9,433 research outputs found
Recovering information of tunneling spectrum from Weakly Isolated Horizon
In this paper we investigate the properties of tunneling spectrum from weakly
isolated horizon(WIH). We find that there are correlations among Hawking
radiations from weakly isolated horizon, the information can be carried out in
terms of correlations between sequential emissions, and the radiation is an
entropy conservation process. We generalize Refs.[11-13]' results to a more
general spacetime. Through revisiting the calculation of tunneling spectrum of
weakly isolated horizon, we find that Ref.[12]'s requirement that radiating
particles have the same angular momenta of unit mass as that of black hole is
not needed, and the energy and angular momenta of emitting particles are very
arbitrary which should be restricted only by keeping the cosmic censorship of
black hole
Design, construction and characterization of a wind tunnel
The wind tunnel is the most fundamental test equipment for aircraft testing and studying aerodynamics. Because of the complexity of the test-subject\u27s geometry, it is difficult to study the aerodynamic pattern simply based on theoretical calculations. Most of the aerodynamics experiments still use wind tunnels. The progress of the wind tunnel is highly related to the advancements in air crafts. Aircraft manufacturing has pushed the wind tunnel technology forward. Wind tunnels can be categorized by the wind speed limit differences, which are controlled by the mechanism of the driving methods, structure applications, etc. In this case, we built a small scale wood based wind tunnel for future testing of “Magnetic Augmented Rotational System (MARS)”. This thesis discusses the low speed wind tunnel, subsonic wind tunnel, transonic wind tunnel, supersonic wind tunnel, hypersonic wind tunnel, high enthalpy hypersonic wind tunnel, and puts the focus on low speed wind tunnel. The characteristics of the low speed wind tunnel and the related data will be presented along with its advantages and shortcomings
- …