Olive Actual “on Year” Yield Forecast Tool Based on the Tree Canopy Geometry Using UAS Imagery

Olive has a notable importance in countries of Mediterranean basin and its profitability depends on several factors such as actual yield, production cost or product price. Actual “on year” Yield (AY) is production (kg tree-1) in “on years”, and this research attempts to relate it with geometrical parameters of the tree canopy. Regression equation to forecast AY based on manual canopy volume was determined based on data acquired from different orchard categories and cultivars during different harvesting seasons in southern Spain. Orthoimages were acquired with unmanned aerial systems (UAS) imagery calculating individual crown for relating to canopy volume and AY. Yield levels did not vary between orchard categories; however, it did between irrigated orchards (7000–17,000 kg ha-1) and rainfed ones (4000–7000 kg ha-1). After that, manual canopy volume was related with the individual crown area of trees that were calculated by orthoimages acquired with UAS imagery. Finally, AY was forecasted using both manual canopy volume and individual tree crown area as main factors for olive productivity. AY forecast only by using individual crown area made it possible to get a simple and cheap forecast tool for a wide range of olive orchards. Finally, the acquired information was introduced in a thematic map describing spatial AY variability obtained from orthoimage analysis that may be a powerful tool for farmers, insurance systems, market forecasts or to detect agronomical problems

Sulfonated poly(vinyl alcohol)/graphene oxide composite membranes for proton exchange membrane fuel cells

Different crosslinked composite membranes of Poly(vinyl Alcohol) PVA with sulfosuccinic acid SSA as crosslinking agent and graphene oxide GO were prepared and characterized as a function of the sulfonating degree and GO percentage of each component. The chemical structure of membranes was confirmed by Fourier transform infrared spectroscopy FTIR. The good dispersion of GO into the polymer matrix was verified by scanning transmission microscopy SEM. The proton conductivity of the membranes in fully hydrated state was also investigated by electrochemical impedance spectroscopy EIS. To measure the potential use of PVA membranes as electrolyte were tested in a single proton exchange membrane fuel cell PEMFC. The results reveal that the addition of graphene oxide GO improves the thermal and mechanical stability of the composite membranes. The proton conductivity of the prepared membranes strongly increases by combination of matrix's sulfonating and introduction of GO nanoparticles. Thus, the sulfonating of the polymer matrix in the 30sPVA/SSA/GO membrane increases the proton conductivity a 42% and a 67% of maximum power density respect its homologue 30PVA/SSA membrane. In addition, 30sPVA/SSA/sGO membrane shows the lowest values of proton conductivity and maximum power density, which is consistent with the obtained water uptake values and confirms the improvement of barrier property of these composite membranes