Physical Sciences and Mathematics Commons^™

Multiple Cut Systems Of Cannabis Sativa L. For Micropropagation Without The Use Of Cytokinins, Molly Mckay

All Theses

Micropropagation is a technique used to propagate clean, high-quality clonal stock plants using plant growth regulators (PGR) in a single harvest batch system. This two-part study uses an in vitro multiple harvest system “hedging” combined with the fed- batch media process, to observe (1) the effects of modified physical state and (2) LED light quality to improve shoot production and quality. In Experiment 1, four genotypes of Cannabis sativa (‘Cherry 1’,‘BaOx’,‘T1’,‘Peach’) were observed in three different physical states: stationary agar (A), stationary Oasis® infused with liquid (OIL_s) and agitated Oasis® infused with liquid (OIL_a). Fifteen …

Bounding The Convex Hull Relaxation Of The Unit Commitment Problem With The Shapley-Folkman Theorem, Lauren Henderson

All Theses

The Unit Commitment (UC) problem finds an optimal schedule for a set of generators by minimizing the total operation cost subject to demand and operational constraints. The UC problem is often modeled with a mixed-integer linear program (MILP). We employ the Shapley-Folkman Theorem to provide a bound on the size of fractional solutions of its convex hull relaxation. This result is used to obtain a bound on the optimality gap between the MILP and the convex hull relaxation, which is further tightened using several problem-specific properties of UC. We conduct extensive numerical experiments to study the tightness of this threshold, …

An Analysis Of The Properties Of Polar Codes, Luke Szramowski

All Theses

Polar Codes have risen to the forefront of practical coding theory, due to their incredible efficiency and ease of construction. Originally introduced by Arikan in his 2009 paper, they are the first code defined with an explicit construction that achieved channel capacity. Moreover, polar codes possess some physically practical properties that make their implementation alluring. In the same paper as mentioned above, Arikan elaborated on his construction and noted that the construction given was one specific instance of a polar code and that there is a family of polar codes that can be produced by the same method. Since this …

Indigenous Ecocinema: Decolonizing Media Environments, Salma Monani

Gettysburg College Faculty Books

Introducing the concepts of d-ecocinema and d-ecocinema criticism, Monani expands the purview of ecocinema studies and not only brings attention to a thriving Indigenous cinema archive but also argues for a methodological approach that ushers Indigenous intellectual voices front and center in how we theorize this archive. Its case-study focus on Canada, particularly the work emanating from the imagineNATIVE Film + Media Arts Festival in Toronto--a nationally and internationally recognized hub in Indigenous cinema networks--provides insights into pan-Indigenous and Nation-specific contexts of Indigenous ecocinema.

This absorbing text is the first book-length exploration foregrounding the environmental dimensions of cinema made by …

The Elusive Nature Of Martian Liquid Brines, Vincent F. Chevrier, Rachel A. Slank

Space and Planetary Science Faculty Publications and Presentations

The possible presence of brines on Mars adds an intriguing dimension to the exploration of Martian environments. Their potential involvement in the formation of recurring slope lineae has sparked debates on the existence of liquid water versus alternative dry processes. In situ instrumentation on rovers and landers has been instrumental in providing valuable data for comprehending the dynamics of brines. Laboratory experiments and thermodynamic simulations conducted under Martian conditions offer insights into the formation and persistence of brines, shedding light on the planet’s current hydrological processes. Despite these findings, the prevailing surface conditions on Mars, characterized by a combination of …

Design And Fabrication Of Graphene Solar Cells For Low-Power Energy Harvesting Systems, Tamzeed Bani Amin

Graduate Theses and Dissertations

This study presents the design and fabrication of graphene-based Schottky junction solar cells integrated into a 3-volt power system for low-power applications. Utilizing standard semiconductor processing methods, including selective oxide removal, metal contact deposition, and large-area graphene transfer, we fabricated solar cells from a silicon wafer coated with a thermal oxide layer. Each individual solar cell generated up to 270 µA of short-circuit current and an open-circuit voltage of 420 mV under illumination. We connected multiple solar cells in series to produce a total output of 3.3 volts, which is sufficient to recharge a 3-volt battery. The system, comprising these …

Marine Clay Maturation Induces Systematic Silicon Isotope Decrease In Authigenic Clays And Pore Fluids, Sonja Geilert, Daniel A. Frick, April N. Abbott, Stefan C. Löhr

