Engineering Commons^™

Investigation Of The Optical Properties Of Insb Thin Films Grown On Gaas By Temperature-Dependent Spectroscopic Ellipsometry, Yuanlan Liang, Fangze Wang, Xuguang Luo, Qingxuan Li, Tao Lin, Ian T. Ferguson, Qingyi Yang, Lingyu Wan, Zhe Chuan Feng

Electrical and Computer Engineering Faculty Research & Creative Works

InSb thin films were grown on GaAs substrates by metal organic chemical vapor deposition (MOCVD) and investigated by temperature-dependent spectroscopic ellipsometry (TD-SE). The refractive index, extinction coefficient, and dielectric function of the InSb films were extracted. The variation of critical point energies (E 1 , E 1 +Δ 1 , E 2 , E1') related to the excited state transitions of InSb and the second energy derivatives of the dielectric function at different temperatures showed that the InSb thin film had high electrical and optical stability at the evaluated temperatures. TD-SE analysis revealed a temperature range suitable for the use …

Toward Controllable And Robust Surface Reconstruction From Spatial Curves, Zhiyang Huang

McKelvey School of Engineering Graduate Student Theses & Dissertations

Reconstructing surface from a set of spatial curves is a fundamental problem in computer graphics and computational geometry. It often arises in many applications across various disciplines, such as industrial prototyping, artistic design and biomedical imaging. While the problem has been widely studied for years, challenges remain for handling different type of curve inputs while satisfying various constraints. We study studied three related computational tasks in this thesis. First, we propose an algorithm for reconstructing multi-labeled material interfaces from cross-sectional curves that allows for explicit topology control. Second, we addressed the consistency restoration, a critical but overlooked problem in applying …

Real-Time Reliable Middleware For Industrial Internet-Of-Things, Chao Wang

McKelvey School of Engineering Graduate Student Theses & Dissertations

This dissertation contributes to the area of adaptive real-time and fault-tolerant systems research, applied to Industrial Internet-of-Things (IIoT) systems. Heterogeneous timing and reliability requirements arising from IIoT applications have posed challenges for IIoT services to efficiently differentiate and meet such requirements. Specifically, IIoT services must both differentiate processing according to applications' timing requirements (including latency, event freshness, and relative consistency of each other) and enforce the needed levels of assurance for data delivery (even as far as ensuring zero data loss). It is nontrivial for an IIoT service to efficiently differentiate such heterogeneous IIoT timing/reliability requirements to fit each application, …

Symmetry And Dopant Diffusion In Inverted Nanopyramid Arrays For Thin Crystalline Silicon Solar Cells, Seok Jun Han

Chemical and Biological Engineering ETDs

In this dissertation, we enhance the efficiency of thin flexible monocrystalline silicon solar cells by breaking symmetry in light trapping nanostructures and improving homogeneity in dopant concentration profile. These thin cells are potentially less expensive than conventional thick silicon cells by using less silicon material and making the cells more convenient to be handled when supported on polymer films. Moreover, these cells are widely applicable due to their flexibility and lightweight. However, for high efficiencies, these cells require effective light trapping and charge collection. We achieve these in cells based on 14-mm-thick free-standing silicon films with light-trapping arrays of nanopyramidal …

Mapping In The Humanities: Gis Lessons For Poets, Historians, And Scientists, Emily W. Fairey

Open Educational Resources

User-friendly Geographic Information Systems (GIS) is the common thread of this collection of presentations, and activities with full lesson plans. The first section of the site contains an overview of cartography, the art of creating maps, and then looks at historical mapping platforms like Hypercities and Donald Rumsey Historical Mapping Project. In the next section Google Earth Desktop Pro is introduced, with lessons and activities on the basics of GE such as pins, paths, and kml files, as well as a more complex activity on "georeferencing" an historic map over Google Earth imagery. The final section deals with ARCGIS Online …

Microsphere-Based Disordered Photonic Structures: Control Of Randomness In Langmuir-Blodgett Assembly And Radiative Cooling Applications, Sarun Atiganyanun

Nanoscience and Microsystems ETDs

Many biological photonic structures in nature exhibit a significant degree of disorder within their periodic framework that enhances their optical properties. However, how such disorder contributes to the unique photonic characteristics is not yet fully understood. To facilitate studies on this topic, we investigated self-assembly of microspheres as a method to controllably introduce randomness to photonic structures. Specifically, we examined Langmuir-Blodgett assembly, a layer-by-layer fabrication technique. We developed and experimentally verified a model for the process and determined a condition of surface pressure and substrate pulling speed that corresponds to a maximum structural order in a layer. Along the trajectory …

