17 research outputs found
Projeto Balde Cheio: resgatando a dignidade do produtor familiar de leite.
Uma das reclamações do setor leiteiro é o fato de os produtores rurais não aplicarem as técnicas e os avanços estudados e alcançados nos institutos de ensino e de pesquisa, o que dificulta a evolução da atividade leiteira. Assim, o objetivo do Projeto Balde Cheio é promover o desenvolvimento da pecuária leiteira, mediante o processo de transferência de muitas dessas tecnologias já disponíveis, para extensionistas de entidades públicas ou privadas, bem como para produtores de leite. Nesse processo, aplica-se uma metodologia em que propriedades leiteiras de cunho familiar são utilizadas como ?sala de aula prática. Essas propriedades familiares servem de exemplo para demonstrar a sua viabilidade técnica e econômica. Atualmente, o Projeto Balde Cheio está implantado em 348 municípios brasileiros, distribuídos em nove Estados. O presente trabalho tem por objetivo relatar e descrever as experiências do Projeto Balde Cheio, coordenado pela Embrapa Pecuária Sudeste, bem como os resultados alcançados. A metodologia utilizada é a de estudos de caso, que envolve a obtenção de dados descritivos por meio da observação direta e entrevista com os participantes da açã
Exact dynamics of a reaction-diffusion model with spatially alternating rates
We present the exact solution for the full dynamics of a nonequilibrium spin
chain and its dual reaction-diffusion model, for arbitrary initial conditions.
The spin chain is driven out of equilibrium by coupling alternating spins to
two thermal baths at different temperatures. In the reaction-diffusion model,
this translates into spatially alternating rates for particle creation and
annihilation, and even negative ``temperatures'' have a perfectly natural
interpretation. Observables of interest include the magnetization, the particle
density, and all correlation functions for both models. Two generic types of
time-dependence are found: if both temperatures are positive, the
magnetization, density and correlation functions decay exponentially to their
steady-state values. In contrast, if one of the temperatures is negative,
damped oscillations are observed in all quantities. They can be traced to a
subtle competition of pair creation and annihilation on the two sublattices. We
comment on the limitations of mean-field theory and propose an experimental
realization of our model in certain conjugated polymers and linear chain
compounds.Comment: 13 pages, 1 table, revtex4 format (few minor typos fixed). Published
in Physical Review
Organic and mineral matter changes due to oil generation, saturation and expulsion processes based on artificial maturation experiments
Hydrous pyrolysis experiments were conducted on immature organic-rich rock with type-I kerogen to evaluate petroleum generation, saturation and expulsion processes. The experiments were carried out under isothermal conditions at ten different temperatures (280° through 360°C) for nine different time spans between 18 and 144h. Rock samples recovered from the experiments were analyzed for total organic carbon (TOC-weight%), Rock-Eval pyrolysis, vitrinite reflectance (Ro%), spectral fluorescence and visual characterization of organic matter under the microscopy. TOC, S2 and HI tend to decrease with increasing temperature and duration of the experiments as expected. The Ro% values reach up to 1.14% in the most severe experiment (i.e. 360°C/96h). The Ro% is believed to be suppressed due to hydrogen incorporation from bitumen. The bitumen production was observed with the increase of transformation index (TI) and two types of bitumen were differentiated by fluorescence color. The bitumen with yellow fluorescence was mainly composed of saturate and aromatic hydrocarbons that were probably generated earlier than the bitumen with brown fluorescence which is rich in NSO compounds. The greatest bitumen saturation occurs at TI around of 41% to 45%, when the S1 reaches its highest values. The decrease of bitumen saturation and consequent oil expulsion is marked by a reduction in S1 values and fluorescence color. This phenomenon occurs simultaneously with the development of fractures and voids in the mineral matrix which reduces the oil retention capability and facilitates the expulsion process. These observations enhanced the understanding of oil generation and saturation processes, as well as primary migration, expulsion and type of generated bitumen
Organic and mineral matter changes due to oil generation, saturation and expulsion processes based on artificial maturation experiments
