Engineering Commons^™

A Study Of Reconfigurable Antennas As A Solution For Efficiency, Robustness, And Security Of Wireless Systems, Rashid Mehmood

Theses and Dissertations

The reconfigurable aperture (RECAP) is a reconfigurable antenna consisting of a dense array of electronically controlled elements, which can be manipulated to support many antenna functions within a single architecture. RECAPs are explored herein as an enabling technology for future software defined and cognitive radio architectures, as well as compact wireless devices supporting many bands and services. First, the concept of a parasitic RECAP is developed and analyzed for various communication applications. This begins with the analysis of existing RECAP topologies (e.g. planar and parasitic) using a hybrid method combining full wave simulations and network analysis. Next, a performance versus …

On The Free Surface Skipping Characteristics Of Highly Deformable Elastic Spheres, Randy C. Hurd

Theses and Dissertations

When a highly deformable elastic sphere impacts a water surface at an oblique angle it can skip several times in a manner similar to a skipping stone. However, this sphere seems to skip more readily and with more ease than a traditional skipping stone. This thesis examines the improved skipping characteristics of highly deformable elastic spheres made from cured silicone rubber. The effect of impact velocity, impact angle, sphere diamter and material shear modulus on ricochet trajectory is experimentally examined using high speed photography and image processing techniques. Experimental evaluation shows that deformation is the primary contributor to an increased …

A Systematic Review Of Technological Advancements To Enhance Learning, Elizabeth A. Cudney, Julie Ezzell

Engineering Management and Systems Engineering Faculty Research & Creative Works

Assessing student learning styles and incorporating thought-provoking activities has been a focus of research for years. Virtual technology and social media are transforming traditional classrooms into training spaces that can be tailored for individual learning patterns and personalized for different skill levels. These technological tools are not only revolutionizing the conventional lecture-based classroom but also beginning to incorporate options such as flipped and blended classrooms. Students in these nontraditional settings are given additional hands-on experience that allows them to become immersed in a variety of subjects. Flipped classrooms in particular use class time effectively by challenging students to prepare prior …

Writing Proficiency In Engineering Technology Students And Skill Development In The Classroom, Anne M. Lucietto, Nichiole Ramirez

School of Engineering Technology Faculty Publications

Little work has been done to understand the engineering technology student. The work that has been done often incorporates engineering technology students into the larger number of engineering students. This masks information that would be helpful in guiding and working with engineering technology students. While this is important, work to further understand these students, we chose to begin by exploring the writing skills of the engineering technology student, developing on other work done in this area. The work place demands the ability to convey thoughts and concepts; however the academic environment is not consistent in the development of writing proficiency. …

Validation Of A Cfd Approach For Gas Turbine Internal Cooling Passage Heat Transfer Prediction, Daniel G. Wilde

Master's Theses

This report describes the development and application of a validated Computational Fluid Dynamics (CFD) modelling approach for internal cooling passages in rotating turbomachinery. A CFD Modelling approach and accompanying assumptions are tuned and validated against academically available experimental results for various serpentine passages. Criteria of the CFD modelling approach selected for investigation into advanced internal cooling flows include accuracy, robustness, industry familiarity, and computational cost.

Experimental data from NASA HOST (HOt Section Technology), Texas A&M, and University of Manchester tests are compared to RANS CFD results generated using Fluent v14.5 in order to benchmark a CFD modelling approach.

Capability of …

Universal Programmable Battery Charger With Optional Battery Management System, Michael Duke Desando

Master's Theses

This report demonstrates improvements made in battery charging and battery management technology through the design of a universal programmable battery charger with optional battery management system attachment. This charger offers improvements in charge efficiency and unique battery charging algorithms to charge a variety of battery chemistries with variety of power requirements. Improvements in efficiency result from a synchronous Buck Controller topology as compared to previous universal chargers that use asynchronous Buck-Boost Converter topologies. This battery charger also surpasses current universal battery chargers by offering different charge modes for different battery chemistries. Charge modes provide the user an option between extending …

Fibroblast-Derived Extracellular Matrix: An Alternative Cell Culture Substrate That Alters Lung Cancer Cell Line Phenotype., Michael Thomas Scherzer

