scholarly journals Electrochemical assessment of pigment-binding-pigment interactions in oil paint deterioration: a case study on indigo and Prussian blue

2020 ◽  
Author(s):  
Antonio Doménech-Carbó ◽  
María Teresa Doménech-Carbó ◽  
Laura Osete-Cortina ◽  
Margherita Donnici ◽  
Nuria Guasch-Ferré ◽  
...  
Keyword(s):  
Prussian Blue ◽  
Uv Radiation ◽  
Paint Film ◽  
Solar Light ◽  
Radical Scavenger ◽  
Binding Media ◽  
Synthetic Oil

Abstract The degradation of synthetic oil paint film specimens containing indigo and Prussian blue pigments and pictorial samples from the Sant Francesc de Paula painting from the museum of Cardedeu (Catalonia, Spain) has been studied by voltammetry of immobilized particles. This technique, combined with SEM-EDX, ATR-FTIR and CG-MS techniques permits to propose a dual scheme for the degradation of the pigments when submitted to natural, UV and UV solar light aging. Under ‘ordinary’ conditions, Prussian blue acts as a radical scavenger moderating the production of ROS produced in the binding media by the action of UV radiation, resulting in the formation of Berlin green and indigo adducts with radicals. In the case of localized areas of the Sant Francesc de Paula paint, strong degradation occurs where Prussian blue acts as a promoter of the indigo oxidation to isatin, thus resulting in a considerable chromatic shift.

scholarly journals Electrochemical assessment of pigments-binding medium interactions in oil paint deterioration: a case study on indigo and Prussian blue

2020 ◽  
Author(s):  
Antonio Doménech-Carbó ◽  
María Teresa Doménech-Carbó ◽  
Laura Osete-Cortina ◽  
Margherita Donnici ◽  
Nuria Guasch-Ferré ◽  
...  
Keyword(s):  
Prussian Blue ◽  
Paint Film ◽  
Attenuated Total Reflectance ◽  
Radical Scavenger ◽  
Binding Medium ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Gas Chromatography Mass Spectroscopy

Abstract The degradation of laboratory oil paint film specimens containing indigo and Prussian blue pigments and pictorial samples from the Sant Francesc de Paula painting exhibited in the Tomàs Balvey Arxiu Museum (Cardedeu (Catalonia), Spain) has been studied by voltammetry of immobilized particles. This technique, combined with light microscopy, scanning electron microscopy-energy dispersive X-ray analysis, nanoindentation-atomic force microscopy, attenuated total reflectance-Fourier-transform infrared spectroscopy and gas chromatography-mass spectroscopy techniques permits the proposal of a dual scheme for the degradation of the pigments when naturally aged and submitted to accelerated UVA aging. Under conditions of moderate temperature, humidity and natural illumination, and low gradients of these parameters, Prussian blue acts as a radical scavenger moderating the production of reactive oxygen species produced in the oil binding medium by the action of ultraviolet radiation, resulting in the formation, in the solid state, of the solid-solution, {KFeIII[FeII(CN)6]}x{FeIII[FeIII(CN)6]}1–x, known as Berlin green, which then promotes the formation of indigo adducts with radicals. In several localized areas of the Sant Francesc de Paula paint showing strong degradation, Prussian blue acts as a promoter of the indigo oxidation to isatin, thus resulting in a considerable chromatic shift.

scholarly journals Electrochemical assessment of pigments-binding media interactions in oil paint deterioration: a case study on indigo and Prussian blue

2020 ◽  
Author(s):  
Antonio Doménech-Carbó ◽  
María Teresa Doménech-Carbó ◽  
Laura Osete-Cortina ◽  
Margherita Donnici ◽  
Nuria Guasch-Ferré ◽  
...  
Keyword(s):  
Prussian Blue ◽  
Paint Film ◽  
Attenuated Total Reflectance ◽  
Radical Scavenger ◽  
Binding Medium ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Gas Chromatography Mass Spectroscopy

Abstract The degradation of laboratory oil paint film specimens containing indigo and Prussian blue pigments and pictorial samples from the Sant Francesc de Paula painting exhibited in the Tomàs Balvey Arxiu Museum (Cardedeu (Catalonia), Spain) has been studied by voltammetry of immobilized particles. This technique, combined with light microscopy, scanning electron microscopy-energy dispersive X-ray analysis, nanoindentation-atomic force microscopy, attenuated total reflectance-Fourier-transform infrared spectroscopy and gas chromatography-mass spectroscopy techniques permits one to propose a dual scheme for the degradation of the pigments when naturally aged and submitted to accelerated UVA aging. Under conditions of moderate temperature, humidity and natural illumination, and low gradients of these parameters, Prussian blue acts as a radical scavenger moderating the production of reactive oxygen species produced in the oil binding medium by the action of ultraviolet radiation, resulting in the formation, in the solid state, of the solid-solution, {KFeIII[FeII(CN)6]}x{FeIII[FeIII(CN)6]}1–x, known as Berlin green, which then promotes the formation of indigo adducts with radicals. In the case of localized areas of the Sant Francesc de Paula paint, strong degradation occurs where Prussian blue acts as a promoter of the indigo oxidation to isatin, thus resulting in a considerable chromatic shift.

