This paper describes the measurement of photovoltaic module performance over a range of temperatures and irradiances according to the international standard IEC 61853 Part 1. The purpose of this work is to assess the reproducibility of power matrix measurements obtained using two methods specified in the standard: under natural sunlight with a tracker, and with a solar simulator. A comparison of results using the third principal method (under natural sunlight without tracker) is also summarised for completeness. The same measurement techniques have been employed to measure four modules of different technologies, namely mono and poly crystalline Si, CdTe and CIS. The method used to vary the irradiance in the natural sunlight with tracker and solar simulator approaches is based on un-calibrated mesh filters. The uniformity and effect on spectrum of the mesh filters have been studied, and the impact of these on the measurements estimated. Measurements from all methods are compared over as much of the ranges as possible. The results show that for all modules, the reproducibility is within the estimated measurement uncertainty. The suitability of the different methods is discussed in light of the results and the limitations of the various methods as applied to different modules technologies. On the basis of the results, parts of IEC 61853 Part 1 will be introduced into the ISO 17025 laboratory accreditation at the European Solar Test Installation (ESTI).
Transarterial chemoembolization (TACE) is the standard of care for the treatment of patients with an intermediate (Barcelona Clinic Liver Cancer [BCLC] B) hepatocellular carcinoma and to bridge patients with an early cancer to liver transplantation (LT). We explored the efficacy of TACE with drug-eluting beads (DEB) in BCLC A patients. Included are all BCLC A patients unsuitable for resection or locoregional ablation who underwent a DEB TACE between 2006 and 2012. Treatment was carried out "a la demande" until complete tumor devascularization or progression beyond Milan criteria. In patients with a complete response (CR), a contrast computed tomography (CT) scan was repeated at 3-month intervals during the first 2 years and then every 6 months alternating with abdominal ultrasound in the subsequent 3 years. Fifty-five patients had 79 tumor nodules ranging 7 to 50 mm; 32 (58%) achieved a CR that was maintained up to 4 and 7 months in 21 (38%) and 17 (31%) patients, respectively. The 24-and 36-month tumor-free survivals were 21% and 9%, respectively. The overall cumulative progression beyond Milan criteria at 3, 6, 12, and 24 months was 2%, 5%, 30%, and 54%. LT eligibility was maintained for a median of 19 months (range, 2-63 months). CR to first TACE was the strongest independent predictor of Milan-in maintenance. In conclusion, DEB TACE may effectively bridge patients with an early cancer to LT, and a CR to the first procedure may guide patient prioritization during the waiting list. Additional supporting information may be found in the online version of this article.
The performance of a PV module at STC [1] is a useful indicator for comparing the peak performance of different module types, but on its own is not sufficient to accurately predict how much energy a module will deliver in the field when subjected to a wide range of real operating conditions [2]. An Energy Rating approach has to be preferred for that aim. It is currently under development the standard series IEC 61853 on Energy Rating, for which only part 1 [3] has been issued. It describes methods to characterize the module performance as a function of irradiance and temperature. The reproducibility of the power matrix measurements obtained by the three different methods specified in the standard, namely: under natural sunlight using a tracking system; under natural sunlight without tracker; and a large area pulsed solar simulator of Class AAA were evaluated and discussed [4,5]. The work here presented is focused on the second method listed above, which explores the real working conditions for a PV device and therefore it represents the situation where Energy Rating procedures are expected to give the largest deviations from the STC predictions. The system for continuous monitoring of module performances, already implemented at ESTI, has been recently replaced with a new system having a number of improvements described in the following. The two system results have been compared showing a discrete compatibility. The two power matrices are then merged together using a weighted average and compared to those acquired with the other two remaining "ideal" systems. An interesting tendency seems to come up from this comparison, making the power rating under real operating conditions an essential procedure for energy rating purposes. a Corresponding
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