1,708 research outputs found

    Tests of N.A.C.A. airfoils in the variable-density wind tunnel Series 230.

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    The results of tests of six airfoils having the N.A.C.A. 230 mean line and varying in thickness from 0.06c to 0.21c are presented. These results agree with previous findings in showing that aerodynamically the best section is one of moderate thickness. The data are of value mainly in connection with the design of tapered wings having sections based on the N.A.C.A. 230 mean line

    Tests in the variable-density wind tunnel of related airfoils having the maximum camber unusually far forward

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    A family of related airfoils having the position of maximum camber unusually far forward was investigated in the variable-density tunnel as an extension of the study recently completed of a large number of related airfoils. The new airfoils gave improved characteristics over those previously investigated, especially in regard to the pitching moment. Some of the new sections are markedly superior to well-known and commonly used sections and should replace them in applications requiring a slightly cambered section of moderate thickness having a small pitching-moment coefficient

    Pressure Distribution Over a Symmetrical Airfoil Section with Trailing Edge Flap

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    Measurements were made to determine the distribution of pressure over one section of an R. A. F. 30 (symmetrical) airfoil with trailing edge flaps. In order to study the effect of scale measurements were made with air densities of approximately 1 and 20 atmospheres. Isometric diagrams of pressure distribution are given to show the effect of change in incidence, flap displacement, and scale upon the distribution. Plots of normal force coefficient versus angle of attack for different flap displacements are given to show the effect of a displaced flap. Plots are given of both the experimental and theoretical characteristic coefficients versus flap angle, in order to provide a comparison with the theory. It is concluded that for small flap displacements the agreement for the pitching and hinge moments is such that it warrants the use of the theoretical parameters. However, the agreement for the lift is not as good, particularly for the smaller flaps. In an appendix, an example is given of the calculation of the load and moments on an airfoil with hinged flap from these parameters

    Tests of N.A.C.A. airfoils in the variable-density wind tunnel Series 43 and 63

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    This note is one of a series covering an investigation of a family of related airfoils. It gives in preliminary form the results obtained from tests in the N.A.C.A. Variable-Density Wind Tunnel of two groups of six airfoils each. One group, the 43 series, has a maximum mean camber of 4 per cent of the chord at a position 0.3 of the chord from the leading edge; the other group, the 63 series, has a maximum mean camber of 6 per cent of the chord at the same position. The members within each group differ only in maximum thickness, the maximum thickness/chord ratios being:0.06, 0.09, 0.12, 0.15, 0.18, and 0.21. The results are analyzed with a view to indicating the variation of the aerodynamic characteristics with profile thickness for airfoils having a certain mean camber line

    Tests of N.A.C.A. airfoils in the variable-density wind tunnel Series 45 and 65

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    This note is one of a series covering an investigation of a number of related airfoils. It presents the results obtained from tests in N.A.C.A. Variable-Density Wind Tunnel of two groups of six airfoils each. One group, the 45 series, has a maximum mean camber of 4 per cent of the chord at a position 0.5 of the chord behind the leading edge, and the other group, the 65 series, has a maximum mean camber of 6 per cent of the chord at the same position. The members within each group differ only in maximum thickness, the maximum thickness/chord ratios being: 0.06, 0.09, 0.12, 0.15, 0.18, and 0.21. The results are analyzed with a view to indicating the variation of the aerodynamic characteristics with profile thickness for airfoils having a certain mean camber line form

    A Child-Centered Response to the Elkins Family Law Task Force

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    In Elkins v. Superior Court, 163 P.3d 160 (Cal. 2007), California’s Supreme Court asked the Judicial Council to form a task force to make recommendations to increase “access to justice” in family court, because it was concerned about rules, policies, and procedures that put self-represented litigants at an unfair disadvantage in parentageand dissolution cases. Neither the task force’s report in 2010 nor the legislation that the report inspired the same year addresses children’s due process rights, even though children ordinarily have no access to justice. This Article shows that due process sometimes requires the trial court to appoint counsel for children to obtain the information the court needs to address children’s interests. This Article also explains why trial courts should not construe the new Elkins laws to impose new and unique restrictions on children’s lawyers, and proposes new legislation and court rules to clarify children’s due process rights and minors’ counsel’s ethical duties when custody is at issue in family court

