Step-like discontinuities in Bose-Einstein condensates and Hawking radiation: dispersion effects

In this paper we extend the hydrodynamic results of [1] and study, analytically, the propagation of Bogoliubov phonons on top of Bose-Einstein condensates with step-like discontinuities by taking into account dispersion effects. We focus on the Hawking signal in the density-density correlations in the formation of acoustic black hole-like configurations.Comment: One figure and few comments added. Version accepted for publication in PR

Diffusion and Stability of Magnetic Nanoparticles in Complex and Biological Fluids

Magnetic nanoparticles are of interest in a variety of applications that take advantage of their manipulation using externally applied magnetic fields. In this talk I will summarize our recent work on characterizing the diffusion and stability of magnetic nanoparticles in complex and biological fluids through their response to time-varying magnetic fields. I will discuss the physical principles of this measurement technique and then demonstrate how quantitative measurements can be made accurately in simple fluids. Then I will show results for nanoparticles suspended in complex fluids, such as gelling solutions, polymer solutions, and polymer melts. Finally, I will present results for measurements of magnetic nanoparticle rotational dynamics in biological fluids, as a means of studying protein adsorption, concentrated protein solutions, and nanoparticle behavior in tissues and blood

In Vivo Quantitative Imaging of Nanoparticles and Cells Using Magnetic Particle Imaging

Magnetic Particle Imaging (MPI) is a new molecular imaging technology capable of unambiguous and quantitative tomographic imaging of the distribution of superparamagnetic nanoparticle tracers in vivo. While the term MPI may be confused with that for Magnetic Resonance Imaging (MRI), the two rely on distinct physics. In MPI, a tomographic image of the distribution of superparamagnetic nanoparticles is constructed by scanning a so-called field free region (FFR) through the domain of interest. Outside the FFR there is a quasi-static bias field strong enough to saturate the magnetic moments of the nanoparticles. But inside the FFR the dipole moments of the nanoparticles are able to respond to a superimposed alternating excitation field. The signal used to construct an image in MPI arises due to the non-linear dynamic magnetization response of the nanoparticle dipole moments to the excitation field inside the FFR. At the field amplitudes and frequencies used in MPI there is no appreciable attenuation in field or signal strength in tissue. Further, while there are magnetic species in the body (e.g., ferritin), they do not contribute an appreciable signal for MPI, allowing for unambiguous imaging of the distribution of one of the superparamagnetic nanoparticle tracers. In this talk I will explain the physics of image generation in MPI, discuss work to understand how imaging performance relates to physical and magnetic properties of the nanoparticles, and discuss our work developing tracers and using MPI to quantify biodistribution of iron oxide nanoparticles in vivo, in the context of tracking nanoparticles and cell therapies

Detecting Plasma Produced by Laser in a Micromachining System as In-process Control

Automated systems have been used in industries with high-volume production because automation has led, for example, the possibility to reduce costs, increase productivity, and increase accuracy, among others. On the other hand, it is also known that the processing laser is ideal for all kind of controls. In this sense, the amount of material produced and removed by laser irradiation on the surface of the substrate might be used as a control variable. Therefore, plasma detector could be used as part of the control system in the machining process in gaseous environments. This work presents the results of the preliminary characterization of this detector designed to measure theplasma generated during laser machining in air (Pamb and Tamb).Fil: Toro Salazar, Cinthya Emma. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia Física (Centro Atómico Constituyentes). Proyecto Tandar; ArgentinaFil: Lasorsa, Carlos Alberto. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia Física (Centro Atómico Constituyentes). Proyecto Tandar; ArgentinaFil: Rinaldi, Carlos Alberto. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia Física (Centro Atómico Constituyentes). Proyecto Tandar; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Universidade Aberta do Brasil (UAB) na UFMT e a democratização do ensino superior em Mato Grosso

Para fomentar a Educação a Distância, o governo federal instituiu o Sistema Universidade Aberta do Brasil (UAB), que integra as instituições públicas que oferecem cursos de nível superior para camadas da população com dificuldade de acesso à formação universitária. Este trabalho mostra a participação da UFMT na democratização do ensino superior em nosso país. Os dados apresentados (11.470 vagas e 5.079 titulados) apontam para uma instituição que se posiciona positivamente frente ao desenvolvimento social, acadêmico e econômico de Mato Grosso, estando presente em 19 municípios polo, comprometida com a interiorização de cursos de formação inicial e continuada de excelente qualidade. Palavras-chave: Democratização. Ensino Superior. EaD no Ensino Superior. UAB/UFMT

