Engineering Commons^™

Development Of Cal Poly's Shock Table, Christopher D. Risner

Master's Theses

Shock is one of the environmental tests that a spacecraft must pass before being cleared for launch. Shock testing poses a challenging data acquisition issue and careful selection of equipment is crucial to creating a successful shock test facility. Cal Poly’s CubeSat programs can currently perform all environmental testing other than shock themselves, so a quality shock table would be useful. Previous groups of students had developed a shock table, and this paper details the improvement and characterization of that shock table’s behavior. Several adjustable parameters were tested and documented to discover trends in the shock table’s response to an …

Design, Analysis, And Simulation Of A Jitter Reduction Circuit (Jrc) System At 1ghz, Run Bin Yu

Master's Theses

The clock signal is considered as the “heartbeat” of a digital system yet jitter which is a variation on the arrival time of the clock edge, could undermine the overall performance or even cause failures on the system. Deterministic jitter could be reduced during the designing process however random jitter during operation is somehow less-controllable and unavoidable. Being able to remove jitter on the clock would therefore play a vital role in system performance improvement.

This thesis implements a 1GHz fully feedforward jitter reduction circuit (JRC) which can be used as an on-chip IP core at clock tree terminals to …

Evaluation Of Efficiency Of Various Materials To Shield From Radiation In Space Using The Monte Carlo Transport Code Called Fluka, Roman Savinov

Master's Theses

The purpose of this study is to improve spacecraft shielding from radiation in space. It focuses on the evaluation of shielding efficiency of different materials. The efficiency of a shield is evaluated by the dose profile within the shield and the amount of dose absorbed by a target using the Monte Carlo transport code called FLUKA. The output of this code is validated by recreating the experiments from published papers and comparing the results. Once the FLUKA’s output is validated, the efficiency of sixteen materials, subject to SPE and GCR sources, are evaluated. The efficiency comparison is made by fixing …

Field Emissions Of (Hydro)Chlorofluorocarbons And Methane From A California Landfill, Alexander H. Sohn

Master's Theses

A comprehensive field investigation was conducted at Potrero Hills Landfill (PHL) located in Suisun City, California to quantify emissions of twelve (hydro)chlorofluorocarbons (i.e. F-gases). The specific target constituents for this study included CFC-11, CFC-12, CFC-113, CFC-114, HCFC-21, HCFC-22, HCFC-141b, HCFC-142b, HCFC-151a, HFC-134a, HFC-152a, and HFC-245fa. The majority of the F-gas emission studies have been conducted outside of the United States and very limited field landfill emission data are available in the United States. Because of historical usage of blowing agents in insulation foams including CFC-11, HCFC-142b, HFC-134a, and HFC-245fa, models reported in literature predicted high F-gas emissions from a landfill …

Quantifying Parkinson's Disease Symptoms Using Mobile Devices, Charles R. Aylward

Master's Theses

Current assessments for evaluating the progression of Parkinson’s Disease are largely qualitative and based on small sets of data obtained from occasional doctor-patient interactions. There is a clinical need to improve the techniques used for mitigating common Parkinson’s Disease symptoms. Available data sets for researching the disease are minimal, hindering advancement toward understanding the underlying causes and effectiveness of treatment and therapies. Mobile devices present an opportunity to continuously monitor Parkinson’s Disease patients and collect important information regarding the severity of symptoms. The evolution of digital technology has opened doors for clinical research to extend beyond the clinic by incorporating …

Nanoindentation Techniques For The Evaluation Of Silicon Nitride Thin Films, Weston T. Mangin

Master's Theses

Silicon nitride thin films are of interest in the biomedical engineering field due to their biocompatibility and favorable tribological properties. Evaluation and understanding of the properties of these films under diverse loading and failure conditions is a necessary prerequisite to their use in biomedical devices. Three wafers of silicon nitride-coated silicon were obtained from Lawrence Livermore National Laboratory and used to create 96 samples. Samples were subjected to nanoindentation testing to evaluate the mechanical properties of the film. Samples were subjected to nanoimpact testing to compare the damage resistance of the film to separate nanoimpact types. Samples were subjected to …

