Quality of tectona grandis for sawn wood production

Forestry companies have invested in genetic improvement to increase wood production in a shorter amount of time. Thus, studies are needed to compare the properties of clonal and seminal wood materials.  The objective of this study was to analyze physical and mechanical properties of Tectona grandis from clonal (C1 and C2) and seminal (S) origin and evaluate the yield and quality of sawn wood subjected to outdoor and oven drying. Genetic material was collected from six, 15-year-old trees. Clone C2 presented the lowest amount of bark, and 51 % heartwood up to half the commercial height, while the heartwood of C1 and S went up to 25 % of the height. The three materials did not differ statistically for maximum angular deviation, pith eccentricity, basic density, Janka hardness, anisotropy, commercial income of sawn wood and the presence of knots. After the drying processes, the bowing and crooking indexes were less than 5 mm.m-1, however, the seminal material showed a higher cracking incidence after outdoor and oven drying. In conclusion, the wood properties of the three materials are similar. In addition, the oven drying process is recommended

Avaliação de adesivos à base de taninos de Pinus caribaea var. bahamensis e de Acacia mearnsii na fabricação de painéis aglomerados

http://dx.doi.org/10.5902/1980509814588This work aimed to evaluate the methods for extraction of tannin from the bark of Pinus caribaea var. bahamensis, as well as to evaluate the technical feasibility of using tannins from the barks of Pinus caribaea var. bahamensis, of Acacia mearnsii, the mixtures of black wattle and pine tannins and the mixture of adhesive urea formaldehyde (UF) with black wattle and pine tannins in the production of adhesives for particleboard. The barks of Pinus caribaea var. bahamensis were fragmented in hammer mill, sieved and extracted under reflux for 2 hours, using a bark: liquor relation of 1:15, in nine treatments. The best extraction was used to obtain large quantities of extracts, which were used in the manufacture of adhesives and mixtures with UF adhesive and tannins of black wattle and the manufacture of particleboard. The addition of sodium sulfite gave higher extraction of tannin, which was extracted with the addition of 5% sodium sulfite. The results showed that both the black wattle tannin, as the bark of Pinus caribaea var. bahamensis have good bonding properties. It is possible to add pine tannin solution to the solution of black wattle and to replace part of the UF adhesive for the wattle tannins up to 25%, without compromising the glue quality. Replacing 10% of UF for tannic extract, both pine and black wattle, did not alter the values of thickness swelling (TS) of the panels. It is possible to obtain good mechanical properties with UF adhesives modified with tannic extracts at a ratio of 10%. The high values found for the internal bond (IB) panels containing tannin extracts showed the potential of these tannic extracts for bonding wood materials.  http://dx.doi.org/10.5902/1980509814588Este trabalho teve por objetivo avaliar os métodos para a extração dos taninos da casca do Pinus caribaea var. bahamensis, assim como verificar a viabilidade técnica de utilização dos taninos da casca de Pinus caribaea var. bahamensis, de Acacia mearnsii, de misturas de taninos de acácia negra e pinus e de misturas do adesivo ureia-formaldeído (UF) com taninos de acácia e pinus na produção de adesivos para aglomerados. As cascas de Pinus caribaea var. bahamensis foram fragmentadas em moinho de martelo, peneiradas, extraídas sob refluxo, por 2 horas, utilizada uma relação casca:licor de 1:15 p:v, em nove tratamentos. A melhor forma de extração foi utilizada para obtenção de grandes quantidades de extratos, que foram utilizados na confecção de adesivos tânicos e nas misturas com adesivo UF e com taninos comerciais de acácia negra na fabricação de painéis aglomerados. A adição de sulfito de sódio proporcionou maior extração de taninos, sendo recomendável a extração com adição de 5% de sulfito de sódio. Os resultados mostraram que tanto os taninos de acácia, quanto os de Pinus caribaea var. bahamensis, apresentam boas propriedades de colagem. É possível a adição de solução tânica de pinus à solução tânica de acácia e também substituir parte do adesivo UF pelos taninos de acácia em até 25% sem comprometer a qualidade da colagem. A substituição de 10% de UF por extrato tânico, tanto de pinus quanto de acácia, não alterou os valores de inchamento em espessura (IE) dos painéis. É possível obter boas propriedades mecânicas com adesivos UF modificados com extratos tânicos na proporção de 10%. Os altos valores encontrados para ligação interna (LI) dos painéis fabricados com extratos tânicos evidenciaram o potencial desses taninos para colagem de painéis de madeira

