Hard hexagon partition function for complex fugacity

We study the analyticity of the partition function of the hard hexagon model in the complex fugacity plane by computing zeros and transfer matrix eigenvalues for large finite size systems. We find that the partition function per site computed by Baxter in the thermodynamic limit for positive real values of the fugacity is not sufficient to describe the analyticity in the full complex fugacity plane. We also obtain a new algebraic equation for the low density partition function per site.Comment: 49 pages, IoP styles files, lots of figures (png mostly) so using PDFLaTeX. Some minor changes added to version 2 in response to referee report

Integrability vs non-integrability: Hard hexagons and hard squares compared

In this paper we compare the integrable hard hexagon model with the non-integrable hard squares model by means of partition function roots and transfer matrix eigenvalues. We consider partition functions for toroidal, cylindrical, and free-free boundary conditions up to sizes $40\times40$ and transfer matrices up to 30 sites. For all boundary conditions the hard squares roots are seen to lie in a bounded area of the complex fugacity plane along with the universal hard core line segment on the negative real fugacity axis. The density of roots on this line segment matches the derivative of the phase difference between the eigenvalues of largest (and equal) moduli and exhibits much greater structure than the corresponding density of hard hexagons. We also study the special point $z=-1$ of hard squares where all eigenvalues have unit modulus, and we give several conjectures for the value at $z=-1$ of the partition functions.Comment: 46 page

Warm-Season Legumes – Challenges and Constraints to Adapting Warm-Season Legumes to Transition Zone Climates with Examples from \u3ci\u3eArachis\u3c/i\u3e

Grass pastures in monoculture are the predominant system in transition zone climates, where warm-season perennial grasses are usually cultivated. Mixed grass-legume pastures are worldwide recognized for having advantages over pure stands, including pasture longevity, N input from biological fixation, efficient nutrient cycling, and greater animal production. The genus Arachis encompasses important and successful warm-season forage legume species cultivated in mixed pastures or in pure stands. Arachis pintoi and Arachis glabrata are potential tropical forage species that can be used in transition zone climates. Mixed pastures with these legumes have been shown to be resilient systems, able to withstand short-term perturbations, like pests, diseases, drought, or flooding. Wide adoption of A. glabrata is constrained by its high cost and slow establishment period. This species has low potential to produce seeds, and rhizomes are required for propagation. Although great seed production is verified in some A. pintoi genotypes, vegetative propagation is also most often used, since seeds are produced underground, and a large-scale commercial seed production depends on the development of an efficient seed harvester. Developing new cultivars with persistent link between seed and peg is a great challenge for breeders. A. pintoi spreads faster than A. glabrata in tropical regions, and the genetic variability for lateral expansion and ground cover in mixed stands must be better understood in humid subtropical climates. The evaluation of Arachis wild germplasm has already shown genetic variability for traits of interest for use in mixed pastures. Studies have also shown that there is genotype x environment interaction considering tropical and subtropical climates. The greatest chances of success in obtaining more adapted, productive, and faster establishing Arachis cultivars for transition zone climates seems to be no longer in the identification of superior wild accessions but in the hybridization and selection through specific breeding programs

Avaliação da ação anti-oxidante de coberturas a base da proteína Z19 do milho BR451 em noz Macadâmia.

bitstream/CNPDIA-2009-09/11887/1/CiT45_2008.pd

Análise comparativa dos espectros de ¹H RMN de óleos comestíveis oxidados.

bitstream/CNPDIA-2009-09/11889/1/CT92_2008.pd

LATTES: a novel detector concept for a gamma-ray experiment in the Southern hemisphere

The Large Array Telescope for Tracking Energetic Sources (LATTES), is a novel concept for an array of hybrid EAS array detectors, composed of a Resistive Plate Counter array coupled to a Water Cherenkov Detector, planned to cover gamma rays from less than 100 GeV up to 100 TeVs. This experiment, to be installed at high altitude in South America, could cover the existing gap in sensitivity between satellite and ground arrays. The low energy threshold, large duty cycle and wide field of view of LATTES makes it a powerful tool to detect transient phenomena and perform long term observations of variable sources. Moreover, given its characteristics, it would be fully complementary to the planned Cherenkov Telescope Array (CTA) as it would be able to issue alerts. In this talk, a description of its main features and capabilities, as well as results on its expected performance, and sensitivity, will be presented.Comment: Proceedings of the 35th International Cosmic Ray Conference (ICRC2017), Busan, South Korea. Presented by R. Concei\c{c}\~{a}o. 8 pages; v2: correct affiliation + journal referenc