7,391 research outputs found
Continued DDT Persistence in Mississippi River Delta Streams: A Case Study
Fish samples representative of several trophic levels were taken from the Wolf and Loosahatchie Rivers of western Tennessee during the early 1980s. Results indicate that DDT, with metabolites DDD and DDE, remains common in fish tissues in these areas and approaches the levels recommended as maxima for human consumption by the U.S. Food and Drug Administration. Samples of top carnivores and forage fishes, particularly the gizzard shad, Dorosoma cepedlanum, commonly exceeded 500 ppb DDE. The results are discussed in light of sediment disturbing activities
A Third-order and a Fourth-order Iteration Process for Nonlinear Equations
Convergence proof and procedure for third-order and fourth-order iteration process for nonlinear equations - Newton-Raphson second-order iteratio
ALTERNATIVES FOR SMALL FARM SURVIVAL: GOVERNMENT POLICIES VERSUS THE FREE MARKET
This paper briefly outlines a topology of small farms and then considers the role of the government versus the market in key public policies such as commodity income support, environment, stability, research, and rural development. A number of options are explored for public policy to better serve small farms, including drastic alternatives such as graduated property taxes on farmland, with exemptions or lower rates for small farms. These and other alternatives are not necessarily recommended. Improved extension education and human resource development offer some of the most promising public policy opportunities to help small farmers.Government, Limited resource, Market, Programs, Research, Rural, Scale, Small farm, Farm Management,
Interacting Electrons on a Square Fermi Surface
Electronic states near a square Fermi surface are mapped onto quantum chains.
Using boson-fermion duality on the chains, the bosonic part of the interaction
is isolated and diagonalized. These interactions destroy Fermi liquid behavior.
Non-boson interactions are also generated by this mapping, and give rise to a
new perturbation theory about the boson problem. A case with strong repulsions
between parallel faces is studied and solved. There is spin-charge separation
and the square Fermi surface remains square under doping. At half-filling,
there is a charge gap and insulating behavior together with gapless spin
excitations. This mapping appears to be a general tool for understanding the
properties of interacting electrons on a square Fermi surface.Comment: 25 pages, Nordita preprint 94/22
Matrix methods for calculating zeros, coefficients, Christoffel numbers, and derivatives of some orthogonal polynomials
Jacobi matrix method for calculating zeros, coefficients, Christoffel numbers, and derivatives of orthogonal polynomial
Scaling Properties of the Two-Chain Model
Scaling properties of a self-dual field-theoretical model, describing two
weakl$spinless Luttinger chains, are studied. A crossover to a sine-Gordon
massive phase, with strongly developed two-particleinterchain correlations, is
described. It is argued that, in a wide range of the in-chain interaction,
renormalization of the interchain hopping amplitude is determined by the
Luttinger liquid effects.Comment: 14 pages Latex, accepted Physics Letters
Acceleration of Wound Healing with High Voltage, Monophasic, Pulsed Current
The purpose of this study was to determine whether high voltage electrical stimulation accelerates the rate of healing of dermal ulcers. Sixteen patients with stage IV decubitus ulcers, ranging in age from 20 to 89 years, participated in the study. The patients were assigned randomly to either a Treatment Group (n = 9) or a Control Group (n = 7). Patients in the Treatment Group received daily electrical stimulation from a commercial high voltage generator. Patients in the Control Group had the electrodes applied daily but received no stimulation. The ulcers of patients in the Treatment Group healed at a mean rate of 44.8% a week and healed 100% over a mean period of 7.3 weeks. The ulcers of patients in the Control Group increased in area an average of 11.6% a week and increased 28.9% over a mean period of 7.4 weeks. The results of this study suggest that high voltage stimulation accelerates the healing rate of stage IV decubitus ulcers in human subjects
Snow cover monitoring by machine processing of multitemporal LANDSAT MSS data
LANDSAT frames were geometrically corrected and data sets from six different dates were overlaid to produce a 24 channel (six dates and four wavelength bands) data tape. Changes in the extent of the snowpack could be accurately and easily determined using a change detection technique on data which had previously been classified by the LARSYS software system. A second phase of the analysis involved determination of the relationship between spatial resolution or data sampling frequency and accuracy of measuring the area of the snowpack
LOCATION OF VERTICALLY LINKED INDUSTRIES UNDER FREE TRADE: CASE STUDIES OF ORANGE JUICE AND TOMATO PASTE IN THE WESTERN HEMISPHERE
The objective of this study was to determine the economic impact on the United States of removing tariff barriers on imports of concentrated orange juice and tomato paste from South America. The study highlighted an agglomeration model of industry location recognizing imperfect competition and increasing returns. The results were contrasted with those from a competitive model with conventional estimates of supply and demand elasticities. Because the assumptions of the models differed, the results also differed. The agglomeration model indicated that the United States would gain market share of production and processing with the removal of tariffs. In contrast, the competitive model indicated that the United States would lose market share in production and processing. According to the competitive model, US consumers would gain, producers would lose, and the government would lose from less tariff revenue, but the gains to consumers would offset losses elsewhere so that national income would rise. In South America, consumers would lose, producers would gain, and national incomes would rise. In the long run, countries would individually and collectively gain from freer trade in fruits and vegetables. Both models indicated that American production and processing of oranges and tomatoes would not be displaced by removing barriers to international trade.oranges, tomatoes, juice, paste, model, agglomeration, competitive, comparative advantage., Industrial Organization, International Relations/Trade,
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