Families of Halo-like invariant tori around L2 in the Earth-Moon Bicircular Problem

The Bicircular Problem (BCP) is a periodic time dependent perturbation of the Earth-Moon Restricted Three-Body Problem that includes the direct gravitational effect of the Sun. In this paper we use the BCP to study the existence of Halo-like orbits around $L_{2}$ in the Earth-Moon system taking into account the perturbation of the Sun. By means of computing families of 2D invariant tori, we show that there are at least two different families of Halo-like quasi-periodic orbits around $L_{2}$

Mission design for LISA Pathfinder

Here we describe the mission design for SMART-2/LISA Pathfinder. The best trade-off between the requirements of a low-disturbance environment and communications distance is found to be a free-insertion Lissajous orbit around the first co-linear Lagrange point of the Sun-Earth system L1, 1.5x 10^6 km from Earth. In order to transfer SMART-2/LISA Pathfinder from a low Earth orbit, where it will be placed by a small launcher, the spacecraft carries out a number of apogee-raise manoeuvres, which ultimatively place it to a parabolic escape trajectory towards L1. The challenges of the design of a small mission are met, fulfilling the very demanding technology demonstration requirements without creating excessive requirements on the launch system or the ground segment.Comment: 7 pages, 6 figures, 5th International LISA Symposium, see http://www.landisoft.de/Markus-Landgra

Analytical treatment of the emittance growth in the main Linacs of future linear colliders

In this paper the single and multibunch emittance growths in the main linac of a linear collider are analytically treated in analogy to the Brownian motion of a molecule, and the analytical formulae for the emittance growth due to accelerating structure misalignment errors are obtained by solving Langevin equation. The same set of formulae is derived also by solving directly Fokker-Planck equation. Comparisons with numerical simulation results are made and the agreement is quite well.Comment: 16 pages, 14 figure

Sensitivity study of surface wind flow of a limited area model simulating the extratropical storm Delta affecting the Canary Islands

In November 2005 an extratropical storm named Delta affected the Canary Islands (Spain). The high sustained wind and intense gusts experienced caused significant damage. A numerical sensitivity study of Delta was conducted using the Weather Research & Forecasting Model (WRF-ARW). A total of 27 simulations were performed. Non-hydrostatic and hydrostatic experiments were designed taking into account physical parameterizations and geometrical factors (size and position of the outer domain, definition or not of nested grids, horizontal resolution and number of vertical levels). The Factor Separation Method was applied in order to identify the major model sensitivity parameters under this unusual meteorological situation. Results associated to percentage changes relatives to a control run simulation demonstrated that boundary layer and surface layer schemes, horizontal resolutions, hydrostaticity option and nesting grid activation were the model configuration parameters with the greatest impact on the 48 h maximum 10 m horizontal wind speed solution

Impact of chemical and meteorological boundary and initial conditions on air quality modeling: WRF-Chem sensitivity evaluation for a European domain

This study evaluates the impact of different chemical and meteorological boundary and initial conditions on the state-of-the-art Weather Research and Forecasting (WRF) model with its chemistry extension (WRF-Chem). The evaluation is done for July 2005 with 50km horizontal resolution. The effect of monthly mean chemical boundary conditions derived from the chemical transport model LMDZ-INCA on WRF-Chem is evaluated against the effect of the preset idealized profiles. Likewise, the impact of different meteorological initial and boundary conditions (GFS and Reanalysis II) on the model is evaluated. Pearson correlation coefficient between these different runs range from 0.96 to 1.00. Exceptions exists for chemical boundary conditions on ozone and for meteorological boundary conditions on PM10, where coefficients of 0.90 were obtained. Best results were achieved with boundary and initial conditions from LMDZ-INCA and GFS. Overall, the European simulations show encouraging results for observed air pollutant, with ozone being the most and PM10 being the least satisfyin

Neurofibroma mediastínico

Varón de 3 añios y 9 meses de edad, remitido por su Pediatra, por hallazgo casual de masa torácica tras práctica de radiografía de tórax, con motivo de una infección respiratoria intercurrente...

Entorno de soporte para el autoaprendizaje en el diseño de circuitos digitales

El diseño de circuitos digitales forma parte de las competencias básicas de los nuevos Grados en Ingeniería Informática e Ingeniería de Telecomunicaciones. Un obstáculo importante para el aprendizaje de dichas competencias es que las herramientas académicas existentes para el diseño de circuitos no permiten validar si un diseño se ajusta a la especificación de partida. En este artículo, se describe un entorno de autoaprendizaje para que los estudiantes puedan realizar ejercicios de diseño de circuitos y recibir un feedback continuo.SUMMARY: The design of digital circuits is a basic competence of the new Degrees in Computer Science and Engineering of Telecommunications. An important hindrance in the learning process of these skills is that the existing academic tools for the design of circuits do not allow the student to validate if his design satisfies the specification. In this article, we describe an online environment where the students can verify their designs with an automatic feedback.Peer Reviewe