Volume 12, Issue 2, January 2015 interactive pdf
https://doi.org/10.33697/ajur.2015.001
Editor’s Note “American Journal of Undergraduate Research Impact Factor“
https://doi.org/10.33697/ajur.2015.002
Design and Development of the Telescope-deployment High-vacuum teleOperated Rover (THOR) in an Airless Body Environment
Chris Womack, Miles Crist, Laura Kruger, Kelsey DeGeorge, Karynna Tuan, & Jack Burns
A Study of Subracks
Samantha Driskill
Cardiac Myocardial Hypertrophy and Altered Swimming Behavior in Xenopus laevis Embryos in Incrementally Increasing Hypergravity
Stacey Howes & Darrell Wiens
Can An Algebraic Diagnostic Test be Used to Predict Final Grades in an Introductory Statistics Class?
Justine Kirksey & Anthony Cooper
A Curve Satisfying K/T = s with constant K>0
Yun Myung Oh and Ye Lim Seo
Does Altering Local Water Availability for an Invasive Plant (Raphanus raphanistrum) Affect Floral Morphology and Reproductive Potential?
Natalia Pirimova, Alison J. Parker, and Lesley G. Campbell
Full details are provided below:
Design and Development of the Telescope-deployment High-vacuum teleOperated Rover (THOR) in an Airless Body Environment
https://doi.org/10.33697/ajur.2015.003
Chris Womack, Miles Crist, Laura Kruger, Kelsey DeGeorge, Karynna Tuan, & Jack Burns
ABSTRACT
The harsh environment on the lunar surface presents unique technological challenges for space exploration. This paper presents research on the design and development of the Telescope-deployment High-vacuum teleOperated Rover (THOR), currently being built and tested in the Lunar and Airless Bodies Simulator (LABS) facility at the University of Colorado Boulder. This rover is fabricated entirely out of cost-effective commercial off-the-shelf (COTS) components and materials. THOR can potentially survive for more than one simulated year in conditions similar to that of the lunar environment, demonstrating the successful initial results of a first phase research study on material and electronic survivability in an extreme environment such as the Moon.
KEYWORDS
Telerobotics, Space Exploration, LUNAR, High-vacuum, Electronic Survivability, Robotics, Engineering
ABOUT THE STUDENT AUTHORS
Chris Womack is currently pursuing a B.S. in both Mechanical Engineering, and Electrical and Computer Engineering. He has been with the LUNAR team for 2 years developing a teleoperated rover. Currently he is collaborating with Lockheed Martin to extend this application to remote control via web apps for telerobotic operations and testing. Miles Crist is a mechanical engineer who recently graduated from the University of Colorado at Boulder. He has worked for NASA’s Lunar Science Institute conducting material and electronic research in support of a lunar far side radio telescope array. Miles operated and maintained a thermal vacuum chamber and was part of a team that developed the Telescope Deployment High VacuumteleOperated Rover (THOR). Miles now works for Crane Aerospace and Electronics designing fuel pumps for a large variety of aircraft. Laura Kruger is a graduate student at the University of Colorado Boulder. She graduated with a BA in Astrophysics and is currently pursuing a MS in Aerospace Engineering and ME in Engineering Management. After working with the LUNAR team for five years as laboratory manager for CU’s lunar simulation thermal-vacuum facility, Laura joined Ball Aerospace as a Systems Engineer in August of 2014. Kelsey DeGeorge is a recent graduate receiving her Bachelor of Science in Mechanical Engineering from the University of Colorado at Boulder. She previously worked as an intern for Shear Engineering Corporation and Real D, Inc. She is currently a Manufacturing Engineer for Schlumberger in Houston, TX providing solutions for both design and manufacture of isolation valves for oilfield services. Karynna Tuan is currently working towards her graduate degree in the 5-year MS/BS program, majoring in Aerospace Engineering with a focus area in Bioastronautics, the study and support of human spaceflight at CU Boulder. She has worked at Space Grant with the PolarCube team for a year, developing a CubeSat to study the Earth’s tropospheric weather patterns and monitor and record temperature profiles. She is continuing her work experience in the industry field at Sierra Nevada Corporation, Space Systems as a Manufacturing Intern.
PRESS SUMMARY
Joint human-robotic space exploration involving the teleoperation of rovers on planetary surfaces is a key strategy defined by the ISECG’s Global Exploration Roadmap. In support of this goal, the LABS (Lunar and Airless Body Simulator) team at the University of Colorado Boulder has developed a lunar simulation thermal-vacuum facility to create an analog environment in which to conduct survivability testing. LABS built a rover, the Telescope-deployment High Vacuum teleOperated Rover, that can operate for extended periods of time in the harsh lunar environment. The rover is fabricated entirely out of cost-effective commercial off-the-shelf (COTS) components and materials, showing the potential of practical, low cost options for future space exploration.
