Estudio del flujo en reactores con tres fases por simulación

Tesis de la Universidad Complutense de Madrid, Facultad de Ciencias Químicas, Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica, leída el 02-07-2001Los reactores con tres fases son usados en una variedad de aplicaciones industriales. Se pueden encontrar ejemplos en las industrias quimica, petroquimica, bioquimica y de procesado de minerales. El trabajo experimental fue llevado a cabo a escala de planta piloto en un tanque con geometria cilindrica y fondo conico(1,25 m de altura y 0,42 m de diametro), agua y aire son usados como las fases liquido y gas en los experimentos, con esferas de vidrio (de diametros 0,25 y 1,00 mm y densidad del solido 2,6 g/cm3) y esferas de plastico (3 mm de diametro y 1,0 g/cm3 de densidad de solido). El aire fue inyectado por medio de 12 boquillas (de 1 mm de diametro) instaladas en el fondo del tanque. El conducto de elevacion fue de diametros 44,82,128 y 240 mm y cada uno de ellos tenia diferentes alturas (1050 y 630 mm). La velocidad de liquido en la corona fue determinada por medio de la tecnica de trazador termico, la fraccion de solidos fue medida por metodos conductimetricos y en el conducto elevador la fraccion de gas fue determinada por metodos menométricos. Se ha desarrollado un modelo hidrodinámico para reactores con tres fases tipo airlift, correlacionando la fraccion de gas en el tubo a partir del modelo de Zuber y Findlay, y la fraccion de solidos en la corona a partir del mismo modelo corregido por la fraccion del liquido en la misma zona anular. Tambien se ha propuesto una expresion adimensional para la predicion de la velocidad superficial de circulacion del liquido en el tubo a partir de la velicidad superficial del gas en el mismo, y de grupos adimensionales tales como el Reynolds del gas, la fraccion de solidos y la de gas en el elevador, asi como de parametros geometricos tales como la razon de diametros de tubo y tanque, de particula y boquilla, la relacion de alturas de elevador y tanque ademas de la razon de densidades de solido y liquido. Por otra parte tambien se ha presentado una expresion para la determinacion del factor de friccion o coeficiente de Fanning en el tubo para las tres en funcion de los mismos factores de forma y parametros adimensionalesDepto. de Ingeniería Química y de MaterialesFac. de Ciencias QuímicasTRUEpu

Multilevel Zero-One Inflated Beta Regression Model for the Analysis of the Relationship between Exogenous Health Variables and Technical Efficiency in the Spanish National Health System Hospitals

Background: This article proposes a methodological innovation in health economics for the second stage analysis of technical efficiency in hospitals. It investigates the relationship between the installed capacity in regions and hospitals and their ownership structure. Methods: A multilevel zero-one inflated beta regression model is employed to model pure technical efficiency more adequately than other models frequently used in econometrics. Results: Compared to publicly managed hospitals, the mean efficiency index of hospitals with public-private partnership (PPP) formulas was 4.27-fold. This figure was 1.90-fold for private hospitals. Concerning the efficiency frontier, the odds ratio (OR) of PPP models vs. public hospitals was 42.06. The OR of private hospitals vs. public hospitals was 8.17. A one standard deviation increase in the percentage of beds in intensive care units increases the odds of being situated on the efficiency frontier by 50%. Conclusions: The proportion of hospital beds in intensive care units relates to a higher chance of being on the efficiency frontier. Hospital ownership structure is related to the mean efficiency index of Spanish National Health Service hospitals, as well as the odds of being situated on the efficiency frontier.EUROPEAN REGIONAL DEVELOPMENT FUND (Operative Program: Andalusia 2014–2020. Ministry of Economy. Knowledge. Business and University. Junta de Andalucía. Spain. Grant number: B-SEJ-266-UGR18

