Curvature(s) of a light wavefront in a weak gravitational field

The geometry of a light wavefront evolving from a flat wavefront under the action of weak gravity field in the 3-space associated to a post-Newtonian relativistic spacetime, is studied numerically by means of the ray tracing method.Comment: 3 pages, 1 fig, Talk given by JFPS at the 12th Marcel Grossmann conference (Paris, July, 2009), submitted to the Proceeding

Geometry of an accelerated rotating disk

We analyze the geometry of a rotating disk with a tangential acceleration in the framework of the Special Theory of Relativity, using the kinematic linear differential system that verifies the relative position vector of time-like curves in a Fermi reference. A numerical integration of these equations for a generic initial value problem is made up and the results are compared with those obtained in other works.Comment: 10 pages, LaTeX, 2 eps figs; typos corrected, added reference, minor changes; submitte

Mass Selection for Adaptation in Antigua Maize (Zea mays L.) Composite

Tropical maize (Zea mays L.) germplasm has had limited use in temperate areas because of photoperiod sensitivity. Antigua germplasm from the island Antigua was introduced co Iowa because of its resistance to important pests of maize and its heterosis exposed m crosses with ocher tropical varieties. Mass selection procedures were used to adapt the Antigua Composite germplasm co Iowa conditions. After. Six cycles of mass selection for earlier silk emergence, the selected Antigua Composite flowered 17 days earlier than the original composite. Grain yield and ocher agronomic traits of the adapted scram of Antigua were similar co chose of adapted varieties

Recaptura de Strophosoma (Neliocarus) burdigalense (Escalera, 1928) en la Península Ibérica (Coleoptera, Curculionidae). Notas sobre su biología y distribución

To date, only the three syntipic specimens of the Iberian endemism Strophosoma (Neliocarus) burdigalense (Escalera, 1928), were known, from Burgos (without more data). The species has been found again in the neighbouring province of Soria (Castilla and Leon), permitting the finding that its biological cycle is completed in Helianthemum hirtum (Cistaceae). The differential characters of the species are commented and biometrical data, images of the adult, aedeagus, its habitat and food plant are provided.Hasta la fecha se conocían solo los tres ejemplares sintípicos del endemismo ibérico Strophosoma (Neliocarus) burdigalense (Escalera, 1928), procedentes de Burgos (sin más datos). La especie ha sido reencontrada en la vecina provincia de Soria (Castilla y León), permitiendo concretar que completa su ciclo biológico en Helianthemum hirtum (Cistaceae). Se comentan sus caracteres diferenciales y se aportan datos biométricos, imágenes del adulto y su edeago, del hábitat y de su planta nutricia

Presencia de Gymnetron vittipenne Marseul, 1876 en la Península Ibérica (Insecta, Coleoptera, Curculionidae). Notas sobre su biología y distribución

The presence of the weevil Gymnetron vittipenne Marseul, 1876 in the Iberian Peninsula is confirmed definitively due to the collection of this species in northern Spain (La Rioja province). Previously this species was quoted as collected near Madrid, but this datum was always considered doubtful. Its presence in the Iberian Peninsula is of great biogeographical interest since its known range is located in eastern Europe and Central Asia. Biological data on this species are given for the first time.Se confirma definitivamente la presencia del curculiónido Gymnetron vittipenne Marseul, 1876 en la Península Ibérica, sobre la base de su hallazgo en el norte de España (provincia de La Rioja). Anteriormente fue registrada de la provincia de Madrid, aunque esa cita fue considerada como dudosa. Su presencia en la Península Ibérica es de gran interés biogeográfico ya que su área de distribución conocida se localiza en Europa oriental y Asia Central. Se aportan por primera vez datos biológicos para esta especie

Plano de la ciudad, puerto, y arsenal de Cartagena [Material cartográfico]: situado el Observatorio de Caballeros Guardias Marinas en latitud N. 37º 35` 50`` y longitud oriental de Cadiz 5º 16`

Escala tambien expresada en: 1/2 milla marítim

A New Family of Reconfigurable Waveguide Filters and Diplexers for High-Power Applications

[EN] In this paper, we discuss how the use of the recently developed modified tuning pin (MTP) can be extended to the design of filters and diplexers implemented in rectangular waveguide, that can be reconfigured in a number of discrete states, and that can be used in high-power payloads. As an application example, the design of two reconfigurable filters and a reconfigurable diplexer is fully described. The highpower behavior of these components (in particular, with respect to corona and multipaction effects) is also studied in detail, in order to demonstrate that the structures that we discuss can operate correctly under highpower conditions. Furthermore, comparisons between simulations and measurements of several prototypes are also included, showing an excellent agreement between simulated and experimental data, thereby fully validating both the design approach and the filter reconfiguration strategy.This work was supported by the Ministerio de Ciencia e Innovacion, Spanish Government, through the Subprojects C43 and C41 of theCoordinated Research and Development Project PID2019-103982RB under Grant MCIN/AEI/10.13039/501100011033Melgarejo, JC.; Ossorio, J.; Cogollos, S.; Guglielmi, M.; San-Blas, AA.; Valencia-Sullca, JF.; Vidal Pantaleoni, A.... (2023). A New Family of Reconfigurable Waveguide Filters and Diplexers for High-Power Applications. IEEE Access. 11:25102-25119. https://doi.org/10.1109/ACCESS.2023.325608125102251191