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Search Publications by: Darine El Haddad (Fed)

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Displaying 1 - 25 of 74

Flexures for Kibble balances: Minimizing the effects of anelastic relaxation

July 1, 2024
Author(s)
Lorenz Keck, Stephan Schlamminger, Rene Theska, Frank Seifert, Darine El Haddad
Modern weighing cells would not be possible without flexure technology. Flexures are thin metal strips that form pivots, and they can be engineered to bend in a prescribed fashion, producing a desired restoring torque. In contrast to other pivots, flexures

The Quantum Electro-Mechanical Metrology Suite

March 27, 2024
Author(s)
Frank Seifert, Lorenz Keck, David B. Newell, Darine El Haddad
The National Institute of Standards and Technology (NIST) is building a robust open-source hardware and software Quantum Electro-Mechanical Metrology Suite (QEMMS) that can provide quantum voltage, resistance, current, mass, and force dissemination

A Macroscopic Mass From Quantum Behavior In An Integrated Approach

December 10, 2022
Author(s)
Frank Seifert, Alireza Panna, Lorenz Keck, Leon Chao, Shamith Payagala, Dean G. Jarrett, Dipanjan Saha, Randolph Elmquist, Stephan Schlamminger, Albert Rigosi, David B. Newell, Darine El Haddad
The revision of the International System of Units (SI) on May 20th, 2019, has enabled new improved experiments to consolidate and simplify electrical and mechanical metrology currently underway. Historically within the SI, the definition of energy was only

Calculation of magnetic forces and torques on the Kibble coil

October 22, 2022
Author(s)
Stephan Schlamminger, Lorenz Keck, Frank Seifert, Leon Chao, Darine El Haddad, Shisong Li
Analytically the force and torques on a coil in a field of magnetic flux density can be calculated one of two ways. The line integral can be conducted along the coil's wire, summing up the differential force contribution. For each differential line segment

Resolution of the paradox of the diamagnetic force on the Kibble coil

January 13, 2021
Author(s)
Stephan Schlamminger, Shisong Li, Rafael Marangoni, Darine El Haddad, Qing Wang, Wei Zhao
Employing very simple electro-mechanical principles known from classical physics, the Kibble balance establishes a very precise and absolute link between quantum electrical standards and macroscopic mass or force measurements. The success of the Kibble

The Design of an Instrument to Realize Small Torque at NIST

August 22, 2020
Author(s)
Leon S. Chao, Rafael Marangoni, Frank C. Seifert, Darine El Haddad, Jon R. Pratt, David B. Newell, Stephan Schlamminger
After the recent redefinition of the International System of Units (SI), torque no longer needs to be traceable to a calibrated mass in a gravitational field suspended from a known lever arm and disseminated through a chain of torque transducers.An SI

The Design and Development of a Tabletop Kibble Balance at NIST

May 23, 2019
Author(s)
Leon S. Chao, Frank C. Seifert, Darine El Haddad, Julian Stirling, David B. Newell, Stephan Schlamminger
On November 16, 2018, the 26th General Conference on Weights and Measures (CGPM) voted unanimously to revise the International System of Units (SI) from a system built on seven base units to one built on seven defining constants and will officially become

The Kibble balance and the kilogram

March 25, 2019
Author(s)
Stephan Schlamminger, Darine El Haddad
Dr. Bryan Kibble invented the watt balance in 1975 to improve the realization of the unit for electrical current, the ampere. With the discovery of the Quantum Hall e ect in 1980 by Dr. Klaus von Klitzing and in conjunction with the previously predicted

The Design and Development of a Tabletop Kibble Balance at NIST

March 20, 2019
Author(s)
Leon S. Chao, Frank C. Seifert, Darine El Haddad, Stephan Schlamminger
A global paradigm shift to redefine the International System of Units (SI) from a system based on seven fundamental units to seven fundamental constants is well under way. More specifically, the unit of mass, the kilogram, will be realized via a fixed