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2021

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Articles 271 - 300 of 27755

Full-Text Articles in Physical Sciences and Mathematics

Evaluation And Improvement Of Nuclear Security Measures At A Radiological Facility In Morocco, Halima Jemmal, Abdelmajid Choukri, Mohammed Mouhib Dec 2021

Evaluation And Improvement Of Nuclear Security Measures At A Radiological Facility In Morocco, Halima Jemmal, Abdelmajid Choukri, Mohammed Mouhib

International Journal of Nuclear Security

Nuclear security combines both concepts of physical security and security culture within a nuclear facility to protect people, property, society and the environment from harmful effects of ionization radiation. Physical security means prevention, detection, and response to unauthorized removal, sabotage, and/or illegal transfer involving radioactive sources and nuclear material. Nuclear security culture is the human factor within the nuclear field which is considered a principal means to support and enhance nuclear security system. This paper presents a study of nuclear security system already established within a radiological facility considering concepts such as: deter, detect, delay, and response layers. This study …


Joint Management Of Upland & Aquatic Habitat For The California Red-Legged Frog & California Tiger Salamander, Kyle E. Verblaauw Dec 2021

Joint Management Of Upland & Aquatic Habitat For The California Red-Legged Frog & California Tiger Salamander, Kyle E. Verblaauw

Master's Projects and Capstones

As federally and state protected amphibians, the California tiger salamander (Ambystoma californiense) and the California red-legged frog (Rana draytonii) are recipients of ample management focus. Both species face a variety of threats, including habitat loss and alteration, introduction of non-native species, spread of disease, and effects of climate change. While management plans for the California tiger salamander and California red-legged frog exist, they frequently do not consider both species in tandem and often contain multiple shortcomings. This document aims to address the shortfalls of current management by providing practical recommendations for jointly managing the upland and …


Physics-Informed Machine Learning To Predict Extreme Weather Events, Rthvik Raviprakash, Jonathan Buchanan, Mahdi Bu Ali Dec 2021

Physics-Informed Machine Learning To Predict Extreme Weather Events, Rthvik Raviprakash, Jonathan Buchanan, Mahdi Bu Ali

Discovery Undergraduate Interdisciplinary Research Internship

Extreme weather events refer to unexpected, severe, or unseasonal weather events, which are dynamically related to specific large-scale atmospheric patterns. These extreme weather events have a significant impact on human society and also natural ecosystems. For example, natural disasters due to extreme weather events caused more than $90 billion global direct losses in 2015. These extreme weather events are challenging to predict due to the chaotic nature of the atmosphere and are highly correlated with the occurrence of atmospheric blocking. A key aspect for preparedness and response to extreme climate events is accurate medium-range forecasting of atmospheric blocking events.

Unlike …


An Analysis Of Two Photometric Redshift Methods And Their Uses For Finding Void Galaxies, Rochelle J. Steele Dec 2021

An Analysis Of Two Photometric Redshift Methods And Their Uses For Finding Void Galaxies, Rochelle J. Steele

Theses and Dissertations

An extensive survey of extragalactic objects with accurate distances is difficult to perform. Distance at that scale is commonly found with redshift and most easily identified with spectroscopic observations, which are time intensive. This is especially a concern when surveying for the elusive, possibly non-existent dwarf galaxies in the centers of voids, whose light would be so faint that a spectroscopic survey to find them would be unreasonably time consuming. Photometric methods to calculate redshift could provide a much quicker way to find distance, but the photometric methods used thus far are characterized by large errors that make them unusable …


Nitrogenase Iron Protein Classification Using Cnn Neural Network, Amer Rez Dec 2021

Nitrogenase Iron Protein Classification Using Cnn Neural Network, Amer Rez

Master's Projects

The nitrogenase iron protein (NifH) is extensively used to study nitrogen fixation, the ecologically vital process of reducing atmospheric nitrogen to a bioavailable form. The discovery rate of novel NifH sequences is high, and there is an ongoing need for software tools to mine NifH records from the GenBank repository. Since record annotations are unreliable, because they contain errors, classifiers based on sequence alone are required. The ARBitrator classifier is highly successful but must be initialized by extensive manual effort. A Deep Learning approach could substantially reduce manual intervention. However, attempts to build a character-based Deep Learning NifH classifier were …


Achieving Fairness Through Load-Balancing In Social Cloud Computing Networks, Kaiyi Huang Dec 2021

Achieving Fairness Through Load-Balancing In Social Cloud Computing Networks, Kaiyi Huang

