8,922 research outputs found
Materials testing of the IUS techroll seal material
As a part of the investigation of the control system failure Inertial Upper Stage on IUS-1 flight to position a Tracking and Data Relay Satellite (TDRS) in geosynchronous orbit, the materials utilized in the techroll seal are evaluated for possible failure models. Studies undertaken included effect of temperature on the strength of the system, effect of fatigue on the strength of the system, thermogravimetric analysis, thermomechanical analysis, differential scanning calorimeter analysis, dynamic mechanical analysis, and peel test. The most likely failure mode is excessive temperature in the seal. In addition, the seal material is susceptible to fatigue damage which could be a contributing factor
Method and apparatus for fabricating improved solar cell modules
A method and apparatus for fabricating an improved solar cell module is described. The apparatus includes a supply drum for feeding a flexible strip having etched electrical circuitry deposited on it a supply drum for feeding into overlying engagement with the flexible strip a flexible tape having a pair of exposed tacky surfaces, and a plurality of rams for receiving and depositing a plurality of solar cells in side-by-side relation on an exposed tacky surface of the tape in electrical contacting engagement with the etched circuitry
Low NO(x) heavy fuel combustor program
The 'low nitrogen oxides heavy fuel combustor' program is described. Main program objectives are to generate and demonstrate the technology required to develop durable gas turbine combustors for utility and industrial applications, which are capable of sustained, environmentally acceptable operation with minimally processed petroleum residual fuels. The program will focus on 'dry' reductions of oxides of nitrogen, improved combustor durability, and satisfactory combustion of minimally processed petroleum residual fuels. Other technology advancements sought include: fuel flexibility for operation with petroleum distillates, blends of petroleum distillates and residual fuels, and synfuels (fuel oils derived from coal or shale); acceptable exhaust emissions of carbon monoxide, unburned hydrocarbons, sulfur oxides and smoke; and retrofit capability to existing engines
An integrated study of earth resources in the State of California based on Skylab and supporting aircraft data
There are no author-identified significant results in this report
Independent particle descriptions of tunneling from a many-body perspective
Currents across thin insulators are commonly taken as single electrons moving
across classically forbidden regions; this independent particle picture is
well-known to describe most tunneling phenomena. Examining quantum transport
from a different perspective, i.e., by explicit treatment of electron-electron
interactions, we evaluate different single particle approximations with
specific application to tunneling in metal-molecule-metal junctions. We find
maximizing the overlap of a Slater determinant composed of single particle
states to the many-body current-carrying state is more important than energy
minimization for defining single particle approximations in a system with open
boundary conditions. Thus the most suitable single particle effective potential
is not one commonly in use by electronic structure methods, such as the
Hartree-Fock or Kohn-Sham approximations.Comment: 4+ pages, 4 figures; accepted to Phys. Rev. B Rapid Communication
Impact of PE Physical Activity Levels on Percent Body Fat: Examined against Healthy Fitness Zone
Please view abstract in the attached PDF file
A Low-speed Investigation of an Annular Transonic Air Inlet
Low-speed wind-tunnel tests were conducted as preliminary steps in the study of fuselage-air-inlet arrangements believed suitable for use at transonic speeds. The forward part of the model consisted of an NACA 1-85-050 cowling located at the base of the long protruding fuselage nose designed to maintain substream surface velocities everywhere ahead of the entrance and thereby to avoid or minimize adverse boundary-layer-shock interaction effects up to low supersonic speeds. Pressure-recovery and surface-pressure measurements are presented for the model with three fuselage nose shapes for ranges of angle of attack and inlet-velocity ratio useful for high-speed fligh
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