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Using quantitative analysis and data provided by the National Center for Education Statistics, we created a regression model that allowed us to calculate the significance of participation in college preparation programs and students’ educational aspirations in relationship to their mathematical success. Understanding the impact of these programs in urban areas is important because it may be one of the few ways minority students are provided with the knowledge and skills needed for higher education. Our interest in mathematical achievement is due to the fact that research shows the highest mathematics course completed in high school to be a strong indicator of whether a student will graduate from college or not. Although 9th grade students who participate in these programs tend to perform more poorly, our results found that a combination of high educational aspirations and participation in these programs can help bring students back up to average mathematics test scores. This suggests that college preparation programs influence students’ educational aspirations, which, in turn, can affect their mathematical achievement.
AEROSPACE, AERONAUTICAL, ASTRONAUTICAL ENGINEERINGFRI-252
INVESTIGATION OF ARTIFICIAL GRAVITY HABITAT DYNAMICS
Engineering Oklahoma State University, Stillwater, OK Future envisioned missions to deep space elicit problems and challenges not fully investigated by the world’s spaceflight organizations. One of the most prominent issues is prolonged exposure to weightlessness. The human body functions day to day with the resistance and force of gravity; in the absence of this phenomenon, bones and muscles swiftly atrophy. Another alarming effect that has been acknowledged in recent years is loss of vision due to prolonged spaceflight. Researchers hypothesize that lack of gravity increases pressure on the optic nerve, thus causing vision loss. An effective way to generate a force similar to gravity is to rotate a body to produce centrifugal force. For a small-scale investigation of this concept, the Oklahoma State University Space Cowboys team has designed an inflatable beam-rotating experiment. The effects of various internal pressures on the beam’s stiffness and rotational stability will be examined. Inflatable structures are lightweight, have a high ratio of deployed-to-packed volume, and could provide sufficient support for a rotating spacecraft that produces an artificial gravity force. The experiment is designed to allow deployment pressure to be altered between test runs (parabolas). As spaceflight becomes more ambitious and missions of longer durations become both desirable and possible, spacecraft designs must provide crewmembers with an Earth-like gravity environment. Therefore, in order to continue expanding our knowledge of the universe, gravitational obstacles such as these must be overcome.
3D MOTION CAPTURE IN REDUCED GRAVITYCarolina Vega Recalde, Alyssa Avery, Zach Barbeau, Calvin Brown, Thomas Verschelden, Nicole Weidman, Jaymie Jordan, James Evans, Jamey Jacob.
Oklahoma State University, Stillwater, OK.
In order to identify the range of motion of a person in a reduced-gravity environment, motion capture is needed.
Motion capture will quantify the movements of the subject and allow the analysis that would follow. The systems considered to meet this criteria would need to be flexible enough to accommodate non-standard data, and reliable enough to collect good data in the dynamic conditions of flight. The Oklahoma State team chose to evaluate 4 off-theshelf systems: Microsoft Kinects, Opti-track Camera System, GoPro 3D Heros, and traditional digital cameras paired with video-grammetry. Each of these systems uses a distinct method of data input and analysis. Additionally, each of the systems chosen showed merit in reliability and accuracy. The team also chose a series of joint movements for the subject to perform to gather examples of joint mobility data.
HIGH ALTITUDE BALLOON LAUNCHLauren Polo1, James Newman.
Hartnell College, Salinas, CA. 2Space Systems Academic Group, Naval Postgraduate School, Monterey, CA.
1 The purpose of this project is to support the ongoing establishment of the Naval Postgraduate School’s aerospace program. Interns are expected to work with other students to accomplish designated altitude in a balloon flight using communication systems and cameras to transmit and receive data. Furthermore, the interns will learn to recover data from the experiments and its applications using calculations based on documented altitude and pressure. The methods used to collect the data were to separately test the equipment that we would be using (such as pressure and temperature sensors), and then collectively test them as they would be functioning during the actual launch of the high altitude balloon. The results of the data are still to come as we have not launched this year’s high altitude balloon.
Based on data from previous launches, we should be able to recover footage from the launch along with the reading from the different sensors and a new satellite that will give us insight into how the payload as a whole works.
173 UNDERGRADUATE POSTER ABSTRACTS
DIRECT FORCE MEASUREMENT ON AN OSCILLATING AIRFOILCarlos Orozco, Frank Lu.
University of Texas at Arlington, Arlington, TX.
The quantification of aerodynamic forces on wing sections allows for the determination of optimum operating conditions (angle of attack, airfoil shape, etc.) for the specific use at hand. However, for oscillating wing sections, aerodynamic forces become complicated by the addition of inertial forces brought about by the pitching motion of the wing section. Thus, a method of directly measuring the lift and drag forces on a cyclically pitching NACA 0012 airfoil while also separating the inertial forces will be developed. A high power stepper motor will be used to cyclically pitch a machined aluminum NACA 0012 airfoil. Strain gages placed on a shaft running through the span of the airfoil will directly measure the lift and drag as the airfoil is pitched through various angles of attack. After the lift and drag data is collected, it will be corrected by subtracting the inertial forces found during the calibration of the strain gages.
Additionally, error due to hysteresis will likely be present in the lift and drag data, and this will need to be accounted for. In this way, the true lift and drag of the oscillating wing section will be determined. For applications that require oscillating wing sections such as wind turbines and biomimetic flight, this method of measuring true aerodynamic forces by accounting for the inertial forces is especially useful.
