Preliminary design-lift/cruise fan research and technology airplane flight control system

This report presents the preliminary design of a stability augmentation system for a NASA V/STOL research and technology airplane. This stability augmentation system is postulated as the simplest system that meets handling qualities levels for research and technology missions flown by NASA test pilots. The airplane studied in this report is a T-39 fitted with tilting lift/cruise fan nacelles and a nose fan. The propulsion system features a shaft interconnecting the three variable pitch fans and three power plants. The mathematical modeling is based on pre-wind tunnel test estimated data. The selected stability augmentation system uses variable gains scheduled with airspeed. Failure analysis of the system illustrates the benign effect of engine failure. Airplane rate sensor failure must be solved with redundancy

Design definition study of a NASA/Navy lift/cruise fan technology V/STOL airplane: Risk assessment addendum to the final report

An assessment of risk, in terms of delivery delays, cost overrun, and performance achievement, associated with the V/STOL technology airplane is presented. The risk is discussed in terms of weight, structure, aerodynamics, propulsion, mechanical drive, and flight controls. The analysis ensures that risks associated with the design and development of the airplane will be eliminated in the course of the program and a useful technology airplane that meets the predicted cost, schedule, and performance can be produced

Impacts of drought in the primary sector of the Central American Dry Corridor

América Central ha sufrido el impacto de diversos eventos hidrometeorológicos extremos, dentro de los cuales se destaca la sequía. Esta ha tenido efectos adversos de distinta índole en la región denominada como el Corredor Seco Centroamericano (CSC). El objetivo de este trabajo fue describir los impactos que han sufrido la agricultura, la ganadería y la economía de los países del CSC debidos a las sequías: agrícola, hidrológica y socioeconómica. Se realizó una revisión a partir de fuentes primarias y secundarias como artículos científicos, reportes de prensa y reportes de estudios de instituciones estatales e internacionales. Los impactos más recurrentes se dan a nivel de granos básicos y ganado vacuno, debidos también en parte al fenómeno del ENOS (El Niño-Oscilación del Sur). Debido a que el CSC es una región con alta vulnerabilidad a la sequía y a otros eventos hidrometeorológicos extremos, es necesario realizar una caracterización adecuada del CSC tomando como línea de base estudios similares a este, que originen un proceso de discusión para el diseño y la implementación de estrategias y políticas públicas anticipadas de adaptación y mitigación de la sequía en el CSC y por ende, conduzca a mejorar la calidad de vida de su población.Central America has suffered the impact of several extreme hydrometeorological events, among which drought stands out. This has had adverse effects of different kinds in the region known as the Central American Dry Corridor (CSC, in Spanish). The objective of this work was to describe the impacts that agriculture, livestock and economy of the CSC countries have suffered due to droughts: agricultural, hydrological and socioeconomic. A review of primary and secondary sources was carried out, such as scientific articles, press reports and studies reports from national and international institutions. The most recurrent impacts are at the level of basic grains and cattle, also due in part to the ENSO (El Niño-Southern Oscillation) phenomenon. Because the CSC is a region with high vulnerability to drought and other extreme hydrometeorological events, it is necessary to carry out an adequate characterization of the CSC taking as a baseline similar studies like this one, that orginate a discussion process for the design and implementation of strategies and anticipated public policies of adaptation and mitigation of the drought in the CSC and therefore, lead to improve the quality of life of its population.Universidad de Costa Rica/[805-B6-143]/UCR/Costa RicaConsejo Nacional para Investigaciones Científicas y Tecnológicas/[]/CONICIT/Costa RicaMinisterio de Ciencia, Tecnología y Telecomunicaciones/[]/MICITT/Costa RicaUniversidad de Costa Rica/[805-A4-906]/UCR/Costa RicaUniversidad de Costa Rica/[805-B7-286]/UCR/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigaciones Geofísicas (CIGEFI

Haetosmia vechti.

20 pages : illustrations (some color) ; 26 cm.Herein we describe the nests (including structure, closure, orientation, and depth of cells) of the bee Haetosmia vechti Peters found nesting in Rehovot, Israel. The nesting biology of H. vechti mirrors the ancestral nesting biology within the Osmia group of the Osmiini. Nests in sandy soil consist of an excavated burrow, ending below in a small cluster of vertical cells. The cells possess firm walls of masticated leaf pulp of Centaurea procurrens Spreng. and Heliotropium suaveolens M. Bieb., and are covered with pebbles and sand grains. The last larval instar and pupa of Haetosmia vechti are described, as is its cocoon. The immature stages exhibit the basic features of megachilid bees, but tend to have a thinner body vestiture compared to other studied taxa. In addition, we report new information on and review published accounts concerning the pollen collecting behavior of the genus Haetosmia Popov, which contains three species. Pollen taken from scopal hairs of 68 females collected at 17 sites in Turkestan, Morocco, Israel, and the United Arab Emirates was identified as originating solely from Heliotropium L. (Boraginaceae), which strongly suggests that all three Haetosmia species are narrowly oligolectic on this plant genus. In females of all three species, the second segment of the labial palpus is densely covered with rather long, apically curved and capitate bristles, an adaptation to collect Heliotropium pollen from anthers that are hidden inside the narrow corolla tube. Similar pollen-harvesting bristles specifically adapted to exploit flowers of Heliotropium seem to have evolved independently a number of times on different continents, in bees of four families

Riesgos hidrometeorológicos en el Corredor Seco Centroamericano: Investigación, acción social y docencia dentro del Espacio de Estudios Avanzados de la Universidad de Costa Rica

Aunque América Central está localizada en zonas tropicales donde el estrés hídrico es relativamente bajo en gran parte de su territorio, hay ciertas regiones donde las sequías son frecuentes. En especial, la aridez climatológica en la zona denominada como «Corredor Seco Centroamericano» (csc), donde las sequías son recurrentes (Quesada-Hernández, Calvo-Solano, Hidalgo, Pérez-Briceño y Alfaro, 2019) (figura 1). El csc es un espacio geográfico con límites imprecisos que se entiende como una zona con características climáticas de bosque tropical seco, con una marcada y prolongada época seca y en el que, durante el reducido periodo de lluvias, existe un latente riesgo de sequías recurrentes que pueden ocurrir por una entrada tardía de la época lluviosa o una prolongación de la canícula con una suspensión prematura de la época lluviosa (Peralta-Rodríguez et al., 2012).Universidad de Costa Rica/[805-B7-286]/UCR/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigaciones Geofísicas (CIGEFI

A multimodal dataset for authoring and editing multimedia content:the MAMEM project

We present a dataset that combines multimodal biosignals and eye tracking information gathered under a human-computer interaction framework. The dataset was developed in the vein of the MAMEM project that aims to endow people with motor disabilities with the ability to edit and author multimedia content through mental commands and gaze activity. The dataset includes EEG, eye-tracking, and physiological (GSR and Heart rate) signals collected from 34 individuals (18 able-bodied and 16 motor-impaired). Data were collected during the interaction with specifically designed interface for web browsing and multimedia content manipulation and during imaginary movement tasks. The presented dataset will contribute towards the development and evaluation of modern human-computer interaction systems that would foster the integration of people with severe motor impairments back into society.</p