Aims and Background Surgical risk is deemed to be higher in the aged population because there are... more Aims and Background Surgical risk is deemed to be higher in the aged population because there are often comorbidities that may affect the postoperative result. This consideration is important for the treatment decision-making for gastric cancer in the elderly. The aim of this study was to identify factors influencing mortality, morbidity, survival and quality of life after curative surgery for gastric cancer in patients aged 75 years and older, and to plan their appropriate management. Methods and Study Design From January 1993 to December 2004, 135 patients underwent surgery at our department because of gastric cancer. Ninety-four of these patients (69.6%) underwent potentially curative gastrectomy. A cross-sectional study of 23 patients aged 75 years and older and 71 younger patients who underwent curative gastrectomy was carried out: patient characteristics, tumor characteristics, management, morbidity, mortality, survival, and quality of life were evaluated. Results Elderly pati...
European review for medical and pharmacological sciences, 2020
OBJECTIVE SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2)-related pneumonia, referre... more OBJECTIVE SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2)-related pneumonia, referred to as COVID-19 (Coronavirus Disease 19), is a public health emergency as it carries high morbidity, mortality, and has no approved specific pharmacological treatments. In this case series, we aimed to report preliminary data obtained with anti-complement C5 therapy with eculizumab in COVID-19 patients admitted to intensive care unit (ICU) of ASL Napoli 2 Nord. PATIENTS AND METHODS This is a case series of patients with a confirmed diagnosis of SARS-CoV2 infection and severe pneumonia or ARDS who were treated with up to 4 infusions of eculizumab as an off-label agent. Patients were also treated with anticoagulant therapy with Enoxaparin 4000 IU/day via subcutaneous injection, antiviral therapy with Lopinavir 800 mg/day + Ritonavir 200 mg/day, hydroxychloroquine 400 mg/day, ceftriaxone 2 g/day IV, vitamine C 6 g/day for 4 days, and were on Non-Invasive Ventilation (NIV). RESULTS We treat...
In this paper, Multi Layer Perceptron neural networks have been trained to identify the position ... more In this paper, Multi Layer Perceptron neural networks have been trained to identify the position of defects in concrete structures analyzed using an ultrasound technique. A diagnostic model obtained by means of Finite Elements techniques has been used to model the ultrasound transmission through a concrete pillar of specified size affected by defects in different positions. The obtained signals have
2017 IEEE 3rd International Forum on Research and Technologies for Society and Industry (RTSI), 2017
In this paper a procedure for the optimization of the bit loading in a PLC system implementing OF... more In this paper a procedure for the optimization of the bit loading in a PLC system implementing OFDM modulation is presented. The optimization strategy aims to find the best compromise between the conflicting objectives of minimal Signal Power, maximal Bit Rate, and minimal Bit Error Rate. The optimization is performed off line by means of a Multi-Objective approach. A set of Pareto solutions is determined, among which the designer has to take the final choice on the basis of the custom requirements. The approach is used to optimize the communication within a distributed energy storage system, which exploits an available electrical car fleet. The power lines supplying the charging points are used for the communication, while the information concerns, for each car, the identification code, the charge state, the schedule of charging/discharging. A unique OFDM modulation is used to dialogue with the whole cars fleet, so that it has to be optimized taking into account the frequency response of any involved power lines.
2018 IEEE 4th International Forum on Research and Technology for Society and Industry (RTSI), 2018
In this work, a fault detection approach for diagnosis of nonlinear systems is presented. This di... more In this work, a fault detection approach for diagnosis of nonlinear systems is presented. This diagnostic approach is performed resorting to a neural predictor of the output of the system, and by using the error prediction as a feature for the diagnosis. The neural predictor is a locally recurrent neural network, which is dynamically trained by using a gradient-based algorithm, where the gradient of the error function is expressed in closed form. The residuals of the prediction are affected by the deviation of the parameters from their nominal values, so that an early detection of the faults can be performed by observing the dynamic of the residuals. The Willamoski-Rossler reaction is used as case study in order to validate the diagnostic approach.
