Search results for "REY"
showing 10 items of 639 documents
Flume experiments for assessing the dye-tracing technique in rill flows
2021
Abstract Flow velocity controls hillslope soil erosion and is a key hydrodynamic variable involved in sediment transport and deposition processes. The dye-tracer technique is one of the most applied methods for measuring velocity of shallow interrill and rill flow. The technique is based on the injection of a tracer in a specific point and the measurement of its speed to travel the known distance from the injection point to a given channel section. The dye-tracer technique requires that the measured surface flow velocity has to be corrected to obtain the mean flow velocity using a correction factor which is generally empirically deduced. The technique has two sources of uncertainties: i) th…
Lifestyle counseling to reduce body weight and cardiometabolic risk factors among truck and bus drivers – a randomized controlled trial
2015
Objectives We conducted a randomized trial among overweight long-distance drivers to study the effects of structured lifestyle counseling on body weight and cardiometabolic risk factors. Methods Men with waist circumference > 100 cm were randomized into a lifestyle counseling (LIFE, N=55) and a reference (REF, N=58) group. The LIFE group participated in monthly counseling on nutrition, physical activity, and sleep for 12 months aiming at 10% weight loss. After 12 months, the REF group participated in 3-month counseling. Assessments took place at 0, 12, and 24 months. Between-group differences in changes were analyzed by generalized linear modeling. Metabolic risk (Z score) was calculated fr…
Approximate Closed-Form Solutions for the Shift Mechanics of Rubber Belt Variators
2009
The mechanical behavior of V-belt variators during the speed ratio shift is different from the steady operation as a gross radial motion of the belt is superimposed to the circumferential motion. The theoretical analysis involves equilibrium equations similar to the steady case, but requires a re-formulation of the mass conservation condition making use of the Reynolds transport theorem. The mathematical model of the belt-pulley coupling implies the repeated numerical solution of a strongly non-linear differential system. Nevertheless, an attentive observation of the numerical diagrams suggests simple and useful closed-form approximations for the four possible working modes of any pulley, o…
Comparative morphology of the postpharyngeal gland in the Philanthinae (Hymenoptera, Crabronidae) and the evolution of an antimicrobial brood protect…
2015
Background Hymenoptera that mass-provision their offspring have evolved elaborate antimicrobial strategies to ward off fungal infestation of the highly nutritive larval food. Females of the Afro-European Philanthus triangulum and the South American Trachypus elongatus (Crabronidae, Philanthinae) embalm their prey, paralyzed bees, with a secretion from a complex postpharyngeal gland (PPG). This coating consists of mainly unsaturated hydrocarbons and reduces water accumulation on the prey’s surface, thus rendering it unfavorable for fungal growth. Here we (1) investigated whether a North American Philanthus species also employs prey embalming and (2) assessed the occurrence and morphology of …
Vicent Blasco Ibáñez: antisemitisme entre tarongers
2018
El discurs de Blasco Ibáñez, en ocasions radical i polèmic, fortament anticlerical, va ser en determinats moments també obertament antisemita. Analitzem les claus de la judeofòbia en Blasco Ibáñez mitjançant l’estudi de l’evolució del prejudici antijueu de l’autor valencià, abans i després del cas Dreyfus, i les dificultats que va tenir per a superar-lo en la seua dimensió més clàssica i tradicional.
Relational analysis and the ethnographic approach : constructing preschool childhood
2021
This article elaborates the relational ontology in an ethnographic study. The aim is to seek relational construction of preschool practice and how children’s positions are constructed in it. The study is based on the understanding that ethnography and relational sociology share the idea that society emerges through repeated relations. The ontological thinking of relational sociology is applied in a micro-level analysis of three episodes from a Finnish preschool. We propose that relations appear in every single ethnographical episode and that carefully analysed repetitive relations can reveal a stabilised organisational structure. The analysis shows how the position of one child is structuri…
Three-dimensional numerical simulations on wind- and tide-induced currents: The case of Augusta Harbour (Italy)
2014
The hydrodynamic circulation in the coastal area of the Augusta Bay (Italy), located in the eastern part of Sicily, is analysed. Due to the heavy contamination generated by the several chemical and petrochemical industries active in the zone, the harbour was declared a Contaminated Site of National Interest. To mitigate the risks connected with the industrial activities located near the harbour, it is important to analyse the hydrodynamic circulation in the coastal area. To perform such analysis, a parallel 3D numerical model is used to solve the Reynolds-averaged momentum and mass balance, employing the k-e turbulence model for the Reynolds stresses. The numerical model is parallelized usi…
Effect of pollens and preys on various biological parameters of the generalist mite Cydnodromus californicus
2009
The generalist phytoseiid mite Cydnodromus californicus (McGregor) (Mesostigmata Phytoseiidae) is considered a very important biocontrol agent of the spider mite Tetranychus urticae Koch both in greenhouses and field. Its capacity to feed alternative foods allows the increase of the population in field, even when the primary prey is not available. To investigate the effect of various alternative food substances present in the Mediterranean agroecosystems on the biological parameters of C. californicus, laboratory trials were carried out using 17 pollens and 3 preys. As it was expected, T. urticae was the best food for both the postembryonic development and the oviposition rate (100% of atta…
Adaptive control of a seven mode truncation of the Kolmogorov flow with drag
2009
Abstract We study a seven dimensional nonlinear dynamical system obtained by a truncation of the Navier–Stokes equations for a two dimensional incompressible fluid with the addition of a linear term modelling the drag friction. We show the bifurcation sequence leading from laminar steady states to chaotic solutions with increasing Reynolds number. Finally, we design an adaptive control which drives the state of the system to the equilibrium point representing the stationary solution.
High Reynolds number Navier-Stokes solutions and boundary layer separation induced by a rectilinear vortex
2013
Abstract We compute the solutions of Prandtl’s and Navier–Stokes equations for the two dimensional flow induced by a rectilinear vortex interacting with a boundary in the half plane. For this initial datum Prandtl’s equation develops, in a finite time, a separation singularity. We investigate the different stages of unsteady separation for Navier–Stokes solution at different Reynolds numbers Re = 103–105, and we show the presence of a large-scale interaction between the viscous boundary layer and the inviscid outer flow. We also see a subsequent stage, characterized by the presence of a small-scale interaction, which is visible only for moderate-high Re numbers Re = 104–105. We also investi…