88
Tuesday morning
Portland
dents were asked to explain the following three fluid dynamics experiments
diagrammatically, graphically, mathematically, and verbally: 1). A simu-
lated blood vessel constriction. 2). Flow through a Venturi apparatus and
3). A free-fall microgravity simulation. Pairs of students were interviewed
before and after coverage of the content in class. In the post-interview
they were given an open-ended question to answer regarding why blood
pressure rises when blood vessels are blocked. Preliminary results indicate
that hands-on exposure to the tactile demonstrations enables qualitative
explanations without relying on mathematical tools.
*Supported by DUE 1044154. Sponsored by James Vesenka
DG10:
11 a.m.-12:30 p.m. Teaching Fluids to IPLS Students
from a Microscopic Viewpoint
Poster – Daniel E. Young, University of New Hampshire, 9 Library Way,
Durham, NH 03824;
Dawn C. Meredith, University of New Hampshire
For introductory life science students, fluid dynamics is a topic that is
important, relevant to biology, and yet difficult to understand conceptu-
ally. Our study focuses on probing understanding of pressure differentials
and friction which underpin ideas of viscosity and fluid flow. Data were
collected from think-aloud/demonstration interviews and were analyzed
using the resource framework to look for productive student reasoning
such as a microscopic viewpoint and gradient driven flow. We investigated
if a multiple-scale view of matter is useful for students when constructing a
model of viscosity and we will present both our model and feedback from
students who have worked through it.
DG11:
11 a.m.-12:30 p.m. Pulse-oximeter and Light Absorption
Poster – Justin C. Dunlap, Portland State University, PO Box 751, Portland,
OR 97207-0751;
Ellynne Kutchera, Misti Byrd, Casey Norlin, Ralf Widenhorn, Portland State
University
The pulse-oximeter is a commonly found device in any hospital or doctor’s
office. The device is capable of measuring a patient’s blood oxygen content
and pulse simply by slipping a small device over a finger tip or ear lobe. We
present a laboratory based around the pulse-oximeter and the physics be-
hind its design and function. Light of two different wavelengths are passed
through the patient’s finger and the transmitted light intensity is measured.
Absorption of light at the two wavelengths varies with the oxygen content
of blood. Students in the laboratory will work with bromothymol-blue
instead of blood. Its absorption characteristics vary with C02 content and
serve as an analog to blood, but permits for easier handling in the labora-
tory. The laboratory exercise allows for optics to be targeted at pre-health
students and presented in a biological context.
DG12:
11-12:30 p.m. Obstacle Course DC Circuits Activity
Poster – Kristin Walker, Pfeiffer University, PO Box 960, Misenheimer, NC
28109;
Carol Ann Midersk,i Catawba College
Although the typical water pipe analogy for DC circuits is helpful for some,
for many students the behavior of water flowing through pipes is not intui-
tive. An obstacle course analogy activity was created to provide an alterna-
tive DC circuit model. In this activity, students are given cards with an ob-
stacle course element on one side and the corresponding circuit element on
the other such as ladder/battery or slide/bulb. The students create obstacle
courses meeting design specifications such as alternate paths (parallel) or
sequential elements (series) and they respond to questions regarding how
contestants proceed through various parts of the course. The students then
flip over the cards to reveal the circuit diagram equivalent, build the circuit,
and relate the brightness of the bulb(s) to their obstacle course analysis.
Although this activity was originally created for middle school age, it was
successfully used in a college introductory physics course.
DG13:
11 a.m.-12:30 p.m. Medical Imaging with Photogates:
A High School or College Activity
Poster – Elliot Mylott, Portland State University, SRTC, 1719 SW 10th Ave.,
Room 134, Portland, OR 97201;
Ryan Klepetka, Justin Dunlap, Ralf Widenhorn, Portland State University
We present a laboratory activity in computed tomography (CT) primarily
composed of a photogate and a rotary motion sensor that can be assembled
quickly and partially automates data collection and analysis. We use an
enclosure made with a light filter that is largely opaque in the visible spec-
trum but mostly transparent to the near IR light of the photogate (880nm)
to scan objects hidden from the human eye. This experiment effectively
conveys how an image is formed during a CT scan and highlights the im-
portant physical and imaging concepts behind CT such as electromagnetic
radiation, the interaction of light and matter, image artifacts and window-
ing. The lab has been used in physics courses for pre-health and life science
majors and results of student assessments will be presented.
DG14:
11 a.m.-12:30 p.m. Measuring Human Power Outdoors
Using GPS and Heart Rate
Poster – Haraldur Audunsson, Reykjavik University, Menntavegur 1, Reykja-
vik, IS 101, Iceland;
GPS devices make it easy to track one’s motion, and therefore potentially
calculate the power output, and at the same time record the heart rate
(HR). The power output calculated from the raw GPS data may depend on
the rate of vertical climb, acceleration, air drag and rolling friction if bik-
ing. Normally the HR increases linearly with the power output. Therefore
the simultaneous analysis of the data from GPS and HR requires the use of
basic physics, numerical methods, programming and physiology. We will
present an example of a student experiment performed outdoors, showing
good correlation between calculated power output and heart rate, but also
a poor correlation, depending on the person’s activity. This experiment
and its analysis can be made as intricate as appropriate, and it appears to
be very motivating since students are using basic physics and common
devices to measure their own performance.
Meet the Editors of AAPT’s Journals During the Meeting
They will be in the AAPT Booth in the Exhibit Hall
during the following times:
Gary White, incoming editor,
The Physics Teacher
Sunday: 8–8:30 p.m. Monday: 12–1 p.m. Tuesday: 1–2 p.m.
David Jackson, editor,
American Journal of Physics
Sunday: 8–8:30 p.m. Monday: 10–10:30 a.m. and 3–4 p.m.
Tuesday: 10–10:30 a.m. and 3:30–4:30 p.m.
GaryWhite
David Jackson
