Carl David Anderson (September 3, 1905 – January 11, 1991) was an American physicist. He is best known for his discovery of the positron in 1932, an achievement for which he received the 1936 Nobel Prize in Physics, and of the muon in 1936.
First-generation semiconductors could not be properly termed “doped- they were simply very impure. Uncontrolled impurities hindered the discovery of physical laws, baffling researchers and evoking pessimism and derision in advocates of the burgeoning “pure” physical disciplines. The eventual banishment of the “dirt” heralded a new era in semiconductor physics, an era that had “purity” as its motto. It was this era that yielded the successes of the 1950s and brought about a new technology of “semiconductor electronics”. Experiments with pure crystals provided a powerful stimulus to the development of semiconductor theory. New methods and theories were developed and tested: the effective-mass method for complex bands, the theory of impurity states, and the theory of kinetic phenomena. These developments constitute what is now known as semiconductor physics. In the last fifteen years, however, there has been a noticeable shift towards impure semiconductors – a shift which came about because it is precisely the impurities that are essential to a number of major semiconductor devices. Technology needs impure semiconductors, which unlike the first-generation items, are termed “doped” rather than “impure” to indicate that the impurity levels can now be controlled to a certain extent.
On April 26, 1986, the worst nuclear reactor accident in history occurred in Chernobyl and contaminated as much as three quarters of Europe. Voices from Chernobyl is the first book to present personal accounts of the tragedy. Journalist Svetlana Alexievich interviewed hundreds of people affected by the meltdown—from innocent citizens to firefighters to those called in to clean up the disaster—and their stories reveal the fear, anger, and uncertainty with which they still live. Comprised of interviews in monologue form, Voices from Chernobyl is a crucially important work, unforgettable in its emotional power and honesty.
Incisive, self-contained account of tensor analysis and the calculus of exterior differential forms, interaction between the concept of invariance and the calculus of variations. Emphasis is on analytical techniques, with large number of problems, from routine manipulative exercises to technically difficult assignments.