Integration of Novel Sensors and Machine Learning for Predictive Maintenance in Medium Voltage Switchgear to Enable the Energy and Mobility Revolutions

The development of renewable energies and smart mobility has profoundly impacted the future of the distribution grid. An increasing bidirectional energy flow stresses the assets of the distribution grid, especially medium voltage switchgear. This calls for improved maintenance strategies to prevent critical failures. Predictive maintenance, a maintenance strategy relying on current condition data of assets, serves as a guideline. Novel sensors covering thermal, mechanical, and partial discharge aspects of switchgear, enable continuous condition monitoring of some of the most critical assets of the distribution grid. Combined with machine learning algorithms, the demands put on the distribution grid by the energy and mobility revolutions can be handled. In this paper, we review the current state-of-the-art of all aspects of condition monitoring for medium voltage switchgear. Furthermore, we present an approach to develop a predictive maintenance system based on novel sensors and machine learning. We show how the existing medium voltage grid infrastructure can adapt these new needs on an economic scale

Attosecond nanoscale near-field sampling

The promise of ultrafast light-field-driven electronic nanocircuits has stimulated the development of the new research field of attosecond nanophysics. An essential prerequisite for advancing this new area is the ability to characterize optical near fields from light interaction with nanostructures, with sub-cycle resolution. Here we experimentally demonstrate attosecond near-field retrieval for a tapered gold nanowire. By comparison of the results to those obtained from noble gas experiments and trajectory simulations, the spectral response of the nanotaper near field arising from laser excitation can be extracted.113023Ysciescopu

Enhanced methane production from wool textile residues by thermal and enzymatic pretreatment

Methane production from two types of wool textile wastes (TW1 and TW2) was investigated. To improve the digestibility of these textiles, different pretreatments were applied, and comprised thermal treatment (at 120 C for 10 min), enzymatic hydrolysis (using an alkaline endopeptidase at different levels of enzymatic loading, at 55 C for 0, 2, and 8 h), and a combination of these two treatments. Soluble protein concentration and sCOD (soluble chemical oxygen demand) were measured to evaluate the effectivity of the different pretreatment conditions to degrade wool keratin. The sCOD as well as the soluble protein content had increased in both textile samples in comparison to untreated samples, as a response to the different pretreatments indicating breakdown of the wool keratin structure.The combined treatments and the thermal treatments were further evaluated by anaerobic batch digestion assays at 55 C. Combined thermal and enzymatic treatment of TW1 and TW2 resulted in methane productions of 0.43 N m(3)/kg VS and 0.27 N m(3)/kg VS, i.e., 20 and 10 times higher yields, respectively, than that gained from untreated samples. The application of thermal treatment by itself was less effective and resulted in increasing the methane production by 10-fold for TW1 and showing no significant improvement for TW2

Pretreatment of Chicken Feather Waste for Improved Biogas Production

This study deals with the utilization of chicken feather waste as a substrate for anaerobic digestion and improving biogas production by degradation of the compact structure of the feather keratin. In order to increase the digestibility of the feather, different pretreatments were investigated, including thermal pretreatment at 120 A degrees C for 10 min, enzymatic hydrolysis with an alkaline endopeptidase [0.53-2.66 mL/g volatile solids (VS) feathers] for 0, 2, or 24 h at 55 A degrees C, as well as a combination of these pretreatments. The effects of the treatments were then evaluated by anaerobic batch digestion assays at 55 A degrees C. The enzymatic pretreatment increased the methane yield to 0.40 Nm(3)/kg VSadded, which is 122 % improvement compared to the yield of the untreated feathers. The other treatment conditions were less effective, increasing the methane yield by 11-50 %. The long-term effects of anaerobic digestion of feathers were examined by co-digestion of the feather with organic fraction of municipal solid waste performed with and without the addition of enzyme. When enzyme was added together with the feed, CH4 yield of 0.485 Nm(3)/kg VS-1 d(-1) was achieved together with a stable reactor performance, while in the control reactor, a decrease in methane production, together with accumulation of undegraded feather, was observed

Caratterizzazione di lesioni focali epatiche in pazienti cirrotici mediante tecnica ecografica contrasto-specifica Pulse Inversion Harmonic Imaging con mezzo di contrasto Levovist

Purpose. To evaluate the capabilities of Pulse Inversion Harmonic Imaging (PIHI) with hepatospecific US contrast agent Levovist in the characterization of focal liver lesions in cirrhotic patients. Materials and methods. Thirty-nine focal hepatic lesions in 25 consecutive cirrhotic patients identified by conventional ultrasound (US), were evaluated by color Doppler (CD), power Doppler (PD) with spectral analysis of tumoural vessels and PIHI. PIHI was performed 30 seconds (vascular phase) and 3-5 minutes (late phase) after Levovist injection. To definitely characterize the evaluated focal hepatic lesions, helical-CT (HCT) enhancement patterns (15 patients) and/or surgical/bioptic histologic findings (10 patients) were considered as reference procedures. Results. Thirty focal hepatic lesions classified as hepatocellular carcinoma (HCC) by reference procedures appeared hypoechoic (n=19), isoechoic (n=5) or hyperechoic (n=6) on conventional US, with basket arterial pattern (n=10), vessels within the tumor (n=6), peripheral arterial pattern (n=4) or no vascular pattern (n=10) on CD/PD evaluation. On PIHI they appeared hyperechoic (n=26) or isoechoic (n=4) in the vascular phase, if compared to the surrounding liver parenchyma, and hypoechoic (n=23) or isoechoic (n=7) in the late phase. Four focal hepatic lesions classified as regenerative nodules (RNs) by reference procedures appeared hypoechoic on conventional US, with peripheral venous/arterial pattern (n=1) or no vascular pattern (n=3) on CD/PD. On PIHI they appeared hypoechoic (n=3) or isoechoic (n=1) in the vascular phase, remaining prevalently hypoechoic (n=3) or isoechoic (n=1) in the late phase. Five focal hepatic lesions classified as hemangioma by reference procedures appeared hyperechoic (n=4) or hypoechoic (n=1) on conventional US with few peripheral venous vessels on CD/PD. On PIHI they revealed progressive fill-in from the periphery toward the centre during the vascular and late phase after Levovist injection. Conclusions. PIHI seems to be a reliable technique to characterize focal lesions in cirrhotic patients

Characterization of focal liver lesions by pulse inversion harmonic imaging (PIHI) with Levovist in patients with cirrhosis

5nonenoneForgacs B; Quaia E; Bertolotto M; Crocè L; Dalla Palma L.Forgacs, B; Quaia, Emilio; Bertolotto, Michele; Croce', Saveria; Dalla Palma, L