Topic
SI derived unit
About: SI derived unit is a research topic. Over the lifetime, 25 publications have been published within this topic receiving 339 citations. The topic is also known as: derived SI unit.
Papers
TL;DR: In this article, it was shown that an incoherence may arise when different units of this type are replaced by a single dimensionless unit, the unit "one", and how to properly include such units into the SI in order to remove the incoherence.
Abstract: The International System of Units (SI) is supposed to be coherent. That is, when a combination of units is replaced by an equivalent unit, there is no additional numerical factor. Here we consider dimensionless units as defined in the SI, {\it e.g.} angular units like radians or steradians and counting units like radioactive decays or molecules. We show that an incoherence may arise when different units of this type are replaced by a single dimensionless unit, the unit "one", and suggest how to properly include such units into the SI in order to remove the incoherence. In particular, we argue that the radian is the appropriate coherent unit for angles and that hertz is not a coherent unit in the SI. We also discuss how including angular and counting units affects the fundamental constants.
64 citations
Book•
30 Jun 1950
TL;DR: In this article, a simplified classification of the plant kingdom is presented, based on SI units with special names, and the periodic table is used to classify the animals of the world.
Abstract: PREFACE DICTIONARY 1. SI units 2. Derived SI units with special names 3. Decimal multiples and submultiples to be used with SI units 4. Conversion of units to SI units 5. Fundamental Constants 6. The solar system 7. Geological time scale 8. Simplified classification of the plant kingdom 9. Simplified classification of the animal kingdom 10. The periodic table
51 citations
TL;DR: Coversion factors base SI units derived SI units with special needs prefixes used with SI units fundamental constants symbols used in electronics spectrum of electromagnetic radiation long-lived elementary particles the chemical elements the periodic table of the elements the radioactive decay series symbols for physical quantites the Greek alphabet Nobel Prize winners in physics as discussed by the authors
Abstract: Coversion factors base SI units derived SI units with special needs prefixes used with SI units fundamental constants symbols used in electronics spectrum of electromagnetic radiation long-lived elementary particles the chemical elements the periodic table of the elements the radioactive decay series symbols for physical quantites the Greek alphabet Nobel Prize winners in physics.
33 citations
1 Nov 2009
TL;DR: The 7th International Workshop on Sap Flow (Seville, Spain, 21-24 October 2008) as mentioned in this paper discussed the use of symbols, units and physical quantities in presentations and during discussions.
Abstract: Some confusion was observed during the 7th International workshop on Sap Flow (Seville, Spain, 21-24 October 2008) with respect to the use of symbols, units and physical quantities in presentations and during discussions. It was therefore decided at the end of the workshop that a technical note would be very useful with the aim to summarize the basics of the “Systeme International des Unites (SI)” and to focus on particular aspects that are relevant for sap flow studies. Starting from a number of standard papers that have been published in the past, an extra effort was made to put sap flow nomenclature against the physical background of plant-water relationships, of water flow in the soil-plant-atmosphere continuum and of transport equations for mass, heat and hydraulic flow. Information is given on the application of SI units and the main SI conventions. Tables are included for practical use of basic and derived SI units and for common abbreviations encountered in sap flow studies. An overview of a coherent nomenclature for sap flow studies, together with definitions of sap flow quantities, symbols and units is given as well.
11 citations
TL;DR: The 21st General Conference on Weights and Measures (CGPM) considered in 1999 a resolution proposing that the neper rather than the bel should be adopted as the coherent derived SI unit The matter remains open for consideration until the next CGPM in 2003 as mentioned in this paper.
Abstract: The 21st General Conference on Weights and Measures (CGPM) considered in 1999 a resolution proposing that the neper rather than the bel should be adopted as the coherent derived SI unit The matter remains open for consideration until the next CGPM in 2003 Further arguments are presented showing the confusion generated by the use of some dimensionless units, while the changes that the SI will have to face in the future are of a quite different nature
9 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2018 | 1 |
| 2014 | 2 |
| 2012 | 1 |
| 2011 | 2 |
| 2009 | 1 |
| 2008 | 2 |