AlpStore Project: A Viable Model for Renewables Exploitation in the Alps

AbstractNowadays, the integration of intermittent and unpredictable Renewable Energy Sources (RESs) has led to new issues for the electrical system. The paper proposes a model, named Virtual Power System (VPS), which enables the management of generators and loads as a single (virtual) entity in order to achieve a “global” benefit, i.e. to improve the capability of the grid to host RESs. Moreover Energy Storage Systems (ESSs) could be integrated in the VPS in order to provide ancillary services: voltage regulation, primary frequency regulation and exchange profiles adjustment for a better RESs programmability. This work proposes a quantitative approach for ESSs design and integration in a VPS. Numerical results are reported with respect to an experimental application in the AlpStore project (Alpine Space Program 2007-2013)

The spatial distribution of bacteria in Grana-cheese during ripening

The microbial composition and its spatial distribution of Grana Trentino, a hard Parmesan-like cheese, was determined, from vat milk to cheese. After cutting along the vertical axis of the cheese wheels, three layers were sampled diagonally across the cheese: under the cheese rind, an intermediate section and the cheese core. After two different ripening periods (9 and 18 months), the cheese samples were analysed using traditional culture dependent and culture independent methods. Milk samples were dominated by mesophilic and psychrophilic bacterial counts. Thermophilic bacteria (Lactobacillus helveticus) were found in high amounts in cooked whey and natural whey starter cultures. After 9 months of ripening, lactic acid bacteria (LAB) counts were higher than those after 18 months. Furthermore, the LAB numbers in the cheese core was lower than those under the rind or in the intermediate section. The main LAB species isolated from milk (Lactococcus lactis, Pediococcus pentosaceus, Streptococcus uberis and Lactococcus garvieae) were not found in the corresponding cheeses. Some differences were observed in the species composition among the three cheese sections. Microbiota under the rind and in the intermediate section was similar and dominated by Lactobacillus paracasei and Lactobacillus rhamnosus. The core, after 18 months of ripening, was characterized by a total absence of LAB. In each sample, all LAB were genotypically grouped and the different biotypes were subjected to several technological tests indicating that some non-starter LAB (NSLAB) displayed technological features that are favorable for the production of Grana Trentino cheese