Recent advances in vibroacoustics
Numerous vibroacoustics advances and problems in the aerospace industry have occurred over the last 15 years. This article addresses some of these that developed from engineering programmatic task-work at the NASA Glenn Research Center at Lewis Field.
Investigation of Acoustic Fields for the Cassini Spacecraft: Reverberant Versus Launch Environments
The characterization and understanding of the acoustic field within a launch vehicle's payload fairing (PLF) is critical to the qualification of a spacecraft and ultimately to the success of its mission. Acoustic measurements taken recently for the Cassini mission have allowed unique opportunities to advance the aerospace industry's knowledge in this field. Prior to its launch, the expected liftoff acoustic environment of the spacecraft was investigated in a full-scale acoustic test of a Titan IV PLF and Cassini simulator in a reverberant test chamber. A major goal of this acoustic ground test was to quantify and verify the noise reduction performance of special barrier blankets that were designed especially to reduce the Cassirii acoustic environment. This paper will describe both the ground test and flight measurements, and compare the Cassini acoustic environment measured during launch with that measured earlier in the ground test. Special emphasis will be given to the noise reduction performance of the barrier blankets and to the acoustic coherence measured within the PLF.
Nietzsche: Philosopher, Psychologist, Antichrist
This classic is the benchmark against which all modern books about Nietzsche are measured. When Walter Kaufmann wrote it in the immediate aftermath of World War II, most scholars outside Germany viewed Nietzsche as part madman, part proto-Nazi, and almost wholly unphilosophical. Kaufmann rehabilitated Nietzsche nearly single-handedly, presenting his works as one of the great achievements of Western philosophy. Responding to the powerful myths and countermyths that had sprung up around Nietzsche, Kaufmann offered a patient, evenhanded account of his life and works, and of the uses and abuses to which subsequent generations had put his ideas.Without ignoring or downplaying the ugliness of many of Nietzsche's proclamations, he set them in the context of his work as a whole and of the counterexamples yielded by a responsible reading of his books. More positively, he presented Nietzsche's ideas about power as one of the great accomplishments of modern philosophy, arguing that his conception of the "will to power" was not a crude apology for ruthless self-assertion but must be linked to Nietzsche's equally profound ideas about sublimation.He also presented Nietzsche as a pioneer of modern psychology and argued that a key to understanding his overall philosophy is to see it as a reaction against Christianity. Many scholars in the past half century have taken issue with some of Kaufmann's interpretations, but the book ranks as one of the most influential accounts ever written of any major Western thinker.