Late energy injection and cosmological constraints in axino dark matter scenarios

Taking into account effects of late energy injection, we examine big bang nucleosynthesis (BBN) constraints on axino dark matter scenarios with long-lived charged sleptons. We calculate 4-body slepton decays into the axino, a lepton, and a quark–antiquark pair since they govern late hadronic energy injection and associated BBN constraints. For supersymmetric hadronic axion models, we present the obtained hadronic BBN constraints and show that they can be more restrictive than the ones associated with catalyzed BBN via slepton-bound-state formation. From the BBN constraints on hadronic and electromagnetic energy release, we find new upper limits on the Peccei–Quinn scale

Post-partum anoestrus in Anglo-Nubian and Saanen goats raised in semi-arid of North-eastern Brazil.

The aim of this study was to verify the length of post-partum anoestrus (PPA) in Anglo-Nubian and Saanen goats raised in North-eastern Brazi

The compound Poisson limit ruling periodic extreme behaviour of non-uniformly hyperbolic dynamics

We prove that the distributional limit of the normalised number of returns to small neighbourhoods of periodic points of non-uniformly hyperbolic dynamical systems is compound Poisson. The returns to small balls around a fixed point in the phase space correspond to the occurrence of rare events, or exceedances of high thresholds, so that there is a connection between the laws of Return Times Statistics and Extreme Value Laws. The fact that the fixed point in the phase space is a repelling periodic point implies that there is a tendency for the exceedances to appear in clusters whose average sizes is given by the Extremal Index, which depends on the expansion of the system at the periodic point. We recall that for generic points, the exceedances, in the limit, are singular and occur at Poisson times. However, around periodic points, the picture is different: the respective point processes of exceedances converge to a compound Poisson process, so instead of single exceedances, we have entire clusters of exceedances occurring at Poisson times with a geometric distribution ruling its multiplicity. The systems to which our results apply include: general piecewise expanding maps of the interval (Rychlik maps), maps with indifferent fixed points (Manneville-Pomeau maps) and Benedicks-Carleson quadratic maps.Comment: To appear in Communications in Mathematical Physic

Copper, nickel and zinc removal by peanut hulls: batch and column studies in mono, tri-component systems and with real effluent

The main goal of this research study was the removal of Cu(II), Ni(II) and Zn(II) from aqueous solutions using peanut hulls. This work was mainly focused on the following aspects: chemical characterization of the biosorbent, kinetic studies, study of the pH influence in mono-component systems, equilibrium isotherms and column studies, both in mono and tri-component systems, and with a real industrial effluent from the electroplating industry. The chemical characterization of peanut hulls showed a high cellulose (44.8%) and lignin (36.1%) content, which favours biosorption of metal cations. The kinetic studies performed indicate that most of the sorption occurs in the first 30 min for all systems. In general, a pseudo-second order kinetics was followed, both in mono and tri-component systems. The equilibrium isotherms were better described by Freundlich model in all systems. Peanut hulls showed higher affinity for copper than for nickel and zinc when they are both present. The pH value between 5 and 6 was the most favourable for all systems. The sorbent capacity in column was 0.028 and 0.025 mmol g-1 for copper, respectively in mono and tri-component systems. A decrease of capacity for copper (50%) was observed when dealing with the real effluent. The Yoon-Nelson, Thomas and Yan’s models were fitted to the experimental data, being the latter the best fit

Estimativa do tamanho amostral em medidas repetidas de circunferência escrotal de bovinos Nelore.

O objetivo deste trabalho foi estimar o tamanho amostral minino (n) de animais pra se detectar diferenca minima significativa entre avaliacoes mensais repetidas da circuferencia escrotal de animais da raca Nelore, dos 10 aos 30 meses de idade, consideradas como 21 condicoes de avaliacao ou medidas repetidas (tratamentos). O valor de n que permite detectar a entre as medias, quando cada individuo e avaliado para t. 2 tratamentos, foi obtido por meio de um programa desenvolvido no statistical Analysis System - SAS, considerando-se o modelo de distribuicao normal t-variada( t=21) com vetor de media zero e matriz de covariancia S, estatistica e distribuicao F com parametro de nao centralidade 2

Transesterification Reactions With Mg-0/i-2 For The Synthesis Of Sitophilate, (2r*, 3s*) 1-ethylpropyl-2-methyl-3-hydroxypentanoate, An Aggregation Pheromone For Sitophilus Granarius Linnaeus, 1785 (coleoptera: Curculionidae)

The concern to minimize the environmental impacts caused by the use of pesticides in agriculture has led researchers to develop new pest control methods. Thus, the technology based on the use of pheromones has been noted for being highly specific substances, that is act only on individuals of the same species. In this context, we describe the synthesis of sitophilate, aggregation pheromone of Sitophilus granarius, a important pest of stored cereal grains. The sitophilate was obtained by transesterification of methyl-2-methyl-3-oxopentanoate with 3-pentanol mediated by Mg-0/I-2, with subsequent reduction of the ketone group of 1-ethylpropyl-2-methyl-3-oxopentanoate using NaBH4 in the presence of a Lewis acid (ZnCl2, MgCl2, CaCl2 and MnCl2). The experimental results showed that the MnCl2 is the most effective for the formation of syn diastereoisomers, since these are the compounds that exert biological activity on the insect.32413014

Qualidade do solo em áreas de plantio convencional sob latossolos do cerrado.

O cultivo convencional envolve o revolvimento e pulverização do solo, aplicação de corretivos e fertilizantes e exposição das partículas de solo. Este cultivo pode alterar a estrutura do solo, o que reflete no índice de qualidade do solo. Assim, o objetivo do presente estudo foi estabelecer índices que expressam a qualidade do solo em áreas de manejo com cultivo convencional em Latossolos sob Cerrado, através da avaliação de atributos físicos e químicos dos solos