Planetary nebulae in the inner Milky Way: new abundances

The study of planetary nebulae in the inner-disk and bulge gives important information on the chemical abundances of elements such as He, N, O, Ar, Ne, and on the evolution of these abundances, which is associated with the evolution of intermediate-mass stars and the chemical evolution of the Galaxy. We present accurate abundances of the elements He, N, S, O, Ar, and Ne for a sample of 54 planetary nebulae located towards the bulge of the Galaxy, for which 33 have the abundances derived for the first time. The abundances are derived based on observations in the optical domain made at the National Laboratory for Astrophysics (LNA, Brazil). The data show a good agreement with other results in the literature, in the sense that the distribution of the abundances is similar to those works.Comment: Accepted for publication in RevMexAA (29 pages, 15 figures, 7 tables, uses rmaa.cls

Planetary nebulae in the inner Milky Way

New abundances of planetary nebulae located towards the bulge of the Galaxy are derived based on observations made at LNA (Brazil). We present accurate abundances of the elements He, N, S, O, Ar, and Ne for 56 PNe located towards the galactic bulge. The data shows a good agreement with other results in the literature, in the sense that the distribution of the abundances is similar to those works. From the statistical analysis performed, we can suggest a bulge-disk interface at 2.2 kpc for the intermediate mass population, marking therefore the outer border of the bulge and inner border of the disk.Comment: 2 pages, 1 figure, uses iaus.cls, in press, IAU Symp. 265, Chemical abundances in the Universe: Connecting the first Stars to Planets, Ed. K. Cunha, M. Spite, B. Barbu

The Impact of Operators' Performance in the Reliability of Cyber-Physical Power Distribution Systems

Cyber-Physical Systems are the result of integrating information and communication technologies into physical systems. One particular case are Cyber-Physical Power Systems (CPPS), which use communication technologies to perform real-time monitoring and operation. These kinds of systems have become more complex, impacting on the systems' characteristics, such as their reliability. In addition, it is already known that in terms of the reliability of Cyber-Physical Power Distribution Systems (CPPDS), the failures of the communication network are just as relevant as the electrical network failures. However, some of the operators' performances, such as response time and decision quality, during CPPDS contingencies have not been investigated yet. In this paper, we introduce a model to the operator response time, present a Sequential Monte Carlo Simulation methodology that incorporates the response time in CPPDS reliability indices estimation, and evaluate the impact of the operator response time in reliability indices. Our method is tested on a CPPDS using different values for the average response time of operators. The results show that the response time of the operators affects the reliability indices that are related to the durations of the failure, indicating that a fast decision directly contributes to the system performance. We conclude that the improvement of CPPDS reliability is not only dependent on the electric and communication components, but also dependent on operators' performance