Engineering Commons^™

The Effect Of Distribution On Product Temperature Profile In Thermally Insulated Containers For Express Shipments, Jay Singh, Sanjiv Jaggia, Koushik Saha

Industrial Technology and Packaging

An uninterrupted cold chain is a continual series of storage and distribution activities that maintain a specific temperature or temperature range. Cold chain solutions typically involve excessive packaging to ensure that the desired product temperature is maintained through the distribution process, thereby increasing the logistics-related costs. There is a myriad of solutions available for shipping temperature-sensitive products, including those constructed with a variety of packaging materials as well as refrigerants. Although static characteristics for thermally insulated packaging solutions such as the R-values of package systems as well as the melting points and heat absorption rates of various refrigerants have been …

Fabrication And Characterization Of A Palladium/Porous Silicon Layer, Nicholas Hong Lui

Master's Theses

When porous silicon is plated with a catalytic metal, the two materials can act together as a single entity whose electrical properties are sensitive to its environment – the sensing component of an electrochemical gas sensor. Etching pores into silicon is an electrochemical process; and which type of doped silicon used is one of its key parameters. For nearly all reported porous silicon gas sensors, the silicon has been of the p-doped variety – because p-doped porous etching is better understood and the layers that result from it are more predictable – despite n-doped silicon having potentially significant benefits in …

Transferability And Robustness Of Real-Time Freeway Crash Risk Assessment, Cameron Shew, Anurag Pande, Cornelius Nuworsoo

Civil and Environmental Engineering

This study examines the data from single loop detectors on northbound (NB) US-101 in San Jose, California to estimate real-time crash risk assessment models. Method: The classification tree and neural network based crash risk assessment models developed with data from NB US-101 are applied to data from the same freeway, as well as to the data from nearby segments of the SB US-101, NB I-880, and SB I-880 corridors. The performance of crash risk assessment models on these nearby segments is the focus of this research. Results: The model applications show that it is in fact possible to use the …

A Compact, Reconfigurable Uhf Communication System Design For Use With Polysat's Embedded Linux Platform, Austin Williams

Master's Theses

The beginning of this thesis provides an overview of the heritage UHF Communication System design flown on CP2, CP3, CP4, CP5, and CP6, summarizing previous analysis of its performance, and providing the justification for a complete system re-design. High level requirements for the new UHF System are defined, and a trade study is performed on state-of-the-art single chip transceivers, low noise amplifiers, and transmit power amplifiers. These components are then designed into a functional communication system, with key components analyzed for proper impedance matching and performance characterization compared to expected datasheet values. Next, the system as a whole is characterized …

Qualitative Methods Used To Develop And Characterize The Circulation Control System On Cal Poly's Amelia, Eric N. Paciano

Master's Theses

The circulation control system onboard Cal Poly's Advanced Model for Extreme Lift and Improved Aeroacoustics was a critical component of a highly complex wind tunnel model produced in order to fulfill the requirements of a NASA Research Announcement awarded to David Marshall of the Aerospace Engineering Department. The model was based on a next generation, 150 passenger, regional, cruise efficient, short take-off and landing concept aircraft that achieved high lift through circulation control wings and over-the-wing mounted engines. The wind tunnel model was 10-ft in span, used turbine propulsion simulators, and had a functioning circulation control system driven from tunnel …

An Analysis Of Eliminating Electroosmotic Flow In A Microfluidic Pdms Chip, Cecile D. Redington

Master's Theses

The goal of this project is to eliminate electroosmotic flow (EOF) in a microfluidic chip. EOF is a naturally occurring phenomenon at the fluid-surface interface in microfluidic chips when an electric field is applied across the fluid. When isoelectric focusing (IEF) is carried out to separate proteins based on their surface charge, the analytes must remain in the separation chamber, and not migrate to adjacent features in the microfluidic chip, which happens with EOF.

