Produçao de compósito plástico-madeira a partir de resíduos da indústria madeireira

O objetivo deste estudo foi produzir compósitos plástico-madeira através da extrusão reativa de polipropileno na presença de anidrido maleico, peróxido de dibenzoila e resíduos de madeira. O estudo foi feito através de um planejamento de experimentos fatorial que envolveu 2 granulometrias de madeira (pó-de-lixa e serragem), 2 níveis de quantidade de madeira (10% e 30%) e 4 níveis de compatibilizante (0%, 1%, 2% e 3%). Os compósitos plástico-madeira foram produzidos em uma extrusora monorrosca de 60 mm. A avaliação dos compósitos foi feita através dos ensaios dos corpos de prova injetados. Os resultados dos ensaios mostraram que os compósitos a partir da serragem apresentaram um desempenho superior aos preparados com o pó-de-lixa. A incorporação do compatibilizante, através da extrusão reativa, resultou em compósitos com melhores propriedades mecânicas. O maior ganho na resistência à tração foi de 19,1% para o compósito 30P2% (30% de pó-de-lixa com 2% de compatibilizante) em relação ao mesmo compósito sem compatibilizante. Também foi observado que os compósitos são recicláveis e, para algumas formulações, a reciclagem dos compósitos melhorou as propriedades. O maior ganho na resistência à tração foi observado para o produto 10S3X (10% de serragem com 3 extrusões) que foi 7,7% superior à sua primeira extrusão. Os compósitos plástico-madeira produzidos foram utilizados como matéria-prima para a produção de vasos para orquídeas e réguas escolares (através do processo de moldagem por injeção), e tubos e perfis (pelo processo de moldagem por extrusão)

Análise fractal de uma floresta ombrófila mista através de imagens de satélite

A paisagem da região sul do Brasil é formada por floresta, campo, água e agricultura entre outros. Mesmo com essa heterogeneidade, o estudo de qualquer elemento da paisagem está relacionado com o todo, tornando-se imprescindível o entendimento dos padrões que compõem essa paisagem. Uma das dificuldades encontradas nas análises desses padrões espaciais, era definir e quantificar as formas irregulares descritas pela natureza. No entanto, desde que Mandelbrot introduziu a teoria dos fractais em 1975, a geometria fractal tem sido utilizada para tratar dessas variações espaciais. Esta pesquisa utilizou os fractais para analisar o padrão da paisagem de uma Floresta Ombrófila Mista localizada no município de General Carneiro - PR. A partir da imagem classificada do Landsat-5 TM, determinou-se os índices da dimensão fractal "D" e do parâmetro de Pareto "a' para cada tipologia, O cálculo da dimensão fractal "D" foi baseado na relação área-perímetro, e o parâmetro de Pareto na relação entre áreas. Com a análise fractal foi possível associar o padrão de cobertura com tais índices. Os resultados mostraram que os fragmentos de araucária são os maiores ("a" =~ 16,5) e têm as bordas mais sinuosas ("D" =~ 1,42). Os menores fragmentos são de capoeira ("a" =~ 13,3), e a classe água tem os fragmentos com as bordas mais simples ("D" =~ 1,25). Este estudo mostrou que a análise fractal fornece índices que diminuem o grau de subjetividade na avaliação e entendimento da fragmentação da paisagem

Solid-state white-light emission from a pyrylium dye obtained in one synthetic step

Seven pyrylium salts have been synthesized by the condensation of p-substituted acetophenones and acetic anhydride, and their photophysical features have been characterized. One of the prepared compounds (7) constitutes the first example of a pyrylium dye displaying white light emission in the solid state

UTILIZAÇÃO DA SERRAGEM NA PRODUÇÃO DE COMPÓSITOS PLÁSTICO-MADEIRA

Esta pesquisa utilizou materiais reciclados para a produção de compósitos plástico-madeira ou WPC (wood-plastic composites). A madeira utilizada na forma de pó e a serragem foram misturadas ao polietileno de baixa densidade - PEBD reciclado em uma extrusora monorrosca de 75 mm de diâmetro. Foram testadas formulações com 10%, 20%, 40% e 50% (em peso) de madeira. O teor de umidade inicial da madeira foi de 5,16% para o pó e 7,32% para a serragem. O conjunto de temperaturas da extrusora variou de 135ºC a 150ºC. Os resultados mostraram que a produção dos compósitos foi possível para as formulações com até 20% de madeira. USE OF SAWDUST IN WOOD-PLASTIC COMPOSITES PRODUCTION Abstract This research aimed the use of recycled materials to produce WPC (wood-plastic composites). The wood was used as sawdust and wood flour and the plastic material used was the low density polyethylene LDPE recycled. The 75 mm single screw extruder was used in the composites production. Formulations with 10%, 20% 40% and 50% (in weight) of wood was tested. The wood humidity content was 5,16% for powder and 7,32% for sawdust. The extruder temperatures ranged from 135ºC to 150ºC. The results showed that the composite production was possible for the formulations up to 20% wood content

