Physical Sciences and Mathematics Commons^™

Senstive Enantiomeric Analysis Of N-Acyl Homoserine Lactones In Bacterial Matrices, Abiud E. Portillo

Chemistry & Biochemistry Dissertations - Archive

Communication between unicellular organism has long been studied with many facets yet to be discovered. A specific type of communication in gram-negative bacteria is quorum sensing (QS). N-acyl homoserine lactones (N-HLs) are the molecular signals in this process. At a critical concentration of N-HLs, all bacteria of the same population stop behaving like individuals and in a concerted manner induce a specific gene expression which ultimately benefits the entire population in major. This phenomenon has been coined with the term quorum sensing with the main signaling molecules dubbed L-N-acyl homoserine lactones (L-N-HL). Quorum sensing signaling pathways have their influence in …

Investigating The Frictional Properties Of Organic Matter And Pore Structure Of Organic-Rich Shales With Atomic Force Microscopy And Scanning Electron Microscopy, Farnood Sobhbidari

Earth & Environmental Sciences Dissertations - Archive

Understanding geomechanical properties of shales, such as stiffness properties and fracture toughness, is important in different areas of petroleum industry-related activities including fracturing efficiency, petroleum flow to the wellbores, and induced seismicity. Nanoscale to microscale experiments on shale samples require a much smaller sample compared to macroscale experiments. This is a major advantage because irregularly-shaped drill cuttings from shales can be used for experimental analyses, such as nanoindentation or atomic force microscopy (AFM). However, a characterization of mechanical properties at the nano- to micro-scale is a relatively new addition to classical geomechanical experiments on shales, and there is still lack …

Approximate Query Processing Using Deep Learning And Database Techniques, Shohedul Hasan

Computer Science and Engineering Dissertations - Archive

Data is generated at an unprecedented rate surpassing our ability to analyze them. In real applications, it is often impractical to find an exact answer by traversing the entire data. As a result, Approximate Query Processing (AQP) is getting extremely popular, which finds an approximate answer in a quick time by sacrificing a fraction of accuracy. This dissertation focuses on developing different AQP techniques to solve fundamental database problems using deep learning. Moreover, we build a fast and scalable algorithm for Quantile Regression, a well-known regression technique that can help minimize the uncertainty in the recent deep learning-based AQP solutions, …

Alpha, Beta-Unsaturated Aldehydes: The Underrepresented Markers Of Disease., Saurin Sutaria

Electronic Theses and Dissertations

The peroxidation of unsaturated fatty acids is a widely recognized metabolic process that creates a complex mixture of volatile organic compounds including aldehydes. Elevated levels of reactive oxygen species in cancer cells promote random lipid peroxidation, which leads to an increase in a variety of aldehydes. Many of these volatile aldehydes are exhaled and are of interest as potential markers of disease. Chapter 1 presents a review of reported aldehydes in the exhaled breath of lung cancer patients. alpha,beta-Unsaturated aldehydes, detected primarily when derivatized during exhaled breath preconcentration, are underreported in the reviewed articles. Chapter 1 concludes with our hypothesis …

Investigating Atmospheric Gravity Waves Using 3-Dimensional Spectral Analysis, Kenneth I. Zia

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Atmospheric gravity waves (GW) are generated from the ground and go into the upper layers of the atmosphere where space begins. These waves have strong effects on the temperature and circulation of the Earth’s atmosphere. The temperature changes caused by these waves are observed through special cameras looking at light that the Earth’s atmosphere naturally emit at night. One of these cameras is placed at McMurdo Station, Antarctica where the long nights are used to see these waves longer than anywhere else. The images captured there are automatically analyzed to determine wave properties to better understand how often they are …

A Long Time Ago In A Galaxy Far, Far Away: A Candidate Z ~ 12 Galaxy In Early Jwst Ceers Imaging, Steven L. Finkelstein, Micaela B. Bagley, Pablo Arrabal Haro, Mark Dickinson, Henry C. Ferguson, Jeyhan S. Kartaltepe, Casey Papovich, Denis Burgarella, Dale D. Kocevski, Marc Huertas-Company, Kartheik G. Iyer, Anton M. Koekemoer, Rebecca L. Larson, Pablo G. Pérez-González, Caitlin Rose, Sandro Tacchella, Stephen M. Wilkins, Katherine Chworowsky, Aubrey Medrano, Alexa M. Morales, Rachel S. Somerville, L. Y. Aaron Yung, Guillermo Barro