Advanced Removal Of 4-Nitrophenol By Emerging And Intensifying Technology Of Emulsion Liquid Membrane With Magnetic Nanoparticles, Qusay Al-Obaidi, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

4-nitrophenol is one of the phenolic compounds found in industrial wastes that needs to be removed from treated wastewater. Emulsion liquid membrane (ELM) has been introduced as a developing technology for advanced wastewater and water treatment. This emerging technology of treatment can be intensified by strategically adding nanoparticles to organic membrane phase (O). To facilitate the industrial implementation of ELM with nanoparticles, we used magnetic iron nanoparticles added to the organic phase (O) in order to recover them by a magnet for reuse. This also assists in de-emulsification step. The results show that with the use of 1% (W/W) of …

Your Internet Data Is Rotting, Paul Royster

University of Nebraska-Lincoln Libraries: Faculty Publications

The internet is growing, but old information continues to disappear daily.

Many MySpace users were dismayed to discover earlier this year that the social media platform lost 50 million files uploaded between 2003 and 2015. The failure of MySpace to care for and preserve its users’ content should serve as a reminder that relying on free third-party services can be risky. MySpace has probably preserved the users’ data; it just lost their content. The data was valuable to MySpace; the users’ content less so.

Preserving content or intellectual property on the internet presents a conundrum. If it’s accessible, then it …

Multifunctional Properties Of Gan Nws Applied To Nanometrology, Nanophotonics, And Scanning Probe Microscopy/Lithography, Mahmoud Behzadirad

Optical Science and Engineering ETDs

GaN nanowires are promising for optical and optoelectronic applications because of their waveguiding properties and large optical bandgap. Recent researches have shown superior mechanical properties of GaN nanowires which promises their use in new research areas e.g. nanometrology. In this work, we develop a scalable two-step top-down approach using interferometric lithography as well a bottom-up growth of NWs using MOCVD, to manufacture highly-ordered arrays of nanowires with atomic surface roughness and desired aspect-ratios to be used in nanophotonics and atomic precision metrology and lithography. Using this method, uniform nanowire arrays were achieved over large-areas (~1 mm²) with aspect-ratio …

Management And Security Of Multi-Cloud Applications, Lav Gupta

McKelvey School of Engineering Graduate Student Theses & Dissertations

Single cloud management platform technology has reached maturity and is quite successful in information technology applications. Enterprises and application service providers are increasingly adopting a multi-cloud strategy to reduce the risk of cloud service provider lock-in and cloud blackouts and, at the same time, get the benefits like competitive pricing, the flexibility of resource provisioning and better points of presence. Another class of applications that are getting cloud service providers increasingly interested in is the carriers' virtualized network services. However, virtualized carrier services require high levels of availability and performance and impose stringent requirements on cloud services. They necessitate the …

Sufficient Conditions For Optimal Control Problems With Terminal Constraints And Free Terminal Times With Applications To Aerospace, Sankalp Kishan Bhan

McKelvey School of Engineering Graduate Student Theses & Dissertations

Motivated by the flight control problem of designing control laws for a Ground Collision Avoidance System (GCAS), this thesis formulates sufficient conditions for a strong local minimum for a terminally constrained optimal control problem with a free-terminal time. The conditions develop within the framework of a construction of a field of extremals by means of the method of characteristics, a procedure for the solution of first-order linear partial differential equations, but modified to apply to the Hamilton-Jacobi-Bellman equation of optimal control. Additionally, the thesis constructs these sufficient conditions for optimality with a mathematically rigorous development. The proof uses an approach …

Coupled Correlates Of Attention And Consciousness, Ravi Varkki Chacko

McKelvey School of Engineering Graduate Student Theses & Dissertations

Introduction: Brain Computer Interfaces (BCIs) have been shown to restore lost motor function that occurs in stroke using electrophysiological signals. However, little evidence exists for the use of BCIs to restore non-motor stroke deficits, such as the attention deficits seen in hemineglect. Attention is a cognitive function that selects objects or ideas for further neural processing, presumably to facilitate optimal behavior. Developing BCIs for attention is different from developing motor BCIs because attention networks in the brain are more distributed and associative than motor networks. For example, hemineglect patients have reduced levels of arousal, which exacerbates their attentional deficits. More …

A High-Throughput Screening Platform For In Vitro Elastic Fiber Production And The Mass Transport Properties Of The Elastic Fiber Compromised Arterial Wall, Austin John Cocciolone

