1,182 research outputs found
SEM-EDS characterization of historic mortar as a tool in archaeometric study: an updated analytical protocol tested on the Roman theatre of Aosta (NW Italy).
Improvements to the analytical protocol of lapis lazuli provenance: first study on Myanmar samples.
New petrographic and geochemical tracers for recognizing the provenance quarry of trachyte of the Euganean Hills, northeastern Italy
SEM-EDS X-ray compositional maps for minero-chemical characterization of ancient pottery: a first application on Adrano pottery (NE Sicily, Italy).
Gobernabilidad en Santa Cruz de la Sierra: Pautas para mayor transparencia y democracia local
A partir de los años ochenta se inició una nueva etapa democrática en Bolivia,
después de quince años de alternar entre gobiernos dictatoriales y constitucionales. La
profundización de la democracia fue prolongada (1978-1982), costosa, lenta y complicada.
El desarrollo de las democracias locales, como parte del proceso general, constituyó un
paso importante en esta consolidación y estuvo marcada por la aprobación de leyes que
promueven la descentralización y la participación popular, tendientes a fortalecer la
institucionalidad pública y a mejorar la calidad de vida de los ciudadanos, con una
distribución más equitativa de los recursos financieros administrados bajo el régimen de
vigilancia y control social. El proceso estuvo matizado por problemas de legitimidad y
gobernabilidad. Una vez superados los unos se presentaron otros, generando un debate
permanente y cambiante sobre el tema
Automated SEM‐EDS pottery classification based on minero‐chemical quantitative parameters: An application on ancient Greek pottery from Adrano (NE Sicily, Italy)
Late metamorphic veins with dominant PS-15 polygonal serpentine in the Monte Avic ultramafite
The ultramafic body of Monte Avic (Aosta Valley, Western Alps,
Italy) consists of antigorite serpentinite and Ti-clinohumite metadunite.
They host late metamorphic veins, up to a couple of centimeters thick,
compact, and homogeneous, with a “porcelain” appearance. Vein colors range
from yellowish to light greenish, light yellowish fading to white, or rare
orange. The veins consist of 15-sector PS-15 polygonal serpentine,
with chemical composition Mg2.85 Fe0.08 Si2.05 O7.05
[OH]3.95. Recognition of this unusual phase is supported by diagnostic
satellite reflections in the X-ray powder diffraction pattern (e.g., at
dobs of 2.502, 2.336, 2.151, and 1.966 Å) TEM images (showing
15-sector polygonal fibers, mostly 200 nm in diameter and a few µm in
length, forming a randomly oriented felt) and a µ-Raman wavenumber,
matching previous data. This different evidence affords the successful
distinction of PS-15 and PS-30, alternatively using TEM images, X-ray powder
diffraction, or the low- and high-wavenumber µ-Raman spectra. At Monte
Avic, the vein emplacement was accompanied by significant fluid pressure, as
suggested by deformation and dismembering of the host rock, with PS-15 grown
within isotropic stress microenvironments characterized by fluid-filled
voids. Random growth of the mass-fiber polygonal serpentine was favored by
low-strain conditions. PS-15 veins formed at the end of the long polyphase
Alpine orogenic evolution, with hydrous fluids possibly deriving from
serpentinite dehydration in the depth.</p
Yttrium Geothermometry Applied to Garnets from Different Metamorphic Grades Analysed by EPMA and µ-PIXE Techniques
Direct and indirect assessment of the amount of naturally occurring asbestos in fractured rocks
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