Digital Commons Network^™

Marsh-Exported Dissolved Organic Matter Fate In Estuaries, Laura Ann Logozzo

Dissertations and Theses

Dissolved organic matter (DOM) is a significant driver of estuarine productivity and nutrient cycling. The colored component of DOM, chromophoric dissolved organic matter (CDOM), impacts coastal optical properties, ocean color, and light attenuation. While marshes are largely considered sinks for carbon due to their high productivity and low soil carbon degradation rates, laterally they are sources of carbon as optically and chemically distinct DOM to surrounding aquatic ecosystems; these inputs are often essential in sustaining a net heterotrophic system. However, the photoreactivity and bioavailability of marsh-exported DOM is largely uncategorized, thus making it difficult to quantify its impacts on estuarine …

Enzymatically Active Microspheres For Self-Propelled Colloidal Engines, Jungeun Park

Dissertations and Theses

Micro- and nano-motors have attracted numerous attentions from various scientific areas due to their potential applications. Most studies on self-propelled colloidal engines have exploited catalytic decomposition of hydrogen peroxide to drive the motor. Since the hydrogen peroxide is caustic, it is not suitable to use in biological applications, encouraging people to develop “greener” fuels. The aim of this research is to study a new transduction mechanism for self-propulsion not tied to hydrogen peroxide, and which can in particular be used with biological molecules as fuels. In this study, we focus on making particles with enzymatic activity which can effectively decompose …

Data Driven Approach For Increasing Power Grid Situational Awareness And Mitigating Cascaded Failures, Yassine Mhandi

Dissertations and Theses

The main purpose of this thesis is to use Artificial Neural network as a tool to monitor system health and performance. In other word Using ANN can increase the system awareness and can be used as a tool to mitigate cascade failure in power grid due to loss of communication in a critical power node and as a result avoid catastrophic phenomena like electric blackout. In this thesis, a modified IEEE 30 bus system is used as a system under study. Modified IEE 30 bus system is IEEE 30 bus system in which 2 sets of its synchronous condensers changed …

Brief Study Of Classification Algorithms In Machine Learning, Ramesh Sankara Subbu

Dissertations and Theses

The purpose of this study is to briefly learn the theory and implementation of three most commonly used Machine Learning algorithms: k-Nearest Neighbors (kNN), Decision Trees and Naïve Bayes. All these algorithms fall under the Classification algorithm category of Unsupervised Machine Learning. This paper is constructed structurally in explaining the working theory behind each algorithm and an implementation of a Machine Learning problem solved by each algorithm. KNN algorithm is designed using Euclidean distance measurement and Decision Trees make use of ID3 algorithm as a basis. We conclude the study by providing an overall picture of its strengths and weaknesses …

A Hybrid State/Event Driven Communication-Based Control For Dc Microgrids, Yusef Esa

Dissertations and Theses

The U.S. electric power industry is undergoing unprecedented changes triggered by the growing electricity demand, and the national efforts to reduce greenhouse gas emissions. Moreover, there is a call for increased power grid resiliency, survivability and self-healing capabilities. As a result of these challenges, the smart grid concept emerged. One of the main pillars of the smart grid is microgrids. In this thesis, the technical merits of clustering multiple microgrids during blackouts on the overall stability and supply availability have been investigated.

We propose to use the existing underground distribution grid infrastructure, if applicable, during blackouts to form microgrid clusters. …

Temporal Variability Of Fluorescent Dissolved Organic Matter At A Brackish, Tidal Marsh-Estuary Interface, Alana B. Menendez

Dissertations and Theses

Marshes are both terrestrial and aqueous, sitting as an intermediate between land and water. Studies over constrained numbers of tidal cycles have demonstrated that these marshes are net exporters of dissolved organic carbon (DOC) to adjoining estuaries, however, there is need for continuous monitoring to better understand the temporal variability of this flux: tidally, seasonally, and during episodic rain events. Through use of a YSI EXO2 sonde, an in situ optical sensor at the interface of the brackish, tidal Kirkpatrick Marsh and Rhode River sub-estuary in Edgewater, Maryland (located on the northwestern shore of the Chesapeake Bay), we were able …

