Los asalariados en la cerealicultura de la Italia meridional, siglos XVIII-XIX

La cerealicultura extensiva de las i1anuras de la Italia meridional se caracteriza, por lo menos desde el bajo medioevo, por el predominio de ia gran explotación con mano de obra asalariada (masseria), con un número elevado de trabajadores agricolas fijos y el recurso estacional a trabajadores que provienen de las áreas de pequeña propiedad y de pequeño arrendamiento. El ensayo, que utiliza fuentes archivísticas de tipo patrimonial y fuentes bibliográfícas, centra su atención en particular en las masserie de la Llanura de Pulla mostrando que, durante el siglo XIX, la extensión del área dedicada a la explotación cerealícola con mano de obra asalariada y del trabajo asalariado no se debe tanto a llamativos procesos de proletarización dentro del área, como a la transformación de áreas de pasto en sembradíos. La oferta de mano de obra proviene de los centros del interior de la Llanura y también se debe a la crisis de la pequeña explotación de las superpobladas colinas limítrofes. En la transformación de la estructura social de la Llanura ínterviene además, a finales del siglo XIX, la precarización de las relaciones de trabajo en la masseria, con la reducción del número de trabajadores estables y el aumento del número de "jornaleros".The extensive grain farming on the Southern Italy plains has been marked, at least since the Late Middle Age, by the prevalence of large farms (masseria) employing a large number of regular labourers and seasonal workers from areas of small holdings and small leaseholders. This article, based on business archives and bibliographic sources, focuses on the masseria in the Apulian Tavoliere. It explains how the expanding area of grain farms with paid workers depends less on the huge inner processes of proletarianization than on increasing of the transformation of grazing areas into ploughed fields during the 19th century. The labour supply came from the Tevoliere inland areas as well as from the crisis of the small farms in the overcrowded surrounding hills. Moreover, at the end of the 19th century, the ever greater use of temporary labour, which meant few regular labourers and the increasing number of day workers, managed to change the social structure of the plain

Electrically tuneable exciton-polaritons through free electron doping in monolayer WS2_2 microcavities

We demonstrate control over light-matter coupling at room temperature combining a field effect transistor (FET) with a tuneable optical microcavity. Our microcavity FET comprises a monolayer tungsten disulfide WS$_2$ semiconductor which was transferred onto a hexagonal boron nitride flake that acts as a dielectric spacer in the microcavity, and as an electric insulator in the FET. In our tuneable system, strong coupling between excitons in the monolayer WS$_2$ and cavity photons can be tuned by controlling the cavity length, which we achieved with excellent stability, allowing us to choose from the second to the fifth order of the cavity modes. Once we achieve the strong coupling regime, we then modify the oscillator strength of excitons in the semiconductor material by modifying the free electron carrier density in the conduction band of the WS$_2$. This enables strong Coulomb repulsion between free electrons, which reduces the oscillator strength of excitons until the Rabi splitting completely disappears. We controlled the charge carrier density from 0 up to 3.2 $\times$ 10$^{12}$ cm$^{-2}$, and over this range the Rabi splitting varies from a maximum value that depends on the cavity mode chosen, down to zero, so the system spans the strong to weak coupling regimes.Comment: Accepted for publicatio

Homogeneously bright, flexible and foldable lighting devices with functionalised graphene electrodes

Alternating current electroluminescent technology allows the fabrication of large area, flat and flexible lights. Presently the maximum size of a continuous panel is limited by the high resistivity of available transparent electrode materials causing a visible gradient of brightness. Here, we demonstrate that the use of the best known transparent conductor FeCl$_{3}$-intercalated few-layer graphene boosts the brightness of electroluminescent devices by 49$\%$ compared to pristine graphene. Intensity gradients observed for high aspect ratio devices are undetectable when using these highly conductive electrodes. Flat lights on polymer substrates are found to be resilient to repeated and flexural strains.Comment: Published on ACS Materials and Interface

Pierre-Marie Delpu, Igor Moullier et Mélanie Traversier (dir.), Le royaume de Naples à l’heure française. Revisiter l’histoire du decennio francese (1806-1815), Villeneuve d’Ascq, Presses universitaires du Septentrion, 2018, 484 p.

Ce volume réunit les contributions présentées lors du colloque qui s’est tenu à l’Institut de Recherches Historiques du Septentrion (IRHiS) de l’Université de Lille-3, du 14 au 16 octobre 2015, organisé avec le LARHRA et le labex EHNE du Centre d’Histoire du xixe siècle, ainsi qu’avec le partenariat du Comité italien pour les célébrations du Bicentenaire du decennio francese et des Universités de Naples Federico II et de la Campanie Luigi Vanvitelli. Les vingt-cinq textes présentés dans le vo..

Is graphene a good transparent electrode for photovoltaics and display applications?

