2,555 research outputs found
Deformable mesh model for cardiac motion estimation from MRI data
Projecte final de carrera realitzat en col.laboració amb l'Illinois Institute of TechnologyThe use of technology in medical applications has expanded tremendously in the last 50 years, playing an important role in diagnosis and treatment of disease. As a consequence of this growth, it has been possible to develop new techniques and processes which allows scientists and physicians to extract potentially life-saving information by peering noninvasively into the human body. One of these techniques, Magnetic Resonance Imaging, has the capacity of providing data which contain information about motion of human tissue. In this project we exploit this characteristic to present a model for estimating left ventricular heart motion through a whole cardiac cycle. The model is based on the utilization of a non-rigid deformable mesh which tracks the intensity variations on the datasets of MRI images. The use of a mesh allows us to interpolate the motion on every point of the myocardial tissue. Although still in his first steps of development, preliminary results here presented demonstrate great potential of our model in terms of efficiency and flexibility versus the other existing models. It constitutes a good alternative for developing full 4D heart models in the future
Sargadelos en los albores del capitalismo industrial español: entre la iniciativa privada y la promoción reformista
Análisis de la génesis de las Reales
Fábricas de Sargadelos desde la perspectiva política del reformismo ilustrado y la historia de las mentalidades, así como sus aspectos económicos en los inicios del capitalismo industrial. Se indagan además las particularidades sociales y militares que conducen al éxito empresarial de Sargadelos hasta la muerte de su fundador, Don Antonio Raimundo Ibáñez. Todo ello planteado en el contexto de la dinámica general española durante el último tercio del siglo XVIII y los comienzos del XIX, coincidiendo con la crisis final del Antiguo Régimen.Departamento de Historia Moderna, Contemporánea y de América, Periodismo y Comunicación Audiovisual y PublicidadGrado en Histori
Simulations of acoustically enhanced heat transfer in fluids
On Earth, heat dissipation of electronics is produced through convective currents due to gravity, that allow the flow of energy to the environment. However, in microgravity, hot particles remain around the heat source due to the absence of buoyancy. In this project, an existing line of research from the Space Exploration Lab in the UPC is followed in the field of acoustic induced heat transfer in fluids. Our project aims to use acoustic actuation to enhance heat transfer in real microgravity conditions in the ZARM Drop Tower, thanks to the DropYourThesis! 2022 program, from the European Space Agency. The objective of this master thesis is to develop simulations that explain the phenomena and to help design an optimal setup for the study. A simple experiment is proposed with two main systems. The first generates an acoustic wave with a piezoelectric transducer and the second heats up a resistance, which actuates as a heat source. COMSOL Multiphysics is used to develop a validated model that will help us understand the Physics behind this phenomenon and achieve optimal setups to explain the governing factors of this interaction for different gravity levels. It is observed that acoustic heat transfer enhancement is highly dependent on time and gravity acceleration. For normal gravity conditions, the effect is noticeable at short timescales and then buoyancy turns into the dominant heat transfer factor over time. For microgravity conditions, data suggests that the effect is mild at short timescales, but it increases steadily over time without showing signs of regression. Heat transfer in microgravity conditions is increased by 10.9% after 16.2s of acoustic actuation using a resonance frequency of 45kHz. It is concluded that there is high potential for the development of a new cooling technology based on ultrasound in microgravity and this thesis establishes a theoretical framework in which future techniques could be based on
Deformable mesh model for cardiac motion estimation from MRI data
Projecte final de carrera realitzat en col.laboració amb l'Illinois Institute of TechnologyThe use of technology in medical applications has expanded tremendously in the last 50 years, playing an important role in diagnosis and treatment of disease. As a consequence of this growth, it has been possible to develop new techniques and processes which allows scientists and physicians to extract potentially life-saving information by peering noninvasively into the human body. One of these techniques, Magnetic Resonance Imaging, has the capacity of providing data which contain information about motion of human tissue. In this project we exploit this characteristic to present a model for estimating left ventricular heart motion through a whole cardiac cycle. The model is based on the utilization of a non-rigid deformable mesh which tracks the intensity variations on the datasets of MRI images. The use of a mesh allows us to interpolate the motion on every point of the myocardial tissue. Although still in his first steps of development, preliminary results here presented demonstrate great potential of our model in terms of efficiency and flexibility versus the other existing models. It constitutes a good alternative for developing full 4D heart models in the future
