Search Results (2,824)

Landscape studies of hunter–gatherer rock art often suffer from logical flaws. Some of these failings stem from the founding question that researchers ask: “Why do some places have images while others do not?” This question is misleading and not particularly helpful in some—but not all—contexts where there is no direct ethnographic evidence to provide an answer. Instead, we suggest that a better question from which to begin is: “How are rock art images related to landscape?”. To answer this question, we examine the relationship between iconography, cosmology and topography in two areas of southern African San rock painting. We argue that cosmology guided iconography and that the imagery, in turn, manipulated topography into landscape for the San. In this view, we do not need to rely on cognitive templates that invest topography a priori with significance that then determines the choice of locale for art. Instead, landscape for the San was socially and symbolically constructed through the placement of imagery. Full article

The restoration of medieval wall paintings often involves the combination of heterogeneous techniques and materials considering their nature and period. One of the many obstacles in the study of the restoration of these types of artifacts is the paucity of sources that remain and the fragmentary nature of the paintings. As support, we can identify information about the modus operandi of the artists and artisans’ workshops that were active in the medieval period. Such information can be derived from important treatises - for example, Theophilus’ mid-12th-century treatise, the Diversarum artium Schedula, and chapter XV of Cennino Cennini’s Book of Art. These all coincide with the paintings presented in this paper, which represent the Virgo Lactans (or Madonna del Latte, Nursing Virgin) and a likely pre-existing figure of a praying woman. The investigated wall paintings are located in the porch of St. Andrew’s church, situated in the neighborhood of Pianoscarano (Viterbo, Central Italy). The historical context and the execution technique of the paintings were carefully studied, supported by a diagnostic and analytical campaign carried out by means of hypercolorimetric multispectral imaging, spot X-ray fluorescence spectroscopy using a portable instrument, Fourier transform infrared spectroscopy, and cross-section analysis. These analyses allowed us to characterize the original materials, the stratigraphic sequence of the paintings, and the previous interventions applied to the paintings’ layers, giving relevant data to support the recently concluded restoration. Full article

This article presents the implementation of the Six Sigma methodology in the electro-discharge texturing process of cold mill work rolls. The final surface quality of sheet metal must meet the specific demands of car body part producers, which require a specific surface texture described by surface microgeometry parameters: the average roughness and the peak density. The requirements for the surface microgeometry of sheet metal are mainly related to improving the formability and adhesion of the paint in the body painting process. These microgeometry parameters can be controlled by the texture of work rolls: this texture is transferred onto the sheet metal surface. The electro-discharge texturing process allows for control of the average roughness and peak density according to individual customer specifications. In this study, a model is proposed to predict the average roughness based on the input parameters of the electro-discharge texturing process: current, voltage, and time. Compared to previous models, this model includes more input parameters. The process suitability was analyzed using control charts, capability indices, and Z scores. The modified weighted product method was used to create a purpose function describing the relationships between the input and output quality parameters. Based on the agreement of the target quality characteristics and the calculated values according to the models obtained, an algorithm to control the texturing process of the work rolls was designed. The proposed model was also validated on results published by other authors and demonstrated good agreement. This study should contribute to the philosophy of continuously improving the surface quality of cold-rolled sheet metal. Full article

A radiocarbon study of a painting that might have been made by Titian or Tintoretto or by their workshops is presented. It could be the lost Titian self-portrait or, more convincingly, the sitter might be the Venetian Andrea Cappello, elected Procuratore de Supra in 1537 AD. Due to the variability in the concentration of atmospheric radiocarbon during the reference period, the calibrated ¹⁴C ages of the painted canvas are 1450–1530 and 1540–1635 AD (2 $\sigma$), while those of the wooden frame are 1504–1597 and 1616–1657 AD (2 $\sigma$). They are also consistent with previous analyses based on scanning macro X-ray fluorescence. These results, combined with stylistic, considerations suggest that the painting was made in the first half of the 16th century by Titian or his workshop. Circumstantial evidence that the painting was executed between 1523 and 1528 is also discussed. Full article

