31,356 research outputs found
Use of ERTS-1 imagery to interpret wind-erosion hazard in the Sandhills of Nebraska
There are no author-identified significant results in this report
Application of ERTS-1 imagery in mapping and managing soil and range resources in the Sand Hills region of Nebraska
Interpretations of imagery from the Earth Resources Technology Satellite (ERTS-1) indicate that soil associations and attendant range sites can be identified on the basis of vegetation and topography using multi-temporal imagery. Optical density measurements of imagery from the visible red band of the multispectral scanner (MSS band 5) obtained during the growing season were related to field measurements of vegetative biomass, a factor that closely parallels range condition class on specific range sites. ERTS-1 imagery also permitted inventory and assessment of center-pivot irrigation systems in the Sand Hills region in relation to soil and topographic conditions and energy requirements
Proof of Bose-Einstein Condensation for Interacting Gases with a One-Particle Spectral Gap
Using a specially tuned mean-field Bose gas as a reference system, we
establish a positive lower bound on the condensate density for continuous Bose
systems with superstable two-body interactions and a finite gap in the
one-particle excitations spectrum, i.e. we prove for the first time standard
homogeneous Bose-Einstein condensation for such interacting systems
The statistics of the grand canonical number density for interacting bosons
It is shown that the weak law of large numbers holds for the grand canonical number density in a system of bosons interacting through a pair potential which is superstable. An estimate of the probability of large deviations is obtained in terms of the canonical free energy density
Neighborhood and Individual Level Socioeconomic Variation in Perceptions of Racial Discrimination
In approaching the study of racial discrimination and health, the neighborhood and individual-level antecedents of perceived discrimination need further exploration. We investigated the relationship between neighborhood and individual-level socioeconomic position (SEP), neighborhood racial composition, and perceived racial discrimination in a cohort of African-American and White women age 40-79 from Connecticut, USA.
Design. The logistic regression analysis included 1249 women (39% African- American and 61% White). Neighborhood-level SEP and racial composition were determined using 1990 census tract information. Individual-level SEP indicators included income, education, and occupation. Perceived racial discrimination was measured as lifetime experience in seven situations.
Results. For African-American women, living in the most disadvantaged neighborhoods was associated with fewer reports of racial discrimination (odds ratio (OR) 0.44; 95% confidence interval (CI) 0.26, 0.75), with results attenuated after adjustment for individual-level SEP (OR 0.54, CI: 0.29, 1.03), and additional adjustment for neighborhood racial composition (OR 0.70, CI: 0.30, 1.63). African-American women with 12 years of education or less were less likely to report racial discrimination, compared with women with more than 12 years of education (OR 0.57, CI: 0.33, 0.98 (12 years); OR 0.51, CI: 0.26, 0.99 (less than 12 years)) in the fully adjusted model. For White women, neither neighborhood-level SEP nor individual-level SEP was associated with perceived racial discrimination.
Conclusion. Individual and neighborhood-level SEP may be important in understanding how racial discrimination is perceived, reported, processed, and how it may influence health. In order to fully assess the role of racism in future studies, inclusion of additional dimensions of discrimination may be warranted
The Large Deviation Principle for the Kac Distribution
We prove that the Large Deviation Principle holds for the distribution of the particle number density (the Kac distribution) whenever the free energy density exists in the thermodynamic limit. We use this result to give a new proof of the Large Deviation Principle for the Kac distribution of the free Boson gas. In the case of mean-field models, non-convex rate functions can arise; this is illustrated in a model previously studied by E.B. Davies
Equilibrium states for the Bose gas
The generating functional of the cyclic representation of the CCR (Canonical
Commutation Relations) representation for the thermodynamic limit of the grand
canonical ensemble of the free Bose gas with attractive boundary conditions is
rigorously computed. We use it to study the condensate localization as a
function of the homothety point for the thermodynamic limit using a sequence of
growing convex containers. The Kac function is explicitly obtained proving
non-equivalence of ensembles in the condensate region in spite of the
condensate density being zero locally.Comment: 21 pages, no figure
Vacuum Solutions of Einstein's Equations in Parabolic Coordinates
We present a simple method to obtain vacuum solutions of Einstein's equations
in parabolic coordinates starting from ones with cylindrical symmetries.
Furthermore, a generalization of the method to a more general situation is
given together with a discussion of the possible relations between our method
and the Belinsky-Zakharov soliton-generating solutions.Comment: 15 pages, version published in Class. Quantum Gra
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