Physical Sciences and Mathematics Commons^™

Geomagnetic Response To The Earthquake In Türkiye And Syria On February 6, 2023, Svetlana Riabova, Sergey Shalimov

Turkish Journal of Earth Sciences

The disturbances in the lower ionosphere during the strong earthquake in Türkiye and Syria and its strongest aftershock on February 6, 2023, are analyzed using data from ground-based magnetometers. The observation points are located at distances 700 to 1600 km from the epicenter of the seismic event. As a characteristic of the ionospheric response to these events, variations in the magnetic field have been analyzed at the İznik, Grocka, Panagjurishte, and Surlari magnetic observatories. Earthquake epicenter is known to be a source of both seismic Rayleigh waves and atmospheric acoustic-gravity waves. Using the difference in velocities, at which these waves …

Stochastic 1-D Reactive Transport Simulations To Assess Silica And Carbonate Phases During The Co2 Reinjection Process In Metasediments, Selçuk Erol

Turkish Journal of Earth Sciences

One proposed method to mitigate carbon emission is to mineralize the CO2 in deep geothermal reservoirs while mixing the coproduced CO2 with the effluent fluid for reinjection. The injection fluid temperature fluctuates due to the mixing process between CO2-charged water and the effluent fluid, and compressor interruptions change the thermodynamic conditions that influence the fluid-rock interaction in the reservoir. Mineral dissolution or precipitations are associated with changes in permeability and porosity that affect the flow and, eventually, the lifespan of the reservoir. A combined stochastic–reactive transport simulation approach is useful for inspection purposes. Moreover, the stochastic algorithm validates the deterministic …

Carboniferous Graptolites (Hemichordata: Graptolithina) From The Dnipro-Donets Depression And Donets Basin, Ukraine, Vitaly Dernov

Turkish Journal of Earth Sciences

Remains of the Carboniferous graptolites ?Ptiograptus sp. and Dictyonema sp. are described from the Donets Basin and the border zone of the Dnipro-Donets Depression and Donets Basin (eastern Ukraine). These graptolites were found in the Mezhova (Visean, Mississippian) and Avilovka (Kasimovian, Pennsylvanian) formations. Dictyonema sp. from the Avilovka Formation is probably the youngest dendroid graptolite to date. The analysis of geological data allowed to make a reasonable assumption about the Late Devonian rather than the Carboniferous age of the graptolite fauna from the Englewood Formation of South Dakota (USA) and the Tournaisian rather than the Cisuralian age of graptolites from …

Deposition Of Organic And Inorganic Carbons On The Turkish Continental Margins (1984–1996), Vedat Edi̇ger, Di̇lek Edi̇ger

Turkish Journal of Earth Sciences

This study reevaluates the published total inorganic carbon (TIC) and total organic carbon (TOC) percentages of 695 seafloor sediment samples collected from the continental margins of the Black Sea, Sea of Marmara, Aegean Sea and Mediterranean Sea between 1984 and 1996. An inverse relationship is observed between the average TIC and TOC percentages in the four seas surrounding Türkiye. The explanation for this phenomenon is closely connected to the terrestrial, marine, climatic, and environmental factors of the continental margins from which the samples were collected.

Biotechnology For Sustainable Materials: Innovating Today For A Greener Tomorrow, Shashi Kant Bhatia, Saurabh Bhatia, Maria Eugenia Inda-Webb, Konstantina Kourmentza, Tae Seok Moon, Vijai Singh, Vishal Ahuja, Jingbo Li, Sanjeet Mehariya, Jikai Zhao

School of Earth, Environmental, & Marine Sciences Faculty Publications

No abstract provided.

Balanced N-Color Compositions, Jesus Omar Sistos Barron, Hua Wang

Mathematical Sciences: Faculty Publications

We introduce the notion of balanced n-color compositions, and consider the related enumeration problems. We also establish bijections with four other combinatorial objects, namely two types of Motzkin lattice paths, pairs of regular compositions with restricted parts, and regular compositions with a centered maximum.

