Anatomia quantitativa da folha e do colmo de Brachiaria brizantha (Hochst. ex A. Rich.) Stapf e B. humidicola (Rendle) Schweick

As características da digestão das forragens podem ser mais bem compreendidas quando complementadas com estudos de anatomia dos tecidos de plantas forrageiras. Com o objetivo de agregar novas informações ao tema, determinou-se a área dos diversos tecidos presentes na folha e no colmo de Brachiaria brizantha e B. humidicola, em três diferentes níveis de inserção no perfilho. O experimento foi conduzido em casa de vegetação, com plantas mantidas em vasos plásticos contendo areia esterilizada e recebendo solução nutritiva de macro e micronutrientes. Após 70 dias do corte de uniformização das parcelas (vasos), coletou-se o segmento do colmo e da folha (limbo e bainha) situado na porção mediana de cada um dos três diferentes níveis de inserção do perfilho estudado. As amostras foram emblocadas em GMA, seccionadas em micrótomo e o laminário fotomicrografado. As fotografias foram digitalizadas e as áreas de tecidos, mensuradas com software Image Tool. Observou-se que o limbo das folhas basilares apresentou menor área de tecido vascular lignificado. Maior área de tecido parenquimático foi observada na bainha e no colmo da B. brizantha. em relação à B. humidicola, a B. brizantha apresentou maior área de tecido vascular lignificado no limbo, bainha e colmo. Maior distância entre os feixes vasculares foi observada no limbo e na bainha, sendo o número de feixes maior no limbo e no colmo.

Cinética da remoção dos extrativos da madeira de Eucalyptus grandis durante polpação Kraft

Kinetics of the removal of Eucalyptus grandis wood extractives during Kraft pulping. The objective of this work was to study the kinetics of the removal of Eucalyptus grandis wood extractives during Kraft pulping. The pulping was done in steel tubular reactors using wood saw under the following conditions: active alkali = 14%, sulfidity = 25%; liquor-to-wood ratio = 10 L kg(-1) of dry wood; and temperatures of 130, 150, 160 and 180 C during 30, 60, 90, 120, 150 and 180 minutes. After pulping, analyses were conducted of the yield and extractives in residue (pulp and reject). Total extractives (ethyl alcohol-toluene (1:2), ethyl alcohol and hot water, respectively) and soluble extractives in acetone were analyzed. The results showed that most extractives are degraded in the first 30 minutes of the pulping process. It was observed that the removal occurs in two different stages: the first is rapid, where the majority of the extractives are removed, and the last is slow, where few extractives are removed.

Variação da massa específica da madeira de Eucalyptus grandis aos 8 anos de idade em função de diferentes níveis de produtividade

It were analyzed Eucalyptus grandis trees of 8 years old in the forest group of Duraflora S/A, with different annual increments based on volume, to the related studies of specific gravity values based on productivity indexes. The methodology used in analysis of specific gravity was the gamma-ray attenuation technique of Americium-241. The Eucalyptus grandis showed a specific gravity decreasing with the increasing of parcel productivity. For a gain of 3,5 m3 in productivity there was a decreasing of 1% in specific gravity. Nevertheless, it was not observed correlation between specific gravity and basal area in a same parcel. The present work stands out too, some of the difficulties found with relation to wood specific gravity determinations and emphasize the importance of take samples in the form of full rounded plates in three or four relative positions in the tree.

Geogenic factors affecting the selenium(IV) distribution in sediments from Madeira River Basin, Brazil

This investigation was carried out at the Madeira River basin, located in the state of Rondônia, Brazilian Amazon. Sediments from Madeira River between Teotônio and Santo Antônio waterfalls along 25 km upstream from Porto Velho, the capital of Rondônia state, and from nine lakes located around Porto Velho municipality were chemically analyzed for Se (IV) in order to evaluate the main factors affecting the Se(IV) distribution in the environment, Selenite ion was chosen to investigate the selenium behavior in the area, because acid conditions are dominant there. The importance of clays, iron oxides, organic matter and minor refractory minerals was considered in order to explain most of the obtained data.

Propriedades de contração na madeira juvenil e adulta de Pinus taeda L.

