16,919 research outputs found
Preliminary results of aerial infrared surveys at Pisgah Crater, California
In-flight tests of airborne infrared scanners, and comparison with field reflectance dat
Estimating and controlling the traffic Impact of a collaborative P2P system
Nowadays, P2P applications are commonly used in the Internet being an important paradigm for the development of distinct services. However, the dissemination of P2P applications also entails some important challenges that should be carefully addressed. In particular, some of the important coexistence problems existing between P2P applications and Internet Service Providers (ISPs) are mainly motivated by the inherent P2P dynamics which cause traffic to scatter across the network links in an unforeseeable way.
In this context, this work proposes a collaborative framework of a Bit- Torrent like system. Using the proposed framework and based on the exchange of valuable information between the application and network levels, some novel techniques are proposed allowing to estimate and control the traffic impact that the P2P system will have on the links of the underlying network infrastructure. Both the framework and the presented techniques were tested resorting to simulation. The results clearly corroborate the viability and effectiveness of the formulated methods
Graviton resonances on two-field thick branes
This work presents new results about the graviton massive spectrum in
two-field thick branes. Analyzing the massive spectra with a relative
probability method we have firstly showed the presence of resonance structures
and obtained a connection between the thickness of the defect and the lifetimes
of such resonances. We obtain another interesting results considering the
degenerate Bloch brane solutions. In these thick brane models, we have the
emergence of a splitting effect controlled by a degeneracy parameter. When the
degeneracy constant tends to a critical value, we have found massive resonances
to the gravitational field indicating the existence of modes highly coupled to
the brane. We also discussed the influence of the brane splitting effect over
the resonance lifetimes.Comment: 15 pages, 8 figure
A dynamic two phase flow model for a pilot scale sodium borohydride hydrogen generation reactor
A two-dimensional, non-isothermal, and dynamic model was developed to describe a sodium borohydride/hydrogen re-actor for stationary use. All relevant transport phenomena were treated in detail and the kinetic model developed previ-ously by the authors was introduced into the algorithm. In this paper the reactive solution was modeled as a two phase flow; with this approach the impact of the hydrogen production on the solution stirring could be observed and quantified. Results showed that not all ruthenium deposited on the nickel foam was used efficiently as catalyst. In fact, most of the reaction occurred in the surface of the catalyst foam and around 70% of the deposited catalyst was not used. It was also demonstrated the importance of the two phase flow approach for a correct simulation of the solution stirring and heat transfer
Self-Similarity of Friction Laws
The change of the friction law from a mesoscopic level to a macroscopic level
is studied in the spring-block models introduced by Burridge-Knopoff. We find
that the Coulomb law is always scale invariant. Other proposed scaling laws are
only invariant under certain conditions.}Comment: Plain TEX. Figures not include
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