Search results for "Ambiente"
showing 10 items of 1727 documents
Names for trace fossils: a uniform approach.
2006
The taxonomic treatment of trace fossils needs a uniform approach, independent of the ethologic groups concerned. To this aim, trace fossils are rigorously defined with regard to biological taxa and physical sedimentary structures. Potential ichnotaxobases are evaluated, with morphology resulting as the most important criterion. For trace fossils related to bioerosion and herbivory, substrate plays a key role, as well as composition for coprolites. Size, producer, age, facies and preservation are rejected as ichnotaxobases. Separate names for undertracks and other poorly preserved material should gradually be replaced by ichnotaxa based on well-preserved specimens. Recent traces may be iden…
Late Quaternary nearshore molluscan patterns from Patagonia: Windows to southern southwestern Atlantic-Southern Ocean palaeoclimate and biodiversity …
2019
Varied approaches (palaeobiodiversity, palaeobiogeography, bioerosion, geochemistry) to unique Patagonian late Quaternary molluscan assemblages in the southwestern Atlantic, with ages especially from interglacial Marine Isotope Stage (MIS) 5e and MIS 1, provide large-scale and long-temporal palaeoenvironmental data for the southern SWA. Together with new patterns of δ18O and δ13C variations in modern, mid-Holocene, and Late to Middle Pleistocene shells of Protothaca antiqua (Bivalvia) and the coeval Pleistocene Tegula atra (Gastropoda), the overall sources of evidence illustrate possible responses to recent palaeoclimate and sea-ice changes around the southernmost SWA-western Antarctica, le…
"Cultura e Tecnica della Partecipazione"
2008
Gli strumenti e le strategie dei processi partecipativi in ambito urbano. Obiettivo è il recupero e la riqualificazione degli ambienti degradati da atti di abuso o uso improprio del costruito.
Late Cenozoic brittle deformation in the Southern Patagonian Andes: Record of plate coupling/decoupling during variable subduction?
2018
The Andes of southern Patagonia experienced a Miocene shift towards faster and higher angle subduction followed by the approach and collision of the Chile oceanic ridge. We present a kinematic study characterizing palaeostress fields computed from brittle tectonics to better constrain upper crustal deformation during this complex scenario. Although previous studies already suggested variable kinematics, it is striking that in a long-lasting subduction environment, the computed palaeostress tensors are mostly strike-slip (55%), while 35% are extensional, and only 10% compressive which are concentrated along a main frontal thrust. Cross-cutting relationships and synsedimentary deformation ind…
Paleontología y ambientes del Triásico Medio en el sector noroccidental de la cordillera ibérica (provs. de Soria y Guadalajara, España)
1991
El Triásico Medio del sector noroccidental de la Cordillera Ibérica está compuesto por dos formaciones carbonáticas, que se corresponden con la unidad carbonática superior del Muschelkalk, y que hacia el NW pasan lateralmente a una formación terrígena. El registro fósil se encuentra en ambos tipos de formaciones. Tanto el estudio tafonómico como sedimentológico, permiten inferir la presencia de elementos acumulados que podrían corresponder a asociaciones autóctonas, compuestas en su mayoría por bivalvos infaunales de medios marinos someros y sometidos a fuerte influencia de terrígenos. Se caracterizan en la zona tres asociaciones faunísticas: 1. Asociación CostatoriaLyriomyophoria, que apar…
Dominating, Protecting, Creating. A Philosophical Essay about Utopianist Attitudes
2017
La cuestión medioambiental acapara cada día la atención internacional y condiciona en buena medida las fantasías condenatorias de la sociedad actual. Persistentemente se nos anuncian finales del mundo y escenarios apocalípticos brotados de la venganza de la naturaleza, víctima, se cuenta, del progreso irresponsable y devastador del ser humano. En este artículo pretendemos reflexionar filosóficamente en torno a los impactos de la acción humana sobre el mundo físico adoptando como objeto de estudio las actitudes de la utopía ante la naturaleza. Nuestra intención principal es la de sugerir una aproximación utopista a los problemas ecológicos que haga frente, por igual, a las contraindicaciones…
Grafting of (3-chloropropyl)-trimethoxy silane on halloysite nanotubes surface
2021
Modified halloysite nanotubes (HNTs-Cl) were synthesized by a coupling reaction with (3-chloropropyl) trimethoxysilane (CPTMS). The incorporation of chloro-silane onto HNTs surface creates HNTs-Cl, which has great chemical activity and is considered a good candidate as an active site that reacts with other active molecules in order to create new materials with great applications in chemical engineering and nanotechnology. The value of this work lies in the fact that improving the degree of grafting of chloro-silane onto the HNT’s surface has been accomplished by incorporation of HNTs with CPTMS under different experimental conditions. Many parameters, such as the dispersing media, the molar…
Oxadiazolyl-Pyridinium as Cationic Scaffold for Fluorinated Ionic Liquid Crystals
2021
The synthesis and characterization of a new class of 1,2,4-oxadiazolylpyridinium as a cationic scaffold for fluorinated ionic liquid crystals is herein described. A series of 12 fluorinated heterocyclic salts based on a 1,2,4-oxadiazole moiety, connected through its C(5) or C(3) to an N-alkylpyridinium unit and a perfluoroheptyl chain, differing in the length of the alkyl chain and counterions, has been synthesized. As counterions iodide, bromide and bis(trifluoromethane)sulfonimide have been considered. The synthesis, structure, and liquid crystalline properties of these compounds are discussed on the basis of the tuned structural variables. The thermotropic properties of this series of sa…
“KNOWLEDGE PROCESSES BUILT-UP ENVIRONMENT RECOVERY AND HERITAGE ENHANCEMENT”
2010
To exchange views about the forms, actions and instruments of “doing architecture”, and to analyse in depth the needs for “recognition”, renewal and sustainable development, means to grasp the intrinsic relationship (gradually established in the course of time) between conservation – cultural heritage enhancement, maintenance, protection and safety – and the innovative aspects deriving from the dynamics of change. Such issues contribute to the delineation of the field of the research experience, and help to produce the terms for the definition of its subject matter KNOWLEDGE PROCESSES, BUILT-UP ENVIRONMENT RECOVERY AND HERITAGE ENHANCEMENT, with the aim of experimenting with methods, proces…
Il paesaggio degradato della “periurbanità” in Agrigento
2010
Il territorio di Agrigento in Sicilia è un esempio alto di “paesaggio storicamente connotato” da salvaguardare e valorizzare. Complessi sono gli “scenari” del paesaggio che caratterizzano il territorio agrigentino: il paesaggio archeologico, il paesaggio rurale, il paesaggio urbano, il paesaggio periurbano. Quest’ultimo è il più contraddittorio in quanto luogo ibrido in cui coesistono caratteri che fanno parte dell’ambiente urbano e dell’ambiente rurale. Il paesaggio periurbano” contiene infatti sia le problematiche causate dalla crescita incontrollata della città, sia le criticità determinate dai pesanti processi di trasformazione degli ambienti agricoli e naturali. Attivare un processo di…