A New Tool to Perform Global Energy Balances in DI Diesel Engines 2014-01-0665

[EN] The generalization of exhaust aftertreatment systems along with the growing awareness about climate change is leading to an increasing importance of the efficiency over other criteria during the design of reciprocating engines. Using experimental and theoretical tools to perform detailed global energy balance (GEB) of the engine is a key issue for assessing the potential of different strategies to reduce consumption. With the objective of improving the analysis of GEB, this paper describes a tool that allows calculating the detailed internal repartition of the fuel energy in DI Diesel engines. Starting from the instantaneous in-cylinder pressure, the tool is able to describe the different energy paths thanks to different submodels for all the relevant subsystems. Hence, the heat transfer from gases to engine walls is obtained with specific convective and radiative models in the chamber and ports; the repartition of the heat flux throughout the engine metal elements towards the oil and coolant is estimated with a lumped capacitance model; finally, the ancillary systems and friction losses are obtained through specific semiempirical submodels. The validation of the tool is performed in a 4- cylinder DI Diesel engine instrumented to perform detailed experimental GEB. Finally, a simple analysis of combined internal and external analysis in the complete engine map shows the effect of operating conditions on each energy term. Thus it is demonstrated the utility of the proposed tool, that complements the experimental heat flow measurements in Diesel engine researches oriented to the reduction of energy consumption.The support of the Universitat Politècnica de València (PAID06-09) and Generalitat Valenciana (GV/2010/045) is greatly acknowledged.Payri González, F.; Olmeda González, PC.; Martín Díaz, J.; Carreño, R. (2014). A New Tool to Perform Global Energy Balances in DI Diesel Engines 2014-01-0665. SAE International Journal of Engines. 7(1):1-17. doi:10.4271/2014-01-0665S1177

Understanding the performance of the multiple injection gasoline partially premixed combustion concept implemented in a 2-Stroke high speed direct injection compression ignition engine

The newly designed Partially Premixed Combustion (PPC) concept operating with high octane fuels like gasoline has confirmed the possibility to combine low NOx and soot emissions keeping high indicated efficiencies, while offering a control over combustion profile and phasing through the injection settings. The potential of this PPC concept regarding pollutant control was experimentally evaluated using a commercial gasoline with Research Octane Number (RON) of 95 in a newly-designed 2-Stroke poppet valves Compression Ignition (Cl) engine for automotive applications. Previous experimental results confirmed how the wide control of the cylinder gas temperature provided by the air management settings brings the possibility to achieve stable gasoline PPC combustion at low and medium speed conditions (1250-2000 rpm) for the whole load range (3.1-10.4 bar IMEP) with good combustion stability (Coefficient of Variation (Coy) of IMEP below 3%), high combustiOn efficiency (over 97%), and low NOx/soot levels. In this context, present research focuses on the two main specific drawbacks of this concept. Firstly, the high Brake Specific Fuel Consumption (BSFC) due to the work required by the mechanical supercharger since the turbocharging system does not provide the suitable pressure ratio at low speeds. Secondly, the high level of noise generated by the combustion process, especially at high loads. Therefore, a dedicated analysis has been carried out to fully exploit the benefits of the gasoline PPC concept combined with the innovative 2-Stroke engine architecture with the aim of identify and break the most relevant trade-offs.The authors kindly recognize the technical support provided by Mr. Pascal Tribotte from RENAULT SAS in the frame of the DREAM-DELTA-68530-13-3205 Project.Benajes Calvo, JV.; Martín Díaz, J.; Novella Rosa, R.; Thein, KJL. (2016). Understanding the performance of the multiple injection gasoline partially premixed combustion concept implemented in a 2-Stroke high speed direct injection compression ignition engine. Applied Energy. 161:465-475. doi:10.1016/j.apenergy.2015.10.034S46547516

A new methodology for uncertainties characterization in combustion diagnosis and thermodynamic modelling

