Magnetic phases evolution in the LaMn1-xFexO3+y system

We have investigated the crystal structure and magnetic properties for polycrystalline samples of LaMn1-xFexO3+y, in the whole range x=0.0 to x=1.0, prepared by solid state reaction in air. All samples show the ORT-2 orthorhombic structure that suppresses the Jahn-Teller distortion, thus favoring a ferromagnetic (FM) superexchange (SE) interaction between Mn^{3+}-O-Mn^{3+}. For x=0.0 the oxygen excess (y ~ 0.09) produces vacancies in the La and Mn sites and generates a fraction around 18% of Mn^{4+} ions and 82% of the usual Mn^{3+} ions, with possible double exchange interaction between them. The Fe doping in this system is known to produce only stable Fe^{3+} ions. We find an evolution from a fairly strong FM phase with a Curie temperature T_{C} ~ 160 K, for x=0.0, to an antiferromagnetic (AFM) phase with T_{N} = 790 K, for x=1.0, accompanied by clear signatures of a cluster-glass behavior. For intermediate Fe contents a mixed-phase state occurs, with a gradual decrease (increase) of the FM (AFM) phase, accompanied by a systematic transition broadening for 0.2 < x < 0.7. A model based on the expected exchange interaction among the various magnetic-ion types, accounts very well for the saturation-magnetization dependence on Fe doping.Comment: 27 pages, 9 figure

Boas práticas de fabricação como estratégia para impedir a contaminação de peixes frescos eviscerados por Salmonella.

As salmonelas são micro-organismos amplamente distribuídos na natureza e possuem como principal reservatório o trato intestinal homem e de aves. No caso de peixes, moluscos e crustáceos, a sua presença está relacionada, principalmente, com o manejo pós-despesca, o qual pode representar um risco sanitário e econômico para os entrepostos de processamento. A partir deste problema, objetivou-se nesse trabalho investigar possíveis causas para a contaminação de peixes eviscerados frescos por spp. em uma agroindústria de pescado.Organizado por: Sílvio Ricardo Maurano; AQUACIÊNCIA 2012

Influencia da nutrição sobre a qualidade do pescado: especial referência aos ácidos graxos.

Reconhecida como uma fonte de proteína de alta qualidade, a carne de pescado tem sido objeto de inúmeras pesquisas relacionadas à sua composição em ácidos graxos, dentre os quais se encontram os popularmente conhecidos como ômega-3, os quais estão diretamente associados à saúde humana pelo seu efeito protetor, principalmente contra doenças cardiovasculares e reumatismo. Nesse sentido, um dos grandes desafios da aquicultura é apresentar ao consumidor um produto final que se assemelhe, em termos nutricionais e sensoriais, aos peixes capturados na natureza que são ricos em ácidos graxos. Este documento faz uma revisão da influência da nutrição nos peixes cultivados sobre a composição de ácidos graxos e a importância dessa como ferramenta para melhorar a qualidade nutricional e agregar valor ao pescado.bitstream/item/101804/1/DOC124.pd

Eficiência do método de desinfestação de explantes de Ilex paraguariensis Saint hilaire por cloreto de mercúrio.

EVINCI. Resumo 009

Reaproveitamento de resíduos sólidos na cadeia agroindustrial do pescado.

Introdução. Pescado no Brasil. Resíduos sólidos. Farinha de pescado. Óleo de pescado. Compostagem de pescado. Referências.bitstream/item/90933/1/cnpasa.doc1.pd

On Matrix Superpotential and Three-Component Normal Modes

We consider the supersymmetric quantum mechanics (SUSY QM) with three- component normal modes for the Bogomol'nyi-Prasad-Sommerfield (BPS) states. An explicit form of the SUSY QM matrix superpotential is presented and the corresponding three-component bosonic zero-mode eigenfunction is investigated.Comment: 17 pages, no figure. Paper accepted for publication in Journal of Physics A: Mathematical and Theoretica

Selection of common bean inbred lines with tolerance to high moisture at harvest.

The occurrence of precipitation / rain in harvest bean causes damage to the product and reduces the yield. The main alternative to mitigate this problem is to obtain cultivars presenting low germination of beans in the pods under conditions of high moisture. The purpose of this study was to verify if there is genetic variability among the common bean inbred lines that are in the phase of recommendation for the South of Minas Gerais, Brazil in regard to tolerance to moisture after harvest, and identify traits that may be routinely used in selection of tolerant lines to these conditions. Ninety-five lines in the phase of recommendation by the Genetic Breeding Program from UFLA were used. After harvest, a sample of plants from each plot was removed for assessments of seed germination in the pods in a moist chamber and water absorption by pod and seed. Eight days after harvest, another sample was removed to assess seed appearance using a scoring scale. The data were submitted to analysis of variance and estimates of the Pearson phenotypic correlations were obtained among traits. Lines differ in relation to tolerance to moisture at the time of harvest, with those of higher tolerance having lighter colored seeds. The main difficulty in selection of common bean lines for tolerance to high moisture at harvest is the repeatability of the environmental conditions among crop seasons. The alternative is assessing the amount of water absorbed by pods

Changing the production chain of Amazonian pirarucu.

This article summarizes these recent findings and envisions how these are impacting the production sector in the short and medium terms. Recent studies in Brazil have addressed the main challenges faced by commercial producers of pirarucu, including breeding, larval rearing, grow-out, feeding, health management, processing and more

Seleção de progênies de feijoeiro com plantas eretas e grãos tipo carioca.

Para confirmar se a população oriunda do cruzamento CVIII-8511 x BRS-Supremo, identificada em um cruzamento dialélico anteriormente realizado é realmente promissora para a seleção de plantas eretas e com boa produtividade de grãos foi realizado o presente trabalho