Physical Sciences and Mathematics Commons^™

Elucidating Peatland Disturbance Ecology And Carbon Dynamics Through The Lens Of Soil Using Infrared Spectrometry, Dominic Uhelski

Dissertations, Master's Theses and Master's Reports

We sought to quantify the fire regimes of peatlands in the hemi-boreal zone of North America, and to understand the qualities of their peat. We used infrared spectrometry to accomplish both goals by gathering spectral information about the organic matter in each sample. We used a series of mixtures of natural peat and natural peat charcoal to isolate the spectral components associated with charcoal concentration. We built a multiple linear regression model which predicts the charcoal concentration in peat samples. We validated our data using nuclear magnetic resonance spectrometry. As a result, we can accurately predict the charcoal concentration of …

Comparing Scoop3d And Gis-Tissa Models For Slope Stability Analysis In Idukki, Kerala, India, Stepan Pikul

Dissertations, Master's Theses and Master's Reports

Landslides are the most destructive hazard in the mountainous Idukki district in the State of Kerala, India. Therefore, evaluating the possible occurrence of landslides and analyzing the factors that trigger failure is an essential part of a reliable landslide assessment. Physics-based models are commonly used to determine potential landslide susceptible areas in terms of Factor of Safety (FS). Recent years have seen the use of physics-based methods for regional-scale landslide susceptibility analysis using geospatial tools. In this study, we compare two physics-based models using the same data from Idukki. The two models are the Geographic Information System-Tool for Infinite Slope …

Stress-State Dependency Of The Deformation Ratio Of Quasi-Elastic Granular Soils Under Cyclic Loading -- Supporting Information, Pingxin Xia, Longtan Shao, Wen Deng

Research Data

Poisson’s ratio, besides its transverse-axial strain ratio definition, also plays a significant role in traditional elastic theory as an elastic constant. However, this elastic role of Poisson’s ratio faces a challenge when applied to quasi-elastic granular soils. A so-called “deformation ratio” is therefore introduced and measured in this paper for quasi-elastic granular soils. With the same definition of the transverse-axial strain ratio as Poisson’s ratio, the stress-state dependency of the deformation ratio and the break-down of conversion relationship of elastic constants are investigated under cyclic triaxial tests. The results show that Poisson’s ratio is consistent with deformation ratio only in …

Unsteady-State Contact Angle Hysteresis During Droplet Oscillation In Capillary Pores: Theoretical Model And Vof Simulation -- Data, Chao Zeng, Wen Deng, Lichun Wang

Unsteady-State Contact Angle Hysteresis during Droplet Oscillation in Capillary Pores: Theoretical Model and VOF Simulation -- Data

Spreadsheet - Data of Figures 2 through 11.

Supporting information

Open Data From The First And Second Observing Runs Of Advanced Ligo And Advanced Virgo, R. Abbott, T. D. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

Advanced LIGO and Advanced Virgo are monitoring the sky and collecting gravitational-wave strain data with sufficient sensitivity to detect signals routinely. In this paper we describe the data recorded by these instruments during their first and second observing runs. The main data products are gravitational-wave strain time series sampled at 16384 Hz. The datasets that include this strain measurement can be freely accessed through the Gravitational Wave Open Science Center at http://gw-openscience.org, together with data-quality information essential for the analysis of LIGO and Virgo data, documentation, tutorials, and supporting software.

Ultralow Velocities Of Caco3 And The Origin Of Seismic Anomalies In The Earth's Upper Mantle, Mingqiang Hou, Ming Hao, Jin Liu, Xiaowan Su, Wen-Yi Zhou, Jin S. Zhang, Rostislav Hrubiak

Earth and Planetary Sciences Faculty and Staff Publications

Calcium carbonate (CaCO₃) is a major mineral host for CO₂ in deep Earth. The physical and chemical properties of CaCO₃ at extreme pressure-temperature (P-T) conditions are important for understanding the CO₂ circulation between the Earth's surface and interior primarily via volcanism and subduction. Using the pulse-echo-overlap method combined with Paris-Edinburgh (PE) press, we measured velocities of CaCO₃ under upper mantle conditions and observed an anomalous velocity drop associated with the amorphization of aragonite. The compressional (V_P) and shear (V_S) wave velocities of the partially amorphized CaCO …