McKelvey School of Engineering Graduate Student Theses & Dissertations

Elastin comprises nearly 50% of the wall in large elastic arteries and has a broad variety of physiological roles. As a structural extracellular matrix protein, elastin is responsible for the reversible elasticity in large arties that dampens pulsatile flow and ultimately reduces the workload on the heart. Structural compromise to the elastic fiber network is apparent in the elastin genetic disorders, supravalvular aortic stenosis and autosomal dominant cutis laxa-1, and acquired elastin disorders including hypertension, atherosclerosis, artery calcification, aneurysms, diabetes, and obesity. All of these disorders lead to an increased incidence of cardiovascular related death and the compromised elastic fiber …

Preclinical Imaging Of Multiple Myeloma Therapy Response, Deep Hathi

McKelvey School of Engineering Graduate Student Theses & Dissertations

Multiple myeloma (MM) is a debilitating hematologic malignancy of terminally differentiated plasma cells in the bone marrow (BM). Advances in therapeutic regimens and the use of autologous stem cell transplantation have significantly improved survival rates and quality of life in patients. However, the disease remains incurable, with shorter, successive remission cycles following relapse. To reduce systemic, off-target toxicity and improve quality of life, there is a need for improved stratification of responding patients. Identification of specific, noninvasive, imaging biomarkers that correlate to therapeutic efficacy is an attractive strategy for stratifying responding patients, since the use of positron emission tomography (PET), …

Quantitative Hyperspectral Imaging Pipeline To Recover Surface Images From Crism Radiance Data, Linyun He

McKelvey School of Engineering Graduate Student Theses & Dissertations

Hyperspectral data are important for remote applications such as mineralogy, geology, agriculture and surveillance sensing. A general pipeline converting measured hyperspectral radiance to the surface reflectance image can provide planetary scientists with clean, robust and repeatable products to work on.

In this dissertation, the surface single scattering albedos (SSAs), the ratios of scattering eciency to scattering plus absorption eciences of a single particle, are selected to describe the reflectance. Moreover, the IOF, the ratio of measured spectral radiance (in the unit of watts per squared-meter and micrometer) to the solar spectral radiance (in the unit of watts per squared-meter and …

Approaches To Understanding The Function Of Intrinsic Activity And Its Relationship To Task-Evoked Activity In The Human Brain, Dohyun Kim

McKelvey School of Engineering Graduate Student Theses & Dissertations

Traditionally neuroscience research has focused on characterizing the topography and patterns of brain activation evoked by specific cognitive or behavioral tasks to understand human brain functions. This activation-based paradigm treated underlying spontaneous brain activity, a.k.a. intrinsic activity, as noise hence irrelevant to cognitive or behavioral functions. This view, however, has been profoundly modified by the discovery that intrinsic activity is not random, but temporally correlated at rest in widely distributed spatiotemporal patterns, so called resting state networks (RSN). Studies of temporal correlation of spontaneous activity among brain regions, or functional connectivity (FC), have yielded important insights into the network organization …

Recent Advances In Low-Cost Particulate Matter Sensor: Calibration And Application, Jiayu Li

McKelvey School of Engineering Graduate Student Theses & Dissertations

Particulate matter (PM) has been monitored routinely due to its negative effects on human health and atmospheric visibility. Standard gravimetric measurements and current commercial instruments for field measurements are still expensive and laborious. The high cost of conventional instruments typically limits the number of monitoring sites, which in turn undermines the accuracy of real-time mapping of sources and hotspots of air pollutants with insufficient spatial resolution. The new trends of PM concentration measurement are personalized portable devices for individual customers and networking of large quantity sensors to meet the demand of Big Data. Therefore, low-cost PM sensors have been studied …

Elucidating The Roles Of Astrocyte-Derived Factors In Recovery And Regeneration Following Spinal Cord Injury, Russell E. Thompson

McKelvey School of Engineering Graduate Student Theses & Dissertations

Central nervous system (CNS) injury often causes some level of long-term functional deficit, due to the limited regenerative potential of the CNS, that results in a decreased quality of life for patients. CNS regeneration is inhibited partly by the development of a glial scar following insult that is inhibitory to axonal growth. The major cell population responsible for the formation this glial scar are astrocytes, which has led to the belief that astrocytes are primarily inhibitory following injury. Recent work has challenged this conclusion, finding that astrocyte reactivity is heterogeneous and that some astrocytes are pro-regenerative following injury. Astrocyte transplantation …