Pacific Faculty Work

We report the discovery of a candidate galaxy with a photo-z of z ~ 12 in the first epoch of the James Webb Space Telescope (JWST) Cosmic Evolution Early Release Science Survey. Following conservative selection criteria, we identify a source with a robust zphot = 11.8-0.2+0.3 (1σ uncertainty) with mF200W = 27.3 and ≥7σ detections in five filters. The source is not detected at λ < 1.4 μm in deep imaging from both Hubble Space Telescope (HST) and JWST and has faint ~3σ detections in JWST F150W and HST F160W, which signal a Lyα break near the red edge of both filters, implying z ~ 12. This object (Maisie's Galaxy) exhibits F115W-F200W > 1.9 mag (2σ lower limit) with a blue continuum slope, resulting in 99.6% of the photo-z probability distribution function favoring z > 11. All data-quality images show no artifacts at the candidate's position, and independent analyses …

Why Energy Efficiency Is Needed In Rwanda, Jean Ishinzibigwi

Op-Eds from ENSC230 Energy and the Environment: Economics and Policies

Perspective on the benefits of energy efficiency and cost savings on energy was changed by the experience of working with the Nebraska Industrial Assessment Center. Visiting various industrial locations in Nebraska to see how different energy-saving techniques are employed to save money on energy costs and reduce energy waste. Rwanda can put several ideas into action to lessen the energy loss, which is too much now.

The government's Ministry of Infrastructure (MININFRA) and other departments are crucial to Rwanda's energy sector. The primary ministry in charge of developing renewable energy is MININFRA (methane, peat, geothermal, solar and wind energy). The …

Stop Methane Emissions, Jacob Anderson

Op-Eds from ENSC230 Energy and the Environment: Economics and Policies

We all know of the worldly issue called global warming. A huge cause of global warming is the emission and buildup of greenhouse gasses in the atmosphere. Carbon dioxide is the leading contributor to global emissions at 74.4% and methane is second at 17.3% (Our World in Data 2019). On August 16, 2022, President Biden signed the Inflation Reduction Act of 2022

which includes a charge that starts in 2024 at $900 per metric ton of methane emitted and will raise to $1500 by 2028 (CRS). This should introduce an incentive for facilities to update their plant, machinery, and equipment …

Bridgeport Poised To Be Site Of Nebraska’S Next Environmental Catastrophe, Kjersten Hyberger

Op-Eds from ENSC230 Energy and the Environment: Economics and Policies

Bridgeport Ethanol LLC is Nebraska’s first ethanol plant to be under contract for Carbon Capture and Sequestration (CCS) in the state. Despite ongoing safety concerns by federal regulators and organized opposition from affected landowners, Carbon America is pushing forward with their plans to have the Bridgeport CCS facility operational by 2024. At a time when Nebraska has barely begun cleanup of the AltEn disaster in Mead, and the agrochemical contamination levels in our soil and groundwater are at historic levels, we cannot carelessly add one more pollutant to the mix.

In May of this year the Legislature passed the Nebraska …

Puerto Rico Left In The Dark, Again, Eulices Garcia

Op-Eds from ENSC230 Energy and the Environment: Economics and Policies

Puerto Rico, the United States third largest island, often gets overlooked when hurricane season comes and goes. Where most of the attention goes to the Florida peninsula or East coast, Puerto Rico is still one of America’s closest territories. As part of America’s extended family, Puerto Rico should not be overlooked when natural disasters occur. When these disasters happen, they can have a tremendous impact on the island itself and the people in it. One major concern that has not been truly fixed yet is the energy crisis in Puerto Rico. Whenever storms hit, there is always a possibility of …

Carbon Capture Is Not Climate Action, Bella Devney

Op-Eds from ENSC230 Energy and the Environment: Economics and Policies

A new technology is being brought to Western Nebraska in the form of Carbon Capture and Storage in the name of climate action, but the health of Nebraska’s environment and people are being ignored. Bridgeport Ethanol Plant announced this fall that they plan to begin building technology that will capture and store “175,000 tons/yr” which is a small percentage of the 4,577 million tons emitted by the US in 2020.

