Search results for " gypsum"

Differenziazione e quantificazione dei carbonati litogenici e pedogenici di Gypsisuoli forestali attraverso l'analisi isotopica

2004

Gli autori riferiscono sui tipi e sui modelli di genesi dei carbonati dei suoli, attraverso l’uso degli isotopi del 13C. Lo studio è stato condotto in un’area dell’interno collinare argilloso siciliano, su suoli che evolvono sui depositi evaporitici della Serie Gessoso-Solfifera. Sono stati scelti cinque pedon su litotipi calcarei e non. I pedon sono stati descritti in campo e campionati secondo la sequenza degli orizzonti genetici; sui campioni di suolo sono state eseguite le seguenti analisi: tessitura, reazione, conducibilità elettrica, gesso, carbonio organico ed inorganico. Inoltre, parallelamente sono state eseguite le analisi isotopiche del carbonio organico ed inorganico. I risultat…

Spontaneous ecological recovery of vegetation in a red gypsum landfill: Betula pendula dominates after 10 years of inactivity

2019

International audience; Red gypsum is the product of the neutralization of titanium dioxide (TiO 2) extraction residue from ilmenite and anatase. The disposal of red gypsum creates heterogeneous plots with layers that may include Fe, Ca, Al, Mg, Mn, S, and other elements and an alkaline pH that makes revegetation complicated and slow. The vertical and horizontal dispersion of the sediment particles are the main concern. Therefore, the establishment of precise vegetation cover is needed to address this issue. One of the aims of this study was (1) to explore the distribution of the spontaneous vegetation found along a red gypsum-formed landfill located at the Ochsenfeld site in eastern France…

Geomorphological and speleological aspects of the Vallone Ponte-Grotte d'Acqua karst system (Sant'Angelo Muxaro - AG)

2009

The geochemical riddle of “low-salinity gypsum” deposits

2022

International audience; Gypsum makes up about one fifth of giant salt deposits formed by evaporation of seawater throughout Earth’s history. Although thermodynamic calculations and precipitation experiments predict that gypsum precipitates when the salinity of evaporating seawater attains about 110 g kg-1, gypsum deposits of the Mediterranean Salt Giant often bear the geochemical signature of precipitation from less saline water masses. Addressing this geochemical riddle is important because marine gypsum deposition and continental gypsum erosion affect the global carbon cycle. We investigated gypsum deposits formed in the marginal basins of the Mediterranean Sea during the Messinian Salini…

Gypsum and giant canes in the Sicilian traditional architecture

2014

Giant cane is a natural, eco-friendly and low-cost product that is very common in the Mediterranean area. As far as the Sicilian tradition is concerned, it has been combined with gypsum, a material with the same qualities. Reeds and gypsum have been used as a traditional composite material that is able to join and improve their peculiarities of lightness and insulation, and to utilize the bearing skill of the hardiest reeds and the fire protection and moulding skills of gypsum. This combination of poor and easy-to-find materials has been used very frequently in Sicilian traditional constructions. It is possible to see roofs with inclined floors; some wooden floors with reeds and gypsum used…

Soils with Gypsic horizon in southern Sicily, Italy

2005

Environmental impact assessment on the Monza cathedral (Italy): A multi-analytical approach

2020

This research deals with the characterization of black crusts collected from the Dome of Monza (Milan, Italy). Air pollution is responsible for the degradation of historical buildings surfaces. In urban and industrial areas, the degradation process is accelerated, due to carbonaceous particles and heavy metals emitted by combustion processes which contribute to the formation of black crust (BCs). In this study the characterization of BC was performed using different analytical techniques such as: HRSEM-EDX, IC, LA-ICP/MS and digital image analysis. In particular, the research focused on the study of "heavy metals" which contribute to the identify the main sources of pollution responsible fo…

First study of gypsum karst in Sicily. The contribution of Olinto Marinelli and Mariano Gemmellaro

2006

Accuracy of fit of implant-supported bars fabricated on definitive casts made by different dental stones

2018

Background The purpose of this study was to evaluate the accuracy of fitting of an implant supported screw-retained bar made on definitive casts produced by 4 different dental stone products. Material and Methods The dental stones tested were QuickRock (Protechno), FujiRock (GC), Jade Stone (Whip Mix) and Moldasynt (Heraeus). Three external hexagon implants were placed in a polyoxymethylene block. Definitive impressions were made using monophase high viscosity polyvinylsiloxane in combination with custom trays. Then, definitive models from the different types of dental stones were fabricated. Three castable cylinders with a machined non-enganging base were cast and connected with a very sma…

Source of calcium for pedogenic CaCO3 formation in benchmark soils of a Mediterranean semiarid environment

2004

Calcic and petrocalcic horizons (Bk and Bkm, respectively) commonly occur in soils of arid and semiarid regions. Studies carried out to investigate the source of calcium in CaCO3 formation have shown that dust and parent materials represent the main sources. The aim of this study was to investigate if gypsum may be a source of calcium for calcium carbonate formation and, eventually, to quantify it. Five soil pedons, developing on “Serie Gessoso- Solfifera”, were selected in a very representative forest Mediterranean ecosystem in Sicily (I). Pedons were opened, described in field and sampled according to the sequence of genetic horizons. Soil samples were analyzed to investigate 87/86Sr rati…