Search results for "paint"
showing 10 items of 605 documents
In vitro analysis of the pH stability of dental bleaching gels during in-office procedures
2021
Background Previous studies have shown that acidic bleaching gels could lead to worse collateral effects during an in-office bleaching procedure, while neutral or basic products leads towards a better experience. Considering this fact, the main purpose of this study was to evaluate the pH behavior of 6 in-office bleaching gels, compared to the information provided by their manufacturers. Material and methods Thirty enamel discs of bovine teeth were prepared, the initial colors of which were measured by a spectrophotometer and then divided into 6 groups. A pH meter was used to measure the pH every 30 seconds until the end of each procedure, when a new color evaluation was then made. The Tuke…
Effect of different protective agents on enamel erosion: An in vitro investigation
2019
Background The purpose of this in vitrostudy was to compare the effect of different protective agents on enamel erosion by measuring mean percentage weight loss. Material and Methods Extracted teeth were sectioned into uniform slabs and enamel specimens were randomly distributed to different groups. Initial weight of all enamel specimens was registered. The protective agents used in this study were Tooth Mousse, MI Paste Plus, Remin Pro and Remin Pro Forte. A control group was treated just with tap water. All the specimens were immersed in Coca-Cola for a total of 8 min at room temperature, dried and weighed. Enamel dissolution caused by acidic soft drink was analyzed: specimens were weighe…
Compositional and microhardness findings in tooth affected by X-linked hypophosphatemic rickets
2020
Background This study aimed to evaluate the X-linked hypophosphatemic rickets (XLHR)-related compositional and microhardness tooth aspects. Material and Methods One affected and one non-affected teeth by XLHR were sectioned transversely, and each section was separated for Micro-Raman spectroscopy, Knoop microhardness and scanning electron microscopy with energy dispersive x-ray microanalysis (SEM-EDS). The outcomes of these analyses were assessed. Results Outcomes of Raman analysis of inorganic/organic components (~958/~1250+~1450 cm−1) and carbonate/phosphate (~1070/~958 cm−1) ratios showed areas of altered enamel and dentin (interglobular dentin, calcospherites, and mantle dentin) with an…
I DIPINTI MURALI STACCATI: CRITICITÀ E NUOVE PROPOSTE
2015
La tesi di Laurea Magistrale a ciclo unico, in "Conservazione e Restauro dei Beni Culturali", della Dottoressa Nicoletta Chiparo, riguarda l'intervento di restauro di un lacerto di dipinto murale staccato, di età paleocristiana, raffigurante un'orante; l’approccio alle problematiche di conservazione del dipinto murale ha suggerito l’avvio di una ricerca bibliografica e di laboratorio sui materiali per la realizzazione degli strati di sacrificio per i dipinti murali staccati. Il dipinto murale, di provenienza incerta e delle dimensioni di cm. 60 di h, cm. 41.5 di larg. mm. 1-3 di sp., rappresenta una figura femminile orante che, per la resa del volto, dei particolari dell’acconciatura e la c…
Determination of Paint Solvents by Vapour Phase Fourier Transform Infrared Spectrometry.
1997
Abstract A fast procedure has been developed for the direct determination of paint solvents. The method is based on the injection of small volumes of untreated solvent mixtures into a heated Pyrex glass reactor in which the sample is volatilized and introduced by means of a flow of nitrogen into an IR multiple pass gas cell and the spectrum in the mid-IR region is registered as a function of time. Data found for samples are interpolated in calibration graphs obtained by injecting different volumes of pure compounds which constitute the solvent mixture. A methylisobutylketone (MIBK) toluene mixture was used as test system to develop the proposed procedure. The method provides a limit of dete…
Identification of lipid binders in old oil paintings by separation of 4-bromomethyl-7-methoxycoumarin derivatives of fatty acids by liquid chromatogr…
2005
A HPLC-fluorescence method for identification of drying oils from binding media or protective film used in pictorial works of art prior to conservation or restoration is proposed. Fluorescence derivatization of fatty acids released by hydrolysis of structural drying oils is studied. The derivatization reagent was 4-(bromomethyl)-7-methoxycoumarin with 18-crown-6 as catalyst. Mobile phase was programmed from methanol-water (90:10 v/v) to methanol-water (100:0 v/v) in 25 min. The excitation and emission wavelengths were 325 and 395 nm, respectively. Under these chromatographic conditions, coumarin derivatives of myristic, palmitic, oleic and stearic acids were satisfactorily resolved. The met…
Klimt artwork: red-pigment material investigation by backscattering Fe-57 Mössbauer spectroscopy, SEM and p-XRF
2017
Material tests were performed on a rediscovered Klimt-artwork "Trompetender Putto". We performed studies on the red colored spots, mainly taken from non-restored parts. MIMOS II Fe-57 Mossbauer spectroscopy (novelty in art-pigment analysis) mainly reveals haematite and crystallized goethite in red colors. Electron microscopy can identify various layers of the original and overpainting of an artwork. The number of layers fluctuates between three and four chemically painted areas. The portable X-ray fluorescence analysis enables to reduce the pigment list to containing mercury (cinnabar), lead, zinc, iron and titanium. Infrared-light-irradiation visualizes the different age of the pigments.
Sacro, erotismo e ironia. Il corpo della donna ne "I Miracoli di Val Morel" di Dino Buzzati
2018
Ne "I miracoli di Val Morel" (1971) – una raccolta di immaginarie pitture votive originarie della valle bellunese e dedicate a Santa Rita – Dino Buzzati contrappone due tipi femminili: la peccatrice e la santa; la donna lussuriosa e la donna casta; la donna della tentazione e la donna della salvezza; la donna che espone il proprio corpo allo sguardo maschile e la donna pudica in abiti agostiniani. Le due figure femminili non costituiscono però una semplice contrapposizione tra due tipi ideali di donna, estetici o moraleggianti, ma la loro compresenza, nel testo verbale e visivo, si lega strettamente alle strategie di veridizione o, detto altrimenti, alla ricerca della verità, tema centrale …
The effects of a saline environment on the durability of commercial photocatalytic paints
2016
The use of photocatalytic products for surface coating of buildings ensures the reduction of certain air pollutants and greater duration of color over time, due to the reduced attitude of air particulate to adhere to the treated surfaces. The world market is producing a wide range of coatings, transparent and opaque, high initial performance, but there is a lack of data on their durability. The knowledge of performance over time of these new products is at the basis of the Regulation (EU) no. 305/2011, which repealed Council Directive 89/106/EEC and introduced the seventh requirement regarding the sustainability and particularly durability of construction works. This study focuses on the as…
Marginal integrity of class V restorations: SEM versus dye penetration.
2006
To perform an in vitro investigation on the marginal integrity of different adhesives (Optibond FL, Scotchbond 1XT, Clearfil SE Bond, Adper Prompt L-Pop, S(3) Bond, iBond exp., Adper Prompt L-Pop) in combination with Tetric Ceram as well as an experimental silorane-restorative (Hermes, Hermes Bond; 3M ESPE) using SEM and dye penetration (2% methylene blue) in a comparative manner.Standardized class V-cavities (3 mm x 1.5 mm) were prepared in 70 extracted human teeth (n=10). The adhesives were applied according to manufacturers' instructions. The cavities were restored with three increments. After finishing and polishing (Sof-Lex discs) and thermocycling (5000x, 5/55 degrees C), replicas wer…