Some factors influencing radiation of sound from flow interaction with edges of finite surfaces

Edges of surfaces which are exposed to unsteady flow cause both strictly acoustic effects and hydrodynamic effects, in the form of generation of new hydrodynamic sources in the immediate vicinity of the edge. An analytical model is presented which develops the explicit sound-generation role of the velocity and Mach number of the eddy convection past the edge, and the importance of relative scale lengths of the turbulence, as well as the relative intensity of pressure fluctuations. The Mach number (velocity) effects show that the important paramater is the convection Mach number of the eddies. The effects of turbulence scale lengths, isotropy, and spatial density (separation) are shown to be important in determining the level and spectrum of edge sound radiated for the edge dipole mechanism. Experimental data is presented which provides support for the dipole edge noise model in terms of Mach number (velocity) scaling, parametric dependence on flow field parameter, directivity, and edge diffraction effects

NIMBUS-5 sounder data processing system. Part 2: Results

The Nimbus-5 spacecraft carries infrared and microwave radiometers for sensing the temperature distribution of the atmosphere. Methods developed for obtaining temperature profiles from the combined set of infrared and microwave radiation measurements are described. Algorithms used to determine (a) vertical temperature and water vapor profiles, (b) cloud height, fractional coverage, and liquid water content, (c) surface temperature, and (d) total outgoing longwave radiation flux are described. Various meteorological results obtained from the application of the Nimbus-5 sounding data processing system during 1973 and 1974 are presented

Information Flow in Entangled Quantum Systems

All information in quantum systems is, notwithstanding Bell's theorem, localised. Measuring or otherwise interacting with a quantum system S has no effect on distant systems from which S is dynamically isolated, even if they are entangled with S. Using the Heisenberg picture to analyse quantum information processing makes this locality explicit, and reveals that under some circumstances (in particular, in Einstein-Podolski-Rosen experiments and in quantum teleportation) quantum information is transmitted through 'classical' (i.e. decoherent) information channels.Comment: PostScript version now available: http://www.qubit.org/people/patrickh/Papers/InformationFlow.p

Marsh Cress, A Bad Weed

The Botany Section receives many letters containing specimens of marsh cress with requests for information as to methods of dealing with the weed. This is especially the case in years when we have had a wet early spring. The persons sending the plants generally state that the weed is especially abundant in oats. In such seasons, from the latter part of April to July 1, from 15 to 20 specimens arc received each week

March Cress, Its Geography and Ecology in Iowa

Early in the spring of 1927 our attention was called to the prevalence of marsh cress in the state. This is not the first season that this weed has been so common. Apparently its appearance is more or less periodic or sporadic, depending upon weather conditions of the previous season

High-Frequency Spin Waves in YBa2Cu3O6.15

Pulsed neutron spectroscopy is used to make absolute measurements of the dynamic magnetic susceptibility of insulating YBa2Cu3O6.15. Acoustic and optical modes, derived from in- and out-of-phase oscillation of spins in adjacent CuO2 planes, dominate the spectra and are observed up to 250 meV. The optical modes appear first at 74 meV. Linear-spin-wave theory gives an excellent description of the data and yields intra- and inter-layer exchange constants of J_parallel =125 meV and J_perp = 11 meV respectively and a spin-wave intensity renormalization Z_chi = 0.4.Comment: postscript, 11 pages, 4 figures, Fig.2 fixe

On the quantum, classical and total amount of correlations in a quantum state

We give an operational definition of the quantum, classical and total amount of correlations in a bipartite quantum state. We argue that these quantities can be defined via the amount of work (noise) that is required to erase (destroy) the correlations: for the total correlation, we have to erase completely, for the quantum correlation one has to erase until a separable state is obtained, and the classical correlation is the maximal correlation left after erasing the quantum correlations. In particular, we show that the total amount of correlations is equal to the quantum mutual information, thus providing it with a direct operational interpretation for the first time. As a byproduct, we obtain a direct, operational and elementary proof of strong subadditivity of quantum entropy.Comment: 12 pages ReVTeX4, 2 eps figures. v2 has some arguments clarified and references update

High energy spin excitations in YBa_2 Cu_3 O_{6.5}

Inelastic neutron scattering has been used to obtain a comprehensive description of the absolute dynamical spin susceptibility $\chi'' (q,\omega)$ of the underdoped superconducting cuprate YBa_2 Cu_3 O_{6.5} ($T_c = 52 K$) over a wide range of energies and temperatures ($2 meV \leq \hbar \omega \leq 120 meV$ and $5K \leq T \leq 200K$). Spin excitations of two different symmetries (even and odd under exchange of two adjacent CuO_2 layers) are observed which, surprisingly, are characterized by different temperature dependences. The excitations show dispersive behavior at high energies.Comment: 15 pages, 5 figure

Recovering quantum information through partial access to the environment

We investigate the possibility of correcting errors occurring on a multipartite system through a feedback mechanism that acquires information from partial access to the environment. A partial control scheme of this kind might be useful when dealing with correlated errors. In fact, in such a case, it could be enough to gather local information to decide what kind of global recovery to perform. Then, we apply this scheme to the depolarizing and correlated errors, and quantify its performance by means of the entanglement fidelity

A high-throughput approach developing lithium-niobium-tantalum oxides as electrolyte/cathode interlayers for high-voltage all-solid-state lithium batteries

The ever-increasing interest in sustainable mobility is driving the development of innovative batteries with increased energy densities relative to currently commercialized lithium-ion batteries. All-solid-state batteries using 5 V-class positive electrodes are one of those batteries due to their larger volumetric energy density and their superior durability. However, their power density tends to be limited by the large charge transfer resistance at their electrolyte/5 V-electrode interfaces; one explanation for this is the development of significant Li+ deficient layers at the interface. Here we propose a new interlayer material that would effectively resolve the Li+ deficient layers. The partially-crystallized Li56Nb22Ta22 oxide was identified using the molecular beam epitaxy (MBE) based high-throughput physical vapor deposition (HT-PVD) approach. Its higher ionic conductivity of 4.2 ?S cm?1 and higher permittivity of 165 when measured at 254 kHz, relative to those of conventional LiNbO3 interlayer (1.8 ?S cm?1 and 95, respectively) will be effective for fast charge transfer reactions at the electrolyte /cathode interfaces in 5 V-class all-solid-state batteries