A case study of renaissance wall paintings in Granada (Spain): historical–artistic analysis, materials characterization, and state of conservation

The research carried out on the wall paintings of Hernán Pérez del Pulgar’s Palace chapel in Granada (Spain) was aimed at determining its historical–artistic, stylistic, technical, and compositional aspects. For this, a 16th century frieze and an 18th century pendentive were studied. The mineralogical, chemical, and textural characterization of the constituent materials and the study of the state of conservation of the paintings have helped to determine the pictorial technique used, identify the nature of the salts present in the paintings, and other pathologies including a dormant fungal attack. To this end, optical microscopy (OM), X-ray diffraction (XRD), Field emission scanning electron microscopy with microanalysis (FESEM-EDS), and micro-Raman spectroscopy (MRS) were used. The information obtained helps clarify important aspects of the painting technique used, laying a basis to ensure effective and suitable conservation and restoration measures on the paintings that will ensure their durability over time.AERIMPACT | Ref. CGL2012-30729EXPOAIR | Ref. P12-FQM-1889Ministerio de Ciencia e Innovación | Ref. PID2020-119838RA-I00Grupo de Investigación de Andalucía | Ref. RNM-17

The fresco wall painting techniques in the Mediterranean area from Antiquity to the present: A review

Fresco wall paintings are one of the oldest artforms in our cultural heritage, dating back to the second millennium BC. In this work, we carry out a thorough review on the evolution of the fresco wall painting technique from Antiquity to the present day. Focused on the Mediterranean area, the aim is to gather in-depth information on different technological aspects of this decorative artform such as execution pro- cedure, materials used and pictorial palette. Considering that the recognition of the pictorial technique ( a fresco, a secco, or a mezzo fresco ) is often difficult since the identification of organic binders can be a challenging issue, the assignment of well-known non-alkaline-resistant pigments to the fresco technique might not always be precise. With this in mind, this review aims to highlight the contradictions found between the bibliographical sources on the fresco technique and recent scientific studies in relation to the preparation of materials, the execution on the wall and the incompatibility of certain pigments with the alkaline environment created by this pictorial technique.Research Projects PID2020-119838RA- I00 and ED431F 2022/07Xunta de Galicia project Limpeza sostible do patrimonio pictorico: optimizacion dos procesos de ablacion laser ( ED431F 2022/07 )Spanish Science and Innovation Ministry project RYC2020-028902-ISpanish Science and Innovation Ministry project RYC2020-028902-IState Research Agency (SRA)Ministry of Science and Innovation under the Research Project PID2020-119838RA-I00Junta de Andalucía Research Group RNM179Funding for open access charge: Universidade de Vigo/CISU

The fresco wall painting techniques in the Mediterranean area from Antiquity to the present: A review

Fresco wall paintings are one of the oldest artforms in our cultural heritage, dating back to the second millennium BC. In this work, we carry out a thorough review on the evolution of the fresco wall painting technique from Antiquity to the present day. Focused on the Mediterranean area, the aim is to gather in-depth information on different technological aspects of this decorative artform such as execution procedure, materials used and pictorial palette. Considering that the recognition of the pictorial technique (a fresco, a secco, or a mezzo fresco) is often difficult since the identification of organic binders can be a challenging issue, the assignment of well-known non-alkaline-resistant pigments to the fresco technique might not always be precise. With this in mind, this review aims to highlight the contradictions found between the bibliographical sources on the fresco technique and recent scientific studies in relation to the preparation of materials, the execution on the wall and the incompatibility of certain pigments with the alkaline environment created by this pictorial technique.Agencia Estatal de Investigación | Ref. PID2020-119838RA-I00Xunta de Galicia | Ref. ED431F 2022/07Agencia Estatal de Investigación | Ref. RYC2020-028902-IUniversidade de Vigo/CISU

Crowdsourcing hypothesis tests: Making transparent how design choices shape research results

To what extent are research results influenced by subjective decisions that scientists make as they design studies? Fifteen research teams independently designed studies to answer fiveoriginal research questions related to moral judgments, negotiations, and implicit cognition. Participants from two separate large samples (total N > 15,000) were then randomly assigned to complete one version of each study. Effect sizes varied dramatically across different sets of materials designed to test the same hypothesis: materials from different teams renderedstatistically significant effects in opposite directions for four out of five hypotheses, with the narrowest range in estimates being d = -0.37 to +0.26. Meta-analysis and a Bayesian perspective on the results revealed overall support for two hypotheses, and a lack of support for three hypotheses. Overall, practically none of the variability in effect sizes was attributable to the skill of the research team in designing materials, while considerable variability was attributable to the hypothesis being tested. In a forecasting survey, predictions of other scientists were significantly correlated with study results, both across and within hypotheses. Crowdsourced testing of research hypotheses helps reveal the true consistency of empirical support for a scientific claim.</div

