240 research outputs found

    Glaciology of the Queen Maud Land Traverse, 1964-65 South Pole - Pole of Relative Inaccessibility

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    The University Archives has determined that this item is of continuing value to OSU's history.An oversnow traverse was made from the South Pole to the Pole of Relative Inaccessibility along a zigzag path of about 800 nautical miles during the period 4 December 1964 to 27 January 1965. The surface varied from very hard with many highly developed sastrugi to very soft and smooth. The average air temperature was -28.8°C, with an absolute maximum of -l8.2°C on 5 January and an absolute minimum of -44.7°C on 26 January. The absolute maximum wind speed recorded was 9.0 m/s on 29 December and 17 January; there was 3 percent calm in December and 1 percent calm in January. Solar halos were frequent. Firn temperatures were taken at 29 sites; the most striking anomaly occurred on the last leg of the traverse where there was an abrupt change in slope and as the height increased the temperature anomalously increased before decreasing as expected. The temperature profile at the Pole of Inaccessibility was similar to that obtained by the Soviets in 1964. Temperature gradients were negative at the South Pole but strikingly positive in the vicinity of the Pole of Inaccessibility. Density profiles to depths of 40 m were taken at 12 sites with a neutron-scattering device; most of the density curves showed a break at a density of 0.52 to 0.54 g/cm3. Snow accumulation studies in pits showed an accumulation generally between 5 and 10g/cm2. Snow accumulation measured at the anemometer mast and the instrument shelter at the Pole of Inaccessibility for the period 14 December 1958 to 30 January 1965 was 3-6 g/cm2/yr.National Science Foundation NSF Grant GA-13

    CHANGING NURSING CARE TIME AS AN EFFECT OF CHANGED CHARACTERISTICS OF THE DIALYSIS POPULATION

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    Background The population of dialysis patients is ageing. Dialysis nurses are confronted with geriatric patients with multiple comorbidities. Nurses are confronted with an increasing burden of care. Objectives The present study focused on the question of whether, over time, the increasing age and comorbidities of the haemodialysis population increased nursing care time. Furthermore, we studied potential changes in the predictors of the required nursing time. Design Observational study. Participants A total of 980 dialysis patients from 12 dialysis centres were included. Measurements Nurses filled out the classification tool for each patient and completed a form for reporting patient characteristics for groups of relevant haemodialysis patients at baseline and after 1 and four years. Changes in patient and dialysis characteristics were analysed, as well as the estimated nursing care time needed. Results An increase in the nursing time needed for dialysis was largely due to decreased mobility, closing of the vascular access and a greater need for psychosocial attention and was most strongly present in incident dialysis patients. The time needed for dialysis decreased as patient participation increased and vascular access changed from catheters to fistulae. Over the four-year period, the average overall needed nursing care time per haemodialysis session did not change. Conclusions Our study shows that the average nursing time needed per patient did not change in the four-year observation period. However, more time is required for incident patients; thus, if a centre has high patient turnover, more nursing care time is needed.</p

    Analysis of the Y(4140) and related molecular states with QCD sum rules

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    In this article, we assume that there exist scalar DDˉ{D}^\ast {\bar {D}}^\ast, DsDˉs{D}_s^\ast {\bar {D}}_s^\ast, BBˉ{B}^\ast {\bar {B}}^\ast and BsBˉs{B}_s^\ast {\bar {B}}_s^\ast molecular states, and study their masses using the QCD sum rules. The numerical results indicate that the masses are about (250500)MeV(250-500) \rm{MeV} above the corresponding DDˉ{D}^\ast -{\bar {D}}^\ast, DsDˉs{D}_s^\ast -{\bar {D}}_s^\ast, BBˉ{B}^\ast -{\bar {B}}^\ast and BsBˉs{B}_s^\ast -{\bar {B}}_s^\ast thresholds, the Y(4140) is unlikely a scalar DsDˉs{D}_s^\ast {\bar {D}}_s^\ast molecular state. The scalar DDˉD^\ast {\bar D}^\ast, DsDˉsD_s^\ast {\bar D}_s^\ast, BBˉB^\ast {\bar B}^\ast and BsBˉsB_s^\ast {\bar B}_s^\ast molecular states maybe not exist, while the scalar DDˉ{D'}^\ast {\bar {D'}}^\ast, DsDˉs{D'}_s^\ast {\bar {D'}}_s^\ast, BBˉ{B'}^\ast {\bar {B'}}^\ast and BsBˉs{B'}_s^\ast {\bar {B'}}_s^\ast molecular states maybe exist.Comment: 19 pages, 36 figures, slight revisio

    Lambda polarization and single-spin left-right asymmetry in diffractive hadron-hadron collisions

