Toward a second generation fuel efficient supersonic cruise aircraft performance characteristics and benefits

The need for greatly improved fuel efficiency and off-design subsonic characteristics is discussed. Engine-airframe matching studies are presented which show the benefits of a configuration designed for much lower supersonic drag levels (blended wing-fuselage) and how well this airframe matches with the new advanced variable-cycle engines. The benefits of advanced takeoff procedures and systems together with the co-annular noise effect in achieving low noise levels with a small cruise-sized engine are discussed. It is concluded that the technology advances when carefully integrated through detailed engine-airframe matching studies on a validated baseline airplane lead to a much improved supersonic cruise aircraft, i.e., more range, less fuel consumption, noise flexibility and satisfactory off-design characteristics

Topological Non--connectivity Threshold in long-range spin systems

We demonstrate the existence of a topological disconnection threshold, recently found in Ref. \cite{JSP}, for generic $1-d$ anisotropic Heisenberg models interacting with an inter--particle potential $R^{-\alpha}$ when $0<\alpha < 1$ (here $R$ is the distance among spins). We also show that if $\alpha$ is greater than the embedding dimension $d$ then the ratio between the disconnected energy region and the total energy region goes to zero when the number of spins becomes very large. On the other hand, numerical simulations in $d=2,3$ for the long-range case $\alpha < d$ support the conclusion that such a ratio remains finite for large $N$ values. The disconnection threshold can thus be thought as a distinctive property of anisotropic long-range interacting systems.Comment: submitted to PR

Collections recueilles par M. le Baron Maurice de Rothschild dans l\u27Afrique orientale Insectes hym\ue9nopt\ue9res: Mellifres

Volume: 15Start Page: 529End Page: 53

Contributions hym\ue9nopt\ue9riques. V.– Hymenoptera mellifera americana nova

Volume: 70Start Page: 77End Page: 8

Hym\ue9nopt\ue8res du Congo Francais Rapport\ue9s par l\u27ing\ue9nieur J. Bouyssou. Mellifera

Volume: 72Start Page: 358End Page: 40

Contributions Hym\ue9nopt\ue9riques

Volume: 68Start Page: 534End Page: 53

\uc9claircissements sur le genre Scrapter et description d\u27une esp\ue8ce nouvelle de Dufourea (Hym\ue9n.)

Volume: 1897Start Page: 61End Page: 6