For this project, a microfluidic chip was designed and commissioned to be photolithographically transferred onto a Si wafer. A PDMS component was then casted on the …

Mechanoadaptation Of Feed Artery Smooth Muscle Cells In The Stem Of The Collateral Circulation, Allison Peck

Biomedical Engineering

Many patients suffering from peripheral arterial occlusive disease (PAOD) experience intermittent claudication, pain during locomotion. Previous studies suggest that this symptom could be explained in part by impaired vasodilation in collateral arteries. In this study, femoral ligation was performed on a murine animal model, stimulating collateral outward remodeling. The mechanism by which a collateral increases its luminal diameter in response to the increase in blood flow following occlusion warrents further investigation due to impaired vasodilation following collateral remodeling. Specifically, resting diameter is elevated in the stem region of the collateral circuit, but this increase in vessel size cannot be explained …

Workshop A - Implementing The "Design Your Process Of Becoming A World Class Engineering Student" Project, Steffen Peuker, Raymond B. Landis

Mechanical Engineering

Many students come into an engineering program lacking a strong commitment to stay in an engineering program and to graduate with an engineering degree. For students to accomplish the challenging goal of graduating in engineering requires a strong commitment, and behaviors and attitudes to follow through that commitment. To strengthen the commitment of the freshman engineering students an innovative project has been developed. The project challenges students to develop their process to become a "World-Class Engineering Student". Having freshman engineering students design their individually tailored learning process as part of a semester long project in the setting of a student …

Implementing Team Based Learning In Freshmen Engineering Courses, Steffen Peuker, Jennifer Peuker

Mechanical Engineering

Team Based Learning (TBL) is a specific pedagogical tool that emphasizes collaborative learning. Oftentimes TBL is confused with group activities and other active learning strategies involving student teams. TBL is distinct because it follows a prescribed sequence of individual work and group work, and includes immediate feedback as well as peer evaluation. TBL is widely used in medical, pharmacy and nursing schools and the use of TBL in engineering education is growing. The advantages of using TBL in the class room include: (1) students are held accountable for individual (pre-class) and group (in-class) work. (2) The responsibility for learning shifts …

A Class-C Amplifier Linearized By A Constant Conduction Angle Biasing Circuit, Gursewak Singh Rai, Vladimir I. Prodanov, Stephen Garber

Electrical Engineering

This work presents a dynamic biasing topology capable of linearizing a Class-C power amplifier (PA). The topology utilizes a control loop that senses the operating conditions of the power device by means of a scaled replica. The loop operates on the principle of keeping the conduction angle constant and thereby ensuring linearity. The work details some of the design considerations that should prove useful to a designer wanting to implement the topology in an RF integrated circuit. Measurement results from a fully-functional low-frequency prototype bring merit to the topology.

Mechanical Design Of Pird (Principal Investigator Rack Drawer) For Sofia, Hari Prasad Shetty Mr., Murali Krishna Kandlagunta Mrs., John Miles Mr., Zaheer Ali Mr.

STAR Program Research Presentations

SOFIA, the world’s largest airborne observatory with 2.5-meter diameter infrared telescope is equipped with 7 instruments: EXES, FIFI-LS, FLITECAM, FORCAST, GREAT, HAWC, and HIPO. Flying at altitudes between 39,000 and 45,000 feet, SOFIA avoids 99% of the atmospheric water vapor, records and analyzes the infrared radiation from the cosmos. SOFIA is able to observe the occultation of stars by solar system objects. By determining the size, compositions, and atmospheric structures of these objects, SOFIA can help answer the questions on creation and evolution of the universe, formation of the stars and planets, and nature of black hole at the center …

Characterization Of Samples For Optimization Of Infrared Stray Light Coatings, Carey L. Baxter, Rebecca Salvemini, Zaheer A. Ali, Patrick Waddell, Greg Perryman, Bob Thompson

