Variabilidade espacial de atributos dendrométricas do eucalipto e de um neossolo quartzarênico a partir da aplicação de calcário ou lama de cal + oxyfertil

Pós-graduação em Agronomia - FEIS

Avaliação dos aspectos de processo no torneamento de madeiras tratadas termicamente

Pós-graduação em Engenharia Mecânica - FEG

Dinâmica populacional e manejo de leptocybe invasa (Hymenoptera: Eulophidae) em plantações de eucalipto

Pós-graduação em Ciência Florestal - FCA

Influence of wood moisture content on modulus of elasticity on tension paralllel to the grain of brasilian species

Periodically, when necessary, standard documents are revised in order to analyze inconsistencies and to include considerations according new realities verified. In this sense, aiming to quantify the wood moisture content influence on modulus of elasticity, it was applied tension tests parallel to the grain for six specimens of different strength classes of wood, considering nominal moisture of 12, 20, 25, and 30% in Brazil. The present paper examine the adequacy of the current Brazilian standard ABNT NBR7190:1997, in review, about the adoption of a first degree equation to describe the influence of wood moisture content for timber structures design. It was obtained a new first degree equation which leads to statically equivalent estimations when compared with results by ABNT NBR7190:1997 equation. However, as recommendations it could be maintain the current expression for the next text of the referred document review, without prejudice to statistical significance of the estimates.

Estudo de dormentes de aço sob solicitações verticais, longitudinais e transversais em via permanente ferroviária

This article presents the results of research conducted on full-scale models, studying the behavior of steel sleepers under the action of static loads, in vertical, longitudinal and transverse directions. For the research models were run with rails TR-68, fixed with elastic system on seven sleepers each type, separately, embedded in standard ballast with 35 cm height and on the basis of compacted soil with 30 cm thick. For the load tests were constructed using reaction systems of vertical and horizontal forces with the objective of applying the requests. The system of readings and data acquisition was fully computerized, obtaining in real time the values of forces and displacements. The results were compared with those installed in the same way with sleepers of wood, mono-block and bi-block prestressed concrete. The analyzed results provided unprecedented parameters in Brazil and of great importance for the design of modern railway permanent way, using steel sleepers.

Influence of storage period of pieces in stiffness of pinus elliottii Glulam Beams

This study aimed to investigate the influence of storage time (0, 48 hours) of Pinus elliottii pieces and the tests to obtaining modulus of elasticity (static bending and transversal vibration) in glued laminated timber beams, produced with resorcinol based adhesive and 0.8 MPa compaction pressure. After pieces were properly prepared, part of them was used in immediate three manufacturing glulam beams, tested after adhesive cure, and part stored for 48 hours under a roof with a temperature of 25°C and relative humidity of 60% for subsequent manufacturing and testing three other glulam beams. Results of analysis of variance (ANOVA) revealed that the storage period was significant influence in modulus of elasticity obtained in static bending test (8% reduction from 0 to 48 hours). This not occurred with modulus of elasticity obtained by transversal vibration test (no significant influence). ANOVA results showed equivalence of means in both test procedures. New researches ire needed to better understand the investigated phenomenon, using new wood species, other storage conditions and a great number of samples.

Influence of the number of load cycles to obtain the stiffness properties of angico preto (Anadenanthera macrocarpa) wood specie

The tests used to obtain the stiffness properties of wood are made with two loading cycles, as defined by the Brazilian standard ABNT NBR 7190 (Design of Timber Structures). However, the possibility of reducing the number of cycles allows decrease the operating time of the machine, resulting in reduced spending on electricity used during the tests. This research aimed to investigate, with the aid of the analysis of variance (ANOVA), the influence of the use of three load cycles to obtain the modulus of elasticity in compression parallel to grain (Ec0), in tensile parallel to the grain (Et0), in bending (Em) and in compression perpendicular to the grain (Ec90) of Angico Preto (Anadenanthera macrocarpa) wood specie. For the number of cycles and stiffness were manufactured 12 samples, totaling 144 specimens. The results of the ANOVA revealed statistical equivalence between the stiffness properties for both load cycle numbers evaluated, indicating that it is possible to carry out the tests with a single charge cycle, allowing savings in time and energy in the operation of the equipment.