Coyotelab - Linux Containers For Educational Use, Michael D. Korcha

Electronic Theses, Projects, and Dissertations

CoyoteLab is an exploration in the use of Linux container technology as a means to simplify the way students in computing fields access and complete laboratory work in their educational career. This project provides two main benefits: creating a simple way for students to log in and access their coursework without anything more than their web browser, and providing course instructors a way to verify that assigned work is completed successfully. Thanks to advances in container technology and the advent of WebSockets, this becomes a middle layer between a WebSocket opened up on the client’s browser and the SSH daemon …

Performance Characterization Of Ceramic Matrix Composites Through Uniaxial Monotonic Tensile Testing, Jóhannes Pétursson

Doctoral Dissertations and Master's Theses

Ceramic matrix composite (CMC) samples were tested in order to characterize their mechanical performance and provide metrics for material process refinement and component design. Monotonic, uniaxial tensile testing of an uncoated carbon fiber reinforced silicon carbide ceramic at room temperature was performed following ASTM standard C1275 to measure ultimate tensile strength and elastic modulus. Equipment verification was carried out through alignment measurement with a gaged tensile specimen using ASTM E1012 to ensure the monotonic nature of the testing equipment. Tensile strength data was treated with Weibull statistical models to produce A and B-basis strength properties for design values.

An alternative …

Traction And Launch Control For A Rear-Wheel-Drive Parallel-Series Plug-In Hybrid Electric Vehicle, Adam Michael Szechy

Doctoral Dissertations and Master's Theses

Hybrid vehicles are becoming the future of automobiles leading into the all-electric generation of vehicles. Electric vehicles come with a great increase in torque at lower RPM resulting in the issue of transferring this torque to the ground effectively. In this thesis, a method is presented for limiting wheel slip and targeting the ideal slip ratio for dry asphalt and low friction surfaces at every given time step. A launch control system is developed to further reduce wheel slip on initial acceleration from standstill furthering acceleration rates to sixty miles per hour. A MATLAB Simulink model was built of the …

2016 Summer-Fall Graduate Recognition Program, Propulsion Research Center, Robert Frederick

PRC Graduate Recognition

This program includes the graduate recognition program for summer and fall 2016. Includes photographs, upcoming events, recent publications, and student profiles.

Investigating The Highest Melting Temperature Materials: A Laser Melting Study Of The Tac-Hfc System, Omar Cedillos-Barraza, Dario Manara, K. Boboridis, Tyson Watkins, Salvatore Grasso, Daniel D. Jayaseelan, Rudy J. M. Konings, Michael J. Reece, William E. Lee

Mechanical and Aerospace Engineering Student Publications and Presentations

TaC, HfC and their solid solutions are promising candidate materials for thermal protection structures in hypersonic vehicles because of their very high melting temperatures (>4000 K) among other properties.  The melting temperatures of slightly hypostoichiometric TaC, HfC and three solid solution compositions (Ta1−xHfxC, with x = 0.8, 0.5 and 0.2) have long been identified as the highest known. In the current  research, they were reassessed, for the first time in the last fifty years, using a laser heating technique.  They were found to melt in the range of 4041–4232 K, with HfC having the highest and TaC the lowest. …

An Ion Detection Scheme Employing Solid State Devices For Use In Portable Mass Spectrometers, Sanjiv Nath Pant

Theses and Dissertations

This thesis presents a solid state approach to the ion detection system used in the back-end of modern mass spectrometers. Although various techniques already exist to detect ions – even with the sensitivity of a single particle, the existing techniques require high voltage or lower operation temperature to counteract the noise inherent in the system. The suggested design presents an alternative to the more popular detection system whereby the requirement of high operation voltage or low operation temperature can be precluded. This is made possible through the gate capacitance of a Metal Oxide Semiconductor Field Effect Transistor (MOSFET). This thesis …

A Secure, Reliable And Performance-Enhancing Storage Architecture Integrating Local And Cloud-Based Storage, Christopher Glenn Hansen

