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2017

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Articles 2521 - 2550 of 12521

Full-Text Articles in Physical Sciences and Mathematics

Light Rare Earth Element Depletion During Deepwater Horizon Blowout Methanotrophy, Alan M. Shiller, Eric W. Chan, D.J. Joung, Molly Redmond, John D. Kessler Sep 2017

Light Rare Earth Element Depletion During Deepwater Horizon Blowout Methanotrophy, Alan M. Shiller, Eric W. Chan, D.J. Joung, Molly Redmond, John D. Kessler

Faculty Publications

Rare earth elements have generally not been thought to have a biological role. However, recent work has demonstrated that the light REEs (LREEs: La, Ce, Pr, and Nd) are essential for at least some methanotrophs, being co-factors in the XoxF type of methanol dehydrogenase (MDH). We show here that dissolved LREEs were significantly removed in a submerged plume of methane-rich water during the Deepwater Horizon (DWH) well blowout. Furthermore, incubation experiments conducted with naturally methane-enriched waters from hydrocarbon seeps in the vicinity of the DWH wellhead also showed LREE removal concurrent with methane consumption. Metagenomic sequencing of incubation …


History Of Computing, George K. Thiruvathukal, David B. Dennis Sep 2017

History Of Computing, George K. Thiruvathukal, David B. Dennis

George K. Thiruvathukal

The social and organizational history of humanity is intricately entangled with the history of technology in general and the technology of information in particular. Advances in this area have often been closely involved in social and political transformations. While the contemporary period is often referred to by such names as the Computing and Information Age, this is the culmination of a series of historical transformations that have been centuries in the making. This course will provide a venue for students to learn about history through the evolution of number systems and arithmetic, calculating and computing machines, and advanced communication technology …


Effects Of A Prescribed Burn On The Adult Butterfly Assemblage Of A Coastal Grassland, J. Nicole Desha, Joseph Colbert, Kimberly M. Andrews, Scott Coleman, C. Tate Holbrook Sep 2017

Effects Of A Prescribed Burn On The Adult Butterfly Assemblage Of A Coastal Grassland, J. Nicole Desha, Joseph Colbert, Kimberly M. Andrews, Scott Coleman, C. Tate Holbrook

Georgia Journal of Science

Coastal grasslands are globally threatened by development and natural succession. In the southeastern United States, these increasingly rare ecosystems are being managed using prescribed fire, but ecological responses to fire management are largely unknown, particularly among nontargeted species. We tested for short-term effects of controlled burning on the abundance and species richness of adult butterflies, which utilize coastal grasslands for nectaring resources and as migratory stopover sites. In February 2015, four plots of coastal grassland on Little St. Simons Island, GA were burned and paired with unburned (control) plots of equal size. Throughout the following summer-fall flight season, we conducted …


The Design Of Interactive Visualizations And Analytics For Public Health Data, Oluwakemi Ola Sep 2017

The Design Of Interactive Visualizations And Analytics For Public Health Data, Oluwakemi Ola

Electronic Thesis and Dissertation Repository

Public health data plays a critical role in ensuring the health of the populace. Professionals use data as they engage in efforts to improve and protect the health of communities. For the public, data influences their ability to make health-related decisions. Health literacy, which is the ability of an individual to access, understand, and apply health data, is a key determinant of health. At present, people seeking to use public health data are confronted with a myriad of challenges some of which relate to the nature and structure of the data. Interactive visualizations are a category of computational tools that …


Improving Speech Recognition For Interviews With Both Clean And Telephone Speech, Sung Woo Choi Sep 2017

Improving Speech Recognition For Interviews With Both Clean And Telephone Speech, Sung Woo Choi

Journal of Undergraduate Research at Minnesota State University, Mankato

High quality automatic speech recognition (ASR) depends on the context of the speech. Cleanly recorded speech has better results than speech recorded over telephone lines. In telephone speech, the signal is band-pass filtered which limits frequencies available for computation. Consequently, the transmitted speech signal may be distorted by noise, causing higher word error rates (WER). The main goal of this research project is to examine approaches to improve recognition of telephone speech while maintaining or improving results for clean speech in mixed telephone-clean speech recordings, by reducing mismatches between the test data and the available models. The test data includes …