Poissons ratios for wood species for structural purposes

The broader knowledge about physical and mechanical properties of wood allows reliable timber structures design. Even little addressed in the literature, in several situations Poisson's ratios are required for the evaluation of stresses acting on structural elements. This study aimed to obtain values of Poisson's ratios (ν), plans Longitudinal-Radial (νLR) and Longitudinal-Tangential (νLT), for species Peroba Rosa (Aspidosperma polyneuron) and Jatobá (Hymenaea courbaril L.). For this purpose, forty samples Peroba Rosa and eight samples of Jatobá were prepared for testing in compression parallel to the grain, following the recommendations of ABNT NBR 7190 standard. The results of means confidence intervals, considered at the level of 5% significance, revealed that the Poisson's ratios νLR e νLT to Peroba Rosa are 0.27 and 0.42, respectively, and 0.25 and 0.43 to Jatobá.

Aplicação de DNA Barcode na identificação de espécies dos gêneros Senna, Lantana e Casearia

Pós-graduação em Biotecnologia - IQ

Chuva e banco de sementes do solo em diferentes sistemas de restauração ecológica da floresta estacional semidecidual

Pós-graduação em Ciência Florestal - FCA

A aplicação da abordagem do Tecnógeno na identificação e classificação dos terrenos e depósitos tecnogênicos no ambiente urbano de Guarapuava-PR

Pós-graduação em Geografia - FCT

Sinais digitais de um durômetro portátil para a estimativa de propriedades de madeiras para dormentes

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Variação dimensional de tábuas de Eucalyptus grandis durante alguns níveis de tempo e temperatura de termorretificação

The objective of this study was evaluate the effects of retification® temperatures and times on thickness variation from Eucalyptus grandis timber. Boards from logs of 30-year-old Eucalyptus grandis trees, from São Paulo Forest Institute in Santa Barbara, Brazil, were thermally modified at 180ºC for 2.5 hours, at 200ºC for 3.0 hours and 200ºC for 4.0 hours. The results showed that: (1) the thermally modified wood at 200°C by 3.0 to 4.0 hours showed increased thickness between 0.698 mm and 0.874 mm due to the internal cracks, (2) the thermally modified wood at 180°C by 2.5 hours has a decreased from 0,177 mm in thickness and the absences of internal cracks.

Avaliação técnica e econômica da colheita de florestas de eucalipto com harvester

The acquisition of machinery used in timber harvesting depends on high financial investment, which implies the need for assessments that allow defining more precisely, what is the machine or the whole more recommended for streamlining the operation. This study aimed to technically and economically evaluating the performance of a harvester in Eucalyptus forest harvest first cut. The technique analysis included a time and movements, productivity, efficiency operational and mechanical availability. The economic analysis included the parameters operational cost, harvesting cost and energy consumption. The results obtained from the technological-economic parameters evidenced that of Diameter at Breast Height directly influenced the productivity of harvester. Consequently the lower costs of forest harvest were obtained for the compartments with wider diameter trees.

Análise da eficiência energética em indústrias madeireiras através da lógica fuzzy

This paper presents the application of fuzzy theory to support the decision of implementing energy efficiency program in sawmills operating in the processing of Pinustaeda and Pinuselliotii. The justification of using a system based on fuzzy theory for analysis of consumption and the specific factors involved, such is the diversity of rates / factors. With the fuzzy theory, we can build a reliable system for verifying actual energy efficiency. The indices and factors characteristic of industrial activity were measured and used as the basis for the fuzzy system. We developed a management system and technology. The system involves the management practices in energy efficiency, maintenance of plant and equipment and the presence of qualified staff. The technological system involves the power factor, load factor, the factor of demand and the specific consumption. The first response provides the possibility of increased energy efficiency and the second level of energy efficiency in the industry studied. With this tool, programs can be developed for energy conservation and energy efficiency in the industrial timber with wide application in this area that is as diverse as production processes. The same systems developed can be used in other industrial activities, provided they are used indices and characteristic features of the sectors involved.