Procedure

A subject takes a breath of 100% oxygen and exhales through a one-way valve measuring nitrogen content and volume. A plot of the nitrogen concentration (as a % of total gas) vs. expired volume is obtained by increasing the nitrogen concentration from zero to the percentage of nitrogen in the alveoli. The nitrogen concentration is initially zero because the subject is exhaling the dead space oxygen they just breathed in (does not participate in alveolar exchange), and climbs as alveolar air mixes with the dead space air. The dead space can be determined from this curve by drawing a vertical line down the curve such that the areas below the curve (left of the line) and above the curve (right of the line) area equal.

Most people with a normal distribution of airways resistances will reduce their expired end-tidal nitrogen concentrations to less than 2.5% within seven minutes. Individuals with high resistance in their airways can take longer than seven minutes to remove all the nitrogen.

Parameters

Also, from those values, additional parameters can be calculated:

See also

References

External links

Category:Tests

Nick Holonyak, Jr. (born November 3, 1928, in Zeigler, Illinois) invented the first practically useful visible LED in 1962 while working as a consulting scientist at a General Electric Company laboratory in Syracuse, New York and has been called "the father of the light-emitting diode". He is a John Bardeen Endowed Chair in Electrical and Computer Engineering and Physics and Professor of electrical and computer engineering at the University of Illinois at Urbana-Champaign where he has been since 1963.

Inventions

In 2006, the American Institute of Physics decided on the five most important papers in each of its journals since it was founded 75 years ago. Two of these five papers, in the journal ''Applied Physics Letters'', were co-authored by Holonyak. The first one, coauthored with S. F. Bevacqua in 1962, announced the creation of the first visible-light LED. The second, co-authored primarily with Milton Feng in 2005, announced the creation of a transistor laser that can operate at room temperatures. Holonyak predicted that his LEDs would replace the incandescent light bulb of Thomas Edison in the February 1963 issue of ''Reader's Digest'', and as LEDs improve in quality and efficiency they are gradually replacing incandescents as the bulb of choice.

Background

Holonyak was John Bardeen's first Ph.D. student at the University of Illinois at Urbana-Champaign. He received his undergraduate, master's, and Ph.D. (1954) from the same university. He created the first visible semiconductor lasers in 1960. In 1963, he again joined Dr. Bardeen, the co-inventor of the transistor, at the University of Illinois and worked on quantum wells and quantum-well lasers.

University of Illinois

10 of his 60 former doctoral students develop new uses for LED technology at Philips Lumileds Lighting Company in Silicon Valley.

Awards and honors

In 1989, Holonyak received the IEEE Edison Medal for 'an outstanding career in the field of electrical engineering with contributions to major advances in the field of semiconductor materials and devices.' Holonyak's former student, Russell Dupuis from the Georgia Institute of Technology, won this same award in 2007.

In 1995, he was awarded the $500,000 Japan Prize for 'Outstanding contributions to research and practical applications of light emitting diodes and lasers.'

In 2003, he was awarded the IEEE Medal of Honor.

He has also received the Global Energy International Prize, the National Medal of Technology, the Order of Lincoln Medallion, and the 2004 Lemelson-MIT Prize, also worth $500,000. He has also received the Frederic Ives Medal of the Optical Society of America.

Many colleagues have expressed their belief that he deserves the Nobel Prize for his invention of the LED. On this subject, Holonyak says, "It's ridiculous to think that somebody owes you something. We're lucky to be alive, when it comes down to it."

On 9 November 2007, Holonyak was honored on the University of Illinois campus with a historical marker recognizing his development of the quantum-well laser. It is located on the Bardeen Engineering Quadrangle near where the old Electrical Engineering Research Laboratory used to stand.

In 2008, he was inducted into the National Inventors Hall of Fame (Announced February 14, 2008) (May 2–3, 2008 at Akron, Ohio).

References

External links

Category:1928 births Category:Members of the United States National Academy of Sciences Category:American people of Rusyn descent Category:Living people Category:American inventors Category:Laser researchers Category:People from Franklin County, Illinois Category:IEEE Medal of Honor recipients Category:University of Illinois at Urbana–Champaign faculty Category:University of Illinois at Urbana–Champaign alumni Category:National Inventors Hall of Fame inductees Category:National Medal of Technology recipients Category:Lemelson-MIT Prize Category:Japan Prize laureates Category:IEEE Edison Medal recipients Category:National Medal of Science laureates Category:Semiconductor physicists Category:Light-emitting diode pioneers

Victoria Leigh Blum (born October 15, 1955), professionally recognized as Tanya Roberts, is an American actress best known for her role in as Julie Rogers on the fifth and final season of ''Charlie's Angels'' (1980-1981) and as Midge Pinciotti on ''That '70s Show'' (1998-2001).

She later headlined the films: ''The Beastmaster'', ''A View to a Kill'', and ''Sheena''. Roberts was groomed as a Hollywood sex symbol during the early 1980s.

Early life

She returned to New York City and became a fashion and cover model. After meeting a psychology student, Barry Roberts (while waiting in line for a movie), she proposed to him in a subway station and they were soon married. While Barry pursued a career as a screenwriter, she began to study at the Actors Studio with Lee Strasberg and Uta Hagen under the name Tanya Roberts.

Acting career

1970s

In 1977, as her husband was securing his own screenwriting career, the couple moved to Hollywood. The following year, Roberts participated in the drama, ''Fingers''. Roles in the 1979 cult-movie, ''Tourist Trap'', ''Racket'' and ''California Dreaming'' followed. Roberts was featured in several television pilots that were never picked up: ''Zuma Beach'' (a 1978 comedy); ''Pleasure Cove'' (1979); and ''Waikiki'' (1980).

1980s

In 1983, Roberts filmed the Italian-made, and little-known adventure, ''Paladini-storia d'armi e d'amori'' (''Paladins—the story of love and arms''; also released as ''Hearts and Armour''), based on the medieval novel, ''Orlando Furioso''. She played the role of Velda, a buxom secretary to private detective, Mike Hammer, in the television movie, ''Murder Me, Murder You''. The two-part pilot spawned the syndicated television series, ''Mickey Spillane's Mike Hammer''. She declined to continue the role in the Mike Hammer series so she could work on her next project, ''Sheena: Queen of the Jungle''. The movie was a box office and critical disaster, garnering her a nomination for "Worst Actress" at the Razzie Awards.

Her subsequent appearance as Bond girl, Stacey Sutton, a well-educated and articulate geologist, in ''A View to a Kill'' (1985), which provided her a number of scenes with Roger Moore's James Bond. She again found herself nominated by the critics for a Razzie Award. Her career took a downturn. Later films in the 1980s included ''Body Slam'' (1987), an action movie set in the professional wrestling world; and ''Purgatory'', a movie about a woman wrongfully imprisoned in Africa.

1990spresent

In 1998, she took the role of Midge Pinciotti on the successful, long-running television sitcom, ''That '70s Show''. Roberts claimed to ''E! True Hollywood Story'' that she left the series in 2001 because her husband, Barry Roberts, had become terminally ill. Barry Roberts died in 2006. In 2008, Tanya Roberts wrote the foreword to the book, ''The Q Guide to Charlie's Angels''.

References

External links

Category:1955 births Category:American film actors Category:American television actors Category:Living people Category:People from the Bronx Category:American people of Irish descent Category:American people of Jewish descent