Engineering Commons^™

Evaluation Of Temporal Damage Progression In Concrete Structures Affected By Asr Using Data-Driven Methods, Vafa Soltangharaei

Theses and Dissertations

Alkali-silica reaction (ASR) is a chemical reaction, which causes damage in concrete structures such as bridges, dams, and nuclear containments and powerplant structures. The ASR-induced damage may endanger the integrity and serviceability of structures. Several methods such as visual inspection, petrographic analysis, demountable mechanical strain gauges, and cracking index have been utilized for study the effect of ASR on structures, which are not always efficient in early damage detection and some are destructive and prohibited in nuclear structures. Nondestructive methods and structural health monitoring techniques can be alternatives for the condition assessment of structures. Among the nondestructive methods, acoustic emission …

Development And Optimization Of Imaging And Image Quantification Techniques For Tissue-Engineered Blood Vessel Mimics, Ashley Turcott

Master's Theses

Blood vessels mimics (BVMs) are tissue-engineered blood vessels used to test vascular devices in an environment that mimics some simple anatomical factors of native blood vessels. It is important to accurately and consistently assess tissue-engineered blood vessels, although there is currently a lack of standardization in Cal Poly’s Tissue Engineering Lab and in the entirety of the field. The goal of this thesis was to develop and optimize imaging and image quantification techniques for tissue-engineered blood vessels.

The first aim of this thesis optimized and compared imaging and assessment techniques for electrospun scaffolds. Images from different SEMs were compared to …

Identification Of Users Via Ssh Timing Attack, Thomas J. Flucke

Master's Theses

Secure Shell, a tool to securely access and run programs on a remote machine, is an important tool for both system administrators and developers alike. The technology landscape is becoming increasingly distributed and reliant on tools such as Secure Shell to protect information as a user works on a system remotely. While Secure Shell accounts for the abuses the security of older tools such as telnet overlook, it still has fundamental vulnerabilities which leak information about both the user and their activities through timing attacks. The OpenSSH client, the implementation included in all Linux, Mac, and Windows computers, sends each …

Combining Machine Learning And Empirical Engineering Methods Towards Improving Oil Production Forecasting, Andrew J. Allen

Master's Theses

Current methods of production forecasting such as decline curve analysis (DCA) or numerical simulation require years of historical production data, and their accuracy is limited by the choice of model parameters. Unconventional resources have proven challenging to apply traditional methods of production forecasting because they lack long production histories and have extremely variable model parameters. This research proposes a data-driven alternative to reservoir simulation and production forecasting techniques. We create a proxy-well model for predicting cumulative oil production by selecting statistically significant well completion parameters and reservoir information as independent predictor variables in regression-based models. Then, principal component analysis (PCA) …

A Feasible Approach To Predicting Time-Dependent Bearing Performance Of Jacked Piles From Cptu Measurements, Lin Li, Jingpei Li, De'an Sun, Weibing Gong

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

In this paper, a simple but feasible approach is proposed to predict the time-dependent load carrying behaviors of jacked piles from CPTu measurements. The corrected cone resistance, which considers the unequal area of the cone rod and the cone, is used to determine the soil parameters used in the proposed approach. The pile installation effects on the changes in the stress state of the surrounding soil are assessed by an analytical solution to undrained expansion of a cylindrical cavity in K0-consolidated anisotropic clayey soil. Considering the similarity and scale effects between the piezocone and the pile, the CPTu measurements are …

Parametric Study Of A Triboelectric Transducer In Total Knee Replacement Application, Alwathiqbellah Ibrahim, Geofrey Yamomo, Ryan Willing, Shahrzad Towfighian

Mechanical Engineering Faculty Scholarship

Triboelectric energy harvesting is a relatively new technology showing promise for biomedical applications. This study investigates a triboelectric energy transducer for potential applications in total knee replacement (TKR) both as an energy harvester and a sensor. The sensor can be used to monitor loads at the knee joint. The proposed transducer generates an electrical signal that is directly related to the periodic mechanical load from walking. The proportionality between the generated electrical signal and the load transferred to the knee enables triboelectric transducers to be used as self-powered active load sensors. We analyzed the performance of a triboelectric transducer when …