Determination of the chemical composition of Eucalyptus spp. For cellulosic pulp production

Funding Information: Funding: This research was partially supported by CAPES (Coordination for the Development of Higher Level Personnel). This work was also partially supported by Base Funding—UIDB/EQU/ 50020/2020 and Programmatic-UIDP/50020/2020 Funding of the Associate Laboratory LSRE-LCM— and UIDB/00511/2020 of the Laboratory for Process Engineering, Environment, Biotechnology and Energy, LEPABE—funded by national funds through FCT/MCTES (PIDDAC). This work was also supported by national funds through FCT, under the Scientific Employment Stimulus Institutional Call (CEECINST/00102/2018) and partially supported by the Associate Laboratory for Green Chemistry—LAQV, financed by national funds from FCT/MCTES (UIDB/50006/2020 and UIDP/50006/2020) and IF/01381/2013/CP1160/CT0007, Investigador FCT program, with financing from the European Social Fund and the Human Potential Operational Program. T.A.S.V. is grateful to the Erasmus Mundus program.The chemical composition of wood is important to assess the quality of this raw material for the industry of cellulosic pulp production. The purpose of this work was to determine the chemical composition of Eucalyptus spp. grown for cellulosic pulp production. Ten Eucalyptus spp. clones with six years of age, located in the municipality of Itamarandiba, Minas Gerais, Brazil, were used. Quantification was obtained for extractives, monosaccharides, uronic acids, acetates, lignin, ash and the phenolic composition of the extracts. In average, clones showed around 2.7% extractives, with a predominance of polar compounds soluble in ethanol and water; 27.7% lignin and 0.3% ash. Glucose was the main sugar detected (64.2%), followed by xylose (19.3%). The main components of the extractives were steroids, fatty acids and aromatic acids, followed by smaller amounts of substituted alkanoic acids, fatty alcohols, glycerol derivatives and triterpenes. The ethanol–water extracts presented total phenol contents ranging from 321.4 to 586.6 mg EAG/g of extract, tannins from 28.1 to 65.1 mg catechin/g of extract and flavonoids from 73.6 to 256.9 mg catechin/g of extract. Clones with a higher holocellulose amount and a lower lignin content showed a higher potential for cellulosic pulp production. These findings are important for the development of high-quality wood based on important traits for the pulp and paper sector.publishersversionpublishe

Properties of osb panels with veneer inclusion

This work aimed to evaluate the effect of veneer inclusion with different wood species, and also different levels of pressing pressure applied in the moment of the veneer inclusion over physicalmechanical properties of already consolidated OSB (Oriented Strand Board) panels. Treatments were arranged in factorial scheme 4 x 2 (four wood types for veneer inclusion – Pinus oocarpa, Eucalyptus urophylla, Parkia gigantocarpa and Brosimum parinariodes; and two pressing pressures – 1 and 2MPa) and also a control (without veneer inclusion). Veneer inclusion was made with 180 g.cm-2 phenol formaldehyde adhesive, in a simple glue line, perpendicular to the external layer of panels. The pressingcycle used was 150ºC for 4 minutes under pressure 1 or 2 MPa pressure depending on the pre-established treatment. It was possible to conclude that: 1) Veneer inclusion with pines, eucalypt and amapá promotedsignificant improvements for physical-mechanical properties of OSB panels, highlighting eucalypt and amapá; 2) There was not a significant effect of the level of pressing pressure over mechanical propertiesof OSB with veneer inclusion; and 3) Regarding physical properties, the highest pressure level (2 MPa) promoted a negative effect in some properties, while veneer inclusion the pressure of 1 MPa generallypromoted significant improvement of all physical properties

CXCR1 and SLC11A1 polymorphisms affect susceptibility to cutaneous leishmaniasis in Brazil: a case-control and family-based study.

