Optimal security-constrained power scheduling by Benders decomposition

This paper presents a Benders decomposition approach to determine the optimal day-ahead power scheduling in a pool-organized power system, taking into account dispatch, network and security constraints. The study model considers the daily market and the technical constraints resolution as two different and consecutive processes. The daily market is solved in a first stage subject to economical criteria exclusively and then, the constraints solution algorithm is applied to this initial dispatch through the redispatching method. The Benders partitioning algorithm is applied to this constraints solution process to obtain an optimal secure power scheduling. The constraints solution includes a full AC network and security model to incorporate voltages magnitudes as they are a critical factor in some real power systems. The algorithm determines the active power committed to each generator so as to minimize the energy redispatch cost subject to dispatch, network and security constraints. The solution also provides the reactive power output of the generators, the value of the transformers taps and the committed voltage control devices. The model has been tested in the IEEE 24-bus Reliability Test System and in an adapted IEEE 118-bus Test System. It is programmed in GAMS mathematical modeling language. Some relevant results are reported.Publicad

Phonographic toys: prejudice and representation in the “pre-cinema” age (1900-1925)

El origen del concepto experiencial de la denominada “sociedad mediática” se remonta mucho más allá de la explosión de las tecnologías de la informática y las telecomunicaciones hacia finales de siglo XX. Durante las primeras décadas del pasado siglo, se desarrolló un proceso de integración de nuevas tecnologías, el cual sentó las bases para el surgimiento del cinema, más que como innovación, como referente indispensable de la moderna sociedad del espectáculo. La conjunción técnica del sonido grabado con la fotografía en movimiento fue fundamental en este proceso. Previo a esta integración se desarrolló un breve período pre-cinema, en el cual surgieron innovaciones de entretenimiento familiar y público, las cuales tomaron forma en una serie de juguetes mecánicos accionados por el mecanismo giratorio del fonógrafo, de reciente invención. Al igual que cualquier juguete convencional o genérico, los llamados “juguetes fonográficos” deben estudiarse como artefactos culturales, esto es, como parte de la cultura material de un grupo social. Más allá del rol del juguete como instrumento genérico de socialización, un gran número de juguetes fonográficos reflejan con claridad una fuerte carga valorativa y una intencionalidad de connotación de elementos de prejuicio y alteridad respecto a raza, género y etnicidad. A través de éste trabajo se analizan varios ejemplos de juguetes fonográficos manufacturados y distribuidos por varias compañías principales entre 1915 y 1920, y se evalúa la forma en que imagen, movimiento, sonido y texto escrito se conjugan en éstos para trasmitir una serie de elementos discursivos y narrativas de alteridad referentes a estos diversos grupos.The origin of the experiential concept known today as the “media society” goes back beyond the so-called explosion of the information and telecommunication technologies at the end of the twentieth century. During the first decades of the last century, a process of integration of new emerging technologies was developed, providing the conditions for the creation of cinema – more than an innovation, as an indispensable reference of the birth of the modern “spectacle society”. The technical integration of recorded sound with moving photography was essential in this process. But short before this crucial integration, a brief “pre-cinema” period emerged, in which several domestic and public entertainment innovations were developed, in the form of a series of mechanical toys activated by the spinning mechanism of the phonograph or gramophone, of recent invention. As any other conventional or generic toy, the so-called “phonotoys” should be considered and studied as cultural artifacts, that is, as part of the material culture of any given social group. Much more than the expected role of toys as conventional means of socialization, a large number of phonotoys reflect a strong values agenda, and a clear intentionality of connotation of prejudice and alter representation of race, genre and ethnicity. In this work we analyze several examples of phonographic toys manufactured and distributed by various companies between 1915 and 1920, identifying the different ways in which visual image, movement, sound and even written texts combine to transmit a series of narratives and discourses regarding these diverse groups

The infrared and molecular environment surrounding the Wolf-Rayet star WR130

We present a study of the molecular CO gas and mid/far infrared radiation arising from the environment surrounding the Wolf-Rayet (W-R) star 130. We use the multi-wavelength data to analyze the properties of the dense gas and dust, and its possible spatial correlation with that of Young Stellar Objects (YSOs). We use CO J=1-0 data from the FCRAO survey as tracer of the molecular gas, and mid/far infrared data from the recent WISE and Herschel space surveys to study the dust continuum radiation and to identify a population of associated candidate YSOs. The spatial distribution of the molecular gas shows a ring-like structure very similar to that observed in the HI gas, and over the same velocity interval. The relative spatial distribution of the HI and CO components is consistent with a photo-dissociation region. We have identified and characterized four main and distinct molecular clouds that create this structure. Cold dust is coincident with the dense gas shown in the CO measurements. We have found several cYSOs that lie along the regions with the highest gas column density, and suggest that they are spatially correlated with the shell. These are indicative of regions of star formation induced by the strong wind and ionization of the WR star.Comment: 15 pages, 12 figures, 6 Tables. Accepted for publication in MNRA

Multiple scattering effects in quasi free scattering from halo nuclei: a test to Distorted Wave Impulse Approximation

Full Faddeev-type calculations are performed for $^{11}$Be breakup on proton target at 38.4, 100, and 200 MeV/u incident energies. The convergence of the multiple scattering expansion is investigated. The results are compared with those of other frameworks like Distorted Wave Impulse Approximation that are based on an incomplete and truncated multiple scattering expansion.Comment: 7 pages, 16 figures, to be published in Phys. Rev.

Empowering Health Information Outreach in New England

The NN/LM empowers change through health information access by raising awareness about National Library of Medicine (NLM) resources such as MedlinePlus.gov and PubMed.gov. Methods to empower change through health information access include training, funding and exhibiting for librarians, health professionals, community based organizations and consumers. Reaching health science librarians and health care professionals with the latest advancements in health information results in better patient care and supports translational research. By increasing access to health information for underserved populations and communities, the NN/LM is a catalyst for change and helps to bridge the digital divide and contribute to health literacy. This poster highlights specific cases of health information outreach by the NN/LM – New England Region. Presented at the North Atlantic Health Sciences Libraries (NAHSL) Annual Meeting, Rockport, ME, October 2009

Emission Quenching in Tetraphenylfuran Crystal: Why This Propeller-Shaped Molecule Does Not Emit in the Condensed Phase

Due to their substantial fluorescence quantum yields in the crystalline phase, propeller-shaped molecules have recently gained significant attention as potential emissive materials for optoelectronic applications. For the family of cyclopentadiene derivatives, light-emission is highly dependent on the nature of heteroatomic substitutions. In this paper, we investigate excited state relaxation pathways in the tetraphenyl-furan molecule (TPF), which in contrast with other molecules in the family, shows emission quenching in the solid-state. For the singlet manifold, our calculations show nonradiative pathways associated with C-O elongation are blocked in both vacuum and the solid state. A fraction of the population can be transferred to the triplet manifold and, subsequently, to the ground state in both phases. This process is expected to be relatively slow due to the small spin-orbit couplings between the relevant singlet-triplet states. Emission quenching in crystalline TPF seems to be in line with more efficient exciton hopping rates. Our simulations help clarify the role of conical intersections, population of the triplet states and crystalline structure in the emissive response of propeller-shaped molecules