Physical Sciences and Mathematics Commons^™

Evaluation Of A Rapid Biosensor Tool For Measuring Pah Availability In Petroleum-Impacted Sediment, Jason Conder, Mehregan Jalalizadeh, (...), Michael A. Unger

VIMS Articles

Decades of research have shown that the concentration of freely dissolved PAH (C_free) in sediment correlates with PAH bioavailability and toxicity to aquatic organisms. Passive sampling techniques and models have been used for measuring and predicting C_free, respectively, but these techniques require weeks for analytical chemical measurements and data evaluation. This study evaluated the performance of a portable, field-deployable antibody-based PAH biosensor method that can provide measurements of PAH C_free within a matter of minutes using a small volume of mechanically-extracted sediment porewater. Four sediments with a wide range of PAHs (ΣPAH 2.4 to 307 …

Revisiting The Ocean Color Algorithms For Particulate Organic Carbon And Chlorophyll-A Concentrations In The Ross Sea, Shuangling Chen, Walker O. Smith Jr., Xiaolei Yu

VIMS Articles

The Ross Sea is the most productive marginal sea in the Southern Ocean and plays an important role in carbon cycling. However, limited sampling of Chlorophyll-a (Chl) and particulate organic carbon (POC) concentrations from research expeditions constrains our understanding of the biogeochemical processes there. Satellites provide a useful tool for synoptic mapping of surface water properties on regional and global scales, yet the general applicability of the published algorithms in the Ross Sea is poorly known. Based on the data collected from 18 cruises in the past 20 years, we analyzed both the NASA standard and locally developed Chl and …

Biophysical Controls Of Marsh Soil Shear Strength Along An Estuarine Salinity Gradient, Megan N. Gillen, Tyler C. Messerschmidt, Matthew L. Kirwan

VIMS Articles

Sea-level rise, saltwater intrusion, and wave erosion threaten coastal marshes, but the influence of salinity on marsh erodibility remains poorly understood. We measured the shear strength of marsh soils along a salinity and biodiversity gradient in the York River estuary in Virginia to assess the direct and indirect im-pacts of salinity on potential marsh erodibility. We found that soil shear strength was higher in monospecific salt marshes (5–36 kPa) than in biodiverse freshwater marshes (4–8 kPa), likely driven by differences in below ground biomass. However, we also found that shear strength at the marsh edge was controlled by sediment characteristics, …

On The Human Appropriation Of Wetland Primary Production, James E. Cloern, Samuel M. Safran, Lydia Smith Vaughn, (...), Elizabeth A. Canuel, J.Letitia Grenier

VIMS Articles

Humans are changing the Earth's surface at an accelerating pace, with significant consequences for ecosystems and their biodiversity. Landscape transformation has far-reaching implications including reduced net primary production (NPP) available to support ecosystems, reduced energy supplies to consumers, and disruption of ecosystem services such as carbon storage. Anthropogenic activities have reduced global NPP available to terrestrial ecosystems by nearly 25%, but the loss of NPP from wetland ecosystems is unknown. We used a simple approach to estimate aquatic NPP from measured habitat areas and habitat-specific areal productivity in the largest wetland complex on the USA west coast, comparing historical and …

A Cross-Scale Study For Compound Flooding Processes During Hurricane Florence, Fei Ye, Wei Huang, Yinglong J. Zhang, Et Al

VIMS Articles

We study the compound flooding processes that occurred in Hurricane Florence (2018), which was accompanied by heavy precipitation, using a 3D creek-to-ocean hydrodynamic model. We examine the important role played by barrier islands in the observed compound surges in the coastal watershed. Locally very high resolution is used in some watershed areas in order to resolve small features that turn out to be critical for capturing the observed high watermarks locally. The wave effects are found to be significant near barrier islands and have contributed to some observed over-toppings and breaches. Results from sensitivity tests applying each of the three …

Diatoms And Their Response To Tectonic Gateway Changes: Case Studies From Southern Hemisphere Sites, Jason James Coenen

