Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

2020

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 15151 - 15180 of 15205

Full-Text Articles in Physical Sciences and Mathematics

Investigating Diel, Seasonal, And Interannual Variability Of Dissolved And Particulate Stable Carbon Isotope Values In A Eutrophic Boreal Lake, Rachel Henderson Jan 2020

Investigating Diel, Seasonal, And Interannual Variability Of Dissolved And Particulate Stable Carbon Isotope Values In A Eutrophic Boreal Lake, Rachel Henderson

Theses and Dissertations (Comprehensive)

Lakes are globally significant sources, sinks, and conduits of carbon. Cultural eutrophication of freshwater promotes the growth of phytoplankton blooms, which can transform, respire, and sequester large amounts of carbon. Analysis of stable carbon isotopes is a common tool to study the movement of carbon through the aquatic carbon cycle. The causes of temporal variability in δ13C values at different timescales are not well understood, and differ between lakes. In this study, I investigated diel, seasonal, and interannual variability in δ13C values of dissolved inorganic carbon (DIC) and particulate organic carbon (POC) in Lake 227, an …


Aggregate Loss Model With Poisson-Tweedie Loss Frequency, Si Chen Jan 2020

Aggregate Loss Model With Poisson-Tweedie Loss Frequency, Si Chen

Theses and Dissertations (Comprehensive)

The aggregate loss model has applications in various areas such as financial risk management and actuarial science. The aggregate loss is the summation of all random losses occurred in a period, and it is governed by both the loss severity and the loss frequency. While the impact of the loss severity on aggregate loss is well studied, less focus is paid on the influence of loss frequency on aggregate loss, which motivates our study. In this thesis, we enrich the aggregate loss framework by introducing the Poisson-Tweedie distribution as a candidate for modelling loss frequency, prove the closedness of Poisson-Tweedie …


Detection And Localization Of Linear Features Based On Image Processing Methods, Sean Cormick Matz Jan 2020

Detection And Localization Of Linear Features Based On Image Processing Methods, Sean Cormick Matz

CGU Theses & Dissertations

In this work, the general problem of the detection of features in images is considered. One of the methods, the orientation detection of lines, utilized the Radon transform (sinogram) of an image to detect lines at different angles in an image. The line thickness algorithm was generated by finding a pattern formed by particular lines in an image. The filtering of reconstructed images dealt with the removal of blur and other artifacts that arose in the course of inverting the Radon transform of an image to attempt to obtain the original image.


Novel Random Forest Methods And Algorithms For Autism Spectrum Disorders Research, Afrooz Jahedi Jan 2020

Novel Random Forest Methods And Algorithms For Autism Spectrum Disorders Research, Afrooz Jahedi

CGU Theses & Dissertations

Random Forest (RF) is a flexible, easy to use machine learning algorithm that was proposed by Leo Breiman in 2001 for building a predictor ensemble with a set of decision trees that grow in randomly selected subspaces of data. Its superior prediction accuracy has made it the most used algorithms in the machine learning field. In this dissertation, we use the random forest as the main building block for creating a proximity matrix for multivariate matching and diagnostic classification problems that are used for autism research (as an exemplary application). In observational studies, matching is used to optimize the balance …


High Order Explicit Semi-Lagrangian Method For The Solution Of Lagrangian Transport And Stochastic Differential Equations, Hareshram Natarajan Jan 2020

High Order Explicit Semi-Lagrangian Method For The Solution Of Lagrangian Transport And Stochastic Differential Equations, Hareshram Natarajan

CGU Theses & Dissertations

A semi-Lagrangian method is developed for the solution of Lagrangian transport equations and stochastic differential equations that is consistent with Discontinuous Spectral Element Method (DSEM) approximations of Eulerian conservation laws. The method extends the favorable properties of DSEM that include its high-order accuracy, its local and boundary fitted properties and its high performance on parallel platforms for the concurrent semi-Lagrangian and Eulerian solution of a class of time-dependent problems that can be described by coupled Eulerian-Lagrangian formulations. Such formulations include the probabilistic models used for the simulation of chemically reacting turbulent flows or particle-laden flows. Motivated by the high-fidelity simulation …


Plasmonic Slab Waveguides: Theory & Application For Sensors, Anum Khattak Jan 2020

Plasmonic Slab Waveguides: Theory & Application For Sensors, Anum Khattak

Theses and Dissertations (Comprehensive)

