A Computational Fluid Dynamics Study On Bidirectional Glenn Shunt Flow With An Additional Pulsatile Flow Through A Modified Blalock-Taussig Shunt, Seda Aslan

LSU New Orleans Theses and Dissertations

The blood flow through the Bidirectional Glenn shunt (BGS) and modified Blalock-Taussig shunt (mBTS) to the pulmonary arteries (PAs) was analyzed using Computational Fluid Dynamics. This study consisted of the steady and pulsatile cases. In case one, the results of blood flow through the BGS for the Newtonian and non-Newtonian viscosity models were compared. Case two focused on having an additional pulsatile blood flow through the mBTS using the non-Newtonian Carreau viscosity model. The geometries were created based on the angiograms. In case one, boundary conditions to be specified at the inlets were obtained from the flow rate measurements via …

Particle Enrichment In Longitudinal Standing Bulk Acoustic Wave Microfluidics, Mingyang Cui

McKelvey School of Engineering Graduate Student Theses & Dissertations

Separation, isolation, and enrichment of targeted nano- and microparticles are critical to a variety of biomedical applications from clinical research (development of therapeutics and diagnostics) to fundamental investigations that require concentration of specific cells from culture, separation of target species from heterogenous mixtures, or controlled perturbation of cells and microorganisms to determine their response to stimuli. Numerous techniques are available for bench-scale and medical settings; however, these traditional approaches are often labor intensive, time-consuming, costly, and/or require modification of the target. Efficiency and specificity are also lacking. Recently, techniques that exploit the similar scales of microfluidic technologies and the intrinsic …

Investigating The Classical And Non-Classical Mechanical Properties Of Gan Nanowires, Mohammad Reza Zamani Kouhpanji

Electrical and Computer Engineering ETDs

Study and prediction of classical and non-classical mechanical properties of GaN is crucial due to the potential application of GaN nanowires (NWs) in piezoelectric, probe-based nanometrology, and nanolithography areas. GaN is mainly grown on sapphire substrates whose lattice constant and thermal expansion coefficient are significantly different from GaN. These discrepancies cause mechanical defects and high residual stresses and strains in GaN, which reduce its quantum efficiency.

Specifically, for nanoscale applications, the mechanical properties of materials differ significantly compared to the bulk properties due to size-effects. Therefore, it is essential to investigate the mechanical properties of GaN NWs using the non-classical …

Surface Acoustic Wave Based Pumping In A Microchannel, Tao Wang, Qi Ni, Nathan B. Crane, Rasim Guldiken

Faculty Publications

Pumping and manipulation of liquids in microfluidic channels is important for many mechanical, chemical and biomedical applications. Surface acoustic wave based devices fabricated on high-efficiency piezoelectric substrates have been recently investigated for mixing and separation application within microfluidic channels. In this paper, we introduce a novel integrated surface acoustic wave based pump for liquid delivery and precise manipulation within a microchannel. The device employs a hydrophobic surface coating (Cytop) in the device design for decreasing the friction force and increasing the bonding. Contrary to previous surface acoustic wave based pump, this device does not need precise layers of water and …

Determining Drag Forces On 3d Printed Shark Skin And The Conditions In Which Drag Forces Are Reduced, Kayla M. Bartnicke

Mechanical Engineering Undergraduate Honors Theses

ABSTRACT

This project was conducted at the University of Arkansas with access to 3D printers and a water tunnel. The project examines drag forces over 3D-printed shark skin. Shark skin was chosen to be studied because of its unique three-pronged denticle shape and the assumption that this unique shape has a purpose, such as drag reduction.

A shark denticle was designed using SolidWorks software, multiplied 164 times creating a total skin area of 17.5 in², and printed using both a MakerBot Replicator 2 3D printer and an Ultimaker 2 Go 3D printer. The shark skin was initially printed …

Next Steps For Mentoring Program, Patrick Gray

Sustainability and Connectivity

This file provides a jump-off position for students in the fall 2017 semester who want to continue work toward a mentoring program.

Design And Development Of A High Altitude Wind Tunnel (Hat), David Ritchie

Research Horizons Day Posters

No abstract provided.

