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Iron oxides, Pb 3 O 4 (red lead) with PbO, azurite and calcite were used as pigments in the Seville City hall façade. A gold gild was present in some areas. A black crust caused by environmental contamination was responsible for the black colour. Acrylic resin and other added materials are also responsible for some of the colour changes. The stone was cleaned, reinforced and innovatively consolidated and protected using suitable materials for restoration. [ABSTRACT FROM AUTHOR]

This work presents the analysis of the deterministic part of human colour perception at the computational, algorithmic and implementation levels. At the computational and algorithmic levels, we invoke the theory of Fuzzy sets. At the implementation level, we present Biologically Inspired Photochromic Fuzzy Logic (BIPFUL) systems that are useful to discriminate between the three regions of the UV spectrum (UV-A, UV-B and UV-C). Such BIPFUL systems have been devised by imitation of the human photosensitive system on retina. After transforming the absorption spectra, originated by the BIPFUL systems under UV-A, UV-B and UV-C, in chromaticity coordinates and vectors in CIE L*a*b* spaces, we have compared their performances through the determination of two parameters: The Colourability and the Eucledian distance. Finally, the guiding principles for the design of new BIPFUL systems are outlined. [ABSTRACT FROM AUTHOR]

A multi-residue method based on two different extraction procedures was developed and compared with liquid chromatography electrospray ionization tandem mass spectrometry analysis of eighteen water-soluble artificial colours including Tartrazine (E102), Chrysoine (E103), Quinoline Yellow (E104), Yellow 2G (E107), Sunset Yellow (E110), Azorubine (E122), Amaranth (E123), Ponceau 4R (E124), Erythrosine (E127), Red 2G (E128), Allura Red (E129), Patent Blue V (E131), Indigo Carmine (E132), Brilliant Blue (E133), Green S (E142), Fast Green (E143), Brilliant Black (E151), and Black 7984 (E152) in sugar and gummy confectionary, ice-cream, and chocolate sweets. Sample preparation included SPE clean-up and liquid–liquid extraction for ice-cream and chocolate sweets. Accuracy was evaluated by recovery experiments. Correlation between response and concentration was obtained with R 2 > 0.98 for all but six colours. Limits of quantification were within the 10–50 μg/kg range for E129; 20–200 μg/kg for E152; 10–250 μg/kg for E103; 10–500 μg/kg for E102, E104, E107, E110, E122, E123, E124, E127, E128, E131, E133; 20–800 μg/kg for E132, 142, 151; and 10–1000 μg/kg for E143. CV for repeatability ranged from 4.0% to 51.0%, while the CV for intermediate reproducibility ranged from 5.8% to 41.4%. Finally, recoveries varied from 84.3% to 166.0%. Together, these demonstrate that the method has been validated for complex matrices and is, thus, fit-for-purpose. [ABSTRACT FROM AUTHOR]

Natural hazards are often communicated visually using colours and maps. However, users' ability to read and understand these products may be hampered by e.g., colour vision deficiency, potentially rendering the products less effective or even counter effective. To study these effects, we conducted two web-based surveys and analysed how to improve visual communication of avalanches, floods, landslides, and dangerous weather hazards. In survey 1 (n = 79), we tested four traffic light colour palettes, three map legends, and three map patterns used for communicating danger levels on the Norwegian website Varsom.no, to improve accessibility for individuals with and without colour vision deficiency (CVD). In survey 2 (n = 960), we tested four versions of traffic light colour palettes on a larger and international population. Survey 2 also tested six versions of Avalanche terrain exposure scale (ATES) maps on individuals with and without CVD varying in nationality, avalanche education and familiarity with ATES. Results suggest that the colours, legends, and maps used on Varsom should be improved, and that danger levels are best communicated with the colour palette used by Meteoalarm.info – in combination with symbols to help users with CVD. This study found that the colour scheme used for ski run difficulty in Europe was efficient for use with ATES maps for participants with and without CVD and is recommended as a worldwide standard for ATES. Further studies and testing of users' understanding are recommended to improve clarity of danger level maps and to improve visualization of ATES classes 0 and 1 on maps. Our studies show the hidden potential for efficient and inclusive communication of natural hazards and highlights the importance of including the needs of CVD users in standardisation efforts. [ABSTRACT FROM AUTHOR]

