Engineering Commons^™

Performance Characteristics Of Posts Embedded In Soil, Brandt M. Humphrey, Karla A. Lechtenberg, John D. Reid, Ronald K. Faller, James C. Holloway

Nebraska Department of Transportation: Research Reports

The primary objective of this research study was to determine the post-soil impact reaction of W6x8.5 (W150x12.6) steel posts and 6-in. x 8-in. (152-mm x 203-mm) Southern Yellow Pine (SYP) posts, specifically along the weak axis. Five bogie tests were conducted on W6x8.5 (W150x12.6) A992 steel posts with a length of 72 in. with embedment depths ranging between of 24 and 40 in. (610 and 1,016 mm). Four bogies tests were conducted on 6-in. x 8-in. (152 mm x 203 mm) SYP posts embedded at depths ranging between 30 and 40 in. (735 and 1,016 mm). The target impact conditions …

Miniaturized Wideband Planar Soft Surfaces For Mutual Coupling Reduction Between Antenna Elements, Said A. Abushamleh

Theses and Dissertations

Miniaturized electromagnetic soft surfaces have promising applications in contemporary wideband portable wireless devices including, Multiple Input Multiple Output (MIMO) systems, dual frequency applications, and mutual coupling reduction among antennas in user terminals utilizing MIMO schemes such as in 4th generation Long-Term Evolution (4G-LTE). The use of textured metallic surfaces over grounded dielectric slab with vias for the suppression of electromagnetic wave propagation for applications including, but not limited to, mutual coupling reduction among closely-spaced antenna elements in antenna arrays, bandwidth enhancement, and gain enhancement has been extensively researched during the past two decades. In this dissertation, novel one-dimensional (1-D) periodic …

Methods Of Extrusion On Demand For High Solids Loading Ceramic Paste In Freeform Extrusion Fabrication, Wenbin Li, Amir Ghazanfari, Ming-Chuan Leu, Robert G. Landers

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Fabrication of highly dense parts with complex geometry by paste-extrusion-based solid freeform fabrication processes requires a precise control of the extrusion flow rate to dispense material on demand, which is often referred as Extrusion-On-Demand (EOD). The extrusion process for aqueous ceramic pastes is complex and difficult to control due to their non-Newtonian behavior, compressibility and inhomogeneity. In this study, three methods of EOD (based on ram extruder, needle valve, and auger valve) are introduced and investigated for the extrusion of high solids loading (i.e., > 50%, volumetric) aqueous alumina paste. Optimal extrusion process parameters for these methods are determined through printing …

Planning Freeform Extrusion Fabrication Processes With Consideration Of Horizontal Staircase Effect, Amir Ghazanfari, Wenbin Li, Ming-Chuan Leu, Robert G. Landers

Mechanical and Aerospace Engineering Faculty Research & Creative Works

An algorithm has been developed to estimate the “horizontal” staircase effect and a technique is proposed to reduce this type of geometrical error for freeform extrusion fabrication processes of 3D “solid” parts. The adaptive rastering technique, proposed in this paper, analyzes the geometry of each layer and changes the width of each line of the raster adaptively in order to reduce the staircase error and increase the productivity simultaneously. For each line, the maximum width that results in a staircase error smaller than a predefined threshold is determined for decreasing the fabrication time or increasing the dimensional accuracy, or both. …

A Framework For Large Scale Fused Pellet Modeling (Fpm) By An Industry Robot, Zhiyuan Wang, Renwei Liu, Todd E. Sparks, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Fused pellet modeling (FPM) is an important method in additive manufacturing technology, where granular material is used instead of filaments. In FPM, prototypes are constructed by the sequential deposition of material layers. As the size of the part increases, the problem of long build times and part deformation becomes critical. In this paper, methods for eliminating the void density during deposition and accuracy control principles for large scale FPM processes are studied. By analyzing the ab initio principles of this process, a mini extruder with variable pitch and progressive diameter screw for the large scale fused deposition is proposed. Based …

Dynamic Characteristics Of Biologically Inspired Hair Receptors For Unmanned Aerial Vehicles, Manohar Chidurala