Wing shape and environmental energy are associated with molecular evolutionary rates in a large avian radiation

2020 ◽  
Author(s):  
David Alejandro Duchêne ◽  
Paola Montoya ◽  
Carlos Daniel Cadena
Keyword(s):  
Uv Radiation ◽  
Positive Association ◽  
Evolutionary Rates ◽  
Wing Morphology ◽  
Geographic Ranges ◽  
Molecular Evolutionary Rates ◽  
Strong Positive Association ◽  
Genomic Regions ◽  
Avian Family

AbstractAmong the macroevolutionary drivers of molecular evolutionary rates, metabolic demands and environmental energy have been a central topic of discussion. The large number of studies examining these associations have found mixed results, and have rarely explored the interactions among various factors impacting molecular evolutionary rates. Taking the diverse avian family Furnariidae as a case study, we examined the association between several estimates of molecular evolutionary rates with a proxy of metabolic demands imposed by flight (wing morphology) and proxies of environmental energy across the geographic ranges of species (temperature and UV radiation). We found a strong positive association between molecular rates in genomic regions that can change the coded amino-acid with wing morphology, environmental temperature, and UV radiation. Strikingly, however, we did not find evidence of such associations with molecular rates at sites not impacting amino-acids. Our results suggest that the demands of flight and environmental energy primarily impact genome evolution by placing selective constraints, instead of being associated with basal mutation rates.

Solar Light and Dopant-Induced Recombination Effects: Photoactive Nitrogen in TiO2 as a Case Study

2010 ◽  
Vol 114 (42) ◽  
pp. 18067-18072 ◽  
Author(s):  
Massimiliano D’Arienzo ◽  
Nicolas Siedl ◽  
Andreas Sternig ◽  
Roberto Scotti ◽  
Franca Morazzoni ◽  
...  
Keyword(s):  
Solar Light

Spatial variability of ultraviolet-absorbing compounds in an aquatic liverwort and their usefulness as biomarkers of current and past UV radiation: A case study in the Atlantic–Mediterranean transition

2015 ◽  
Vol 518-519 ◽  
pp. 248-257 ◽  
Author(s):  
Laura Monforte ◽  
Rafael Tomás-Las-Heras ◽  
María-Ángeles Del-Castillo-Alonso ◽  
Javier Martínez-Abaigar ◽  
Encarnación Núñez-Olivera
Keyword(s):  
Spatial Variability ◽  
Uv Radiation

Abatement of the major contaminants present in olive oil industry wastewaters by different oxidation methods: ozone and/or UV radiation versus solar light

2001 ◽  
Vol 44 (5) ◽  
pp. 325-330 ◽  
Author(s):  
M.A. Miranda ◽  
A.M. Amat ◽  
A. Arques
Keyword(s):  
Olive Oil ◽  
Uv Radiation ◽  
Reaction Times ◽  
Oil Industry ◽  
Solar Light ◽  
General Mechanism ◽  
Careful Study ◽  
Coumaric Acid ◽  
Cinnamic Acids ◽  
Acid Media

Four different cinnamic acids (caffeic acid, ferulic acid, p-coumaric acid and cinnamic acid) present in olive oil wastewaters, were treated with advanced oxidation methods: ozone and/or UV radiation. Basic and acid media were tested. Differences between all four acids were found, both in the reaction times and the intermediates formed. Based on a careful study of these intermediates and the variation of their concentrations all along the reaction time, a general mechanism for the degradative oxidation of cinnamic acids is proposed. These results are compared with those obtained with solar light, using a pyrylium salt as a catalyst.

scholarly journals Analysis of relationships between ultraviolet radiation (295–385 nm) and aerosols as well as shortwave radiation in North China Plain

2008 ◽  
Vol 26 (7) ◽  
pp. 2043-2052 ◽  
Author(s):  
X. Xia ◽  
Z. Li ◽  
P. Wang ◽  
M. Cribb ◽  
H. Chen ◽  
...  
Keyword(s):  
Uv Radiation ◽  
Zenith Angle ◽  
Solar Zenith Angle ◽  
Precipitable Water ◽  
Ground Level ◽  
Weather Conditions ◽  
Northern China ◽  
Shortwave Radiation ◽  
Relevant Variables

Abstract. The fraction of ultraviolet (UV) radiation to broadband shortwave (SW) radiation (FUV=UV/SW) and the influences of aerosol, precipitable water vapor content (PWV) and snow on FUV were examined using two year's worth of ground-based measurements of relevant variables in northern China. The annual mean FUV was 3.85%. Larger monthly values occurred in summer and minimum appeared in winter. Under cloudless condition, FUV decreased linearly with τ500 nm and the resulting regression indicated a reduction of about 26% in daily FUV per unit τ500 nm, implying that aerosol is an efficient agent in lowering the ground-level UV radiation, especially when the sun is high. Given that the annual mean τ500 nm is 0.82, aerosol induced reduction in surface UV radiation was from 24% to 74% when the solar zenith angle (θ) changed from 20° to 80°. One cm of PWV led to an increase of about 17% in daily FUV. One case study of snow influence on surface irradiance showed that UV and SW radiation increased simultaneously when the ground was covered with snow, but SW radiation increased much less than UV radiation. Accordingly, FUV increased by 20% for this case. Models were developed to describe the dependence of instantaneous UV radiation on aerosol optical depth, the cosine of the solar zenith angle (μ), and clearness index (Kt) under both clear and all-weather conditions.

Social Enterprises and SDGs: A Case Study of SELCO Solar Light Pvt. Ltd, India

2022 ◽  
pp. 221-235
Author(s):  
Tapan Sarker ◽  
Subhendu Dey ◽  
Anish Yousaf ◽  
Abhishek Mishra
Keyword(s):  
Social Enterprises ◽  
Solar Light
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