567 research outputs found
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The matching of a "one-dimensional" numerical simulation and experiment results for low viscosity Newtonian and non-Newtonian fluids during fast filament stretching and subsequent break-up
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The Effect of Inkjet Ink Composition on Rheology And Jetting Behaviour
This work presents recent results on the way linear and non linear viscoelastic properties of the fluids affect the jetting
mechanism. Recent progress on quantitative characterising both high frequency linear (LVE) and non-linear (NLVE) viscoelasticity
of fluids allows fluids to be assessed for their jettability before using such materials in a DoD print head. In term of linear viscoelastic measurements, the Piezo Axial Vibrator (PAV) was used to probe the rheology of the fluids on a frequency range
between 10Hz and 10000Hz. A filament stretching apparatus, called the “Cambridge Trimaster”, was used in combination with
high speed cinematography, to characterize the fluids high speed stretching and break-up behaviour. The series of fluids investigated here consist in dilutions of mono disperse polystyrene with different molecular weight (110, 210, 306 and 488 kg/mol respectively) diluted in diethyl phthalate. The choice of polymer weights and concentrations were chosen to match both the
complex viscosity and the LVE. However, non linear rheological data experiments exhibit differences in the fluid relaxation time
and filament break-up mechanism. Ultra-high speed cinematography of DoD jetting events were correlated with filament break-up experiments and demonstrated that fluid rheology provides valuable information on the jetting quality of the fluids
Femtosecond time-resolved phase-change microscopy and ablation threshold calculations to understand ultrafast laser ablation
El trabajo recoge experimentos realizados en una configuración sonda-prueba haciendo uso de un láser de femtosegundos, con el objetivo de comprender los fenómenos de ablación de materiales sólidos ras irradiación con láseres de pulso ultracorto.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
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On the modeling of viscoelastic droplet impact dynamics
This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.In this paper, a numerical modeling of the impact, spreading, and eventually rebound of a viscoelastic droplet is reported. The numerical model is based on the volume of fluid (VOF) method coupled with the FENE-CR constitutive equations, and accounts for both the surface tension and the substrate wettability. The FENE-CR constitutive equations are used to model the polymer solution, while taking advantage of its rheological characterization. The comparison is performed between droplets of Newtonian solvent and a monodisperse polymer solution. The droplet impact on both hydrophilic and superhydrophobic substrate is analyzed through a detailed analysis of the spreading diameter evolution. It is found that while the droplet kinematic phase seems independent of the substrate and fluids properties, the recoiling phase is highly related to all of them. In addition the model infers a critical polymer concentration above which the droplet rebound from a superhydrophobic substrate is suppressed. The simulation is of particular interest to ink-jet processing, and demonstrates the capability of the model to handle complex non-Newtonian droplet dynamics
Estudio de los impactos ambientales de los cruces de gasoductos con ríos vadeables
El río Cigüela y su afluente Valdepineda (Cuenca, España) fueron afectados por el cruce de un gasoducto, en Diciembre de 2001, mediante la técnica convencional "cruce subálveo" que consta de tres fases: instalación de la pista de trabajo, apertura de zanja y rehabilitación. Con el objetivo de evaluar el impacto de las distintas etapas de la obra en el medio acuático, se está llevando a cabo un estudio que se centra en el efecto de los sólidos en suspensión en las comunidades macrobentónicas e ícticas. Se presentan los resultados preliminares obtenidos en la fase de apertura de zanja, donde se observa un valor muy elevado de movilización de sólidos en suspensión (hasta 5000 mg/l), alcanzando las mayores concentraciones en los 100 primeros metros aguas abajo del punto de cruce. Estos sólidos en suspensión podrían ser la causa del aumento significativo de la sedimentación de las partículas de tamaño comprendido entre 50-250 μm y 250-500 μm en los 30 primeros metros aguas abajo del punto de cruce. Por otro lado, no se han observado diferencias en el valor del índice BMWP' en las distintas estaciones de muestreo. Sin embargo, en la fase de rehabilitación, se encuentra una diferencia significativa en la frecuencia de distribución de algunas de las