40 resultados para Plackett-burman designs
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Originalmente na forma de citações de consagrados autores norte-americanos, pontuando os mais significativos temas sobre a biblioteca do futuro, em um período de dez anos (1983-1994), este riquíssimo estado-da-arte é agora traduzido e condensado em língua portuguesa e devidamente autorizado pelo Council on Library Resources (CLR), de Washington, D.C., USA. Para maior alcance desta matéria emergente, adotou-se uma fala pessoal, didática e interpretativa, obedecendo, porém, à orgânica do original, na ordem a saber: introdução, visão do futuro, definições de bibliotecas digitais; publicação impressa versus digital, aplicações e instrumentos de acesso à informação tecnológica; editoração, papéis e motivação dos atores e projetos no sistema digital; projetos e bibliotecas do futuro, incluindo o perfil do bibliotecário de referência e o papel das escolas de biblioteconomia; para onde vão as bibliotecas na virada do século e um senso de urgência. Finda-se com uma bibliografia e um índice conjugado de autores e assuntos.
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The objective of this work was to determine the most appropriated chemical treatment to be used to dry grapes cv. Rubi for raisin production. Drying curves for convective drying with air at 50ºC, in a tray drier, were obtained for grapes submitted to chemical pretreatments with different concentrations of potassium carbonate and olive oil, and different dipping times, according to factorial designs. Convective drying curves were also obtained for grapes pretreated in aqueous suspensions of soybean lecithin, at varied lecithin concentrations and dipping times. Page model was adjusted to the experimental drying curves, and the calculated drying times showed that the best pretreatment consisted in dipping grapes for 2 minutes in a 5% olive oil and 6% K2CO3 emulsion, at 50ºC, which resulted in a drying time close to that of the pretreatment with 2.5% of olive oil, but with a lower consumption of this substance. In addition, the immersion of grapes in an aqueous suspension of 2% soy lecithin, at 50ºC, for 5 minutes, resulted in a total drying time slightly higher than the most effective pretreatment.
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The objectives of this work were to analyze theoretical genetic gains of maize due to recurrent selection among full-sib and half-sib families, obtained by Design I, Full-Sib Design and Half-Sib Design, and genotypic variability and gene loss with long term selection. The designs were evaluated by simulation, based on average estimated gains after ten selection cycles. The simulation process was based on seven gene systems with ten genes (with distinct degrees of dominance), three population classes (with different gene frequencies), under three environmental conditions (heritability values), and four selection strategies. Each combination was repeated ten times, amounting to 25, 200 simulations. Full-sib selection is generally more efficient than half-sib selection, mainly with favorable dominant genes. The use of full-sib families derived by Design I is generally more efficient than using progenies obtained by Full-Sib Design. Using Design I with 50 males and 200 females (effective size of 160) did not result in improved populations with minimum genotypic variability. In the populations with lower effective size (160 and 400) the loss of favorable genes was restricted to recessive genes with reduced frequencies.
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The objectives of this work were to evaluate the genotype x environment (GxE) interaction for popcorn and to compare two multivariate analyses methods. Nine popcorn cultivars were sown on four dates one month apart during each of the agricultural years 1998/1999 and 1999/2000. The experiments were carried out using randomized block designs, with four replicates. The cv. Zélia contributed the least to the GxE interaction. The cv. Viçosa performed similarly to cv. Rosa-claro. Optimization of GxE was obtained for cv. CMS 42 for a favorable mega-environment, and for cv. CMS 43 for an unfavorable environment. Multivariate analysis supported the results from the method of Eberhart & Russell. The graphic analysis of the Additive Main effects and Multiplicative Interaction (AMMI) model was simple, allowing conclusions to be made about stability, genotypic performance, genetic divergence between cultivars, and the environments that optimize cultivar performance. The graphic analysis of the Genotype main effects and Genotype x Environment interaction (GGE) method added to AMMI information on environmental stratification, defining mega-environments and the cultivars that optimized performance in those mega-environments. Both methods are adequate to explain the genotype x environment interactions.
