Investigation of electrical noise in selenium-immersed thermistor bolometers

The selenium immersed, thermistor bolometer, IR detector failed due to spurious and escalating electrical noise outburst as a function of time at elevated temperatures during routine ground based testing in a space simulated environment. Spectrographic analysis of failed bolometers revealed selenium pure zones in the insulating selenium arsenic (Se-As) glass film which surrounds the active sintered Mn, Ni, Co oxide flake. The selenium pure film was identified as a potentially serious failure mechanism. Significant changes were instituted in the manufacturing techniques along with more stringent process controls which eliminated the selenium pure film and successfully produced 22study bolometers

Towards a Semantic Gas Source Localization under Uncertainty

Towards a Semantic Gas Source Localization under Uncertainty.Communications in Computer and Information Science book series (CCIS, volume 855), doi:10.1007/978-3-319-91479-4_42This work addresses the problem of efficiently and coherently locating a gas source in a domestic environment with a mobile robot, meaning efficiently the coverage of the shortest distance as possible and coherently the consideration of different gas sources explaining the gas presence. The main contribution is the exploitation, for the first time, of semantic relationships between the gases detected and the objects present in the environment to face this challenging issue. Our proposal also takes into account both the uncertainty inherent in the gas classification and object recognition processes. These uncertainties are combined through a probabilistic Bayesian framework to provide a priority-ordered list of (previously observed) objects to check. Moreover the proximity of the different candidates to the current robot location is also considered by a cost function, which output is used for planning the robot inspection path. We have conducted an initial demonstration of the suitability of our gas source localization approach by simulating this task within domestic environments for a variable number of objects, and comparing it with an greedy approach.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

PPAR gamma pro12Ala polymorphism and type 2 diabetes: a study in a spanish cohort

Type 2 diabetes (T2D) is a disease whose occurrence is increasing prevalent in westernized civilizations and is responsible for the proliferation in the morbidity and total mortality of patients with cardiovascular diseases, worldwide. However, the complexity in the treatment and prevention of T2D arises from the intricacy of the many physical and biological factors involved in its etiology. Impaired pathways for insulin signaling have been implicated as one the many factors in the development of T2D Individual peroxisome proliferator-activated receptors (PPARs) have previously exhibited associations with alterations of lipid profiles, fat tissue and T2D and displayed complications derived from high levels of glucose. However, PPARgamma has not yet been associated with the development or developmental pathways of T2D. We performed an observational study a Spanish cohort in order to better understand the association between the SNP PPARgamma polymorphism Pro12Ala in our patients and the incidence of T2D and other cardiovascular complications. We study did not find a statistically significant relationship between the Pro12Ala and T2D development in our cohort, future observations will help us to know the association with vascular disease in patients with T2D

Plan prospectivo estrátegico 2012 de Napa -NTS : una visión prospectiva de la empresa NAPA NTS frente al TLC.

Tesis (Magíster en Administración de Empresas) -- Universidad del Norte. Programa de Maestría en Administración de Empresas, 2008.Teniendo en cuenta la permanente apertura de fronteras comerciales que se viene dando desde la década pasada, que ha llevado a la globalización de la economía, así como la gran dependencia de la empresa NAPA-NTS, de las relaciones comerciales binacionales entre Colombia Estados Unidos de América, por tener esta empresa el 85% de sus proveedores de repuestos originarios de ese país, se ha hecho necesario el análisis de los factores expuestos a cambios en la ecuación de negocios de NAPA-NTS, con la firma del tratado de libre comercio entre los dos países, mediante la realización de una prospectiva estratégica al año 2012. El objetivo principal de este trabajo es proponer un plan prospectivo para NAPA-NTS para el año 2012, mediante la metodología teórica para la construcción de prospectivas estratégicas y la utilización de los softwares MICMAC y MACTOR. El resultado obtenido en el proyecto fue el plan prospectivo de NAPA-NTS para el año 2012 con la suscripción del TLC entre Colombia y Estados Unidos de América, en el cual se consiguió la identificación de las variables claves del cambio, la descripción del eje estratégico de las variables claves del cambio, el Señalamiento de escenarios posibles prospectivos que puedan ser utilizados como la base del plan estratégico y la determinación de los actores claves que pueden generar un cambio en el nuevo ambiente de negocios de NAPA NTS con el TLC. Como conclusión del trabajo realizado, se determina la implementación de una estrategia de diferenciación, sobre la base de un producto de alta calidad apoyado sobre una cadena de distribución fortalecida y con territorios muy bien definidos y una estrategia de penetración del mercado consistente en incrementar la participación de la empresa con sus características de distribución comercial en los mercados en los que opera y con los productos actuales, es decir, en el desarrollo del negocio básico

