Avaliação de fontes de amônia para conservação do feno de alfafa (Medicago sativa L.) armazenado com alta umidade

O estudo foi desenvolvido com o objetivo de avaliar duas fontes de amônia (amônia anidra-NH3 ou uréia) para conservação do feno de alfafa (Medicago sativa L.) armazenado com alta umidade. Foram estudados os seguintes tratamentos: A - feno com 12 a 15% de umidade e não-tratado; B - feno com 24 a 27% de umidade e tratado com 1,0% de NH3 na MS; C - feno com 24 a 27% de umidade e tratado com 0,9% de uréia na MS; D - feno com 24 a 27% de umidade e tratado com 1,8% de uréia na MS; E - feno com 34 a 37% de umidade e tratado com 0,9% de uréia na MS; e F - feno com 34 a 37% de umidade e tratado com 1,8% de uréia na MS. Os fenos permaneceram sob lona plástica, hermeticamente fechada, por 60 dias. Foram realizadas amostragens para identificação de fungos nos fenos, aos 0 e 60 dias pós-tratamento, e determinação da composição química, avaliando-se os teores de proteína bruta (PB) e dos constituintes da parede celular. Nas quantidades testadas, somente a NH3 foi eficiente no controle dos fungos. Nos tratamentos com uréia, apesar de haver controle dos gêneros Aspergillus e Penicillium, os demais gêneros presentes foram suficientes para deterioração dos fenos. Merece destaque o gênero Paecilomyces, que apresentou alta incidência em todos os fenos tratados. A quantidade utilizada de NH3 foi insuficiente para promover mudanças significativas na composição química dos fenos, exceto nos teores de PB, que aumentaram com o uso de 1,0% de NH3, quando comparados com o não-tratado.

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.

As variaveis relevo e 'solo' na distribuicao desigual da umidade do solo. Avaliacao preliminar.

In a general way the analysis of soil water content enabled one to define which of the colluvium units hold larger water retention capacity. They are: Bela Vista, Piracema I, Campo Alegre, Bom Retiro and Treviso II. These results suggest that the contact zones among alostratigraphic units with high and low water retention capacity are potential zones for the generation of subsurface flow (throughflow). -from English summary

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.

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.

Força de compressão e umidade no perfil de dissolução da hidroclorotiazida

The aim of this work was to evaluate the influence of compression force and humidity in the dissolution profile of tablets formulation. As hidroclorotyiazide presents real problems of bioavailability, it was incorporate as standard drug in a formulation of tablets to study the mechanical resistance, time of disintegration and dissolution profile in function of humidity and compression force. The time of disintegration was not affected by the compression force, but it was influenced by humidity. The dissolution profile was altered by the compression force and for the humidity as well. Both factors can alter the bioavailability of drugs dispensed in the form of tablets.

Otimização da distância de extração de madeira com forwarder

The activities and management operations of wood harvesting do not have good computational tools available to help the forest technicians with the task of cost reduction. In many cases, machines of high investment are used in wood harvesting without adequate operation planning; consequently, the cost per hour of these machines, which is high, could be reduced. Using technological resources such as the Geographic Information Systems (GIS) integrated with the Global Positioning System (GPS), which are the basis of precision harvesting. In this research, a technological tool capable of calculating and optimizing the average skidding distance of the forwarder was developed. It was used in stands of different sizes and formats through mathematical techniques and available functionalities in the Geographic Information System GRASS. The developed tool, called optimized model, divides the stand in small parts in relation to shorter skidding distances. The main variable considered was the alignment of plantation. The model was tested in eucalypt stands located in the State of São Paulo. Sixteen stands were randomly selected: eight with a rectangular polygon form, and eight with irregular polygon form. The main variables were collected in these stands. Results showed that the optimized model developed, is efficient and flexible. It was possible to divide the stands in small parts resulting in smaller skidding medium distances. The stands with irregular form had shorter skidding medium distances than the rectangular stands.

Energia de briquetes produzidos com rejeitos de resíduos sólidos urbanos e madeira de Eucalyptus grandis

The incentive for consumption and production in large quantity in modern society generates enormous amounts of urban solid residues in the form of municipal solid waste (MSW). With the intention of reducing these residues of the municipal waste tips and to generate energy, briquettes with mixtures of MSW and residues of Eucalyptus grandis were produced. The briquettes were manufactured with 0, 5, 10, 15, 20 and 25% of MSW in the mixture with wood waste and 12% of moisture content. The analyzed parameters used to choose the best treatments were combustion analysis versus ash content, mechanical strength and energy content. The briquettes up to 10% of MSW showed low resistance, and above 15% showed large increase in ash content. Therefore, the treatment that fulfilled the requirements for combustion versus ash content and mechanical resistance was of at least 15% of MSW, since the source of the ash is unidentified. Considering the net energy content, the best treatment was 25% of MSW, with 17,175 kJ kg-1. Nevertheless, it is strongly advised that further studies related to gas emissions are necessary.

Variação genética para caracteres anatômicos e retração volumétrica e sua correlação com a densidade básica da madeira em uma população base de Eucalyptus camaldulensis Dehn

Eucalyptus camaldulensis has great importance in Brazil because of their phenotypic plasticity for different environmental conditions, as soils, altitudes and rainfall. This study is an investigation of a base population of E. camaldulensis from Australia through a progeny test implanted in Selvíria, MS. The trial was established in a randomized block design, with 25 families and 60 replications of single tree plots. Genetic parameters for anatomic traits and volume shrinkage were estimated, as well as their correlations with wood basic density. No significant differences among progenies were observed for the traits studied. The additive genetic variation coefficient at individual and among progeny levels ranged from low (0.26%) to high (16.98%). The narrow sense heritability at individual and family means levels also ranged from low (0.01) to high (0.87). This indicates that some traits are under strong genetic control and can be improved by selection. In the present situation, in order to attain the highest genetic gains, the sequential selection among and within progeny would be recommended.

Variação genética para caracteres silviculturais e anatômicos da madeira em progênies de Myracrodruon urundeuva (Engler) Fr. Allem

The aims of this study were to evaluate the variation and to estimate genetic parameters for silvicultural anatomic wood traits for genetic breeding of a Myracrodruon urundeuva (Engler) Fr. Allem, population from Selvíria-MS. For this, from samples of a progeny test established in the Fazenda de Ensino, Pesquisa e Extensão da Faculdade de Engenharia de Ilha Solteira/UNESP, macroscopic anatomic wood traits of M. urundeuva (tangential diameter and vases frequency per mm2) and growth traits were measured (height, DBH and stem form). Genetic parameters were estimated in 28 open-pollinated progenies, in three replications and 10 plants per plot, using a REML/BLUP approach. Between the analysed traits, the DBH is the most indicated for selection for timber production, because it presented the highest values of coefficient of genetic variation, heritabilities and selective accuracy. Between the anatomic traits, the vessels frequency in the pith showed the highest values for genetic parameters. For pulp yield, based on the multi-effect index, the strategy of selecting the best trees for vessels frequency in the pith, independent of the progeny, permitted to obtain substantial gains by mass selection, without progeny test.