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Test Tube Insertable Filter Device for Semen Swim-Up Separation
No full textThe complete senior project report was submitted to the project advisor and sponsor. The results of this project are of a confidential nature and will not be published at this time
Dual Base Sige Is-Hbt For Use In Biosensing Applications
Get PDFThe proposed research is for a novel SiGe-based Ion-Sensitive Dual Hetero-junction Bipolar Transistor (IS-HBT) to be used in both trans-dermal biological sensing as well as Lab-on-Chip (LOC) applications. The end goals for the device designed are two: For one, the research done for this work will be used to substantiate the claims made by Zafar et al. [1] that an HBT-style structure is better suited for biosensing application rather than a conventional Field Effect Transistor (FET) based geometries. Secondly, it provides the final element to be integrated along with a selectivity membrane, as well as with a reverse-iontophoresis system to enact trans-dermal sensing of potassium ions in a wearer’s body. The novelty of the device stems from the proposed modified wedding-cake structure lending itself to be easily implemented in a wearable package, the fact that it will act as both a transduction device as well as provide preamplification of signals. If successful, future researchers and/or corporations will have at their disposal a label-free advanced biosensor design that is integration-ready with currently available standard SiGe-BiCMOS processes
3D Printed Microfluidic Fabrication Methodology, Characterization, Mechanical Design, and Applications in Electrostatic Artificial Muscles and Benthic Microbial Fuel Cells
Get PDFThe fabrication of microfluidic devices often requires specialized methods. The development of these methods requires careful characterization and understanding of the processes involved. Using primarily PolyJet 3D printing technology, microfluidics offers a wide scope of applications such as microfluidic benthic microbial fuel cells (MBMFCs) and electrostatic artificial muscles. MBMFCs benefit from the confinement of the microbes resulting in close proximity between the electrode and the organisms. Using a modular design called the Sponge, assembly and upscaling is possible. Electrostatic artificial muscles benefit from a microfluidic approach due to the non-linearity of electrostatic attraction creating disproportionate benefits when miniaturized. When designed with the proper architectures, these muscles offer great promise. 3D printing these MBMFCs and artificial muscles allows for mass producibility and scalability. An approach combining 3D printing and microfluidics facilitates the further development and implementation of these technologies
Peer Collaborative Networks in Undergraduate Computing Classrooms
Get PDFPeers are an invaluable resource for students at undergraduate universities. Many factors can impact how students form connections, some of which are tied to the students’ identities. While social networks have been studied in the context of universities, little research has been done specifically about peer collaboration and even less in the context of computer science classes. Our research aims to gain an understanding of how peer networks form in computing classes and the effect of being involved in one on students’ academic performances. We collected survey data (n = 139) about students’ peer collaborative behaviors in computer science classes. Several patterns were observed. Students were more likely to collaborate with students with their same demographic identity, including gender and ethnicity. A student’s demographic identity had no predictive quality on their participation in a peer network. Students who participated in a peer network had a higher grade performance in the class compared to students who did not
Energy-Efficient Path Planning for Vehicles Using Static Terrain and Elevation Data
No full textThis report conducts a comparative performance analysis of Artificial Potential Fields (APF) against Q-Learning for efficiently navigating static elevated terrains. In the real world, often agents need to navigate rugged environments with power consumption constraints. With the aid of Q-Learning and APF, I determine general approaches for agents to navigate uneven real world environments from a known source and destination. In this paper, I start with a review of the current literature on efficient path planning, build a model to demonstrate these path-planning algorithms in action, and conclude with simulation results to show the effectiveness and efficiency of the different path-planning algorithms. Path planning is the problem of finding a collision-free path for an agent from a starting point to a destination in an efficient manner. Efficiency for the purposes of this paper is defined as minimizing the amount of energy consumed to get from the source to the destination. All the simulation code is written in Python and is available in Appendix B - I. Terrains are represented as grayscale 2-dimensional images corresponding to elevation. The height maps are real land masses collected from the web[1]. I use the combination of multiple equations to create a cost function to analyze and understand how the cost (energy consumption) of a given path varies with respect to the cost function parameters for each model. Using the results from select runs on the height maps, I provide my findings and the potential positive and negative aspects of each methodology. The goal is to use these findings to make navigation inferences for vehicles in real world environments that will minimize energy consumption