Exploring Methodologies To Improve Lignin Utilization In Biorefineries, James Meyer

McKelvey School of Engineering Graduate Student Theses & Dissertations

The increasing world population, coupled with an improving quality of life, has driven a rapidly increasing demand for fuels, chemicals, and materials. Fossil carbon feedstocks, such as petroleum, are currently being consumed to meet these demands. The utilization of these feedstocks has negative impacts on human and environmental health, which are undoubtedly intensifying as a result of the increased reliance required to meet these demands. As an alternative way to meet these demands, biorefineries generate a wide range of fuels, chemicals, and materials from biomass, a renewable and sustainable resource. Current second-generation biorefineries use a plant-based feedstock, lignocellulosic biomass, comprised …

Improved Orthopaedic Repairs Through Mechanically Optimized, Adhesive Biomaterials, Stephen Wheeler Linderman

McKelvey School of Engineering Graduate Student Theses & Dissertations

Despite countless surgical advances over the last several decades refining surgical approaches, repair techniques, and tools to treat tendon and tendon-to-bone injuries, we are still left with repair solutions that rely on fairly crude underlying mechanical principles. Musculoskeletal soft tissues have evolved to transfer high loads by optimizing stress distribution profiles across the tissue at each length scale. However, instead of mimicking these natural load transfer mechanisms, conventional suture approaches are limited by high load transfer across only a small number of anchor points within tissue. This leads to stress concentrations at anchor points that often cause repair failure as …

Defect Chemistry And Ion Intercalation During The Growth And Solid-State Transformation Of Metal Halide Nanocrystals, Bo Yin

McKelvey School of Engineering Graduate Student Theses & Dissertations

Abstract of the Dissertation

Defect Chemistry and Ion Intercalation During the Growth and Solid-State Transformation of Metal Halide Nanocrystals

Semiconductor metal halides as light-sensitive materials have applications in multiple areas, such as photographic film, antibacterial agents and photocatalysts. One focus of this dissertation is to achieve novel morphologies of ternary silver bromoiodide (AgBr1-xIx, 0

For the silver halide system, we demonstrate that the anion composition of AgBr1-xIx nanocrystals determines their shape through the introduction of twin defects as the nanocrystals are made more iodide-rich. AgBr1-xIx nanocrystals grow as single-phase, solid solutions with the rock salt crystal structure for anions compositions …

Top 10 Mistakes In Environmental Data Management, Stephanie Lein, Matthew Miller, Deanna Aungst

World of Coal Ash Proceedings

No abstract provided.

The Future Of Geomembrane Installation: Utilizing Smart Technology & Data Acquisition To Enhance Installation Standards, Project Qc/Qa And Reporting, Allen Bullock

World of Coal Ash Proceedings

No abstract provided.

Evaluation Of 'Off-Spec' Biomass, Co-Fired And Reclaimed Ashes For Use In Concrete, Daniel Benkeser, Xenia Wirth, N.N. Nortey Yeboah, Chris Shearer

World of Coal Ash Proceedings

No abstract provided.

Nu-Rock Process To Make Nu-Concrete Products And Concrete Replacement., Maroun George Rahme

World of Coal Ash Proceedings

No abstract provided.

Synthesis Of Coal Bottom Ash (Cba)-Based Geopolymer With Microwave Energy Appended To Conventional Dry-Oven Curing Process, Hyo Kim, Cheol-Woo Park, Jun-Seong Park

World of Coal Ash Proceedings

No abstract provided.

Evaluation Of The Application Of Bottom Ashes From Thermoelectric In Concrete Blocks For Pavements, Webert Silva, Suelly Barroso, Antonio Cabral

World of Coal Ash Proceedings

No abstract provided.

Recovery Of Carbonaceous Solid Residue (Char) From Coal Ash To Use As Possible Substitute Graphite-Based Materials In Green Energy Applications, Ana C. Santos, Charlotte J. Badenhorst, Barbara Białecka, Joanna Całus-Moszko

World of Coal Ash Proceedings

No abstract provided.

Use Of Supplementary Cementitious Materials In Full-Depth Reclamation Of Asphalt Pavements, Omar Amer, Prasad Rangaraju

World of Coal Ash Proceedings

No abstract provided.

Demonstration Of A Dredge-Fed Fly Ash Hydraulic Classifier/Thickener At The Cardinal Power Plant Pond, Tom Robl, Anne Oberlink

World of Coal Ash Proceedings

No abstract provided.