2,074 research outputs found
Geological, hydrogeological and thermal characterization of deep subsoil (Marche Region, Italy) linked to use of low enthalpy geothermal heat pumps
Cap rock efficiency of geothermal systems in fold-and-thrust belts: Evidence from paleo-thermal and structural analyses in Rosario de La Frontera geothermal area (NW Argentina)
Cap rock characterization of geothermal systems is often neglected despite fracturing may reduce its efficiency and favours fluid migration. We investigated the siliciclastic cap rock of Rosario de La Frontera geothermal system (NW Argentina) in order to assess its quality as a function of fracture patterns and related thermal alteration. Paleothermal investigations (XRD on fine-grained fraction of sediments, organic matter optical analysis and fluid inclusions on veins) and 1D thermal modelling allowed us to distinguish the thermal fingerprint associated to sedimentary burial from that related to fluid migration. The geothermal system is hosted in a Neogene N-S anticline dissected by high angle NNW- and ENE-striking faults. Its cap rock can be grouped into two quality categories: âą rocks acting as good insulators, deformed by NNWâSSE and EâW shear fractures, NNE-SSW gypsum- and N-S-striking calcite-filled veins that developed during the initial stage of anticline growth. Maximum paleo-temperatures (< 60 °C) were experienced during deposition to folding phases.âą rocks acting as bad insulators, deformed by NNW-SSE fault planes and NNW- and WNW-striking sets of fractures associated to late transpressive kinematics. Maximum paleo-temperatures higher than about 115 °C are linked to fluid migration from the reservoir to surface (with a reservoir top at maximum depths of 2.5 km) along fault damage zones.This multi-method approach turned out to be particularly useful to trace the main pathways of hot fluids and can be applied in blind geothermal systems where either subsurface data are scarce or surface thermal anomalies are lacking.Fil: Maffucci, R.. Universita Degli Studi Della Tuscia; Italia. Universita Degli Studi Roma Tre; ItaliaFil: Corrado, Sveva. Universita Degli Studi Roma Tre; ItaliaFil: Aldega, L.. Instituto de Investigaciones Universitarias Roma la Sapienza; ItaliaFil: Bigi, S.. Instituto de Investigaciones Universitarias Roma la Sapienza; ItaliaFil: Chiodi, Agostina Laura. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Salta. Instituto de Investigaciones en EnergĂa no Convencional. Universidad Nacional de Salta. Facultad de Ciencias Exactas. Departamento de FĂsica. Instituto de Investigaciones en EnergĂa no Convencional; ArgentinaFil: Di Paolo, L.. Eni E&P Division; ItaliaFil: Giordano, G.. Universita Degli Studi Roma Tre; ItaliaFil: Invernizzi, C.. Universita Degli Di Camerino; Itali
QUANTUM ESTIMATION DISCRIMINATION IN CONTINUOUS VARIABLE AND FERMIONIC SYSTEMS
In this PhD thesis we address the problem of characterizing quantum states and parameters of systems that are of particular interest for quantum technologies. In the first part we consider continuous variable systems and in particular Gaussian states; we address the estimation of quantities characterizing single-mode Gaussian states as the displacement and squeezing parameter and we study the improvement in the parameter estimation by introducing a Kerr nonlinearity. Moreover, we address the discrimination of noisy channels by means of Gaussian states as probe states considering two problems: the detection of a lossy channel against the alternative hypothesis of an ideal lossless channel and the discrimination of two Gaussian noisy channels. In the last part of the thesis, we consider the one dimensional quantum Ising model in a transverse magnetic field. We exploit the recent results about the geometric approach to quantum phase transitions to derive the optimal estimator of the coupling constant of the model at zero and finite temperature in both cases of few spins and in the thermodynamic limit. We also analyze the effects of temperature and the scaling properties of the estimator of the coupling constant. Finally, we consider the discrimination problem for two ground states or two thermal states of the model
The role of hydrogeological conditions and thermophysical properties o the evaluation of geothermal exchange potential
The role of hydrogeological conditions and thermophysical properties on the evaluation of geothermal exchange potential in Central Italy
