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Articles 31 - 60 of 156694

Full-Text Articles in Engineering

Ternary Polar Intermetallics Within The Pt/Sn/R Systems (R = La− Sm): Stannides Or Platinides?, Melissa L. Rhodehouse, Volodymyr Smetana, Chris Celania, Anja-Verena Mudring, Gerd H. Meyer May 2020

Ternary Polar Intermetallics Within The Pt/Sn/R Systems (R = La− Sm): Stannides Or Platinides?, Melissa L. Rhodehouse, Volodymyr Smetana, Chris Celania, Anja-Verena Mudring, Gerd H. Meyer

Ames Laboratory Accepted Manuscripts

Starting generally with a 4:6:3 molar ratio of Pt, Sn, and R (where R = La–Sm), with or without the application of a NaCl flux, seven ternary compounds were obtained as single crystals. The platinides Pt4Sn6R3 (R = La–Nd) crystallize with the Pt4Ge6Pr3 type of structure (oP52, Pnma, a = 27.6–27.8 Å, b = 4.59–4.64 Å, c = 9.33–9.40 Å). With R = Pr, Pt4Sn6Pr3–x (oP52, Pnma, a = 7.2863(3) Å, b = 4.4909(2) Å, c = 35.114(1) Å) is also obtained, which might be considered a ...


Tympanal Asymmetry In A Parasitoid Fly: Small Asymmetries Produce Big Gains, Max Mikel-Stites, Anne E. Staples May 2020

Tympanal Asymmetry In A Parasitoid Fly: Small Asymmetries Produce Big Gains, Max Mikel-Stites, Anne E. Staples

Biology and Medicine Through Mathematics Conference

No abstract provided.


Influence Of Separator Surface Charge On The Nucleation And Penetration Dynamics Of Metal Electrodes In Concentrated Electrolytes, Sikuang Wang May 2020

Influence Of Separator Surface Charge On The Nucleation And Penetration Dynamics Of Metal Electrodes In Concentrated Electrolytes, Sikuang Wang

Engineering and Applied Science Theses & Dissertations

No abstract provided.


Development And Application Of Elliptic Blending Lag K-Omega Sst Standard And Wall-Distance-Free Turbulence Model, Wenjie Shang May 2020

Development And Application Of Elliptic Blending Lag K-Omega Sst Standard And Wall-Distance-Free Turbulence Model, Wenjie Shang

Engineering and Applied Science Theses & Dissertations

In recent decades, Computational Fluid Dynamics (CFD) has become the most widely used technology to understand the fundamental complex fluid dynamics of turbulent flows as well as for modeling of turbulent flows in industrial applications. In industrial applications, the widely used methodology is to solve Reynolds-Average Navier-Stokes Equations (RANS) equations in conjunction with a turbulence model since it strikes a balance between accuracy and computational cost compared to other high fidelity approaches namely the Large Eddy Simulation (LES) and Direct Numerical Simulation (DNS), There are a large number of turbulence models proposed in past five decades, majority of them are ...


Exploring Usage Of Web Resources Though A Model Of Api Learning, Finn Voichick May 2020

Exploring Usage Of Web Resources Though A Model Of Api Learning, Finn Voichick

Engineering and Applied Science Theses & Dissertations

Application programming interfaces (APIs) are essential to modern software development, and new APIs are frequently being produced. Consequently, software developers must regularly learn new APIs, which they typically do on the job from online resources rather than in a formal educational context. The Kelleher–Ichinco COIL model, an acronym for “Collection and Organization of Information for Learning,” was recently developed to model the entire API learning process, drawing from information foraging theory, cognitive load theory, and external memory research. We ran an exploratory empirical user study in which participants performed a programming task using the React API with the goal ...


Numerical Investigation Of Wind Turbine Airfoils Under Clean And Dusty Air Conditions, Siyuan Chen May 2020

Numerical Investigation Of Wind Turbine Airfoils Under Clean And Dusty Air Conditions, Siyuan Chen

Engineering and Applied Science Theses & Dissertations

The focus of research in this thesis is on numerical simulation of airflow around wind turbine airfoils (S809, S814 and S1210) under both clean and dusty air conditions by using Computational Fluid Dynamics (CFD). The physical geometries of the airfoils and the meshing processes are completed in the ANSYS Mesh package ICEM. The simulations and post-processing are done by ANSYS FLUENT. For cases of clean air condition, Spalart–Allmaras (SA), realizable k-ε and Wray-Agarwal (WA) turbulence models are employed in the calculations. The results are compared with the experimental data for validation. For dusty air condition, simulation of the two-phase ...


