oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2020 ( 5 )

2019 ( 368 )

2018 ( 583 )

2017 ( 593 )

Custom range...

Search Results: 1 - 10 of 380666 matches for " Angélica de Cássia Oliveira Carneiro "
All listed articles are free for downloading (OA Articles)
Page 1 /380666
Display every page Item
Potential of forestry residue briquetting of Seridó region species in Rio Grande do Norte State, Brazil Potencial de briquetagem de resíduos florestais da regi o do Seridó, no Rio Grande do Norte
Rosimeire Cavalcante dos Santos,Angélica de Cássia Oliveira Carneiro,Renato Vinícius Oliveira Castro,Alexandre Santos Pimenta
Pesquisa Florestal Brasileira , 2011, DOI: 10.4336/2012.pfb.68.285
Abstract: This study aimed to evaluate the potential use of waste generated by forestry species that occur in semiarid northeastern at Seridó region, Rio Grande do Norte, for the briquettes production, determine the physical and mechanical briquettes properties, and to correlate the wood density with the density after the briquettes production and briquettes density with the compressive strength. Thirty-two trees were collected (eight species with four replications). The wood physical and chemical properties evaluation were held under a completely randomized design. For the variables related to briquette, it was adopted the same design with three replicates for each species, totalizing 24 sampling units. The briquettes produced with jurema-preta wood stood out as a function to higher fixed carbon content, calorific value and higher compressive strength flat. The briquettes made from waste of imburana wood had the worst performances for the studied parameters. It was observed a negative correlation between the wood density and the gain of apparent relative density of the briquettes and a positive correlation between the briquettes density and the compressive strength of flat.
Adesivos à base de taninos das cascas de duas espécies de eucalipto para produ??o de chapas de flocos
Vital, Benedito Rocha;Carneiro, Angélica de Cássia Oliveira;Pimenta, Alexandre Santos;Della Lucia, Ricardo Marius;
Revista árvore , 2004, DOI: 10.1590/S0100-67622004000400011
Abstract: eucalyptus grandis and eucalyptus pellita bark tannins were extracted with hot water, with addition of 4,5% of sodium sulfite, for a three hours period, at temperatures of 70oc and 100oc, respectively. the tannins were reacted with acetic acid and sodium sulfite, for reduction of adhesive viscosity. calorimetric exploratory differential techniques were used to determine adhesive kinetic parameters. flakeboards were fabricated with pinus elliottii wood flakes, using 8% or 10% of eucalyptus grandis or eucalyptus pellita tannin-based adhesives or 8 % of commercial urea-formaldehyde adhesive. board properties were determined according to astm d-1037 standard. except for moisture related properties, the boards fabricated only with tannin-based adhesive were superior to the minimally acceptable ansi/a 208.1-93 standard. the flakeboards fabricated with eucalyptus grandis bark tannins were better than those fabricated with eucalyptus pellita bark tannins.
Propriedades de chapas de flocos fabricadas com adesivo de uréia-formaldeído e de taninos da casca de Eucalyptus grandis W. Hill ex Maiden ou de Eucalyptus pellita F. Muell.
Carneiro, Angélica de Cássia Oliveira;Vital, Benedito Rocha;Pimenta, Alexandre Santos;Della Lucia, Ricardo Marius;
Revista árvore , 2004, DOI: 10.1590/S0100-67622004000500011
Abstract: bark tannins of eucalyptus grandis and eucalyptus pellita were extracted with 4,5% sodium sulfite in hot water solution for a period of three hours. solution temperatures were 70 and 100oc, for eucalyptus grandis and eucalyptus pellita bark respectively. tannins were reacted with acetic acid and sodium sulfite to reduce adhesive viscosity. adhesive formulations were prepared adding 0, 25, 50, 75 or 100% of tannin adhesives to the commercial urea-formaldehyde adhesive. flakeboards were fabricated with 8% resin content. board properties were determined according to astm d-1037 standards. except for humidity, all board properties were superior to the values established by ansi.a 208.1-93 commercial standard. addition of tannins to the urea-formaldehyde adhesive improved some properties.
Longitudinal and radial variation of extractives and total lignin contents in a clone of Eucalyptus grandis W.Hill ex Maiden x Eucalyptus urophylla S. T. Blake
Marina Donária Chaves Arantes,Paulo Fernando Trugilho,José Tarcísio Lima,Angélica de Cássia Oliveira Carneiro
CERNE , 2011,
Abstract: The objective of this work was to determine concentrations of extractives and total lignin along with their radial and longitudinal variations in wood from a clone of Eucalyptus grandis W.Hill ex Maiden x Eucalyptus urophylla S. T. Blake at age six years. Longitudinal samples were taken at 2%, 10%, 30% and 70% of the commercial height of trees, and radial samples were taken from each longitudinal position, the number of samples depending on the diameter of each disk. Results led to the conclusion that, overall, concentrations of extractives and total lignin in the wood tended to decrease with increasing distance from the pith and tended to increase in portions closer to the tree base.
