Breakdown of the Fermi-liquid regime in the 2D Hubbard model from a two-loop field-theoretical renormalization group approach

We analyze the particle-hole symmetric two-dimensional Hubbard model on a square lattice starting from weak-to-moderate couplings by means of the field-theoretical renormalization group (RG) approach up to two-loop order. This method is essential in order to evaluate the effect of the momentum-resolved anomalous dimension $\eta(\textbf{p})$ which arises in the normal phase of this model on the corresponding low-energy single-particle excitations. As a result, we find important indications pointing to the existence of a non-Fermi liquid (NFL) regime at temperature $T\to 0$ displaying a truncated Fermi surface (FS) for a doping range exactly in between the well-known antiferromagnetic insulating and the $d_{x^2-y^2}$-wave singlet superconducting phases. This NFL evolves as a function of doping into a correlated metal with a large FS before the $d_{x^2-y^2}$-wave pairing susceptibility finally produces the dominant instability in the low-energy limit.Comment: 9 pages, 9 figures; published in Phys. Rev.

Colonização de fragmentos de árvores para produção de inóculo de Armillaria sp.

Organizado por Patricia Póvoa de Mattos, Celso Garcia Auer, Rejane Stumpf Sberze, Katia Regina Pichelli e Paulo César Botosso

Design and construction of a low-cost remotely piloted aircraft for precision agriculture applications

ArticleThis study aimed to construct a low cost RPA capable of recording georeferenced images. For the construction of the prototype of a quadcopter type RPA, only essential materials were used to allow stable flight. A maximum total weight of 2 kg was stipulated, including frame weight, electronic components, motors and cameras. The aircraft was programmed using a low-cost microcontroller widely used in prototyping and automation research. An electronic circuit board is designed to facilitate the connection of the microcontroller with the other components of the design. Specific software was used for flight control. The prototype was built successfully, being able to lift stable and controllable flight. However, we still need to acquire equipment and programming components capable of enabling autonomous images and flights. The final cost of the RPA was on average $427.00 on average 50in the Brazilian ARP market ($ 772.81 to $ 1,288.00

Chirikov Diffusion in the Asteroidal Three-Body Resonance (5,-2,-2)

The theory of diffusion in many-dimensional Hamiltonian system is applied to asteroidal dynamics. The general formulations developed by Chirikov is applied to the Nesvorn\'{y}-Morbidelli analytic model of three-body (three-orbit) mean-motion resonances (Jupiter-Saturn-asteroid system). In particular, we investigate the diffusion \emph{along} and \emph{across} the separatrices of the (5,-2,-2) resonance of the (490) Veritas asteroidal family and their relationship to diffusion in semi-major axis and eccentricity. The estimations of diffusion were obtained using the Melnikov integral, a Hadjidemetriou-type sympletic map and numerical integrations for times up to $10^{8}$ years.Comment: 27 pages, 6 figure

Produção de inóculo de Trichoderma viride para o controle da armilariose em Pinus spp.

Organizado por Patricia Póvoa de Mattos, Celso Garcia Auer, Rejane Stumpf Sberze, Katia Regina Pichelli e Paulo César Botosso

Avaliação dos gradientes de umidade formados durante a secagem da madeira de Pinus elliottii var. elliottii.

Este trabalho foi desenvolvido com o propósito de compreender melhor o processo de secagem da madeira de Pinus elliottii var. elliottii, através do estudo dos gradientes de umidade, como subsídio para o controle da mancha marrom. A técnica utilizada foi a de atenuação de raios gama. Observou-se que a secagem inicia-se pelo lenho inicial, evolui da superfície para o interior das peças e, posteriormente, para o lenho tardio. A água capilar encontra-se presente na superfície da madeira, mesmo em estágios mais avançados do processo de secagem.bitstream/item/103379/1/AvaliacaoGradientes0001.pd

IMPACT OF INTERACTION P AND Zn ON BIOFORTIFICATION OF BEAN

INTRODUCTION: A large part of the world population has low levels of micronutrients, especially pregnant women and children in developing countries. Zinc (Zn) is a micronutrient, performing many functions in the organism. Biofortifcation aims to increase the concentration of certain mineral in parts consumed of the cultivated plants. The crops of most interest are those that constitute the basic diet for the majority of the population, including beans. Two main strategies are used in biofortification, selection of cultivars more favorable to biofortification and increase the micronutrient dose. Biofortification of bean with Zn is difficult due to interaction with phosphorus (P). The decrease in zinc absorption caused by phosphorus depends on soil atributes such as pH, cation exchange capacity and direct reaction with Zn and subsequent precipitation. The increase of the dose of Zn can reduce the absorption of iron by plants by competitve inhibition. This study aimed to evaluate the interaction between P and Zn about biofortication in two bean cultivars, evaluating the concentration of Zn and iron in the grain and production