258 research outputs found

    The Black's place in the city image: Afroeuropeans and urban representations in Europe

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    In this session, we will investigate the visibility/invisibility and the inclusion/exclusion of African populations and people of African descent, within the physical and imaginary borders of Europeans cities with a colonial history. Focusing on both the material and immaterial aspects of the image construction, we will engage in debates concerned with the involvement of African populations and their descendants in current urban representations.info:eu-repo/semantics/publishedVersio

    Das políticas de habitação ao espaço urbano: trajetória espacial dos afrodescendentes na área metropolitana de Lisboa

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    O presente artigo tem por objetivo explorar a geografia residencial das populações afrodescendentes da Área Metropolitana de Lisboa resultante das políticas de habitação adotadas nos últimos 60 anos. O enquadramento teórico será elaborado em torno da categoria “afrodescendentes”, que abrange os imigrantes provenientes das antigas colónias portuguesas em África, bem como os seus descendentes. Embora esses grupos sejam diversificados e plurais, destaca-se o facto de serem grupos sociais consolidados e históricos da cidade. Com efeito, uma revisão das estatísticas e dos relatórios oficiais revela que têm sido uma presença constante na cidade desde o início da sua história moderna. Em seguida, olhando para as últimas seis décadas através de uma revisão sistemática da literatura, é possível identificar as três fases principais que marcaram a evolução das políticas de habitação: a primeira fase, desde a década de 60 à de 90 do século passado, foi marcada principalmente pela ambiguidade institucional do regime de propriedade; a segunda fase, de 1993 a 2000, ocorreu durante a execução do Programa Especial de Realojamento (PER), programa nacional de habitação social; e a terceira fase, iniciada há cerca de 15 anos, foi caracterizada pelo processo de reabilitação urbana que ainda está em curso. A natureza das políticas adotadas e as consequências sócio-urbanísticas que afetaram as populações afrodescendentes serão examinadas distintamente. Não obstante a escassez dos dados, o presente artigo visa o reconhecimento da marginalização residencial dos afrodescendentes no espaço metropolitano de Lisboa como resultado das políticas de habitação em apreço

    Thermal, electric and durability characterization of supercaps for energy back-up of automotive ECU

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    A new generation of mechatronic devices, such as the E-latch for door closure, is introduced in the automotive field to replace mechanical systems with electro-actuated parts with embedded electronic control unit (ECU) connected to the main vehicle network. Due to severe automotive safety-critical requirements an energy back-up solution is proposed, based on supercaps and boost converter, to ensure E-latch operation even in case of main battery failure. An in-depth thermal, electrical and durability characterization of the supercaps proves the suitability of the energy back-up unit for automotive applications

    A 1000-yr-old tsunami in the Indian Ocean points to greater risk for East Africa

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    The December 2004 Sumatra-Andaman tsunami prompted an unprecedented research effort to find ancient precursors and quantify the recurrence time of such a deadly natural disaster. This effort, however, has focused primarily along the northern and eastern Indian Ocean coastlines, in proximal areas hardest hit by the tsunami. No studies have been made to quantify the recurrence of tsunamis along the coastlines of the western Indian Ocean, leading to an underestimation of the tsunami risk in East Africa. Here, we document a 1000-yr- old sand layer hosting archaeological remains of an ancient coastal Swahili settlement in Tanzania. The sedimentary facies, grain-size distribution, and faunal assemblages indicate a tsunami wave as the most likely cause for the deposition of this sand layer. The tsunami in Tanzania is coeval with analogous deposits discovered at eastern Indian Ocean coastal sites. Numerical simulations of tsunami wave propagation indicate a megathrust earthquake generated by a large rupture of the Sumatra-Andaman subduction zone as the likely tsunami source. Our findings provide evidence that teletsunamis represent a serious threat to coastal societies along the western Indian Ocean, with implications for future tsunami hazard and risk assessments in East Africa

    First ROV exploration of the Perth Canyon: Canyon setting, faunal observations, and anthropogenic impacts.

