422 research outputs found

    NASA Tech Briefs, October 2013

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    Topics include: A Short-Range Distance Sensor with Exceptional Linearity; Miniature Trace Gas Detector Based on Microfabricated Optical Resonators; Commercial Non-Dispersive Infrared Spectroscopy Sensors for Sub-Ambient Carbon Dioxide Detection; Fast, Large-Area, Wide-Bandgap UV Photodetector for Cherenkov Light Detection; Mission Data System Java Edition Version 7; Adaptive Distributed Environment for Procedure Training (ADEPT); LEGEND, a LEO-to-GEO Environment Debris Model; Electronics/Computers; Millimeter-Wave Localizers for Aircraft-to-Aircraft Approach Navigation; Impedance Discontinuity Reduction Between High-Speed Differential Connectors and PCB Interfaces; SpaceCube Version 1.5; High-Pressure Lightweight Thrusters; Non-Magnetic, Tough, Corrosion- and Wear-Resistant Knives From Bulk Metallic Glasses and Composites; Ambient Dried Aerogels; Applications for Gradient Metal Alloys Fabricated Using Additive Manufacturing; Passivation of Flexible YBCO Superconducting Current Lead With Amorphous SiO2 Layer; Propellant-Flow-Actuated Rocket Engine Igniter; Lightweight Liquid Helium Dewar for High-Altitude Balloon Payloads; Method to Increase Performance of Foil Bearings Through Passive Thermal Management; Unibody Composite Pressurized Structure; JWST Integrated Science Instrument Module Alignment Optimization Tool; Radar Range Sidelobe Reduction Using Adaptive Pulse Compression Technique; Digitally Calibrated TR Modules Enabling Real-Time Beamforming SweepSAR Architectures; Electro-Optic Time-to-Space Converter for Optical Detector Jitter Mitigation; Partially Transparent Petaled Mask/Occulter for Visible-Range Spectrum; Educational NASA Computational and Scientific Studies (enCOMPASS); Coarse-Grain Bandwidth Estimation Scheme for Large-Scale Network; Detection of Moving Targets Using Soliton Resonance Effect; High-Efficiency Nested Hall Thrusters for Robotic Solar System Exploration; High-Voltage Clock Driver for Photon-Counting CCD Characterization; Development of the Code RITRACKS; and Enabling Microliquid Chromatography by Microbead Packing of Microchannels

    Development and characterisation of Monolithic Active Pixel Sensor prototypes for the upgrade of the ALICE Inner Tracking System

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    ALICE (A Large Ion Collider Experiment) is dedicated to the study and characterisation of the Quark-­‐Gluon Plasma (QGP), exploiting the unique potential of ultrarelativistic heavy-­‐ion collisions at the CERN Large Hadron Collider (LHC). The increase of the LHC luminosity leading up to about 50 kHz Pb-­‐Pb interaction rate after the second long shutdown (in 2018-­‐2019) will offer the possibility to perform high precision measurements of rare probes over a wide range of momenta. These measurements are statistically limited or not even possible with the present experimental set up. For this reason, an upgrade strategy for several ALICE detectors is being pursued. In particular, it is foreseen to replace the Inner Tracking System (ITS) by a new detector which will significantly improve the tracking and vertexing capabilities of ALICE in the upgrade scenario. The new ITS will have a barrel geometry consisting of seven layers of Monolithic Active Pixel Sensors (MAPS) with high granularity, which will fulfil the material budget, readout and radiation hardness requirements for the upgrade. Intensive R&D has been carried out in the last four years on MAPS in the framework of the ALICE ITS upgrade. Various small scale sensors have been designed in the TowerJazz 0.18 um imaging sensor technology to study noise, charge collection efficiency and signal-­‐to-­‐noise ratio. This work presents the main characterization results obtained from the measurements performed on two small scale prototypes (MIMOSA-­‐32 and MIMOSA-­‐32ter) with X-­‐ray sources and beams of particles. The architecture of an innovative full scale MAPS prototype (Alice Pixel Detector, ALPIDE) is also presented that is based on an AC-­‐sensitive front end and on a hit-­‐ driven readout. The first results on the ALPIDE prototype showed that the sensor is fully functional and that it provides performance in terms of readout time, power density and noise much better than the state of the art MAPS based on the rolling shutter readout, which makes this type of sensors very attractive for employment in the new ALICE ITS