Hydrous pyrolysis experiments were conducted on immature organic-rich rock with type-I kerogen to evaluate petroleum generation, saturation and expulsion processes. The experiments were carried out under isothermal conditions at ten different temperatures (280° through 360°C) for nine different time spans between 18 and 144h. Rock samples recovered from the experiments were analyzed for total organic carbon (TOC-weight%), Rock-Eval pyrolysis, vitrinite reflectance (Ro%), spectral fluorescence and visual characterization of organic matter under the microscopy. TOC, S2 and HI tend to decrease with increasing temperature and duration of the experiments as expected. The Ro% values reach up to 1.14% in the most severe experiment (i.e. 360°C/96h). The Ro% is believed to be suppressed due to hydrogen incorporation from bitumen. The bitumen production was observed with the increase of transformation index (TI) and two types of bitumen were differentiated by fluorescence color. The bitumen with yellow fluorescence was mainly composed of saturate and aromatic hydrocarbons that were probably generated earlier than the bitumen with brown fluorescence which is rich in NSO compounds. The greatest bitumen saturation occurs at TI around of 41% to 45%, when the S1 reaches its highest values. The decrease of bitumen saturation and consequent oil expulsion is marked by a reduction in S1 values and fluorescence color. This phenomenon occurs simultaneously with the development of fractures and voids in the mineral matrix which reduces the oil retention capability and facilitates the expulsion process. These observations enhanced the understanding of oil generation and saturation processes, as well as primary migration, expulsion and type of generated bitumen
Organic and mineral matter changes due to oil generation, saturation and expulsion processes based on artificial maturation experiments
Hydrous pyrolysis experiments were conducted on immature organic-rich rock with type-I kerogen to evaluate petroleum generation, saturation and expulsion processes. The experiments were carried out under isothermal conditions at ten different temperatures (280° through 360°C) for nine different time spans between 18 and 144h. Rock samples recovered from the experiments were analyzed for total organic carbon (TOC¿weight%), Rock-Eval pyrolysis, vitrinite reflectance (Ro%), spectral fluorescence and visual characterization of organic matter under the microscopy. TOC, S2 and HI tend to decrease with increasing temperature and duration of the experiments as expected. The Ro% values reach up to 1.14% in the most severe experiment (i.e. 360°C/96h). The Ro% is believed to be suppressed due to hydrogen incorporation from bitumen. The bitumen production was observed with the increase of transformation index (TI) and two types of bitumen were differentiated by fluorescence color. The bitumen with yellow fluorescence was mainly composed of saturate and aromatic hydrocarbons that were probably generated earlier than the bitumen with brown fluorescence which is rich in NSO compounds. The greatest bitumen saturation occurs at TI around of 41% to 45%, when the S1 reaches its highest values. The decrease of bitumen saturation and consequent oil expulsion is marked by a reduction in S1 values and fluorescence color. This phenomenon occurs simultaneously with the development of fractures and voids in the mineral matrix which reduces the oil retention capability and facilitates the expulsion process. These observations enhanced the understanding of oil generation and saturation processes, as well as primary migration, expulsion and type of generated bitumen
Organic and mineral matter changes due to oil generation, saturation and expulsion processes based on artificial maturation experiments
Hydrous pyrolysis experiments were conducted on immature organic-rich rock with type-I kerogen to evaluate petroleum generation, saturation and expulsion processes. The experiments were carried out under isothermal conditions at ten different temperatures (280° through 360°C) for nine different time spans between 18 and 144h. Rock samples recovered from the experiments were analyzed for total organic carbon (TOC-weight%), Rock-Eval pyrolysis, vitrinite reflectance (Ro%), spectral fluorescence and visual characterization of organic matter under the microscopy. TOC, S2 and HI tend to decrease with increasing temperature and duration of the experiments as expected. The Ro% values reach up to 1.14% in the most severe experiment (i.e. 360°C/96h). The Ro% is believed to be suppressed due to hydrogen incorporation from bitumen. The bitumen production was observed with the increase of transformation index (TI) and two types of bitumen were differentiated by fluorescence color. The bitumen with yellow fluorescence was mainly composed of saturate and aromatic hydrocarbons that were probably generated earlier than the bitumen with brown fluorescence which is rich in NSO compounds. The greatest bitumen saturation occurs at TI around of 41% to 45%, when the S1 reaches its highest values. The decrease of bitumen saturation and consequent oil expulsion is marked by a reduction in S1 values and fluorescence color. This phenomenon occurs simultaneously with the development of fractures and voids in the mineral matrix which reduces the oil retention capability and facilitates the expulsion process. These observations enhanced the understanding of oil generation and saturation processes, as well as primary migration, expulsion and type of generated bitumen