5,805 research outputs found

    Uhlenbeck-Ford model: phase diagram and corresponding-states analysis

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    CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESUsing molecular dynamics simulations and nonequilibrium thermodynamic-integration techniques we compute the Helmholtz free energies of the body-centered-cubic (bcc), face-centered-cubic (fcc), hexagonal close-packed, and fluid phases of the Uhlenbeck-Ford model (UFM) and use the results to construct its phase diagram. The pair interaction associated with the UFM is characterized by an ultrasoft, purely repulsive pair potential that diverges logarithmically at the origin. We find that the bcc and fcc are the only thermodynamically stable crystalline phases in the phase diagram. Furthermore, we report the existence of two reentrant transition sequences as a function of the number density, one featuring a fluid-bcc-fluid succession and another displaying a bcc-fcc-bcc sequence near the triple point. We find strong resemblances to the phase behavior of other soft, purely repulsive systems such as the Gaussian-core model (GCM), inverse-power-law, and Yukawa potentials. In particular, we find that the fcc-bcc-fluid triple point and the phase boundaries in its vicinity are in good agreement with the prediction supplied by a recently proposed corresponding-states principle [J. Chem. Phys. 134, 241101 (2011); Europhys. Lett. 100, 66004 (2012)]. The particularly strong resemblance between the behavior of the UFM and GCM models are also discussed.96317CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESSem informação2013/08293-7Sem informaçãoWe gratefully acknowledge support from the Brazilian agencies CNPq, Fapesp, Capes, and the Center for Computational Engineering and Sciences-Fapesp/Cepid Grant No. 2013/08293-7. Part of the calculations were performed at CCJDR-IFGW-UNICAMP and CENAPAD-SP. The authors acknowledge the National Laboratory for Scientific Computing (LNCC/MCTI, Brazil) for providing HPC resources of the SDumont supercomputer, which have contributed to the research results reported in this paper. URL: http://sdumont.lncc.b

    Desempenho produtivo de genótipos de cebola em vertissolo no Vale do São Francisco.

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    Com o objetivo de selecionar genótipos de cebola com mais alta produtividade para o Vale do São Francisco, conduziu-se um experimento no período de abril a agosto de 2003, no Campo Experimental de Mandacaru, Juazeiro-BA. O delineamento experimental utilizado foi em blocos cmpleto ao acaso, com doze genótipos (Sawana Sweet, TPR 91970; Legend; IPA 11; Encino; EX-07593000; EX-07595001; EX-07592000; EX-19013; EX-07595002; Superex e Brisa) e quatro repetições. A produtividade total de bulbos variou de 19,10 a 45,11 t. ha-1, sendo o genótipo Legend o menos produtivo (19,10 t. ha-1), não se observando diferenças estatísticas entre os demais tratamentos. A produtividade comercial oscilou entre 15,62 a 43,05 t. ha-1, sobressaindo-se os genótipos IPA 11, Superex, Sawana Sweet, EX-07595002, Brisa, TPR 91970, Ex-19013 e Ex-07592000. O número de bulbos comerciais por parcela oscilou entre 84,00 a 101,00 bulbos. A massa fresca do bulbo variou de 119,33 a 221,00 g. bulbo-1 , com maiores massas para os genótipos EX-07593001, IPA 11, EX-07595002 e Supere

    A escultura religiosa de Soares dos Reis e a iconografia da Virgem para Guimarães.

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    112 Jan.-Dez. 2002, p. 385-408

    Ganho de fitomassa e acúmulo de N atmosférico em plantas de feijão-caupi inoculadas com rizóbio.

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    Este trabalho teve como objetivo verificar o ganho de matéria seca e o acúmulo de N na parte aérea de plantas de feijão-caupi [Vigna unguiculata (L.) Walp] inoculadas com estirpes de rizóbio específicas

    Mitigation of Mombasa Grass (Megathyrsus maximus) dependence on nitrogen fertilization as a function of inoculation with Azospirillum brasilense.

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    ABSTRACT Using biological inputs to improve the efficiency of nitrogen fertilizers represents an alternative for the cultivation of grasses in tropical regions. Azospirillum brasilense is a species of plant growth promoting bacteria widely studied and used in inoculants. Thus, this study aimed to evaluate the performance of Mombasa grass ( Megathyrsus maximus ) in association with A. brasilense and nitrogen (N) fertilization. The study was conducted under field conditions in Araguaína-Tocantins State, between December 2017 and May 2018. The treatments were arranged in randomized blocks, in a 5 × 2 factorial arrangement, with five doses of N fertilization (0, 25, 50, 75, and 100 kg ha-1) combined with two inoculation treatments (inoculated and non inoculated), in four replicates. For the number of tillers and root production, the inoculation efficiency varied as a function of the supplied N doses. However, the percentage of leaf N was higher for inoculated plants regardless of the application of nitrogen. In the absence of nitrogen fertilization, it was possible to increase forage production by up to 36 % with inoculation

    Immunophenotypic characterization of normal blood CD56+lo versus CD56+hi NK‐cell subsets and its impact on the understanding of their tissue distribution and functional properties

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    Blood Cells Mol Dis. 2001 Jul-Aug;27(4):731-43. Immunophenotypic characterization of normal blood CD56+lo versus CD56+hi NK-cell subsets and its impact on the understanding of their tissue distribution and functional properties. Lima M, Teixeira MA, Queirós ML, Leite M, Santos AH, Justiça B, Orfão A. Service of Clinical Hematology, Unit of Cytometry, Hospital Geral de Santo António, Porto, Portugal. [email protected] Abstract In the present study we have compared the immunophenotypic characteristics of the CD56+lo and CD56+hi NK-cell subsets in a group of normal healthy adults. Our results show that CD56+hi NK-cells display greater light-scatter properties than CD56+lo NK-cells at the same time they have higher levels of CD25 and CD122 IL-2 chains, together with a higher reactivity for HLA-DR and CD45RO and lower levels of CD45RA, supporting that, as opposed to the majority of the CD56+lo population, CD56+hi NK-cells might correspond to a subset of activated circulating NK-lymphocytes. Higher expression of the CD2 and CD7 costimulatory molecules found for the CD56+hi NK-cells would support their greater ability to respond to various stimuli. In addition, CD56+hi NK-cells expressed higher levels of several adhesion molecules such as CD2, CD11c, CD44, CD56, and CD62L compared to CD56+lo NK-cells, supporting a particular ability of these cells to migrate from blood to tissues and/or a potential advantage to form conjugates with target cells. Interestingly, CD56+lo and CD56+hi NK-cells showed a different pattern of expression of killer receptors that might determine different activation requirements for each of these NK-cell subsets. For instance, absence or low levels of CD16 expression might explain the lower antibody-dependent cytotoxicity activity of CD56+hi NK-cells. On the other hand, the virtual absence of expression of the CD158a and NKB1 immunoglobulin-like and the greater reactivity for the CD94 lectin-like killer receptors on CD56+hi in comparison to CD56+lo NK-cells might determine different MHC-class I specificities for both NK-cell subsets, a possibility that deserves further studies to be confirmed. PMID: 11778657 [PubMed - indexed for MEDLINE

    Caracterização de Genótipos de Cebola Quanto ao Conteúdo de Quercetina.

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