Simulation And Analysis Of A Drilling Fluid Using A Herschel-Bulkley Model, Daniel Powell

Mechanical Engineering ETDs

In the study, a drilling fluid with known properties is analyzed and simulated in the laminar regime through a pipe with dimensions of 1.5m in length and 0.02m in diameter. The purpose of the conducted analysis is to demonstrate the advantages of the Herschel-Bulkley model currently used in the oil and gas industry for analyzing non-Newtonian drilling fluids.

For comparison, the analysis is also performed using more simple models for non-Newtonian fluids such as the Bingham Plastic model and the Power Law model and for a Newtonian fluid (water). In addition to analytical models, computations are conducted using …

Primary Blast Waves Induced Brain Dynamics Influenced By Head Orientations, Yi Hua, Yugang Wang, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

There is controversy regarding the directional dependence of head responses subjected to blast loading. The goal of this work is to characterize the role of head orientation in the mechanics of blast wave-head interactions as well as the load transmitting to the brain. A three-dimensional human head model with anatomical details was reconstructed from computed tomography images. Three different head orientations with respect to the oncoming blast wave, i.e., front-on with head facing blast, back-on with head facing away from blast, and side-on with right side exposed to blast, were considered. The reflected pressure at the blast wave-head interface positively …

Superpositioning High Power Lasers For Mid-Air Image Formations, Auston Viotto

UCARE: Research Products

This research evaluates different methods to create voxels, 3-dimensional pixels, in air without the need for special glasses or reflections off of surfaces. Research on the advantages of superimposing or the culmination, focusing, of laser light will be conducted. The point of superpositioning/culmination will be evaluated by the brightness of the voxel due to the Rayleigh Scatter Effect. The voxel’s brightness is dependent on the laser output strength and inversely proportional to its wavelength. Once a superimposed/culminated voxel has been created in the lab the next step will be to manipulate the location of the voxel through 3-dimensional space. This …

Corgi: Compute Oriented Recumbent Generation Infrastructure, Christopher Allen Hunt

Master's Theses

Creating a bicycle with a rideable geometry is more complicated than it may appear, with today’s mainstay designs having evolved through years of iteration. This slow evolution coupled with the bicycle’s intricate mechanical system has lead most builders to base their new geometries off of previous work rather than expand into new design spaces. This crutch can lead to slow bicycle iteration rates, often causing bicycles to all look about the same. To combat this, several bicycle design models have been created over the years, with each attempting to define a bicycle’s handling characteristics given its physical geometry. However, these …

Project Plan - Mentoring, Abigail Lisjak, Patrick Gray, Timothy Leonard, Adam Foster

Sustainability and Connectivity

A presentation that includes the ideal goal for the project as well as how the project can relate to the other projects in the class.

Binder-Jet Printing Of Fine Stainless Steel Powder With Varied Final Density, Mohsen Ziaee, Eric M. Tridas, Nathan B. Crane

Faculty Publications

Binder jetting is an additive manufacturing process that produces relatively weak porous parts that are strengthened through sintering and/or infiltration. This paper reports on two different methods of preparing fine 316 stainless steel powder and their impact on the final sintered density and dimensions relative to direct printing into -22 micron powder. The first method uses agglomerates of fine powder. In the second, nylon 12 powders are mixed with the steel powder as a fugitive space holder to increase porosity. Sintered density and sintering shrinkage of agglomerate material are shown to vary with the density of the spread powder bed. …

Skin Strain Measurement To Predict Knee Joint Angles Through Nanocomposite Stain Gauges, Adin Martineau, James Tracy, Gavin Collins, Parker Rosquist, Dustin A. Bruening, Matt K. Seeley, David T. Fullwood, Anton E. Bowden

Biomedical Engineering Western Regional Conference

Explores the possibility of using high deflection nanocomposite strain gauges as knee joint angle sensor.

Redesign Of Computer Keyboards For Hospital And Consumer Use, Kent Williams, Brian Jensen, Anton Bowden

Biomedical Engineering Western Regional Conference

Application of carbon nanotube coatings to computer keyboards in order to reduce the spread of bacteria in hospitals and homes.

