Engineering Commons^™

Anomalous Stranski-Krastanov Growth Of (111)-Oriented Quantum Dots With Tunable Wetting Layer Thickness, Christopher F. Schuck, Simon K. Roy, Trent Garrett, Paul J. Simmonds

Materials Science and Engineering Faculty Publications and Presentations

Driven by tensile strain, GaAs quantum dots (QDs) self-assemble on In_0.52Al_0.48As(111)A surfaces lattice-matched to InP substrates. In this study, we show that the tensile-strained self-assembly process for these GaAs(111)A QDs unexpectedly deviates from the well-known Stranski-Krastanov (SK) growth mode. Traditionally, QDs formed via the SK growth mode form on top of a flat wetting layer (WL) whose thickness is fixed. The inability to tune WL thickness has inhibited researchers’ attempts to fully control QD-WL interactions in these hybrid 0D-2D quantum systems. In contrast, using microscopy, spectroscopy, and computational modeling, we demonstrate that for GaAs(111)A QDs, we …

Normalization Of Unconstrained Handwritten Words In Terms Of Slope And Slant Correction, Suman Kumar Bera, Akash Chakrabarti, Sagnik Lahiri, Elisa H. Barney Smith, Ram Sarkar

Electrical and Computer Engineering Faculty Publications and Presentations

In offline handwritten text slope (or skew) and slant are inevitably introduced, but to varying degrees depending on several factors, such as the writing style, speed and mood of the writers. Therefore slope and slant detection in offline handwritten text and their subsequent correction have become the critical preprocessing steps for document analysis and retrieval systems to neutralize the variability of writing styles and to improve the performance of word and character recognition systems. In this paper, we present new methods that use two novel core-region detection techniques to estimate both the slope and slant angles of offline handwritten word …

Machine Learning Predictions Electronic Couplings For Charge Transport Calculations Of P3ht, Evan D. Miller, Matthew L. Jones, Mike M. Henry, Bryan Stanfill, Eric Jankowski

Materials Science and Engineering Faculty Publications and Presentations

The purpose of this work is to lower the computational cost of predicting charge mobilities in organic semiconductors, which will benefit the screening of candidates for inexpensive solar power generation. We characterize efforts to minimize the number of expensive quantum chemical calculations we perform by training machines to predict electronic couplings between monomers of poly-(3-hexylthiophene). We test five machine learning techniques and identify random forests as the most accurate, information-dense, and easy-to-implement approach for this problem, achieving mean-absolute-error of 0.02 [× 1.6 × 10⁻¹⁹ J], R² = 0.986, predicting electronic couplings 390 times faster than quantum chemical calculations, …

Secure Two-Party Protocol For Privacy-Preserving Classification Via Differential Privacy, Manish Kumar

Boise State University Theses and Dissertations

Privacy-preserving distributed data mining is the study of mining on distributed data—owned by multiple data owners—in a non-secure environment, where the mining protocol does not reveal any sensitive information to the data owners, the individual privacy is preserved, and the output mining model is practically useful. In this thesis, we propose a secure two-party protocol for building a privacy-preserving decision tree classifier over distributed data using differential privacy. We utilize secure multiparty computation to ensure that the protocol is privacy-preserving. Our algorithm also utilizes parallel and sequential compositions, and applies distributed exponential mechanism to ensure that the output is differentially-private. …

In Silico Sequence Optimization For The Reproducible Generation Of Dna Structures, Michael D. Tobiason

Boise State University Theses and Dissertations

Biologically, deoxyribonucleic acid (DNA) molecules have been used for information storage for more than 3 billion years. Today, modern synthesis tools have made it possible to use synthetic DNA molecules as a material for engineering nanoscale structures. These self-assembling structures are capable of both resolutions as fine as 4 angstroms and executing programed dynamic behavior. Numerous approaches for creating structures from DNA have been proposed and validated, however it remains commonplace for engineered systems to exhibit unexpected behaviors such as low formation yields, poor performance, or total failure. It is plausible that at least some of these behaviors arise due …