The magnetorotational instability (MRI) is considered to be one of the most powerful sources of t... more The magnetorotational instability (MRI) is considered to be one of the most powerful sources of turbulence in hydrodynamically stable quasi-Keplerian flows, such as those governing accretion disk flows. Although the linear stability of these flows with applied external magnetic field has been studied for decades, the influence of the instability on the outward angular momentum transport, necessary for the accretion of the disk, is still not well known. In this work we model Keplerian rotation with Taylor-Couette flow and imposed azimuthal magnetic field using both linear and nonlinear approaches. We present scalings of instability with Hartmann and Reynolds numbers via linear analysis and direct numerical simulations (DNS) for the two magnetic Prandtl numbers of 1.4 • 10 −6 and 1. Inside of the instability domains modes with different axial wavenumbers dominate, resulting in sub-domains of instabilities, which appear different for each P m. The DNS show the emergence of 1and 2-frequency spatio-temporally oscillating structures for P m = 1 close the onset of instability, as well as significant enhancement of angular momentum transport for P m = 1 as compared to P m = 1.4 • 10 −6 .
We explore the degradation behaviour under continuous illumination and direct oxygen exposure of ... more We explore the degradation behaviour under continuous illumination and direct oxygen exposure of inverted unencapsulated formamidinium(FA)CsPb(IBr), CHNHPbI, and CHNHPbICl perovskite solar cells. We continuously test the devices in-situ and in-operando with current-voltage sweeps, transient photocurrent, and transient photovoltage measurements, and find that degradation in the CHNHPbICl solar cells due to oxygen exposure occurs over shorter timescales than FACsPb(IBr) mixed-cation devices. We attribute these oxygen-induced losses in the power conversion efficiencies to the formation of electron traps within the perovskite photoactive layer. Our results highlight that the formamidinium-caesium mixed-cation perovskites are much less sensitive to oxygen-induced degradation than the methylammonium-based perovskite cells, and that further improvements in perovskite solar cell stability should focus on the mitigation of trap generation during ageing.
ABSTRACT A numerical experiment of a new MagnetoHydroDynamic (MHD) generator is presented. The pr... more ABSTRACT A numerical experiment of a new MagnetoHydroDynamic (MHD) generator is presented. The proposed device does not need an external magnetic field to work, but it performs the energy conversion by means of the induction principle. This is possible thanks to a pulsed ionization of the fluid current, carried out with an electrode dipped in the fluid current, followed by a charge separation with a stationary electric field. In this work a study has been done to evaluate and improve the performance of the proposed device.
Groundwater is the main source of drinking water and it has a vital importance in developed and d... more Groundwater is the main source of drinking water and it has a vital importance in developed and developing countries. Computational models of groundwater are required to ensure its suitable management. Such models are useful to design remediation strategies in polluted aquifers.
This paper fits in the multi-physics analysis of an innovative conceptual design of Magneto-Hydro... more This paper fits in the multi-physics analysis of an innovative conceptual design of Magneto-Hydrodynamic (MHD) inductive generator, coupled with a Thermo-Acoustic (TA) resonator. The thermo-acoustic effect occurs when an intense gradient of temperature is present along the axial direction of a duct containing a gas. Such effect allows the heat to be statically converted into mechanical energy of vibration. If the gas is ionized and the charges of opposite sign are separated into two clouds, an alternate electric current is associated to the thermo-acoustic vibration. That current, in its turn, can induce an electromotive force into a magnetically coupled coil. In this way, a thermo-electric conversion is performed, without solid moving parts or matter transport. A FEM analysis has been performed to assess the suitability of the complete energy transformation chain. In particular, the possibility that the charge carriers are involved in the vibration motion is investigated. An acoust...
International Journal of Applied Electromagnetics and Mechanics, 2018
The aim of the proposed work is to study the optimal design of an innovative Thermo-Acoustic-Magn... more The aim of the proposed work is to study the optimal design of an innovative Thermo-Acoustic-Magneto-Hydro-Dynamic electric generator, with particular reference to the Magneto-Hydro-Dynamic section. A multi-objective optimization algorithm, which makes use of a Tabu Search meta-heuristic, has been developed to this purpose. Thermo-Acoustic and Magneto-Hydro-Dynamic energy conversion processes give a great advantage by converting energy without solid moving components. This makes the cited technologies very interesting for the low weight, the low maintenance costs, and the high conversion efficiency. The design of the generator has to be optimized by considering conflicting objectives, i.e., maximizing the output power, minimizing the applied electrical voltage, and minimizing mass and size of the device. Therefore, a multiobjective vectorial optimization approach is mandatory. A fully vector scheme has been implemented that takes under control both the Pareto optimality of the solutions, and the uniformity in the Pareto front sampling.