Strained Alkyne Polymers Capable Of Spaac Via Ring-Opening Metathesis Polymerization, Rajeshwar Vasdev, Wilson Luo, Kyle Classen, Michael Anghel, Samantha Novoa, Mark S. Workentin, Joe B. Gilroy

Chemistry Publications

The incorporation of strained alkynes into polymers is generally achieved by employing step-growth polymerization methods or post-polymerization reactions. Here, we demonstrate that cyclopropenone-masked strained alkynes are tolerant to chain-growth ring-opening metathesis polymerization, and that, upon post-polymerization photochemical demasking with loss of CO, the strained alkyne group appended to each repeating unit can be used to prepare functional (e.g., fluorescent or redox-active) polymers from a common polymer backbone. We support our claims about polymer transformations throughout the manuscript through the inclusion of a complete set of model reactions and characterization data for analogous molecular species. The findings of this …

Digital Forensic Readiness Intelligence Crime Repository, Victor R. Kebande, Nickson M. Karie, Kim-Kwang R. Choo, Sadi Alawadi

Research outputs 2014 to 2021

It may not always be possible to conduct a digital (forensic) investigation post-event if there is no process in place to preserve potential digital evidence. This study posits the importance of digital forensic readiness, or forensic-by-design, and presents an approach that can be used to construct a Digital Forensic Readiness Intelligence Repository (DFRIR). Based on the concept of knowledge sharing, the authors leverage this premise to suggest an intelligence repository. Such a repository can be used to cross-reference potential digital evidence (PDE) sources that may help digital investigators during the process. This approach employs a technique of capturing PDE from …

Utilizing The Food–Pathogen Metabolome To Putatively Identify Biomarkers For The Detection Of Shiga Toxin-Producing E. Coli (Stec) From Spinach, Snehal R. Jadhav, Rohan M. Shah, Avinash V. Karpe, Robert S. Barlow, Kate E. Mcmillan, Michelle L. Colgrave, David J. Beale

Research outputs 2014 to 2021

Shiga toxigenic E. coli (STEC) are an important cause of foodborne disease globally with many outbreaks linked to the consumption of contaminated foods such as leafy greens. Existing methods for STEC detection and isolation are time-consuming. Rapid methods may assist in preventing contaminated products from reaching consumers. This proof-of-concept study aimed to determine if a metabolomics approach could be used to detect STEC contamination in spinach. Using untargeted metabolic profiling, the bacterial pellets and supernatants arising from bacterial and inoculated spinach enrichments were investigated for the presence of unique metabolites that enabled categorization of three E. coli risk groups. A …

Sub-Micron Moulding Topological Mass Transport Regimes In Angled Vortex Fluidic Flow, Thaar M. D. Alharbi, Matt Jellicoe, Xuan Luo, Kasturi Vimalanathan, Ibrahim K. Alsulami, Bediea S. Al Harbi, Aghil Igder, Fayed A. J. Alrashaidi, Xianjue Chen, Keith A. Stubbs, Justin M. Chalker, Wei Zhang, Ramiz A. Boulos, Darryl B. Jones, Jamie S. Quinton, Colin L. Raston

Research outputs 2014 to 2021

Shear stress in dynamic thin films, as in vortex fluidics, can be harnessed for generating non-equilibrium conditions, but the nature of the fluid flow is not understood. A rapidly rotating inclined tube in the vortex fluidic device (VFD) imparts shear stress (mechanical energy) into a thin film of liquid, depending on the physical characteristics of the liquid and rotational speed,ω, tilt angle,θ, and diameter of the tube. Through understanding that the fluid exhibits resonance behaviours from the confining boundaries of the glass surface and the meniscus that determines the liquid film thickness, we have established specific topological mass transport regimes. …