Traditional Lingnan gardens, one of the three major types of Chinese garden design, have evolved over nearly a millennium, embodying the distinctive craftsmanship and aesthetic sensibilities of the Lingnan region. The architectural elements of doors and windows in these gardens serve as key expressions of regional cultural identity. This study focuses on four renowned Lingnan gardens (e.g., Yuyin Garden in Guangzhou, Liang Garden in Foshan, Qinghui Garden in Shunde, and Ke Garden in Dongguan) as primary case studies to examine the typologies, decorative characteristics, and aesthetic qualities of their doors and windows. Based on aesthetic imagery, the research elucidates both the functional and structural principles governing these designs, while also exploring their aesthetic resonance with traditional Chinese arts, such as calligraphy, painting, and poetry. By deepening the theoretical understanding of the formal and artistic features of Lingnan garden doors and windows, this study contributes to advancing the scholarly discourse on traditional garden architecture and supports the ongoing cultural preservation of this important heritage. Full article

Since people spend most of their time in indoor environments, they are continuously exposed to various contaminants that threaten human health. The air quality in these settings is therefore a crucial factor in maintaining health safety. In order to reduce the concentration of indoor air pollutants and improve air quality, photocatalytic oxidation has drawn the attention of researchers. This study aims to provide a comprehensive view of the nanomaterials used in the photocatalytic oxidation of the most common pollutants in indoor environments. The effects of various parameters like humidity, airflow, deposition time, and light intensity were also evaluated, as they can significantly influence photocatalytic reactions. The most common nanomaterials used in photocatalysis are TiO₂-based and, in this study, they were classified and examined based on their morphology. TiO₂ doping with metals and non-metals has demonstrated an enhancement of its adsorption properties and photocatalytic efficiency for the removal of several pollutants. The role of carbon-based nanomaterials in photocatalysis was also evaluated due to their adsorption capabilities towards various pollutants. In addition, other less common photocatalysts such as ZnO, MnO₂, WO₃, CeO₂, and CdS also exhibited high photocatalytic activity for pollutant degradation. Applications of these photocatalysts in air purifiers, paints, and building materials e.g., concrete, glass, and wallpapers, lead to efficient reduction of pollutants in indoor settings. Full article

Medicine is struggling with the constantly rising incidence of breast cancer. The key to this fight is to be able to speed up diagnosis, as rapid diagnosis reduces the number of aggressive or advanced cases. For this process to be effective, it is necessary to have the right attitude toward diagnosis as a research practice. Our critical analysis of diagnosis, as a methodology of medical science, reflects on it as a research practice that is regulated in a socio-subjective way by a methodological culture. This position allows us to contrast critical methodological culture with the habitual–practical, or methodical, culture of practicing diagnosis. We point to the interpretative status of medical analyses performed by medical historians by referring to Italian Renaissance paintings and historical–artistic interpretations. In this field, analyzing disputes between researchers as a clash of methodologies in the ways interpretation transforms signs into meaning is a critical methodological reflection. Medicine is a diverse scientific discourse with a paradigmatic structure in which new ways of conducting diagnostic tests may appear. It is only possible to see this from the methodological level. In addition, passive respect for existing patterns of conduct hinders an exchange of views between researchers, which limits the possibility of correcting research procedures. The ultimate consequence of such passivity is an inability to improve diagnosis, which, in turn, harms the interests of patients. In this regard, it is worth remembering that the paramount objective of diagnosis is not the disease, but the patient. Full article

Historical tempera paints exposed to pollutant gases suffer chemical and mineralogical deterioration which manifests through physical changes. Knowledge about these changes is fundamental to develop strategies for preventive conservation of wall paintings. In this research, binary tempera mock-ups composed of calcite, gypsum or lead white mixed with a proteinaceous binder (i.e., egg yolk or rabbit glue) were exposed to an aging test by using SO₂-rich atmosphere exposure to learn about the degradation mechanisms and forms related to the pigment–binder interaction. Reference (unaltered) and aged mock-ups were studied from a physical point of view, characterizing the morphological changes by using stereomicroscopy and profilometry, color variations by using spectrophotometry, gloss changes, and reflectance changes by using a hyperspectral camera. Also, mineralogical and chemical changes were studied by means of X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy with energy-dispersive X-ray spectroscopy. Egg-yolk-based paints showed higher chromatic changes than their counterparts made of rabbit glue binder. Also, sulfate and sulfite salts precipitated on the surface of the aged paints regardless of their binder, influencing the painting reflectance which subsequently increased. Egg-yolk-based mock-ups exhibited roughness increases while the rabbit-glue-based paints showed roughness reduction, with the exception of lead-white-based paints. Therefore, the important influence of the type of binder and the interaction between the binder and the pigment on the durability of tempera paints in atmospheres rich in SO₂ was confirmed. Full article

