3,145 research outputs found

    Corrosion protection of hot dip galvanized steel in mortar

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    Corrosion of steel in concrete is one of the major causes of structure degradation, requiring expensive maintenance. The using of hot dip galvanized steel (HDGS) has been recognized as one effective measure to increase the service life of reinforced concrete structures in marine environmental. However, HDGS corrodes in contact with high alkaline environment of fresh concrete. Although this initial corrosion process allows the formation of a protecting layer barrier, the corrosion that occurs initially is harmful and chromate conversion layers are usually used to prevent it. Due to toxicity of Cr(VI), these kinds of pre-treatments have been forbidden and hybrid coatings have been proposed as alternatives [1-3]. To evaluate the performance of these coatings, beyond the laboratory characterization, in situ tests in real conditions should be performed. An electrochemical system to measure the macrocell current density (igal) was designed to evaluate the degradation of HDGS coated samples with different organic-inorganic hybrid films, embedded in mortar during 70 days, using an automatic data acquisition system. This system revealed to be feasible and highly sensitive to coatings degradation. Also, allow distinguishing different hybrid coatings with different thicknesses.The authors would like to gratefully acknowledge the financial support from Fundação para a Ciência e Tecnologia (FCT) for the PhD grant SFRH/BD/62601/2009 and the financial support by Centro de Química [project F-COMP-01-0124-FEDER-022716 (ref. FCT Pest-C/Qui/UI0686/2011)-FEDER-COMPETE]. The authors would also like to thank Hugo Marques Gomes for assisting in the schematic representations.info:eu-repo/semantics/publishedVersio

    On the cost of database clusters reconfiguration

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    Database clusters based on share-nothing replication techniques are currently widely accepted as a practical solution to scalability and availability of the data tier. A key issue when planning such systems is the ability to meet service level agreements when load spikes occur or cluster nodes fail. This translates into the ability to provision and deploy additional nodes. Many current research efforts focus on designing autonomic controllers to perform such reconfiguration, tuned to quickly react to system changes and spawn new replicas based on resource usage and performance measurements. In contrast, we are concerned about the inherent impact of deploying an additional node to an online cluster, considering both the time required to finish such an action as well as the impact on resource usage and performance of the cluster as a whole. If noticeable, such impact hinders the practicability of self-management techniques, since it adds an additional dimension that has to be accounted for. Our approach is to systematically benchmark a number of different reconfiguration scenarios to assess the cost of bringing a new replica online. We consider factors such as: workload characteristics, incremental and parallel recovery, flow control and outdatedness of the recovering replica. As a result, we show that research should be refocused from optimizing the capture and transmition of changes to applying them, which in a realistic setting dominates the cost of the recovery operation.Work supported by the Spanish Government under research grant TIN2006-14738-C02-02

    Biometric evaluation of morpho-agronomic traits in pepper lines and hybrids

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    Objetivou-se avaliar linhagens e h?bridos de pimenta (Capsicum chinense e C. annuum) afim de obter informa??es sobre o desempenho agron?mico, heterose, heterobeltiose, correla??es fenot?picas e dissimilaridade gen?tica. Foram avaliadas as linhagens PIM-030, BGH-433, BGH-4285, Numex Sweet, Numex Garnet e os h?bridos simples Numex Sweet x PIM-030, Numex Garnet x PIM-030 e BGH-4285 x BGH-433. O experimento foi conduzido com oito tratamentos e quatro repeti??es, em casa de vegeta??o, no campus JK da UFVJM. Foram avaliadas 22 caracter?sticas morfoagron?micas. No h?brido BGH-4285 x BGH-433 foi observado maior heterose e heterobeltiose para produtividade total de frutos e produtividade de massa seca total de frutos, sendo interessante aos futuros programas de melhoramento. Observa-se que plantas de maior porte tendem a ser mais produtivas com maiores massas fresca dos frutos e frutos com pericarpo mais espesso, frutos maiores com maiores pedicelos e com sementes mais densas, sendo importante para a produ??o de p?prica. As linhagens BGH-433, BGH-4285 e PIM-030 s?o as mais recomendadas para uso em programas de melhoramento.In this study, we aimed to evaluate pepper lines and hybrids (Capsicum chinense and C. annuum) in order to obtain information on agronomic performance, heterosis, heterobeltiosis, phenotypic correlations and genetic dissimilarity. We evaluated lines PIM-030, BGH-433, BGH-4285, Numex Sweet, Numex Garnet and simple hybrids Numex Sweet x PIM-030, Numex Garnet x PIM-030 and BGH-4285 x BGH-433. The research was conducted with eight treatments and four replications in a greenhouse, at campus JK of UFVJM. Twenty two agronomic traits were evaluated. The hybrid BGH-4285 x BGH-433 presents higher heterosis and heterobeltiosis for total fruit productivity and productivity of total fruit dry mass, information of great value for future breeding studies. The authors noticed that larger plants tend to be more productive and present higher fruit fresh mass and also fruits with thicker pericarp, as well as larger fruits having longer pedicels with denser seeds, important for production of paprika. Lines BGH-433, BGH-4285 and PIM-030 are the most recommended to be used in breeding programs

