Search results for " Thermal"

Novel Wireless Sensor System for Dynamic Characterization of Borehole Heat Exchangers

2011

The design and field test of a novel sensor system based in autonomous wireless sensors to measure the temperature of the heat transfer fluid along a borehole heat exchanger (BHE) is presented. The system, by means of two specials valves, inserts and extracts miniaturized wireless sensors inside the pipes of the borehole, which are carried by the thermal fluid. Each sensor is embedded in a small sphere of just 25 mm diameter and 8 gr weight, containing a transceiver, a microcontroller, a temperature sensor and a power supply. A wireless data processing unit transmits to the sensors the acquisition configuration before the measurements, and also downloads the temperature data measured by the…

The jets and disc of SS 433 at super-Eddington luminosities

2009

We examine the jets and the disc of SS 433 at super-Eddington luminosities with 600 times Eddington critical accretion rate by time-dependent two-dimensional radiation hydrodynamical calculations, assuming alpha-model for the viscosity. One-dimensional supercritical accretion disc models with mass loss or advection are used as the initial configurations of the disc. As a result, from the initial advective disc models with alpha =0.001 and 0.1, we obtain the total luminosities 2.5x10^{40} and 2.0x10^{40} erg/s. The total mass-outflow rates are 4x10^{-5} and 10^{-4} solar-mass/yr and the rates of the relativistic axial outflows in a small half opening angle of 1 degree are about 10^{-6} solar…

THE EFFECT OF GADOLINIUM ON THE ESR RESPONSE OF ALANINE AND AMMONIUM TARTRATE EXPOSED TO THERMAL NEUTRONS

2008

Many efforts have been made to develop neutron capture therapy (NCT) for cancer treatment. Among the challenges in using NCT is the characterization of the features of the mixed radiation field and of its components. In this study, we examined the enhancement of the ESR response of pellets of alanine and ammonium tartrate with gadolinium oxide exposed to a thermal neutron beam. In particular, the ESR response of these dosimeters as a function of the gadolinium content inside the dosimeter was analyzed. We found that the addition of gadolinium improves the sensitivity of both alanine and ammonium tartrate. However, the use of gadolinium involves a reduces in or abolishes tissue equivalence b…

The role of transportation and its involved sources of energy in the environmental assessment of marble producing sites

2018

Marble is acquiring large popularity as building material. Since building materials are now required to be characterized by high energy and environmental performances, marble is entailed to fulfill top-level requirements. About its environmental performances an important European Decision establishes criteria for the award of the Community eco-label to this material. Unfortunately, this Decision is focused on mining and processing activities, seemingly neglecting marble transport. In contrast, this phase affects the whole working chain because it releases (pollutant) emissions and involves the use of primary and, in case, secondary energy sources. Here, the focus is on the role played by tr…

Il miglioramento energetico nel recupero degli edifici storici. Applicazione al patrimonio architettonico palermitano

L'architettura storica può assumere un ruolo rilevante nel raggiungimento degli obiettivi europei di efficienza energetica per il settore edile, obiettivi che, tuttavia, devono essere compatibili con la conservazione del patrimonio storico e del suo valore culturale. A tal fine è necessario far riferimento ai caratteri specifici dell'architettura storica e alla sua dimensione locale. La presente tesi, sulla base di tale assunto, esamina le prestazioni energetiche degli edifici storici e il loro potenziale miglioramento, concentrandosi sul patrimonio architettonico di Palermo, caso di studio significativo per l'area mediterranea. La ricerca, condotta con riferimento sia alla scala urbana sia…

Local structure of perovskites ReO3and ScF3with negative thermal expansion: interpretation beyond the quasiharmonic approximation

2016

We propose an approach beyond the quasiharmonic approximation for interpretation of EXAFS and XRD data and for ab initio calculations of electronic and vibration properties of materials with negative thermal expansion. Ab initio electronic structure and lattice dynamics calculations for cubic and distorted ScF3 were performed using the linear combination of atomic orbitals (LCAO) method. The band gap obtained in calculations for ScF3 is equal to 10.54 eV and agree well with the expected value. The calculated infrared spectra of F displaced (FD) cubic ScF3 allow us to predict that its mean Sc-F-Sc angle within NTE deviates from 180 degree.

Effect of electrolytical hydrogenation on the thermal stability and crystallization kinetics of METGLASS MBF-50

2007

The effect of electrolytical hydrogenation on both the surface and volume crystallization kinetics and thermal stability of amorphous alloy METGLASS MBF-50 has been investigated. The surface crystallization has been investigated by the exoelectron emission (EEE) technique, whereas the volume crystallization has been followed by differential thermal analysis (DTA). It has been found that both the surface and volume crystallization of investigated material occur in two stages. The surface crystallization occurs at temperature lower and with activation energy distinctly smaller than the volume crystallization. Hydrogenation of the investigated metallic glass enhances its thermal stability by i…

Effect of electrolytical hydrogenation on the thermal stability and crystallization kinetics of metallic glass Fe79Si9B12

2011

The effect of electrolytical hydrogenation on both the surface and volume crystallization kinetics and thermal stability of amorphous alloy Fe79Si9B12 has been investigated. The parameters of the surface and volume crystallization (temperature, activation energy) have been determined applying the exoelectron emission (EEE) and differential thermal analysis (DTA) methods, respectively. It has been found that the surface crystallization of investigated material occurs at temperature much lower and with activation energy smaller than the volume crystallization. The determination of the activation energies for the volume and surface crystallization by the combination of DTA and EEE techniques e…

Effect of the milling conditions on the degree of amorphization of selenium by milling in a planetary ball mill

2007

The effect of the milling parameters (rotation speed of the milling device and duration of milling) on the phase composition of the products of milling of fully crystalline selenium has been investigated. The milling was conducted using a planetary micromill and the phase composition of the milling products was determined by differential thermal analysis. It has been found that ball milling leads to the partial amorphization of the starting crystalline material. The content of amorphous phase in the milling products depends, in a rather complicated way, on the milling parameters. At the milling parameters adopted in the present study, the milling product was never fully amorphous. The compl…

Parametric thermal analysis for the optimization of Double Walled Tubes layout in the Water Cooled Lithium Lead inboard blanket of DEMO fusion reactor

2019

Abstract Within the roadmap that will lead to the nuclear fusion exploitation for electric energy generation, the construction of a DEMOnstration (DEMO) reactor is, probably, the most important milestone to be reached since it will demonstrate the technological feasibility and economic competitiveness of an industrial-scale nuclear fusion reactor. In order to reach this goal, several European universities and research centres have joined their efforts in the EUROfusion action, funded by HORIZON 2020 UE programme. Within the framework of EUROfusion research activities, ENEA and University of Palermo are involved in the design of the Water-Cooled Lithium Lead Breeding Blanket (WCLL BB), that …