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period
period
period 1. Second-order geologic time unit which is the equivalent of the chronostratigraphic unit ‘
system’. Periods are subdivided into
epochs; together, several periods constitute an
era. When used formally the initial letter of the term is capitalized, e.g. the
Devonian Period.
2. (
T) The time that elapses between repetitions of the same phase of a wave-form, i.e. the time taken to complete one cycle. For a simple harmonic function,
T = 2π/ω where ω is the angular velocity; for a wavetrain of single
frequency f,
T = 1/
f = λ/
V where λ is the
wavelength and
V the
phase velocity.
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SECRETARY CHU ANNOUNCES DETERMINATION OF NO ADVERSE MATERIAL IMPACT FOR URANIUM TRANSFER TO FUND PORTSMOUTH CLEANUP
Transcript from: Regulatory Intelligence Data; 11/12/2009; ; 494 words
; ...calendar years 2009 and 2010for cleanup at the Portsmouth Gaseous Diffusion Plant, so long as the totaltransfer during that period does not exceed 1,125 metric tons of uranium.The uranium transfers will be consistent with the policies reflected inthe...
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September 11 Suspects To Be Tried In U.S.
Transcript from: NPR Morning Edition; 11/13/2009; ; 700+ words
; ...going to have to deal with that as they push for these trials. You know, they're supposed to be a 45-day notification period. Basically, they're going to have to tell members of Congress who are going to have to accept these guys 45 days in advance...
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Galbraith's Actions May Hurt Independent Advice [DP]
Transcript from: NPR Morning Edition; 11/13/2009; ; 700+ words
; ...along the Iraq- Turkey border documenting the use of chemical weapons, and I was in Kurdistan during the 1991 uprising and the period thereafter, obviously with no thought to future business activity. KELEMEN: One Iraq watcher, Reidar Visser of the Norwegian...
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Defense Lawyer Describes Meeting With Hasan
Transcript from: NPR All Things Considered; 11/11/2009; ; 700+ words
; ...about that? Col. GALLIGAN: Well, let me tell you, I've spent 30 years in the Army, you can't help when you leave that period of time serving and working with soldiers, it's almost inevitable that you do like I did. As soon as I retired, the great...
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From The Vaults, A Look At Early Indie-Movie History [DP]
Transcript from: NPR All Things Considered; 11/11/2009; ; 700+ words
; ...t know 90 percent of the history of this fascinating early period. PAILTHORP: Historian Kathy Fuller-Seeley teaches media...Thanhouser's efforts are truly changing the way we understand this period of early film history. PAILTHORP: Historian Kathy Fuller...
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How Safe Is It? Seymour Hersh On Pakistan's Arsenal
Transcript from: NPR Fresh Air; 11/12/2009; ; 700+ words
; ...ended. After years of substantial investments by the American people, governance in Afghanistan must improve in a reasonable period of time. What do you think the significance of this is? Mr. SEYMOUR HERSH (Journalist, The New Yorker): Well, assuming...
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Virginia Governor Denies Clemency For Sniper
Transcript from: NPR All Things Considered; 11/10/2009; ; 700+ words
; ...area. In Montgomery County, Maryland, just north of the district, five people were shot and killed at random in a 24-hour period. They were doing the most mundane things: shopping, mowing the grass, getting gas. More shootings followed in Virginia...
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Letters: Health Care Mural, Digital Library
Transcript from: NPR All Things Considered; 11/10/2009; ; 476 words
; ...cross- eyed within 10 years. If a full-size computer screen is bad for your eyes, focusing on a tiny one for prolonged periods must be much worse. NORRIS: Last week we asked you to send us questions for three military thinkers featured in our recent...
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PROPOSALS FOR LONG-TERM FISCAL STABILITY:MAYA MACGUINEAS
Transcript from: Congressional Testimony; 11/10/2009; 700+ words
; ...unanticipated crises. If wehad been running budget surpluses during the period of economic growthprior to the downturn, we would have had...we have faced. However, we are now sandwichedin between a period where we ran structural budget deficits when we shouldhave run...
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INNOCENCE PROTECTION ACT:BARRY MATSON
Transcript from: Congressional Testimony; 11/10/2009; 700+ words
; ...retainedexpert testimony and consulted with many other experts in preparation oftheir defense. After a lengthy pre-trial period, the case was set for trial.After many days of testimony and argument, Calhoun was convicted and ajury of his peers recommended...
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wisent
Book article from: The Columbia Encyclopedia, Sixth Edition
...In the wild the wisent is a forest animal; it browses on leaves, ferns, and bark. Females give birth after a gestation period of 9 to 10 months, usually to a single calf. Abundant in Europe in prehistoric times, wisents remained numerous until the...
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AIDS
Book article from: The Columbia Encyclopedia, Sixth Edition
...develop normally. The definition of AIDS has been refined as more knowledge has become available. In general it refers to that period in the infection when the CD4 count goes below 200 (from a normal count of 1,000) or when the characteristic opportunistic...
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Klara Zetkin
Book article from: The Columbia Encyclopedia, Sixth Edition
...the right-wing, Russophile element of the party, and was (1920-32) a Communist member of the Reichstag. During that period she spent much of her time in Russia. Zetkin was a profound student of Marxist thought; she wrote several works on socialism...
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Sture
Book article from: The Columbia Encyclopedia, Sixth Edition
...the Univ. of Uppsala. A member of a Danish Sture family, Svante Sture, d. 1512, succeeded him as regent. His rule was a period of continual warfare. His son and successor as regent was Sten Sture, the younger, c.1492-1520. He vigorously asserted...
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Sumerian and Babylonian art
Book article from: The Columbia Encyclopedia, Sixth Edition
...round skull are revealed in bas-relief and inlay work of the period. Examples of the famous votive stone sculptures of Sumer discovered...glory of Sumer was revived from 2200 to 2100 BC During this period the great ziggurat of the moon god at Ur was built. Invasions...
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