Electronic Theses and Dissertations

Poor lung cancer survival can largely be contributed to the metastatic cells that invade and spread throughout the body. The tumor microenvironment (TME) is composed of multiple cell types, as well as non-cellular components. The TME plays a critical role in the development of metastatic cancers by providing migratory cues that change the growing tumor’s properties. The Extracellular Matrix (ECM), a main component of the TME, has been shown to change composition during tumor progression, allowing cancer cells to invade tissue and survive away from the primary cancer site. Although the ECM is well-known to influence the fate of tumor …

Simulation Of Drainage Rates Of A Flexible Fiber Network On Wire Screen, Yihsin Tang

Masters Theses

A forming process of a fiber mat over a filter or wire net/screen, which can move horizontally, is numerically simulated. A lattice Boltzmann equation is used to simulate fluid velocity, vorticity and structures and a lattice spring model is employed to mimic the collective motion of up to 750 flexible fibers, with aspect ratio of 20.

The interaction between the fluid and fibers is handled by an immersed boundary method. The fiber motion is driven by the hydrodynamic forces and the gravity of both fluid and solid fibers and disturbed by the horizontal shear force between the fluid and the …

Climatic, Ecophysiological, And Phenological Controls On Plant Ecohydrological Strategies In Seasonally Dry Ecosystems, Giulia Vico, Sally E. Thompson, Stefano Manzoni, Annalisa Molini, John D. Albertson, Jarcilene S. Almeida-Cortez, Philip A. Fay, Xue Feng, Andrew J. Guswa, Hu Liu, Tiffany G. Wilson, Amilcare Porporato

Engineering: Faculty Publications

Large areas in the tropics and at mid-latitudes experience pronounced seasonality and inter-annual variability in rainfall and hence water availability. Despite the importance of these seasonally dry ecosystems (SDEs) for the global carbon cycling and in providing ecosystem services, a unifying ecohydrological framework to interpret the effects of climatic variability on SDEs is still lacking. A synthesis of existing data about plant functional adaptations in SDEs, covering some 400 species, shows that leaf phenological variations, rather than physiological traits, provide the dominant control on plant-water-carbon interactions. Motivated by this result, the combined implications of leaf phenology and climatic variability on …

Integration Of Evs And Dgs Into The Electric Power System For Grid Modernization, Mohammad Nikkhah Mojdehi

Dissertations - ALL

Electric power systems (EPSs) are rapidly becoming more complex. Penetration of distributed generators (DGs) are increasing rapidly. Among them, DG units with intermittent renewables resources, such as solar or wind, are attracting more attention. Moreover, plug in electric vehicles (EVs) are expected to be deployed in large numbers over the next decade. These changes present opportunities as well as challenges for reliable and efficient operation of EPS.

Integrating EVs in large scale, would result in over-loading of EPS. Interconnection of DGs could impact adversely on the system operation including power quality and safety of the EPS. However, due to the …

Unmanned Aircraft Systems: Air-Ground Channel Characterization For Future Applications, David W. Matolak, Ruoyu Sun

Faculty Publications

Unmanned aircraft systems (UASs) are being used increasingly worldwide. These systems will operate in conditions that differ from conventional piloted aircraft, and this implies that the airground (AG) channel for UASs can differ significantly from the traditional, simple, AG channel models. After providing some background and motivation, we describe the AG channel features and our efforts in measuring and modeling the AG channel. Some example measurement and model results-for the path loss and the Ricean K-factor-are provided to illustrate some of the interesting AG channel characteristics that are still being investigated.

