Physical Sciences and Mathematics Commons^™

Impacts Of Grazing Management On Cattle Distribution And Non‐Point Source Pollution From Pastures In The Central United States, M. Haan, J. Russell, D. Bear, D. Morrical

IGC Proceedings (1993-2023)

No abstract provided.

Gradient Analysis Of Saline Groundwater Dynamics Along Spatial Transects In The Chaco, Albrecht F. Glatzle, L. Reimer, G. Roth, J. Cobo Nuñez

IGC Proceedings (1993-2023)

No abstract provided.

River Restoration And Economic Development Through Grassland Management: A Case Study Of The James River, South Dakota, U.S.A., Jeremy P. Duehr, Richard G. Wiebe

IGC Proceedings (1993-2023)

No abstract provided.

Strain And Stress Relationships For Optical Phonon Modes In Monoclinic Crystals With Β-Ga2O3 As An Example, Rafal Korlacki, Megan Stokey, Alyssa Lynn Mock, Sean Knight, Alexis Papamichail, Vanya Darakchieva, Mathias Schubert

Department of Electrical and Computer Engineering: Faculty Publications

Strain-stress relationships for physical properties are of interest for heteroepitaxial material systems, where strain and stress are inherent due to thermal expansion and lattice mismatch. We report linear perturbation theory strain and stress relationships for optical phonon modes in monoclinic crystals for strain and stress situations which maintain the monoclinic symmetry of the crystal. By using symmetry group analysis and phonon frequencies obtained under various deformation scenarios from density-functional perturbation theory calculations on β-Ga₂O₃, we obtain four strain and four stress potential parameters for each phonon mode. We demonstrate that these parameters are sufficient to …

2020 Advancing Regional Climate Adaptation, San Diego Regional Climate Collaborative

San Diego Regional Climate Collaborative

The San Diego region has a long history of being a leader in climate action and is working to advance regional and collaborative climate resilience efforts. Over the last decade, the region has been working to expand its holistic understanding of vulnerabilities to climate change impacts, including: Sea Level Rise, Wildfire, Water, and Equity. Adaptation planning is critical for communities to address the assessed climate vulnerabilities and to implement resilience strategies to prepare for future conditions and impacts before they happen.

Instrumental Vs. Expressive: A Study Of Voter Behavior Models Through The Lens Of Identity In The 2016 Presidential Election, Kaitlyn Fales

Honors Projects in History and Social Sciences

Studying voter behavior through the lens of identity is central to making sense of the 2016 presidential election. The traditional models for explaining voter behavior are rational choice and behavioralism. The former is grounded in instrumental partisanship and a voter’s issue positions, with the latter grounded in an expressive, psychological attachment to partisanship. More recent, social identity theory related models discuss voter behavior through group belonging and the partisan mega-identity (Mason 2018). My analysis used the ANES 2016 Time Series Study. To measure a voter’s issue positions, I created a new Identity Index alongside the expansion of an established Issue …

The Waterfall Crisis, Guiliana G. Grisaffi

English Department: Research for Change - Wicked Problems in Our World

While the Earth’s surface is 71% covered in water, that does not mean that one day all our water could be gone. The current global water crisis is not just a water crisis-it is a waterfall crisis. One wicked, terrible problem that leads to many other wicked problems, a waterfall crisis. Millions of women and young girls are taken out of work and school and instead forced to collect and gather fresh water for their families. Children are suffering from irreversible health consequences from toxic, contaminated water, an example of a health consequence is a lower IQ from lead poisoning. …

Demographic Impacts Of Climate-Induced Migration And Environmental Shocks And Stressors In Cameron Parish, Louisiana, John Green Iii

Honors Theses

No abstract provided.

A Novel Mutation Of The Narrow Leaf 1 Gene Adversely Affects Plant Architecture In Rice (Oryza Sativa L.), Prasanta K. Subudhi, Richard S. Garcia, Sapphire Coronejo, Teresa B. De Leon

Faculty Publications

Plant architecture is critical for enhancing the adaptability and productivity of crop plants. Mutants with an altered plant architecture allow researchers to elucidate the genetic network and the underlying mechanisms. In this study, we characterized a novel nal1 rice mutant with short height, small panicle, and narrow and thick deep green leaves that was identified from a cross between a rice cultivar and a weedy rice accession. Bulked segregant analysis coupled with genome re-sequencing and cosegregation analysis revealed that the overall mutant phenotype was caused by a 1395-bp deletion spanning over the last two exons including the transcriptional end site …

A Coded Aperture Microscope For X-Ray Fluorescence Full-Field Imaging, D. P. Siddons, A. J. Kuczewski, A. K. Rumaiz, R. Tappero, M Idir, K. Nakhoda, J. Khanfri, V. Singh, E. R. Farquhar, M. Sullivan, D. Abel, D. J. Brady, X. Yuan

