bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stereo-EEG recordings extend known distributions of canonical movement-related oscillations
Authors: Rockhill Alexander P , Mantovani Alessandra , Stedelin Brittany , Nerison Caleb S , Raslan Ahmed M , Swann Nicole C 
Published: December 2022

Abstract

Objective. Previous electrophysiological research has characterized canonical oscillatory patterns associated with movement mostly from recordings of primary sensorimotor cortex. Less work has attempted to decode movement based on electrophysiological recordings from a broader array of brain areas such as those sampled by stereoelectroencephalography (sEEG), especially in humans. We aimed to identify and characterize different movement-related oscillations across a relatively broad sampling of brain areas in humans and if they extended beyond brain areas previously associated with movement. Approach. We used a linear support vector machine to decode time-frequency spectrograms time-locked to movement, and we validated our results with cluster permutation testing and common spatial pattern decoding. Main results. We were able to accurately classify sEEG spectrograms during a keypress movement task versus the inter-trial interval. Specifically, we found these previously-described patterns: beta (13–30 Hz) desynchronization, beta synchronization (rebound), pre-movement alpha (8–15 Hz) modulation, a post-movement broadband gamma (60–90 Hz) increase and an event-related potential. These oscillatory patterns were newly observed in a wide range of brain areas accessible with sEEG that are not accessible with other electrophysiology recording methods. For example, the presence of beta desynchronization in the frontal lobe was more widespread than previously described, extending outside primary and secondary motor cortices. Significance. Our classification revealed prominent time-frequency patterns which were also observed in previous studies that used non-invasive electroencephalography and electrocorticography, but here we identified these patterns in brain regions that had not yet been associated with movement. This provides new evidence for the anatomical extent of the system of putative motor networks that exhibit each of these oscillatory patterns.
Towards a mesoscale physical modeling framework for stereotactic-EEG recordings
Authors: Mercadal Borja , Lopez-Sola Edmundo , Galan-Gadea Adrià , Al Harrach Mariam , Sanchez-Todo Roser , Salvador Ricardo , Bartolomei Fabrice , Wendling Fabrice , Ruffini Giulio 
Published: December 2022

Abstract

Objective. Stereotactic-electroencephalography (SEEG) and scalp EEG recordings can be modeled using mesoscale neural mass population models (NMMs). However, the relationship between those mathematical models and the physics of the measurements is unclear. In addition, it is challenging to represent SEEG data by combining NMMs and volume conductor models due to the intermediate spatial scale represented by these measurements. Approach. We provide a framework combining the multi-compartmental modeling formalism and a detailed geometrical model to simulate the transmembrane currents that appear in layer 3, 5 and 6 pyramidal cells due to a synaptic input. With this approach, it is possible to realistically simulate the current source density (CSD) depth profile inside a cortical patch due to inputs localized into a single cortical layer and the induced voltage measured by two SEEG contacts using a volume conductor model. Based on this approach, we built a framework to connect the activity of a NMM with a volume conductor model and we simulated an example of SEEG signal as a proof of concept. Main results. CSD depends strongly on the distribution of the synaptic inputs onto the different cortical layers and the equivalent current dipole strengths display substantial differences (of up to a factor of four in magnitude in our example). Thus, the inputs coming from different neural populations do not contribute equally to the electrophysiological recordings. A direct consequence of this is that the raw output of NMMs is not a good proxy for electrical recordings. We also show that the simplest CSD model that can accurately reproduce SEEG measurements can be constructed from discrete monopolar sources (one per cortical layer). Significance. Our results highlight the importance of including a physical model in NMMs to represent measurements. We provide a framework connecting microscale neuron models with the neural mass formalism and with physical models of the measurement process that can improve the accuracy of predicted electrophysiological recordings.
Modeling transcranial magnetic stimulation coil with magnetic cores
Authors: Makaroff Sergey N , Nguyen Hieu , Meng Qinglei , Lu Hanbing , Nummenmaa Aapo R , Deng Zhi-De 
Published: December 2022

