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Changed to -10*log_10(Output power / input power). Reference in [7] is wrong. When discussing attenuation in optics, the quantity should be negative. That formula gives a dB gain. New reference needed. —Preceding unsigned comment added by 169.234.12.117 (talk) 21:53, 30 January 2010 (UTC)[reply]
Wrong! attenuation is a positive quantity, and is implemented normally in formula, similar to I_0=exp(-alpha*z) —Preceding unsigned comment added by 169.234.3.206 (talk) 05:27, 1 February 2010 (UTC)[reply]
In the section on attenuation in optics it states that the units of intensity are Watts (W). This is simply wrong.
Intensity is Power per Area, so ither it should be Intensity (W/m^2) or Power (W). In both cases the formula can be used as the area is the same. So power or intensity are fine, but the units should not be mixed. — Preceding unsigned comment added by 134.3.129.103 (talk) 18:41, 11 August 2016 (UTC)[reply]
Shouldn't this be in Wiktionary? I propose either moving or copying the article there.
--Falsifian Come to think of it, there are too many pages that link here. I'll copy it over if it's not already there. --Falsifian 16:30, 2004 Nov 22 (UTC)
I think that a seperate article should be created relating Attenuation to the process of RNA termination
A sentence or two could be added to describe the diffuse attenuation coefficient of downward propagatin radiation, as it is used in limnology, e.g. k(d)=-1/z ln (Iz/I0) [ see Kirk - Light and photosynthesis in aquatic ecosystems ] —Preceding unsigned comment added by 193.170.92.170 (talk) 10:52, 25 January 2011 (UTC)[reply]
a disambiguation page is needed, for people like me who arrive at the physics attenuation page but are looking for attenuation (biology)
Attenuation
should the value for lung really be twice that of bone? i should think it would be the other way round or similar Rtcoles 16:43, 29 April 2007 (UTC)[reply]
The last reference link is not working. Does anyone know which university was originally referenced, and what their URL is now? Ackbeet 15:03, 11 September 2007 (UTC)[reply]
I'm worried about the values of the attenuation coefficients for water (and also the units and naming) - Kinsler, in "Fundamentals of acoustics" (3rd ed.) says that acoustic attenuation coefficients (a) are measured in Nepers/m (Np/m) and absorption coefficients (alpha) in dB/m. Using his eqn 7.52 (and experimental data in fig 7.5) gives an absorption coefficient of 0.21dB/m at 1MHz. This is very different to the value of 23dB/m at 1MHz found in this table. Comments please? —Preceding unsigned comment added by 152.78.32.144 (talk) 16:40, 9 September 2010 (UTC)[reply]
I've updated the values for attenuation constants using a more recent reference, which itself is a compendium of measurements from the literature. As the previous commenter noticed, there was a typo in the value for water in the previous table, which listed a value two orders of magnitude larger than the correct value probably due to a meter/cm unit mistake (Nepers/m vs Nepers/cm). Other values have shifted as well, but by a factor of ~2 or less. David s graff (talk) 14:48, 7 October 2010 (UTC)[reply]
" Attenuation of a signal's power by n decibels is equivalent to attenuating its amplitude by 2n decibels."
Shouldn't this be the other way around? If , then an attenuation of n decibels in voltage will cause an attenuation of 2n decibels in signal power. Or what is meant by amplitude? — Preceding unsigned comment added by 141.2.242.226 (talk) 08:11, 20 September 2011 (UTC)[reply]
Shouldn't this be f^2? This paper: http://rennes.ucc.ie/~bill/repository/2013-IEEE_IUS-1432.pdf indicates that the attenuation of ultrasound through air is related by the square of the frequency.
Answer written on December 18, 2013:
It can be with
typically between 1 and 2 depending on the medium. For biological tissue it is often assumed to be close to 1.
Please see e.g. http://en.wikipedia.org/wiki/Acoustic_attenuation
I think the table should be under Attenuation coefficient instead of (or in addition to) here. Mintz l (talk) 15:35, 23 May 2014 (UTC)[reply]
The comment(s) below were originally left at Talk:Attenuation/Comments, and are posted here for posterity. Following several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section.
It needs to be improved to become a B-article. Adding more text would be a start and also more references. Snailwalker | talk 16:13, 15 October 2006 (UTC)[reply] |
Last edited at 16:13, 15 October 2006 (UTC). Substituted at 08:33, 29 April 2016 (UTC)
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