Engineering Commons^™

Ict Competencies In Eight Mayan-Speaking Communities Of Mexico: Preliminary Findings, J. Gabriel D. Domínguez Castillo, Alexander N. Chen, Mark E. Mcmurtrey Ph.D., Edith J. Cisneros Cohernour, Marianne Gabriel

Journal of International Technology and Information Management

The skills related to the use of information and communication technologies (ICT) were examined in this study within the context of eight communities with a high degree of vulnerability and diversity. The objectives of the study were: a) to conduct a diagnosis of thirteen competencies related to the use of ICT in eight Mayan-speaking communities in the state of Yucatan, Mexico, and b) to examine such variables as gender, marital status, and the education level of their parents. in relation to the degree of ICT among these youth.

The findings indicate that there are differences in the use of technology …

Evaluation Of Selected Watershed Characteristics To Identify Best Management Practices To Reduce Nebraskan Nitrate Loads From Nebraska To The Mississippi/Atchafalaya River Basin, Aaron R. Mittelstet, Troy E. Gilmore, Tiffany Messer, Daran Rudnick, Thomas Heatherly

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Nebraskan streams contribute excess nitrogen to the Mississippi/Atchafalaya River Basin and Gulf of Mexico, which results in major water-quality impairments. Reducing the amount of nitrogen (N) exported in these streams requires the use of best management practices (BMPs) within the landscape. However, proper BMP utilization has rarely been statistically connected to potential controls of N export within watersheds, particularly precipitation and soil characteristics. In this study, 19 watershed variables were evaluated in five categories (hydrological, physiographic, point sources, land use, and soil properties) to determine the characteristics that influenced variable nitrate nitrogen (NO₃-N) concentrations in 17 Nebraska watersheds …

Advanced Selection Methodologies For Dnazymes In Sensing And Healthcare Applications, Sandeep Kumar, Shikha Jain, Neeraj Dilbaghi, Amrik Singh Ahluwalia, Ashraf Aly Hassan, Ki-Hyun Kim

Department of Civil and Environmental Engineering: Faculty Publications

DNAzymes have been widely explored owing to their excellent catalytic activity in a broad range of applications, notably in sensing and biomedical devices. These newly discovered applications have built high hopes for designing novel catalytic DNAzymes. However, the selection of efficient DNAzymes is a challenging process but one that is of crucial importance. Initially, systemic evolution of ligands by exponential enrichment (SELEX) was a labor-intensive and time-consuming process, but recent advances have accelerated the automated generation of DNAzyme molecules. This review summarizes recent advances in SELEX that improve the affinity and specificity of DNAzymes. The thriving generation of new DNAzymes …

Interactions Between Dislocations And Three-Dimensional Annealing Twins In Face Centered Cubic Metals, Yanxiang Liang, Xiaofang Yang, Mingyu Gong, Guisen Liu, Qing Liu, Jian Wang

Department of Mechanical and Materials Engineering: Faculty Publications

Annealing twins often form in metals with a face centered cubic structure during thermal and mechanical processing. Here, we conducted molecular dynamic (MD) simulations for copper and aluminum to study the interaction processes between {1 1 1}1/2 <1 1 0> dislocations and a three-dimensional annealing twin. Twin boundaries are characterized with Σ3{1 1 1} coherent twin boundaries (CTBs) and Σ3{1 1 2} incoherent twin boundaries (ITBs). MD results revealed that dislocation-ITB interactions affect slip transmission for a dislocation crossing CTBs, facilitating the nucleation of Lomer dislocation.

Corrosion Initiation And Propagation On Carburized Martensitic Stainless Steel Surfaces Studied Via Advanced Scanning Probe Microscopy, Armen Kvryan, Corey M. Efaw, Kari A. Higginbotham, Olivia O. Maryon, Paul H. Davis, Elton Graugnard, Michael F. Hurley

Materials Science and Engineering Faculty Publications and Presentations

Historically, high carbon steels have been used in mechanical applications because their high surface hardness contributes to excellent wear performance. However, in aggressive environments, current bearing steels exhibit insufficient corrosion resistance. Martensitic stainless steels are attractive for bearing applications due to their high corrosion resistance and ability to be surface hardened via carburizing heat treatments. Here three different carburizing heat treatments were applied to UNS S42670: a high-temperature temper (HTT), a low-temperature temper (LTT), and carbo-nitriding (CN). Magnetic force microscopy showed differences in magnetic domains between the matrix and carbides, while scanning Kelvin probe force microscopy (SKPFM) revealed a 90–200 …

