42,767 research outputs found
Coupling of phonons to a helium atom adsorbed on graphite
We compute the self-energy for a ^4He atom adsorbed on graphite to second order in the phonon coupling. The phonon contributions amount to several degrees Kelvin. The imaginary part corresponds to a lifetime of some 10^(-11) s
Evaluation of the North Dakota Agricultural Mediation Service: July 1993 - October 1994
Agricultural Finance,
Systematic Development of Trans-Theoretically Based Behavioral Risk Management Programs
The authors explain the development and use of a behavioral Risk management strategy. It is designed for developing interventions to change behaviors, e.g., to lower the Risk of AIDS. The advantage of their strategy is said to be its structure combined with flexibility. Intervenors are not restricted to a single model in determining factors most relevant to changing Risky behavior
Beyond capitalism and liberal democracy: on the relevance of GDH Cole’s sociological critique and alternative
This article argues for a return to the social thought of the often ignored early 20th-century English thinker GDH Cole. The authors contend that Cole combined a sociological critique of capitalism and liberal democracy with a well-developed alternative in his work on guild socialism bearing particular relevance to advanced capitalist societies. Both of these, with their focus on the limitations on ‘free communal service’ in associations and the inability of capitalism to yield emancipation in either production or consumption, are relevant to social theorists looking to understand, critique and contribute to the subversion of neoliberalism. Therefore, the authors suggest that Cole’s associational sociology, and the invitation it provides to think of formations beyond capitalism and liberal democracy, is a timely and valuable resource which should be returned to
Wind tunnel wall interference in V/STOL and high lift testing: A selected, annotated bibliography
This bibliography, with abstracts, consists of 260 citations of interest to persons involved in correcting aerodynamic data, from high lift or V/STOL type configurations, for the interference arising from the wind tunnel test section walls. It provides references which may be useful in correcting high lift data from wind tunnel to free air conditions. References are included which deal with the simulation of ground effect, since it could be viewed as having interference from three tunnel walls. The references could be used to design tests from the standpoint of model size and ground effect simulation, or to determine the available testing envelope with consideration of the problem of flow breakdown. The arrangement of the citations is chronological by date of publication in the case of reports or books, and by date of presentation in the case of papers. Included are some documents of historical interest in the development of high lift testing techniques and wall interference correction methods. Subject, corporate source, and author indices, by citation numbers, have been provided to assist the users. The appendix includes citations of some books and documents which may not deal directly with high lift or V/STOL wall interference, but include additional information which may be helpful
EXPORT ENHANCEMENT STRATEGIES FOR SMALL AND MEDIUM RURAL AND AGRICULTURAL FIRMS
Literature reports that small and medium firms face greater difficulty in obtaining the necessary export market information and in obtaining financing than do larger firms. Accordingly, the United States has many export promotion and enhancement services, but there is little documentation on the impacts of these services on small and medium rural and agricultural firms. The objectives of this project were to 1) analyze the export assistance needs of small and medium rural and agricultural firms operating in the Northern Plains region at different stages of the export or internationalization process, 2) identify available export assistance and promotion services offered at the federal and state levels to meet the needs of these firms, and 3) identify factors that may increase the effectiveness of export assistance programs. The primary assistance these firms wanted from the government was help in documenting their exports. The primary reasons firms did not seek government assistance were a lack of knowledge of the service and the service is not useful. The most often used non-government information sources were trade or industry associations and banks. Accordingly, policy makers should emphasize programs that complement efforts of private organizations and that target the needs and interests of the firms.export, rural, agriculture, export assistance, Northern Plains, government, Community/Rural/Urban Development, International Development,
Quasi-one dimensional fluids that exhibit higher dimensional behavior
Fluids confined within narrow channels exhibit a variety of phases and phase
transitions associated with their reduced dimensionality. In this review paper,
we illustrate the crossover from quasi-one dimensional to higher effective
dimensionality behavior of fluids adsorbed within different carbon nanotubes
geometries. In the single nanotube geometry, no phase transitions can occur at
finite temperature. Instead, we identify a crossover from a quasi-one
dimensional to a two dimensional behavior of the adsorbate. In bundles of
nanotubes, phase transitions at finite temperature arise from the transverse
coupling of interactions between channels.Comment: 8 pages, 5 figures, presented at CMT3
A lumped parameter mathematical model for simulation of subsonic wind tunnels
Equations for a lumped parameter mathematical model of a subsonic wind tunnel circuit are presented. The equation state variables are internal energy, density, and mass flow rate. The circuit model is structured to allow for integration and analysis of tunnel subsystem models which provide functions such as control of altitude pressure and temperature. Thus the model provides a useful tool for investigating the transient behavior of the tunnel and control requirements. The model was applied to the proposed NASA Lewis Altitude Wind Tunnel (AWT) circuit and included transfer function representations of the tunnel supply/exhaust air and refrigeration subsystems. Both steady state and frequency response data are presented for the circuit model indicating the type of results and accuracy that can be expected from the model. Transient data for closed loop control of the tunnel and its subsystems are also presented, demonstrating the model's use as a control analysis tool
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