LSU New Orleans Theses and Dissertations

The highly optimized performance of nature’s creations and biological assemblies has inspired the development of their engineered counter parts that can potentially outperform conventional systems. In particular, bat wings are populated with air flow hair receptors which feedback the information about airflow over their surfaces for enhanced stability and maneuverability during their flight. The hairs in the bat wing membrane play a role in the maneuverability tasks, especially during low-speed flight. The developments of artificial hair sensors (AHS) are inspired by biological hair cells in aerodynamic feedback control designs. Current mathematical models for hair receptors are limited by strict simplifying …

A Method For Visualizing Poetic Texts Using L-Systems (L-Sisŭt'em Ŭl Iyonghan Si T'Eksŭtŭ Sikakhwa Pangbŏp L시스템을 이용한 시 텍스트 시각화 방법), Wayne De Fremery, Jusub Kim

Barowsky School of Business | Faculty Patents

본 발명은 시 텍스트 시각화 방법에 관한 것으로, (a) 시각화 장치에 입력된 시의 텍스트를 순서대로 스캐닝하는 단계; (b) L 시스템 모델을 통해 상기 시의 구조를 식물의 구조와 매칭시키고, 상기 텍스트의 형태소 및 모음을 식물의 채도와 명도와 매칭시켜 컴파일링 하는 단계; (c) 컴파일된 상기 텍스트의 명령어에 따라 렌더링하여 페인팅하고, 상기 식물의 그림을 생성하는 단계; 및 (d) 생성된 상기 그림을 상기 시각화 장치의 표시창에 표시하는 단계를 포함한다.이와 같이 본 발명은 시 텍스트의 시각화에 정보 전달 기능 외에 심미성을 부가하여 시각화 결과 자체가 엔터테인먼트적인 요소를 가지고 가며 직관적인 영감까지 줄 수 있는 창작물이 되도록 하는 새로운 시각화 방법을 제공한다.

The invention relates to …

A Comparative Technological Review Of Hybrid Csp-Biomass Chp Systems In Europe, C. M. Iftekhar Hussain, Aidan Duffy, Brian Norton

Conference Papers

This paper aims to explore different solar technologies and its suitability for hybridization with biomass for combined heat and power (CHP) generation in Europe. Although hybrid solar-biomass research and demonstration is in its infancy, it has the potential to provide dispatchable renewable energy at a significant scale over many areas in Europe. Therefore, this review examines the technical and economic reported performances on hybrid systems in order to assess the technical and economic viabilities of newly-emerging projects. Three different combinations of solar and biomass technologies are discussed in this paper: solar tower (ST) - biomass, parabolic trough (PT) - biomass …

Photoluminescent Silicon Nanoparticles: Fluorescent Cellular Imaging Applications And Photoluminescence (Pl) Behavior Study, Sheng-Kuei Chiu

Dissertations and Theses

Molecular fluorophores and semiconductor quantum dots (QDs) have been used as cellular imaging agents for biomedical research, but each class has challenges associated with their use, including poor photostability or toxicity. Silicon is a semiconductor material that is inexpensive and relatively environmental benign in comparison to heavy metal-containing quantum dots. Thus, red-emitting silicon nanoparticles (Si NPs) are desirable to prepare for cellular imaging application to be used in place of more toxic QDs. However, Si NPs currently suffer poorly understood photoinstability, and furthermore, the origin of the PL remains under debate.

This dissertation first describes the use of diatomaceous earth …

Stretch-Induced Increase In Cardiac Contractility Is Independent Of Myocyte Ca2+ While Block Of Stretch Channels By Streptomycin Improves Contractility After Is-Chemic Stunning, Samhita Rhodes, Amadou K. S. Camara, Mohammed Aldakkak, James S. Heisner, David F. Stowe

Open Access Publishing Support Funded Articles

Stretching the cardiac left ventricle (LV) enhances contractility but its effect on myoplasmic [Ca²⁺] is controversial. We measured LV pressure (LVP) and [Ca²⁺] as a function of intra-LV stretch in guinea pig intact hearts before and after 15 min global stunning ± perfusion with streptomycin (STM), a stretch-activated channel blocker. LV wall [Ca²⁺] was measured by indo-1 fluorescence and LVP by a saline-filled latex balloon inflated in 50 μL steps to stretch the LV. We implemented a mathematical model to interpret cross-bridge dynamics and myofilament Ca²⁺ responsiveness from the instantaneous relationship between [Ca …

Api-Based Acquisition Of Evidence From Cloud Storage Providers, Andres E. Barreto

LSU New Orleans Theses and Dissertations

Cloud computing and cloud storage services, in particular, pose a new challenge to digital forensic investigations. Currently, evidence acquisition for such services still follows the traditional approach of collecting artifacts on a client device. In this work, we show that such an approach not only requires upfront substantial investment in reverse engineering each service, but is also inherently incomplete as it misses prior versions of the artifacts, as well as cloud-only artifacts that do not have standard serialized representations on the client.