Mechanisms Of Shear Zone Localization And Raman Thermobarometry In Spinel Peridotites From The Alpine Fault, New Zealand, Emily J. Lubicich

Dissertations and Theses

A suite of xenoliths from two localities on South Island, New Zealand, exhibit rare microstructures and provide information on deformation during the early stages of development of the Alpine Fault. The first set of samples has evidence of dislocation creep with subgrains, recrystallized grains, undulose extinction and a lattice preferred orientation. These samples also show evidence of post deformation static grain growth with polygonal grains, 120° triple junctions, and euhedral grains within larger grains of the same phase. Samples from the second locality also show evidence of dislocation creep but with minimal static grain growth. This set also has a …

Nature Versus Culture: Lower Manhattan Land Art By Charles Simonds, Walter De Maria, And Alan Sonfist, Farrar Fitzgerald

Dissertations and Theses

No abstract provided.

A Phylogenetic And Environmental Analysis Of Brazilian Placosoma Lizards, Kai A. Farje-Van Vlack

Dissertations and Theses

Placosoma is a genus comprised of the Brazilian spectacled lizards P. champsonotus, P. cipoense, P. cordylinum, P. glabellum, and P. limaverdorum. While P. champsonotus, P. cordylinum, and P. glabellum occupy the southern coast of Brazil, P. cipoense is found in the montane grasslands north of that range, and P. limaverdorum was recently discovered in forest isolates that persist within the semi-arid Caatinga. This study elucidates the ecological and evolutionary relationships among these morphologically similar lizards. Using mitochondrial and nuclear gene sequences, genus-wide phylogenies were inferred through Bayesian inference and a species tree approach, …

2d Vector Map And Database Design For Indoor Assisted Navigation, Luciano Caraciolo Albuquerque

Dissertations and Theses

In this paper we implemented a 2D Vector Map, map editor and Database design intended to provide an efficient way to convert cad files from indoor environments to a set of vectors representing hallways, doors, exits, elevators, and other entities embedded in a floor plan, and save them in a database for use by other applications, such as assisted navigation for blind people.

A graphical application as developed in C++ to allow the user to input a CAD DXF file, process the file to automatically obtain nodes and edges, and save the nodes and edges to a database for posterior …

Abstracts 2017: Highlights Of Student Research And Creative Endeavors, Columbus State University

Abstracts: Highlights of Student Research and Creative Endeavors

What follows is a collection of abstracts summarizing the scholarship conducted by undergraduates at Columbus State University during the 2016-2017 academic year. These projects highlight undergraduates research in a variety of disciplines, ranging from literary analysis to laboratory based sciences. The abstracts represent many ongoing projects on our campus and catalog those that have been published or presented. This volume begins with projects that have been selected for presentations at national, regional and statewide disciplinary conferences. Among them are several that have garnered awards for outstanding undergraduate scholarship. Projects that have received competitive research grants, including our campus Student Research …

ผลประโยชน์ทางด้านสิ่งแวดล้อมจากกิจกรรมธนาคารขยะในชุมชนนาราชควาย อำเภอเมือง จังหวัดนครพนม, พัชญทัฬห์ กิณเรศ

Thai Environment

No abstract provided.

ขยะติดเชื้อ และการจัดการขยะติดเชื้อในโรงพยาบาล กรณีศึกษา จังหวัดภูเก็ต, เพ็ญศิริ เอกจิตต์

Thai Environment

No abstract provided.

การจัดการน้ำในพื้นที่ลุ่มน้ำลี้ แนวคิดการปฏิบัติติดตามแบบแผนนิเวศวัฒนธรรม, สามารถ ใจเตี้ย

Thai Environment

No abstract provided.

Ozone มีคุณแต่ก็ให้โทษ, ธีรพล คังคะเกตุ

Thai Environment

No abstract provided.