STAR Program Research Presentations

NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA) is a converted 747SP that houses a 2.5 m telescope that observes the sky through an opening in the side of the aircraft. Because it flies at altitudes up to 45,000 feet, SOFIA gets 99.99% transmission in the infrared. Multiple science instruments mount one at a time on the telescope to interpret infrared and visible light from target sources. Ball Infrared Black (BIRB) currently coats everything that the optics sees inside the telescope assembly (TA) cavity in order to eliminate noise from the glow of background sky, aircraft exhaust, and other sources. A …

Smart Sampling Of Noble Gases To Detect Underground Nuclear Explosions, Lindsey M. Skelton, Steven Hunter, Charles Carrigan

STAR Program Research Presentations

One element of the Comprehensive Nuclear Test Ban Treaty (CTBT) is the provision for an on site inspection (OSI). The purpose of an OSI is to monitor for the occurrence of an underground nuclear explosion (UNE) in violation of the treaty. Detection of certain rare radioactive noble gases transported to the surface can be an excellent indicator of a UNE. These gases can be very difficult to capture and require specialized sampling methods. This study aims to determine an algorithm that will increase the efficiency of the subsurface gas sampling technique being used to detect UNEs. Continuous sampling of subsurface …

Life Support: Long Term Storage Of Solid Waste In An Enclosed Membrane System, Emmy O. Trieu, Michael Flynn, Rocco Mancinelli

STAR Program Research Presentations

In deep space missions, maintaining life support is of the utmost priority. In such a closed system, human waste must be stored and treated. Simulated feces (ersatz) will be inoculated with microbes representing normal fecal flora, mixed with urine brine and shredded refuse of products typically used in space missions. Composting methods often use alternating layers of waste with scraps of carboniferous materials (finely shredded refuse). By preparing membrane bags with a homogenized ersatz and carboniferous refuse mixture and membrane bags with alternating layers of ersatz and carboniferous refuse, it may be possible to monitor anaerobic thermophillic digestion of the …

If It Isn’T Tested, It Doesn’T Work: Automated Verification Of Sofia Data Handling Software, Garrett Holthaus, Brett Stroozas, Zaheer Ali

STAR Program Research Presentations

This project involves writing code to automate the verification testing of the Data Handling Working Group (DHWG) software tools for the Stratospheric Observatory for Infrared Astronomy (SOFIA). The DHWG tools extract engineering data from SOFIA missions. Engineering data includes a variety of information on the operations and status of SOFIA systems during a flight, including computer network traffic, user commands, and images acquired from cameras mounted on the telescope assembly. It is important to review engineering data because this data can lead to the discovery of any problems or inefficiencies in SOFIA hardware and software. Analysis of engineering data can …

C-Ring Contaminate Identification By Spectroscopy And Elemental Mapping, Thien Q. Vu-Nguyen, Bernice Mills

STAR Program Research Presentations

A silver plated steel c-ring used to seal two steel pieces together was found to have contamination upon disassembly. Auger and x-ray fluorescence spectroscopy and mapping were used to identify the contaminate as molybdenum disulfide lubricant. Recommendations were made to avoid such contamination in the future.

Creating A Package In R, Brit Schneiders, Eric Archer

STAR Program Research Presentations

In a time of increasingly efficient technology and data production, scientists are producing data faster than it can be analyzed. Therefore, user accessibility to data analysis is becoming more and more critical. In general, researchers have a set of raw data and want an efficient means to their final analysis. A package serves as that means by creating a set of functions and making them accessible to the user. Often, a user has a small piece of code to run (a single R script, for example), and that script requires the use of certain functions, which are contained in a …

Characterization Of The Drilling Via The Vibration Augmenter Of Rotary-Drills And Sound Signal Processing Of Impacted Pipe As A Potential Water Height Assessment Tool, Nicholas Morris

