bluuebunny/crossref_metadata_2025_split huggingface dataset:
A statistical analysis of exhaled respiratory droplet trajectory distribution in view of assessing the risk of infectious disease transmission
Authors: Cavazzuti M , Campanelli L , Tartarini P 
Published: December 2023

Abstract
In the present work an analytical model of exhaled droplet trajectory and evaporation is employed to perform a preliminary statistical analysis of the droplet spatial distribution. The analysis is carried out for a set of over twenty thousand droplets distributed in the range of diameters from 0.1 μm to 1 mm. The type of respiratory events modelled are mouth breathing and speaking. The analytical model employed has been recently developed by the authors. It implements the fundamental laws of fluid dynamics and convection-diffusion, and features a 2D empirical numerical model of buoyant intermittent jet modelling the exhaled breath cloud. A discrete random walk turbulent dispersion model is also included allowing statistical analysis of the droplet trajectory to be performed. With proper boundary conditions any type of respiratory event can be simulated making the model particularly versatile. From the analysis, spatial virus concentration maps are derived for the largest droplets falling to the ground, and for the smaller droplets remaining airborne in the area in front of an infected emitter and successively uniformly dispersed in the ambient. This allows to estimate the risk of infection by fomite, direct inhalation and indirect inhalation routes, and provide a better understanding of infectious disease transmission risks.
Building a Renewable Energy Community for the Tor Sapienza district in Rome
Authors: Romano G , Margani P , Mancini F , Battisti A 
Published: December 2023

Abstract
The transition away from fossil fuels towards a carbon-neutral, clean and circular economy is one of the greatest challenges of our time. Energy communities are one of the tools to re-structure our energy systems by harnessing the energy and allowing citizens to participate actively in the energy transition and thereby enjoy greater benefits.
The definition of Renewable Energy Communities (RECs) given by the European Commission, places the REC as an association that produces and shares renewable energy, generating and managing cost-effective green energy autonomously, reducing CO2 emissions and energy waste. Observing this definition, the new Italian regulations concerning RECs boost distributed generation, encouraging the development of ‘zero-mile’ local energy production and smart grids. This research aims to evaluate the conditions to propose a REC in the Tor Sapienza district, as an Italian prototype, assessing the possibilities and advantages of transforming it into a large-scale sustainable infrastructure by means of a deep energy transition and the active role of local citizens, public administrations and small and medium-sized enterprises. Thanks to an in-depth technological, environmental and demographic survey of the neighbourhood, the study focuses on the retrofitting of a social housing complex in Tor Sapienza, as the main prosumer of the REC.
Analysis of the electrical and thermal behaviour of Li-ion batteries using 0D and 3D-CFD approaches with validation on experimental data
Authors: Reina L , Grigore C , Cicalese G , Fontanesi S 
Published: December 2023

Abstract
Due to their characteristics, lithium-ion cells are the reference in the construction of a battery pack for electric vehicles (EVs). Despite this, their use is strongly affected by the operating temperature because the materials they are made of are thermally stable only in a relatively limited range around ambient temperature. Cell modelling and simulation become therefore essential in the design of the cell, of the battery pack and of its auxiliary systems to optimize performance while maintaining sufficient safety margins.
In the present study, two zero-dimensional equivalent circuit models of a commercial Li-ion cell are developed and tuned in order to predict the electrical and thermal behaviour of the cell. The models are validated and compared with experimental data found in the scientific literature referring to both dynamic and static tests. This comparison shows the importance of tuning the model parameters, which are decisive for the accuracy of the simulation.
Using a commercial tool dedicated to battery modelling, a three-dimensional model is then developed to investigate the electrical and thermal behaviour of the cell from a spatial point of view. The results obtained are aligned with those found in the scientific literature.
With the present work, it has been possible to simulate and analyse the global behaviour of the cell (0D model) as well as its detailed behaviour (3D model) using relatively modest computational resources, thus constituting a solid base for more complex modelling such as that of a battery pack and its cooling system.
Tribological investigation of friction coefficient in pneumatic seals with a special pin-on-disc setup
Authors: Mazza Luigi , Trivella Andrea , Goti Edoardo 
Published: December 2023

