Dose Optimization in Cardiovascular Interventional Radiology

The thesis treat the patient dose optimization in Carbon Dioxide Angiography and dose reduction with the using of Clarity Philips in EP procedures. Carbon dioxide angiography is based on the visualization (i.e., the radiographic contrast) of gas bubbles injected in blood vessels. By using an experimental X-ray bench, it has been measured the energy response of a flat panel detector (Varian CB4030) and, with a dedicated phantom and a software simulation, the image contrast of vessels injected with Iodine and CO2. The results show that the contrast generated by carbon dioxide is about one fourth of that obtained with iodine, demonstrating that CO2 angiography should use different radiological settings with respect to iodine angiography. In particular, a kVp increase have a lower reduction of CNR with carbon dioxide than with iodinated CM, suggesting possible technological improvements in fluoroscopy protocols. The aim of the second work has been to evaluate the patient dose comparison between before and after the introduction of the Philips Clarity system upgrade. The retrospective study has been made on 561 procedures of pacemaker (PM) and implantable cardioverter defibrillator (ICD) implantations (134 pre, 192 post), and 235 procedures of radio frequency ablation (RFA) procedures (91 pre, 144 post). The pre and post sets are compared over clinical details in order to define an average patient for each intervention type. Each procedure has been studied over single irradiation event collected in the Structure Dose Report (SDR). The Dose-Area Product (PkA) cumulative quantities is not normal distributed over a single procedure type, so a log-normal hypothesis has been made. The results shows a significant reduction of the for the PkA equal to 54% over all the procedures. The total fluoroscopy time didn’t change appreciably and this shows in first instance that that the subjective image quality didn't change too

SALVI - sala de aula virtual : contribuição para a comunicação sincrona em educação mediada por computador

Orientador: Sergio Ferreira do AmaralTese (doutorado) - Universidade Estadual de Campinas, Faculdade de EducaçãoDoutorad

Developing front-end Web 2.0 technologies to access services, content and things in the future Internet

The future Internet is expected to be composed of a mesh of interoperable web services accessible from all over the web. This approach has not yet caught on since global user?service interaction is still an open issue. This paper states one vision with regard to next-generation front-end Web 2.0 technology that will enable integrated access to services, contents and things in the future Internet. In this paper, we illustrate how front-ends that wrap traditional services and resources can be tailored to the needs of end users, converting end users into prosumers (creators and consumers of service-based applications). To do this, we propose an architecture that end users without programming skills can use to create front-ends, consult catalogues of resources tailored to their needs, easily integrate and coordinate front-ends and create composite applications to orchestrate services in their back-end. The paper includes a case study illustrating that current user-centred web development tools are at a very early stage of evolution. We provide statistical data on how the proposed architecture improves these tools. This paper is based on research conducted by the Service Front End (SFE) Open Alliance initiative

Characterization of the future demand of internet users in Brazil: a contribution for the development of governmental politics to digital inclusion and internet access

The Internet is one of the most important sources for content and services to which the simple user has become an important collaborator. Forecasting the Internet usage should provide guidance focused on improvements and adequate policies for its growth, popularity, help in digital and social inclusion. According to the relevance of the Internet to the society, the purpose of this paper is to report the evolution of the Internet in Brazil, showing its actual scenario and making predictions considering the evolution of technology and the usage of the web in different scenarios. During the development of this study, some statistical methods will be used, such as the Gompertz and the linear regression methods to make predictions to be used in the decision making process. Analysis of the results, according to quantitative research done by research institutes, provides the integration between the presented technique and the performed procedures.A Internet é atualmente uma das principais fontes de distribuição de conteúdos e serviços em ambientes abertos, da qual o usuário comum vem se tornando cada vez mais um importante consumidor e fornecedor. Neste sentido, a possibilidade de predição do crescimento da demanda, permitiria ajustes adequados dos recursos que a constituem de forma que possibilite investimentos e políticas adequadas, quer seja para seu crescimento e popularização, quer seja para inclusão digital e social. Considerando a relevância da Internet para a sociedade, o propósito deste artigo é analisar a evolução de demanda da Internet, identificando e detalhando seu panorama atual e com predições de como será em futuro próximo, tomando como base parâmetros de evolução tecnológica e uso da Internet em diversos cenários. Serão utilizados os métodos estatísticos de regressão linear e Gompertz para gerar as previsões de demanda como apoio para tomadas de decisões. Análises dos resultados obtidos por meio de pesquisas quantitativas feitas por institutos de pesquisas fazem a integração entre a técnica apresentada e os procedimentos executados