Abstract

Objective. Accurate modeling of transcranial magnetic stimulation (TMS) coils with the magnetic core is largely an open problem since commercial (quasi) magnetostatic solvers do not output specific field characteristics (e.g. induced electric field) and have difficulties when incorporating realistic head models. Many open-source TMS softwares do not include magnetic cores into consideration. This present study reports an algorithm for modeling TMS coils with a (nonlinear) magnetic core and validates the algorithm through comparison with finite-element method simulations and experiments. Approach. The algorithm uses the boundary element fast multipole method applied to all facets of a tetrahedral core mesh for a single-state solution and the successive substitution method for nonlinear convergence of the subsequent core states. The algorithm also outputs coil inductances, with or without magnetic cores. The coil–core combination is solved only once i.e. before incorporating the head model. The resulting primary TMS electric field is proportional to the total vector potential in the quasistatic approximation; it therefore also employs the precomputed core magnetization. Main results. The solver demonstrates excellent convergence for typical TMS field strengths and for analytical B–H approximations of experimental magnetization curves such as Froelich’s equation or an arctangent equation. Typical execution times are 1–3 min on a common multicore workstation. For a simple test case of a cylindrical core within a one-turn coil, our solver computed the small-signal inductance nearly identical to that from ANSYS Maxwell. For a multiturn rodent TMS coil with a core, the modeled inductance matched the experimental measured value to within 5%. Significance. Incorporating magnetic core in TMS coil design has advantages of field shaping and energy efficiency. Our software package can facilitate model-informed design of more efficiency TMS systems and guide selection of core material. These models can also inform dosing with existing clinical TMS systems that use magnetic cores.
Effect of pre-irradiation defects on helium trapping and diffusion in RAFM steel
Authors: Duan Xiuxuan , Jin Shuoxue , Song Yamin , Wang Yanli , Xiong Yi , Zhang Weiping , Li Shilei , Cao Xingzhong 
Published: December 2022

Abstract
In order to analyze the effect of pre-irradiation defects on helium trapping and diffusion behaviors in detail by slow positron beam, Si ion with high energies (300 keV and 6 MeV) and 100 eV helium plasma were sequentially introduced into reduced activation ferritic/martensitic steel. Massive microscopic defects were observed in Si ion irradiated specimens. Low energy helium (∼100 eV) atoms could diffuse into much deeper region in metals without displacement damage. In the diffusion process of helium atoms, they would be trapped by the Si-ion pre-irradiation defects. The formation of He-vacancy complexes would affect the annihilation of positrons with the electrons in pre-irradiation defects and decrease the S parameters. The shallow region defects induced by 300 keV irradiation have more obvious advantage of hindering the diffusion of helium over the deep defects than that in 6 MeV irradiation. Thus, the pre-introduced defects can trap effectively helium atoms and hinder their diffusion.
Energy Performance of Annual Operation of Heat Pump Coupled with Ground Ice Storage and Photovoltaic/Thermal modules
Authors: Noro Marco , Mancin Simone , Zilio Claudio 
Published: December 2022

Abstract
The use of heat pumps for annual climatization is a suitable mean of achieving the 2030 European decarbonization target (-55% with respect to 1990 CO2 emissions). The use of seasonal energy storages allows to store one of the two contemporaneous effects (thermal and cooling energy) produced by the heat pump to be used successively when it is necessary. This paper focuses on a dynamic simulation to size the heating and cooling plant and define a suitable control logic for a refurbished building located in northern Italy. The plant is set up by an electric heat pump in annual operation, coupled with a ground ice storage. Ice produced during heating operation is used in summer to face cooling loads (free cooling). PhotoVoltaic/Thermal modules allow to increase the grid independency and to reduce primary energy consumption of the plant as they can be suitably cooled in any season, by recovering heat for domestic hot water or the ground. A dynamic simulation of the system allows for a full description of the behaviour of the ice tank during the charging and discharging processes. In addition, a primary energy performance analysis of the whole plant is reported, also in comparison to a dual source heat pump configuration for the same building.
Use of sustainable Phase Change Material (PCM) in mortars for building energy efficiency
Authors: Sarcinella Antonella , de Aguiar Josè Luis Barroso , Frigione Mariaenrica 
Published: December 2022

AbstractAcademic and industrial research are moving towards the development of innovative solutions and materials able to limit energy consumption for the thermoregulation of a building. One solution is the use of phase change materials (PCMs) that can absorb, store, and release energy according to their physical state that changes when the ambient temperatures changes. In this work, new sustainable PCMs were developed through the “form-stable” method according to the principles of Circular Economy. The new PCM materials consisted, in fact, of an inert matrix (obtained as byproduct of stone processing) impregnated by low toxic, low flammable polymer, namely polyethylene glycol (PEG). The PEG/stone composite materials were used to replace the fine aggregates in mortars based on different binders providing the mortars with thermoregulation performance. A comprehensive characterization was performed on the new PCMs by evaluating their thermal stability and thermal efficiency. The main properties (in fresh and hardened states) of the mortars with or without PCMs were analyzed. The mortars containing PCMs were also subjected to further investigations to evaluate their thermal behavior in response to external climatic conditions. Encouraging results were obtained, confirming the effectiveness of the mortars containing the new PCMs in the thermoregulation of indoor environments.
Energy audit of 1900s buildings for sustainable renovation
Authors: Cardinale Nicola , Negro Elisabetta , Selicati Valeria 
Published: December 2022