Abstract
This article presents an experimental method for measuring friction in seals for pneumatic actuators using a pin-on-disk tribometer in a linear reciprocating sliding motion. A special device was designed to test a segment of seal cut out of a seal ring to replicate the working conditions of the piston seals. Friction tests were carried out with spring-energised seals made of graphite-filled PTFE. The counterpart for the friction test was a portion of an actual cylinder barrel of a pneumatic actuator. The coefficient of friction was measured under different loads to replicate several mounting preloads. Moreover, the experimental results were compared to the friction coefficient measured with a flat pin of the same seal material against a flat counterpart. The comparison between the two test setups allowed the authors to study the effect of the contact geometry and the applied load on the tribological performance of the seal. These preliminary measurements of stiffness and coefficient of friction are the basis for further investigations and measurements of elastic, viscoelastic and friction properties at the lip-barrel contact to develop a wear-damage model of lip seals.
Techno-economic analysis of hydrogen production via photovoltaic, battery and electrolysis: plant sizing and hydrogen cost.
Authors: Tamburrano G. , Zotto L. Del , Zuccari F. , Caponi R. , Santiangeli A. , Di Matteo U , Orecchini F. , Bocci E. 
Published: December 2023

Abstract
Photovoltaic reached more than 20% panel efficiency and less than 20% system efficiency losses and 1 M€/MW cost. Similar cost is reached by electrolyzer meanwhile the efficiency can be more than 60% from 3% to 110% of the nominal power. Battery cost reached less than 0.5 M€/MWh meanwhile efficiency is higher and lifetime has reached more than 20.000 cycle if uses are within 20-80% of the state of charge. With these values the battery can be downsized (owing to the large % of electrolyzer nominal power) but still hydrogen production cost from photovoltaic is not competitive. These paper analyses what can be the better size among photovoltaic, battery and electrolyzer in order to reach the lowest hydrogen production cost with a sensitivity analysis on representative parameters (efficiencies, CAPEX and OPEX) for these technologies.
Non linear model predictive control strategy for the energy management of a P4 parallel hybrid electric vehicle
Authors: Teodosio Luigi , Bellis Vincenzo De , Landolfi Enrico , Marino Matteo , Giordano Giuseppe , Malfi Enrica , Piras Marco 
Published: December 2023

Abstract
In this paper, the energy management strategies (EMS) as main fuel saving approaches are studied for a P4 parallel hybrid electric vehicle (HEV). The multiple power sources of the analysed HEV (one thermal engine and two electric motors) and the different vehicle driving conditions increase the complexity in designing an optimal EMS. To efficiently solve the fuel minimization problem, a non linear Model Predictive Control (NL-MPC) is proposed as energy optimization strategy of the examined HEV. First, a vehicle simulation model is developed in Matlab/Simulink environment. A NL-MPC-controller is designed, implemented into the adopted code and coupled to the vehicle model. The effectiveness of developed NL-MPC approach is evaluated in two different driving cycles, also including various initial battery State of Charge. A comparison with a well-recognized real-time EMS strategy, namely heuristic/rule based (RB) approach, is performed over WLTC and a Real Driving Cycle (RDC). The numerical outcomes demonstrate the capability of NL-MPC controller at significantly improving the fuel consumption with respect to the RB strategy (maximum advantage of 9% and 15% over WLTC and RDC), thus providing an excellent and robust method in the HEV powertrain control with satisfactory performance.
Turbocompound energy recovery option on a turbocharged diesel engine
Authors: Battista Davide Di , Bartolomeo Marco Di , Prospero Federico Di , Diomede Domenico Di , Carapellucci Roberto , Cipollone Roberto 
Published: December 2023

