1,952,489 research outputs found
Optical projector system Patent
Optical projector system for establishing optimum arrangement of instrument displays in aircraft, spacecraft, other vehicles, and industrial instrument console
The NASA High-Speed Research Program
Since its inception, one of NASA's commitments has been to develop the technology to advance aeronautics. As such, a new High-Speed Research Program was activated to develop the technology for industry to build a High-Speed Civil Transport - a second generation Supersonic Transport (SST). The baseline for this program is the British Concorde, a major technological achievement for its time, but an aircraft which is now both technologically and economically outdated. Therefore, a second generation SST must satisfy environmental concerns and still be economically viable. In order to do this, it must have no significant effect on the ozone layer, meet Federal Air Regulation 36, Stage 3 for community noise, and have no perceptible sonic boom over populated areas. These three concerns are the focus of the research efforts in Phase 1 of the program and are the specific areas covered in the technical video report
Beam
An interactive multichannel sound installation, part of Dialogic Assemblages, a collateral exhibition for the Kochi Muziris Biennale 2014.
Beam is a sonic investigation of the ‘hidden’ maritime world that delivers our everyday life - the clothes we wear, the fuel in our cars and the food we eat. Despite the fact that 90% of everything travels by sea we know or see very little of the world that surrounds it. For this installation we have conducted intensive research and sonic fieldwork in Kochi centred around its harbour and the five lighthouses on the Kerala coast that communicate with all sea going traffic coming in or out of Kochi harbour. We have recorded places where cargo is packed, loaded, unloaded and inspected and all aspects of the fishing industry from small scale fishing with the famous chinese fishing nets to the industrial scale capture, sale and packing of fish. We have listened to the sea in many of its moods and talked to past generations of people who arrived in Kochi by sea from other parts of India and the world and who have made their living shipping spices from India. We have climbed lighthouses and pondered their poetic and arcane relationship with the sea and all who sail upon it and we have listened to the radio communications between ships and land.
The resulting installation in interactive - our recordings are controlled in real time by the AIS (Automatic Identification Signal) data that is transmitted from the ships which are now in and around Kochi harbor.
Beam was made in collaboration with students from Srishti Institute of Art, Design and Technology, Bangalore, India
Thermodielectric radiometer
Radiometer measures microsecond pulses of radiant flux in the presence of electromagnetic noise. It consists of a charged capacitor that delivers a voltage pulse proportional to the thermally induced depolarization of its polymeric dielectric
Alternating direction implicit methods for parabolic equations with a mixed derivative
Alternating direction implicit (ADI) schemes for two-dimensional parabolic equations with a mixed derivative are constructed by using the class of all A sub 0-stable linear two-step methods in conjunction with the method of approximation factorization. The mixed derivative is treated with an explicit two-step method which is compatible with an implicit A sub 0-stable method. The parameter space for which the resulting ADI schemes are second order accurate and unconditionally stable is determined. Some numerical examples are given
Coherent Beam-Beam Tune Shift of Unsymmetrical Beam-Beam Interactions with Large Beam-Beam Parameter
Coherent beam-beam tune shift of unsymmetrical beam-beam interactions was
studied experimentally and numerically in HERA where the lepton beam has a very
large beam-beam parameter (up to ). Unlike the symmetrical case of
beam-beam interactions, the ratio of the coherent and incoherent beam-beam tune
shift in this unsymmetrical case of beam-beam interactions was found to
decrease monotonically with increase of the beam-beam parameter. The results of
self-consistent beam-beam simulation, the linearized Vlasov equation, and the
rigid-beam model were compared with the experimental measurement. It was found
that the coherent beam-beam tune shifts measured in the experiment and
calculated in the simulation agree remarkably well but they are much smaller
than those calculated by the linearized Vlasov equation with the single-mode
approximation or the rigid-beam model. The study indicated that the single-mode
approximation in the linearization of Vlasov equation is not valid in the case
of unsymmetrical beam-beam interactions. The rigid-beam model is valid only
with a small beam-beam parameter in the case of unsymmetrical beam-beam
interactions.Comment: 32 pages, 13 figure
Input-output subroutine package UOM IOS FOR the IBM 7090/7094
Input-output subroutine package for IBM 7090/7094 computer monitoring system
Universal vortex-state Hall conductivity of YBa2Cu3O7 single crystals with differing correlated disorder
The vortex-state Hall conductivity ([sigma][sub]xy) of YBa2Cu3O7 single crystals in the anomalous-sign-reversal region is found to be independent of the density and orientation of the correlated disorder. After the anisotropic-to-isotropic scaling transformation is carried out, a universal scaled Hall conductivity [sigma][bar][sub]xy is obtained as a function of the reduced temperature (T/T[sub]c) and scaled magnetic field strength (H[bar]) for five samples with different densities and orientation of controlled defects. The transport scattering times {tau], derived from applying the model given by Feigel'man et al (Feigel'man M V, Geshkenbein V B, Larkin A I and Vinokur V M 1995 Pis. Zh. Eksp. Teor. Fiz. 62 811 (Engl. Transl. 1995 JETP Lett. 62 835)) to the universal Hall conductivity [sigma bar](T/T[sub]c, H[bar]), are consistent in magnitude with those derived from other measurements for quasiparticle scattering, and are much smaller than the thermal relaxation time of vortex displacement and than the vortex–defect interaction time. Our experimental results and analyses therefore suggest that the anomalous sign reversal in the vortex-state Hall conductivity is associated with the intrinsic properties of type-II superconductors, rather than extrinsic disorder effects
Numerical calculations of two dimensional, unsteady transonic flows with circulation
The feasibility of obtaining two-dimensional, unsteady transonic aerodynamic data by numerically integrating the Euler equations is investigated. An explicit, third-order-accurate, noncentered, finite-difference scheme is used to compute unsteady flows about airfoils. Solutions for lifting and nonlifting airfoils are presented and compared with subsonic linear theory. The applicability and efficiency of the numerical indicial function method are outlined. Numerically computed subsonic and transonic oscillatory aerodynamic coefficients are presented and compared with those obtained from subsonic linear theory and transonic wind-tunnel data
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