Physical Sciences and Mathematics Commons^™

Effects Of N-Acetylcysteine Amide In Preventing/Treating Cataracts, Sri Krishna Yasaswi Maddirala

Doctoral Dissertations

"Cataract, the opacification of an eye lens, is a common pathological abnormality of the lens accounting for approximately 50% of all blindness. The only effective treatment currently available for a cataract is the surgical removal of the affected lens and replacement with an artificial lens for the restoration of vision. Although, cataract surgery is considered to be a very successful procedure in terms of visual outcome, the cost of surgery, need for trained personnel and surgeons, and postsurgical complications, limit the worldwide availability and accessibility of this procedure. Hence, alternative preventive and treatment procedures are worthy of investigation. The lens …

Photogenerated O-Azaxylylenes: Mechanistic Studies And Synthetic Applications, William Cole Cronk

Electronic Theses and Dissertations

This research sets out to build upon excited state o-azaxylylene cycloaddition. The mechanism behind the excitation and cycloaddition process of photogenerated o-azaxylylenes was determined experimentally. Time-correlated single-photon counting, steady-state spectroscopy, triplet quenching experiments, and quantum yield studies provided evidence suggesting that excited state intramolecular proton transfer is followed by intersystem crossing and stepwise addition to the tethered unsaturated pendant.

In keeping with the principles of diversity oriented synthesis, a modular approach was taken to gain access to a diverse array of N,O,S-Polyheterocycles which were modified postphotochemically via Suzuki coupling to yield fused biaryls. Cycloaddition products, outfitted with halogens …

Riemannian Geometry (Abstract), Chikako Mese

Kenneth C. Schraut Memorial Lectures

Riemannian Geometry studies the geometry of curved spaces. It originated with the ideas of the Bernhard Riemann in the 19th century extending Gaussian geometry, or the study of geometry of curves and surfaces contained in 3 dimensional Euclidean space.

Sixteenth Kenneth C. Schraut Memorial Lecture (Poster), University Of Dayton. Department Of Mathematics

Kenneth C. Schraut Memorial Lectures

No abstract provided.

Tigra Scientifica Volume Ii, Issue 1

Tigra scientifica

It is our pleasure to welcome readers to the Fall 2015 issue of Tigra scientifica Science News Magazine. This is the 10th issue in this series of exemplary writings by students enrolled in Clemson University’s Creative Inquiry (CI) course, Popular Science Journalism. Science and technology have an enormous impact on society. Thus, science journalists shoulder the responsibility of transmitting accurate, comprehensible, and timely information to bridge the gap between scientists and the general public. A talented group of Clemson University undergraduate students has embraced this responsibility to produce this magazine.

Linkages Between Water Challenges And Land Use Planning In Megacities, Enjie Li, Joanna Endter-Wada, Shujuan Li

Joanna Endter-Wada

No abstract provided.

A Systems-Based Approach To Address Unintended Consequences Of Demand-Driven Transportation Planning In National Parks And Public Lands, Steven Lawson, Peter Newman, Christopher Monz

Christopher Monz

No abstract provided.

Voigt, Reuss, Hill, And Self-Consistent Techniques For Modeling Ultrasonic Scattering, Christopher M. Kube, Joseph A. Turner

Department of Mechanical and Materials Engineering: Faculty Publications

An elastic wave propagating in a metal loses a portion of its energy from scattering caused by acoustic impedance differences existing at the boundaries of anisotropic grains. Theoretical scattering models capture this phenomena by assuming the incoming wave is described by an average elastic moduli tensorC_0ijkl (x) that is perturbed by a grain with elasticityC_ijkl (x ') where the scattering event occurs when x = x’. Previous models have assumed that C_0ijkl (x) is the Voigt average of the singlecrystal elastic moduli tensor. However, this assumption …

Acoustic Nonlinearity Parameters For Transversely Isotropic Polycrystalline Materials, Christopher M. Kube, Joseph A. Turner