ANATOMIC AND CHEMICAL CHARACTERISTICS OF Eucalyptus CLONES WOOD AND ITS INFLUENCE UPON BONDING
Celiana Kátia Pereira Lima,Fábio Akira Mori,Lourival Marin Mendes,Angélica de Cássia Oliveira Carneiro
CERNE , 2007,
Abstract: Wood is a heterogeneous and complex material made up from different elements distributed along the trunk in several proportions. Associated with hygroscopicity, they have an influence on wood processing, including bonding. Therefore the present study sought, not only through the anatomic characterization and measurement but also through the total extractive content in Eucalyptus clones wood, to find out the correlation between the quality and the bonding junctions. Pearson correlations were used, considering 39 and 26 clones in interaction with the urea- formaldehyde sticker. The anatomic characteristics, relative to frequency and size of conducting vessels, radial parenchyma and its total extractive content presented correlation with the evaluation of clone’s bonding quality as well as with the percentage of wood failure and glue-line shear.
Thermogravimetric analysis of eucalyptus clones as a subside for charcoal production
Rosimeire Cavalcante dos Santos,Angélica de Cássia Oliveira Carneiro,Paulo Fernando Trugilho,Lourival Marin Mendes
CERNE , 2012,
Abstract: In Brazil, the use of wood for energy generation has been related to the charcoal production, due to the existing demand for the product by the steelworks sector. The tree species used in its great majority, are of the genus Eucalyptus. Nevertheless, regarding the variations that occur in the wood quality of the above cited genus, it is necessary to study them, since that fact can bring about negative consequences in both the quality and yield of charcoal, which will reflect negatively on the operations of the iron and steel industries blast furnaces. The work investigated the quality of the wood from different genetic materials of eucalyptus for charcoal production by means of thermogravimetric analysis. In the study, the resistance to the thermal degradation of wood and the qualitative and quantitative features of charcoal were taken into consideration. It was found that the highest peaks of thermal degradation occurred in the range of temperature between 300 and 4000C, the genetic material was the one which presented the lowest loss of total mass and the three was the less stable, having those presented, respectively, higher and lower gravimetric yield in charcoal; all the tested genetic materials presented satisfactory gravimetric results both in yield and in quality.
Properties of particleboards fabricated with eucalyptus (Eucalyptus urophylla), parica (Schizolobium amazonicum) and vassoura (Sida spp.) particles
Juliana Jerásio Bianche,Angélica de Cássia Oliveira Carneiro,Benedito Rocha Vital,Flávia Alves Pereira
CERNE , 2012,
Abstract: The genus Sida may become a promising alternative source for the production of particleboards. Nowadays it is used for manufacturing ropes due to the quality of its fibers, however, there is no research relating the production of particleboards using this lignocelluloses material. This study aimed to evaluate the effect of eucalyptus (Eucalyptus urophylla), paricá (Schizolobium amazonicum) and vassoura (Sida spp.) on the physical and mechanical properties of particleboard. Particleboard contained 25, 50, 75 and 100% of eucalyptus and paricá or eucalytus and vassoura or paricá an vassoura were fabricated. Two (6% and 8%) amounts of urea-formaldehyde adhesive were used. The physical and mechanical properties were determined according to NBR / ABNT 14810-3 (ASSOCIA O BRASILEIRA DE NORMAS TéCNICAS - ABNT, 2002). It was observed that increase in resin content in the improved some physical and mechanical properties. It was concluded that the amount of vassoura particles on panels had different effects depending on the species used. The increase in the percentage of vassoura particles in the Eucalyptus panels did not affect the internal bond, screw withdrawal and hardness. Increasing the percentage of vassoura particles on the panels produced with paricá did not affect its hardness and resistance to screw withdrawal. The panels produced with vassoura particle absorbed more water and, consequently, increased the thickness swelling, and therefore is not recommended for use in environments with high humidity. It was concluded that the genus Sida, in general, has potential for particleboard production.
Estrutura anat?mica da madeira e qualidade do carv?o de Mimosa tenuiflora (Willd.) Poir