Obese Children With Metabolic Syndrome Have 3 Times Higher Risk To Have Nonalcoholic Fatty Liver Disease Compared With Those Without Metabolic Syndrome, Dimitrios Papandreou, Mirey Karavetian, Zacharoula Karabouta, Eleni Andreou

All Works

Copyright © 2017 Dimitrios Papandreou et al. Background: The aim of this study was to investigate the relationship between metabolic syndrome (MS) and nonalcoholic fatty liver disease (NAFLD) in obese children. One hundred and twenty-five subjects aged 11-12 years old participated in the study. Methods: Anthropometric and biochemical indices were measured, including lipid and liver profile, blood glucose, serum insulin, and liver ultrasound. Results: Forty-four children (58.6%) were found to have MS. Insulin resistance was present in 78 (62.4%) children. Patients with MS were more likely to have NAFLD (P <; 0.001). Children with NAFLD had significantly higher body mass index, waist circumference, triglycerides, fasting insulin, and lower high-density lipoprotein compared to patients with normal livers (P < 0.001). Insulin resistance was significantly higher in children with NAFLD (P <; 0.001). Obese children presenting with MS were 3.01 (2.87-3.57, P < 0.002) times more likely to develop NAFLD compared to those without metabolic syndrome after adjustment of cofounders. Conclusions: Obese children with MS have a higher risk of developing NAFLD. Weight management and early prevention should be the first line of treatment to prevent any possible health issues later on.

Fish Assemblage Structure Indicates Limited Restoration Progress Over A Lustrum Of A Severely Degraded Estuary In Southern Tamaulipas, Mexico, Alejandro Fierro-Cabo, Carlos E. Cintra-Buenrostro

School of Earth, Environmental, & Marine Sciences Faculty Publications

Today the biggest incentive to attempt the restoration and protection of estuarine systems is their widely recognized ecological and economic importance. In the reconstruction of an estuary where the original aquatic communities disappeared before the restoration interventions, the fish assemblage is an adequate source of indicators of initial recovery. Following substantial restoration efforts, this study reports on the biannual for a lustrum monitoring and assessment of a severely degraded estuary (Garrapatas) in terms of its fish assemblage using a reference estuary (Barberena) in Tamaulipas, Mexico. Twenty fishes were associated with the restoring and reference estuaries. Species composition (richness, abundance, dominance) …

Effect Of Different Debranning Degrees On The Qualities Of Whole Wheat Flour And Chinese Steamed Bread, Jikai Zhao, Fengcheng Wang, Wenjun Fu, Mengjie Wang

School of Earth, Environmental, & Marine Sciences Faculty Publications

Abstract: Strong gluten, middle-strong gluten and middle gluten wheat were used as raw materials to obtain whole wheat flour by dry debranning process, and the effect of different debranning degrees on the quality of wheat kernel, whole wheat flour and Chinese steamed bread was evaluated. The results showed that the ash content, hardness index and thousand kernel weight of wheat kernels were decreased with increasing debranning degree by 0.17%, 1.0–1.5 and 1.74–1.82 g, respectively, whereas the volume weight was increased by 22.0–23.4 g/L. The contents of ash and damaged starch in whole wheat flour were decreased by 0.12%–0.14% and 1.0–2.1 …

Molecular And Biochemical Responses Of Hypoxia Exposure In Atlantic Croaker Collected From Hypoxic Regions In The Northern Gulf Of Mexico, Md. Saydur Rahman, Peter Thomas

School of Earth, Environmental, & Marine Sciences Faculty Publications

A major impact of global climate change has been the marked increase worldwide in the incidence of coastal hypoxia (dissolved oxygen, DOhif-α; neuronal nitric oxide synthase, nNOS; and insulin-like growth factor binding protein, igfbp mRNAs and protein carbonyl (PC, an oxidative stress indicator) content were elevated several-fold in brain and liver tissues of croaker collected from nGOM hypoxic sites. All of these molecular and biochemical biomarkers were also upregulated ~3-10-fold in croaker brain and liver tissues within 1–2 days of hypoxia exposure in controlled laboratory experiments. These results suggest that hif-αs, nNOS and igfbp-1 transcripts and PC contents …