Carbon can be captured from the atmosphere itself or in the Ethanol Plant’s case from the point of the CO2 production. After carbon is captured from the plant’s smokestack, it …

Nuclear Energy, Evan Detina

Op-Eds from ENSC230 Energy and the Environment: Economics and Policies

The use of nuclear power as a primary energy source is a controversial discussion. However, if reversing or stopping the effects of climate change is our main goal, then this is a top contender. Fossil fuels account for 34 billion tons of emissions annually according to Ritchie, Hannah, et al. (2020). Instead, we can create energy through nuclear fission. I believe nuclear energy should become a much larger player in the energy game.

The first practical use of nuclear power became apparent on December 2, 1942 when a physicist, Enrico Fermi, develOp-ed a self-sustaining nuclear fission reaction at the University …

Big Blue Wind Project: Why Solar May Be A Better Solution For Nebraska's Energy Future Than Wind, Page Nippert

Op-Eds from ENSC230 Energy and the Environment: Economics and Policies

With nonrenewable resources such as coal and oil causing greenhouse gas emissions, a shift to renewable resources is needed not only to reduce CO₂ emissions, but also to allow energy independence. The switch to renewable resources is vital, and in Nebraska, these resources are being introduced commonly as solar and wind farms depending on the area.

NextEra Energy is proposing The Big Blue Wind project in Jefferson County. I’m opposing this project for reasons similar to why it’s being proposed – for the environment and the community.

The project aims to benefit the community economically by creating jobs, county …

New Natural Gas Pipeline Benefits Europe And Africa, Victor Moreno Lozano

Op-Eds from ENSC230 Energy and the Environment: Economics and Policies

European countries have agreed to start filling up their natural gas gap, with the new natural gas pipeline from Africa. Nigeria and Morocco agreed to develop this pipeline in 2016, but after the beginning of the Ukraine-Russia war, things have speeded up.

After the economical punishments Europe imposed on Russia, Russia decided to increase the price of the natural gas exported to Europe and decrease the amount of gas. Most European countries have a big dependency on Russia's natural gas, countries like Germany import 50% of their natural gas from Russia.

Since winter is coming up, European countries are dealing …

Are Electric Cars A Solution In Rwanda?, Elysee Ndayishimiye

Op-Eds from ENSC230 Energy and the Environment: Economics and Policies

Numerous studies have been conducted that demonstrate how environmentally friendly electric vehicles are. They produce fewer greenhouse gases, which makes them an effective way to reduce both air pollution and greenhouse emissions. In order to combat rising air pollution and support a green city initiative, Rwanda considered introducing more electric vehicles. The Global Electric Mobility Program, run by the United Nations Environment Program (UNEP), aims to assist low- and middle-income nations in switching from conventional (gas) to electric vehicles. Rwanda has joined this program. Due to the high cost of switching to electric vehicles in poor nations like Rwanda and …

Ancient Marine Sediment Dna Reveals Diatom Transition In Antarctica, Linda Armbrecht, Michael E. Weber, Maureen E. Raymo, Victoria L. Peck, Trevor Williams, Jonathan Warnock, Yuji Kato, Iván Hernández-Almeida, Frida Hoem, Brendan Reilly, Sidney Hemming, Ian Bailey, Yasmina M. Martos, Marcus Gutjahr, Vincent Percuoco, Claire Allen, Stefanie Brachfeld, Fabricio G. Cardillo, Zhiheng Du, Gerson Fauth, Chris Fogwill, Marga Garcia, Anna Glüder, Michelle Guitard, Ji Hwan Hwang, Mutsumi Iizuka, Bridget Kenlee, Suzanne O’Connell, Lara F. Pérez, Thomas A. Ronge, Osamu Seki, Lisa Tauxe

