Zooming to the study area in GIScience research: a three stage approach

6-8 Apri

The Λ0\Lambda_0 Polarization and the Recombination Mechanism

We use the recombination and the Thomas Precession Model to obtain a prediction for the $\Lambda _0$ polarization in the $p+p \to \Lambda_0+X$ reaction. We study the effect of the recombination function on the $\Lambda_0$ polarization.Comment: 4 pages, LaTex, 1 figures included, aipproc.sty included. Talk presented at Simposio Latino Americano de Fisica de Altas Energias, Merida, Mexico, November 199

Penurunan Viabilitas Benih Padi (Oryza Sativa L.) melalui Beberapa Metode Pengusangan Cepat

Availability of seed lots with different viabilities is very important as the material for invigoration studies. Acceleratedor rapid aging methods is expected to serve seeds with different viabilities for those studies. The objective of this study was toobtain efficient seeds rapid aging method of rice seeds. The study consisted of three experiments i.e. rapid aging with ethanolgas, soaking seed in liquid ethanol (96%) and exposing seeds to 41 oC temperature and ± 100% relative humidity. Eachexperiment was arranged in a randomized block design with single factor that was length of aging with three replications.There were eight rice varieties used in this study, i. e. three varieties of upland rice, two verieties of lowland rice, and threevarieties of swamp rice. The results showed that the physical aging method could not produce reliable data due to fungusinfection on the treated seed. It was found that generally 60% and 50% viabilities of rice seed could be obtain by ethanol gastreatment for 4.9 and 5.3 hours, as well as by liquid ethanol for 4.0 and 4.4 minutes, respectively. Rapid aging method withliquid ethanol was the fastest and simplest method for decreasing seed viability of rice

CFD and Experimental Study in the Optimization of an Energy Converter for Low Heads

This paper deals with new design of low head turbines, as feasible solutions to solve the lack of energy in rural and remote areas, or to provide energy from urban water pipe systems. Propeller turbines are then the subject of this research because they are suitable for small heads, discharges with little variability, easy to manufacture and with low costs associated. Hence, the aims are the design of quite simple tubular propeller turbines and the analysis of hydrodynamic behaviour for different number and configuration of blades, based on CFD analyses and experimental tests development. An advanced hydrodynamic code based on the finite volume method, as well as blades configuration and mesh specific models are used for the impeller and the turbine design. The blade geometry is optimized using mathematical formulations and experimental results, concerning the possible range of operation under best efficiency conditions. Performance curves are obtained for typical characteristic parameters allowing comparisons between CFD and experimental results. Based on the similarity theory applied to turbomachines it is possible to evaluate the hydrodynamic behaviour through a tubular propeller for different sizes, in a scale model application

BV equivalence with boundary

An extension of the notion of classical equivalence of equivalence in the Batalin–Vilkovisky (BV) and Batalin–Fradkin–Vilkovisky (BFV) frameworks for local Lagrangian field theory on manifolds possibly with boundary is discussed. Equivalence is phrased in both a strict and a lax sense, distinguished by the compatibility between the BV data for a field theory and its boundary BFV data, necessary for quantisation. In this context, the first- and second-order formulations of nonabelian Yang–Mills and of classical mechanics on curved backgrounds, all of which admit a strict BV–BFV description, are shown to be pairwise equivalent as strict BV–BFV theories. This in particular implies that their BV complexes are quasi-isomorphic. Furthermore, Jacobi theory and one-dimensional gravity coupled with scalar matter are compared as classically equivalent reparametrisation-invariant versions of classical mechanics, but such that only the latter admits a strict BV–BFV formulation. They are shown to be equivalent as lax BV–BFV theories and to have isomorphic BV cohomologies. This shows that strict BV–BFV equivalence is a strictly finer notion of equivalence of theories