Disorder effects at low temperatures in La_{0.7-x}Y_{x}Ca_{0.3}MnO_{3} manganites

With the aim of probing the effect of magnetic disorder in the low-temperature excitations of manganites, specific-heat measurements were performed in zero field, and in magnetic fields up to 9 T in polycrystalline samples of La_{0.7-x}Y_{x}Ca_{0.3}MnO_{3}, with Y concentrations x=0, 0.10, and 0.15. Yttrium doping yielded the appearance of a cluster-glass state, giving rise to unusual low-temperature behavior of the specific-heat. The main feature observed in the results is a strong enhancement of the specific-heat linear term, which is interpreted as a direct consequence of magnetic disorder. The analysis was further corroborated by resistivity measurements in the same compounds.Comment: 9 pages, 2 figure

Produção comercial de sementes de Paspalum notatum var. notatum.

Paspalum notatum é uma espécie perene de gramínea, rústica, de origem pan-americana, de grande importância econômica em vários países, utilizada como pastagem tanto nativa quanto cultivada e como cobertura vegetal permanente de superfícies de solo. No Brasil, a variedade notatum dessa espécie é frequentemente cultivada como gramado, em especial nas regiões Sudeste e CentroOeste, onde é conhecida como grama-batatais e por alguns outros nomes regionais. Essa variedade é uma das poucas alternativas disponíveis para a formação de gramados no País.bitstream/item/213146/1/Documentos-136.pd

Aplicação de técnicas multivariadas na seleção de genótipos de plantas para gramados resistentes a insetos.

Resumo publicado em: REUNIÃO ANUAL DA REGIÃO BRASILEIRA DA SOCIEDADE INTERNACIONAL DE BIOMETRIA, 60.; SIMPÓSIO DE ESTATÍSTICA APLICADA À EXPERIMENTAÇÃO AGRONÔMICA, 16., 2015, Presidente Prudente. Resumos... Presidente Prudente: Rbras, 201

Characterization of the potential of native grasses for use as lawns.

Since long lawns have been cultivated worldwide to perform a large variety of functions. Brazilian lawns have been constituted by a reduced number of species and cultivars. This work was developed with the purpose of estimating the potential of use as lawns presented by the members of a collection of accesses of native species of Paspalum and Axonopus (Poaceae). The following characteristics were evaluated: maximum vertical growth height, speed of soil cover, speed of regrowth, dry mass production, ornamental quality, weed encroachment and demand for mowing. Several accessions presented desirable characteristics and can therefore be included in programs aiming the development of cultivars for lawns intended for use in a variety of situations. The results here reported and discussed represent an experimental verification of the potential of the Brazilian flora to offer plants for use as lawns, reinforce the importance of native genetic resources and contribute to the continuity of research aimed at the development of this type of cultivars in Brazil

Antibiose de Paspalum spp. à cigarrinha-das-pastagens Mahanarva spectabilis Distant (Hemiptera: Cercopidae).

As pastagens plantadas no Brasil compreendem cerca de 160 milhões de hectares, sendo 92% da área formada por cultivares dos gêneros Urochloa e Megathyrsus