Marine Science

Marine silicate alteration exerts a major influence on marine carbon and cation cycles, but has proven difficult to quantify. In this context, silicon isotopes of marine pore fluids became an important tracer. However, poorly constrained silicon isotope signatures of precipitates produced during silicate alteration (i.e. authigenic clays) remain a major source of uncertainty. Here we present in situ silicon isotope analyses of marine authigenic clays (intergrown iron-smectites and iron-glauconites) occurring within recent sediments from the Oregon margin, eastern North Pacific. We identify a trend to lower silicon isotopes (from −2.24‰ to −3.17‰), accompanied by decreasing aluminum/silicon ratios and increasing potassium …

Recreational Fishing For Western Rock Lobster: Estimates Of Participation, Effort And Catch In 2023/24, Claire B. Smallwood, Karina L. Ryan, Alissa C. Tate

Fisheries Research Reports

The Western Rock Lobster (WRL) (Panulirus cygnus) is the most commonly caught Rock Lobster (RL) species in Western Australia. Catches from the commercial and recreational sectors are required to determine and monitor Total Allowable Commercial Catch (TACC), Total Allowable Recreational Catch (TARC) and the proportion of Allowable Harvest Level (AHL) achieved. The TARC is set at 5% of the AHL and evaluated in the harvest strategy based on a 5-year average.

Data for the recreational sector are obtained using phone-recall surveys to provide annual estimates of participation, fishing effort and retained catch (by numbers) from recreational fishers who hold a …

Rice Response To Struvite And Other Phosphorus Fertilizers In A Phosphorus-Deficient Soil Under Simulated Furrow-Irrigation, Jonathan B. Brye, Diego Della Lunga, Kristofor R. Brye

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Wastewater-recovered phosphorus (P), in the form of the mineral struvite (MgNH₄PO₄⋅6H₂O), may provide a sustainable alternative to decreasing rock-phosphate reserves. Struvite can be generated via precipitation methods, potentially reducing the amount of P runoff to aquatic ecosystems. The objective of this greenhouse tub study was to evaluate the effects of chemically- and electrochemically precipitated struvite (CPST and ECST, respectively) on above- and belowground plant response in a hybrid rice (Oryza sativa) cultivar grown using furrow-irrigation compared to other common fertilizer-P sources [i.e., triple super phosphate (TSP) and diammonium phosphate (DAP)]. Rice was …

Evaluation Of 3d Beach Profiles: A New Method For Monitoring Changes In Beach Morphology And Grain Size, Kalinda Ellen Roberts

Graduate Masters Theses

Beach profiles are a simple and affordable approach to monitoring changes in beach morphology. However, traditional methods offer limited resolution and dimension. Recent advancements in technologies, particularly structure-from-motion (SfM) and grain size detection models (GSDMs), can be integrated into conventional beach profiling techniques, enabling more detailed spatial and temporal analysis of slope and grain sizes. This research introduces a new technique for coastal monitoring, termed “3D Beach Profiles,” which integrates SfM technology to create high-resolution three-dimensional digital surface models (DSMs) and orthomosaics of beach surfaces. These digital surfaces enable the extraction of beach slopes with orders of magnitude more data …

The Use Of Two-Dimensional Detectors For Snapshot And High Accuracy Imaging Ellipsometry, Jeremy A. Vanderslice

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Ellipsometry is a powerful and sensitive optical technique used to characterize thin film thickness and optical properties by measuring changes in the polarization state of light upon reflection or transmission. This dissertation investigates novel ellipsometry configurations that use two-dimensional detectors to enhance measurement speed, spatial resolution, or accuracy of ellipsometry measurements. The study involves the development of three different ellipsometry configurations, encompassing mechanical prototypes, mathematical models, and test measurements to evaluate each system.

Advisor: Jeffrey Shield

Analysis Of Impulsive Differential Equation Models Of Cell Populations Undergoing Radiation Therapy, Abigail D'Ovidio Long

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Radiation therapy is a mode of treatment which is implemented for approximately 50% of cancer patients. Treatment needs to be able to kill cancer cells, but also do minimal damage to surrounding healthy tissue. We propose two main impulsive differential equation models of radiation therapy to capture the periodic nature of the treatment. These models build off of previous studies using clinical data to ensure biological relevance. The first model incorporates only cancer cell populations, and we provide parameter relationships which theoretically ensure treatment outcomes of cancer eradication, cancer approaching a carrying capacity, and cancer approaching a periodic solution. We …