Department of Mechanical and Materials Engineering: Faculty Publications

This article considers polycrystalline materials with macroscopic elastic anisotropy and the effect of the anisotropy on the quadratic nonlinearity parameter used to describe second harmonic generation in solids. The polycrystal is assumed to have transversely isotropic elastic symmetry, which leads to a directional dependence of the nonlinearity parameters. Additionally, the anisotropy leads to second harmonic generation from an input shear wave. Estimates of the longitudinal and shear wave nonlinearity parameters are given as a function of single-crystal elastic constants, macroscopic anisotropy constants, and propagation direction. An inverse model is presented that relates measured nonlinearity parameters to the macroscopic anisotropy constants. …

Acoustic Attenuation Coefficients For Polycrystalline Materials Containing Crystallites Of Any Symmetry Class, Christopher M. Kube, Joesph A. Turner

Department of Mechanical and Materials Engineering: Faculty Publications

This letter provides a theoretical extension to the elastic properties of polycrystals in order to describe elastic wave scattering from grain boundaries. The extension allows the longitudinal and shear attenuation coefficients for scattering to be derived and is valid for polycrystals containing crystallites of any symmetry class. Attenuation curves are given for polycrystalline SiO₂, ZrO₂, and SnF₂, which contain monoclinic crystallites. This work will allow ultrasonic techniques to be applied to new classes of materials containing nontrivial microstructures.

Interfacial Electronic Structure At The Ch3nh3pbi3/Moox Interface, Peng Liu, Xiaoliang Liu, Lu Lyu, Haipeng Xie, Hong Zhang, Dongmei Niu, Han Huang, Cheng Bi, Zhengguo Xiao, Jinsong Huang, Yongli Gao

Department of Mechanical and Materials Engineering: Faculty Publications

Interfacial electronic properties of the CH₃NH₃PbI₃ (MAPbI₃)/M_oOx interface are investigated using ultraviolet photoemission spectroscopy and X-ray photoemission spectroscopy. It is found that the pristine MAPbI₃ film coated onto the substrate of poly (3,4-ethylenedioxythiophene) poly(styrenesulfonate)/indium tin oxide by two-step method behaves as an n-type semiconductor, with a band gap of ~1.7 eV and a valence band edge of 1.40 eV below the Fermi energy (EF). With the MoOx deposition of 64A ° upon MAPbI3, the energy levels of MAPbI3 shift toward higher binding energy by 0.25 eV due to electron transfer …

Erratum: “The Operation Mechanism Of Poly (9,9-Dioctylfluorenyl-2,7-Diyl) Dots In High Efficiency Polymer Solar Cells” [Appl. Phys. Lett. 106, 193904 (2015)], Chunyu Liu, Yeyuan He, Xinyuan Zhang, Zhiqi Li, Jinfeng Li, Liang Shen, Zhihui Zhang, Wenbin Guo, Shengping Ruan

Department of Mechanical and Materials Engineering: Faculty Publications

We have noticed an error in Fig. 7 of the original article. Figs. 7(a) and 7(b) should be exchanged and the revised figure is shown below. We apologize for this error.¹

The Operation Mechanism Of Poly(9,9-Dioctylfluorenyl-2,7-Diyl) Dots In High Efficiency Polymer Solar Cells, Chunyu Liu, Yeyuan He, Xinyuan Zhang, Zhiqi Li, Liang Shen, Zhihui Zhang, Wenbin Guo, Shengping Ruan

Department of Mechanical and Materials Engineering: Faculty Publications

The highly efficient polymer solar cells were realized by doping poly(9,9-dioctylfluorenyl-2,7-diyl) (PFO) dots into active layer. The dependence of doping amount on devices performance was investigated and a high efficiency of 7.15% was obtained at an optimal concentration, accounting for a 22.4% enhancement. The incorporation of PFO dots (Pdots) is conducted to the improvement of Jsc and fill factor mainly due to the enhancement of light absorption and charge transport property. Pdots blended in active layer provides an interface for charge transfer and enables the formation of percolation pathways for electron transport. The introduction of Pdots was proven an effective …