Fluorescence properties of amido-substituted 2,3-naphthalimides: Excited-state intramolecular proton transfer (ESIPT) fluorescence and responses to Ca2+ ions

2,3-Naphthalimide derivatives incorporating trifluoroacetamido (3a) and methansulfonamido (3b) functionalities at the 1-position were prepared and their intramolecular excited state proton transfer (ESIPT) fluorescence and responses to metal ions were investigated. Compound 3a displayed normal fluorescence in the amide form in toluene and MeCN and no response to metal cations in the corresponding amidate ion form. In contrast, compound 3b gave off dual emission assignable to normal and ESIPT fluorescence. Additionally, the amidate form of compound 3b displayed off-on fluorescence response to Ca2+

Photochemical reactions of halogenated aromatic 1,3-diketones in solution studied by steady state, one- and two-color laser flash photolyses

Photochemical processes of 4-tert-butyl-4'-methoxydibenzoylmethane (Avobenzone, AB), 4-phenylbenzoylbenzoyl-, 4-phenylbenzoyl-2'-furanyl- and 4-phenylbenzoyl-2'-thenoylmethanes (PB@Ph, PB@F and PB@T, respectively) substituted with Br and Cl at the C2 position were studied by stationary and laser flash photolyses in solution. The absorption spectral features showed that the molecular structures of the halogenated diketones are in the keto forms while those of halogen-free diketones are in the enol forms. The excited singlet and triplet state energies were determined from the absorption and emission spectra. From the absorption spectral changes upon steady state photolysis of brominated diketones in ethanol, the corresponding halogen-free diketones were formed due to Br elimination being the major photochemical process. The determined quantum yields for the formation of the halogen-free diketones were independent of the amount of dissolved oxygen, indicating that the elimination process is an event in the excited singlet (S-1) states. In contrast, from the observed absorption spectra obtained upon photolysis of chlorinated AB and PB@Ph, it was inferred that Norrish type I is the major photochemical reaction in the S-1 states in acetonitrile. Chlorinated PB@F and PB@T were found to undergo Cl elimination in the S-1 states in cyclohexane to form the corresponding halogen-free diketones. Laser photolysis studies of brominated AB in acetonitrile and ethanol provided a transient absorption spectrum ascribable to the Avobenzone radical (ABR) produced by debromination as the initial intermediate, followed by the AB formation in ethanol. The quenching rate constant of ABR by ethanol and the quantum yield of the AB formation via ABR were determined. These observations provided evidence that H-atom abstraction of ABR from ethanol is responsible for the AB formation. Conversely, laser flash photolysis of brominated and chlorinated PB@Ph, PB@F and PB@T demonstrated the formation of the triplet-triplet absorption spectra. No chemical reactions were found to occur in the triplet (T-1) states. Two-color two-laser photolysis studies were carried out on the T-1 state of chlorinated PB@Ph, PB@F and PB@T, resulting in the formation of the corresponding halogen-free diketones. These observations confirmed the occurrence of Cl elimination in the highly excited triplet (T-n, n >= 2) states. Based on the computed bond dissociation energies for the C-halogen and C-C bonds, switching mechanisms of dehalogenation and alpha-cleavage were discussed.This work has been supported by a Grant-in-Aid for Scientific Research (26288032) from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japanese Government. MY thanks Cosmetrogy Foundation for the financial support. Prof. Teruo Shinmyozu and Dr Kenta Goto at Kyusyu University are acknowledged for performing the mass spectroscopy of PP253 and PP283.Yamaji, M.; Suwa, Y.; Shimokawa, R.; Paris, C.; Miranda Alonso, MÁ. (2015). Photochemical reactions of halogenated aromatic 1,3-diketones in solution studied by steady state, one- and two-color laser flash photolyses. Photochemical & Photobiological Sciences. 