Restoring Lake Urmia: Moving Beyond A Uniform Lake Level (2-Page Summary), Somayeh Sima, Dory Rosenberg, Wayne A. Wurtsbaugh, Sarah E. Null, Karin M. Kettenring

Watershed Sciences Faculty Publications

More than 5 million people live near Lake Urmia in northwestern Iran, one of the world's largest hypersaline lakes. Over the past two decades, the lake has lost 95% of its volume, lake level has dropped more than 7 m, and lake restoration has gained widespread interest. The government seeks a uniform "ecological" target lake level of 1274.1 m above sea level to lower salinity below 240 gL^-1 and recover brine shrimp (Artemia spp.) and flamingos (Phoenicopterus roseus).

We have synthesized over 40 years of available data, defined 8 ecosystem services for human health, water quality, ecology, recreation, and …

An Aviation Weather Preflight Decision Support Tool To Improve Ga Pilots' Preflight And Inflight Performance, Jayde M. King

Doctoral Dissertations and Master's Theses

Low hour, inexperienced General Aviation (GA) pilots account for the majority of weather-related incidents, which often result in fatalities. Previous research identifies poor preflight planning practices and a lack of aviation weather knowledge as key contributing factors to the high novice private pilot accident and fatality rate. Research invested into resolving these issues often attempt to introduce new inflight weather technology to assist pilots with weather avoidance. However, these interventions usually result in pilots using the information to strategically navigate closer to degraded weather conditions (Beringer & Ball, 2004; Burgess & Thomas, 2004). Therefore, the purpose of this study was …

Study On New Sampling Plans And Optimal Integration With Proactive Maintenance In Production Systems, Sinan Obaidat

Graduate Theses and Dissertations

Sampling plans are statistical process control (SPC) tools used mainly in production processes. They are employed to control processes by monitoring the quality of produced products and alerting for necessary adjustments or maintenance. Sampling is used when an undesirable change (shift) in a process is unobservable and needs time to discover. Basically, the shift occurs when an assignable cause affects the process. Wrong setups, defective raw materials, degraded components are examples of assignable causes. The assignable cause causes a variable (or attribute) quality characteristic to shift from the desired state to an undesired state.

The main concern of sampling is …

Red Blood Cell Dynamics On Non-Uniform Grids Using A Lattice Boltzmann Flux Solver And A Spring-Particle Red Blood Cell Model, Brendan Walsh

Doctoral

The Computational Haemodynamics Research Group (CHRG) in Technological University Dublin is developing a computational fluid dynamics (CFD) software package aimed specifically at physiologically-realistic modelling of blood flow. A physiologically-realistic model of blood flow involves calculating the deformation of individual red blood cells (RBCs) and the contribution of this deformation to the overall blood flow. The CHRG has developed an enhanced spring-particle RBC structural model that is capable of modelling the full stomatocyte-discocyteechinocyte (SDE) transformation. This RBC model, incorporated into a fluid dynamics solver, will provide a physiologically-realistic blood flow model. In this work the overall plasma flow is modelled using …

Effects Of Physical And Chemical Characteristics Of Slags And Cements On Durability Of Portland Cement-Slag Blended Systems, Farzaneh Nosouhian

USF Tampa Graduate Theses and Dissertations

Ground granulated blast furnace slag (GGBFS) which is a commonly used supplementary cementitious material (SCM) needs to be more investigated for improving durability of concrete elements and service life of concrete structures. This research focuses on the effect of the physical and chemical characteristics of GGBFS and portland cement on durability of portland cement-slag blended systems. The effect of cement replacement level is also investigated using control mixes (no slag) and four different levels of slag content. To this end, eight GGBFS and eight portland cements were selected based on their physical characteristics and chemical composition. Four series of experimental …

International Year Of Glass, Bill Fahrenholtz

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

Predicting Effective Fracture Toughness Of Zrb₂-Based Ultra-High Temperature Ceramics By Phase-Field Modeling, Arezoo Emdadi, Jeremy Lee Watts, William Fahrenholtz, Greg Hilmas, Mohsen Asle Zaeem

