Ildeu Soares Martins

Custo de produção das biomassas de eucalipto e capim-elefante para energia

Nesse estudo, objetivou-se estabelecer o custo de producao da unidade energetica gerada pela biomassa do eucalipto (Eucalyptus sp.), em diferentes tratamentos silviculturais, e pela biomassa do capim-elefante (Pennisetum sp.), e aplicar uma analise de sensibilidade para verificar as influencias de fatores como o tratamento silvicultural do eucalipto, a producao volumetrica de cada especie, o custo da terra e a taxa de juros nos custos de producao analisados. Foi demonstrado que o tratamento do eucalipto em plantio adensado e em curtissima rotacao de dois anos, com reforma do povoamento a cada seis anos, teve um custo medio de producao (CMPr) superior ao sistema convencional com rotacao a cada seis anos e reforma aos 18. Observou-se, tambem, que o eucalipto apresenta, em media, um CMPr de R

Avaliação da produtividade, conteúdo e eficiência de utilização de nutrientes em genótipos de Eucalyptus spp. no vale do Jequitinhonha, MG.

4,41/Gj, inferior ao do capim-elefante, que, em media, e de R

Avaliação do nível de ruído em marcenarias no Distrito Federal, Brasil

5,44/Gj, mesmo com a capacidade que o ultimo tem de producao anual superior de materia seca. O capim-elefante tem a possibilidade de competir com o eucalipto quando um conjunto de condicoes se forma como taxa de juros igual ou superior a 8% a.a., preco da terra elevado e volume do capim-elefante igual ou acima de 35 toneladas de materia seca por hectare por ano.

Avaliação da morfologia interna de sementes de Terminalia argentea (Combretaceae) pelo teste de raios X

The hybridization of eucalyptus species can provide more productive hybrids and with a high efficiency of nutrient absorption and, or, nutrient use, depending on the combined species. In this context, the present work was undertaken in the Jequitinhonha Valley region, Minas Gerais, and its objectives were: to determine the productivity, content and use efficiency of N, P, K, Ca and Mg in interspecific hybrids of Eucalyptus spp. In each plot, the diameters were measured at breast height (DBH) in all the trees, and three trees with diameter similar to the average mean were felled. The volume of the trees was estimated by the Smallian method, using the height, diameter and the bark thickness at the base and at 25, 50, 75 and 100 % of the commercial height. The fresh weight of the wood, bark, leaves and branches was determined in the field, and samples from them were collected for the determination of dry matter. The log samples consisted of collected disks with bark, from the base and at 25, 50, 75 and 100 % of the commercial height. The samples of vegetable tissues were analyzed for: N, P, K, Ca and Mg. The results obtained did not show significant differences for the production of crown biomass between the eucalyptus hybrids of the same age. However, the production of log biomass presented significant differences and the naturally pollinated hybrids of Eucalyptus urophylla were 50.0 % and 69.0 % more productive compared with the hybrids of Eucalyptus urophylla with Eucalyptus grandis and Eucalyptus urophylla with descendants of the crossing of Eucalyptus camaldulensis with Eucalyptus grandis , respectively. Also, these hybrids allocated larger amount of biomass in the log (92.3 %) in relation to the crown (7.7 %), and they were more efficient in the absorption and use of N, P, K, Ca and Mg. The conclusions were that: 1) same aged hybrids of Eucalyptus urophylla from natural or controlled pollinations did not differ in their crown biomass; 2) log biomass was reduced in the hybrids from controlled pollination between Eucalyptus urophylla with Eucalyptus grandis and Eucalyptus urophylla with descendants of the crossing of Eucalyptus camaldulensis with Eucalyptus grandis ; 3) hybrids of Eucalyptus urophylla from natural pollination were more productive and more efficient in the absorption and efficiency of use of N, P, K, Ca and Mg and 4) hybrids of Eucalyptus urophylla with descendants of the crossing of Eucalyptus camaldulensis with Eucalyptus grandis are less productive and less efficient in the absorption and use of N, P, K, Ca and Mg.