A Study of Subracks
https://doi.org/10.33697/ajur.2015.004
Samantha Driskill
ABSTRACT
Racks were introduced in 1959 by G. Wraith and J. Conway as a wreckage of groups, and have been used in various topics of mathematics. In this project, we aim to establish certain classical results known for subgroups on subracks.
KEYWORDS
Racks, Subracks, Quandle, Group, Centralizer, Dimension
ABOUT THE STUDENT AUTHOR
Samantha Driskill worked on this project during her senior year (2012 – 2013) at Southwestern
Oklahoma State University. She graduated in the spring of 2014 with two Bachelor of Science degrees (Mathematics and Mathematics Education). She was the president of the Mathematics club and a recipient of multiple awards in the math department. Samantha is currently a full-time teacher at Del city high school in Oklahoma.
PRESS SUMMARY
The theory of racks is strongly connected to the theory of conjugation in groups. Roughly, racks are
described as groups in which the group operation is discarded and only the concept of conjugation is left. In this paper, we investigate and introduce on racks some notions well-developed in groups, and apply those notions in a few examples.
Cardiac Myocardial Hypertrophy and Altered Swimming Behavior in Xenopus laevis Embryos in Incrementally Increasing Hypergravity
https://doi.org/10.33697/ajur.2015.005
Stacey Howes & Darrell Wiens
ABSTRACT
Every living organism on earth has developed and evolved in unit gravity (1G) conditions. It is likely that any deviation from Earth’s standard gravity will influence development, particularly at early stages. Previous reports from this lab showed that total length is reduced and that ventricle size is increased during development at 7G. The objective of the present study was to investigate the effect of increasing levels of hypergravity on the development of the ventricular myocardial wall and the neuromuscular responsiveness of Xenopus laevis. At early gastrulation, embryos were placed in a centrifuge simulating 7G, 10G, 15G or 17G until they reached stage 45 (feeding tadpole stage, approximately 72 hours from initiation of gastrulation). Mortality was low and only the 17G exposure induced significant mortality. Immediately following centrifugation, the embryos were stimulated by touching with a probe to test neuromuscular responsiveness. With increasing G forces, responsiveness to this test was incrementally reduced. A quarter of the embryos were fixed and their body dimensions were measured. One group of remaining live embryos, those exposed to 7G, was maintained and swimming behavior was observed during daily 5-minute periods for 52 days. Overall, abnormal swimming behavior was found in 33% of 7G embryos and in 2% of controls during this time. These embryos were later subjected to an orientation-swimming test. Hypergravity-exposed embryos required, on average, one second longer (9% of time required) to become oriented. From the embryos exposed to increasing G levels and then fixed, we found that total length was reduced successively at increasing hypergravity levels, but the snout-vent proportion of total length increased. Stained sections of the fixed embryos revealed that the thickness of the ventricle wall was increased, especially the interior ridge component (trabeculae / papillary muscles). The data demonstrates that hypergravity has persistent effects on the development of the ventricular myocardial wall, neuromuscular responsiveness, and equilibrium organs.
KEYWORDS
Hypergravity, Xenopus, Embryo, Behavior, Myocardium, Hypertrophy
ABOUT THE STUDENT AUTHOR
Stacey Howes is from Fairfax, Iowa and graduated from the University of Northern Iowa (UNI) in May, 2014. At UNI she majored in biology and carried out this research for her University and Biology Honors thesis. She submitted an abstract describing aspect of this work for presentation at the 2013 annual meeting of the American Society for Space and Gravitational Research in New Orleans, La. Her abstract was accepted and at the meeting she presented a poster and was also invited to give a talk. She received recognition for one of the best talks given by an undergraduate student at the meeting. Stacey is now pursuing studies at the University of Iowa College of Dentistry.
PRESS SUMMARY
Life on earth has developed and evolved in unit gravity (1G) conditions and it is likely that any deviation in this force would affect early development. The objective of this study was to investigate the effect of increasing levels of gravitational force on the development of body dimensions, the cardiac muscular wall and the neuromuscular responsiveness of the African Clawed frog Xenopus laevis. Early embryos were placed in a centrifuge simulating 7G, 10G, 15G or 17G until they reached the feeding tadpole stage, and then they were examined and tested. We found that with increasing G forces, responsiveness was incrementally reduced, aberrant swimming behavior was more frequent, and orientation ability was slower. Their total length was reduced successively at increasing hypergravity levels, but the snout-vent proportion of total length increased. The thickness of the ventricle wall was increased, especially the interior ridges, suggesting hypertrophy. Our data demonstrate that hypergravity has persistent effects on the development of the ventricular myocardial wall, neuromuscular responsiveness, and equilibrium organs.
