43,702 research outputs found
Computer program to determine the irrotational nozzle admittance
Irrotational nozzle admittance is the boundary condition that must be satisfied by combustor flow oscillations at nozzle entrance. Defined as the ratio of axial velocity perturbation to the pressure perturbation at nozzle entrance, nozzle admittance can also be used to determine whether wave motion in nozzle under consideration adds or removes energy from combustor oscillations
Design and fabrication of metallic thermal protection systems for aerospace vehicles
A program was conducted to develop a lightweight, efficient metallic thermal protection system (TPS) for application to future shuttle-type reentry vehicles, advanced space transports, and hypersonic cruise vehicles. Technical requirements were generally derived from the space shuttle. A corrugation-stiffened beaded-skin TPS design was used as a baseline. The system was updated and modified to incorporate the latest technology developments and design criteria. The primary objective was to minimize mass for the total system
Development of advanced fuel cell system (phase 4)
For abstract, see N76-23686
Gravothermal Catastrophe, an Example
This work discusses gravothermal catastrophe in astrophysical systems and
provides an analytic collapse solution which exhibits many of the catastrophe
properties. The system collapses into a trapped surface with outgoing energy
radiated to a future boundary, and provides an example of catastrophic
collapse.Comment: To appear in Phys. Rev.
On The Relevance Of Fair Sampling Assumption In The Recent Bell Photonic Experiments
In the experimental verification of Bell's inequalities in real photonic
experiments, it is generally believed that the so-called fair sampling
assumption (which means that a small fraction of results provide a fair
statistical sample) has an unavoidable role. Here, we want to show that the
interpretation of these experiments could be feasible, if some different
alternative assumptions other than the fair sampling were used. For this
purpose, we derive an efficient Bell-type inequality which is a CHSH-type
inequality in real experiments. Quantum mechanics violates our proposed
inequality, independent of the detection-efficiency problems.Comment: 13 pages, no figure, one table. Last versio
Cultivation and use of bryophytes as experimental material
Bryophytes can be grown successfully if keptmoist, supplied
with nutrients, and out of direct sunlight. They remain greener
on peat than on sand. However, difficulties were encountered when
attempting to grow mosses and liverworts in an unshaded
glasshouse, in spring and summer. Even spraying hourly with water
did not prevent scorching and desiccation.
Growth can be measured using a variety of techniques; height
measurement and shoot elongation from thread markers proved the
most reliabl
Spectral universality of strong shocks accelerating charged particles
As a rule, the shock compression controls the spectrum of diffusively
accelerated particles. We argue that this is not so if the backreaction of
these particles on the shock structure is significant. We present a
self-similar solution in which the accelerated particles change the flow
structure near the shock so strongly that the total shock compression may
become arbitrarily large. Despite this, the energy spectrum behind the shock is
close to E^{-3/2} independently of anything at all.Comment: Submitted to ApJL, 4 pages, 1 figure, uses revtex and boxedep
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