Through surface plasmon polaritons (SPPs) that propagate along the interface between a metal and a dielectric material, plasmonic waveguides have the ability to confine light at subwavelength scale beyond the diffraction limit, which opens a promising platform to further downsize the active and passive photonic devices. The fields of the SPPs have maximum amplitude at the metal/dielectric interface and decay exponentially toward both media, where the penetration of the fields in the dielectric is very susceptible to the change in the refractive index of the dielectric. This makes surface plasmon resonance (SPR) a remarkable technique in sensor applications to investigate …


Monitoring Environmental Change Using A Participatory Modified Photovoice Approach With Indigenous Knowledge Holders In Kakisa, Northwest Territories, Kaitlin Kok Jan 2020

Monitoring Environmental Change Using A Participatory Modified Photovoice Approach With Indigenous Knowledge Holders In Kakisa, Northwest Territories, Kaitlin Kok

Theses and Dissertations (Comprehensive)

In response to growing pressures from climate change and the lack of a monitoring strategy for food security at a local and regional level in the Northwest Territories, there is an urgency for residents to record their own images of change in relation to harvester safety. This thesis explores the connection between geographic information systems, sustainable food systems, indigenous knowledge and the importance of place. The objective of this study is two-fold: (a) to develop a monitoring system in conjunction with the community of Kakisa and (b) to increase the resilience of the local food system. The methods used derive …


A Comprehensive Analysis Of Smart Ship Systems And Underlying Cybersecurity Issues, Dennis Bothur Jan 2020

A Comprehensive Analysis Of Smart Ship Systems And Underlying Cybersecurity Issues, Dennis Bothur

Theses : Honours

The maritime domain benefits greatly from advanced technology and ubiquitous connectivity. From “smart” sensors to “augmented reality”, the opportunities to save costs and improve safety are endless. The aim of this dissertation is to study the capabilities of smart ship systems in the context of Internet-of-Things and analyse the potential cybersecurity risks and challenges that smart technologies may introduce into this accelerating digital economy.

The first part of this work investigates the architecture of a “Smart Ship System” and the primary subsystems, including the integrated bridge, navigation and communication systems, networking, operational systems, and sensor networks. The mapping of the …


Text Mining Methods For Analyzing Online Health Information And Communication, Sifei Han Jan 2020

Text Mining Methods For Analyzing Online Health Information And Communication, Sifei Han

Theses and Dissertations--Computer Science

The Internet provides an alternative way to share health information. Specifically, social network systems such as Twitter, Facebook, Reddit, and disease specific online support forums are increasingly being used to share information on health related topics. This could be in the form of personal health information disclosure to seek suggestions or answering other patients' questions based on their history. This social media uptake gives a new angle to improve the current health communication landscape with consumer generated content from social platforms. With these online modes of communication, health providers can offer more immediate support to the people seeking advice. Non-profit …


Estimating Free-Flow Speed With Lidar And Overhead Imagery, Armin Hadzic Jan 2020

Estimating Free-Flow Speed With Lidar And Overhead Imagery, Armin Hadzic

Theses and Dissertations--Computer Science

Understanding free-flow speed is fundamental to transportation engineering in order to improve traffic flow, control, and planning. The free-flow speed of a road segment is the average speed of automobiles unaffected by traffic congestion or delay. Collecting speed data across a state is both expensive and time consuming. Some approaches have been presented to estimate speed using geometric road features for certain types of roads in limited environments. However, estimating speed at state scale for varying landscapes, environments, and road qualities has been relegated to manual engineering and expensive sensor networks. This thesis proposes an automated approach for estimating free-flow …


Deep Neural Architectures For End-To-End Relation Extraction, Tung Tran Jan 2020

Deep Neural Architectures For End-To-End Relation Extraction, Tung Tran

Theses and Dissertations--Computer Science

The rapid pace of scientific and technological advancements has led to a meteoric growth in knowledge, as evidenced by a sharp increase in the number of scholarly publications in recent years. PubMed, for example, archives more than 30 million biomedical articles across various domains and covers a wide range of topics including medicine, pharmacy, biology, and healthcare. Social media and digital journalism have similarly experienced their own accelerated growth in the age of big data. Hence, there is a compelling need for ways to organize and distill the vast, fragmented body of information (often unstructured in the form of natural …


Microdialysis: A Method For Quantifying In Situ Nitrogen Fluxes In Soil Microsites, Srusti Maddala, Mary C. Savin, Julie A. Stenken, Lisa S. Wood Jan 2020