STAR Program Research Presentations

The focus of the internship has been on two topics: a) Characterize the drilling performance of a novel percussive augmenter – this drill was developed by the JPL’s Advanced Technologies Group and its performance was characterized; and b) Examine the feasibility of striking a pipe as a means of assessing the water height inside the pipe. The purpose of this investigation is to examine the possibility of using a simple method of applying impacts to a pipe wall and determining the water height from the sonic characteristic differences including damping, resonance frequencies, etc. Due to multiple variables that are relevant …

The Design And Fabrication Of An Electrostatically Actuated Diaphragm With A Silicon-On-Insulator Wafer, Elizabeth L. Brooks

Master's Theses

Electrostatically actuated silicon membranes were designed, modeled, fabricated, and characterized. The intended application was for use in a microspeaker. Fabrication issues necessitated the use of thick diaphragms with a large gap between the electrodes. The devices did not function as speakers but did show actuation with a high DC voltage. Device dimensions were chosen by examining membrane mechanics, testing the processing steps required for device fabrication, and modeling with COMSOL. Several adhesives were researched to fabricate the device sidewalls, including BCB, PMMA, and TRA-Bond F112. A method for patterning PMMA through photolithography was found using a scanning electron microscope. Masks …

Design, Fabrication And Test Of An Operationally Responsive Aircraft With Niirs Evaluated Imager, Colin Burt

Master's Theses

Unmanned Aerial Systems (UAS) are a growing asset. Currently UAS are on the cutting edge with resources being spent developing the capabilities mostly for military use. This project is intended to create a system for non-defense customers. Specifically, the Operationally Responsive Aircraft (ORA) will appeal to academic institutions, individual consumers, future customers new to the UAS industry, as well as anybody trying to get airtime for custom sensors.

The system developed in this project utilizes dual aluminum external payload bays attached to a ParkZone Radian aircraft. Each external payload bay can contain approximately 500 $\text{cm}^3$, with a height and width …

Finite Element Models Of The Knee & Hip Joints: Using Opensim To Predict Muscle Forces, Kevin S. Jones, Spencer D. Wangerin, Jeffrey D. Pyle, Stephen M. Klisch, Scott J. Hazelwood

STAR Program Research Presentations

Quantitative data of stresses and strains in the cartilage of the knee and hip joints are required to design prostheses and can be used to give accurate advice to patients with cartilage damage as to which activities should be avoided. Instrumented hip implants can only give the overall resultant force in the joint, not the stresses and strains throughout the cartilage. Finite Element (FE) models of the Knee and Hip are being constructed in order to obtain the stresses and strains in articular (of the joint) cartilage. Muscle forces and joint contact forces are required as inputs to these FE …

Tools And Methods To Optimize The Analysis Of Telescopic Performance Metrics On Sofia, Steven R. Wilson, Holger Jakob, Stefan Teufel, Zaheer Ali, Jeffrey Van Cleve, Brian Eney, Greg Perryman

STAR Program Research Presentations

SOFIA is an infrared observatory mounted on a modified 747 engineered to do infrared astronomy at 45000 feet. The telescope equipment contains a number of sensors and stabilizers that allow the telescope to capture images while mounted in a moving plane. We have developed methods to analyze the performance of the telescope assembly that will help improve the stabilization and image capturing performance of the observatory. Here we present reusable methods to analyze telescope performance data that will enable improvements in the quality of the scientific data that is produced by the SOFIA. This poster focuses on the multi-flight performance …

Feedback Stabilization At Spear3, Daniel Kelley, Jeff Corbett

STAR Program Research Presentations

The SPEAR3 synchrotron lightsource at SLAC relies on a sophisticated radio frequency (RF) timing system to maintain current – electrons – in the storage ring. One problem SPEAR3 operators have dealt with is the thermal expansion of one of the cables supporting this RF timing system. As the cable expands and contracts with the diurnal rise and fall of the sun, the phase of the RF in the cable shifts. This shifting phase affects the timing accuracy of electron injections into the storage ring.