Master's Projects

Cloud-based computing networks have taken over the digital landscape. From small non-profits to large multinational corporations, more and more entities have been offloading computing effort to the cloud in order to take advantage of the increased cost-efficiency and scalability of cloud computing. One of the new types of cloud that have emerged is the P2P cloud, which disengages from a traditional datacenter setup by allowing users to instead share their own computing hardware into a cloud to take advantage of cloud computing’s advantages at an even lower cost. However, this new paradigm comes with a slew of challenges, notably, security …


The Impact Of Programming Language’S Type On Probabilistic Machine Learning Models, Sherif Elsaid Dec 2021

The Impact Of Programming Language’S Type On Probabilistic Machine Learning Models, Sherif Elsaid

Master's Projects

Software development is an expensive and difficult process. Mistakes can be easily made, and without extensive review process, those mistakes can make it to the production code and may have unintended disastrous consequences.

This is why various automated code review services have arisen in the recent years. From AWS’s CodeGuro and Microsoft’s Code Analysis to more integrated code assistants, like IntelliCode and auto completion tools. All of which are designed to help and assist the developers with their work and help catch overlooked bugs.

Thanks to recent advances in machine learning, these services have grown tremen- dously in sophistication to …


Unbuilding: How Deconstruction Is Saving The Planet By Giving Building Materials A Second Life, Diana M. Ducroz Dec 2021

Unbuilding: How Deconstruction Is Saving The Planet By Giving Building Materials A Second Life, Diana M. Ducroz

Capstones

In 2018, more than 600 million tons of construction and demolition (C&D) waste was generated in the United States, more than twice the volume of ordinary trash created by American households and businesses. Even though 80-95% of this concrete, asphalt, steel, wood, drywall, glass and brick can be reused, repurposed or recycled, a quarter of it – or 145 million tons in 2018 – ends up in landfills. Thirty million tons of wood alone – often sturdy, irreplaceable old-growth lumber – is being trashed every year.

Now, a budding ‘build reuse’ movement, made up of environmentalists, architects, historic preservationists, city …


Computational Thinking For Teachers, Susan Imberman Dec 2021

Computational Thinking For Teachers, Susan Imberman

Open Educational Resources

This is a syllabus for a course in computational thinking. The course described introduces preservice and inservice teachers to the fundamental concepts of computer science, including web design, coding, ethics, computational thinking, course resources, etc.


Request For Change (Rfc) To The Final Butte Reduction Works (Brw) Smelter Area Mine Waste Remediation And Contaminated Groundwater Hydraulic Control Site Phase Iii Quality Assurance Project Plan (Qapp) (Rfc-Brw-2021-03), Josh Bryson Dec 2021

Request For Change (Rfc) To The Final Butte Reduction Works (Brw) Smelter Area Mine Waste Remediation And Contaminated Groundwater Hydraulic Control Site Phase Iii Quality Assurance Project Plan (Qapp) (Rfc-Brw-2021-03), Josh Bryson

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.


Task Classification During Visual Search Using Classic Machine Learning And Deep Learning, Devangi Vilas Chinchankar Dec 2021

Task Classification During Visual Search Using Classic Machine Learning And Deep Learning, Devangi Vilas Chinchankar

Master's Projects

In an average human life, the eyes not only passively scan visual scenes, but most times end up actively performing tasks including, but not limited to, searching, comparing, and counting. As a result of the advances in technology, we are observing a boost in the average screen time. Humans are now looking at an increasing number of screens and in turn images and videos. Understanding what scene a user is looking at and what type of visual task is being performed can be useful in developing intelligent user interfaces, and in virtual reality and augmented reality devices. In this research, …


Dynamic Resource Management Of Fog-Cloud Computing For Iot Support, Mariia Surmenok Dec 2021

Dynamic Resource Management Of Fog-Cloud Computing For Iot Support, Mariia Surmenok

Master's Projects

The internet of things (IoT) is an integrated part of contemporary life. It includes wearable devices, such as smart watches and cell phones, as well as sensors for Smart City. Fog computing can improve the efficiency and battery life of IoT devices by offloading tasks to fog cloud. It is important to have fog clusters near the IoT device for faster data offload. The goal of this project is to develop dynamic resource allocation for on-demand fog computing cluster to efficiently deploy tasks from IoT. This report studies the different research papers about the current state of resource management in …


Privacy Preserving For Multiple Computer Vision Tasks, Amala Varghese Wilson Dec 2021

