Ara es mostren els items 1-20 de 20

  • Active control of the surface potential of nanostructured layers 

    Domínguez Pumar, Manuel; Kowalski, Lukasz; Llobet, E.; Calavia, Raül (2016-01-21)
    Article
    Accés obert
    The objective of this letter is to show the first results obtained with a control designed to keep the average surface potential of a nanostructured layerconstant. This condition is equivalent to keeping constant the ...
  • Applications of hot film anemometry to space missions 

    Jiménez Serres, Vicente; Domínguez Pumar, Manuel; Ricart Campos, Jordi; Kowalski, Lukasz; Navarro, Sara; torres, josefina; Castañer Muñoz, Luis María (VDE Conference Publications, 2008)
    Text en actes de congrés
    Accés restringit per política de l'editorial
    In this paper the most important constraints of the wind sensors for the Martian atmosphere are described, along with an overview of the past successful designs. Practically all the data available today about the Martian ...
  • A self-calibrating closed loop circuit for configurable constant voltage thermal anemometers 

    Gorreta Mariné, Sergio; Barajas Ojeda, Enrique; Kowalski, Lukasz; Atienza García, María Teresa; Domínguez Pumar, Manuel; Jiménez Serres, Vicente (Institution of Electrical Engineers, 2015-09-17)
    Article
    Accés obert
  • Contribution to advanced hot wire wind sensing 

    Kowalski, Lukasz (Centre de Publicacions del Campus Nord SCCL (CPET), 2009)
    Comunicació de congrés
    Accés obert
  • Contribution to advanced hot wire wind sensing 

    Kowalski, Lukasz (Universitat Politècnica de Catalunya, 2016-01-22)
    Tesi
    Accés obert
    The thermal anemometry is a method which allows to estimate wind magnitude be the mean of measuring heat transfer to the ambient in a forced convection process. For Earth's atmosphere condition, this method is typically ...
  • Heat flow dynamics in thermal systems described by diffusive representation 

    Domínguez Pumar, Manuel; Atienza García, María Teresa; Kowalski, Lukasz; Novio Vázquez, Santiago; Gorreta Mariné, Sergio; Jiménez Serres, Vicente; Silvestre Bergés, Santiago (Institute of Electrical and Electronics Engineers (IEEE), 2016-09-01)
    Article
    Accés obert
    The objective of this paper is to analyze the dynamics of heat flow in thermal structures working under constant temperature operation. This analysis is made using the tools of sliding mode controllers. The theory is ...
  • Hypobaric chamber for wind sensor testing in Martian condictions 

    Kowalski, Lukasz; García Molina, Francisco Miguel (IEEE Press. Institute of Electrical and Electronics Engineers, 2011)
    Text en actes de congrés
    Accés restringit per política de l'editorial
    In this paper we will describe the installation of a low pressure stainless steel horizontal chamber to be used in preliminary tests of a Mars atmosphere wind sensor. It includes custom made additional QF ports, electric ...
  • In situ size sorting in CVD synthesis of Si microspheres 

    Garin Escriva, Moises; Fenollosa Esteve, Roberto; Kowalski, Lukasz (Macmillan Publishers, 2016-12-08)
    Article
    Accés obert
    Silicon microspheres produced in gas-phase by hot-wall CVD offer unique quality in terms of sphericity, surface smoothness, and size. However, the spheres produced are polydisperse in size, which typically range from 0.5¿µm ...
  • Low pressure spherical thermal anemometer for space missions 

    Kowalski, Lukasz; Jiménez Serres, Vicente; Domínguez Pumar, Manuel; Gorreta Mariné, Sergio; Silvestre Bergés, Santiago; Castañer Muñoz, Luis María (Institute of Electrical and Electronics Engineers (IEEE), 2013)
    Text en actes de congrés
    Accés restringit per política de l'editorial
    The novelty of this 2D thermal anemometer is the spherical compact and robust design with improved sensitivity in the range of 600-900Pa of carbon dioxide pressure and 0.25 to 10 m/s wind speed. The small size (11.2mm ...
  • Model identification of time-varying diffusive systems 

    Atienza García, María Teresa; Kowalski, Lukasz; Gorreta Mariné, Sergio; Pons Nin, Joan; Jiménez Serres, Vicente; Domínguez Pumar, Manuel (2018)
    Text en actes de congrés
    Accés restringit per política de l'editorial
    This paper presents a characterization method based on diffusive representation for a class of linear or nonlinear time-varying diffusive systems. The system variation with time may come as a result of the own actuation ...
  • On the boundary layer development and heat transfer from a sphere at moderate Reynolds numbers 

    Rodríguez Pérez, Ivette María; Lehmkuhl, Oriol; Soria Guerrero, Manel; Gómez, Samuel; Domínguez Pumar, Manuel; Kowalski, Lukasz (2018)
    Text en actes de congrés
    Accés restringit per política de l'editorial
    Direct and large-eddy numerical simulations have been performed for a heated sphere at Reynolds numbers 200, 300, 500, 750, 1000 and 104, in the context of the development of a spherical wind sensor for Mars atmosphere ...
  • On the effects of free-stream turbulence intensity in the fluid flow and heat transfer from a sphere at subcritical Reynolds numbers 

