18 research outputs found
Energy and thermodynamical study of a small innovative compressed air energy storage system (micro-CAES)
There is a growing interest in the electrical energy storage system, due to the high penetration of the energy produced by renewable sources, the possibility of leveling the absorption peak of the electric network (peak shaving) and the advantage of separating the production phase from the exertion phase (time shift). Compressed air energy storage systems (CAES) are one of the most promising technologies of this field, because they are characterized by a high reliability, low environmental impact and a remarkable energy density. The main disadvantage of big systems is that they depend on geological formations which are necessary to the storage. The micro-CAES system, with a rigid storage vessel, guarantees a high portability of the system and a higher adaptability even with distributed or stand-alone energy productions. This article carries out a thermodynamical and energy analysis of the micro-CAES system, a result of the mathematical model created in a Matlab/Simulink® environment. New ideas will be discussed, as the one concerning the quasi-isothermal compression/expansion, through the exertion of a biphasic mixture, that will increase the total system efficiency and enable a combined production of electric, thermal and refrigeration energies. This is something promising for the development of an experimental devic
Applications of Micro-CAES Systems: Energy and Economic Analysis☆
Abstract The present study concerns the development of a micro-CAES system for thermal and electrical energy storage for residential and non-residential users (shelter/remote users including), in order to reduce energy costs and increase the reliability of energy supply from renewable sources. The micro-CAES system allows you to store the electricity generated from renewable and conventional sources to pressure energy. Further thermal energy can be recovered from conversion process, stored and used for space heating or hot water. The micro-CAES allows you to reduce peak energy demand by utilities (peak shaving), decrease the size of the power generation devices (downsizing), reduce the power of the contract with the grid operator, size the system on the load curve power users in order to increase energy efficiency and economic sustainability reducing management costs with the advantage to reduce operating costs, use of non-toxic materials, zeroing of GHG emissions (zero emission). The innovative technology is based on high-efficiency energy storage process via storage of compressed air at high pressure, quasi-isothermal compression of a mixture air-liquid for heat storage and supply of electrical power constant during the expansion. The air-liquid mixture with excellent ratio between the phases allows you to obtain quasi-isothermal compression, with maximum compression efficiency and high thermal exchange, it enables to have a constant electrical power during the expansion, at a constant pressure during discharge. A dedicated software enables to manage the micro-CAES system to adapt its operation as a function of external conditions and user requirements. An energetic and economic analysis has been performed identifying the optimal size reference. The power supply system provides for the integration of small wind and photovoltaic with a storage system based on micro-CAES. The technological challenge is to be able to ensure a constant power level selected throughout the day
Site response analyses for complex geological and morphological conditions: relevant case-histories from 3rd level seismic microzonation in Central Italy
The paper presents the results of 5 case studies on complex site e ects selected within the project for the level 3 seismic microzonation of several municipalities of Central Italy dam- aged by the 2016 seismic sequence. The case studies are characterized by di erent geo- logical and morphological con gurations: Monte San Martino is located along a hill slope, Montedinove and Arquata del Tronto villages are located at ridge top whereas Capitignano and Norcia lie in correspondence of sediment- lled valleys. Peculiarities of the sites are constituted by the presence of weathered/jointed rock mass, fault zone, shear wave veloc- ity inversion, complex surface and buried morphologies. These factors make the de ni- tion of the subsoil model and the evaluation of the local response particularly complex and di cult to ascertain. For each site, after the discussion of the subsoil model, the results of site response numerical analyses are presented in terms of ampli cation factors and acceleration response spectra in selected points. The physical phenomena governing the site response have also been investigated at each site by comparing 1D and 2D numerical analyses. Implications are deduced for seismic microzonation studies in similar geological and morphological conditions.Published5741–57775T. Sismologia, geofisica e geologia per l'ingegneria sismicaJCR Journa
Minimal Extrathyroidal Extension in Predicting 1-Year Outcomes: A Longitudinal Multicenter Study of Low-to-Intermediate-Risk Papillary Thyroid Carcinoma (ITCO#4)
Background: The role of minimal extrathyroidal extension (mETE) as a risk factor for persistent papillary thyroid carcinoma (PTC) is still debated. The aim of this study was to assess the clinical impact of mETE as a predictor of worse initial treatment response in PTC patients and to verify the impact of radioiodine therapy after surgery in patients with mETE.