Privacy Preserving For Multiple Computer Vision Tasks, Amala Varghese Wilson

Master's Projects

Privacy-preserving visual recognition is an important area of research that is gaining momentum in the field of computer vision. In a production environment, it is critical to have neural network models learn continually from user data. However, sharing raw user data with a server is less desirable from a regulatory, security and privacy perspective. Federated learning addresses the problem of privacy- preserving visual recognition. More specifically, we closely examine and dissect a framework known as Dual User Adaptation (DUA) presented by Lange et al. at CVPR 2020, due to its novel idea of bringing about user-adaptation on both the server-side …


Design And Synthesis Of Small Molecular Probes For Cns And Kidney Disorders, Swagat H. Sharma Dec 2021

Design And Synthesis Of Small Molecular Probes For Cns And Kidney Disorders, Swagat H. Sharma

Theses & Dissertations

The G protein regulated inwardly rectifying potassium channels (GIRK) are a family of inwardly rectifying potassium channels and are key effectors in signaling pathways. GIRK 1/2 channel subunit, predominantly found in the brain, is involved pathophysiology of various neurological disorders including, but not limited to, epilepsy, anxiety, Parkinson's, pain, reward, and addiction. Previously, our laboratory had identified a series of urea containing molecules as GIRK1/2 preferring activators. Unfortunately, the urea series suffers from significant PK liabilities (solubility, brain penetration and high clearance). The chapter 1 of the dissertation describes our efforts in developing three new series of activators with improved …


Approximate Likelihood Based Estimations For Joint Models With Intractable Likelihoods, Karl Stessy M. Bisselou Dec 2021

Approximate Likelihood Based Estimations For Joint Models With Intractable Likelihoods, Karl Stessy M. Bisselou

Theses & Dissertations

This dissertation focuses on the development of approximation approaches for the joint modeling (JM) of repeated measures data and time-to-event data in the presence of analytically or numerically intractable likelihoods. Current likelihood-based inferences for JMs show several limitations including (i) intractability of integrals during marginal likelihood derivations due to the complexity in computations, and (ii) the large number of nuisance parameters (unobserved) posing a problem with convergence. The h-likelihood (HL) and synthetic likelihood (SL) are two computationally efficient estimation approaches that overcome these challenges.

In the presence of extremely high censoring rates, the HL can produce bias parameter estimates. We …


A Literature Review Of Wetland Treatment Systems Used To Treat Runoff Mixtures Containing Antibiotics And Pesticides From Urban And Agricultural Landscapes, Emily R. Nottingham, Tiffany L. Messer Dec 2021

A Literature Review Of Wetland Treatment Systems Used To Treat Runoff Mixtures Containing Antibiotics And Pesticides From Urban And Agricultural Landscapes, Emily R. Nottingham, Tiffany L. Messer

Biosystems and Agricultural Engineering Faculty Publications

Wetland treatment systems are used extensively across the world to mitigate surface runoff. While wetland treatment for nitrogen mitigation has been comprehensively reviewed, the implications of common-use pesticides and antibiotics on nitrogen reduction remain relatively unreviewed. Therefore, this review seeks to comprehensively assess the removal of commonly used pesticides and antibiotics and their implications for nitrogen removal in wetland treatment systems receiving non-point source runoff from urban and agricultural landscapes. A total of 181 primary studies were identified spanning 37 countries. Most of the reviewed publications studied pesticides (n = 153) entering wetlands systems, while antibiotics (n = 29) had …


Spin-Dependent Electronic Transport In Noncollinear Antiferromagnetic Antiperovskites, Gautam Gurung Dec 2021

Spin-Dependent Electronic Transport In Noncollinear Antiferromagnetic Antiperovskites, Gautam Gurung

Department of Physics and Astronomy: Dissertations, Theses, and Student Research

Spin-dependent properties are the heart of spintronic devices. Spintronics exploits electron’s spin, in addition to charge, to process and store the information. Recently, antiferromagnetic (AFM) spintronics has emerged as a subfield of spintronics, where an AFM order parameter (the Néel vector) is exploited to control spin-dependent transport properties. Due to being robust against magnetic perturbations, producing no stray fields, and exhibiting ultrafast dynamics, antiferromagnets can serve as promising functional materials for spintronic applications.