    Dynamics of a hyperbolic system that applies at the onset of the oscillatory instability

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    A real hyperbolic system is considered that applies near the onset of the oscillatory instability in large spatial domains. The validity of that system requires that some intermediate scales (large compared with the basic wavelength of the unstable modes but small compared with the size of the system) remain inhibited; that condition is analysed in some detail. The dynamics associated with the hyperbolic system is fully analysed to conclude that it is very simple if the coefficient of the cross-nonlinearity is such that , while the system exhibits increasing complexity (including period-doubling sequences, quasiperiodic transitions, crises) as the bifurcation parameter grows if ; if then the system behaves subcritically. Our results are seen to compare well, both qualitatively and quantitatively, with the experimentally obtained ones for the oscillatory instability of straight rolls in pure Rayleigh - Bénard convection

    Synonymy of Orthomus susanae Serrano & Borges, 2009 with Orthomus annae (Donabauer, 2008) (Coleoptera: Carabidae)

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    Copyright © 2012 Magnolia Press.[...]. Some time after the publication of their paper in Zootaxa, the authors found out that another Madeiran Orthomus species had been described one month earlier (Donabauer 2008). Taking in consideration the morphological characteristics of the specimens described in both papers and the coincidence of the type localities no doubts remained regarding the synonymy between the two species

    Unusual association of NDM-1 with KPC-2 and armA among Brazilian Enterobacteriaceae isolates

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    We report the microbiological characterization of four New Delhi metallo-beta-lactamase-1 (bla(NDM-1))-producing Enterobacteriaceae isolated in Rio de Janeiro, Brazil. bla(NDM-1) was located on a conjugative plasmid and was associated with Klebsiella pneumoniae carbapenemase-2 (bla(KPC-2)) or aminoglycoside-resistance methylase ( armA), a 16S rRNA methylase not previously reported in Brazil, in two distinct strains of Enterobacter cloacae. Our results suggested that the introduction of bla(NDM-1) in Brazil has been accompanied by rapid spread, since our isolates showed no genetic relationship.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo, Dept Med, Lab Especial Microbiol Clin, São Paulo, SP, BrazilDASA, Lab Diagnost Amer, São Paulo, SP, BrazilUniversidade Federal de São Paulo, Dept Med, Lab Especial Microbiol Clin, São Paulo, SP, BrazilWeb of Scienc

    Simcluster: clustering enumeration gene expression data on the simplex space

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    Transcript enumeration methods such as SAGE, MPSS, and sequencing-by-synthesis EST "digital northern", are important high-throughput techniques for digital gene expression measurement. As other counting or voting processes, these measurements constitute compositional data exhibiting properties particular to the simplex space where the summation of the components is constrained. These properties are not present on regular Euclidean spaces, on which hybridization-based microarray data is often modeled. Therefore, pattern recognition methods commonly used for microarray data analysis may be non-informative for the data generated by transcript enumeration techniques since they ignore certain fundamental properties of this space.