SELF AGGREGATING CHITOSAN PARTICLES FOR HEMOSTATIC APPLICATIONEhab Abdelaziz, Shaunak Pandya, C. Mauli Agrawal.
University of Texas at San Antonio, San Antonio, TX.
Uncontrolled hemorrhage remains to be the leading cause of potentially preventable deaths on the battlefield. Trauma resulting in massive blood loss has been shown to induce coagulopathy and demands use of external agents to achieve hemostasis. Currently used hemostatic agents include topical water absorbing agents such as chitosan.
Here, we report a modified chitosan in particle form that can self-aggregate when in solution. Chitosan (~200 kDa molecular weight and ~80% degree of deacetylation) micro/macro particles were synthesized using different spray drying techniques. Biotin avidin chemistry has been used for modification of chitosan particles. Chitosan particles were surface modified using EZ-link® biotinylation reagents at different mol% of amine groups, i.e., 1-20. Some of these particles were further modified by addition of NeutrAvidin™ to form avidinylated chitosan particles. We hypothesized that biotinylated and avidinylated chitosan particles would stay inert in dry form but would form quick aggregates in saline or blood. Aggregation behavior of particles was studied using microscopy, and the effect of aggregation of particles was studied on human red blood cells. Microscopy showed significant aggregation of particles compared to non-modified chitosan, and rheology data demonstrated increase in viscosity of whole blood when mixed with self-aggregating particles. We have demonstrated successful use of biotin avidin chemistry for fabrication of self-aggregating chitosan particles. This system has a great potential to be used as an efficient hemostatic agent.
(Partially funded by NIGMS MBRS-RISE GM060655.) SAT-264
TATTOO-BASED POTENTIOMETRIC ION-SELECTIVE SENSORS FOR EPIDERMAL PH MONITORINGAlexandra Martinez1, Joseph Wang1, Amay Bandodkar1, Vinci Hung2.
University of California, San Diego, La Jolla, CA, 2University of Toronto, Toronto, Ontario, CA.
1 We will discuss the fabrication and characterization of novel tattoo-based solid-contact ion-selective electrodes (ISEs) for non-invasive potentiometric monitoring of epidermal pH levels. The new fabrication approach combines commercially available temporary transfer tattoo paper with conventional screen printing and solid-contact polymer ISE methodologies. The resulting tattoo-based potentiometric sensors exhibit rapid, sensitive response to a wide range of pH changes with no carryover effects. Furthermore, the tattoo ISE sensors endure repetitive mechanical deformation, which is a key requirement of wearable and epidermal sensors. The flexible and conformal nature of tattoo sensors enable them to be mounted on nearly any exposed skin surface for real-time pH monitoring of human perspiration, as illustrated by the response during a strenuous physical activity. The resulting tattoo-based ISE sensors offer considerable promise as wearable potentiometric sensors suitable for diverse applications. The
174 UNDERGRADUATE POSTER ABSTRACTS
tattoo ISE sensors were able to tolerate the complex mechanical deformations experienced by the human skin during exercise. The tattoo ISE sensors thus exhibit substantial potential as practical, body-worn devices for continuous physiological monitoring. The new potentiometric sensing concept can be readily expanded to epidermal monitoring of other clinically relevant sweat electrolytes such as sodium, potassium, calcium, or magnesium.
QUANTIFYING CELLULAR PROLIFERATION IN CO-CULTURE MODELSTerrence Garcia, Jacqueline De Lora, Alice Martinic, James Freyer.
University of New Mexico, Albuquerque, NM.
Monolayer culture is common for studying cancer on a cellular level. Growing tumor cells alone does not account for the more complex cell-to-cell interactions that occur in a tumor. We have designed a monolayer method for coEngineering culturing cancerous and non-cancerous cells as a first step toward investigating cell-to-cell interactions in tumors.
We cultured MCF-7 breast adenocarcinoma and 184A1 breast normal epithelial cells as mono- and co-cultures using standard monolayer growth curve protocols. In order to differentiate the two cell types in a co-culture, MCF-7 cells were stained with a red membrane dye (CellVue Claret), and 184A1 cells were stained with a green membrane dye (PKH27). In addition to allowing independent assay of the growth of each cell type in a mixture, the intensity of the membrane stains can also be used to measure the proliferation index based on dilution of the dye during cell division.
The fraction of cells in each cell cycle phase was also determined using standard DNA content analysis by flow cytometry. Growth curves for monocultures gave doubling times of 24 hours for MCF-7 and 44 hours for 184A1. We are currently conducting co-culture growth curves with initial cell ratios of 10:90 (tumor:normal), 50:50, and 90:10. Cell counts and flow cytometry of cells harvested from co-cultures will allow us to determine the doubling time, proliferative fraction, and cell cycle position for each cell line at each time during monolayer growth. After characterizing monolayer co-cultures, we will repeat these experiments using co-cultures grown as 3D multicellular spheroids.
CALCIUM CARBONATE NANOPARTICLES: SYNTHESIS, CHARACTERIZATION, AND POTENTIAL DRUG
DELIVERY APPLICATIONAlexis Catala, Mark Appleford.
University of Texas at San Antonio, San Antonio, TX.