241 research outputs found
Glaciology of the Queen Maud Land Traverse, 1964-65 South Pole - Pole of Relative Inaccessibility
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
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
In this article, we assume that there exist scalar , , and
molecular states, and study their masses using
the QCD sum rules. The numerical results indicate that the masses are about
above the corresponding ,
, and thresholds, the Y(4140) is unlikely a scalar molecular state. The scalar ,
, and molecular states maybe not exist, while the scalar , , and
molecular states maybe exist.Comment: 19 pages, 36 figures, slight revisio
Lambda polarization and single-spin left-right asymmetry in diffractive hadron-hadron collisions
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 polarization in the diffractive
process, , is much higher than that in the inclusive
reaction, . We make predictions for the left-right asymmetry,
A_N, and for the spin transfer, , in the single-spin process
and suggest further experimental tests of the
proposed picture.Comment: 14 pages, 3 ps-figures. Phys. Rev. D (in press
Analysis of the vertexes , and radiative decays ,
In this article, we study the vertexes and with the light-cone QCD sum rules, then assume the vector meson
dominance of the intermediate , and , and
calculate the radiative decays and .Comment: 28 pages, 4 tables, revised versio
Novel Structure Function for Photon Fragmentation into a Hyperon and Transverse Polarization in Unpolarized Electron-Positron Annihilation
The possibility is examined for the inclusive in unpolarized
electron-positron annihilation to be transversely polarized. Due to final-state
interactions, there exists a novel structure function for the
inclusive hyperon (or any other baryons) production from the
unpolarized time-like photon fragmentation, which makes contribution to the
transverse 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
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
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 . At low temperatures, they exhibit anomalous oscillations in
their flux dependence.The shape of the functions converges to the sawtooth
function periodic with .Comment: RevTex 8 pages. one figure. to appear in Phys.Rev.
Mass spectrum of the axial-vector hidden charmed and hidden bottom tetraquark states
In this article, we perform a systematic study of the mass spectrum of the
axial-vector hidden charmed and hidden bottom tetraquark states using the QCD
sum rules, and identify the as an axial-vector tetraquark state
tentatively.Comment: 24 pages, 38 figures, slight revisio
Lowest-Landau-level theory of the quantum Hall effect: the Fermi-liquid-like state
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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