Résumé–Cet article traite de la découverte de lithopone phosphorescent sur des dessins à l'aquarelle, datés entre 1890 et 1905, de l'artiste Américain John La Farge et de l'histoire du lithopone dans l'industrie des pigments à la fin du 19e et au début du 20e siècle. Malgré de nombreuses qualités souhaitables pour une utilisation en tant que blanc dans les aquarelles et les peintures à l'huile, le développement du lithopone comme pigment pour artistes a été compliqué de par sa tendance à noircir lorsqu'il est exposé au soleil. Sa disponibilité et son usage par les artistes demeurent incertains parce que les catalogues des marchands de couleurs n'étaient généralement pas explicites à indiquer si les pigments blancs contenaient du lithopone. De plus, lors d'un examen visuel, le lithopone peut être confondu avec le blanc de plomb et sa phosphorescence de courte durée peut facilement être ignorée par l'observateur non averti. À ce jour, le lithopone phosphorescent a seulement été documenté sur une autre œuvre: une aquarelle de Van Gogh. En plus de l'histoire de la fabrication du lithopone, cet article décrit le mécanisme de sa phosphorescence et son identification à l'aide de la spectroscopie Raman et de la spectrofluorimétrie.
You can find more information about EFSA’s work in the area of food additives on our website
Heavy-duty tension springs are designed to withstand high levels of force and pressure, making them ideal for applications requiring strong resistance and durability. Heavy-duty tension springs are commonly used in industrial machinery, automotive suspensions, and agricultural equipment.
The sleek and minimalistic design of these boards can complement a variety of decor styles, from modern and industrial to bohemian and eclectic The sleek and minimalistic design of these boards can complement a variety of decor styles, from modern and industrial to bohemian and eclecticmetal grid display board. They are a great way to display artwork, photographs, and other decorative items in a contemporary and stylish way.In conclusion, concrete formwork accessories, including wall ties, adjustable brick ties, and rolled steel bars, are crucial for creating stable and durable concrete structures. Partnering with reputable concrete accessories suppliers ensures access to high-quality products that meet the stringent demands of modern construction. By utilizing the right accessories, contractors can enhance the strength, stability, and longevity of their projects, ultimately contributing to safer and more reliable buildings and infrastructure.
Moreover, they also contribute to fire resistance, sound insulation, and overall thermal performance of the building envelope Moreover, they also contribute to fire resistance, sound insulation, and overall thermal performance of the building envelopebrick ties to stud wall.There are several different types of wall ties available, including stainless steel wall ties, galvanized wall ties, and helical wall ties. The type of wall tie used will depend on the specific requirements of the wall being constructed, as well as the environmental conditions in which the wall will be exposed.
expansion ties. By interacting with people from different backgrounds, cultures, and industries, individuals and organizations can gain new insights and approaches to their work. This can lead to more effective decision-making, problem-solving, and overall growth.