1,353 research outputs found
The Effects Of Medicare Payment Changes On Nursing Home Staffing
In light of persistent shortcomings in nursing home care quality and evidence that lower nurse staffing levels could be harmful to residents, we examine whether staffing levels are affected by changes in Medicare reimbursement rates. We exploit a 2006 change in Medicare’s methodology for adjusting provider payments for geographic differences in costs, a change that generated plausibly exogenous variation in nursing facility reimbursement rates. Our method compares facilities with higher and lower shares of Medicare resident days, which were differentially exposed to the payment changes we examine. Using panel data on US nursing homes from 2003 through 2009, we find that higher Medicare payments increased nurse staffing hours per resident day. Additional results suggest that changes in Medicare payments did not affect other measures of quality
Tropical Crops and Resilience to Climate Change
It is anticipated that agricultural output will have to increase by 70% to feed a global population of more than 9 billion by the year 2050 (Benkeblia 2012). The capacity of global high-intensity farming systems to continue to guarantee productive returns while maintaining system stability will eventually decline, and thus new opportunities for agriculture are being realized in tropical environments. As population growth is greatest in tropical regions, and commensurate with rapid industrialization and change in traditional land use practices, it is presumed that equatorial production systems will be some of the most vulnerable to climate change
High temperature x ray diffraction determination of the body-centered-cubic-face-centered-cubic transformation temperature in (Fe 70Ni 30) 88Zr 7B 4Cu 1 nanocomposites
In situ high-temperature x ray diffraction and magnetization measurements were performed on a melt-spun (Fe70Ni30)88Zr7B4Cu1 amorphous alloy to follow its structural evolution. At 728 K, a bcc-FeNi phase was observed as the primary crystallization product followed by transformation to an fcc phase rv773 K. During cooling to room temperature, the fcc-to-bcc transformation was not observed, and the metastable fcc-NiFe phase was retained at room temperature
Experimental study of ceramic coated tip seals for turbojet engines
Ceramic gas-path seals were fabricated and successfully operated over 1000 cycles from flight idle to maximum power in a small turboshaft engine. The seals were fabricated by plasma spraying zirconia over a NiCoCrAlX bond boat on the Haynes 25 substrate. Coolant-side substrate temperatures and related engine parameters were recorded. Post-test inspection revealed mudflat surface cracking with penetration to the ceramic bond-coat interface
Hole Doping Effects on Spin-gapped Na2Cu2TeO6 via Topochemical Na Deficiency
We report the magnetic susceptibility and NMR studies of a spin-gapped
layered compound
Na2Cu2TeO6 (the spin gap 250 K), the hole doping effect on the
Cu2TeO6 plane via a topochemical Na deficiency by soft chemical treatment, and
the static spin vacancy effect by nonmagnetic impurity Zn substitution for Cu.
A finite Knight shift at the Te site was observed for pure
Na2Cu2TeO6.
The negative hyperfine coupling constant is an evidence for
the existence of a superexchange pathway of the Cu-O-Te-O-Cu bond. It turned
out that both the Na deficiency and Zn impurities induce a Curie-type magnetism
in the uniform spin susceptibility in an external magnetic field of 1 T, but
only the Zn impurities enhance the low-temperature Na nuclear
spin-lattice relaxation rate whereas the Na deficiency suppresses it. A spin
glass behavior was observed for the Na-deficient samples but not for the
Zn-substituted samples. The dynamics of the unpaired moments of the doped holes
are different from that of the spin vacancy in the spin-gapped Cu2TeO6 planes.Comment: 4 pages, 7 figures, to be published in J. Phys. Soc. Jpn. Vol. 75,
No. 8 (2006
NMR characterization of spin-1/2 alternating antiferromagnetic chains in the high-pressure phase of (VO)2P2O7
Local-susceptibility measurements via the NMR shifts of P and V
nuclei in the high-pressure phase of (VO)PO confirmed the
existence of a unique alternating antiferromagnetic chain with a zero-field
spin gap of 34 K. The P nuclear spin-lattice relaxation rate scales with
the uniform spin susceptibility below about 15 K which shows that the
temperature dependence of both the static and dynamical spin susceptibilities
becomes identical at temperatures not far below the spin-gap energy.Comment: 6 pages, 5 figures; To be published in J. Phys. Condens. Matte
Absence of Edge Localized Moments in the Doped Spin-Peierls System CuGeSiO
We report the observation of nuclear quadrupole resonance (NQR) of Cu from
the sites near the doping center in the spin-Peierls system
CuGeSiO. The signal appears as the satellites in the Cu NQR
spectrum, and has a suppressed nuclear spin-lattice relaxation rate indicative
of a singlet correlation rather than an enhanced magnetic correlation near the
doping center. Signal loss of Cu nuclei with no neighboring Si is also
observed. We conclude from these observations that the doping-induced moments
are not in the vicinity of the doping center but rather away from it.Comment: 4 pages, 4 figures, accepted for publication in Phys. Rev. Let
High speed electric motors based on high performance novel soft magnets
Novel Co-based soft magnetic materials are presented as a potential substitute for electrical steels in high speed motors for current industry applications. The low losses, high permeabilities, and good mechanical strength of these materials enable application in high rotational speed induction machines. Here, we present a finite element analysis of Parallel Path Magnetic Technology rotating motors constructed with both silicon steel and Co-based nanocomposite. The later achieved a 70% size reduction and an 83% reduction on NdFeB magnet volume with respect to a similar Si-steel design.Fil: Silveyra, Josefina MarÃa. Universidad de Buenos Aires. Facultad de Ingenieria. Departamento de Fisica. Laboratorio de Sólidos Amorfos; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de TecnologÃas y Ciencias de la IngenierÃa; Argentina; ArgentinaFil: Leary, A. M.. University Of Carnegie Mellon; Estados UnidosFil: DeGeorge, V.. University Of Carnegie Mellon; Estados UnidosFil: Simizu, S.. Advanced Materials Corporation; Estados UnidosFil: McHenry, M. E.. University Of Carnegie Mellon; Estados Unido
Magnetic flux jumps in textured Bi2Sr2CaCu2O(8+d)
Magnetic flux jumps in textured Bi2Sr2CaCu2O(8+d) have been studied by means
of magnetization measurements in the temperature range between 1.95 K and Tc,
in an external magnetic field up to 9 T. Flux jumps were found in the
temperature range 1.95 K - 6 K, with the external magnetic field parallel to
the c axis of the investigated sample. The effect of sample history on magnetic
flux jumping was studied and it was found to be well accounted for by the
available theoretical models. The magnetic field sweep rate strongly influences
the flux jumping and this effect was interpreted in terms of the influence of
both flux creep and the thermal environment of the sample. Strong flux creep
was found in the temperature and magnetic field range where flux jumps occur
suggesting a relationship between the two. The heat exchange conditions between
the sample and the experimental environment also influence the flux jumping
behavior. Both these effects stabilize the sample against flux instabilities,
and this stabilizing effect increases with decreasing magnetic field sweep
rate. Demagnetizing effects are also shown to have a significant influence on
flux jumping.Comment: 10 pages, 6 figures, RevTeX4, submitted to Phys. Rev.
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