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Antarctica is one of the most vulnerable regions to climate change on Earth and studying the past and present responses of this polar marine ecosystem to environmental change is a matter of urgency. Sedimentary ancient DNA (sedaDNA) analysis can provide such insights into past ecosystem-wide changes. Here we present authenticated (through extensive contamination control and sedaDNA damage analysis) metagenomic marine eukaryote sedaDNA from the Scotia Sea region acquired during IODP Expedition 382. We also provide a marine eukaryote sedaDNA record of ~1 Mio. years and diatom and chlorophyte sedaDNA dating back to ~540 ka (using taxonomic marker genes SSU, LSU, …

Obstacles In Learning Algorithm Run-Time Complexity Analysis, Bailey Licht

Theses/Capstones/Creative Projects

Algorithm run-time complexity analysis is an important topic in data structures and algorithms courses, but it is also a topic that many students struggle with. Commonly cited difficulties include the necessary mathematical background knowledge, the abstract nature of the topic, and the presentation style of the material. Analyzing the subject of algorithm analysis using multiple learning theories shows that course materials often leave out key steps in the learning process and neglect certain learning styles. Students can be more successful at learning algorithm run-time complexity analysis if these missing stages and learning styles are addressed.

Spacecraft Charging Test Considerations For Composite Materials, Allen Andersen, Wousik Kim, J. R. Dennison, Brian Wood, Todd A. Schneider, Jason Vaughn, Kenneth H. Wright Jr., Nelson W. Green, Eric Suh, Joel Schwartz, Abdul-Majeed Azad

Journal Articles

Composite materials present a growing challenge for spacecraft charging assessments. We review some recent lessons learned for charging tests of composite materials using both parallel-plate and electron beam test geometries. We also discuss examples of materials that exhibit significant variations between samples, despite them all having the same trade name.

A Comprehensive Analysis Of The Evolution Of Coastal Flooding In Texas And Louisiana For Application In Risk Assessment, Joshua Pulcinella

Earth & Environmental Sciences Dissertations - Archive

Coastal communities of the northern Gulf of Mexico have historically been at risk of flooding from tropical cyclone induced storm surge and extreme precipitation. Relative sea level rise resulting from a combination of increasing global mean sea level and regional subsidence presents an escalating threat that requires a comprehensive assessment of changing flood risks for the area. This study examines how coastal flooding events are changing and focuses on the future risks to communities and infrastructure in Texas and Louisiana. Utilizing historic tide gauge observations, tropical cyclone records, and associated storm tide data, the frequency, duration, and magnitude of events …

A Continuously Renewed Copper Electrode For Constant-Potential Amperometry, Andrew T. Franklin

Chemistry & Biochemistry Theses - Archive

Pulsed amperometric detection (PAD) is a well-established technique used for the detection of electroactive compounds following Ion Chromatography (IC). Target analytes, such as carbohydrates and amino acids, typically have no suitable chromophores and are not detectable by suppressed conductivity following IC separation. While direct current (DC) amperometry is simpler, the formation of oxidation products quickly fouls the electrode surface; PAD removes these products extending electrode longevity for up to ~2 weeks of operation. To further extend electrode lifespans, a new strategy is introduced herein using DC amperometry on a sacrificial copper wire anode. The wire face continually dissolves under oxidative …

Graph Representation Learning For Heterogeneous Multimodal Biomedical Data, Nhat Chau Tran

Computer Science and Engineering Dissertations - Archive

The emergence of high-throughput sequencing technology has generated a wealth of “multi-omics” data, capturing information about different types of biomolecules at multiple levels. Since large-scale genomics, transcriptomics, and proteomics data are becoming publicly available, integrated systems analysis utilizing these data sources has taken the front seat in deriving valuable insights for identifying cancer biomarkers or predicting interactions and functions for novel molecules such as LncRNAs. The graph representation learning paradigm can address these challenging tasks as among the most promising approaches to improve predictions over sparsely annotated molecular entities and to provide representation capacity and interpretability over heterogeneous and hierarchically …

Understanding Human Actions: Cognitive Assessment And Action Segmentation Using Human Object Interaction, Saif Sayed

Computer Science and Engineering Dissertations - Archive

Automatic understanding of human behavior has several applications in medicine and surveillance. Analysing human actions can enable cognitive assessment of children by measuring their hyperactivity and response inhibition which can give physicians better understanding of their cognitive state. Automatic and non-invasive assessment for cognitive disorders will increase the affordability and reach for these detection methods and can prove life-changing in child’s development. Human activity can also be analysed in common settings such as cooking in kitchen and understanding the information of human object interaction can give priors on the underlying activity they are performing. In the first section, we focus …

Mgrre_Thinsections_Mgrre-129_9, Mgrre

Thin Sections

No abstract provided.

