Tunable asymmetric magnetoimpedance effect in ferromagnetic NiFe/Cu/Co films

We investigate the magnetization dynamics through the magnetoimpedance effect in ferromagnetic NiFe/Cu/Co films. We observe that the magnetoimpedance response is dependent on the thickness of the non-magnetic Cu spacer material, a fact associated to the kind of the magnetic interaction between the ferromagnetic layers. Thus, we present an experimental study on asymmetric magnetoimpedance in ferromagnetic films with biphase magnetic behavior and explore the possibility of tuning the linear region of the magnetoimpedance curves around zero magnetic field by varying the thickness of the non-magnetic spacer material, and probe current frequency. We discuss the experimental magnetoimpedance results in terms of the different mechanisms governing the magnetization dynamics at distinct frequency ranges, quasi-static magnetic properties, thickness of the non-magnetic spacer material, and the kind of the magnetic interaction between the ferromagnetic layers. The results place ferromagnetic films with biphase magnetic behavior exhibiting asymmetric magnetoimpedance effect as a very attractive candidate for application as probe element in the development of auto-biased linear magnetic field sensors.Comment: 5 figure

Field-theoretical renormalization group for a flat two-dimensional Fermi surface

We implement an explicit two-loop calculation of the coupling functions and the self-energy of interacting fermions with a two-dimensional flat Fermi surface in the framework of the field theoretical renormalization group (RG) approach. Throughout the calculation both the Fermi surface and the Fermi velocity are assumed to be fixed and unaffected by interactions. We show that in two dimensions, in a weak coupling regime, there is no significant change in the RG flow compared to the well-known one-loop results available in the literature. However, if we extrapolate the flow to a moderate coupling regime there are interesting new features associated with an anisotropic suppression of the quasiparticle weight Z along the Fermi surface, and the vanishing of the renormalized coupling functions for several choices of the external momenta.Comment: 16 pages and 22 figure

Manguezais: potencial fonte de microrganismos para o uso como agentes de biocontrole da podridão radicular e promotores de crescimento de plantas em hidroponia.

Resumo: Microrganismos residentes de manguezais são adaptados aos baixos teores de oxigênio e flutuações de salinidade, condições encontradas em ambientes hidropônicos. Essa adaptação ecológica torna esses microrganismos em potenciais agentes de controle biológico de podridões radiculares, importantes doenças que incidem sobre cultivos hidropônicos e promotores de crescimento de plantas, pois um dos principais problemas encontrados no biocontrole e na promoção de crescimento em hidroponia é a baixa adaptação dos microrganismos introduzidos. O objetivo do trabalho foi avaliar a capacidade de 28 isolados de microrganismos residentes de manguezais no controle da podridão radicular causada por Pythium aphanidermatum e na promoção de crescimento em pepino hidropônico. Dentre os microrganismos avaliados para o controle da doença em mini-hidroponia, utilizando plântulas de pepino, Gordonia rubripertincta SO-3B-2, uma mistura de isolados (G. rubripertincta SO-3B-2, MB- P3A-49, MB-P3-C68 e SO-3L-3 de Pseudomonas stutzeri) e Bacillus cereus AVIC-3-6 aumentaram a sobrevivência das plântulas. Em condições de casa-de-vegetação, G. rubripertincta SO-3B-2 e P. stutzeri MB-P3A-49 promoveram o crescimento vegetal das plantas não infestadas com o patógeno. Concluimos que, microrganismos residentes de manguezais são potenciais agentes de controle biológico da podridão radicular e da promoção de crescimento em cultivos hidropônicos. Mangrove microbes are well adapted to low oxygen and salinity fluctuation environments, conditions found in hydroponic systems. This ecological adaptation makes these microbes suitably adapted for use in hydroponic crops as biological control agents of root rot, important disease in hydroponic crops; and as plant growth promoters, because one of the most important issues found in the biocontrol and plant growth promotion in hydroponic crops is the low survival of the added microbes to the nutrient solution. The aim of this work was to evaluate the ability of 28 mangrove microbes strains for the control of root rot caused by Pythium aphanidermatum and growth promotion in hydroponic cucumber. Among the 28 strains evaluated to disease control in small-hydroponic system using cucumber seedlings, Gordonia rubripertincta SO-3B-2, the mix strains (G. rubripertincta SO-3B-2, MB-P3A-49, MB-P3-C68 and SO-3L-3 of Pseudomonas stutzeri), and Bacillus cereus AVIC-3-6 increased the seedlings survival. In greenhouse conditions G. rubripertincta SO-3B-2 and P. stutzeri MB- P3A-49 increased growth of plants not infested with the pathogen. We conclude that microbes from mangroves have potential value as biocontrol agents and growth promotion in hydroponic crops.bitstream/item/48672/1/boletim-59.pd

RNAseq reveals hydrophobins that are involved in the adaptation of aspergillus nidulans to lignocellulose

Background Sugarcane is one of the world’s most profitable crops. Waste steam-exploded sugarcane bagasse (SEB) is a cheap, abundant, and renewable lignocellulosic feedstock for the next-generation biofuels. In nature, fungi seldom exist as planktonic cells, similar to those found in the nutrient-rich environment created within an industrial fermenter. Instead, fungi predominantly form biofilms that allow them to thrive in hostile environments. Results In turn, we adopted an RNA-sequencing approach to interrogate how the model fungus, Aspergillus nidulans, adapts to SEB, revealing the induction of carbon starvation responses and the lignocellulolytic machinery, in addition to morphological adaptations. Genetic analyses showed the importance of hydrophobins for growth on SEB. The major hydrophobin, RodA, was retained within the fungal biofilm on SEB fibres. The StuA transcription factor that regulates fungal morphology was up-regulated during growth on SEB and controlled hydrophobin gene induction. The absence of the RodA or DewC hydrophobins reduced biofilm formation. The loss of a RodA or a functional StuA reduced the retention of the hydrolytic enzymes within the vicinity of the fungus. Hence, hydrophobins promote biofilm formation on SEB, and may enhance lignocellulose utilisation via promoting a compact substrate-enzyme-fungus structure. Conclusion This novel study highlights the importance of hydrophobins to the formation of biofilms and the efficient deconstruction of lignocellulose

Biomassa aérea e equações para sua estimativa em Eucalyptus benthamii.

meses.Resumo

Aether field coupled to the electromagnetic field in the TFD formalism

In this paper, the aether field, which leads to the violation of Lorentz symmetries, coupled with the electromagnetic field is considered. In order to study thermal and size effects in this theory, the Thermo Field Dynamics (TFD) formalism is used. TFD is a real-time quantum field theory that has an interesting topological structure. Here three different topologies are taken, then three different phenomena are calculated. These effects are investigated considering that the aether field can point in different directions. The results obtained are compared with the usual results of the Lorentz invariant electromagnetic field.Comment: 15 pages, accepted for publication in EPJ

Apparent Recovery of Surface Applied Nitrogen Fertilizer by a Coastcross Pasture

Nitrogen recoveries from five levels of urea and ammonium nitrate surface-applied on coastcross pasture, grown on a dark red latosol (Hapludox), in São Carlos, SP, Brazil, under tropical altitude climate, were estimated. Significant differences occurred within periods (P \u3c 0.05), depending on climatic conditions. Under adequate plant growth conditions, mean N recovery from urea was about 67%, sometimes reaching 80%, of that from ammonium nitrate. Recovery of ammonium nitrate varied from 45 to 68% of applied N