Theses and Dissertations

The constant evolution of new varieties of computing systems - cloud computing, mobile devices, and Internet of Things, to name a few - have necessitated a growing need for highly reliable, available, secure, and high-performing storage systems. While CPU performance has typically scaled with Moore's Law, data storage is much less consistent in how quickly performance increases over time. One method of improving storage performance is through the use of special storage architectures. Such architectures often include redundant arrays of independent disks (RAID). RAID provides a meaningful way to increase storage performance on a variety of levels, some higher-performing than …

Ignimbrites To Batholiths, Chad Deering

TechTalks

Ignimbrites sample large magma reservoirs in the Earth’s upper crust, sometimes digging deep enough to link the volcanic realm with the plutonic world. Integrating textural, petrological, geochemical, and geochronological information on such deposits with geophysical signals suggest incremental growth and evolution of subvolcanic magma bodies that are dominated by high crystallinity mush zones, but sometimes remain sufficiently liquid to erupt. The eruptible upper portions are either extracted melt from the mush and constitute only a small volumetric fraction of the vertically extensive mushy batholithic magma body. The high-flux, ignimbrite flare-up phases are typically preceded by waxing magmatism that prime the …

Non-Invasive Real Time, Accurate And Affordable Monitoring Of Hemoglobin And Vital Parameters For Icu Patients, Harsh S. Modi

Theses and Dissertations

The measurement of hemoglobin concentration (Hb), oxygen consumption (mL and %), and partial pressure of oxygen inside the lungs are vital parameters in early prediction of respiratory diseases such as sepsis, septic shock, acute respiratory distress syndrome (ARDS) etc. The availability of these parameters in real time can play a crucial role in management of modes and parameters of the ventilators. The real time monitoring of patient’s vital signals in intensive care units can reduce the number of blood tests, time and cost spent inside the intensive care units. The medical conditions such as blood loss from surgery or an …

Life-Cycle Benefit-Cost Analysis Of Safety Related Improvements On Roadways, Jordan Browne Frustaci

Theses and Dissertations

The Highway Safety Manual (HSM) lists four different methods for determining the change in crash frequency in order of reliability. Currently, the Utah Department of Transportation (UDOT) uses the fourth reliable method. The goal of this research was to develop a tool that the most reliable method mentioned in the HSM could be used to perform life-cycle benefit-cost analyses. A spreadsheet program was built that performs the HSM's Part C Predictive Method for 11 different roadway segment types mentioned in HSM using Excel macros and Visual Basic for Applications (VBA) programming. Intersections were not included in this spreadsheet program as …

Design, Construction, And Preliminary Testing Of A Square Cross-Sectional Mixing Chamber, Holly Holmes-Smith

Chemical Engineering Undergraduate Honors Theses

Throughout the US, large quantities of chlorine are produced and transported by rail. In the past, train accidents led to deadly accidental releases and the need for mass evacuation. However, moving people unnecessarily may cause pandemonium or danger to health for sensitive members of the public. In these past cases, the models used for evacuation distances did not accurately predict the impact of the chlorine release, but these models did not take into account the reactivity of chlorine. Because chlorine is a highly reactive gas, it is absorbed into the surrounding environment which reduced the amount of chlorine in the …

Multi-Axial Fiber Optic Reference Strain Sensor For Flexible Dynamics Of Structures, Gabriel Lapilli

Theses and Dissertations

Launch vehicles are in an ever-decreasing weight trend, with bodies becoming more slender to reduce aerodynamic loading. Mass and stiffness tend to be opposing concepts when designing launch vehicles: a stiffer structure means it is usually heavier. Lower stiffness on launch vehicles may produce excessive vibrations during flight, reducing the performance, operating characteristics and safety margins of the vehicle. It also impacts flight dynamics: as the vehicle flies, the orientation of its thrusters and actuators are impacted by the vibrations, creating potential instabilities in the control schemes. This is currently accounted for by using single-point inertial measurements and feeding the …