Desarrollo básico de algoritmos, hardware y electrónica de control en la Nariz electrónica Patagonia

Se desarrolló una nariz electrónica (NE) con algoritmos de procesamiento y hardware completo. Este nuevo instrumento denominado “Patagonia” permitió identificar olores. Mediante métodos analíticos y criterios propios de adquisición y análisis de señales, se implementaron algoritmos de reconocimiento de muestras. Se utilizó Transformada Onditas, Análisis de Componentes Principales, Análisis discriminatorios lineales y cuadráticos, Redes neuronales y análisis de las constantes de desorción de los com¬puestos. Se desarrolló un software con interfaz de usuario simple para poder proveer narices electrónicas comerciales. Se midieron distintas muestras de café, aceites y jugos entre otros alimentos. Se discriminaron correctamente las muestras obteniendo resultados satisfactorios.An electronic nose (EN) with data processing algorithms and complete hardware was developed. This new instrument called “Patagonia” enables to identify odors. Sample recognition algorithms using self-developed analytical methods and criteria of signal acquisition and analysis were implemented. Wavelet transform, principal component analysis, linear and quadratic discriminate analysis, neural networks and analysis of the constants of desorption of compounds were used. Software with a simple user interface to provide commercial electronic noses was developed. Different types of coffee, oils and juices from other foods were measured. Samples were correctly discriminated and satisfactory results were obtained.Fil: Vorobioff, Juan. Comisión Nacional de Energía Atómica. Gerencia de Área de Investigación y Aplicaciones no Nucleares. Gerencia de Desarrollo Tecnológico y Proyectos Especiales. Departamento de Micro y Nanotecnología; ArgentinaFil: Rinaldi, Carlos Alberto. Comisión Nacional de Energía Atómica. Gerencia de Área de Investigación y Aplicaciones no Nucleares. Gerencia de Desarrollo Tecnológico y Proyectos Especiales. Departamento de Micro y Nanotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Boggio, Norberto Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia de Área de Investigación y Aplicaciones no Nucleares. Gerencia de Desarrollo Tecnológico y Proyectos Especiales. Departamento de Micro y Nanotecnología; Argentin

Nanostructuring of Material Surfaces by Laser Ablation

Irradiation of materials such as iron and silicon with single nanosecond laser pulses produces nanostructures on its surfaces. Nevertheless, the deposition before irradiation of thin films on the surface of the silicon wafers can modify the shapes of these structures. Upon laser irradiation, different effects are produced on the surfaces of monocrystalline silicon wafers coated with a thin film of Si3N4 than on that of bare ones. After irradiation with a Nd:YAG laser pulse of 532 nm, the coated silicon surface presents a nanostructure that, due to its hydrophobic behavior, can be used for biological applications such as cell growth. On the other hand, the nanostructures formed on the surface of metals, such as iron, make them more resistant to oxidation processes by changing their oxidation potentials

Implementation of a Nomarsky interferometer for the characterization of ablative laser propulsion processes

En este trabajo se presenta la implementación de un interferómetro de Nomarsky diseñado para medir el impulso específico de combustibles utilizados en sistemas de propulsión por ablación láser. En primer lugar se validó la técnica con combustibles conocidos. Posteriormente, se aplicó a la medición del impulso específico de combustibles binarios metal/sal desarrollados por nuestro grupo de investigación [1]. Esto permitió a su vez, determinar la eficiencia de dichos combustibles.In this paper the implementation of a Nomarsky interferometer designed for the measurement of the specific impulse of propellants used in laser ablative propulsion are presented. The technique was first validated with known propellants. Subsequently, it was applied to the measurement of the specific impulse of binary metal/salt propellants developed by our research group [1]. This allowed the efficiency of these propellants to be determined.Fil: Toro Salazar, Cinthya Emma. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; ArgentinaFil: Rinaldi, Carlos Alberto. Comisión Nacional de Energía Atómica. Gerencia de Área de Investigación y Aplicaciones no Nucleares. Gerencia de Desarrollo Tecnológico y Proyectos Especiales. Departamento de Micro y Nanotecnología; ArgentinaFil: Azcárate, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; Argentin