Abstract
The transportation sector is living a transition era in which hybrid and electrified vehicles are replacing conventional vehicles, based on internal combustion engines. This is pushed by the recognized need for reducing fuel consumption and tailpipe emissions, considering primary pollutants and carbon dioxide as a greenhouse gas. In the transition path, hybridization and partial electrification of the powertrain play a crucial role. In this regard, the need for on-board electrical energy storage and utilization is increasing significantly and the possibility to recover wasted energy and convert it into electrical form is mandatory. This is especially true for commercial and heavy-duty vehicles, where full electrification is more difficult to be implemented. Waste Heat Recovery (WHR) has therefore become so important for vehicles, not only to directly reduce fuel consumption and related emissions but also to improve the feasibility of a generation of vehicles with a higher degree of hybridization that considers, for example, the electrification of auxiliaries following the so-called auxiliaries-on-demand management. Wasted heat refers mainly to exhaust heat from gases, where about one third of the fuel energy is disposed of. Among the various systems for WHR, engine turbo-compounding is approaching a mature technology. This technological option makes use of an additional turbine on the exhaust line of the engine, downstream of the turbocharging one, which converts the residual gas enthalpy into mechanical form. In this paper, the F1C Iveco 3.0 L turbocharged diesel engine is considered for verifying the performances of a turbo-compounding system. The engine was mounted on a dynamic engine test bench. In particular, the interactions with the original engine produced on the exhaust line were studied. Backpressure effects on the engine introduced by turbo-compounding were evaluated reversed in terms of extra fuel consumption. Moreover, the new equilibrium of the turbocharger was assessed and the related modifications to the engine were measured considering that the turbocharger has a control strategy based on the so-called Variable Geometry Turbine (VGT), via the modification of the Inlet Guide Vanes (IGV). The presence of a secondary turbine for WHR opens to a wider possibility of actuating the IGV and, so, the possibility to optimize the recovery considering the integrated system and all its degrees of freedom.
Hybrid-electric power unit for an ultralight aircraft
Authors: Pisapia A. M. , Volza A. , Savioli T. , Martini P. , Mattarelli E. 
Published: December 2023

Abstract
High power-weight ratio, reliability and efficiency are the main design goals for the propulsion system of ultralight aircraft (mass up to 650 kg). For power outputs beyond 40 kW, 4-stroke multi-cylinder SI engines are the most widespread solution, while pure electric powertrains do not appear at the moment as a practical proposition. Four stroke diesel engines would also be very attractive, in particular for military applications, but their weight is significantly higher than their gasoline powered counterpart. The goal of the study presented in this article is to develop a hybrid-electric power unit for ultralights, running on heavy fuels (diesel, kerosene, jet fuels). Reference is made to Falco EVO, by Leonardo, originally equipped by the Rotax 912 ULS/S engine (peak power 73.5 kW, weight about 60 kg): the proposed power unit has the same cylinders layout, smaller overall dimensions and almost equivalent weight. The thermal engine is an innovative two-stroke unit, coupled in parallel to a permanent magnet electric motor. The design and optimization of the hybrid power unit has been supported by CAE tools, including CAD and CFD simulations.
The results of the study show that the new hybrid system can save about 30% of fuel mass at the typical cruise conditions, and it can increase the peak power output up to 20%, compared to the reference Rotax engine. The reduction of fuel consumption can be translated into an equivalent increment of the operative range of the aircraft, or into an increase of payload (+30%, considering the Falco EVO aircraft). Finally, compared to the Rotax engine, the hybrid power unit exhibits significantly lower CO2 emissions (from -12% to -37%), thanks to the improvement of fuel efficiency.
Evaluation of the efficiency of a hybrid ICE vehicle fuelled with hydrogen compared with a fuel cell vehicle, based on a simulation model
Authors: Aliberti Dario , Ortenzi Fernando , Battaglia Vincenzo La , Marini Stefano , Vellucci Francesco 
Published: December 2023