In this work, we introduce the concept of API-based evidence acquisition for cloud services, which addresses these concerns …

Adaptive Online Transient Stability Assessment Of Power Systems For Operational Purposes, Hussain Hassan Al Marhoon

LSU New Orleans Theses and Dissertations

Online stability assessment is an important problem that has not been solved completely yet. The purpose of this research is to tackle online transient stability assessment. Currently, most utility companies use step-by-step integration in order to set protective equipment so that they effectively work for critical contingencies. However, there are times an unforeseen contingency may occur which may cause the system to transit and the protective equipment to misoperate and does not isolate the disturbed part of the system. This research introduces a method that automatically determines a group of generators that participate in system separation and hence transient instability. …

Comparative Analysis Of Load Flow Techniques For Steady State Loading Margin And Voltage Stability Improvement Of Power Systems, Santosh Togiti

LSU New Orleans Theses and Dissertations

Installation of reactive compensators is widely used for improving power system voltage stability. Reactive compensation also improves the system loading margin resulting in more stable and reliable operation. The improvements in system performance are highly dependent on the location where the reactive compensation is placed in the system. This paper compares three load flow analysis methods - PV curve analysis, QV sensitivity analysis, and Continuation Load Flow - in identifying system weak buses for placing reactive compensation. The methods are applied to three IEEE test systems, including modified IEEE 14-bus system, IEEE 30-bus system, and IEEE 57-bus system. Locations of …

Numerical Solutions Of Generalized Burgers' Equations For Some Incompressible Non-Newtonian Fluids, Yupeng Shu

LSU New Orleans Theses and Dissertations

The author presents some generalized Burgers' equations for incompressible and isothermal flow of viscous non-Newtonian fluids based on the Cross model, the Carreau model, and the Power-Law model and some simple assumptions on the flows. The author numerically solves the traveling wave equations for the Cross model, the Carreau model, the Power-Law model by using industrial data. The author proves existence and uniqueness of solutions to the traveling wave equations of each of the three models. The author also provides numerical estimates of the shock thickness as well as maximum strain $\varepsilon_{11}$ for each of the fluids.

Communication: Antibody Stability And Behavior On Surfaces, Derek B. Bush, Thomas A. Knotts Iv

Faculty Publications

Antibody microarrays have the potential to revolutionize molecular detection in scientific, medical, and other biosensor applications, but their current use is limited because of poor reliability. It is hypothesized that one reason for their poor performance results from strong antibody-surface interactions that destabilize the antibody structure and create steric interference for antigen recognition. Using a recently developed coarse-grain protein-surface model that has been parameterized against experimental data, antibody-surface interactions for two antibody orientations on two types of surfaces have been investigated. The results show that regardless of attachment geometry, antibodies tend to collapse onto hydrophobic surfaces and exhibit lower overall …

Interview With Pat Walsh, Rca Heritage Program

RCA Oral History Transcripts

Interview with Pat Walsh for the RCA Heritage Program Oral History grant.

Interview With Joe Howe, Rca Heritage Program

RCA Oral History Transcripts

Interview with Joe Howe for the RCA Heritage Program Oral History grant.

Evaluation Of Data-Path Topologies For Self-Timed Conditional Statements, Navaneeth Prasannakumar Jamadagni

Dissertations and Theses

This research presents a methodology to evaluate data path topologies that implement a conditional statement for an average-case performance that is better than the worst-case performance. A conditional statement executes one of many alternatives depending on how Boolean conditions evaluate to true or false. Alternatives with simple computations take less time to execute. The self-timed designs can exploit the faster executing alternatives and provide an average-case behavior, where the average depends on the frequency of simple and complex computations, and the difference in the completion times of simple and complex computations. The frequency of simple and complex computations depends on …

Orbital Debris Mitigation Policy And Unique Challenges For Small Satellites, J. C. Liou, David Jarkey

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by J. C. Liou and David Jarkey titled "Orbital Debris Mitigation Policy and Unique Challenges for Small Satellites" at the Small Satellite Conference on August 10, 2015.