On A Generalization Of A Theorem Of Ibukiyama To Evaluate Three Imprimitive Character Sums, Brad Isaacson

Publications and Research

In a previous paper, we expressed three families of character sums by certain generalized Bernoulli functions which in turn were expressed by generalized Bernoulli numbers via a complicated and indirect process. In this paper, we generalize a theorem of Ibukiyama to directly express these generalized Bernoulli functions by generalized Bernoulli numbers. As a result, we can express the three families of character sums by generalized Bernoulli numbers in a more elegant fashion than was done before.

A Novel Consumer-Centric Metric For Evaluating Hearing Device Audio Performance, Vinaya Manchaiah, Steve Taddei, Abram Bailey, De Wet Swanepoel, Hansapani Rodrigo

School of Mathematical & Statistical Sciences Faculty Publications

Background and Aim: The emergence of direct-to-consumer hearing devices has introduced confusion in making appropriate choices, highlighting the need for users to be well-informed for optimal device selection. Currently, no established metric offers insights into the sound performance of these devices. This study aimed to introduce and assess a novel consumer-centric metric (i.e., SoundScore) for hearing device audio performance.

Method: The SoundScore metric was created based on five dimensions of hearing device audio performance (i.e., speech benefit in quiet and moderate, speech benefit in loud, own voice perception, feedback control, streamed music sound quality). Tests were conducted under lab conditions …

A Combinatorial Proof Of A Partition Perimeter Inequality, Hunter Waldron

Michigan Tech Publications

The partition perimeter is a statistic defined to be one less than the sum of the number of parts and the largest part. Recently, Amdeberhan, Andrews, and Ballantine proved the following analog of Glaisher’s theorem: for all m ≥ 2 and n ≥ 1, there are at least as many partitions with perimeter n and parts repeating fewer than m times as there are partitions with perimeter n with parts not divisible by m. In this work, we provide a combinatorial proof of their theorem by relating the combinatorics of the partition perimeter to that of compositions. Using this technique, …

Composition-Theoretic Series And False Theta Functions, William Keith, Robert Schneider, Andrew V. Sills

Michigan Tech Publications

Many natural partition-theoretic series can be equally readily interpreted as compo-sition-theoretic series, but this viewpoint seems to have not been much employed in either theory. We consider some of the consequences of this viewpoint. As examples, we give results concerning the reciprocals of Ramanujan’s theta functions and of the false theta functions of L. J. Rogers, and raise an array of questions related to these. Part of this study may be considered a natural dual of the truncated pentagonal number theorem of Andrews and Merca.

Bagging Improves The Performance Of Deep Learning-Based Semantic Segmentation With Limited Labeled Images: A Case Study Of Crop Segmentation For High-Throughput Plant Phenotyping, Yinglun Zhan, Yuzhen Zhou, Geng Bai, Yufeng Ge

Department of Statistics: Faculty Publications

Advancements in imaging, computer vision, and automation have revolutionized various fields, including field-based high-throughput plant phenotyping (FHTPP). This integration allows for the rapid and accurate measurement of plant traits. Deep Convolutional Neural Networks (DCNNs) have emerged as a powerful tool in FHTPP, particularly in crop segmentation—identifying crops from the background—crucial for trait analysis. However, the effectiveness of DCNNs often hinges on the availability of large, labeled datasets, which poses a challenge due to the high cost of labeling. In this study, a deep learning with bagging approach is introduced to enhance crop segmentation using high-resolution RGB images, tested on the …

Carbon Sequestration In Peatlands: Using Environmental Proxies To Understand The Impact Of A Changing Climate On Global Carbon Storage, Sarah Schuller, Don Sullivan

DU Undergraduate Research Journal Archive

Peatlands are a type of terrestrial wetland ecosystem in which consistently waterlogged conditions prevent the decomposition of organic matter. These conditions allow for sequestered carbon in plant matter to remain stored in the soil to such a great degree that peatlands store more carbon than all other vegetation types in the world combined. By inhibiting decomposition, the composition of water-rich peat soil remains representative of the environmental conditions during the period in which the peat was formed. The collected peat samples can then be utilized as environmental proxies to determine historical temperature, moisture, and carbon content and extrapolated to predict …

