Search Results (258)

Development of forming methods for surface-coated metals is a current concern due to their economic and environmental advantages. For a successful forming operation, it is necessary that both components, the substrate and the coating, are able to withstand stress without damage until the final shape and dimensions are reached. This goal can be achieved through good knowledge of the elastic and plastic properties of the substrate and the coating, the compatibility between them, the appropriate surface treatment, and the rigorous control of technological forming parameters. Our study was carried out with flat specimens of pre-painted Al 99.0 sheet that were electromagnetically formed by bulging. Forming behavior was investigated as depending on the initial thickness of the substrate, on the aluminum sheet pretreatment, as well as on the plastic deformation path of the metal–paint structure. To verify the damage to the paint layer, tests with increasing strains were performed, and the interface between the metal and the coating layer was investigated by scanning electron microscopy. The obtained results indicate that electromagnetic forming of pre-painted sheets can be a feasible method for specific applications if the forming degree of the substrate is tightly correlated with the type of desired coating and with the pretreatment method used for the metal surface. Full article

Ceramic dental prosthetics with internal metal structures are made from a cobalt–chromium alloy that is coated with ceramic. This study aims to validate surface treatments for the metal that enhance the adhesion of the ceramic coating under masticatory forces. Surface conditioning is performed using mechanical methods, like sandblasting (SB), and thermal methods, such as oxidation (O). The ceramic coating is applied to the metal component following the conditioning process, which can be conducted using either a single method or a combination of methods. Each conditioned sample undergoes characterization through various techniques, including drop shape analysis (DSA), scanning electron microscopy (SEM), X-ray diffraction (EDX), and atomic force microscopy (AFM). After the ceramic coating is applied and subjected to thermal sintering, the metal–ceramic samples are mechanically tested to assess the adhesion of the ceramic layer. The research findings, illustrated by scanning electron microscopy (SEM) images of the metal structures’ surfaces, indicate that alloy powder particles ranging from 10 to 50 µm were either adhered to the surfaces or present as discrete dots. Particles that exceed the initial design specifications of the structure can be smoothed out using sandblasting or mechanical finishing techniques. The energy-dispersive spectroscopy (EDS) results show that, after sandblasting, fragments of aluminum oxide remain trapped on the surface of the metal structures. These remnants are considered impurities, which can negatively impact the adhesion of the ceramic to the metal substrate. The analysis focuses on the exfoliation of the ceramic material from the deformed metal surfaces. The results emphasize the significant role of the sandblasting method and the micro-topography it creates, as well as the importance of the oxidation temperature in the treatment process. Drawing on 25 years of experience in dental prosthetics and the findings from this study, this publication aims to serve as a guide for applying the ceramic bonding layer to metal surfaces and for conditioning methods. These practices are essential for enhancing the adhesion of ceramic materials to metal substrates. Full article

In this article, a multidisciplinary methodological approach for studying a wooden panel painting is applied. The theoretical framework, within which this research has arisen, is the application of state-of-the-art non-destructive techniques for addressing issues concerning the constituting parts and composing materials of the artwork. Hereby, a post-Byzantine icon was studied, which was dated back to 1836. It is a painting executed on a wooden panel, with a decorated wooden frame attached. The artifact was thoroughly investigated through the application of infrared thermography (IRT), multispectral imaging (MSI), and macroscopic X-ray fluorescence spectrometry (MA-XRF). These analyses provided crucial information about the verso of the painting (i.e., the wooden panel and the frame) and allowed for the revelation of important details of the recto of the painting, which were not visible due to the presence of an old, decayed varnish. Additionally, through the detailed mapping of the distribution of various chemical elements on the recto of the painting and the frame, it was possible to identify the materials used and techniques employed. It is therefore shown that, when combined, the non-destructive methodologies in consideration can provide adequate information referring to the materiality and state of preservation of panel paintings, permitting the conservator to proceed to a tailored conservation treatment. Full article

