Robert W. Coakley
Department of Physics
University of Southern Maine
P.O. Box 9300
Portland, ME 04104-9300
coakley@usm.maine.edu
(207) 780 4733
(207) 228 8288 - fax
Research Interests
Brillouin Light Scattering from liquids with an aim of determining
hypersonic sound velocity and acoustic absorption
coefficients. Experiments with isopropanol are currently
under way. Part of the thrust of this project is to see what can
be done with a 1 mW HeNe laser. So far, the temperature
coefficient of the hypersonic (f about 3GHz) sound velocity has been
measured to be about -5 m/s/deg C. The 25 degree sound velocity
is about 1200 m/s in that same frequency range. Analysis has been
completed for linewidths, both as a function of temperature and as a
function of acoustic wave number. The Brillouin linewidths have a
clear temperature dependence, decreasing by about a factor of two over
our 18 to 31 degree temperature range. More experimental and data
reduction work remains to be done on the temper dependence of line
widths. The second step of
this project is to study water-alcohol mixtures. So far, we have
had difficulty with sample
preparation. Surprisingly, extremely
well filtered water added to extremely well filtered water results in a
mixture that acts like there is dust in it.
Teaching Info
When I teach a course, I usually maintain an informational web
page. The links to those pages appear below. If someone
else is teaching the course, these pages will not be relevant. If
I am not currently teaching one of the courses below, you might find
that the link is broken.
Physics 111K -
Elements of Physics I
Physics 112 -
Elements of Physics II - Spring semester
Physics 112 -
Elements of Physics II - Summer session
Physics
114K - Introductory Lab I
Physics
116 - Introductory Lab II
Physics 121K
and 123 - General Physics - Summer session
Physics 223 -
Classical Physics II
Physics 225 - Classical Physics III
Physics 251 -
Principles of Electronics
Teaching Schedule:
(This information tends to get out of date)
Fall 2008
Physics 111K
Physics 114K
Summer 2009
Physics 121K
Physics 123
Physics 112