Du Undergraduate Showcase Abstracts: Research, Scholarship, And Creative Works, August Alexander, Kevin Summers, E. Paige Lloyd, Alyssa Aragon, Lauren Wols, Erica Larson, Colton Arciniaga, Lily Baeza, Ellie Barnett-Cashman, Sidney Barbier, Maverick Bartholomew, Ryan Bell, Trevor Briggs, Amanda Brown, Cory Marchi, Maddy Pontius, Jennifer Gallagher, Claire Kwok, Channing Bullock, Alex Mccollister, Kim Gorgens, Daniela Chavez, Yamilet Espinoza Nuñez, Giovanni Valladares Giron, William Christensen, Olivia Kachulis, Daniel Cierasynski, Brandon Cohen, Spenser Dobbs, Lindsay Goolsby, Noah Craver, Nyah Cubbison, Liam Doherty, Nicole Doris, Yan Qin, Alexander Nguyen, Lily Harmon, Shubh Todi, Naichen Zhao, Noah Fagello, Stacia Fritz, Paola Gascot-Chinea, Alex Volkova, Janelyn Geronimo, Elsie Harrington, Shane Simmons, Clarice Hise, Laura Moreno Palmer, Henry Xu, Yesu Leela Pasupula, Emily Fisher, Zachary Hogan, Colin Kleckner, Alyssa Knaus, Erin Kubat, Sam Werkema, Katie Lamberton, Lilliya Larson, Allie Leary, Vanessa Leon-Gamez, James H. Gallagher, E. Dale Broder, Robin M. Tinghitella, Emma Loeber, Alina Mali, Ixchel Marquez, Lauren Mcgrath, Ella Matthews, Grace Naegelen, Audrey Ng, Megan Lucyshyn, Rachel Brough, Alexandra Norman, Joe Ontiveros Rodriguez, Ben Dossett, Ori Miller, Janamejay Sharma, Christopher Reardon, Vincent Pandey, Regan Parish, Ren Pratt, Alisha Pravasi, Sanchari Das, Cari Reichel, Emma Robson, Victoria Rockwell, Jayce Rumsey, Steven Said, Norah Schroder, Alaina Smith, Shannon Murphy, Shujan A. Sharafeldeen, Stanley M. Kanai, James T. Nichols, David E. Clouthier, Macalia R. Augustus, Daniel Silva Rios, Scott Simpson, Anna Sparling, Chase Spurbeck, Kimberly Chiew, Christine Stadnik-Poteroba, Jacqueline Stephenson, Evelyn Stovin, Mia Supan, Lauren Tapper, Will Thrush, Anna Vogt, Michaela Walheim, Jon Weber, Hunter Whitehouse, Kansas Wood, Hayley Sayre, Lydia Mccann, Maread Mclaughlin, Kelly Krumrie, Olivia Wuttke

DU Undergraduate Research Journal Archive

Abstracts from the DU Undergraduate Research Showcase.

A Systems Theoretic View Of Speculative Realism, Martin Zwick

Complex Systems Faculty Publications and Presentations

Recent developments in Continental philosophy have included the emergence of a school of “speculative realism,” which rejects the human-centered orientation that has long dominated Continental thought. Proponents of speculative realism differ on several issues, but many agree on the need for an object-oriented ontology. Some speculative realists identify realism with materialism, while others accord equal reality to objects that are non-material, even fictional. Several thinkers retain a focus on difference, a well-established theme in Continental thought. This paper looks at speculative realism from the perspective of systems theory. Many of the tenets of speculative realism have long been features of …

Dynamic Hydrogel-Metal-Organic Framework System Promotes Bone Regeneration In Periodontitis Through Controlled Drug Delivery, Weicheng Chiu, Anqi Li, Yulin Dai, Weichang Li, Xinchun Zhang

Faculty, Staff and Student Publications

Periodontitis is a prevalent chronic inflammatory disease, which leads to gradual degradation of alveolar bone. The challenges persist in achieving effective alveolar bone repair due to the unique bacterial microenvironment's impact on immune responses. This study explores a novel approach utilizing Metal-Organic Frameworks (MOFs) (comprising magnesium and gallic acid) for promoting bone regeneration in periodontitis, which focuses on the physiological roles of magnesium ions in bone repair and gallic acid's antioxidant and immunomodulatory properties. However, the dynamic oral environment and irregular periodontal pockets pose challenges for sustained drug delivery. A smart responsive hydrogel system, integrating Carboxymethyl Chitosan (CMCS), Dextran (DEX) …