Keywords: carbon nanotube, bacteria, antimicrobial, keyboard, design, MRSA, biofilm

A Nanocomposite Sensor Neck Sleeve For Tracking In Vivo Spine Kinematics In The Alpaca, Colton Porter Graham, Anton Bowden

Biomedical Engineering Western Regional Conference

Chronic low back pain in the US is often attributed to intervertebral disc degeneration. Camelids, particularly alpacas, pose a potential model for spinal treatment due to similarity of the spinal structure and vertical loading. Alpacas also exhibit a high rate of natural disc degeneration. To gain more understanding about how disc degeneration is caused in alpacas it is necessary to understand the loading and motion of the alpaca cervical spine. The goal of the present work was to incorporate nanocomposite sensors into a custom-designed neck sleeve to track the daily in-vivo neck motion of an alpaca in its natural environment.

The Effect Of Biocomposite Material In A Composite Structure Under Compression Loading, Benjamin Andrew Sweeney

Master's Theses

While composite structures exhibit exceptional strength and weight saving possibilities for engineering applications, sometimes their overall cost and/or material performance can limit their usage when compared to conventional structural materials. Meanwhile ‘biocomposites’, composite structures consisting of natural fibers (i.e. bamboo fibers), display higher cost efficiency and unique structural benefits such as ‘sustainability’. This analysis will determine if the integration of these two different types of composites are beneficial to the overall structure. Specifically, the structure will consist of a one internal bamboo veneer biocomposite ply; and two external carbon fiber weave composite plies surrounding the bamboo biocomposite. To acquire results …

Dirichlet Process Gaussian Mixture Models For Real-Time Monitoring And Their Application To Chemical Mechanical Planarization, Jia (Peter) Liu, Omer F. Beyca, Prahalad K. Rao, Zhenyu (James) Kong, Satish T. S. Bukkapatnam

Department of Mechanical and Materials Engineering: Faculty Publications

The goal of this work is to use sensor data for online detection and identification of process anomalies (faults). In pursuit of this goal, we propose Dirichlet process Gaussian mixture (DPGM) models. The proposed DPGM models have two novel outcomes: 1) DP-based statistical process control (SPC) chart for anomaly detection and 2) unsupervised recurrent hierarchical DP clustering model for identification of specific process anomalies. The presented DPGM models are validated using numerical simulation studies as well as wireless vibration signals acquired from an experimental semiconductor chemical mechanical planarization (CMP) test bed. Through these numerically simulated and experimental sensor data, we …

Pin Router Duplicator Base, Matthew Tebo

All Undergraduate Projects

The idea for the following project came from the Lean Manufacturing class that is offered at Central Washington University. In this class the manufacturing processes is demonstrated through the production of guitar kits. A problem with the class is that the CNC machine gets backed up causing a bottleneck in the production line. The solution to this problem was to make a pin router duplicator. A pin router duplicator is a device that allows the operator to trace a finished part with a pin while a router mimics its movements, cutting a new part. The component that is looked into …

Strained Hybrid Perovskite Thin Films And Their Impact On The Intrinsic Stability Of Perovskite Solar Cells, Jingjing Zhao, Yehao Deng, Haotong Wei, Xiaopeng Zheng, Zhenhua Yu, Yuchuan Shao, Jeffrey E. Shield, Jinsong Huang

Department of Mechanical and Materials Engineering: Faculty Publications

Organic-inorganic hybrid perovskite (OIHP) solar cells have achieved comparable efficiencies to those of commercial solar cells, although their instability hinders their commercialization. Although encapsulation techniques have been developed to protect OIHP solar cells from external stimuli such as moisture, oxygen, and ultraviolet light, understanding of the origin of the intrinsic instability of perovskite films is needed to improve their stability. We show that the OIHP films fabricated by existing methods are strained and that strain is caused by mismatched thermal expansion of perovskite films and substrates during the thermal annealing process. The polycrystalline films have compressive strain in the out-of-plane …