Contact interaction in an unitary ultracold Fermi gas

An ultracold Fermi atomic gas at unitarity presents universal properties that in the diluted limit can be well described by a contact interaction. By employing a guide function with correct boundary conditions and making simple modifications to the sampling procedure we are able to handle for the first time a true contact interaction in a quantum Monte Carlo calculation. The results are obtained with small variances. Our calculations for the Bertsch and contact parameters are in excellent agreement with published experiments. The possibility of using a more faithfully description of ultracold atomic gases can help uncover features yet unknown of the ultracold atomic gases. In addition, this work paves the way to perform quantum Monte Carlo calculations for systems interacting with contact interactions, where in many cases the description using potentials with finite effective range might not be accurate

Zero-range Fermi gas along the BCS-BEC crossover

FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFAPEG - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE GOIÁSProperties of the ground state of an unpolarized ultracold Fermi gas along the BCS-BEC crossover are investigated by the variational and diffusion Monte Carlo methods. We apply the Wigner-Bethe-Peierls boundary condition in our calculations to avoid any bias from using an interatomic potential with finite effective range. Properties for several values of the scattering length are studied in the range -8 <= 1/ak(F) <= 4, including the unitary limit. The contact parameters as a function of scattering length are obtained by fitting the pair distribution functions for particles with different spins. The energies and contact parameters are in very good agreement with experimental data reported in the literature.100515FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFAPEG - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE GOIÁSFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFAPEG - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE GOIÁS2016/17612-7Sem informaçãoThe authors acknowledge financial support from the Brazilian agencies Fundacao de Amparo a Pesquisa do Estado de Sao Paulo project (Proc. No. 2016/17612-7). Part of the computations was performed at the Centro Nacional de Processamento de Alto Desempenho em Sao Paulo. R.P. acknowledges the Fundacao de Amparo a Pesquisa do Estado de Goias and the computer resources of the Laboratorio de Computacao Cientifica - Universidade Federal de Goias. K.E.S. was supported by NSF Grant No. PHY-1404405

Avaliação da Conservação de Couve Minimamente Processada pela Medida do Tempo de Relaxação Transversal da RMN.

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Agricultural colonization impact on the tropical rain forest: the case of Machadinho Project (Rondonia-Brasil).

Machadinho is a Colonization Project created by the National Institute of Colonization and Agrary Reform (INCRA) in 1982 as part of the POLONOROESTE Project, financed by the World Bank. It is located in Rondonia State (western region of Brazilian Amazonia) and has a population of approximately 32,000 habitants living in an area of 209,000 ha divided in 2,934 plots of land for farming, 17 Florest Reserves, 15 urban areas and one airport. The 1986 and 1989 EMBRAPA's study showed that: 1) the agriculture's practice is totally manual; 2) settlers use the strategy of great multiplicity of small investments (animal or vegetal production) to avoid losses; 3) the use of modern technology is limited; 4) productivity is low; 5) life condition is of almost complete misery; 6) the capacity of capitalization is small; 7) there is a high incidence of diseases (such as malaria). These aspects have kept the same since 1982, however the allotment of space and resources for several activities have not kept the same in time. The great majority of agriculturists follow a production system, therefore confirming the non-random land use hypotesis. The capitalization level causes a diferentiation in this system, because it acelerates the process. The use of chain-saw, for instance, increases considerable the deforest area for cultivation. Therefore, showing that this kind of equipment is very useful in Colonization Projects in the brazilian tropical rain forest

Novo instrumento automático para medida de pressão intracelular em vegetais.

Neste trabalho será mostrado como o modelo do instrumento é utilizado de forma a auxiliar no projeto de uma sonda de pressão automática, além dos resultados práticos obtidos em experimentos de bancada para caracterização da sonda. A versão da sonda de pressão usada para o trabalho foi a de compensação térmica e a automação é baseada na teoria de Sistemas de Controle.bitstream/CNPDIA/8123/1/CiT17_2002.pd

Abordagem de sistemas de controle para desenvolvimento de instrumento de medida de pressão intracelular.

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Modelo Validado de Sonda de Pressão para Medida de Relações de Água em Plantas.

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Modelagem e automação de uma sonda termoelástica para medidas de parâmetros relativos a fisiologia vegetal.

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Estimativa de emissões de gases de efeito estufa provenientes da queima de residuos da cana-de-açúcar no estado de São Paulo no período de 1986 a 2008.

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