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Verdigris is made by placing a plate or blade of copper, brass or bronze, slightly warmed, into a vat of fermenting wine, leaving it there for several weeks, and then scraping off and drying the green powder that forms on the metal. The process of making verdigris was described in ancient times by Pliny. It was used by the Romans in the murals of Pompeii, and in Celtic medieval manuscripts as early as the 5th century AD. It produced a blue-green which no other pigment could imitate, but it had drawbacks; it was unstable, it could not resist dampness, it did not mix well with other colors, it could ruin other colors with which it came into contact., and it was toxic. Leonardo da Vinci, in his treatise on painting, warned artists not to use it. It was widely used in miniature paintings in Europe and Persia in the 16th and 17th centuries. Its use largely ended in the late 19th century, when it was replaced by the safer and more stable chrome green. Viridian, also called chrome green, is a pigment made with chromium oxide dihydrate, was patented in 1859. It became popular with painters, since, unlike other synthetic greens, it was stable and not toxic. Vincent van Gogh used it, along with Prussian blue, to create a dark blue sky with a greenish tint in his painting Cafe terrace at night.
When was Prussian blue patented?
A: unanswerable

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The first regular broadcasts started on January 1, 2004 when the Belgian company Euro1080 launched the HD1 channel with the traditional Vienna New Year's Concert. Test transmissions had been active since the IBC exhibition in September 2003, but the New Year's Day broadcast marked the official launch of the HD1 channel, and the official start of direct-to-home HDTV in Europe.
 What event was first broadcasted on March 1, 2004?
A: unanswerable

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On 12 July 2007, European Court of Human Rights when dismissing the appeal by Nikola Jorgić against his conviction for genocide by a German court (Jorgic v. Germany) noted that the German courts wider interpretation of genocide has since been rejected by international courts considering similar cases. The ECHR also noted that in the 21st century "Amongst scholars, the majority have taken the view that ethnic cleansing, in the way in which it was carried out by the Serb forces in Bosnia and Herzegovina in order to expel Muslims and Croats from their homes, did not constitute genocide. However, there are also a considerable number of scholars who have suggested that these acts did amount to genocide, and the ICTY has found in the Momcilo Krajisnik case that the actus reu, of genocide was met in Prijedor "With regard to the charge of genocide, the Chamber found that in spite of evidence of acts perpetrated in the municipalities which constituted the actus reus of genocide".
The ethnic cleansing perpetrated by the Serbs against Bosnia-Herzegovina was conducted with what ultimate goal in mind?
A: expel Muslims and Croats from their homes

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Many applications of silicate glasses derive from their optical transparency, which gives rise to one of silicate glasses' primary uses as window panes. Glass will transmit, reflect and refract light; these qualities can be enhanced by cutting and polishing to make optical lenses, prisms, fine glassware, and optical fibers for high speed data transmission by light. Glass can be colored by adding metallic salts, and can also be painted and printed with vitreous enamels. These qualities have led to the extensive use of glass in the manufacture of art objects and in particular, stained glass windows. Although brittle, silicate glass is extremely durable, and many examples of glass fragments exist from early glass-making cultures. Because glass can be formed or molded into any shape, and also because it is a sterile product, it has been traditionally used for vessels: bowls, vases, bottles, jars and drinking glasses. In its most solid forms it has also been used for paperweights, marbles, and beads. When extruded as glass fiber and matted as glass wool in a way to trap air, it becomes a thermal insulating material, and when these glass fibers are embedded into an organic polymer plastic, they are a key structural reinforcement part of the composite material fiberglass. Some objects historically were so commonly made of silicate glass that they are simply called by the name of the material, such as drinking glasses and reading glasses.
What type of glass products can be used for reinforcement?
A:
unanswerable