1,000 research outputs found
Propulsion Technologies for Future Aircraft Generations: A NASA Perspective
No abstract availabl
Next Generation Aircraft Electrical Power Systems and Hybrid/All Electric Aircraft
Presentation to Aerospace Electrical Systems Expo, providing an overview of NASA's work on hybrid electric and all electric propulsion and projecting technology needs
Green Propulsion Technologies for Advanced Air Transports
Air transportation is critical to U.S. and Global economic vitality. However, energy and climate issues challenge aviations ability to be sustainable in the long term. Aviation must dramatically reduce fuel use and related emissions. Energy costs to U.S. airlines nearly tripled between 1995 and 2011, and continue to be the highest percentage of operating costs. The NASA Advanced Air Transports Technology Project addresses the comprehensive challenge of enabling revolutionary energy efficiency improvements in subsonic transport aircraft combined with dramatic reductions in harmful emissions and perceived noise to facilitate sustained growth of the air transportation system. Advanced technologies and the development of unconventional aircraft systems offer the potential to achieve these improvements. The presentation will highlight the NASA vision of revolutionary systems and propulsion technologies needed to achieve these challenging goals. Specifically, the primary focus is on the N+3 generation; that is, vehicles that are three generations beyond the current state of the art, requiring mature technology solutions in the 2025-30 timeframe, which are envisioned as being powered by Hybrid Electric Propulsion Systems
Propulsion Technologies for Future Aircraft Generations: Clean, Lean, Quiet, and Green
No abstract availabl
Electrified Aircraft Propulsion Development
The benefits of electrified aircraft propulsion improves aircrafts like single aisle transports, enables new configurations of vertical take-off landing aircrafts and revitalizes the economic case for small short-range aircraft services. Future strategies and markets for supersonic and commercial transport are proposed
The lowland seasonally dry subtropical forests in central Argentina: vegetation types and a call for conservation
The native woody vegetation from the Espinal phytogeographic province in central Argentina, found in subtropical-warm temperate climates, represents part of the southernmost seasonally dry forest in South America. Although this vegetation has been studied for over a century, a complete phytosociological survey is still needed. This lack of knowledge makes its spatial delimitation and the establishment of efficient conservation strategies particularly difficult. The main goals of this study were to classify these forests and assess their current forest cover and to better define the extent of the Espinal phytogeographic province in Córdoba region, central Argentina. Study area: Espinal Phytogeographic Province in Córdoba region, central Argentina (ca. 101,500 km2). Methods: We sampled 122 stands following the principles of the Zürich-Montpellier School of phytosociology; relevés were classified through the ISOPAM hierarchical analysis. The extent of the Espinal phytogeographic province was established by overlaying previous vegetation maps, and a map showing the current distribution of forest patches was constructed based on a supervised classification of Landsat images. Results: Four woody vegetation types of seasonally dry subtropical forest were identified based on the fidelity and the abundance of diagnostic species: (1) Aspidosperma quebracho-blanco forest; (2) Zanthoxylum coco forest; (3) Geoffroea decorticans forest; and (4) Prosopis caldenia forest. These vegetation types were segregated along gradients of temperature and precipitation seasonality and soil-texture and sodium content. The remaining forest patches represent 3.43% of the extent of the Espinal province in Córdoba region of which only 1.05% is represented in protected areas. Conclusions: We present a classification of the Espinal forest based on a complete floristic survey. Despite the dramatic forest loss reported, our results show that some forest patches representative of the Espinal are still likely to be found in the area. However, urgent measures should be taken to establish new protected natural areas in order to preserve the last remaining forest patches.Taxonomic reference: Catálogo de las Plantas Vasculares del Cono Sur (Zuloaga et al. 2008) and its online update (http://www.darwin.edu.ar).Abbreviations: ISOMAP = isometric feature mapping; ISOPAM = isometric partitioning around medoids.Keywordscentral Argentina, chorotype, diagnostic species, dry subtropical forest, Espinal phytogeographic province, exotic spFil: Zeballos, Sebastián Rodolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Giorgis, Melisa Adriana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Cabido, Marcelo Ruben. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Acosta, Alicia Teresa Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Università degli Studi di Roma Tre; ItaliaFil: Iglesias, María del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Cantero, Juan Jose. Universidad Nacional de Río Cuarto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentin
Formación universitaria humanismo y conocimiento
El libro está integrado por seis capítulos, los cuales representan el fruto de la investigación que desarrolla el Cuerpo Académico: “Estudios de la Universidad”, adscrito al Instituto de Estudios sobre la Universidad (IESU), de la Universidad Autónoma del Estado de México. El propósito de los siguientes trabajos es abrir una serie de caminos que permitan pensar el ser y quehacer de la universidad en el siglo XXI. Los temas resaltan la necesidad e importancia de pensar la educación universitaria en pos de una formación que le dé sentido a la existencia humana.La función social de las universidades se ancla en la base de una formación del ser humano tanto en su ser como en la ciencia y el conocimiento. Formar significa construir desde sí mismo y para los otros la condición de la humanidad. La universidad en ese sentido tiene la tarea de promover en el universitario las condiciones para la formación de la persona, desde todo tipo de conocimientos y saberes. El propósito de los siguientes trabajos es abrir una serie de caminos que permitan pensar el ser y quehacer de la universidad en el siglo XXI. Los temas resaltan la necesidad e importancia de pensar la educación universitaria en pos de una formación que le dé sentido a la existencia humana.UAE
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