Testing a Model of Flow and Heat Transfer for U-shaped Geothermal Exchangers
Among renewable resources, geothermal energy is one of the most promising for its independence on
weather conditions. However, design and installation of borehole heat exchangers on low enthalpy regions
must consider numerous influencing factors. Here, we focus on the efficiency improvement in hot water
production and heating and cooling of buildings of a pilot geothermal plant, which was implemented as part
of a hybrid system within the frame of a research project at the University of Camerino (Italy). The aims of
the geothermal plant were to study the subsoil thermal properties and monitoring the parameters of the system
during operation. As an important application for the design and sizing of low enthalpy geothermal systems,
we propose a mathematical model to study the heat transfer between the fluid circulating in the pipes and the
underground, where the mutual influence between the soil and the exchanger is considered. We present results
of these approximated solutions based on experimental measurements acquired in the actual geothermal
exchangers. Laboratory and in situ tests were also carried out to investigate the underground thermal
properties and thermal regime of the heterogeneous soil sedimentary succession
Mucopexy-recto anal lifting: a standardized minimally invasive method of managing symptomatic hemorrhoids, with an innovative suturing technique and the HemorPex System®
BACKGROUND:
Conservative surgery of hemorrhoidal disease is less painful than traditional hemorrhoidectomy, and mucopexy has less risk of serious postoperative complications than stapled hemorrhoidopexy. The aim of this study was to evaluate the safety and effectiveness of a standardized, modified hemorrhoidopexy, named Mucopexy-Recto Anal Lifting (MuRAL) with the HemorPex System (HPS) in patients with symptomatic III and IV degree hemorrhoids.
METHODS:
Patients were enrolled from May 2013 to Dec 2015 and operated on with the MuRAL technique, based on arterial ligation and mucopexy at 6 locations, using a standardized clockwise/anti-clockwise rotation sequence of the HPS anoscope. Follow-up controls were carried out by independent observers, as follows: a digital exploration 3 weeks after the intervention, digital exploration plus proctoscopy at 3 and 12 months and repeated at a 12 months interval. Patients who did not strictly follow the postoperative controls were excluded from the study. Primary outcome measurement was the recurrence rate. Secondary measurements were: operative time, hospital stay, postoperative pain, postoperative symptoms and satisfaction score.
RESULTS:
We operated on 126 patients (72 males, mean age 53.9, range 29-83): 87 (69.6%) with III degree and 39 with IV degree hemorrhoids; 13 patients had a MuRAL as a revisional procedure of a previous operation for hemorrhoids. Mean duration of follow-up was 554 days (range 281-1219). Four patients were excluded from the study. One-year recurrence rate was 4.1%. The mean duration of the intervention was 29.5 minutes (range 23-60) and 92 patients (73%) were discharged during the same day of the operation. Pain VAS Score in the first, second and third postoperative day was 3.9, 2.5, and 1.9, respectively. Twenty-two patients (18%), all submitted to spinal anesthesia, had postoperative acute urinary retention. Fecal urgency, observed in 18.8% of patients at the first control, disappeared within one year after the operation. Mean time to return to normal activity was 8 days (range 5 -10). The patient satisfaction scores at one-year follow up were 31.1% excellent, 57.4% good, 7.4% fairly good and 4.1% poor. In patients with III degree hemorrhoids operative time was significantly shorter, postoperative pain better and transient fecal urgency lower than in IV degree patients. In our experience the standardization of MuRAL operation with HPS, turned out to be a safe and effective minimally invasive approach in managing symptomatic III and IV degree hemorrhoids, avoiding the risk of severe complications, with the possibility to perform a redo-MuRAL in the event of recurrence.
CONCLUSIONS:
In our series up to 88% of the patients reported a good, or excellent one-year satisfaction score. Further comparative randomized studies with longer follow-up period are needed
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