4,768 research outputs found
A sample of religious understanding and beliefs of an urban church congregation
Thesis (M.S.)--Boston Universit
Local spin polarization in underdoped cuprates with impurities
We present a theory of magnetic (Ni) and nonmagnetic (Zn) impurities
substituted into planar Cu sites in the normal state of underdoped cuprates
exhibiting a spin gap. Both types of impurities induce magnetic moments on
neighboring Cu sites. In the case of Ni these moments partially screen the
inherent impurity spin, resulting in an effective S=1/2 moment. The
characteristic Kondo scale is found to have a power-law dependence on the
coupling constant. We investigate the spatial shape of the impurity-induced
spin density, taking into account the presence of short-ranged AF correlations,
and calculate the ^{17}O NMR line broadening induced by impurity doping.Comment: To appear in: Physica C, Proceedings of ACS '9
The Abundance of Interstellar Nitrogen
Using the HST Goddard High Resolution Spectrograph (GHRS), we have obtained
high S/N echelle observations of the weak interstellar N I 1160, 1161 A
absorption doublet toward the stars Gamma Cas, Lambda Ori, Iota Ori, Kappa Ori,
Delta Sco, and Kappa Sco. In combination with a previous GHRS measurement of N
I toward Zeta Oph, these new observations yield a mean interstellar gas phase
nitrogen abundance (per 10 H atoms) of 10 N/H = 75 +/- 4. There are no
statistically significant variations in the measured N abundances from
sightline to sightline and no evidence of density-dependent depletion from the
gas-phase. Since N is not expected to be depleted much into dust grains in
these diffuse sightlines, its gas-phase abundance should reflect the total
interstellar abundance. Consequently, the GHRS observations imply that the
abundance of interstellar nitrogen (gas plus grains) in the local Milky Way is
about 80% of the solar system value of 10 N/H = 93 +/- 16. Although this
interstellar abundance deficit is somewhat less than that recently found for
oxygen and krypton with GHRS, the solar N abundance and the N I oscillator
strengths are too uncertain to definitively rule out either a solar ISM N
abundance or a 2/3 solar ISM N abundance similar to that of O and Kr.Comment: 14 pages, LaTeX, 2 Postscript figures; ApJ Letters, in pres
Thermal and hygrometric properties of traditional calcarenite stones in the area of Palermo
Il contributo espone le misure di conducibilit\ue0 termica svolte su tre conci di calcarenite conchiliare e la caratterizzazione igrometrica di uno di essi. I risultati sono confrontati con i dati termici e igrometrici riportati dalle norme tecniche esistenti (UNI 10351, UNI EN ISO 10456, UNI EN 1745).The energy improvement of historic buildings requires detailed knowledge of the thermal and hygrometric properties of traditional materials and components. These data should be collected for specific local contexts, where the features of historic constructions are comparable. For the purpose of developing this tool for the architectural heritage of Palermo, this research focuses on calcarenite stones, the material traditionally used in the construction of the local historic masonry, and illustrates the thermal and hygrometric characterization of three calcarenite samples, taken from two historic buildings in the Sicilian city
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