108,978 research outputs found
Theory of Feshbach molecule formation in a dilute gas during a magnetic field ramp
Starting with coupled atom-molecule Boltzmann equations, we develop a
simplified model to understand molecule formation observed in recent
experiments. Our theory predicts several key features: (1) the effective
adiabatic rate constant is proportional to density; (2) in an adiabatic ramp,
the dependence of molecular fraction on magnetic field resembles an error
function whose width and centroid are related to the temperature; (3) the
molecular production efficiency is a universal function of the initial phase
space density, the specific form of which we derive for a classical gas. Our
predictions show qualitative agreement with the data from [Hodby et al, Phys.
Rev. Lett. {\bf{94}}, 120402 (2005)] without the use of adjustable parameters
The Effect of Income, Ethnicity/Race and Institutional Factors on Mortgage Borrower Behavior
Studies examining mortgage choice behavior generally assume a frictionless mortgage market in which borrower decisions are influenced only by economic variables. This study explores the interface between demographic and institutional factors inherent in mortgage market logistics and the information flow that affects borrower behavior. The efficiency of these processes is particularly important when studying inner city real estate markets, since these markets are disproportionately represented by low income and minority households. The effect of institutional factors was examined by conducting a survey of borrower behavior in metropolitan Washington, DC. The secondary data findings indicate that ethnicity /race and income are jointly sensitive to borrower decision, confirming the clientele effect. The primary data findings also indicate that institutional factors influence mortgage choice. Similarly, borrowers are influenced by the channel chosen to evaluate market information. However, income was not found to be a significant determinant of borrower behavior.
Energy and environmental burdens of organic and non-organic agriculture and horticulture
Production of 10 major commodities in England and Wales was studied using Life Cycle Analysis (LCA). Organic and non-organic (contemporary conventional) systems were compared. Organic production was generally less energy consuming, except for poultry meat, eggs and tomatoes. Environmental burdens, such as global warming potential or eutrophication were often greater per unit of production from organic than non-organic systems
ADAPTIVE PLANNING UNDER PRICE UNCERTAINTY IN PORK PRODUCTION
Livestock Production/Industries, Risk and Uncertainty,
Changing patterns of religious affiliation, church attendance and marriage across five areas of Europe since the early 1980s: trends and associations
This study draws on three waves of the European Values Survey (conducted between 1981 and 1984, between 1989 and 1993, and between 1999 and 2004) across five countries for which full data are available (Great Britain, Italy, the Netherlands, Northern Ireland, Spain, and Sweden) in order to address five research questions. Question one examined changes in religious affiliation. Across all five countries, the proportions of the non-affiliated increased. Question two examined changes in church attendance. Across all five countries, the proportions of the non-attenders increased. Question three examined changes in marital status. Across all five countries the proportions of the population checking the category 'married' declined, although in Spain the decline was marginal. Question four examined the association between religious affiliation and being married. The religious affiliated were more likely to be married than the non-affiliated. Question five examined the association between church attendance and being married. Weekly attenders were more likely to be married than the non-attenders. Overall these data support the close association between religion and marriage across five European countries (where there are very different religious climates) and support the hypothesis that changing religious values and changing family values go hand-in-hand
The administration of research. An interpretive summary of the Proceedings of the National Conference on the Administration of Research, 1947-1964
Research management and administration - summary of conference proceeding
Analysis of Nd3+:glass, solar-pumped, high-powr laser systems
The operating characteristics of Nd(3+):glass lasers energized by a solar concentrator were analyzed for the hosts YAG, silicate glass, and phosphate glass. The modeling is based on the slab zigzag laser geometry and assumes that chemical hardening methods for glass are successful in increasing glass hardness by a factor of 4. On this basis, it was found that a realistic 1-MW solar-pumped laser might be constructed from phosphate glass 4 sq m in area and 2 mm thick. If YAG were the host medium, a 1-MW solar-pumped laser need only be 0.5 sq m in area and 0.5 cm thick, which is already possible. In addition, Nd(3+) doped glass fibers were found to be excellent solar-pumped laser candidates. The small diameter of fibers eliminates thermal stress problems, and if their diameter is kept small (10 microns), they propagate a Gaussian single mode which can be expanded and transmitted long distances in space. Fiber lasers could then be used for communications in space or could be bundled and the individual beams summed or phase-matched for high-power operation
Development and application of a local linearization algorithm for the integration of quaternion rate equations in real-time flight simulation problems
High angular rates encountered in real-time flight simulation problems may require a more stable and accurate integration method than the classical methods normally used. A study was made to develop a general local linearization procedure of integrating dynamic system equations when using a digital computer in real-time. The procedure is specifically applied to the integration of the quaternion rate equations. For this application, results are compared to a classical second-order method. The local linearization approach is shown to have desirable stability characteristics and gives significant improvement in accuracy over the classical second-order integration methods
Chern-Simons Invariants of Closed Hyperbolic 3-Manifolds
The Chern-Simons invariants of irreducible U(n)- flat connections on compact
hyperbolic 3-manifolds of the form {\Gamma}\H^3 are derived. The explicit
formula for the Chern-Simons functional is given in terms of Selberg type zeta
functions related to the twisted eta invariants of Atiyah-Patodi-Singer.Comment: 10 pages, 2 diagram
POTENTIAL ECONOMIC IMPACTS OF THE REVISED ENVIRONMENTAL PROTECTION AGENCY "CAFO RULE"
Environmental Economics and Policy,
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