    A Label Free CMOS-Based Smart Petri Dish for Cellular Analysis

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    RÉSUMÉ Le dépistage de culture cellulaire à haut débit est le principal défi pour une variété d’applications des sciences de la vie, y compris la découverte de nouveaux médicaments et le suivi de la cytotoxicité. L’analyse classique de culture cellulaire est généralement réalisée à l’aide de techniques microscopiques non-intégrées avec le système de culture cellulaire. Celles-ci sont laborieuses spécialement dans le cas des données recueillies en temps réel ou à des fins de surveillance continue. Récemment, les micro-réseaux cellulaires in-vitro ont prouvé de nombreux avantages dans le domaine de surveillance des cellules en réduisant les coûts, le temps et la nécessité d’études sur des modèles animaux. Les microtechniques, y compris la microélectronique et la microfluidique,ont été récemment utilisé dans la biotechnologie pour la miniaturisation des systèmes biologiques et analytiques. Malgré les nombreux efforts consacrés au développement de dispositifs microfluidiques basés sur les techniques de microscopie optique, le développement de capteurs intégrés couplés à des micropuits pour le suivi des paramètres cellulaires tel que la viabilité, le taux de croissance et cytotoxicité a été limité. Parmi les différentes méthodes de détection disponibles, les techniques capacitives offrent une plateforme de faible complexité. Celles-ci ont été considérablement utilisées afin d’étudier l’interaction cellule-surface. Ce type d’interaction est le plus considéré dans la majorité des études biologiques. L’objectif de cette thèse est de trouver des nouvelles approches pour le suivi de la croissance cellulaire et la surveillance de la cytotoxicité à l’aide d’un réseau de capteurs capacitifs entièrement intégré. Une plateforme hybride combinant un circuit microélectronique et une structure microfluidique est proposée pour des applications de détection de cellules et de découverte de nouveaux médicaments. Les techniques biologiques et chimiques nécessaires au fonctionnement de cette plateforme sont aussi proposées. La technologie submicroniques Standard complementary metal-oxide-Semiconductor (CMOS) (TSMC 0.35 μm) est utilisée pour la conception du circuit microélectronique de cette plateforme. En outre, les électrodes sont fabriquées selon le processus CMOS standard sans la nécessité d’étapes de post-traitement supplémentaires. Ceci rend la plateforme proposée unique par rapport aux plateformes de dépistage de culture cellulaire à haut débit existantes. Plusieurs défis ont été identifiés durant le développement de cette plateforme comme la sensibilité, la bio-compatibilité et la stabilité et les solutions correspondantes sont fournies.----------ABSTRACT High throughput cell culture screening is a key challenge for a variety of life science applications, including drug discovery and cytotoxicity monitoring. Conventional cell culture analysis is widely performed using microscopic techniques that are not integrated into the target cell culture system. Additionally, these techniques are too laborious in particular to be used for real-time and continuous monitoring purposes. Recently, it has been proved that invitro cell microarrays offer great advantages for cell monitoring applications by reducing cost, time, and the need for animal model studies. Microtechnologies, including microelectronics and microfluidics, have been recently used in biotechnology for miniaturization of biological and analytical systems. Despite many efforts in developing microfluidic devices using optical microscopy techniques, less attention have been paid on developing fully integrated sensors for monitoring cell parameters such as viability, growth rate, and cytotoxicity. Among various available sensing methods, capacitive techniques offer low complexity platforms. This technique has significantly attracted attentions for the study of cell-surface interaction which is widely considered in biological studies. This thesis focuses on new approaches for cell growth and cytotoxicity monitoring using a fully integrated capacitive sensor array. A hybrid platform combining microelectronic circuitry and microfluidic structure is proposed along with other required biological and chemical techniques for single cell detection and drug discovery applications. Standard submicron complementary metal–oxide–semiconductor (CMOS) technology (TSMC 0.35 μm) is used to develop the microelectronic part of this platform. Also, the sensing electrodes are fabricated in standard CMOS process without the need for any additional post processing step, which makes the proposed platform unique compared to other state of the art high throughput cell assays. Several challenges in implementing this platform such as sensitivity, bio-compatibility, and stability are discussed and corresponding solutions are provided. Specifically, a new surface functionalization method based on polyelectrolyte multilayers deposition is proposed to enhance cell-electrode adherence and to increase sensing electrodes’ life time. In addition, a novel technique for microwell fabrication and its integration with the CMOS chip is proposed to allow parallel screening of cells. With the potential to perform inexpensive, fast, and real-time cell analyses, the proposed platform opens up the possibility to transform from passive traditional cell assays to a smart on-line monitoring system

