Parallel modernities. Notes on artistic modernity in the Southern Cone of Latin America: The case of Paraguay

The author of this article is one of the most important intellectuals in the Latin American artistic scene. Focusing on the particular case of Paraguay, which was governed by the dictatorship of Alfred Stroessner from 1954 until 1989, Escobar traces the modernist impulse in Paraguay and traces its complicated and disturbed relationship with European and North American models and antecedents: Neo-Impressionism, Cubism, Expressionism, Abstraction, and similar. While they reflect the particular political conditions under which the artists worked, the diverse and many-voiced Paraguayan responses also offer an exemplary set of responses that shed light on the development of twentieth-century modernist art and visual culture across the broader South American continent

Particular Integrability and (Quasi)-exact-solvability

A notion of a particular integrability is introduced when two operators commute on a subspace of the space where they act. Particular integrals for one-dimensional (quasi)-exactly-solvable Schroedinger operators and Calogero-Sutherland Hamiltonians for all roots are found. In the classical case some special trajectories for which the corresponding particular constants of motion appear are indicated.Comment: 13 pages, typos correcte

A prototype reactor to compost agricultural wastes of Fusagasuga Municipality. Colombia

Crop and animal production generate a high level of organic waste that causes negative effects on the environment and communities. The use of composting processes can improve the quality of these biowastes. Additionally, the application of technologies such as telemetry and remote sensors, allows optimizing the transformation of organic matter in a more controlled and efficient way. The city of Fusagasugá is well known in agriculture. However, it lacks sustainable management of the organic waste system. In this study, after a three-dimensional electromechanical design, a prototype reactor to compost agricultural wastes of Fusagasuga municipality will provide. The capacity of this prototype reactor is considered to be 20 litres. In order to control temperature and humidity of biowastes in different working conditions, it is used A PI controller with 3 temperature and a humidity sensors. With these sensors the compost materials temperature and humidity will remain at 65 °C and 55–60%. By using a special form of temperature sensor placement, the time to oxygenate the compost materials will be found. Furthermore, this system is integrated by a Human-Machine Interface (HMI), which allows the supervision and manipulation from a remote access user

Runaway evaporation for optically dressed atoms

Forced evaporative cooling in a far-off-resonance optical dipole trap is proved to be an efficient method to produce fermionic- or bosonic-degenerated gases. However in most of the experiences, the reduction of the potential height occurs with a diminution of the collision elastic rate. Taking advantage of a long-living excited state, like in two-electron atoms, I propose a new scheme, based on an optical knife, where the forced evaporation can be driven independently of the trap confinement. In this context, the runaway regime might be achieved leading to a substantial improvement of the cooling efficiency. The comparison with the different methods for forced evaporation is discussed in the presence or not of three-body recombination losses

Bose-Einstein Condensation of 88^{88}Sr Through Sympathetic Cooling with 87^{87}Sr

We report Bose-Einstein condensation of $^{88}$Sr, which has a small, negative s-wave scattering length ($a_{88}=-2$\,$a_0$). We overcome the poor evaporative cooling characteristics of this isotope by sympathetic cooling with $^{87}$Sr atoms. $^{87}$Sr is effective in this role in spite of the fact that it is a fermion because of the large ground state degeneracy arising from a nuclear spin of $I=9/2$, which reduces the impact of Pauli blocking of collisions. We observe a limited number of atoms in the condensate ($N_{max}\approx 10^4$) that is consistent with the value of $a_{88}$ and the optical dipole trap parameters.Comment: 4 pages, 4 figure

Fundamentos de ciencias físicas y químicas para los nuevos títulos de grado de maestro de primaria

Se presenta una adaptación de bloques correspondientes a fundamentos básicos de física y fundamentos básicos de química, que podrían formar parte de las futuras asignaturas correspondientes al módulo didáctico disciplinar Aprendizaje y enseñanza de las ciencias experimentales, del Título de Grado de Maestro de Educación Primaria. Se describen las tareas que se han llevado a cabo para elaborar o adaptar recursos, diseñar la guías de trabajo y planificar la organización docente. Finalmente, se analizan los primeros datos obtenidos tras recoger información sobre la implementación de estos recursos durante el curso 2008/09

Flavor Delta(54) in SU(5) SUSY Model

We design a supersymmetric SU (5) GUT model using \Delta (54), a finite non-abelian subgroup of SU (3)f . Heavy right handed neutrinos are introduced which transform as three-dimensional repre-sentation of our chosen family group. The model successfully reproduces the mass hierarchical mass structures of the Standard Model, and the CKM mixing matrix. It then provides predictions for the light neutrino with a normal hierarchy and masses such that m{\nu},1 \approx 5\times10-3 eV, m{\nu}, 2 \approx 1\times 10-2 eV, and m{\nu},3 \approx 5 \times 10-2 eV. We also provide predictions for masses of the heavy neutrinos, and correc- tions to the tri-bimaximal matrix that fit within experimental limits, e.g. a reactor angle of -7.31o. A simple modification to our model is introduced at the end and is shown to also produce predictions that fall well within those limits.Comment: 22 page

Percepción de estudiantes de magisterio sobre clases reales de ciencias en centros escolares de Irlanda

Este trabajo forma parte de una investigación consistente en emplear la percepción de los estudiantes de magisterio durante el prácticum, para estudiar las clases reales de ciencias en la etapa de primaria. En esta fase del proyecto hemos reunido datos procedentes de centros escolares de Irlanda, en los que se analizan recursos como laboratorios, huertos escolares, así como aspectos organizativos y metodológicos. Estos resultados permiten abordar una primera aproximación a una valoración comparativa con la situación encontrada en los centros españoles