1,379 research outputs found
Preliminary validation of an indirect method for discharge evaluation of Pertuso Spring (Central Italy)
This paper deals with the results of the first year of the Environmental Monitoring Plan, related to the catchment project of Pertuso Spring, which is going to be exploited to supply an important water network in the South part of Roma district. The study area is located in the Upper Valley of the Aniene River (Latium, Central Italy), in the outcrop of Triassic-Cenozoic carbonate rocks, and belong to an important karst aquifer. Pertuso Spring is the main outlet of this karst aquifer and is the one of the most important water resource in the southeast part of Latium Region, used for drinking, agriculture and hydroelectric supplies. Karst aquifer feeding Pertuso Spring is an open hydrogeological system aquifer characterized by complex interactions and exchanges between groundwater and surface water which influence the aquifer water budget. Thus, evaluation of groundwater discharge from this karst spring can be affected by difficulties in performing measurements because of the insufficient knowledge about water transfer processes in the hydrological cycle and geometry of drainage conduits.
The aim of this paper is to assess the interactions between karst aquifer feeding Pertuso Spring and Aniene River based on stream discharge measurements and water geochemical tracer data in order to validate an indirect method for karst spring discharge evaluation. As a matter of fact, in this paper, there are presented the results of the application of Magnesium as a reliable tracer of karst spring discharge. This indirect method is based on the elaboration of surface water discharge measurements in relationship with Mg2+ concentration values, determined as for groundwater, coming from Pertuso Spring, as for surface water sample, collected upstream and downstream of Pertuso Spring, along Aniene River streamflow. The application of Magnesium as an environmental tracer provides a means to evaluate discharge of Pertuso Spring, as it came up to be a marker of the mixing of surface water and groundwater. On the other hand, the Magnesium ion concentration provides information for the identification of groundwater flow systems and the main hydrogeochemical processes affecting the composition of water within the karst aquifers
Parameterized model order reduction of delayed systems using an interpolation approach with amplitude and frequency scaling coefficients
When the geometric dimensions become electrically large or signal waveform rise times decrease, time delays must be included in the modeling. We present an innovative PMOR technique for neutral delayed differential systems, which is based on an efficient and reliable combination of univariate model order reduction methods, amplitude and frequency scaling coefficients and positive interpolation schemes. It is able to provide parameterized reduced order models passive by construction over the design space of interest. Pertinent numerical examples validate the proposed PMOR approach
The NW sector of the Sicily Channel: geometry and evolution of inverted structural lineaments
The 3-D trend of anticline axial planes, fault planes and surfaces has been reconstructed in the offshore area between
the Egadi Islands and the Sciacca High from the interpretation of multichannel seismic reflection profiles and well data
(available from the VIDEPI project database). In particular, isopach maps generated for the five seismic units of age
between Cretaceous and Quaternary allowed highlighting the space-time migration of the tectonic processes. The
western portion of the studied area covers the submerged prolongation of the inner sector of the Sicilian-Maghrebian
chain, limited in the NW and in the SE by two tectonic lineaments running along the western and eastern margins of the
Adventure Bank: the Maghrebian Thrust Front and Adventure Thrust Front, respectively (see Argnani et al., 1986). The
eastern portion is characterized by transpressive zones orientated NNE-SSW identifying the Separation Belt that partly
corresponds to the foreland area which contains the Gela Nappe Thrust.
Age constraints indicate that contraction related to the Sicilian-Maghrebian fold and thrust belt migrated
progressively towards the southeast. The emplacement of the western front is attributable to the Middle-Upper Miocene
while that of the eastern front is Plio-Pleistocene. Within this tectonic framework, two tectonic basins were identified on
the basis of the different trend, age and evolution. The Adventure foredeep exhibits the maximum thickness of 500 m in
correspondence of the Adventure Plateau. Here, the younger Gela foredeep displays minor depth showing a thickness
increase towards the Gela Nappe and the Pantelleria graben.
Positive inversion structures form by the Plio-Pleistocene compressional reactivation of preexisting structures
limiting the Saccense and Trapanese domains were recognized the offshore sector between Mazara and Sciacca.
Moreover, a correlation between the Campobello di Mazara-Castelvetrano alignment as proposed by Barreca et al.,
2013, Ferranti et al., this meeting, and the tectonic units recognized in their offshore prolongation has been recognized.
Therefore, we propose that in this area contractional tectonics is still active (see also Pepe et al., this meeting), and
occurs on high-angle, NW-dipping crustal ramps (Monaco et al., 1996)
Parameterized thermal macromodeling for fast and effective design of electronic components and systems
We present a parameterized macromodeling approach to perform fast and effective dynamic thermal simulations of electronic components and systems where key design parameters vary. A decomposition of the frequency-domain data samples of the thermal impedance matrix is proposed to improve the accuracy of the model and reduce the number of the computationally costly thermal simulations needed to build the macromodel. The methodology is successfully applied to analyze the impact of layout variations on the dynamic thermal behavior of a state-of-the-art 8-finger AlGaN/GaN HEMT grown on a SiC substrate
Architecture and Pliocene to Recent evolution of the offshore prolongation of the Granitola - Castelvetrano Thrust System (Sicily Channel)
High-resolution, seismic profiles were recorded in the offshore of Mazara - Punta Granitola with the purpose of
reconstructing the architecture and Pliocene to Recent evolution of the south-west prolongation of the Granitola-
Castelvetrano Thrust System, identified as an active structure possibly related to destructive historical earthquakes
(Barreca et al., 2014; Ferranti et al., this meeting).
A number of seismic units were identified. The oldest one is interpreted as representative of the Lower Pliocene
pelagic deposits known in the region as Trubi. Lower-middle Pleistocene calcarenites are widespread along the
continental shelf (CS) between Mazara del Vallo while their top rapidly deepens moving southeast-ward Capo
Granitola. In this area, lower-middle Pleistocene calcarenites are unconformably overlain by the late Pleistocene-
Holocene deposits. These latter are thin or absent NW of Punta Granitola along the CS, at water depth less than ~30 m,
suggesting that this sector experienced uplift during the Quaternary.
Small scale, NW- and SE-displacing reverse faults are observed along the CS where they cut the lower-middle
Pleistocene calcarenites and offset the seafloor. South-eastwards, south-east-verging, reverse faults affect lower-middle
Pleistocene calcarenites as well as the late Pleistocene-Holocene layers, suggesting that fault displacement acted during
the post-LGM.
Growth folding of Upper Pleistocene-Holocene deposits and thrust faults, predominantly dipping to the NW,
affecting Pliocene rocks are observed in the immediate offshore Capo Granitola.
The integration of the new data with those obtained from multi-channel profiles suggests that the active folds and
thrusts are the uppermost expression of steep crustal ramps (Monaco et al., 1996; Lavecchia et al., 2007; Meccariello et
al., this meeting) which upthrust the Saccense platform at depth
Fast identification of Wiener-Hammerstein systems using discrete optimisation
A fast identification algorithm for Wiener-Hammerstein systems is proposed. The computational cost of separating the front and the back linear time-invariant (LTI) block dynamics is significantly improved by using discrete optimisation. The discrete optimisation is implemented as a genetic algorithm. Numerical results confirm the efficiency and accuracy of the proposed approach
Comment on "Was the 2003 European summer heat wave unusual in a global context?" by Thomas N. Chase et al
- …