Search results for "Heating"
showing 10 items of 248 documents
Determination of a pre-heating sequence for the DONES Target Assembly
2021
Abstract Within the activities promoted by the EUROfusion consortium in support of the design and construction of the DEMO Oriented NEutron Source (DONES), a mock-up of its Target Assembly (TA), based on the configuration with a “bayonet” Back-Plate (BP) and available at ENEA Brasimone labs, is being adopted for the execution of experimental activities aiming at the validation of specific aspects of the target design. Despite the “integral”-TA concept is the current reference, experimental tests concerning the TA pre-heating phase are not significantly affected by the TA concept and are still representative even though conducted on the bayonet-TA concept. Indeed, the main objective of the p…
Multi-Objective Optimization of Urban Microgrid Energy Supply According to Economic and Environmental Criteria
2019
This study is focused on the optimization of the annual cost and greenhouse impact related to the supply of natural gas and electricity of an urban microgrid through the installation of components as renewable energy sources, energy storage units and converters. As input parameters of the optimization model, the energy demand of a medium density urban district was estimated, while average costs and emissions of equipment were collected in market reports and literature. The outputs of the model are the optimal size and the schedule of each component. Moreover, optimization analysis was carried out for two different scenarios, comparing Italian and Vietnamese energy system cost and environmen…
Study of voltage decrease in organic light emitting diodes during the initial stage of lifetime
2016
Abstract We report the results of lifetime DC testing at constant current of not-encapsulated organic light emitting diodes (OLEDs) based on Tris (8 idroxyquinoline) aluminum (Alq3) as emitting material. In particular, a voltage decrease during the initial stage of the lifetime test is observed. The cause of this behavior is also discussed, mainly linked to initial Joule self-heating of the device, rising its temperature above room temperature until thermal equilibrium is reached at steady state.
Crafting messages to fight dishonesty: A field investigation of the effects of social norms and watching eye cues on fare evasion
2021
Abstract The impact of watching eyes cues and descriptive social norm messages on fare evasion was studied in two experiments that were conducted in two railway stations in France. In Study 1, a natural field experiment, passengers were exposed for a two-week period to either a control eye-cues poster or to an experimental eye-cues with a social norm messaging campaign. In Study 2, an artefactual experiment in the field, participants in the experimental train station were asked to participate in a lying task before and after they were exposed to the messaging campaign. The results from both studies suggest that although watching eye cues alone are not effective in a crowded train station, e…
Zastosowanie magazynów ciepła do celów grzewczych i c.w.u
2018
Magazynowanie energii jest kluczowym zagadnieniem dla rozwoju energetyki odnawialnej. W obszarze budownictwa i inżynierii komunalnej, poza innymi formami, zachodzi konieczność magazynowania energii w postaci termicznej, rozumianej jako zwiększenie energii wewnętrznej układu magazynującego lub wykorzystanie przemian fazowych. Technologie wykorzystujące procesy sorpcyjne, lub efekty termiczne reakcji chemicznych są tu raczej mniejsze zastosowanie. Energię termiczną w najmniejszej skali magazynujemy w zasobnikach ciepłej wody użytkowej, w zbiornikach buforowych instalacji grzewczych. Większe instalacje realizowane są dla obiektów użyteczności publicznej, takich jak szpitale, biurowce. Duże mag…
Reheating the Standard Model from a hidden sector
2016
We consider a scenario where the inflaton decays to a hidden sector thermally decoupled from the visible Standard Model sector. A tiny portal coupling between the hidden and the visible sectors later heats the visible sector so that the Standard Model degrees of freedom come to dominate the energy density of the Universe before Big Bang Nucleosynthesis. We find that this scenario is viable, although obtaining the correct dark matter abundance and retaining successful Big Bang Nucleosynthesis is not obvious. We also show that the isocurvature perturbations constituted by a primordial Higgs condensate are not problematic for the viability of the scenario.
Dielectric Characterization of Fruit Nectars at Low RF Frequencies
2015
Dielectric properties of apple, apricot, peach, and pear nectars were studied in the frequency range from 15 kHz to 30 MHz and the temperature range from 25 to 60 degrees C. Both the relative dielectric constants and the dielectric loss factors decreased by increasing frequency and increased linearly with increasing temperature with values in the order 10(4)-10(2) and 10(5)-10(2), respectively. The power dissipation densities and the power penetration depths were found to increase linearly with temperature. Power dissipation densities remained essentially constant for all the samples while power penetration depths decreased significantly on increasing frequency. The dependence of each of th…
Phase Transition in Niobophosphate Glass-Ceramic
2011
Phase transition during crystallization of glass to glass-ceramic in system P2O5-CaO-Nb2O5-Na2O was studied. Several heating rates were compared – 1, 2, 5, 11 and 20°Cmin-1. DTA, XRD, FTIR and Raman analyses were performed. Niobophosphate glass-ceramic is found to form utterly different crystalline phases depending on maximal heating temperature, heating rate and time of maximal temperature maintenance. Crystallization temperatures of the same phases are strongly dependent on heating rate, while crystallinity of obtained phases is not. At lower temperatures poorly crystalline phosphates (Ca3(PO4)2, Ca10Na(PO4)7, Ca2P2O7) and niobates (NaNbO3 and Nb2O5) are identified. At higher temperatures…
Reconnection nanojets in the solar corona
2020
P.A. acknowledges STFC support from grant numbers ST/R004285/2 and ST/T000384/1 and support from the International Space Science Institute, Bern, Switzerland to the International Teams on ‘Implications for coronal heating and magnetic fields from coronal rain observations and modeling’ and ‘Observed Multi-Scale Variability of Coronal Loops as a Probe of Coronal Heating’. This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement no. 647214). P.T. was also supported by contracts 8100002705 and SP02H1701R from Lockheed-Martin to the Smithsonian Astrophysical Observatory (SAO), and NASA c…
On the Coronal Temperature in Solar Microflares
2020
We present a study of solar imaging and spectral observations of a microflare, focusing on the temperature diagnostics provided by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory, and the Extreme-Ultraviolet Imaging Spectrometer (EIS) on board Hinode. Our data analysis, in particular from the emission in the 131 and 94 Å channels, indicates that the heated plasma reaches temperatures of ≿10 MK, at odds with a previous analysis of the same event, and we discuss the reason for the discrepancy. A particularly interesting aspect is the likely presence of the Fe XXIII 263.76 Å line, though weak, in EIS spectra in the early phases of the event, supporting the presen…