286 research outputs found
Modulated surface waves in large-aspect-ratio horizontally vibrated containers
We consider the harmonic and subharmonic modulated surface waves that appear upon horizontal vibration along the surface of the liquid in a two-dimensional large-aspect-ratio (length large compared to depth) container, whose depth is large compared to the wavelength of the surface waves. The analysis requires us also to consider an oscillatory bulk flow and a viscous mean flow. A weakly nonlinear description of the harmonic waves is made which provides the threshold forcing amplitude to trigger harmonic instabilities, which are of various qualitatively different kinds. A linear analysis provides the threshold amplitude for the appearance of subharmonic waves through a subharmonic instability. The results obtained are used to make several specific qualitative and quantitative predictions
Manipulating modern diesel engine particulate emission characteristics through butanol fuel blending and fuel injection strategies for efficient diesel oxidation catalysts
Designing a multilingual dictionary of genetic terms (English, French, German and Spanish) for the European Portal Eurogene and the International Scientific Community
In the framework of the DICGENETIC Project Applying Information Technologies to Designing an English-French-German-Spanish Dictionary of Genetic Terms, financed by the Regional Government of Castilla y León, the distinguished research group team Intersemiotics, Translation and New Technologies was assigned to design an online multimedia terminology dictionary to be integrated in the learning platform Moodle. The objective of this dictionary is to provide service to users of the European genetics portal Eurogene and also to the international scientific community, with a subsequent electronic version and via the Internet
Interaction of diesel engine soot with NO2 and O2 at diesel exhaust conditions. Effect of fuel and engine operation mode
This work shows a study of the reactivity of twelve different types of soot with either NO2 or O2 under reacting conditions typically present in diesel particulate filters (DPFs). The soot samples were obtained from the combustion of four conventional and alternative fuels (diesel, biodiesel and two paraffinic fuels) in a diesel engine bench operated under three different engine operation modes: a typical urban-driving mode and two variations to this mode to assess the effect of the injection settings. The main objective of the work is to relate the oxidative reactivity of the soot to the nature and the origin of each sample. The possible simultaneous elimination of soot and NOx at typical diesel exhaust conditions is examined, as well. The reactivity tests were performed in a laboratory quartz gas flow reactor, discontinuous for the solid. The soot-NO2 interaction was studied with 200 ppm of NO2 at 500 °C and the soot-O2 interaction was studied with 5% O2 at 500 °C and 600 °C. The experimental results were used to determine the time needed for the complete conversion of carbon (t) through the use of the equations of the Shrinking Core Model for solid-gas reactions with decreasing size particle and chemical reaction control. In general, the t values show that the diesel fuel generates a less reactive soot than biodiesel or the alternative paraffinic fuels. In addition, increasing the injection pressure or adding a post-injection to the original injection strategy generates a more reactive soot. These findings point out that there is potential to achieve efficient regeneration processes in DPFs through other fuels than conventional ones and via engine calibration
Encuentros científicos: una experiencia paleontológica sin salir del aula
El entorno de aprendizaje que proporciona la escuela debe trabajar de manera paralela los aspectos curriculares, como la enseñanza de las ciencias, y la formación de la ciudadanía en valores sociales, como la igualdad de género. En este contexto se realizó el proyecto de centro Encuentros científicos en el CRA La Llitera (Huesca). Durante el mismo se buscó información sobre el papel de la mujer en diversas disciplinas científicas. En este contexto se realizó el proyecto de centro Encuentros científicos en el CRA La Llitera (Huesca). Durante el mismo se buscó información sobre el papel de la mujer en diversas disciplinas científicas. Entre estas investigadoras se dieron a conocer paleontólogas, lo que dio pie a la realización de los siguientes talleres paleontológicos, que, debido a la situación sanitaria derivada de la COVID-19, fueron guiados de manera virtual desde la Universidad de Zaragoza..
The Hopkins Verbal Learning Test and screening for dementia
The present study investigated the sensitivity and specificity of the Hopkins Verbal
Learning Test (HVLT) for demented patients (n=82, using NINCDS criteria) and 114
healthy controls - equivalent in age, years of education and gender–ratio - from the
Oxford Project To Investigate Memory and Ageing. The HVLT ‘Total recall’ score had
87% sensitivity and 98% specificity for dementia using a cut-off score of 14.5. Using a
'Memory' score (the sum of the 'Total Recall' and the 'Discrimination Index') with a cutoff
score of 24.5 gave a 91% sensitivity and 98% specificity for Alzheimer’s disease
cases when compared to controls. Unlike the MMSE, the HVLT has no ceiling effects
and does not have to be adjusted for education. We conclude that the HVLT is an easy
to administer, quick and well tolerated tool for the screening of dementia
Airplane materials compatibility with blends of fossil kerosene JET A1 with biokerosenes from babassu, palm kernel and coconut oils
The aviation companies are facing some problems that argue in favor of biofuels: Rising cost of traditional fuel: from 0.71 USD/gallon in May 2003 to 3.09 USD/gallon in January 2012. Environmental concerns: direct emissions from aviation account for about 3 % of the EU’s total greenhouse gas emissions. The International Civil Aviation Organization (ICAO) forecasts that by 2050 they could grow by a further 300-700 %. On December 20th 2006 the European Commission approved a law proposal to include the civil aviation sector in the European market of carbon dioxide emission rights (European Union Emissions Trading System, EUETS
Interactions between aftertreatment systems architecture and combustion of oxygenated fuels for improved low temperature catalysts activity
Investigation of the lubrication properties and tribological mechanisms of oxygenated compounds
Weakly dissipative Faraday waves in 2D large aspect ratio annuli
Weakly dissipative parametrically excited (by vertical vibration) surface gravity-capillary waves in a two-dimensional, horizontally periodic container are considered. A set of equations is derived for the coupled evolution of the left- and right-traveling surface waves and the associated mean flow, in the case when the container depth is small compared to its length but large compared to the wavelength of the excited waves. The stability of the spatially uniform standing waves (SWs) is first analyzed and then the large time spatio-temporal behavior of the system beyond threshold is numerically studied. The viscous mean flow is found to drastically affect the dynamics of the system and the resulting surface wave patterns
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