Microdialysis: A Method For Quantifying In Situ Nitrogen Fluxes In Soil Microsites, Srusti Maddala, Mary C. Savin, Julie A. Stenken, Lisa S. Wood

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Microdialysis, a diffusion-based sampling technique commonly used in biomedical research, has recently been recognized as a candidate for monitoring chemical changes in the rhizosphere. The information it provides about nutrient diffusion may improve nitrogen use efficiency, leading to enhanced management and success of restoration projects. The objective of this study was to determine the efficacy of microdialysis sampling to quantify the relative recoveries (RR%) of nitrate-N and ammonium-N, the two inorganic nitrogen compounds typically found in soil. The effects of microdialysis flow rate, sample medium concentration, and the presence of both analytes in solution on the relative recoveries obtained from …


Corn Response To Wastewater-Recycled Phosphorus Fertilizers, Shane R. Ylagan, Kristofor R. Brye Jan 2020

Corn Response To Wastewater-Recycled Phosphorus Fertilizers, Shane R. Ylagan, Kristofor R. Brye

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

The ability to recycle phosphorus (P) from wastewaters could provide a sustainable, continuous source of P that might also help protect surface water quality from P enrichment. The mineral struvite (MgNH4PO4 · 6H2O) is an understudied material that can be created from P- and nitrogen (N)-containing wastewater and has been shown to have agricultural fertilizer value. The objective of this study was to evaluate the effects of electrochemically precipitated struvite (ECST), chemically precipitated struvite (Crystal Green; CG), diammonium phosphate (DAP), monoammonium phosphate (MAP), rock phosphate (RP), and triple superphosphate (TSP) on corn (Zea mays) response in a greenhouse pot study. …


Stylized 2d Fabrication Of Non-Photorealistic Images, Athina Panotopoulou Jan 2020

Stylized 2d Fabrication Of Non-Photorealistic Images, Athina Panotopoulou

Dartmouth College Ph.D Dissertations

A current trend in computer graphics is the use of programmable tools that allow non-experts to engage in the design of physical prototypes. Within fabrication, one area of research focuses on non-photorealistic images which are stylized to depict a particular aesthetic quality or convey key information. In cases where authenticity is demanded or the images need to be manipulated, fabrication is necessary. Non-photorealistic image fabrication involves two challenges: identifying and abstracting key information during design and considering material restrictions during fabrication. This thesis showcases two examples for fabricating new types of non-photorealistic images, the first involving watercolors, and the second …


Bow Lake (Station 1 - Ledges) 2020 Water Quality Highlight Report, Robert Craycraft Jan 2020

Bow Lake (Station 1 - Ledges) 2020 Water Quality Highlight Report, Robert Craycraft

UNH Cooperative Extension

A Water Quality Highlight Report by UNH CE Lakes Lay Monitoring Program for Bow Lake, Station - 1 Ledges (Barrington and Northwood, NH) for 2020.


Methyl Ketones From Carboxylic Acids As Valuable Target Molecules In The Biorefinery, Olivier Marie, Alexey Ignatchenko, Michael Renz Jan 2020

Methyl Ketones From Carboxylic Acids As Valuable Target Molecules In The Biorefinery, Olivier Marie, Alexey Ignatchenko, Michael Renz

Chemistry Faculty/Staff Publications

For the preparation of methyl ketones, cross Ketonic Decarboxylation, i.e., the formation of a ketone from two different carboxylic acids, and the reketonization, i.e., the transformation of a carboxylic acid into a ketone employing a ketone as alkyl transfer agent, may be interesting alternatives to classical pathways involving metal-organic reagents.

The fine chemical 2-undecanone was chosen as model compound and ketonic decarboxylation and reketonization evaluated by Green Chemistry matrices, namely the carbon atom efficiency and the e-factor. The e-factor of the reaction of decanoic acid with acetic acid was less than five and, therewith, in the acceptable range for bulk …


Simulation Based Inference In Epidemic Models, Tejitha Dharmagadda Jan 2020

Simulation Based Inference In Epidemic Models, Tejitha Dharmagadda

Theses, Dissertations and Culminating Projects

From ancient times to the modern day, public health has been an area of great interest. Studies on the nature of disease epidemics began around 400 BC and has been a continuous area of study for the well-being of individuals around the world. For over 100 years, epidemiologists and mathematicians have developed numerous mathematical models to improve our understanding of infectious disease dynamics with an eye on controlling and preventing disease outbreak and spread. In this thesis, we discuss several types of mathematical compartmental models such as the SIR, and SIS models. To capture the noise inherent in the real-world, …


