887 resultados para timber sleepers
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Pós-graduação em Engenharia Mecânica - FEG
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This study aimed to investigate physical performance of particleboards produced with waste from sawmills, containing different wood species, and two adhesives: urea-formaldehyde (UF) based resin and castor-oil (PU) based bi-component polyurethane resin. Panels were produced with nominal density 0.8gcm(-3); pressing temperature 110 degrees C; pressing time 10 min; specific pressure 5 MPa. Water absorption (2 and 24h); thickness swelling (2 and 24h); density; and moisture content were investigated. Results confirmed that the produced panels presented compatible physical properties in comparison with other researches referred in literature, proving the feasibility of inputs employed. Panels produced PU showed better performance than those produced with UF.
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The wood of Eucalyptus tereticornis is intensively used for timber, structures, buildings, poles, posts and coal. The aim of this study was to estimate genetic parameters and genetic and phenotypic correlations in growth and stem form traits of 52 open-pollinated progenies of E. tereticornis sampled from three Australian populations (20 progenies from Helenvale, 19 from Ravenshoe and 13 from Mt. Garnet). The progenies were compared with three commercial control also from Australian. The experimental design used was the compact family block, with the effect of provenance allocated in the plots and progenies within provenances in the subplots. Ten repetitions of the 52 treatments, sub-plots with six plants and the spacing of 3 x 2 m was used. At 25 years of age it was measured the diameter at breast height (DBH), total height, true volume and the stem form. We found genetic variation amon and within the three provenances and the possibility of obtaining high gains from mass selection and individual among and within progenies. The provenance Helenvale showed the best development for DBH, height and volume. The traits DBH, height and volume showed high genetic correlations (> 0.9), indicating the possibility to use the indirect selection. The coefficient of heritability on a progeny mean for the traits DBH and height was median, being 0.31 and 0.30, respectively. The expected genetic gain with the selection were estimated at 12.4% for DBH and 8.5 % for plant height. These results will subsidize the transformation of the provenance and progeny test in a seedling seed orchard and a clonal seed orchard.
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To design connections between timber parts with metal dowels (nails or bolts), two phenomena must be considered: bending of the metal dowel and the embedment strength in the wood. The Brazilian Standard ABNT NBR 7190:1997 proposes the methods used in the laboratory tests to determine the embedment strength with the metal dowell and, in the absence of testing, specifies relations to calculate the embedment strength from the compression strength. The aim of this research was to compare the embedment strength values obtained by experimental tests and calculated by the relationships established by the Brazilian Standard ABNT NBR 7190:1997. By the results of the hypothesis tests, it was possible to conclude that the estimate of the embedment strength parallel to the grain proposed by the Brazilian standard ABNT NBR 7190:1997, establishing equivalence with the strength compression results in the same direction, must be effective to the wood species Pinus taeda L., however, the same was not found in the perpendicular direction with respect to the grain, possibly explained by the alpha(e) values in the equation to calculed fe(90)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Classificação de tábuas de madeira usando processamento de imagens digitais e aprendizado de máquina
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Pós-graduação em Agronomia (Energia na Agricultura) - FCA
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Pinus taeda is one of the main timber trees in Brazil, occupying 1.8 million ha with an annual productivity of 25-30 m(3) ha(-1). Another important species is Araucaria angustifolia, belonging to the fragile Rainforest biome, which for decades has been a major source of timber in Brazil. Some diseases that affect the roots and/or the stem of these trees and cause "damping-off" of the seedlings, with economic and environmental losses for the forest sector, are caused by the plant pathogenic fungi Fusarium sp. or Armillaria sp. This research project intended to isolate actinobacteria from the Araucaria rhizosphere, which present an antagonistic effect against these fungi. After the selection of the best pathogen inhibitors, morphologic characteristics, enzyme production, and their effect on the growth of Pinus taeda were studied. The actinobacteria were tested for their antagonistic capacity against Fusarium sp. in Petri plates with PDA as substrate. The inhibition zone was measured after 3, 5, 7, and 10 days. Of all the isolates tested, only two of them maintained inhibition zones up to 4 mm for 10 days. The inhibition of Armillaria sp. was tested in liquid medium and also in Petri dishes through the evaluation of the number of the fungal rhizomorphs in dual culture with the actinobacteria. It was found that all five isolates were able to inhibit the rhizomorph production, with the best performance of the isolate A43, which was capable of inhibiting both fungi, Fusarium and Armillaria. In a greenhouse experiment, the effect of five isolates on the growth of Pinus taeda seedlings was tested. Plant height, stem diameter, root and shoot dry matter were determined. The Streptomyces isolate A43 doubled plant growth. These results may lead to the development of new technologies in the identification of still unknown bacterial metabolites and new management techniques to control forest plant diseases.