Proceedings of the Third International Conference on Railway Technology: Research, Development and Maintenance
This paper deals with the peak-to-average-power-ratio (PAPR) issue, which typically affects the d... more This paper deals with the peak-to-average-power-ratio (PAPR) issue, which typically affects the digital transmission on power line communication (PLC) systems. In these systems, the power line is exploited as a communication multicarriers channel, where the sub-channels are made mutually independent by using orthogonal frequencies (orthogonal frequency division multiplexing or OFDM). Each component carries a string of bits associated with both amplitude and phase, which then represents the routed information. On the other hand, depending on the phases of the sub-carriers, the OFDM signal which has to be transmitted could present high instantaneous peaks. These peaks could saturate the transmitting amplifiers, modifying the shape of the OFDM symbol and then affecting its information content. Furthermore, such spikes give rise to electromagnetic compatibility issues for the electric devices. In this paper, the selected mapping (SLM) method is applied to mitigate the PAPR phenomenon. This method consists in shifting the phases of the components in order to minimize the amplitude of the peaks. The determination of the optimal set of phase shifts is a very complex problem, so that the SLM approaches proposed in the literature all resort to iterative algorithms to solve it. On the other hand, as this calculation has to be performed online, both the computational cost and the effect on the bit error rate (BER) cannot be established a priori. In this paper, an analytical approach is presented and its performance is evaluated for the case study of a PLC system implemented in a train locomotive.
8th Mediterranean Conference on Power Generation, Transmission, Distribution and Energy Conversion (MEDPOWER 2012), 2012
In the last years, several data communication over the emerging smart grid system has been implem... more In the last years, several data communication over the emerging smart grid system has been implemented on the existing low voltage power lines, which have high performance and limited costs. The most common Power Line Communication (PLC) technologies adopt OFDM as modulation scheme. However the Peak-to-Average Power Ratio (PAPR) of OFDM is an undesirable problem that has to be reduced. For this purpose, in this work, a new semi-analytical method is proposed, which allows one to solve the problem at low computational cost and at the same time to preserve the information content on the signal. The suitability of the proposed method has been validated on a case study represented by a real case problem. (5 pages)
2012 IEEE International Energy Conference and Exhibition (ENERGYCON), 2012
ABSTRACT Renewable energy exploitation in the urbanized areas has been receiving an increased att... more ABSTRACT Renewable energy exploitation in the urbanized areas has been receiving an increased attention over recent years because the proximity to electricity users makes it possible to obtain better global efficiency and to save territory. In this work a new wind energy system that uses the roof of the building in combination with a centripetal turbine is presented. This - could be considered as an amplifier of the wind speed that should allow the wind turbine to work under both lower and higher velocities than the conventional aerogenerators and therefore to increase its delivered power output. Considering the local wind climate of the area of interest, in this work, firstly, a Computational Fluid Dynamics (CFD) model is used to simulate the flow into the eolic system. Then, a laboratory-scale prototype has been made in order to test the potentialities of the proposed system for fulfillment of energy demands.
COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, 2005
PurposeTo present a neural network‐based approach to the design of electromagnetic devices.Design... more PurposeTo present a neural network‐based approach to the design of electromagnetic devices.Design/methodology/approachA neural model is created which reproduces the relationship between the design parameters of the device and the performance parameters, typically field values.FindingsThe neural model is a single hidden layer MLP network, trained by using a set of cases calculated, for example, by means of a finite element analysis. The design problem can be solved by fixing the performance values at the output of the network and by calculating the corresponding input values. The relationship between the input and the output of the neural network is represented by three equations systems. By means of these three systems, we can forward the domain of the input, and we can back propagate the desired output throughout the network layers. In such a way, both the domain of the design parameters and the domain of the desired performances values can be projected in the same space. Whatever ...