A Multi-Value Sequence Generated By Power Residue Symbol And Trace Function Over Odd Characteristic Field, Yasuyuki Nogami, Satoshi Uehara, Kazuyoshi Tsuchiya, Nasima Begum, Hiroto Ino, Robert Morelos-Zaragoza

Faculty Publications

This paper proposes a new multi-value sequence generated by utilizing primitive element, trace, and power residue symbol over odd characteristic finite field. In detail, let p and k be an odd prime number as the characteristic and a prime factor of p-1, respectively. Our proposal generates k-value sequence T={ti | ti=fk(Tr(ωi)+A)}, where ω is a primitive element in the extension field $\F{p}{m}$, Tr(⋅) is the trace function that maps $\F{p}{m} \rightarrow \f{p}$, A is a non-zero scalar in the prime field $\f{p}$, and fk(⋅) is a certain mapping function based on k-th power residue symbol. Thus, the proposed sequence has …

Long-Term Biofilm Tests With Silver Contained Electrospun Polymer Mats, Bo Peng

Dissertations - ALL

It has been reported that wounds heal faster and better in a moist, enclosed environment. Wound dressings are designed to fulfill such demands. In addition, wound dressings protect wounds from subsequent physical harm and bacterial infection. Among various types of wound dressings, electrospun wound dressings are widely marketed due to desired properties. For instance, electrospun polymers are highly porous. Water and oxygen that are necessary for cells are permeable through the porous structure. Moreover, electrospun polymers have high surface area to volume ratio. This property allows polymers to absorb extra exudate from wounds efficiently. In this study, several silver-releasing electrospun …

Pressure Reduction On Wide Culverts With Eps Geofoam Backfill, Stephen Singh

Dissertations - ALL

Buried structures may be subjected to excessive stresses that are detrimental to their expected service life. A review of previous design methods shows that there are effective methods to reduce loadings on narrow culverts. The Induced Trench Method introduces compressible fill over a buried structure to mobilize positive arching, and transfer stresses to the side fills. However, this method has not been studied with Bridge Culverts (large spanning culverts). This study evaluates the use of EPS (Expanded Polystyrene, Geofoam) as a compressible/lightweight fill material. The displacements and stresses of the classic narrow trench are examined in detail using the finite …

Identification Of Key Players In Networks Using Multi-Objective Optimization And Its Applications, R Chulaka Gunasekara

Dissertations - ALL

Identification of a set of key players, is of interest in many disciplines such as sociology, politics, finance, economics, etc. Although many algorithms have been proposed to identify a set of key players, each emphasizes a single objective of interest. Consequently, the prevailing deficiency of each of these methods is that, they perform well only when we consider their objective of interest as the only characteristic that the set of key players should have. But in complicated real life applications, we need a set of key players which can perform well with respect to multiple objectives of interest.

In this …

Risk-Aware Planning For Sensor Data Collection, Jeffrey Hudack

Dissertations - ALL

With the emergence of low-cost unmanned air vehicles, civilian and military organizations are quickly identifying new applications for affordable, large-scale collectives to support and augment human efforts via sensor data collection. In order to be viable, these collectives must be resilient to the risk and uncertainty of operating in real-world environments. Previous work in multi-agent planning has avoided planning for the loss of agents in environments with risk. In contrast, this dissertation presents a problem formulation that includes the risk of losing agents, the effect of those losses on the mission being executed, and provides anticipatory planning algorithms that consider …

On The Design And Analysis Of Secure Inference Networks, Venkata Sriram Siddhardh Nadendla

Dissertations - ALL

Parallel-topology inference networks consist of spatially-distributed sensing agents that collect and transmit observations to a central node called the fusion center (FC), so that a global inference is made regarding the phenomenon-of-interest (PoI). In this dissertation, we address two types of statistical inference, namely binary-hypothesis testing and scalar parameter estimation in parallel-topology inference networks. We address three different types of security threats in parallel-topology inference networks, namely Eavesdropping (Data-Confidentiality), Byzantine (Data-Integrity) or Jamming (Data-Availability) attacks. In an attempt to alleviate information leakage to the eavesdropper, we present optimal/near-optimal binary quantizers under two different frameworks, namely differential secrecy where the difference …