This paper had the objective of studying variability of radial, tangential, longitudinal and volumetric shrinkage between the juvenile and mature wood, from a 35 year-old Pinus taeda L., from Horto Florestal of Manduri at São Paulo State, Brazil. First of all the experimental program determinations were related to the juvenile wood, region of the transition and region of the mature wood, using anatomical analysis (length of the axial tracheids), according to ABNT and IAWA codes. Results had shown that the area of juvenile wood of this species occurs approximately until the 20th growth ring, being more representative until the 12th ring. The transition area of this wood occurs between the 12th and 20th growth ring. In the second part of the work the shrinkage of the juvenile and mature wood were evaluated. Values of the radial, tangential and volumetric shrinkage were smaller and more variable on the juvenile wood. The longitudinal shrinkage did not present significant differences between the two wood types; medium values were slightly inferior and very variable on juvenile wood related to mature wood.

Retratibilidade da madeira de Pinus caribæa var. hondurensis e de Eucalyptus grandis e suas relações com a umidade e densidade

It had been studied the dimensional variations Pinus caribæa var. hondurensis and Eucalyptus grandiswood, emphasizing the axial, radial, tangential and volumetric shrinkage. The results had shown that the volumetric shrinkage of Pinus and Eucalyptus varied according to an exponential curve, R V=R Vmaxe -ku. The total or maximum volumetric shrinkage showed a linear behavior with the specific gravity on basis of ovendry mass and volume and the same behavior as respect of the specific gravity, where the adjusted equations were, respectively: R vmax = 3,01 + 19,15,oo e R vmax = 1,96 + 24,28,ob. It was also verified that the tangential shrinkage was 1,3 times greater than the radial one and 9,0 times greater than the axial one.

Anatomia foliar com ênfase nos tricomas secretores e análise cromatográfica do óleo essencial de Melissa officinalis L. (Lamiaceae)

Adult leaves of Melissa officinalis L. (Lamiaceae) harvested during the time of budding had been used in the study of the leaf anatomy in the identification of the secretory structures. The material was fixed in FAA 50%, dehydrated in alcoholic series (ethyl), infiltrated in paraffin, sectioned at 13 mm, staining and later analyzed through optic microscopy. Also it was carried through a study in gaseous chromatography for attainment of the rude essential oil. Analyses of transversal sections of the leaf of Melissa officinalis, has identified the presence of two types of trichomes secretory: peltate and capitate, beyond the presence of trichome tector. Trichome capitate, identified in literature as (type I), presents variations in its morphology in relation to the cells number stalk and the head secretory cells number. The chromatographic analysis of the essential oil identified the presence of monoterpenes, in two major components, responsible for more than 87.8% of the relative composition in the rude oil, beyond sesquiterpenes in smaller proportions.

Parâmetros genéticos para caracteres de crescimento, de produção e tecnológicos da madeira em clones de Eucalyptus spp

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Mensuração do comprimento das fibras para a determinação da madeira juvenil em Eucalyptus citriodora

The juvenile wood has peculiar characteristics from the anatomical structure and physical-mechanical properties, considering these aspects the knowledge of the wood is essential for wood adequate utilization. The aim of this work was to determinate the zone of juvenile wood of pith-bark direction in Eucalyptus citriodora. The juvenile and mature wood zones were determined across fiber length measurement in various height in the tree stem. Results showed that juvenile wood zone occurs approximately up to the 45 at 55 mm from the pith.

Anatomia do músculo abdutor crural caudal do gato doméstico (Felis catus domesticus, Linnaeus 1758)

The frequency and the morphology of the abductor cruris caudalis muscle were studied in 58 adult unknown breed cats. The sample included 36 females and 22 males. After the dissection, were found a frequency for the presence of the same muscle of 98.3%. The abductor cruris caudalis muscle appears symmetrically in 35 females (97.2%) and 22 males (100.0%). When present, it were originated on the transversal process of the 1st vertebrae caudales, in the glutea region, below the gluteus superficialis muscle, throughing almost all the thigh under biceps femoris muscle, where it make a parallel relation with the sciatic nerve, receiving nervous ramifications of the same in 78.3% of the cases. The medium found for the width and thickness of his muscle venter was respectively of 2.03 mm and 0.35 mm. Its insertion occurs on the biceps femoris muscles approximate to the fascia cruris, where both finish fusing theirselves.