1,742 research outputs found
Ground-state energy of a high-density electron gas in a strong magnetic field
The high-density electron gas in a strong magnetic field B and at zero
temperature is investigated. The quantum strong-field limit is considered in
which only the lowest Landau level is occupied. It is shown that the
perturbation series of the ground-state energy can be represented in analogy to
the Gell-Mann Brueckner expression of the ground-state energy of the field-free
electron gas. The role of the expansion parameter is taken by instead of the field-free Gell-Mann Brueckner
parameter r_s.Comment: 4 pages, 2 figures, to appear in the proceedings of the 1999
International Conference on Strongly Coupled Coulomb Systems (St.Malo
How "efficient" are dairy farms in mountain areas?
Pure Technical Efficiency scores of Austrian dairy farms are estimated econometrically on the basis of data envelopment analysis and bootstrapping. In a second stage, using the same assumptions on the distribution of error terms, the distances of farms to their production possibility curve are estimated as functions of farm attributes. Since some of these attributes refer to natural conditions which are more or less unfavourable, the farms in the sample are facing individual frontiers. The distinction between sectorial and individual frontiers gives rise to a distinction between “overall” and “firm-level” efficiency. Using overall efficiency for the calculation of possible savings from a move to the frontier will overestimate these savings and underestimate the efficiency of a farm relative to the conditions in which it operates.DEA, efficiency, dairy farms, Farm Management, Livestock Production/Industries,
The use of relativistic action in strong-field nonlinear photoionization
Nonlinear relativistic ionization phenomena induced by a strong linearly
polarized laser field are considered. The starting point is the classical
relativistic action for a free electron moving in the electromagnetic field
created by a strong laser beam. This action has been used to calculate
semiclassical transition rates. Simple analytical expressions for the
ionization rate, the photoelectron emission velocity and for the drift momentum
distribution of the photoelectron have been found. The analytical formulas
apply to nonrelativistic bound systems as well as to initial states with an
energy corresponding to the upper boundary of the lower continuum and to the
tunnel as well as the multiphoton regime. In the case of a nonrelativistic
bound system we recover the Keldysh formula for the ionization rate.
Relativistic effects in the initial state lead to a weak enhancement of the
rate of sub-barrier ionization and to the appearance of a nonzero photoelectron
leaving velocity.Comment: 6 pages, 2 figure
Formulation and optimization of the energy-based blended quasicontinuum method
We formulate an energy-based atomistic-to-continuum coupling method based on
blending the quasicontinuum method for the simulation of crystal defects. We
utilize theoretical results from Ortner and Van Koten (manuscript) to derive
optimal choices of approximation parameters (blending function and finite
element grid) for microcrack and di-vacancy test problems and confirm our
analytical predictions in numerical tests
Development of protective coatings for tantalum T-22 alloy Final summary report
Oxidation resistance tests of protective coatings for tantalum allo
The persistence of small dairy farms in Austria from an economic perspective
In the international comparison the structure of milk production in Austria is small scale. The present study presents two theoretical approaches to explain the persistence of small dairy farms in Austria: the opportunity cost principle and the theory of the agricultural household. With regard to the first one it is debatable whether the flat rates really can represent the costs of own production factors in their alternative uses in small enterprises. An illustration on the basis of production cost accounts shows that small dairy farms with no possibilities for the utilization of their own production factors (especially for labour) can cover the production costs by revenues only. Secondly it is argued that agricultural production is likely to continue in small dairy farms as long as the enterprise contributes persistently to the household income of the family. Indicators from the Farm Accountancy Data Network (FADN) of voluntarily participating farms in Austria support the notion that labour is allocated efficiently between the enterprise and the household in small operations in order to achieve maximum total income. The study proposes arguments according to which it can be expected that rather small dairy farms are going to be a prominent presence in Austrian agriculture also in the future.Small dairy farms, production costs, farm household, opportunity costs, FADN, Consumer/Household Economics, Q12, R20,
In the Name of Diversity: Why Mandatory Diversity Statements Violate the First Amendment and Reduce Intellectual Diversity in Academia
In the 1950s and 1960s in many parts of the country, a professor could be fired or never hired if he refused to denounce communism or declare loyalty to the United States Constitution. The University of California system took the lead in enforcing these loyalty oaths. These loyalty oaths were challenged all the way up to the United States Supreme Court and were soundly rejected, establishing the centrality of academic freedom and open inquiry on the university campus. So why are loyalty oaths making their resurgence in the form of mandatory diversity statements? Universities have begun requiring faculty members to declare fealty to a particular worldview and approach towards matters of diversity. In an irony that appears to be missed on campus diversity bureaucrats, these statements are being deployed in the name of diversity. And in another historical irony, this trend has once again been spearheaded in the University of California system. While these diversity statement were initially conceived of as just an additional factor to be weighed along with academic merit, teaching, and service, the purpose and use of these statements has radically morphed over the past few years. At some of the campuses today, a prospective professor who does not produce a diversity statement that will satisfy diversity bureaucrats, will be excluded from consideration without a review of any other aspect of his application. And the rubrics that are being deployed engage in blatant viewpoint discrimination, as well as a viewpoint based evaluation of the applicant’s research. At these campuses, it is unlikely, for instance, that an aspiring professor who shares the viewpoint Chief Justice Roberts that “[t]he way to stop discrimination on the basis of race is to stop discriminating on the basis of race,” could be hired. Can a university employ such viewpoint based criterion in its hiring process, or do the First Amendment rights of individual professors foreclose such viewpoint based discrimination?
This article examines this question in the context of the long standing debate over the First Amendment rights of Professors, and trends in academia that have undermine professorial academic freedom. It argues that diversity statements must be carefully scrutinized by Courts and that if they are being used as ideological litmus tests, as they clearly are at the University of California, they must be struck down as unconstitutional
Electrophoretic deposition of gradated oxidation resistant coatings on tantalum-10 tungsten alloy
Material selection and electrophoretic deposition studies of high temperature oxidation resistant coatings on tantalum-10 tungsten allo
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