Double Acting Liberation Of Ni And Co In The Pre-Treatment Process To Increase Recovery Of Nickel From Low-Grade Nickel Laterite, Eni Febriana, Muhamad Irham Mulyadi, Wahyu Mayangsari, Januar Irawan, Iwan Setiawan, Ahmad Maksum, Florentinus Firdiyono, Soesaptri Oediyani, Agus Budi Prasetyo, Johny W. Soedarsono

Journal of Sustainable Mining

This study highlights the effectiveness of employing double-acting liberation to release Ni and Co from the complex phases of the low-grade nickel laterite. It includes the addition of concentrated sulphuric acid and NaF as well as the heat treatment prior to roasting and leaching processes to improve the destruction of the complex phases contained. The finding describes that dehydration of iron sulfate and decomposition of the lizardite at a lower temperature, 270°C, were occurred in the pre-treatment process, followed by hematite formation in the roasting process. It subsequently accelerated Ni and Co extraction in the pregnant solution and omitted Fe …

Synthesis Of Geopolymer Using Coal Fly Ash And Corn Stover, Anu Paneru

Master's Theses

The development of each nation is dependent on its infrastructure, and nations are competing with others in infrastructure, especially in the construction of roadways, since they play a vital role in the economic and social development of the nation. The conventional materials used for road construction are cement and asphalt, which pose significant environmental challenges. This thesis explores the potential of fly ash (FA) and corn stover (CS) in synthesizing geopolymer, as an alternative material for the construction of roads. The study examines the impact of FA and CS percentages and the particle sizes of CS on the compressive strength, …

Estimating Increased Transient Water Storage With Increases In Beaver Dam Activity, Konrad Hafen, Joseph M. Wheaton, Brett B. Roper, Philip Bailey, William W. Macfarlane, Bethany T. Neilson, Christopher J. Tennant

Watershed Sciences Faculty Publications

Dam building by beaver (Castor spp.) slows water movement through montane valleys, increasing transient water storage and the diversity of residence times. In some cases, water storage created by beaver dam construction is correlated to changes in streamflow magnitude and timing. However, the total amount of additional surface and groundwater storage that beaver dams may create (and, thus, their maximum potential impact on streamflow) has not been contextualized in the water balance of larger river basins. We estimate the potential transient water storage increases that could be created at 5, 25, 50, and 100% of maximum modeled beaver dam capacity …

Reports Of Autosomal Recessive Disease And Consanguineous Mating Within The Human Population, Johnathon L. Schluter

Master's Theses

It is anecdotally evident when investigating published reports of autosomal recessive disease that a substantial number of cases are the result of related (consanguineous) mating. This research seeks to quantify the percent of manuscripts describing autosomal recessive diseases published between 2000 and 2020 in which consanguineous mating is indicated. We analyzed 602 peer-reviewed manuscripts to identify the percentage of cases presented in which consanguineous mating was indicated, the underlying genes (novel gene or new mutation) and geographical region. These papers were accessed through a specific set of parameters on the free access PubMed Central (PMC) database. A total of 552 …

On The T-Degree Of Anderson Thakur Polynomials In The Case Of Fields Of Order P Where P Is A Prime, Joshua Bush

Master's Theses

The Anderson Thakur polynomials are of great interest in the investigation of zeta values. Here, we address the question of their degree in finite fields of the form Fp. We define a graph that is closely connected to Anderson Thakur polynomials and which represents a polynomial we denote as Anxn−1. Collections of terms of this polynomial are equating with the vertices of the graph and are vanishing or nonvanishing. The vanishing structure of the graph is analyzed and we conclude with a simple degree formula.