Electrical Conductivity Testing as Applied to the Assessment of Freshly Collected Kielmeyera coriacea Mart. Seeds

This research was carried out in a carpentry in the Federal District, Brazil, with the objective to evaluate and to compare the noise level emitted by the machines used in the manufacture of furniture in four establishments. The evaluation was made with the one noise level measured and it was located as to ear of the worker while operating the machine as per NR15 norm. Six machines were evaluated. The statistical analysis was done using factorial design and mean test. The results indicated significant differences at 5% probability level among machines in the four companies. The mean noise level was of 92,16 dB(A). The highest value was found in the buzz saw in company 4 (101 dB(A)). The horizontal wimble was the only machine in all the companies that fitted with in the limits allowed in the NR15 norm (85 dB(A)) for a daily working of 8 hours. The other machines presented problems related to the noise emission.

Avaliação do Potencial Energético de Bambusa vulgaris em Função da Idade

Forest species, especially those from the Cerrado, are characterised by a high incidence of predation, empty fruit and deficiency in embryo formation. The objective of the present work was to evaluate the internal morphology of seeds of Terminalia argentea Mart. et Zucc. by X-ray testing, and to verify its relationship to germination. The experiment was conducted at the Laboratory for Image Analysis of the Department for Plant Production, at the Escola Superior Luis de Queiroz, in the city of Piracicaba, in the state of Sao Paulo, Brazil. Three batches of seeds of T. argentea were collected and taken to the laboratory, where radiographic analysis of 200 seeds from each lot was carried out. The seeds were placed 28.0 cm from the source of the X-ray emissions, digital equipment from Faxitron X-ray, model MX-20 DC 12. The seeds were then classified according to their internal morphology as seen in the radiographs, with three categories being established: full, empty and misshapen seeds. Germination tests were performed for each category of seed. The statistical design employed was a factorial scheme of three groups and three categories. From the results obtained in this work, use of X-ray testing of seeds of Terminalia argentea is promising for the detection of the fruit quality of the seed lots, aiding in the separation of empty seeds and those with embryonic abnormalities, and precluding their storage or immediate use. X-ray testing at an intensity of 26 kV for 1.2 seconds was effective in assessing the internal morphology of seeds of Terminalia argentea.

ALTERNATIVAS DE ÍNDICES DE SELEÇÃO EM UMA POPULAÇÃO DE Eucalyptus grandis Hill ex Maiden

Assessment of seed vigor has long been an important tool of seed quality control programs. The conductivity test is a promising method for assessment of seed vigor, but proper protocols for its execution have yet to be established. The objective of this study was to assess the efficiency of electrical conductivity (EC) testing as a means of assessing the viability of freshly collected Kielmeyera Coriacea Mart. seeds. The test was performed on individual seeds rather than in a bulk configuration. Seeds were soaked for different periods (30 min, 90 min, 120 min., 180 min, and 240 min) at a constant temperature of 25°C. Conductivity was then measured with a benchtop EC meter.

Comparação entre os processos de seleção entre e dentro e o de seleção combinada, em progênies de Eucalytpus grandis

This study aimed to perform an energy evaluation of Bambusa vulgaris ex JC Wendl. var. vulgaris for ages 1, 2 and 3 years old. Samples from the positions along the stem (base, middle and top) were collected in commercial plantation, managed for energy production. The content of volatile material, ash and fixed carbon, high heat combustion, basic density and energy density, content of extract, holocelulose and the total lignin of B. vulgaris were determined. The results indicate that the age of 1 to 3 years old showed increased ash content, basic density and energy density, reduction of volatile material, fixed carbon content and heat combustion. And also indicate increased ash content, basic density and energy density; decreased volatile material, fixed carbon content and heat combustion from base to top. Considering the energy density as the best, we can say that the quality of Bambusa vulgaris biomass as energy input improves with increasing age and the upper portions of the stemsproduce more energy per unit volume.