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Search Publications by: Zeina J. Kubarych (Fed)

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Displaying 26 - 50 of 76

Calibration of dynamic sensors for noncontact-atomic force microscopy

August 12, 2011
Author(s)
Gordon A. Shaw, Jon R. Pratt, Zeina J. Kubarych
Access to quantitative information on surface forces in noncontact-atomic force microscopy (NC-AFM) requires the accurate calibration of several key sensor parameters. This work outlines a dynamic method for calibrating the spring constant of tuning fork

Vacuum technology considerations for mass metrology

July 1, 2011
Author(s)
Patrick J. Abbott, Zeina J. Kubarych
Vacuum weighing of mass artifacts eliminates the necessity of air buoyancy correction and its contribution to the measurement uncertainty. Vacuum weighing is also an important process in the experiments currently underway for the redefinition of the SI

Getting Closer to Redefining the Kilogram

October 30, 2009
Author(s)
Zeina J. Kubarych
A redefinition to replace the last remaining artifact based SI unit, the kilogram, may occur as early as 2011. This article presents a short summary of the status of current international efforts focused on the redefinition and the internationally agreed

Linking Air and Vacuum Mass Measurement by Magnetic Levitation

May 12, 2009
Author(s)
Zeina J. Kubarych, Patrick J. Abbott, Edwin R. Williams, Ruimin Liu, Vincent J. Lee, Hung-Kung Liu
This paper describes a new approach to directly link air and vacuum mass measurements using magnetic levitation techniques. This procedure provides direct traceability to national standards, presently defined in air, without requiring the estimate of

Constant Pressure and Vacuum Transporter for 1 kg Mass Standards

September 8, 2008
Author(s)
Vincent J. Lee, Zeina J. Kubarych
This report describes the design and intended use of a constant pressure and vacuum transporter for transferring 1 kg mass standards between different locations and environments without compromising the atmospheric conditions and therefore maintaining

Magnetic Levitation System for the Dissemination of a Non-Artifact Based Kilogram

November 27, 2007
Author(s)
Zeina J. Kubarych, Patrick J. Abbott, Edwin R. Williams, Ruimin Liu, Vincent J. Lee
We describe a new approach to directly link air and vacuum mass measurements. This approach uses magnetic levitation along with vacuum and balance technology to realize vacuum mass measurements. It provides direct traceability to the International

Final Report on CIPM Key Comparison of 1 kg Standards in Stainless Steel (CCM.M-K1)

October 1, 2004
Author(s)
R S. Davis, C Aupetit, L O. Becerra, W Bich, N Bignell, G D. Chapman, J.-H. Chung, J Coarasa, Stuart Davidson, N G. Domostroeva, Kitty Fen, M Glaser, W G. Lee, M Lecollinet, Q Li, R Spurny, J Verbeek, Zeina J. Kubarych, A Ooiwa, A Torino
This report describes a Key Comparison of 1 kg standards in stainless steel undertaken by the Consultative Committee on Mass and Related Quantities (CCM) and piloted by the Bureau International des Poids et Mesures (BIPM). The comparisons were carried ou

Effects of Cleaning on the US Prototype Kilograms

January 1, 2001
Author(s)
Zeina J. Kubarych, R S. Davis
This paper dicusses the stability of national prototype kilograms No. 4 and No. 20, belonging to the United States. Calibration history, changes in mass with respect to time, and effects on mass and surface profiles due to cleaning and washing are

The Kilogram and Measurements of Mass and Force

January 1, 2001
Author(s)
Zeina J. Kubarych, Simone L. Yaniv
This paper describes the facilities, measurement capabilities, and ongoing research activities in the areas of Mass and Force at the National Institute of Standards and Technology (NIST). The first section of the paper is devoted to mass metrology and

Status of Mass Metrology at NIST in 2000

January 1, 2000
Author(s)
Zeina J. Kubarych
This paper summarizes the activities in mass metrology at NIST. It includes a description of the facilities and the procedures used in the dissemination of the mass unit. This paper also discusses the research efforts to understand and characterize the

The Kilogram: Last remaining artifact

April 1, 1999
Author(s)
Zeina J. Kubarych
The unit of mass, the kilogram, is the last remaining basic unit defined by an artifact. Worldwide efforts are underway to replace the artifact-based definition with invariant alternatives. This paper describes briefly the history of the kilogram, the