Faculty Publications

The design and construction of an instrument for full-field imaging of the X-ray fluorescence emitted by a fully illuminated sample are presented. The aim is to produce an X-ray microscope with a few micrometers spatial resolution, which does not need to scan the sample. Since the fluorescence from a spatially inhomogeneous sample may contain many fluorescence lines, the optic which will provide the magnification of the emissions must be achromatic, i.e. its optical properties must be energy-independent. The only optics which fulfill this requirement in the X-ray regime are mirrors and pinholes. The throughput of a simple pinhole is very …

A Natural Frenet Frame For Null Curves On The Lightlike Cone In Minkowski Space ℝ⁴₂, Nemat Abazari, Martin Bohner, Ilgin Sağer, Alireza Sedaghatdoost, Yusuf Yayli

Mathematics and Statistics Faculty Research & Creative Works

In this paper, we investigate the representation of curves on the lightlike cone ℚ³₂ in Minkowski space ℝ⁴₂ by structure functions. In addition, with this representation, we classify all of the null curves on the lightlike cone ℚ³₂ in four types, and we obtain a natural Frenet frame for these null curves. Furthermore, for this natural Frenet frame, we calculate curvature functions of a null curve, especially the curvature function κ₂ = 0 , and we show that any null curve on the lightlike cone is a helix. Finally, we find all curves with constant curvature functions.

Potential Link Between Compromised Air Quality And Transmission Of The Novel Corona Virus (Sars-Cov-2) In Affected Areas, M. G. Manoj, M. K. Satheesh Kumar, K. T. Valsaraj, C. Sivan, Soumya K. Vijayan

Faculty Publications

The emergence of a novel human corona virus disease (COVID-19) has been declared as a pandemic by the World Health Organization. One of the mechanisms of airborne transmission of the severe acute respiratory syndrome corona virus (SARS-CoV-2) amid humans is through direct ejection of droplets via sneezing, coughing and vocalizing. Nevertheless, there are ample evidences of the persistence of infectious viruses on inanimate surfaces for several hours to a few days. Through a critical review of the current literature and a preliminary analysis of the link between SARS-CoV-2 transmission and air pollution in the affected regions, we offer a perspective …

A Solution For Funding The Development Of Technology In Oilwell Drilling, Dalmo S. Amorim, Otto L. A. Santos, Ricardo C. Azevedo, Ana Carolina Chieregati

Faculty Publications

This article proposes a novel methodology to solve an existing gap in benchmark definition by the adoption of statistically defined benchmarks as references to test products or technical procedures. In a win-win partnership, remuneration is made upon realistic bases of comparison being proportional to existing risks. However, establishing values for benchmarks is rarely unanimous if asked to different persons involved in drilling analysis. Conventional benchmarking, which enhances few results and leaves aside poor operational performances, produces references that do not properly represent the geological environment. Nonetheless, when testing new products, it serves as reference to remunerate suppliers. The review of …

Sdstate Sustainability Newsletter: Vol. 5 Issue 2, Jennifer Mclaughlin

SD State Sustainability Newsletter

Content:

• SDSU in Princeton Review's 2021 Guide to Green Schools

• Facilities & Services Adds Electric Delivery Vehicle to Fleet

• Wokini Initiative Included in AASHE's 2020 Sustainable Campus Index

• 5 Tips for a Sustainable Holiday

• Inaugural Sustainability Ambassador Program Completed Last Week

The Decline Of The Mid-Range Jump Shot In Basketball: A Study Of The Impact Of Data Analytics On Shooting Habits In The Nba, Shawn Kilcoyne

Honors Projects in Mathematics

The purpose of this thesis paper is to investigate the strategic shift away from the mid-range jump shot in basketball over the past decade. This paper will cover the rationale for the decline of the mid-range, as well as the general impact of data analytics on the way the game of basketball is played at the professional level. Following a review of the existing literature relating to the use of analytics in the NBA, this paper will analyze the differences in shooting habits between two seven-season periods. Data visualization tools, including boxplots, statistical trends, and distribution plots, will be used …

How To Find The Dependence Based On Measurements With Unknown Accuracy: Towards A Theoretical Justification For Midpoint And Convex-Combination Interval Techniques And Their Generalizations, Somsak Chanaim, Vladik Kreinovich

Departmental Technical Reports (CS)

In practice, we often need to find regression parameters in situations when for some of the values, we have several results of measuring this same value. If we know the accuracy of each of these measurements, then we can use the usual statistical techniques to combine the measurement results into a single estimate for the corresponding value. In some cases, however, we do not know these accuracies, so what can we do? In this paper, we describe two natural approaches to solving this problem. In addition to describing general techniques, our results also provide a theoretical explanation for several semi-heuristic …

