While algae have demonstrated significant potential as a raw material due to the high intracellular concentration of carbohydrates and proteins, a primary limitation as a biofuel feedstock is due to the fact that an economically feasible method of extraction has yet to be offered. Algae samples, acquired from a local waste treatment facility, were combined with abrasive materials and subjected to ultrasonication for specific time intervals. It was found that the synergistic effect of sonication in the presence of abrasive material, such as silicon beads or sand, could extract adequate protein and carbohydrate to be utilized in fermentation processes.

Oceanographic applications of robotics are as varied as the undersea environment itself. As underwater robotics moves toward the study of dynamic processes with multiple vehicles, there is an increasing need to distill large volumes of data from underwater vehicles and deliver it quickly to human operators. While tethered robots are able to communicate data to surface observers instantly, communicating discoveries is more difficult for untethered vehicles. The ocean imposes severe limitations on wireless communications; light is quickly absorbed by seawater, and tradeoffs between frequency, bitrate and environmental effects result in data rates for acoustic modems that are routinely as low as tens of bits per second. These data rates usually limit telemetry to state and health information, to the exclusion of mission-specific science data. In this thesis, I present a system designed for communicating and presenting science telemetry from untethered underwater vehicles to surface observers. The system's goals are threefold: to aid human operators in understanding oceanographic processes, to enable human operators to play a role in adaptively responding to mission-specific data, and to accelerate mission planning from one vehicle dive to the next. The system uses standard lossy compression techniques to lower required data rates to those supported by commercially available acoustic modems (O(10)-O(100) bits per second). As part of the system, a method for compressing time-series science data based upon the Discrete Wavelet Transform (DWT) is explained, a number of low-bitrate image com- pression techniques are compared, and a novel user interface for reviewing transmitted telemetry is presented. Each component is motivated by science data from a variety of actual Autonomous Underwater Vehicle (AUV) missions performed in the last year.

We present an indoor wireless localization system that is capable of room-level localization based solely on 802.11 network signal strengths and user-supplied training data. Our system naturally gathers dense data in places that users frequent while ignoring unvisited areas. By utilizing users, we create a comprehensive localization system that requires little off-line operation and no access to private locations to train. We have operated the system for over a year with more than 200 users working on a variety of laptops. To encourage use, we have implemented a live map that shows user locations in real-time, allowing for quick and easy friend-finding and lost-laptop recovery abilities. Through the system’s life we have collected over 8,700 training points and performed over 1,000,000 localizations. We find that the system can localize to within 10 meters in 94% of cases.

Abdominal aortic aneurysms (AAA’s) are characterized by a permanent and irreversible enlargement of the abdominal aorta to at least 150 percent its expected normal size. Endovascular treatment of AAA’s with endografts has gained tremendous popularity in the last decade, largely due to decreased perioperative mortality and faster recovery times, when compared to open surgical repair. Although endografts are an appealing treatment option for many patients, some device design and safety issues have yet to be addressed. One of the biggest problems with endografts is their tendency to shift their position in the patient anatomy over time. The forces that cause this shift and their relation to endograft design are not well understood. In addition, the degree of blood damage due to the insertion of an endograft into the abdominal aorta has not been quantified. The following studies were completed in order to investigate the issues described above. 1. Calculation of endograft displacement force in patient-specific device models. This study used electron-beam computed tomography (CT) image data to generate patient-specific anatomical models using novel segmentation techniques. The patient models were then virtually modeled to represent three different endograft designs, based on aortic stent-graft devices already available in the U.S. or currently in clinical trials. Computational Fluid Dynamics (CFD) simulations were run to characterize the hemodynamic factors for each patient and a total displacement force was calculated for each model. Results show that the location of the device bifurcation impacts the overall displacement force, with proximal bifurcation endograft designs generating a lesser force than distal bifurcation designs. 2. Characterization of blood damage due to endograft placement. Patient-specific computational models were created to represent endograft features that partially obstruct blood flow to the renal arteries, which is sometimes necessary to attain complete exclusion of the aneurysm after deploying the device. Findings show that the insertion of an endograft causes a two-fold increase in blood damage. However, the magnitude of blood damage is within acceptable safety standards. 3. Benchtop testing of red blood cell damage. A benchtop experimental setup was created to measure the damage to red blood cells under various flow conditions and flow obstructions. Samples were characterized at different time points using light scatter methods to determine cell volume and hemoglobin concentration. Results indicate that significant damage to red blood cells occurs only after prolonged exposure (>103 seconds) to high shear (>4000 dynes/cm2) conditions. In addition, the presence of flow obstructions creates red blood cell fragments, instead of destroying the cells entirely. Future directions for this work include additional CFD modeling of devices in more patients treated with different aortic stent graft designs to derive statistical significance relative to various design and anatomical features and extend the analysis to the evaluation of devices used for the treatment of thoracic aortic aneurysms (TAA’s). Follow-up studies on device migration studies can also be completed in the cohort of patients where the endograft displacement forces were calculated. Further, blood damage models that incorporate the fragmentation of red blood cells can be developed.