Nanoscale Optical And Correlative Microscopies For Quantitative Characterization Of Dna Nanostructures, Christopher Michael Green

Boise State University Theses and Dissertations

Methods to engineer nanomaterials and devices with uniquely tailored properties are highly sought after in fields such as manufacturing, medicine, energy, and the environment. The macromolecule deoxyribonucleic acid (DNA) enables programmable self-assembly of nanostructures with near arbitrary shape and size and with unprecedented precision and accuracy. Additionally, DNA can be chemically modified to attach molecules and nanoparticles, providing a means to organize active materials into devices with unique or enhanced properties. One particularly powerful form of DNA-based self-assembly, DNA origami, provides robust structures with the potential for nanometer-scale resolution of addressable sites. DNA origami are assembled from one large DNA …

Characterization Of Zirconium Oxides Part I: Raman Mapping And Spectral Feature Analysis, Corey M. Efaw, Jordan L. Vandegrift, Michael Reynolds, Samuel Mcmurdie, Brian J. Jaques, Hui Xiong, Michael F. Hurley

Materials Science and Engineering Faculty Publications and Presentations

Raman mapping of sectioned zirconium cladding oxides was performed to analyze different spectral features before and after breakaway, as well as between zirconium and its alloys Zr-2.65Nb, Zry-3, and Zry-4. Oxide phase composition, or percent tetragonality, was defined to compare tetragonal to monoclinic zirconia. Percent tetragonality was spatially mapped to support distinction of zirconia phase distribution. A tetragonal-rich layer was seen at the metal/oxide interface, while post-breakaway samples exhibited increased amount of tetragonal phase in the bulk of their oxides. Spatial mapping of spectral peak location and half-width at half-maximum was accomplished to distinguish differences in stability mechanisms of tetragonal-rich …

Controlling Strain Energy Density In 3d Cellular Collagen Constructs During Complex Loads, Katherine Hollar

Boise State University Theses and Dissertations

Mechanical stimulation applied to damaged soft tissues, such as ligament, can promote tissue remodeling to accelerate healing. To help identify treatments that encourage ligament healing, bioreactors have been designed to subject 3D cellularized constructs to various loading conditions in order to determine the mechanical mechanisms that trigger cell-mediated repair. An innovative approach is to use a bioreactor to apply controlled states of biaxial stress to study the effects of strain energy density and distortion energy on cell activity. Tissue distortion has been linked to changes in the structure and function of ligament, yet the specific impact of distortion energy on …

Improved Study Of Side-Channel Attacks Using Recurrent Neural Networks, Muhammad Abu Naser Rony Chowdhury

Boise State University Theses and Dissertations

Differential power analysis attacks are special kinds of side-channel attacks where power traces are considered as the side-channel information to launch the attack. These attacks are threatening and significant security issues for modern cryptographic devices such as smart cards, and Point of Sale (POS) machine; because after careful analysis of the power traces, the attacker can break any secured encryption algorithm and can steal sensitive information.

In our work, we study differential power analysis attack using two popular neural networks: Recurrent Neural Network (RNN) and Convolutional Neural Network (CNN). Our work seeks to answer three research questions(RQs):

RQ1: Is it …

Effects Of Magnetic Domain And Twin Boundary Interactions On Magneto-Mechanical Properties Of Magnetic Shape Memory Alloys, Medha Veligatla

Boise State University Theses and Dissertations

Magnetic shape memory (MSM) alloys deform substantially when exposed to a magnetic field. This recoverable plastic deformation occurs through crystallographic twinning. Thereby the internal magnetic domain structure modulates the deformation mechanisms through the interaction of magnetic domains with twin boundaries. We study the meso scale magneto-structural interactions that affect the macroscopic material properties of MSM alloys. The study at the meso length scale is most effective as it allows for resolving interactions at magnetic domain wall width resolution with reasonable computing cost. We apply micromagnetics simulations to evaluate the evolution of magnetic domains, their interaction with twin boundaries, the distribution …

