2008 Proceedings - St. Cloud State University

Abstracts
Session J Science and Engineering I South Glacier
Sartell Valves, Inc. AWWA Valve Project
Valves are used to control the flow of fluid for everything from chemicals in an oil refinery to city water supplies. Many of these valves vary
in size from just a few inches (0.075 m) diameter to over 120 inches (3 m). There are butterfly valves, ball valves, plug valves, and others.
For this project, ball valves will be explained in further detail. Ball valves have a semi-spherical flow control geometry which has an opening
(or port) through the center for the open position and faces which stop flow via seals when the ball is rotated by an actuator. As part of this
project, advanced valve geometries, seat shapes, seat materials, and modeling techniques are utilized to minimize the actuation torque.
Computer-aided design software, SolidWorks, was used extensively to assist in the design of the ball valve. A variety of seal shapes and
materials were analyzed to provide the necessary sealing forces during closing. Experiments were performed on different seal materials to
determine necessary material properties and friction behaviors. Computer modeling techniques, such as finite element and computation
fluid dynamics methods, were used to assess pressure and velocity implications for each design. Analytical bolted joint and bearing design
techniques were also employed.
Presentation Index: J3
Time: 11:40 a.m.
Department: Mechanical and Manufacturing Engineering
Project Sponsor(s):
Student Presenter(s): Meyer, Kyle; Carlson, Ryan
Covey, Steve
Prosthetic Aortic Heart Valve Fatigue Tester
The desire for a machine to fatigue test prosthetic heart valves was expressed by Boston Scientific Inc. The need for such a machine
stems from the ethical and regulation requirement that the heart valves be tested for fatigue before being used in human patients. The
initial steps in the design process consisted of background research. Research was conducted in heart function, blood properties and
current fatigue test machines. This research lead to the determination of the proper conditions in which the heart valve needed to be
tested and the fluid properties surrounding blood flow. In addition, the research pointed out the strengths and weaknesses of current
designs. After such research, design ideas were brought forth and considered. Initially three ideas were considered: two of which used a
liquid and one which used a gas to cycle the heart valve while holding the valve in a static position. Further research led to the discarding
of all three ideas. Design ideas were once again developed and agreed upon. The final design idea uses a concept in which the valve
itself is actually moved in a liquid medium. This design idea will allow the heart valve to be cycled at rates exceeding 20 Hz while
maintaining constant transvalvular pressures. In addition, the design will allow for the monitoring of load on the valve.
Presentation Index: J4
Time: 12:00 p.m.
Department: Mechanical and Manufacturing Engineering
Project Sponsor(s):
Student Presenter(s): Larson, Jaclyn; Beuning, Mark; Miller, Jon
Covey, Steve
Session K Helping People Succeed Lady's Slipper
Novice ESL Teachers' Process of Developing Their Own Way of Written Feedback on Student Writing
This study explores novice second language teachers' process of learning to provide written feedback on their students' writing over a
period of time (16 weeks). Participants in this study are five second language writing instructors who are also candidates of Master's
degree in Teaching English as a Second Language. All of these participants were in their first or second semester of teaching academic
writing at the time of data collection. Present study will analyze the following data: (1) these instructors' ten different journal entries written
immediately after they provided written feedback on their students' writings; three interviews (at the beginning of semester, after mid-term
exam, and after final exam) with each of these five teachers; and two observations (at the beginning of semester and at the end of
semester) of three teachers while they correct, provide written comments, and grade their students' writing samples. This study focused on
these novice second language writing teachers' beliefs, strategies, and their decision-making processes related to providing written
feedback. The presentation will report the results from a preliminary analysis of partial data from the entire study since the data collection
of this study will still be in progress at the time of presentation. The presentation will be based on the analysis of at least seven journals out
of ten from each writing instructor, two interviews with each instructor, and first observations of three teachers providing written feedback
on students' essays. The findings from this study will provide practical implication for language teaching and language teacher training.
Presentation Index: K1
Time: 11:00 a.m.
Department: English as a Second Language
Project Sponsor(s):
Student Presenter(s): Nakamura, Shinobu
Kim, Choon; Robinson, James
St. Cloud State University Student Research Colloquium 44
April 22, 2008