Structural And Functional Alterations In Neocortical Circuits After Mild Traumatic Brain Injury, Michal Vascak

Theses and Dissertations

National concern over traumatic brain injury (TBI) is growing rapidly. Recent focus is on mild TBI (mTBI), which is the most prevalent injury level in both civilian and military demographics. A preeminent sequelae of mTBI is cognitive network disruption. Advanced neuroimaging of mTBI victims supports this premise, revealing alterations in activation and structure-function of excitatory and inhibitory neuronal systems, which are essential for network processing. However, clinical neuroimaging cannot resolve the cellular and molecular substrates underlying such changes. Therefore, to understand the full scope of mTBI-induced alterations it is necessary to study cortical networks on the microscopic level, where neurons …

The Effects Of Irrelevant Information And Minor Errors In Client Documents On Assessments Of Misstatement Risk And Sample Size, Edward Lynch

Theses and Dissertations

This dissertation consists of three studies. The first study conducts a 2 by 2 experiment to examine how auditors are influenced by the presence of irrelevant information and minor errors (i.e., “dirty documents”) when reviewing audit evidence produced by the client. This study tasks 97 public accountants to review audit evidence and finds some evidence that dirty documents influence an auditor’s assessment of the likelihood of account misstatement and the appropriate sample size.

In order to demonstrate the usefulness of eye-tracking and to help generate potential research topics, the second study reviews extant literature in other disciplines where eye-tracking technology …

Investigations Into Structure And Properties Of Atomically-Precise Transition Metal-Chalcogenide Clusters Of Crte And Ligated Cr6te8(Pet3)6, Anthony F. Pedicini

Theses and Dissertations

The complete understanding of a clusters electronic structure, the primary mechanisms for its properties and stabilization is necessary in order to functionalize them for use as building blocks within novel materials. First principle theoretical studies have been carried out upon the electronic properties of Cr_xTe_y (x = 1 – 6, y = 0 – 8, x + y ≤ 14), as well as for the larger triethylphosphine (PEt₃) ligated cluster system of Cr₆Te₈(PEt₃)₆. Together, we aim to use the information garnered from the smaller clusters to address …

An Algorithm To Improve Deformable Image Registration Accuracy In Challenging Cases Of Locally-Advanced Non-Small Cell Lung Cancer, Christopher L. Guy

Theses and Dissertations

A common co-pathology of large lung tumors located near the central airways is collapse of portions of lung due to blockage of airflow by the tumor. Not only does the lung volume decrease as collapse occurs, but fluid from capillaries also fills the space no longer occupied by air, greatly altering tissue appearance. During radiotherapy, typically administered to the patient over multiple weeks, the tumor can dramatically shrink in response to the treatment, restoring airflow to the lung sections which were collapsed when therapy began. While return of normal lung function is a positive development, the change in anatomy presents …

Study Of The Photoluminescence Spectra Of Mg-Doped Gan, Puranjan Ghimire

Theses and Dissertations

We have studied luminescence properties of Mg-doped GaN grown by hydride vapor phase epitaxy. Steady state photoluminescence (PL) spectra have been analyzed. Exciton, ultraviolet luminescence (UVL) and blue luminescence (BL) bands are the dominant PL bands in the spectra. At low temperature, Exciton and UVL bands show almost no shift with excitation intensity, whereas the BL band blueshifts by almost 0.4 ���� with increasing excitation intensity by seven orders of magnitude. Such shifting nature of bands with excitation intensity is explained by assuming that the BL band is detected from the region of the sample where potential fluctuations are very …

Investigation On Genetic Modifiers Of Age At Onset Of Major Depressive Disorder, Huseyin Gedik