Poly(N,N-dimethyl-n-octadecylammonium p-styrenesulfonate) (PSS-DMODA) polymers were prepared and investigated as organogelators for low-polarity aromatic solvents. Gels were prepared by heating polymer solutions (2.5–20% w/v polymer) at elevated temperature and then cooling in an ice bath. Gelation was confirmed by the formation of self-supporting samples that did not flow when inverted 180°. Measurement of the gel transition temperature by inversion testing showed a dependence on the concentration of the polymer, the molecular weight of the polymer, and the gelled solvent. Cavitation rheology measurements on a subset of the gels demonstrated that they were viscoelastic solids. Scanning electron microscopy measurements of freeze-dried xerogels and polarized optical microscopy measurements showed the formation of network structures and birefringent samples, respectively. Aging studies showed syneresis of the gels especially at low concentration and temperature. Gelation was interpreted using a model for reversibly associating polymers. The gelation was attributed to the clustering of the ionic groups to form a physically cross-linked network that restricts the motion of the chains. These polyelectrolyte–surfactant complexes should be a useful class of organogelators as a number of characteristics of the polymer (molecular weight, ionic groups, side-chain length) can be independently varied to tune the properties of the resultant organogels.

Unmanned aerial vehicles (UAVs) have a so-far untapped potential to operate at high speeds through cluttered environments. Many of these systems are limited by their adhoc reactive controllers using simple visual cues like optical flow. Here we consider the problem of formally verifying an output-feedback controller for an aircraft operating in an unknown environment. Using recent advances in sums-of -squares programming that allow for efficient computation of barrier functions, we search for global certificates of safety for the closed-loop system in a given environment. In contrast to previous work, we use rational functions to globally approximate non-smooth dynamics and use multiple barrier functions to guard against more than one obstacle. We expect that these formal verification techniques will allow for the comparison, and ultimately optimization, of reactive controllers for robustness to varying initial conditions and environments.

Due to variations in donations and volunteer support, maximizing effectiveness is crucial to the survival of nonprofit organizations. This project evaluates the ability of Six Sigma, TQM, ISO 9000 and Malcolm Baldrige criteria to help a small nonprofit in the healthcare industry better manage its processes. Six Sigma is the framework selected as it is straightforward, small-organization friendly, exhibits timely results, and is quick to implement. The Six Sigma DMAIC methodology is applied to the nonprofit to define the organizational stakeholders, processes and goals, and then FMEA is used to determine appropriate areas to target for initial corrective actions. Corrective actions are successfully implemented on the area of highest impact, the volunteer feedback form. The DMAIC process used for this nonprofit may be adapted and applied to other nonprofits seeking to begin use of quality approaches.

We develop an aircraft and control system that is capable of repeatedly performing a high speed (7m/s or 16 MPH) "knife-edge" maneuver through a gap that is smaller than the aircraft's wingspan. The maneuver consists of flying towards a gap, rolling to a significant angle, accurately navigating between the obstacles, and rolling back to horizontal. The speed and roll-rate required demand a control system capable of highly precise, repeatable maneuvers. We address the necessary control theory, path planning, and hardware requirements for such a maneuver, and give a proposal for a new system that may improve upon the existing techniques.