Assessing The Capabilities And Limitations Of Privatizing State Environmental Remediation Programs, Robert B. Oleksy Jan 2020

Assessing The Capabilities And Limitations Of Privatizing State Environmental Remediation Programs, Robert B. Oleksy

Theses, Dissertations and Culminating Projects

In 2012, environmental remediations in the state of New Jersey were modified to proceed under the supervision of a Licensed Site Remediation Professional (LSRP), rather than under the management of the New Jersey Department of Environmental Protection (NJDEP). The LSRP program was set forth in the Site Remediation Reform Act (SRRA), which was established to accelerate the investigation and remediation of over 20,000 contaminated sites in the state. The program created major modifications to the management of site remediations by privatizing the process. Under the new program, a licensed individual from the private sector is designated as a LSRP, and …


Distance Oracles For Interval Graphs Via Breadth-First Rank/Select In Succinct Trees, Meng He, J. Ian Munro, Yakov Nekrich, Sebastian Wild, Kaiyu Wu Jan 2020

Distance Oracles For Interval Graphs Via Breadth-First Rank/Select In Succinct Trees, Meng He, J. Ian Munro, Yakov Nekrich, Sebastian Wild, Kaiyu Wu

Michigan Tech Publications

We present the first succinct distance oracles for (unweighted) interval graphs and related classes of graphs, using a novel succinct data structure for ordinal trees that supports the mapping between preorder (i.e., depth-first) ranks and level-order (breadth-first) ranks of nodes in constant time. Our distance oracles for interval graphs also support navigation queries – testing adjacency, computing node degrees, neighborhoods, and shortest paths – all in optimal time. Our technique also yields optimal distance oracles for proper interval graphs (unit-interval graphs) and circular-arc graphs. Our tree data structure supports all operations provided by different approaches in previous work, as well …


Fast Preprocessing For Optimal Orthogonal Range Reporting And Range Successor With Applications To Text Indexing, Younan Gao, Meng He, Yakov Nekrich Jan 2020

Fast Preprocessing For Optimal Orthogonal Range Reporting And Range Successor With Applications To Text Indexing, Younan Gao, Meng He, Yakov Nekrich

Michigan Tech Publications

Under the word RAM model, we design three data structures that can be constructed in O(n√lg n) time over n points in an n×n grid. The first data structure is an O(n lg n)-word structure supporting orthogonal range reporting in O(lg lg n + k) time, where k denotes output size and is an arbitrarily small constant. The second is an O(n lg lg n)-word structure supporting orthogonal range successor in O(lg lg n) time, while the third is an O(n lg n)-word structure supporting sorted range reporting in O(lg lg n + k) time. The query times of these …


Critiquing Antipatterns In Novice Code, Leo C. Ureel Ii Jan 2020

Critiquing Antipatterns In Novice Code, Leo C. Ureel Ii

Dissertations, Master's Theses and Master's Reports

Students in introductory computer science courses, are learning to program. Indeed, most students perceive that learning to code is the central topic explored in the courses. Students spend an enormous amount of time struggling to learn the syntax and understand semantics of a particular language. Instructors spend a similar amount of time reading student code and explaining the meaning of the cryptic error messages displayed by compilers. Messages provided by compilers are intended to give feedback on the adherence of one’s code to the language specification and conventions. Unfortunately, these message are geared towards experts who have a clear understanding …


Modeling And Counteracting Exposure Bias In Recommender Systems, Sami Khenissi, Olfa Nasraoui Jan 2020

Modeling And Counteracting Exposure Bias In Recommender Systems, Sami Khenissi, Olfa Nasraoui

Faculty and Staff Scholarship

What we discover and see online, and consequently our opinions and decisions, are becoming increasingly affected by automated machine learned predictions. Similarly, the predictive accuracy of learning machines heavily depends on the feedback data that we provide them. This mutual influence can lead to closed-loop interactions that may cause unknown biases which can be exacerbated after several iterations of machine learning predictions and user feedback. Machine-caused biases risk leading to undesirable social effects ranging from polarization to unfairness and filter bubbles. In this paper, we study the bias inherent in widely used recommendation strategies such as matrix factorization. Then we …


Galaxy And Mass Assembly (Gama): Properties And Evolution Of Red Spiral Galaxies, Smriti Mahajan, Kriti Kamal Gupta, Rahul Rana, M. J.I. Brown, S. Phillipps, Joss Bland-Hawthorn, M. N. Bremer, S. Brough, Benne W. Holwerda, A. M. Hopkins, J. Loveday, Kevin Pimbblet, Lingyu Wang Jan 2020

