Search results for "Mineral"

The production cycle of lime based plasters in the Late Roman settlement of Scauri, Island of Pantelleria (Italy)

2016

This paper deals with the archaeometric study and analysis of lime based plasters recently found in the archaeological settlement of Scauri, located in the homonymous bay at the island of Pantelleria (central Mediterranean, Strait of Sicily). The Bay of Scauri is sited in the south-west part of the island. It can be considered a natural harbour overlooking the coast of Cape Bon in Tunisia. Since the 1999, the archaeological importance of place was reconsidered thanks to the recovering of huge remains of a Late Roman settlement dating back to the 4th-5th century AD. A production quarter, a residential area, a necropolis and a religious area were brought to light. The economy of the settlemen…

Evaluación microestructural de materiales nanoparticulados preparados a partir de caolines

2009

En el presente trabajo se han seleccionado dos caolines con características microestructurales muy diferenciadas, y se les ha aplicado un tratamiento mecánico con un molino de discos de giro excéntrico empleando dos accesorios de distinta efectividad; un conjunto de copa y cilindro de ágata (ag) y otro de copa, anillo y cilindro de acero recubierto de carburo de wolframio (CW). Los materiales sin tratar y los generados en la molienda se han caracterizado microestructuralmente a través de tres métodos diferentes de análisis basados en datos de difracción de rayos X, y por microscopía electrónica de barrido. Se ha complementado la caracterización de los materiales con estudios de determinació…

Etude des concepts sensoriels dans le domaine du vin : de la représentation à la molécule

2022

Mineral Reactions in the Geological Underground Induced by H2 and CO2 Injections

2014

Abstract The R&D project H2STORE is part of the German program to reduce environmental pollution by energy production and in saving fossil natural resources. Thereby physico-chemical processes in the CO2-H2 system by organic and inorganic reactions receive increasing attention. In H2STORE siliciclastic reservoirs and their caprocks from 25 well sites in Germany and Austria are investigated by different analytical methods before and after H2/CO2 batch experiments under sample specific reservoir conditions (p, T, XFluid). Mineral dissolution, precipitation and their impact on reservoir quality (poro-perm, fluid pathways) and on the generation of methane by microbial metabolism triggered by CO…

A comparative study of different formulations of poultices for soluble salts removal from experimental plasters

2017

Soluble salts extractive capability of some commercial materials currently used in plaster restoration sector (ArbocelTM plus sepiolite; ArbocelTM, sepiolite and sand; Westox-Cocoon®) were tested in the present study, with the aim to evaluate their efficiency, their compatibility with the substrates as well as in terms of costs and duration of intervention. The three poultice products were first characterized in terms of porosimetric distribution. The desalination tests have been performed on samples of plaster specially formulated and made at the laboratory. Experimental specimens were then brought into contact with a solution of Na2SO4 0.3 M. The efficiency rating of these different types…

Antifouling Mortars for Underwater Restoration

2022

This research has focused on the assessment of the compositional features and mechanical and antifouling performances of two different mortars formulated for an underwater setting, and which contain Mg(OH)2 as an antifouling agent. Regarding the mechanical characterization, the uniaxial compressive strength and flexural strength were measured. The composition of the materials was explored by differential thermal/thermogravimetric analysis (DTA-TG), X-ray diffraction analysis (XRPD), and scanning electronic microscopy (SEM) coupled with EDS microanalysis. The assessment of the biological colonization was evaluated with colorimetric analysis and image analysis. The results suggest that both m…

THE MOSAIC OF THE FRIGIDARIUM OF “VILLA BONANNO” IN PALERMO: MINERALOGICAL AND PETROGRAPHIC ANALYSES FOR IN SITU CONSERVATION AND RESTORATION INTERVE…

2018

The topic of this study was the mineralogical and petrographic characterization of bedding mortars (made of different layers) and tesserae of Roman age (3rd century A.D.), taken from the mosaic of the Frigidarium of “Villa Bonanno”, brought to light by archaeological excavations conducted in the historical centre of Palermo. The collected samples have been analysed by thin-section optical microscopy (PLM), and scanning electron microscopy coupled with energy dispersive spectrometry (SEM-EDS). The study was aimed to define the “recipe” (composition of aggregate and binder, aggregate size distribution, aggregate/binder ratio), in order to assess the provenance of raw m…

Time-gated Raman and laser-induced breakdown spectroscopy in mapping of eudialyte and catapleiite

2020

Raman analysis of rock samples containing rare earth elements (REEs) is challenging due to the strong fluorescence, which may mask the weaker Raman signal. In this research, time‐gated (TG) Raman has been applied to the construction of the mineral distribution map from REE‐bearing rock. With TG Raman, material is excited with a short subnanosecond laser pulse, and the Raman signal is collected within a picosecond‐scale time window prior to the formation of a strong fluorescent signal by means of single‐photon avalanche diode array. This allows signal readout with a significantly reduced fluorescence background. TG Raman maps are used to reveal the location of valuable minerals and are compa…

Spatial-temporal analysis of hospitalizations with death caused by oral cancer in Brazil and its correlation with the expansion of healthcare coverag…

2022

Oral cancer (OC) is a growing public health problem worldwide. In Brazil, the National Oral Health Policy, implemented in 2004, expanded access to oral health services and prioritized OC care. However, it is not known whether this expansion resulted in a reduction in hospital admissions with death. This study aimed to analyze the proportion of hospital admissions who progressed to death due to OC in Brazil from 2007 to 2019 and its correlation with the coverage of health services. This study is an ecological, longitudinal, and analytical study of hospital admissions with death due to OC recorded in the Brazilian Hospital Information System. The following analyses were performed: descriptive…

Sicily: a geological laboratory

2018

“Geologists at risk of extinction”: this is the opening sentence of an article of March 29, 2016 of “Il Sole 24ORE”, (1) that fits well the difficult situation that this professional category is experiencing in recent years. It has been witnessed, in fact, a strong reduction in the educational offer in both the school and university system, with the number of Departments in Earth Sciences dropped from 29 to 8, accompanied by a progressive reduction in enrollment and graduates, from 1140 in 2002 to 586 in 2008 (2). Numbers that make you think, especially if contextualized to the Italian territory, widely characterized by the hydrogeological, seismic and volcanological risk, in whose preventi…