Local Rural Knowledge And Early Childhood Informal Science Education In Rural Nebraska, Sarah Michelle Paulos

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

This study aims to discover the existing experiences that lead to local rural knowledge (LRK) of specific rural Northeast Nebraska communities. This information will assist in understanding the impact that LRK has on young children’s science knowledge in rural communities. By engaging in hands-on experiences and interactions, science learning goals for children may be achieved and developed through science outreach programs. During Phase 1 of this study, adults in the selected rural communities participated in an online survey indicating their knowledge of various common rural phrases with the option to share personal stories of experiences and family history. This information …

Variable Selection In Distance Metric Learning And Triplet Constraints For Deep Learning Based Ordinal Classification, James D. Clothier

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

The purpose of this research is to augment linear and kernelized ordinal distance metric learning (L/KODML) techniques with a proposed variable selection methodology that integrates the Sequential Multi-Response Feature Selection (SMuRFS) algorithm. Additionally, we aim to embed ordinal triplet constraints into a deep learning architecture, and to propose a general framework for deep learning-based ordinal classification. A variety of simulation studies and real data experiments were conducted to evaluate the various methodologies. For the distance metric learning and variable selection, results showed that the integration of SMuRFS performed effective variable selection and improved prediction accuracy. For the triplet constraints, incorporating …

Performance Of Acoustic Telemetry And Space Use Of Pallid Sturgeon In The Lower Platte River, Nebraska, Christopher F. Pullano

School of Natural Resources: Dissertations, Theses, and Student Research

Pallid Sturgeon (Scaphirhynchus albus) are centenarian, potamodromous, rheophiles that historically occupied the Missouri River and Mississippi River basins. Listed on the U.S. Endangered Species Act in 1990, population declines are attributed to habitat fragmentation and degradation, as well as overharvest, and hybridization. A knowledge gap exists regarding the extent to which tributaries facilitate key life stages for Pallid Sturgeon. This study evaluated the capacity of acoustic telemetry to monitor the movements of Pallid Sturgeon in a shallow, braided tributary to the Missouri River. The specific objectives were to (1) evaluate the environmental variables influencing the performance of acoustic …

Occupancy Of Fish Species Of Greatest Conservation Need And Temporal Patterns Of Assemblage Occurrence In Sandhills Ecoregion, Nebraska Streams, Braxton M. Newkirk

School of Natural Resources: Dissertations, Theses, and Student Research

Fish species’ occurrence is influenced by environmental conditions across multiple spatial and temporal scales. Alteration to stream systems has the potential to affect occurrence patterns of fish species. Stream systems of the North American Great Plains face threats originating from climate change and anthropogenic activities resulting in negative implications for many fish species. The Sandhills Ecoregion, Nebraska is considered one of the largest intact grasslands in North America, and thus may experience fewer threats than surrounding areas. Stream systems of the Sandhills Ecoregion are home to 12 fish species of greatest conservation need (SGCN). Little context exists regarding the environmental …

Spatial Ecology Of American Bison On Vermejo Park Ranch, New Mexico, Kate Ann Asmus

School of Natural Resources: Dissertations, Theses, and Student Research

American bison (Bison bison) are a keystone species that impact grassland productivity, plant diversity, and landscape heterogeneity. We used GPS telemetry and a replicate herbivore grazing experiment on Vermejo Park Ranch in northeastern New Mexico to advance understanding of bison spatial ecology and grazing dynamics. First, we evaluated the potentially disparate influences of forage productivity and site fidelity on the size and selection of home ranges of bison. Home range size was strongly negatively influenced by forage productivity. However, home range selection was influenced more strongly by site fidelity than spatial variation in forage, as bison selected home …

Regulating Robo-Advisors In An Age Of Generative Artificial Intelligence, Daniel Schwarcz, Tom Baker

Law & Economics Working Papers

New generative Artificial Intelligence (AI) tools can increasingly engage in personalized, sustained and natural conversations with users. This technology has the capacity to reshape the financial services industry, making customized expert financial advice broadly available to consumers. However, AI’s ability to convincingly mimic human financial advisors also creates significant risks of large-scale financial misconduct. Which of these possibilities becomes reality will depend largely on the legal and regulatory rules governing “robo-advisors” that supply fully automated financial advice to consumers. This Article consequently critically examines this evolving regulatory landscape, arguing that current U.S. rules fail to adequately limit the risk that …

A Review Of The Philosophy Of Flood Risk Communication And Education: New Insights Informed By Critical Complexity, Timothy Lutz

