Topic
Neper
About: Neper is a research topic. Over the lifetime, 13 publications have been published within this topic receiving 91 citations. The topic is also known as: Np.
Papers
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
TL;DR: In this article, the analysis of zero-THz spectra is extended to include fourth and sixth spectral moments, and the usual dielectric loss (e″(ω)) and power absorption (α(ω)/neper cm −1 ) spectral features are supplemented by ω 2 α(ω) and ω 4 α (ω).
6 citations
TL;DR: In this article, the use of special units for logarithmic ratio quantities is reviewed, without reference to the units, as is standard practice in any system of quantities and units.
Abstract: The use of special units for logarithmic ratio quantities is reviewed. The neper is used with a natural logarithm (logarithm to the base e) to express the logarithm of the amplitude ratio of two pure sinusoidal signals, particularly in the context of linear systems where it is desired to represent the gain or loss in amplitude of a single-frequency signal between the input and output. The bel, and its more commonly used submultiple, the decibel, are used with a decadic logarithm (logarithm to the base 10) to measure the ratio of two power-like quantities, such as a mean square signal or a mean square sound pressure in acoustics. Thus two distinctly different quantities are involved. In this review we define the quantities first, without reference to the units, as is standard practice in any system of quantities and units. We show that two different definitions of the quantity power level, or logarithmic power ratio, are possible. We show that this leads to two different interpretations for the meaning and numerical values of the units bel and decibel. We review the question of which of these alternative definitions is actually used, or is used by implication, by workers in the field. Finally, we discuss the relative advantages of the alternative definitions.
5 citations
TL;DR: In this article, the attenuation of ultrasonic wave in sodium has been measured by the pulse transmission method in the temperature range from 20 to 160°C through the melting temperature of 97.8°C.
Abstract: The attenuation of ultrasonic wave in sodium has been measured by the pulse transmission method in the temperature range from 20 to 160°C through the melting temperature of 97.8°C. The frequency of sound used was 1 MHz. The typical value of attenuation in solid phase was 0.279 neper/cm, and that in liquid phase was 0.201 neper/cm. At the melting point, a large absorption of ultrasonic wave was seen and its value amounted to 0.51 neper/cm in the melting process and 1.21 neper/cm in the solidification process. The increase of the attenuation at the melting point may be due to the Rayleigh scattering, which is appreciable in the mixed state of the liquid and the suspending crystallites. By combining the present results with our previous data on sound velocity, discussion was made on the variation of elastic and anelastic properties of sodium during its melting and solidification processes.
2 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 1 |
| 2007 | 1 |
| 2005 | 1 |
| 2002 | 2 |
| 2001 | 2 |
| 1995 | 1 |