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Computational Fluid Dynamics Modeling Of Proppant Static Settling Velocity In High Viscosity Friction Reducers, Chen Yuan

Masters Theses

"In the current petroleum fracturing industry, it is necessary to understand the downhole migration and settling velocity of the proppant. If we can master this information well, it will be a great help to obtain effective propped fracture conductivity. In order to study the transport of proppants in the well, we used laboratory experiments and computer numerical simulations to compare the results to get a meaningful conclusion. We spent a lot of time building models on a powerful computer and comparing the experimental conclusions. We finally decided to use computational fluid dynamics (CFD) as the simulation platform, discrete phase method …

Modified Surface Relief Layer Created By Holographic Lithography: Application To Selective Sodium And Potassium Sensing, Sabad-E Gul, Luke O'Neill, John Cassidy, Izabela Naydenova

Articles

Point-of-care diagnostics will rely upon the development of low-cost, noncomplex, and easily integrated systems in order to examine biological samples such as blood and urine obtained from the patient. The development of metal ion sensors is a subject of significant relevance for physiological samples. The level of different blood electrolytes, mainly H+, Na+, K+ and Cl− is considerably used to monitor irregular physiologies. The particular challenge in biosensing, and in fact for any other sensor, is signal differentiation between non-specifically bound material and the specific detecting of the target molecule/ion. The biosensors described in this paper are fabricated by a …

Molecular Memory With Downstream Logic Processing Exemplified By Switchable And Self-Indicating Guest Capture And Release, Brian Daly, Thomas S. Moody, Allen J.M. Huxely, Chaoyi Yao, Benjamin Schazmann, Andre Alves-Areias, John F. Malone, H.Q. Nimal Gunaratne, Peter Nockemann, A. Prasanna De Silva

Articles

Molecular-logic based computation (MLBC) has grown by accumulating many examples of combinational logic gates and a few sequential variants. In spite of many inspirations being available in biology, there are virtually no examples of MLBC in chemistry where sequential and combinational operations are integrated. Here we report a simple alcohol-ketone redox interconversion which switches a macrocycle between a large or small cavity, with erect aromatic walls which create a deep hydrophobic space or with collapsed walls respectively. Small aromatic guests can be captured or released in an all or none manner upon chemical command. During capture, the fluorescence of the …

Highly Selective Fluorimetric Turn-Off Detection Of Copper (Ii) By Two Different Mechanisms In Calix[4]Arene-Based Chemosensors And Chemodosimeters, Justine O'Sullivan, John Colleran, Brendan Twamley, Frances Heaney

Articles

Isoxazolo‐pyrene tethered calix[4]arenes selectively detect copper(II) ions without interference from related perchlorate ions. The fluorescence emission of the probes, synthesised by nitrile oxide alkyne cycloaddition, and characterised by spectroscopic and crystallographic data, is rapidly reduced by Cu(II) ions. Detection limits are in the micromolar or sub‐micromolar range (0.3–3.6 μM) based on a 1 : 1 sensor:analyte interaction. Voltammetric behaviour and 1H NMR data provide new insights into the sensing mechanism which is dependent on the calixarene substitution pattern. When the calixarene lower rim is fully substituted, Cu(II) detection occurs through a traditional chelation mechanism. In contrast, for calixarenes 1,3‐disubstituted on …

Nanomole Silver Detection In Chloride-Free Phosphate Buffer Using Platinum And Gold Micro- And Nanoelectrodes, Prabhakar Sidambaram, John Colleran

Articles

The electrochemical determination of ultra-low concentrations of silver requires reliable, reproducible measurements using sensitive analytical techniques. To date, the electrochemical determination of silver in biological buffers and pH neutral media has not been successful in terms of reproducibility. In this work, we report on the determination of ultra-low concentrations of silver in chloride-free phosphate buffer solution (PB, pH 7.4). Detection was conducted at gold and platinum micro and nanoelectrodes using anodic stripping voltammetry (ASV). The micro and nanoelectrodes were fabricated using a Sutter P-2000 laser puller, with physical and electrochemical characterization revealing flat disk-shaped working surfaces of 10–15 μm (microelectrode) …

Low-Resolution Models For The Interaction Dynamics Of Coated Gold Nanoparticles With Β2-Microglobulin, Giorgia Brancolini, Hender Lopez, Stefano Corni, Valentina Tozzini