Surface Analytical Investigation On Organometal Triiodide Perovskite, Chengong Wang, Xiaoliang Liu, Congcong Wang, Zhengguo Xiao, Cheng Bi, Yuchuan Shao, Jinsong Huang, Yongli Gao

Department of Mechanical and Materials Engineering: Faculty Publications

In a little over a year, there has been an unexpected breakthrough and rapid evolution of highly efficient solid-state hybrid solar cells based on organometal trihalide perovskite materials. This technology has the potential to produce solar cells with the very highest efficiencies while retaining the very lowest cost. The authors have measured the electronic density of states of CH₃NH₃PbI₃ using ultraviolet photoemission spectroscopy (UPS), inverse photoemission spectroscopy (IPES), and x-ray photoemission spectroscopy (XPS). The valence band maximum and conduction band minimum positions are obtained from the UPS and IPES spectra, respectively, by linear extrapolation of …

Phase Transformation And Magnetic Properties Of Rapidly Solidified Mn-Al-C Alloys Modified With Zr, Yunlong Geng, Micheal J. Lucis, Pamela Rasmussen, Jeffrey E. Shield

Department of Mechanical and Materials Engineering: Faculty Publications

Mn_54-xAl₄₃C₃Zr_x (x=1, 3) alloys were prepared by rapid solidification followed by heat treatment to produce the ferromagnetic s phase. The substitution of Zr for Mn in the structure resulted in an increase of the saturation magnetization (Ms) compared to that of Mn_54-xAl₄₃C₃. While the highest Ms (12861 emu/g) was obtained in Mn_54-xAl₄₃C₃Zr₁, the coercivity was also improved to 1.62 kOe, compared to 1.25 kOe for Mn_54-xAl₄₃C₃. To further improve the coercivity through grain …

Virtue Ethics: Examining Influences On The Ethical Commitment Of Information System Workers In Trusted Positions, John Max Gray

CCE Theses and Dissertations

Despite an abundance of research on the problem of insider threats, only limited success has been achieved in preventing trusted insiders from committing security violations. Virtue ethics may be an approach that can be utilized to address this issue. Human factors such as moral considerations impact Information System (IS) design, use, and security; consequently they affect the security posture and culture of an organization. Virtue ethics based concepts have the potential to influence and align the moral values and behavior of information systems workers with those of an organization in order to provide increased protection of IS assets. An individual’s …

Incremental Sparse-Pca Feature Extraction For Data Streams, Jean-Pierre Nziga

CCE Theses and Dissertations

Intruders attempt to penetrate commercial systems daily and cause considerable financial losses for individuals and organizations. Intrusion detection systems monitor network events to detect computer security threats. An extensive amount of network data is devoted to detecting malicious activities.

Storing, processing, and analyzing the massive volume of data is costly and indicate the need to find efficient methods to perform network data reduction that does not require the data to be first captured and stored. A better approach allows the extraction of useful variables from data streams in real time and in a single pass. The removal of irrelevant attributes …

A Predictive Modeling System: Early Identification Of Students At-Risk Enrolled In Online Learning Programs, Mary L. Fonti

CCE Theses and Dissertations

Predictive statistical modeling shows promise in accurately predicting academic performance for students enrolled in online programs. This approach has proven effective in accurately identifying students who are at-risk enabling instructors to provide instructional intervention. While the potential benefits of statistical modeling is significant, implementations have proven to be complex, costly, and difficult to maintain. To address these issues, the purpose of this study is to develop a fully integrated, automated predictive modeling system (PMS) that is flexible, easy to use, and portable to identify students who are potentially at-risk for not succeeding in a course they are currently enrolled in. …

