10 research outputs found

    Development of a day-ahead solar power forecasting model chain for a 250 MW PV park in India

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    Due to the steep rise in grid-connected solar Photovoltaic (PV) capacity and the intermittent nature of solar generation, accurate forecasts are becoming ever more essential for the secure and economic day-ahead scheduling of PV systems. The inherent uncertainty in Numerical Weather Prediction (NWP) forecasts and the limited availability of measured datasets for PV system modeling impacts the achievable day-ahead solar PV power forecast accuracy in regions like India. In this study, an operational day-ahead PV power forecast model chain is developed for a 250 MWp solar PV park located in Southern India using NWP-predicted Global Horizontal Irradiance (GHI) from the European Centre of Medium Range Weather Forecasts (ECMWF) and National Centre for Medium Range Weather Forecasting (NCMRWF) models. The performance of the Lorenz polynomial and a Neural Network (NN)-based bias correction method are benchmarked on a sliding window basis against ground-measured GHI for ten months. The usefulness of GHI transposition, even with uncertain monthly tilt values, is analyzed by comparing the Global Tilted Irradiance (GTI) and GHI forecasts with measured GTI for four months. A simple technique for back-calculating the virtual DC power is developed using the available aggregated AC power measurements and the inverter efficiency curve from a nearby plant with a similar rated inverter capacity. The AC power forecasts are validated against aggregated AC power measurements for six months. The ECMWF derived forecast outperforms the reference convex combination of climatology and persistence. The linear combination of ECMWF and NCMRWF derived AC forecasts showed the best result

    Use of Piezoelectric Immunosensors for Detection of Interferon-Gamma Interaction with Specific Antibodies in the Presence of Released-Active Forms of Antibodies to Interferon-Gamma

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    In preliminary ELISA studies where released-active forms (RAF) of antibodies (Abs) to interferon-gamma (IFNg) were added to the antigen-antibody system, a statistically significant difference in absorbance signals obtained in their presence in comparison to placebo was observed. A piezoelectric immunosensor assay was developed to support these data and investigate the effects of RAF Abs to IFNg on the specific interaction between Abs to IFNg and IFNg. The experimental conditions were designed and optimal electrode coating, detection circumstances and suitable chaotropic agents for electrode regeneration were selected. The developed technique was found to provide high repeatability, intermediate precision and specificity. The difference between the analytical signals of RAF Ab samples and those of the placebo was up to 50.8%, whereas the difference between non-specific controls and the placebo was within 5%–6%. Thus, the piezoelectric immunosensor as well as ELISA has the potential to be used for detecting the effects of RAF Abs to IFNg on the antigen-antibody interaction, which might be the result of RAF’s ability to modify the affinity of IFNg to specific/related Abs

    Hydration of the Carboxylate Group in Anti-Inflammatory Drugs: ATR-IR and Computational Studies of Aqueous Solution of Sodium Diclofenac

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    Diclofenac (active ingredient of Voltaren) has a significant, multifaceted role in medicine, pharmacy, and biochemistry. Its physical properties and impact on biomolecular structures still attract essential scientific interest. However, its interaction with water has not been described yet at the molecular level. In the present study, we shed light on the interaction between the steric hindrance (the intramolecular N–H···O bond, etc.) carboxylate group (−CO<sub>2</sub><sup>–</sup>) with water. Aqueous solution of sodium declofenac is investigated using attenuated total reflection-infrared (ATR-IR) and computational approaches, i.e., classical molecular dynamics (MD) simulations and density functional theory (DFT). Our coupled classical MD simulations, DFT calculations, and ATR-IR spectroscopy results indicated that the −CO<sub>2</sub><sup>–</sup> group of the diclofenac anion undergoes strong specific interactions with the water molecules. The combined experimental and theoretical techniques provide significant insights into the spectroscopic manifestation of these interactions and the structure of the hydration shell of the −CO<sub>2</sub><sup>–</sup> group. Moreover, the developed methodology for the theoretical analysis of the ATR-IR spectrum could serve as a template for the future IR/Raman studies of the strong interaction between the steric hindrance −CO<sub>2</sub><sup>–</sup> group of bioactive molecules with the water molecules in dilute aqueous solutions
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