31,037 research outputs found
De l'ère de la communication aux marchés de la communication
No full textBernard Miège and Yves de la Haye discuss the field of communication research starting with three queries : how does society speak of itself as a world of communication ? are we witnessing the birth of a new culture, in the ethnological sense ? and what are the ricochet-effects of State intervention into the domain of public communication ?Bernard Miège et Yves de la Haye traitent de la définition du champ de la recherche en communication à partir de trois lignes de questionnement : comment le monde social se donne-t-il à lire comme un monde de la com¬ munication ? assistons-nous à la formation d'une nouvelle culture au sens ethnologique du terme ? et quels sont les effets-ripostes de la prise en charge de l'État d'opérations de communication publique ?Bernard Miège et Yves de la Haye hablan sobre la definición en el campo de la investigación en comunicación a partir de tres enfoques : ¿como es que el mundo social se ve a si mismo como un mundo de comunicación ? ¿asistimos a la formación de una nueva cultura , en el sentido etnológico del término ? cuáles son los efectos resultantes cuando el Estado se hace cargo de la comunicación pública ?Miège Bernard, de la Haye Yves. De l'ère de la communication aux marchés de la communication. In: Communication. Information Médias Théories, volume 6 n°2-3,1984. Les représentations. pp. 202-220
Studio del ciclo biologico di Halyomorpha halys alle condizioni ambientali dell’Emilia Romagna (Italia)
No full textHalyomorpha halys, Heteroptera pentatomidae di origine asiatica, è un insetto polifago con più di 300 piante ospiti segnalate, tra cui piante da frutto, orticole, ornamentali e spontanee e il cui ciclo biologico a seconda delle condizioni climatiche, può presentare fino a due generazioni per anno. Le punture di suzione attraverso cui adulti e ninfe si nutrono sono causa di deformazioni e suberificazioni nei frutti colpiti e di conseguenti perdite economiche dovute alla loro incommerciabilità. Negli Stati Uniti, dove è presente da circa vent’anni H. halys rappresenta uno dei più importanti problemi fitosanitari per i frutteti e la causa di perdite economiche per diversi milioni di dollari. In Italia è stata identificata per la prima volta nel 2012 in Emilia Romagna in provincia di Modena; a tre anni dall’identificazione si è assistito a un’estensione della distribuzione di H. halys dalle zone focolaio verso la Romagna, numerose regioni del Nord e centro Italia; nelle zone di prima infestazione sono stati segnalati incrementi dei danni su pero con apici del 100% di frutti colpiti in bordura. L’assenza di nemici naturali all’esterno dell’areale di origine, l’elevata polifagia così come il numero di generazioni per anno e la mobilità ne fanno un fitofago di difficile gestione. Questo studio ha lo scopo di indagare la biologia di Halyomorpha halys alle condizioni ambientali di temperatura e fotoperiodo dell’Emilia Romagna; a tale scopo si è effettuato uno studio della mortalità in fase di svernamento e uno studio del ciclo biologico. Cimici svernanti sono state raccolte da diversi siti e poste all’interno di scatole di legno riempite con cartone monitorando l’andamento dell’uscita dallo svernamento e la mortalità a fine svernamento. Alcune delle cimici sopravvissute al precedente studio sono state sessate e accoppiate e ne sono state monitorate giornalmente mortalità, fecondità e tempi di sviluppo per tutte le generazioni. Dallo studio è emerso che il periodo di uscita dallo svernamento si concentra tra fine Marzo e fine Maggio con una mortalità del 76% e che alle condizioni ambientali dell’Emilia Romagna H. halys è in grado di compiere due generazioni con importanti differenze di longevità e fecondità tra le stesse. I risultati ottenuti saranno indispensabili per la realizzazione di modelli previsionali utili nella gestione dell’avversità sul territorio regionale
Ordering of organic molecules on templated surfaces
No full textThis thesis describes the controlled growth of molecular nanostructures using modified metallic and semiconductor surfaces. The Ag/Si(lll)-(root3 x root3),the Sn/Cu(100) surface alloy system and the Bi/Si(100) nanolines and (2xn) surfaces were all investigated as suitable substrates for the controlled growth of pentacene, (C22H14) or trimesic acid, (C6H3(COOH)3) organic molecules. The following techniques were used in this study; Scanning Tunnelling Microscopy (STM), Low Energy Electron Diffraction (LEED), Normal Incident X-Ray Standing Waves (NIXSW) and Temperature Programmed Desorption (TPD).
The room temperature growth and ordering of trimesic acid on the AgfSi(ll1)-(root3 x root3) surface was investigated. An oblique unit cell was determined and a model proposed for the highly ordered close-packed domains.
The discovery of a new submonolayer phase on Sn/Cu(100) and the re-examined known phase are discussed. New models for these reconstructions are proposed. Adsorption of trimesic acid at room temperature on the clean substrate the lowest Sn coverage phase were studied. Two new Sn coverage dependent structures were discovered and bonding schemes in upright and flat orientations are discussed.
