8,388 research outputs found

    Neurofuzzy model of an industrial process, reducing complexity by using principal component analysis

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    XVI Congreso Español sobre Tecnologías y Lógica Fuzzy Valladolid, 1-3 de febrero de 2012A Neurofuzzy model of a mixing chamber pressure has been proposed. The process is a part of a copper smelter plant. The principal component analysis (PCA) method has been used to reduce the inputs space for a recurrent fuzzy model. The coupling among variables and their mutual influence between themselves, are taken into account by the projection into the PCA axis. The model have been validated with real data from the factory. The validation result shows that the model is suitable for simulation.Ministerio de Ciencia e Innovación DPI2010-21589-C05-0

    Modelling the primary drying step for the determination of the optimal dynamic heating pad temperature in a continuous pharmaceutical freeze-drying process for unit doses

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    In the pharmaceutical industry, traditional freeze-drying of unit doses is a batch-wise process associated with many disadvantages. To overcome these disadvantages and to guarantee a uniform product quality and high process efficiency, a continuous freeze-drying process is developed and evaluated. The main differences between the proposed continuous freeze-drying process and traditional freeze-drying can be found firstly in the freezing step during which the vials are rotated around their longitudinal axis (spin freezing), and secondly in the drying step during which the energy for sublimation and desorption is provided through the vial wall by conduction via an electrical heating pad. To obtain a more efficient drying process, the energy transfer has to be optimised without exceeding the product and process limits (e.g. cake collapse, choked flow). Therefore, a mechanistic model describing primary drying during continuous lyophilisation of unit doses based on conduction via heating pads was developed allowing the prediction of the optimal dynamic power input and temperature output of the electric heating pads. The model was verified by experimentally testing the optimal dynamic primary drying conditions calculated for a model formulation. The primary drying endpoint of the model formulation was determined via in-line NIR spectroscopy. This endpoint was then compared with the predicted model based endpoint. The mean ratio between the experimental and model based predicted drying time for six verification runs was 1.05 +/- 0.07, indicating a good accordance between the model and the experimental data

    Development of a compact, IoT-enabled electronic nose for breath analysis

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    In this paper, we report on an in-house developed electronic nose (E-nose) for use with breath analysis. The unit consists of an array of 10 micro-electro-mechanical systems (MEMS) metal oxide (MOX) gas sensors produced by seven manufacturers. Breath sampling of end-tidal breath is achieved using a heated sample tube, capable of monitoring sampling-related parameters, such as carbon dioxide (CO2), humidity, and temperature. A simple mobile app was developed to receive real-time data from the device, using Wi-Fi communication. The system has been tested using chemical standards and exhaled breath samples from healthy volunteers, before and after taking a peppermint capsule. Results from chemical testing indicate that we can separate chemical standards (acetone, isopropanol and 1-propanol) and different concentrations of isobutylene. The analysis of exhaled breath samples demonstrate that we can distinguish between pre- and post-consumption of peppermint capsules; area under the curve (AUC): 0.81, sensitivity: 0.83 (0.59–0.96), specificity: 0.72 (0.47–0.90), p-value: <0.001. The functionality of the developed device has been demonstrated with the testing of chemical standards and a simplified breath study using peppermint capsules. It is our intention to deploy this system in a UK hospital in an upcoming breath research study

    Operationally Efficient Propulsion System Study (OEPSS) data book. Volume 4: OEPSS design concepts

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    This study was initiated to identify operations problems and cost drivers for current propulsion systems and to identify technology and design approaches to increase the operational efficiency and reduce operations costs for future propulsion systems. To provide readily usable data for the Advanced Launch System (ALS) program, the results of the OEPSS study have been organized into a series of OEPSS Data Books. This volume describes three propulsion concepts that will simplify the propulsion system design and significantly reduce operational requirements. The concepts include: (1) a fully integrated, booster propulsion module concept for the ALS that avoids the complex system created by using autonomous engines with numerous artificial interfaces; (2) an LOX tank aft concept which avoids potentially dangerous geysering in long LOX propellant lines; and (3) an air augmented, rocket engine nozzle afterburning propulsion concept that will significantly reduce LOX propellant requirements, reduce vehicle size and simplify ground operations and ground support equipment and facilities

