969 resultados para Superficial opening


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Forest roads are frequently pointed as source of environmental problems related to erosion and they also influence harvest cost due to maintenance operations. Roads not well designed are sources of hydrological problems on catchments and the current attention to sustainability of forest exploration projects point out to the need of diagnostics tools for guiding the redesign of the road system. At this study, runoff hydrological indicators for forest road segments were assessed in order to identify critical points of erosion and water concentration on soils. A road network of a forest production area was divided into 252 road segments that were used as observations of four variables: mean terrain slope, main segment slope, LS factor and topographic index. The data analysis was based on descriptive statistics for outliers' identification, principal component analysis and for variability study between variables and between observations, and cluster analysis for similar segments groups' identification. The results allowed classifying roads segments into five mains road types: road on the ridge, on the valley, on the slopes, on the slopes but in a contour line and on the steepest slope. The indicators were able to highlight the most critical segments that differ of others and are potential sources of erosion and water accumulation problems on forest roads. The principal component analysis showed two main variability sources related to terrain topographic characteristics and also road design, showing that indicators represent well those elements. The methodology seems to be appropriated for identification of critical road segments that need to be redesigned and also for road network planning at new forest exploration projects.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this experiment, 18 hybrid steers, from the ages between 16 and 20 months, were submitted to the removal of the penis apical ligament to provoke a penis deviation. After passed 30 days, to be tested, the animals were put together to the females that were in heat. It was verified the formation of the ventral and right lateral penis deviation with incapacity of the copula. The bovines were submitted to the autologous implant from the one following superficial portion tendon from the superficial flexor fingers muscle, on the top of albuginea tunic, replacing the apical penis ligament removed. The material implanted was well tolerated, appearance a few inflammatory cells and formation of the fibrous conjunctive tissue, causing resistant adherence and capacity of sustaining the free penis extremity. The bovines, when were among the females that were in heat, did not show a penis deviation nor sexual behavior modification. The method revealed itself satisfactory and it can be indicated to correct ventral and right lateral penis deviation in bovines.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Includes bibliography

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Incluye Bibliografía

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Spanish, french and portuguese versions available

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Forecast of biological consequences of climate changes depend on both long-term observations and the establishment of carbon budgets within pelagic ecosystems, including the assessment of biomasses and activities of all players in the global carbon cycle. Approximately 25% of oceanic primary happen over continental shelves, so these are important sites for studies of global carbon dynamics. The Brazilian Continental Shelf (BCS) has sparse and non-systematic in situ information on phytoplankton biomass, making products derived from ocean color remote sensing extremely valuable. This work analyzes chlorophyll concentration (Chl) estimated from four ocean color sensors (CZCS, OCTS, SeaWiFS and MODIS) over the BCS, to compare Chl and annual cycles meridionally. Also, useful complementary ocean color variables are presented. Chl gradients increased from the central region towards north and south, limited by estuarine plumes of Amazon and La Plata rivers, and clear annual Chl cycles appear in most areas. In southern and central areas, annual cycles show strong seasonal variability while interannual and long-term variability are equally important in the remaining areas. This is the first comparative evaluation of the Chl over the BCS and will aid the understanding of its long-term variability; essential initial step for discussions of climate changes.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Includes Bibliography

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This study was carried out to evaluate the effects of surface application of lime rates on soil chemical attributes and soybean yield in a no-tillage system. It was installed a field experiment in a factorial 2×4, and the factors were: two types of lime (calcitic and dolomitic); four rates (0.0 - 0.5 - 1.0 and 1.5 t ha-1 of CaCO3), in a completely randomized blocks experimental design, with four replications. The experiment was located in Matupá, Mato Grosso State, Brazil, being the work developed between November 2006 and May 2007. The evaluations were chemical attributes in the soil layers (0,0-2,5 cm, 2,5-5,0 cm and 5,0-10,0 cm), and the productive characteristics of soybean. Application of lime increased the soil pH (CaCl 2), the exchangeable Ca and Mg, the effective CEC and the base saturation only in the soil surface layer. The two limes were different only for Ca and Mg values in the first layer of soil, and only for the Mg values in the layer of 2,5-5,0 cm. The surface liming in no-tillage system did not change soybean yield.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Includes bibliography