Abstract: Ironstones and iron-rich limestones regularly occur as components of time-specific intervals of the Palaeozoic as well as in younger times (Brett et al., 2012--this issue). Silurian sediments deposited at high latitudes along the peri-Gondwana border are characterized by black and white limestone and graptolitic shale sequences. Those in the Carnic Alps (southern Austria) additionally contain colourful pink to red limestones and ironstones. Laminated structures such as the (ferruginous)-coatings around skeletal fragments (mostly trilobites and some cephalopods and echinoderms) and stromatolitic features along discontinuity surfaces display dark red, green, white and brownish colours due to the presence of goethite, magnetite, hematite, chamosite, calcite and subordinate apatite. Confocal laser Raman microscopy and complementary microscopic analysis of these ferruginous laminated structures document the presence of carbonaceous matter associated with fossilized microbial structures in the form of stromatolites, filaments and coccoids, suggesting a microbial role in the colouring of the Silurian world of the Carnic Alps. Iron concentrations up to 30× that of matrix and surrounding non-ferruginous rocks suggest blooms of iron microbe activity in response to the time-specific occurrence of chemically charged sea water during global biotic events. [Copyright &y& Elsevier]

Abstract: The Union of European Beverages Associations (UNESDA) has undertaken a screening exercise to determine whether any of the colours used in non-alcoholic beverages has the potential for high consumers to exceed the acceptable daily intake (ADI). The organisation undertook a survey of its membership to identify current use levels in non-alcoholic beverages. Information about the consumption of beverages and other foods that can contain the colours was derived from UK survey data because UK consumers were shown to represent some of the highest in the EU. A methodology was developed which added the intake of high level consumers of beverages to average intakes from all other uses to estimate total high level intake. A hierarchical approach used maximum approved use levels (where available) at the first tier and, if intakes exceed the ADI or maximum use levels were not available, UNESDA usage survey data at the second tier. Of the 33 colours approved for use in beverages nine were eliminated from further consideration at Tier 1. A further 22 colours were eliminated from further consideration at Tier 2. Two colours (E101 riboflavins and E110 sunset yellow) required further evaluation but under practical use conditions neither of these colours had the potential to exceed its ADI. Some colours used in beverages are permitted quantum satis in other foods and so permitted use levels were not available. Further information is required about these uses to determine whether total intakes from all foods have the potential to exceed ADIs. [Copyright &y& Elsevier]

Abstract: In 2002, the Joint FAO/WHO Expert Committee on Food Additives requested information relating to the toxicity, intake and specifications of annatto. Previous intake estimates for annatto provided ambiguous results because the bixin/norbixin content of annatto extract was unclear. European annatto producers consulted with the food industry to determine use levels of specific annatto extracts. These data were combined with the levels of bixin/norbixin in particular extracts to estimate the concentration of bixin/norbixin in foods. Concentrations in food were combined with data about food consumption using various methods to estimate consumer intakes, which ranged from less than 1–163% of the acceptable daily intake (0.065mg/kgbw/day). Higher intake estimates are conservative because they assume that a consumer always chooses a food that is coloured with annatto extracts. In practice this is extremely unlikely, since annatto is associated only with certain product/flavour combinations. [Copyright &y& Elsevier]

Monitoring over a 12 month period in the Sanae creek flow in acid mine drainage, Donghae coal mine area, demonstrates that the concentrations of dissolved metals and sulphate are highest during autumn when water flow in the creek is at its lowest. The highest pH values of the stream were measured in April and May, whereas the lowest pH was recorded in October. The Fe concentration of stream water rapidly decreased downstream due to the precipitation of Fe oxyhydroxide and/or oxyhydroxysulfate phases in the stream. Mineral precipitates in the creek in the Donghae mine area show various colours such as brownish yellow (Munsell colour 9.5 YR hues), reddish brown (Munsell colour 3.5 YR hues) and white depending on seasons and distance from the pollution source in the creek. Such phenomena are attributed to the variation in pH and chemical composition of stream water caused by seasonal factors. The measured pH ranges in stream water of the brownish yellow, white and reddish brown precipitates are pH 3.2–4.5, 4.5–6.0 and 5.3–6.9, respectively. [Copyright &y& Elsevier]