SO₂-Induced Aging of Hematite- and Cinnabar-Based Tempera Paint Mock-Ups: Influence of Binder Type/Pigment Size and Composition

Hematite- and cinnabar-based paint mock-ups prepared with either rabbit glue or egg yolk binder were artificially aged in an SO2-rich atmosphere, as a model system for investigating the deterioration of tempera paints exposed to an industrial atmosphere. The overall research aim was to identify the type of degradation occurring in tempera paints and the different alteration mechanisms related to the physical, mineralogical and chemical characteristics of the paint. Tempera mock-ups were prepared by mixing binder (egg yolk or rabbit glue) and pigment (cinnabar of different particle sizes or hematite) and were then exposed to SO2 for 2 months in accelerated aging tests. The colour, gloss, reflectance, roughness and micro-texture of the surfaces of the mock-ups were determined before and after the tests. In addition, chemical and mineralogical changes were determined by X-ray Powder Diffraction (XRPD), Attenuated Total Reflection-Fourier Transform Infrared spectroscopy (ATR-FTIR) and Scanning Electron Microscopy with Energy-Dispersive X-ray Spectroscopy (SEM-EDS) analysis. Colorimetric changes were confirmed, mainly in the cinnabar-based paints containing egg yolk, and in the hematite-based paints containing rabbit glue. Neoformed mineral phases have not been detected by XRPD, but precipitation of gypsum on the exposed surfaces has been confirmed by SEM. For cinnabar-based paints, the amount of sulfate-rich deposits was higher on egg yolk mock-ups than on rabbit glue samples, though the opposite was observed for the hematite-based paints. This confirmed the influence of the binder composition and pigment-binder tandem in the susceptibility to SO2 deposition. Pigment particle size did not have a clear influence on the physical and chemical changes in the tempera mock-ups during the ageing tests

A Broad Line-width, Compact, Millimeter-bright Molecular Emission Line Source near the Galactic Center

A compact source, G0.02467–0.0727, was detected in Atacama Large Millimeter/submillimeter Array 3 mm observations in continuum and very broad line emission. The continuum emission has a spectral index α ≈ 3.3, suggesting that the emission is from dust. The line emission is detected in several transitions of CS, SO, and SO _2 and exhibits a line width FWHM ≈ 160 km s ^−1 . The line profile appears Gaussian. The emission is weakly spatially resolved, coming from an area on the sky ≲1″ in diameter (≲10 ^4 au at the distance of the Galactic center, GC). The centroid velocity is v _LSR ≈ 40–50 km s ^−1 , which is consistent with a location in the GC. With multiple SO lines detected, and assuming local thermodynamic equilibrium (LTE) conditions, the gas temperature is T _LTE = 13 K, which is colder than seen in typical GC clouds, though we cannot rule out low-density, subthermally excited, warmer gas. Despite the high velocity dispersion, no emission is observed from SiO, suggesting that there are no strong (≳10 km s ^−1 ) shocks in the molecular gas. There are no detections at other wavelengths, including X-ray, infrared, and radio. We consider several explanations for the millimeter ultra-broad-line object (MUBLO), including protostellar outflow, explosive outflow, a collapsing cloud, an evolved star, a stellar merger, a high-velocity compact cloud, an intermediate-mass black hole, and a background galaxy. Most of these conceptual models are either inconsistent with the data or do not fully explain them. The MUBLO is, at present, an observationally unique object

Soluciones de Ingeniería Aplicadas a Problemas en la Industria

La necesidad de aprender a diseñar y construir es inherente a la ingeniería. Se considera como uno de los rasgos que componen el concepto de la ingeniería desde su enfoque diferenciador de las ciencias básicas, y que es validado desde lo disciplinar por las ciencias de la ingeniería. Estas últimas, se reconocen como herramientas que permiten alcanzar o implementar metas a través del proceso de diseño. Así bien, en el proceso de diseño de soluciones a problemas reales a través de la ingeniería, se aplica una amplia gama de herramientas asociadas entre otros campos, a la gestión de la calidad y la investigación de operaciones. Las herramientas pueden basarse en control de la calidad, modelos de inventarios, de transporte, almacenamiento, selección de proveedores, pronósticos, producción, localización de centros, distribución en planta, entre otras. El objetivo de estos diseños consiste en encontrar soluciones exactas o aproximadas; desde el campo de la investigación de operaciones, se focaliza el desarrollo de modelos de optimización, simulación o combinaciones de estos, que permitan tomar decisiones eficientes