Aims Functional tests have demonstrated minimal loss of vaginal closure force with age. So we tested the null hypotheses that age neither affects the maximum cross-sectional area (CSA) nor the volume of the levator muscle. Corresponding hypotheses were also tested in the adjacent obturator internus muscle, which served as a control for the effect of age on appendicular muscle in these women. Methods Magnetic resonance images of 15 healthy younger (aged 21–25 years) and 12 healthy older nulliparous women (aged >63 years) were selected to avoid the confounding effect of childbirth. Models were created from tracing outlines of the levator ani muscle in the coronal plane, and obturator internus in the axial plane using 3D Slicer v. 3.4. Muscle volumes were calculated using Slicer, while CSA was measured using Imageware™ at nine locations. The hypotheses were tested using repeated measures analysis of variance with P  Results The effect of age did not reach statistical significance for the decrease in levator ani muscle maximum CSA or the decrease in volume (4.3%, P = 0.62 and 10.9%, 0.12, respectively). However, age did significantly adversely decrease obturator internus muscle maximum CSA and volume (24.5% and 28.2%, P  Conclusions Unlike the adjacent appendicular muscle, obturator internus, the levator ani muscle in healthy nullipara does not show evidence of significant age-related atrophy.

Perimeter patrol enhances the utility of autonomous surface vehicles (ASVs) by enabling many security and scientific missions, including harbor protection, water sampling, and geological survey. We present a novel approach to perimeter patrol that uses only two sensors: commercial off-the-shelf available marine radar and the heading information from a GPS. Our algorithm performs computer vision morphological operations on the radar image to find a suitable path around shore and choose an appropriate next waypoint. Our method has proved robust to a variety of field conditions, allowing us to demonstrate the autonomous navigation of a 3.5 km perimeter lake.

Wetlands offer a variety of services, such as pollutant removal from point and nonpoint sources, flood attenuation, and habitat for biodiversity. Constructed wetlands can be used in agricultural watersheds to protect surface waters from pollution by agricultural activities. A particular concern for the agricultural Midwest is the high nitrate export from agricultural fields that affects water quality at local and regional scales, including hypoxia in the Gulf of Mexico. Nitrogen export primarily originates in the Upper Mississippi and Ohio River Basins. Tiledrained lands, characteristic of west central Indiana, have greater nitrate losses than un-tiled lands. Constructed wetlands have been proposed as a partial solution to intercept nitrate between agricultural lands and downstream waters. In order to most efficiently use constructed wetlands to treat nitrate exported from tile-drained lands, these wetlands should be carefully placed in the landscape to intercept high nitrate loads and sized according to their contributing areas. In this thesis a methodology is presented for strategically placing constructed wetlands in the landscape, and this methodology is applied to an 8-digit hydrologic unit (HUC) in west central Indiana. Results showed 19 sites that are suitable for wetland placement, requiring conversion of 0.1% of the entire 8-digit watershed. These wetlands would intercept approximately 3% of nitrate-rich waters from tiledrained lands, removing approximately 1% of all nitrate exported. To better estimate nitrate removal in these headwater wetlands, the Soil and Water Assessment Tool (SWAT) was applied to a watershed within the 8-digit HUC where three potential wetland sites were found. Simulated wetlands removed nitrate in every month having flow. These three modeled wetlands consistently removed 17-36% of annual incoming nitrate, culminating in a 5% decrease in average nitrate loads at the watershed outlet. If placed strategically, wetlands can efficiently remove nitrate from tile-drained flow, but the extent of their impact in the landscape is dependent on the suitability of local conditions for wetland placement, as well as the specific criteria used for siting wetlands.

This thesis describes the development of two segmented ion trap systems for quantum information experiments and investigations of novel quantum measurements. We report successful loading of 40Ca+ ions in one of the trap systems and the successful demonstration of the partial collapse and revival of the wavefunction of an ion qubit using the system. We describe the operation of ion trap systems with segmented electrodes and develop a practical strategy for choosing the voltages to apply to the electrode segments to obtain desired trapping potentials and correct for stray fields. The linearity of the Laplace equation results in a linear map from the configuration space of electrode voltages to the function space of electric potentials in the trap. We decompose the electrode configuration space into basis vectors whose corresponding potentials have intuitive meaning. We describe attempts at loading Ca+ ions in a micro-scale segmented ion trap built at Lucent Technologies. The Lucent Trap is a planar ion trap fabricated using lithographic techniques on a silicon substrate. We experienced several problems with this trap and were unable to successfully load ions in it. A second ion trap, built at the University of Liverpool, is described. The Liverpool trap has miniature segmented electrodes constructed using conventional machining. We describe loading of Ca+ ions, and the demonstration of stable trapping with long ion lifetimes and stable electric and magnetic fields. The Liverpool trap is used to demonstrate non-projective “partial” measurements of a qubit wavefunction, which result in non-unitary, non-projective evolution of the wavefunction dubbed partial collapse. This effect can be reversed by performing another partial measurement, but only if the second measurement results in a particular outcome. When this outcome is observed, the qubit wavefunction is restored to the original state. An exact restoration occurs when both measurements are ideal, and we quantify the success of our demonstration by quantum process tomography. We obtain process fidelity >0:65 for a wide variation in strength of the partial collapse from 0

