F-8 supercritical wing flight pressure, Boundary layer, and wake measurements and comparisons with wind tunnel data

Data for speeds from Mach 0.50 to Mach 0.99 are presented for configurations with and without fuselage area-rule additions, with and without leading-edge vortex generators, and with and without boundary-layer trips on the wing. The wing pressure coefficients are tabulated. Comparisons between the airplane and model data show that higher second velocity peaks occurred on the airplane wing than on the model wing. The differences were attributed to wind tunnel wall interference effects that caused too much rear camber to be designed into the wing. Optimum flow conditions on the outboard wing section occurred at Mach 0.98 at an angle of attack near 4 deg. The measured differences in section drag with and without boundary-layer trips on the wing suggested that a region of laminar flow existed on the outboard wing without trips

Room-temperature observation and current control of skyrmions in Pt/Co/Os/Pt thin films

We report the observation of room-temperature magnetic skyrmions in Pt/Co/Os/Pt thin-film heterostructures and their response to electric currents. The magnetic properties are extremely sensitive to inserting thin Os layers between the Co-Pt interface resulting in reduced saturation magnetization, magnetic anisotropy and Curie temperature. The observed skyrmions exist in a narrow temperature, applied-field and layer-thickness range near the spin-reorientation transition from perpendicular to in-plane magnetic anisotropy. The skyrmions have an average diameter of 2.3{\mu}m and transport measurements demonstrate these features can be displaced with current densities as low as J = 2x10^4 A/cm^2 and display a skyrmion Hall effect.Comment: 17 pages, 5 figure

A fast acting electrical servo for the actuation of full span, Fowler-type wing flaps in DLC applications: A detail design study

The philosophy and detail design of an electro-mechanical actuator for Fowler-type wing flaps which have a response time constant of 0.025 seconds are described. A conventional electrical servomotor with a power rating twice the maximum power delivered to the load is employed along with adaptive, gain-scheduled feedback and various logic circuits, including one to remove electrical excitation from the motor during extended periods when no motion of the flap is desired

Systems development of a stall/spin research facility using remotely controlled/augmented aircraft models. Volume 1: Systems overview

A ground based, general purpose, real time, digital control system simulator (CSS) is specified, developed, and integrated with the existing instrumentation van of the testing facility. This CSS is built around a PDP-11/55, and its operational software was developed to meet the dual goal of providing the immediate capability to represent the F-18 drop model control laws and the flexibility for expansion to represent more complex control laws typical of control configured vehicles. Overviews of the two CSS's developed are reviewed as well as the overall system after their integration with the existing facility. Also the latest version of the F-18 drop model control laws (REV D) is described and the changes needed for its incorporation in the digital and analog CSS's are discussed

Las tecnologías en la escuela inclusiva : nuevos escenarios, nuevas oportunidades

Por las conclusiones que se plantean en este artículo relativas al encuentro de dos culturas, tan distantes y con un mismo origen, como son la latinoamericana y la española, se ha de dar la enhorabuena al Comité Organizador del Congreso Tecnoneet-Ciiee 2006, que agrupa al 4º Congreso de Tecnología Educativa y Atención a la Diversidad, Tecnoneet, y al 6º Congreso Iberoamericano de Informática Educativa Especial, CIIEE; celebrado en Murcia (España), los días 28, 29 y 30 de septiembre de 2006. Sobre todo por el esfuerzo realizado en pro de la inclusión educativa, la integración de ambas culturas en la práctica docente, la correlación de las TIC a los dos lados del Atlántico, el apoyo de dos lenguas hermanas: "España y Latinoamérica en el mismo cruce de caminos" y el compartir problemáticas comunes, metodológicas, de prioridades, estrategias de evaluación e intervención, etc. En el resumen hablan de que han compartido la preocupación por evitar que la introducción de las Tecnologías de la Información y la Comunicación suponga una nueva forma de exclusión social y digital capaz de ampliar el abismo que separa a los países iberoamericanos y, dentro de cada país, a los grupos de ciudadanos y ciudadanas con y sin discapacidad. Manifiestan su inquietud por que la brecha digital sea más profunda en el ámbito doméstico que en el plano internacional. En el Encuentro de ambos Congresos se trataron problemáticas tan en candelero como son: (1) Aspectos que dificultan al discapacitado para el uso de las TICs: Poca flexibilización de las estructuras, demasiado trabajo individualizado en clase, falta de asesoramiento y formación. (2) Aspectos y tendencias que facilitan, como son: Redes de apoyo en Internet para la investigación y la cooperación, la enseñanza virtual como opción formativa y de aprendizaje accesible, Recursos multimedia por competencias, Multiplicidad de periféricos, (3) Modelos, estrategias y tecnologías emergentes: Objetos digitales para el aprendizaje, Interculturalidad y minorías étnicas, La neurociencia en la intervención educativa, Software libre, conocimiento abierto

Unruh effect detection through chirality in curved graphene

We analyze a generalization of the analogue Unruh effect based on curved graphene. To this end, we consider the fourth order in derivatives field theoretic version of the Pais-Uhlenbeck oscillator, for which the Unruh effect may be interpreted as the creation of two different particles with different masses, corresponding to two Klein-Gordon subsystems. For our model, unlike the standard case, electron chirality on the graphene sheet plays a main role as chirality is essential to distinguish the couple of particles predicted by the Unruh effect associated to the Pais-Uhlenbeck field model.Comment: 12 pages, no figure

Skin friction measuring device for aircraft

A skin friction measuring device for measuring the resistance of an aerodynamic surface to an airstream is described. It was adapted to be mounted on an aircraft and is characterized by a friction plate adapted to be disposed in a flush relationship with the external surface of the aircraft and be displaced in response to skin friction drag. As an airstream is caused to flow over the surface, a potentiometer connected to the plate for providing an electrical output indicates the magnitude of the drag

Bioinspired snapping-claw apparatus to study hydrodynamic cavitation effects on the corrosion of metallic samples

A creative low-cost and compact mechanical device that mimics the rapid closure of the pistol shrimp claw was used to conduct electrochemical experiments, in order to study the effects of hydrodynamic cavitation on the corrosion of aluminum and steel samples. Current-time curves show significant changes associated with local variations in dissolved O2 concentration, cavitation-induced erosion and changes in the nature of the surface corrosion products