Police Opinions Of Digital Evidence Response Handling In The State Of Georgia: An Examination From The Viewpoint Of Local Agencies’ Patrol Officers, Tanya Macneil

CCE Theses and Dissertations

This research examined opinions of local law enforcement agencies’ patrol officers in the State of Georgia regarding preparedness and expectations for handling of digital evidence. The increased criminal use of technology requires that patrol officers be prepared to handle digital evidence in many different situations. The researcher’s goal was to gain insight into how patrol officers view their preparedness to handle digital evidence as well as their opinions on management expectations regarding patrol officers’ abilities to handle digital evidence. The research focused on identifying whether a gap existed between patrol officers’ opinions of digital evidence and the patrol officers’ views …

Use Of Entropy For Feature Selection With Intrusion Detection System Parameters, Frank Acker

CCE Theses and Dissertations

The metric of entropy provides a measure about the randomness of data and a measure of information gained by comparing different attributes. Intrusion detection systems can collect very large amounts of data, which are not necessarily manageable by manual means. Collected intrusion detection data often contains redundant, duplicate, and irrelevant entries, which makes analysis computationally intensive likely leading to unreliable results. Reducing the data to what is relevant and pertinent to the analysis requires the use of data mining techniques and statistics. Identifying patterns in the data is part of analysis for intrusion detections in which the patterns are categorized …

Designing An Effective Information Security Policy For Exceptional Situations In An Organization: An Experimental Study, George S. Antoniou

CCE Theses and Dissertations

An increasing number of researchers are recognizing the importance of the role played by employees in maintaining the effectiveness of an information security policy. Currently, little research exists to validate the relationship between the actions (behaviors) taken by employees in response to exceptional situations (antecedents) regarding an organization’s information security policy, the impact (consequences) those actions have on an organization, and the motives that prompt those actions. When these exceptional situations occur, employees may feel compelled to engage in behaviors that violate the terms of an information security policy because strict compliance with the policy could cause the organization to …

The Construction And Validation Of An M-Learning Framework For Online And Blended Learning Environments, Dick T. Hamann

CCE Theses and Dissertations

With the wide adoption of mobile technologies, new opportunities exist with regard to how these technologies can be used to support teaching and learning. However, there is limited empirical evidence on the use of mobile learning (m-learning) frameworks that support adult students in online and blended learning environments and consider ways to support administrators, faculty, and students in the adoption of mobile technologies for teaching and learning.

The goal was to develop and validate an m-learning framework capturing the administrative, communication, and instructional elements that must be considered when integrating m-learning technologies to support adult community college students. Using design …

Applying The Component Display Theory To The Instructional Design And Development Of An Educational Mobile Application, Trelisa Glazatov

CCE Theses and Dissertations

Mobile technologies present an opportunity for scholars and practitioners to extend the application of instructional design theories and models to a mobile learning environment. The goal was to examine mobile learning design and development issues, validate and extend the instructional design theory, Component Display Theory (CDT), to the development of mobile learning activities, and recommend guiding principles for mobile learning system development.

Using a formative research approach, which focuses on improving design theory for instructional practices and processes, CDT was used to design a tutorial mobile application targeting faculty professional development. This design instance was formatively evaluated to determine how …

Motivation And Learning Of Non-Traditional Computing Education Students In A Web-Based Combined Laboratory, Michael Jesse Green

CCE Theses and Dissertations

Hands-on experiential learning activities are an important component of computing education disciplines. Laboratory environments provide learner access to real world equipment for completing experiments. Local campus facilities are commonly used to host laboratory classes. While campus facilities afford hands-on experience with real equipment high maintenance costs, restricted access, and limited flexibility diminish laboratory effectiveness. Web-based simulation and remote laboratory formats have emerged as low cost options, which allow open access and learner control. Simulation lacks fidelity and remote laboratories are considered too complex for novice learners.