Inclusion Of A Dithiadiazolyl Radical In A Seemingly Non-Porous Solid, Varvara I. Nikolayenko,, Leonard J. Barbour, Ana Arauzo, Javier Campo, Jeremy M. Rawson, Delia A. Haynes Sep 2017

Inclusion Of A Dithiadiazolyl Radical In A Seemingly Non-Porous Solid, Varvara I. Nikolayenko,, Leonard J. Barbour, Ana Arauzo, Javier Campo, Jeremy M. Rawson, Delia A. Haynes

Chemistry and Biochemistry Publications

Inclusion of the dithiadiazolyl radical PhCNSSN• into the dynamically porous metallocycle [Cu2(L1)2Cl4], where L1 is the bidentate ligand 1,3-bis(imidazol-1-ylmethyl)-2,4,6- trimethylbenzene, has been achieved by gas phase diffusion. Single crystal X-ray diffraction, powder X-ray diffraction, UV-visible spectroscopy, EPR and SQUID magnetometry studies confirm inclusion of the radical into this seemingly non-porous material, and illustrate the presence of antiferromagnetic coupling between the paramagnetic host and guest species. The radical guest is readily released by heating or by the addition of solvent (CH2Cl2).


Using The Nasa Worldwind Agrosphere Web App As A Climate Change Modeling Tool In The Classroom, Nicholas Rubel, Patrick Hogan, Stacey Chen, Endia Irazarry, Atreya Iyer, John Nguyen, Mingda Tang Sep 2017

Using The Nasa Worldwind Agrosphere Web App As A Climate Change Modeling Tool In The Classroom, Nicholas Rubel, Patrick Hogan, Stacey Chen, Endia Irazarry, Atreya Iyer, John Nguyen, Mingda Tang

STAR Program Research Presentations

Climate change is a clear and imminent threat to the world today. While there are Next Generation Science Standards (NGSS) for teaching climate change in the classroom, students may have a difficult time understanding the seriousness of the issue. One of the standards in the NGSS is for students to develop their own explanation of climate change and its impact. That’s where AgroSphere comes in. AgroSphere is a web-based app that utilizes NASA open-source software WorldWind. WorldWind allows developers to create their own Java, Android, or web-based apps that can display data on the globe. AgroSphere displays historical weather (climate) …


Weakly Horospherically Convex Hypersurfaces In Hyperbolic Space, Vincent Bonini, Jie Qing, Jingyong Zhu Sep 2017

Weakly Horospherically Convex Hypersurfaces In Hyperbolic Space, Vincent Bonini, Jie Qing, Jingyong Zhu

Mathematics

In Bonini et al. (Adv Math 280:506–548, 2015), the authors develop a global correspondence between immersed weakly horospherically convex hypersurfaces ϕ:Mn→Hn+1 and a class of conformal metrics on domains of the round sphere Sn . Some of the key aspects of the correspondence and its consequences have dimensional restrictions n≥3 due to the reliance on an analytic proposition from Chang et al. (Int Math Res Not 2004(4):185–209, 2004) concerning the asymptotic behavior of conformal factors of conformal metrics on domains of Sn . In this paper, we prove a new lemma about the asymptotic behavior of a functional combining the …


Optical Studies Of The Solution Phase Reduction And Stabilization Of Indigo Tetrasulfonate In Polyelectrolyte Complexes, Becca Hoene, Dion Rivera Sep 2017

Optical Studies Of The Solution Phase Reduction And Stabilization Of Indigo Tetrasulfonate In Polyelectrolyte Complexes, Becca Hoene, Dion Rivera

All Faculty Scholarship for the College of the Sciences

Ultraviolet-visible (UV-vis) and fluorescence spectroscopy have been used to characterize the polyelectrolyte complexes (PECs) formed when potassium indigo tetrasulfonate (ITS) interacts with poly diallydimethylammonium chloride (PDADMAC) through columbic attraction in the presence of the reducing agent sodium bisulfite, NaHSO3. The PDADMAC facilitates both the reduction of the ITS and the stabilization of the reduced state of the ITS in an atmospheric oxygen environment. Dilutions of the dye solution show that the PEC is stable to dilutions of at least 1 to 1000. UV–vis studies indicate that the reduced ITS (ITSred) forms what is likely a J-aggregate in the presence of …


Stem Gateway Peer Learning Facilitators Professional Development Curriculum, Janeth Pena Sep 2017

Stem Gateway Peer Learning Facilitators Professional Development Curriculum, Janeth Pena

STEM Gateway

The learning object is a collection of professional development presentations and resources for guiding staff and faculty in training and implementing a Peer Learning Facilitators program, as developed by the STEM Gateway Program, intended for use within an Active Learning classroom environment. The materials were designed and implemented during the University of New Mexico STEM Gateway Project, funded by the U.S. Department of Education Title V program during 2012-2016.