An Efficient Low Voltage Dc Microgrid With Power Array Conversion For Commercial Buildings, Zhiqing Wu

Theses and Dissertations

PV solar energy is becoming increasingly more prevalent in electricity generation for residential and commercial buildings. Since PV solar directly supplies DC power, a DC microgrid is an ideal platform for PV energy resource in building applications. Existing DC power converters typically have low power conversion efficiency at light and heavy load conditions. Much research has been done on efficiency improvement of DC converters, but material, technology, and manufacturing processes all impose limitations on efficiency gain. This paper addresses the efficiency improvement of a DC microgrid with a power array conversion (PAC) for a commercial building application. The PAC configuration …

Numerical Study On Seakeeping Performance Of Hydrofoil Assisted Submersible Trimaran (Hast), Yuchen Lin

Theses and Dissertations

The present study focuses on the seakeeping characteristics of Hydrofoil Assisted Submersible Trimaran (HAST). The seakeeping performance is an important part in ship design because it effects the comfort, control, resistance and safety. The motions in wave will reduce the performance of ship which is designed and optimized in calm water. The heave and pitch motions of HAST in calm water and regular waves have been investigated by STAR CCM+, a CFD analysis program. The theory of numerical simulation based on STAR CCM+ has been presented. The basic theory of seakeeping performance studies has been discussed. A series of simulations …

Ict: In-Field Calibration Transfer For Air Quality Sensor Deployments, Yun Cheng, Xiaoxi He, Zimu Zhou, Lothar Thiele

Research Collection School Of Computing and Information Systems

Recent years have witnessed a growing interest in urban air pollution monitoring, where hundreds of low-cost air quality sensors are deployed city-wide. To guarantee data accuracy and consistency, these sensors need periodic calibration after deployment. Since access to ground truth references is often limited in large-scale deployments, it is difficult to conduct city-wide post-deployment sensor calibration. In this work we propose In-field Calibration Transfer (ICT), a calibration scheme that transfers the calibration parameters of source sensors (with access to references) to target sensors (without access to references). On observing that (i) the distributions of ground truth in both source and …

Changes In Snow Phenology From 1979 To 2016 Over The Tianshan Mountains, Central Asia, Tao Yang, Qian Li, Sajjad Ahmad, Hongfei Zhou, Lanhai Li

Civil and Environmental Engineering and Construction Faculty Research

Snowmelt from the Tianshan Mountains (TS) is a major contributor to the water resources of the Central Asian region. Thus, changes in snow phenology over the TS have significant implications for regional water supplies and ecosystem services. However, the characteristics of changes in snow phenology and their influences on the climate are poorly understood throughout the entire TS due to the lack of in situ observations, limitations of optical remote sensing due to clouds, and decentralized political landscapes. Using passive microwave remote sensing snow data from 1979 to 2016 across the TS, this study investigates the spatiotemporal variations of snow …

Timeline2gui: A Log2timeline Csv Parser And Training Scenarios, Mark Debinski, Parvathy Mohan, Frank Breitinger

Electrical & Computer Engineering and Computer Science Faculty Publications

Crimes involving digital evidence are getting more complex due to the increasing storage capacities and utilization of devices. Event reconstruction (i.e., understanding the timeline) is an essential step for investigators to understand a case where a prominent tool is Log2Timeline (a tool that creates super timelines which is a combination of several log files and events throughout a system). While these timelines provide great evidence and help to understand a case, they are complex and require tools as well as training scenarios. In this paper we present Timeline2GUI an easy-to-use python implementation to analyze CSV log files create by Log2Timeline. …

Inactivation Of The Bacterial Pathogens Staphylococcus Pseudintermedius And Acinetobacter Baumannii By Butanoic Acid, G. M. Kennedy, M. Y. Min, J. F. Fitzgerald, M. T. Nguyen, S. L. Schultz, M. T. Crum, Jeffrey A. Starke, M. A. Butkus, D. D. Bowman, M. P. Labare

Civil and Environmental Engineering Faculty Research and Publications

Aims

This study was performed to evaluate the efficacy of butanoic acid against bacterial pathogens including Acinetobacter baumannii and Staphylococcus pseudintermedius.

