Resonance scattering of sound by a small gaseous object of arbitrary form

The acoustic scattering amplitude for a dilute gaseous object of arbitrary form in a liquid medium is determined self-consistently for the case of linear dimension small as compared to the wavelength. A scatterer of bulk modulus β, and density p, in a medium of bulk modulus II and density p may exhibit monopole resonance scattering at a frequency w,= (4πβoC / pV)l, in which V is the volume and C is the capacitance in electrostatic units of a conducting replica of the scatterer. The criterion for occurrence of the resonance phenomenon is 3Fβo/β 1 is minimum for a sphere. Dipole scattering is given in terms of the polarizability dyadic of a nonconducting replica of dielectric constant p/po, and is negligibly small in a neighborhood of the resonance frequency.The Office of Naval Research under Contract Nonr-1367(00), NR 261-102

Aboard the Space Shuttle

Livability aboard the space shuttle orbiter makes it possible for men and women scientists and technicians in reasonably good health to join superbly healthy astronauts as space travelers and workers. Features of the flight deck, the mid-deck living quarters, and the subfloor life support and house-keeping equipment are illustrated as well as the provisions for food preparation, eating, sleeping, exercising, and medical care. Operation of the personal hygiene equipment and of the air revitalization system for maintaining sea level atmosphere in space is described. Capabilities of Spacelab, the purpose and use of the remote manipulator arm, and the design of a permanent space operations center assembled on-orbit by shuttle personnel are also depicted

Creative activities and skills for bright and gifted children to supplement the Scott, Foresman and Company new basic readers for grade two

Thesis (Ed.M.)--Boston Universit

Strangeness Saturation: Dependence on System-Size, Centrality and Energy

The dependence of the strangeness saturation factor on the system size, centrality and energy is studied in relativistic heavy-ion collisions.Comment: contribution for Proc. 19th Winter Workshop on Nuclear Dynamics, Breckenridge, February 8-15, 200

Some Weyl modules of the algebraic groups of type E6E_6

Let $G$ be a simple algebraic group of type $E_6$ over an algebraically closed field of characteristic $p>0$. We determine the submodule structure of the Weyl modul es with highest weight $r\omega_1$ for $0\leq r\leq p-1$, where $\omega_1$ is the fundamental weight of the standard $27$-dimensional module. In the process, the structures of other Weyl modules with highest weights linked to $r\omega_1$ are also found. %We also give some computations for the Weyl modules with highest weights %of the form $r(\omega_1+\omega_6)$, which arise in the study of %the graph automorphism and associated twisted finite groups.Comment: 25 page

Sphaerodactylus kirbyi

Number of Pages: 2Integrative BiologyGeological Science

Nonlinear optics with less than one photon

We demonstrate suppression and enhancement of spontaneous parametric down- conversion via quantum interference with two weak fields from a local oscillator (LO). Pairs of LO photons are observed to upconvert with high efficiency for appropriate phase settings, exhibiting an effective nonlinearity enhanced by at least 10 orders of magnitude. This constitutes a two-photon switch, and promises to be useful for a variety of nonlinear optical effects at the quantum level.Comment: 8 pages, 5 figure