Why Ancient Egyptians Preferred Some Sum-Of-Inverses Representations Of Fractions?, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

Ancient Egyptians represented a fraction as a sum of inverses of natural numbers, with the smallest possible number of terms. In our previous paper, we explained that this representation makes sense since it leads to the optimal way of solving a problem frequently mentioned in the Egyptian papyri: dividing bread between workers. However, this does not explain why ancient Egyptians preferred some representations with the same number of terms but not others. For example, to represent 2/3, they used the sum 1/2 + 1/6 but not the sum 1/3 + 1/3 with the same number of terms. In this paper, …

What If You Are Late On Several (Relatively Small) Tasks?, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

In practice, we sometimes end up in a situation when we are late on several relatively small tasks. We cannot finish them all, so which ones should we do first? We show that in general, this is an NP-complete problem. In the typical situation when all the tasks are of approximately the same importance and requires approximately the same time to finish, we can have an explicit solution to this problem. In a nutshell, the resulting (somewhat counterintuitive) recommendation is to start with things which are not yet late or only a few days late. Actually, this recommendation makes sense: …

A Possible (Qualitative) Explanation Of The Hierarchy Problem In Theoretical Physics, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

One of the important open problem in theoretical physics is the hierarchy problem: how to explain that some physical constant are many orders of magnitude larger than others. In this paper, we provide a possible qualitative explanation for this phenomenon.

Possibility To Algorithmically Check: Yet Another Reason Why Current Definitions Have Been Selected In Elementary Mathematics, Christian Servin, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

At first glance, many definitions in mathematics -- especially in elementary mathematics -- seem arbitrary. Why is 1 not considered a prime number? Why is a square considered to be a particular case of a parallelogram -- in some old textbooks, a parallelogram was defined in such a way as to exclude the square. In his 2018 article, Art Duval explained many such definitions by a natural requirement to make the corresponding results (theorems) as simple as possible. However, elementary mathematics is not just about theorems and proofs, it is also about computations. In this paper, we show that from …

Why Strings, Why Quark Confinement: A Simple Qualitative Explanation, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

In this pedagogical article, we recall the infinities problem of modern physics, and we show that the natural way to overcome this problem naturally leads to strings and to quark confinement.

Why Quantiles Are A Good Description Of Volatility In Economics: A Pedagogical Explanation, Sean R. Aguilar, Vladik Kreinovich, Uyen Pham

Departmental Technical Reports (CS)

To make investment decisions, we need to know, for each financial instrument, not only its expected return -- but also how the actual return may deviate from its expected value. A numerical measure of such deviations is known as volatility. Originally, volatility was measured by the srabdard deviation from the expected price, but it turned out that this measure does not always adequately describe our perception of volatility. Empirically, it turned out that quantiles are a more adequate description of volatility. In this paper, we provide an explanation of this empirical phenomenon.

Should Fighting Corruption Always Be One Of The Main Pre-Requisites For Economic Help?, Sean R. Aguilar, Vladik Kreinovich

Departmental Technical Reports (CS)

In general, corruption is bad. In many cases, it makes sense to make fighting corruption one of the main pre-requisites for getting financial help: we do not want this money to line the pockets of corrupted officials, we want to help the people. In this paper, we argue, however, that in some cases -- of over-regulated and/or oppressive regimes -- too much emphasis on fighting corruption may be counter-productive: instead of helping people, it may hurt them.

Being Active In Research Makes A Person A Better Teacher And Even Helps When Working For A Company, Francisco Zapata, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

At first glance, it looks like being active in research is not necessarily related to a person's success in being a teacher or being a productive company employee -- moreover, it looks like research distracts from other tasks. Somewhat surprisingly, however, in practice, the best teachers and the best employees are actually the ones who are active in research. In this paper, we provide an explanation for this seemingly counter-intuitive phenomenon.

Why Min, Max, Opening, And Closing Stock Prices Are Empirically Most Appropriate For Predictions, And Why Their Linear Combination Provides The Best Estimate For Beta, Somsak Chanaim, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

While we have moment-by-moment prices of each stock, we cannot use all this information to predict the future stock prices, we need to combine them into a few characteristics of the daily stock price. Empirically, it turns out that the best characteristics are the lowest daily price, the highest daily price, the opening price, and the closing price. In the paper, we provide a theoretical explanation for this empirical phenomenon. We also explain why empirically, it turns out that the best way to find the stock's beta coefficient is to consider a convex combination of the about four characteristics.