This work provides a synthesis of an initial experience in the development of accessible imaging techniques and their implementation on a real case: the analysis of colonial Hispano-American paintings at the Complejo Museográfico Provincial “Enrique Udaondo” (Luján, Buenos Aires). It discusses different aspects related to the possibilities of obtaining, using, and reusing equipment and materials locally, as well as details of the ways of acquiring images for photography on site. It also provides information about the composition and conservation state of selected artworks, complementing image analysis with portable X-ray fluorescence (XRF) data, and reflects on articulated/collaborative work in situ as a methodology for transferring knowledge and skills. The project aims to contribute to strengthening Latin American sustainability by creating accessible non-invasive tools for heritage conservation institutions, highlighting the value of regional capacities to approach heritage studies from collaborative and ethical proposals that promote sovereignty and reduce dependence on external inputs. Full article

Contemporary muralism is a constantly expanding form of urban art, whose preservation is highly debated and for which no specific preventive conservation measures have been defined. The degradation of painting materials remains a dramatic issue as mural paintings undergo rapid and inevitable chemical–physical reactions, leading to their aesthetic decay and chemical–mechanical disintegration. This work started with interviews with, and questionnaires given to experts in the field from which various needs emerged, including defining a testing protocol for the study of the compatibility and effectiveness of organic coatings to protect street art painted surfaces. Five protective formulations available on the market were selected and applied on mock-ups realized with three different types of paintings (alkyd, acrylic, and styrenic). The efficacy and affinity of the five protective treatments in relation to the different underlying painting layers were investigated. The adopted testing protocol enabled understanding the protection efficacy and compatibility of the different tested formulations in relation to the type of painting and wall preparation. The typology of the underlying paint mainly influences the final aesthetic result, while the application of the primer may play a relevant role in terms of the protection effectiveness, confirming the importance of pre-treating the substrate before painting. The results clearly show that there is still no specific and effective protection system that is appropriate for all commercial paints used by street artists. Full article

Cinnabar has been used as a red pigment for centuries, but its degradation significantly impacts the aesthetic quality of historical paintings, particularly murals. Therefore, investigating the preparation method and transformation process of HgS is highly significant for mural research. In this study, we compared different sulfur sources for HgS synthesis and precisely synthesized α-HgS and β-HgS by adjusting the S/HgCl₂ ratio. SEM and XRD analyses under optimal conditions demonstrated that spherical β-HgS-1.2 exhibited significant morphological differences in comparison with α-HgS-1.0 and α-HgS-1.5. Elemental analysis of HgS was conducted using XPS and ICP-MS for qualitative and quantitative insights. Based on the potential mechanism of cinnabar discoloration, two strategies for converting black β-HgS to α-HgS were proposed and successfully implemented by adding sulfur or HgCl₂. Full article

Liquid jets impinging on surfaces are widely found in various industrial processes, such as spray painting, high-pressure water jets, and dishwashers. The liquid jets can break up into sprays with discrete, small-scale features that are difficult to reveal. This work proposes a multiscale solver in OpenFOAM that achieves two-way conversion by capturing the large-scale interface using the Volume of Fluid (VOF) approach and tracing small-scale droplets using the Discrete Phase Model (DPM). By comparing the VOF–DPM solver with the standard VOF solver, the conservation of mass and momentum, as well as the accuracy of the new solver are verified. Considering that, in spraying processes, collisions mainly occur after the liquid jet breaks up into multiple droplets, we simplify the model to focus on the collision of droplets with walls at different speeds and contact angles, corresponding to different materials. The results indicate that, as the speed increases, splashing becomes more likely and the droplets spurt further. It is also found that an increase of contact angle will increase the mean diameter of the discrete droplets. Overall, this multiscale solver can accurately capture both large-scale interfaces and small-scale droplets, offering wide application prospects. Full article