Here we present a software tool, Simcluster, designed to perform clustering analysis for data on the simplex space. We present Simcluster as a stand-alone command-line C package and as a user-friendly on-line tool. Both versions are available at: http://xerad.systemsbiology.net/simcluster.

Simcluster is designed in accordance with a well-established mathematical framework for compositional data analysis, which provides principled procedures for dealing with the simplex space, and is thus applicable in a number of contexts, including enumeration-based gene expression data

    Finite size effects near the onset of the oscillatory instability

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    A system of two complex Ginzburg - Landau equations is considered that applies at the onset of the oscillatory instability in spatial domains whose size is large (but finite) in one direction; the dependent variables are the slowly modulated complex amplitudes of two counterpropagating wavetrains. In order to obtain a well posed problem, four boundary conditions must be imposed at the boundaries. Two of them were already known, and the other two are first derived in this paper. In the generic case when the group velocity is of order unity, the resulting problem has terms that are not of the same order of magnitude. This fact allows us to consider two distinguished limits and to derive two associated (simpler) sub-models, that are briefly discussed. Our results predict quite a rich variety of complex dynamics that is due to both the modulational instability and finite size effects

    Incidência do míldio em cebola sob adubação mineral e orgânica.

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    Analisou-se a relação entre adubação mineral e orgânica sobre a incidência de míldio (Peronospora destructor) em cebola (Allium cepa). O trabalho constituiu-se de dois experimentos localizados em Ituporanga, conduzidos entre agosto e dezembro de 1998. O experimento 1, com fontes orgânicas, constou dos tratamentos: esterco de suínos, esterco de aves, composto, esterco de peru e húmus, na dosagem de 75 kg/ha de N; esterco de suínos, na dosagem de 37,5 kg/ha de N; adubação mineral, 30-120-60 kg/ha de N-P2O5-K2O; 60-240-120 kg/ha de N-P2O5-K2O e testemunha sem adubação. O experimento 2 constou dos tratamentos: fontes minerais, 30-120-60 kg/ha de N-P2O5-K2O; 90-360-180 kg/ha de N-P2O5-K2O; 75 kg/ha de N; 225 kg/ha de N; 80 kg/ha de P2O5; 240 kg/ha de P2O5; 60 kg/ha de K2O; 180 kg/ha de K2O; esterco de suínos + fosfato natural, em três combinações, 7,9+0,1, 15,7+0,2 e 47,2+0,6 t/ha, respectivamente; testemunha sem adubação. Não houve diferença entre as fontes mineral e orgânica sobre a incidência de míldio. A relação entre nutrientes e doença foi variável entre datas de amostragem e distinta para fontes minerais e orgânicas

    Avocado (Persea americana) pulp improves cardiovascular and autonomic recovery following submaximal running: a crossover, randomized, double-blind and placebo-controlled trial

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    Previous studies have demonstrated that regular avocado consumption presents advantageous effects on cardiovascular system. However, little attention has been paid to the use of avocado as a dietary supplement, in particular, for individuals involved in physical exercise training. Therefore, this study aims to evaluate the effect of acute avocado pulp intake on cardiovascular and autonomic recovery subsequent to moderate exercise. Using a crossover, randomized, double-blind and placebo-controlled trial design, 16 healthy female adults underwent two protocols: Avocado pulp (600 mg in capsule) and placebo (600 mg starch in capsule). After the ingestion of Avocado pulp or placebo, the subjects were seated for 60 min at rest, followed by running on a treadmill at a submaximal level and then remained seated for 60 min during recovery from the exercise. Heart rate (HR), heart rate variability (HRV) [rMSSD, SD1, HF (ms2)] and skin conductance were evaluated before and during exercise, as well as during recovery. HR, systolic blood pressure, HRV and skin conductance recovered faster when subjects were given avocado pulp prior to exercise. In conclusion, avocado pulp improved cardiovascular and autonomic recovery after exercise, suggesting a reduced risk of cardiovascular events after exertion. The current results support the beneficial effects of ingestion of avocado prior to submaximal treadmill running
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