Stochastic Operation Optimization of the Smart Savona Campus as an Integrated Local Energy Community Considering Energy Costs and Carbon Emissions

Aiming at integrating different energy sectors and exploiting the synergies coming from the interaction of different energy carriers, sector coupling allows for a greater flexibility of the energy system, by increasing renewables’ penetration and reducing carbon emissions. At the local level, sector coupling fits well in the concept of an integrated local energy community (ILEC), where active consumers make common choices for satisfying their energy needs through the optimal management of a set of multi-carrier energy technologies, by achieving better economic and environmental benefits compared to the business-as-usual scenario. This paper discusses the stochastic operation optimization of the smart Savona Campus of the University of Genoa, according to economic and environmental criteria. The campus is treated as an ILEC with two electrically interconnected multienergy hubs involving technologies such as PV, solar thermal, combined heat and power systems, electric and geothermal heat pumps, absorption chillers, electric and thermal storage. Under this prism, the ILEC can participate in the day-ahead market (DAM) with proper bidding strategies. To assess the renewables’ uncertainties, the roulette wheel method is used to generate an initial set of scenarios for solar irradiance, and the fast forward selection algorithm is then applied to preserve the most representative scenarios, while reducing the computational load of the next optimization phase. A stochastic optimization model is thus formulated through mixed-integer linear programming (MILP), with the aim to optimize the operation strategies of the various technologies in the ILEC, as well as the bidding strategies of the ILECs in the DAM, considering both energy costs and carbon emissions through a multi-objective approach. Case study results show how the optimal bidding strategies of the ILEC on the DAM allow minimizing of the users’ net daily cost, and, as in the case of environmental optimization, the ILEC operates in self-consumption mode. Moreover, in comparison to the current operation strategies, the optimized case allows reduction of the daily net energy cost in a range from 5 to 14%, and the net daily carbon emissions in a range from 6 to 18%

A Contact-less Method for Monitoring the Detachments in the Architectural Coverings of Ancient Structures by using 'ULTRAINO'

Detecting the presence, the position and the extension of the detachments in architectural coverings is at the base of the analysis of the state of conservation of ancient structures. Many non-destructive investigation methodologies have been used, and the ultrasound technique applied through the use of parametric transducers appears be very promising. The use of parametric transducers to detect structural defects has been widely proven, but normally the systems 'off the shelf' are not focused: these systems have beams with dimensions of the order of tens of cm, Recently, the introduction of a parametric transducer driven by an Arduino board, called Ultraino, has allowed to have available a focused parametric transducer at very low cost. The use of 'Ultraino' permits to obtain beams with focal areas of the order of millimeters, at very small distances from the radiating device. This advantage, combined with the possibility of driving the device by a Matlab script, permits to implement the well-known technique of the measurement of the impulsive response in the audio range, and extract the acoustic reflectivity of the superficial point under test. Finally, the entire instrumentation has a very low price and it is easily portable and usable in situ

A Fast and Low-Cost "Mouse" for Analyzing the Bonding State of Wall Coverings

The Non-Destructive investigations used until now to detect the presence of detachments in wall coverings are hardly executable in situ. For these motivations, we designed an automatic system, similar to a "mouse", portable, battery powered, and with a clear, fast, and accurate read-out. It use the technique of detection based on the "stiffness measure" of the cover: the surface is hit with a small "hammer" to measure the impact time. The aim of this work was to develop a system that, starting from the basic concepts known in literature, and making use of a powerful but economical 32 bit Arduino-like board, allows to obtain a pocket tester easily usable by any maintenance technician, with a cost of the device very low, while maintaining an efficient measurement methodology

An Active Acoustic Back Cover Based on Piezoelectric Elements

A trackpad is a pointing device, featuring a tactile sensor, able to translate the motion and position of a user's finger, or a stylus, to a relative position on the device screen. In this work, we analyze the possibility to use the back cover of tablets or smartphones as trackpad, capable of detecting the presence and position of a finger on their external surface. In order to convert the smart device back cover in a trackpad we glue on its inner surface, some small, thin piezoelectric plates. The proposed trackpad was analyzed by FEM in order to understand how many piezoelectric plates are needed and where they must be placed along the inner cover surface; the device resolution and sensitivity varying the finger position was also analyzed, confirming the device capabilities