Zero-G Exercise Equipment
Get PDFIn a micro-gravitational environment, the body undergoes less loading than that found on Earth. This leads to muscular atrophy, Osteoporosis, decreases in protein synthesis, and various other undesirable outcomes. To prevent this, astronauts undergo a strict exercise regime to maintain their health. The current exercise equipment available for spacecraft is large, heavy, complicated to use, costly, and unsafe. There is a definite need for the re-engineering of the exercise equipment to be used by astronauts while in microgravity environments to rectify these issues
Design, Manufacturing, and Testing of a Cold Gas Thruster System With Minimized Actuators
No full textCold gas thrusters are commonly used on spacecraft for in-space attitude control and adjustment. These thrusters use inert gases stored at high pressures to create small amounts of thrust and typically have multiple fixed outlets, each controlled by its own actuated valve, to control the direction the thrust is directed. Having individual outlets with their own actuated valve leads to a great amount of power drawn for the individual actuators, as well as general added complexity by having a large number of parts. To address this issue, this thesis investigates an attempt to minimize the number of actuators required for a cold gas thruster system to operate.
This thesis details the design, analysis, electronics integration, manufacturing, and testing of a cold gas thruster system with as few actuators as possible. In addition, a thrust target, a maximum response time, and a long duration test regime were set as requirements to drive the design.
From these goals and requirements, a cold gas thruster system that uses a single central selector valve to control the actuation of four outlets while only using two motors was designed. The selector valve design uses a sleeve that rotates and moves vertically to align ports in the valve to allow the propellant gas to flow freely through the valve and to the nozzle where thrust is produced. The sleeve is rotated by a motor connected to a pair of gears, and the vertical motion is controlled by a motor with a lead screw.
Along with the mechanical design of the system, a great amount of compressible flow fluids analysis was performed. This analysis was used to determine the geometry of the outlet nozzle and its tolerances. In addition, a model was created using MATLAB and Simulink to predict the pressure drops throughout the system. This model is used to estimate the necessary pressure regulator outlet pressure that produces the nominal thrust.
The electronic control panel was developed to control the motors as well as to obtain performance data. Stepper motors were used to control the selector valve and controlled by a Teensy microcontroller board and custom libraries to operate the stepper motors simultaneously. Pressure and thrust data were collected from sensors that report the data to an Arduino microcontroller.
The testing performed was highly successful with the thrust requirement and the long duration test regime requirements were achieved, while the maximum response time requirement was missed, but not by a large margin. The targeted thrust was able to be produced, and the required endurance test profile was successfully performed. The response time requirement was met for two out of the three valve actuation motions and was slightly exceeded for the last one
Analyzing TMS 402 -22 : Design of Special Reinforced Masonry Shear Walls
Get PDFThis experiment examines possible inconsistencies in the TMS 402-22 masonry code between Section 7.3.2.5 and Section 9.3.5.6.2, regarding the requirements for special boundary elements in Special Reinforced Masonry Shear Walls. By investigating the two sections, it can be determined whether the two sections are in accordance with each other regarding aspect ratio. Tensile forces and strains are calculated respectively for each wall and block type and are compared to the respective tensile yield forces and ductile strains. This determines which respective boundary elements go past yield and become ductile. Based on this determination, recommendations can be made to the TMS 402-22 Code to accurately describe what is necessary for boundary elements and upon what conditions for masonry shear walls
Modeling The Effectiveness Of Bioremediation On Methyl Tertiary-Butyl Ether In Groundwater