Effect Of Corrective Surgery On Lower Limb Mechanics In Patients With Crouch Gait, Adelle Milholland

Boise State University Theses and Dissertations

Crouch gait a progressively degrading gait deviation associated with the neurological disorder cerebral palsy. If left untreated it can lead to anterior knee pain and a loss of ambulation. At present there exists no agreed upon metric for determining the surgical procedures used to treat crouch gait and there is insufficient means to analytically compare the results of different procedures. The aims of this thesis work were to create a pipeline to transform a patient’s gait analysis data into a finite element model, develop a model of sufficient complexity to evaluate a range of outcomes by which to judge the …

Isolated Nucleus Stiffens In Response To Low Intensity Vibration, Joshua Newberg

Boise State University Theses and Dissertations

The nucleus, central to all cellular activity, relies on both direct mechanical input and its molecular transducers to sense and respond to external mechanical stimuli. This response occurs by regulating intra-nuclear organization that ultimately determines gene expression to control cell function and fate. It has long been known that signals propagate from an extracellular environment to the cytoskeleton and into nucleus (outside-in signaling) to regulate cell behavior. Emerging evidence, however, shows that both the cytoskeleton and the nucleus have inherent abilities to sense and adapt to mechanical force, independent of each other. While it has been shown that isolated nuclei …

Demand-Side Load Management Using Single-Phase Residential Static Var Compensators, Muhammad Kamran Latif

Boise State University Theses and Dissertations

Distribution systems are going through a structural transformation from being radially-operated simple systems to becoming more complex networks to operate in the presence of the distributed energy resources (DERs) with significant levels of penetration. It is predicted that the share of electricity generation from DERs will keep increasing as the world is moving away from the power generation involving carbon-emission and towards cleaner energy sources such as solar, wind, and biofuels. However, the unstable behavior of the renewables resources presents challenges to the already existing distribution systems. One such problem is when the distribution feeder experience variable power supply due …

Oxidation Behavior Of Welded Zry-3, Zry-4, And Zr–1nb Tubes, Jordan Vandegrift, Clemente J. Parga, Ben Coryell, Darryl P. Butt, Brian J. Jaques

Materials Science and Engineering Faculty Publications and Presentations

The Transient Reactor Test (TREAT) facility is a research reactor designed to simulate rapid transients to test new fuel designs. TREAT's cladding is exposed to unique conditions compared to normal water reactors. These conditions include: exposure to air at high temperatures (≥600 °C), rapid heating (≈700 °^C/_s), and cladding geometry that includes chamfers and welds. This work investigates the effects of chamfering and welding on the oxidation behavior of zirconium alloys (Zircaloy-3, Zircaloy-4, and Zr–1Nb). Tube specimens were examined under isothermal and transient conditions in dry and humid air. The effect of weld type (tungsten inert …

Inas(111)A Homoepitaxy With Molecular Beam Epitaxy, Kevin D. Vallejo, Trent A. Garrett, Kathryn E. Sautter, Kevin Saythavy, Baolai Liang, Paul J. Simmonds

Materials Science and Engineering Faculty Publications and Presentations

The authors have established a robust set of growth conditions for homoepitaxy of high-quality InAs with a (111)A crystallographic orientation by molecular beam epitaxy (MBE). By tuning the substrate temperature, the authors obtain a transition from a 2D island growth mode to step-flow growth. Optimized MBE parameters (substrate temperature = 500 °C, growth rate = 0.12ML/s, and V/III ratio ≥ 40) lead to the growth of extremely smooth InAs(111)A films, free from hillocks and other 3D surface imperfections. The authors see a correlation between InAs surface smoothness and optical quality, as measured by photoluminescence spectroscopy. This work establishes InAs(111)A as …

