Co-seismic and post-seismic changes in groundwater discharge: first results from the epicentral region of the central Italy 2016 earthquake

Earthquakes, groundwater flow, carbonate aquifers

MAN OR NATURE? THE ROLE OF NATURAL EVENTS IN THE ABANDONING OF THE ROMAN TOWN OF CARSULAE (TIBER BASIN ITALY)

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A Multi-Model Approach Using Statistical Index and Information Criteria to Evaluate the Adequacy of the Model Geometry in a Fissured Carbonate Aquifer (Italy)

A conceptual model related to a mountain aquifer that is characterized by a lack of data of hydrogeological parameters and boundary conditions, which were based on a single available observational dataset used for calibration, was studied using numerical models. For the first time, a preliminary spatial-temporal analysis has been applied to the study area in order to evaluate the real extension of the aquifer studied. The analysis was based on four models that were characterized by an increasing degree of complexity using a minimum of two zones and a maximum of five zones, which consequently increased the number of adjustable parameters from a minimum of 10 to a maximum of 22, calibrated using the parameter estimation code PEST. Statistical index and information criteria were calculated for each model, which showed comparable results; the information criteria indicated that the model with the low number of adjustable parameters was the optimal model. A comparison of the simulated and observed spring hydrographs showed a good shape correspondence but a general overestimation of the discharge, which indicated a good fit with the rainfall time series and a probably incorrect extension of the aquifer structure: the recharge contributes more than half of the total outflow at the springs but is not able to completely feed the springs

Identification of the nonlinear behaviour of a cracked RC beam through the statistical analysis of the dynamic response

SUMMARY This study investigates a new identification procedure suitable to deal with nonlinear systems. The proposed approach is made up of three main parts: system excitation with a band-limited white noise, solution of the Fokker–Planck equation that describes the motion of the structure in a parametric form and identification of the unknown system parameters by minimizing a suitable functional. The new procedure is able, for instance, to assess the severity of cracking caused by the shrinkage or by the overcoming of the concrete tensile strength in reinforced concrete (RC) structures. Cracked RC elements, in fact, exhibit a nonlinear behaviour due to different values of the flexural stiffness that depends on the opening of the cracks. Some numerical simulations allowed verifying the applicability of the procedure. Copyright # 2008 John Wiley & Sons, Ltd

Active displacement control of a wind-exposed mast

The present paper describes the use of an active mass damper for the reduction of the wind-induced displacements of a full-scale mast built for the purpose at the University of Perugia (Italy). After a brief description of the mock-up structure and the bench tests carried out to characterize the active control device, the results of the tests and the numerical simulations performed to optimize the control gain parameters are displayed. The comparison between the results of the numerical simulations and those from the experimental tests highlighted the effects of the unavoidable imperfections of the physical system, such as the limitation of the available power, the presence of friction, the limited extension of the moveable masses' strokes and the computation time delays, that reduce the effectiveness of the control system. With the best gain parameters, several full-scale tests have been executed to observe the behaviour of the structure under wind loads. The comparison between the performance of the uncontrolled and the controlled structure clearly showed the effectiveness of the proposed technique for the reduction of both displacements and vibrations. Copyright © 2006 John Wiley & Sons, Ltd

Natural and anthropic changes on landscapes: signs and designs in a river system. The study-case of the Potenza River final sector (Porto Recanati, Italy)

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DSGSDs induced by post glacial decompression in central Apennine (Italy)

During the last 30 years of studies in the field of mass movements located in the calcareous-marly and marly-sandy Apennines (Umbria-Marches and Latium-Abruzzi regions), over to a large number of landslides with different dimensions, even a lot of deep-seated gravitational slope deformations (DSGSDs) have been recognized and analysed. These phenomena are also located in that sector of central Italy affected by a cold climate during the past and actually temperate (central Apennine chain)

Minimally Invasive Video-Assisted Parathyroidectomy: Lesson Learned from 137 cases

Abstract: Background: Since February 1997, a technique of minimally invasive video-assisted parathyroidectomy (MIVAP) was developed at our institution for the treatment of sporadic primary hyperparathyroidism (sPHPT). In this study we analyzed the entire series of patients who underwent MIVAP during the last 3 years. Study Design: One hundred thirty-seven patients with sPHPT were selected for MIVAP. Selection criteria were: diagnosis of single adenoma based on preoperative localization studies (ultrasonography, sestamibi scintigraphy, or both), and no previous neck surgery or concomitant large multinodular goiter. The procedure, already described, is performed by a gasless video-assisted technique through a single 1.5-cm central skin incision above the sternal notch. Quick, intraoperative parathyroid hormone assay was used in 134 cases (97.8%) to confirm the complete removal of all hyperfunctioning parathyroid tissue. Results: Mean operative time was 54.3 +/- 22.6 minutes. The conversion rate was 8.8%. One laryngeal nerve palsy was registered (0.7%), as was one case of persistent hyperparathyroidism. In six patients (4.4%) a transient symptomatic postoperative hypocalcemia was observed. Two thyroid lobectomies were associated using the same minimally invasive access. At a mean followup of 15.4 +/- 10.6 months, all but two patients were normocalcemic. The cosmetic result was considered excellent by most of the patients (92.8%). Conclusions: Although not all patients with sPHPT are eligible for MIVAP, this approach can now be proposed in a bigger proportion (67% of patients). As already demonstrated in a previous study, also in a large series of patients, after greater experience has been achieved, the results and the operative time are the same as in traditional surgery, with better cosmetic result and a less painful course. (J Am Coll Surg 2000; 191:613-618. (C) 2000 by the American College of Surgeons)