12 research outputs found
Ensaio sobre epistemologia pedologica : 1. Definiçao de solo. 2. Natureza e comportamento do solo
Litosol: suas características e provável gênese
Some of the characteristics peculiar to Litosois are discussed based on data published on Litosois occurring in the States of São Paulo and Paraná. Litosois are the first stages of development of a soil. Litosois probably originate through the exposure of the rockbed caused by an excessive relief. Rock weathering processes are intensive, prevailing those of chemical nature rather than those processes in which physical phenomena dominate. The A horizon has a high organic matter content (2% to 10%). Silt and clay amount to approximately 50% of the fine earth in the A horizon, with the exception of Litosois originated from sandstone and granite. The SiO2/Al2O3 relationship of the soil's colloidal complex and the clay's cation exchange capacity indicate that it is quite probable the presence of 2:1 type clay in Litosois derived from basic rocks
Cellulose mill liquid alkaline waste and gypsum as a substitute for lime in soils
Alkaline liquid effluent from cellulose factories was used in an experimental study to appraise the feasibility of utilizing this material with industrial gypsum (residual material from superphosphate production) for the correction of soil acidity. A soil + gypsum column was prepared and leached with the sodium rich industrial waste. Soil pH was raised but the amont of material needed bring it to 6.5 was found to vary with soil chemical composition and soil acidity buffering capacity. The soil leachate was richer in Na when gypsum was presented. Results obtained show that industrial gypsum combined with alkaline waste neutralizes soil acidity, increases soil calcium content and prevents sodium accumulation in the soil.Foram coletados vários efluentes alcalinos da fábrica de celulose a fim de estudar a utilização destes junto com fosfogesso na correção da acidez do solo. Avaliou-se o poder de neutralização dos efluentes e a lixiviação de sódio na presença de fosfogesso numa coluna de terra. A aplicação do efluente eleva o pH do solo e o volume de efluente necessário para atingir pH 6,5 depende da sua composição química e o poder tampão de acidez do solo. A lixiviação de sódio é maior quando o fosfogesso é incorporado ao solo. A combinação do efluente com o fosfogesso corrige a acidez do solo, aumenta o teor de cálcio e, ao mesmo tempo, reduz o acúmulo de sódio no solo
The CP violating phase \delta_{13} and the quark mixing angles \theta_{13}, \theta_{23} and \theta_{12} from flavour permutational symmetry breaking
The phase equivalence of the theoretical mixing matrix derived
from the breaking of the flavour permutational symmetry and the standard
parametrization advocated by the Particle Data Group is
explicitly exhibited. From here, we derive exact explicit expressions for the
three mixing angles , , , and the CP
violating phase in terms of the quark mass ratios and the parameters and
characterizing the preferred symmetry breaking pattern. The computed
values for the CP violating phase and the mixing angles are:
, ,
, and , which coincide
almost exactly with the central values of the experimentally determined
quantities.Comment: 25 pages, we added an estimation of a reasonable range of values for
the quark mass ratios and the corresponding quark mixing matrix elements.
Accepted in Phys. Rev. D, 01 April 200