Challenges and Technical Requirements for Integration of Renewable Energy Sources in Cuban Electric System

The decision of the Cuban Government to massively introduce Renewable Energy Sources (RES) as a way to change the energy matrix, and in particular, the electricity matrix, is presented as an opportunity to introduce not only sources of energy friendly with the environment, but also make the contributions that, without limiting the development of the country, respond to the UN Millennium Development Goals (UNMDG). However, the large-scale use of RESs in an electrical system such as Cuba, isolated and not interconnected to other systems, can have a group of challenges that must be taken into consideration when it is exploited, since it does not incorporate only new technologies, some of which depend on weather conditions such as solar, wind and hydro technology for the production of electricity, but allow us to think about the introduction of emerging technologies that can increase the penetration of RES in the electrical system and introduce new management concepts, both territorially and nationally. The present work reflects on this, from some experiences that have been analyzed in different research works carried out at CIPEL, plus other International experiences

Caracterização físico-química e determinação de compostos bioativos em casca de bacuri.

O bacuri é um fruto típico da região Amazônica, de grande apelo comercial, mas que apresenta baixo rendimento em polpa. A maior parte do fruto é composta pela casca que é tratada como resíduo agroindustrial. O objetivo desse trabalho foi caracterizar físico-quimicamente a casca do bacuri, assim como também avaliar a presença de compostos bioativos. Utilizou-se o processo de liofilização como forma de preservar esses compostos para as análises e os resultados indicaram que a casca apresentou valores significativos na composição centesimal, destacando-se fibras (23,07%). Em termos de compostos bioativos, compostos fenólicos (1734,8 mg ácido gálico/100 g ) foi o destaque, embora as demais determinações também tenham sido significativas. Dessa forma, pode-se concluir que a casca do bacuri tem um enorme potencial para agregação de valor

OH spectral evolution of oxygen-rich late-type stars

We investigated the main-line spectral evolution with shell thickness of oxygen rich AGB stars. The study is based on a sample of 30 sources distributed along the IRAS colour-colour diagram. The sources were chosen to trace the Miras with thick shells and the whole range of OH/IR stars. The Miras exhibit a 1665 MHz emission strength comparable to that at 1667 MHz. Even though the Miras of the study have quite thick shells, their spectral characteristics in both main lines attest to a strong heterogeneity in their OH shell with, in particular, the presence of significant turbulence and acceleration. The expansion velocity has been found to be about the same at 1665 and 1667 MHz, taking into account a possible velocity turbulence of 1-2km/s at the location of the main-line maser emission. An increase in the intensity ratio 1667/1665 with shell thickness has been found. A plausible explanation for such a phenomenon is that competitive gain in favour of the 1667 MHz line increases when the shell is getting thicker. There is an evolution in the spectral profile shape with the appearance of a substantial inter-peak signal when the shell is getting thicker. Also, inter-peak components are found and can be as strong as the external standard peaks when the shell is very thick. This trend for an increase of the signal in between the two main peaks is thought to be the result of an increase of the saturation with shell thickness. All sources but two - a Mira and an OH/IR star from the lower part of the colour-colour diagram - are weakly polarized. The strong polarization observed for those two particular objects is thought to be the result of perturbations in their shells.Comment: 19 pages, 12 figures, accepted for publication in A&

Extraordinary optical transmission through patterned subwavelength apertures.

Light propagating through a subwavelength aperture can be dramatically increased by etching a grating in the metal around the hole. Moreover, light that would typically broadly diverge when passing through an unpatterned subwavelength hole can be directed into a narrow beam by utilizing a specific pattern around the aperture. While the increased transmission and narrowed angular emission appear to defy far-field diffraction theory, they are consistent with a fortuitous plasmon/photon coupling. In addition, the coupling between photons and surface plasmons affects the emissivity of a surface comprised of such structures. These properties are useful across several strategic areas of interest to Sandia. A controllable emission spectrum could benefit satellite and military application areas. Photolithography and near-field microscopy are natural applications for a system that controls light beyond the diffraction limit in a manner that is easily parallelizable. Over the one year of this LDRD, we have built or modified the numerical tools necessary to model such structures. These numerical codes and the knowledge base for using them appropriately will be available in the future for modeling work on surface plasmons or other optical modeling at Sandia. Using these tools, we have designed and optimized structures for various transmission or emission properties. We demonstrate the ability to design a metallic skin with an emissivity peak at a pre-determined wavelength in the spectrum. We optimize structures for maximum light transmission and show transmitted beams that beat the far-field diffraction limit

Composição química e nutricional da polpa de açaí: comparação entre as variedades roxa e branca.

O açaí roxo é hoje largamente conhecido e comercializado no Brasil e no mundo. Entretanto, há alguns anos o açaí branco vem ganhando destaque na comercialização nos centros urbanos da Amazônia. Pouco se conhece quanto à composição desse tipo de açaí e dessa forma, o objetivo desta pesquisa foi avaliar a polpa extraída de genótipos de açaí roxo e branco quanto à composição química e nutricional. Os resultados mostraram que a variabilidade genética afeta a composição do açaí de forma significativa. Lipídios são os principais constituintes das polpas e o açaí branco apresentou os genótipos com os maiores teores. O açaí branco também se destacou em fibras e proteínas, já o açaí roxo em termos de compostos bioativos. Além da diferença entre os tipos de açaí, observaram-se variações significativas entre genótipos de um mesmo tipo em praticamente todas as determinações, porém em compostos bioativos essas diferenças mostraram-se ainda maiores