Graduate Research Theses & Dissertations

This dissertation covers three major transitions in Earth's climate system throughout theCenozoic (the past 65 million years of Earth's history). The progressive breakup of the super continent Pangea and the ultimate change in ocean circulation (and redistribution of heat) as a result of tectonic events dating back to the Mesozoic, primed Earth's climate system for cooling and ultimately bipolar glaciation. Climate transitions in three distinct environments were studied using absolute diatom abundance, diatom assemblages, and geochemical tracers of diatoms (i.e., biogenic silica weight%). Two geographic regions are the focus of this dissertation work. Region one is the Ross Embayment of …

Dynamical Downscaling Projections Of Late 21st Century U.S. Landfalling Hurricane Activity, Thomas R. Knutson, Joseph J. Sirutis, Morris A. Bender, Robert E. Tuleya

CCPO Publications

U.S. landfalling tropical cyclone (TC) activity was projected for late 21st century conditions using a two-step dynamical downscaling framework. A regional atmospheric model, run for 27 seasons, generated tropical storm cases. Each storm case was re-simulated (up to 15 days) using the higher resolution GFDL hurricane model. Thirteen CMIP3 or CMIP5 modeled climate change projections were explored as scenarios. Robustness of projections was assessed using statistical significance tests and comparing the sign of changes derived from different models. The proportion of TCs (tropical storms and hurricanes) making U.S. landfall increases for the warming scenarios (by order 50% or more). For …

Measurement Study Of Energy Impact On Blockchain Technologies: Cryptocurrency Mining, Qaylin Holliman

Cybersecurity: Deep Learning Driven Cybersecurity Research in a Multidisciplinary Environment

Blockchain technology facilitates the flow of information and the speed of information through a faster and more decentralized network. It has its advantages as compared to more centralized networks and legacy networks. With the evolution of mainstream technology, blockchains is predicted to be more effective and sufficient to consumers and commercial companies. In this paper, blockchains will be scaled to cryptocurrency mining, where cryptocurrencies utilize blockchain technology to record transactions and orders. Mining will also be examined through energy consumption, the algorithms behind some cryptocurrencies, their sustainability issue, and resolutions to combat high energy consumption. While the pace of energy …

Documenting Macrophytes And Thier Habitat Preferences In Southeastern South Dakota, Jessica Kading, Lan Xu

Natural Resource Management Faculty Publications

One of the most pressing environmental problems that waterbodies currently face is eutrophication. When eutrophication occurs in lakes, phytoplankton dominance increases and macrophyte (aquatic plant) populations decrease. Macrophyte population fluctuation can be used to detect eutrophication and indicate lake health. Despite this novel use of macrophytes, the state of South Dakota has few, if any, baseline public records of its macrophyte species. In an effort to establish a record and work towards the use of macrophytes as potential eutrophication indicators in South Dakota, this study seeks to provide a better understanding of the macrophytes that occur in the southeastern portion …

Automatic Hierarchy Expansion For Improved Structure And Chord Evaluation, Katherine M. Kinnaird, Brian Mcfee

Statistical and Data Sciences: Faculty Publications

No abstract provided.

The Risk Of Physical Multimorbidity In People With Psychotic Disorders: A Systematic Review And Meta-Analysis, Myanca Rodrigues, Joshua C. Wiener, Saverio Stranges, Bridget L. Ryan, Kelly K. Anderson

Epidemiology and Biostatistics Publications

Background: The occurrence of multiple co-occurring chronic health conditions, known as multimorbidity, is associated with decreases in quality of life for patients and poses unique challenges for healthcare systems. Since people with psychotic disorders have an excess of physical health conditions compared to the general population, they may also be at a higher risk for multimorbidity. We conducted a systematic review and meta-analysis to quantify the prevalence and excess risk of multimorbidity among people with psychotic disorders, relative to those without psychosis.