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Small-scale farmers in the Brazilian Amazon collectively hold tenure over more than 12 million ha of permanent forest reserves, as required by the Forest Code. The trade-off between forest conservation and other land uses entails opportunity costs for them and for the country, which have not been sufficiently studied. We assessed the potential income generated by multiple use forest management for farmers and compared it to the income potentially derived from six other agricultural land uses. Income from the forest was from (i) logging, carried out by a logging company in partnership with farmers' associations; and (ii) harvesting the seeds of Carapa guianensis (local name andiroba) for the production of oil. We then compared the income generated by multiple-use forest management with the income from different types of agrarian systems. According to our calculations in this study, the mean annual economic benefits from multiple forest use are the same as the least productive agrarian system, but only 25% of the annual income generated by the most productive system. Although the income generated by logging may be considered low when calculated on an annual basis and compared to incomes generated by agriculture, the one-time payment after logging is significant (US$5,800 to US$33,508) and could be used to implement more intensive and productive cropping systems such as planting black pepper. The income from forest management could also be used to establish permanent fields in deforested areas for highly productive annual crops using conservation agriculture techniques. These techniques are alternatives to the traditional land use based on periodic clearing of the forest. Nevertheless, the shift in current practices towards adoption of more sustainable conservation agriculture techniques will also require the technical and legal support of the State to help small farmers apply these alternatives, which aim to integrate forest management in sustainable agricultural production systems.
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Transport is one the essential services for the development of most economic activities. In the forestry sector, the main transport used to carry wood from the forest to local consumption is road. The transport increases the producing costs of wood and may be responsible of a high percentage in the final price of the wood sold in the industry. To reduce the company’s costs and increase the efficiency of forest production those transport activities must be analyzed and improved. In that context, an economic analysis is the main objective of this work, evaluating three different types of log transport from a sawmill in São Paulo´s Southwest region. For this, a data collection was done to compound the costs and the incomes of timber transport, and that way, to do the economic analyses of each transport. The monitoring activities were done in the second 2013 half-year and the research achieved economic viability results utilizing tools and methods of Economic Engineering
Análise granulométrica do compósito cimentício produzido com adição de resíduos de madeira e escória
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Since the early twenty-first century, the construction sector has been the second largest on the rise in the Brazilian industrial sector, with a growth of 1.4% in 2012, and is likely to remain at this level for a long time. However, unlike decades ago, the industry has been seeking in its manufacturing process, sustainable materials, encompassing in their works the concept of sustainability. Thus, the timber sector seeks to satisfy a market increasingly demanding, innovating techniques and utilization being less aggressive to the environment. The purpose of this study was to produce and evaluate the mechanical strength of the composite cement with the addition of wood residues and slag low oven. Therefore, it was made 42 specimen cement-slag-wood, carried out in two steps. Since at the first, it was varied only the slag particle size, and at the second, through the best result of the previous step, it was varied the wood particles granulometry. The mechanical performance of the composite was evaluated by the results obtained in the compression test and the physical test for determining the density of the material. In the first step of the process can be concluded that the best result was achieved with the use of slag particles retained on the 60 mesh sieve. In the second phase of the study concluded that the best results were achieved with wood particles with the large particles, i.e. particles retained on the 10 mesh sieve. Both in the first and in the second step it can be seen that there has been the influence of the particle size of the waste materials. With the obtained results, could be evaluated that the use of waste for the production of cement-slag-wood composite showed lower performance when compared to the results obtained in studies without the use of waste. However, some applications are feasible to be performed with the use of composite wood-cement-slag