Mgrre_Thinsections_Mgrre-129_10, Mgrre

Thin Sections

No abstract provided.

Mgrre_Thinsections_Mgrre-129_13, Mgrre

Thin Sections

No abstract provided.

Statistical Analysis Of Aquifer Hydraulic Properties By A Continuous Pumping Tomography Test: Application To The Boise Hydrogeophysical Research Site, Kan Bun Cheng, Gedeon Dagan, Warren Barrash, Michael Cardiff, Avinoam Rabinovich

Geosciences Faculty Publications and Presentations

Characterizing aquifer heterogeneity is paramount for accurate flow and transport modeling. In this work, we present a new approach for statistical analysis of hydraulic properties in continuous pumping tomography tests of a phreatic aquifer. The method entails determining equivalent hydraulic conductivity (K_eq), specific storage (S_s,eq), and specific yield (S_y,eq) at many locations in the field and then calculating statistical moments of the equivalent properties, assuming they are random space variables. Equivalent properties are defined as the ones pertinent to a homogeneous aquifer for which the head time …

New Jump Operators On Equivalence Relations, John D. Clemens, Samuel Coskey

Mathematics Faculty Publications and Presentations

We introduce a new family of jump operators on Borel equivalence relations; specifically, for each countable group Γ we introduce the Γ-jump. We study the elementary properties of the Γ-jumps and compare them with other previously studied jump operators. One of our main results is to establish that for many groups Γ, the Γ-jump is proper in the sense that for any Borel equivalence relation E the Γ-jump of E is strictly higher than E in the Borel reducibility hierarchy. On the other hand, there are examples of groups Γ for which the Γ-jump is not proper. To establish properness, …

Decision Making Under Uncertainty With A Special Emphasis On Geosciences And Education, Laxman Bokati

Open Access Theses & Dissertations

In many practical situations, we need to make a decision. In engineering, we need to decideon the best design of a system, and, for existing systems - on the best control strategy. In financial applications, we need to decide what is the best way to invest money. In geosciences, we need to decide whether we should explore a possible mineral deposit - or whether we should perform more experiments and measurements (and what exactly). In some cases, we can compute the exact consequences of each decision - e.g., if we are controlling a satellite. However, in many other cases, we …

Generation Of Phase Transitions Boundaries Via Convolutional Neural Networks, Christopher Alexis Ibarra

Open Access Theses & Dissertations

Accurate mapping of phase transitions boundaries is crucial in accurately modeling the equation of state of materials. The phase transitions can be structural (solid-solid) driven by temperature or pressure or a phase change like melting which defines the solid-liquid melt line. There exist many computational methods for evaluating the phase diagram at a particular point in temperature (T) and pressure (P). Most of these methods involve evaluation of a single (P,T) point at a time. The present work partially automates the search for phase boundaries lines utilizing a machine learning method based on convolutional neural networks and an efficient search …

Rational Design Of Precisely Tailored Electrocatalysts For Efficient And Durable Electrocatalytic Devices, Mohmed Sanad Noufal

Open Access Theses & Dissertations

Due to their superior conversion efficiency, high power density, and green nature, sustainable energy technologies such as Fuel cells and Zinc-air batteries, once installed to produce green hydrogen fuel as well as energy storage devices, are expected to play an essential role in reducing the environmental effect of human transportation by replacing fossil fuels. However, the current bottleneck for the low-temperature polymer membrane fuel cells that dominate the fuel cell vehicle market is the sluggish kinetics of the oxygen reduction reaction (ORR) at the cathode. The slow ORR kinetics significantly reduce the efficiency of chemical-electrical energy conversion. Similarly, hydrogen production …