concili del VI secolo. Si tratta di tre concili a carattere nazionale (visigoto, franco, burgundo) nel senso che tendono a veicolare l’idea che alla loro organizzazione presieda una compattezza politica e un’unità geografica. Questi concili appaiono preparatori – sotto vari punti di vista – degli sviluppi che si realizzeranno nei secoli dell’alto medioevo. E sono, inoltre, particolarmente indicativi per cogliere il ruolo delle strutture ecclesiastiche e della religione nelle dinamiche di governo dei nuovi regimi. / ENGLISH: The paper aims at highlighting some aspects of how councils worked as catalysing means of the political, social and cultural transformative processes in the passage from the Gallic-Roman age to the so-called Roman-Barbarian kingdoms. The study focuses on the first three councils of the sixth century. They are “national” councils (Visigoth, Frank, Burgund) as they aspire to convey the idea that their organization is the result of a political compactness and a
territorial unity. From various points of view, these councils appear preparatory to the developments that would take place in the Early Middle Ages; they are also particularly emblematic for the understanding of the role of episcopacies and religion in the ruling dynamics of the
new regimes