Cfd Analysis Of A Wind Turbine Airfoil With Flap, Heyou Tan May 2020

Cfd Analysis Of A Wind Turbine Airfoil With Flap, Heyou Tan

Engineering and Applied Science Theses & Dissertations

The focus of this thesis is to evaluate the aerodynamic performance of NREL S809 airfoil (widely used airfoil for wind turbine blades) with a trailing-edge flap by numerical simulations. In the simulations, the geometry of the flap and the gap between the main element and the flap are varied. The airfoil geometry is created in Design Modeler and structured mesh around the airfoil is generated using meshing software ICEM. Simulations are performed using the Reynolds-Averaged Navier-Stokes (RANS) equations with SST k-ω, Spalart-Allmaras (SA) and Wray-Agarwal (WA) turbulence models at Reynolds number 106 at angles of attack of 0, 5o, 10o ...


Cfd Evaluation Of Blood Flow In An Improved Blalock-Taussig Shunt Using Patient Specific Geometries, Zhenghao Lin May 2020

Cfd Evaluation Of Blood Flow In An Improved Blalock-Taussig Shunt Using Patient Specific Geometries, Zhenghao Lin

Engineering and Applied Science Theses & Dissertations

Blalock-Taussig (BT) Shunt is a palliative surgical procedure used during a Norwood surgery on a newborn baby suffering from cyanotic heart defects. The BT Shunt can increase blood flow in patients’ pulmonary artery which can ease the “Blue Baby Syndrome.” Currently used BT Shunts do not produce a balanced flow distribution to the pulmonary arteries (PAs) which can cause high wall shear stress (WSS) and blood flow separation resulting in blood clots. A modified BT Shunt was designed to partially solve this problem. In our previous work [1], the modified BT Shunt was shown by numerical simulations to have the ...


Exploring Attacks And Defenses In Additive Manufacturing Processes: Implications In Cyber-Physical Security, Nicholas Deily May 2020

Exploring Attacks And Defenses In Additive Manufacturing Processes: Implications In Cyber-Physical Security, Nicholas Deily

Engineering and Applied Science Theses & Dissertations

Many industries are rapidly adopting additive manufacturing (AM) because of the added versatility this technology offers over traditional manufacturing techniques. But with AM, there comes a unique set of security challenges that must be addressed. In particular, the issue of part verification is critically important given the growing reliance of safety-critical systems on 3D printed parts.

In this thesis, the current state of part verification technologies will be examined in the con- text of AM-specific geometric-modification attacks, and an automated tool for 3D printed part verification will be presented. This work will cover: 1) the impacts of malicious attacks on ...


Predicate Informed Syntax-Guidance For Semantic Role Labeling, Sijia Wang May 2020

Predicate Informed Syntax-Guidance For Semantic Role Labeling, Sijia Wang

Engineering and Applied Science Theses & Dissertations

In this thesis, we consider neural network approaches to the semantic role labeling task in seman-tic parsing. Recent state-of-the-art results for semantic role labeling are achieved by combiningLSTM neural networks and pre-trained features. This work offers a simple BERT-based modelwhich shows that, contrary to the popular belief that more complexity means better performance,removing LSTM improves the state of the art for span-based semantic role labeling. This modelhas improved F1 scores on both the test set of CoNLL-2012, and the Brown test set of CoNLL-2005 by at least 3 percentage points.In addition to this refinement of existing architectures, we ...


Blood Flow Simulation Of Particle Trapping In Models Of Arterial Bifurcations, Qihang Xu May 2020

Blood Flow Simulation Of Particle Trapping In Models Of Arterial Bifurcations, Qihang Xu

Engineering and Applied Science Theses & Dissertations

This thesis describes the particle trapping mechanism in blood flow in different arterial bifurcation models. For validation of CFD calculations, a T-junction model and a Y-junction model are analyzed. In both the models, there is one inlet pipe with two outlet pipes creating a symmetric bifurcation at some angle from the centerline of the inlet pipe. Naiver-Stokes (RANS) equations are solved for single phase laminar flow using the commercial CFD software ANSYS Fluent. After validation, Eulerian simulations are performed by using the Discrete Phase Model (DPM) for two-phase flow with particles injected in different bifurcation models with bifurcation angle of ...


