Photovoltaic (PV) system performance is influenced by several factors, including irradiance, temperature, shading, degradation, mismatch losses, soiling, etc. Shading of a PV array, in particular, either complete or partial, can have a significant impact on its power output and energy yield, depending on array configuration, shading pattern, and the bypass diodes incorporated in the PV modules. In this paper, the effect of partial shading on multicrystalline silicon (mc-Si) PV modules is investigated. A PV module simulation model implemented in P-Spice is first employed to quantify the effect of partial shading on the I-V curve and the maximum power point (MPP) voltage and power. Then, generalized formulae are derived, which permit accurate enough evaluation of MPP voltage and power of mc-Si PV modules, without the need to resort to detailed modeling and simulation. The equations derived are validated via experimental results.

The capability of distributed generation (DG) resources to regulate their reactive output power remains currently unexploited, particularly in the case of LV networks, where DG sources operate at unity power factor (pf). In this paper, the impact of various pf regulation methods is evaluated for DG sources connected to the LV level. Typical LV feeders with high PV penetration levels are assumed and the effect on voltage profile and feeder losses is evaluated, to quantify the benefits from each pf regulation policy. (4 pages)

The role of nutrition in the management of asthma in obese patients is of increasing interest due to their limited response to inhaled corticosteroids. Some studies note that through diet and lifestyle, there can be an improvement in asthma control. The aim of the present study was to investigate the adherence to the Mediterranean Diet and its association with asthma severity and quality of life in patients with bronchial asthma. This is a cross-sectional study of 85 patients (70.6% female), with a mean age of 57 years, from the General University Hospital of Larissa and, more specifically, patients of the outpatient asthma clinic. Data were collected with the use of specific questionnaires. In relation to BMI, 12.9% of participants were of a normal weight, 45.9% were overweight, 25.9% were obese level I, 5.9% were obese level II, and 9.4% were in the morbidly obese range. Based on the Med Diet Score (ranging from 21 to 35), most participants (85.9%) reported moderate adherence to the Mediterranean Diet. Further analysis examined the correlations of the PCS-12 score with the frequency of consumption of each of the 11 food categories, as well as all demographic and health behavior variables. The ranked correlations indicated a significant relationship between PCS-12 score and Med Diet adherence and the consumption of alcoholic beverages (r = 0.437, p < 0.05), in accordance with the Mediterranean Diet suggestions, as well as a negative relationship with BMI score (r = −0.454, p < 0.010). Moreover, significant correlations were also present between the physical quality of life and AQLQ score and work type, as well as gender, age, and marital status. The results of our study showed a high rate of obesity in patients with asthma at the General University Hospital of Larissa and moderate adherence to the Mediterranean Diet. Increased BMI and alcoholic beverage consumption in asthma patients were significant predictors of lower physical health-related quality of life. In conclusion, personal and society-level interventions are required to effectively address obesity and poor diet in patients with asthma.

Photovoltaic system performance is influenced by a variety of factors such as irradiance, temperature, shading, degradation, mismatch losses, soiling, etc. Especially shading, complete or partial, can have a significant contribution to the reduction of power output, depending mainly on the PV array configuration, the shading pattern and the existence of bypass diodes incorporated in the PV module design. In order to obtain the maximum power from a PV generator, it is of great importance to evaluate the complex effects of shading on the P-V and I-V curves.