Fire In Semi-Arid Shrublands And Woodlands: Spatial And Temporal Patterns In An Australian Landscape, Eddie Van Etten, Robert A. Davis, Tim S. Doherty

Research outputs 2014 to 2021

Semi-arid landscapes are of interest to fire ecologists because they are generally located in the climatic transition zone between arid lands (where fires tend to be rare due to lack of fuel, but are enhanced following large rainfall episodes) and more mesic regions (where fire activity tends to be enhanced following severe rainfall deficits). Here we report on the characteristics of the contemporary fire regimes operating in a semi-arid region of inland south-western Australia with rainfall averaging around 300 mm per annum. To characterize fire regimes, we analyzed a geodatabase of fire scars (1960–2018) to derive fire preferences for each …

Prediction Of Mean Wave Overtopping At Simple Sloped Breakwaters Using Kernel-Based Methods, Shabnam Hosseinzadeh, Amir Etemad-Shahidi, Ali Koosheh

Research outputs 2014 to 2021

The accurate prediction of the mean wave overtopping rate at breakwaters is vital for a safe design. Hence, providing a robust tool as a preliminary estimator can be useful for practitioners. Recently, soft computing tools such as artificial neural networks (ANN) have been developed as alternatives to traditional overtopping formulae. The goal of this paper is to assess the capabilities of two kernel-based methods, namely Gaussian process regression (GPR) and support vector regression for the prediction of mean wave overtopping rate at sloped breakwaters. An extensive dataset taken from the EurOtop database, including rubble mound structures with permeable core, straight …

Characterizations Of The Discrete Lindley And Discrete Poisson-Lindley Distributions, Gholamhossein G. Hamedani, Mahrokh Najaf

Mathematical and Statistical Science Faculty Research and Publications

Certain characterizations of the discrete Lindley and discrete Poisson-Lindley distributions, originally introduced by Bakouch, Jazi and Nadarjah (2014) and Sankaran (1970), respectively, are presented. Al-Babtain, Gemeay and Afify (2020) revisited these distributions and provided estimation methods and actuarial measures as well as their applications in medicine. This short note is intended to complete, in some way, Al-Babtain, Gemeay and Afify (2020)’s work. It should be mentioned that the probability mass functions reported in the two papers mentioned above are not correct. In this note, it will be explained why they are not correct.

Diatom Hotspots Driven By Western Boundary Current Instability, Hilde Oliver, Weifeng G. Zhang, Walker O. Smith Jr., Et Al

VIMS Articles

Climatic changes have decreased the stability of the Gulf Stream (GS), increasing the frequency at which its meanders interact with the Mid-Atlantic Bight (MAB) continental shelf and slope region. These intrusions are thought to suppress biological productivity by transporting low-nutrient water to the otherwise productive shelf edge region. Here we present evidence of widespread, anomalously intense subsurface diatom hotspots in the MAB slope sea that likely resulted from a GS intrusion in July 2019. The hotspots (at ∼50 m) were associated with water mass properties characteristic of GS water (∼100 m); it is probable that the hotspots resulted from the …

Onset Of Runaway Fragmentation Of Salt Marshes, Orencio Duran Vinent, Ellen R. Herbert, Daniel J. Coleman, Joshua D. Himmelstein, Matthew L. Kirwan

VIMS Articles

Salt marshes are valuable but vulnerable coastal ecosystems that adapt to relative sea level rise (RSLR) by accumulating organic matter and inorganic sediment. The natural limit of these processes defines a threshold rate of RSLR beyond which marshes drown, resulting in ponding and conversion to open waters. We develop a simplified formulation for sediment transport across marshes to show that pond formation leads to runaway marsh fragmentation, a process characterized by a self-similar hierarchy of pond sizes with power-law distributions. We find the threshold for marsh fragmentation scales primarily with tidal range and that sediment supply is only relevant where …

Connectivity: Insights From The U.S. Long Term Ecological Research Network, David M. Iwaniec, Michael Gooseff, Katherine N. Suding, David S. Johnson, Et Al