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    © The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Trotter, J. A., Pattiaratchi, C., Montagna, P., Taviani, M., Falter, J., Thresher, R., Hosie, A., Haig, D., Foglini, F., Hua, Q., & McCulloch, M. T. First ROV exploration of the Perth Canyon: Canyon setting, faunal observations, and anthropogenic impacts. Frontiers in Marine Science, 6, (2019):173, doi:10.3389/fmars.2019.00173.This study represents the first ROV-based exploration of the Perth Canyon, a prominent submarine valley system in the southeast Indian Ocean offshore Fremantle (Perth), Western Australia. This multi-disciplinary study characterizes the canyon topography, hydrography, anthropogenic impacts, and provides a general overview of the fauna and habitats encountered during the cruise. ROV surveys and sample collections, with a specific focus on deep-sea corals, were conducted at six sites extending from the head to the mouth of the canyon. Multi-beam maps of the canyon topography show near vertical cliff walls, scarps, and broad terraces. Biostratigraphic analyses of the canyon lithologies indicate Late Paleocene to Late Oligocene depositional ages within upper bathyal depths (200–700 m). The video footage has revealed a quiescent ‘fossil canyon’ system with sporadic, localized concentrations of mega- and macro-benthos (∼680–1,800 m), which include corals, sponges, molluscs, echinoderms, crustaceans, brachiopods, and worms, as well as plankton and nekton (fish species). Solitary (Desmophyllum dianthus, Caryophyllia sp., Vaughanella sp., and Polymyces sp.) and colonial (Solenosmilia variabilis) scleractinians were sporadically distributed along the walls and under overhangs within the canyon valleys and along its rim. Gorgonian, bamboo, and proteinaceous corals were present, with live Corallium often hosting a diverse community of organisms. Extensive coral graveyards, discovered at two disparate sites between ∼690–720 m and 1,560–1,790 m, comprise colonial (S. variabilis) and solitary (D. dianthus) scleractinians that flourished during the last ice age (∼18 ka to 33 ka BP). ROV sampling (674–1,815 m) spanned intermediate (Antarctic Intermediate Water) and deep waters (Upper Circumpolar Deep Water) with temperatures from ∼2.5 to 6°C. Seawater CTD profiles of these waters show consistent physical and chemical conditions at equivalent depths between dive sites. Their carbonate chemistry indicate supersaturation (Ωcalcite ∼ 1.3–2.2) with respect to calcite, but mild saturation to undersaturation (Ωaragonite ∼ 0.8–1.4) of aragonite; notably some scleractinians were found living below the aragonite saturation horizon (∼1,000 m). Seawater δ13C and nuclear bomb produced Δ14C compositions decrease in the upper canyon waters by up to ∼0.8‰ (<800 m) and 95‰ (<500 m), respectively, relative to measurements taken nearby in 1978, reflecting the ingress of anthropogenic carbon into upper intermediate waters.This work was supported by research funding from the Australian Research Council to MM (FL120100049) and JT (FT160100259), the Italian National Programme of Antarctic Research (PNRA16-00069 Graceful Project) to PM and MT, the Australian Institute of Nuclear Science and Engineering to MM, JT, JF, RT, MT, PM (AINSE Award 16/009). Supplementary oceanographic data are funded through Integrated Marine Observing System (IMOS) supported by the Australian Government

    Linking coastal and seafloor morphological features along the eastern side of the Maltese archipelago

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    The integration of detailed geomorphological information from the present subaerial exposures of the Maltese archipelago, with morphobathymetric data obtained from the adjacent continental margin may serve in understanding processes active in shaping the archipelago since the Last Glacial Maximum. In perspective, this appears also to be of fundamental importance to better define the kinematics of active gravitational processes occurring along the coastlines. Preliminary results reveal the existence of submerged morphologies comparable to subaerial analogous. A case in point is circular depressions at shallow depth interpreted as inundated former karst features like sinkholes on-land. This is probably the case also of fractured plateaus surrounded by detached blocks identified offshore, which are comparable to terrestrial landforms formed by lateral spreading. Other relevant features identified on the continental margin and easily correlatable with morphologies on land include meandering river valleys.peer-reviewe

    Images from a drowned prehistoric landscape : the eastern side of the maltese archipelago

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    Offshore research carried out to map the seafloor on the north-eastern Maltese margin resulted in the first acquisition of multibeam bathymetric data imaging with detail the seascape. The surveys were conducted during cruises MEDCOR and DECORS in December 2009 and August 2011 respectively onboard R/V Urania. These missions mapped the north-eastern Maltese continental margin from off north Gozo to the southern tip of Malta. These data have been integrated by further high-resolution multibeam records acquired during cruise RICS 2010 onboard R/V Hercules on the shallow eastern margin between southern Gozo and north Malta.peer-reviewe

    Application of Hyperspectral Imaging to Underwater Habitat Mapping, Southern Adriatic Sea

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    Hyperspectral imagers enable the collection of high-resolution spectral images exploitable for the supervised classification of habitats and objects of interest (OOI). Although this is a well-established technology for the study of subaerial environments, Ecotone AS has developed an underwater hyperspectral imager (UHI) system to explore the properties of the seafloor. The aim of the project is to evaluate the potential of this instrument for mapping and monitoring benthic habitats in shallow and deep-water environments. For the first time, we tested this system at two sites in the Southern Adriatic Sea (Mediterranean Sea): the cold-water coral (CWC) habitat in the Bari Canyon and the Coralligenous habitat off Brindisi. We created a spectral library for each site, considering the different substrates and the main OOI reaching, where possible, the lower taxonomic rank. We applied the spectral angle mapper (SAM) supervised classification to map the areal extent of the Coralligenous and to recognize the major CWC habitat-formers. Despite some technical problems, the first results demonstrate the suitability of the UHI camera for habitat mapping and seabed monitoring, through the achievement of quantifiable and repeatable classifications

    The effects of irrigation on groundwater quality and quantity in a human-modified hydro-system: The Oglio River basin, Po Plain, northern Italy

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    For several hundred years, farming in the Po Plain of Italy (46,000 km2, 20 million inhabitants) has been supported by intensive surface irrigation with lake and river water. Despite the longevity of irrigation, its effects on the quality and quantity of groundwater is poorly known and so is investigated here through seasonal measurements of hydraulic heads and water quality in groundwaters, rivers, lake, springs and rainwaters. In the north of the study region, an unconfined coarse-grained alluvial aquifer, infiltration of surface irrigation water, sourced from the Oglio River and low in NO3, contributes much to aquifer recharge (up to 88%, as evidenced by a δ2H-Cl/Br mixing model) and has positive effects on groundwater quality by diluting high concentrations of NO3 (decrease by 17% between June and September). This recharge also helps to maintain numerous local springs that form important local micro-environments. Any increase in water-use efficiency in irrigation will reduce this recharge, imperil the spring environments, and lessen the dilution of NO3 leading to increasing NO3 concentrations in groundwater. These findings can be extended by analogy to the entire Po Plain region and other surface-water-irrigated systems worldwide where inefficient irrigation methods are used and similar hydrogeological features occur
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