Overview Of The Orbital Debris Problem, J. C. Liou

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by J. C. Liou titled "Overview of the Orbital Debris Problem" at the Small Satellite Conference on August 10, 2015.

Impedance-Matching Analysis In Ir Leaky-Wave Antennas, Navaneeth Premkumar, Yuancheng Xu, Brian A. Lail

Electrical Engineering and Computer Science Faculty Publications

Planar leaky-wave antennas (LWA) that are capable of full-space scanning have long since been the pursuit for applications including, but not limited to, integration onto vehicles and into cameras for wide-angle of view beam-steering. Such a leaky-wave surface (LWS) was designed for long-wave infrared frequencies with frequency scanning capability. The LWS is based on a microstrip patch array design of a leaky-wave impedance surface and is made up of gold microstrip patches on a grounded zinc sulphide substrate. A 1D composite right/left-handed (CRLH) metamaterial made by periodically stacking a unit cell of the LWS in the longitudinal direction to form …

Infrared Surface Phonon Polariton Waveguides On Sic Substrate, Yuchen Yang, Franklin Muriuki Manene, Brian A. Lail

Electrical Engineering and Computer Science Faculty Publications

Surface plasmon polariton (SPP) waveguides harbor many potential applications at visible and near-infrared (NIR) wavelengths. However, dispersive properties of the metal in the waveguide yields weakly coupled and lossy plasmonic modes in the mid and long wave infrared range. This is one of the major reasons for the rise in popularity of surface phonon polariton (SPhP) waveguides in recent research and micro-fabrication pursuit. Silicon carbide (SiC) is a good candidate in SPhP waveguides since it has negative dielectric permittivity in the long-wave infrared (LWIR) spectral region, indicative that coupling to surface phonon polaritons is realizable. Introducing surface phonon polaritons for …

Multi-Coupled Resonant Splitting With A Nano-Slot Metasurface And Pmma Phonons, Michael F. Finch, Brian A. Lail

Electrical Engineering and Computer Science Faculty Publications

Coupled-resonances can be used in applications that include, but are not limited to, surface-enhanced infrared spectroscopy (SEIRS), surface-enhanced Raman spectroscopy (SERS), biosensing, and index sensing. Fano resonance in analogue plasmonic systems has been described as the coupling of a bright (superradiant) mode and a dark (subradiant) mode via the near field.Dark and bright mode interactionsareinvestigated with the use of a Fano resonant metamaterial (FRMM) where the metamaterial is a dual nano-slot metasurface on a silicon cavity. The FRMM is numerically simulated using Ansys High Frequency Structure Simulator (HFSS). The FRMM is coupled to the carbon double bond in polymethyl methacrylate …

Geotechnical Field Reconnaissance: Gorkha (Nepal) Earthquake Of April 25, 2015 And Related Shaking Sequence, Youssef M.A. Hashash, Binod Tiwari, Robb E.S. Moss, Domniki Asimaki, Kevin B. Clahan, D. Scott Kieffer, Doug S. Dreger, Amy Macdonald, Chris M. Madugo, H. Benjamin Mason, Menzer Pehlivan, Deepak Rayamajhi, Indra Acharya, Basanta Adhikari

Civil and Environmental Engineering

The April 25, 2015 Gorkha (Nepal) Earthquake and its related aftershocks had a devastating impact on Nepal. The earthquake sequence resulted in nearly 9,000 deaths, tens of thousands of injuries, and has left hundreds of thousands of inhabitants homeless. With economic losses estimated at several billion US dollars, the financial impact to Nepal is severe and the rebuilding phase will likely span many years. The Geotechnical Extreme Events Reconnaissance (GEER) Association assembled a reconnaissance team under the leadership of D. Scott Kieffer, Binod Tiwari and Youssef M.A. Hashash to evaluate geotechnical impacts of the April 25, 2015 Gorkha Earthquake and …