Using Swat To Simulate Crop Yields And Salinity Levels In The North Fork River Basin, Usa, Aaron R. Mittelstet, Daniel E. Storm, Art L. Stoecker

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Crop yields and salinity levels in the North Fork of the Red River (North Fork River) basin, located in southwestern Oklahoma and the Texas Panhandle, were analyzed based on the diverse climate in the region. Saline irrigation water is a major problem in the basin. The Elm Fork Creek flows through salt deposits, making the creek and its receiving stream, the North Fork River, too saline to use for irrigation. This greatly reduces the number of hectares that can be utilized for agricultural crops within the basin. A baseline SWAT model was setup, calibrated and validated to simulate streamflow and …

Smaller And More Efficient Ac To Dc Converter For Laptops, Jacob Dye

Electrical Engineering

The goal of this project is to create a laptop charger that does not have a big box converter. This will be better for the user because the big box converter always gets in the way. This will be accomplished by designing a cable that has several smaller components in it. Figure 1 shows a high level block diagram of how this design could look. The cable must still be able to handle all the power requirements of a laptop charger: to convert high voltage AC to the DC charging voltage. It must also be able to vary the current …

High-Throughput Screening Using Fourier-Transform Infrared Imaging, Erdem Sasmaz, Kathleen Mingle, Jochen A. Lauterbach

Faculty Publications

Efficient parallel screening of combinatorial lib­ra ries is one of the most challenging aspects of the high­throughput (HT) heterogeneous catalysis workflow. Today, a number of methods have been used in HT catalyst studies, including various optical, mass­spectrometry, and gas­chromatography techniques. Of these, rapid­scanning Fourier­transform infrared (FTIR) imaging is one of the fastest and most versatile screening techniques. Here, the new design of the 16­channel HT reactor is presented and test results for its accuracy and reproducibility are shown. The performance of the system was evaluated through the oxidation of CO over commercial Pd/Al2O3 and cobalt oxide nanoparticles synthesized with different …

Photosynthetic Performance And Anti-Oxidative Response Of Cornus Controversa Seedlings Under Cadmium And Lead Stress, Xinyu Huang, Yonglei Jiang, Xiaomao Cheng, Lilan Deng, Xuncheng Liu

Faculty Publications

The photosynthetic efficiency of Cornus controversa leaves was decreased significantly under Cd treatment while it was not affected by Pb exposure. Cd decreased while Pb treatment increased the chlorophyll contents of Cornus controversa leaves. Furthermore, the peroxidase (GPX) activities were decreased after Cd treatment while elevated by Pb exposure in Cornus controvera seedlings. In addition, both Cd and Pb exposures increased the malondialdehyde (MDA) and proline contents and elevated the superoxide dismutase (SOD) activities of Cornus controvera seedlings. Collectively, these results indicated that Cornus controversa may be more tolerant to Pb than Cd toxicity. This finding will contribute to the …

On The Assessment Of Reliability In Probabilistic Hydrometeorological Event Forecasting, Caleb Matthew Dechant, Hamid Moradkhani

Civil and Environmental Engineering Faculty Publications and Presentations

Probabilistic forecasts are commonly used to communicate uncertainty in the occurrence of hydrometeorological events. Although probabilistic forecasting is common, conventional methods for assessing the reliability of these forecasts are approximate. Among the most common methods for assessing reliability, the decomposed Brier Score and Reliability Diagram treat an observed string of events as samples from multiple Binomial distributions, but this is an approximation of the forecast reliability, leading to unnecessary loss of information. This article suggests testing the hypothesis of reliability via the Poisson-Binomial distribution, which is a generalized solution to the Binomial distribution, providing a more accurate model of the …

Seismic Retrofit Benefit Considering Statewide Transportation Assessment, Selamawit Tesfayesus Mehary, Peter Dusicka

Civil and Environmental Engineering Faculty Publications and Presentations

The purpose of this study was to identify and demonstrate a methodology to prioritize bridges for retrofit in the State of Oregon. Given the limited resources available, retrofitting all vulnerable bridges in the foreseeable future would not be practical. Instead, a retrofit strategy needs to be developed to prioritize the inventory and enumerate the retrofit cost. In this study, a prioritization methodology used a holistic assessment of overall roadway system to consider highway route segments, rather than individual bridges. The overall assessment was based on a cost-benefit analysis including retrofit cost, expected economic loss (with or without retrofit) and social …

The Use Of Polleverywhere In Engineering Technology Classes To Student Stimulate Critical Thinking And Motivation, Otilia Popescu, Laura C. Chezan, Vukica M. Jovanovic, Orlando M. Ayala

