Air recovery assessment on high-pressure pneumatic systems

A computational simulation and experimental work of the fluid flow through the pneumatic circuit used in a stretch blow moulding machine is presented in this paper. The computer code is built around a zero-dimensional thermodynamic model for the air blowing and recycling containers together with a non-linear time-variant deterministic model for the pneumatic three stations single acting valve manifold, which, in turn, is linked to a quasi-one-dimensional unsteady flow model for the interconnecting pipes. The flow through the pipes accounts for viscous friction, heat transfer, cross-sectional area variation, and entropy variation. Two different solving methods are applied: the method of characteristics and the Harten-Lax-Van Leer (HLL) Riemann first-order scheme. The numerical model allows prediction of the air blowing process and, more significantly, permits determination of the recycling rate at each operating cycle. A simplified experimental set-up of the industrial process was designed, and the pressure and temperature were adequately monitored. Predictions of the blowing process for various configurations proved to be in good agreement with the measured results. In addition, a novel design of a valve manifold intended for the polyethylene terephthalate (PET) plastic bottle manufacturing industry is also presented.Peer ReviewedPostprint (author's final draft

On a rigorous interpretation of the quantum Schrödinger–Langevin operator in bounded domains with applications

AbstractIn this paper we make it mathematically rigorous the formulation of the following quantum Schrödinger–Langevin nonlinear operator for the wavefunctionAQSL=iℏ∂t+ℏ22mΔx−λ(Sψ−〈Sψ〉)−Θℏ[nψ,Jψ] in bounded domains via its mild interpretation. The a priori ambiguity caused by the presence of the multi-valued potential λSψ, proportional to the argument of the complex-valued wavefunctionψ=|ψ|exp{iℏSψ}, is circumvented by subtracting its positional expectation value,〈Sψ〉(t):=∫ΩSψ(t,x)nψ(t,x)dx, as motivated in the original derivation (Kostin, 1972 [45]). The problem to be solved in order to find Sψ is mostly deduced from the modulus-argument decomposition of ψ and dealt with much like in Guerrero et al. (2010) [37]. Here ℏ is the (reduced) Planck constant, m is the particle mass, λ is a friction coefficient, nψ=|ψ|2 is the local probability density, Jψ=ℏmIm(ψ¯∇xψ) denotes the electric current density, and Θℏ is a general operator (eventually nonlinear) that only depends upon the macroscopic observables nψ and Jψ. In this framework, we show local well-posedness of the initial-boundary value problem associated with the Schrödinger–Langevin operator AQSL in bounded domains. In particular, all of our results apply to the analysis of the well-known Kostin equation derived in Kostin (1972) [45] and of the Schrödinger–Langevin equation with Poisson coupling and enthalpy dependence (Jüngel et al., 2002 [41])

Size-Controlled Water-Soluble Ag Nanoparticles

Ag nanoparticles of two different sizes (1 and 4 nm) were prepared within an apoferritin cavity by using an Ag+-loaded apoferritin as a nanoconfined environment for their construction. The initial amount of Ag' ions injected in the apoferritin cavity dictates the size of the final Ag particles. The protein shell prevents bulk aggregation of the metal particles, which renders them water soluble and extremely stable

Stratigraphy of the Cordubian-Ovetian (Lower Cambrian) Transition in the Occidental Iberian Chain (Spain)

