Performance analysis and neural modelling of a greenhouse integrated photovoltaic system

In the modern agriculture, greenhouses are well established as technological solutions aimed to increase plants productivity and crops quality. Greenhouses can include added capabilities for the energy generation by the integration of photovoltaic solar modules in their cladding areas provided that the blocking effect of photosynthetically active radiation is not significant for plants growing. After a comprehensive literature survey on the integration of photovoltaic systems in greenhouses, this work describes the results of an experience carried out at Almería (South Eastern Spain), where it has been built and monitored a 1.024 m² pilot photovoltaic greenhouse. The experimental set up has consisted of a greenhouse roof 9.79% coverage ratio by means of 24 flexible thin film modules, installed in two different checkerboard configurations. The obtained results indicate that, for the conditions of the undertaken experiment, the yearly electricity production normalised to the greenhouse ground surface is 8.25 kW h m^?2, concordant to previous findings for the used type of modules. In addition to this, an artificial neural network model has been elaborated to predict the electricity instantaneous production of the system, showing the suitability of this modelling technique for complex and non linear systems, as it is the case of the constructively integrated PV plants, either in greenhouses and buildings, where both impinging radiation and system configuration are highly constrained by the pre-existing structures.     

Occurrence of pharmaceutically active compounds during 1-year period in wastewaters from four wastewater treatment plants in Seville (Spain)

Several pharmaceutically active compounds have been monitored during 1-year period in influent and effluent wastewater from wastewater treatment plants (WWTPs) to evaluate their temporal evolution and removal from wastewater and to know which variables have influence in their removal rates. Pharmaceutical compounds monitored were four antiinflammatory drugs (diclofenac, ibuprofen, ketoprofen and naproxen), an antiepileptic drug (carbamazepine) and a nervous stimulant (caffeine). All of the pharmaceutically active compounds monitored, except diclofenac, were detected in influent and effluent wastewater. Mean concentrations measured in influent wastewater were 6.17, 0.48, 93.6, 1.83 and 5.41 microg/L for caffeine, carbamazepine, ibuprofen, ketoprofen and naproxen, respectively. Mean concentrations measured in effluent wastewater were 2.02, 0.56, 8.20, 0.84 and 2.10 microg/L for caffeine, carbamazepine, ibuprofen, ketoprofen and naproxen, respectively. Mean removal rates of the pharmaceuticals varied from 8.1% (carbamazepine) to 87.5% (ibuprofen). The existence of relationships between the concentrations of the pharmaceutical compounds, their removal rates, the characterization parameters of influent wastewaters and the WWTP control design parameters has been studied by means of statistical analysis (correlation and principal component analysis). With both statistical analyses, high correlations were obtained between the concentration of the pharmaceutical compounds and the characterization parameters of influent wastewaters; and between the removal rates of the pharmaceutical compounds, the removal rates of the characterization parameters of influent wastewaters and the WWTP hydraulic retention times. Principal component analysis showed the existence of two main components accounting for 76% of the total variability.     

Influence of Irrigation Modalities (Irrigation Management and Dryland), Fruit Ripening,and Cultivation Modality (Organic and Conventional) on Quality and Chemosensory Profile of Hojiblanca and Picual Extra Virgin Olive Oils

A study with controlled field and authentic samples of olives, obtained in similar conditions of soil, climate, region, harvest, and with the same cultivation techniques and considering simultaneously different agronomic factors (olive variety, fruit ripening degree, irrigation, and organic or conventional production system) is performed to evaluate their influence on quality and added value of extra virgin olive oil (EVOO). Agronomical and physicochemical parameters, polyphenols, tocopherols, and fatty acid composition and volatile and sensory profiles are determined in Hojiblanca and Picual VOOs obtained from different fruit ripening degrees and different cultivation modalities (conventional with and without irrigation, and organic with irrigation). Among volatile compounds, 1-hydroxy-2-propanone, (E)-linalool oxide, and 2-acetylfuran are described for the first time in EVOO. The variable that most influences the chemosensory composition of EVOOs is the variety, followed by the stage of ripeness, and, within each variety, the cultivation modality. Organic irrigation differ from conventional modalities, showing significant differences in acidity, stability, tocopherol and polyphenol contents, fatty acid composition, and sensory attributes. Practical Applications: Results are of great importance, due to their applicability to the EVOO sector, allowing one to know the qualitative, chemical and organoleptic differences between organic and conventional EVOO, and factors that improve the quality and performance of EVOO.     

Changes on free amino acids during the alcoholic fermentation of strawberry and persimmon

Changes in amino acids and ammonium were monitored during the alcoholic fermentation of strawberry and persimmon purees. Fermentations were carried out either by autochthonous or by commercial yeasts. The amino acid content in strawberry and persimmon was lower than that of grapes but enough to successfully perform the alcoholic fermentation, showing a different consumption pattern. Arginine, although is not present in the most strawberry substrates, appears in strawberry wines (2.75–3.36 mg L^?1). Additionally, as opposed to grape wine, an exceptional high consumption of proline was observed during the alcoholic fermentation of strawberry purees. The consumption of amino acids was highly influenced by the substrate and the S. cerevisiae strain used for the fermentation process. These results were confirmed by principal component analysis, which was able to group the samples based on substrate, harvest or yeast strain, considering the amino acids as variables.     

Concentration of Docosahexaenoic Acid (DHA) by Selective Alcoholysis Catalyzed by Lipases

The aim of this work was to obtain acylglycerols from tuna oil (23 % weight DHA) rich in docosahexaenoic acid (DHA) by selective ethanolysis, catalyzed by lipases. First, seven immobilized lipases were tested and the best DHA concentration and recovery in the acylglycerol fraction were attained with Lipozyme TL IM^® from Thermomyces lanuginosus, Lipozyme RM IM from Rhizomucor miehei, and lipase from Thermomyces lanuginosus immobilized on Immobead 150. As it is the cheapest, Lipozyme TL IM^® was selected to optimize the reaction conditions. The influence of temperature, reaction time, and ethanol/oil and lipase/oil ratios were studied. Under the optimized conditions (35 °C, ethanol/oil molar ratio 2.3, lipase/oil ratio 5 % weight and 48 h) and for a 56 % conversion, acylglycerols were obtained with a 45 % DHA concentration and 90 % recovery. In these optimized conditions the reaction was scaled up to 766 g of tuna oil and carried out in a batch stirred tank reactor, with the lipase contained in a cartridge filter attached to the stirring rod. The results were similar to those obtained on the smaller scale. The DHA-enriched acylglycerols were separated from the ethyl esters by evaporation of the latter in a short-path vacuum distiller, where the influence of distillation temperature was studied. At 170 °C DHA-rich acylglycerols (44 % DHA) were recovered in the residue with 94.5 % purity and 72 % recovery.     

Consumer acceptance of new strawberry vinegars by preference mapping

Consumers’ acceptance of new strawberry vinegars was evaluated, and trained panellists described their sensory profiles. Four strawberry vinegars, three produced from puree and one from cooked must, were evaluated jointly. Due to obtaining the highest percentage of consumer acceptance, cooked strawberry must vinegar was considered to be the best. This vinegar stood out in general impression, raisin, and liqueur attributes. Internal preference maps confirmed a higher acceptance level for the strawberry vinegars over commercial vinegar. External preference mapping, obtained by PLS2 analysis, revealed that the main sensory attributes driving consumers’ preferences are raisin, toasted caramel, spicy, and liqueur aroma.