An anthocyanin, 1, with the novel 4-substituted aglycone, 5-carboxypyranopelargonidin, was isolated in small amounts from the acidified, methanolic extract of strawberries, Fragaria ananassa Duch., by preparative HPLC after purification by partition against ethyl acetate, Amberlite XAD-7 and Sephadex LH-20 column chromatography. It was identified mainly by 2D NMR spectroscopy and electrospray LC-MS as the 3-O-β-glucopyranoside of 5-carboxy-2-(4-hydroxyphenyl)-3,8-dihydroxy-pyrano[4,3,2-de]-1-benzopyrylium, an anthocyanidin which is homologous to 5-carboxypyranomalvidin (vitisidin A) reported in red wines and 5-carboxypyranocyanidin recently isolated from red onions. By comparison of UV–Vis absorption spectra, 1 showed in contrast to 2, pelargonidin 3-O-β-glucopyranoside, a local absorption peak around 360 nm, a hypsochromic shift (8 nm) of the visible absorption maximum, and lack of a distinct UV absorption peak around 280 nm. The similarities between the absorption spectra of 1 in various acidic and neutral buffer solutions implied restricted formation of the instable colourless equilibrium forms, which are typical for most anthocyanins in weakly acidic solutions. The molar absorptivity (∊) of 1 varied little with pH contrary to similar values of for instance the major anthocyanin in strawberry, 2. However, 2 revealed higher ∊-values than 1 at all pH values except 5.1. At pH 5.1, the ∊-value of 1 (6250) was nearly four times the corresponding value of 2 (1720), which showed the potential of 5-carboxypyranopelargonidin derivatives as colorants in solutions with pH around 5. The colours of 1 and 2 in buffered solutions with pH 1.1 and pH 6.9 have been described by the CIELAB coordinates hab (hue angle), C* (chroma), and L* (lightness). [Copyright &y& Elsevier]

Coloured substances are often assumed to behave differently in the algal growth inhibition test due to shading of the algae. We have investigated EU-notifications of new substances and found no significant differences in algal test results between colours and non-colours. A modified method to differentiate between shading and toxicity is not satisfactory, because the method used to determine the shading effect is incorrect. Due to the shaking of the test flasks in the algal test intermittent light conditions are achieved which lead to a higher growth rate than expected from proposed tests with constant reduced light conditions. This will result in overestimation of the shading effect and thus to underestimation of chemical toxicity. Furthermore, we showed in experiments with the reference substance potassium dichromate that reduced light can reduce the measurable toxicity of chemicals.Comparing our results with approaches proposed in the literature, a simple approach to reduce effects of undesired shading when testing coloured substances is to achieve light saturation for the algae by increasing illumination at least to the upper limit given in test guidelines (120 μE s−1 m−2) and, optionally, to reduce the light path by choosing smaller test volumes. [Copyright &y& Elsevier]

The effects of an alternative physical pre-treatment for enhancing the drying rate of different plums (Stanley, Angeleno®, and Empress), are evaluated by means of the principal chemical parameters and by skin colour. The pre-treatment consists of the superficial abrasion of the plums'' peels using an inert abrasive material to remove the cuticular waxy layer, the limiting factor for moisture loss. The drying process was carried out at 60 °C to reduce the plums'' quality loss, the latter being assessed by analysing the changes in skin colour, sugars by HPLC, total phenols, total anthocyanins, and reactive substances to the vanillin–HCl reagent. The proposed physical pre-treatment, without significantly altering the other qualitative characteristics of the plums, markedly reduced the dehydration time and, as a result, caused a smaller loss of sugars in Empress and Angeleno than Stanley plums. [Copyright &y& Elsevier]

• Special Issue on 4th IC3EM 2020. • Science, Techniques, Surveillance. • The importance of Science. • Fluorescent dyes. [ABSTRACT FROM AUTHOR]

Abstract: This paper illustrates the combustion synthesis of transition metal ions (cobalt, manganese and nickel)-doped ZnO-based ceramic pigments. The combustion synthesized ceramic pigments have been characterized by powder XRD and diffuse reflectance spectra. All the samples are crystalline in nature. Cobalt, manganese and nickel are present at Zn site as Co2+, Mn2+ and Ni2+, respectively. Simultaneous doping of two or three transition metal ions results in various shades of colour. [Copyright &y& Elsevier]