Aims and Background Surgical risk is deemed to be higher in the aged population because there are... more Aims and Background Surgical risk is deemed to be higher in the aged population because there are often comorbidities that may affect the postoperative result. This consideration is important for the treatment decision-making for gastric cancer in the elderly. The aim of this study was to identify factors influencing mortality, morbidity, survival and quality of life after curative surgery for gastric cancer in patients aged 75 years and older, and to plan their appropriate management. Methods and Study Design From January 1993 to December 2004, 135 patients underwent surgery at our department because of gastric cancer. Ninety-four of these patients (69.6%) underwent potentially curative gastrectomy. A cross-sectional study of 23 patients aged 75 years and older and 71 younger patients who underwent curative gastrectomy was carried out: patient characteristics, tumor characteristics, management, morbidity, mortality, survival, and quality of life were evaluated. Results Elderly pati...
European review for medical and pharmacological sciences, 2020
OBJECTIVE SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2)-related pneumonia, referre... more OBJECTIVE SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2)-related pneumonia, referred to as COVID-19 (Coronavirus Disease 19), is a public health emergency as it carries high morbidity, mortality, and has no approved specific pharmacological treatments. In this case series, we aimed to report preliminary data obtained with anti-complement C5 therapy with eculizumab in COVID-19 patients admitted to intensive care unit (ICU) of ASL Napoli 2 Nord. PATIENTS AND METHODS This is a case series of patients with a confirmed diagnosis of SARS-CoV2 infection and severe pneumonia or ARDS who were treated with up to 4 infusions of eculizumab as an off-label agent. Patients were also treated with anticoagulant therapy with Enoxaparin 4000 IU/day via subcutaneous injection, antiviral therapy with Lopinavir 800 mg/day + Ritonavir 200 mg/day, hydroxychloroquine 400 mg/day, ceftriaxone 2 g/day IV, vitamine C 6 g/day for 4 days, and were on Non-Invasive Ventilation (NIV). RESULTS We treat...
In this paper, Multi Layer Perceptron neural networks have been trained to identify the position ... more In this paper, Multi Layer Perceptron neural networks have been trained to identify the position of defects in concrete structures analyzed using an ultrasound technique. A diagnostic model obtained by means of Finite Elements techniques has been used to model the ultrasound transmission through a concrete pillar of specified size affected by defects in different positions. The obtained signals have
2017 IEEE 3rd International Forum on Research and Technologies for Society and Industry (RTSI), 2017
In this paper a procedure for the optimization of the bit loading in a PLC system implementing OF... more In this paper a procedure for the optimization of the bit loading in a PLC system implementing OFDM modulation is presented. The optimization strategy aims to find the best compromise between the conflicting objectives of minimal Signal Power, maximal Bit Rate, and minimal Bit Error Rate. The optimization is performed off line by means of a Multi-Objective approach. A set of Pareto solutions is determined, among which the designer has to take the final choice on the basis of the custom requirements. The approach is used to optimize the communication within a distributed energy storage system, which exploits an available electrical car fleet. The power lines supplying the charging points are used for the communication, while the information concerns, for each car, the identification code, the charge state, the schedule of charging/discharging. A unique OFDM modulation is used to dialogue with the whole cars fleet, so that it has to be optimized taking into account the frequency response of any involved power lines.
2018 IEEE 4th International Forum on Research and Technology for Society and Industry (RTSI), 2018
In this work, a fault detection approach for diagnosis of nonlinear systems is presented. This di... more In this work, a fault detection approach for diagnosis of nonlinear systems is presented. This diagnostic approach is performed resorting to a neural predictor of the output of the system, and by using the error prediction as a feature for the diagnosis. The neural predictor is a locally recurrent neural network, which is dynamically trained by using a gradient-based algorithm, where the gradient of the error function is expressed in closed form. The residuals of the prediction are affected by the deviation of the parameters from their nominal values, so that an early detection of the faults can be performed by observing the dynamic of the residuals. The Willamoski-Rossler reaction is used as case study in order to validate the diagnostic approach.