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Essential oils are products from plants and can be located in parts or in its entirety. There are several methods for its extraction, where the most suitable depends on the plant or the use of the essence. The main species cultivated in Brazil are the Corymbia citriodora, Eucalyptus globulus and Eucalyptus staigeriana. The Corymbia citriodora is a species that was introduced in Brazil along with other species, with the initial objective of timber production. The yield of oil can range from 0.5 % to 3.0% according to the literature and this can be optimized by reducing the moisture content of the leaves. Studies show that the lower water content in the leaves allows the vapor stream generated in the extractor can drag, more efficiently, the volatiles stored in the cells as compared with the green material. The drying of the sheets is important for companies, so that there is transport of water, increasing the volume of the sheets to distillation and hence a greater volume of oil. The objective of this study was to compare the drying methods, analyzing the income of the essence and determine the best method to optimize the yield of essential oil. Experimental tests were performed natural drying 10, 15 and 20 days and fluidized with times of 60, 90 and 120 minutes and after drying were extractions of the oil. The results obtained for fresh leave yield was 1.20 % and the drying time which showed the highest yield was 15 and 20 days with 2.90 % and 2.70 % yield, respectively, with the lowest level humidity of 16%. The yields obtained in fluidized bed drying did not change as the natural drying to between 1.64% and 1.7%. It is concluded that the decreased level of the sheets increases the yield of oil and the temperature in the fluidized bed is essential for the removal of water from the leaves necessary to increase the yield
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The manufacture of plywood panel already has about eighty years in Brazil. In general, plywood panels differ by their nature, composition and manufacturing; the most common MDF, OSB, particle and the joist. Some of these products can be generated fromindustrial waste, as the panelblockboard, you can use in their training waste destop boards (Battens), from industrial processes or processing of primary wood. This work aims to present the detailed study of the economic viability of utilization of industrial solid waste timber through the acquisition of a machine amarradeira of joists in a wood processing unit in city Itapeva-SP. We studied the application of wastein the composition of kernels blockboard panel tied its commercial acceptance and future prospects market. We noticed great economic advantage in investing in the study, compared with the transformation process of the joists in biomass energy, although the investment decision involves not only financial matters but also the acceptance market the product to be manufactured
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The Sanding is a complex process involving many variables that affect the quality of the part produced, working mainly in the timber industry in the production of panels (MDF, MDP, HDF, etc...) and furniture. However, these industries use the sanding process empirically, not optimizing it. The aim of this study was to compare the behavior of sandpaper white aluminum oxide (OA-white) and Black silicon carbide (SiC-black), analyzing variables in the process as: strength, power, emission, vibration, wear particle size of sanding, and its consequences on the surface finish of the workpiece. Made the process of plane grinding samples of Pinus elliottii, processed in parallel to the fibers, which were sanded with sandpaper grain OA white and black 3-SiC abrasive conditions (new, moderately eroded and severely eroded) grain sizes in 3 (80, 100, and 120 mesh). 6 replicates was performed for each condition tested. Each trial was captured output variables of the sanding process: strength, power, emission and vibration. With two stages totaling 108 trials. After the sanded samples, it has the same surface quality by raising the surface roughness Ra. Through experiment, it can be concluded that abrasives OA-white tended to have higher strength, power, emissions and less vibration in the sanding process, compared to the SiC-black. However, surface finish exhibited similar to the particle size of 80 to 100 mesh, worn abrasive conditions. However, the particle size of 120 mesh, obtained by the roughness of sandpaper OA-bank was higher compared to SiC-black to all conditions of sandpaper due to its toughness