| 1. |
- De Julián Fernández, C., et al.
(författare)
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Study of the gas optical sensing properties of Au-polyimide nanocomposite films prepared by ion implantation
- 2005
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Ingår i: Sensors and actuators. B, Chemical. - : Elsevier BV. - 0925-4005 .- 1873-3077. ; 111-112:SUPPL., s. 225-229
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Tidskriftsartikel (refereegranskat)abstract
- Au-polyimide nanocomposites have been synthesized by implanting Au + ions in pyromellitic dianhydride-4,4′ oxydianiline polyimide films prepared by glow discharge vapor deposition polymerisation (GDVDP). A structural and optical characterization shows that Au clusters grow only implanting 5 × 1016 Au+/cm2. This sample class shows interesting dynamic optical absorption sensing responses towards methanol and ethanol vapors in the spectral range corresponding to the surface plasmon resonance (SPR) peak of the gold nanoparticles. Traditional surface plasmon resonance measurements performed onto virgin polyimide thin films in controlled atmosphere show a sensing activity due to a variation of the film thickness and of the real part of refractive index. The comparison of the results obtained onto virgin films and implanted ones suggests that the sensing mechanisms can be attributed both to the modification of polymer optical properties and to the chemical activity of gold nanoparticles. © 2005 Elsevier B.V. All rights reserved.
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| 2. |
- Carturan, S., et al.
(författare)
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Formation of silver nanoclusters in transparent polyimides by Ag-K ion-exchange process
- 2007
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Ingår i: European Physical Journal D. - : Springer Science and Business Media LLC. - 1434-6060 .- 1434-6079. ; 42:2, s. 243-251
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Tidskriftsartikel (refereegranskat)abstract
- Silver nanoclusters embedded in two transparent fluorinated polyimides, 4,4'-hexafluoroisopropylidene diphthalic anhydride - 2,3,5,6-tetramethyl paraphenylene diamine (6FDA-DAD) and 3,3',4,4' - biphenyltetracarboxylic acid dianhydride - 1,1-bis(4-aminophenyl)-1-phenyl-2,2,2-trifluoroethane (BPDA-3F), have been produced by surface modification with KOH aqueous solution followed by K-assisted Ag doping and thermal reduction in hydrogen atmosphere. The reaction rate of the nucleophilic hydrolysis in KOH, studied by Fourier transform infrared spectroscopy (FT-IR) and Rutherford backscattering spectrometry (RBS), depends on the polyimide chemical structure. After ion-exchange in AgNO 3 solution and subsequent annealing, the polyimide structure recovery was monitored by FT-IR whereas the characteristic surface plasmon absorption band of silver nanoparticles was evidenced by optical absorption measurements. The structure of silver nanoclusters as related to size and size distribution in the different polyimide matrices was thoroughly investigated by Transmission electron microscopy (TEM) and X-ray diffraction (XRD). The collected data evidenced a uniform distribution of Ag clusters of nanometric size after thermal treatment at 300 °C in both polyimides. For the same ion-exchange treatment parameters and annealing temperature, XRD analyses evidenced the presence of crystallites with similar sizes. © EDP Sciences/Società Italiana di Fisica/Springer-Verlag 2007.
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| 3. |
- Bonafini, F., et al.
(författare)
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Evaluating indoor and outdoor localization services for LoRaWAN in Smart City applications
- 2019
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Ingår i: Proceedings. - : Institute of Electrical and Electronics Engineers Inc.. - 9781728104294 ; , s. 300-305
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Konferensbidrag (refereegranskat)abstract
- Nowadays, wireless technologies penetrate all aspects of our lives. 'Internet of Things' (IoT) and 'Location- Based Services' are the pillars of Smart City concept. The IoT smart objects surrounding us are an integral part of the Internet, thanks to their computational and communication capabilities. In such applications, location information can be exploited in all the layers of the stack, from the application level (e.g., to correctly interpret measurements from sensor nodes deployed on the field), down to the physical level (e.g., for sensing coverage). One of the most viable solutions for Smart City wireless connectivity seems to be the use of long-range, low-power and low-throughput low-power wide area networks (LPWANs). In this work, the authors devise the jointly use of LPWANs with widely-diffused and well-accepted localization techniques, as the Global Positioning Systems (GPS, outdoor) and real-time location systems (RTLS, indoor), for Smart Campus applications. In particular, a LoRaWAN node equipped with both GPS and Ultra Wide Bandbased UWB-RTLS has been developed and tested in real-world scenarios. Experimental results demonstrate the feasibility of the proposed approach; in particular, location errors are in the order of few tens of meters for GPS and in the order of few tens of centimeters for UWB. © 2019 IEEE.
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| 4. |
- Carturan, S., et al.
(författare)
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Polyimide-based scintillators studied by ion beam induced luminescence
- 2005
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Ingår i: IEEE Transactions on Nuclear Science. - 0018-9499 .- 1558-1578. ; 52:3 II, s. 748-751
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Tidskriftsartikel (refereegranskat)abstract
- New organic scintillators for ionizing radiation sensors are synthesized by dispersing dye molecules into chemically imidized polyimide hosts in order to obtain detection systems with improved radiation resistance with respect to the traditional polyvinyltoluene-based materials. Nile red (NR) and rhodamine B (RB) are dispersed at different concentrations in polyimides derived from the following monomers: 6FDA-DAD, 6FDA-DAB, and BPDA-3F. Scintillating thin films are produced by the spin coating technique. Scintillation tests are performed both on pure polyimides and on binary systems by means of ion beam induced luminescence (IBIL), in which the emission spectrum is collected during the irradiation of the films with a 4He+ beam. From the intensity and the degradation rate of the IBIL signal during irradiation, the scintillation efficiency with respect to NE102 and the radiation hardness of the produced films are calculated. © 2005 IEEE.