Methods: We searched the MEDLINE, EMBASE, and PsycINFO databases, and conducted forward and backward citation tracing of included …

Characterization Of Microbial Populations In Landfill Leachate, Umut M. Bicim, Hanna Fulford, Lori A. Hoagland, Alejandro R. Sanchez, Amisha D. Shah, Inez Hua

Discovery Undergraduate Interdisciplinary Research Internship

In the United States, municipal solid waste (MSW) landfills remain a potential mining source of recoverable materials, including but not limited to critical, precious, and rare earth metals found in electronic waste. This is possible due to collectible leachate that filters through MSW landfills, carrying metals, nutrients of value, and microbes—some of which may hold key metal bioleaching properties—within. The purpose of this study is to begin analyzing leachate from MSW landfills in the American Midwest to understand the composition of microbial communities within these landfills. Landfill leachate samples sourced in northern Indiana, representing the landfill process during unique times …

Biden’S “Blue” Hydrogen Plan Is Not The Answer, Ryan Martz

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

The excitement about hydrogen as a fuel and energy source is similar to buying an electric vehicle (EV) thinking it will reduce your personal CO₂ emissions. On the surface, it seems great! No greenhouse gas emissions while driving is certainly better than the greenhouse gasses released from a normal combustion engine car, but when you consider other effects, it’s no longer as great. What if the grid that you plug your EV into is powered primarily by coal? What about the environmental and human rights impacts of mining the materials to make the batteries? What about the lack of …

Integrated Geophysical Investigation Of Near-Surface Faults - Sassafras Ridge, New Madrid Seismic Zone, Usa, Cooper Cearley

Theses and Dissertations--Earth and Environmental Sciences

The New Madrid Seismic Zone (NMSZ) is a large source of seismic hazard within the central and eastern United States. Seismogenic source parameters such as active fault location, slip rate, total displacement, and strain accommodation is poorly constrained due to the masking effect of the Mississippi Embayment sediment and agricultural practices on structures and surface expressions. Consequently, noninvasive geologic and geophysical investigation of the subsurface is needed to characterize seismogenic sources. Recent investigation of the Reelfoot Fault found that there is a strain accommodation enigma between the dextral offset at seismogenic depth versus the surface expression, Reelfoot Scarp. This strain …

Annual Report 2020 Conservation And Survey Division, Robert Matthew Joeckel

Conservation and Survey Division

The Conservation and Survey Division (Nebraska Geological Survey), the natural resource survey component of the School of Natural Resources, is a unique, multi-disciplinary research, service and data-collection organization established by state statute in 1921.

The Division's mission is to investigate and record information about Nebraska's geologic history, its rock and mineral resources, the quantity and quality of its water resources, land cover and other aspects of its geography, as well as the nature, distribution and uses of its soils.

Magnetism In Curved Geometries, Robert Streubel, Evgeny Y. Tsymbal, Peter Fischer

Robert Streubel Papers

Curvature impacts physical properties across multiple length scales, ranging from the macroscopic scale, where the shape and size vary drastically with the curvature, to the nanoscale at interfaces and inhomogeneities in materials with structural, chemical, electronic, and magnetic short-range order. In quantum materials, where correlations, entanglement, and topology dominate, the curvature opens the path to novel characteristics and phenomena that have recently emerged and could have a dramatic impact on future fundamental and applied studies of materials. Particularly, magnetic systems hosting non-collinear and topological states and 3D magnetic nanostructures strongly benefit from treating curvature as a new design parameter to …

The Chemistry Of Superelectrophilic Phosphonium Ions, Nathan David Scanlon

Graduate Research Theses & Dissertations

A series of aryl-substituted phosphines have been prepared using superelectrophilic aromatic substitution chemistry. This chemistry involves reactive phosphonium-carbenium dications and related species. In addition to low molecular weight aryl-substituted phosphines, we also are able to prepare functionalized polystyrene products.