Analysis of conventionally controlled PEMFC based on a distributed parameter model

Presentado al IV Iberian Symposium on Hydrogen, Fuel Cells and Advanced Batteries celebrado en Estoril (Portugal) del 26 al 28 de junio de 2013.The proton exchange membrane fuel cells (PEMFC) have been incorporated to a wide range of portable, stationary and automotive applications. However, PEMFC are still not accepted as a practical power generator. The key challenge is to reduce the cost and achieve a high performance and long life of the cells. Variations in the concentrations of reactants, as well as temperature, have significant effects on the performance and durability of PEMFC. All these variables exhibit spatial dependence along the channel, which needs to be taken into account in order to progress towards a PEMFC operation that is efficient and mitigates degradation. To this end, a controlled PEM fuel cell study is done through a distributed parameter simulation model. A conventional stoichiometry control objective is considered in order to analyze the behavior of spatial profiles of some important variables and, therefore, point out the importance of considering distributed parameter models in control design.Peer Reviewe

Modelling microbial exchanges between forms of soil nitrogen in contrasting ecosystems

Although nitrogen (N) is often combined with carbon (C) in organic molecules, C passes from the air to the soil through plant photosynthesis, whereas N passes from the soil to plants through a chain of microbial conversions. However, dynamic models do not fully consider the microorganisms at the centre of exchange processes between organic and mineral forms of N. This study monitored the transfer of ¹⁴C and ¹⁵N between plant materials, microorganisms, humified compartments, and inorganic forms in six very different ecosystems along an altitudinal transect. The microbial conversions of the ¹⁵N forms appear to be strongly linked to the previously modelled C cycle, and the same equations and parameters can be used to model both C and N cycles. The only difference is in the modelling of the flows between microbial and inorganic forms. The processes of mineralization and immobilization of N appear to be regulated by a two-way microbial exchange depending on the C : N ratios of microorganisms and available substrates. The MOMOS (Modelling of Organic Matter of Soils) model has already been validated for the C cycle and also appears to be valid for the prediction of microbial transformations of N forms. This study shows that the hypothesis of microbial homeostasis can give robust predictions at global scale. However, the microbial populations did not appear to always be independent of the external constraints. At some altitudes their C : N ratio could be better modelled as decreasing during incubation and increasing with increasing C storage in cold conditions. The ratio of potentially mineralizable-¹⁵N/inorganic-¹⁵N and the ¹⁵N stock in the plant debris and the microorganisms was modelled as increasing with altitude, whereas the ¹⁵N storage in stable humus was modelled as decreasing with altitude. This predicts that there is a risk that mineralization of organic reserves in cold areas may increase global warming

Chemical Evolution of Irregular and Blue Compact Galaxies

We discuss the chemical evolution of metal poor galaxies and conclude that their oxygen deficiency is not due to: the production of black holes by massive stars or a varying slope of the Initial Mass Function, IMF, at the high-mass end. A varying IMF at the low-mass end alone or in combination with: (a) an outflow of oxygen-rich material, (b) an outflow of well-mixed material, and (c) the presence of dark matter that does not participate in the chemical evolution process, is needed to explain their oxygen deficiency. Outflow of material rich in oxygen helps to account for the large helium to oxygen mass ratio values derived from these objects, but it works against explaining the carbon to oxygen mass ratio and the heavy elements minus carbon and oxygen to oxygen mass ratio values.Comment: 26 pages, plain Tex, a postscript version with the figures included is available at ftp://132.248.1.7/papers/chem_evolution/irr_bcg.tar ; ApJ accepte