Understanding And Improving Security Of The Android Operating System, Edward Paul Ratazzi

Dissertations - ALL

Successful realization of practical computer security improvements requires an understanding and insight into the system's security architecture, combined with a consideration of end-users' needs as well as the system's design tenets. In the case of Android, a system with an open, modular architecture that emphasizes usability and performance, acquiring this knowledge and insight can be particularly challenging for several reasons. In spite of Android's open source philosophy, the system is extremely large and complex, documentation and reference materials are scarce, and the code base is rapidly evolving with new features and fixes. To make matters worse, the vast majority of …

Structure, Dynamics And Rheology Of Surfactant Micelles And Micelle-Nanoparticle Solutions: A Molecular Dynamics Study, Abhinanden Sambasivam

Dissertations - ALL

Surfactant micelles are widely used in a number of industrial, commercial and household products and processes. Understanding flow-microstructure coupling in micellar systems can benefit applications ranging from targeted drug delivery and detergency to enhanced oil recovery and hydrofracking. Amongst micellar fluids, wormlike micelles (WLMs) are extremely interesting due to their structural similarity to polymers and their ability to constantly undergo scission and recombination at equilibrium. More recently, much has been generated in studying the effect of adding colloidal particles to WLMs. Colloidal particles can not only add functionality to the fluid but also act as viscosity modifiers. Such solutions can …

Developing The Three Dimensional Tumor Model For Melanoma Drug Screening, Guochang Ye

Theses and Dissertations

Two-dimensional (2D) Tissue Culture Treated Plastic (TCTP) is widely used for cancer drug screening and has dominated the field for a long time. Compared with traditional two dimensional cell culture, a three dimensional tumor model may able to provide more reliable experimental results related to drug screening and discovery. With the development of nanoparticle chemotherapies, there is a need for ways to better investigate and characterize the effect of the 3D tumor environment. Cerium oxide nanoparticles, Nanoceria, is one of the potential solutions being explored for treating melanoma in the future in combination with conventional chemotherapies. This is attributed to …

Practical Knowledge In Electrical Engineering : Applying Lessons From Industry To The Classroom., Tayce Lassiter

Electronic Theses and Dissertations

Objective: To identify and develop solutions for known gaps in existing electrical engineering curricula, by creating instruction modules applicable in a variety of settings. These instructional packages include: conductor sizing, conduit routing, how to read and create a P&ID, arc flash calculations, and area classification. With regards to conductor sizing, the importance of specifying the correct size of conductor, the standard sizes of conductors, the types of conductor insulation, and finally detail the calculations of conductor sizing and voltage drop will be discussed. The conduit routing module will introduce the student to basic guidelines of conduit routing as well as …

Dynamic Warehouse Optimization Using Predictive Analytics., Parvaneh Jahani

Electronic Theses and Dissertations

The forward area is a small area of a warehouse with a low picking cost. Two approaches that are investigated for selecting the SKUs of this area and the allocated space are the static and the dynamic approaches. In the case that decisions about the forward area are made periodically (e.g. yearly) and the products' demand patterns are completely ignored, the FRP is static. We developed two heuristics that solve the large discrete assignment, allocation, and sizing problem simultaneously. Replenishing the same product in the same place of the forward area brings about a ``Locked" layout of the fast picking …

Leveling The Playing Field: Teacher Perception Of Integrated Stem, Engineering, And Engineering Practices, Bridgette Fincher

Graduate Theses and Dissertations

The purpose of this study was to describe the perceptions and approaches of 14 third-through-fifth grade Arkansan elementary teachers towards integrative engineering and engineering practices during 80 hours of integrated STEM professional development training in the summer and fall of 2014. This training was known as Project Flight. The purpose of the professional development was to learn integrated STEM content related to aviation and to write grade level curriculum units using Wiggins and McTighe’s Understanding by Design curriculum framework. The current study builds upon on the original research.

Using a mixed method exploratory, embedded QUAL[quan] case study design and a …