Methods and Results

Vegetative bacteria were exposed to butanoic acid in vitro and log reduction was quantified using viable count assays. The maximum (8 and 9) log inactivation was determined by qualitatively assaying for growth/no-growth after a 48-h incubation (37°C). Membrane integrity after exposure to butanoic acid was determined by propidium iodide staining, scanning electron microscopy, membrane depolarization and inductively coupled plasma analysis. Cytosolic pH was measured by 5-(6-)carboxyfluorescein succinimidyl ester.

Conclusions

Inhibitory concentrations of butanoic acid ranged …

A Fire Protection Life Safety Analysis Of Permian Oil Plaza, Nick Francis

Fire Protection Engineering: Culminating Experience Project Reports

The Permian Oil Plaza (POP) is a four story building located in Midland, TX. This facility was designed to provide over 200,000 square feet of office space to approximately 500 employees. The building was constructed of unprotected non-combustible (Type II-B) building materials and was completed in late 2015. An assessment of the building’s fire and life safety systems was performed to ensure these systems were designed and installed in a manner that meets, or exceeds, the intent of pertinent building codes and fire safety standards. This assessment included a prescriptive based analysis, as well as a performance-based analysis. The prescriptive …

Torsional Stiffness Of A Race Car, Reiley A. Schraeger, Cameron Kao, Raymond Deng, Omar Roman

Mechanical Engineering

Torsional stiffness plays a major role in any road vehicle. To understand torsional stiffness of a vehicle and make future iterations and improvements, a proper torsional stiffness jig is required to prove accurate and useful data. This report encompasses the new and improved testing jig and potential improvement ideas for more accurate results. With real data result relating to FEA calculations, designers can be confident in the FEA changes to torsional stiffness is accurate and will yield the probably results they desired. This report shows the methodology, manufacturing process and testing procedure to use on any Baja or SAE vehicle …

Cal Poly Supermileage Electric Vehicle Drivetrain And Motor Control Design, Clarisa Joy Howe, Christopher Joseph Mclaughlin, Erik Alvarado, Enyi Liang

Mechanical Engineering

The Cal Poly Supermileage Vehicle team is a multidisciplinary club that designs and builds high efficiency vehicles to compete internationally at Shell Eco-Marathon (SEM). Cal Poly Supermileage Club has been competing in the internal combustion engine (ICE) category of the competition since 2007. The club has decided it is time to expand their competition goals and enter their first battery electric prototype vehicle. To this end, a yearlong senior design project was presented to this team of engineers giving us the opportunity to design an electric powertrain with a custom motor controller. This system has been integrated into Ventus, the …

5th/6th Graders And Preservice Teachers Explore Engineering And Coding In A Combined After-School Technology Club/Educational Technology Course, Jennifer Kidd, Sam Sacks, Krishnanand Kaipa, Kelly Rippard

Teaching & Learning Faculty Publications

Elementary schools are increasingly encouraged to adopt STEM education efforts that include engineering and programming, yet pre-service teachers (PSTs) are not traditionally prepared to teach these subjects. This pilot study describes an innovative preparation experience designed to help PSTs gain experience and confidence in these areas. As part of an undergraduate educational technology course, PSTs led an after-school technology club at a local public school. PSTs enrolled in the course worked alongside fifth and sixth grade students on a series of collaborative design challenges that culminated in the creation of animal-inspired robots. The “WoW Club”, as it came to be …

Nuclear Data Covariance Analysis Of An Energy Tuning Assembly For Simulating Nuclear Weapon Environments, Nicholas J. Quartemont

Theses and Dissertations

An energy tuning assembly was characterized to spectrally shape the National Ignition Facility neutron source to a notional thermonuclear and prompt fission neutron spectrum to approximate a boosted nuclear device. This research performed nuclear data covariance analysis to predict the performance of the energy tuning assembly to create the objective spectrum, assessed anticipated experimental outcomes, and determine the fission products produced in a highly enriched uranium foil in the sample cavity. Nuclear data covariance impacted the neutron fluence energy distribution by a few percent for a large energy range of the neutron fluence. Neutron flux unfolding techniques provided broad spectral …

Application Of Metamaterials For Multifunctional Satellite Bus Enabled Via Additive Manufacturing, Michael A. Macchia

