Bergson and Plotinus on Freedom

This article deals with the concept of freedom in Bergson and in Plotinus. This concept is a central one in Bergson’s work, as he himself remarks many times: it is on this concept that he builds his thought and starting from it he interrogates the thought that precedes his. In investigating the presence of this concept in Plotinus, Bergson sees it as linked to the concept of the individuality of the soul, and to this te concept of freedom would be confined in Plotinus’ thought. What follows will question Bergson’s reading, showing that the concept of freedom in Plotinus is much more pervasive and closer to that of Bergson than Bergson himself thought. The result of this comparison will be to suggest that both philosophers understand freedom as will. Instead of closing the problem, this conclusion opens up new questions both historical and philosophical: Can the concept of will be seen as a foundational one in the history of philosophy since its Greek inception? Is will the more radical concept under which to think freedom

A method for obtaining the I-V curve of photovoltaic arrays from module voltages and its applications for MPP tracking

For the purpose of control and monitoring of a Photovoltaic (PV) system its current-voltage (I-V) charac- teristic curve is traced. Usually such a test involves the interruption of the normal operation of the PV systems. In this paper a method for tracing the I-V curve from on-site measurements is proposed. During the measurement of the characteristic curve the normal operation of the PV system is not inter- rupted. The subjects of tracing the characteristic curve and Maximum Power Point Tracking (MPPT) of PV arrays are generally dealt with separately but the proposed method performs the measurement of the characteristic curve quickly and so it can also be utilized for MPPT purposes. Simulations and experi- ments have been conducted to confirm the operation of the proposed metho

probability models to assess the seismic safety of rigid block like structures and the effectiveness of two safety devices

Abstract When subject to earthquakes, some objects and structures, such as statues, obelisks, storage systems, and transformers, show a dynamic behavior that can be modeled considering the object/structure as a rigid block. Several papers have studied the dynamic behavior of both stand-alone rigid blocks and systems where rigid blocks have been paired with safety devices to prevent or delay the overturning of the blocks. Although the safety devices have generally been proven to be effective, their effectiveness changes substantially varying the parameters that characterize the system and the seismic input. This paper compares the seismic responses of stand along rigid blocks with those of blocks coupled with two candidate safety devices: an isolating base and a pendulum mass damper. To account for the relevant uncertainties, probabilistic seismic demand models are developed using a Bayesian approach. The probabilistic models are then used along with the overturning capacities of the blocks to construct fragility curves that give a prediction of the probability of overturning occurrence as a function of some characteristics of the blocks, of the safety devices, as well as of the seismic excitation, i.e. the slenderness of the body and the peak ground acceleration. The data needed to develop the probabilistic model are obtained integrating the nonlinear equations of motion of the two systems subject to selected ground motions. In the end, some numerical examples are proposed

A Smart Battery Management System for Photovoltaic Plants in Households Based on Raw Production Forecast

A basic battery management system (BMS) permits the safe charge/discharge of the batteries and the supply of loads. Batteries are protected to avoid fast degradation: the minimum and maximum state-of-charge (SOC) limits are not exceeded and fast charge/discharge cycles are not permitted. A more sophisticated BMS connected to a photovoltaic (PV) generator could also work with the double purpose of protecting storage and reducing peak demand. Peak reduction by storage generally requires the forecast of consumption and PV generation profiles to perform a provisional energy balance. To do it, it is required to have accurate information about production profiles, that is, to have at disposal accurate weather forecasts, which are not easily available. In the present work, an efficient BMS in grid-connected PV plants for residential users is described. Starting from raw 1-day ahead weather forecast and prediction of consumption, the proposed BMS preserves battery charge when it is expected high load and low PV production and performs peak shaving with a negligible reduction in self-sufficiency

Variable parameters for a single exponential model of photovoltaic modules in crystalline-silicon

The correct approximation of parallel resistance (Rp) and series resistance (Rs) poses a major challenge for the single diode model of the photovoltaic module (PV). The bottleneck behind the limited accuracy of the model is the static estimation of resistive parameters. This means that Rp and Rs, once estimated, usually remain constant for the entire operating range of the same weather condition, as well as for other conditions. Another contributing factor is the availability of only standard test condition (STC) data in the manufacturer’s datasheet. This paper proposes a single-diode model with dynamic relations of Rp and Rs. The relations not only vary the resistive parameters for constant/distinct weather conditions but also provide a non-iterative solution. Initially, appropriate software is used to extract the data of current-voltage (I-V) curves from the manufacturer’s datasheet. By using these raw data and simple statistical concepts, the relations for Rp and Rs are designed. Finally, it is proved through root mean square error (RMSE) analysis that the proposed model holds a one-tenth advantage over numerous recently proposed models. Simultaneously, it is low complex, iteration-free (0 to voltage in maximum power point Vmpp range), and requires less computation time to trace the I-V curve