    Rodríguez Pérez, Ivette María; Lehmkuhl, Oriol; Soria Guerrero, Manel; Gomez, Samuel; Domínguez Pumar, Manuel; Kowalski, Lukasz (2018)
    Comunicació de congrés
    Accés restringit per política de l'editorial
    In this work, the effect of the free-stream turbu-lence on the heat transfer and the near wake behind a sphere is studied at moderate Reynolds numbers of ¿¿ ¿ ¿¿¿¿ and ¿¿ ¿ ¿¿¿. Turbulence delays the sep-aration of the ...
  • REMS: the environmental sensor suite for the Mars Science Laboratory rover 

    Gómez Elvira, J.; Armiens, C.; Castañer Muñoz, Luis María; Domínguez Pumar, Manuel; Genzer, M.; Gómez, Francisco; Haberle, Robert M.; Harris, Aiden M.; Jiménez Serres, Vicente; Kahanpää, H.; Kowalski, Lukasz; Lepinette, A.; Martín, Jacques Wesley; Martínez Frías, Jesús; McEwan, I.; Mora, L.; Moreno, Jose C.; Navarro, S.; De Pablo, M.A.; Peinado, V.; Peña, A.; Polkko, J.; Ramos, Miguel; Renno, Nilton O.; Ricart, Jordi; Richardson, M.; Rodríguez Manfredi, José Antonio; Romeral, Julio; Sebastián, Eduardo M.; Serrano, Jaime; De La Torre Juárez, Manuel; Torres, Jose Antonio; Torrero, F.; Urquí, R.; Vázquez, L.; Velasco, T.; Verdasca, J.; Zorzano, M.P.; Martín Torres, Javier (2012-09)
    Article
    Accés restringit per política de l'editorial
    The Rover Environmental Monitoring Station (REMS) will investigate environ- mental factors directly tied to current habitability at the Martian surface during the Mars Sci- ence Laboratory (MSL) mission. Three major ...
  • Self-calibrating closed-loop circuit for configurable constant voltage thermal anemometers 

    Gorreta Mariné, Sergio; Barajas Ojeda, Enrique; Kowalski, Lukasz; Atienza García, María Teresa; Domínguez Pumar, Manuel; Jiménez Serres, Vicente (Institution of Electrical Engineers, 2015-09-17)
    Article
    Accés obert
    A new circuit is described which applies a configurable voltage across an RTD while the current flowing through it is measured with a current mirror. The circuit also allows working with voltages above the IC supply voltage ...
  • Sliding mode analysis applied to improve the dynamical response of a spherical 3D wind sensor for Mars atmosphere 

    Atienza García, María Teresa; Kowalski, Lukasz; Gorreta Mariné, Sergio; Jiménez Serres, Vicente; Castañer Muñoz, Luis María; Domínguez Pumar, Manuel (2017-11-01)
    Article
    Accés obert
    The objective of this paper is to show how the structure of a thermal wind anemometer can be tuned to ensure a fast response when the sensor works in closed loop configuration (constant temperature operation). If the thermal ...
  • Smart control of chemical gas sensors for the reduction of their time response 

    Domínguez Pumar, Manuel; Kowalski, Lukasz; Calavia, Raul; Llobet, E. (2016-06-28)
    Article
    Accés obert
    The objective of this paper is to show the first results obtained with a gas sensor made of Au-functionalized WO3 nanoneedles working under a closed-loop control designed to reduce its time response. The average temperature ...
  • Spherical wind sensor for the atmosphere of mars 

    Kowalski, Lukasz; Atienza García, María Teresa; Gorreta Mariné, Sergio; Jiménez Serres, Vicente; Domínguez Pumar, Manuel; Silvestre Bergés, Santiago; Castañer Muñoz, Luis María (2016-04-01)
    Article
    Accés obert
    A novel wind speed and direction sensor designed for the atmosphere of Mars is described. It is based on a spherical shell divided into four triangular sectors according to the central projection of tetrahedron onto the ...
  • Thermal dynamics modeling of a 3D wind sensor based on hot thin film anemometry 

    Atienza García, María Teresa; Kowalski, Lukasz; Gorreta Mariné, Sergio; Jiménez Serres, Vicente; Domínguez Pumar, Manuel (2018-02-01)
    Article
    Accés obert
    The objective of this paper is to obtain time-varying models of the thermal dynamics of a 3D hot thin film anemometer for Mars atmosphere. To this effect, a proof of concept prototype of the REMS (Rover Environmental ...
  • Time-varying thermal dynamics modeling of the prototype of the REMS wind sensor 

    Atienza García, María Teresa; Kowalski, Lukasz; Gorreta Mariné, Sergio; Jiménez Serres, Vicente; Domínguez Pumar, Manuel (2017)
    Text en actes de congrés
    Accés obert
    The objective of this work is to show the results from the analysis of the thermal dynamics of a prototype of the REMS 3D wind anemometer using the tools of Diffusive Representation (DR). DR is a mathematical tool that ...
  • Using a Second Order Sigma-Delta Control to Improve the Performance of Metal-Oxide Gas Sensors 

    Kowalski, Lukasz; Pons Nin, Joan; Navarrete, Eric; Llobet Valero, Eduard; Domínguez Pumar, Manuel (Multidisciplinary Digital Publishing Institute (MDPI), 2018-02-23)
    Article
    Accés obert
    Controls of surface potential have been proposed to accelerate the time response of MOX gas sensors. These controls use temperature modulations and a feedback loop based on first-order sigma-delta modulators to keep ...