Morphological, pedigree, and molecular distances and their association with hybrid wheat performance
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The objectives of this work were to estimate the genetic distance among wheat genotypes using morphological, pedigree, molecular, and combined morphological and molecular measures, to determine the correlations between these measures, and to evaluate the combining ability of the genotypes. Three generations and two planting designs were studied. Six wheat genotypes were crossed using a diallel design. The F1, F2 and F3generations were evaluated in the field, in the crop seasons of 2003, 2004 and 2005, under spaced plant and full-row planting designs. The estimated general and specific combining abilities of tested hybrids were influenced both by the generation and the planting design. The correlation coefficients among the distance measures and between these measures and genotype performances of different generations for the two planting designs were low to moderate. In order to obtain a more precise estimate of the genetic distance among cultivars and its association with the hybrid performance, more than one generation, planting design, and genetic distance estimation technique should be employed.
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The objective of this work was to set up ideal conditions for conidia mass production of Dicyma pulvinata. Four isolates were compared in terms of their growth and conidia production on various substrates (grains of parboiled rice, common rice, maize and wheat, besides chipped maize and rice husk), temperatures (19, 22, 25, 28 and 31ºC), growth containers (aluminum trays, polypropylene bags and Erlenmeyers) and light regimes (continuous darkness, 6 and 12 hours of light/darkness, and continuous light). Temperature effects on conidia germination capacity were also evaluated. The experiments were done in randomized complete block designs, in factorial arrangements (isolates x treatments - substrates, containers, temperatures and light regimes), with four replicates. In general, parboiled rice and polypropylene bags provided the best development of the fungus. Complete darkness and 6 hours of light increased mycelial growth, whereas continuous light favored sporulation. All tested temperatures favored the cultures of the fungus, except 31ºC. Temperatures between 19 and 25ºC ensure spore germination of more than 76%.
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The objective of this work was to evaluate the effect of drought on genetic parameters and breeding values of cassava. The experiments were carried out in a completely randomized block design with three replicates, under field conditions with (WD) or without (FI) water deficit. Yield of storage roots (RoY), shoot (ShY), and starch (StY), as well as the number of roots (NR), and root dry matter content (DMC) were evaluated in 47 cassava accessions. Significant differences were observed among accessions; according to heritability, these differences had mostly a genetic nature. Heritability estimates for genotypic effects () ranged from 0.25±0.12 (NR) to 0.60±0.18 (DMC), and from 0.51±0.17 (NR) to 0.80±0.21 (RoY and StY) for WD and FI, respectively, as a consequence of greater environmental influence on WD. Selective accuracy was lower in WD, and ranged from 0.71 (NR) to 0.89 (RoY, DMC, and StY). However, genetic gains were quite high and ranged from 24.43% (DMC) to 113.41% (StY), in WD, and from 8.5% (DMC) to 75.70% (StY) in FI. These genetic parameters may be useful for defining which selection strategies, breeding methods, and experimental designs are more suitable to obtain cassava genetic gains for tolerance to drought.
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The lack of good quality planting material has limited the expansion and contributed to yield reduction of the Brazilian pineapple culture. Alternatives of 'Pérola' pineapple slips management were studied aiming at obtaining superior planting material within a shorter time period and making good use of healthy slips of low vigor, that are commonly discarded by growers. Two experiments were carried out at the Experimental Field of Embrapa Cassava & Fruits, Cruz das Almas, Bahia, Brazil, and another one in a commercial plantation in the region of Itaberaba, BA, using blocks or entirely randomized designs with at least four replications. In the first one, the development of slips of different initial sizes (6 to 20 cm long), when grown on mother plants after fruit harvest, was compared with that of slips grown in a nursery after their removal from the mother plants. It became clear that larger slips grow more vigorously and that the removal from the mother plant delays their growth. However, results from the second study showed that those slips grown in nursery had vegetative and agronomic performance similar to that of conventional slips and close to that of plantlets produced from plant stem sections. Independently from the type of planting material used, the larger ones presented a more vigorous growth and produced higher yields. In the third study, it was observed the influence of mineral fertilization, pest control and growth regulator application after fruit harvest on slip development. The treatments applied did not significantly accelerate slip growth. Slips reached 50 cm length and at least 300 g fresh weight within 90 days after fruit harvest, indicating that vigorous plants have enough nutritional storage material for slips development.