This paper introduces an efficient localization algorithm for robotic systems, utilizing deep learning to identify and exploit natural fiduciary patterns within the environment. Diverging from conventional localization techniques that depend on artificial markers, this method capitalizes on the inherent environmental features to enhance both accuracy and computational efficiency. By integrating advanced deep learning frameworks with natural scene analysis, the proposed algorithm facilitates robust, real-time localization in dynamic and unstructured settings. The resulting approach offers significant improvements in adaptability, precision, and operational efficiency, representing a substantial contribution to the field of autonomous robotics. We are aiming at analyzing an automotive manufacturing scenario to achieve robotic localization related to a moving target. To work with a simpler and more accessible scenario we have chosen a demonstrative context consisting of a laboratory wall containing some elements. This paper will focus on the first part of the case study, with a continuation planned for future work. It will demonstrate a scenario in which a camera is mounted on a robot, capturing images of the underside of a car (which we assume to be represented by a gray painted surface with specific elements to be described in Materials and Methods). These images are processed by a convolutional neural network (CNN), designed to detect the most distinctive features of the environment. The extracted information is crucial, as the identified characteristic areas will serve as reference points for the real-time localization of the industrial robot. In this work, we have demonstrated the potential of leveraging natural fiduciary patterns for efficient and accurate robot localization. By utilizing deep learning, specifically convolutional neural networks. The experimental results suggest that this approach is not only feasible but also scalable across a wide range of applications, including industrial automation autonomous vehicles, and aerospace navigation. As robots increasingly operate in environments where computational efficiency and adaptability are paramount, our methodology offers a viable solution to enhance localization without compromising accuracy or speed. The proposal of an algorithm that enables the application of the proposed method for natural fiduciary patterns based on neural networks to more complex scenarios is highlighted, along with the efficiency of the method for robot localization compared to others. Full article

Thermal coating paints offer a passive strategy to reduce heat gain in buildings, improve ventilation, and lower energy consumption. This study investigates the effectiveness of these technologies by comparing different housing structures and environmental conditions. Specifically, it examines thermal envelope solutions for cool roofs in homes along the Colombian Caribbean Coast. We quantify the thermal impacts using experimental data collected from 120 houses across eight municipalities in the Magdalena Department, Colombia. The research details the technology and analytical methods employed, focusing on thermal reductions achieved through thermal coatings to potentially reduce energy demand. A comprehensive measurement system, incorporating temperature and humidity sensors, is developed to assess the impact of the coatings. Thermal comfort is evaluated according to the ASHRAE 55 standard, with temperature reductions calculated for each house treated with thermal coatings. A methodology is applied to evaluate the thermal reduction between a house with a coating solution versus a house without it. The results show a temperature reduction on a house-by-house basis, from 1.5% to 16%. On average, the results yield a significant 7% reduction in thermal load. Additionally, a mobile application is developed to disseminate the results of this research, promoting the social appropriation of science among the involved communities. Full article

This research aims to evaluate the effectiveness of protective coatings in preventing the corrosion of steel in the marine environment. Electrochemical tests were performed on S355JR steel immersed in natural seawater (Black Sea, Port Constanta) over a period of 22 weeks, using electrochemical techniques such as the evolution of the open circuit potential (OCP) and linear polarization resistance to calculate R_p and the corrosion rate (V_corr). The investigated steel surfaces included (a) S355JR steel blasted with Al₂O₃, (b) S355JR steel blasted and coated with epoxy primer enriched with zinc, (c) S355JR steel blasted and coated with epoxy primer and polyurethane paint, and (d) S355JR steel blasted and subsequently coated with epoxy primer and then polyurethane paint to which kreutzonit particles had been added. The proportion of kreutzonit particles added to the polyurethane paint was 2 wt% of the total mass of the paint. Subsequently, the samples were subjected to morphological analyses and cross-sectional analysis by scanning electron microscopy (SEM), topographical characterization (roughness and microhardness), and structural assessments (FTIR and XRD), as well as an analysis of hydrophobicity (contact angle). The results of this study revealed significant differences in corrosion behavior between the different surfaces and coatings tested. Electrochemical analysis revealed that the coating with epoxy primer and polyurethane paint to which kreutzonit particles had been added provided the best corrosion protection in the marine environment during immersion. Full article