The Impact Of A Smartlab Implementation On Rural Schools In North Dakota, Tonya M. Greywind May 2020

The Impact Of A Smartlab Implementation On Rural Schools In North Dakota, Tonya M. Greywind

Dissertations, Theses, and Projects

This mixed methods quasi-experimental phenomenological study investigated the impact that a SmartLab® implementation had on four rural schools in the state of North Dakota. This study featured semi structured interview questions for facilitators, semi-structured focus group questions for students, and a digital literacy pre and post assessment (DLA) that was administered to students. This study looked at student learning in terms of twenty-first century skills, teacher and student perspectives in terms of student learning as well as teacher perspectives on the impact of the SmartLab® on their own teaching methods.

Two facilitators from two of the four schools were interviewed ...


Prada: Portable Reusable Accurate Diagnostics With Nanostar Antennas For Multiplexed Biomarker Screening, Xiaona Wen, Yu-Chuan Ou, Holly F. Zarick, Xin Zhang, Anthony B. Hmelo, Quinton J. Victor, Eden P. Paul, Joseph M. Slocik, Rajesh R. Naik, Leon M. Bellan, Eugene C. Lin, Rizia Bardhan May 2020

Prada: Portable Reusable Accurate Diagnostics With Nanostar Antennas For Multiplexed Biomarker Screening, Xiaona Wen, Yu-Chuan Ou, Holly F. Zarick, Xin Zhang, Anthony B. Hmelo, Quinton J. Victor, Eden P. Paul, Joseph M. Slocik, Rajesh R. Naik, Leon M. Bellan, Eugene C. Lin, Rizia Bardhan

Chemical and Biological Engineering Publications

Precise monitoring of specific biomarkers in biological fluids with accurate biodiagnostic sensors is critical for early diagnosis of diseases and subsequent treatment planning. In this work, we demonstrated an innovative biodiagnostic sensor, portable reusable accurate diagnostics with nanostar antennas (PRADA), for multiplexed biomarker detection in small volumes (~50 μl) enabled in a microfluidic platform. Here, PRADA simultaneously detected two biomarkers of myocardial infarction, cardiac troponin I (cTnI), which is well accepted for cardiac disorders, and neuropeptide Y (NPY), which controls cardiac sympathetic drive. In PRADA immunoassay, magnetic beads captured the biomarkers in human serum samples, and gold nanostars (GNSs) “antennas ...


Polystyrene-Block-Polydimethylsiloxane As A Potential Silica Substitute For Polysiloxane Reinforcement, Liyang Shen, Tung-Ping Wang, Fang-Yi Lin, Sabrina Torres, Thomas Robison, Sri Harsha Kalluru, Nacú B. Hernández, Eric W. Cochran May 2020

Polystyrene-Block-Polydimethylsiloxane As A Potential Silica Substitute For Polysiloxane Reinforcement, Liyang Shen, Tung-Ping Wang, Fang-Yi Lin, Sabrina Torres, Thomas Robison, Sri Harsha Kalluru, Nacú B. Hernández, Eric W. Cochran

Chemical and Biological Engineering Publications

Here we report microphase-separated poly(styrene-block-dimethylsiloxane) (PS-b-PDMS) as a reinforcing filler in PDMS thermosets that overcomes the long-standing problem of aging in the processing of silica-reinforced silicone. Surprisingly, PS-b-PDMS reinforced composites display comparable mechanical performance to silica-modified analogs, even though the modulus of PS is much smaller than that of silica and there is no evidence of percolation with respect to the rigid PS domains. We have found that a few unique characteristics contribute to the reinforcing performance of PS-b-PDMS. The strong self-assembly behavior promotes batch-to-batch repeatability by having well-dispersed fillers. The ...


Rapid Restoration Techniques For Software-Defined Networks, Ali Malik, Ruairí De Fréin, Benjamin Aziz May 2020

Rapid Restoration Techniques For Software-Defined Networks, Ali Malik, Ruairí De Fréin, Benjamin Aziz

Articles

There is increasing demand in modern day business applications for communication networks to be robust and reliable due to the complexity and critical nature of such applications. As such, data delivery is expected to be reliable and secure even in the harshest of environments. Software-Defined Networking (SDN) is gaining traction as a promising approach for designing network architectures which are robust and flexible. One reason for this is that separating the data plane from the control plane, increases the controller’s ability to configure the network rapidly. When network failure events occur, the network manager may trade-off the optimality of ...


