Search results for "banc"

A Phase-Locked Loop for the Synchronization of Power Quality Instruments in the Presence of Stationary and Transient Disturbances

2007

Power quality instrumentation requires accurate fundamental frequency estimation and signal synchronization, even in the presence of both stationary and transient disturbances. In this paper, the authors present a synchronization technique for power quality instruments based on a single-phase software phase-locked loop (PLL), which is able to perform the synchronization, even in the presence of such disturbances. Moreover, PLL is able to detect the occurrence of a transient disturbance. To evaluate if and how the synchronization technique is adversely affected by the application of stationary and transient disturbing influences, appropriate testing conditions have been developed, taking int…

The impact of soil erosion on soil fertility and vine vigor. A multidisciplinary approach based on field, laboratory and remote sensing approaches

2018

Soil erosion processes in vineyards, beyond surface runoff and sediment transport, have a strong effect on soil organic carbon (SOC) loss and redistribution along the slope. Variation in SOC across the landscape can determine differences in soil fertility and vine vigor. The goal of this research was to analyze the interactions among vines vigor, sediment delivery and SOC in a sloping vineyard located in Sicily. Six pedons were studied along the slope by digging 6 pits up to 60 cm depth. Soil was sampled every 10 cm and SOC, water extractable organic carbon (WEOC) and specific ultraviolet absorbance (SUVA) were analyzed. Erosion rates, detachment and deposition areas were measured by the po…

Trawling disturbance effects on the trophic ecology of two co-generic Astropectinid species

2015

Physical disturbance by trawling can have both negative and positive effects on populations of scavenging benthic organisms. In the present study the impact of fishing activity on feeding behaviour of the two Astropectinids, Astropecten bispinosus and A. irregularis , was assessed based on stomach contents analysis. The study was carried out along trawled seabed highlighting the positive response of the two facultative scavengers to carrion generated by trawl disturbance. Furthermore, there was greater food specialization in areas that were more heavily exploited by trawling. This specialisation could be linked to the availability of certain prey that results from the passage of fishing gea…

Fire in Protected Areas - the Effect of Protection and Importance of Fire Management

2012

Fires are important but socially and economically unwanted disturbances of the ecosystems. They cannot be considered as a problem, they are global phenomena. Protected areas are created to protect biodiversity, and strict protection is often applied, forgetting that fire had shaped that that we aim to protect. This harsh protection is producing important changes in the protected habitats and is increasing their vulnerability to destructive wildfires. Thus, it is of major interest to incorporate fire management in the protected areas plan, including the (re)use of prescribed fire and traditional burning in order to reintroduce fire regimens, fundamental to the landscape sustainability. This …

EXTREMELY LOW FREQUENCY (50Hz) MAGNETIC FIELD INFLUENCES PHYSICO-CHEMICAL PROPERTIES OF WATER

2019

The influence of 50 Hz sinusoidal magnetic field on physico-chemical properties of water was studied. Tanks with distilled water (120 mL) were individually exposed to action of homogenous 50 Hz magnetic fields, using a Helmholtz coils system. For magnetically exposure have been used different values of magnetic flux density (between 1 and 5 mT) and different durations of exposure (between 5 and 240 minutes). By means of this experimental study the physico-chemical properties of exposed water samples compared with the control ones have explored. Density, viscosity, surface tension, pH, oxygen concentration and electrical conductivity were recorded. Some physico-chemical parameters analyzed i…

Differential Effect on the Determinants of the Late Payments According to the Economic Cycle

2018

From 2004 to 2007, the Spanish financial system grew at a very rapid rate. However, from 2008 to 2012 impairment losses amounted equivalent to 25% of Spanish GDP.The objective of this paper is investigate how have affected the main problems that have suffered the Spanish economy on the late payments on Spanish credit institutions. And to check whether the effect of these problems is different on stages of growth with respect to the stages of crisis.The main results, according the test Chow, confirmed that there is a structural break in the model in 2007. Also the increase in unemployment increases the late payments   and this increase is greater in the stages of growth compared to the stage…

Colorimetric determination of alcohols in spirit drinks using a reversible solid sensor

2018

Abstract A sensor for the colorimetric estimation of the alcoholic content has been developed based on the entrapment of the reagent (4-N,N-dioctylamino)-4‘-trifluoroacetylazobenzene (ETHT 4001) into polydimethylsiloxane (PDMS) modified with tretraethylorthosilicate (TEOS). When exposed to an alcoholic media, the sensor delivers ETHT 4001 so that it reacts with alcohols, resulting in a change in the solution color. The diffusion of the entrapped ETHT 4001 from the polymeric sensor to the working solution depends on the hydrophobicity of both the sensor matrix and the media, while the time of exposure determines whether the reagent reacts with methanol, or with methanol and ethanol. Thus, th…

Spectroscopic study of the aluminium/lumogallion system in the presence of non-ionic surfactants

1987

Abstract The effects of different non-ionic ethylene oxide condensate surfactants on the fluorescence and the molecular absorption of the aluminium/lumogallion system are reported. Ethylene oxide condensates with fatty alcohols give higher micellar enhancement factors than tert-octylphenols or nonylphenols; ethylene oxide/propylene oxide copolymers provide only a 50% increase in the fluorescence of the complex. The aluminium/lumogallion seems to form mixed micelles with the fatty alcohol condensates; the strong complex/micelle interaction provides increased absorbance of the complex at 500 nm and higher fluorescence enhancement, allowing the detection of 0.11 μg l −1 aluminium.

Rapport à l'attention de M. Jacques ATTALI: Instance culturelle en vue de la promotion de la démocratie

1991

Disturbance-induced emigration: an overlooked mechanism that reduces metapopulation extinction risk.

2021

Emigration propensity (i.e., the tendency to leave undisturbed patches) is a key life-history trait of organisms in metapopulations with local extinctions and colonizations. Metapopulation models of dispersal evolution typically assume that patch disturbance kills all individuals within the patch, thus causing local extinction. However, individuals may instead be able to leave a patch when it is disturbed, either by fleeing before being killed or simply because the disturbance destroys the patch without causing mortality. This scenario may pertain to a wide range of organisms from horizontally transmitted symbionts, to aquatic insects inhabiting temporary ponds, to vertebrates living in fra…