BACKGROUND: L. braziliensis causes cutaneous (CL) and mucosal (ML) leishmaniasis. Wound healing neutrophil (PMN) and macrophage responses made following the bite of the vector sand fly contribute to disease progression in mice. To look at the interplay between PMN and macrophages in disease progression in humans we asked whether polymorphisms at genes that regulate their infiltration or function are associated with different clinical phenotypes. Specifically, CXCR1 (IL8RA) and CXCR2 (IL8RB) are receptors for chemokines that attract PMN to inflammatory sites. They lie 30-260 kb upstream of SLC11A1, a gene known primarily for its role in regulating macrophage activation, resistance to leishmaniasis, and wound healing responses in mice, but also known to be expressed in PMN, macrophages and dendritic cells. METHODS: Polymorphic variants at CXCR1, CXCR2 and SLC11A1 were analysed using Taqman or ABI fragment separation technologies in cases (60 CL; 60 ML), unrelated controls (n = 120), and multicase families (104 nuclear families; 88 ML, 250 CL cases) from Brazil. Logistic regression analysis, family-based association testing (FBAT) and haplotype analysis (TRANSMIT) were performed. RESULTS: Case-control analysis showed association between the common C allele (OR 2.38; 95% CI 1.23-4.57; P = 0.009) of CXCR1_rs2854386 and CL, supported by family-based (FBAT; Z score 2.002; P = 0.045) analysis (104 nuclear families; 88 ML, 250 CL cases). ML associated with the rarer G allele (Z score 1.999; P = 0.046). CL associated with a 3' insertion/deletion polymorphism at SLC11A1 (Z score 2.549; P = 0.011). CONCLUSIONS: The study supports roles for CXCR1 and SLC11A1 in the outcome of L. braziliensis infection in humans. Slc11a1 does not influence cutaneous lesion development following needle injection of Leishmania in mice, suggesting that its role here might relate to the action of PMN, macrophage and/or dendritic cells in the wound healing response to the sand fly bite. Together with the CXCR1 association, the data are consistent with hypotheses relating to the possible role of PMN in initiation of a lesion following the delivery of parasites via the sand fly bite. Association of ML with the rare derived G allele suggests that PMN also have an important positive role to play in preventing this form of the disease.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

Adaptability, stability, and genetic divergence of conilon coffee in Alto Suaçuí, Minas Gerais, Brazil.

The objective of this study was to describe the genetic parameters, adaptability, and stability of clones from the Coffea canephora variety ?Vitória Incaper 8142?, and the genetic divergence between them. Following 12 and 24 months of plant growth, several traits were evaluated, including stem diameter, plant height, canopy diameter, number of plagiotropic branches, and number of nodes per plagiotropic branch. The agronomic performance of four crops was determined using measurements of productivity, yield, percentage of floating grains, and grade of the beans. Variability was observed between the clones for the majority of the traits measured. The clones V7, V10, V12, and V13 were the most stable and displayed the highest degree of adaptation for the studied traits, and thus these clones will be used to establish a base population suited to the growing conditions in Alto Suaçuí, Minas Gerais, Brazil. Additionally, the genetic dissimilarity identified between clones allowed suitable clone combinations to be proposed for use in future crosses

