1,355,271 research outputs found
A decentralized approach for enabling advanced ancillary services through distributed energy sources
No full textThis thesis reports the results carried out by the author during the three-year activities of the XXXV cycle of the Ph.D. course in Electrical and Information Engineering at Politecnico di Bari. The main goal of this work was to implement a decentralized approach to enable the provision of Ancillary Services (AS) by means of Distributed Energy Resources (DERs).
As a first step, an analysis of Regulations, Directives, and Network Codes at the national and European level was carried out to define the future framework of the electricity market. In addition, papers and technical reports concerning eight European projects, such as SmarNet, CoordiNet, FLEXCoop, OSMOSE, inteGRIDy, eDREAM, ADDRESS, and evolvDSO have been analyzed with the aim to define the state of the art about the provision of AS by means of DERs. In particular, a set of coordination schemes was identified from those proposed in the literature to coordinate the use of DERs among Transmission System Operators (TSOs) and Distribution System Operators (DSOs). These coordination schemes are classified into centralized and decentralized architectures, depending on the possibility of System Operators of managing their respective networks. In addition, the main methodologies proposed in the literature to perform optimal dispatch of flexibility resources in a TSO-DSO coordination framework, taking technical and grid constraints into account, have been identified and presented.
In order to enable DERs in AS provision and coordinate system operators in their usage, a few methodologies suitable for decentralized architectures were developed and presented in this work. In particular, a new algorithm based on a three-phase optimal power flow routine for mapping the flexibility area at the point of interconnection (POI) between transmission and distribution grids was provided. Furthermore, two alternative methodologies to aggregate flexibility resources located in distribution networks interfaced with the TN in multiple POIs were described. In addition, a Benders decomposition algorithm able to optimize TN and DN flexibility resources for congestion management in a few decentralized coordination schemes was also implemented. The proposed methodologies were validated by means of simulation tests conducted on a power system including transmission and distribution grids.
The last part of this thesis investigated how innovative grid services, such as Synthetic Inertia (SI) and Fast Frequency Response (FFR), may be also provided through fast control dispatchable resources located at the distribution grid level. With this aim, a low-cost controller for end-user applications able to generate a SI law for dispatchable DERs was developed and tested through Power Hardware-in-the-Loop (PHIL) tests. Similarly, PHIL tests were also carried out to investigate the capability of LED lamps of public lighting systems to be controlled with the aim to provide SI and FFR actions. Experimental results validated the proposed decentralized approaches
Acoustic and visual pacesetter influence on the energy expenditure in a cycling exercise
No full textBACKGROUND: The aim of this study was to evaluate the effects of acoustic and visual pacesetters on the energy expenditure in a steady state 30-minute long cycling. METHODS: Eighteen healthy male subjects (age 27.6±4.59 years; height 1.78±0.07 m; body mass 80.1±7.85 kg) performed a 30-minute submaximal exercise at a constant workload on a cycle ergometer. The imposed workload required a metabolic expenditure corresponding to 70% of ventilatory threshold for each subject. Energy expenditure - expressed as a caloric equivalent relative to the total net oxygen consumption during exercise - was evaluated using three conditions: control (CT), no external pacesetter; acoustic (AT), listening to rhythmic acoustic stimuli at 120 beat per minute; and visual (VT), seeing footage consisting of eight different images in a looped sequence at 120 frames per minute. RESULTS: All measured parameters qualified the exercise as requiring mainly an aerobic metabolism, showing no pain and no fatigue. AT and VT energy expenditure (5.0±0.44 and 4.9±0.39 MET respectively) were significantly lower compared to CT (5.5±0.49 MET), while no difference between AT and VT were recognized. CONCLUSIONS: This study confirmed the ergogenic effect of the acoustic pacesetter on a 30-minute steady state rhythmic exercise. Novelty is that the visual pacesetter too was able to increase the mechanical efficiency as the same manner than the acoustic one. The present setting adopting visual pacesetter could be used in special categories, such as the deaf or in innovative technological tools as head-mounted display devices
Distributed SAR Chronogram and Timing Issues for RODiO Mission
No full textThis paper focuses on the timing analysis for a Distributed Synthetic Aperture Radar (DSAR) system exploiting an opportunity illuminator. This is the case of RODiO, which is a new mission concept funded by the Italian Space Agency (ASI) for a Phase A study in the framework of ALCOR program. RODiO's aim is to match the growing trend towards the miniaturization of satellites and new Synthetic Aperture Radar (SAR) applications. For this reason, RODiO consists in a cluster of four receiving-only CubeSats flying in a close formation and exploiting the independent PLATiNO-1 satellite as a transmitter. Because of the nature of RODiO mission, simultaneous observations with respect to the monostatic illuminator are needed. Through the comparison of monostatic and bistatic chronograms, a timing analysis is performed in the paper in order to assess the effects of DSAR geometry on simultaneous observation opportunities, aiding the design of the system
Preliminary product and system observational requirements for RODiO mission
