Search results for "Rust"
showing 10 items of 1659 documents
An updated checklist and biogeography of the Sardinian large branchiopods, with a focus on Spinicaudata (Crustacea, Branchiopoda)
2021
Author(s): Marrone, Federico; Alfonso, Giuseppe; Cottarelli, Vezio; Botta, Marco Massimo; Koepp, Christian; Stoch, Fabio | Abstract: The large branchiopod fauna of Sardinia is reviewed based both on literature and newly collected data. Based on the available evidence, 13 taxa are present on the island (8 Anostraca, 2 Notostraca, and 3 Spinicaudata). Among them, the finding of the spinicaudatan Leptestheria dahalacensis is new for Sardinia, while the spinicaudatans Cyzicus bucheti and Eulimnadia sp. were overlooked in the most recent synopses on the fauna of the island due to misidentifications. Conversely, Cyzicus tetracerus and Limnadia lenticularis, previously erroneously reported based o…
L'applicazione delle regole di concorrenza nel mercato globale-locale: istanze di tutela, sfide ed opportunità
2015
La globalizzazione pone dal punto di vista antitrust nuove sfide, legate alla necessità di individuare le regole giuridiche e gli strumenti per intervenire in mercati i cui confini trascendono non solo la dimensione nazionale, ma addirittura quella europea. In questi contesti il controllo esercitato dalle singole autorità nazionali diventa, infatti, sempre più complicato e, per certi aspetti marginale, mentre quello realizzato all’interno della rete europea richiede alcuni aggiustamenti, necessari a incidere efficacemente sulle condotte tenute nell’arena globale
Atmospheric Corrosion Investigation in Industrial, Marine and Rural Environments in South-East Brazil
2002
ASTM 283-C, AISI 304 and 316-L steel specimens (called coupons) were exposed in marine, industrial and rural area(s) for different periods ranging between 1–12 months, in four different season campaigns. The corrosion rate was determined by chemical loss measurements. Rust characterization was performed by XRD, SEM, optical, and Mossbauer spectroscopy (in transmission and backscattering geometry). Superparamagnetic maghemite and goethite were found as corrosion products. Magnetic goethite and feroxyhite decrease with time of exposure. Lepidochrosite is detected and its intensity increase with the atmospheric exposure time. The results obtained from XRD and Mossbauer are in good agreement.
Zircon ages and Hf isotopic systematics reveal vestiges of Mesoproterozoic to Archaean crust within the late Neoproterozoic–Cambrian high-grade terra…
2012
Abstract Late Neoproterozoic to Cambrian ages have been widely recorded from the Southern Granulite Terrain (SGT) of India and were correlated with global tectono-thermal (Pan-African) events associated with amalgamation of the Gondwana supercontinent. We report results of single zircon dating from a charnockite and a granitic augen–gneiss from the SGT using SHRIMP and evaporation techniques, complemented by zircon Hf isotopic systematics. The SHRIMP data for zircons in the charnockite are spread along a well-defined discordia line suggesting variably strong lead–loss during the late Neoproterozoic Pan-African event. A concordant grain yielded a 207 Pb/ 206 Pb age of 1893 ± 13 Ma, and the u…
Single zircon ages, PT evolution and Nd isotopic systematics of high-grade gneisses in southern Malawi and their bearing on the evolution of the Moza…
2001
Abstract The high grade gneiss assemblage of central and southern Malawi belongs to the Neoproterozoic Mozambique belt of East Africa, and reached peak metamorphic conditions at 900±70°C and 9.5±1.5 kbar, followed by an isobaric cooling path. We report single zircon U–Pb and Pb–Pb ages and Nd isotopic data for orthogneisses and metapelites collected around Lilongwe and farther south in the region around Blantyre and Zomba. The ages document three distinct events, (1) a Kibaran-age period of intrusion of calc-alkaline granitoids around 1040–929 Ma; Nd isotope data indicate overall juvenile compositions consistent with a magmatic arc environment, or emplacement into thinned continental crust …
Du Toit Memorial Lecture 1999: The Mozambique belt of East Africa and Madagascar: significance of zircon and Nd model ages for Rodinia and Gondwana s…
2001
This paper discusses the question as to whether or not the high-grade metamorphic rocks exposed in the Mozambique belt (MB) of East Africa and Madagascar have played any role in the formation and dispersal of the supercontinent Rodinia, believed to have existed between ~1000 and ~750 Ma. First, there is little evidence for the production of significant volumes of ~1300 to ~1000 Ma (Kibaran- or Grenvillian-age) continental crust in the MB, except, perhaps, in parts of northern Mozambique. This crust cannot be related conclusively to either magmatic accretion processes along the active margin(s) of Rodinia, or to a collision event during continental collision and accretion leading to amalgama…
Service public d’eau en régie : vers une gouvernance efficace ?
2021
In the French water sector, some large cities have put an end to public service delegations entrusted to private operators and have chosen to return in public control, which may seem surprising in view of the new public management advocating the private sector model. In a water sector, a “natural monopoly” marked by strong moral hazard, information asymmetries and many uncertainties, public service delegations continue to raise serious governance issues both theoretically and empirically, despite more restrictive regulations. A three-year intervention-research in a new régie, public operator, contributed to the implementation of management tools. The multiple data collected (documents, inte…
The roles of the state and social licence to operate? Lessons from nuclear waste management in Finland, France, and Sweden
2019
The concept of social licence to operate (SLO) is an increasingly popular tool for companies to manage their relations with the local communities. SLO is very seldom used in the nuclear sector, which has nevertheless applied similar approaches, under notions such as partnership and participatory governance. This article explores the specific challenges that the application of SLO faces in the nuclear waste management (NWM) sector, by applying an often-used SLO framework of Boutilier and Thomson to illustrative case studies concerning nuclear waste repository projects in Finland, France and Sweden. Among the specificities of this sector, the article focuses on the central roles of the state …
Geochronology of the mid-German crystalline rise west of the River Rhine
1996
The mid-German crystalline rise has its westernmost exposures at the western margin of the Rhine graben in the southern Pfalz and the northern Alsace. The outcrops are made up of granitoid rocks and minor volcano-sedimentary sequences. Radiometric ages obtained by U/Pb, Pb/Pb, Sm/Nd and Rb/Sr analyses of the igneous rocks from this area range from ∼433 to ∼325 Ma thus covering a time span from the Silurian to the end of the lower Carboniferous. Because the investigated rocks are — according to their chemical composition — largely related to subduction zone environments, the following three geodynamical scenarios are postulated, always taking subduction of oceanic crust beneath the mid-Germa…