Get PDFMethyl tertiary-butyl ether (MTBE) and its degraded form tertiary-butyl alcohol (TBA) are both known carcinogens that have contaminated groundwater aquifers across the United States. MTBE is a synthesized compound, once widely used as an additive in gasoline to increase oxygenation. Because of its popularity, MTBE was released into the environment primarily through fuel combustion and leaking underground storage tanks. These two compounds are known to be recalcitrant to most conventional physico-chemical treatment methods. Previous studies have suggested that bioremediation is effective at degrading MTBE and TBA in contaminated groundwater. Bioremediation involves the injection of oxygen, nutrients, and pre-adapted bacterial cultures into contaminated groundwater to increase the rate of natural biodegradation. In this study, a historically documented spill in Cambria, CA was modeled employing the Groundwater Modeling System software (GMS) to compare the effectiveness of the baseline treatment approach to that of in-situ bioremediation. MODFLOW was used to simulate groundwater flow, while MT3DMS was used to simulate dispersal and biodegradation of MTBE. Well data from public records was used as comparative values for hydraulic head and MTBE concentrations. Additional information from cleanup reports provided data for the physical properties of the aquifer. This included bedrock elevation, soil types, and storativity. Conductance, recharge rate, and hydraulic conductivity were calibrated using Parameter Estimation Software (PEST). The constants applied in MT3DMS simulations, such as dispersivity values, molecular diffusion coefficients, and retardation factors, were calculated manually using available, semi-empirical approaches. The model was first run emulating bioremediation using a high first order biodegradation rate estimated to be 8.6 day-1. This was compared to an instance of natural attenuation, with a first order biodegradation rate of 0.0074 day-1.
The case study investigated herein primarily implemented a pump and treat system relying on granular activated carbon and a series of trickling filters and clarifiers. Pump and treat operations began in 2000 and officially ended by the start of 2015. Even though treatment was terminated, the preliminary remedial goal for MTBE was not achieved. In the model created for this project, the bioremediation simulation predicted attainment of this treatment goal by 2010 after starting treatment in 2002. This increase in predicted removal rate over conventional approaches suggests bioremediation may be a viable and effective treatment technique when removing MTBE from groundwater. This predicted rate of removal suggests that bioremediation is more effective than the techniques used during the Cambria cleanup. It is important to note, there were many assumptions and simplifications made during the creation of the model. This includes the calibrated parameter values obtained from PEST iterations along with calculated parameter estimates regarding MTBE fate and transport. During set up, it was assumed that soil type consisted solely of silty clay and the bedrock layer was at a constant 45 ft below ground level. Additionally, the modeled in-situ bioremediation scenario assumes a best-case scenario, with the high first order biodegradation rate. For future modeling improvements, it is recommended to conduct onsite field testing to obtain degradation rates that more closely reflect rates found in the modeled region. A more complete mapping of the aquifer would also provide the model with increased reliability. Future models should also evaluate additional MTBE spill events and how differing terrains impact the effectiveness of in-situ bioremediation of MTBE
A Hardware-In-The-Loop Star Tracker Test Bed
Get PDFAs the use of small satellites for advanced space missions continues to grow, the importance of low mass and cost three-axis attitude stabilization systems increases as well, with these systems requiring high accuracy attitude knowledge. Star trackers provide the most accurate attitude knowledge of any type of attitude sensor, but the high cost, size, and weight of commercial star trackers can be prohibitive to small satellite missions. Many simple star trackers have been developed using commercial off-the-shelf camera sensors and processing hardware, but the challenge remains in testing and characterizing these devices. A common solution is night sky tests, in which the star tracker is held up to the night sky to image the star field and perform attitude determination. Commercial star trackers, on the other hand, are regularly tested with manufacturer provided star field images that attach directly to the sensor. These methods, however, severely limit the sky conditions that can be used in testing. Night sky tests depend on weather and can only image regions of the sky the user has access to, while lab-based testing uses the few provided still images. This thesis presents a hardware-in-the-loop star tracker test bed developed for comprehensive ground-based testing of both in-house and commercial star trackers. The system consists of a small screen to display a star field, a simple in-house camera star tracker, and a microprocessor. This test bed allows any star field image to be simulated. The system is set up for use on a stationary tabletop, but its small size lends itself for use with a spacecraft dynamics platform, which can facilitate testing of control algorithms using real star tracker output