Engineering Commons^™

Modeling And Experimental Methods To Predict Oxygen Distribution In Bone Defects Following Cell Transplantation, Christopher M. Heylman, Sharon Santoso, Melissa D. Krebs, Gerald M. Saidel, Eben Alsberg, George F. Muschler

Biomedical Engineering

We have developed a mathematical model that allows simulation of oxygen distribution in a bone defect as a tool to explore the likely effects of local changes in cell concentration, defect size or geometry, local oxygen delivery with oxygen-generating biomaterials (OGBs), and changes in the rate of oxygen consumption by cells within a defect. Experimental data for the oxygen release rate from an OGB and the oxygen consumption rate of a transplanted cell population are incorporated into the model. With these data, model simulations allow prediction of spatiotemporal oxygen concentration within a given defect and the sensitivity of oxygen tension …

A Strategy For Integrating Essential Three-Dimensional Microphysiological Systems Of Human Organs For Realistic Anticancer Drug Screening, Christopher Heylman, Agua Sobrino, Venktesh S. Shirure, Christopher Cw Hughes, Steven C. George

Biomedical Engineering

Cancer is one of the leading causes of morbidity and mortality around the world. Despite some success, traditional anticancer drugs developed to reduce tumor growth face important limitations primarily due to undesirable bone marrow and cardiovascular toxicity. Many drugs fail in clinical development after showing promise in preclinical trials, suggesting that the available in vitro and animal models are poor predictors of drug efficacy and toxicity in humans. Thus, novel models that more accurately mimic the biology of human organs are necessary for high-throughput drug screening. Three-dimensional (3D) microphysiological systems can utilize induced pluripotent stem cell technology, tissue engineering, and …

Determination Of Specific Gravity Of Municipal Solid Waste, Nazli Yesiller, James Hanson, Jason Taylor Cox, Danielle E. Noce

Civil and Environmental Engineering

This investigation was conducted to evaluate experimental determination of specific gravity (G_s) of municipal solid waste (MSW). Water pycnometry, typically used for testing soils was adapted for testing MSW using a large flask with 2000 mL capacity and specimens with 100–350 g masses. Tests were conducted on manufactured waste samples prepared using US waste constituent components; fresh wastes obtained prior and subsequent to compaction at an MSW landfill; and wastes obtained from various depths at the same landfill. Factors that influence specific gravity were investigated including waste particle size, compaction, and combined decomposition and stress history. The …

A Control-Chart Based Method For Solder Joint Crack Detection - Conference Proceeding, Jianbiao Pan

Industrial and Manufacturing Engineering

Many researchers have used different failure criteria in the published solder joint reliability studies. Since the reported time-to-failure would be different if different failure criteria were used, it would be difficult to compare the reported reliability life of solder joints from one study to another. The purpose of this study is to evaluate the effect of failure criteria on the reported thermal fatigue life and find out which failure criterion can detect failure sooner. First, the application of the control-chart based method in a thermal cycling reliability study is described. The reported time-to-failure data were then compared based on four …

Analyst B: Analysis Of The Utexas1 Passive Linear Surface Wave Dataset, Robb E.S. Moss

Civil and Environmental Engineering

A linear array consisting of 24 1 Hz geophones at 10 m spacing was used to measure the passive surface waves at the UTexas1 site. This paper describes analysis of this dataset using three different methods: ESPAC (extended spatial autocorrelation), f-k (frequency-wavenumber), and ReMi (refraction microtremor). Dispersion curves were developed using each method and the median trends as well as the uncertainty about the medians are compared. The dispersion curves were then individually inverted to estimate shear wave velocity profiles. The inversion results are compared, and a bounded best-estimate shear wave velocity profile is presented. For the site conditions, specific …

Updating And Revising Star Camera For Future Flights Of Balloon Borne Experiment, Krystle N. Sy, Seth Hillbrand

STAR Program Research Presentations

The BLAST (Balloon-borne Large Aperture Submillimeter Telescope) experiment surveys the galaxy from altitudes of 100,000 ft in order to answer important cosmological questions, such as how stars are formed. This experiment is conducted above Antarctica to minimize unwanted noise. Two star cameras are used in the navigation systems to identify known stars. The cameras take pictures and match stars in the image to known star positions from a catalog stored in the star camera's computer. This is done using code written in C++, a computer programming language. In order to modernize the system, the code needs to be updated. A …