Circumferences Of 3-Connected Claw-Free Graphs, Ii, Zhi-Hong Chen Sep 2017

Circumferences Of 3-Connected Claw-Free Graphs, Ii, Zhi-Hong Chen

Scholarship and Professional Work - LAS

For a graph H , the circumference of H , denoted by c ( H ) , is the length of a longest cycle in H . It is proved in Chen (2016) that if H is a 3-connected claw-free graph of order n with δ ≥ 8 , then c ( H ) ≥ min { 9 δ − 3 , n } . In Li (2006), Li conjectured that every 3-connected k -regular claw-free graph H of order n has c ( H ) ≥ min { 10 k − 4 , n } . Later, Li posed …


Neuronal Correlation Parameter In The Idea Of Thermodynamic Entropy Of An N-Body Gravitationally Bounded System, Ioannis Haranas, Ioannis Gkigkitzis, Ilias S. Kotsireas, Carlos Austerlitz Sep 2017

Neuronal Correlation Parameter In The Idea Of Thermodynamic Entropy Of An N-Body Gravitationally Bounded System, Ioannis Haranas, Ioannis Gkigkitzis, Ilias S. Kotsireas, Carlos Austerlitz

Physics and Computer Science Faculty Publications

Understanding how the brain encodes information and performs computation requires statistical and functional analysis. Given the complexity of the human brain, simple methods that facilitate the interpretation of statistical correlations among different brain regions can be very useful. In this report we introduce a numerical correlation measure that may serve the interpretation of correlational neuronal data, and may assist in the evaluation of different brain states. The description of the dynamical brain system, through a global numerical measure may indicate the presence of an action principle which may facilitate a application of physics principles in the study of the human …


Managing Nitrous Oxide Emissions In Agricultural Fields, Mark S. Coyne, Wei Ren Sep 2017

Managing Nitrous Oxide Emissions In Agricultural Fields, Mark S. Coyne, Wei Ren

Plant and Soil Sciences Research Report

Agriculture is a major contributor to atmospheric nitrous oxide (N2O) (Smith et al., 2014; Tian et al., 2015). Unfortunately, nitrous oxide destroys stratospheric ozone (O3) which protects us from ultraviolet radiation (Cicerone, 1989) and it increases ground level O3, whichis an air pollutant threatening human health and food production. Nitrous oxide is also 298 times more potent than an equivalent amount of carbon dioxide (CO2) in terms of trapping and absorbing reflected solar radiation (Forster et al., 2007). Basic chemistry and physics assure us that increased levels of N2O in the …


On ΤΣ-Quasinormal Subgroups Of Finite Groups, James C. Beidleman, Alexander N. Skiba Sep 2017

On ΤΣ-Quasinormal Subgroups Of Finite Groups, James C. Beidleman, Alexander N. Skiba

Mathematics Faculty Publications

Let σ = {σiiI} be a partition of the set of all primes P and G a finite group. A set H of subgroups of G is said to be a complete Hall σ-set of G if every member ≠ 1 of H is a Hall σi-subgroup of G for some i I and H contains exactly one Hall σi-subgroup of G for every i such that σiπ(G) ≠ ∅.

