Search results for "LOCI"

Genetic and Ecotypic Differentiation in a Californian Plant Polyploid Complex (Grindelia, Asteraceae)

2014

Studies of ecotypic differentiation in the California Floristic Province have contributed greatly to plant evolutionary biology since the pioneering work of Clausen, Keck, and Hiesey. The extent of gene flow and genetic differentiation across interfertile ecotypes that span major habitats in the California Floristic Province is understudied, however, and is important for understanding the prospects for local adaptation to evolve or persist in the face of potential gene flow across populations in different ecological settings. We used microsatellite data to examine local differentiation in one of these lineages, the Pacific Coast polyploid complex of the plant genus Grindelia (Asteraceae). W…

EXPERIMENTAL INVESTIGATION OF FLOW VELOCITY FIELD AND TURBULENCE FLOW CHARACTERISTICS

2011

Fractional Spectral Moments for Digital Simulation of Multivariate Wind Velocity Fields

2012

In this paper, a method for the digital simulation of wind velocity fields by Fractional Spectral Moment function is proposed. It is shown that by constructing a digital filter whose coefficients are the fractional spectral moments, it is possible to simulate samples of the target process as superposition of Riesz fractional derivatives of a Gaussian white noise processes. The key of this simulation technique is the generalized Taylor expansion proposed by the authors. The method is extended to multivariate processes and practical issues on the implementation of the method are reported.

Pore fabric geometry inferred from magnetic and acoustic anisotropies in rocks with various mineralogy, permeability and porosity.

2014

14 pages; International audience; he ferrofluid impregnation technique combined with anisotropy of magnetic susceptibility measurements (AMSff) is one of the ways to analyze the 3-D geometry of the pore space in a rock and indirectly to infer the anisotropy of permeability. We applied this method on different types of rocks (sandstones and carbonates) with a range of different porosity values (10-30%) and permeability (1 mD to 1 D). To get additional information on both the pore aspect ratio and the directional anisotropy we used another technique, measuring the anisotropy of P-waves velocity (APV) in dry and water saturated conditions. Comparing between both methods shows that despite the …

Identifying wave and turbulence components in wind-driven shallow basins

2012

Wind-induced waves play an important role in shallow lake hydro- and sediment dynamics. That is why field measurements are important for the validation of their estimation methods, especially in shallow waters. In the first part of the present paper a method is introduced to improve the interpretation of the measured data, applicable both for pressure and velocity data. Replacing the turbulence-affected tail of the measured spectrum with a fitted power function causes a considerable 8-10% difference in the derived bulk wave parameters so this procedure is worth to be done. In the second part an appropriate technique to obtain wave features from 3D velocity time series will be described. The…

The peach volatilome modularity is reflected at the genetic and environmental response levels in a QTL mapping population

2014

Background: The improvement of fruit aroma is currently one of the most sought-after objectives in peach breeding programs. To better characterize and assess the genetic potential for increasing aroma quality by breeding, a quantity trait locus (QTL) analysis approach was carried out in an F-1 population segregating largely for fruit traits. Results: Linkage maps were constructed using the IPSC peach 9 K Infinium (R) II array, rendering dense genetic maps, except in the case of certain chromosomes, probably due to identity-by-descent of those chromosomes in the parental genotypes. The variability in compounds associated with aroma was analyzed by a metabolomic approach based on GC-MS to pro…

Dynamic Behaviour of an Axially Moving Plate Undergoing Small Cylindrical Deformation Submerged in Axially Flowing Ideal Fluid

2011

Abstract The out-of-plane dynamic response of a moving plate, travelling between two rollers at a constant velocity, is studied, taking into account the mutual interaction between the vibrating plate and the surrounding, axially flowing ideal fluid. Transverse displacement of the plate (assumed cylindrical) is described by an integro-differential equation that includes a local inertia term, Coriolis and centrifugal forces, the aerodynamic reaction of the external medium, the vertical projection of membrane tension, the bending resistance, and external perturbation forces. In the two-dimensional model thus set up, the aerodynamic reaction is found analytically as a functional of the cylindri…

Control of hysteretic instability in rotating machinery by elastic suspension systems subject to dry and viscous friction

2010

Abstract Most of the undesired whirling motions of rotating machines can be efficiently reduced by supporting journal boxes elastically and controlling their movement by viscous dampers or by dry friction surfaces normal to the shaft axis, which rub against the frame. In the case of dry dampers, resonance ranges of the floating support configuration can be easily cut off by planning a motionless adhesive state of the friction surfaces. On the contrary, the dry friction contact must change automatically into sliding conditions when the fixed support resonances are to be feared. Moreover, the whirl amplitude can be restrained throughout the speed range by a proper choice of the suspension-to-…

Rotor whirl damping by dry friction suspension systems

2008

An efficient and automatic attenuation technique for the whirling motion of rotating machinery can be achieved by supporting the journal boxes elastically and providing them with suitable rubbing surfaces subject to dry friction normal to the shaft axis. The critical flexural speeds are easily cut off and the whirl amplitude is minimized throughout the frequency range. Confining the usual operative angular speed of the rotor in the range of adhesive contact between the dry friction surfaces, there is no significant increase of power dissipation or heat production as a whole due to this type of suspension system, whose task is just to suppress the resonant peaks when passing the critical spe…

Flow Resistance in Step-Pool Rills

2017

Rills evolve morphologically, and the adjustment of rill channel geometry to flow affects the relationships among velocity, discharge, and slope. The resistance to flow in step-pool rills is mainly due to form-induced mechanisms and, in comparison, grain resistance is of minor significance. Previous studies on rill flow resistance have been performed exclusively for grainresistance conditions and use a stream flow equation. In this study, a new flow resistance equation, deduced by applying dimensional analysis and self-similarity theory, was applied to rill flow in step-pool channels. First, the incomplete self-similarity hypothesis was used for establishing a power flow velocity profile wh…