4,906 research outputs found
Application of a Two-Parameter Quantum Algebra to Rotational Spectroscopy of Nuclei
A two-parameter quantum algebra is briefly investigated
in this paper. The basic ingredients of a model based on the symmetry, the -rotator model, are presented in detail. Some general
tendencies arising from the application of this model to the description of
rotational bands of various atomic nuclei are summarized.Comment: 8 pages, Latex File, to be published in Reports on Mathematical
Physic
An Rotor Model for Rotational Bands of Superdeformed Nuclei
A nonrigid rotor model is developed from the two-parameter quantum algebra
. [This model presents the symmetry and
shall be referred to as the qp-rotor model.] A rotational energy formula as
well as a qp-deformation of E2 reduced transition probabilities are derived.
The qp-rotor model is applied (through fitting procedures) to twenty rotational
bands of superdeformed nuclei in the , 150 and 190 mass regions.
Systematic comparisons between the qp-rotor model and the q-rotor model of
Raychev, Roussev and Smirnov, on one hand, and a basic three-parameter model,
on the other hand, are performed on energy spectra, on dynamical moments of
inertia and on B(E2) values. The physical signification of the deformation
parameters q and p is discussed.Comment: 24 pages, Latex File, to appear in IJMP
DEVELOPMENT OF MINIMUM COST, INCENTIVE BASED PLAN FOR THE IMPLEMENTATION OF A TECHNOLOGY STANDARD FOR COFFEE PROCESSING IN HONDURAS
In Honduras, traditional coffee processing is the cause of two problems: poor coffee quality and contaminated water. In this study we propose to replace traditional coffee processing plants with a network of improved ecological plants that would be optimally located in a sub-watershed. The method is an adaptation of a spatial integer linear programming that determines the optimal location and size of new coffee processing plants. We applied the method to a typical sub-watershed in the hillsides of western Honduras and show that coffee quality can be improved and contamination can be reduced substantially at a relatively low cost. We also calculated the incentive for small farmers to give up home processing. We find that the incentive is much lower than the premium that could be obtained from an improved coffee quality.Agribusiness,
A System of Interest in Spectroscopy: The qp-Rotor System
A rotor system, having the symmetry afforded by the two-parameter quantum algebra Uqp(u(2)), is investigated in this communication. This system is useful in rotational spectroscopy of molecules and nuclei. In particular, it is shown to lead to a model (viz., the qp-rotor model) for describing (via an energy formula and a qp-deformation of E2 reduced transition probabilities) rotational bands of deformed and superdeformed nuclei
The importance of habitat quality for marine reserve fishery linkages
We model marine reserve - fishery linkages to evaluate the potential contribution of habitat-quality improvements inside a marine reserve to fish productivity and fishery catches. Data from Mombasa Marine National Park, Kenya, and the adjacent fishery are used. Marine reserves increase total fish biomass directly by providing refuge from exploitation and indirectly by improving fish habitat in the reserve. As natural mortality of the fish stock decreases in response to habitat enhancement in the reserve, catches increase by up to 2.6 tonnes (t).km(-2).year(-1) and total fish biomass by up to 36 t.km(-2). However, if habitat-quality improvement reduces the propensity of fish to move out of the reserve, catches may fall by up to 0.9 t.km(-2).year(-1). Our results indicate that habitat protection in reserves can underpin fish productivity and, depending on its effects on fish movements, augment catches
TRADE-OFFS BETWEEN ECONOMIC EFFICIENCY AND CONTAMINATION BY COFFEE PROCESSING A BIOECONOMIC MODEL AT THE WATERSHED LEVEL IN HONDURAS
In Honduras, traditional coffee processing is the cause of two major problems: poor coffee quality and contaminated water. In this paper we present a method that determines the trade-off between economic efficiency and contamination in a Honduran sub-watershed. The method is a bioeconomic model based on mathematical programming that stimulates the functioning of the interlinked economic and ecological processes in the sub-watershed. We compare various scenarii where the model is given the possibility of replacing traditional coffee processing plants with a network of improved ecological plants. For different levels of contamination the model determines the optimal location and size of new coffee processing plants along river streams by minimizing transport, variable and fixed costs. The restrictions of the system are the volume of wet coffee to be processed, the available stream water, and in the alternative scenarii, investment capital and contaminant concentration in the river. We apply the method to a typical sub-watershed in the hillsides of western Honduras and show that coffee quality can be improved and contamination can be reduced substantially at a relatively low cost.coffee, environment, water quality, mathematical programming, transport cost, spatial analysis, watershed, Honduras., Environmental Economics and Policy,
Search for supersymmetric particles assuming R-parity non-conservation in collisions at =192 to 208 GeV
Evaluación económica de productos con potencial de mercado para pequeños productores: uso de la programación lineal con fincas de los municipios de Yorito y Sulaco
Circumstellar environment of RX Puppis
The symbiotic Mira, RX Pup, shows long-term variations in its mean light
level due to variable obscuration by circumstellar dust. The last increase in
extinction towards the Mira, between 1995 and 2000, has been accompanied by
large changes in the degree of polarization in the optical and red spectral
range. The lack of any obvious associated changes in the position angle may
indicate the polarization variations are driven by changes in the properties of
the dust grains (e.g. variable quantity of dust and variable particle size
distribution, due to dust grain formation and growth) rather than changes in
the viewing geometry of the scattering region(s), e.g. due to the binary
rotation.Comment: Paper presented at Torun 2000 conference on Post-AGB objects as a
phase of stellar evolution; 8 pages, 3 figure
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