A Parametric Study For In-Pile Use Of The Thermal Conductivity Needle Probe Using A Transient, Multilayered Analytical Model, Courtney Hollar, Austin Fleming, Kurt Davis, Ralph Budwig, Colby Jensen, David Estrada

Materials Science and Engineering Faculty Publications and Presentations

By utilizing an in-pile measurement, thermal conductivity can be determined under prototypic conditions over a range of burnup. In this work we develop a multilayer quadrupoles analytical model to describe the transient thermal interactions between a line heat source (i.e. needle probe) and cylindrical nuclear fuel geometry for inpile thermal conductivity measurements. A finite element analysis of the detailed needle probe geometry was compared to results from the analytical model to verify the assumptions made in the analytical model. Experimentally, the needle probe was used to measure the thermal properties of polytetrafluoroethylene (PTFE) and stainless steel 304 with three different …

Kinetics Of Silver Photodiffusion Into Amorphous S-Rich Germanium Sulphide – Neutron And Optical Reflectivity, Yoshifumi Sakaguchi, Hidehito Asaoka, Maria Mitkova

Electrical and Computer Engineering Faculty Publications and Presentations

Silver photodiffusion is one of the attractive photo-induced changes observed in amorphous chalcogenides. In this research, we focus on amorphous S-rich germanium sulphide and study the kinetics of the silver photodiffusion by neutron reflectivity, as well as optical reflectivity. It was found from the neutron reflectivity profiles with 30 s time resolution that silver dissolved into the germanium sulphide layer, forming a metastable reaction layer between the Ag and the germanium sulphide layers, within 2 min of light exposure. Subsequently, silver slowly diffused from the metastable reaction layer to the germanium sulphide host layer until the Ag concentration in both …

Utilizing A Single Silica Nanospring As An Insulating Support To Characterize The Electrical Transport And Morphology Of Nanocrystalline Graphite, David Estrada, Paul H. Davis, Twinkle Pandhi

Materials Science and Engineering Faculty Publications and Presentations

A graphitic carbon, referred to as graphite from the University of Idaho thermolyzed asphalt reaction (GUITAR), was coated in silica nanosprings and silicon substrates via the pyrolysis of commercial roofing tar at 800 °C in an inert atmosphere. Scanning electron microscopy and transmission electron microscopy images indicate that GUITAR is an agglomeration of carbon nanospheres formed by the accretion of graphitic flakes into a ~100 nm layer. Raman spectroscopic analyses, in conjunction with scanning electron microscopy and transmission electron microscopy, indicate that GUITAR has a nanocrystalline structure consisting of ~1–5 nm graphitic flakes interconnected by amorphous sp³ bonded carbon. …

A Simple Method To Characterize High Rate Twin Boundary Kinetics In Ni-Mn-Ga, Bibek Karki, Peter Müllner

Materials Science and Engineering Faculty Publications and Presentations

Experimental characterization of twin boundary kinetics is essential to systematically test and reproduce the actuation properties of Magnetic Shape Memory (MSM) elements at high rates. Here, we present a simple, nondestructive, experimental method to quantify the dynamic response of an MSM crystal and extract the major material properties that govern its kinetics. The tested sample is subjected to a mechanical pulse that is produced by a simple off-the-shelf solenoid. The mechanical pulse leads to actuation of the tested MSM Ni–Mn–Ga single crystal within 10 ms, during which the twin boundary velocity varies between zero and 2 m/s. The displacement and …

Heat Wave Intensity Duration Frequency Curve: A Multivariate Approach For Hazard And Attribution Analysis, Omid Mazdiyasni, Mojtaba Sadegh, Felicia Chiang, Amir Aghakouchak