Oliveira, Elisabeth de;Vital, Benedito Rocha;Pimenta, Alexandre Santos;Della Lucia, Ricardo Marius;Ladeira, Ana Márcia M.;Carneiro, Angélica de Cássia Oliveira;
Revista árvore , 2006, DOI: 10.1590/S0100-67622006000200018
Abstract: the objective of this work was to determine anatomical characteristics, and dimensions of fibers, vessels and parenchyma and ray cells of mimosa tenuiflora (willd.) poir wood. fibers wall fraction, the percentage of fibers, vessels and ray and parenchyma cells, as well as density and charcoal production and properties were determined. the wood of mimosa teniflora presents predominantly solitary, geminated and multiple porous in radial groups; porous distributed in uniform diffuse porosity; axial parenchyma paratracheal vasicentric, confluent vasicentric, aliform and confluent aliform; multiseriate, biseiat rays and, less frequently, uniseriate ones; very short fibers with thick walls. charcoal yield was 39.68% with a 0.51g/cm3 density, 71.79% carbon content and 6886cal/g calorific value.
Quality of Wood and Charcoal from Eucalyptus Clones for Ironmaster Use
Bárbara Luísa Corradi Pereira,Aylson Costa Oliveira,Ana Márcia Macedo Ladeira Carvalho,Angélica de Cássia Oliveira Carneiro,Larissa Carvalho Santos,Benedito Rocha Vital
International Journal of Forestry Research , 2012, DOI: 10.1155/2012/523025
Abstract: Considering the wide variety of species and clones of Eucalyptus cultivated in Brazil, it is necessary to search for new information on wood properties, so that the selection of genetically superior material may be successful. The present study aimed to determine the properties of wood and charcoal from different clones of Eucalyptus spp. Six clones at the age of 7.5 years were evaluated and the samples were from a clonal, located in the city of Lassance, Minas Gerais, Brazil. Basic density, chemical composition, and higher heating value were determined. Carbonizations in a laboratory kiln were done and the levels of volatile matter, ash, and fixed carbon, higher heating value, and bulk density of the charcoal produced were determined. Evaluated genetic materials showed differences in their properties. According to research results, several properties of wood should be considered together for the selection of clones for charcoal production. However, basic density and chemical composition of wood, especially high contents of lignin and low contents of extractives, are the properties that had more influence on charcoal yield and its quality. Concerning charcoal production for steelmaking, clone 6 stood out and, conversely, clone 4 showed inferior properties to those of others. 1. Introduction Area occupied by forest plantations in Brazil reached over 6,500,000?ha, of which 74.8% are Eucalyptus plantations, in 2011 [1]. In the same year, Brazilian consumption of logs from plantations of Eucalyptus for charcoal production was close to 17,000,000 cubic meters, representing 10.0% of total consumption of logs [1]. These data confirm the importance of Eucalyptus in Brazil, which has been the focus of several studies due to concerns about wood quality and homogeneity. Charcoal quality and its production depend, among other factors, on the quality of wood used, which is defined by a set of chemical, physical, mechanical, and anatomical properties, usually interdependent. Nevertheless, regarding the variations that occur in the wood quality of the above cited genus, it is necessary to study it, for this fact may bring about negative consequences in both the quality and yield of charcoal, which will negatively reflect on the operations of the iron and steel industries blast furnaces [2]. Forestry companies and Brazilian research centers have been motivated to seek solutions to produce homogeneous charcoal, with high yield, high quality, and low cost. Therefore, the technological characteristics of wood should also be considered and not only the economic and
Efeito da hidrólise ácida dos taninos de Eucalyptus grandis w. hill ex Maiden nas propriedades dos adesivos tanicos
Carneiro, Angélica de Cássia Oliveira;Vital, Benedito Rocha;Frederico, Pedro Gustavo Ulisses;Santos, Rosimeire Cavalcante dos;Sousa Júnior, Wagner Patrício de;
Revista árvore , 2009, DOI: 10.1590/S0100-67622009000400016
Abstract: the objective of this research was to evaluate the effect of the acid hydrolysis of eucalyptus grandis w. hill ex maiden bark tannins on the properties of tannic adhesives. adhesives were synthesized with tannins hydrolyzed at four ph values, three reaction times and 10% of formaldehyde based on the tannin dry weight. ninety-six glued joints were prepared with eucalyptus grandis thin boards. shear resistance and wood failure percentage were determined according to the astm d 2339-93 standards. it was concluded that tannin hydrolysis decreased adhesive viscosity and increased the glue line shear resistance. however, it was observed a low percentage of wood failure.
Page 1 /380666
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.