Biasing of Capacitive Micromachined Ultrasonic Transducers

Capacitive micromachined ultrasonic transducers (CMUTs) represent an effective alternative to piezoelectric transducers for medical ultrasound imaging applications. They are microelectromechanical devices fabricated using silicon micromachining techniques, developed in the last two decades in many laboratories. The interest for this novel transducer technology relies on its full compatibility with standard integrated circuit technology that makes it possible to integrate on the same chip the transducers and the electronics, thus enabling the realization of extremely low-cost and high-performance devices, including both 1-D or 2-D arrays. Being capacitive transducers, CMUTs require a high bias voltage to be properly operated in pulse-echo imaging applications. The typical bias supply residual ripple of high-quality high-voltage (HV) generators is in the millivolt range, which is comparable with the amplitude of the received echo signals, and it is particularly difficult to minimize. The aim of this paper is to analyze the classical CMUT biasing circuits, highlighting the features of each one, and to propose two novel HV generator architectures optimized for CMUT biasing applications. The first circuit proposed is an ultralow-residual ripple (<5 μV) HV generator that uses an extremely stable sinusoidal power oscillator topology. The second circuit employs a commercially available integrated stepup converter characterized by a particularly efficient switching topology. The circuit is used to bias the CMUT by charging a buffer capacitor synchronously with the pulsing sequence, thus reducing the impact of the switching noise on the received echo signals. The small area of the circuit (about 1.5 cm2) makes it possible to generate the bias voltage inside the probe, very close to the CMUT, making the proposed solution attractive for portable applications. Measurements and experiments are shown to demonstrate the effectiveness of the new approaches presented

3D Ultrasound palm vein pattern for biometric recognition

In this work, an ultrasound technique for achieving 3D palm vein patterns for biometric recognition purposes is proposed and experimentally tested. Commercial ultrasound imaging machine and linear arrays have been employed. Both imaging and power Doppler analysis have been performed to detect veins. The probe is moved in the directional orthogonal to the array by an automated scanning system and at each step a 2D frame is captured and stored to form a 3D matrix. The data from the 3D matrix are elaborated for achieving 3D ultrasonic vein patterns. The proposed technique has been applied to acquire hand vein patterns of about a dozen of distinct volunteers, which are opportunely rendered and discussed

Element shape design of 2-D CMUT arrays for reducing grating lobes

Fully populated two-dimensional (2-D) arrays are needed to produce high quality ultrasonic volumetric images for real-time applications, but they present many challenges for their physical realization because of the large number of elements. In fact, lambda/2 and lambda minimum spacing between elements is required, respectively, for pyramidal and rectilinear scanning in order to avoid unwanted grating lobes (GLs). However, in past years, capacitive micromachined ultrasonic transducer (CMUT) technology has made possible the production of arrays with large flexibility in element shape and size. In this paper, this property is analyzed, and a new element shape, based on the concept of spatial interpenetration of adjacent elements, is proposed in order to design fully populated 2-D CMUT arrays, with a low number of elements, whose beam characteristics are valid for volumetric imaging. Through the use of simulations, it is demonstrated that arrays with pitch larger than lambda (up to 3 lambda) used for rectilinear scanning, have notably lower GLs than the equivalent standard arrays designed according to the classical squared element shape. As consequence, the proposed geometry has the advantage of reducing the number of elements (up to a factor of 9) and of enlarging the element size, implying an increase of the SNR relative to the single element. When beam steering is required, arrays can be designed with pitch equal to lambda, reducing the number of elements by a factor of 4 if the maximum steering angle is limited to plusmn15deg

Capacitive micro-fabricated ultrasonic transducers for biometric applications

Two capacitive micro-fabricated ultrasonic transducers (cMUT) are evaluated for application in biometric recognition. Both transducers are 192 elements linear arrays, fabricated using the Reverse Process™ previously reported by some of the authors, and allow broadband operation at a center frequency of 12 MHz. The transducers have different pitches and acoustic lenses to allow different resolutions and focal lengths. 3D images of biometric characteristics such as palmprint and fingerprint are obtained by moving the transducer along the elevation direction and acquiring the B-scan for each scan step using a commercial ultrasound scanner; the main features of the proposed technique, also compared with conventional techniques, are presented and discusse