RESUMO
Degradation reduces the capability of solar photovoltaic (PV) production over time. Studies on PV module degradation are typically based on time-consuming and labor-intensive accelerated or field experiments. Understanding the modes and methodologies of degradation is critical to certifying PV module lifetimes of 25 years. Both technological and environmental conditions affect the PV module degradation rate. This paper investigates the degradation of 24 mono-crystalline silicon PV modules mounted on the rooftop of Egypt's electronics research institute (ERI) after 25 years of outdoor operation. Degradation rates were determined using the module's performance ratio, temperature losses, and energy yield. Visual inspection, I-V characteristic measurement, and degradation rate have all been calculated as part of the PV evaluation process. The results demonstrate that the modules' maximum power ([Formula: see text]) has decreased in an average manner by 23.3% over time. The degradation rates of short-circuit current ([Formula: see text]) and maximum current ([Formula: see text]) are 12.16% and 7.2%, respectively. The open-circuit voltage ([Formula: see text]), maximum voltage ([Formula: see text]), and fill factor ([Formula: see text]) degradation rates are 2.28%, 12.16%, and 15.3%, respectively. The overall performance ratio obtained for the PV system is 85.9%. After a long time of operation in outdoor conditions, the single diode model's five parameters are used for parameter identification of each module to study the effect of aging on PV module performance.
RESUMO
OBJECTIVE: Multiple myeloma is an incurable hematological malignancy. Currently, the use of proteasome inhibitors could be superior to chemotherapy-based regimen in the treatment of this disease. However, resistance to bortezomib combination therapy still occurs in some patients. So, this research work aims to assess CD69 and CD56 expression in these cases and their relation to the response to therapy. MATERIALS AND METHODS: Immunophenotyping by 4-color multi-parameter flow cytometry was carried out on 98 multiple myeloma cases. Clonal plasma cells were gated by co-expression of CD38 with CD138 with low SSC, negative or dim CD45. RESULTS: Double negative CD69 and CD56 (47.9%) multiple myeloma cases were associated with high serum ß2 microglobulin, creatinine, calcium and low serum albumin. There was also a significant correlation between the absence of these markers with osteolytic lesions and unfavorable cytogenetic t (4;14) (p < 0.001). Moreover, there was a highly significant correlation between CD69- and CD56- with non-response to bortezomib combination therapy in multiple myeloma patients (p < 0.0001). Regression analysis for the prediction of non- response to treatment in these cases using different prognostic indicators revealed that high serum ß2 microglobulin, unfavorable cytogenetic, advanced stage, and low expression of CD69 and CD56 were poor predictors of non-response. CONCLUSION: CD69 in association with CD56 could be an independent prognostic factor in multiple myeloma cases. It could be used in the routine laboratory assessment for refining stratification and timely therapeutic decision for highly cost therapy in developing countries.
