899 resultados para Operational Productivity


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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Reservoirs are artificial environments built by humans, and the impacts of these environments are not completely known. Retention time and high nutrient availability in the water increases the eutrophic level. Eutrophication is directly correlated to primary productivity by phytoplankton. These organisms have an important role in the environment. However, high concentrations of determined species can lead to public health problems. Species of cyanobacteria produce toxins that in determined concentrations can cause serious diseases in the liver and nervous system, which could lead to death. Phytoplankton has photoactive pigments that can be used to identify these toxins. Thus, remote sensing data is a viable alternative for mapping these pigments, and consequently, the trophic. Chlorophyll-a (Chl-a) is present in all phytoplankton species. Therefore, the aim of this work was to evaluate the performance of images of the sensor Operational Land Imager (OLI) onboard the Landsat-8 satellite in determining Chl-a concentrations and estimating the trophic level in a tropical reservoir. Empirical models were fitted using data from two field surveys conducted in May and October 2014 (Austral Autumn and Austral Spring, respectively). Models were applied in a temporal series of OLI images from May 2013 to October 2014. The estimated Chl-a concentration was used to classify the trophic level from a trophic state index that adopted the concentration of this pigment-like parameter. The models of Chl-a concentration showed reasonable results, but their performance was likely impaired by the atmospheric correction. Consequently, the trophic level classification also did not obtain better results.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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A time-and-motion study in wood processing of the Eucalyptus harvester's operational cycle was developed. The objective was to evaluate wood harvesters working under several site conditions. The research includes two kinds of harvesters while processing wood to supply paper and cellulose factories, as follows: a machine with twin tires and other one with large tracks, both connected to a different head harvester models. The forestry species were Eucalyptus saligna Smith and Eucalyptus grandis Hill ex Maiden, seven and eight years old, in slope terrains ranging from 0% to 10% degrees, under harvesting systems used by Votorantim and Suzano forestry companies, in São Paulo State, Brazi. Considering all field research, results disclosed that, for some conditions, both machines have shown mathematical correlation between some mechanical wood operation within the processing operational cycle and the saw logs production. All the mathematical correlations were found to express logarithmical models.

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A study was carried out into the use of charcoal as a supplementary fuel in the iron-ore sintering process. The primary fuel was coke breeze and anthracite with 0, 10, 25, 50 and 100% replacement of the energy input with charcoal to produce sinter. This was achieved by considering the carbon content of each fuel and its corresponding participation on fuel blending, in order to have the same carbon input in each test run. An extensive analysis of the environmental impact was carried out regarding the atmospheric pollutants characterization (dust, sulphur dioxide, nitrogen oxides, carbon monoxide, carbon dioxide, methane, total hydrocarbons, and dioxins and furans). Experimental results indicate that fuel blending where 50% of the heat input was provided by charcoal may be comparable with those using 100% coke, under normal sintering conditions, and may result in a 50% reduction on greenhouse gas emission. It was also observed that while dust, methane and hydrocarbons emissions increased, the total dioxins and furans, expressed as polychlorinated dibenzodioxins/furans, decreased approximately 50% when compared with operation with 100% coke.

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Pós-graduação em Agronomia (Produção Vegetal) - FCAV

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One of the main challenges in the mining sector at present, related to the optimization of mineral assets, consists in to find the best proportion of each geological material to be mined and homogenized to ensure high productivity and stability in ore processing plants. The stability of a mineral processing plant is factor for achieving operational excellence, as a stable performance of the plants ensures economy and adherence to financial planning businesses. Is already well Know that the feed rate of the processing plants is dependent on the hardness and quality of the ore. Therefore, the ore behavior predictability is the solution to ensure the stability of mineral processing plants. This work was developed in Anglo American Phosphate Brazil Ltda., at the Fazenda Chapadão Phosphate Mine, located in the southeastern portion of the state of Goiás, in the municipalities of Catalão and Ouvidor. The phosphate ore is the result of supergene apatite concentration in the weathering profile of the alkaline ultramafic phlogopitized rocks, intruded by foscoritic and carbonatitic rocks series. The weathering profile has about 100 meters thick and is divided into three basic types, from top to bottom, coinciding with decreasing intensity of weathering: oxidized ore, micaceous ore and weathered rock. In each portion of this weathering profile, mainly near the contacts between these three divisions, are hard materials, cemented by minerals such as apatite, quartz, goethite, monazite and barite. The different features presented by these materials makes to be vital the correct identification, quantification and location of different hard materials in the mine area, to maximize its use. The main objective of this study was to define the type of cementation of hard materials which predominates in each portion of the weathering profile in the mine, as well as their relationship with the protolith. The work involved geological mapping, channel sampling...

