Community reactions to aircraft noise - Noise measurements

Acoustical and social data on community reactions to aircraft nois

Comparative evaluation of twenty pilot workload assessment measure using a psychomotor task in a moving base aircraft simulator

A comparison of the sensitivity and intrusion of twenty pilot workload assessment techniques was conducted using a psychomotor loading task in a three degree of freedom moving base aircraft simulator. The twenty techniques included opinion measures, spare mental capacity measures, physiological measures, eye behavior measures, and primary task performance measures. The primary task was an instrument landing system (ILS) approach and landing. All measures were recorded between the outer marker and the middle marker on the approach. Three levels (low, medium, and high) of psychomotor load were obtained by the combined manipulation of windgust disturbance level and simulated aircraft pitch stability. Six instrument rated pilots participated in four seasons lasting approximately three hours each

Control System Optimization for Saturn 5 Launch Vehicles Using Gradient Techniques Final Report

Control system optimization for Saturn 5 launch vehicles using gradient technique

A study for development of aerothermodynamic test model materials and fabrication technique

A literature survey, materials reformulation and tailoring, fabrication problems, and materials selection and evaluation for fabricating models to be used with the phase-change technique for obtaining quantitative aerodynamic heat transfer data are presented. The study resulted in the selection of two best materials, stycast 2762 FT, and an alumina ceramic. Characteristics of these materials and detailed fabrication methods are presented

Unified theory of the semi-collisional tearing mode and internal kink mode in a hot tokamak: implications for sawtooth modelling

In large hot tokamaks like JET, the width of the reconnecting layer for resistive modes is determined by semi-collisional electron dynamics and is much less than the ion Larmor radius. Firstly a dispersion relation valid in this regime is derived which provides a unified description of drift-tearing modes, kinetic Alfven waves and the internal kink mode at low beta. Tearing mode stability is investigated analytically recovering the stabilising ion orbit effect, obtained previously by Cowley et al. [Phys. Fluids (29) 3230 1986], which implies large values of the tearing mode stability parameter "Delta prime" are required for instability. Secondly, at high beta it is shown that the tearing mode interacts with the kinetic Alfven wave and that there is an absolute stabilisation for all "Delta prime" due to the shielding effects of the electron temperature gradients, extending the result of Drake et. al [Phys. Fluids (26) 2509 1983] to large ion orbits. The nature of the transition between these two limits at finite values of beta is then elucidated. The low beta formalism is also relevant to the m=n=1 tearing mode and the dissipative internal kink mode, thus extending the work of Pegoraro et al. [Phys. Fluids B (1) 364 1989] to a more realistic electron model incorporating temperature perturbations, but then the smallness of the dissipative internal kink mode frequency is exploited to obtain a new dispersion relation valid at arbitrary beta. A diagram describing the stability of both the tearing mode and dissipative internal kink mode, in the space of "Delta prime" and beta, is obtained. The trajectory of the evolution of the current profile during a sawtooth period can be plotted in this diagram, providing a model for the triggering of a sawtooth crash.Comment: 37 pages, updated version, accepted, to appear on Plasma Physics and Controlled Fusio

The Effect of Plasma Beta on High-n Ballooning Stability at Low Magnetic Shear

An explanation of the observed improvement in H-mode pedestal characteristics with increasing core plasma pressure or poloidal beta, as observed in MAST and JET, is sought in terms of the impact of the Shafranov shift, d', on ideal ballooning MHD stability.Comment: 18 pages, 5 figures. This is an author-created, un-copyedited version of an article submitted for publication in Plasma Physics and Controlled Fusion. IoP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from i

Susceptibility of White Spruce Seed Sources to Yellowheaded Spruce Sawfly, \u3ci\u3ePikonema Alaskensis,\u3c/i\u3e(Hymenoptera: Tenthredinidae)

A field caging technique was used to test the susceptibility of 25 white spruce, Picea glauca (Moench) Voss, seed sources to attack by Pikonema alaskensis (Rohwer). No sig- nificant differences were found in the number of eggs laid, number of dessicated eggs, or number of egg slits. Percent oviposition differed significantly within a tree, the south side having more eggs. Bud size differed significantly within trees and between trees but not between seed sources. The number of sawfly eggs laid on a bud could not be related to bud size. There was no significant difference in susceptibility of the seed sources studied to Pikonema alaskensis

Something to do with Schrödinger spacetimes

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Physics, 2009.Includes bibliographical references (p. 62-63).We present a brief review of the AdS/CFT correspondence and the progress made toward building a realistic gravity/gauge theory duality for a non-relativistic conformal field theory. In particular, we highlight many of the computational tools necessary for such a program before introducing one such model duality. The model presented exhibits the symmetry group of Schrodinger's equation along with conformal symmetry. A black hole can be placed in this spacetime to study a finite temperature duality. In the low-frequency, long-distance limit at finite temperature classical hydrodynamics can be used to determine the retarded Green's functions of the field theory, which can be computed from the gravity dual. This facilitates the calculation of several characteristic quantities including the shear viscosity and the shear diffusion constant giving results consistent with other hydrodynamic analyses of the system.by Connor W. McEntee.S.B

Magnetic compressibility and ion-temperature-gradient-driven microinstabilities in magnetically confined plasmas

The electromagnetic theory of the strongly driven ion-temperature-gradient (ITG) instability in magnetically confined toroidal plasmas is developed. Stabilizing and destabilizing effects are identified, and a critical $\beta_{e}$ (the ratio of the electron to magnetic pressure) for stabilization of the toroidal branch of the mode is calculated for magnetic equilibria independent of the coordinate along the magnetic field. Its scaling is $\beta_{e}\sim L_{Te}/R,$ where $L_{Te}$ is the characteristic electron temperature gradient length, and $R$ the major radius of the torus. We conjecture that a fast particle population can cause a similar stabilization due to its contribution to the equilibrium pressure gradient. For sheared equilibria, the boundary of marginal stability of the electromagnetic correction to the electrostatic mode is also given. For a general magnetic equilibrium, we find a critical length (for electromagnetic stabilization) of the extent of the unfavourable curvature along the magnetic field. This is a decreasing function of the local magnetic shear