| Date |
Time |
Location |
Event |
Monday
March 30th
|
3:15 pm
|
SB1 107 |
Dr. Jon Nelson, Physics Faculty Candidate
Lecturer at the College of Science and Engineering
Ritsumekan University
Kusatsu, Japan
Snow needles vs dendrites & ice plates vs
rosettes: Why should we
care?
Ice
in the environment, particularly snow, has long
drawn the interest of naturalists and captured
the imagination of people all over the world.
But ice is no mere curiosity. Ice crystals in
the atmosphere play important roles in lightning,
rain initiation, ozone depletion, planetary
reflectivity, and water transport. Over the
years, the unique structural, electrical, and
chemical properties of ice have attracted the
minds of scientists such as Bridgeman, Pauling,
and Onsager. Yet many mysteries of ice still
elude us. One such mystery is the crystal habit
problem: What causes ice to grow in a needle
shape at one temperature, yet grow as a six-cornered
dendrite only a few degrees colder? Understanding
this and related behavior will be crucial to
improving quantitative predictions about weather
and climate problems. In this talk, I describe
how a serendipitous discovery in the lab helped
resolve part of the long-standing habit problem
and why ice physics will likely remain a fertile
research area for physicists and chemists for
many years to come.
|
Monday
April 6th
|
3:15 pm
|
SB1 107 |
Dr. Sean Kirkpatrick
Department of Biomedical Engineering
Oregon Health and Science University
Portland, Oregon
A Speckled Look at Some Very Soft Problems
Speckle
is a ubiquitous phenomena in all modes of coherent imagery, be it optical,
ultrasonic or x-ray. For most people,
speckle is a noise problem that degrades the quality of images and an annoying
issue that simply must be dealt with.
For others, speckle is a rich source of information about the physics of
the object being imaged. This talk will
take the latter viewpoint. The dynamic
behavior of laser speckle originating from soft condensed matter, including
biological tissues, provides clues about the physical, mechanical, and
biochemical nature of the matter at scale sizes ranging from the molecular
domain up to the level of multi-cellular architecture. In this talk, the physical origins of laser
speckle along with a variety of experiments in which laser speckle is exploited
to reveal the nature of biological structures and other forms of soft condensed
matter will be discussed.
|
Wednesday
April 8th
|
3:15 pm |
SB1 107 |
Chris Butenhoff, Physics Faculty Candidate
Lecturer at Physics Department
Portland State University
Portland, Oregon
Can we constrain current inventories of greenhosue gases?
Applications of biophysical models and remote sensing.
Inventories of greenhouse gas emissions are important for a number of
reasons. They are important drivers of radiative forcing in climate
models, they act as precursors to the production of aerosols and other
atmospheric constituents, and are used to create global budgets that
can identify sources to target for control. Inventories can improve our
capability to predict how emissions will respond to climate change.
Perhaps of most importance, accurate inventories are required for
implementation of planned climate change legislation and carbon trading
instruments. To be effective and efficient, these inventories need to
be constrained and verified. This is challenging since many sources are
biogenic in nature and are consequently diffuse and highly variable in
time and space, making them difficult to constrain with sparse
land-based measurements. As a result, there is an emerging use of
remote sensing products and biophysical models due to their ability to
reflect and monitor changes at small temporal and spatial scales. This
talk will highlight the use of some of these tools to help understand
the methane budget.
|
Monday
April 20th |
3:15 pm |
SB1 107 |
Professor W Neumann
Chair of Crystallography
Institute of Physics
Humboldt University
Berlin, Germany
Electron Microscopy of Nanostructured Materials
Nanostructured
materials from almost all classes of materials are of great interest
because the reduced dimensionality may drastically change the physical
properties. In general, these properties are a function of size,
shape, arrangement and chemical composition of the nano-sized materials.
The potential applicability of modern transmission electron microscopy
(TEM) will be demonstrated for different nano-sized materials,
particularly for semiconductor islands, nanowires, quantum dots and for
soft magnetic materials. A detailed insight in the correlation
between microstructure/microchemistry and materials properties requires
the combined use of imaging, diffraction and analytical TEM.
The possibilities and limitations of the various TEM methods applied will be critically evaluated.
|
Friday
April 24th |
7:30 pm |
SB1 107 |
Dr. David Hackleman
School of Chemical, Biological, and Environmental Engineering
Oregon State University
Corvallis, Oregon
Biodiesel: A tool for engaging everyone in sustainable practices; and interesting science to support a clean future.
Over the last several years, students at OSU have
actively participated in Biodiesel work throughout the state of Oregon, have taken ideas to EPA sponsored events and even worked on projects in distant nations. High School, First Year through Graduate Students
have contributed ideas and at the same time had the opportunity to
exercise their developing understanding of Science and Engineering on a very relevant and practical, yet challenging area of study. The
activities have ranged from Anthropology, Bioscience, Physics, Engineering, Cellular and Molecular Biology to Business aspects. The talk will
first cover some basics of Biodiesel and it's byproducts of manufacture
and then briefly outline some of the actions that various students have performed with an objective on enabling the viewer to identify other opportunities to both improve this type of carbon neutral fuel and energize others in the concepts and practices of sustainable
actions.
|
Monday
May 4th
|
3:15 pm
|
SB1 107 |
Dr. Ginger McKee
Wolfram Research
Champaign, Illinois
Mathematica 7 in Education and Research
This
talk illustrates capabilities in Mathematica 7 that are directly
applicable for use in teaching and research on campus. Topics of
this technical talk include:
- 2D and 3D visualization
- Dynamic interactivity
- On-demand scientific data
- Example-driven course materials
- Symbolic interface construction
- Practical and theoretical applications
Current
users will benefit from seeing the many improvements and new features
of Mathematica 7, but prior knowledge of Mathematica is not required.
|
Friday
May 8th |
5:00 pm |
HOFF 109 |
4th Annual Mark Gurevitch Memorial Lecture
Dr. Sidney Altman
1989 Nobel Laureate in Chemistry
Sterling Professor of Molecular, Cellular, and Developmental Biology
Professor of Chemistry, Biophysical Chemistry and Organic Chemistry
Yale University, New Haven, Connecticut
From physics to molecular biology.
