533 resultados para Determinação de matéria inorgânica


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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The radiation budget in agricultural crops is very important on the microclimate characterization, on the water losses determination and on dry matter accumulation of vegetation. This work describes the radiation budget determination in a green beans crop (Phaseolus vulgaris L.), in Botucatu, SP, Brazil (22° 54′S; 48° 27′W; 850 m), under two different conditions: the normal field culture and in a polyethylene greenhouse. The densities of fluxes of radiation were used to construct diurnal curves of the components of global radiation (Rg), reflected radiation (Rr), net radiation (Rn).The arithmetic's relations allowed to obtain the components net short-waves (Rc) and net long-waves (Rl). The analysis of these components related to the leaf area index (LAI) in many phenological phases of the culture showed Rg distributed in 68%, 85%, 17% and 66%, 76%, 10% to Rn, Rc and Rl in the internal and external ambients in a polyethylene greenhouse, respectively.

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The nylon bag in situ degradation thecnique was employed to compare the data of the CNCPS to the ruminal degradability of the dry matter and crude protein in corn silage, soybean meal and sorghum grain, in four rumen fistulated Nellore steers, averaging 36 months of age and 520 kg of liveweight. A randomized complete block experimental design was used, where animals constituted the blocks. Two levels of concentrate, 18 and 39 %, were used in the diets. The forage used in the diets was corn silage and the concentrate ingredients were: soybean meal, cottonseed meal, corn grain and sorghum grain. There was a reduction in the potentially by degradable fraction (B) of the dry matter(DM) of the corn silage and sorghum grain with an increase in the concentrate level of the diet; however, the degradation rate(c) of the silage was similar for the two diets and the sorghum grain showed an increase of 28.4 %. The B fraction of the DM from the soybean meal was not affected by the diet, but its rate (c) was reduced by 18.1 %. The same effect was observed for the rate(c) of crude protein(CP) of the soybean meal, with a reduction of 38.1 %. The values for the effective degradability of the two fractions were not affected by the diet when the lag time was not considered. When lag time was considered, the degradability values of the studied feeds were superior in both fractions.

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The effect of Mg levels in nutrient solution upon root, stem, leaf, fruit and total dry matter production of common bean (Phaseolus vulgaris L. cv. Carioca) was studied. Bean plants were grown in Hoagland & Arnon n. 2 solution modified to obtain 2.4, 24.3, 48.6, 72.9 and 97.2 ppm of Mg. The experimental design was a split-plot factorial replicated three times with five Mg levels and five samplings which were done fortnightly. Results were compared with those observed in plants submitted to a nutrient solution with 48.6 ppm of Mg concentration, considered the ideal Mg content. Only a mild prejudicial effect was observed with Mg excessive levels. Stem, leaves and total dry matter were higher when 2.4 ppm were used, suggesting this level as the concentration chosen for the culture of common bean.

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An equation based on heat transfer theory was presented to estimate the rate of heat loss from cattle exposed to a tropical environment, specified by the air temperature, humidity, solar radiation, and wind speed. The animals' variables (sweating rate, rectal temperature, respiratory rate, surface temperature, haircoat color, and body weight) were considered together with environmental variables (air temperature and humidity, solar radiation, wind speed, and globe temperature). The equation allows the prediction of (a) the metabolic heat production level necessary to balance heat losses under specified environmental conditions; (b) the combination of environmental factors that provide a determined heat flux between a given animal and its environment.

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Seeds of Astronium fraxinifolium (Anarcadiaceae) were collected in two years, and submitted to tests of seed germination and vigour (first count, aging and electric conductivity), in order to verify the potencial of conservation and if variations in the seed quality presented on association with genetic parameters. Coefficient of heritability in average (ĥm 2) were 0.91 and 0.97 to germination; 0.90 and 0.96 to first count; 0.93 and 0.97 to aging and 0.95 and 0.99 to electric conductivity, for seeds collected in 1997 and 1998, respectively, evidencing a great heritability to all studied characteristics. Genetic variability was influenced more by environmental conditions of blooming and harvest of seeds than storage time.

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Staphylococcus aureus is a very important hospital and community pathogen. This species is related to supurative disease, systemic and widespread metastatic lesions. The ability of S. aureus to develop resistance to antibiotics, more recently to methicillin, associates this bacteria with epidemic outbreaks of severe nosocomial infection. The source of staphylococcal infection is a patient with a staphylococcal lesion or a career member of the hospital staff. We aimed to detect the frequency of S. aureus isolated from anterior nares and oral cavities among the hospital staff in Bauru - SP, and to determine the antibiotic susceptibility of the isolates. Within 213 of the staff members analyzed. S. aureus was found in 94 (44.13%) of careers, with 47 (50%) of nasal carriers, 23 (24.4%) of oral carriers and 24 (25.5%) of both carriers. The biochemical characteristics analyzed for the species identification were similar to S. aureus ATCC 29213. All strains identified as S. aureus showed varied sensibility to the antimicrobial agents tested. No vancomicin resistant strains and only 8 (8.5%) strains with oxacilin resistance were found.