Among antiferromagnets, high Néel temperature noncollinear antiperovskites ANMn3 (A = Ga, Ni, Sn, and Pt) are interesting due to their magnetic group symmetry supporting non-trivial spin-dependent …


Poor Acclimation To Experimental Field Drought In Subalpine Forest Tree Seedlings, Alex Goke, Patrick H. Martin Dec 2021

Poor Acclimation To Experimental Field Drought In Subalpine Forest Tree Seedlings, Alex Goke, Patrick H. Martin

Biological Sciences: Faculty Scholarship

The ability of tree species to acclimate and tolerate projected increases in drought frequency and intensity has fundamental implications for future forest dynamics with climate change. Inquiries to date on the drought tolerance capacities of tree species, however, have focused almost exclusively on mature trees with scant in situ work on seedlings, despite the central role that regeneration dynamics play in forest responses to changing conditions. We subjected naturally established seedlings of co-dominant subalpine conifer species (Abies lasiocarpa and Picea engelmannii) in the southern Rocky Mountains to 2 years of in situ summer precipitation exclusion, simulating summer drought …


Chromatic Quasisymmetric Class Functions For Combinatorial Hopf Monoids, Jacob A. White Dec 2021

Chromatic Quasisymmetric Class Functions For Combinatorial Hopf Monoids, Jacob A. White

School of Mathematical & Statistical Sciences Faculty Publications

We study the chromatic quasisymmetric class function of a linearized combinatorial Hopf monoid. Given a linearized combinatorial Hopf monoid H, and an H-structure h on a set N, there are proper colorings of h, generalizing graph colorings and poset partitions. We show that the automorphism group of h acts on the set of proper colorings. The chromatic quasisymmetric class function enumerates the fixed points of this action, weighting each coloring with a monomial. For the Hopf monoid of graphs this invariant generalizes Stanley's chromatic symmetric function and specializes to the orbital chromatic polynomial of Cameron and Kayibi.

We also introduce …


Pentagonal Extensions Of The Rationals Ramified At A Single Prime, Pablo Miguel Rodriguez Dec 2021

Pentagonal Extensions Of The Rationals Ramified At A Single Prime, Pablo Miguel Rodriguez

Theses and Dissertations

In this thesis, we define a certain group of order 160, which we call a hyperpentagonal group, and we prove that every totally real D5-extension of the rationals ramified at only one prime is contained in a hyperpentagonal extension of the rationals. This generalizes a result of Doud and Childers (originally conjectured by Wong) that every totally real S3 extension of the rationals ramified at only one prime is contained in an S4 extension.


Comparing The Efficiency Of A Marsh-Sill And Oyster Reef Balls In Attenuating Waves, Navid Tahvildari, Alexa Leone Dec 2021

Comparing The Efficiency Of A Marsh-Sill And Oyster Reef Balls In Attenuating Waves, Navid Tahvildari, Alexa Leone

December 17, 2021: Natural and Nature-Based Solutions (Part 2)

No abstract provided.


Carbon Sequestration Benefits Of Coastal Restoration, Brendan Player Dec 2021

Carbon Sequestration Benefits Of Coastal Restoration, Brendan Player

December 17, 2021: Natural and Nature-Based Solutions (Part 2)

No abstract provided.


Living Shorelines Achieve Functional Equivalence To Natural Fringe Marshes Across Multiple Ecological Metrics, Robert E. Isdell, Donna Marie Bilkovic, Amanda G. Guthrie, Molly M. Mitchell, Randolph M. Chambers, Matthias Leu, Carl Hershner Dec 2021

Living Shorelines Achieve Functional Equivalence To Natural Fringe Marshes Across Multiple Ecological Metrics, Robert E. Isdell, Donna Marie Bilkovic, Amanda G. Guthrie, Molly M. Mitchell, Randolph M. Chambers, Matthias Leu, Carl Hershner

December 17, 2021: Natural and Nature-Based Solutions (Part 2)

No abstract provided.


Agenda- Hampton Roads Sea Level Rise/Flooding Adaptation Forum, Ben Mcfarlane, Wie Yusuf Dec 2021

Agenda- Hampton Roads Sea Level Rise/Flooding Adaptation Forum, Ben Mcfarlane, Wie Yusuf

December 17, 2021: Natural and Nature-Based Solutions (Part 2)

Agenda for the Hampton Roads Sea Level Rise/Flooding Adaptation Forum on December 17, 2021 via Virtual Forum.