Abstract
With the renewed interested in the application of hydrogen on transportation, promoted also by the EU policies, the natural technology to adopt such energy vector is the fuel cell. The aim of this paper is to compare the performances, in terms of efficiency, hybrid internal combustion engine vehicles fuelled with hydrogen and fuel cell vehicles. The potential advantages, in using the ICEs, in a parallel hybrid powertrain, even if its efficiency is lower than fuel cell one, are the more efficient transmission efficiency, due to the fact that the engine is directly connected to the wheel through a gearbox, that has traditionally a very high efficiency, while the storage system help the engine when its efficiency is very low, recovering also energy during regenerative brakes. A fuel cell vehicle is generally a series hybrid vehicle, where the fuel cell has a higher efficiency than ICE, but the energy conversion from fuel cell to the electric motor has a lower efficiency. The expected result of this comparison is that the ICE hydrogen fuelled is able to recover the great part of the efficiency Gap with a higher powertrain efficiency. The study has been made using an in-house simulation code written in ENEA, using as input data the characteristic of two different vehicles, with, their electric subsystems (battery storage, electric motors, converters etc) control strategies running fixed driving cycles (e.g. the WLTC driving cycle) and comparing the fuel consumption end the efficiency.
Development of diagnostic instrumentations for fuel cells based on consumer electronics
Authors: Dalberto Thomas , Battistella Francesco , Colbertaldo Paolo 
Published: December 2023

Abstract
The decarbonization process is pushing the energy sector into a transition towards clean energy vectors. In the hard-to-abate sectors, such as heavy-duty transport and industry, hydrogen can act as an energy carrier and a sector coupler. Key devices for hydrogen exploitation are fuel cells. Diagnostic is a crucial element for safety and efficiency during operation. This work regards the development process – from the conception to the validation and use – of an acquisition system made of consumer electronic components. By measuring differential voltage at high frequency, it enables to perform Electrochemical Impedance Spectroscopy (EIS). The system consists of an Arduino board running a self-developed circuit composed of an operational amplifier, an analog-to-digital converter, and a buffer memory. The system is designed to be expanded with multiple synchronized modules to monitor several cells at once. The module can be applied to a single cell or a group of cells (e.g., a stack) by tuning the operational amplifier. A dedicated software has also been developed, involving assembly language to achieve the required speed performance. The circuit has been validated using a function generator to apply sinusoids with frequencies between 100 Hz and 10 kHz and amplitudes of 10-500 mV (reflecting the EIS requirements on a single cell). An oscilloscope is used to double-check the generated signal. The results proved that the system features errors below 3% on amplitude and below 0.3% on frequency. Finally, the developed system has been tested against a commercial device performing EIS measurements. The obtained impedance values generally differ by less than 3% in the range of interest, while a few specific frequencies are affected by external disturbances.
Thermo-economic optimization of a 100 kW air-to-water heat pump for heating purposes in residential units
Authors: Viscardi I , Viscito L , Ferraro L Del , Mauro A W 
Published: December 2023

Abstract
In order to reach the ambitious objectives of carbon neutrality by 2050 and the limitation of the ambient temperature rise at 1.5 °C, several intensive energy fields such as heating and cooling appliances should be decarbonized. On this regard, electric heat pumps represent the most promising solutions to replace old and inefficient conventional boilers and comply with the ecological transition through the increase of electric energy production by means of renewable sources. In this paper, a thermo-economic optimization analysis of a 100 kW air-to-water electric heat pump is proposed. The appliance is designed to produce hot water at 55 °C. The developed model employs phenomenological equations calibrated on real data and manufacturer datasheets for compressor, heat exchangers, and costs. Different design options, including the heat exchangers size and the choice of the working fluid (among R32, propane R290, ammonia R717, R454C), are presented and discussed. The Pareto analysis is then employed to find the best possible configurations in terms of costs and performance.
DOE optimization of a liquid cold plate used in a thermal management system for power converters in the railway sector through 3D CFD analysis
Authors: De Rosa R , Romagnuolo L , Frosina E , Senatore A 
Published: December 2023