Cells have the ability to actively sense their mechanical environment and respond to both substrate stiffness and stretch by altering their adhesion, proliferation, locomotion, morphology, and synthetic profile. In order to elucidate the interrelated effects of different mechanical stimuli on cell phenotype in vitro, we have developed a method for culturing mammalian cells in a two-dimensional environment at a wide range of combined levels of substrate stiffness and dynamic stretch. Polyacrylamide gels were covalently bonded to flexible silicone culture plates and coated with monomeric collagen for cell adhesion. Substrate stiffness was adjusted from relatively soft (G' = 0.3 kPa) to stiff (G' = 50 kPa) by altering the ratio of acrylamide to bis-acrylamide, and the silicone membranes were stretched over circular loading posts by applying vacuum pressure to impart near-uniform stretch, as confirmed by strain field analysis. As a demonstration of the system, porcine aortic valve interstitial cells (VIC) and human mesenchymal stem cells (hMSC) were plated on soft and stiff substrates either statically cultured or exposed to 10% equibiaxial or pure uniaxial stretch at 1Hz for 6 hours. In all cases, cell attachment and cell viability were high. On soft substrates, VICs cultured statically exhibit a small rounded morphology, significantly smaller than on stiff substrates (p < 0.05). Following equibiaxial cyclic stretch, VICs spread to the extent of cells cultured on stiff substrates, but did not reorient in response to uniaxial stretch to the extent of cells stretched on stiff substrates. hMSCs exhibited a less pronounced response than VICs, likely due to a lower stiffness threshold for spreading on static gels. These preliminary data demonstrate that inhibition of spreading due to a lack of matrix stiffness surrounding a cell may be overcome by externally applied stretch suggesting similar mechanotransduction mechanisms for sensing stiffness and stretch.

This paper presents our work in solving one of the weakest links in 802.11-based indoor-localization: the training of ground-truth received signal strength data. While crowdsourcing this information has been demonstrated to be a viable alternative to the time consuming and accuracy-limited process of manual training [2], one of the chief drawbacks is the rate at which a system can be trained. We demonstrate an approach that utilizes users’ calendar and appointment information to perform interactionless training of an 802.11- based indoor localization system. Our system automatically determines if a user attended a calendar event, resulting in accuracy comparable to our previously published largescale crowdsourced deployment. We find that no other user interaction is necessary to train the system to that level of accuracy when calendar data are available. In ideal conditions, this technique can reduce training time by over a factor of six

Diversity in the information people see and attend to can help people and groups make better decisions, can help people learn and correct inaccurate beliefs, and can help people see ideas with which they do not agree as legitimate. Media policy in the United States has long had a focus on promoting audiences’ exposure to diverse information. The rationale for this goal has been that accurate beliefs and perceptions are necessary for good decision-making and for good governance in democratic society, and that development of these accurate beliefs requires some degree of exposure to information that challenges one’s existing beliefs and opinions. The Internet has brought more choice for what news and information individuals can access. Observers have warned that existing media policies are ill-suited for guaranteeing exposure to political diversity in the Internet age, as people are able to choose more freely from an ever-increasing variety of sources, many of which cater to and present a very narrow range of viewpoints. Given this range of choice, they argue, Americans will increasingly live in ideological echo chambers and polarization of different political groups will increase. Republicans and Democrats already read different newspapers and watch different TV news stations. They read different political books. They even live in different places. The sources to which they attend are echo chambers: left-leaning and right-leaning blogs rarely link to each other and comment threads contain little disagreement. If people prefer to avoid hearing challenging views, we may see even greater political fragmentation in information consumption as people get better tools for filtering the news based on their own reactions and reactions of other people like them.

A graphic novel on engineering epistemology.