10,492 research outputs found

    Application of input-output analysis to a simple model emphasizing agriculture (A study of the interdependence of agriculture and other sectors of the national economy)

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    With growing commercializa1ion of the national economy, agriculture and industry have become increasingly interdependent. The development has extended so far that the major problems found in agriculture now are those growing out of interdependence with other sectors of the national exchange economy. A slight swell in farm production, relative to employment and output in the rest of the economy, causes a rapid recession of farm income. A small decline in farm output, relative to employment in the national economy, causes farm prices to spiral upward. Then, too, it is known that depression or prosperity in agriculture is largely a function of the state ·of economic affairs in non-agricultural sectors of the national economy. While a few of these general qualitative interrelationships between agricultural and other sectors of the economy are known, knowledge of the exact quantitative inter-relationships is meager. More quantitative information of the economic inter-relationships will be important in the years ahead. The major and basic problems which face the agricultural sector of the national economy are in the realm of interdependence coefficients

    Where Is Your Farm Today?

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    The typical farm business is different from most nonfarm businesses. In farming, there\u27s a close interdependence between the farm household and the farm business- they can\u27t be separated into two distinct units as in most other industries

    Interdependence between the farm business and the farm household with implications on economic efficiency

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    In no other industry is the interdependence between the consuming household and the business firm so strong as in agriculture. The farm is a complete economic unit by itself. The business and household units are intertwined in the farm with production and consumption taking place in one central spot. Hence limited resources are allocated between the two in accordance with the preferences of the family. The economic problems of a farm exactly parallel those of a national economy and include the three major areas of choice and decision: (1) the allocation of resources or income between current and future consumption, (2) the allocation of limited resources or income in current production and (3) the distribution of current consumption income between different individuals. In reality, the first decision is largely one of allocation in production over time. Problems of production and consumption allocation at the farm level have received little attention in the general body of economic principIes. In general, the economic principles applicable to the business firm have been developed independently of the consumption unit, and the logic of the consuming unit has been developed independently of the business firm. A more realistic approach for agriculture is to consider production and consumption as interdependent units

    Thermoelectric effects in a strongly correlated model for Nax_xCoO2_2

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    Thermal response functions of strongly correlated electron systems are of appreciable interest to the larger scientific community both theoretically and technologically. Here we focus on the infinitely correlated t-J model on a geometrically frustrated two-dimensional triangular lattice. Using exact diagonalization on a finite sized system we calculate the dynamical thermal response functions in order to determine the thermopower, Lorenz number, and dimensionless figure of merit. The dynamical thermal response functions is compared to the infinite frequency limit and shown to be very weak functions of frequency, hence, establishing the validity of the high frequency formalism recently proposed by Shastry for the thermopower, Lorenz number, and the dimensionless figure of merit. Further, the thermopower is demonstrated to have a low to mid temperature enhancement when the sign of the hopping parameter tt is switched from positive to negative for the geometrically frustrated lattice considered.Comment: 16 pages, 10 figures, color version available at http://physics.ucsc.edu/~peterson/mrpeterson-condmat-NCO.pdf. V.2 has fixed minor typos in Eq. 11, 19, 25, and 26. V.3 is a color versio

    William (Bill) Peterson's contributions to ocean science, management, and policy

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    © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Schwing, F. B., Sissenwine, M. J., Batchelder, H., Dam, H. G., Gomez-Gutierrez, J., Keister, J. E., Liu, H., & Peterson, J. O. William (Bill) Peterson's contributions to ocean science, management, and policy. Progress in Oceanography, 182, (2020): 102241, doi:10.1016/j.pocean.2019.102241.In addition to being an esteemed marine ecologist and oceanographer, William T. (Bill) Peterson was a dedicated public servant, a leader in the ocean science community, and a mentor to a generation of scientists. Bill recognized the importance of applied science and the need for integrated “big science” programs to advance our understanding of ecosystems and to guide their management. As the first US GLOBEC program manager, he was pivotal in transitioning the concept of understanding how climate change impacts marine ecosystems to an operational national research program. The scientific insight and knowledge generated by US GLOBEC informed and advanced the ecosystem-based management approaches now being implemented for fishery management in the US. Bill held significant leadership roles in numerous international efforts to understand global and regional ecological processes, and organized and chaired a number of influential scientific conferences and their proceedings. He was passionate about working with and training young researchers. Bill’s academic affiliations, notably at Stony Brook and Oregon State Universities, enabled him to advise, train, and mentor a host of students, post-doctoral researchers, and laboratory technicians. Under his collegial guidance they became critical independent thinkers and diligent investigators. His former students and colleagues carry on Bill Peterson’s legacy of research that helps us understand marine ecosystems and informs more effective resource stewardship and conservation

    The Lorentz force in atmospheres of CP stars: θ\theta Aurigae

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    Several dynamical processes may induce considerable electric currents in the atmospheres of magnetic chemically peculiar (CP) stars. The Lorentz force, which results from the interaction between the magnetic field and the induced currents, modifies the atmospheric structure and induces characteristic rotational variability of the hydrogen Balmer lines. To study this phenomena we have initiated a systematic spectroscopic survey of the Balmer lines variation in magnetic CP stars. In this paper we continue presentation of results of the program focusing on the high-resolution spectral observations of A0p star \aur (HD 40312). We have detected a significant variability of the Hα\alpha, Hβ\beta, and Hγ\gamma spectral lines during full rotation cycle of the star. This variability is interpreted in the framework of the model atmosphere analysis, which accounts for the Lorentz force effects. Both the inward and outward directed Lorentz forces are considered under the assumption of the axisymmetric dipole or dipole+quadrupole magnetic field configurations. We demonstrate that only the model with the outward directed Lorentz force in the dipole+quadrupole configuration is able to reproduce the observed hydrogen line variation. These results present new strong evidences for the presence of non-zero global electric currents in the atmosphere of an early-type magnetic star.Comment: 10 figure

    Intermediate resolution H-beta spectroscopy and photometric monitoring of 3C 390.3 I. Further evidence of a nuclear accretion disk

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    We have monitored the AGN 3C390.3 between 1995 and 2000.Two large amplitude outbursts, of different duration, in continuum and H beta light were observed ie.: in October 1994 a brighter flare that lasted about 1000 days and in July 1997 another one that lasted about 700 days were detected. The flux in the H beta wings and line core vary simultaneously, a behavior indicative of predominantly circular motions in the BLR.Important changes of the Hbeta emission profiles were detected: at times, we found profiles with prominent asymmetric wings, as those normaly seen in Sy1s, while at other times, we observe profiles with weak almost symmetrical wings, similar to those seen in Sy1.8s. We found that the radial velocity difference between the red and blue bumps is anticorrelated with the light curves of H beta and continuum radiation.e found that the radial velocity difference between the red and blue bumps is anticorrelated with the light curves of H-beta and continuum radiation. Theoretical H-beta profiles were computed for an accretion disk, the observed profiles are best reproduced by an inclined disk (25 deg) whose region of maximum emission is located roughly at 200 Rg. The mass of the black hole in 3C 390.3, estimated from the reverberation analysis is Mrev = 2.1 x 10^9 Msun, ie. 5 times larger than previous estimatesComment: 18 pages, 13 figures, 4 tables. to appear in Astronomy and Astrophysic
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