Materials Science and Engineering Faculty Research & Creative Works

The effective fracture toughness (EFT) of ZrB₂-C ceramics with different engineered microarchitectures was numerically evaluated by phase-field modeling. To verify the model, fibrous monoliths (elongated hexagonal ZrB₂-rich cells in a continuous C-rich matrix) with different volume fractions of a C-rich phase were considered. Architectures containing 10 and 30 vol% of C-rich phase showed EFT values about 42% more than that of pure ZrB₂. Increasing the C-rich phase to 50 vol%, dropped toughness significantly, which is in agreement with the experimental results. Replacing hexagonal cells with cylindrical, triangular, or square cells of the same cross-sectional …

A Temperature Sensor For Measuring Dielectric Loss Heating In A Dielectrophoresis Device, Imtiaz Hossen

Master's Theses (2009 -)

Dielectrophoresis is an extensively used technique in the field of biomedical science that manipulates particles in a non-uniform electric field. One of its drawbacks is heat dissipation during the DEP operation that raises the local temperature of the DEP device. Temperature increases during dielectrophoresis (DEP) can affect the response of biological entities and ignoring the effect can mislead the result of the analysis. The heating mechanism of a DEP device is typically considered to be the result of Joule heating as bare electrodes are used in a conductive solution. However, when electrodes are insulated from the solution the presence of …

Speeding Up Particle Filter Algorithm For Tracking Multiple Targets Using Cuda Programming, Jinhua Zhang

Master's Theses (2009 -)

This thesis proposes to work on a parallelization method to speed up the computational runtime of the particle filter algorithm for multiple targets tracking. CUDA programming is utilized to execute the original implementation of the particle filter algorithm on GPU. The thesis provides a detailed discussion of the background information on the relevant topics. And then a presentation of the code architecture changes is followed. The detailed CUDA-based implementation is illustrated and discussed, which is followed by a discussion andcomparison of the results obtained from a series of tests.In this thesis, the introduction and description of the basic …

Determining The Correlation Between Plantar Pressure And Joint Kinematics While Running, Fadumo Khalid Mohamud

Master's Theses (2009 -)

Running provides many health benefits, but there is a risk for lower extremity injuries. Previous studies have performed simultaneous assessments of plantar pressure and joint kinematics; however, they have not investigated correlations between these parameters. The goal of this study was to assess correlations between joint kinematics and plantar pressure metrics during the stance phase.Fifteen female and eleven male recreational runners ran ten trials in this study. The joint kinematics were measured using the Vicon MX system and plantar pressure metrics were measured with the Quasar pressure treadmill. Spearman rho correlation tests were performed to determine correlations between joint …

Investigation Of Optimization Targets For Predictive Simulation Of Human Gait With Model Predictive Control, Jessica Brianne Thayer

Master's Theses (2009 -)

The design and development of gait-related treatments and devices is inhibited by anabsence of predictive gait models. Understanding of human gait and what motivates walkingpatterns is still limited, despite walking being one of the most routine human activities. While asignificant body of literature exists on gait modeling and optimization criteria to achievesimulated, normal gait, particularly with neuromuscular models, few studies have aimed to applyoptimization targets which approximate metabolic cost to mechanical gait models. Even fewerhave attempted this predictively, with no joint angle data specified a priori. The Sunmodel [31], [32] is one such …

Using Drone-Based Fully Convolutional Network For The Determination Of Construction Site Elevations, Sisi Han

Master's Theses (2009 -)

This thesis presents the research results of using the Fully Convolutional Network (FCN) model to densely match pixels and accurately determine elevations utilizing low-high ortho-images on a construction site. The research project has three major tasks. First, this researcher developed the FCN model to build up the relations between the reference pixels’ patches from the low-ortho-image and the target pixels’ patches from the high-ortho-image, which are approximate 2:1 scale relations. The developed FCN model has two convolutional blocks and one max-pooling layer in the middle. 286,292 samples of well-matched reference patches and target patches were collected for training the FCN …

Human Behavior Is A Significant Flaw In Maintaining Cyber Security, Elizabeth Jackson