Earth & Space Sciences Faculty Publications

The approach to flooding in the U.S. is strongly influenced by research and practices that place the responsibility for managing risk on scientific and technical experts. But there is a recognition that the public generally needs to be more engaged and responsible. There is currently a disconnect between the objective knowledge of experts and the more subjective ways in which people experience floods and flood risk. To bridge this gap, I start with a review of the philosophy that informs government policies and the societal worldview. While societal leaders have maintained a mechanistic vision of a world that is ultimately …

Counting Catalan: An Experimental Evaluation Of The Mixing Time For The Triangulation Markov Chain, Roy Gotlieb

Master's Theses

Monte Carlo Markov chains (MCMCs) are used in many areas as a way to model a system’s behavior. By running a probabilistic simulation on a system’s state space, we can estimate properties of the system that could be untenable to directly compute. It is of interest to determine how quickly a Markov chain mixes\textemdash that is, settles into its stationary distribution. One such chain is induced by taking a binary search tree and performing a rotation or flip on one of its edges. We know that this chain eventually settles into the uniform distribution, but the time complexity bounds on …

Container Runtime Vulnerability Mitigation Using User Namespace Isolation, Alexander Edsell

Electronic Theses, Projects, and Dissertations

Although containers have revolutionized application deployment by allowing for rapid and consistent deployment, their growing adoption has also raised significant security concerns. Each container is an isolated instance of an operating system that comes pre-packaged with the users desired applications. With multiple containers running on a host machine, an adversary can potentially break out of the container into the host machine. This project investigates the effectiveness of user namespace isolation as a security mechanism to mitigate container escape vulnerabilities that target the container’s runtime.

The research questions are: Question 1, does user namespace isolation mitigate container runtime vulnerabilities that target …

The Significance Of Continuous User Authentication On Mobile Devices, Mikayla Lawrence

Electronic Theses, Projects, and Dissertations

With the constant evolution of technology specifically on mobile devices, keeping personal and sensitive information safe has become increasingly vital. Continuous user authentication marks a major step forward in mobile security because it provides ongoing verification of user identity beyond the initial log in. This research explores the significance of continuous user authentication systems across mobile devices through literature-based analysis. The following research questions are addressed: (Q1) How effective are continuous user authentication methods in mitigating mobile device threats? (Q2) What are the vulnerabilities associated with continuous user authentication systems on mobile devices? (Q3) How do different continuous user authentication …

Assessing Khumbu Region Glaciers Mass Balance Change Using Geospatial Techniques From 2012 To 2024, Yashvi Jagatbhai Shah

Electronic Theses, Projects, and Dissertations

The glaciers in the Hindu Kush Himalaya are critical for sustaining the water supply of South Asia's major rivers, upon which over 230 million people, both in the mountainous regions and lowland areas, depend. Climate change is driving rapid glaciers melt near the summit of Mount Everest, located at an elevation of approximately 7,906 meters (25,938 feet). This has resulted in glacier thinning occurring up to 80 times faster than the original ice formation. However, due to their disposition in a complex topographic setting and inaccessible terrain, continuous glacier observations pose significant challenges.

This study evaluated the mass balance of …

Jamming Precoding In Af Relay-Aided Plc Systems With Multiple Eavessdroppers, Zhengmin Kong, Jiaxing Cui, Li Ding, Tao Huang, Shihao Yan

Research outputs 2022 to 2026

Enhancing information security has become increasingly significant in the digital age. This paper investigates the concept of physical layer security (PLS) within a relay-aided power line communication (PLC) system operating over a multiple-input multiple-output (MIMO) channel based on MK model. Specifically, we examine the transmission of confidential signals between a source and a distant destination while accounting for the presence of multiple eavesdroppers, both colluding and non-colluding. We propose a two-phase jamming scheme that leverages a full-duplex (FD) amplify-and-forward (AF) relay to address this challenge. Our primary objective is to maximize the secrecy rate, which necessitates the optimization of the …

Locally Varying Geostatistical Machine Learning For Spatial Prediction, Francky Fouedjio, Emet Arya

Research outputs 2022 to 2026

Machine learning methods dealing with the spatial auto-correlation of the response variable have garnered significant attention in the context of spatial prediction. Nonetheless, under these methods, the relationship between the response variable and explanatory variables is assumed to be homogeneous throughout the entire study area. This assumption, known as spatial stationarity, is very questionable in real-world situations due to the influence of contextual factors. Therefore, allowing the relationship between the target variable and predictor variables to vary spatially within the study region is more reasonable. However, existing machine learning techniques accounting for the spatially varying relationship between the dependent variable …

