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Search Publications by: Thomas C Larason (Fed)

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Displaying 26 - 50 of 105

IR-enhanced Si reference detectors for 1-step scale transfers from 300 nm to 1000 nm

November 20, 2014
Author(s)
George P. Eppeldauer, Thomas C. Larason, Jeanne M. Houston, Robert E. Vest, Uwe Arp, Howard W. Yoon
IR-enhanced Si photodiodes have improved radiometric and electronic characteristics as compared to other widely used Si photodiodes and can be used as responsivity standards in the wavelength range from 300 nm to 1000 nm. Their low predicted uncertainty

Wavelength Dependent UV Inactivation and DNA Damage of Adenovirus 2 as Measured by Cell Culture Infectivity and Long Range Quantitative PCR

November 22, 2013
Author(s)
Sara E. Beck, Roberto A. Rodriguez, Karl G. Linden, Thomas M. Hargy, Thomas C. Larason, Harold B. Wright
Adenovirus is regarded as the most resistant pathogen to ultraviolet (UV) disinfection due to its demonstrated resistance to monochromatic, low-pressure (LP) UV irradiation at 254 nm. This resistance has resulted in high UV dose requirements for all

Measuring the UV Action Spectra of Pathogens and Surrogates

September 22, 2013
Author(s)
Karl G. Linden, Harold B. Wright, Sara E. Beck, Thomas M. Hargy, Thomas C. Larason, Randi M. McCuin
The use of bioassays to determine reduction equivalent doses delivered by UV reactors is recognized as an effective measure of UV disinfection systems. Low pressure (LP) UV delivered in controlled collimated beam systems provides dose response curves which

Using a Tunable Ultraviolet Laser for the Inactivation of Water Pathogens

September 22, 2013
Author(s)
Thomas C. Larason, Keith R. Lykke, Ping-Shine Shaw, Lin Chungsan
Ultraviolet (UV) radiation effectively inactivates common pathogens found in ground and surface waters such as Cryptosporidium, Giardia, and most bacterial pathogens (e.g. E. coli). Water treatment facilities are now using UV radiation for disinfection of

Extension of the NIST spectral power-responsivity calibration service to 2500 nm

March 2, 2012
Author(s)
George P. Eppeldauer, Howard W. Yoon, Jinan Zeng, Thomas C. Larason, Jeanne M. Houston, Vladimir Khromchenko
The National Institute of Standards and Technology (NIST) is working to extend the upper wavelength limit of the spectral power-responsivity calibration service from 1800 nm to 2500 nm. This extension is based on extended-InGaAs (EIGA) transfer- and

Calibrations of Current-to-Voltage Transimpedance Amplifiers Using Electrical Standards

June 13, 2010
Author(s)
Howard W. Yoon, George P. Eppeldauer, Dean G. Jarrett, Thomas C. Larason, Wan-Seop Kim
For photocurrent measurements with low uncertainties, a wide-dynamic range current-to-voltage converter traceable to resistance standards has been developed at the NIST. The design and calibration of the converter standard are described. For validation

Report on the Key Comparison CCPR K2.a-2003

October 30, 2009
Author(s)
Yoshihiro Ohno, Steven W. Brown, Thomas C. Larason
Under the framework of Mutual Recognition Arrangement (MRA) for national measurements standards and for calibration and measurement certificates issued by National Metrology Institutes (NMIs) signed in 1999, an international comparison of spectral

Extension of the NIST tristimulus colorimeter for solid-state light source measurements

May 29, 2009
Author(s)
George P. Eppeldauer, Carl C. Miller, Thomas C. Larason, Yoshihiro Ohno
In order to obtain improved color measurement uncertainties for solid state light (SSL) sources, the second generation tristimulus colorimeter of NIST has been extended with a fifth channel to perform efficient matrix corrections for the spectral mismatch