A New Lc-Ms/Ms Technique For Separation Of Gangliosides Using A Phenyl-Hexyl Column: Systematic Separation According To Sialic Acid Class And Ceramide Subclass, Ashta Lakshmi Prasad Gobburi, Eric Wekesa Kipruto, Denise M. Inman, David J. Anderson

Chemistry Faculty Publications

A LC-MS/MS technique separated the bovine and mouse brain gangliosides monosialotetrahexosylgangliosides (GM1), disialotetrahexosylgangliosides (GD1a), trisialotetrahexosylgangliosides (GT1b) and tetrasialotetrahexosylgangliosides (GQ1b) using a phenyl-hexyl HPLC column and employing a linear methanol gradient in water, which is 0.028% in ammonium hydroxide. The gangliosides were separated according to sialic acid class, and within a particular class, gangliosides having different ceramide carbon chain lengths were also separated. All gangliosides of a particular sialic acid class eluted in characteristic retention time windows in the order of GQ1b, (earliest), GT1b, GD1a, and GM1 (latest). Within each specific retention time window for a particular ganglioside class, gangliosides were …

Ion-Molecule Interactions Enable Unexpected Phase Transitions In Organic-Inorganic Aerosol, David S. Richards, Kristin L. Trobaugh, Josefina Hajek-Herrera, C. L. Price, C. S. Sheldon, J. F. Davies, Ryan D. Davis

Chemistry Faculty Research

Atmospheric aerosol particles are commonly complex, aqueous organic-inorganic mixtures, and accurately predicting the properties of these particles is essential for air quality and climate projections. The prevailing assumption is that aqueous organic-inorganic aerosols exist predominately with liquid properties and that the hygroscopic inorganic fraction lowers aerosol viscosity relative to the organic fraction alone. Here, in contrast to those assumptions, we demonstrate that increasing inorganic fraction can increase aerosol viscosity (relative to predictions) and enable a humidity-dependent gel phase transition through cooperative ion-molecule interactions that give rise to long-range networks of atmospherically relevant low-mass oxygenated organic molecules (180 to 310 Da) …

The Role Of Eolian-Fluvial Interactions And Dune Dams In Landscape Change, Late Pleistocene-Holocene, Mojave Desert, Usa, Mark R. Sweeney, Eric V. Mcdonald, Lucas P. Chabela, Paul R. Hanson

School of Natural Resources: Faculty Publications

The formation of the Kelso Dunes in the eastern Mojave Desert, California, was a landscape-changing event triggered by an increase in sediment supply that followed the incision of Afton Canyon by the Mojave River ca. 25 ka. Eastward migration of sand dunes occurred along a well-defined eolian trans­port corridor. Dunes temporarily blocked washes resulting in substantial aggradation of eolian and fluvial sediments. Stratigraphic exposures reveal numerous fining-up sequences with interbedded eolian sands that provide evidence of dune dams and subsequent aggradation. Luminescence ages reveal that dune blocking and aggradation correspond to a regional pulse of alluvial fan sedimentation that occurred …

Reinvestigation Of The Intrinsic Magnetic Properties Of (Fe1-Xcox)2b Alloys And Crystallization Behavior Of Ribbons, Tej Nath Lamichhane, Olena Palasyuk, Vladimir P. Antropov, Ivan A. Zhuravlev, Kirill Belashchenko, Ikenna C. Nlebedim, Kevin W. Dennis, Anton Jesche, Matthew J. Kramer, Sergey L. Bud'ko, R. William Mccallum, Paul C. Canfield, Valentin Taufour

Kirill Belashchenko Publications

New determination of the magnetic anisotropy from single crystals of (Fe_1-xCo_x)2B alloys are presented. The anomalous temperature dependence of the anisotropy constant is discussed using the standard Callen-Callen theory, which is shown to be insufficient to explain the experimental results. A more material specific study using first-principles calculations with disordered moments approach gives a much more consistent interpretation of the experimental data. Since the intrinsic properties of the alloys with x=0.3-0.35 are promising for permanent magnets applications, initial investigation of the extrinsic properties are described, in particular the crystallization of melt spun ribbons with Cu, Al, …

Chapter 1.1: 3-D Surface Visualization Of Ph Titration “Topos”: Equivalence Point Cliffs, Dilution Ramps And Buffer Plateaus, Garon C. Smith, Md Mainul Hossain, Patrick Maccarthy

Water Topos: A 3-D Trend Surface Approach to Viewing and Teaching Aqueous Equilibrium Chemistry

3-D topos can be generated to visualize how pH behaves during titration and dilution procedures. The surfaces are constructed by plotting computed pH values above a composition grid with volume of base added in one direction and overall system dilution on the other. Surficial features correspond to behavior in aqueous solutions. Equivalence point breaks become cliffs that pinch out with dilution. Buffer effects become plateaus. Dilution alone generates 45^o ramps. Sample surfaces are analyzed for acetic acid, CH₃COOH (a weak monoprotic acid); hydrochloric acid, HCl (a strong acid); oxalic acid, HOOCCOOH (a weak diprotic acid) and L-histidine …