A Meta-Heuristic Optimization Procedure for the Identification of the Nonlinear Model Parameters of Hydraulic Dampers Based on Experimental Dataset of Real Working Conditions

Hydralic dampers are widely implemented in railway vehicle suspension stages, especially in high-speed passenger trains. They are designed to be mounted in different positions to improve comfort, stability, and safety performances. Numerical simulations are often used to assist the design and optimization of these components. Unfortunately, hydraulic dampers are highly nonlinear due to the complex fluid dynamic phenomena taking place inside the chambers and through the by-pass orifices. This requires accurate damper models to be developed to estimate the influence of the nonlinearities of such components during the dynamic performances of the whole vehicle. This work aims at presenting a new parametric damper model based on a nonlinear lumped element approach. Moreover, a new model tuning procedure will be introduced. Differently from the typical sinusoidal characterization cycles, this routine is based on experimental tests of real working conditions. The set of optimal model parameters will be found through a metaheuristic iterative approach able to minimize the differences between numerical and experimental damper forces. The performances of the optimal model will be compared with the ones of the most common Maxwell model generally implemented in railway multibody software programs

Alfalfa Response to Phosphorus Sources Associated with the Application of Liming and Gypsum-Shoot Numbers

Alfalfa (Medicago sativa L.) was grown in a Typic Mapluolox soil with triple superphosphate (TS), Gafsa phosphate (GP) and GP with gypsum (GP + G). Three rates of phosphorus application were used 50, 100 and 200 mg P dm-3, before and after liming. Alfalfa was harvested three times. Basal and axillary shoot numbers in alfalfa increased with increasing phosphorus rates. Shoots were produced in higher number with GP in comparison with TS. GP + G resulted in higher basal shoot number than GP. However, there was no gypsum effect on axillary shoot numbers. Liming before or after TS, GP and GP + G application had similar responses on shoot numbers

GRB 970228 Within the EMBH Model

We consider the gamma-ray burst of 1997 February 28 (GRB 970228) within the ElectroMagnetic Black Hole (EMBH) model. We first determine the value of the two free parameters that characterize energetically the GRB phenomenon in the EMBH model, that is to say the dyadosphere energy, $E_{dya}=5.1\times10^{52}$ ergs, and the baryonic remnant mass $M_{B}$ in units of $E_{dya}$, $B=M_{B}c^{2}/E_{dya}=3.0\times10^{-3}$. Having in this way estimated the energy emitted during the beam-target phase, we evaluate the role of the InterStellar Medium (ISM) number density (n$_{ISM}$) and of the ratio ${\cal R}$ between the effective emitting area and the total surface area of the GRB source, in reproducing the observed profiles of the GRB 970228 prompt emission and X-ray (2-10 keV energy band) afterglow. The importance of the ISM distribution three-dimensional treatment around the central black hole is also stressed in this analysis.Comment: 4 pages, 1 figure, to appear in the Proceedings of the Los Alamos "Gamma Ray Burst Symposium" in Santa Fe, New Mexico, September 8-12 2003 (AIP Conf. Ser.), CHAPTER: GRB Connection to Supernova