Articles

A large number of low-resolution models have been proposed in the last decades to reduce the computational cost of molecular dynamics simulations for bio-nano systems, such as those involving the interactions of proteins with functionalized nanoparticles (NPs). For the proteins, “minimalist” models at the one-bead-per residue (Cα-based) level and with implicit solvent are well established. For the gold NPs, widely explored for biotechnological applications, mesoscale (MS) models treating the NP core with a single spheroidal object are commonly proposed. In this representation, the surface details (coating, roughness, etc.) are lost. These, however, and the specificity of the functionalization, have been …

Impact Of Plasma Treatment On Acoustic Properties Of Natural Cellulose Materials, Sanja S. Pavlović, Snežana B. Stanković, Andrijana Žekić, Miloš Nenadović, Dušan M. Popović, Vladimir Milosavljevic, Goran B. Poparić

Articles

Low-temperature plasma is widely used in many surface treatment technologies for modifications of the physical properties of different polymeric materials. In the present work, we have examined the modification of acoustical properties of natural cellulose materials (cotton, hemp) by the radio-frequency argon plasma. We have observed an increase of the sound absorption coefficient due to the plasma treatment for certain range of applied powers. An analysis of elementary processes which happened during plasma–material interaction was conducted. Additional analyses related to material characterizations were performed in order to resolve structural and chemical changes of plasma treated materials. The micro-mechanical modification of …

Concentric Double Hollow Grid Cathode Discharges, C. T. Teodorescu-Soare, S. A. Irimiciuc, C. Ionita, D. G. Dimitriu, B. Hodoroaba, T. O'Hara, O. Vasilovici, L. Amarandi, R. W. Schrittwieser

Articles

A new cathode system, consisting of two concentric spherical hollow grids with two aligned orifices, is investigated by space-resolved Langmuir probe measurements and non-linear dynamics analysis. Negative biases of this spherical hollow grids arrangement lead to the formation of two complex space charge structures in the regions of the orifices. The overall dynamics of the current-voltage characteristic (I–V characteristic) of each discharge is characterized by strong oscillatory behaviour with various waveforms correlated with jumps in the static I–V characteristics. Space-resolved measurements through the two aligned orifices of the two grids show a peak increase of the electron temperature and particle …

Common Data Set, 2018-2019, Planning, Research, And Policy Analysis

Common Data Set (2001-present)

Common Data Set 2018-2019 for Illinois State University

2018 Patent Law Decisions Of The Federal Circuit, Lori Gordon

American University Law Review

No abstract provided.

Senate Democracy: Our Lockean Paradox, Eric W. Orts

American University Law Review

No abstract provided.

Two-Sided Internet Markets And The Need To Assess Both Upstream And Downstream Impacts, Rob Frieden

American University Law Review

No abstract provided.

Reply To Commentary By R Duggleby (2019), Edward J. Steele, Shirwan Al-Mufti, Kenneth Augustyn, Rohana Chandrajith, John P. Coghlan, S. G. Coulson, Et Al.

Michigan Tech Publications, Part 1

No abstract provided.

University Assessment Services, Beginning College Survey Of Student Engagement: Transfer Student Institutional Report, 2019, Illinois State University

Student Success

Beginning College Survey of Student Engagement (BCSSE) Transfer Student Institutional Report, University Assessment Services, Illinois State University, 2019.

University Assessment Services, Beginning College Survey Of Student Engagement: First-Year Student Institutional Report, 2019, Illinois State University

Student Success

Beginning College Survey of Student Engagement (BCSSE) First-Year Student Institutional Report, University Assessment Services, Illinois State University, 2019.

Time-To-Event Analysis For Sports Injury Research Part 1: Time-Varying Exposures, Rasmus Oestergaard Nielsen, Michael Lejbach Bertelsen, Daniel Ramskov, Merete Møller, Adam Hulme, Daniel Theisen, Caroline F. Finch, Lauren Victoria Fortington, Mohammad Ali Mansournia, Erik Thorlund Parner

Research outputs 2014 to 2021

BACKGROUND: ‘How much change in training load is too much before injury is sustained, among different athletes?’ is a key question in sports medicine and sports science. To address this question the investigator/practitioner must analyse exposure variables that change over time, such as change in training load. Very few studies have included time-varying exposures (eg, training load) and time-varying effect-measure modifiers (eg, previous injury, biomechanics, sleep/stress) when studying sports injury aetiology.