This study investigates Hispano-Muslim plasterworks, exemplified by the Cuarto Real de Santo Domingo, the Madraza, and the Alhambra in Granada, focusing on cleaning methods to remove oil-based repaintings without damaging the original polychromies. To this end, samples replicating traditional materials (gypsum coating, pigments, and binders) and techniques (tempera painting) were prepared and subjected to an artificial ageing protocol (AAP). Subsequently, cleaning tests aimed at removing the oil repaintings were performed to recover the original polychromies. Analytical techniques, including Fourier Transform Infrared Spectroscopy (FTIR), Gas Chromatography–Mass Spectrometry (GC–MS), and colorimetry, were employed to evaluate ageing effects and cleaning efficacy. Results revealed significant chromatic alterations in vermilion and azurite bound with animal glue, while ochre remained comparatively stable. Chemical analyses indicated marked binder deterioration, including protein denaturation in animal glue and oxidation/polymerization in linseed oil. Cleaning tests demonstrated that both a heptane–acetone gel and a novel polyamidoamine–glycine (PAAGLY) treatment effectively removed oil-based repaintings while preserving the original layers. These findings highlight the critical role of pigment–binder interactions in conservation strategies and advocate for selective, minimally invasive restoration methods. Full article

Floating aquatic vegetation and algal blooms are increasing with global warming, potentially reducing UVB exposure and, consequently, vitamin D (vit-D) synthesis in freshwater turtles. Vit-D mediates calcium metabolism and overall health, yet the effects of floating aquatic vegetation on vit-D levels remain unclear, as is whether turtles actively avoid habitats with abundant floating vegetation. Here, we address these questions by quantifying vit-D₃ levels in the blood of adult female painted turtles (Chrysemys picta) exposed to high-vegetation (darker/colder) or clear-water (lighter/warmer) treatments for one month outdoors and one month indoors at a single temperature during late summer and early fall. The observed circulating vit-D₃ levels resembled those reported for other freshwater turtles, declined over time in both treatments, and were marginally lower under high vegetation after 60 days compared to clear water. However, this difference disappeared after correcting for lymph contamination and multiple comparisons, suggesting that perhaps adult females are robust to the effect of floating vegetation, but whether they were buffered by vit-D₃ stores in lipids is unclear. Additionally, in subsequent years, females were exposed to habitat choice experiments and exhibited a strong preference for high floating vegetation over clear water, both as a group (outdoors) and individually (outdoors, and indoors at 21 °C and 26 °C), consistent with known benefits conferred by floating vegetation (food, predator avoidance). While no ill effects of high vegetation nor behavioral avoidance were detected here, longer experiments at different seasons on both sexes and varying ages are warranted before concluding whether painted turtles are truly resilient in their vit-D levels or if, instead, a tradeoff exists between the known benefits of floating vegetation and potential [yet unidentified] detrimental effects (lower dissolved oxygen or vit-D) when vegetation is overgrown for extended periods. Full article

Objective: This study evaluated the efficacy of a novel interproximal fluoride delivery device, Cav-Aid^®, in remineralizing initial proximal caries, comparing it with conventional fluoride treatments. Methods: Initial caries lesions were produced on bovine enamel blocks by subjecting the blocks to a 3-day demineralization process by plaque growth in a mixed-species microbial caries model. After demineralization, the baseline surface microhardness (SMHb) was measured. The blocks were embedded into cavities prepared on the proximal surfaces of extracted human teeth to simulate natural interproximal contacts. The teeth were randomly assigned to six treatment groups (20/group): artificial saliva (AS), Cav-Aid^® only (CA), Cav-Aid^®/fluoride toothpaste (CA+F), fluoride varnish applied via flossing (FV-Floss), fluoride varnish applied via painting on the interdental cleavage (FV-Paint), and daily fluoride mouthrinse (F-Mouthrinse). The samples then underwent a 14-day pH cycling protocol to simulate remineralization conditions. The post-treatment SMH (SMHr) was measured. Statistical analysis comprised paired t-tests and ANOVA/Tukey’s post hoc comparisons (p < 0.05). Results: All fluoride-treated groups exhibited significant increases in SMHr compared with SMHb (p < 0.001). CA+F group showed the highest percentage remineralization (27.39%), followed by CA (22.16%), then the FV and mouthrinse groups (9.25–11.80%). The AS group exhibited the lowest remineralization (4.89%). CA+F demonstrated significantly greater remineralization than FV or mouthrinse (p < 0.05). However, there was no significant difference between CA alone and CA+F. Also, there was no significant difference between CA alone and FV-Floss or FV-Paint (p > 0.05). Conclusions: Within the limit of the present study, the Cav-Aid^® targeted fluoride delivery system demonstrated greater efficacy than FV alone in interproximal remineralization. Dual-modality fluoride treatments (CA+F) provided the greatest remineralization benefits, highlighting the importance of sustained fluoride exposure. Full article