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| 5. |
- Carturan, S., et al.
(författare)
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Polyimide-based scintillators studied by ion beam induced luminescence
- 2004
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Ingår i: IEEE Nuclear Science Symposium Conference Record. - 1095-7863. ; 2, s. 869-873
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Tidskriftsartikel (refereegranskat)abstract
- New organic scintillators for ionizing radiation sensors are synthesized by dispersing dye molecules into chemically imidized polyimide hosts in order to obtain detection systems with improved radiation resistance with respect to the traditional polyvinyltoluene based materials. Nile Red and Rhodamine B are dispersed at different concentrations in polyimides derived from the following monomers 6FDA-DAD, 6FDA-DAB and BPDA-3F. Scintillating thin films are produced by the spin coating technique. Scintillation tests are performed both on pure polyimides and on binary systems by means of Ion Beam Induced Luminescence (IBIL), in which the emission spectrum is collected during the irradiation of the films with a 4He+ beam. From the intensity and the degradation rate of the IBIL signal during irradiation, the scintillation efficiency with respect to NE102 and the radiation hardness of the produced films are calculated. © 2004 IEEE.
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| 6. |
- Rinaldi, S., et al.
(författare)
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An experimental characterization of time of arrival accuracy for time synchronization of medium voltage smart grid solutions
- 2019
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Ingår i: AMPS 2019 Proceedings. - : Institute of Electrical and Electronics Engineers Inc.. - 9781728100753
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Konferensbidrag (refereegranskat)abstract
- The time synchronization of smart grid devices is a critical feature for the successful application of advanced grid monitoring and control techniques. Synchronization mechanisms based on the accurate estimation of the Time of Arrival (ToA) of network messages-sent over power line cables-are a promising solution to achieve synchronization tasks over distribution lines. In this paper, a chirp-based synchronization technique over the Medium Voltage (MV) grid has been proposed and characterized. Such approach has the benefit of not requiring the installation of a dedicated infrastructure, thanks to the exploitation of power distribution lines for the transmission of time synchronization data. The effectiveness of the approach has been experimentally evaluated on a simplified MV line available in a testing laboratory. Although, the tested chirp has a limited frequency bandwidth (80 kHz), the maximum variation of the ToA estimation is on the order of 3.5 μs, which fulfills the requirements of most smart grid applications. © 2019 IEEE.
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| 7. |
- Rinaldi, S., et al.
(författare)
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Design of a Time Dissemination System Using Chirp Modulation for Medium Voltage Smart Grid Applications
- 2020
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Ingår i: IEEE Transactions on Instrumentation and Measurement. - : Institute of Electrical and Electronics Engineers Inc.. - 0018-9456 .- 1557-9662. ; 69:9, s. 6686-6695
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Tidskriftsartikel (refereegranskat)abstract
- The monitoring and the management of smart grid require an advanced communication infrastructure. The time synchronization is among the most important services such an infrastructure should offer. Several solutions are available to disseminate the time information in a distributed system; for instance, most of the times a global positioning system (GPS) receiver is used to recover accurate time information. However, GPS receivers need a clear view of the sky. Other solutions, like the use of a network-based synchronization mechanism, require a dedicated communication infrastructure, which is not always feasible for economical reason. Thus, the use of the power grid itself to disseminate a time signal is extremely interesting. The aim of this article is to investigate the possibility to distribute a time signal over a medium voltage (MV) grid using a chirp-based modulation. The timing data are coded using IRIG-B time code. Such an approach does not require the installation of a dedicated infrastructure, and it is noninvasive, because the signal is transmitted on a different band with the respect to power line communication (PLC). The effectiveness of the approach has been experimentally evaluated on a test MV line available in a laboratory. Although the tested chirp-based symbol has a limited frequency bandwidth (80 kHz), the jitter in the identification of the start of frame is on the order of 7.5 μ s, fulfilling the requirements of the most smart grid applications. © 1963-2012 IEEE.
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| 8. |
- Rinaldi, S., et al.
(författare)
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Software-based time synchronization for integrating power hardware in the loop emulation in IEEE1588 power profile testbed
- 2019
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Ingår i: Proceedings. - : IEEE Computer Society. - 9781538676066
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Konferensbidrag (refereegranskat)abstract
- Modern power systems are becoming more and more complex, in order to handle the growing spread of Renewables and of Electric Vehicle charging stations. The control capability relies on the integration of Information and Communication Technology (ICT), including accurate time distribution mechanisms, such as the IEEE 1588 protocol, to the existing distribution grid infrastructure. The validation of such complex systems can hardly be performed in real environments, for both technical and economic reasons. Power Hardware in the Loop (PHIL) emulation systems have already been demonstrated to be effective for this scope. The design of a testbed for the validation of IEEE 1588 power profile based on PHIL solutions requires the capability to synchronize the time bases of the elements forming the testbed. Commercial PHIL systems often offer proprietary synchronization solutions, but these approaches cannot be applied in the general case. In this paper, a software-based solution, able to time synchronize PHIL with IEEE 1588 devices, has been investigated. Such a solution has the advantage that it does not require dedicated hardware, thus it can be applied to different PHIL systems. The experimental characterization highlights that, using such approach, it is possible to reach a time synchronization with an expanded uncertainty (k=3) of 0.75 μs, more than enough to correctly emulate events on the power grid. © 2019 IEEE.
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