Cybersecurity Undergraduate Research Showcase

Human behavior and data security utilization must be intertwined; in order to mitigate the negative effects of cyber attacks. No consumer wants their data hacked, breached, stolen, shared or wiped out. It is imperative to survey the type of education is needed to keep users safe and interested in securing their data. This can be done by simply seeking out the consumer's view of data security. The information obtained would allow the cybersecurity community to offer a simple way for consumers to protect their mobile data. There is a constant interaction between human behavior and the need for increased data …

Task-Specific Versus Impairment-Based Training On Locomotor Performance In Individuals With Chronic Spinal Cord Injury: A Randomized Crossover Study, Jennifer K. Lotter, Christopher E. Henderson, Abby Plawecki, Molly E. Holthus, Emily H. Lucas, Marzieh M. Ardestani, Brian D. Schmit, George Hornby

Biomedical Engineering Faculty Research and Publications

Background. Many research studies attempting to improve locomotor function following motor incomplete spinal cord injury (iSCI) focus on providing stepping practice. However, observational studies of physical therapy strategies suggest the amount of stepping practice during clinical rehabilitation is limited; rather, many interventions focus on mitigating impairments underlying walking dysfunction. Objective. The purpose of this blinded-assessor randomized trial was to evaluate the effects of task-specific versus impairment-based interventions on walking outcomes in individuals with iSCI. Methods. Using a crossover design, ambulatory participants with iSCI >1-year duration performed either task-specific (upright stepping) or impairment-based training for up to 20 sessions over ≤6 …

The Neural Foundations Of Handedness: Insights From A Rare Case Of Deafferentation, S.A.L. Jayasinghe, F. R. Sarlegna, Robert A. Scheidt, R. L. Sainburg

Biomedical Engineering Faculty Research and Publications

The role of proprioceptive feedback on motor lateralization remains unclear. We asked whether motor lateralization is dependent on proprioceptive feedback by examining a rare case of proprioceptive deafferentation (GL). Motor lateralization is thought to arise from asymmetries in neural organization, particularly at the cortical level. For example, we have previously provided evidence that the left hemisphere mediates optimal motor control that allows execution of smooth and efficient arm trajectories, while the right hemisphere mediates impedance control that can achieve stable and accurate final arm postures. The role of proprioception in both of these processes has previously been demonstrated empirically, bringing …

Comparing The Effectiveness Of Osha-10 Online And In-Person Safety Courses: Case Study, Timothy R. Bartolomei

Construction Management

Since 1970, the Occupational Safety and Health Act (OSHA) was designed to create a safe workplace for everyone, has increased safety awareness, and decreased occurrences of injury and death on construction-related job sites. Until 2001, construction safety education was taught through face-to-face interaction between an instructor and an employee. However, in 2001, safety courses became available through multiple online platforms with the ability to be completed virtually. Online safety courses provide an alternative from face-to-face training and allow the employee to complete the training at their own pace. However, some research indicates that online safety courses are not as effective …

Adaptive Large Neighborhood Search For Vehicle Routing Problem With Cross-Docking, Aldy Gunawan, Audrey Tedja Widjaja, Pieter Vansteenwegen, Vincent F. Yu

Research Collection School Of Computing and Information Systems

Cross-docking is considered as a method to manage and control the inventory flow, which is essential in the context of supply chain management. This paper studies the integration of the vehicle routing problem with cross-docking, namely VRPCD which has been extensively studied due to its ability to reducethe overall costs occurring in a supply chain network. Given a fleet of homogeneous vehicles for delivering a single type of product from suppliers to customers through a cross-dock facility, the objective of VRPCD is to determine the number of vehicles used and the corresponding vehicle routes, such that the vehicleoperational and transportation …

Gender Differences And Cockpit Design, Susan Archer, Heidi Brewer, Stacie Fain, Stephanie Smith

Student Works

The design project reported in this paper examined female pilots’ experiences with how well or poorly cockpit design allowed them to safely accomplish their flying missions. The general aviation aircraft cockpit is not designed for female pilots, often causing them to find ways to adapt to the cockpit in order to operate the aircraft safely. Two primary focal areas for adaptations address issues with accessibility of controls and “viewability” inside and outside the cockpit. The design team used a Situation Awareness-Oriented Interface Design (SAOD) approach in preparing cockpit design recommendations for general aviation aircraft that would accommodate female pilots.