Theses and Dissertations

Space systems require materials with superior stiffness to weight ratios to provide structural integrity while minimizing mass. Additive manufacturing processes enable the design of metamaterials that exceed the performance of naturally occurring materials in addition to allowing the integration of non-structural functions. This research explored the use of a high stiffness, high density, small melt pool track width AM material, Inconel 718, to enable the production of metamaterials with finer features possible than can possibly be created using a lower density aluminum alloy material. Various metamaterials were designed utilizing thin wall triply periodic minimal surface infilled sandwich structures. The performance …

A Focal Plane Array And Electronics Model For Cmos And Ccd Sensors In The Afit Sensor And Scene Emulation Tool (Asset), Fernando D. Fernandez

Theses and Dissertations

Electro-optical and infrared (EO/IR) sensor models are useful tools that can facilitate understanding a system's behavior without expensive and time-consuming testing of an actual system. EO/IR models are especially important to the military industry where truth data is required but is sometimes impractical to obtain through experimentation due to expense or difficulties in procuring hardware. This work describes implementation of a focal plane array (FPA) model of charge-coupled device (CCD) and complementary metal-oxide semiconductor (CMOS) photodetectors as a component in the Air Force Institute of Technology (AFIT) Sensor and Scene Emulation Tool (ASSET). The FPA model covers conversion of photo-generated …

Optical And Electron Paramagnetic Resonance Characterization Of Point Defects In Semiconductors, Elizabeth M. Scherrer

Theses and Dissertations

Point defects in two semiconductor materials, both with promising optical properties, are investigated. The first material, CdSiP₂, is a nonlinear optical material in which absorption bands due to point defects can hinder performance when used in frequency conversion applications in the infrared. The second material, Sn₂P₂S₆, is a photorefractive material where point defects with specific properties are needed to optimize response in dynamic holography applications. Electron paramagnetic resonance (EPR) spectroscopy is used to identify the electronic structure of defects and their charge states. Correlations between EPR spectra and optical absorption allow assignments …

Computational And Experimental Development Of 2d Anisotropic Photonic Crystal Metamaterials, James A. Ethridge

Theses and Dissertations

The future of optical devices involves manipulation of nanoscale structure in order to achieve full control over the properties of the device. In fields as diverse as directed energy, remote sensing, optical communications and optical computing, these devices promise to greatly improve performance and efficiency. To advance this further, novel samples that incorporate both photonic crystal (PhC) structure and metamaterial properties, known as PhC metamaterials, are proposed. These PhC metamaterials allow for complete control over the directionality of the light-matter interaction to serve in these new applications. To develop this technology, first, metamaterials with no PhC structure are fabricated using …

Effects Of Steel Type And Sandblasting Pretreatment On The Solid-Liquid Compound Casting Characteristics Of Zinc-Coated Steel/Aluminum Bimetals, Jesik Shin, Taehyeong Kim, Kyoungmook Lim, Hoon Cho, Daeho Yang, Changyeol Jeong, Sung Yi

Mechanical and Materials Engineering Faculty Publications and Presentations

Effects of zinc-coated steel type and steel surface sandblasting pretreatment in the solid-liquid compound casting of layered type steel/aluminum bimetals were investigated. The Zn coating behavior and its effects on interfacial microstructure evolution and fracture mechanism were also discussed. The aluminum fluidity in thin plate type flow channels formed by the steel insert and the mold wall primarily depended on the insert surface roughness and secondarily on the wettability. As-galvanized (GI) steel/aluminum bimetal joints showed the bonding strength of 20 MPa and more, while galvannealed (GA) steels showed poor bonding. The interfacial bonding zone consisted of most Al13Fe4, Al8Fe2Si, Al4.5FeSi …

To Burn-In, Or Not To Burn-In: That’S The Question, Ephraim Suhir

Mechanical and Materials Engineering Faculty Publications and Presentations

In this paper it is shown that the bathtub-curve (BTC) based time-derivative of the failure rate at the initial moment of time can be considered as a suitable criterion of whether burn-in testing (BIT) should or does not have to be conducted. It is also shown that the above criterion is, in effect, the variance of the random statistical failure rate (SFR) of the mass-produced components that the product manufacturer received from numerous vendors, whose commitments to reliability were unknown, and their random SFR might vary therefore in a very wide range, from zero to infinity. A formula for the …

Analysis Of The Forming Characteristics For Cu/Al Bimetal Tubes Produced By The Spinning Process, Kai Jin, Qiwei Yuan, Jie Tao, Joseph P. Domblesky, Xunzhong Guo