Abstract
This project focuses on the dynamic modelling of two buildings: a school and a public building, both located in the Basilicata and Puglia regions. In order to define the passive energy requirement of the building and propose some energy efficiency solutions, an energy diagnosis was conducted in dynamic settings on these structures. The EnergyPlus™ calculation code is the method utilized for energy diagnosis in the dynamic regime. The dynamic technique enables simulation of real-world building circumstances and plant design based on real-world requirements and building management.
Both buildings have significant historical significance, therefore improving their energy efficiency must take this into account.
In the design of energy efficiency solutions, the enclosure’s properties are critical. It is the primary source of heat loss and sunlight gain, and it has an impact on indoor comfort.
It is vital to consider often contradicting features of the building’s casing, such as heating, cooling, and natural and artificial lighting, when designing the building’s casing. For example, large levels of natural light must be allowed without excessive solar gains during the summer while still ensuring an acceptable quantity of solar earnings during the winter to reduce heating loads. As a result, the efficient configuration can’t just look at one element at a time; it has to look at all of them at the same time, taking into account all of the interactions between the many sources of energy usage. Thermo-hygrometric comfort is another factor to consider when it comes to protecting the human condition.
The goal of integrated design for a long-term major redevelopment is to establish the best balance between energy efficiency and environmental burdens, not just during the operational period, but throughout the life cycle. During the redesign process, resources such as life cycle analysis (LCA - Life Cycle Assessment) can be used to objectively quantify the possible environmental implications of new materials, systems, and energy flows (from their supply up to future disposal scenarios at the end of life). Furthermore, by comparing several project options, it is possible to identify which, with the same energy efficiency, causes the least environmental damage. Economic and social sustainability analyses can also be combined.
Modern building relief techniques (geometric, material, and thermal) were applied in this study for energy diagnosis and LCA analysis to determine the optimal design options for environmental impacts. The thermal power plants that the solution proposes are completely integrated within the buildings in which they will be put and manage to ensure a perfect mix of energy savings, economic savings, and environmental sustainability.
Effect of nanofluid on a Low-enthalpy geothermal plant
Authors: Buonomo B , Ciccarelli V , Manca O , Nardini S , Plomitallo R E 
Published: December 2022

Abstract
In Italy 40% of total energy consumption is destined for buildings. To reduce energy consumption and consequently achieve a reduction in carbon dioxide emissions, it is necessary to design well and build better. The technologies that make it possible to increase the energy saving of buildings for civil use are linked to three main aspects: envelope, insulation, and air conditioning; high efficiency systems, integrated building-plant design, use of appliances and lighting with low energy consumption, use of energy from renewable sources; building automation. In this work, the energy demand of a building located in Campania is supplied by a low-enthalpy geothermal plant where the working fluid is a nanofluid. Building thermal loads and performance of the geothermal plant are evaluated by means of TRNSYS®. Borehole heat exchangers design is carried out by means of the ASHRAE procedure. The geothermal system is designed considering the geological characteristics of the site, the characteristics of the geothermal plant and energy conversion system. The performance of the system is evaluated for different nanofluid as working fluid, water-Al2O3, water-CuO and water-SiO2, for several nanoparticle concentrations.
Energy Storage System based on Biomimetic Strategies: Concept Design and Performance Assessment in Buildings
Authors: Dodón Alisson , Quintero Vanessa , Austin Miguel Chen 
Published: December 2022

Abstract
Due to the constant growth in energy demand worldwide, renewable systems require more maintenance and electrical energy generation, which also involves an increase in storage capacity. Solar energy is one of the renewable sources with the greatest opportunity to cover this increasing demand as it promises in areas of power generation for residential, commercial, and industrial applications. Currently, there are several conventional electricity energy storage systems whose contributions have been presented at a building scale; batteries being the last the most used in the market for their ability to react instantly to changes in energy demand, but they are not totally eco-friendly. Nowadays, alternatives are being searched to reduce the ecological footprint that continues affecting the environment. To decrease carbon emissions and propose a “green” storage system, this research implements biomimetic strategies following the steps of the problem-based approach with the operating principle of lithium-ion batteries as a basis. As a result, a preliminary design of an equivalent circuit is presented that simulates the behavior of a natural cell based on the energy admission and storage processes of an oriental hornet, as well as the discharge mechanism of an electric eel.
Performance Assessment of Hydraulic Micro Relief Valve
Authors: Chiavola O , Frattini E , Palmieri F 
Published: December 2022