Can An Algebraic Diagnostic Test be Used to Predict Final Grades in an Introductory Statistics Class?
https://doi.org/10.33697/ajur.2015.006
Justine Kirksey & Anthony Cooper
ABSTRACT
The Department of Mathematics and Statistics at California State University Sacramento has been using the Intermediate Algebra Diagnostic (IAD) test as a proxy tool to screen students intending to enroll in an introductory statistics course (Stat 1). However, the use of an algebraic test as a diagnostic tool for a statistics course has been questioned by some faculty members and students at this university. The regression models used in this study (simple linear regression, hierarchical linear regression, and logistic regression) show that higher IAD scores are related to higher final grades in Stat 1, even after adjusting for different instructors. Inferences were also made in this study to predict a passing grade and passing rates in Stat 1 based on the bounds of the confidence and prediction intervals obtained for the IAD scores with these models.
KEYWORDS
Linear Regression, Logistic Regression, Statistics Diagnostic Test, Algebra Diagnostic Test, MDTP, Introductory Statistics
ABOUT THE STUDENT AUTHORS
Anthony Cooper is a mathematics major at California State University-Sacramento (CSUS). He is a
non-traditional student that returned to college after working in a bank for 10 years and then serving children and families in an afterschool program for over 15 years. He is currently finishing his major and teaching credential studies at CSUS preparing for a career in education.
Justine Kirksey graduated from CSU, Sacramento Spring 2014 with her BA degree in Biology, minor in Mathematics. She is beginning her teaching credential program at National University in September to pursue her career as a mathematics and science high school teacher.
PRESS SUMMARY
The use of the intermediate algebra diagnostic (IAD) test as a screening tool for a statistics course (Stat 1) in the Department of Mathematics and Statistics at California State University Sacramento has been questioned by some faculty members and students at this university. The statistical analysis in this study shows that higher IAD scores are indeed related to higher final grades in Stat 1, even after adjusting for different instructors when using a sample of over 550 students who have taken this course. Inferences were also made in this study to predict passing grades and passing rates in Stat 1 when using IAD scores as predictors.
A Curve Satisfying K/T = s with constant K>0
https://doi.org/10.33697/ajur.2015.007
Yun Myung Oh and Ye Lim Seo
ABSTRACT
In the present paper, we investigate a space curve in which the curvature is constant and the torsion is a linear function. The aim of this paper is to find an explicit formula for this space curve when the ratioof the torsion to the curvature is a linear function when the curvature is constant.
KEYWORDS
Space Curve, Curvature, Torsion, General Helix, Frenet Frame, Series Solution, Rectifying Curve
ABOUT THE STUDENT AUTHOR
Ye Lim Seo is an undergraduate student at Andrews University. She has shown strong interest in mathematics
and has received several math awards.
PRESS SUMMARY
The first chapter of undergraduate differential geometry is about the curves in 3-dimensional space. Because one of famous results about the general helix is that it has the constant ratio of torsion to curvature, a natural question is to think about the next simple case: the ratio of torsion to curvature as a linear function. Using the idea of series solution to the differential equation, one can find the curve explicitly with the extra condition that the curvature is a constant.
Does Altering Local Water Availability for an Invasive Plant (Raphanus raphanistrum) Affect Floral Morphology and Reproductive Potential?
https://doi.org/10.33697/ajur.2015.008
Natalia Pirimova, Alison J. Parker, and Lesley G. Campbell
ABSTRACT
Abiotic environmental variation can have dramatic effects on plant floral morphology and nectar or
pollen rewards. In response, pollinators may change their foraging behavior and distribution and if
pollinators change their foraging behavior or distribution, this could have dramatic effects on the
reproductive success of plant populations. To start tackling this problem, we measured the response of floral morphology (corolla diameter, stamen length, and ovule number) of Raphanus raphanistrum to experimental manipulations of field soil moisture. As soil moisture increased, corolla diameter and anther length grew. We expect these changes to provide more visitation rewards for insects in moist conditions. Therefore, water availability influences growth and development of flowers, and may have dramatic effects on insect community dynamics.
KEYWORDS
Floral Rewards, Climate, Rain-out Shelters, Flower Morphology, Raphanus raphanistrum, Brassicaceae
ABOUT THE STUDENT AUTHOR
Natalia Pirimova graduated from Ryerson University in May, 2012 with a BS degree in Biology and then graduated from Centennial College in January, 2014 with a post-baccalaureate in a Medical Laboratory Technician field. She is currently a practicing phlebotomist and a medical laboratory technician at St. Michael’s Hospital in Toronto, Ontario.
PRESS SUMMARY
As has been widely discussed recently, climatic conditions and specifically rainfall patterns, of our
planet are changing dramatically. Changes in rainfall may alter the attractiveness of flowers to insect pollinators. We manipulated water availability (both increasing and decreasing soil moisture) and measured the consequences of water availability on flower size in an agricultural weed, wild radish. We concluded that increasing water availability may make flowers more attractive to insect visitors.