Combustion diagnosis based on in-cylinder pressure signals as well as 0D thermodynamic modelling, are widely used to study and optimize the combustion in reciprocating engines. Both approaches share some uncertainties regarding the sub-models and the experimental installation that, for the sake of accuracy, must be reduced as much as possible in order to obtain reliable results. A methodology, based on the sensitivity effect of such uncertainties on heat release and simulated pressure, is proposed to adjust their values. The methodology is capable of identifying the separate influence of each parameter and to provide a set of values thanks to the Multi-Variable linear regression (MLR) in motoring conditions. The method is flexible enough to deal with different number of uncertainties and can be applied to different engines and thermodynamic models. The final results of the adjustment are validated in combustion conditions, showing an improvement of the apparent combustion efficiency of about 7% with respect to the reference values.The support of the Generalitat Valenciana (BEST/2010/145) is greatly acknowledged.Benajes Calvo, JV.; Olmeda González, PC.; Martín Díaz, J.; Carreño Arango, R. (2014). A new methodology for uncertainties characterization in combustion diagnosis and thermodynamic modelling. Applied Thermal Engineering. 71(1):389-399. https://doi.org/10.1016/j.applthermaleng.2014.07.010S38939971

Careón ophiolite, NW Spain: Suprasubduction zone setting for the youngest Rheic Ocean fl oor

The Careón ophiolite (Galicia, NW Iberian Massif) shows lithological and geochemical features suggestive of an origin in a suprasubduction zone setting. As with other Devonian ophiolites in the European Variscan belt, it was generated within a contracting Rheic Ocean. This setting and the general absence of large Silurian-Devonian volcanic arcs on both of the Rheic Ocean margins strongly suggest that this ocean was closed by intraoceanic subduction directed to the north. This subduction removed the older normal (N) mid-oceanic-ridge basalt (MORB) oceanic lithosphere and gave rise to a limited volume of new suprasubduction zone oceanic lithosphere. The Careón ophiolite is a key element in understanding the evolution of the Rheic Ocean, which was the main oceanic domain that closed during the Paleozoic convergence of Gondwana and Laurussia, preceding the assembly of Pange

New records of culicidae (Diptera) in agricultural oases of San Juan Province, Argentina

We report eight new Culicidae records from San Juan province, Argentina: Anopheles argyritarsis Robineau-Desvoidy, 1827; Anopheles neomaculipalpus Curry, 1931; Culex acharistus Root, 1927; Culex apicinus Philippi, 1965; Culex maxi Dyar, 1928; Culex quinquefasciatus Say, 1823; Culex saltanensis Dyar, 1928; and Haemagogus spegazzinii Brethes, 1912. The geographic distribution of Aedes aegypti (Linnaeus, 1762), Aedes albifasciatus (Macquart, 1838), Anopheles pseudopunctipennis Theobald, 1901, Culex pipiens Linneaus, 1758, Culex tramazayguesi Duret, 1954, and Psorophora cyanescens (Coquillet, 1902) is extended. Data on collection localities, types of breeding sites and health importance are also presented.Fil: Díaz Nieto, Leonardo Martín. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto y Museo de Ciencias Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Murúa Bruna, Albérico Fernando. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto y Museo de Ciencias Naturales; ArgentinaFil: Cano Schirado, Florencia Andrea. Ministerio de Salud Publica. - Gobierno de la Provincia de San Juan. Ministerio de Salud Publica.; ArgentinaFil: Laurito, Magdalena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Centro de Investigaciones Entomológicas de Córdoba; ArgentinaFil: Almiron, Walter Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Centro de Investigaciones Entomológicas de Córdoba; ArgentinaFil: Salvá, Liliana. Ministerio de Salud Publica. - Gobierno de la Provincia de San Juan. Ministerio de Salud Publica.; Argentin

Proteoma de la saliva de Ornithodoros moubata: comparativa entre machos y hembras

Comunicaciones a congreso

Construcción de microarrays de proteínas a partir de genotecas de expresión para el estudio de la interfase molecular garrapata-hospedador

Comunicaciones a congreso