qualitative thermal characterization and cooling of lithium batteries for electric vehicles

The paper deals with the cooling of batteries. The first step was the thermal characterization of a single cell of the module, which consists in the detection of the thermal field by means of thermographic tests during electric charging and discharging. The purpose was to identify possible critical hot points and to evaluate the cooling demand during the normal operation of an electric car. After that, a study on the optimal configuration to obtain the flattening of the temperature profile and to avoid hot points was executed. An experimental plant for cooling capacity evaluation of the batteries, using air as cooling fluid, was realized in our laboratory in ENEA Casaccia. The plant is designed to allow testing at different flow rate and temperatures of the cooling air, useful for the assessment of operative thermal limits in different working conditions. Another experimental facility was built to evaluate the thermal behaviour changes with water as cooling fluid. Experimental tests were carried out on the LiFePO4 batteries, under different electric working conditions using the two loops. In the future, different type of batteries will be tested and the influence of various parameters on the heat transfer will be assessed for possible optimal operative solutions

An experimental and numerical investigation of the use of liquid flow in serpentine microchannels for microelectronics cooling

This paper presents a combined experimental and numerical investigation of single-phase water flow and heat transfer in serpentine rectangular microchannels embedded in a heated copper block. The performance of four different microchannel heat sink (MCHS) configurations are investigated experimentally, the first having an array of straight rectangular microchannels (SRMs), while the other have single (SPSMs), double (DPSMs) and triple path multi-serpentine rectangular microchannels (TPSMs). Three-dimensional conjugate heat transfer models are developed for both laminar and turbulent single-phase water flows in each of these MCHSs and the governing flow and energy equations solved numerically using finite elements. The numerical predictions of pressure drop (∆P) and average Nusselt number (〖Nu〗_avg) are in good agreement with experimental data, and indicated that the single path serpentine microchannel (SPSM) leads to a 35% enhancement of the 〖Nu〗_avg at a volumetric flow rate of 0.5 l/min and a 19% reduction in total thermal resistance (R_th) compared to the conventional SRM heat sink. However, this enhancement is at the expense of a large (up to ten-fold) increase in ∆P compared to the SRM heat sink, so that a suitable compromise must be struck between heat transfer and pressure drop in practical MCHS designs

Status of Muon Collider Research and Development and Future Plans

The status of the research on muon colliders is discussed and plans are outlined for future theoretical and experimental studies. Besides continued work on the parameters of a 3-4 and 0.5 TeV center-of-mass (CoM) energy collider, many studies are now concentrating on a machine near 0.1 TeV (CoM) that could be a factory for the s-channel production of Higgs particles. We discuss the research on the various components in such muon colliders, starting from the proton accelerator needed to generate pions from a heavy-Z target and proceeding through the phase rotation and decay ($\pi \to \mu \nu_{\mu}$) channel, muon cooling, acceleration, storage in a collider ring and the collider detector. We also present theoretical and experimental R & D plans for the next several years that should lead to a better understanding of the design and feasibility issues for all of the components. This report is an update of the progress on the R & D since the Feasibility Study of Muon Colliders presented at the Snowmass'96 Workshop [R. B. Palmer, A. Sessler and A. Tollestrup, Proceedings of the 1996 DPF/DPB Summer Study on High-Energy Physics (Stanford Linear Accelerator Center, Menlo Park, CA, 1997)].Comment: 95 pages, 75 figures. Submitted to Physical Review Special Topics, Accelerators and Beam

Should I give kids money? The role of pocket money on at-risk behaviors in Italian adolescents

Background. Discussion on the impact of pocket money on positive behaviors is still debated. Objective. To investigate the effect of diverse money allowance schemes on risky behaviors (smoking, alcohol, binge drinking, drug use, gambling) during adolescence. Method. 989 students aged 15 from Lombardy (Italy) reported information on money availability in the 2018 wave of the Health Behaviour in School-aged Children study. To analyze the relationship between money availability and risky behaviors we computed odds ratios and 95% confidence intervals through unconditional multiple logistic regression models. Results. Spending more than 10€ weekly was associated with higher likelihood to smoke, binge drink or gamble. Receiving pocket money (rather than receiving money upon request) was related to higher likelihood to engage in risky behaviors. Conclusions. Pocket money may have a negative impact on adolescents, particularly with a substantial amount of money. More research is needed to understand why providing money only if needed may serve as a protective factor against risky behaviors

A New Chicane Experiment in PEP-II to Test Mitigations of the Electron Cloud Effect for Linear Colliders

Beam instability caused by the electron cloud has been observed in positron and proton storage rings, and it is expected to be a limiting factor in the performance of future colliders [1-3]. The effect is expected to be particularly severe in magnetic field regions. To test possible mitigation methods in magnetic fields, we have installed a new 4-dipole chicane experiment in the PEP-II Low Energy Ring (LER) at SLAC with both bare and TiN-coated aluminum chambers. In particular, we have observed a large variation of the electron flux at the chamber wall as a function of the chicane dipole field. We infer this is a new high order resonance effect where the energy gained by the electrons in the positron beam depends on the phase of the electron cyclotron motion with respect to the bunch crossing, leading to a modulation of the secondary electron production. Presumably the cloud density is modulated as well and this resonance effect could be used to reduce its magnitude in future colliders. We present the experimental results obtained during January 2008 until the April final shut-down of the PEP-II machine

Advances in modelling of biomimetic fluid flow at different scales

The biomimetic flow at different scales has been discussed at length. The need of looking into the biological surfaces and morphologies and both geometrical and physical similarities to imitate the technological products and processes has been emphasized. The complex fluid flow and heat transfer problems, the fluid-interface and the physics involved at multiscale and macro-, meso-, micro- and nano-scales have been discussed. The flow and heat transfer simulation is done by various CFD solvers including Navier-Stokes and energy equations, lattice Boltzmann method and molecular dynamics method. Combined continuum-molecular dynamics method is also reviewed

Immigrant urban hot-spots in Europe: identification, mapping, comparison and visualization

The aim of the research was to identify and qualify immigrant hot-spots in European cities, defined as those neighbourhoods with the highest concentration of foreigners. The analysis covered seven countries - France, Germany, Great Britain, Ireland, Italy, Netherlands, Spain

The Tourism 'Sprawl' and Urban Changes in Rome

Being originally concentrated in the inner-city centre, tourism accommodation services have increasingly expanded in the last decades toward the semi-periphery and periphery of Rome. The tourism ‘sprawl’ is mostly the result of spontaneous decisions by firms and, partially, of deliberate urban planning strategies. Using historical data on the location of tourism attractions, hotels and other accommodation services, the research aims at analysing and interpreting the spatial distribution of tourism within the city of Rome in association with a wider set of urban changes, including suburbanization, the evolution of mobility and gentrification. The aim is to evaluate the main drives of tourism decentralization and its impact on the centre and on the periphery and, finally, on urban tourism as a human experience