VIMS Articles

Ecosystems across the United States are changing in complex and surprising ways. Ongoing demand for critical ecosystem services requires an understanding of the populations and communities in these ecosystems in the future. This paper represents a synthesis effort of the U.S. National Science Foundation-funded Long-Term Ecological Research (LTER) network addressing the core research area of “populations and communities.” The objective of this effort was to show the importance of long-term data collection and experiments for addressing the hardest questions in scientific ecology that have significant implications for environmental policy and management. Each LTER site developed at least one compelling case …

The Role Of Aerodynamic Resistance In Thermal Remote Sensing-Based Evapotranspiration Models, Ivonne Trebs, Kaniska Mallick, Nishan Bhattarai, Mauro Sulis, Jamie Cleverly, William Woodgate, Richard Silberstein, Nina Hinko-Najera, Jason Beringer, Wayne S. Meyer, Zhongbo Su, Gilles Boulet

Research outputs 2014 to 2021

Aerodynamic resistance (hereafter ra) is a preeminent variable in evapotranspiration (ET) modelling. The accurate quantification of ra plays a pivotal role in determining the performance and consistency of thermal remote sensing-based surface energy balance (SEB) models for estimating ET at local to regional scales. Atmospheric stability links ra with land surface temperature (LST) and the representation of their interactions in the SEB models determines the accuracy of ET estimates. The present study investigates the influence of ra and its relation to LST uncertainties on the performance of three structurally different SEB models. It used data from nine Australian OzFlux eddy …

Mgrre_Pureoilscouttickets_Gillen_1_21091080490000, Michigan Geological Repository For Research And Education

Legacy Scout Tickets from Pure Oil Company

No abstract provided.

Volcanological Evolution Of Pantelleria Island (Strait Of Sicily) Peralkaline Volcano: A Review, Silvio G. Rotolo, Stéphane Scaillet, Fabio Speranza, John C. White, Rebecca Williams, Nina J. Jordan

EKU Faculty and Staff Scholarship

Pantelleria volcano has a particularly intriguing evolutionary history intimately related to the peralkaline composition of its explosively erupted magmas. Due to the stratigraphic complexity, studies over the last two decades have explored either only the pre-Green Tuff ignimbrite volcanism or the post-Green Tuff activity. We here focus on the whole evolutionary history, detailing the achievements since the first pioneering studies, in order to illustrate how the adoption and integration of progressively more accurate methods (40Ar/39Ar, paleomagnetism, petrography, and detailed field study) have provided many important independent answers to unresolved questions. We also discuss rheomorphism, a distinct feature at Pantelleria, at …

Genesis Of Trondhjemite By Low-Pressure Fraction Anatexis Of Hornblende-Gabbro At Alvand Plutonic Complex (Hamedan, Nw Iran): Insights From Geochemical Modelling., Federico Lucci, Adel Saki, Mirmohammad Miri, Ahmad Rabiee, John C. White

EKU Faculty and Staff Scholarship

Amphibole-dominated dehydration melting of gabbro is the primary process responsible for the genesis of adakites, low-K tonalites, modern trondhjemites, and plagiogranites aswell as Archean tonalite-trondhjemite-granodiorite suites that represent the earliest examples of continental crust. Previous literature has mostly focused on the role of Al-rich amphibole during anatexis of a mafic source and many of these studies have investigated this process through experimental melting runs. However, due to experimental boundary conditions, little is known about partial melting of amphibole-bearing mafic rock at temperatures < 800°C for upper crustal conditions (pressure < 500 MPa). Classic and forward thermobarometric modelling suggests that in situ trondhjemite leucosomes, hosted by Cheshmeh-Ghasaban mafic metatexites (Alvand Plutonic Complex, Hamedan, NW Iran), represent a rare natural case study of a low-temperature incipient amphibole-dominated anatectic event of a mafic source with a primary assemblage (Pl+Hbl+Cpx+Bt+Opx) typical of a hornblende-bearing gabbroic rock.