A web-based combined laboratory format incorporates the benefits of each format while mitigating the …

Math In The Dark: Tools For Expressing Mathematical Content By Visually Impaired Students, Patricia M. Mcdermott-Wells

CCE Theses and Dissertations

Blind and visually impaired students are under-represented in the science, technology, engineering, and mathematics disciplines of higher education and the workforce. This is due primarily to the difficulties they encounter in trying to succeed in mathematics courses. While there are sufficient tools available to create Braille content, including the special Nemeth Braille used in the U.S. for mathematics constructs, there are very few tools to allow a blind or visually impaired student to create his/her own mathematical content in a manner that sighted individuals can use. The software tools that are available are isolated, do not interface well with other …

Security Frameworks For Machine-To-Machine Devices And Networks, Michael Demblewski

CCE Theses and Dissertations

Attacks against mobile systems have escalated over the past decade. There have been increases of fraud, platform attacks, and malware. The Internet of Things (IoT) offers a new attack vector for Cybercriminals. M2M contributes to the growing number of devices that use wireless systems for Internet connection. As new applications and platforms are created, old vulnerabilities are transferred to next-generation systems. There is a research gap that exists between the current approaches for security framework development and the understanding of how these new technologies are different and how they are similar. This gap exists because system designers, security architects, and …

Motivating The Solicited And Unsolicited Sharing Of Tacit Knowledge Through The Process Of Externalization, Sheila Yvonne Sorensen

CCE Theses and Dissertations

While several U. S. firms have invested in Knowledge Management (KM) tools and software, it has become apparent that investments must be made in additional facets of KM, such as knowledge sharing (KS), thought by many researchers to be the most important component of KM. Of the two types of KS, explicit and tacit, the sharing of tacit knowledge has been shown to contribute the most to an organization’s performance. However, since tacit knowledge is difficult to both convey and acquire, this unshared tacit knowledge may ultimately harm an organization when, without the appropriate knowledge, individuals cannot effectively perform their …

Implicit Measures And Online Risks, Lucinda W. Wang

CCE Theses and Dissertations

Information systems researchers typically use self-report measures, such as questionnaires to study consumers’ online risk perception. The self-report approach captures the conscious perception of online risk but not the unconscious perception that precedes and dominates human being’s decision-making. A theoretical model in which implicit risk perception precedes explicit risk evaluation is proposed. The research model proposes that implicit risk affects both explicit risk and the attitude towards online purchase. In a direct path, the implicit risk affects attitude towards purchase. In an indirect path, the implicit risk affects explicit risk, which in turn affects attitude towards purchase.

The stimulus used …

Uncertainty Quantification Of Turbulence Model Closure Coefficients For Transonic Wall-Bounded Flows, John Anthony Schaefer

Masters Theses

"The goal of this work was to quantify the uncertainty and sensitivity of commonly used turbulence models in Reynolds-Averaged Navier-Stokes codes due to uncertainty in the values of closure coefficients for transonic, wall-bounded flows and to rank the contribution of each coefficient to uncertainty in various output flow quantities of interest. Specifically, uncertainty quantification of turbulence model closure coefficients was performed for transonic flow over an axisymmetric bump at zero degrees angle of attack and the RAE 2822 transonic airfoil at a lift coefficient of 0.744. Three turbulence models were considered: the Spalart-Allmaras Model, Wilcox (2006) k-ω Model, and the …

Haverstraw Bay Benthic Mapping Project Gis Data, Robert M. Cerrato

SoMAS Research Data

High-resolution backscatter and bathymetric maps created by multibeam and sidescan sonar surveys were used to identify five different seafloor bottom types within Haverstraw Bay. Grab samples were collected within these areas to characterize sediment properties and macrofauna. Selected sampling locations were revisited and seafloor images were obtained with an HD underwater camera. Multivariate analysis was used to identify the most important factors explaining variations in community structure. Results indicated that categorical variables defining bottom types, grain size, and water depth can explain about 42% of community structure variation. In addition, shell length data collected for Rangia cuneata, an introduced species, …