8,819 research outputs found
Tradeoff analysis of technology needs for public service helicopters
The design requirements for a family or type of Public Service Helicopter (PSH) is examined which will satisfy the needs of municipal and state governments in the following mission areas: Emergency Medical Service--Airborne Rescue Squad; Law Enforcement; Search and Rescue; and Environmental Control (Fire Fighting, Pollution, Resource Management). The report compares both design and performance requirements as specified by the PSH user's group against current technological capabilities, RTOPS and US Army LHX design requirements. The study explores various design trade-offs and options available to the aircraft designer/manufacturer in order to meet the several criteria specified by the PSH user's group. In addition, the report includes a brief assessment of the feasibility of employing certain advanced rotorcraft designs to meet the stringent combination of operational capabilities desired by the Public Service Helicopter Users
Data compilation and evaluation of space shielding problems. Radiation hazards in space, volume III
Radiation hazards of interplanetary space and related shielding problem
An algorithm for determining program feasibility of a multi-mode PAM commutator telemetry system Technical report no. 10
Algorithm formulation for evaluation of strapping arrangement programs for PAM multimode commutation system of Saturn telemetry syste
Statistical quality control applied to a telemetry system acceptance prodedure Technical report no. 13
Statistical quality control applied to telemetry system acceptance procedur
Computer programs for shielding problems in manned space vehicles
Computer programs for shielding problems in manned space vehicles - proton penetration code
Jovian plasma torus interaction with Europa. Plasma wake structure and effect of inductive magnetic field: 3D Hybrid kinetic simulation
The hybrid kinetic model supports comprehensive simulation of the interaction
between different spatial and energetic elements of the Europa
moon-magnetosphere system with respect a to variable upstream magnetic field
and flux or density distributions of plasma and energetic ions, electrons, and
neutral atoms. This capability is critical for improving the interpretation of
the existing Europa flyby measurements from the Galileo Orbiter mission, and
for planning flyby and orbital measurements (including the surface and
atmospheric compositions) for future missions. The simulations are based on
recent models of the atmosphere of Europa (Cassidy et al., 2007; Shematovich et
al., 2005). In contrast to previous approaches with MHD simulations, the hybrid
model allows us to fully take into account the finite gyroradius effect and
electron pressure, and to correctly estimate the ion velocity distribution and
the fluxes along the magnetic field (assuming an initial Maxwellian velocity
distribution for upstream background ions). In this paper we discuss two tasks:
(1) the plasma wake structure dependence on the parameters of the upstream
plasma and Europa's atmosphere (model I, cases (a) and (b) with a homogeneous
Jovian magnetosphere field, an inductive magnetic dipole and high oceanic shell
conductivity); and (2) estimation of the possible effect of an induced magnetic
field arising from oceanic shell conductivity. This effect was estimated based
on the difference between the observed and modeled magnetic fields (model II,
case (c) with an inhomogeneous Jovian magnetosphere field, an inductive
magnetic dipole and low oceanic shell conductivity).Comment: 36 pages, 13 figures, paper was submitted to Planetary and Space
Science in Nov. 2011, special volume "Outer Planets" but still under revie
Development of Replacement Heifers using Combinations of Three Forage Types and Feed Supplements (with or without Broiler Litter)
The proper management of replacement heifers is an essential component of successful cow/calf operations. The level of management and nutrition applied to replacement heifers as calves and yearlings can impact their subsequent reproductive performance and productivity
Analysis of the linearity characteristics, tape recorders and compensation effects in the FM/FM telemetry system
Linearity characteristics, tape recorder effects, and tape speed compensation effects in FM/FM TELEMETRY syste
Stability and dynamical properties of Rosenau-Hyman compactons using Pade approximants
We present a systematic approach for calculating higher-order derivatives of
smooth functions on a uniform grid using Pad\'e approximants. We illustrate our
findings by deriving higher-order approximations using traditional second-order
finite-differences formulas as our starting point. We employ these schemes to
study the stability and dynamical properties of K(2,2) Rosenau-Hyman (RH)
compactons including the collision of two compactons and resultant shock
formation. Our approach uses a differencing scheme involving only nearest and
next-to-nearest neighbors on a uniform spatial grid. The partial differential
equation for the compactons involves first, second and third partial
derivatives in the spatial coordinate and we concentrate on four different
fourth-order methods which differ in the possibility of increasing the degree
of accuracy (or not) of one of the spatial derivatives to sixth order. A method
designed to reduce roundoff errors was found to be the most accurate
approximation in stability studies of single solitary waves, even though all
derivates are accurate only to fourth order. Simulating compacton scattering
requires the addition of fourth derivatives related to artificial viscosity.
For those problems the different choices lead to different amounts of
"spurious" radiation and we compare the virtues of the different choices.Comment: 12 figure
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