Civil Engineering Faculty Publications and Presentations

Atmospheric warming is projected to intensify heat wave events, as quantified by multiple descriptors, including intensity, duration, and frequency. While most studies investigate one feature at a time, heat wave characteristics are often interdependent and ignoring the relationships between them can lead to substantial biases in frequency (hazard) analyses. We propose a multivariate approach to construct heat wave intensity, duration, frequency (HIDF) curves, which enables the concurrent analysis of all heat wave properties. Here we show how HIDF curves can be used in various locations to quantitatively describe the likelihood of heat waves with different intensities and durations. We then …

Comparison Of The Electrical Response Of Cu And Ag Ion-Conducting Sdc Memristors Over The Temperature Range 6 K To 300 K, Kolton Drake, Tonglin Lu, Md. Kamrul H. Majumdar, Kristy A. Campbell

Electrical and Computer Engineering Faculty Publications and Presentations

Electrical performance of self-directed channel (SDC) ion-conducting memristors which use Ag and Cu as the mobile ion source are compared over the temperature range of 6 K to 300 K. The Cu-based SDC memristors operate at temperatures as low as 6 K, whereas Ag-based SDC memristors are damaged if operated below 125 K. It is also observed that Cu reversibly diffuses into the active Ge₂Se₃ layer during normal device shelf-life, thus changing the state of a Cu-based memristor over time. This was not observed for the Ag-based SDC devices. The response of each device type to sinusoidal …

Elementary School Student Development Of Stem Attitudes And Perceived Learning In A Stem Integrated Robotics Curriculum, Yu-Hui Ching, Dazhi Yang, Sasha Wang, Youngkyun Baek, Steve Swanson, Bhaskar Chittoori

Educational Technology Faculty Publications and Presentations

Robotics has been advocated as an emerging approach to engaging K-12 students in learning science, technology, engineering, and mathematics (STEM). This study examined the impacts of a project-based STEM integrated robotics curriculum on elementary school students’ attitudes toward STEM and perceived learning in an afterschool setting. Three elementary school teachers and 18 fourth to sixth graders participated in an eight-week-long program. Quantitative and qualitative data were collected and analyzed, and showed students’ attitudes toward math improved significantly at the end of the robotics curriculum. Three specific areas of learning were identified, including STEM content learning and connection, engagement and perseverance, …

Implementing Population-Based Mass Drug Administration For Malaria: Experience From A High Transmission Setting In North Eastern Uganda, Richard Elliott

Materials Science and Engineering Faculty Publications and Presentations

Background: Mass drug administration (MDA) is a suggested mean to accelerate efforts towards elimination and attainment of malaria-free status. There is limited evidence of suitable methods of implementing MDA programme to achieve a high coverage and compliance in low-income countries. The objective of this paper is to assess the impact of this MDA delivery strategy while using coverage measured as effective population in the community and population available.

Methods: Population-based MDA was implemented as a part of a larger program in a high transmission setting in Uganda. Four rounds of interventions were implemented over a period of 2 years at …

Dynamic Modeling Of A Suspended And Shock Isolated System In Seismic Loading, Emilie Murphy

Boise State University Theses and Dissertations

A dynamic model for a suspended and shock isolated system is derived and implemented in MATLAB’s Simulink software. The purpose of this implementation is to create a design tool which is modularized to be able to accommodate any configuration of a similar system in any kind of loading. The design tool is used to compute the level of acceleration experienced at specific points in space within the system in the presence of seismic events, as typified by the dynamic displacement caused by the Sumatra, Indonesia earthquake of 2007. It is determined that under this 8.4 magnitude earthquake, accelerations within the …

Effect Of Subgrade Conditions On Pavement Analysis And Performance Prediction: A Study For Idaho Conditions, Md Jibon

Boise State University Theses and Dissertations

The Mechanistic-Empirical (M-E) pavement design approach detailed in the Mechanistic-Empirical Pavement Design Guide (MEPDG), and subsequently implemented through AASHTOWare^® Pavement ME Design relies extensively on detailed material properties that ultimately govern the analysis and performance prediction results. For unbound materials like soils and aggregates, Resilient Modulus (M_R) is the most critical input parameter affecting layer response under vehicular and environmental loading. Representing a material’s ability to ‘recover’ after loading, resilient modulus is determined in the laboratory through repeated load triaxial testing. Although the original test protocol to measure the resilient modulus value of a soil or aggregate …

