1,721,015 research outputs found
Punturo R., Rizzo G., Buccione R., Visalli R., Indelicato V., Cirrincione R., 2024. Petrography, Geochemistry and Mineralogy of Serpentinite Rocks in the Ophiolite Units at the Calabria and Basilicata regions, Southern Apennine (Italy): state of the art and ongoing research. SGI SIMP Joint Conference, Bari 3-5 September 2024.
No full textHighly-porous light-weight bricks produced recycling organic waste
No full textUnder the motivation (https://ec.europa.eu/programmes/horizon2020/) of the Horizon2020 program, increasing efforts have been addressed in recent years to the introduction of sustainable products into the marketplace and enhancing awareness on eco-labelling, promoting environmental protection, human health, and supporting sustainable development. Waste products generated by industry and other human activities may represent a new primary resource if reused in the production process, thus saving primary geo-resources, reducing manufacturing costs, and limiting extension of waste deposits, all pressing priorities for our society. Moreover, the growing demand of low cost and highly-porous bricks in building construction materials has provided improvement in thermal insulation of the final product. From literature, organic-type additives are the most frequently used as poreforming agents because they combust during the firing process of brick production. In this work, residues from wine production were used to produced new highly-porous light-weight bricks. Following a multi-analytical approach, pores formed from this pore-forming agent were investigated also in terms of the properties they confer to this new type of bricks. Here we present the preliminary results on mineralogical evolution and physical properties of the experimental brick type obtained using clay materials chemically rich in SiO2 (57.77 wt.%) and Al2O3 (14.14 wt.%), where 10 % (vol.) of dry milled grapes were added with a grain-size up to 2 mm. Due to the large dimension of part of the pores, porosity was explored both by hydric texts and image analysis at the scanning electron microscope on three differently oriented large sections (4.5 x 3 cm2). Thermal insulation analysis was here interpreted in relation to the pore volume and distribution. All the data were compared with those obtained from standard bricks produced using the same base clay. Grapes combustion, indeed, increases the porosity of the final product both in terms of total efficient porosity (%) and in pore dimensions, resulting in enhanced thermal insulation properties. Large size of pores, moreover, favors a good durability moderating possible residual crystals trapped from salt solutions and damages caused by increased volume of ice when in freeze-thaw conditions. These characteristics and valuable aesthetic properties bode assessments for a possible implementation of the new mix into the marke
PT-path reconstruction via unraveling of complex zoning pattern from image assisted analysis: The case of the atoll garnets of the Aspromonte-Peloritani Unit (northeastern Sicily-Italy).
No full textGarnet micaschists nearby Santa Lucia del Mela - Peloritani Mountains (North-eastern Sicily, Italy), were studied by integrating information obtained from petrographic and image-assisted analyses of mineral phase compositions by using X-ray maps and thermodynamic modeling. These rocks are characterized by the presence of atoll garnets, and preserve a continuous array of textures from pristine garnets, through peninsula or island textures, to atoll textures. Completely substituted garnets represent the final stage of the process. These textures result from the metamorphic evolution of the rocks, consisting of two main stages of recrystallization-deformation events. The sequence of mineral parageneses associated to successive deformation events is as follows: early D1 is characterized by the assemblage wm1 + chl1 + bt1 + pl1 + grt1 + qtz + ilm + ap; late D1 by grt2 + wm2 + chl2+ bt2 + pl2 + qtz + ilm + ap + hem; D2 (associated to garnet core transformation) by grt3 + bt3 + pl3 + wm3 + qtz + chl3 + ilm. On the basis of textural observations and mineral parageneses, the atoll formation is related to the substitution of garnet cores during the D2 stage, with the consumption of garnet cores (grt1) and production of new garnet rim (grt3) with wm, bi, qtz and pl. The recognition of the different stages of garnet growth and associated parageneses has been obtained using image analysis coupled with compositional maps, performed via multivariate statistical analysis of four selected X-Ray map arrays. Following the textural and mineral-chemical analyses, PT conditions associated to the three recrystallisation stages have been determined via pseudosection computations. Results indicate that the analyzed rock-types have recorded a clock-wise PT trajectory during the Variscan orogeny, defined by a prograde evolution, in amphibolite facies conditions, preserved in relic garnet cores, followed by an initial decompressional evolution toward lower amphibolite facies conditions associated to a partial heating. During this last stage the multi stadial atollization process took place, retrogradely evolving toward a green-schist facies conditions, constrained through the compositions of the pseodomorphyc mineral aggregates gradually substituting previously formed garnets
Integrated geological and petrographic study supporting the interpretation of ancient artefacts: the case history of Palagonia area (SE Sicily)
No full textA little area located in the northern margin of the Hyblean Plateau (SE Sicily), close to the little town of Palagonia (administrative territory of Catania), in the archaeological area of Caltagirone, was studied by means of geological and petrographic integrated surveys.
The starting point for the study was the occasional discovery of
an uninterpreted ancient artefact, whose manufacture was our
subject of interest.
The geological-geomorphological study consists of detailed field
mapping at 1:10.000 scale and of the reconstruction of the stratigraphy and of the hydrogeological setting of the site.
The area is characterized by a succession of interbedded volcanic
and sedimentary litotypes ranging in time from the late
Pliocene to Holocene affected by tectonic episodes causing the
14 formation of a graben-horst setting.
In detail, the find is located close to a graben whose floor was
occupied by a lake (now disappeared) in the Holocene time, representing
a superficial aquifer system. Furthermore, the detailed
reconstruction of the stratigraphic succession, represented by a
thick horizon of vulcanoclastites (late Pliocene-early Pleistocene)
overlapped by a thin level of calcarenites (early Pleistocene) was
coupled with petrographic investigations, that emphasized the
degree of alteration of the volcanoclastic sequence, as testified by
the widespread occurrence of secondary authigenic minerals such
as clayey material that substitute volcanic glass and primary minerals
and, at the same time, fills in the open vesicles; this process
determines an increase in impermeability of the site’s substratum
compared to the overlying calcarenite. Thus, the geological and petrographic
data suggest the presence during the recent past, of a
shallow unconfined aquifer.
The collected data, that testify a probable high availability of
water, are in agreement with the direct observation of the ancient
artefact, mainly represented by a system of circular and squared
chambers linked by narrow trenches, of which we also estimated
potential the water amount that could be stored in
Petrography and geochemestry of porhyritic clasts of Tortonian conglomerates of north-central Sicily: Paleogeographic and Paleotectonic Implications
No full textGoing Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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