AIM: To discuss advanced statistical methods suitable for the complex analysis of time-varying exposures such as changes in training load and injury-related outcomes.

CONTENT: Time-varying exposures and time-varying effect-measure …

Understanding Visitor Expectations For Responsible Tourism In An Iconic National Park: Differences Between Local And International Visitors, Angus Morrison-Saunders, Michael Hughes, Jenny Pope, Anneli Douglas, Jan-Albert Wessels

Research outputs 2014 to 2021

A survey on expectations for responsible tourism was administered to 201 visitors to the iconic Kruger National Park, comprising 55% South African nationals and 45% international tourists. Using Likert-scale questions, respondents were invited to indicate the level of importance they attached to 38 aspects of responsible tourism. Space was also provided for open comments. Conservation of biodiversity and geological features were rated very highly by both groups while aspects related to the local community, though considered important overall, were ranked lowest overall, with international tourists rating this category as more important than South Africans. Aspects related to traffic and access …

Security And Accuracy Of Fingerprint-Based Biometrics: A Review, Wencheng Yang, Song Wang, Jiankun Hu, Guanglou Zhang, Craig Valli

Research outputs 2014 to 2021

Biometric systems are increasingly replacing traditional password- and token-based authentication systems. Security and recognition accuracy are the two most important aspects to consider in designing a biometric system. In this paper, a comprehensive review is presented to shed light on the latest developments in the study of fingerprint-based biometrics covering these two aspects with a view to improving system security and recognition accuracy. Based on a thorough analysis and discussion, limitations of existing research work are outlined and suggestions for future work are provided. It is shown in the paper that researchers continue to face challenges in tackling the two …

Doppler Radar-Based Non-Contact Health Monitoring For Obstructive Sleep Apnea Diagnosis: A Comprehensive Review, Vinh Phuc Tran, Adel Ali Al-Jumaily, Syed Mohammed Shamsul Islam

Research outputs 2014 to 2021

Today’s rapid growth of elderly populations and aging problems coupled with the prevalence of obstructive sleep apnea (OSA) and other health related issues have affected many aspects of society. This has led to high demands for a more robust healthcare monitoring, diagnosing and treatments facilities. In particular to Sleep Medicine, sleep has a key role to play in both physical and mental health. The quality and duration of sleep have a direct and significant impact on people’s learning, memory, metabolism, weight, safety, mood, cardio-vascular health, diseases, and immune system function. The gold-standard for OSA diagnosis is the overnight sleep monitoring …

Eagle Executive Magazine, Georgia Southern University

College of Business: News & Publications

• College News
• Department News
• Experiential Learning
• Graduate Programs
• Big News
• Annual Report
• Alumni News
• Development News

Undergraduate Catalog, Georgia Southern University

Undergraduate & Graduate Catalogs

No abstract provided.

Examining The Effects Of Energy Drinks On Academic Performance, Alyssa P. Roberson

College of Graduate Studies: Theses & Dissertations

Reports of energy drink (ED) consumption have grown among the United States population. Research suggests reasons for consumption vary across populations, including increased attention and enhanced endurance performance. However, ED consumers could suffer from negative effects of ED, including health problems, caffeine overdose, and death. Energy drink consumption is also linked to substance use. Despite risks of consuming ED, heavy use of EDs remains among college students, often to help with academic performance; however, research has not examined effects of ED consumption on perceived and actual academic performance. This study evaluated relationships among ED consumption, self-efficacy, and academic performance in …

Emotional Intelligence Instruction For Millennials In Undergraduate Education, Jason M. Pollett

College of Graduate Studies: Theses & Dissertations

The purpose of this study was to examine the improvement, if any, of emotional intelligence scores of students who participated in and completed the specified professional development seminar. In addition, this study aimed to examine the relationship between emotional intelligence subscales of students enrolled in a professional development seminar that focuses on enhancing the emotional intelligence. The research design for this study was an ex post facto, quasi-experimental correlational quantitative research design. Data from the 371 students who enrolled in the Professional Development Seminar course during academic years 2015-2017 served as the sample for this study.