Let τH(A) = {σiσ …


East African Weathering Dynamics Controlled By Vegetation-Climate Feedbacks, Sarah J. Ivory, Michael M. Mcglue, Geoffrey S. Ellis, Adam Boehlke, Anne-Marie Lézine, Annie Vincens, Andrew S. Cohen Sep 2017

East African Weathering Dynamics Controlled By Vegetation-Climate Feedbacks, Sarah J. Ivory, Michael M. Mcglue, Geoffrey S. Ellis, Adam Boehlke, Anne-Marie Lézine, Annie Vincens, Andrew S. Cohen

Earth and Environmental Sciences Faculty Publications

Tropical weathering has important linkages to global biogeochemistry and landscape evolution in the East African rift. We disentangle the influences of climate and terrestrial vegetation on chemical weathering intensity and erosion at Lake Malawi using a long sediment record. Fossil pollen, microcharcoal, particle size, and mineralogy data affirm that the detrital clays accumulating in deep water within the lake are controlled by feedbacks between climate and hinterland forest composition. Particle-size patterns are also best explained by vegetation, through feedbacks with lake levels, wildfires, and erosion. We develop a new source-to-sink framework that links lacustrine sedimentation to hinterland vegetation in tropical …


Photonic Band Structure Of Diamond Colloidal Crystals In A Cholesteric Liquid Crystal, Setarehalsadat Changizrezaei, Colin Denniston Sep 2017

Photonic Band Structure Of Diamond Colloidal Crystals In A Cholesteric Liquid Crystal, Setarehalsadat Changizrezaei, Colin Denniston

Physics and Astronomy Publications

In this paper, we demonstrate the presence of a photonic band gap for a diamond lattice structure made of particles with normal anchoring inside a cholesteric liquid crystal. As is typical for liquid crystals (LCs), there is considerable contrast between the dielectric constant parallel ε∥ and perpendicular ε⊥ to the director, with ε∥/ε⊥∼4 here. It is shown that the size of the photonic band gap is directly related to the size of colloidal particles and the contrast between the dielectric constant in the particles and the extreme values of ε in the LC medium (one needs either ε in the …


Zr-Doped Tio2 As A Thermostabilizer In Plasmon-Enhanced Dye-Sensitized Solar Cells, Anastasia Pasche, Bernd Grohe, Silvia Mittler, Paul A. Charpentier Sep 2017

Zr-Doped Tio2 As A Thermostabilizer In Plasmon-Enhanced Dye-Sensitized Solar Cells, Anastasia Pasche, Bernd Grohe, Silvia Mittler, Paul A. Charpentier

Physics and Astronomy Publications

Harvesting solar energy is a promising solution toward meeting the world’s evergrowing energy demand. Dye-sensitized solar cells (DSSCs) are hybrid organic–inorganic solar cells with tremendous potential for commercial application, but they are plagued by in efficiency due to their poor sunlight absorption. Plasmonic silver nanoparticles (AgNPs) have been shown to enhance the absorptive properties of DSSCs, but their plasmonic resonance can cause thermal damage resulting in cell deterioration. Hence, the influence of Zr-doped TiO2 on the efficiency of plasmon-enhanced DSSCs was studied, showing that 5 mol.% Zr-doping of the photoactive TiO2 material can improve the photovoltaic performance of DSSCs by …


Synthesis And Antitumor Activity Of N-Triazol-5-Yl-Oxazolidin-4-One Derivatives., R. Luo, S. Guo, Shilong Zheng, Guangdi Wang, X. Bao, L. He Sep 2017

Synthesis And Antitumor Activity Of N-Triazol-5-Yl-Oxazolidin-4-One Derivatives., R. Luo, S. Guo, Shilong Zheng, Guangdi Wang, X. Bao, L. He

Faculty and Staff Publications

Fifteen novel N-triazol-5-yl-oxazolidin-4-ones were synthesized through a few of steps from the benzaldehydes. It was found that N-iodosuccinimide (NIS) can promote intramolecular amination reaction which is the key step of the syntheses, which will be used as new method for the intramolecular formation of nitrogen-containing heterocycles. Part of the compounds were evaluated for their anticancer activity. Among them, compounds 6a, 6b and 6c showed moderate antiprolifiration activity toward human breast cancer cells MDA-MB-231 cell lines, while the mild activity of 6a, 6b and 6d against human cervical cancer HeLa cell lines was confirmed in vitro assay.