Comparación técnica y económica de edificios de cinco pisos con sótano con la NSR -98 y NSR-10 para la microzonificación sísmica de Bogotá
El constante desarrollo urbano en conjunto con los fenómenos causados por la naturaleza, en especial los movimientos de acomodación de placas tectónicas y liberación de energía en la reacomodación de materiales, más conocidos como sismos, han obligado a la recopilación de información a través de la red sismológica nacional. La información obtenida de esta, junto con el estudio de microzonificación sísmica ha demostrado que se tienen que hacer ajustes para el diseño y construcción de edificaciones. A raíz de estos eventos, se han creado y modificado códigos y normas enfocadas a la construcción, en donde el objetivo principal no solo es la consolidación de una edificación, sino que las obras civiles en general propendan por la preservación de la vida humanaPregrad
Impact of public transport strikes on traffic and pollution in the city of Barcelona
Altres ajuts: Acord transformatiu CRUE-CSICThis work has been supported by the Barcelona Council (20S01909-001). Jordi Perdiguero thanks the finantial support of Secretaria d'Universitats i Recerca del departament d'Empresa i Coneixement de la Generalitat de Catalunya (2020 PANDE 00058).Many Spanish cities' air contains excessive levels of pollutants caused by traffic. These pollutants are associated with high concentrations of vehicles in urban and surrounding areas, such as Madrid and Barcelona. According to the World Health Organization (WHO), 96.8% of Spain's population breathe polluted air. This paper provides empirical evidence on the effect of public transport strikes on Barcelona's air quality through an econometric analysis. The period analyzed included 147 days of some kind of public transport strike: bus (57), metro (21), trains (71), and tram (4); and also four general strikes. The estimates show that public transport strikes increases the concentration level of SO2, CO, PM, and NOX throughout the city, especially in the case of metro and RENFE trains. These results also allow us to understand how commuters substitute transport modes and to propose specific policies to increase public transport use
Detection of non-melanoma skin cancer by in vivo fluorescence imaging with fluorocoxib A.
Non-melanoma skin cancer (NMSC) is the most common form of cancer in the US and its incidence is increasing. The current standard of care is visual inspection by physicians and/or dermatologists, followed by skin biopsy and pathologic confirmation. We have investigated the use of in vivo fluorescence imaging using fluorocoxib A as a molecular probe for early detection and assessment of skin tumors in mouse models of NMSC. Fluorocoxib A targets the cyclooxygenase-2 (COX-2) enzyme that is preferentially expressed by inflamed and tumor tissue, and therefore has potential to be an effective broadly active molecular biomarker for cancer detection. We tested the sensitivity of fluorocoxib A in a BCC allograft SCID hairless mouse model using a wide-field fluorescence imaging system. Subcutaneous allografts comprised of 1000 BCC cells were detectable above background. These BCC allograft mice were imaged over time and a linear correlation (R(2) = 0.8) between tumor volume and fluorocoxib A signal levels was observed. We also tested fluorocoxib A in a genetically engineered spontaneous BCC mouse model (Ptch1(+/-) K14-Cre-ER2 p53(fl/fl)), where sequential imaging of the same animals over time demonstrated that early, microscopic lesions (100 μm size) developed into visible macroscopic tumor masses over 11 to 17 days. Overall, for macroscopic tumors, the sensitivity was 88% and the specificity was 100%. For microscopic tumors, the sensitivity was 85% and specificity was 56%. These results demonstrate the potential of fluorocoxib A as an in vivo imaging agent for early detection, margin delineation and guided biopsies of NMSCs
Alternative Under Frecuency Load Disconection Methodology Based on Semi-Adaptative Model
Stability analysis in electrical power systems is based on the study in dynamic state of the voltage and frequency, since at the moment that there is some contingency it fluctuates drastically due to the primary and secondary controls of the voltage and frequency to the power systems that act on the generators. In order to solve the possible stability problems that may arise in power systems, various techniques have been developed that act on the generating machines for their protection as well as on the loads for the power cut. The present investigation proposes an alternative methodology for load disconnection by low frequency as an option to save the power system from a possible blackout due to instability due to a fall in the frequency, managing to improve the results affected by other improved techniques, the frequency change range, frequency deviation and the effects of demand disconnection. The proposed methodology was tested in the IEEE 14 bus system
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