[Resumen] Este trabajo analiza los afloramientos de la Formación Embid (Cámbrico Inferior) existentes en el borde nororiental de la Cadena Ibérica Occidental, entre las localidades de Torrijo de la Cañada y Villalengua (unidad estructural de Moros). Con este objetivo se han realizado dos perfiles estratigráficos y estudiado sus litofacies. Asimismo, se pone de manifiesto el contenido paleoicnológico más representativo. La aparición de distintos ejemplares del icnogénero Astropolichnus separados 200 m. en la serie estratigráfica plantea la necesidad de reconsiderar la precisión de este incofósil como indicador bioestratigráfico. Debido a la ausencia de afloramientos superficiales de la Formación Bámbola, estos materiales constituyen las rocas más antiguas.de esta Cadena. Finalmente, se propone al perfil To1 como hipoestratotipo de la Formación Embid en la Cadena Ibérica Occidental.[Abstract] This work presents a study of the Embid Formation, the oldest formation cropped out in the Occidental Iberian Chain (NE Spain). This outcrop is placed in the nucleus of the Moros structural unit (ALVARO et al., 1992), located in the nonheastern contact of this Chain with the Calatayud-Teruel Teniary basin, between Villalengua and Torrijo de la Cañada localities (Zaragoza Province). We have studied two sections of the Embid Formation (To1 and T02). The first one, 250 m. thick, is the most complete and shows the best exposition of the area. It is proposed as the hipostratotype of the Embid Formation in this Chain. In To1, four terms (El to E4) of this formation and other at the beginning of the Jalón Formation al) have been recognized, according to the sandstone/shale ratio. The ichnofossils and other sedimentary structures studied here suggest, for terms E2 and E4-J1, a litoral to shallow sublitoral environment (tidal flat and tidal channels, influenced by tidal and wave effects), and a sublitoral (circalitoral) environment with episodic levels influenced by storms currents and/or hard tides, for the terms El and E3. The northeastwards To2 section, 150 m. thick, shows a similar evolution, but a more distal character. The wide development of subtidal sand bodies as well as the low diversity and wealth of biogenic structures, suggest a shoreface sedimentation, with a intercalated episode influenced by tidal action. The materials of this section are assigned to the Embid Formation for its lithology, the lack of white quarzites (that characterize the underlying Bámbola Formation) and the ichnofossil record. In spite of palichnological, lithological and sedjmentological affinities between both profils, we can not give an accurate correlation of both sequences. The section To1 records a shallower episode (E2), reaching subaerial exposure in the Cordubian-Ovetian transition. It is the first time this episode has been recognized in the Iberian Chains, and it is considered as a local process. A second shallower episode is placed in the transition of the Embid-Jalón Formations (E4-J1). It has been recognized in other outcrops of the Iberian Chains and LIÑAN & GAMEZ (in press) have proposed a correlation of this regressive episode with the Woodlands Regression (BRASIER, 1985). On the other hand, Astropolichnus ichnogenus is recorded in different levels of same section (200 m. separated), for the first-time in the Iberian Chains. This fact will force to reconsider the accuracy of this ichnofossil as biostratigraphical marker. Finally, a progresive eastwards distallity of the sediments is inferred by comparison with similar outcrops of the Oriental Iberian Chain, by the existence of the first local"shallower episode, placed in the more suroccidental outcrop of the basin (To1), and by the northeastwards paleocurrents directions. These data support the existence of an emerged area beside the occidental margin of the Cantabrian-Iberian Basin as was pointed by LOTZE (1961), and also proposed in the cantabrian sector of this basin by ARAMBURU el al. (1992)

Análisis biomecánico de la técnica individual de los finalistas masculinos del lanzamiento de peso en el Campeonato del Mundo de Atletismo Valencia 08

El objetivo de este estudio ha sido realizar un análisis descriptivo de la técnica individual de los ocho finalistas masculinos de lanzamiento de peso en el Campeonato del Mundo de Atletismo de Pista Cubierta, celebrado en Valencia, 2008. Para este estudio, se han utilizado técnicas fotogramétricas tridimensionales (3D) a partir de la filmación del gesto con dos cámaras de video sincronizadas temporalmente a 100 Hz, analizándose el mejor lanzamiento de cada atleta. Se parte de un análisis temporal, donde se ha dividido el gesto en seis fases. A partir de esas fases, se describen las gráficas de velocidad tangencial del CG y el peso con respecto al tiempo. A continuación, se registraron los factores que determinan la trayectoria del peso durante el vuelo (factores de producto), así como el compromiso de otros factores causales que determinan la eficacia del lanzamiento de peso. Además de confirmar la relación entre los factores de producto, los resultados ponen de manifiesto que cada lanzador utiliza una secuencia temporal y ritmo de ejecución propio e individual, confirmándose que la ejecución técnica del lanzamiento de peso es individual y está condicionada por características antropométricas, capacidad muscular y el grado de automatización de la secuencia temporal individual.The aim of this study is to make a descriptive analysis of the individual technique of the eight men finalists in the shot put in the 2008 Valencia Indoor World Championships. To do this three-dimensional photogrammetric techniques (3D) were used, filming the action with two video cameras temporally synchronized at 100 Hz. Six puts were recorded during the men’s final, subsequently analysing the longest throw of each putter. A temporal analysis was first made, dividing the throwing action into six phases. Starting from these phases, graphs of the tangential velocity of the thrower’s CG and the time taken in the shot are described. Then the factors that determine the trajectory of the shot during flight (product factors) and the contribution of the other causal factors for the efficiency of the put are recorded. As well as confirming the relation between the product factors, the results show that each thrower uses his/her own temporal sequence and rhythm of execution, confirming that the technical execution of the shot put is individual and conditioned by anthropometrical characteristics, muscular capacity and the degree of automation of the individual temporal sequence.Peer Reviewe

Particle dispersion processes in two-dimensional turbulence: a comparison with 2-D kinematic simulation.

International audienceWe study numerically the comparison between Lagrangian experiments on turbulent particle dispersion in 2-D turbulent flows performed, on the one hand, on the basis of direct numerical simulations (DNS) and, on the other hand, using kinematic simulations (KS). Eulerian space-time structure of both DNS and KS dynamics are not comparable, mostly due to the absence of strong coherent vortices and advection processes in the KS fields. The comparison allows to refine past studies about the contribution of non-homogeneous space-time 2-D Eulerian structure on the turbulent absolute and relative particle dispersion processes. We particularly focus our discussion on the Richardson's regime for relative dispersion