Current Productions Carnuntum, German Limes and Radiopast

[EN] The here presented three chosen projects mark out different techniques of production and their transmission of content. The differentiated impact on the public absorption of the transported content are described dependent to experiences with it in exhibitions and publications, and can be used to rectify future approaches of similar topics. In most of these productions, technical difficulties were observed and solved through extensive use of different tools and techniques to achieve a reasonable output and represent our current state of knowledge which we would like to share. The documentation of the production as well as the communication between the production and research team is indispensable to the sucsess of these media formats.[ES] Presento tres proyectos elegidos que delimitan técnicas diferentes de la producción y su transmisión de contenido. El impacto diferenciado en la absorción pública del contenido es descrito dependiente a experiencias con ello en exposiciones y publicaciones, y puede ser usado para rectificar futuros acercamientos de temas similares. En la mayor parte de estas producciones, las dificultades técnicas fueron estudiadas y solucionadas por el uso extenso de instrumentos diferentes y técnicas para conseguir una salida razonable y representar nuestro estado del conocimiento que nos gustaría compartir. La documentación de la producción así como la comunicación entre la producción y grupo de investigación es indispensable en estos formatos multimedia.The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/2007- 2013) under grant agreement n° 230679, under the action Marie Curie – People IAPP, with the Project entitled “Radiography of the past. Integrated non-destructive approaches to understand and valorise complex archaeological sitesHumer, F.; Gugl, C.; Pregesbauer, M.; Vermeulen, F.; Corsi, C.; Klein, M. (2011). Current Productions Carnuntum, German Limes and Radiopast. Virtual Archaeology Review. 2(4):131-137. https://doi.org/10.4995/var.2011.4569OJS13113724CORSI C., DE DAPPER M., DE PREZ S., VERMEULEN F. (2005). Geoarchaeological observations on the Roman town of Ammaia, Internet Archaeology 19.CORSI C., VERMEULEN F. (2007). Elementi per la ricostruzione del paesaggio urbano e suburbano della città romana di Ammaia in Lusitania, Lusitania, Archeologia Aerea 3: 13-30.DEPREZ S., DE DAPPER M. & DE JAEGER C. (2006), The water supply of the Roman town of Ammaia (Northeastern Alentejo, Portugal): a geoarchaeological case study, Publicações da Associação Portuguesa de Geomorfólogos 3: 109-133.MANTAS V. (2000). A sociedade luso-romano do município de Ammaia, in: Gorges J.-G. & Nogales Basarrate T. (Eds.), Sociedad y cultura en Lusitania romana, Mérida, Museo Nacional de Arte Romano: 391-420.http://www.carnuntum.co.at/ , http://www.carnuntum-db.at/, http://www.limes.co.at/, http://7reasons.at/http://www.limeswelten.net/, http://www.arctron.de/, http://7reasons.at

Advances in geometrical parametrization and reduced order models and methods for computational fluid dynamics problems in applied sciences and engineering: Overview and perspectives

Several problems in applied sciences and engineering require reduction techniques in order to allow computational tools to be employed in the daily practice, especially in iterative procedures such as optimization or sensitivity analysis. Reduced order methods need to face increasingly complex problems in computational mechanics, especially into a multiphysics setting. Several issues should be faced: stability of the approximation, efficient treatment of nonlinearities, uniqueness or possible bifurcations of the state solutions, proper coupling between fields, as well as offline-online computing, computational savings and certification of errors as measure of accuracy. Moreover, efficient geometrical parametrization techniques should be devised to efficiently face shape optimization problems, as well as shape reconstruction and shape assimilation problems. A related aspect deals with the management of parametrized interfaces in multiphysics problems, such as fluid-structure interaction problems, and also a domain decomposition based approach for complex parametrized networks. We present some illustrative industrial and biomedical problems as examples of recent advances on methodological developments

Indocyanine Green Nanoparticles : Are They Compelling for Cancer Treatment?

Indocyanine green (ICG) is a Food and Drug Administration\u2013approved near-infrared fluorescent dye, employed as an imaging agent for different clinical applications due to its attractive physicochemical properties, high sensitivity, and safety. However, free ICG suffers from some drawbacks, such as relatively short circulation half-life, concentration-dependent aggregation, and rapid clearance from the body, which would confine its feasible application in oncology. Here, we aim to discuss encapsulation of ICG within a nanoparticle formulation as a strategy to overcome some of its current limitations and to enlarge its possible applications in cancer diagnosis and treatment. Our purpose is to provide a short but exhaustive overview of clinical outcomes that these nanocomposites would provide, discussing opportunities, limitations, and possible impacts with regard to the main clinical needs in oncology