6,785 research outputs found
Apollo experience report: Communications used during recovery operations
Apollo program experience in recovery-support communications is reviewed, and the working relationships among NASA, the Department of Defense, and commercial communications facilities are discussed. The organization, facilities, philosophy, and funding of recovery-support communications are described. The relocation of two recovery control centers is discussed, as are the functions of primary and secondary recovery ships, aircraft, and relay satellities. The possibility of using ships of opportunity for recovery operations is considered. Finally, the means by which money, manpower, and resources have been saved and longlines leased are delineated
Spectral slicing X-ray telescope with variable magnification
A telescope for viewing high frequency radiation (soft X-ray, extreme ultraviolet) is described. This telescope has a long focal length with a selection of magnifications despite a short housing. Light enters the telescope and is reflected by the telescope's primary optical system to one of several secondary mirrors at different locations on a movable frame. The secondary mirrors have varying degrees of magnification and select narrow spectral slices of the incident radiation. Thus, both the magnification and effective focal length field of view and wavelength can be altered by repositioning the moving frame. Configurations for spaceborne applications are discussed
Well-Posed Two-Temperature Constitutive Equations for Stable Dense Fluid Shockwaves using Molecular Dynamics and Generalizations of Navier-Stokes-Fourier Continuum Mechanics
Guided by molecular dynamics simulations, we generalize the
Navier-Stokes-Fourier constitutive equations and the continuum motion equations
to include both transverse and longitudinal temperatures. To do so we partition
the contributions of the heat transfer, the work done, and the heat flux vector
between the longitudinal and transverse temperatures. With shockwave boundary
conditions time-dependent solutions of these equations converge to give
stationary shockwave profiles. The profiles include anisotropic temperature and
can be fitted to molecular dynamics results, demonstrating the utility and
simplicity of a two-temperature description of far-from-equilibrium states.Comment: 19 pages with 10 figures, revised following review at Physical Review
E and with additional figure/discussion, for presentation at the
International Summer School and Conference "Advanced Problems in Mechanics"
[Saint Petersburg, Russia] 1-5 July 2010
A Sense of Duty: Retiring the Special Relationship Rule and Holding Gun Manufacturers Liable for Negligently Distributing Guns
In response to recent litigation brought against the gun industry on behalf of individuals and municipalities victimized as a result of the negligent marketing, design, and distribution of guns, the gun industry has argued that they cannot be held responsible for the victims\u27 injuries because they have no special relationship with the victims. Without a special relationship, gun manufacturers claim to have no duty whatsoever to design, market, or distribute guns in a reasonable fashion. This article examines the fallacies inherent in the gun industry\u27s special relationship argument and discusses the factual, legal and policy grounds that support holding the gun industry responsible for its role in facilitating the misuse of guns
Letter to William Younger regarding SEAALL letterhead, August 24, 1972
A letter from M. E. Hoover to William Younger regarding proposed changes to an order for SEAALL letterhead
Letter from B. E. Hoover to B. R. Colson
Letter from B. E. Hoover to B. R. Colson dated 4 October 1912. The correspondence is hand written on H. and H. Company letterhead
Remarks on NonHamiltonian Statistical Mechanics: Lyapunov Exponents and Phase-Space Dimensionality Loss
The dissipation associated with nonequilibrium flow processes is reflected by
the formation of strange attractor distributions in phase space. The
information dimension of these attractors is less than that of the equilibrium
phase space, corresponding to the extreme rarity of nonequilibrium states. Here
we take advantage of a simple model for heat conduction to demonstrate that the
nonequilibrium dimensionality loss can definitely exceed the number of
phase-space dimensions required to thermostat an otherwise Hamiltonian system.Comment: 5 pages, 2 figures, minor typos correcte
Fixed-optics four-dimensional emittance measurement at the Spallation Neutron Source
A hadron beam with a uniform charge density, elliptical transverse profile,
and small four-dimensional (4D) emittance could mitigate space charge effects
in circular accelerators and improve collider performance. A phase space
painting method to generate such a distribution is being tested in the
Spallation Neutron Source (SNS) accumulator ring. A critical component of these
efforts is to measure the 4D emittance of the beam. Reconstruction of the 4D
emittance from wire-scanner data is a well-known technique. In this paper, we
discuss the implementation of a variant of the multi-optics method using the
four available wire-scanners near the SNS target, as well as the modification
of the wire-scanner region to utilize the fixed-optics method, a method that is
preferred due to its speed but can potentially lead to unacceptable bias and
uncertainty in the reconstructed emittances. We then demonstrate the usefulness
of the fixed-optics method by reconstructing the 4D emittance as a function of
time during accumulation in the SNS ring
The Extended Range X-Ray Telescope center director's discretionary fund report
An Extended Range X-Ray Telescope (ERXRT) of high sensitivity and spatial resolution capable of functioning over a broad region of the X-ray/XUV portion of the spectrum has been designed and analyzed. This system has been configured around the glancing-incidence Wolter Type I X-ray mirror system which was flown on the Skylab Apollo Telescope Mount as ATM Experiment S-056. Enhanced sensitivity over a vastly broader spectral range can be realized by the utilization of a thinned, back-illuminated, buried-channel Charge Coupled Device (CCD) as the X-ray/XUV detector rather than photographic film. However, to maintain the high spatial resolution inherent in the X-ray optics when a CCD of 30 micron pixel size is used, it is necessary to increase the telescope plate scale. This can be accomplished by use of a glancing-incidence X-ray microscope to enlarge and re-focus the primary image onto the focal surface of the CCD
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