This study focused on …

Predictors Of Community College Students’ Academic Success In The Corequisite Model, Damon Andrews

College of Graduate Studies: Theses & Dissertations

The purpose of this quantitative study was to determine predictors of community college student academic success in the corequisite model. Academic success was defined dichotomously on a pass or fail basis. The population in this study included 1,933 students that enrolled in at least one corequisite English and/or mathematics course at the college between the fall semester of 2015 and summer semester of 2018. The predictors examined were a student’s sex, race, age at time of enrollment, Pell grant recipient status, first-generation college student status, high school GPA, placement test scores, academic major, time spent receiving academic tutoring in college’s …

Computing The Role That Women Hold In The Technology And Computing Fields, Rachel L F Mccombs

College of Graduate Studies: Theses & Dissertations

This research was conducted as a thesis project to study what roles women have played in information technology over time, how those roles have changed over time, and what caused those roles to change. It was also to study how personal life experiences may have affected their roles and careers in the technology field. Influential women in IT of the past were studied and compared to determine any common factors between them.

Essays On Mixture Models, Trevor R. Camper

College of Graduate Studies: Theses & Dissertations

When considering statistical scenarios where one can sample from populations that are not of interest for the purposes of a study, bivariate mixture models can be used to study the effect that this missampling can have on parameter estimation. In this thesis, we will examine the behavior that bivariate mixture models have on two statistical constructs: Cronbach's alpha \cite{C51}, and Spearman's rho \cite{S04}. Chapter 1 will introduce notions of mixture models and the definition of bias under mixture models which will serve as the central concept of this thesis. Chapter 2 will investigate a particular psychometric issue known as insufficient …

Security Analysis Of The Internet Of Things Using Digital Forensic And Penetration Testing Tools, Olajide Ojagbule

College of Graduate Studies: Theses & Dissertations

We exist in a universe where everything is related to the internet or each other like smart TVs, smart telephones, smart thermostat, cars and more. Internet of Things has become one of the most talked about technologies across the world and its applications range from the control of home appliances in a smart home to the control of machines on the production floor of an industry that requires less human intervention in performing basic daily tasks. Internet of Things has rapidly developed without adequate attention given to the security and privacy goals involved in its design and implementation. This document …

Quantized Circulation In Racetrack Atomtronic Circuits At Non-Zero Temperature, Benjamin R. Eller

College of Graduate Studies: Theses & Dissertations

We extend previous theoretical investigations of the creation of quantized circulation states by stirring Bose-Einstein condensates (BEC) confined in ``racetrack" potentials. The previous study, {\em Producing Smooth Flow in Atom Circuits by Stirring}, used the Gross-Pitaevskii equation (GPE), which is valid at $T=0$ K. Here we use a non-zero temperature model based on the Zaremba, Nikuni, Griffin (ZNG) theory to simulate stirring racetrack BECs. The two main goals of this thesis are 1) to understand the effects of temperature on the production of circulation and 2) to understand the mechanism by which the circulation is excited. We find that it …

Gallai-Ramsey Number For Classes Of Brooms, Benjamin J. Hamlin

College of Graduate Studies: Theses & Dissertations

Given a graph $G$, we consider the problem of finding the minimum number $n$ such that any $k$ edge colored complete graph on $n$ vertices contains either a rainbow colored triangle or a monochromatic copy of the graph $G$, denoted $gr_k(K_{3}:G)$. More precisely we consider $G=B_{m,\ell}$ where $B_{m,\ell}$ is a broom graph with $m$ representing the number of vertices on the handle and $\ell$ representing the number of bristle vertices. We develop a technique to reduce the difficulty of finding $gr_{k}(K_{3}:B_{m,\ell})$, and use the technique to prove a few cases with a fixed handle length, but arbitrarily many bristles. Further, …

Conflict Free Connectivity And The Conflict-Free-Connection Number Of Graphs, Travis D. Wehmeier

College of Graduate Studies: Theses & Dissertations

We explore a relatively new concept in edge-colored graphs called conflict-free connectivity. A conflict-free path is a (edge-) colored path that has an edge with a color that appears only once. Conflict-free connectivity is the maximal number of internally disjoint conflict-free paths between all pairs of vertices in a graph. We also define the c-conflict-free-connection of a graph G. This is the maximum conflict-free connectivity of G over all c-colorings of the edges of G. In this paper we will briefly survey the works related to conflict-free connectivity. In addition, we will use the probabilistic method to achieve a bound …