Effect Of Sex On The Accumulation Of Hepatic Mercury In Mallards Wintering In Louisiana, Latorya E. Mason

Master's Theses

The increase in mercury production through anthropogenic activities has led to a global crisis of mercury pollution that poses a significant threat to the health of both humans and wildlife. Aquatic ecosystems are especially at risk due to the creation of methylmercury, a toxic form of mercury, by sulfate-reducing bacteria in anoxic sediments and soils. Methylmercury enters the food chain where it bioaccumulates in individual organisms and then biomagnified with increasing trophic level. Aquatic birds are useful bioindicators of many pollutants, including mercury, due to their abundance and position in the food chain. Previous studies have primarily focused on mercury …

Comparing Proliferation Rates And Collagen Production Of Cells Treated With Cuhars, Katie Elizabeth Mckenzie

Master's Theses

Cartilage is the padding in joints that protects the bones and aids in motion. Problems with the cartilage in the knee can be caused by mechanical damage or diseases like osteoarthritis. Chondrocytes make cartilage. The objective of this study is to determine the doubling time of chondrocytes per passage. I also want to determine the base amount of collagen-II created by chondrocytes as they age. I also want to determine how long it takes CuHARS to break down in different cell medias. Chondrocytes, human dermal fibroblasts, and CRL 2303 cells were grown and cultured for over a year. During that …

Exploring A Fly Ash-Based Grouting Material For Toughening Through In Situ Polymerization Of Acrylamide, Zhang Yuehong, Wang Xiaodong, Wang Hai, Wu Boqiang, Ji Zhongkui, Zhu Shibin, Han Le, Feng Longfei

Coal Geology & Exploration

Efficiently controlling the water inflow (loss) of burnt rocks in the roof of coal mining faces requires grouting reinforcement materials with excellent compressive toughness. Silicate cement-based grouting materials, characterized by low costs, have been extensively applied to grouting reinforcement in coal mines. However, their hardened grout is susceptible to deformation, exhibiting poor toughness. By employing the in-situ polymerization of acrylamide (AM) for toughening, this study investigated the effects of AM, cross-linking agent, initiator, and water-cement ratio on the setting time, swelling capacity, compressive strength, and toughness index of the fly ash-based grouting materials. Furthermore, the microstructures of the hardened grout …

Some Reflections On The Application Of Machine Learning To Research Into The Theoretical System Of Mine Water Prevention And Control, Yao Hui, Yin Huichao, Liang Manyu, Yin Shangxian, Hou Enke, Lian Huiqing, Xia Xiangxue, Zhang Jinfu, Wu Chuanshi

Coal Geology & Exploration

The theoretical system of mine water prevention and control encompasses three fundamental aspects: disaster-causing mechanisms, risk evaluation, and disaster prediction. This theoretical system, having undergone rapid development over the past 20 years, aims to gain insights into the behavior characteristics of mine water and predict its evolutionary trend, thus serving the prevention and control of water disasters in mining areas. Applying machine learning, a powerful tool for data analysis and mining in the era of big data, to research into the theoretical system has garnered considerable attention. This study focuses on the specific applications of machine learning to the three …

Construction And Analysis Of A Method For Grading Long-Term Vegetation Carbon Sink In Waste Dumps Of An Open-Pit Coal Mine, Yang Fei, Cui Kuankuan, Zhang Chengye, Li Jun, Wang Jinyang, Du Tianmeng, Zhang Haoran

Coal Geology & Exploration

Vegetation carbon sink serves as a crucial indicator for the ecological assessment of an open-pit coal mine. The accurate inversion and grading of vegetation carbon sink play a significant role in exploring the ecological restoration of coal mines. This study proposed a method for grading vegetation carbon sink of an open-pit coal mine based on the particle swarm optimization (PSO) algorithm. Specifically, using a light use efficiency (LUE) model, this study first determined the spatio-temporal distributions of the 2005‒2020 vegetation carbon sink in the waste dumps of the Shengli No.1 open-pit coal mine through inversion based on Landsat images and …

Dynamic Simulations And Applicability Evaluation Of Novel Perforation Techniques, Bi Gang, Yuan Peijie, Han Fei, Fu Shuaishuai, Wu Jiemin, Ma Ying