especies de peces presentes en el río, además se observa un claro efecto barrera para la ictiofauna al eliminar la pista de trabajo.The Cigüela River and its tributary, Valdepineda (Cuenca, España) were affected by the crossing of a natural gas pipeline, in December 2001, by means of the conventional technique "open-cut water crossing" that consists of three different works: installation of the right-of-way, excavation and backfill of the pipeline trench, and restoration. In order to assess the impacts of these different activities on the aquatic environment, we are carrying out a study that is focused on the effects of suspended solids in the benthic and fish communities. Preliminary results of this study are presented on the excavation and backfill of the pipeline trench, that indicate that a very high value of suspended solids mobilisation is observed (up to 5000 mg/l), reaching the higher concentrations in the first 100 meters downstream of the crossing site. These suspended solids might be responsible for the significant increase in the sedimentation of the particles of sizes 50-250 μm and 250-500 μm in the 30 first meters downstream of the crossing site. On the other hand, we have not found differences in the values of the BMWP' index at the different sampling sites. Nevertheless, in the restoration phase , there is a significant difference in the distribution frequency of some fish species that appear in the river and also a clear barrier effect is observed for fishes when eliminating the right-of-way
Time-resolved laser-induced phase change microscopy: understanding laser-matter effects at the femtosecond scale
LA comunicación describe el desarrollo instrumental y las aplicaciones con un microscopio de cambio de fase con resolución de femtosegundos que se ha puesto a punto en el LAboratorio LAser de la UMAUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Still no evidence that risk-taking and consumer choices can be primed by mating motives: Reply to Sundie, Beal, Neuberg, and Kenrick (2019)
Shanks et al. (2015) challenged the evidence that various forms of decision making can be influenced by romantic/mating primes. In their comment, Sundie, Beal, Neuberg, and Kenrick (2019) question both the meta-analysis and the 8 studies Shanks et al. reported, and describe an alternative p-curve analysis that they interpret as showing that romantic priming is a genuine phenomenon. In this reply, we comment on several contradictions in Sundie et al.’s article. First, they suggest that Shanks et al.’s replication experiments yielded different results from the original studies because we failed to appreciate the contextual sensitivity of romantic priming effects, but this argument rests largely on evidence from the very studies we were unable to replicate, and a wealth of other evidence suggests that social priming effects are largely invariant across samples and settings. Second, Sundie et al. criticize the selection rule by which Shanks et al. identified relevant priming studies, but then go on to include exactly the same set of studies in their p-curve analysis. Third, they criticize Shanks et al.’s selection of statistical results from these studies and propose a much wider selection, but then acknowledge that their selection process is poorly suited to assessing publication bias and p-hacking. Fourth, we show that their p-curve analysis, far from demonstrating that this literature is unaffected by p-hacking, in fact shows the exact opposite. Sundie et al. claim that Shanks et al.’s priming manipulation was demonstrably weak, but their argument is based on a confusion between different dependent measures. We conclude that romantic priming remains unproven, and urge researchers in this field to undertake high-powered preregistered replication studies. (PsycINFO Database Record (c) 2019 APA, all rights reserved
La Academia de Murillo y la Facultad de Bellas Artes 400 años después
El 11 de enero de 1660 algunos artistas sevillanos, entre quienes se encontraban Bartolomé Esteban Murillo, Francisco de Herrera el Mozo y Juan de Valdés Leal, fundaban en Sevilla, en unas estancias de la Casa Lonja, una Academia del arte de la Pintura, siendo éste el primer establecimiento de enseñanza artística con el que contó la ciudad.
En la actualidad, la Facultad de Bellas Artes de la Universidad de Sevilla, como centro superior de enseñanzas artísticas de la ciudad, se siente heredera de esta primigenia institución y, por ello, en el año en el que rememoramos el cuatricentenario del nacimiento de Murillo ha querido participar activamente en los factos conmemorativos de quien fue el primer
presidente de su más remoto precedente
Implantes inmediatos con restauración inmediata en situaciones de alto riesgo estético
Poster en jornada o congres
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