Engineering Technology Faculty Publications

Critical thinking is considered one of the most important aspects of the learning process at the college level, especially in the field of engineering technology. However, developing critical thinking can prove to be quite challenging. It takes a lot of instructional effort and support for undergraduate students enrolled in engineering technology programs to develop the ability to analyze, adequately synthesize conceptual knowledge, and then apply that knowledge to practical problem-solving situations. This ability is a critical component of any successful completion of job responsibilities for future engineers. In this study we examine the effectiveness of the web-based polling system Polleverywhere …

Experimental Evaluate Gas Separation Using Ranuehilsch Vortex Tube, Ali Salah Omar Owiemer Omar Owiemer

Theses

Through experimental investigation, this study is offering a closer look into the performance of the vortex tube energy separation and a better understanding of the effect of the vortex tube length, diameter and internal tapering angle on the energy separation. Also the study addresses the effect of inlet pressure on the performance of the vortex tube and the effect of different working fluids (Air, H2 and O2). The vortex tube is a thermal static tube that was discovered by the French scientist George Ranque in 1933 and it is used to separate compressed gas flow into two different streams: one …

Control Strategies For Improving The Performance Of Heaving Wave Energy Converters, Mohammed Abdi Jama.

Dissertations

The main objective of this study is to develop control strategies to enhance the performance of single-body heaving wave energy converters (WECs). Maximizing the energy captured from sea waves while respecting the physical and thermal limitations of the WEC is of a paramount importance for any control strategy to be effective. In addition, it is desirable for the controller to be less vulnerable to model uncertainties and external disturbances. A complete wave-to-wire dynamic model has been derived for the heaving WEC. This includes models that describe the system hydrodynamic forces using the linear wave theory and models that describe the …

Improving Automatic Name-Face Association Using Celebrity Images On The Web, Zhineng Chen, Bailan Feng, Chong-Wah Ngo, Caiyan Jia, Xiangsheng Huang

Research Collection School Of Computing and Information Systems

This paper investigates the task of automatically associating faces appearing in images (or videos) with their names. Our novelty lies in the use of celebrity Web images to facilitate the task. Specifically, we first propose a method named Image Matching (IM), which uses the faces in images returned from name queries over an image search engine as the gallery set of the names, and a probe face is classified as one of the names, or none of them, according to their matching scores and compatibility characterized by a proposed Assigning-Thresholding (AT) pipeline. Noting IM could provide guidance for association for …

Retail Precinct Management: A Case Of Commercial Decentralization In Singapore, Robert De Souza, Hoong Chuin Lau, Mark Goh, Lindawati, Wee-Siong Ng, Puay-Siew Tan

Research Collection School Of Computing and Information Systems

The synchronized last mile logistics concept seeks to address, through coordinated collaboration, several challenges that hinder reliability, cost efficiency, effective resource planning, scheduling and utilization; and increasingly, sustainability objectives. Subsequently, the meeting of service level and contractual commitments are competitively impacted with any loss of efficiency. These challenges, against a backdrop of Singapore, can essentially be addressed in selected industry sectors through a better understanding of logistics structures; innovative supply chain designs and coordination of services, operations and processes coupled with concerted policies and supply chain strategies.

History-Based Controller Design And Optimization For Partially Observable Mdps, Akshat Kumar, Shlomo Zilberstein

Research Collection School Of Computing and Information Systems

Partially observable MDPs provide an elegant framework forsequential decision making. Finite-state controllers (FSCs) are often used to represent policies for infinite-horizon problems as they offer a compact representation, simple-to-execute plans, and adjustable tradeoff between computational complexityand policy size. We develop novel connections between optimizing FSCs for POMDPs and the dual linear programfor MDPs. Building on that, we present a dual mixed integer linear program (MIP) for optimizing FSCs. To assign well-defined meaning to FSC nodes as well as aid in policy search, we show how to associate history-based features with each FSC node. Using this representation, we address another challenging …