Mechanical Engineering Faculty Research and Publications

Tube spinning technology represents a process with high forming precision and good flexibility and is increasingly being used in the manufacture of bimetal composite tubular structures. In the present study, a forming analysis of clad tube and base tube in spinning process was conducted through numerical simulations and experiments. There was an equivalent stress transition on the interface since the stress transmission was retarded from clad tube to base tube. The yield strength became a main consideration during a design bimetal composite tube. Meanwhile, the strain distributions in axial direction, tangential direction, and radial direction were also investigated to determine …

Study Of Various Construction Job Functions To Address Workforce Challenge, Abraham Bonilla, Dhaval Gajjar, Kenneth Sullivan

The Professional Constructor

Lack of construction workforce is one of the most predominant challenges faced by the construction industry. It is predicted that the industry will have a major shortage of skilled labor in the next decade due to the retirement of baby boomers and the lack of new talent entering the industry to replace these baby boomers. To attract young talent into the construction industry, it is critical to make them aware about the industry regarding various job functions as it relates to job satisfaction, compensation and career fulfilment. The purpose of this study is to gain insight of various construction job …

Consumer Perception And Willingness To Pay For Extended New Home Warranties, C. Todd Usher, Joseph M. Burgett

The Professional Constructor

Construction standards and methods for building new homes has improved over the last two decades resulting in significant improvements in energy efficiency, comfort, indoor air quality, and durability of new homes. Despite these improvements, the most common builder warranty for a new home in the United States ranges from 6 months to two years in duration. During the past two decades, manufacturer warranties on other durable goods such as automobiles has increased significantly. This study measures consumer perceptions of extended 12 year new home warranties with a survey completed by 162 adults in the United States. The results indicate that …

Towards Ai Welfare Science And Policies, Soenke Ziesche, Roman Yampolskiy

Faculty and Staff Scholarship

In light of fast progress in the field of AI there is an urgent demand for AI policies. Bostrom et al. provide “a set of policy desiderata”, out of which this article attempts to contribute to the “interests of digital minds”. The focus is on two interests of potentially sentient digital minds: to avoid suffering and to have the freedom of choice about their deletion. Various challenges are considered, including the vast range of potential features of digital minds, the difficulties in assessing the interests and wellbeing of sentient digital minds, and the skepticism that such research may encounter. Prolegomena …

Experimental Study And Modeling Of The Gm-I Dependence Of Long-Channel Mosfets, Michael Fong Cheng

Master's Theses

This thesis describes an experimental study and modeling of the current-transconductance dependence of the ALD1106, ALD1107, and CD4007 arrays. The study tests the hypothesis that the I-gm dependence of these 7.8 µm to 10 µm MOSFETs conforms to the Advanced Compact Model (ACM). Results from performed measurements, however, do not support this expectation. Despite the relatively large length, both ALD1106 and ALD1107 show sufficiently pronounced ‘short-channel’ effects to render the ACM inadequate. As a byproduct of this effort, we confirmed the modified ACM equation. With an m factor of approximately 0.6, it captures the I-gm dependence with sub-28% maximum error …

Perturbation Based Decomposition Of Semg Signals, Rachel Huettinger

Master's Theses

Surface electromyography records the motor unit action potential signals in the vicinity of the electrode to reveal information on muscle activation. Decomposition of sEMG signals for characterization of constituent motor unit action potentials in terms of amplitude and firing times is useful for clinical research as well as diagnosis of neurological disorders. Successful decomposition of sEMG signals would allow for pertinent motor unit action potential information to be acquired without discomfort to the subject or the need for a well-trained operator (compared with intramuscular EMG). To determine amplitudes and firing times for motor unit action potentials in an sEMG recording, …

Experimental Optical Pulse Picker For Lawrence Livermore National Lab, Alexander Thomas Wargo

Master's Theses

Proprietary.

Development Of A Myoelectric Detection Circuit Platform For Computer Interface Applications, Nickolas Andrew Butler

Master's Theses

Personal computers and portable electronics continue to rapidly advance and integrate into our lives as tools that facilitate efficient communication and interaction with the outside world. Now with a multitude of different devices available, personal computers are accessible to a wider audience than ever before. To continue to expand and reach new users, novel user interface technologies have been developed, such as touch input and gyroscopic motion, in which enhanced control fidelity can be achieved. For users with limited-to-no use of their hands, or for those who seek additional means to intuitively use and command a computer, novel sensory systems …