Ising Spin Glass in a Transverse Magnetic Field

We study the three-dimensional quantum Ising spin glass in a transverse magnetic field following the evolution of the bond probability distribution under Renormalisation Group transformations. The phase diagram (critical temperature $T_c$ {\em vs} transverse field $\Gamma$) we obtain shows a finite slope near $T=0$, in contrast with the infinite slope for the pure case. Our results compare very well with the experimental data recently obtained for the dipolar Ising spin glass LiHo$_{0.167}$Y$_{0.833}$F$_4$, in a transverse field. This indicates that this system is more apropriately described by a model with short range interactions than by an equivalent Sherrington-Kirkpatrick model in a transverse field.Comment: 7 pages, RevTeX3, Nota Cientifica PUC-Rio 23/9

Sanitary analysis of asymptomatic and damaged grains of maize in Tocantins, Brazil.

In the climatic conditions of the state of Tocantins, fungi have been considered limiting factors to the production of maize (Zea mays), since they favor the pathogens development in all plant parts at different stages, including during the ripening and post-harvest of maize grains. The aim of this study was to identify and quantify the fungi present in asymptomatic and damaged grains of 11 maize cultivars. For sanitary analysis, the filter paper method (Blotter test) was used. In the study, 12 maize-grain-associated genres were found: Fusarium, Aspergillus, Penicillium, Cladosporium, Trichoderma, Bipolaris, Phoma, Curvularia, Rizhopus, Colletotrichum, Papularia, and Nigrospora. There was a little variation in the diversity of genres found in damaged and asymptomatic grains, taking into account the growing seasons. The highest incidence was observed of the Fusarium genus, followed by Cladosporium, Aspergillus and Penicillium, respectively, which were associated with all the evaluated cultivars grains. The cultivars showed low percentage of damaged grains in the evaluated conditions

Parasitismo gastrintestinal de ovinos SRD em diferentes ofertas de biomassa de capim-buffel no Semiárido pernambucano.

Zootec 2011

Disorder and the effective Mn-Mn exchange interaction in Ga1−x_{1-x}Mnx_xAs diluted magnetic semiconductors

We perform a theoretical study, using {\it ab initio} total energy density-functional calculations, of the effects of disorder on the $Mn-Mn$ exchange interactions for $Ga_{1-x}Mn_xAs$ diluted semiconductors. For a 128 atoms supercell, we consider a variety of configurations with 2, 3 and 4 Mn atoms, which correspond to concentrations of 3.1%, 4.7%, and 6.3%, respectively. In this way, the disorder is intrinsically considered in the calculations. Using a Heisenberg Hamiltonian to map the magnetic excitations, and {\it ab initio} total energy calculations, we obtain the effective \JMn, from first ($n=1$) all the way up to sixth ($n=6$) neighbors. Calculated results show a clear dependence in the magnitudes of the \JMn with the Mn concentration $x$. Also, configurational disorder and/or clustering effects lead to large dispersions in the Mn-Mn exchange interactions, in the case of fixed Mn concentration. Moreover, theoretical results for the ground-state total energies for several configurations indicate the importance of a proper consideration of disorder in treating temperature and annealing effects

Anthonomus grandis Boheman, 1843 (Coleoptera: Curculionidae).

bitstream/CENARGEN/29594/1/cot157.pd

Recuperação e distribuição do nitrogênio fornecido a videiras jovens.

O objetivo deste trabalho foi estimar a recuperação e a distribuição do N fornecido a videiras jovens. O experimento foi realizado em casa de vegetação na Embrapa Uva e Vinho, Bento Gonçalves, RS. Foram utilizadas videiras da cultivar Riesling Itálico e Chardonnay, enxertadas no porta-enxerto 101-14 Mgt. Foi cultivada uma planta por vaso contendo 3,5 kg de um Neossolo Litólico. A solução de sulfato de amônio com 2% de átomos 15N, na dose de 185,60 mg de N foi aplicada na superfície do solo depois do transplante das videiras. As plantas foram coletadas em seis épocas, e separadas em folhas, porta-enxerto + enxerto, raízes grossas e finas. Todas as partes das videiras foram secadas em estufa, para determinação da produção de matéria seca e análise do N total e 15N. A maior recuperação do N do fertilizante pelas videiras jovens ocorreu em épocas próximas ao fornecimento do N. A maior quantidade de N acumulado nas videiras derivou-se de formas diferentes daquelas do N fornecido. As folhas e raízes foram o maior compartimento de N total e N derivado do fertilizante

The impact of massclusivity campaigns on perceptions and brand love of Gucci online brand communities’ members

The current research aims to understand the impact of Massclusivity (massive and exclusive) campaigns on the brand love through online brand communities (OBC) interactions. Authors designed a netnography research with the purpose of analysing the interactions between a brand - the luxury fashion brand Gucci – and its online brand community on Facebook, during a specific period of time defined according to the launch of a Massclusivity campaigns of this brand. We collect a total of 10,689 interactions from March 2017 to March 2018. Findings highlight that the development of massclusivity campaigns have several impacts, such as generate awareness towards the brand, increases consumers’ engagement on SNP, and promotes communities’ expansion. These are directly connected to the interest that this type of marketing strategies generates towards the brands, which may be considered powerful to luxury brands who intend to diversify their audience and become more competitive