siting assessment for kinetic energy turbines an emplacement study for sea and river applications

Abstract The siting and design of a Tidal Energy Converter (TEC) require the characterization of the flow velocity field acting in terms of space and time, in order to assess the hydrodynamic forces, to calculate the structural loading and power capacity, also helping investment strategy and project financing. In this framework, the selection of the emplacement site is of paramount importance for optimizing efficiency of TEC. In this study, we propose site assessment procedures for emplacement of TEC machines, comparing a sea tidal site with two rivers ones. Sites differ each other from geomorphological characteristics. The Cook Inlet (South-Central Alaska) is a large subarctic estuary, which extends about 250 km from Anchorage bay to the Pacific Ocean. Tidally dominated currents control the hydrographic regime, with water levels and currents periodically influenced by tides from the Gulf of Alaska, which are significantly amplified as approaching Anchorage bay. The Chang Jiāng river (also named Yangtze, China) is the longest in Asia and the third in the world, with a huge flow rate. The Pearl River Estuary (China) has a length of about 70 km, a width of about 15 km and an average depth of about 4.8 m. It is deeper than 20 m in its eastern part, and discharges into a microtidal environment along the northern shelf of the South China Sea. The TEC performances have been compared in the three different geomorphological environments. Results show how TEC in rivers can perform up to 5.47 kW/m2, a huge value compared to the wide sea turbines, able to perform up to 10.76 kW/m2

Siting assessment for Kinetic Energy Turbines: an emplacement study for sea and river applications

Abstract The siting and design of a Tidal Energy Converter (TEC) require the characterization of the flow velocity field acting in terms of space and time, in order to assess the hydrodynamic forces, to calculate the structural loading and power capacity, also helping investment strategy and project financing. In this framework, the selection of the emplacement site is of paramount importance for optimizing efficiency of TEC. In this study, we propose site assessment procedures for emplacement of TEC machines, comparing a sea tidal site with two rivers ones. Sites differ each other from geomorphological characteristics. The Cook Inlet (South-Central Alaska) is a large subarctic estuary, which extends about 250 km from Anchorage bay to the Pacific Ocean. Tidally dominated currents control the hydrographic regime, with water levels and currents periodically influenced by tides from the Gulf of Alaska, which are significantly amplified as approaching Anchorage bay. The Chang Jiāng river (also named Yangtze, China) is the longest in Asia and the third in the world, with a huge flow rate. The Pearl River Estuary (China) has a length of about 70 km, a width of about 15 km and an average depth of about 4.8 m. It is deeper than 20 m in its eastern part, and discharges into a microtidal environment along the northern shelf of the South China Sea. The TEC performances have been compared in the three different geomorphological environments. Results show how TEC in rivers can perform up to 5.47 kW/m2, a huge value compared to the wide sea turbines, able to perform up to 10.76 kW/m2

Analysing stress field conditions of the Colima Volcanic Complex (Mexico) by integrating finite-element modelling (FEM) simulations and geological data

In recent decades, finite-element modelling (FEM) has become a very popular tool in volcanological studies and has even been used to describe complex system geometries by accounting for multiple reservoirs, topography, and heterogeneous distribution of host rock mechanical properties. In spite of this, the influence of geological information on numerical simulations is still poorly considered. In this work, 2D FEM of the Colima Volcanic Complex (Mexico) is provided by using the Linear Static Analysis (LISA) software in order to investigate the stress field conditions with increasingly detailed geological data. By integrating the published geophysical, volcanological, and petrological data, we modelled the stress field considering either one or two magma chambers connected to the surface via dykes or isolated (not connected) in the elastic host rocks (considered homogeneous and non-homogeneous). We also introduced tectonic disturbance, considering the effects of direct faults bordering the Colima Rift and imposing an extensional far-field stress of 5 MPa. We ran the model using the gravity in calculations. Our results suggest that an appropriate set of geological data is of pivotal importance for obtaining reliable numerical outputs, which can be considered a proxy for natural systems. Beside and beyond the importance of geological data in FEM simulations, the model runs using the complex feeding sys- tem geometry and tectonics show how the present-day Colima volcanic system can be considered in equilibrium from a stress state point of view, in agreement with the long-lasting open conduit dynamics that have lasted since 1913

Pancreaticoduodenectomy for malignancies in children

Malignant tumors of the common bile duct or of the pancreas head are uncommon in childhood [Perez EA, Gutierrez JC, Koniaris LG, Neville HL, Thompson WR, Sola JE. Malignant pancreatic tumors: incidence and outcome in 58 pediatric patients. J Pediatr Surg. 2009; Jan; 44 (1): 197-203]. With radical surgery being the standard cure for nonmetastatic diseases, pancreaticoduodenectomy (PD) is the best choice when the tumor is localized in the head of the pancreas, or in the lower portion of the common bile duct. The purpose of the present study is to describe five consecutive children managed by PD, and reviewing the particular aspects and results of this rare procedure in children

Meso-Rex Bypass as alternative technique for portal vein reconstruction at- or after- liver transplantation in children: review and perspectives.

Direct portal revascularization can be achieved by interposing a vascular graft between the SMV and the Rex recessus (left portal vein system): the MRB. To review indications and results of the procedure in the setting of pediatric liver transplantation, reports were selected from the English literature. Previously reported series were updated to analyze long-term outcome. A new series was added and analyzed as a complementary set of cases. A total of 51 cases were analyzed. With a 96% overall patient survival rate and a 100% long-term patency rate when the IJV is used for the bypass, MRB achieves a very successful physiologic cure of chronic portal hypertension and restores the portal flow into and through the liver graft. It also has been used successfully for primary revascularization of liver grafts, as well as for managing early acute portal vein thrombosis episodes. The use of this procedure in conjunction with other strategies and techniques might be of interest for transplant surgeons, particularly those caring for children

Strutture morfologiche e funzionali delle classi vascolari del Bronzo Finale e della prima età del ferro in Italia meridionale

Analisi tipologica e funzionale dei reperti ceramici provenienti da contesti, principalmente funerari, dell'età tardo-protostorica dell'Italia meridionale; proposta di nomenclatura; considerazioni qualitative e morfometrico - quantitative; confronto tra siti e aree