Microstructure Of Injection Moulding Machine Mould Clamping Mechanism: Design And Motion Simulation, Z. Jin, Y. Zhang, X. Wang, J. Williams, Z. Liu, Z. Huang, D. Falkner, G. Zhou, L. Dong, J. Zhuang, Zhe Wang Sep 2017

Microstructure Of Injection Moulding Machine Mould Clamping Mechanism: Design And Motion Simulation, Z. Jin, Y. Zhang, X. Wang, J. Williams, Z. Liu, Z. Huang, D. Falkner, G. Zhou, L. Dong, J. Zhuang, Zhe Wang

Faculty and Staff Publications

With the advent of intelligence technologies, more and more machines and devices are involved in the creation of complex structures. In the intelligent manufacturing industries, mouldings including injection moulding, blow moulding, compression moulding, and others play critical roles in manufacturing highly precise parts required for building intelligent machines (such as computers, cell phones, robots etc.). The performance of the clamping mechanism directly affects the quality of the microstructure of injection products. The design of the injection moulding mould clamping mechanism is based on the microstructure characteristics of the trip of the toggle lever mechanism ratio, speed ratio, and force amplification …


Green Leasing Internship: Final Presentation, 2017, Emily Quinton Sep 2017

Green Leasing Internship: Final Presentation, 2017, Emily Quinton

Campus Sustainability Office Publications, Reports and Presentations

Presentation slides from summer 2017 Green Leasing Internship, Portland State University


Student Fellows 2017-2018, Place Sep 2017

Student Fellows 2017-2018, Place

PLACE Historical Documents

This document provides biographies of PLACE student fellows at Linfield College for 2017-2018.


Faculty Fellows 2017-2018, Place Sep 2017

Faculty Fellows 2017-2018, Place

PLACE Historical Documents

This document provides biographies of PLACE faculty fellows at Linfield College for 2017-2018.


The Digital Citizen, Place Sep 2017

The Digital Citizen, Place

PLACE Historical Documents

This document explains the PLACE theme at Linfield College for 2017-2018 (The Digital Society: The Digital Citizen).


Physical Water Scarcity Metrics For Monitoring Progress Towards Sdg Target 6.4: An Evaluation Of Indicator 6.4.2 “Level Of Water Stress”, D. Vanhama, A. Y. Hoekstra, Y. Wada, F. Bouraoui, A. De Roo, Mesfin Mekonnen, W. J. Van De Bund, O. Batelaan, P. Pavelic, W. G.M. Bastiaanssen, M. Kummu, J. Rockström, J. Liu, B. Bisselink, P. Ronco, A. Pistocchi, G. Bidoglio Sep 2017

Physical Water Scarcity Metrics For Monitoring Progress Towards Sdg Target 6.4: An Evaluation Of Indicator 6.4.2 “Level Of Water Stress”, D. Vanhama, A. Y. Hoekstra, Y. Wada, F. Bouraoui, A. De Roo, Mesfin Mekonnen, W. J. Van De Bund, O. Batelaan, P. Pavelic, W. G.M. Bastiaanssen, M. Kummu, J. Rockström, J. Liu, B. Bisselink, P. Ronco, A. Pistocchi, G. Bidoglio

Daugherty Water for Food Global Institute: Faculty Publications

Target 6.4 of the recently adopted Sustainable Development Goals (SDGs) dealswith the reduction ofwater scarcity. To monitor progress towards this target, two indicators are used: Indicator 6.4.1 measuring water use efficiency and 6.4.2 measuring the level of water stress (WS). This paper aims to identify whether the currently proposed indicator 6.4.2 considers the different elements that need to be accounted for in a WS indicator.WS indicators compare water use with water availability.We identify seven essential elements: 1) both gross and net water abstraction (or withdrawal) provide important information to understand WS; 2) WS indicators need to incorporate environmental flow requirements …


Need For A Large-N Array (And Wavelets And Differences) To Determine The Assumption-Free 3-D Earth Model, Solymar Ayala Cortez, Aaron A. Velasco, Vladik Kreinovich Sep 2017

Need For A Large-N Array (And Wavelets And Differences) To Determine The Assumption-Free 3-D Earth Model, Solymar Ayala Cortez, Aaron A. Velasco, Vladik Kreinovich

Departmental Technical Reports (CS)