Vegetation Effects On Coastal Foredune Initiation: Wind Tunnel Experiments And Field Validation For Three Dune-Building Plants, Bianca Reo Charbonneau, Stephanie M. Dohner, John P. Wnek, Don Barber, Phoebe Zarnetske, Brenda B. Casper

Geology Faculty Research and Scholarship

As the land-sea interface, foredunes buffer upland habitats with plants acting as ecosystem engineers shaping topography, and thereby affecting storm response and recovery. However, many ecogeomorphic feedbacks in coastal foredune formation and recovery remain uncertain in this dynamic environment. We carried out a series of wind tunnel experiments testing how the morphology, density, and configuration of three foredune pioneer dune building plant species influence the most basic stage of dune initiation — nebkha formation around individual plants. We established monocultures of native Ammophila breviligulata and Panicum amarum and invasive Carex kobomugi in 1 m × 1 m planter boxes of …

Population-Specific Resilience Of Halophila Ovalis Seagrass Habitat To Unseasonal Rainfall, An Extreme Climate Event In Estuaries, Chanelle L. Webster, Kieryn L. Kilminster, Marta Sánchez Alarcón, Katherine Bennett, Simone Strydom, Sian Mcnamara, Paul S. Lavery, Kathryn M. Mcmahon

Research outputs 2014 to 2021

1. Extreme climate events are predicted to alter estuarine salinity gradients exposing habitat-forming species to more frequent salinity variations. The intensity and duration of these variations, rather than the mean salinity values ecosystems are exposed to, may be more important in influencing resilience but requires further investigation.
2. Precipitation, including the frequency, intensity and timing of occurrence, is shifting due to climate change. A global analysis on the timing of rainfall in estuarine catchments was conducted. In 80% of the case studies, the maximum daily rainfall occurred in the dry season at least once over the 40-year period and could be classified …

A Glm Approach To Decomposing Wage Differential: Evidence From The Psid., Kassahun Mamo Geleta

Graduate Research Theses & Dissertations

The persistent gender wage differential, though declining through time, is the source of motivation to study the subject.A notable method to deal with the disparity is Oaxaca Blinder decomposition in combination with OLS estimation. This study follows a different approach that does not require the normality assumption and the log transformation of the wage variable. The study employs a generalized linear model (GLM) approach to estimate determinants of wage (measured in level) and combines the results with the Oaxaca Blinder decomposition method. The latter method quantifies the proportion of the wage gap which emanates from characteristics difference between men and …

Analysis Of A Time-Delayed Hiv/Aids Epidemic Model With Education Campaigns, Sedar Ngoma, Dawit Denu, Rachidi B. Salako

Mathematics

We consider a time-delayed HIV/AIDS epidemic model with education dissemination and study the asymptotic dynamics of solutions as well as the asymptotic behavior of the endemic equilibrium with respect to the amount of information disseminated about the disease. Under appropriate assumptions on the infection rates, we show that if the basic reproduction number is less than or equal to one, then the disease will be eradicated in the long run and any solution to the Cauchy problem converges to the unique disease-free equilibrium of the model. On the other hand, when the basic reproduction number is greater than one, we …

Data Supporting Development And Validation Of Liquid Chromatography Tandem Mass Spectrometry Method For The Quantitative Determination Of Bile Acids In Feces, Armaghan Shafaei, Joanna Rees, Claus T. Christophersen, Amanda Devine, David Broadhurst, Mary C. Boyce

Research outputs 2014 to 2021

Measuring bile acids in feces has an important role in disease prevention, diagnosis, treatment, and can be considered a measure of health status. Therefore, the primary aim was to develop a sensitive, robust, and high throughput liquid chromatography tandem mass spectrometry method with minimal sample preparation for quantitative determination of bile acids in human feces applicable to large cohorts. Due to the chemical diversity of bile acids, their wide concentration range in feces, and the complexity of feces itself, developing a sensitive and selective analytical method for bile acids is challenging. A simple extraction method using methanol suitable for subsequent …