Atomic Layer Deposition Derived Zirconia Coatings on Ni‐Rich Cathodes in Solid‐State Batteries: Correlation Between Surface Constitution and Cycling Performance

Protective coatings are required to address interfacial incompatibility issues in composite cathodes made from Ni-rich layered oxides and lithium thiophosphate solid electrolytes (SEs), one of the most promising combinations of materials for high energy and power density solid-state battery (SSB) applications. Herein, the preparation of conformal ZrO2 nanocoatings on a LiNi0.85Co0.10Mn0.05O2 (NCM85) cathode-active material (CAM) by atomic layer deposition (ALD) is reported and the structural and chemical evolution of the modified NCM85 upon heat treatment—a post-processing step often required to boost battery performance—is investigated. The coating properties are shown to have a strong effect on the cyclability of high-loading SSB cells. After mild annealing (≈400 °C), the CAM delivers high specific capacities (≈200 mAh g−1 at C/10) and exhibits improved rate capability (≈125 mAh g−1 at 1C) and stability (≈78% capacity retention after 200 cycles at 0.5C), enabled by effective surface passivation. In contrast, annealing temperatures above 500 °C lead to the formation of an insulating interphase that negatively affects the cycling performance. The results of this study demonstrate that the preparation conditions for a given SE/CAM combination need to be tailored carefully and ALD is a powerful surface-engineering technique toward this goal

implementation of the virtual camber transformation into the open source software qblade validation and assessment

Abstract Thanks to the renewed interest in vertical-axis wind turbines, research efforts are devoted at improving the accuracy of present simulation tools, many of which are underdeveloped if compared to those for horizontal-axis turbines. In particular, recent studies demonstrated that a correction for the "virtual camber" effect has a major impact on the simulation. In cycloidal motion indeed the blade aerodynamics are equivalent to those of a virtually-transformed airfoil with a camber line defined by its arc of rotation. In this study, the implementation of a specific module to account for the virtual camber effect in the Open-Source code QBlade is presented. The effectiveness of the model is then validated by four 1-blade and a full 3-blade H-Darrieus turbines, for which both experimental measurements and detailed CFD calculations were available. A sensitivity analysis on the impact of the virtual camber correction on the accuracy of a low-order simulation model has been carried out as a function of the chord-to-radius ratio and the airfoil thickness-to-chord ratio. Reference thresholds for the model applicability are presented for both variables

Source Management In DC Microgrids: An Industrial Application

Industrial direct current (DC) microgrids offer multiple advantages for production factories. They enable higher energy and resource efficiency not only for the production energy supply but also for integrating renewable energy resources. The basic control method of DC microgrids, namely droop control, fits the industrial application due to its decentralized and robust nature. However, in the case of droop control, the DC bus voltage deviates from the nominal value for slowly fluctuating load situations. For this reason, an additional control level for voltage restoration, called secondary control or source management, is necessary. This paper presents hierarchical control for voltage restoration in industrial DC microgrids. The control shifts the current supplied to the DC bus in case the load increases over or decreases below a defined voltage band for a certain period. In addition, the designed control is tested on a real industrial DC microgrid which includes typical industrial loads of up to 50 kW, such as robots of different sizes and CNC machine tools. The control performance with different parameters of the source management is assessed. The results show that the designed control restores the voltage level without creating instabilities in the microgrid for all tested scenarios