This study introduces a pilot protocol for evaluating the environmental impact of materials used in the conservation of canvas paintings, applying a Life Cycle Impact Assessment (LCIA) approach. There are five common treatment phases: disinfection, consolidation (including paint layer softening and stabilization), varnish removal, and retouching. These interventions were assessed across three scenarios: Baseline Scenario; Scenario 1, involving material substitution; and Scenario 2, focusing on process optimization. The analysis reveals that solvent-intensive phases, particularly paint softening with Methyl Ethyl Ketone (MEK) and varnish removal using White Spirit and ethanol, have the highest environmental impacts, including climate change, ecotoxicity, and human toxicity. Biocidal treatments, although used in small quantities, also show significant toxicity impacts. Scenario 1 demonstrates that targeted substitution with lower-impact solvents can reduce key impact categories, while Scenario 2 indicates that operational improvements lead to more moderate but widespread benefits. The results confirm that even in specialized fields such as cultural heritage conservation, measurable environmental improvements are achievable through informed material choices and more efficient application practices. Full article

To improve the laser cleaning surface quality of composite layers on Al alloy surfaces, a method of determining the optimal cleaning parameters is proposed that is based on the response surface methodology. It involves constructing a mathematical model of the input variables (laser power, scanning speed, repetition frequency, and defocusing amount). Laser cleaning experiments were conducted to analyze the effects of process parameters on paint removal performance. Using the response surface methodology (RSM), a relationship model was developed to link key factors, including paint layer removal thickness and surface roughness. The results indicate that the optimal process parameters are as follows: a laser power of 291 W, frequency of repetition of 166 kHz, scanning speed of 8425 mm/s, and defocusing amount of −17 mm. A verification test was performed to confirm the optimal parameters for the process. The error ranges for the thickness and roughness of the laser paint removal were within 1.9 μm~3.8 μm and −0.573 μm~−0.419 μm, respectively, indicating that the response surface method can be used to predict and optimize the quality of laser paint removal. These findings provide valuable insights into the laser treatment of composite paint layers on Al alloys and contribute to advances in surface treatment technology for Al alloys. Full article