Estuaries As Filters For Riverine Microplastics: Simulations In A Large, Coastal-Plain Estuary, Alexander G. Lopez, Raymond G. Najjar, Marjorie A.M. Friedrichs, Michael A. Hickner, Denice H. Wardrop

VIMS Articles

Public awareness of microplastics and their widespread presence throughout most bodies of water are increasingly documented. The accumulation of microplastics in the ocean, however, appears to be far less than their riverine inputs, suggesting that there is a “missing sink” of plastics in the ocean. Estuaries have long been recognized as filters for riverine material in marine biogeochemical budgets. Here we use a model of estuarine microplastic transport to test the hypothesis that the Chesapeake Bay, a large coastal-plain estuary in eastern North America, is a potentially large filter, or “sink,” of riverine microplastics. The 1-year composite simulation, which tracks …

Anticipating And Adapting To The Future Impacts Of Climate Change On The Health, Security And Welfare Of Low Elevation Coastal Zone (Lecz) Communities In Southeastern Usa, T. Allen, J. Behr, (...), Jon Derek Loftis, Molly Mitchell, Karinna Nunez, Et Al

VIMS Articles

Low elevation coastal zones (LECZ) are extensive throughout the southeastern United States. LECZ communities are threatened by inundation from sea level rise, storm surge, wetland degradation, land subsidence, and hydrological flooding. Communication among scientists, stake-holders, policy makers and minority and poor residents must improve. We must predict processes spanning the ecological, physical, social, and health sciences. Communities need to address linkages of (1) human and socioeconomic vulnerabilities; (2) public health and safety; (3) economic concerns; (4) land loss; (5) wetland threats; and (6) coastal inundation. Essential capabilities must include a network to assemble and distribute data and model code to …

Preparing Scientists, Policy-Makers, And Managers For A Fast-Forward Future, Richard B. Norgaard, John A. Wiens, (...), Elizabeth A. Canuel, Et Al

VIMS Articles

Ecosystems in the Sacramento–San Joaquin Delta are changing rapidly, as are ecosystems around the world. Extreme events are becoming more frequent and thresholds are likely to be crossed more often, creating greater uncertainty about future conditions. The accelerating speed of change means that ecological systems may not remain stable long enough for scientists to understand them, much less use their research findings to inform policy and management. Faced with these challenges, those involved in science, policy, and management must adapt and change and anticipate what the ecosystems may be like in the future. We highlight several ways of looking ahead—scenario …

Long-Term Trends In Chesapeake Bay Remote Sensing Reflectance: Implications For Water Clarity, Jessica S. Turner, Carl T. Friedrichs, Marjorie A.M. Friedrichs

VIMS Articles

While ecosystem health is improving in many estuaries worldwide following nutrient reductions, inconsistent trends in water clarity often remain. The Chesapeake Bay, a eutrophic estuary with a highly populated watershed, is a crucial testbed for these concerns. Improved efforts are needed to understand why some measurements of downstream estuarine water clarity appear to be uncorrelated with watershed management actions, and multiple metrics of clarity are needed to address this issue. To complement in situ measurements, satellite remote sensing provides an additional tool with which to assess long-term change in water clarity. In this study, remote sensing reflectance (Rrs) from the …

Valorization Of Xylan In Agroforestry Waste Streams, Harrison Appiah

Graduate Theses, Dissertations, and Problem Reports

Valorization of Xylan in Agroforestry Waste Streams.

Harrison Appiah

Microwave-assisted deep eutectic solvent and gamma-valerolactone metallic chloride catalyzed conversion of xylan to furfural were investigated using a 2x3 factorial experimental design at two levels of percent microwave power, reaction time, and catalyst concentration. The levels of each factor studied were (20%, 60% microwave power, 2, 4 minutes, and 10, 20mg) respectively. The effect of three metallic chloride catalysts (LiCl, FeCl3.6H20, CuCl2) on the conversion of xylan to furfural was also investigated. The gamma-valerolactone-ferric chloride sent system exhibited the highest mean yield of furfural (56.50%). The next highest furfural yield of …