Search results for " ground"
showing 10 items of 229 documents
A Maximizing Hydraulic Radius (MHR) method for defining cross-section limits in rills and ephemeral gullies
2021
Abstract In this paper, a new method for determining the cross-section limits in rills and ephemeral gullies is proposed. This method is based on the estimate of the actual depth ha of each cross-section, which is the particular depth distinguishing the channel from the hillslope areas. The analysis showed that the actual depth corresponds to a particular bank slope sta occurring for the maximum value of the hydraulic radius R. The method was applied using a volumetric approach for calculating the hydraulic radius as the ratio between the volume of the whole investigated channel and its boundary lateral surface. The value of the bank slope st was derived by the DEM of the whole channel late…
Submarine groundwater discharge investigations in Sicilian and Brazilian coastal waters using an underwater gamma-ray spectrometer
2006
Abstract Submarine groundwater discharge (SGD) in coastal zones was monitored using in situ underwater gamma-ray spectrometry of radon decay products ( 214 Bi). Several sites were visited during the IAEA'2002 expedition to south-eastern Sicily, where SGD variations were observed in the Donnalucata boat basin. The continuous monitoring carried out for 3 days at the site closest to the coast revealed an anticorrelation dependence of 222 Rn concentration with tide and salinity. The 222 Rn activity concentrations in seawater varied from 2.3 kBq m −3 (during high tides) to 4.8 kBq m −3 (during low tides). In situ gamma-ray spectrometric measurements were also carried out during the IAEA–UNESCO'2…
Electrical Safety of Resonant Grounding
2019
The resonant grounding is one of the possible methods of system neutral grounding for the medium-voltage distribution. IEEE standards do define this grounding configuration, but important advantages and drawbacks of the resonant grounding might not be fully known, due to its rather uncommon application in North America. On the other hand, resonant grounding in Europe is imposed by the increased requirements for power quality, especially for medium-voltage industrial users, and imposed to electric utilities by Regulatory Authorities, with the purpose to protect the interests of users and consumers. Level of the continuity of the service, magnitude and phase of ground-fault currents, magnitud…
A Tool-Based Approach for Essentializing Software Engineering Practices
2019
Software Engineers work using highly diverse methods and practices, and general theories in software engineering are lacking. A recent attempt at creating a common ground in the area of software engineering methodologies has been the Essence Theory of Software Engineering. Essence is a method-agnostic progress management framework and a meta-method for Software Engineering (SE). However, tooling for Essence is still lacking. Without dedicated tools and other instruments, a meta-method such as Essence is cumbersome to utilize by practitioners and students. Indeed, Essence currently suffers from a lack of widespread practitioner adoption. In this paper, we thus present an Open Source tool for…
Testing the use of an image-based technique to measure gully erosion at Sparacia experimental area
2017
The first part of this investigation was aimed at testing the use of a three‐dimensional (3D) digital terrain model and a quasi‐tridimensional (2.5D) digital elevation model obtained by a large series of oblique images of eroded channels taken from consumer un‐calibrated and non‐metric cameras. For two closed earth channels having a different sinuosity, the ground measurement of some cross sections by a profilometer (P) was carried out and their real volume was also measured. The comparison among the three methods (3D, 2.5D, and P) pointed out that a limited underestimation of the total volume always occurs and that the 3D method is characterized by the minimum difference between measured a…
Effect of dual biotic stress on plant volatile synomones used by egg parasitoids
2014
Studies on semiochemical communication have demonstrated that broad bean plant, Vicia faba, emits volatile synomones induced by feeding and oviposition activities of the southern green stink bug, Nezara viridula, which recruit the egg parasitoid Trissolcus basalis. However plants growing in agro-ecosystems can be attacked by several herbivore species that could affect both above and belowground plant tissues with possible consequences for parasitoid recruitment. For example, broad bean plants can also be attacked by the leaf weevil, Sitona lineatus, and simultaneous attacks by the southern green stink bug and the leaf weevil can occur in agro- ecosystems. The purpose of this work was to inv…
Distribution of Volatile Organic Compounds in Sicilian groundwaters analysed by Head Space Solid Phase Micro Extraction coupled with Gas Chromatograp…
2008
This work presents the results of an assessment of the existence and concentration of 13 volatile organic compounds (VOCs) in groundwaters from 14 hydrological basins in Sicily (25,710 km2). On the basis of hydrological, hydrogeochemical and geological studies, 324 sampling points were selected. All groundwater sampled were collected twice, from October to December 2004 and from February to May 2005, and were analysed to determine the concentration and spatial distribution of the VOCs in the aquifers. The need to analyze a large number of samples in a short space of time so as to obtain quantitative analyses in trace concentration levels spurred us to create a new analytical method, both si…
Architecture of the NYT caldera and inner resurgent dome (Pozzuoli Bay, Campi Flegrei): new insights from seismic reflection and DInSAR data
2016
The Campi Flegrei and its offshore prolongation (Pozzuoli Bay) are a volcanic area dominated by a collapse caldera associated with the Neapolitan Yellow Tuff (NYT) eruption, occurred at ~15 ka BP, and by an intra-caldera resurgent dome. We present new insights into: a) the geometry and kinematics of faults formed inside and at the edge of the caldera, b) the architecture of the caldera and the resurgent dome, and c) the relationship between the structural elements of the caldera and ground deformation. This work is based on the integration of single- and multi- channel seismic, swath bathymetry data and ground deformation maps. The main results highlight that the NYT caldera, offshore, is c…
Architecture of the NYT caldera and inner resurgent dome (Pozzuoli Bay, Campi Flegrei): new insights from seismic reflection and DInSAR data
2016
The Campi Flegrei and its offshore prolongation (Pozzuoli Bay) are a volcanic area dominated by a collapse caldera associated with the Neapolitan Yellow Tuff (NYT) eruption, occurred at ~15 ka BP, and by an intra-caldera resurgent dome. We present new insights into: a) the geometry and kinematics of faults formed inside the caldera, b) the architecture of the resurgent dome, and c) the relationship between the structural elements of the resurgent dome and ground deformations. This work is based on the integration of high- and ultra-high resolution seismic data, swath bathymetry data and ground deformation maps. The main results highlight that the NYT caldera, offshore, is characterized by a…
Uso del nocciolino di oliva come materiale di riempimento di biotrincee per la denitrificazione biologica in situ di acque di falda
2016
Tra le varie possibilità di intervento per la rimozione dei nitrati dalle acque di falda, notevole interesse suscita il trattamento in situ dei plume contaminati mediante la realizzazione di biotrincee denitrificanti scavate in situ e naturalmente attraversate dalle acque di falda. Tra i materiali di origine organica che sono stati testati per tali applicazioni, il nocciolino di olive è risultato uno dei più idonei alle potenziali applicazioni di pieno campo. Tale tipo di materiale possiede un elevato contenuto di carbonio organico totale, prossimo al 50%, e una percentuale di lignina prossima al 45% in peso. Il lavoro proposto riporta i risultati di una campagna sperimentale eseguita media…