1,814 research outputs found
A catalog of radio observations of Jupiter 1961-1964
Catalog of radio observations of Jupiter 1961 to 196
Some Wood Properties of Plantation Pines, Pinus Caribaea and Pinus Oocarpa
Pinus caribaea and Pinus oocarpa plantations in Brazil provided test trees from 4 to 17 years old. Wood of Pinus oocarpa exhibited slightly higher stiffness and bending and compression strengths than that of Caribbean pine. Increasing age was correlated with increases in these mechanical properties, and, in many cases, specific gravity.Patterns of wood density distribution were determined by X-ray and water-displacement methods within cross sections from different heights of trees. In both species, tracheid length increased steadily with age and was greater in latewood than in earlywood
Strength and Stiffness of Preservative-Treated Marine Piles
An assessment was made of the effect of preservative treatments on bending strength and stiffness of full-sized marine piles and small specimens derived from them and on the compression strength of pile sections. Preservative-treated Southern pine and Douglas-fir piles were generally lower in strength than untreated piles. Dual treatments of ACA plus creosote and CCA plus creosote reduced strength more than single treatments with these preservatives. Stiffness and strength in compression were not affected by preservative treatment. Statistical associations between MOE and MOR values of small specimens and full-sized piles in bending were extremely small
A conditional-phase switch at the single-photon level
We present an experimental realization of a two-photon conditional-phase
switch, related to the ``-'' gate of quantum computation. This gate
relies on quantum interference between photon pairs, generating entanglement
between two optical modes through the process of spontaneous parametric
down-conversion (SPDC). The interference effect serves to enhance the effective
nonlinearity by many orders of magnitude, so it is significant at the quantum
(single-photon) level. By adjusting the relative optical phase between the
classical pump for SPDC and the pair of input modes, one can impress a large
phase shift on one beam which depends on the presence or absence of a single
photon in a control mode.Comment: 8 pages, 4 figure
Coherent analysis of quantum optical sideband modes
We demonstrate a device that allows for the coherent analysis of a pair of
optical frequency sidebands in an arbitrary basis. We show that our device is
quantum noise limited and hence applications for this scheme may be found in
discrete and continuous variable optical quantum information experiments.Comment: 3 pages, 3 figures, submitted to Optics Letter
Quantum-inspired interferometry with chirped laser pulses
We introduce and implement an interferometric technique based on chirped
femtosecond laser pulses and nonlinear optics. The interference manifests as a
high-visibility (> 85%) phase-insensitive dip in the intensity of an optical
beam when the two interferometer arms are equal to within the coherence length
of the light. This signature is unique in classical interferometry, but is a
direct analogue to Hong-Ou-Mandel quantum interference. Our technique exhibits
all the metrological advantages of the quantum interferometer, but with signals
at least 10^7 times greater. In particular we demonstrate enhanced resolution,
robustness against loss, and automatic dispersion cancellation. Our
interferometer offers significant advantages over previous technologies, both
quantum and classical, in precision time delay measurements and biomedical
imaging.Comment: 6 pages, 4 figure
Turbulent length-time scales distributions in hydraulic jumps
Airâwater flow measurements were performed in hydraulic jump flows for a range of inflow Froude numbers. The experiments were conducted in a large-sized facility using phase-detection intrusive probes. The void fraction measurements showed the presence of an advective diffusion shear layer where the air concentration vertical distributions were successfully compared with an analytical solution of the advective diffusion equation for air bubbles. In the airâwater shear layer, a new empirical relationship between the maximum air concentration decay as a function of both the distance from the jump toe and the inflow Froude number was derived. Airâwater turbulent time and length scales were deduced from auto- and cross-correlation analyses based on the method of Chanson (2007). The result provided some characteristic transverse time and length scales of the eddy structures advecting the air bubbles in the developing shear layer. The turbulence time scale data showed an increase with the relative elevation above the bed, as well as some decrease with increasing distance from the toe. The dimensionless integral turbulent length scale Lxz/d1 was closely related to the inflow depth
Controlling stereoselectivity by enzymatic and chemical means to access enantiomerically pure (1S,3R)-1-benzyl-2,3-dimethyl-1,2,3,4-tetrahydroisoquinoline derivatives
A chemoenzymatic strategy for the synthesis of enantiomerically pure novel alkaloids (1S,3R)- 1-benzyl-2,3-dimethyl-1,2,3,4-tetrahydroisoquinolines is presented. The key steps are the biocatalytic stereoselective reductive amination of substituted 1-phenylpropan-2-one derivatives to yield chiral amines employing microbial x-transaminases, and the diastereoselective reduction of a Bischlerâ Napieralski imine intermediate by catalytic hydrogenation in the presence of palladium on charcoal, leading exclusively to the desired cis-isomerFil: Orden, Alejandro Agustin. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico San Luis. Instituto de Investigaciones en TecnologĂa QuĂmica; Argentina;Fil: Schrittwieser, Joerg H.. University of Graz. Department of Chemistry, Organic and Bioorganic Chemistry; Austria;Fil: Resch, Verena. University of Graz. Department of Chemistry, Organic and Bioorganic Chemistry; Austria;Fil: Mutti, Francesco G.. University of Graz. Department of Chemistry, Organic and Bioorganic Chemistry; Austria;Fil: Kroutil, Wolfgang. University of Graz. Department of Chemistry, Organic and Bioorganic Chemistry; Austria
- âŠ