Effect of particle polydispersity on the irreversible adsorption of fine particles on patterned substrates

We performed extensive Monte Carlo simulations of the irreversible adsorption of polydispersed disks inside the cells of a patterned substrate. The model captures relevant features of the irreversible adsorption of spherical colloidal particles on patterned substrates. The pattern consists of (equal) square cells, where adsorption can take place, centered at the vertices of a square lattice. Two independent, dimensionless parameters are required to control the geometry of the pattern, namely, the cell size and cell-cell distance, measured in terms of the average particle diameter. However, to describe the phase diagram, two additional dimensionless parameters, the minimum and maximum particle radii are also required. We find that the transition between any two adjacent regions of the phase diagram solely depends on the largest and smallest particle sizes, but not on the shape of the distribution function of the radii. We consider size dispersions up-to 20% of the average radius using a physically motivated truncated Gaussian-size distribution, and focus on the regime where adsorbing particles do not interact with those previously adsorbed on neighboring cells to characterize the jammed state structure. The study generalizes previous exact relations on monodisperse particles to account for size dispersion. Due to the presence of the pattern, the coverage shows a non-monotonic dependence on the cell size. The pattern also affects the radius of adsorbed particles, where one observes preferential adsorption of smaller radii particularly at high polydispersity.Comment: 9 pages, 5 figure

Recent advances and open challenges in percolation

Percolation is the paradigm for random connectivity and has been one of the most applied statistical models. With simple geometrical rules a transition is obtained which is related to magnetic models. This transition is, in all dimensions, one of the most robust continuous transitions known. We present a very brief overview of more than 60 years of work in this area and discuss several open questions for a variety of models, including classical, explosive, invasion, bootstrap, and correlated percolation

Efeito do processamento térmico na composição química, compostos bioativos e atividade antioxidante de cultivares de feijão-caupi.

This study aimed to determine the effect of cooking on the centesimal compositions, the content of bioactive compounds, and antioxidant activities in beans of the cowpea cultivars. The beans were cooked without soaking (1:5 w/v) in a pressure cooker for 780 seconds..

Mineral content, phenolic compounds and bioactive amines of cheese bread enriched with cowpea.

Cheese bread presents great acceptance and market expansion. Due to the lack of standardization in its manufacturing, various ingredients can be added. It was aimed to determine the content of minerals, bioactive compounds and antioxidant activity in cheese bread enriched with biofortified cowpea. Two formulations were prepared, standard cheese bread (without cowpea) and enriched cheese bread. The minerals were analyzed using the plasma emission spectrometry technique with inductive coupling, phenolic compounds and antioxidant activity were determined by spectrophotometry and the amines by High Performance Liquid Chromatography. All analyzes were performed in triplicate and for the comparison of the means between two variables, Student?s t-test was applied and for multiple comparisons, the Tukey test. It was observed that the enriched cheese bread is source of copper, zinc and sodium and presents high content of calcium, phosphorus and magnesium, considering the recommendations for the children?s audience. The concentrations of total phenolics, flavonoids and condensed tannins increased significantly with the introduction of cowpea. It was also observed an significant increase of spermidine, cadaverine and agmatine. The antioxidant activity was statistically higher in enriched cheese bread. It is concluded, therefore, that cheese bread with cowpea contributes to the supply of minerals and bioactive compounds

Genetic variation and correlation of agronomic traits in meadow bromegrass (Bromus riparius Rehm) clones.

Meadow bromegrass (Bromus riparius Rehm.) is a recently introduced pasture grass in western Canada. Its leafy production and rapid regrowth have made it a major grass species for pasturing beef animals in this region. As relatively little breeding work kas been done on this species, there is little information on its breeding behaviour. The main objective of this study was to estimate total genetic variability, broad-sense heritability, phenotypic and genetic correlations. Forty-four meadow bromegrass clones were evaluated for agronomic characters. Genetic variation for dry matter yield, seed yield, fertility index, harvest index, plant height, plant spread, crude protein, neutral de ter gent fiber and acid de ter gent fiber, was significant. Broad-sense heritability estimates exceeded 50% for all characters. Heritability estimates were at least 3.5 times greater than their standard errors. Phenotypic and genetic correlation between all possible characters were measured There was general agreement in both sign and magnitude between genetic and phenotypic correlations. Correlations between the different characters demonstrated that it is possible to simultaneously improve seed and forage yield. Based on the results, it appears that the development of higher yielding cultivars with higher crude protein, and lower acid and neutral detergent fibers concentration should be possible

Neutron Charge Radius: Relativistic Effects and the Foldy Term

The neutron charge radius is studied within a light-front model with different spin coupling schemes and wave functions. The cancellation of the contributions from the Foldy term and Dirac form factor to the neutron charge form factor is verified for large nucleon sizes and it is independent of the detailed form of quark spin coupling and wave function. For the physical nucleon our results for the contribution of the Dirac form factor to the neutron radius are insensitive to the form of the wave function while they strongly depend on the quark spin coupling scheme.Comment: 12 pages, 5 figures, Latex, Int. J. Mod. Phys.

Desenvolvimento de mudas de pinhão-manso (Jatropha curcas L.) submetidas a diferentes substratos e sombreamentos.

Este trabalho teve como objetivo avaliar o efeito de diferentes substratos e níveis de sombreamento no desenvolvimento de mudas de pinhão-manso (Jatropha curcas L. Os frutos foram colhidos em uma área comercial. Após beneficiamento e assepsia, duas sementes foram semeadas em sacos de polietileno de aproximadamente 3 litros, preenchidos com quatro diferentes substratos. Sendo eles, solo (S); areia (A); S1-A1-NPK (solo + areia, na proporção de 1:1, com 5 g de NPK 6:24:12 por litro de substrato); S1-A2-NPK (solo + areia, na proporção de 1:2, com 5 g de NPK 6:24:12 por litro de substrato); S1-A1-E1 (solo + areia + esterco curtido, na proporção de 1:1:1); S1-A1-E1 NPK (solo + areia + esterco curtido, na proporção de 1:1:1, com 5 g de NPK 6:24:12 por litro de substrato). O experimento foi conduzido em três diferentes intensidades de sombreamento: 0% (a céu aberto), 25% e 75% (em telado, com tela sombrite). O delineamento utilizado foi em blocos casualizados, em um esquema fatorial 4 x 3 (quatro substratos x três sombreamentos), perfazendo um total de 12 tratamentos. As plântulas mantidas em sombreamento de 25% apresentaram, em geral, melhores resultados para todas as variáveis avaliadas. Conclui-se que tanto o sombreamento como o substrato interferiram na emergência da espéci