Intermediate mass stars: updated models

A new set of stellar models in the mass range 1.2 to 9 $M_{\odot}$ is presented. The adopted chemical compositions cover the typical galactic values, namely $0.0001 \le Z \le 0.02$ and $0.23 \le Y \le 0.28$. A comparison among the most recent compilations of similar stellar models is also discussed. The main conclusion is that the differencies among the various evolutionary results are still rather large. For example, we found that the H-burning evolutionary time may differ up to 20 %. An even larger disagreement is found for the He-burning phase (up to 40-50 %). Since the connection between the various input physics and the numerical algorithms could amplify or counterbalance the effect of a single ingredient on the resulting stellar model, the origin of this discrepancies is not evident. However most of these discrepancies, which are clearly found in the evolutionary tracks, are reduced on the isochrones. By means of our updated models we show that the ages inferred by the theory of stellar evolution is in excellent agreement with those obtained by using other independent methods applied to the nearby Open Clusters. Finally, the theoretical initial/final mass relation is revised.Comment: 35 pages, 24 figures, 4 tables, accepted for publication in the Astrophisycal Journa

Resolved photometry of extragalactic young massive star clusters

We present colour-magnitude diagrams (CMDs) for a sample of seven young massive clusters in the galaxies NGC 1313, NGC 1569, NGC 1705, NGC 5236 and NGC 7793. The clusters have ages in the range 5-50 million years and masses of 10^5 -10^6 Msun. Although crowding prevents us from obtaining photometry in the central regions of the clusters, we are still able to measure up to 30-100 supergiant stars in each of the richest clusters, along with the brighter main sequence stars. The resulting CMDs and luminosity functions are compared with photometry of artificially generated clusters, designed to reproduce the photometric errors and completeness as realistically as possible. In agreement with previous studies, our CMDs show no clear gap between the H-burning main sequence and the He-burning supergiant stars, contrary to predictions by common stellar isochrones. In general, the isochrones also fail to match the observed number ratios of red-to-blue supergiant stars, although the difficulty of separating blue supergiants from the main sequence complicates this comparison. In several cases we observe a large spread (1-2 mag) in the luminosities of the supergiant stars that cannot be accounted for by observational errors. This spread can be reproduced by including an age spread of 10-30 million years in the models. However, age spreads cannot fully account for the observed morphology of the CMDs and other processes, such as the evolution of interacting binary stars, may also play a role.Comment: 15 pages, 12 figures, accepted for publication in A&

Marine Solar Charger

When fishermen go on extended fishing or recreational trips, they use 12VDC batteries to charge various loads: such as fish finders, LED lights and cellular devices. The main objective for team The Solars is to provide an alternative source of power in the form of a solar battery charging station for kayakers who need to recharge their 12VDC batteries. The design incorporates many different features, including an automated solar tracking system that helps optimize the time to charge the battery, a custom charge controller and a universal mount system that can be used on different kayaks

How living labs can achieve long-term livability through business models and funding opportunities

Living labs are a well-known but little-understood idea. Over the last decades, more Living Labs have been established for creating innovation and solving challenging problems of the modern world. The core of the Living Labs is that they use user-centered approaches considering the different actors' opinions, making way for more collaborative and participatory methods. An ambitious project called Soil Mission uses Living Labs and Lighthouses as its primary method for leading the transition toward healthier soils in Europe. This research will focus only on Living Labs. Even though Living Labs have created a prosperous environment for Research& Innovation, most of the time fail to stay alive for a more extended period than only one project. Two central problems have been identified after research: the lack of successful business models and funding. Little research has been done to identify the reasons behind these two problems. This study will mainly focus on exploring the two challenges in depth and propose ways of dealing with them so the Soil Mission’s Living Labs can achieve long-term livability. A qualitative approach will be used, and through interviews and analyzing case studies the researcher is expected to gain more insight into this topic and answer the research questions. In the end, recommendations will be given based on the data that will arise. Key Words: Soil Mission, Living Labs, Business Model, Fundin