    Acoustics for underwater neutrino telescopes

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    En esta tesis se tratan diferentes aspectos de la acústica presente en un telescopio submarino de neutrinos, principalmente en dos vertientes: en el sistema de posicionamiento acústico utilizado para la monitorización de las posiciones de los módulos ópticos presentes a lo largo del detector, así como en sistemas para detección acústica de neutrinos, técnica que actualmente está en fase de estudio. Todos los estudios realizados están enmarcados dentro de dos colaboraciones europeas para el diseño, construcción y operación de telescopios submarinos de neutrinos: Antares (en fase de operación) y KM3NET (en fase de diseño). Objetivos. Los objetivos de este trabajo pueden resumirse en los siguientes aspectos: - Estudios y análisis del sistema de posicionamiento acústico de Antares. Desarrollo del software para la para la automatización del procesado de los datos de dicho sistema e incorporación de los resultados en la base de datos del experimento. Análisis de los datos proporcionados por dicho sistema con el fin de validar su correcto funcionamiento. - Diseño y desarrollo del sistema de posicionamiento acústico para KM3NeT, telescopio unas 20 veces más grande que Antares. - Estudios para la evaluación de la generación acústica paramétrica para el desarrollo de un calibrador compacto capaz de generar señales tipo neutrino útiles en sistemas de detección acústica. Elementos de la metodología a destacar. Cabe destacar aquí que el trabajo se ha desarrollado en el marco de dos colaboraciones internacionales: ANTARES y KM3NeT, financiados con fondos europeos y nacionales. Por su contexto y el carácter de las actividades realizadas ha sido necesaria la formación en distintos campos: telescopios de neutrinos y astropartículas, pero también en otras áreas como la acústica submarina. Además, se ha desarrollado diversas capacidades y destrezas en diversos ámbitos: en instrumentación, en aplicaciones informáticas, en análisis de datos, etc. Más concretamente, se ha trabajado en aplicaciones informáticas para los desarrollos y análisis en ANTARES.Bou Cabo, M. (2011). Acoustics for underwater neutrino telescopes [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/10989Palanci

    Preliminary Electrical Designs for CTEx and AFIT Satellite Ground Station

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    This thesis outlines the design of the electrical components for the space-based ChromoTomography Experiment (CTEx). CTEx is the next step in the development of high-speed chromotomography at the Air Force Institute of Technology. The electrical design of the system is challenging due to the large amount of data that is acquired by the imager and the limited resources that is inherent with space-based systems. Additional complication to the design is the need to know the angle of a spinning prism that is in the field of view very precisely for each image. Without this precise measurement any scene that is reconstructed from the data will be blurry and incomprehensible. This thesis also outlines how the control software for the CTEx space system should be created. The software ow is a balance of complex real time target pointing angles and simplicity to allow the system to function as quick as possible. This thesis also discusses the preliminary design for an AFIT satellite ground station based upon the design of the United States Air Force Academy\u27s ground station. The AFIT ground station will be capable of commanding and controlling satellites produced by USAFA and satellites produced by a burgeoning small satellite program at AFIT

    NASA Tech Briefs, April 2010

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    Topics covered include: Active and Passive Hybrid Sensor; Quick-Response Thermal Actuator for Use as a Heat Switch; System for Hydrogen Sensing; Method for Detecting Perlite Compaction in Large Cryogenic Tanks; Using Thin-Film Thermometers as Heaters in Thermal Control Applications; Directional Spherical Cherenkov Detector; AlGaN Ultraviolet Detectors for Dual-Band UV Detection; K-Band Traveling-Wave Tube Amplifier; Simplified Load-Following Control for a Fuel Cell System; Modified Phase-meter for a Heterodyne Laser Interferometer; Loosely Coupled GPS-Aided Inertial Navigation System for Range Safety; Sideband-Separating, Millimeter-Wave Heterodyne Receiver; Coaxial Propellant Injectors With Faceplate Annulus Control; Adaptable Diffraction Gratings With Wavefront Transformation; Optimizing a Laser Process for Making Carbon Nanotubes; Thermogravimetric Analysis of Single-Wall Carbon Nanotubes; Robotic Arm Comprising Two Bending Segments; Magnetostrictive Brake; Low-Friction, Low-Profile, High-Moment Two-Axis Joint; Foil Gas Thrust Bearings for High-Speed Turbomachinery; Miniature Multi-Axis Mechanism for Hand Controllers; Digitally Enhanced Heterodyne Interferometry; Focusing Light Beams To Improve Atomic-Vapor Optical Buffers; Landmark Detection in Orbital Images Using Salience Histograms; Efficient Bit-to-Symbol Likelihood Mappings; Capacity Maximizing Constellations; Natural-Language Parser for PBEM; Policy Process Editor for P(sup 3)BM Software; A Quality System Database; Trajectory Optimization: OTIS 4; and Computer Software Configuration Item-Specific Flight Software Image Transfer Script Generator
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