Enhanced Biocompatibility of NiTi (Nitinol) Via Surface Treatment and Alloying

It is projected that by 2020, there will be 138 million Americans over 45, the age at which the increased incidence of heart diseases is documented. Many will require stents. This multi-billion dollar industry, with over 2 million patients worldwide, 15% of whom use Nitinol stents have experienced a decline in sales recently, due in part to thrombosis. It is a sudden blood clot that forms inside stents. As a result, the Food and Drug Administration and American Heart Association are calling for a new generation of stents, new designs and different alloys that are more adaptable to the arteries. The future of Nitinol therefore depends on a better understanding of the mechanisms by which Nitinol surfaces can be rendered stable and inert. In this investigation, binary and ternary Nitinol alloys were prepared and subjected to various surface treatments such as electropolishing (EP), magnetoelectropolishing (MEP) and water boiling & passivation (W&P). In vitro corrosion tests were conducted on Nitinol alloys in accordance with ASTM F 2129-08. The metal ions released into the electrolyte during corrosion tests were measured by Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). Biocompatibility was assessed by observing the growth of human umbilical vein endothelial cells (HUVEC) on the surface of Nitinol alloys. Static and dynamic immersion tests were performed by immersing the Nitinol alloys in cell culture media and measuring the amount of metal ions released in solution. Sulforhodamine B (SRB) assays were performed to elucidate the effect of metal ions on the growth of HUVEC cells. The surfaces of the alloys were studied using Scanning Electron Microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS) respectively. Finally, wettability and surface energy were measured by Contact Angle Meter, whereas surface roughness was measured by Atomic Force Microscopy (AFM). All the surface treated alloys exhibited high resistance to corrosion when compared with untreated alloys. SRB assays revealed that Ni and Cu ions exhibited greater toxicity than Cr, Ta and Ti ions on HUVEC cells. EP and MEP alloys possessed relatively smooth surfaces and some were composed of nickel oxides instead of elemental nickel as determined by XPS. MEP exhibited lowest surface energy and lowest surface roughness.

Cultura da representação de arquitetura: concursos de projeto, Brasil 2008-2011

This thesis deepens the issues pointed out in our master's dissertation (2009) and the following texts about architectural projects representation presented in architectural competitions. It aims to identify the representation culture of projects from architectural competitions. Were there common ways to argue among successful architects? Which were them? How extent the various arguments are consistent or what is the discursive coherent? Which interlocutors were privileged in argumentation, the requesting ones or those that evaluate the proposals? To answer these questions, we began from a correlation suggested by TOSTRUP (1999) among some drawings – plans, sections, façades, perspective, details or texts - and emphasized aspects in a project argumentation (place, zoning, environmental comfort, energy efficiency, etc.). On the top of this, we add functions that DURAND (2003) indicates relevant to architectural representations: conception, communication or seduction and execution. Other writers, such as COLLINS (1971), COLLYER (2004), MOON (2005), BANDEIRA (2007), and OXMAN (2008) in different ways, offered us subsidies to relate kinds of architectural representations with specific functions or strategies of persuasion. Thus, for 08 Brazilian competitions, occurred between 2008 – 2011, we analyzed the requests from the brief of the official announcement, the evaluations of the jurors, and the boards of the winning designs – graphical and textual representations. That allowed us to observe a representation culture predominantly based on perspectives and plans, even been articulated in different arguments. This may emphasize since objective aspects as building execution to appeals of mere visual seduction. In what regards to the audience, even when the official announcement resembled to one another, the winners’ argumentation were different, suggesting a possible jury’s privilege as an interlocutor.

Design and implementation of a relative localization system for ground and aerial robotic teams