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In this work was developed an alternative methodology to separation of aquatic organic matter (AOM) present in natural river waters. The process is based in temperature decreasing of the aqueous sample under controlled conditions that provoke the freezing of the sample and separation of the dark extract, not frozen and rich in organic matter. The results showed that speed of temperature decreasing exerts strongly influence in relative recovery of organic carbon, enrichment and time separation of the organic matter present in water samples. Elemental composition, infrared spectra and thermal analysis results showed that the alternative methodology is less aggressive possible in the attempt of maintaining the integrity of the sample.

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This paper supplies a revision about the main techniques of extraction, clean-up and pre-concentration of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) in water and soil samples, as well as chromatographic methods and immune assays for its identification and quantification.

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Maytenus ilicifolia and Maytenus aquifolia (Celastraceae) both designated espinheira-santa have proven anti-ulcer activity. Morphologic similarities between leaves of espinheira-santa and mata-olho (Sorocea bonplandii), has motivated fakes in the market of phytotherapy. The present work consisted of the anatomical study, including stem and leaf, of the species M. ilicifolia, M. aquifolia and S. bomplandii. Samples of adult leaves and stem of plants located in the cities of Maringá and Marialva were collected. Both are located in the northwest region of Paraná State. The botanical material was prepared with using usual techniques of anatomy. The leaves of both Maytenus species presented great similarities, characterizing itself for the presence of epidermal cells with straight walls, biseriate palisade tissue, petiole vascular system represented by unique amphicribal bundle and sclereids, which were present in the stems of these two species. S. bomplandii leaves differed of Maytenus species for presenting epidermal cells with undulated walls, uniserite palisade tissue, petiole vascular system represented by many collateral bundles and gelatinous fibres. Non-glandular trichomes, glandular trichomes, and laticifer only occur in S. bomplandii.

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E grandis seedlings of Bofete progeny, cultivated in nurseries of Eucatex Florestal, were collected at ages of 55, 69, 83, and 97 days, separated into leaves, stem, and roots. The seedlings were then placed in identified paper bags, and oven-dried until weight became constant. They were then weighed and chemically analyzed for the determinate of dry matter production, concentrations and accumulation of N, P, K, Ca, Mg, S, B, Cu, Fe, Mn, and Zn in the several seedling ages. The distribution of total dry matter weight complied with the following descending order: leaf > stem > roots. Conversely to expectations, the highest concentrations of nutrients occurred in leaves for N and Mn only. Seedling hardened process resulted in N and S deficiency. The sequence of macronutrient concentration in seedlings at the time of shipment was the following: leaf > root > stem for N; root = stem > leaf for P; leaf = root = stem for K; stem > root > leaf for Ca; root > leaf > stem for Mg and S. All macronutrient concentrations in organs decreased with age, except for Ca. Concentrations of Cu, Fe, and Zn in all seedling specimens decreased with age. The sequence of micronutrient concentrations in seedling specimens at the time of shipment was the following: root >stem = leaf for B; root > stem > leaf for Cu and Fe; root > leaf > stem for Zn, and leaf > stem > root for Mn. At the time of shipment, at 97 days of age, K was the most extracted macronutrient of all, followed in a descending order by Ca, N, Mg, P, and e S. At the end of the seedling production rotation, Mn was the most extracted micronutrient, followed by Fe, Zn, Cu, and B.

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The instrumentation applied to the Charpy test machine allows the accompaniment of the specimen answer front the impact load, in form of a sign characteristically dynamic representative of the deformation process and it fractures of material tested. The main advantages of the rehearsal conventional Charpy: low cost, manufacturing sample facilities and simple handle the machine. With the instrumentation, the number of information regarding the process of fracture of the specimen increases. In this work discusses the influence of the hammer geometry in determination of the force during the process of specimen fracture submitted to the instrumented impact test Charpy-V. The purpose is obtaining a hammer, in conformity with Norma ISO 14.556, with great sensibility to register the force during the impact. Two geometries different from hammers were instrumented and rehearsed with material of low tenacity, in this case the steel ABNT 4140 in the condition of having normalized. It could be proven as larger the sensibility of the hammer, adult will be the effects of the shock waves in the strain gages of the transducer.

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Soils submitted to the same management system in places with small relief variation manifest different spatial variability on their attributes. The objective of this work was to evaluate the spatial variability of the geometric medium diameter, aggregates in the >2 mm class, aggregates in the 2-1 mm class and organic matter of an Oxisol under culture of the sugarcane. Samplings of the soil in regular intervals of 10 m, in grid form, totaling 100 points, collected in the depths of 0.0-0.2 m and 0.2-0.4 m were made. Data were submitted to descriptive statistics, geostatistics and in sequence to kriging analyzes. Values of the variation coefficient were low for organic matter in the depth of 0.0-0.2 m, mean in the depth of 0.2-0.4 m, high for geometric medium diameter and mean for aggregates in the >2 mm class, aggregates in the 2-1 mm class in all studied depths. The occurrence of space dependence was observed for all the variables, and the largest ones were observed in the depth of 0.0-0.2 m. Small variations in the forms of the relief condition spatial variability differentiated for organic matter and stability of aggregates in the studied depths.

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The objective of this work was to compare the results of measuring the specific gravity (SG) of laying hen eggs by using a weighing apparatus and the saline flotation method (SFM). Two hundred eggs from two genetic lines were distributed randomly into two groups of 50 eggs per genetic line and were submitted to two different sequences of SG measurement. Not significant differences were found between the two methods. The weighing apparatus measured the SG of the eggs accurately as the SFM.