Methods: We reviewed all records in the Italian Thyroid Cancer Observatory (ITCO) database and selected 2237 consecutive patients with PTC who satisfied the inclusion criteria (PTC with no lymph node metastases and at least 1 year of follow-up). For each case, we considered initial surgery, histological variant of PTC, tumor diameter, recurrence risk class according to the American Thyroid Association (ATA) risk stratification system, use of radioiodine therapy, and initial therapy response, as suggested by ATA guidelines.
Results: At 1-year follow-up, 1831 patients (81.8%) had an excellent response, 296 (13.2%) had an indeterminate response, 55 (2.5%) had a biochemical incomplete response, and 55 (2.5%) had a structural incomplete response. Statistical analysis suggested that mETE (odds ratio [OR] 1.16, p=0.65), tumor size >2 cm (OR 1.45, p=0.34), aggressive PTC histology (OR 0.55, p=0.15), and age at diagnosis (OR 0.90, p=0.32) were not significant risk factors for a worse initial therapy response. When evaluating the combination of mETE, tumor size, and aggressive PTC histology, the presence of mETE with a >2 cm tumor was significantly associated with a worse outcome (OR 5.27, 95% CI, p=0.014). The role of radioiodine ablation in patients with mETE was also evaluated. When considering radioiodine treatment, propensity score-based matching was performed, and no significant differences were found between treated and non-treated patients (p=0.24).
Conclusions: This study failed to show the prognostic value of mETE in predicting initial therapy response in a large cohort of PTC patients without lymph node metastases. The study suggests that the combination of tumor diameter and mETE can be used as a reliable prognostic factor for persistence and could be easily applied in clinical practice to manage PTC patients with low-to-intermediate risk of recurrent/persistent disease
CMS physics technical design report : Addendum on high density QCD with heavy ions
Peer reviewe
Optimization of Multifunctional UWB Planar Phased Arrays
A planar topology of multifunctional C-X band wide-scan array is analyzed, based on the class of the aperture-coupled stacked patches. Performance is aimed at achieving both wide-band and wide-scan capabilities. The theoretical and the technological aspects that affect correct design and effective realization of the array structure are addressed. In particular, possible improvements of the active reflection coefficient behaviour are analysed by suitably acting on the geometry of the elements
The Aterno valley strong-motion array: Seismic characterization and determination of subsoil model
The paper focuses on the strong motion array deployed in the upper Aterno River Valley, in the immediate outskirts north-west of the town of L'Aquila, which is part of the Italian Strong Motion Network operated by the Department of Civil Protection. The array is composed of six accelerometric stations located along a cross section of the valley. The importance of this array relies on the fact that a large amount of high-quality records were obtained during the 2009 L'Aquila seismic sequence, from both the mainshock and several aftershocks. These data are especially important to investigate site effects in sediment-filled valleys during moderate earthquakes in epicentral area because well-documented observational studies are very limited in the literature. However, the main drawback for the study of site effects in the Aterno valley is the lack of a detailed knowledge of the geometry of the valley, soil layering and dynamic properties of materials. The main motivation for this study stems from the need to provide a reliable subsoil model of the valley coupled with high-quality strong motion data. Based on the above, in the framework of S4 project, a major effort was undertaken to get a trustworthy cross section of the valley by an ad hoc investigation, comprising geological and geotechnical surveys as well as an extensive geophysical campaign, characterized by both active and passive measurements. These results were complemented by additional geological and geotechnical data available in the literature. By merging all the information acquired, a 2D subsoil model of the transversal section of the upper Aterno valley has been produced. The valley is characterised by an asymmetric shape with a shallower rock basement at the western edge of the valley that deepens at the valley centre. Moreover, based on the results of geophysical tests, representative Vs values were assigned to the different lithologic units forming the alluvial deposits filling the valley. Shear wave velocity is a fundamental parameter for ground response studies and it is also effective in classifying the accelerometric station from a seismic point of view. The 2D model may be therefore, considered a benchmark model for future studies of site effects. It will offer the possibility to examine site effects with a complex underlying geology and to validate the results of numerical simulations of site response analyses with the numerous observations from earthquake recordings, both for weak and strong ground motion conditions. © 2011 Springer Science+Business Media B.V