1,720,987 research outputs found
Residue analysis by GC-MS and FT-IR Spectroscopy on roman amphorae from the archaeological site “Nuovo Mercato Testaccio” (Rome)
No full textLo studio dei residui organici su reperti archeologici attraverso un approccio interdisciplinare
No full textVessels and function: the contribution of residue analysis on the ceramics from Hierapolis, Phrygia (Turkey
No full textNovel attribute of organic-inorganic hybrid coatings for protection and preservation of materials (stone and wood) belonging to cultural heritage
No full textIn order to protect a material belonging to Cultural Heritage (i.e., stone, wood) from weathering, and in turn to preserve its beauty and historical value for the future generations, the contact with external harmful agents, particularly water, must be avoided, or at least limited. This task can be successfully obtained with the use of a protective organic coating. The use of nano-metric reinforcing agents in conventional polymeric coatings demonstrated to be a successful route in achieving better protective performance of the films and improved physical properties, even in extreme environments. The present paper would, therefore, review the more recent findings in this field. Generally speaking, when a hydrophobic product is applied on its surface, the stone material will absorb less water and consequently, less substances which may be harmful to it. An efficient organic coating should also supply wear and abrasion resistance, resistance to aggressive chemicals, excellent bond to the substrate; finally, it should be also able to guarantee vapor exchange between the environment and the material interior, i.e., the material should keep the same water vapor
permeability as if it was un-protected. To regard to the conservation of wood artifacts, protective treatments for wood will preserve the material from environmental agents and biological attack. Hence, potential advantages of hybrid (organic–inorganic) nano-composite coatings for stone/wood have been found to be: Enhanced mechanical properties in comparison to the pure polymeric matrix, due to the reinforcing effect of the nano-filler; superior barrier properties (the presence of the nano-filler hinders the ingress of water and/or potentially harmful chemicals); optical clarity and transparency. It has been found that the efficacy of a nano-filled coating strongly depends on the effectiveness of the method used to uniformly disperse the nano-filler in the polymeric matrix. Furthermore, the presence of nano-particles should not impair the viscosity of the organic matrix,
in order to employ the conventional techniques of application for coatings
Food preparation and consumption in the Messapian settlement of San Vito dei Normanni, (south-eastern Italy): organic residues analysis on pottery vessels of Archaic age
No full textPhase Change Materials for Energy Efficiency in Buildings and Their Use in Mortars
No full textThe construction industry is responsible for consuming large amounts of energy. The development of new materials with the purpose of increasing the thermal efficiency of buildings is, therefore, becoming, imperative. Thus, during the last decades, integration of Phase Change Materials (PCMs) into buildings has gained interest. Such materials can reduce the temperature variations, leading to an improvement in human comfort and decreasing at the same time the energy consumption of buildings, due to their capability to absorb and release energy from/in the environment. In the present paper, recent experimental studies dealing with mortars or concrete-containing PCMs, used as passive building systems, have been examined. This review is mainly aimed at providing information on the currently investigated materials and the employed methodologies for their manufacture, as well as at summarizing the results achieved so far on this subject
Experimental Cold-Cured Nanostructured Epoxy-Based Hybrid Formulations: Properties and Durability Performance
Full text linkDifferent hybrid epoxy formulations were produced and cold-cured, monitoring the properties development during low temperature curing and aging. All systems were based on silane functionalized bis-phenol A (DGEBA) resins (Part A), cured at ambient temperature with two amine hardeners (Part B). The different components of the formulations were selected on their potential capability to bring about enhancements in the glass transition temperature. The durability of the produced hybrids was probed in comparison to the corresponding neat epoxies by monitoring changes in glass transition temperature (Tg) and flexural mechanical properties after exposure to different levels of humidity and immersion in water and at temperatures slightly higher than the local ambient temperature, in order to simulate the conditions encountered during summer seasons in very humid environments. The thermal degradation resistance of the hybrid systems was also evaluated by thermogravimetric analysis
Oleo/hydrophobic coatings containing nano-particles for the protection of stone materials having different porosity
No full textConservation strategies to limit the degradation of stone materials are being constantly developed. To this aim, new materials are designed to confer hydrophobic properties and anti-graffiti protection to the treated surfaces. Hybrid nanocomposites, based on inorganic nano-particles added to an organic matrix, have been recently proposed for treatments of stone surfaces, obtaining promising and innovative properties. In the present paper, an experimental product based on fluorine resin containing SiO2 nano-particles, a commercial fluorine-based product and a silicon-based material
were applied as protective coatings on two calcareous stones (compact and porous) widely employed in the Mediterranean region. All the studied products are expected to provide both water and anti-graffiti protection to both stones’ surfaces. The rheological characterization of the liquid products, changes in color of the surfaces, and variations in water vapor permeability allowed the compatibility of the protective systems applied to stones to be evaluated. Water–stone contact angle measurements and water absorption by capillarity were used to control the action against water ingress. The oleophobicity was assessed by measuring the oil–stone contact angle. The experimental nano-filled product proved to be a suitable hydrophobic coating for compact and porous stones; furthermore, it provides high oleophobicity to the treated surfaces, as required for anti-graffiti systems
Removal and toxicity effects of chloramphenicol and acid orange solutions using zero-valent iron nanoparticles
No full textAn azo dye, acid orange (AO7), and an antibiotic, chloramphenicol (CAP), were selected as target compounds to evaluate the efficiency of zero-valent iron nanoparticles (nZVI) in the removal of contaminants of emerging concern (CECs). Synthesized nZVI were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis before and after the treatment process. The removal of both contaminants increased with of nZVI dosage (0.1125 g/L - 1 g/L), from 41 % up to 93 % for CAP and from 17 % up to 97 % for AO7, after 10 min of reaction. The SEM analysis performed at the end of the treatment revealed that, as result of the oxidation of nZVI, the chain-like structure completely disappeared whereas Fe and O were evenly distributed on the sample surface. At acidic conditions the removal of CAP and AO7 after 10 min of reaction reached 87 % and 84 %, respectively. At alkaline condition 69 % and 46 % of CAP and AO7 removal could be achieved after 80 min of reaction. The treatments with nZVI greatly reduced the toxicity of the starting CAP and AO7 solutions for all Artemia franciscana life stages but further efforts are necessary to achieve nZVI immobilization onto macroscopic supports
L’analisi funzionale delle ceramiche altomedievali nel Salento: il contributo delle indagini sui residui organici
No full textIl lavoro illustra alcuni risultati
della ricerca multidisciplinare, archeologica e
archeometrica, condotta in stretta sinergia da
archeologici e chimici, al fine di offrire un
contributo ai più vasti e complessi temi della
ricostruzione del paesaggio rurale del Salento
e dell’alimentazione umana fra Tardoantico e
Medioevo. A tale scopo, un certo numero di
reperti ceramici, rinvenuti nel corso degli scavi
condotti dall’Università del Salento su alcuni
siti di età medievale, sono stati sottoposti ad
analisi archeometriche, per determinare la
natura dei residui organici assorbiti
dal corpo ceramico e, in alcuni casi, visibili
come incrostazioni sulla superficie interna dei
contenitori
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