646 research outputs found

    Spin tests of a low-wing monoplane to investigate scale effect in the model test range, May 1941

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    Concurrent tests were performed on a 1/16 and a 1/20 scale model (wing spans of 2.64 and 2.11 ft. respectively) of a modern low wing monoplane in the NACA 15 foot free-spinning wind tunnel. Results are presented in the form of charts that afford a direct comparison between the spins of the two models for a number of different conditions. Qualitatively, the same characteristic effects of control disposition, mass distribution, and dimensional modifications were indicated by both models. Quantitatively, the number of turns for recover and the steady spin parameters, with the exception of the inclination of the wing to the horizontal, were usually in good agreement

    An approximate spin design criterion for monoplanes, 1 May 1939

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    An approximate empirical criterion, based on the projected side area and the mass distribution of the airplane, was formulated. The British results were analyzed and applied to American designs. A simpler design criterion, based solely on the type and the dimensions of the tail, was developed; it is useful in a rapid estimation of whether a new design is likely to comply with the minimum requirements for safety in spinning

    Project Mercury: the Program and Its Objectives

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    Project Mercury is reviewed in the light of experience gained thus far in the technical implementation of this Nation's initial program for manned orbital flight. Initial guidelines formulated for the Mercury program are reviewed, together with some of the technical considerations that have influenced the design of the capsule and the operational plan for the booster-capsule vehicle. The role of the astronaut in the Mercury program is discussed, and some observations are made concerning the impact of the Mercury program on future manned space ventures

    Number development and children with Specific Language Impairment.

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    The aims of this chapter is to investigate whether the number skills of children with specific language impairment (SLI) differ from those of their typically developing peers, matched in nonverbal reasoning, and a group of younger typically developing children matched on language comprehension. It assesses whether small number quantification accuracy accounts for additional variation in number tasks beyond the other influences. How children develop competence with numbers and why they differ so much in their progress are important questions whether one is concerned with numeracy, the skills and knowledge for dealing with numerical information in everyday life, or mathematics, the sciences dealing with the logic of quantity, shape, and arrangement. The study of number development in children with SLI has the potential to contribute both to the understanding of the factors that influence children's progress generally and to the knowledge base for professionals working with these children. Previous work on number in children with SLI had indicated selective impairments: children with SLI showed impaired procedural skills, particularly in counting, from an early age but less impaired understanding of number, for example counting principles. An investigation of children with SLI provided ample evidence of the continuing deficit in counting and calculation

    Methods of analyzing wind-tunnel data for dynamic flight conditions

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    The effects of power on the stability and the control characteristics of an airplane are discussed and methods of analysis are given for evaluating certain dynamic characteristics of the airplane that are not directly discernible from wind tunnel tests alone. Data are presented to show how the characteristics of a model tested in a wind tunnel are affected by power. The response of an airplane to a rolling and a yawing disturbance is discussed, particularly in regard to changes in wing dihedral and fin area. Solutions of the lateral equations of motion are given in a form suitable for direct computations. An approximate formula is developed that permits the rapid estimation of the accelerations produced during pull-up maneuvers involving abrupt elevator deflections

    Methods of analyzing wind-tunnel data for dynamic flight conditions

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    The effects of power on the stability and the control characteristics of an airplane are discussed and methods of analysis are given for evaluating certain dynamic characteristics of the airplane that are not directly discernible from wind-tunnel tests alone. Data are presented to show how the characteristics of a model tested in a wind tunnel are affected by power. The response of an airplane to a rolling and a yawing disturbance is discussed, particularly in regard to changes in wing dihedral and fin area. Solutions of the lateral equations of motion are given in a form suitable for direct computations. An approximate formula is developed that permits the rapid estimation of the accelerations produced during pull-up maneuvers involving abrupt elevator deflections

    Communication aids in the classroom: the views of education staff and speech and language therapists involved with the Communication Aids Project

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    The findings presented in this paper are part of an independent evaluation study of the Communication Aids Project (CAP). The study was carried out between July 2003 and April 2004 and looked at the impact of CAP on children receiving communication aids and evaluated the CAP strategy of assessment and delivery. In this paper the views of education staff and speech and language therapists who were working with communication aid users in school are presented. The professionals who were interviewed provided positive feedback on the existence of CAP, on the assessment for the communication aid, particularly where the use of the aid in the classroom was considered, and on the children's increased participation in classroom and learning activities since receiving the aid. They also highlighted the issue of managing parents' expectations regarding the use of aids and the value of and need for continued training for professionals working with communication aids in the classroom. The authors of this article, Jannet Wright, senior lecturer, Chris Donlan, senior lecturer, Caroline Newton, lecturer, and Michael Clarke, lecturer, from University College London; Claire Lister, from the Institute of Child Health, London; and Jasmina Cherguit, assistant psychologist, draw upon their findings to develop recommendations for future policy, practice and professional development
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