The growing volume of plastic waste from end-of-life vehicles presents environmental concerns, driving efforts to integrate recycled plastics. This study investigates the possibility of using recycled plastic from automotive parts (painted and unpainted bumpers, fuel tanks) as a 10% filler in the core layer of three-layer particleboards (P) and evaluates its impact on physical properties (water absorption—WA and thickness swelling—TS), mechanical properties (internal bonding strength—IB, modulus of rupture—MOR, modulus of elasticity—MOE and screw driving torque—SDT) and volatile organic compounds—VOC emissions. The boards were produced using conventional hot-pressing technology and analyzed according to applicable standards. Based on the results, the density of the reference (P) was 0.72 g·cm⁻³, while wood–plastic composites ranged from 0.70 g·cm⁻³ to 0.72 g·cm⁻³. After 24 h, WA reached 40% for reference (P) and from 36.9% (for (P) containing unpainted bumpers) to 41.9% (for (P) containing fuel tanks). TS reached 18% for (P) and from 16.8% (for (P) containing unpainted bumpers and fuel tanks) to 18.1% (for (P) containing painted bumpers). Plastic is a hydrophobic material and it is assumed that by increasing the proportion of plastic filler in the particleboards, the WA and TS of prepared boards will decrease. From the point of view of mechanical properties, values for (P) containing plastic filler were slightly lower compared to reference (P). The lowest value of IB (0.39 MPa) were reached for (P) containing painted bumpers. Plastic surface treatment could interfere with adhesion between the plastic and adhesive, weakening the bond in the core layer. For this reason, is preferable to use unpainted fillers, which provide better adhesive properties and higher structural integrity. VOC emissions from wood components consisted primarily of monoterpenes such as α-pinene, 3-carene and limonene. Adding 10% plastic to the particleboard did not increase overall VOC emissions. On the other hand, combining wood and plastic particles resulted in a reduction in overall VOC emissions. The findings confirm that recycled automotive plastics can be effectively incorporated into particleboards, maintaining standard performance while reducing reliance on virgin wood materials, making them a viable and sustainable alternative for furniture and interior applications. Full article

Wood is often used as an interior surface finish in buildings, including exposed cross-laminated timber panels and other structural mass timber members. Building occupants generally have a positive reaction to visible wood elements used in building interiors due to the visual qualities associated with wood being a natural material. This study aims to identify any thermal comfort impacts of wood interior environments using subjective occupant-reported perceived thermal sensation during two experiments conducted in a climate chamber fitted with either white-painted gypsum wallboard or unfinished laminated Douglas Fir wall panels. In the first experiment, the thermal environment was continually varied while the visual stimulus of the wall type remained constant. Irrespective of wood or white wall treatment type, thermal history played a significant role in the perceived thermal comfort of participants under continually modulating temperatures. In the second experiment, a slightly warm steady-state thermal environment was maintained while one of the two wall treatments was revealed from behind a black curtain. While the shift in thermal sensation toward neutral was greater with wood walls than with white walls, the difference was not found to be statistically significant and appears to diminish after 15 min of exposure to the new visual surroundings. Full article

One of the key problems in the billet and shaped casting of aluminum alloys is the presence of various undesirable inclusions and impurities in the melt, which can serve as stress concentrators in the finished product, as well as dissolved hydrogen, which contributes to the formation of porosity. The interaction of aluminum with other gases produced by the combustion of fuel particles, oil, and paint materials brought into the furnace together with charge and scrap increases the amount of nitrides, oxides, carbides, and sulfides in the melt. Flux treatment is widely used as protection of aluminum alloys from oxidation and removal of impurities. The present paper reports the data of a comparative analysis of five widely used flux compositions based on sodium, potassium, and magnesium chlorides. The study covers the following aspects: chemical composition, moisture content, melting temperature and melting range, particle size distribution, and refining ability as measured by the change in Na, Ca, and H₂ content after melt treatment. Full article

Vehicle color coatings have long been recognized as a factor influencing road safety, particularly regarding their impact on speed perception and crash risk. This study aims to examine how different vehicle color coatings affect drivers’ perception of speed under nighttime driving conditions, with a specific focus on sustainability and visibility. A controlled laboratory experiment was conducted using a driving simulator to replicate realistic night traffic scenarios. A total of 161 participants evaluated passenger vehicles in four distinct color treatments, white (high-reflective paint), yellow (matte safety film), blue (glossy metallic finish), and black (low-reflective coating), at two speeds: 30 km/h and 50 km/h. Participants’ perceived speeds were collected and analyzed using standardized statistical methods. Results indicated a consistent pattern: speed was overestimated at 30 km/h and underestimated at 50 km/h across all vehicle colors. Lighter-colored vehicles (white and yellow) were perceived as moving faster than darker-colored vehicles (blue and black), with significant differences between black and yellow (30 km/h), yellow and blue (30 km/h), and black and white (50 km/h). Additionally, female participants tended to estimate higher speeds than male participants across most conditions. Other individual factors, such as place of residence, driver’s license type, driving experience, and frequency of driving, also showed measurable effects on speed perception. By using a simulator and accounting for diverse demographic characteristics, the study highlights how perceptual biases related to vehicle color can influence driver behavior. These findings emphasize the importance of considering vehicle color in traffic safety strategies, including driver education, vehicle design, and policy development aimed at reducing crash risk. Full article