Coal Geology & Exploration

The development and improvement of perforated completion techniques hold great practical significance and value for efficient testing and exploitation of oil and gas fields. However, conventional shaped-charge perforation for well completion of low-permeability reservoirs (e.g., low-permeability coal seams) suffered high seepage resistance and reduced productivity due to the presence of compaction damage zones. To achieve enhanced exploitation efficiency of low-permeability reservoirs, novel perforation techniques, including self-cleaning and after-effect perforation, have been proposed. However, their perforation performance and applicability remain ambiguous. Based on the explicit time integration algorithm and fluid-structure interaction mechanism of LS-DYNA, this study proposed a method for finite …

A Simulation Study Of Mechanisms Behind Water Inrush From Fault-Bearing Floors Of Ultra-Thick Coal Seams Under Loading And Unloading At Significantly Variable Amplitude, Li Hao, Zhu Kaipeng, Guo Guoqiang, Zhou Yang, Kang Zhiqin

Coal Geology & Exploration

Ultra-thick coal seams feature large stope spaces and extensive disturbance ranges. Significantly variable amplitude loading and unloading are prone to cause the fault rupture of floors of ultra-thick coal seams, inducing water disasters. Numerical simulation serves as a critical method for revealing the fault reactivation and water inrush mechanisms at the floors of ultra-thick coal seams. The key of this method is to accurately inflect the coupling characteristics of rock mass rupture and fissure water under significantly variable amplitude loading and unloading. This study determined the correlations of the damage variable with plastic strain and stress, deriving the equations for …

Queering Futures With Data-Driven Speculation: The Design Of An Expanded Mixed Methods Research Framework Integrating Quantitative, Qualitative, And Practice-Based Modes, Jess Parris Westbrook

College of Education Theses and Dissertations

Queering’ questions, unlearns, disrupts, and transforms approaches, expectations, and realities. Futures are time and change. The approach I have designed to operationalize Queering and futures, or Queering futures, is the Queering Futures Framework (QFF). The Queering Futures Framework (QFF) is a brand-new transdisciplinary research framework intersecting values, positionality, complexity, Queerness themes, and futures praxis. This framework expands traditional mixed methods research conventions by integrating quantitative, qualitative, and practice-based research modes and mindsets. The Queering Futures Framework (QFF) prototype presented in this dissertation functions as a test case and proof of concept. The prototype quantitative mode measures attitudes towards AI, and …

Debris Fan Produced By Failure Of Canyon-Blocking Pyroclastic Flows, Michael L. Cummings

Geology Faculty Publications and Presentations

Ash-rich pyroclastic flows from the cataclysmic eruption of Mount Mazama (~7700 yr. B. P.), Cascade volcanic arc, Oregon, entered and blocked the narrow, bedrock-lined canyon of the Williamson River approximately 35 to 44 km from the source volcano. The blockage impounded a body of water which then released producing four stratigraphic units in the downstream debris fan. The four stratigraphic units are a boulder core comprised of locally sourced bedrock boulders and three sand-rich units including a fine-grained sand unit, a sandy pumice gravel (±basalt/hydrovolcanic tuff) unit, and a pumice pebble-bearing, crystal-rich sand unit. Hand-drilled auger holes up to ~1.6 …

Geochemical Characteristics And Influencing Factors Of Deep Coalbed Methane In The Linxing-Shenfu Block, Wu Peng, Hu Weiqiang, Li Yangbing, Ma Litao, Li Yong, Zhao Fei, Niu Yanwei, Chen Jianqi, Li Panpan, Liu Zaizhen, Li Chenchen, Cao Di, Liu Cheng

Coal Geology & Exploration

Identifying the origin and geochemical characteristics of deep coalbed methane (CBM) is critical for its exploration and production. This study examined the desorbed gas from deep-CBM parameter wells in the Linxing-Shenfu block on the eastern margin of the Ordos Basin. It systematically tested the composition, content, and carbon isotopes of CBM in coal seams Nos. 8 and 9. In combination with the degree of thermal evolution, gas-bearing properties, coal seam burial depths, geological structures, and hydrogeologic conditions, it delved into the geochemical characteristics and influencing factors of deep CBM. The results show that the deep CBM in the study area …