No full textRODiO is an innovative mission concept selected by the Italian Space Agency (ASI) for a phase A study in the framework of the ALCOR program. RODiO consists of a cluster of 4 passive CubeSat receivers aiming to fly in a Large Baseline Bistatic (LBB) configuration with ASI PLATiNO-1 (PLT-1) Satellite. The mission objective is to serve as an in-orbit demonstrator of both the Distributed Synthetic Aperture Radar (DSAR) concept and a novel hybrid propellant rocket propulsion system for formation reconfiguration. RODiO also aims at delivering new SAR products for scientific and commercial downstream. The DSAR image resulting from the coherent combination of the stack of low performance bistatic data can be exploited to complement information from the monostatic image generated by the illuminator. The incoherent combination of these images allows for the demonstration of novel products. They are expected to actively contribute to several application ambits such as Digital Elevation Model (DEM) generation, Maritime Monitoring, and Civil Protection, Transport & Safety. Specifically, eight significant products have been identified: Radargrammetric DEM, Ship detection, Wake Analysis, Infrastructure Monitoring, Land Deformation Map, Flood Risk Map, Multi-baseline Radargrammetric DEM, and Multi-baseline Ship Velocity Map. Every product has then been characterized, leading to several observational requirements. The paper discusses the mission goals and the products identified as obtainable, focusing on the correspondent system observational requirements for their generation
RODIO Mission Status and Future Developments
No full textRODiO is an ASI Project based on an innovative mission concept developed in Italy by the University of Naples Federico II. The mission relies on a cluster of 4 CubeSats flying in formation with ASI PLATiNO-1 (PLT-1) SAR mission. The CubeSat cluster flies at a safe distance of tens of km from PLT-1, and formation-flying techniques are used to keep all the CubeSats in the cluster within an overall envelope of a few hundred meters. Each CubeSat embarks a receiving-only X-band SAR instrument able to collect bistatic echoes exploiting PLT-1 as an opportunity illuminator. In addition, one of the CubeSats embarks a novel hybrid rocket propulsion unit that enables high thrust (10 N) orbit reconfiguration. RODiO Phase A ended in December 2023 confirming mission feasibility and proposing solutions for radar antenna and deployment mechanisms, receiver electronics, hybrid propulsion unit and formation flying able to comply with a 16 U CubeSat
Long-baseline multistatic and bistatic SAR products: Application to the RODiO mission
No full textIn-Orbit Demonstration (IOD) missions represent flight opportunities to acquire data on spacecraft and space environment and to demonstrate new techniques at system, subsystem, and payload level. Realizing this type of mission means accepting a greater level of risk. However, when very compact and relatively simple platforms like CubeSats are adopted, this becomes admissible since costs can be kept low. Distributed Synthetic Aperture Radar (SAR) is a novel Earth Observation (EO) technique for microwave imaging. It uses multiple cooperating receivers and suitable processing to enable performance and products that exceed those of the single components of the system. RODiO (Radar for earth Observation by synthetic aperture Distributed on a cluster of CubeSats equipped with high-technology micro-propellers for new Operative services) is an IOD of the distributed SAR concept. The mission is based on four, 16 U, CubeSats, that embark a receiving-only X-band SAR instrument able to collect bistatic echoes exploiting a monostatic SAR as an opportunity illuminator, i.e PLATiNO-1 mission. Distributed SAR demonstration is thus pursued in RODiO combining the principles of both multistatic and bistatic SAR. The paper, moving from mission goals, individuates different families of EO products that RODiO can demonstrate, e.g. in the contest of ground motion, digital elevation models, and ship detection. The main result is the definition of the RODiO system requirements for product generation that drive satellites and payload design
Aristeo e il culto di Zeus a Ceo presso Apollonio Rodio ed Euforione
No full textStudio comparativo di un passo delle Argonautiche di Apollonio Rodio e di un frammento di Euforione, incentrati sul culto di Zeus istituito a Ceo da Ariste
Il regionalismo differenziato tra attuazione e resistenze
No full textPresentazione agli Atti del convegn
Home is the new gym: Exergame as a potential tool to maintain adequate fitness levels also during quarantine
No full textPurpose. With the coronavirus outbreak, the preventive measures include staying at home and isolation, increasing sedentary behaviours and risk for worsening of chronic diseases. To explore alternative forms of home-based physical activity, the study aim was to evaluate physiological (heart rate [HR], respiratory exchange ratio [RER], oxygen consumption [ O2], energy expenditure [EE], metabolic equivalent task [MET]) and psychological (session rating of perceived exertion [sRPE], enjoyment) parameters of real (Zumba® class [ZC]) and exergame (Zumba® Fitness Rush [ZFR]) activities in relation to sex. Methods. Overall, 12 female (age: 24.7 ± 0.9 years) and 8 male (age: 25.3 ± 2.1 years) college students randomly performed 2 experimental 60-min sessions, ZC and ZFR, during which HR (expressed as percentage of individual maximal HR [%HRmax]), O2, RER, MET and EE were measured. After each session, sRPE and Physical Activity Enjoyment Scale (PACES) were used to monitor exercise intensity and enjoyment, respectively. Results. Main effects for sex (p = 0.02) and modality (p < 0.0001) emerged for %HRmax, with women showing higher values than men and ZC showing higher values than ZFR. EE presented main effects for sex (p < 0.0001) and modality (p = 0.0002), with higher values in men and in ZC. Main effect (p = 0.0001) for modality emerged also for O2 and MET, with higher values in ZC regardless of sex. No significant differences were observed for RER, sRPE, or PACES. Conclusions. Although ZC elicited higher cardiovascular and metabolic responses, ZFR, classified as a moderate-to-vigorous activity, could be used to maintain regular physical activity in a safe home environment during the coronavirus crisis
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