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This study aimed to technically and economically evaluate the Forwarder performance in the first cutting wood extraction from a Eucalyptus grandis plantation. Technical analysis included a movement and timing study by continuous method, and the productivity was determined using the extracted wood volume in cubic meters. Economical analysis included operational costs parameters and wood extraction cost. Results referred to the effective operational performance. Loading and unloading activities responded for more than ¾ of the total time of effective Forwarder operational cycle. Operational costs were influenced by maintenance and repair costs. The estimated cost of extraction was US$ 0.97 per cubic meter.

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The acquisition of machinery used in timber harvesting depends on high financial investment, which implies the need for assessments that allow defining more precisely, what is the machine or the whole more recommended for streamlining the operation. This study aimed to technically and economically evaluating the performance of a harvester in Eucalyptus forest harvest first cut. The technique analysis included a time and movements, productivity, efficiency operational and mechanical availability. The economic analysis included the parameters operational cost, harvesting cost and energy consumption. The results obtained from the technological-economic parameters evidenced that of Diameter at Breast Height directly influenced the productivity of harvester. Consequently the lower costs of forest harvest were obtained for the compartments with wider diameter trees.

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The aim of the work was to evaluate the productivity, leaf nutrient content and soil nutrient concentration in maize (Zea mays L.) grown in sequence with black oats (Avena strigosa Schreb.) under Leucaena diversifolia alley cropping agroforestry system (AFS) and traditional management system/sole crop (without trees-TS), after two years of cultivation following a randomized block design. The experiment was carried out in the Brazilian Association of Biodynamic Agriculture, in Botucatu—S?o Paulo, Brazil. Treatments were: control (C), chemical fertilizer application (F), biomass of L. diversifolia alley cropping application (B), biomass of L. diversifolia alley cropping + chemical fertilizer application (B + F). In the second year of management it was observed that black oat yield was higher in treatments B + F and F with significant difference in relation to the others treatments in both systems, followed by treatment B. Between systems, only treatment B showed significant difference, with higher yield value corresponding to AFS, reflecting the efficiency of AFS to promote soil fertility. Maize production presented the second year of cultivation an increasing trend in all treatments in both production systems. This result may be due to the cumulative effect of mineralization and maize straw and oats, along the experiment. How productivity was higher in the AFS system, could also be occurring effect of biological nitrogen fixation, water retention and reduction of extreme microclimate through the rows of L. diversifolia. Comparing the AFS and TS, it was observed that the concentration of N in leaf tissue was higher in the AFS treatments, probably due to nitrogen fixation performed through the rows of L. diversifolia, that is a nitrogen fixing tree species. After two years, carbon stocked in soil show higher values in the treatments biomass + fertilizer and biomass application, in both systems, AFS and TS.

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The United States National Ice Center (NIC) provides weekly ice analyses of the Arctic and Antarctic using information from ice reconnaissance, ship reports and high-resolution satellite imagery. In cloud-covered areas and regions lacking imagery, the higher-resolution sources are augmented by ice concentrations derived from Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave/Imager (SSMII) passive-microwave imagery. However, the SSMII-derived ice concentrations are limited by low resolution and uncertainties in thin-ice regions. Ongoing research at NIC is attempting to improve the utility of these SSMII products for operational sea-ice analyses. The refinements of operational algorithms may also aid future scientific studies. Here we discuss an evaluation of the standard operational ice-concentration algorithm, Cal/Val, with a possible alternative, a modified NASA Team algorithm. The modified algorithm compares favorably with CallVal and is a substantial improvement over the standard NASA Team algorithm in thin-ice regions that are of particular interest to operational activities.

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We present the results of an operational use of experimentally measured optical tomograms to determine state characteristics (purity) avoiding any reconstruction of quasiprobabilities. We also develop a natural way how to estimate the errors (including both statistical and systematic ones) by an analysis of the experimental data themselves. Precision of the experiment can be increased by postselecting the data with minimal (systematic) errors. We demonstrate those techniques by considering coherent and photon-added coherent states measured via the time-domain improved homodyne detection. The operational use and precision of the data allowed us to check purity-dependent uncertainty relations and uncertainty relations for Shannon and Renyi entropies.