Abstract
The thermal management system for power electronics is becoming a key factor in order to guarantee optimal working conditions, efficiency and safety of those components. In the field of liquid-cooled power electronics, the design of an optimal liquid cold plate (LCP) is fundamental to increase the heat transfer, minimizing the maximum temperature and the pressure drop. This work presents an optimization procedure of a finned extruded profile of an LCP for insulated gate bipolar transistor (IGBT) power module, for railway propulsion. The optimization has been performed through DOE, by considering different values of several control factors (shape of the fin, length of the fin, pitch between the channels created by the fins), in order to minimize the LCP maximum temperature and the pressure drop between inlet and outlet. The combination of different values of control factors results in 18 prototypes, which have been compared using three-dimensional CFD simulations, performed in Ansys Fluent environment. The influence of parameters variation on the objective functions (i.e. maximum temperature of the liquid cold plate and pressure drop) has been verified.
Assessment of the derating methods for centrifugal pump performance handling non-Newtonian fluids
Authors: Zanini Nicola , Suman Alessio , Piovan Mattia , Pinelli Michele 
Published: December 2023

Abstract
Oil and Gas applications commonly require the displacement of a huge amount of processing fluids. In most cases, these fluids consist of solid rock particles transported by water, e.g. kaolin or bentonite powder, which show non-Newtonian behavior. For this kind of fluid positive displacement pumps are usually recommended, but where high flow rates have to be guaranteed, centrifugal pumps are installed. Since most of the manufacturers provided the performance curves only with water, choosing the appropriate centrifugal pump to handle mineral slurries may be very challenging. Since the viscosity of this kind of fluids varies with the imposed stress and rheology, pumping this type of fluids can lead to a considerable variation in the pump head, and thus, overall efficiency is difficult to-be-predicted. Several reliable methods to predict the centrifugal pump performance in handling high-viscous Newtonian fluids can be found in literature, e.g. the well-known Hydraulic Institute method. Nevertheless, no general practical correlations are provided for non-Newtonian fluids. Previous experimental investigations on centrifugal pumps reported high-performance instabilities at low flow rates when non-Newtonian fluids are considered. Further investigations are needed to define which parameters in the pump fluid interaction have to be considered in the derating process. In this work, an assessment of the prediction quality of the existing derating methods from the literature is carried out. For this purpose, the data obtained from previous experimental investigations on a small commercial centrifugal pump handling mixtures of water and kaolin are considered.
Discussion on the Application of Integrated Aerogeophysical Method in Urban Site Selection and Construction
Authors: Wang Peijian , Zhang Wei , Li Jiangkun , JunfengLiu  , Deng Zhiqiang , Wang Yuanzhi 
Published: December 2023

Abstract
As the construction of "Belt and Road Initiative" continues to advance, cities and large-scale infrastructure construction will be ushered in along the route, and there is an urgent need to quickly identify the geological situation of the engineering survey needs. Aerial physical prospecting has the characteristics of high efficiency and low cost, which can quickly identify the regional geology in a large area and provide geophysical basis for urban site selection and construction decisions, and has great potential in China’s "Belt and Road Initiative" construction.
Electrical Resistivity Tomography for Urban Underground Space by COMSOL Multiphysics
Authors: Xie Jing , Cui Yi-An , Luo Yijian , Zhang Lijuan , Chen Hang 
Published: December 2023

Abstract
The development and utilization of urban underground space are of great significance to urban sustainable development. Geophysical methods have the characteristics of non-destructive detection, and electrical resistivity tomography has an obvious response to underground resistivity structure and can be used in urban underground space exploration. In this paper, COMSOL Multiphysics is used to realize the finite-element simulation of geoelectric models, and electrical resistivity tomography is used to explore resistivity anomalies of karst and fault models in urban underground environments. The results show that electrical resistivity tomography can identify karst and fault distribution effectively, and COMSOL Multiphysics promises to be a powerful tool for exploring urban underground space.