Effects Of Hard-To-Soft Segment Ratios On The Synthesis And Physico-Mechanical Properties Of Polyurethane Films, Aaron C. Wilson May 2020

Effects Of Hard-To-Soft Segment Ratios On The Synthesis And Physico-Mechanical Properties Of Polyurethane Films, Aaron C. Wilson

Mechanical Engineering Theses

Blood-contacting cardiovascular stents often induce a secondary clotting event due to unrestricted enzymatic activities. The use of hemocompatible polyurethane coatings on these implantable devices is one of the most promising methods to reduce device rejection. In this study, four commercial polyurethane films of various thicknesses and compositions were evaluated for their anticoagulation properties. Results suggested that these films exhibited excellent thermal and physico-mechanical properties while capable of increasing contact time with blood plasma by over a thousand-fold as compared to a control surface. Due to the unknown structure and composition of these commercial films, polyurethane samples were synthesized from toluene ...


Fabrication Of Nanoscale Columnar Diodes By Glancing Angle Deposition, Jacob D. Weightman May 2020

Fabrication Of Nanoscale Columnar Diodes By Glancing Angle Deposition, Jacob D. Weightman

Macalester Journal of Physics and Astronomy

Glancing angle deposition (GLAD) is a process in which thin films are deposited onto a substrate with obliquely incident vapor together with precisely controlled azimuthal substrate rotation. Ballistic shadowing effects due to the oblique incidence produce nanoscale structures, and a variety of feature shapes, including tilted columns, helices, and vertical columns can be achieved by varying the azimuthal rotation during the deposition process. Due to this control of morphology and the compatibility of the process with a wide variety of materials, GLAD films have found applications in a variety of fields including sensing, photonics, photovoltaics, and catalysis, where they are ...


Large Scale Grid Integration Of Wind And Solar Power With Storage, Nicholas Moore May 2020

Large Scale Grid Integration Of Wind And Solar Power With Storage, Nicholas Moore

Macalester Journal of Physics and Astronomy

The current energy grid in the United States is dominated by carbon intense energy generation methods that are based on production when and where it is required. However, solar and wind power have proved themselves as the most promising carbon free energy generation sources. Due to the unpredictable and uncontrollable nature of energy production from solar and wind, large scale integration of these resources into the electric grid will require robust storage capacity. In this project, we model the energy grid of the Midcontinent Independent System Operator (MISO) energy region with high concentrations of solar and wind power to analyze ...


Congressional Committee Resources On Space Policy During The 115th Congress (2017-2018): Providing Context And Insight Into Us Government Space Policy, Bert Chapman May 2020

Congressional Committee Resources On Space Policy During The 115th Congress (2017-2018): Providing Context And Insight Into Us Government Space Policy, Bert Chapman

Libraries Faculty and Staff Presentations

Article 1 of the US Constitution assigns the US Congress numerous responsibilities. These include creating new laws, revising existing laws, funding government programs, and conducting oversight of these programs' performance. Oversight of US Government agency space policy programs is executed by various congressional space policy committees including the House and Senate Science Committees, Armed Services, and Appropriations Committees. These committees conduct many public hearings on space policy, which invite expert witnesses to testify on US space policy programs and feature debate on the strengths and weaknesses of these programs. Documentation produced by these committees is widely available to the public ...


Trading Up: Exchanging Our Data For A Better Life, Nathan Turner May 2020

Trading Up: Exchanging Our Data For A Better Life, Nathan Turner

Marriott Student Review

We live in a data-driven economy. Many people feel like consumers are on the losing end of an economic data-battle with tech giants, but this is simply not true; our data can drive innovation. That’s right—personal data collected from you and me can influence new technologies that will improve our lives. This should excite us, but our fear of losing data privacy can quell our excitement for progress and even restrict innovation. Our quality of life has already begun to improve through data driven innovation, and technological progress is not slowing down. If we let our fear of ...


New Policies Give Solar Users An Economic Boost, Olivia Fowler May 2020

New Policies Give Solar Users An Economic Boost, Olivia Fowler

Marriott Student Review

The future looks bright for Solar Energy, as more States and Territories in the United States commit to moving to 100% renewable energy. What are the different states and territories committing to exactly, and what economic incentives are they bringing? Find out in this article by author Olivia Fowley.


The Inaugural Readership And Authorship Report Of The Journal Of Pre-College Engineering Education Research (J-Peer), Senay Purzer, Emily Jones May 2020

The Inaugural Readership And Authorship Report Of The Journal Of Pre-College Engineering Education Research (J-Peer), Senay Purzer, Emily Jones

Journal of Pre-College Engineering Education Research (J-PEER)

The Journal of Pre-College Engineering Education Research (J-PEER) approaches a decade of publications since its launch in 2011. This inaugural report presents metrics and statistics on J-PEER's readership and authorship, looking specifically at data from 2019, along with reflections from the founding and immediate-past editors.


Security Camera Using Raspberry Pi, Tejendra Khatri May 2020

Security Camera Using Raspberry Pi, Tejendra Khatri

Student Academic Conference

No abstract provided.