Galaxy And Mass Assembly (Gama): Properties And Evolution Of Red Spiral Galaxies, Smriti Mahajan, Kriti Kamal Gupta, Rahul Rana, M. J.I. Brown, S. Phillipps, Joss Bland-Hawthorn, M. N. Bremer, S. Brough, Benne W. Holwerda, A. M. Hopkins, J. Loveday, Kevin Pimbblet, Lingyu Wang

Faculty and Staff Scholarship

We use multiwavelength data from the Galaxy And Mass Assembly (GAMA) survey to explore the cause of red optical colours in nearby (0.002 < z < 0.06) spiral galaxies. We show that the colours of red spiral galaxies are a direct consequence of some environment-related mechanism(s) that has removed dust and gas, leading to a lower star formation rate. We conclude that this process acts on long time-scales (several Gyr) due to a lack of morphological transformation associated with the transition in optical colour. The specific star formation rate (sSFR) and dust-to-stellar mass ratio of red spiral galaxies is found to be statistically lower than blue spiral galaxies. On the other hand, red spirals are on average 0.9 dex more massive, and reside in environments 2.6 times denser than their blue counterparts. We find no evidence of excessive nuclear activity, or higher inclination angles to support these as the major causes for the red optical colours seen in ≳47 per cent of all spirals in our sample. Furthermore, for a small subsample of our spiral galaxies that are detected in H I, we find that the SFR of gas-rich red spiral galaxies is lower by ∼1 dex than their blue counterparts.


2-(Di­Phenyl­Methyl­Idene)-2,3-Di­Hydro-1h-Inden-1-One, Tao Zhang, Vilmar Bandero, Tom Mccabe, Neil Frankish, Helen Sheridan Jan 2020

2-(Di­Phenyl­Methyl­Idene)-2,3-Di­Hydro-1h-Inden-1-One, Tao Zhang, Vilmar Bandero, Tom Mccabe, Neil Frankish, Helen Sheridan

Articles

In the title mol­ecule, C22H16O, the indanone ring system is approximately planar with a dihedral angle between the fused rings of 5.13 (14)°. Two benzene rings are linked together at one side of a double bond, sitting on either side of the indanone ring system and making dihedral angles of 70.30 (12) and 44.74 (13)° with it. In the crystal, hydrogen bonding is not present, but weak C—H⋯π or π–π inter­actions occur and mol­ecules form a sheet-like structure in the bc plane.


Dissipation Of Pesticide Residues On Grapes And Strawberries Using Plasma-Activated Water, Chaitanya Sarangapani, Laurence Scally, Miroslav Gulan, P. J. Cullen Jan 2020

Dissipation Of Pesticide Residues On Grapes And Strawberries Using Plasma-Activated Water, Chaitanya Sarangapani, Laurence Scally, Miroslav Gulan, P. J. Cullen

Articles

In this study, we present a novel atmospheric air plasma discharge for the generation of plasma-activated water (PAW), with the aim of reducing pesticide residues on fresh fruit. For this purpose, a large discharge volume pin-to-plate cold plasma reactor was employed. The pesticide-spiked grapes and strawberries were processed with varying PAW concentrations to study their efficacies for pesticide degradation combined with an evaluation of any induced changes in key nutritional and quality attributes. The results suggest that the reduction of chlorpyrifos was 79% on grapes and 69% on strawberries while that of carbaryl was 86% on grapes and 73% on …


Synthesis And Design Of Novel Polymer Grafted Nanoparticles Relevant To Drug Delivery Vehicles For Biomedical Application, Maan Abduldiyem Hassan Al-Ali Jan 2020

Synthesis And Design Of Novel Polymer Grafted Nanoparticles Relevant To Drug Delivery Vehicles For Biomedical Application, Maan Abduldiyem Hassan Al-Ali

Theses and Dissertations

The modification of inorganic nanoparticles with organic polymer chains has become a significant field of study for the engineering of advanced nanocomposite materials. This dissertation presents the design, synthesis, and characterization of novel polymer grafted silica nanoparticles as new strategies to combat bacterial resistance. Described herein is the synthesis of monomers that have been graft polymerized onto silica nanoparticles that can be used as a delivery drug vehicle for biomedical applications. The polymerization of these monomers was performed via reversible addition-fragmentation chain transfer (RAFT) polymerization. The molecular design of the RAFT agents that are attached to the surfaces of the …