My
travels from a nascent physicist to a student of molecular biology will
be described in some detail. What I did in molecular biology and
how my training in physics played a role will also be summarized.
|
Monday
May 18th |
3:15 pm |
SB1 107 |
Dr. David Evans
Sharp Research Labs of North America
Vancouver, Washington
Thermodynamics at the Nanoscale.
Nanostructures
are becoming increasingly important as technological components for
applications ranging widely from sensors and photonics to energy harvesting,
and even conventional electronic devices.
Even so, much of the science of the nanoscale still remains
observationally based and generally empirical.
Nevertheless, there are a number of research efforts directed toward
modeling at the atomic scale and consequent understanding of nanoscale
physics. This includes everything from
sophisticated quantum mechanics to simple “ball-and-stick” models. However, classical thermodynamic concepts
have not been widely applied to nanostructures.
The reason for this is quite simple: conventional thermodynamics is
conceptually limited to macroscopic systems.
This is both a strength and weakness.
Indeed, because the underlying microscopic physics is generally treated
in an grossly averaged sense, thermodynamics can be widely applied to any type
of material or process for which temperature is well-defined. However, this also generally precludes
consideration of very small systems. To
remedy this, more than forty years ago Terrell L. Hill, then at the University of Oregon, developed an approach extending
thermodynamics to “small scales” such as characterized by colloid particles,
surfactant micelles, protein molecules and similar structures. This field languished in the intervening
decades, but now such structures are recognized as falling under the general
rubric of “nanotechnology”. In this
talk, Hill’s methods will be discussed and extended and some representative
systems described. It is hoped that this
will motivate further development of nanoscale thermodynamics and its practical
application to technology
|
Monday
June 1st |
3:15 pm |
SB1 107 |
Dr. Armin Rest
Department of Physics
Harvard University
Cambridge, Massachussetts
Also, of the National Optical Astronomy Observatory
Light Echoes of Ancient and Historic Supernovae
Tycho
Brahe's observations of a supernova (SN) challenged the church dogma
that the celestial realm was unchanging. 436 years later we have
once again seen the light that Tycho saw: some of the light from that
SN reflected off dust clouds and is only now reaching Earth.
These light echoes, as well as light echoes detected from other
supernovae, give us a very rare opportunity in astronomy: direct
observation of the cause (the supernova explosion) and the effect (the
supernova remnant) of the same astronomical event. Under some
circumstances, possible asymmetry in the SN explosion can also be
studied by comparing spectra of light echoes at different angles around
the SN remnant. In addition, in cases where the scattering dust
is favorably positioned, the geometric distance to the SN remnant can
be determined using polarization measurements. I will present
data from the SuperMACHO and Echoes of Historical Supernovae projects
and discuss examples where we have used these techniques.
|
Thursday
June 4th |
7:30 pm |
SB2 101 |
Dr. Loren Pankratz
Consultation Psychologist and Clinical Professor
Oregon Health Sciences University
Portland, OR
When Table-Rapping Nearly Upset the Apple Cart of Science.
Following the outbreak of spiritualism in 1848, people from all walks
of life sat at tables with the expectation of experiencing the presence
of spirits. With only their fingertips touching the top, the table
would tilt upward or rotate around on its feet. This action was not created
by pressure from the fingers, people insisted, because no effort was
exerted. Moreover, tables tapped out messages and even levitated above the
floor, often with no one even touching it. Many were convinced that these responses showed evidence of life beyond
the grave. In a war of pamphlets, Reverend Nathanial Godfrey insisted
that philosophical investigation was useless here because science had to stop
at the border of the natural. Godfrey provided evidence that the
movement of tables was caused by satanic agency. Others
claimed that the tables moved because of natural forces.
The candidates included magnetism, electricity, focused gravitation,
magneto-odylic force, or a yet unknown "fluid." Someone
said that rapping had sprung up as plentiful as mushrooms and as
worthless as
toadstools. But people demanded answers. Some of the most
prominent scientists of
the day investigated these wonders including Michael Faraday, Sir
William
Crookes, and Alfred Russel Wallace, Darwin's cofounder of the theory of
evolution.
|
For
questions regarding Departmental Seminars for Spring 2009, please
contact Dr. Rolf Koenenkamp at rkoe@pdx.edu.
To
subscribe to the Physics Event Announcements email list, please go to: https://www.lists.pdx.edu/lists/listinfo/physics_seminar/.
Students
taking this seminar for credit, need to hand in 2
brief reports and 2 longer reports on 4 presentations of the department
seminar series. (Short reports: 500 words/presentation, long
reports 800 words/presentation). Deliver hard copy to SB2 room
128 anytime before the Friday before the Final Exam week.
|