TOWARD THE REDEFINITION OF THE KILOGRAM FROM THE 28Si INTERNATIONAL RESEARCH PROJECT

2013 ◽  
Vol 24 ◽  
pp. 1360001
Author(s):  
KENICHI FUJII
Keyword(s):  
International Research ◽  
International System ◽  
Physical Constant ◽  
Standard Uncertainty ◽  
Research Project ◽  
Avogadro Constant ◽  
Counting Procedure ◽  
System Of Units ◽  
Fundamental Physical ◽  
International Research Project

In the international system of units, the kilogram in the only SI base unit still defined by a material artefact. In order to redefine this unit with a fundamental physical constant, an international research project was launched in 2004 for determining the Avogadro constant, NA, by counting the atoms in an isotopically enriched 28Si crystal. The counting procedure relies on the measurements of the molar and atomic volumes of 1 kg spheres made of the 28Si crystal. In 2011, the project succeeded in measuring the Avogadro constant with a smallest standard uncertainty, 3.0 × 10−8 NA. Because of an unexpected metallic contamination at the surface of the spheres, the measurement uncertainty was larger than the target of the project by a factor of 1.5. In order to further reduce the uncertainty, a new international research project was launched in 2012. Outline of the new project and the improvements of the measurements will be introduced at the forum. Note from Publisher: This article contains the abstract only.

Analyzing Museum Collections in Scandinavia

Museum Worlds ◽  
2016 ◽  
Vol 4 (1) ◽  
pp. 126-137
Author(s):  
Niklas Ytterberg
Keyword(s):  
International Research ◽  
Museum Collections ◽  
Research Institutions ◽  
Research Strategies ◽  
Research Project ◽  
Historical Museums ◽  
Southern Scandinavia ◽  
International Research Project

ABSTRACTThis article emanates from studies and analyses of collections in cultural-historical museums in Sweden, Denmark, and Norway within the international research project CONTACT, concerning contacts between the aforementioned countries in southern Scandinavia during the Middle Neolithic (approximately 3000 BCE). This case study intends to raise questions related to research strategies at the museums holding the collections, in relation to the demand from research institutions using them. In what ways could these strategies coincide, and in what ways could they diverge? In what ways could we improve the research strategies for a better use of the collections?

scholarly journals The NIST Johnson Noise Thermometry System for the Determination of the Boltzmann Constant

2017 ◽  
Vol 122 ◽  
Author(s):  
Nathan E. Flowers-Jacobs ◽  
Alessio Pollarolo ◽  
Kevin J. Coakley ◽  
Adam C. Weis ◽  
Anna E. Fox ◽  
...  
Keyword(s):  
International System ◽  
Standard Uncertainty ◽  
Boltzmann Constant ◽  
Correlated Noise ◽  
Johnson Noise ◽  
Noise Thermometry ◽  
Relative Standard ◽  
System Of Units ◽  
Johnson Noise Thermometry

In preparation for the redefinition of the International System of Units (SI), five different electronic measurements of the Boltzmann constant have been performed using different Johnson noise thermometry (JNT) systems over the past seven years. In this paper, we describe in detail the JNT system and uncertainty components associated with the most recent National Institute of Standards and Technology (NIST) determination of the Boltzmann constant: k = 1.380642 9(69) × 10−23 J/K, with a relative standard uncertainty of 5.0 × 10−6 and relative offset of −4.05 × 10−6 from the Committee on Data for Science and Technology (CODATA) 2014 recommended value. We discuss the input circuits and the approach we used to match the frequency response of two noise sources. We present new measurements of the correlated noise of the 4 K on-chip resistors in the quantum-accurate, pseudorandom, voltage-noise source, which we used to estimate the correlated, frequency-dependent, nonthermal noise in our system. Finally, we contrast our system with those used in other measurements and speculate on future improvements.

scholarly journals Definition of the mole (IUPAC Recommendation 2017)

2018 ◽  
Vol 90 (1) ◽  
pp. 175-180 ◽  
Author(s):  
Roberto Marquardt ◽  
Juris Meija ◽  
Zoltán Mester ◽  
Marcy Towns ◽  
Ron Weir ◽  
...  
Keyword(s):  
International System ◽  
International Committee ◽  
Fundamental Physical Constants ◽  
Weights And Measures ◽  
Technical Report ◽  
System Of Units ◽  
Iupac Recommendation ◽  
Definition Of ◽  
Base Units ◽  
Fundamental Physical

AbstractIn 2011 the General Conference on Weights and Measures (CGPM) noted the intention of the International Committee for Weights and Measures (CIPM) to revise the entire International System of Units (SI) by linking all seven base units to seven fundamental physical constants. Of particular interest to chemists, new definitions for the kilogram and the mole have been proposed. A recent IUPAC Technical Report discussed these new definitions in relation to immediate consequences for the chemical community. This IUPAC Recommendation on the preferred definition of the mole follows from this Technical Report. It supports a definition of the mole based on a specified number of elementary entities, in contrast to the present 1971 definition.

Planning a medical student directed international research project

BMJ ◽  
2014 ◽  
pp. g2038
Author(s):  
Lindsey E Roeker ◽  
Maria Bachman ◽  
Nirmala Narla ◽  
Rochelle Molitor ◽  
Kathryn Handlogten ◽  
...  
Keyword(s):  
Medical Student ◽  
International Research ◽  
Research Project ◽  
International Research Project

Youth Ministry in a World of Diversity: A review of the international research project on youth spirituality

2007 ◽  
Vol 6 (1) ◽  
pp. 70-91 ◽  
Author(s):  
Paul McQuillan
Keyword(s):  
United States ◽  
International Research ◽  
Youth Ministry ◽  
The United States ◽  
Valuable Contribution ◽  
Research Project ◽  
The United Kingdom ◽  
The World ◽  
African Perspective ◽  
International Research Project

The research project came about at the suggestion of Nick Shepherd and was intended to source articles from IASYM members from around the world to outline the issues surrounding youth spirituality today. The articles generated by this collaboration included two each from Australia, the United States and the United Kingdom and a very valuable contribution from an African perspective.

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