Long-Distance Dispersal By Eastern Gray Squirrels In Suburban Habitats, Noah G. Perlut Jan 2020

Long-Distance Dispersal By Eastern Gray Squirrels In Suburban Habitats, Noah G. Perlut

Environmental Studies Faculty Publications

Natal dispersal by Sciurus carolinensis (Eastern Gray Squirrel) is poorly understood, given so rarely reported, yet dispersal patterns in small mammals can affect seed dispersal and predation, as well as population dynamics of predators. Herein, I document long-distance dispersal by 3 Eastern Gray Squirrels from the suburban coastal campus of the University of New England in Biddeford, ME. Mean dispersal distance was 10.1 km (min–max = 6.3–14.5 km), occurring in random directions (SW, S, NW). These results, combined with the previous studies, better describe the distribution of natal dispersal by Eastern Gray Squirrel—critical information in understanding population processes and potentially …


Effects Of Oxygen Modification On The Structural And Magnetic Properties Of Highly Epitaxial La0.7sr0.3mno3 (Lsmo) Thin Films, Shalini Kumari, Navid Mottaghi, Chih-Yeh Huang, Robbyn Trappen, Ghadendra Bhandari, Saeed Yousefi, Guerau Cabrera, Mohindar S. Seehra, Mikel B. Holcomb Jan 2020

Effects Of Oxygen Modification On The Structural And Magnetic Properties Of Highly Epitaxial La0.7sr0.3mno3 (Lsmo) Thin Films, Shalini Kumari, Navid Mottaghi, Chih-Yeh Huang, Robbyn Trappen, Ghadendra Bhandari, Saeed Yousefi, Guerau Cabrera, Mohindar S. Seehra, Mikel B. Holcomb

Faculty & Staff Scholarship

La0.7Sr0.3MnO3, a strong semi-metallic ferromagnet having robust spin polarization and magnetic transition temperature (TC) well above 300 K, has attracted significant attention as a possible candidate for a wide range of memory, spintronic, and multifunctional devices. Since varying the oxygen partial pressure during growth is likely to change the structural and other physical functionalities of La0.7Sr0.3MnO3 (LSMO) films, here we report detailed investigations on structure, along with magnetic behavior of LSMO films with same thickness (~30 nm) but synthesized at various oxygen partial pressures: 10, 30, 50, 100, 150, 200 and 250 mTorr. The observation of only ( …


Household Water Security: An Analysis Of Water Affect In The Context Of Hydraulic Fracturing In West Virginia, Appalachia, Bethani Turley, Martina Angela Caretta Jan 2020

Household Water Security: An Analysis Of Water Affect In The Context Of Hydraulic Fracturing In West Virginia, Appalachia, Bethani Turley, Martina Angela Caretta

Faculty & Staff Scholarship

Hydraulic fracturing has been booming in the last decade in the United States. While natural gas extraction and production has improved the national energy security, it has raised questions around the water security of those communities where extraction is taking place. Both scientists and residents are concerned about hydraulic fracturing’s impacts on surface- and groundwater, especially regarding how hydraulic fracturing impacts residents’ access to safe household well water. In the past decade, the Marcellus Shale has been developed in Northwestern West Virginia, yet the human geography dimensions of oil and gas extraction in West Virginia remain to be investigated. This …


The Transition From Planar To En Echelon Morphology In A Single Vein In Shale: Insights From X-Ray Computed Tomography Scanning, Graham Dm Andrews, Sarah R. Brown, Johnathan Moore, Dustin Crandall, Paige Mackey Jan 2020

The Transition From Planar To En Echelon Morphology In A Single Vein In Shale: Insights From X-Ray Computed Tomography Scanning, Graham Dm Andrews, Sarah R. Brown, Johnathan Moore, Dustin Crandall, Paige Mackey

Faculty & Staff Scholarship

En echelon fractures and veins are among the most common and distinctive geological structures, yet their three-dimensional forms and relationships to surrounding structures are commonly unclear. X-ray computed tomography (CT) offers an unrivaled ability to examine structures within rocks in three dimensions, and it is applied here to a sample of drill core from the Marcellus Shale of southwestern Pennsylvania (USA). CT images yield qualitative and quantitative data on the transition from a pyrite-rich planar vein to an en echelon veinlet array, and on the heterogeneity of veinlets within the array. Using a combination of three- and two-dimensional images, geometric …