Parameter Estimation And Dynamic State Observer Design For Vapor Compression Systems, Travis D. Pruitt

Boise State University Theses and Dissertations

Between cooling our house, our workplace, and keeping our food cold both in home and commercially (among other uses), the vapor compression cycle (VCC) is a common method for removing heat from various environments and it accounts for a significant amount of the energy used throughout the world. Therefore, with an ever-growing demand for more efficient processes and reduced energy consumption, improving the ability to accurately model, predict the performance of, and control VCC systems is beneficial to society as whole.

While there is much information available regarding the performance for some of the components found in VCC systems, much …

Exploring The Use Of Data From Newer Technologies In Road Design, Mahamudul Hasan

Boise State University Theses and Dissertations

The use of Light Detection and Ranging (Lidar) is widespread currently all over the world including the United States. Though on-the-ground surveying and photogrammetric surveying are the more common methods to acquire terrain information, Lidar data is being increasingly used for this purpose due to its various advantages. Various research indicates that the accuracy of Lidar data has increased enough to make its use suitable for diverse applications. One potential application that is explored in this research is the use of terrain models generated from Lidar data in road design. To make such use possible we need to be assured …

Minos: Unsupervised Netflow-Based Detection Of Infected And Attacked Hosts, And Attack Time In Large Networks, Mousume Bhowmick

Boise State University Theses and Dissertations

Monitoring large-scale networks for malicious activities is increasingly challenging: the amount and heterogeneity of traffic hinder the manual definition of IDS signatures and deep packet inspection. In this thesis, we propose MINOS, a novel fully unsupervised approach that generates an anomaly score for each host allowing us to classify with high accuracy each host as either infected (generating malicious activities), attacked (under attack), or clean (without any infection). The generated score of each hour is able to detect the time frame of being attacked for an infected or attacked host without any prior knowledge. MINOS automatically creates a personalized traffic …

Oxidation Behavior Of Zirconium, Zircaloy-3, Zircaloy-4, Zr-1nb, And Zr- 2.5nb In Air And Oxygen, Jordan L. Vandegrift, Patrick M. Price, John-Paul Stroud, Clemente J. Parga, Isabella J. Van Rooyen, Brian J. Jaques, Darryl P. Butt

Materials Science and Engineering Faculty Publications and Presentations

The Transient Reactor Test (TREAT) facility at the Idaho National Laboratory currently utilizes a legacy Zircaloy- 3 cladding, which is no longer commercially available. TREAT is air cooled and routinely operates at temperatures well above that of traditional reactor designs. This study investigates the oxidation behavior of pure zirconium and its alloys (Zircaloy-3, Zircaloy-4, Zr-1Nb, Zr-2.5Nb) in Ar+20%O₂ and N₂+20%O₂ atmospheres at temperatures ranging from 400–800 °C to determine which alloy should be implemented as TREAT's cladding. While the oxidation behavior of zirconium based cladding materials has been extensively documented, this study focuses on direct comparison …

Simulation Of A Time-Varying Distributed Cathode In A Linear Format Crossed-Field Amplifier, Marcus Pearlman, Jim Browning

Electrical and Computer Engineering Faculty Publications and Presentations

The effects of a temporally modulated, distributed cathode in a linear format crossed-field amplifier (CFA) are simulated in VSim and analyzed. A linear format, 150 MHz, low power (100 W), moderate gain (7 dB), meander line CFA is used as the basis for the simulation model. This paper describes simulations with different time-varying distributed cathodes in which electron injection is modulated at the RF frequency both in and out of phase with the RF input. At low RF input power the modulated electron injection dominates the operation. Injecting in phase with the RF input shows gain increases from 23 dB …