Aerodynamic Design And Development Of The Sunswift Iv Solar Racing Car, Graham Doig, Chris Beves

Aerospace Engineering

The aerodynamic design and development of the University of New South Wales' ultra-low-drag solar-electric Sunswitt IV car is described, detailing the student-led design process from initial concept sketches to the completed vehicle. The body shape was established and relined over a period of six months in 2008-2009, almost entirely using computational fluid dynamics. The guiding philosophy was that predictable handling and drag minimization in challenging, changing wind conditions of the type commonly seen during the World Solar Challenge across Australia was preferable to high performance only on 'perfect' days. The car won its class in the 2009 and 2011 World …

Implications Of Compressibility Effects For Reynolds-Scaled Testing Of An Inverted Wing In Ground Effect, G. Doig, Tracie J. Barber, Sammy Diasinos

Aerospace Engineering

The influence of compressibility around an isolated inverted wing at a fixed Reynolds number was examined as relevant to the issue of wind tunnel scaling effects. Three-dimensional simulations were conducted for low ground clearances, at: full scale and a Mach number of 0.088, at 50% scale at Mach 0.176, and at 25% scale at Mach 0.352. As the scale was reduced, the increasing peak local Mach number between the wing and the ground resulted in a higher propensity of the flow to separate towards the trailing edge, and for incompressible or full-scale CFD to underestimate the lift and drag coefficients …

Groundwater Challenges, Charles M. Burt

BioResource and Agricultural Engineering

There are some old lessons that continue to repeat themselves throughout the history of irrigation. For example, it has become a common understanding that accumulated salinity from irrigation spelled the doom of some ancient civilizations in the Middle East. Despite this ancient knowledge, today we still have numerous irrigated basins in which there is no outlet for high-salinity drainage flows.

Likewise, groundwater is something that traditionally has not been well understood, and is often treated as an ever-present back-up plan for irrigation. The “water rights” laws in the western US and elsewhere almost exclusively formalized rules about and concentrated on …

Flow Measurement Options For Canal Turnouts, Kyle Feist, Charles M. Burt

BioResource and Agricultural Engineering

Volumetric record-keeping, billing, and allocations at irrigation district delivery points (turnouts) are the norm, rather than the exception for most California irrigation districts. However, many older districts are just beginning these efforts, and other districts are trying to improve existing hardware and procedures. Volumetric accounting with high accuracy and a reasonable price presents unique engineering challenges for irrigation districts because of the variety of existing structures and configurations at irrigation delivery points. Because it is likely that irrigation districts will attempt to utilize existing devices, or slightly modify them, there is a need for standardized installation and/or calibration. This paper …

Irrigation System Regulating (Buffer) Reservoirs, Charles M. Burt

BioResource and Agricultural Engineering

Regulating reservoirs (also known as "balancing" or "buffer" reservoirs) are very commonly used in western US irrigation district modernization projects with canal systems. Some districts have a dozen or more reservoirs within total service areas of 20,000 – 40,000 ha. This paper presents details of sizing and control of flows into and out of the reservoirs.

Groundwater Nitrate In California: What Should Be Done?, Charles M. Burt

BioResource and Agricultural Engineering

Charle's Burt PowerPoint presentation discusses current issues concerning nitrates in groundwater in California, as well as recommendations made to the State Water Board by the Nitrate Task Force.

Evolution Of Perturbations In Flow Field Mechanics, Samantha R. Bell, David Forliti, Nils Sedano, Kriss Vanderhyde

STAR Program Research Presentations

This project explores the stability analysis of a given flow field. Specifically, where the peak disturbance occurs in a flow as this is the disturbance that is most likely to occur. In rocket combustion, it is important to understand where the maximum disturbance occurs so that the mixing of fuel can be stabilized. The instabilities are the results of frequencies in the area surrounding the flow field. The linear stability governing equations are employed to better understand the disturbance. The governing equations for continuity and momentum in the x and y directions are used to form an equation for the …