Cis-Resveratrol Upregulates Tyrosyl-Trna Synthetase And Inhibits The Proliferation Of Select Breast Cancer Cell Lines, Marion Cone Hope Iii

Theses and Dissertations

Breast cancer is one of the most commonly occurring cancers in women. 70% of breast cancer patients express ERα and are treated with tamoxifen (Tam), a drug that is used to directly target ERα. However, 20-30% of cancer patients develop a resistance to Tam. This resistance leads to a worse prognosis and other treatments such as DNA damaging drugs or radiation to eliminate these cells. Resveratrol (RSV) is a polyphenolic- compound found in plants such as grapes and hellebore and is known to evoke anti-cancer effects. While natural resveratrol exists as a mixture of both cis- and trans- isomers, so …

The Hybridization Of A Graphene And Silicon Carbide Schottky Optoelectronic Device By The Incorporation Of A Lead Sulfide Quantum Dot Film, Joshua Letton

Theses and Dissertations

The work that follows examines the impact of lead sulfide quantum dots on a native epitaxial graphene (EG) SiC Schottky device, resulting in a hybrid optoelectronic device which presents a possible avenue towards a novel hybrid carbide-based Schottky solar cell. The active (n-type SiC) and contact (graphene) layers for the Schottky junction of the device were grown epitaxially using a novel technique incorporating tetrafluorosilane (TFS) as a precursor gas. The bare EG/SiC device was characterized based on its I-V behavior in dark and under illumination for both forward and reverse bias conditions. The initial characterization demonstrated the expected Schottky diode …

Enhancing Single And Two-Phase Heat Transfer Of Microgap Heat Sinks Using Nano-Structure Coatings, Yueyang Zhao

Theses and Dissertations

Due to the shrinking size and increasing power of electronics, the heat flux generated by electronic devices has greatly increased and imposed challenges to thermal management technologies. Numerous cooling technologies have been developed to cool high-power electronics. Among them, flow boiling in microchannels or a microgap has been one of the most efficient ways to remove high heat flux, which requires less coolant compared with single-phase cooling techniques. However, the flow boiling instability is the one of the most challenging issues, which lead to the premature critical heat flux (CHF) conditions and deteriorate heat transfer rate. The capillary force generated …

New Models For Truck Appointment Problem And Extensions, Mohammad Torkjazi

Theses and Dissertations

The problematic issues surrounding gate congestion at marine container terminals have been well documented. Random truck arrivals at maritime container terminals are one of the primary reasons for gate congestion. Gate congestion negatively affects the terminal’s and drayage firms’ productivity and the surrounding communities in terms of air pollution and noise. To alleviate gate congestion, more and more terminals in the U.S. are utilizing a truck appointment system (TAS).

The first study proposes a novel approach for designing a Truck Appointment System (TAS) intended to serve both the marine container terminal operator and drayage operators. The aim of the proposed …

Design Of High Efficiency Wireless Power Thansfer System With Nonlinear Resonator, Yibing Zhang

Theses and Dissertations

Wireless power transfer technology (WPT) has been rapidly developed in recent years. The primary benefit of WPT is that it replaces the traditional wire charging with a cordless charging method. WPT technology has been applied in many fields, such as bio-implants, electric vehicles, and wirelessly charging systems. According to the different energy transmission mechanism, WPT technology can be divided into magnetic field coupling (includes magnetically coupled inductive and magnetically-coupled resonant), microwave radiation, laser emission, electrical-field coupling, and ultrasonic transmission type. Among these technologies, the magnetic resonance coupling method has a better promise because of its long transfer distance and high …

Fundamental Studies Of Oxygen Electrocatalysis In Alkaline Electrochemical Cells, Victoria F. Mattick

Theses and Dissertations

Until recently the world’s main source of energy has been fossil fuels, such as coal and petroleum. However, these energy sources are polluting our planet, becoming scarce and increasingly inaccessible, and are costly to extract. Therefore, much attention has been directed to harvesting clean, abundant, and renewable energy, such as solar rays and wind. However, the intermittency of solar and wind power generation requires an effective energy buffering solution (aka energy storage) to become efficient and reliable. With high efficiency and energy density, rechargeable batteries and reversible fuel cells are two of the best methods for this purpose. Unfortunately, a …