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Among all activities related to the management of science and technology in Brazil, program monitoring and evaluation is certainly one of the less developed and most needed. There are no universal methodologies that can be applied. In essence programs can be evaluated by relating their achievements to pre-established goals. A second strategy is to compare programs similar in nature, utilizing as reference common indicators. Finally programs can be evaluated by their socio-economic impact comparing investments to outcomes. All strategies mentioned require appropriate program design monitoring and expert independent evaluation. In Brazil as in many other countries including developed ones this activity is complicated by the fact that programs vary widely in their scope and goals. In Brazil program designs often do not specify clearly their purposes and output indicators, many are not monitored properly which makes evaluation difficult. Consequently science and technology programs are difficult to be compared to each other, and even evaluated on the basis of pre-established goals. In PADCT monitoring and evaluation proved to be the most challenging activities. Two lessons however were learnt. One is that the process of monitoring and evaluation has to be continuously exposed to criticism to be perfected; and the second is that the evaluation process must not be exhausted shortly after investments since translation of scientific knowledge into industrial applications may prove to be a lengthy process. In this exercise we certainly do not pretend to evaluate the QEQ subprogram but to organize some of the information produced by different sources related to this subject, including the PADCT administration. We use somewhat each strategy described: compare the outputs of the QEQ to predetermined proposed goals (particularly in PADCT II), compare the QEQ to other PADCT subprograms, and specify some outputs in terms of technological and industrial applications. Finally, we utilize this opportunity to discuss science and technology M&E in general and the complexity of developing this area in Brazil.
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A review about the state-of-the-art of flow injection analysis (FIA) -- capillary electrophoresis (CE) systems is presented. The basic principles of flow injection and capillary electrophoresis are briefly revised. The main aspects of the FIA-CE hybridization, including advantages and shortcomings, are discussed. Some applications involving all different designs are also presented. This review covers the literature from 1997 up to 2000.
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The most important features of the CE-ICP hyphenation, as well as its advantages and drawbacks as a tool for speciation are discussed. The fundamental principles of capillary electrophoresis and inductively coupled plasma mass spectrometry are also presented. Some applications involving different designs proposed in the literature to couple CE and ICP system for elemental speciation are reviewed.
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This work describes, through examples, a simple way to carry out experimental design calculations applying an spreadsheets. The aim of this tutorial is to introduce an alternative to sophisticated commercial programs that normally are too complex in data input and output. An overview of the principal methods is also briefly presented. The spreadsheets are suitable to handle different types of computations such as screening procedures applying factorial design and the optimization procedure based on response surface methodology. Furthermore, the spreadsheets are sufficiently versatile to be adapted to specific experimental designs.
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This manuscript shows an overview of the solid oxide fuel cell (SOFC) technology based on industrial developments. The information presented has been collected mostly at conferences that the authors attended. It is observed that several companies have been pursuing the development of the SOFC technology. Significant advances in stability and power density have raised the economic interest in this technology recently. It is revealed that the SOFC materials are essentially the same ones that have been used in the past decades, and that the two most important designs of pre-commercial SOFC prototypes are the tubular and planar ones.
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This paper reports the development of a methodology for simultaneously determining As, Cd and Pb, employing GF AAS with polarized Zeeman-effect background correction. In order to make the procedure applicable, the influence of pyrolysis and atomization temperatures and the amount of chemical modifiers were studied. Factorial and central composite designs were used to optimize these variables. Precision and accuracy of the method were investigated using Natural Water Reference material, Nist SRM 1640. Results are in agreement with certified values at the 95% confidence limit when the Student t-test is used. This methodology was used for quality control of purified water for hemodialysis.
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This work aimed to assess the photocatalytic degradation of a model odor compound (dimethyl disulfide, DMDS), found in liquid and gaseous wastes of plants for processing poultry byproducts. The effect of pH and temperature on adsorption and photocatalytic degradation was evaluated through factorial experimental designs. The results suggest the presence of an optimum region for adsorption, at 45.0 ºC and pH 4.0. In the photocatalytic runs an optimum for temperature and pH was also observed. At 45 ºC and pH 4.0 the removal of DMDS was 99% after 60 min of irradiation.