QUES: The structure of QD-LEDs used for the electrical-excitation scheme is similar to basic design of OLEDs. A layer of quantum dots is sandwiched between layers of electron-transporting and hole-transporting materials. An applied electric field causes electrons and holes to move into the quantum dot layer and recombine forming an exciton that excites a QD. This scheme is commonly studied for quantum dot display. The tunability of emission wavelengths and narrow bandwidth is also beneficial as excitation sources for fluorescence imaging. Fluorescence near-field scanning optical microscopy (NSOM) utilizing an integrated QD-LED has been demonstrated.

What is one material used in electrical-excitation?
What is the answer?
ANS: hole-transporting materials
QUES: The first known European explorer to reach Bermuda was Spanish sea captain Juan de Bermúdez in 1503, after whom the islands are named. He claimed the apparently uninhabited islands for the Spanish Empire. Paying two visits to the archipelago, Bermúdez never landed on the islands, but did create a recognisable map of the archipelago. Shipwrecked Portuguese mariners are now thought to have been responsible for the 1543 inscription in Portuguese Rock (previously called Spanish Rock). Subsequent Spanish or other European parties are believed to have released pigs there, which had become feral and abundant on the island by the time European settlement began. In 1609, the English Virginia Company, which had established Jamestown in Virginia (a term originally applied to all of the North American continent) two years earlier, permanently settled Bermuda in the aftermath of a hurricane, when the crew and passengers of the Sea Venture steered the ship onto the surrounding reef to prevent its sinking, then landed ashore.

In what year did Jaun de Bermudez first reach Bermuda?
What is the answer?
ANS: 1503
QUES: The term Muslim world, also known as Islamic world and the Ummah (Arabic: أمة‎, meaning "nation" or "community") has different meanings. In a religious sense, the Islamic Ummah refers to those who adhere to the teachings of Islam, referred to as Muslims. In a cultural sense, the Muslim Ummah refers to Islamic civilization, exclusive of non-Muslims living in that civilization. In a modern geopolitical sense, the term "Islamic Nation" usually refers collectively to Muslim-majority countries, states, districts, or towns.

When speaking of religion, what does Ummah refer to?
What is the answer?
ANS:
those who adhere to the teachings of Islam