Bagrada hilaris (known as painted bug) is a pest native to India, Southeast Asia, and middle and central Africa and was reported as invasive in the southwestern USA, Hawaii, Mexico, South America, and two Mediterranean islands. The feeding activity results in extensive damage to economically important Brassicaceae crops. Among sustainable alternatives to synthetic pesticides, the Sterile Insect Technique (SIT) is considered a promising strategy because it relies on the release of competitive sterile males that can reduce the pest reproduction. In this study, the efficacy of different doses of gamma irradiation (60, 80, and 100 Gy) was evaluated to identify the treatment that would ensure high sterility without compromising the competitiveness of the treated males. Observational tests showed that the doses of 60 Gy and 80 Gy showed no difference in mating times compared to non-irradiated males, in contrast to 100 Gy. Thus, 80 Gy was identified as the most promising dose. For further investigation, tests were conducted under choice and no-choice conditions at 80 Gy for three days. The results showed that irradiated males had a comprehensive higher mating rate than non-irradiated males, and under choice conditions, they were often preferred by females, confirming that SIT has potential as an environment-friendly method for controlling B. hilaris. Full article

This study conducted an on-site monitoring of 28 representative coating enterprises in Hangzhou City and successfully constructed the localized component spectrum of volatile organic compounds (VOC) emissions from the industrial coating industry. These coating enterprises, which have a total VOC emission of approximately 7113 tons, accounting for 17.6% of the city’s total industrial VOC emissions, primarily emit benzene derivatives, ketones, esters, and halogenated hydrocarbons. Using the maximum incremental reactivity (MIR) method, the ozone formation potential (OFP) was calculated based on the annual VOC emissions from the industry. The OFP values for the different types of enterprises had significant variations, with the general equipment manufacturing, metal products, and electrical machinery industries exhibiting the highest contributions. Research results indicate that differentiated management approaches are needed for specific emission characteristics in each sub-industry, including promoting the use of water-based paints and clean production technologies, adopting efficient volatile organic compound treatment technologies, and establishing stricter emission standards with regular monitoring of highly reactive compounds. These measures are crucial for achieving more effective environmental management and continuous improvement of air quality. Full article

BOAM is a family-based method in which children and parents together create an explanatory, personal and systemic diagnosis. Based on ten playful and visual models, the therapist provides universal psychoeducation to gain insight into the personal, relational and contextual causes of the child’s problems for a shared understanding of how to approach them. This case report describes a seven-session BOAM trajectory in a family with a 6-year-old child with emotional and behavioural dysregulation, such as frequent temper tantrums, hitting her infant sister, and threatening with knives. In this case report, the course of the sessions is described, including the way the family applied the BOAM models within their (cultural) family values. The mother completed questionnaires on child psychopathology (Child Behaviour Checklist), executive functioning (Behaviour Rating Inventory of Executive Function), parenting stress (Parenting Stress Index) and partner relationship (Family Functioning Questionnaire) at baseline, pretest, post-test, and 3- and 5-month follow-up, and the father completed questionnaires on child psychopathology and parenting stress at baseline and 5-month follow-up. Parents reported clinically significant improvements, as calculated with reliable change indexes, in child externalising psychopathology, self-regulation, and parenting stress (post-test and 3- and 5-month follow-up). BOAM is a short and accessible method for psychoeducation, diagnostics and treatment. BOAM seems to be an effective intervention for this family; however, more research is necessary to demonstrate its effectiveness. This case report painted a vivid picture of how family conversations can be structured and targeted using the models. Full article