A common feedback control algorithm PID (Proportional Integral Derivative) has countless applications in engineering. PID feedback …

Extending The Shelf Life Of Solid Rocket Motors Through Mechanical Activation Of, Emilio J. Cantu, Hope Klukovich, Timothy Haddad

STAR Program Research Presentations

A great deal of interest has been given to extending the life of our fleet of solid rocket motors. Once poured, these motors are essentially stored, unused, and are therefore subject to various environmental conditions. Cycling between high and low temperatures causes thermal expansion and contraction of motor materials. This will eventually lead to cracks forming and propagating in the rocket motor, rendering it unreliable and thus must be re-poured at great expense. A common binder material used in these motors is hydroxy-terminated polybutadiene (HTPB), which when cured with a diisocyanate, creates the solid matrix to house the energetic materials …

Interaction Of A Shock Tube Exhaust Flow With A Non-Pre-Mixed Flame, Graham Doig, Zebulan Johnson, Rachel Mann

Aerospace Engineering

No abstract provided.

Low-Pressure Testing: Microirrigation Emitters, Charles M. Burt, Kyle Feist

BioResource and Agricultural Engineering

ITRC tested 28 different pressure-compensating (PC) models of microirrigation emitting devices from a total of nine manufacturers in order to compare independent laboratory testing with manufacturer specifications. It is the intention of this report to investigate the ability of currently marketed products to operate in a truly low pressure irrigation system where energy inputs, in the form of pump discharge requirements, can be minimized.

Low-Pressure Testing: Pressure Regulating Valves, Charles M. Burt, Kyle Feist

BioResource and Agricultural Engineering

ITRC tested performance characteristics of pressure regulating valves from a variety of manufacturers. The purpose of the testing was to evaluate the ability of different models of valves to regulate the pressure in a low-pressure system. The testing concentrated on three specific valve performance characteristics: minimal variance from the target downstream pressure caused by changes in flow rate or inlet pressure; minimal hysteresis in outlet pressures; minimal pressure loss (at low inlet pressures) across the valve.

Vascular Reactivity Of Immature Arterialized Capillaries, Sara Hellstrom

Biomedical Engineering

Peripheral arterial occlusive disease (PAOD) is a globally prevalent cardiovascular disease in which atherosclerotic plaques narrow arterial lumen diameters and restrict blood flow to down stream tissues. The impact of these occlusions can be mitigated by collateral vessels that connect parallel arterial branches and act as natural bypasses to maintain perfusion. Some patients with PAOD may not have robust collateral networks to accommodate ischemic tissues in the event of an occlusion and, therefore, may be more susceptible to hypoxia and tissue necrosis. In animal models that lack collateral arterioles, capillaries can arterialize and form functional collaterals; however, in the early …

Smarter Neat Nets, Ryan Swords Dehaven

Master's Theses

This paper discusses a modification to improve usability and functionality of a ge- netic neural net algorithm called NEAT (NeuroEvolution of Augmenting Topolo- gies). The modification aims to accomplish its goal by automatically changing parameters used by the algorithm with little input from a user. The advan- tage of the modification is to reduce the guesswork needed to setup a successful experiment with NEAT that produces a usable Artificial Intelligence (AI). The modified algorithm is tested against the unmodified NEAT with several different setups and the results are discussed. The algorithm shows strengths in some areas but can increase the …

Finite Element Analysis And Validation Of Hip Joints With The Main Types Of Femoroacetabular Impingement, Kevin Lucas Mitchell

Master's Theses

Current research suggests that femoroacetabular impingement can be a cause of osteoarthritis. Femoroacetabular impingement is a condition that can affect both the femur and the pelvis of an individual. Femoroacetabular impingement can cause damage to the hip joint and its surrounding tissues. The articular cartilage and the labrum are both affected by this condition. A cam impingement is where a bony protrusion develops at the femoral head/neck junction. A pincer impingement is where a bony protrusion develops at the acetabular rim. Often, patients are seen with a combination of both impingements. The main goal of this study was to computationally …