  • Opening Remarks and Introductions: Ben McFarlane, Hampton Roads Planning District Commission and Dr. Wie Yusuf, Old Dominion University and Virginia Sea Grant
  • Navid Tahvildari, of Old Dominion University: Comparing the Efficiency of a Marsh-Sill and Oyster Reef Balls in Attenuating Waves
  • Brendan Player, of Stantec: Carbon Sequestration Benefits of Coastal Restoration
  • Robert Isdell, of Virginia Institute of Marine Science: Living Shorelines Achieve Functional Equivalence to Natural Fringe Marshes Across Multiple Ecological Metrics
  • Closing Remarks and Reminders


Epa Region 8 Qa Document Review Crosswalk, Nikia Greene Dec 2021

Epa Region 8 Qa Document Review Crosswalk, Nikia Greene

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.


Draft Residential Metals Abatement Program Quality Assurance Project Plan (Non-Residential Parcels - Indoor Dust), Elsie King, Christopher Berg, Thomas J. Beckman Dec 2021

Draft Residential Metals Abatement Program Quality Assurance Project Plan (Non-Residential Parcels - Indoor Dust), Elsie King, Christopher Berg, Thomas J. Beckman

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.


Residential Metals Abatement Program Quality Assurance Project Plan (Non-Residential Parcels - Indoor Dust), Environmental Resource Management (Erm), Elsie King, Christopher Berg, Thomas J. Beckman Dec 2021

Residential Metals Abatement Program Quality Assurance Project Plan (Non-Residential Parcels - Indoor Dust), Environmental Resource Management (Erm), Elsie King, Christopher Berg, Thomas J. Beckman

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.


Distribution, Abundance And Natural Enemies Of The Invasive Tomato Leafminer, Tuta Absoluta (Meyrick) In Kenya, G. Kinyanjui, F. M. Khamis, F. L.O. Ombura, E. U. Kenya, S. Ekesi, S. A. Mohamed Dec 2021

Distribution, Abundance And Natural Enemies Of The Invasive Tomato Leafminer, Tuta Absoluta (Meyrick) In Kenya, G. Kinyanjui, F. M. Khamis, F. L.O. Ombura, E. U. Kenya, S. Ekesi, S. A. Mohamed

All Peer-Reviewed Publications

Tuta absoluta (Meyrick) has become a serious menace to sustainable production of tomato in Kenya. A survey was conducted between April 2015 and June 2016 to determine its distribution, abundance, infestation, and damage levels on tomato, and associated natural enemies. Trap counts of T. absoluta moths were recorded in all surveyed 29 counties, which indicated its nationwide distribution irrespective of altitude. Tuta absoluta was present in both open fields and greenhouses. The highest moth/trap/day was 115.38 ± 15.90. Highest leaf infestation was 92.22% and the highest number of mines and larvae per leaf were 3.71 ± 0.28 and 2.16 ± …


Influence Of Grassland Management And Grazing By Different Farm Animals On Animal Performance And Flora Alterations, W. Jentsch, H.-D. Matthes, A. Admasu, H. Möhring Dec 2021

Influence Of Grassland Management And Grazing By Different Farm Animals On Animal Performance And Flora Alterations, W. Jentsch, H.-D. Matthes, A. Admasu, H. Möhring

IGC Proceedings (1977-2023)

The objectives of this study were to test the possibilities of using different farm animals for landscape care on extensive pasture, taking into account their particular performance, and to analyse alterations of the flora in consequence of grazing by different animals and various pasture management. Salers had the highest (836g/d) and Galloways (584g/d) the lowest live weight gain as compared with the other breeds (771g/d). Lambs had higher live weight when grazing together with cattle and horses (mixed grazing) than under one species grazing. The number of legume increased and that of grass decreased. Following 3 years the grazing animals …


Animal Production From Tropical Pastures Renovated By Subsoiling And Fertilization In The Cerrados Of Brazil, Valéria P. B. Euclides, Manuel C. M. Macedo, M. P. Oliveira Dec 2021

Animal Production From Tropical Pastures Renovated By Subsoiling And Fertilization In The Cerrados Of Brazil, Valéria P. B. Euclides, Manuel C. M. Macedo, M. P. Oliveira

IGC Proceedings (1977-2023)

A grazing trial was conducted, to study the effects of fertilization on the maintenance of the productivity of four tropical grasses. The paddocks were subsoiled, and dived into halves: one (LF1) received 400 kg/ha of a fertilizer formula 0-20-20.and the other (LF2) 800 kg/ha of the same fertilizers, in January 1995. Annually, 50 kg/ha of N was applied. The productivity on LF2 pastures was greater than that on FL1 pastures, averaging 520 and 410 kg of liveweight gain/ha/year. A double strategy should be followed to sustain animal production in the savanna: maintain soil P over a critical value of 3.0 …