Higher Institute on Territorial Systems for Innovation
PORTO Publications Open Repository TOrinoNot a member yet
91193 research outputs found
Sort by
Towards Printable Natural Dielectric Cloaks via Inverse Scattering Techniques
No full textThe synthesis of non-magnetic 2D dielectric cloaks as proper solutions of an inverse scattering problem is addressed in this paper. Adopting the relevant integral formulation governing the scattering phenomena, analytic and numerical approaches are exploited to provide new insights on how frequency and direction of arrival of the incoming wave may influence the cloaking mechanism in terms of permittivity distribution within the cover region. In quasi-static (subwavelength) regime a solution is analytically derived in terms of homogeneous artificial dielectric cover with ε < ε0, which is found to be a necessary and sufficient condition for achieving omnidirectional cloaking. On the other hand, beyond quasi-static regime, the cloaking problem is addressed as an optimization task looking for only natural dielectric coatings with ε > ε0 able to hide the object for a given number of directions of the incident field. Simulated results confirm the validity of both analytic and numerical methodologies and allow to estimate effective bandwidths both in terms of frequency range and direction of arrival of the impinging field
Glass waste^3 recovery: new technologies for corks and plastic separation
No full textNowadays the selection and the treatment of the glass waste is implemented in processing plants where, through sorting the foreign bodies and separation from Pb crystal, opaque bodies and the metals, a secondary raw material (SRM) - named cullet - is obtained, suitable for glass products and a glassy waste (glass waste 2) still not accepted by the glass factories. While the recovery of primary glass waste is already spread and technological known, the secondary glass waste (glass waste2) is recovered by few companies in Italy from some years. Consequently the recovery of the waste of this secondary recovery process of glass waste is new (glass waste3) and therefore to optimize, in order to reach an economic and sustainable industrial process solution. With the aim of optimizing the plant of SASIL already existing for the recovery of the "glass waste3", innovative technologies have been studied and executed. The major difficulty is in the automatic separation of materials as plastic lightweight, synthetic stoppers and cork stoppers that can nowadays find a market. In particular the solved problem is the separation for materials whose density is < 1, using non-impacting methods. The particle distribution and characterization of the waste in entrance in plant and the products obtained in different stage of treatment have been used to dimension the new plant and to suggest new kind of treatment. Among the innovative process suggested two density separation have been performed: - separation by means jig concentrators; - separation of new method of bath suction. In this research the jig concentrator, at difference of the previous research don't use floatation principle but only fluid motion (without chemical addition and collectors). The same is for the "bath suction apparatus" that it needs only of water to execute the separation. The separation of efficiencies are major than 80% both for jig concentrators, for the separation of heavy plastic and glass from plastic lightweight and synthetic stoppers and cork stoppers, and for bath suction apparatus that led to separate plastic lightweight from synthetic stoppers and cork stoppers. On the base of laboratory results, a new treatment plant has been designed and economic evaluation have been made. The materials to be trade as secondary raw materials (SRM) are about 87.5% of the total feeding and they are glass, plastic lightweight, ferrous metals, non-ferrous metals, synthetic stoppers and cork stoppers. These percentage should be related to the high amount of this kind of waste to be valorized (glass waste 3), landfilled in the plant in Italy and ready to be recovered, after the implementation of the right industrial technology
GreenLab: autonomous low power system extending multi-constellation GNSS acquisition in Antarctica
No full textThe opportunity to extend monitoring campaigns in Antarctica, overcoming the limitations of the current fixed installations and getting data directly on-field, becomes increasingly attractive for researchers and scientists. The GreenLab is an energy-efficient and self-sufficient system specifically conceived for critical environments. It is equipped with a multi-constellation GNSS receiver and low power systems for computing and communications. Exploiting an automatically reconfigurable antenna, the GreenLab enables a real-time sharing of received data with the base station while optimizing power consumption. This paper presents the deployment and validation of the first GreenLab prototype, during the XXXII summer campaign in Antarctica. Acquired data have been compared to existing GNSS receivers already installed in Antarctica in fixed observatories, with encouraging results
Influence of the ac-Stark shift on GPS atomic clock timekeeping