The main focus of this thesis is to address the relative localization problem of a heterogenous team which comprises of both ground and micro aerial vehicle robots. This team configuration allows to combine the advantages of increased accessibility and better perspective provided by aerial robots with the higher computational and sensory resources provided by the ground agents, to realize a cooperative multi robotic system suitable for hostile autonomous missions. However, in such a scenario, the strict constraints in flight time, sensor pay load, and computational capability of micro aerial vehicles limits the practical applicability of popular map-based localization schemes for GPS denied navigation. Therefore, the resource limited aerial platforms of this team demand simpler localization means for autonomous navigation. Relative localization is the process of estimating the formation of a robot team using the acquired inter-robot relative measurements. This allows the team members to know their relative formation even without a global localization reference, such as GPS or a map. Thus a typical robot team would benefit from a relative localization service since it would allow the team to implement formation control, collision avoidance, and supervisory control tasks, independent of a global localization service. More importantly, a heterogenous team such as ground robots and computationally constrained aerial vehicles would benefit from a relative localization service since it provides the crucial localization information required for autonomous operation of the weaker agents. This enables less capable robots to assume supportive roles and contribute to the more powerful robots executing the mission. Hence this study proposes a relative localization-based approach for ground and micro aerial vehicle cooperation, and develops inter-robot measurement, filtering, and distributed computing modules, necessary to realize the system. The research study results in three significant contributions. First, the work designs and validates a novel inter-robot relative measurement hardware solution which has accuracy, range, and scalability characteristics, necessary for relative localization. Second, the research work performs an analysis and design of a novel nonlinear filtering method, which allows the implementation of relative localization modules and attitude reference filters on low cost devices with optimal tuning parameters. Third, this work designs and validates a novel distributed relative localization approach, which harnesses the distributed computing capability of the team to minimize communication requirements, achieve consistent estimation, and enable efficient data correspondence within the network. The work validates the complete relative localization-based system through multiple indoor experiments and numerical simulations. The relative localization based navigation concept with its sensing, filtering, and distributed computing methods introduced in this thesis complements system limitations of a ground and micro aerial vehicle team, and also targets hostile environmental conditions. Thus the work constitutes an essential step towards realizing autonomous navigation of heterogenous teams in real world applications.

Protein and Drug Design Algorithms Using Improved Biophysical Modeling

This thesis focuses on the development of algorithms that will allow protein design calculations to incorporate more realistic modeling assumptions. Protein design algorithms search large sequence spaces for protein sequences that are biologically and medically useful. Better modeling could improve the chance of success in designs and expand the range of problems to which these algorithms are applied. I have developed algorithms to improve modeling of backbone flexibility (DEEPer) and of more extensive continuous flexibility in general (EPIC and LUTE). I’ve also developed algorithms to perform multistate designs, which account for effects like specificity, with provable guarantees of accuracy (COMETS), and to accommodate a wider range of energy functions in design (EPIC and LUTE).

Application of Numerical Methods to Study Arrangement and Fracture of Lithium-Ion Microstructure

The focus of this work is to develop and employ numerical methods that provide characterization of granular microstructures, dynamic fragmentation of brittle materials, and dynamic fracture of three-dimensional bodies.

We first propose the fabric tensor formalism to describe the structure and evolution of lithium-ion electrode microstructure during the calendaring process. Fabric tensors are directional measures of particulate assemblies based on inter-particle connectivity, relating to the structural and transport properties of the electrode. Applying this technique to X-ray computed tomography of cathode microstructure, we show that fabric tensors capture the evolution of the inter-particle contact distribution and are therefore good measures for the internal state of and electronic transport within the electrode.

We then shift focus to the development and analysis of fracture models within finite element simulations. A difficult problem to characterize in the realm of fracture modeling is that of fragmentation, wherein brittle materials subjected to a uniform tensile loading break apart into a large number of smaller pieces. We explore the effect of numerical precision in the results of dynamic fragmentation simulations using the cohesive element approach on a one-dimensional domain. By introducing random and non-random field variations, we discern that round-off error plays a significant role in establishing a mesh-convergent solution for uniform fragmentation problems. Further, by using differing magnitudes of randomized material properties and mesh discretizations, we find that employing randomness can improve convergence behavior and provide a computational savings.

The Thick Level-Set model is implemented to describe brittle media undergoing dynamic fragmentation as an alternative to the cohesive element approach. This non-local damage model features a level-set function that defines the extent and severity of degradation and uses a length scale to limit the damage gradient. In terms of energy dissipated by fracture and mean fragment size, we find that the proposed model reproduces the rate-dependent observations of analytical approaches, cohesive element simulations, and experimental studies.

Lastly, the Thick Level-Set model is implemented in three dimensions to describe the dynamic failure of brittle media, such as the active material particles in the battery cathode during manufacturing. The proposed model matches expected behavior from physical experiments, analytical approaches, and numerical models, and mesh convergence is established. We find that the use of an asymmetrical damage model to represent tensile damage is important to producing the expected results for brittle fracture problems.

