662 research outputs found

    Dr. George V. Calhoun

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    "Dr. Calhoun began the work of establishing the Marine Hospital at Port Townsend where he remained until 1875 when he entered private practice…

    Clarence B. Bagley, A Brief Biography

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    "That Mr. Bagley loved Seattle was most apparent , for he fought every influence destructive to its advancement… When once asked concerning longevity of life he answered, 'Be active, keep interested in your fellow man, gave a hobby or so on tap, and stay in this part of the world, which is better than all the other parts put together.

    The theoretical reflectance of X-rays from optical surfaces

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    The theoretical reflectance of X-rays from various materials and evaporated films is presented. A computer program was written that computes the reflected intensity as a function of the angle of the incident radiation. The quantities necessary to generate the efficiency and their effect on the data are demonstrated. Five materials were chosen for evaluation: (1) fused silica, (2) chromium, (3) beryllium, (4) gold, and (5) a thin layer contaminant. Fused silica is a versatile and common material; chromium has high reflection efficiency at X-ray wavelengths and is in the middle of the atomic number range; beryllium contains a single atomic shell and has a low range atomic number; gold contains multiple atomic shells and has a high atomic number; the contaminant is treated as a thin film in the calculations and results are given as a function of thickness for selected wavelengths. The theoretical results are compared to experimental data at lambda = 8.34 A

    Teleportation of Nonclassical Wave Packets of light

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    We report on the experimental quantum teleportation of strongly nonclassical wave packets of light. To perform this full quantum operation while preserving and retrieving the fragile non-classicality of the input state, we have developed a broadband, zero-dispersion teleportation apparatus that works in conjunction with time-resolved state preparation equipment. Our approach brings within experimental reach a whole new set of hybrid protocols involving discrete- and continuous-variable techniques in quantum information processing for optical sciences

    High purity bright single photon source

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    Using cavity-enhanced non-degenerate parametric downconversion, we have built a frequency tunable source of heralded single photons with a narrow bandwidth of 8 MHz, making it compatible with atomic quantum memories. The photon state is 70% pure single photon as characterized by a tomographic measurement and reconstruction of the quantum state, revealing a clearly negative Wigner function. Furthermore, it has a spectral brightness of ~1,500 photons/s per MHz bandwidth, making it one of the brightest single photon sources available. We also investigate the correlation function of the down-converted fields using a combination of two very distinct detection methods; photon counting and homodyne measurement.Comment: 9 pages, 4 figures; minor changes, added referenc

    Versatile Wideband Balanced Detector for Quantum Optical Homodyne Tomography

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    We present a comprehensive theory and an easy to follow method for the design and construction of a wideband homodyne detector for time-domain quantum measurements. We show how one can evaluate the performance of a detector in a specific time-domain experiment based on electronic spectral characteristic of that detector. We then present and characterize a high-performance detector constructed using inexpensive, commercially available components such as low-noise high-speed operational amplifiers and high-bandwidth photodiodes. Our detector shows linear behavior up to a level of over 13 dB clearance between shot noise and electronic noise, in the range from DC to 100 MHz. The detector can be used for measuring quantum optical field quadratures both in the continuous-wave and pulsed regimes with pulse repetition rates up to about 250 MHz.Comment: 11 pages, 8 figures, 1 tabl

    Does the quark-gluon plasma contain stable hadronic bubbles?

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    We calculate the thermodynamic potential of bubbles of hadrons embedded in quark-gluon plasma, and of droplets of quark-gluon plasma embedded in hadron phase. This is a generalization of our previous results to the case of non-zero chemical potentials. As in the zero chemical potential case, we find that a quark-gluon plasma in thermodynamic equilibrium may contain stable bubbles of hadrons of radius R1R \simeq 1 fm. The calculations are performed within the MIT Bag model, using an improved multiple reflection expansion. The results are of relevance for neutron star phenomenology and for ultrarelativistic heavy ion collisions.Comment: 12 pages including 8 figures. To appear in Phys. Rev.

    Interactions between uptake of amino acids and inorganic nitrogen in wheat plants

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    Soil-borne amino acids may constitute a source of nitrogen (N) for plants in various terrestrial ecosystems but their importance for total N nutrition is unclear, particularly in nutrient-rich arable soils. One reason for this uncertainty is lack of information on how the absorption of amino acids by plant roots is affected by the simultaneous presence of inorganic N forms. The objective of the present study was to study absorption of glycine (Gly) and glutamine (Gln) by wheat roots and their interactions with nitrate (NO<sub>3</sub><sup>−</sup>) and ammonium (NH<sub>4</sub><sup>+</sup>) during uptake. The underlying hypothesis was that amino acids, when present in nutrient solution together with inorganic N, may lead to down-regulation of the inorganic N uptake, thereby resulting in similar total N uptake rates. Amino acids were enriched with double-labelled <sup>15</sup>N and <sup>13</sup>C, while NO<sub>3</sub><sup>−</sup> and NH<sub>4</sub><sup>+</sup> acquisition was determined by their rate of removal from the nutrient solution surrounding the roots. The uptake rates of NO<sub>3</sub><sup>−</sup> and NH<sub>4</sub><sup>+</sup> did not differ from each other and were generally about twice as high as the uptake rate of organic N when the different N forms were supplied separately in concentrations of 2 mM. Nevertheless, replacement of 50% of the inorganic N with organic N was able to restore the N uptake to the same level as that in the presence of only inorganic N. Co-provision of NO<sub>3</sub><sup>−</sup> did not affect glycine uptake, while the presence of glycine down-regulated NO<sub>3</sub><sup>−</sup> uptake. The ratio between <sup>13</sup>C and <sup>15</sup>N were lower in shoots than in roots and also lower than the theoretical values, reflecting higher C losses via respiratory processes compared to N losses. It is concluded that organic N can constitute a significant N-source for wheat plants and that there is an interaction between the uptake of inorganic and organic N

    Maize seed orientation in the substrate and its influences on germination, seedling structure, and transmission of Fusarium moniliforme

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    A research paper on maize seed orientation.The percentage of seedlings emerging during the first 4 days after sowing and the mesocotyl length after 7 days in sand at 25°C was strongly influenced by the orientation of the seed in the seedbed. Maize seeds emerged faster when oriented vertically with the pedicel end facing down (VD) or horizontally with the embryal side facing up (HU). The mesocotyl portion of the seedling was shorter (t 1mm) when sown at HU and VD, providing a fast and easy emergence to the seedling. It was much longer (20mm) when the seed was oriented horizontally with the embryal side facing down (HD) and vertically with the pedicel end facing up (VU). We concluded that the length of the mesocotyl portion of the seedling varies with the orientation of the seed in the substrate at the same depth. The seeds sown in the orientation HU and VU disclosed a higher germination of 95 percent and 88 percent respectively, compared to the seeds sown in the orientation HD and VD which had 68 percent and 53 percent germination respectively. Seed to seedling transmission of Fusarium moniliforme was recorded at a ratio of 1:1 in the untreated seeds, and infection of the fungus was found in the third leaf lamina and other sections of 10 day old seedlings. This demonstrates for the first time the systemic development of F. moniliforme above the crown portion of 10 day old seedlings. Treatment with Thiram contact fungicide improves the germination of highly infected seeds and also reduces the seed to seedling transmission of F. moniliforme. The efficiency of this seed treatment depended on the orientation of the seeds in the seedbed

    Dr. George V. Calhoun

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    "Dr. Calhoun began the work of establishing the Marine Hospital at Port Townsend where he remained until 1875 when he entered private practice…
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