34 research outputs found

    Conglomerados asiáticos y regionalismo en el Cono Sur americano

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    La globalización está redefiniendo los espacios, procesos y actores del desarrollo latinoamericano. El propósito de este artículo es analizar los nuevos procesos de integración y los emergentes sistemas de negocios en el Cono Sur latinoamericano a la luz de los vínculos con las economías del Este asiático. En particular, estudia los niveles y formas de interacción de los agentes económicos asiáticos, principalmente los grandes grupos empresariales japoneses y coreanos en los dos espacios económicos latinoamericanos: México, Centroaméricay el Caribe, por una parte, y el Cono Sur latinoamericano por la otra

    Overview of the instrumentation for the Dark Energy Spectroscopic Instrument

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    The Dark Energy Spectroscopic Instrument (DESI) embarked on an ambitious 5 yr survey in 2021 May to explore the nature of dark energy with spectroscopic measurements of 40 million galaxies and quasars. DESI will determine precise redshifts and employ the baryon acoustic oscillation method to measure distances from the nearby universe to beyond redshift z > 3.5, and employ redshift space distortions to measure the growth of structure and probe potential modifications to general relativity. We describe the significant instrumentation we developed to conduct the DESI survey. This includes: a wide-field, 3.°2 diameter prime-focus corrector; a focal plane system with 5020 fiber positioners on the 0.812 m diameter, aspheric focal surface; 10 continuous, high-efficiency fiber cable bundles that connect the focal plane to the spectrographs; and 10 identical spectrographs. Each spectrograph employs a pair of dichroics to split the light into three channels that together record the light from 360–980 nm with a spectral resolution that ranges from 2000–5000. We describe the science requirements, their connection to the technical requirements, the management of the project, and interfaces between subsystems. DESI was installed at the 4 m Mayall Telescope at Kitt Peak National Observatory and has achieved all of its performance goals. Some performance highlights include an rms positioner accuracy of better than 0.″1 and a median signal-to-noise ratio of 7 of the [O ii] doublet at 8 × 10−17 erg s−1 cm−2 in 1000 s for galaxies at z = 1.4–1.6. We conclude with additional highlights from the on-sky validation and commissioning, key successes, and lessons learned
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