Abstract
Directly operated relief valves often exhibit abnormal or unstable behavior resulting in noise, premature wear, degraded performance, and failure. In this work, an investigation is carried out to assess the role of the hydraulic damper on the poppet element. The article reports the details of the investigation approach, integrating specific experimental tests with lumped-parameter modelling.Starting from a reference layout, the hydraulic behavior of different damper configurations is characterized (ranging from undamped to strongly damped poppets), for pressure and flow-rate conditions typically encountered in micro-hydraulic power packs. Depending on the damper design, the poppet operation ranges from unacceptability (due to noise) to fine-tuned response. The investigation give the chance to highlight how the damper layout impacts on the valve behaviour, in terms of pressure overshoot and settling time and provides the necessary information for relief valve design, modelling and analysis.
Detailed simulations of an aircraft fuel system by means of Simulink
Authors: Sciatti F , Tamburrano P , De Palma P , Distaso E , Amirante R 
Published: December 2022

Abstract
The fuel system is one of the most important and complex parts of aircraft, being tasked with suppling the correct quantity of fuel to the aircraft engine during all operative conditions, from flight to ground operation. It must operate efficiently in any condition to guarantee safety and reliability. A fuel system for kerosene-based fuels (i.e., jet fuels) is a combination of hydraulic components, namely, tanks, pumps, bypass valves, safety valves, servovalves. The aim of this paper is to provide an accurate simulation model of an entire fuel system for gas turbine (turboprop and turbofan) engines, which can be used by manufacturers and researchers to evaluate the performance of the fuel system under different operating conditions for given components or to select the geometries of the components to obtain specific performance levels. The numerical code is developed in the Simulink environment, which is a software package widely used in industry. A detailed description of the model is provided in this paper, and results under specific operating conditions are shown and discussed. The power consumption of the system is assessed as well, with indication of the main sources of losses, which will be useful for current EU projects aimed at reducing the power consumption of aircraft.
A lumped parameter and CFD combined approach for the lubrication analysis of a helical gear transmission
Authors: Muzzioli G , Paini G , Denti F , Paltrinieri F , Montorsi L , Milani M 
Published: December 2022

Abstract
This paper proposes a combined 1D-3D approach for the lubrication analysis of a standard transmission including two helical gears. A lumped parameter model of the entire lubrication system is developed to predict the flow distribution within the circuit and the localized pressure drops along the lines. This model considers the geometrical features of the real system, and it combines the experimental characteristic curves of the main hydraulic components. The steady-state condition is investigated, and the corresponding lubrication flow is provided as a boundary condition for a three-dimensional CFD model. The overset mesh method is employed to address the instantaneous position of the gears in the contact region and the Volume of Fluid (VOF) model assesses the multi-phase phenomenon. The turbulent behavior of the flow is described by the two-equation realizable k-ε model, and the incompressible assumption is made for both oil and air. The effect of different nozzles configurations on the lubrication efficiency is analyzed and the internal system fluid-dynamics is investigated to point out the oil path. The numerical results are discussed in terms of the volume fraction of oil on the gears teeth, the passive torques at the shafts and the associated power losses under specific operating conditions.
Accuracy Assessment of the Eulerian Two-phase Model for the CFD Simulation of Gas Bubbles Dynamics in Alkaline Electrolyzers
Authors: Dreoni M , Balduzzi F , Ferrara G , Bianchini A 
Published: December 2022

Abstract
To date, the most industrially developed technology to produce green hydrogen is represented by alkaline water electrolysis (AWE). To improve on design and efficiency of these devices, however, multiphysics simulations based on Computational Fluid Dynamics (CFD) are needed, able to account for electrophysical phenomena and multiphase flows. Focusing on internal flow optimization, the requirements for CFD simulations are anyhow extremely challenging, since solving the gas bubbles’ motion implies the solution of a two-phase flow characterized by very low Reynolds numbers and a high fraction of dispersed gas. Despite some interesting studies have been presented in the literature so far, validation of CFD results with detailed experimental measurements is quite rare and, therefore, the reliability of the adopted modelling approaches is not assessed yet. This study presents the results of a multivariate CFD analysis of an electrochemical cell and its validation through a literature test case. Bubbles generation is introduced as a source term, thus overlooking for the moment the electrochemistry to focus on fluid-dynamics. In particular, attention is given to the Eulerian multiphase modelling, investigating the influence of both the inter-phase interaction sub-models’ settings (e.g., lift and drag forces, virtual-mass force) and the general settings of the simulation. The mean velocity field of the PIV-measured bubbles is considered to assess the accuracy of numerical predictions, while the available high-definition flow pictures allow a qualitative assessment of the bubbles size and location. CFD results are shown to be in decent agreement with experimental data and able to reproduce the key flow features such as the spreading of the bubble curtains and the gas shifting towards the inner part of the cell. The effect of the bubbles’ diameter and of source layer thickness is also discussed.