Chemoselective Transfer Hydrogenation Of Nitroarenes Catalyzed By Highly Dispersed, Supported Nickel Nanoparticles, Chengjun Jiang, Zeyu Shang, Xinhua Liang

Chemical and Biochemical Engineering Faculty Research & Creative Works

A recyclable highly dispersed Ni/SiO₂ catalyst was prepared by atomic layer deposition. Chemo selective reduction of nitroarenes was studied using the prepared Ni/SiO₂ as the catalyst and hydrazine hydrate as a hydrogen donor. Different kinds of nitroarenes were converted to the corresponding anilines with high yields. The high activity of the catalysts could be a result of the highly dispersed Ni nanoparticles. (Chemical Presented).

Network Structure, Network Flows And The Phenomenon Of Influence In Online Social Networks: An Exploratory Empirical Study Of Twitter Conversations About Youtube Product Categories, Nitin Venkat Mayande

Dissertations and Theses

Traditional marketing models are swiftly being upended by the advent of online social networks. Yet, practicing firms that are engaging with online social networks neither have a reliable theory nor sufficient practical experience to make sense of the phenomenon. Extant theory in particular is based on observations of the real world, and may thus not apply to online social networks. Practicing firms may consequently be misallocating a large amount of resources, simply because they do not know how the online social networks with which they interact are organized.

The purpose of this dissertation is to investigate how online social networks …

An Implantable Device To Regulate Urination Through Deep Brain Stimulation, Jesse E. Bucksot, Muhammad A. Arafat, Pedro Irazoqui

The Summer Undergraduate Research Fellowship (SURF) Symposium

Urinary Incontinence (UI) is a disease in which patients lose control of their bladder. It is particularly common in elderly women having a prevalence of as much as 30% to 50% [1]. Many of these patients are left without successful treatment. A recent study has shown a new option for treatment that consists of deep brain stimulation (DBS) at a site known as the periaqueductal gray (PAG) [2, 3]. To test the effectiveness of this treatment, chronic stimulation of the PAG should be used in animals to see if it can reliably prevent micturition in the long term. A device …

Grain Boundary Migration Of Nio-Mgo Alloys, Xin Li Phuah, David Lowing, John Blendell

The Summer Undergraduate Research Fellowship (SURF) Symposium

Grain boundary engineering offers enhanced control of microstructure development during processing, leading to improved final material properties. However, using the effects of the interfacial energy anisotropy on grain boundary mobility to control microstructure development is not well understood. The NiO-MgO system is studied as it has complete solid solubility and a transition in the faceting behavior with composition due to changes in the interfacial energy anisotropy. NiO-MgO powders were produced through the amorphous citrate process and modifications to the process were made to reduce particle and agglomerate size. The powders were pressed and sintered in various conditions to produce fine …

Simulating Low-Frequency Sonic Pulsations To Achieve Thrombolysis, Joseph C. Muskat, Matthew C. Pharris, Charles F. Babbs

The Summer Undergraduate Research Fellowship (SURF) Symposium

Cardiovascular thrombosis may result in critical ischemia to a range of anatomical regions, constituting a leading cause of death in the United States. Current invasive treatments for such arterial blockages often yield blood clot recurrence, resulting in repeated hospitalization of patients. This research aims to show how internally introduced pressure oscillations may be used to initiate thrombolysis. We present a novel computational model for determining the resonant frequency and corresponding deformation of an idealized thrombus. Sinusoidal pressure differences across the thrombus induce axial displacements of frequency dependent amplitude. The maximum peak displacement occurs at a resonant frequency of 73 Hz …

Synthesis And Characterization Of 2d Atomic Layers, Adam Charnas, Gang Qiu, Peide Ye

The Summer Undergraduate Research Fellowship (SURF) Symposium

As electronic devices have continued to become smaller, a pressing need has developed for new technologies in order to surpass current size constraints. As such, 2-dimensional materials have become a topic of great interest in experimental device research. Monolayer black phosphorus, or phosphorene, is one such 2D material which shows significant potential as a p-type semiconductor. Phosphorene exhibits a number of unique and desirable electrical properties such as a layer-dependent band gap, high carrier mobility, and anisotropic conductivity. An investigation into optimal growth of black phosphorus, the precursor material to phosphorene, as well as characterization of phosphorene-based devices will be …