Theses and Dissertations

Major Depressive Disorder (MDD) is a complex multifactorial disorder, which would lead to disability. Environmental and genetic factors are involved in MDD etiology. The aim of this project was to identify loci modifying age at onset (AAO) of MDD using survival models after adjusting for Childhood Sexual Abuse (CSA). To achieve this aim, a dataset was made available by the China Oxford and VCU Experimental Research on Genetic Epidemiology (CONVERGE) consortium. The study population had 5,220 controls and 5,282 cases with MDD. We performed two univariate association analyses using Cox Proportional Hazard (Cox PH) models. These two are Full Sample …

Preparation And Evaluation Techniques Of Porous Materials And Mixed Matrix Membranes For Targeted Co2 Separation Applications, Tsemre Tessema

Theses and Dissertations

The use of porous sorbents for physisorptive capture of CO₂ from gas mixtures has been deemed attractive due to the low energy penalty associated with recycling of such materials. Porous organic polymers (POPs) have emerged as promising candidates with potential in the treatment of pre- and post- fuel combustion processes to separate CO₂ from gas mixtures. Concurrently, significant advances have been made in establishing calculation methods that evaluate the practicality of porous sorbents for targeted gas separation applications. However, these methods rely on single gas adsorption isotherms without accounting for the dynamic gas mixtures encountered in real-life applications. …

Drinking Motives Underlying Internalizing And Externalizing Pathways To Alcohol Misuse In College Students, Jeanne Savage

Theses and Dissertations

Alcohol misuse, including heavy episodic use and negative consequences, is a major public health concern and a particular problem among college students. The etiology of alcohol misuse is not well resolved, with multiple and often contradictory factors implicated in its development. Genetic factors influence alcohol misuse but few specific genes have been identified. A potential reason for these challenges is that alcohol misuse is phenotypically and genetically heterogeneous; that is, there are multiple causal pathways underlying its development. Previous typologies have suggested that distinct internalizing and externalizing pathways are involved, with corresponding differences in profiles of personality, temperament, and comorbid …

Accurate Acoustic Ranging System Using Android Smartphones, Mohammadbagher Fotouhi

Theses and Dissertations

ACCURATE ACOUSTIC RANGING SYSTEM USING ANDROID SMARTPHONES

By Mohammadbagher Fotouhi, Master of Science

A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science at Virginia Commonwealth University

Virginia Commonwealth University 2017

Major Director: Dr. Ruixin Niu, Associate Professor of Department of Electrical and Computer Engineering

In this thesis, we present the design, implementation, and evaluation of an android ranging system, a high-accuracy acoustic-based ranging system which allows two android mobile phones to learn their physical distance from each other.

In this system we propose a practical solution for accurate ranging based on acoustic communication …

Cooperative Wideband Spectrum Sensing Based On Joint Sparsity, Ghazaleh Jowkar

Theses and Dissertations

COOPERATIVE WIDEBAND SPECTRUM SENSING BASED ON JOINT SPARSITY

By Ghazaleh Jowkar, Master of Science

A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science at Virginia Commonwealth University

Virginia Commonwealth University 2017

Major Director: Dr. Ruixin Niu, Associate Professor of Department of Electrical and Computer Engineering

In this thesis, the problem of wideband spectrum sensing in cognitive radio (CR) networks using sub-Nyquist sampling and sparse signal processing techniques is investigated. To mitigate multi-path fading, it is assumed that a group of spatially dispersed SUs collaborate for wideband spectrum sensing, to determine whether or not …

Development Of General Purpose Liquid Chromatography Simulator For The Exploration Of Novel Liquid Chromatographic Strategies, Lena N. Jeong

Theses and Dissertations

The method development process in liquid chromatography (LC) involves optimization of a variety of method parameters including stationary phase chemistry, column temperature, initial and final mobile phase compositions, and gradient time when gradient mobile phases are used. Here, a general simulation program to predict the results (i.e., retention time, peak width and peak shape) of LC separations, with the ability to study various complex chromatographic conditions is described. The simulation program is based on the Craig distribution model where the column is divided into discrete distance (Δz) and time (Δt) segments in a grid and is …