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Optimal conditions for the microwave-assisted enzymatic synthesis of biodiesel have been developed by a full 2(2) factorial design leading to a set of seven runs with different combinations of molar ratio and temperature. The main goal was to reduce the reaction time preliminarily established by a process of conventional heating. Reactions yielding biodiesel, in which beef tallow and ethanol used as raw materials were catalyzed by lipase from Burkholderia cepacia immobilized on silica-PVA and microwave irradiations within the range of 8-15 W were performed to reach the reaction temperature. Under optimized conditions (1:6 molar ratio of beef tallow to ethanol molar ratio at 50A degrees C) almost total conversion of the fatty acid presented in the original beef tallow was converted into ethyl esters in a reaction that required 8 h, i.e., a productivity of about 92 mg ethyl esters g(-1) h(-1). This represents an increase of sixfold for the process carried out under conventional heating. In general, the process promises low energy demand and higher biodiesel productivity. The microwave assistance speeds up the enzyme catalyzed reactions, decreases the destructive effects on the enzyme of the operational conditions such as, higher temperature, stability, and specificity to its substrate, and allows the entire reaction medium to be heated uniformly.

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The herbicides glyphosate and paraquat have been used by Brazilian soybean producers to obtain crop desiccation and to anticipate and uniformity at harvest. However, improper use of herbicides can to occasion problems in agronomic and physiologic characteristics of crop. This study aimed to evaluate the use of the glyphosate and paraquat herbicides as a desiccant for growing soybeans. The experiment was conducted in 2005/06 crop year, in an experimental design of randomized blocks with four replications. Treatments were arranged in two factorial design, 3x3x5x2 and 3x2x5x2: two desiccants (glyphosate and paraquat) and control (without drying), three and two growth stages (R6, R7 and R8) and (R7 and R8) for varieties MSOY 6101 of superprecocious cycle, and MG / BR 46 (Conquista) of precocious cycle, respectively, five sampling times (2, 4, 6, 8 and 10 days after application) and two positions in the plants on the ground assessment (apex and base). Was evaluated for seed Production, mass and water content of 100 seeds. Desiccants tested were effective in reducing the water content of seeds, without affecting productivity and mass of 100 seeds.

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Background. Nuclear factor kappa B (NF kappa B) plays a potential role in tolerance by orchestrating onset and resolution of inflammation and regulatory T cell differentiation through subunit c-Rel. We characterized cellular infiltrates and expression of NF kappa B1, c-Rel and its upstream regulators phosphatidylinositol 3-kinase/RAC-alpha serine/threonine kinase, in allograft biopsies from patients with spontaneous clinical operational tolerance (COT). Methods. Paraffin-fixed kidney allograft biopsies from 40 patients with COT (n=4), interstitial rejection (IR; n=12), borderline changes (BC; n=12), and long-term allograft function without rejection (NR; n=12) were used in the study. Cellular infiltrates and immunohistochemical expression of key proteins of the NF kappa B pathway were evaluated in the cortical tubulointerstitium and in cellular infiltrates using digital image analysis software. Results were given as mean +/- SEM. Results. Biopsies from patients with COT exhibited a comparable amount of cellular infiltrate to IR, BC, and NR (COT, 191 +/- 81; IR, 291 +/- 62; BC, 178 +/- 45; and NR, 210 +/- 42 cells/mm(2)) but a significantly higher proportion of forkhead box P3-positive cells (COT, 11%+/- 1.7%; IR, 3.5%+/- 0.70%; BC, 3.4%+/- 0.57%; and NR, 3.7%+/- 0.78% of infiltrating cells; P=0.02). c-Rel expression in cellular infiltrates was significantly elevated in IR, BC, and NR when analyzing the number of positive cells per mm(2) (P=0.02) and positive cells per infiltrating cells (P=0.04). In contrast, tubular PI3K and c-Rel expression were significantly higher in IR and BC but not in NR compared with COT (P=0.03 and P=0.006, respectively). With RAC-alpha serine-threonine kinase, similar tendencies were observed (P=0.2). Conclusions. Allografts from COT patients show significant cellular infiltrates but a distinct expression of proteins involved in the NF kappa B pathway and a higher proportion of forkhead box P3-positive cells.