The magnetorotational instability (MRI) is considered to be one of the most powerful sources of t... more The magnetorotational instability (MRI) is considered to be one of the most powerful sources of turbulence in hydrodynamically stable quasi-Keplerian flows, such as those governing accretion disk flows. Although the linear stability of these flows with applied external magnetic field has been studied for decades, the influence of the instability on the outward angular momentum transport, necessary for the accretion of the disk, is still not well known. In this work we model Keplerian rotation with Taylor-Couette flow and imposed azimuthal magnetic field using both linear and nonlinear approaches. We present scalings of instability with Hartmann and Reynolds numbers via linear analysis and direct numerical simulations (DNS) for the two magnetic Prandtl numbers of 1.4 • 10 −6 and 1. Inside of the instability domains modes with different axial wavenumbers dominate, resulting in sub-domains of instabilities, which appear different for each P m. The DNS show the emergence of 1and 2-frequency spatio-temporally oscillating structures for P m = 1 close the onset of instability, as well as significant enhancement of angular momentum transport for P m = 1 as compared to P m = 1.4 • 10 −6 .
We explore the degradation behaviour under continuous illumination and direct oxygen exposure of ... more We explore the degradation behaviour under continuous illumination and direct oxygen exposure of inverted unencapsulated formamidinium(FA)CsPb(IBr), CHNHPbI, and CHNHPbICl perovskite solar cells. We continuously test the devices in-situ and in-operando with current-voltage sweeps, transient photocurrent, and transient photovoltage measurements, and find that degradation in the CHNHPbICl solar cells due to oxygen exposure occurs over shorter timescales than FACsPb(IBr) mixed-cation devices. We attribute these oxygen-induced losses in the power conversion efficiencies to the formation of electron traps within the perovskite photoactive layer. Our results highlight that the formamidinium-caesium mixed-cation perovskites are much less sensitive to oxygen-induced degradation than the methylammonium-based perovskite cells, and that further improvements in perovskite solar cell stability should focus on the mitigation of trap generation during ageing.
ABSTRACT A numerical experiment of a new MagnetoHydroDynamic (MHD) generator is presented. The pr... more ABSTRACT A numerical experiment of a new MagnetoHydroDynamic (MHD) generator is presented. The proposed device does not need an external magnetic field to work, but it performs the energy conversion by means of the induction principle. This is possible thanks to a pulsed ionization of the fluid current, carried out with an electrode dipped in the fluid current, followed by a charge separation with a stationary electric field. In this work a study has been done to evaluate and improve the performance of the proposed device.
Groundwater is the main source of drinking water and it has a vital importance in developed and d... more Groundwater is the main source of drinking water and it has a vital importance in developed and developing countries. Computational models of groundwater are required to ensure its suitable management. Such models are useful to design remediation strategies in polluted aquifers.
This paper fits in the multi-physics analysis of an innovative conceptual design of Magneto-Hydro... more This paper fits in the multi-physics analysis of an innovative conceptual design of Magneto-Hydrodynamic (MHD) inductive generator, coupled with a Thermo-Acoustic (TA) resonator. The thermo-acoustic effect occurs when an intense gradient of temperature is present along the axial direction of a duct containing a gas. Such effect allows the heat to be statically converted into mechanical energy of vibration. If the gas is ionized and the charges of opposite sign are separated into two clouds, an alternate electric current is associated to the thermo-acoustic vibration. That current, in its turn, can induce an electromotive force into a magnetically coupled coil. In this way, a thermo-electric conversion is performed, without solid moving parts or matter transport. A FEM analysis has been performed to assess the suitability of the complete energy transformation chain. In particular, the possibility that the charge carriers are involved in the vibration motion is investigated. An acoust...
International Journal of Applied Electromagnetics and Mechanics, 2018
The aim of the proposed work is to study the optimal design of an innovative Thermo-Acoustic-Magn... more The aim of the proposed work is to study the optimal design of an innovative Thermo-Acoustic-Magneto-Hydro-Dynamic electric generator, with particular reference to the Magneto-Hydro-Dynamic section. A multi-objective optimization algorithm, which makes use of a Tabu Search meta-heuristic, has been developed to this purpose. Thermo-Acoustic and Magneto-Hydro-Dynamic energy conversion processes give a great advantage by converting energy without solid moving components. This makes the cited technologies very interesting for the low weight, the low maintenance costs, and the high conversion efficiency. The design of the generator has to be optimized by considering conflicting objectives, i.e., maximizing the output power, minimizing the applied electrical voltage, and minimizing mass and size of the device. Therefore, a multiobjective vectorial optimization approach is mandatory. A fully vector scheme has been implemented that takes under control both the Pareto optimality of the solutions, and the uniformity in the Pareto front sampling.