Evaluation Of Design Tools For The Micro-Ram Air Turbine, Victor Fidel Villa

Master's Theses

The development and evaluation of the design of a Micro-Ram Air Turbine (µRAT), a device being developed to provide power for an autonomous boundary layer measurement system, has been undertaken. The design tools consist of a rotor model and a generator model. The primary focus was on developing and evaluating the generator model for the prediction of generator brake power and output electrical power with and without rectification as a function of shaft speed and electrical load, with only basic manufacturer specifications given as inputs. A series of motored generator evaluation test were conducted at speeds ranging from 9,000 to …

Veloelectric: Creating A Device That Harvests Energy From Bicycles, Austin Hall, Daniel Stohr, Tj Fox

Mechanical Engineering

Long distance mountain bikers, bike-packers, and many bikers in developing countries rely on electrical devices for safety and communication. These specific groups of people operate in areas with little to no electricity, and often times have no power to sustain their devices. The purpose of this Cal Poly senior project, VeloElectric, was to design, build, and test a kinetic energy harvester for bicycles that can be used to charge common mobile devices via USB. This senior project team created a device that attaches directly to a bicycle and uses vibrations to generate energy, which in turn powers a variety of …

Renal Artery Stent Fatigue Test, Braden Cooper, Munir Eltal, Jennifer Hawthorne, Ashley Schaefer

Mechanical Engineering

In today’s world of medical innovation, regulations and requirements set by organizations such as the Food and Drug Administration (FDA), the International Organization for Standardization (ISO), and ASTM International (American Society for Testing and Materials) can inhibit rapid innovation by demanding rigorous testing of new designs. For arterial stents, the standard is that each design must be tested to simulate 10 years of life in an environment congruent to an in vivo environment. Endologix in Irvine, California develops and manufactures minimally invasive treatments for aortic diseases, with a focus on stent grafts for the treatment of abdominal aortic aneurysms (AAA). …

Electric Commuter Multicopter, Marley Hunter Miller, Blake Sperry, Ike Sheppard, Olliver Fredrick Kunz, Sam Juday, Alex O'Hearn, Kyle Seth Kruse, Arthur Norwood, Jarrell Washington

Mechanical Engineering

This document describes the design, analysis, and overall goals of the Electric Commuter Multicopter (ECM) Senior Project. It was presented by Bob Addis and Bill Burner to the senior mechanical engineering class of 2015 at Cal Poly, San Luis Obispo. The progress and development of the project are described in detail and to an extent that an individual or group with similar aspirations can construct their own multicopter or expand upon this one. The goal of this project is to create an Ultralight, as defined by FAA Part 103, commuter multicopter vehicle capable of transporting an individual to and from …

Ir Barcode Reader, Isaac Lambing, Justin Gronet, Tony Ly, Mark Berry

Mechanical Engineering

BrandWatch Technologies is a company based in Portland, Oregon that seek to detect counterfeit products in the supply chain. BrandWatch has created a taggant material, a physical marker, that can be printed over barcodes or added to the ink used to print the barcodes themselves. This material, while invisible to the naked eye, is detectable using technology that they have developed.

BrandWatch enlisted the help of a four man team of Cal Poly Mechanical Engineering students to combine this technology with that of a barcode scanner. The device, capable of scanning barcodes, detecting the presence of the taggant material, and …

Heart Valve Leaflet Deflection Testing Apparatus, Brandon Cunnane, Andrew Krasts, Jackson Kunz, Steven Warnert

Mechanical Engineering

The information contained in this report is confidential and proprietary information of Edwards Lifesciences.

Analysis Of Compression Creep Deformation Of 7050 Aluminum Large Scale Open Die Forgings During The Solution Heat Treatment Process, Ashley Lopez, Elysha Cole

Materials Engineering

A stress, ranging from 104.17 to 166.67 psi, was applied to 0.5 in diameter cylindrical samples of 7050 aluminum using a manufactured fixture that applies stress using an indenter with a diameter of 0.127 in. The stress range used replicates the stresses produced on large scale forgings weighing up to 4000 lbs. We chose a maximum, medium and low stress as our stress parameters. The samples were placed into the fixture for stability then placed in a furnace heated to 890°F which is the solution heat treatment temperature for 7050 aluminum. The heat treatment times varied between 4 and 24 …