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    We discuss Lambda polarization and single-spin left-right asymmetry in diffractive hadron-hadron scattering at high energies. We show that the physical picture proposed in a recent Letter is consistent with the experimental observation that Λ\Lambda polarization in the diffractive process, ppΛK+ppp\to \Lambda K^+p, is much higher than that in the inclusive reaction, ppΛXpp\to \Lambda X. We make predictions for the left-right asymmetry, A_N, and for the spin transfer, DNNΛD_{NN}^\Lambda, in the single-spin process p()pΛK+pp(\uparrow)p\to \Lambda K^+p and suggest further experimental tests of the proposed picture.Comment: 14 pages, 3 ps-figures. Phys. Rev. D (in press

    Analysis of the vertexes ΞQΞQV\Xi_Q^*\Xi'_Q V, ΣQΣQV\Sigma_Q^*\Sigma_Q V and radiative decays ΞQΞQγ\Xi_Q^*\to \Xi'_Q \gamma, ΣQΣQγ\Sigma_Q^*\to \Sigma_Q \gamma

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    In this article, we study the vertexes ΞQΞQV\Xi_Q^*\Xi'_Q V and ΣQΣQV\Sigma_Q^* \Sigma_Q V with the light-cone QCD sum rules, then assume the vector meson dominance of the intermediate ϕ(1020)\phi(1020), ρ(770)\rho(770) and ω(782)\omega(782), and calculate the radiative decays ΞQΞQγ\Xi_Q^*\to \Xi'_Q \gamma and ΣQΣQγ\Sigma_Q^*\to \Sigma_Q \gamma.Comment: 28 pages, 4 tables, revised versio

    Novel Structure Function for Photon Fragmentation into a Λ\Lambda Hyperon and Transverse Λ\Lambda Polarization in Unpolarized Electron-Positron Annihilation

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    The possibility is examined for the inclusive Λ\Lambda in unpolarized electron-positron annihilation to be transversely polarized. Due to final-state interactions, there exists a novel structure function F^(z,Q2)\hat F(z,Q^2) for the inclusive Λ\Lambda hyperon (or any other baryons) production from the unpolarized time-like photon fragmentation, which makes contribution to the transverse Λ\Lambda polarization in the unpolarized electron-positron annihilation.Comment: RevTex, 4 pages, the version appearing in Phys. Rev.

    Electron Exchange Coupling for Single Donor Solid-State Qubits

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    Inter-valley interference between degenerate conduction band minima has been shown to lead to oscillations in the exchange energy between neighbouring phosphorus donor electron states in silicon \cite{Koiller02,Koiller02A}. These same effects lead to an extreme sensitivity of the exchange energy on the relative orientation of the donor atoms, an issue of crucial importance in the construction silicon-based spin quantum computers. In this article we calculate the donor electron exchange coupling as a function of donor position incorporating the full Bloch structure of the Kohn-Luttinger electron wavefunctions. It is found that due to the rapidly oscillating nature of the terms they produce, the periodic part of the Bloch functions can be safely ignored in the Heitler-London integrals as was done by Koiller et. al. [Phys. Rev. Lett. 88,027903(2002),Phys. Rev. B. 66,115201(2002)], significantly reducing the complexity of calculations. We address issues of fabrication and calculate the expected exchange coupling between neighbouring donors that have been implanted into the silicon substrate using an 15keV ion beam in the so-called 'top down' fabrication scheme for a Kane solid-state quantum computer. In addition we calculate the exchange coupling as a function of the voltage bias on control gates used to manipulate the electron wavefunctions and implement quantum logic operations in the Kane proposal, and find that these gate biases can be used to both increase and decrease the magnitude of the exchange coupling between neighbouring donor electrons. The zero-bias results reconfirm those previously obtained by Koiller.Comment: 10 Pages, 8 Figures. To appear in Physical Review

    Persistent edge currents for paired quantum hall states

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    We study the behavior of the persistent edge current for paired quantum Hall states on the cylinder. We show that the currents are periodic with the unit flux ϕ0=hc/e\phi_0=hc/e. At low temperatures, they exhibit anomalous oscillations in their flux dependence.The shape of the functions converges to the sawtooth function periodic with ϕ0/2\phi_0/2.Comment: RevTex 8 pages. one figure. to appear in Phys.Rev.

    Lowest-Landau-level theory of the quantum Hall effect: the Fermi-liquid-like state

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    A theory for a Fermi-liquid-like state in a system of charged bosons at filling factor one is developed, working in the lowest Landau level. The approach is based on a representation of the problem as fermions with a system of constraints, introduced by Pasquier and Haldane (unpublished). This makes the system a gauge theory with gauge algebra W_infty. The low-energy theory is analyzed based on Hartree-Fock and a corresponding conserving approximation. This is shown to be equivalent to introducing a gauge field, which at long wavelengths gives an infinite-coupling U(1) gauge theory, without a Chern-Simons term. The system is compressible, and the Fermi-liquid properties are similar, but not identical, to those in the previous U(1) Chern-Simons fermion theory. The fermions in the theory are effectively neutral but carry a dipole moment. The density-density response, longitudinal conductivity, and the current density are considered explicitly.Comment: 32 pages, revtex multicol
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