One of the main objectives of geophysical seismic analysis is to determine the Earth's structure. Usually, to determine this structure, geophysicists supplement the measurement results with additional geophysical assumptions. An important question is: when is it possible to reconstruct the Earth's structure uniquely based on the measurement results only, without the need to use any additional assumptions? In this paper, we show that for this, one needs to use large-N arrays -- 2-D arrays of seismic sensors. To actually perform this reconstruction, we need to use differences between measurements by neighboring sensor and we need to apply wavelet analysis to …


Retrospective Application Of Human Reliability Analysis For Oil And Gas Incidents: A Case Study Using The Petro-Hra Method, Ronald L. Boring, Martin Rasmussen, Thomas A. Ulrich, Harold S. Blackman Sep 2017

Retrospective Application Of Human Reliability Analysis For Oil And Gas Incidents: A Case Study Using The Petro-Hra Method, Ronald L. Boring, Martin Rasmussen, Thomas A. Ulrich, Harold S. Blackman

Division of Research and Economic Development Publications and Presentations

Human reliability analysis (HRA) may be performed prospectively for a newly designed system or retrospectively for an as-built system, typically in response to a safety incident. The SPAR-H HRA method was originally developed for retrospective analysis in the U.S. nuclear industry. As HRA has found homes in new safety critical areas, HRA methods developed predominantly for nuclear power applications are being used in novel ways. The Petro-HRA method represents a significant adaptation of the SPAR-H method for petroleum applications. Current guidance on Petro-HRA considers only prospective applications of the method, such as for review of new systems to be installed …


How To Be A Successful Organic Chemist, Alexander H. Sandtorv Sep 2017

How To Be A Successful Organic Chemist, Alexander H. Sandtorv

PDXOpen: Open Educational Resources

How to be a successful organic chemist is meant as an introductory text for undergraduates taking organic chemistry teaching labs. The text is a clear and practical introduction to safety, chemical handling, organic chemistry techniques, and lab reports.

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Mobile In-Situ Visualization, Mahdi Abbaspour Tehrani Sep 2017

Mobile In-Situ Visualization, Mahdi Abbaspour Tehrani

Link Foundation Modeling, Simulation and Training Fellowship Reports

In this work we present a new distributed technique to geometrically calibrate multiple projectors on a fiducial free arbitrary surface using multiple casually aligned cameras where every point of the surface is seen by at least one camera. Using a multi-step method that uses binary blob patterns, we estimate robustly the display’s 3D surface geometry, the cameras’ extrinsic parameters, and the intrinsic and extrinsic parameters of the multiple projectors.


A Geometric Derivation Of The Irwin-Hall Distribution, James E. Marengo, Lucas Stefanic, David L. Farnsworth Sep 2017

A Geometric Derivation Of The Irwin-Hall Distribution, James E. Marengo, Lucas Stefanic, David L. Farnsworth

Articles

The Irwin-Hall distribution is the distribution of the sum of a finite number of independent identically distributed uniform random variables on the unit interval. Many applications arise since round-off errors have a transformed Irwin-Hall distribution and the distribution supplies spline approximations to normal distributions. We review some of the distribution’s history. The present derivation is very transparent, since it is geometric and explicitly uses the inclusion-exclusion principle. In certain special cases, the derivation can be extended to linear combinations of independent uniform random variables on other intervals of finite length.The derivation adds to the literature about methodologies for finding distributions …


Non‐Linear Thresholds Characterize The Relationship Between Reef Fishes And Mangrove Habitat, Geoffrey S. Shideler, Rafael J. Araujo, Brian K. Walker, Jeremiah Blondeau, Joseph E. Serafy Sep 2017

Non‐Linear Thresholds Characterize The Relationship Between Reef Fishes And Mangrove Habitat, Geoffrey S. Shideler, Rafael J. Araujo, Brian K. Walker, Jeremiah Blondeau, Joseph E. Serafy

Marine & Environmental Sciences Faculty Articles

A significant obstacle to evaluating the importance of mangrove habitat to coral reef fishes has been the difficulty of disentangling its effects from other subtidal/nearshore habitats or human population pressures. Florida's seascape, unlike most others, has been extensively surveyed and mapped, and there are reliable estimates of human population density. Despite many studies that have correlated reef fish abundance with nearby mangrove habitat, some researchers continue to question the importance of mangroves to reef fishes. Previous studies that have investigated the mangrove–reef fish subsidy effect have applied methods that either compared averages or examined linear relationships; yet there is a …