PublishedReviewThe current standard material used for transparent electrodes in displays, touch screens and solar cells is indium tin oxide (ITO) which has low sheet resistance (10 Ω/□), high optical transmission in the visible wavelength (85%) and does not suffer of optical haze. However, ITO is mechanically rigid and incompatible with future demands for flexible applications. Graphene materials share many of the properties desirable for flexible transparent conductors, including high optical transparency, high mechanical flexibility and strength. Whilst pristine graphene is not a good transparent conductor, functionalised graphene is at least 1000 times a better conductor than its pristine counterpart and it outperforms ITO. Here the authors review recent work on a novel graphene-based conductor with sheet resistance as low as 8.8 Ω/□ and 84% optical transmission. This material is obtained by ferric chloride (FeCl 3) intercalation into few-layer-graphene (FLG), giving rise to a new system which is the best known flexible and transparent electricity conductor. FeCl 3-FLG shows no significant changes in the electrical and structural properties for a long exposure to air, to high levels of humidity and at temperatures of up to 150°C in atmosphere. These properties position FeCl 3-FLG as a viable and attractive replacement to ITO.Engineering and Physical Sciences Research Council (EPSRC)Royal Society International Exchanges Schem

Novel highly conductive and transparent graphene based conductors

Future wearable electronics, displays and photovoltaic devices rely on highly conductive, transparent and yet mechanically flexible materials. Nowadays indium tin oxide (ITO) is the most wide spread transparent conductor in optoelectronic applications, however the mechanical rigidity of this material limits its use for future flexible devices. Here we report novel transparent conductors based on few layer graphene (FLG) intercalated with ferric chloride (FeCl3) with an outstandingly high electrical conductivity and optical transparency. We show that upon intercalation a record low sheet resistance of 8.8 Ohm/square is attained together with an optical transmittance higher than 84% in the visible range. These parameters outperform the best values of ITO and of other carbon-based materials, making these novel transparent conductors the best candidates for future flexible optoelectronics

All-graphene photodetectors

notes: PMCID: PMC3694352Copyright © 2013 American Chemical Society.Published versionWe investigate the optoelectronic properties of novel graphene/FeCl3-intercalated few-layer graphene (FeCl3-FLG, dubbed graphexeter) heterostructures using photovoltage spectroscopy. We observe a prominent photovoltage signal generated at the graphene/FeCl3-FLG and graphene/Au interfaces, whereas the photovoltage at the FeCl3-FLG/Au interface is negligible. The sign of the photovoltage changes upon sweeping the chemical potential of the pristine graphene through the charge neutrality point, and we show that this is due to the photothermoelectric effect. Our results are a first step toward all-graphene-based photodetectors and photovoltaics.Engineering and Physical Sciences Research Council (EPSRC

Straining graphene using thin film shrinkage methods.

types: Journal Article; Research Support, Non-U.S. Gov'tThis is an open access article that is freely available in ORE or from the publisher's web site. Please cite the published version.Theoretical works suggest the possibility and usefulness of strain engineering of graphene by predicting remarkable properties, such as Dirac cone merging, bandgap opening and pseudo magnetic field generation. However, most of these predictions have not yet been confirmed because it is experimentally difficult to control the magnitude and type (e.g., uniaxial, biaxial, and so forth) of strain in graphene devices. Here we report two novel methods to apply strain without bending the substrate. We employ thin films of evaporated metal and organic insulator deposited on graphene, which shrink after electron beam irradiation or heat application. These methods make it possible to apply both biaxial strain and in-plane isotropic compressive strain in a well-controlled manner. Raman spectroscopy measurements show a clear splitting of the degenerate states of the G-band in the case of biaxial strain, and G-band blue shift without splitting in the case of in-plane isotropic compressive strain. In the case of biaxial strain application, we find out the ratio of the strain component perpendicular to the stretching direction is at least three times larger than what was previously observed, indicating that shrinkage of the metal or organic insulator deposited on graphene induces both tensile and compressive strain in this atomically thin material. Our studies present for the first time a viable way to apply strain to graphene without the need to bend the substrate.GCOE for Phys. Sci. FrontierProject for Developing Innovation Systems, MEXT, JapanGrant-in-Aid for Young Scientists AMEXT KAKENHI “Science of Atomic Layers”JST Strategic International Cooperative Programs (DFG-JST and EPSRC-JST

Negative symptoms as key features of depression among cannabis users: a preliminary report.

OBJECTIVE: Cannabis use is frequent among depressed patients and may lead to the so-called "amotivational syndrome", which combines symptoms of affective flattening and loss of emotional reactivity (i.e. the so-called "negative" symptomatology). The aim of this study was to investigate the negative symptomatology in depressed patients with concomitant cannabis use disorders (CUDs) in comparison with depressed patients without CUDs. PATIENTS AND METHODS: Fifty-one patients with a diagnosis of Major Depressive Disorder (MDD) and concomitant CUD and fifty-one MDD patients were enrolled in the study. The 21-Item Hamilton Depression Rating Scale (HDRS) and the negative symptoms subscales of the Positive and Negative Syndrome Scale (PANSS) were used to assess depressive and negative symptomatology. RESULTS: Patients with cannabis use disorders presented significantly more severe negative symptoms in comparison with patients without cannabis use (15.18 ± 2.25 vs 13.75 ± 2.44; t100 = 3.25 p = 0.002). DISCUSSION: A deeper knowledge of the "negative" psychopathological profile of MDD patients who use cannabis may lead to novel etiopathogenetic models of MDD and to more appropriate treatment approaches