Search results for " Varnish"

A step forward in disclosing the secret of stradivari's varnish by NMR spectroscopy

2017

It is commonly thought that the varnishes used by the great violin-maker Antonio Stradivari may have a role in determining not only the esthetical features but also the acoustic properties of his instruments, and the idea of a “lost secret” is still widespread among musicians and violin-makers. Previous scientific researches on varnish samples of Stradivari's instruments revealed that they were generally made by a mix of linseed oil with and colophony or metal rosinates in different ratios ranging between 75/25 (oil/resin) and 60/40 (oil/rosinate). However, it is still not clear whether the mixture composition can be related to any structural and/or functional feature of the resulting varni…

A Portable Dynamic Laser Speckle System for Sensing Long-Term Changes Caused by Treatments in Painting Conservation

2018

[EN] Dynamic laser speckle (DLS) is used as a reliable sensor of activity for all types of materials. Traditional applications are based on high-rate captures (usually greater than 10 frames-per-second, fps). Even for drying processes in conservation treatments, where there is a high level of activity in the first moments after the application and slower activity after some minutes or hours, the process is based on the acquisition of images at a time rate that is the same in moments of high and low activity. In this work, we present an alternative approach to track the drying process of protective layers and other painting conservation processes that take a long time to reduce their levels …

Comparison of combined application treatment with one-visit varnish treatments in an orthodontic population

2013

Objective: To evaluate the effect of chlorhexidine-thymol varnish alone, its combination with chlorhexidine-fluo - ride containing dentifrice and fluoride varnish on oral hygiene and caries prevention in orthodontic patients. Study design: Sixty patients, aged 12-18, with orthodontic fixed appliances were randomly assigned into three groups as follows: Group 1 (n=20): 1% chlorhexidine and 1% thymol varnish (Cervitec ® Plus); Group 2 (n=20): Cervitec ® Plus+ 0.2% chlorhexidine and 0.2% sodium fluoride (900 ppm fluoride) (Cervitec ® Gel)); and Group 3 (n=20): 0.1% fluoride varnish (Fluor Protector ® ). Mutans streptococci (MS), lactobacilli (LB) levels, buffering capacity (BC), visible plaque…

La torre del Tempo: il punto di vista del chimico

2013

L’obiettivo del presente lavoro è stato quello di valutare la tipologia di lega metallica, il suo degrado e la tipologia di vernice dell’opera in ferro policroma “La Torre del Tempo” di E. Tadini. A tale scopo sono state effettuate delle misure di Microscopia Ottica, Diffrattometria a raggi X, Spettroscopia micro-Raman e Spettroscopia NMR. The goal of this study was to evaluate the type and the of conservation state of the metal alloy and the type of varnish of samples coming from “La Torre del Tempo” E. Tadini. The samples were characterized by Optical Microscopy, X-ray Diffractometry, micro-Raman Spectroscopy and NMR spectroscopy.

Complementary remineralizing effect of self-assembling peptide (P11-4) with CPP-ACPF or fluoride : an in vitro study

2020

Background Self-assembling peptide has been recently introduced to promote hard tissue regeneration for treating early non-cavitated carious lesions. This study investigates the efficacy of biomimetic self-assembling peptide (P11-4) on enamel remineralization combined with CPP-ACPF or fluoride. Material and methods Artificial enamel lesions were created on buccal surface of 60 specimens and were randomly assigned to six groups according to the remineralizing agent: G1-(Control, artificial saliva), G2-(Fluoride varnish), G3-(CPP-ACPF varnish), G4-(Self-assembling peptide), G5-(Self-assembling peptide+fluoride varnish), G6-(Self-assembling peptide+CPP-ACPF varnish). All products were applied …

Gas chromatography-mass spectrometry characterization of the varnish and glue of an ancient 18th century double bass.

2007

A GC–MS investigation is conducted on the double bass “Panormus”, property of Conservatorio di Musica “Vincenzo Bellini” in Palermo. The most important components of the varnish (fatty acids) and of the glue (proteinaceous amino acids), with which the musical instrument was treated in the past, are determined. The analyses are carried out by prior derivatization of fatty acids by acidic methanol and of amino acids by acidic methanol and trifluoroacetic anhydride (TFAA). Analytes identification is achieved by direct comparison with several reference materials and the use of a digitized library.

Microanalytical methods for in-situ high-resolution analysis of rock varnish at the micrometer to nanometer scale

2015

Abstract A wide range of analytical techniques were used to investigate rock varnish from different locations (Negev, Israel; Knersvlakte, South Africa; Death Valley and Mojave Desert, California): a 200 nm-femtosecond laser ablation-inductively coupled plasma-mass spectrometer (LA-ICP-MS), an electron probe microanalyzer (EPMA), focused ion beam (FIB) slicing, and scanning transmission X-ray microscopy–near edge X-ray absorption fine structure spectroscopy (STXM–NEXAFS). This combination enables comprehensive high-spatial-resolution analysis of rock varnish. Femtosecond LA-ICP-MS and EPMA were used for quantitative determination of element concentrations. In-situ measurements were conducte…

Fungi and Sediments

2000

Fungi are saprophytic organisms that can form lichens in symbiosis with an alga. Along with lichens, they excrete large quantities of organic acids, contributing to rock dissolution and neoformation of crystals, mainly oxalates and carbonates. Fungi contribute to the accumulation of manganese and iron as desert varnish and play a major role in the calcium cycle inside calcretes and carbonate soils in arid zones. Fungi constitute an important part of calcified filaments found in calcretes. They are covered with calcium oxalate crystals, which can transform into calcite during early diagenesis. They can also precipitate needle-fiber calcite, a common form of CaCO3 found in soils and calcretes…

Caratterizzazione delle vernici da antichi strumenti musicali.

2011

Impact of public preventive programmes on oral quality of life of 11 to 12-yr-old school students

2007

Objectives: The objective was to analyze the impact of preventive programmes on oral quality of life in school students aged 11-12 yrs. Study design: In the school year 1996/97, a quasi-experimental study was initiated in Granada province with four groups of students aged 6-7 yrs: Sealant + Fluoride (sealants on first permanent molars applied in the health centre for a 3-yr active programme, and fluoride varnish applied every four months for 3 yrs, n=65), Sealant (only sealants, n=80), Fluoride (only fluoride varnish, n=107) and Control group (n=59). All students were examined every 6 months at school during the 3-yr active programme and received an oral health report after each examination…