Investigation Of A Possible Cretaceous-Paleogene Boundary Layer In The Hell Creek Formation Near Ekalaka, Montana, U.S.A., Joshua Marvin Schwartz

Graduate Research Theses & Dissertations

The Hell Creek Formation is known for its abundant vertebrate fossils from the end of the Cretaceous. Its internal stratigraphy is poorly defined and it is therefore difficult to determine the precise stratigraphic location of a paleontological feature. This challenge could be overcome if a consistently appearing easily recognizable time horizon, such as the Chicxulub impact debris, or a well defined formational contact could be identified over a wide area of the Hell Creek Formation exposure, but these have been difficult to establish in some localities. The Carthage Institute of Paleontology (CIP) has collected Hell Creek specimens near Ekalaka, Montana …

Modularly Equidistant Numerical Semigroups, José Carlos Rosales, Manuel Baptista Branco, Márcio Andre Traesel

Turkish Journal of Mathematics

IfS is a numerical semigroup and s ∈ S , we denote by next$_{S}$(s) = min {x ∈ S s < x}. Leta be an integer greater than or equal to two. A numerical semigroup is equidistant modulo a if next$_{S}$((s) - s - 1 is a multiple of a for every s ∈ S . In this note, we give algorithms for computing the whole set of equidistant numerical semigroups modulo a with fixed multiplicity, genus, and Frobenius number. Moreover, we will study this kind of semigroups with maximal embedding dimension.

Ulam-Hyers Stability Results For A Novel Nonlinear Nabla Caputo Fractional Variable-Order Difference System, Danfeng Luo, Thabet Abdeljawad, Zhiguo Luo

Turkish Journal of Mathematics

This paper is concerned with a kind of nonlinear Nabla Caputo fractional difference system with variable-order and fixed initial valuable. By applying Krasnoselskii's fixed point theorem, we give some sufficient conditions to guarantee the existence results for the considered fractional discrete equations. In addition, we further consider the Ulam-Hyers stability by means of generalized Gronwall inequality. At last, two typical examples are delineated to demonstrate the effectiveness of our theoretical results.

A New Recursive Formula Arising From A Determinantal Expression For Weighted Delannoy Numbers, Muhammet Ci̇hat Dağli

Turkish Journal of Mathematics

In this paper, we obtain a determinantal expression for weighted Delannoy numbers, from which we give a new recurrence relation for it. For the special case of our formula, we compute central weighted Delannoy number in terms of weighted Delannoy number.

Hilbert Series Of Tangent Cones For Gorenstein Monomial Curves In $\Mathbb{A}^{4}(K)$, Anargyros Katsabekis

Turkish Journal of Mathematics

In this paper, we study the Hilbert series of the tangent cone of Gorenstein monomial curves in the 4-dimensional affine space. We give an explicit formula for the reduced Hilbert series of the tangent cone of a noncomplete intersection Gorenstein monomial curve whose tangent cone is Cohen-Macaulay.

On The Number Of Non-$G$-Equivalent Minimal Abelian Codes, Fatma Altunbulak Aksu, İpek Tuvay

Turkish Journal of Mathematics

Let $G$ be a finite abelian group. Ferraz, Guerreiro, and Polcino Milies (2014) proved that the number of $G$-equivalence classes of minimal abelian codes is equal to the number of $G$-isomorphism classes of subgroups for which corresponding quotients are cyclic. In this article, we prove that the notion of $G$-isomorphism is equivalent to the notion of isomorphism on the set of all subgroups $H$ of $G$ with the property that $G/H$ is cyclic. As an application, we calculate the number of non-$G$-equivalent minimal abelian codes for some specific family of abelian groups. We also prove that the number of non-$G$-equivalent …

Close-To-Convexity Of A Class Of Harmonic Mappings Defined By A Third-Order Differential Inequality, Eli̇f Yaşar, Si̇bel Yalçin Tokgöz

Turkish Journal of Mathematics

In this paper, we consider a class of normalized harmonic functions in the unit disk satisfying a third-order differential inequality and we investigate several properties of this class such as close-to-convexity, coefficient bounds, growth estimates, sufficient coefficient condition, and convolution. Moreover, as an application, we construct harmonic polynomials involving Gaussian hypergeometric function which belong to the considered class. We also provide examples illustrating graphically with the help of Maple.

