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The importance of oxygen in the winemaking process is widely known, as it affects the chemical aspects and therefore the organoleptic characteristics of the final product. Hence, it is evident the usefulness of a continuous and real-time measurements of the levels of oxygen in the various stages of the winemaking process, both for monitoring and for control. The WOW project (Deployment of WSAN technology for monitoring Oxygen in Wine products) has focused on the design and the development of an innovative device for monitoring the oxygen levels in wine. This system is based on the use of an optical fiber to measure the luminescent lifetime variation of a reference metal/porphyrin complex, which decays in presence of oxygen. The developed technology results in a high sensitivity and low cost sensor head that can be employed for measuring the dissolved oxygen levels at several points inside a wine fermentation or aging tank. This system can be complemented with dynamic modeling techniques to provide predictive behavior of the nutrient evolution in space and time given few sampled measuring points, for both process monitoring and control purposes. The experimental validation of the technology has been first performed in a controlled laboratory setup to attain calibration and study sensitivity with respect to different photo-luminescent compounds and alcoholic or non-alcoholic solutions, and then in an actual case study during a measurement campaign at a renown Italian winery.

This paper reports an extensive analysis of the degradation of deep-ultraviolet light-emitting diodes submitted to dc stress test. The study was carried out by means of combined electrical and optical characterization techniques. Results described in the paper indicate that the following: i stress can induce a significant decrease in the optical power emitted by the devices; ii optical power decrease is more prominent at low measuring current levels, thus suggesting that degradation is related to an increase in the concentration of defects; iii stress induces a significant increase in the green-yellow parasitic emission of the devices; and iv stress causes a localized increase in the apparent charge distribution profiles in the active region of the devices. Experimental evidence collected within this work suggest that degradation is due to an increase in the defectiveness in the active layer of the devices, with subsequent worsening of their radiative efficiency

No abstract

Pseudoaneurysm treatment with overlapping stents may be a useful technique to reduce flow and enhance thrombosis in the aneurysmal sac. We treated a pseudoaneurysm of the left carotid artery in a patient with a history of bilateral carotid thromboendarterectomy by placing three stents and overlapping them at the level of the aneurysmal neck. Nine month follow-up revealed almost complete pseudoaneurysm exclusion and patency of the carotid artery.