    A Child-Centered Response to the Elkins Family Law Task Force

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    In Elkins v. Superior Court, 163 P.3d 160 (Cal. 2007), California’s Supreme Court asked the Judicial Council to form a task force to make recommendations to increase “access to justice” in family court, because it was concerned about rules, policies, and procedures that put self-represented litigants at an unfair disadvantage in parentageand dissolution cases. Neither the task force’s report in 2010 nor the legislation that the report inspired the same year addresses children’s due process rights, even though children ordinarily have no access to justice. This Article shows that due process sometimes requires the trial court to appoint counsel for children to obtain the information the court needs to address children’s interests. This Article also explains why trial courts should not construe the new Elkins laws to impose new and unique restrictions on children’s lawyers, and proposes new legislation and court rules to clarify children’s due process rights and minors’ counsel’s ethical duties when custody is at issue in family court

    A wireless sensor-based mobile music environment complied from a graphical language

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    Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2007.Includes bibliographical references (p. 79-80).In this thesis I demonstrate a framework for a wireless sensor-based mobile music environment. Most prior work has not been truly portable. Those that were have focused on external data as opposed to properties of the listener. In this project I built a short-range wireless sensor network (using the ZigBee protocol and an accelerometer) and a compiler for PureData, a graphical music processing language. With these parts, I realized a synchronized music experience that generates a soundtrack based on the listener's movement. By synchronizing the music to the user's natural rhythms, it encourages the user to maintain a given pace for a longer period of time. I describe extensions to this example that point to a future of portable interactive music tied to exercise and physical activity.by Robert N. Jacobs.M.Eng

    Tests of related forward-camber airfoils in the variable-density wind tunnel

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    A recent investigation of numerous related airfoils indicated that positions of camber forward of the usual location resulted in an increase of the maximum lift. As an extension of this investigation, a series of forward-camber airfoils has been developed, the members of which show airfoil characteristics superior to those of the airfoils previously investigated. The primary object of this report is to present fully corrected results for airfoils in the useful range of shapes. With the data thus made available, an airplane designer may intelligently choose the best possible airfoil-section shape for a given application and may predict to a reasonable degree the aerodynamic characteristics to be expected in flight from the section shape chosen

    Vascular Injury After Whole Thoracic X-Ray Irradiation in the Rat

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    Purpose To study vascular injury after whole thoracic irradiation with single sublethal doses of X-rays in the rat and to develop markers that might predict the severity of injury. Methods and Materials Rats that received 5- or 10-Gy thorax-only irradiation and age-matched controls were studied at 3 days, 2 weeks, and 1, 2, 5, and 12 months. Several pulmonary vascular parameters were evaluated, including hemodynamics, vessel density, total lung angiotensin-converting enzyme activity, and right ventricular hypertrophy. Results By 1 month, the rats in the 10-Gy group had pulmonary vascular dropout, right ventricular hypertrophy, increased pulmonary vascular resistance, increased dry lung weights, and decreases in total lung angiotensin-converting enzyme activity, as well as pulmonary artery distensibility. In contrast, irradiation with 5 Gy resulted in only a modest increase in right ventricular weight and a reduction in lung angiotensin-converting enzyme activity. Conclusion In a previous investigation using the same model, we observed that recovery from radiation-induced attenuation of pulmonary vascular reactivity occurred. In the present study, we report that deterioration results in several vascular parameters for ≤1 year after 10 Gy, suggesting sustained remodeling of the pulmonary vasculature. Our data support clinically relevant injuries that appear in a time- and dose-related manner after exposure to relatively low radiation doses
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