BifSi(100)-(2xn) surface was exploited as a template for the ordered growth of pentacene, which exhibited orientation specific adsorption. The Bi/Si(100)-(2xn) single domain surface created on vicinal silicon was used to test the suitable of Daresbury 4.2 beamline for NIXSW Imaging experiments and the quality of the results are discussed
Government equity and money: John Law’s system in 1720 France
No full textJohn Law’s System was a radical restructuring of French public finances, carried out from 1716 to 1720. It involved on the one hand a conversion of the existing French public debt into something like government equity, on the other hand the replacement of commodity money with fiat money. For strategic reasons, Law supported the equity at too high a level, resulting in uncontrolled money creation. The System ended with the recreation of a public debt at, surprisingly, the same level as before.France ; Debts, Public ; Money
Combination of Advanced Optical Modelling with Electrical Simulation for Performance Evaluation of Practical 4-terminal Perovskite/c-Si Tandem Modules
No full textAbstractThe perovskite solar cell is considered a promising candidate as the top cell for high-efficiency tandem devices with crystalline silicon (c-Si) bottom cells, contributing to the cost reduction of photovoltaic energy. In this contribution, a simulation method, involving optical and electrical modelling, is established to calculate the performance of 4-terminal (4T) perovskite/c-Si tandem devices on a mini-module level. Optical and electrical characterization of perovskite and c-Si solar cells are carried out to verify the simulation parameters. With our method, the influence of transparent conductive oxide (TCO) layer thickness of perovskite top cells on the performance of tandem mini-modules is investigated in case of both tin-doped indium oxide (ITO) and hydrogen-doped indium oxide (IO:H). The investigation shows that optimization of TCO layer thickness and replacement of conventional ITO with highly transparent IO:H can lead to an absolute efficiency increase of about 1%. Finally, a practical assessment of the efficiency potential for the 4T perovskite/c-Si tandem mini-module is carried out, indicating that with a relatively simple 4T tandem module structure the efficiency of a single-junction c-Si mini-module (19.3%) can be improved by absolute 4.5%
Parasitic copepods from Egyptian Red Sea fishes: Bomolochidae Claus, 1875
No full text© The Author(s) 2015
Open Access - This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The attached file is the published version of the article.NHM Repositor
High-efficiency black IBC c-Si solar cells with poly-Si as carrier-selective passivating contacts
No full textIn this work, we present the application of poly-Si carrier-selective passivating contacts (CSPCs) as both polarities in interdigitated back-contacted (IBC) solar cell architectures. We compared two approaches to form a gap between the back-surface field (BSF) and emitter fingers. It is proved that the gaps prepared by both approaches are efficient in preventing carriers’ recombination. To minimize the reflection losses, we developed a novel modulated surface texturing (MST) structure as anti-reflection coating (ARC). It is obtained by superposing a nano-textured SiO2 layer on the conventional micro-textured pyramids, which are passivated with a-Si:H / SiNx:H layers. This approach decouples the light harvesting from the Si surface passivation, which potentially results in the highest possible optical and electrical performances of the solar cells. The reflectance (R) of the MST-ARC is very close to that of the high-aspect ratio nano-structured silicon (black-Silicon), achieving R < 1% between 450 and 1000 nm. The J0 of MST-ARC passivated Si surface (6.3 fA/cm2) is the same as that of standard a-Si:H/SiNx:H layers passivated pyramidally-textured Si surface. By applying this novel MST-ARC in our IBC solar cell, the highest JSC observed in a device is 42.2 mA/cm2 with a VOC as high as 701 mV. A spectral response enhancement in case of the MST-ARC cell is observed over the whole wavelength range with respect to the cell with standard SiNx:H ARC. The highest efficiency achieved in this work is 23.0%, with the potential to reach 24.0% in short term by using more conductive metal fingers.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Photovoltaic Materials and DevicesElectrical Sustainable Energ
El deporte en los diseños curriculares de Educación Superior : Educación Física Argentina
No full textPensar en una formación profesional de excelencia en Educación Física debe implicar el análisis profundo de los conceptos e ideas que pretenden constituir el campo de este saber. Esto resulta sumamente relevante si se trata de los diseños curriculares para la formación de losfuturos profesores y/o licenciados del campo en distintas partes del país. Aquello que un profesor de Educación Física debería saber, lo social y lo natural, la formación general y la formación específica, la selección de los contenidos y la manera de conceptualizarlos, son aspectos que deben ser pensados y debatidos en miras de construir un marco teórico coherente y sólido para la formación profesional. En este sentido, y enmarcado tanto en un proyecto de investigación más amplio denominado "Las practicas corporales en la Educación Superior" como en un subgrupo encargado del estudio las prácticas deportivas en dicho contexto, es que se proponen algunas aproximaciones para el análisis de los discursosreferidos al Deporte en los diseños curriculares para la formación de profesores de Educación Física de distintas provincias del país.Fil: De La Haye, Jessica. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina
Hybrid Si/SiC Switch Modulation with Minimum SiC MOSFET Conduction in Grid Connected Voltage Source Converters
No full textIn this article, a hybrid Si/Si carbide (SiC) switch (HyS) modulation with minimum SiC MOSFET conduction (mcHyS) is experimentally characterized, so as to derive its conduction and switching performance. These are later used to derive a silicon (Si) area analytical model for the HyS configuration. The chip area model is used to benchmark the mcHyS modulation concepts against single-technology switches and typical HyS modulation when considering the implementation of a 100-kW two-level voltage-source converter (VSC) deployed for three industrial applications: photovoltaic inverter, electric vehicle fast-charging station, and battery storage systems for grid ancillary service. The two additional switching events of the SiC MOSFET, which differentiate the mcHyS modulation from the typical HyS one, are proven to happen in soft switching; therefore, the mcHyS switching performances are not penalized. Furthermore, the analysis presented shows how the studied mcHyS modulation performs against the single semiconductor technology and the typical HyS solution in terms of cost and power conversion efficiency. More specifically, it is shown that the HyS solutions are particularly competitive versus the full Si-based VSCs when the application at hand often operates at low partial loads. Finally, a 10-kW two-level VSC assembled with mcHyS is tested, so as to compare its efficiency versus single-technology switches.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.DC systems, Energy conversion & StorageIntelligent Electrical Power Grid
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