Existence Of Nonnegative Solutions For Discrete Robin Boundary Value Problems With Sign-Changing Weight, Yan Zhu

Turkish Journal of Mathematics

In this paper,~we are concerned with the following discrete problem first $$\left\{ \begin{array}{ll} -\Delta^{2}u(t-1)=\lambda p(t)f(u(t)), &t\in[1,N-1]_{\mathbb{Z}},\\ \Delta u(0)=u(N)=0,\\ \end{array} \right. $$ where $N>2$~is an integer,~$\lambda>0$~is a parameter,~$p:[1,N-1]_{\mathbb{Z}}\rightarrow\mathbb{R}$~is a sign-changing function,~$f:[0,+\infty)\rightarrow[0,+\infty)$~is a continuous and nondecreasing function.~$\Delta u(t)=u(t+1)-u(t)$,~$\Delta^{2}u(t)=\Delta(\Delta u(t))$.~By using the iterative method and Schauder's fixed point theorem,~we will show the existence of nonnegative solutions to the above problem. Furthermore, we obtain the existence of nonnegative solutions for discrete Robin systems with indefinite weights.

Volume Properties And Some Characterizations Of Ellipsoids In ${\Bbb E}^{N+1}$, Dong-Soo Kim, Incheon Kim, Young Ho Kim

Turkish Journal of Mathematics

Suppose that $M$ is a strictly convex and closed hypersurface in ${\Bbb E}^{n+1}$ with the origin $o$ in its interior. We consider the homogeneous function $g$ of positive degree $d$ satisfying $M=g^{-1}(1)$. Then, for a positive number $h$ the level hypersurface $g^{-1}(h)$ of $g$ is a homothetic hypersurface of $M$ with respect to the origin $o$. In this paper, for tangent hyperplanes $\Phi_h$ to $g^{-1}(h)$ ($0

Korovkin Type Approximation Via Triangular $A-$Statistical Convergence On An Infinite Interval, Seli̇n Çinar, Sevda Yildiz, Kami̇l Demi̇rci̇

Turkish Journal of Mathematics

In the present paper, using the triangular $A-$statistical convergence for double sequences, which is an interesting convergence method, we prove a Korovkin-type approximation theorem for positive linear operators on the space of all real-valued continuous functions on $\left[ 0,\infty \right)\times \left[ 0,\infty \right) $ with the property that have a finite limit at the infinity. Moreover, we present the rate of convergence via modulus of continuity. Finally, we give some further developments.

Almost Quasi Clean Rings, Tufan Özdi̇n

Turkish Journal of Mathematics

The element $q$ of a ring $R$ is called quasi-idempotent element if $q^2=uq$ for some central unit $u$ of $R$, or equivalently $q=ue$, where $u$ is a central unit and $e$ is an idempotent of $R$. In this paper, we define that the ring $R$ is almost quasi-clean if each element of $R$ is the sum of a regular element and a quasi-idempotent element. Several properties of almost-quasi clean rings are investigated. We prove that every quasi-continuous and nonsingular ring is almost quasi-clean. Finally, it is determined that the conditions under which the idealization of an $R$-module $M$ is almost …

Preservers Of The Local Spectral Radius Zero Of Jordan Product Of Operators, Mhamed Elhodaibi, Somaya Saber

Turkish Journal of Mathematics

Let $\mathscr{B}(X)$ be the algebra of all bounded linear operators on an infinite-dimensional complex Banach space $X$, and denote by $r_{T}(x)$ the local spectral radius of any operator $T \in \mathscr{B}(X)$ at any vector $x \in X$. In this paper, we characterize surjective maps $\phi$ on $ \mathscr{B}(X)$ satisfying $ r_{\phi(T)\phi(A) + \phi(A)\phi(T)}(x)=0$ if and only if $ r_{TA+AT}(x)=0 $

Mixed Lagrange Function In Minimax Fractional Programming Problems, Shunchin Ho

Turkish Journal of Mathematics

In this paper, the aim of this work to study mixed Lagrange function for the minimax fractional programming problem with nonsmooth exponential $(p,r)$-invex functions with respect to $\eta$. We introduced a new concept of saddle point for a mixed Lagrange function. We present the equivalence between a saddle point of the mixed Lagrange function and an optimal solution in the considered minimax fractional programming problem under appropriate nonsmooth exponential $(p,r)$-invexity hypotheses.