Predictive Analysis Of Ethanol Prices With Machine Learning, Benjamin Schilling May 2020

Predictive Analysis Of Ethanol Prices With Machine Learning, Benjamin Schilling

Student Academic Conference

Overview of a predictive analysis regression developed using machine learning alongside ETL process techniques.


Estimating The Tempo Of Audio Files, Parker Ostertag May 2020

Estimating The Tempo Of Audio Files, Parker Ostertag

Student Academic Conference

On the market today, there exists a multitude of software that allows for the detection and prediction of beats per minute (BPM) contained in audio files. There are both free and monetized versions of these programs, but there is one thing that they all have in common: they are inaccurate. This is simply because the science behind beat detection is unfinished, and may never be. In this project, I decided to use a method of audio peak detection to help me detect the tempo that may exist in any audio file. I started by researching existing programs and the science ...


Engineering Ionomer Materials For Addressing Ohmic Resistances In Electrochemical Desalination And Waste Heat Recovery, Varada Menon Palakkal May 2020

Engineering Ionomer Materials For Addressing Ohmic Resistances In Electrochemical Desalination And Waste Heat Recovery, Varada Menon Palakkal

LSU Doctoral Dissertations

Water scarcity and energy availability present important challenges that need to be addressed in the coming centuries. In the front of water technologies, desalting brackish water is of extreme importance for thermal electric power plants, chemical manufacturing plants, and other industrial operations that treat and reuse their water utilities. Membrane capacitive deionization (MCDI) is an energy efficient desalination technique that has drawn attention from commercial entities. Most material research studies on MCDI focus on enhancing electrode performance while little emphasis is given to rationale design of ion-exchange membranes (IEMs). In this work, the ionic conductivity, permselectivity, and thickness for three ...


Alternative Methods, Hunter Stabler May 2020

Alternative Methods, Hunter Stabler

LSU Master's Theses

ABSTRACT

In the realm of precognitive artmaking, the artist’s role is that of an antenna. One must be receptive to the subtle, invisible flow of creative novelty in order to participate in the involuntary channeling of new ideas, new processes, and alternative methods of creative production. Carving out new territory within the realm of static art is a primary objective for my artistic process. By utilizing digital fabrication tools, paired with my affinity for intricate craft and optical metagrobolization, I have created a body of work that invents alternative processes and unique aesthetic languages.

Digital imaging, digital modeling and ...


Intersection Illumination – Collision Correlation: How Does Street Lighting Affect Roadway Safety?, Josh R. Pinchek May 2020

Intersection Illumination – Collision Correlation: How Does Street Lighting Affect Roadway Safety?, Josh R. Pinchek

Aurora: The Research Journal of Ohio Northern University

Understanding the relationship between roadway intersection safety and street lighting is essential to developing effective intersection lighting standards. This study uses data from the Ohio Department of Transportation’s (ODOT) Accident Databases (1 million+ accidents over 10 years) to explore the relationship between street lamps and accident occurrence via comparative statistics. Accident occurrence ratios, calculated based upon seasonally categorized, time-matched accident data are compared and reported with and without artificial lighting as a variable.

The results of the study indicate that artificial lighting is an important factor on accident rate occurrence via a correlation between lighting and roadway safety, guiding ...


High Powered Rocketry Emphasizing Dual-Deployment Recovery Systems, Mckayla J. Hoskin May 2020

High Powered Rocketry Emphasizing Dual-Deployment Recovery Systems, Mckayla J. Hoskin

Honors College Theses

This paper outlines the overall project completed by MACH during the 2019-2020 school year to fulfill the requirements for EGR 498 and EGR 499 as well as the honors thesis requirements. The scope of the paper covers the design and construction of a high powered rocket as per the requirements set by the NASA Student Launch Competition, with a focus on components of dual-deployment recovery systems. Brainstorming, design, optimization, testing, re-design, and components of a high powered rocket are all discussed, though final testing remains incomplete due to complications from COVID-19. Simulation results and launch predictions are included to compensate ...


Methods To Detect Forgeries In Static Signatures, Jennifer Lauriello May 2020

Methods To Detect Forgeries In Static Signatures, Jennifer Lauriello

Honors Theses

Statistical and machine learning approaches to forgery detection in offline sig- natures are attempted and evaluated. Offline signatures are static signatures found on physical media, mainly a piece of paper. A dataset of 330 signatures for 33 people is used, containing five genuine and five forged signatures for each person. The statistical analysis approach proves more successful than a machine learning approach, likely due to the size of the dataset.