Isidore of Seville, writing in the 7th century, claimed that the Latin word Maurus was derived from the Greek mauron, μαύρον, which is the Greek word for black. Indeed, by the time Isidore of Seville came to write his Etymologies, the word Maurus or "Moor" had become an adjective in Latin, "for the Greeks call black, mauron". "In Isidore’s day, Moors were black by definition…"
Who claimed that Maurus was derived from the Greek mauron?
Isidore of Seville

For air dielectric capacitors the breakdown field strength is of the order 2 to 5 MV/m; for mica the breakdown is 100 to 300 MV/m; for oil, 15 to 25 MV/m; it can be much less when other materials are used for the dielectric. The dielectric is used in very thin layers and so absolute breakdown voltage of capacitors is limited. Typical ratings for capacitors used for general electronics applications range from a few volts to 1 kV. As the voltage increases, the dielectric must be thicker, making high-voltage capacitors larger per capacitance than those rated for lower voltages. The breakdown voltage is critically affected by factors such as the geometry of the capacitor conductive parts; sharp edges or points increase the electric field strength at that point and can lead to a local breakdown. Once this starts to happen, the breakdown quickly tracks through the dielectric until it reaches the opposite plate, leaving carbon behind and causing a short (or relatively low resistance) circuit. The results can be explosive as the short in the capacitor draws current from the surrounding circuitry and dissipates the energy.
What is one factor that critically affects the breakdown voltage of the capacitor?
the geometry of the capacitor conductive parts

From the 1880s to 1914, the European powers expanded their control across the African continent, competing with each other for Africa’s land and resources. Great Britain controlled various colonial holdings in East Africa that spanned the length of the African continent from Egypt in the north to South Africa. The French gained major ground in West Africa, and the Portuguese held colonies in southern Africa. Germany, Italy, and Spain established a small number of colonies at various points throughout the continent, which included German East Africa (Tanganyika) and German Southwest Africa for Germany, Eritrea and Libya for Italy, and the Canary Islands and Rio de Oro in northwestern Africa for Spain. Finally, for King Leopold (ruled from 1865–1909), there was the large “piece of that great African cake” known as the Congo, which, unfortunately for the native Congolese, became his personal fiefdom to do with as he pleased in Central Africa. By 1914, almost the entire continent was under European control. Liberia, which was settled by freed American slaves in the 1820s, and Abyssinia (Ethiopia) in eastern Africa were the last remaining independent African states. (John Merriman, A History of Modern Europe, Volume Two: From the French Revolution to the Present, Third Edition (New York: W. W. Norton & Company, 2010), pp. 819–859).
Where in Africa did Portuguese have control?
southern Africa