No full textThe ac-Stark shift (or light shift) is a fundamental aspect of the field/atom interaction arising from virtual transitions between atomic states, and as Alfred Kastler noted, it is the real-photon counterpart of the Lamb shift. In the rubidium atomic frequency standards (RAFS) flying on Global Positioning System (GPS) satellites, it plays an important role as one of the major perturbations defining the RAFS' frequency: the rf-discharge lamp in the RAFS creates an atomic signal via optical pumping and simultaneously perturbs the atoms' ground-state hyperfine splitting via the light shift. Though the significance of the light shift has been known for decades, to date there has been no concrete evidence that it limits the performance of the high-quality RAFS flying on GPS satellites. Here, we show that the long-term frequency stability of GPS RAFS is primarily determined by the light shift as a consequence of stochastic jumps in lamplight intensity. Our results suggest three paths forward for improved GPS system timekeeping: (1) reduce the light-shift coefficient of the RAFS by careful control of the lamp's spectrum; (2) operate the lamp under conditions where lamplight jumps are not so pronounced; and (3) employ a light source for optical pumping that does not suffer pronounced light jumps (e.g., a diode laser)
The educational experience at Politecnico di Torino to develop and increase the capability in aircraft layout comprehension and definition
No full textTechnology roadmaps derivation methodology for European hypersonic and re-entry space transportation systems
No full text
One-year longitudinal study on teachers' voice parameters in secondary-school classrooms: relationships with voice quality assessed by perceptual analysis and voice objective measures
No full textThis longitudinal work explores the relationships between three analyses used for assessing teachers' voice use: the voice monitoring during lessons that describes the teachers' Vocal Behavior (VB), the perceptual assessment of voice by speech-language pathologists and the estimation of objective parameters from vocalizations to define teachers' Vocal Performance (VP). About thirty Italian teachers from secondary schools were involved at the beginning and at the end of a school year. In each period, teachers' vocal activity was monitored using the Voice Care device, which acquires the voice signal through a contact microphone fixed at the neck to estimate sound pressure level, fundamental frequency and voicing time percentage. Once in each period, two speech-language pathologists performed a perceptual assessment of teachers' voice using the GIRBAS-scale. On that occasion, teachers vocalized a sustained vowel standing in front of a sound level meter in a quiet room. Jitter, Shimmer and other parameters were extracted using Praat, while a new metric of Cepstral-Peak-Prominance-Smoothed was estimated with a MATLAB script. Several relationships between the outcomes of each analysis were investigated, e.g. statistical differences between the dimension "G" from GIRBAS-scale and objective measures for VB and VP, and correlations between objective measures and perceptual ratings were assessed
Prosumer behaviour in emerging electricity systems
No full textThis dissertation investigates the interface between technology and society in the emerging electricity systems and in particular the role of the energy prosumer in the energy transition. It contributes to the understanding of the role of consumers in emerging electricity systems within the current EU energy policy context where consumer active participation is regarded as "a prerequisite for managing the energy transition successfully and in a cost-effective way". Emerging energy systems are characterized by a high level of complexity, especially for what concerns the behaviour of social actors. Social actors interact through physical and social networks by sharing information and learning from one another through social interactions. These interactions determine self-organization and emergent behaviours in energy consumption patterns and practices. I argue that the best suited tool to study emergent behaviours in energy consumption patterns and practices, and to investigate how consumers' preferences and choices lead to macro behaviours is agent based modelling. To build a sound characterization of the energy prosumer, I review the current social psychology and behavioural theories on sustainable consumption and collect evidence from EU energy prosumers surveys, studies and demand side management pilot projects. I employ these findings to inform the development of an agent based model of the electricity prosumer, Subjective Individual Model of Prosumer - SIMP, and its extended version, SIMP-N, that includes the modelling of the social network. I apply SIMP and SIMP-N models to study the emergence in consumer systems and how values and beliefs at consumer level (as defined by social psychology and behavioural theories and informed by empirical evidence) and social dynamics lead to macro behaviours. More specifically, I explore the diffusion of smart grid technologies enabled services among a population of interacting prosumers and evaluate the impact of such diffusion on individual and societal performance indicators under different policy scenarios and contextual factors. The analysis of the simulation results provides interesting insights on how different psychological characteristics, social dynamics and technological elements can strongly influence consumers' choices and overall system performance. I conclude proposing a framework for an integrated approach to modelling emerging energy systems and markets that extend the SIMP model to also include markets, distribution system operator and the electricity network