Search results for "LOCI"

Image Processing and Measurement of the Bubble Properties in a Bubbling Fluidized Bed Reactor

2022

The efficiency of a fluidized bed reactor depends on the bed fluid dynamic behavior, which is significantly influenced by the bubble properties. This work investigates the bubble properties of a bubbling fluidized bed reactor using computational particle fluid dynamic (CPFD) simulations and electrical capacitance tomography (ECT) measurements. The two-dimensional images (along the reactor horizontal and vertical planes) of the fluidized bed are obtained from the CPFD simulations at different operating conditions. The CPFD model was developed in a commercial CPFD software Barracuda Virtual Reactor 20.0.1. The bubble behavior and bed fluidization behavior are characterized form the bubble pro…

Study of the column efficiency using gradient elution based on Van Deemter plots.

2018

Performance of chromatographic columns is of major importance in the development of more efficient separation methods. So far, a common practice is to study the column behavior in isocratic elution by modifying the flow rate and fitting the theoretical plate height values versus the mobile phase linear velocity, according to the Van Deemter equation. In this work, an approach is presented to extend the measurement of efficiency to linear gradient elution, where the mean retention factor is kept constant at each assayed flow. This avoids a possible source of uncertainty due to the change in the distribution equilibria profile, and makes the mean interactions with the stationary phase in grad…

Prediction of Peak Shape and Characterization of Column Performance in Liquid Chromatography as a Function of Flow Rate

2015

Traditionally, column performance in liquid chromatography has been studied using information from the elution of probe compounds at different flow rates through van Deemter plots, which relate the column plate height to the linear mobile phase velocity. A more recent approach to characterize columns is the representation of the peak widths (or the right and left peak half-widths) for a set of compounds versus their retention times, which, for isocratic elution, give rise to almost linear plots. In previous work, these plots have been shown to facilitate the prediction of peak profiles (width and asymmetry) with optimization purposes. In this work, a detailed study on the dependence of the …

Attitude and speed in young people. Implementation of a program of driver education

2009

Contemporary Theories of change of attitudes defends that these depends on the way to think, to act and to feel of the people. If we touch upon each one of these three main components related between we can influence in the predisposition to act. The application of a program of speed self-control to ample of young drivers, using a design pretest- postest with control group and using a Factor Analysis shows that is possible the change of attitudes.

Velocity estimation in wideband mobile stations equipped with multiple antennas

2009

©2009 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. Article also available from publisher: http://dx.doi.org/10.1109/VETECS.2009.5073907 A new method is proposed for estimating the velocity of wideband mobile stations (MSs) equipped with multiple antennas. The MS speed is determined using the well-known relationship between the direction-of-arrivals (DOAs) and the Doppler frequency shifts experienced by the mult…

A second strain gradient elasticity theory with second velocity gradient inertia – Part I: Constitutive equations and quasi-static behavior

2013

Abstract A multi-cell homogenization procedure with four geometrically different groups of cell elements (respectively for the bulk, the boundary surface, the edge lines and the corner points of a body) is envisioned, which is able not only to extract the effective constitutive properties of a material, but also to assess the “surface effects” produced by the boundary surface on the near bulk material. Applied to an unbounded material in combination with the thermodynamics energy balance principles, this procedure leads to an equivalent continuum constitutively characterized by (ordinary, double and triple) generalized stresses and momenta. Also, applying this procedure to a (finite) body s…

Velocità e correttezza nell’attribuzione del genere grammaticale: il ruolo della trasparenza morfologica della vocale finale di parola.

2010

RELAZIONE ENTROPICA TRA LA VELOCITA’ MEDIA E LA VELOCITà MASSIMA: verifica sperimentale in un canale meandriforme

2015

Il modello di entropia sviluppato da Chiu (1988) consente di correlare la velocità media, um, e umax mediante una relazione lineare, um,=Φ(M) umax, che dipende dal parametro entropico, M, caratteristico della sezione fluviale. Tale formulazione è stata verificata su diversi corsi d’acqua naturali con differenti caratteristiche idrauliche e geometriche (Ammari et al. 2010, Xia, 1997; Moramarco et al. , 2004). Nel presente lavoro, l’attenzione è rivolta alla verifica della relazione entropica tra la velocità media e la velocità massima al variare delle configurazioni planimetriche del canale (andamento rettilineo e andamento curvilineo) e in presenza di elementi forzanti come la curvatura del…

Threshold-based vestibular adaptation to cross-coupled canal stimulation

2008

Prior experiments have demonstrated that people are able to adapt to cross-coupled accelerations associated with head movements while spinning at high rotation rates (e.g., 23 rpm or 138°/s). However, while adapting, subjects commonly experience serious side effects, such as motion sickness, non-compensatory eye movements, and strong and potentially disorienting illusory body tilt or tumbling sensations. In the present study, we investigated the feasibility of adaptation using a threshold-based method, which ensured that the illusory tilt sensations remained imperceptible or just barely noticeable. This was achieved by incrementally increasing the angular velocity of the horizontal centrifu…

Non-Homogeneous Tension Profile

2013

In this chapter, we will look at the influence of a skewed tension profile on the divergence instability of a travelling, thin elastic plate. The travelling plate is subjected to axial tension at the supports, but the tension distribution along the supports is not uniform. For the nonuniformity, we will use a linear distribution. First, we will perform a dynamic analysis of small time-harmonic vibrations, after which we will concentrate on the divergence instability problem. We will see that a small inhomogeneity in the applied tension may have a large effect on the divergence modes, and that inhomogeneity in the tension profile may significantly decrease the critical velocity of the plate.