98
Portland
Tuesday afternoon
England. This poster includes a summary of that history. Adding “upreach”
opportunities for student achievement, Mainely Physics has become the
statewide organizer for the Maine Middle School State Science Olympiad
(M²S³O). Also, a new outreach variation called Mainely Physics: P.S.I.
(Physics Scene Investigation) alters the Road Show concept into a ‘phys-
ics hands-on event’ with multiple “content learning unit environments”
(CLUEs) with ~50 stations of a variety of experiments providing clues to
the solution of a “meta-problem” mystery. Poster will detail some of the
apparatus used in this programming. Initial support funding from the
WYP2005 Physics on the Road program, with additional support from the
Bauder Fund.
EG10:
4-5 p.m. Quantized Conductance in a Constricted Gold
Wire
Poster – Herbert Jaeger, Miami University, Department of Physics, Oxford,
OH 45056;
Anthony J. Silvidi, Khalid F. Eid, Miami University
Quantum mechanical behavior of electrons in a gold wire manifests
itself by steps in the conductivity that are clearly observed as the wire
is stretched. We present a setup that demonstrates this effect using a
manually operated bending beam to break and reconnect the gold wire
to obtain the quantized behavior. In order to have better process control
we have added a computer-controlled piezo-crystal. Data accumulation
is performed with a National Instruments DAQ system controlled by a
computer running LabVIEW software. Moreover we will present details on
a stand-alone control and acquisition system using the newly introduced
Arduino Due microcontroller.
EG11:
4-5 p.m. Stokes-Mueller Polarimeters for the Advanced
Lab
Poster– Adam S. Green, University of St. Thomas, 2115 Summit Ave., OWS
153, Saint Paul, MN 55105;
Anthony J. Vella, University of Rochester
Drew M. Mader, University of New Mexico
A versatile, low-cost polarimeter can be constructed from circularly polar-
izing film and a filter wheel. The polarimeter can incorporate a standard
photodiode to measure all four Stokes parameters of light. An optional
addition of a chopper wheel and lock-in amplifier allows for detection of
low levels of diffusely scattered light. If used with an inexpensive camera in
place of the photodiode, the device becomes a Stokes imaging polarimeter,
and color filters in front of the camera allow for rudimentary spectropo-
larimetric imaging. Furthermore, two filter-wheel polarimeters can be
used in conjunction; one as a polarization state generator and the other
as an analyzer; to determine the complete 4x4 Mueller matrix of a target.
As with the Stokes polarimeter, this configuration can be used in imaging
or non-imaging applications. These polarimeters, which can be manually
operated or automated, open up a broad range of experimental opportuni-
ties for students.
EG12:
4-5 p.m. Systematic Error in Ultrasonic Rangefinder
Acceleration Measurements
Poster – Chris Kaneshiro,* California State University, Chico, Department
of Physics, Campus Box 202, Chico, CA 95929-0202; ckaneshiro@mail.
csuchico.edu
Eric Ayars, California State University, Chico
Ultrasonic rangefinders measure the position of an object by sending out
a pulse of high-frequency sound and timing how long it takes for an echo
to return from the object. When measuring moving objects, the speed-
of-sound delay in the outgoing pulse causes a systematic error in the
distance measurement. The distance error is generally negligible if object
velocities are small compared to the speed of sound; but we show that the
functional form of the position error causes a significant systematic error
in the acceleration calculated from that position data. The systematic error
in calculated acceleration, for a typical free-fall experiment, is sufficient to
explain the error seen in an introductory-lab measurement of
g
.
Sponsored by Eric Ayars
EG13:
4-5 p.m. Teaching Labs on Electronics for
Instrumentation Training
Poster – Yongkang Le, Fudan University, No. 220 Handan Road, Shanghai
200433;
Mai Ye, Fudan University
Aimed processing of electric signal is a very important part of the realiza-
tion of many instruments. Teaching labs designed for training on instru-
mentation should reveal the art and science of this process. Two teaching
labs designed for this purpose will be reported. The first lab demonstrates
the influence of the sampling resistor on the time response of an optoelec-
tric detector. The second lab demonstrates a simple possibility to extract
varying weak signal from a strong DC background.
EG14:
4-5 p.m. The iPAD as a Virtual Oscilloscope in
Introductory Physics Laboratories*
Poster – Roberto Ramos, Indiana Wesleyan University, 4201 South Wash-
ington St., Marion, IN 46953;
Angela Garriott, Robert Burchell, Indiana Wesleyan University
The use of tablets as pedagogical tools in physics and electronics is
becoming popular. While the many knobs and switches of a conventional
oscilloscope may cause anxiety to non-physics, non-engineering students,
a tablet such as an iPAD is less intimidating and has a friendlier touch-
pad interface. We report our experience in using the iPAD as a virtual
oscilloscope in an introductory algebra-based physics laboratory course.
Using a commercial electronic accessory called OSCIUM iMSO-104, we
turned the iPAD into a single-channel, virtual oscilloscope for measuring
the relaxation time constant of RC- and RL-circuits. Using student surveys
and direct observation, we report student responses to this new platform,
versus using a conventional oscilloscope. We evaluate the iPAD-based
virtual oscilloscope and its current technical limitations.
*Web:
EG15: 4-5 p.m. Using Smartphones as Science Laboratory
Instruments*
Poster – Kyle Forinash, Indiana University Southeast, 4201 Grant Line Road,
New Albany, IN 47150;
Raymond F. Wisman, Indiana University Southeast
Smartphones and tablets available today have the computational power
for data analysis such as the Fast Fourier Transform as well as built-in sen-
sors such as accelerometers, magnetometers, microphones, speakers, and
GPS. With existing apps, portable electronic devices can potentially bring
a laboratory experience to the student outside of the classroom or lab.
An additional valuable feature of smartphones and similar devices is the
headset port which offers a method to communicate with external circuits
and sensors, greatly enhancing the potential for use as a laboratory data
collection tool. In this presentation we look at the use of mobile devices
as laboratory data collection tools and demonstrate simple examples of a
smartphone communicating with an external circuit via the headset port.
* R. Wisman and K. Forinash, “Smartphones as portable oscilloscopes for physics
labs,”
Phys Teach.
50
, 242 (2012). K. Forinash and R. Wisman, “Smartphones – Ex-
periments with an external thermistor circuit,”
Phys. Teach.
50,
566 (2012).
EG16:
4-5 p.m. Wind Tunnel and Fluid Dynamics
Poster – Joel C.. Berlinghieri, The Citadel, Physics Department, Grimsley
Hall, 171 Moultrie St., Charleston, SC 29409;
Ryan Boodee, The Citadel
Undergraduate students at The Citadel majoring in the physical sciences
or engineering, and therefore having the proper prerequisites, may add a
minor in aeronautics to their major degree. As part of the equipment for
that program the Physics Department has an AEROLAB EWT wind tun-
nel. An experiment for the measurement and analysis of drag coefficients
for simple-shaped objects is presented with scaling in size and airspeed.
All airspeeds are slow enough that the analysis can treat air as an incom-
pressible fluid.