Proceedings of the Third International Conference on Railway Technology: Research, Development and Maintenance
This paper deals with the peak-to-average-power-ratio (PAPR) issue, which typically affects the d... more This paper deals with the peak-to-average-power-ratio (PAPR) issue, which typically affects the digital transmission on power line communication (PLC) systems. In these systems, the power line is exploited as a communication multicarriers channel, where the sub-channels are made mutually independent by using orthogonal frequencies (orthogonal frequency division multiplexing or OFDM). Each component carries a string of bits associated with both amplitude and phase, which then represents the routed information. On the other hand, depending on the phases of the sub-carriers, the OFDM signal which has to be transmitted could present high instantaneous peaks. These peaks could saturate the transmitting amplifiers, modifying the shape of the OFDM symbol and then affecting its information content. Furthermore, such spikes give rise to electromagnetic compatibility issues for the electric devices. In this paper, the selected mapping (SLM) method is applied to mitigate the PAPR phenomenon. This method consists in shifting the phases of the components in order to minimize the amplitude of the peaks. The determination of the optimal set of phase shifts is a very complex problem, so that the SLM approaches proposed in the literature all resort to iterative algorithms to solve it. On the other hand, as this calculation has to be performed online, both the computational cost and the effect on the bit error rate (BER) cannot be established a priori. In this paper, an analytical approach is presented and its performance is evaluated for the case study of a PLC system implemented in a train locomotive.
8th Mediterranean Conference on Power Generation, Transmission, Distribution and Energy Conversion (MEDPOWER 2012), 2012
In the last years, several data communication over the emerging smart grid system has been implem... more In the last years, several data communication over the emerging smart grid system has been implemented on the existing low voltage power lines, which have high performance and limited costs. The most common Power Line Communication (PLC) technologies adopt OFDM as modulation scheme. However the Peak-to-Average Power Ratio (PAPR) of OFDM is an undesirable problem that has to be reduced. For this purpose, in this work, a new semi-analytical method is proposed, which allows one to solve the problem at low computational cost and at the same time to preserve the information content on the signal. The suitability of the proposed method has been validated on a case study represented by a real case problem. (5 pages)
2012 IEEE International Energy Conference and Exhibition (ENERGYCON), 2012
ABSTRACT Renewable energy exploitation in the urbanized areas has been receiving an increased att... more ABSTRACT Renewable energy exploitation in the urbanized areas has been receiving an increased attention over recent years because the proximity to electricity users makes it possible to obtain better global efficiency and to save territory. In this work a new wind energy system that uses the roof of the building in combination with a centripetal turbine is presented. This - could be considered as an amplifier of the wind speed that should allow the wind turbine to work under both lower and higher velocities than the conventional aerogenerators and therefore to increase its delivered power output. Considering the local wind climate of the area of interest, in this work, firstly, a Computational Fluid Dynamics (CFD) model is used to simulate the flow into the eolic system. Then, a laboratory-scale prototype has been made in order to test the potentialities of the proposed system for fulfillment of energy demands.
COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, 2005
PurposeTo present a neural network‐based approach to the design of electromagnetic devices.Design... more PurposeTo present a neural network‐based approach to the design of electromagnetic devices.Design/methodology/approachA neural model is created which reproduces the relationship between the design parameters of the device and the performance parameters, typically field values.FindingsThe neural model is a single hidden layer MLP network, trained by using a set of cases calculated, for example, by means of a finite element analysis. The design problem can be solved by fixing the performance values at the output of the network and by calculating the corresponding input values. The relationship between the input and the output of the neural network is represented by three equations systems. By means of these three systems, we can forward the domain of the input, and we can back propagate the desired output throughout the network layers. In such a way, both the domain of the design parameters and the domain of the desired performances values can be projected in the same space. Whatever ...
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Papers by A. Montisci