    Detección de fallas usando Análisis de Componentes Principales y Modelado de Valor Medio en un motor a gas natural de 2 MW

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    This paper describes the combination of statistical techniques and mathematical modeling in order to developed a fault detection system in a 2 MW natural gas engine under actual operation conditions. The Mixing chamber, turbochargers, intake and exhaust manifolds, cylinders, throttle and bypass valves, and the electric generator, which are the main components of the gas engine, were studied under a mean value engine to complement the statistical analysis. Objective: The main objective of this paper is to integrate two approaches in order to relate the faults with the changes of mean thermodynamic values of the system, helping to sustain the engine in optimal operating conditions in terms of reliability. The Principal Component Analysis (PCA), a multivariate statistical fault detection technique, was used to analyze the historical data from the gas engine to detect abnormal operation conditions, by means of statistical measures such as Square Prediction Error (SPE) and T2. These abnormal operation conditions are categorized using cluster techniques and contributions plots, to later examine its causes with the support of the results of a mean value mathematical model proposed for the system. The integration of the proposed methods allowed successfully identify which component or components of the engine might be malfunctioning. Once combined, these two methods were able to accurately predict and identify faults as well as shut downs of the gas engine during a month of operation. Statistical analysis was used to detect faults on a 2 MW industrial gas engine, also the result were compared with a mean value model in order to detect variations of the thermodynamic properties of the system at abnormal conditions.Este artículo describe la combinación de técnicas estadísticas y modelos matemáticos para desarrollar un sistema de detección de fallas en un motor de gas natural de 2 MW bajo condiciones reales de operación. La cámara de mezcla, los turbocompresores, los múltiples de admisión y escape, los cilindros, las válvulas throttle, bypass y el generador eléctrico, que son los principales componentes del motor de gas, fueron estudiados bajo un motor de valor medio para complementar el análisis estadístico. El objetivo principal de este trabajo es integrar dos enfoques para relacionar los fallos con los cambios de los valores medios termodinámicos del sistema, ayudando a mantener el motor en condiciones óptimas de funcionamiento en términos de confiabilidad. El Análisis de Componentes Principales (PCA), una técnica estadística multivariante de detección de fallas, se utilizó para analizar los datos históricos del motor a gas para detectar condiciones anormales de operación, por medio de indicadores estadísticos tales como el Error de Predicción Cuadrado (SPE) y T2. Estas condiciones anormales de operación se categorizan mediante técnicas de clústeres y diagramas de contribuciones, para luego examinar sus causas con el apoyo de los resultados de un modelo matemático de valor medio propuesto para el sistema. La integración de los métodos propuestos permitió identificar satisfactoriamente qué componente o componentes del motor podrían estar funcionando mal. Una vez combinados, estos dos métodos fueron capaces de predecir e identificar con precisión las fallas, así como las paradas del motor de gas durante un mes de funcionamiento. Se utilizó el análisis estadístico para detectar fallas en un motor de gas industrial de 2 MW, también se comparó el resultado con un modelo de valor medio para detectar variaciones de las propiedades termodinámicas del sistema en condiciones anormales

    Space Station CMIF extended duration metabolic control test

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    The Space Station Extended Duration Metabolic Control Test (EMCT) was conducted at the MSFC Core Module Integration Facility. The primary objective of the EMCT was to gather performance data from a partially-closed regenerative Environmental Control and Life Support (ECLS) system functioning under steady-state conditions. Included is a description of the EMCT configuration, a summary of events, a discussion of anomalies that occurred during the test, and detailed results and analysis from individual measurements of water and gas samples taken during the test. A comparison of the physical, chemical, and microbiological methods used in the post test laboratory analyses of the water samples is included. The preprototype ECLS hardware used in the test, providing an overall process description and theory of operation for each hardware item. Analytical results pertaining to a system level mass balance and selected system power estimates are also included

    Supercritical fluid and pharmaceutical applications. Part I: Process classification

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    The supercritical fluid technology has been target of many pharmaceuticals investigations in particles production for almost 35 years. This is due to the great advantages it offers over others technologies currently used for the same purpose. A brief history is presented, as well the classification of supercritical technology based on the role that the supercritical fluid (carbon dioxide) performs in the process.FAPESP (São Paulo, Brazil – project 2012/01333-0) for financial suppor
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