Characterization Of Water-Soluble Inorganic Ions And Carbonaceous Aerosols In The Urban Atmosphere In Amman, Jordan, Afnan Al-Hunaiti, Zaid Bakri, Xinyang Li, Lian Duan, Asal Al-Abdallat, Andres Alastuey, Mar Viana, Sharif Arar, Tuukka Petäjä, Tareq Hussein

Michigan Tech Publications

The urban particulate matter (PM) carbonaceous and water-soluble ions were investigated in Amman, Jordan during May 2018–March 2019. The PM2.5 total carbon (TC) annual mean was 7.6 ± 3.6 μg/m3 (organic carbon (OC) 5.9 ± 2.8 μg/m3 and elemental carbon (EC) 1.7 ± 1.1 μg/m3), which was about 16.3% of the PM2.5. The PM10 TC annual mean was 8.4 ± 3.9 μg/m3 (OC 6.5 ± 3.1 μg/m3 and elemental carbon (EC) 1.9 ± 1.1 μg/m3), about 13.3% of the PM10. The PM2.5 total water-soluble ions annual mean was 7.9 ± 1.9 μg/m3 (about 16.9%), and that of the PM10 was …

Where And How Are Undergraduate Students Developing Dispositions Needed For The Geoscience Workforce?, Kaelyn Lagerwall

Boise State University Theses and Dissertations

Dispositions, such as the desire to learn, work ethic, initiative, and organization, are defined as internal attributes, attitudes, or values that stimulate action. Rather than being intrinsic traits, dispositions can be learned and are considered a dynamic and evolving arrangement of interconnected components. Dispositions are highly desired and valuable to the workforce, playing a critical role in gaining and maintaining employment; they are frequently mentioned in job advertisements for bachelor-level geoscientists. Therefore, it is important to understand where and how geoscience students are developing these dispositions as part of their degree programs. We surveyed faculty in geoscience departments at two …

From Classroom To Career: Preparing Future Geoscientists For Workforce Success, Gregory Shafer

Boise State University Theses and Dissertations

The wide range of career opportunities for geoscience students, combined with a changing workforce, makes it more challenging for undergraduate programs to adequately prepare students for their careers. Therefore, it is important for geoscience programs to have a comprehensive view of the workforce needs and what barriers students may encounter when transitioning to the workforce. This dissertation identifies key skills and competencies essential for bachelor-level geoscientists, as well as potential barriers for recent graduates entering the workforce. The study analyzed entry-level geoscience job advertisements using a case-insensitive code matching function in MATLAB and conducted interviews with geoscience employers to identify …

Investigation Of Magnesium-Potassium Phosphates As Potential Nuclear Waste Form For The Immobilization Of Minor Actinides, Hans Conrad Zur Loye, Petr Vecernik, Monika Kiselova, Vlastislav Kašpar, Hana Korenkova, Vlastimil Miller, Petr Bezdicka, Jan Šubrt, Natalija Murafa, Volodymyr Shkuropatenko, Sergey Sayenko

Faculty Publications

Several recent studies have evaluated technologies of spent nuclear fuel processing specifically for solidifying transuranic (TRU) waste as a by-product of fission. Of the TRU group, plutonium and the minor actinides will be responsible for the bulk of the radiotoxicity and heat generation of spent nuclear fuel in the long term (300 to 20,000 years). In this study, we investigated magnesium potassium phosphate (MKP)-based compounds as host waste forms for the encapsulation of inactive trivalent Nd and Sm as analogues of the minor trivalent actinides, Am and Cm. Waste forms were fabricated under ambient atmospheric conditions by adding 5 wt.% …

An Adaptive And Parallel Direct Solver For Elliptic Partial Differential Equations, Damyn Chipman

Boise State University Theses and Dissertations

We introduce the quadtree-adaptive Hierarchical Poincaré-Steklov (QAHPS) method, an adaptive direct method for solving elliptic partial differential equations on a hierarchy of adaptively refined finite volume meshes. The QAHPS method builds up a solution operator set with O(N^3/2) complexity that acts as the factorization of the system matrix, with linear O(N) complexity for the application of the solution operator set to any number of right-hand side vectors. As the solution operator set is built up by merging local subdomains, it can be adapted as the mesh is refined and coarsened. The method is an …