UMIDADE DE EQUILÍBRIO DE PAINÉIS OSB EM FUNÇÃO DA UMIDADE RELATIVA E DA TEMPERATURA AMBIENTE

http://dx.doi.org/10.5902/1980509820661The study aimed to obtain statistical models to estimate the equilibrium moisture content of OSB panels as a function of temperature and relative humidity of air, as well as evaluate the effect of some production variables on the equilibrium moisture content of the panels. The experimental design consisted of six processing conditions, three air temperature and six relative humidity of air. In the processing conditions, were evaluated three different thicknesses of the strand particles (0.4, 0.7 and 1.0 mm), two apparent densities of panels (0.65 and 0.90 g/cm³) and three levels of pressure in the pressing of the panels (40, 60 and 80 kgf/cm²). For each treatment four panels were produced with the wood of Pinus taeda and 6% of phenol formaldehyde adhesive. In the evaluation of the experiment was considered a completely randomized design arranged in a factorial triple 6 x 6 x 3, in order words, six production variables (processing conditions), three air temperatures (30, 40 and 50°C) and 6 relative humidity (40, 50, 60, 70, 80, 90%). The means were compared statistically by Scott-Knott test at the 5% level of significance. The modeling the equilibrium moisture content of OSB panels was performed with fit the multiple polynomial models for each treatment. Based on measurements of accuracy and the results can be concluded that: 1) it is recommended to use the model UEQ = β0 + β1UR + β2UR² + β3UR³ + β4Temp + ε for indirect estimation of equilibrium moisture content of OSB panels 2) The temperature shows linear influence on the equilibrium moisture content of the panels, while the relative humidity of air shows behaving of third order polynomial, and the relative humidity of air affects more pronouncedly the equilibrium moisture content of OSB panels than the ambient temperature; 3) In respect of the effect of production variables, the pressing of pressure of 80 kgf/cm² and the increased the thickness of the strand particles to 1.0mm thick promoted trend of reductions in average of the equilibrium moisture content of OSB panels. But the increased density of the panel promoted the trend of increasing of equilibrium moisture content of OSB panels; and 4) The use of multiple polynomial models allows that are produced contours to obtain the values of equilibrium moisture content of OSB as a function of relative humidity and temperature of the place where the panel is exposed, standing out for its convenience of use. http://dx.doi.org/10.5902/1980509820661O trabalho teve como objetivo obter modelos estatísticos para a estimativa da umidade de equilíbrio de painéis OSB em função da temperatura e da umidade relativa do ar, assim como também avaliar o efeito de algumas variáveis de produção sobre a umidade de equilíbrio dos painéis. O delineamento experimental se constituiu de seis condições de processamento, três temperaturas do ar e seis umidades relativas do ar. Nas condições de processamento, foram avaliadas três diferentes espessuras das partículas strand (0,4; 0,7 e 1,0 mm), duas densidades aparentes do painel (0,65 e 0,90 g/cm³) e também três níveis de pressão na prensagem dos painéis (40, 60 e 80 kgf/cm²). Para cada tratamento foram produzidos quatro painéis com a madeira de Pinus taeda e 6% de adesivo fenol-formaldeído. Na avaliação do experimento foi considerado um delineamento inteiramente casualizado disposto em esquema fatorial triplo 6 x 3 x 6, ou seja, 6 variáveis de produção (condições de processamento), 3 temperaturas do ar (30, 40 e 50°C) e 6 umidades relativas (40, 50, 60, 70, 80, 90%). As médias foram comparadas estatisticamente pelo Teste Scott-Knott em nível de 5% de significância. A modelagem da umidade de equilíbrio dos painéis OSB foi realizada mediante o ajuste de modelos polinomiais múltiplos para cada tratamento. Com base nas medidas de precisão e nos resultados obtidos pode-se concluir que: 1) recomenda-se a utilização do modelo  UEQ = β0 + β1UR + β2UR² + β3UR³ + β4Temp + ε  para a estimativa indireta da umidade de equilíbrio dos painéis OSB; 2) A temperatura apresenta influência linear na umidade de equilíbrio dos painéis, enquanto que a umidade relativa do ar apresenta comportamento polinomial de terceira ordem, sendo que a umidade relativa do ar influência de forma mais pronunciada a umidade de equilíbrio dos painéis OSB do que a temperatura ambiente; 3) Quanto ao efeito das variáveis de produção, a pressão de prensagem de 80 kgf/ cm² e o aumento da espessura das partículas strand para 1,0 mm de espessura promoveu tendência de reduções nos valores médios de umidade de equilíbrio dos painéis OSB. Já o aumento da densidade do painel promoveu uma tendência de aumento da umidade de equilíbrio dos painéis OSB; e 4) O uso de modelos polinomiais múltiplos permite que sejam produzidas curvas de nível para a obtenção dos valores de umidade de equilíbrio dos painéis OSB em função da umidade relativa e da temperatura do local onde o painel esta exposto, se destacando pela sua praticidade de utilização

Effect of extractives on wood color of heat treated Pinus radiata and Eucalyptus pellita

Heat treatment can change wood color without any use of environmentally harmful chemicals, and the efficiency of this process depends on the raw material to be treated. The objective of this study was to evaluate the influence of extractives on the color change of Eucalyptus pellita and Pinus radiata wood during heat treatment. The extractives were extracted in cold water and in dichloromethane as well as totally removed and the wood was treated at 170°C and 200°C for three hours under atmospheric pressure and in presence of air for evaluating the lightness (L*), green-red coordinate (a*), blue-yellow coordinate (b*), color saturation (C) and tonality angle (H) values. Pinus radiata wood was more resistantto discoloration by heat treatment. The removal of total and cold water-soluble extractives before heat treatment changed the L* value of Pinus radiata, a* value of Eucalyptus pellita, and b*, C, and H valuesof both species. Removal of extractives soluble in dichloromethane did not affect the color of heat treated wood. Thus, understanding the influence of extractives on heat treated wood can allow adapting the raw material to the process for enhancing the applicability of heat treatment for changing wood color