Long-term modulation of mitochondrial Ca2+ signals by protein kinase C isozymes

The modulation of Ca2+ signaling patterns during repetitive stimulations represents an important mechanism for integrating through time the inputs received by a cell. By either overexpressing the isoforms of protein kinase C (PKC) or inhibiting them with specific blockers, we investigated the role of this family of proteins in regulating the dynamic interplay of the intracellular Ca2+ pools. The effects of the different isoforms spanned from the reduction of ER Ca2+ release (PKCα) to the increase or reduction of mitochondrial Ca2+ uptake (PKCζ and PKCβ/PKCδ, respectively). This PKC-dependent regulatory mechanism underlies the process of mitochondrial Ca2+ desensitization, which in turn modulates cellular responses (e.g., insulin secretion). These results demonstrate that organelle Ca2+ homeostasis (and in particular mitochondrial processing of Ca2+ signals) is tuned through the wide molecular repertoire of intracellular Ca2+ transducers

Statistical techniques applied to the automatic diagnosis of dermoscopic images

An image based system implementing a well‐known diagnostic method is disclosed for the automatic detection of melanomas as support to clinicians. The software procedure is able to recognize automatically the skin lesion within the digital image, measure morphological and chromatic parameters, carry out a suitable classification for the detection of structural dermoscopic criteria provided by the 7‐Point Check. Original contribution is referred to advanced statistical techniques, which are introduced at different stages of the image processing, including the border detection, the extraction of low‐level features and scoring of high order features (namely dermoscopic criteria). The proposed approach is experimentally tested with reference to a large image set of pigmented lesions

The quality of life in extracorporeal life support survivors: single-center experience of a long-term follow-up

Objective: To evaluate the health-related quality of life on a very long-term follow-up in patients treated with extracorporeal membrane oxygenation (ECMO) during neonatal and pediatric age. Design: Prospective follow-up study. Setting: Pediatric Intensive Care Unit of a tertiary-care University-Hospital. Patients: Out of 20 neonates and 21 children treated with ECMO in our center, 24 patients underwent short-term neurological follow-up. Twenty of them underwent long-term neurological follow-up. Intervention: Short-term follow-up was performed at 18 months and consisted in clinical evaluation, electroencephalography, and neuroimaging. Long-term follow-up was performed in 2017, at the mean period 19.72 years from ECMO (median 20.75, range 11.50-24.08) and consisted in a standardized questionnaires self-evaluation (PedsQL 4.0 Generic Core Scale) of health-related quality of life and an interviewed about the presence of organ morbidity, school level, or work position. Measurements and main results: Sixty-one percent (25/41) of the patients survived within 30 days after ECMO treatment. Short-term follow-up was performed in 24 patients (1 patient but died before the evaluation): 21 patients (87%) showed a normal neurological status, and 3 developed severe disability. Long-term follow-up was performed in 20 long-term survivors (3 patients were not possible to be contacted and considered lost to follow-up): mean age of patients at long-term follow-up was 21.23 (median 20.96, range 13.33-35.58) years; 90% (18/20) of them have no disability with a complete normal quality of life and 95% have no cognitive impairment. Conclusions: ECMO represents a life-saving treatment for infants and children with respiratory and/or heart failure; survivors show a good quality of life comparable to healthy peers

Towards the Complete Self-Sufficiency of a nZEBs microgrid by Photovoltaic Generators and Heat Pumps: Methods and Applications

The present paper proposes a multidisciplinary procedure to correctly design a microgrid of all-electric nZEBs (nearly Zero Energy Buildings) from both electrical and thermal points of view. The procedure is suitable for new buildings supplied by local renewables, without the use of fossil fuel and with zero emissions. First, the thermal demand of each single nZEB is assessed, as a function of the installation site, building layout and physics, and material composing the envelope. Thanks to heat pumps, the thermal demand is transformed in electric load. Thus, the total electric consumption profiles, which include user's appliances and heating/cooling, are studied and compared with Photovoltaic (PV) generation supported by electrochemical storages. Both PV and batteries are simulated thanks to appropriate models. Regarding the PV production assessment, the present work proposes an improvement with respect to the use of traditional models, and it is based on experimental results on PV generators of recent production. The design methodology is applied to a real case of “energy community” composed of three nZEB units, that will be built in the campus of Politecnico di Torino, available to students and staff. The three units share PV production and storage capacity to reach the complete grid-independence