The impact of this work is that designers of lithium-ion battery components can employ the numerical methods presented herein to analyze the evolving electrode microstructure during manufacturing, operational, and extraordinary loadings. This allows for enhanced designs and manufacturing methods that advance the state of battery technology. Further, these numerical tools have applicability in a broad range of fields, from geotechnical analysis to ice-sheet modeling to armor design to hydraulic fracturing.

On-body characterization of planar differential antennas for multiple, wide, and narrow bands

This paper reports the results of the on-body experimental tests of a set of four planar differential antennas, originated by design variations of radiating elements with the same shape and characterized by the potential for covering wide and narrow bands. All the antenna designs have been implemented on low-cost FR4 substrate and characterized experimentally through on-body measurements. The results show the impact of the proximity to the human body on antenna performance and the opportunities in terms of potential coverage of wide and narrow bands for future ad hoc designs and implementations through wearable substrates targeting on-body and off-body communication and sensing applications.

D2.5 - First bundle of dashboard components

This document describes the core components to create customizable game analytics and dashboards: their present status; links to their full designs and downloadable versions; and how to configure them, and take advantage of the analytics visualizations and the underlying architecture of the platform. All the dashboard components are working with data collected using the xAPI data format that the RAGE project has developed in collaboration with ADL Co-Lab.

Copyright and Parody:Taking Backward the Gowers Review

In 2006 the Gowers Review of Intellectual Property made a series of recommendations for reforming the intellectual property regime to better serve the interests of both consumers and industry. Among the proposed recommendations was that an exception for parody be introduced within the Copyright Designs and Patents Act 1988. In January 2008 the Intellectual Property Office (the IPO) launched the first part of a two-stage consultation process on exceptions to copyright. As part of that consultation process, the IPO proposed a ‘fair dealing style exception’ for parody, and sought views on whether a new exception should be introduced as well as what form it might take. In December 2009 the IPO launched the second stage of this consultation process. The second consultation document rejected the case for a new parody exception. This article considers the place of parody within the copyright regime and the objections levelled against the introduction of an exception set out within the IPO's second consultation document. It invites the IPO to reconsider its decision not to recommend the introduction of a specific exception for parody within the UK.

Study of Alternate Pavement Designs, 1968

This report is submitted pursuant to a contract dated August 30, 1967, between the Iowa State Highway Commission and Howard, Needles, Tammen & Bergendoff, Consulting Engineers, in connection with studies determining (11,A) alternate pavement designs, and (11,B) criteria for geometric design studies. Included herein is that portion of the report covering Paragraph 11,A, comprising preparation of alternate type pavement designs (Portland Cement and Asphaltic Concrete) for the Cedar Valley Freeway and proposed US-518 from 1-80 to US-30. These alternate pavement designs consider quality and availability of aggregates, soil conditions and traffic information, to determine details and dimensions of pavement design. Comparative cost studies were prepared from alternate design data and recommendations as to pavement type are presented for Commission review.

Bodily Experience and Restricted Conditions in Contemporary Art

The Doctoral research was carried out with the primary purpose of reviewing past practice designs and for identifying how body movements contributes to these designs. The context in which the body movements are understood are that of discipline enforced by culture and other physio-biological restraints. A discussion on the relationships of body experience in restricted conditions are carried out, which includes the interaction between movement and space in the application of painting, moulding, biological markers, and moving images. The discipline, socially acceptable practices and regulations present in the researcher’s personal life and culture frame the artworks and a fascinating exploration of dynamics between freedom of movement in artwork construction and restrain of behaviour has been analyzed. In the process of art production, significant points discussed were with respect to the identification, succession and repetition of habitual acts. In addition, bodily movement could be considered as a synthesis of spatiality and temporality. The key point which contains the elements of time and space remains relevant to my creative practice and theoretical research. The core interest of my practice is in understanding the settings and simple rules for bodily movement, which is inspired by the past and forms a possible creation for the future. In this research, the attempt was not to display a comprehensive understanding on how body influences the design of art but rather to explain how understanding body movements provides a trace of my works, from origin, the working process and to completion. Relevant artworks and reflection of personal experiences are discussed as needed to help the reader gain more insight on the interactions of body in art creations.

Policy and Design Guidelines for Trees in a Growing Seattle

Thesis (Master's)--University of Washington, 2016-08