14(9):1673-1684. https://doi.org/10.1039/c5pp00211g16731684149Gacoin, P. (1972). Studies of the Triplet State of Carbonyl Compounds. I. Phosphorescence of β‐Diketones. The Journal of Chemical Physics, 57(4), 1418-1425. doi:10.1063/1.1678420Vila, A. J., Lagier, C. M., & Olivieri, A. C. (1991). Proton transfer in solid 1-phenylbutane-1,3-dione and related 1,3-diones as studied by carbon-13 CPMAS NMR spectroscopy and AM1 calculations. The Journal of Physical Chemistry, 95(13), 5069-5073. doi:10.1021/j100166a031Gonzenbach, H., Hill, T. J., & Truscott, T. G. (1992). The triplet energy levels of UVA and UVB sunscreens. Journal of Photochemistry and Photobiology B: Biology, 16(3-4), 377-379. doi:10.1016/1011-1344(92)80025-qRoscher, N. M., Lindemann, M. K. O., Bin Kong, S., Cho, C. G., & Jiang, P. (1994). Photodecomposition of several compounds commonly used as sunscreen agents. Journal of Photochemistry and Photobiology A: Chemistry, 80(1-3), 417-421. doi:10.1016/1010-6030(94)01043-9Schwack, W., & Rudolph, T. (1995). Photochemistry of dibenzoyl methane UVA filters Part 1. Journal of Photochemistry and Photobiology B: Biology, 28(3), 229-234. doi:10.1016/1011-1344(95)07118-lAndrae, I., Bringhen, A., Böhm, F., Gonzenbach, H., Hill, T., Mulroy, L., & Truscott, T. . (1997). A UVA filter (4-tert-butyl-4′-methoxydibenzoylmethane): photoprotection reflects photophysical properties. Journal of Photochemistry and Photobiology B: Biology, 37(1-2), 147-150. doi:10.1016/s1011-1344(96)07330-7Dubois, M., Gilard, P., Tiercet, P., Deflandre, A., & Lefebvre, M. A. (1998). Photoisomerisation of the sunscreen filter PARSOL © 1789. Journal de Chimie Physique et de Physico-Chimie Biologique, 95(2), 388-394. doi:10.1051/jcp:1998149Gasparro, F. P., Mitchnick, M., & Nash, J. F. (1998). A Review of Sunscreen Safety and Efficacy. Photochemistry and Photobiology, 68(3), 243-256. doi:10.1111/j.1751-1097.1998.tb09677.xCantrell, A., & McGarvey, D. J. (2001). Photochemical studies of 4-tert-butyl-4′-methoxydibenzoylmethane (BM-DBM). Journal of Photochemistry and Photobiology B: Biology, 64(2-3), 117-122. doi:10.1016/s1011-1344(01)00226-3Chatelain, E., & Gabard, B. (2001). Photostabilization of Butyl methoxydibenzoylmethane (Avobenzone) and Ethylhexyl methoxycinnamate by Bis-ethylhexyloxyphenol methoxyphenyl triazine (Tinosorb S), a New UV Broadband Filter¶. Photochemistry and Photobiology, 74(3), 401. doi:10.1562/0031-8655(2001)0742.0.co;2Wetz, F., Routaboul, C., Lavabre, D., Garrigues, J.-C., Rico-Lattes, I., Pernet, I., & Denis, A. (2004). Photochemical Behavior of a New Long-chain UV Absorber† Derived from 4-tert-Butyl-4′-Methoxydibenzoylmethane¶. Photochemistry and Photobiology, 80(2), 316. doi:10.1562/2004-03-09-ra-106.1Damiani, E., Rosati, L., Castagna, R., Carloni, P., & Greci, L. (2006). Changes in ultraviolet absorbance and hence in protective efficacy against lipid peroxidation of organic sunscreens after UVA irradiation. Journal of Photochemistry and Photobiology B: Biology, 82(3), 204-213. doi:10.1016/j.jphotobiol.2005.03.011Dondi, D., Albini, A., & Serpone, N. (2006). Interactions between different solar UVB/UVA filters contained in commercial suncreams and consequent loss of UV protection. Photochemical & Photobiological Sciences, 5(9), 835. doi:10.1039/b606768aAspée, A., Aliaga, C., & Scaiano, J. C. (2007). Transient Enol Isomers of Dibenzoylmethane and Avobenzone as Efficient Hydrogen Donors toward a Nitroxide Pre-fluorescent Probe†. Photochemistry and Photobiology, 83(3), 481-485. doi:10.1562/2006-08-01-ra-992Damiani, E., Baschong, W., & Greci, L. (2007). UV-Filter combinations under UV-A exposure: Concomitant quantification of over-all spectral stability and molecular integrity. Journal of Photochemistry and Photobiology B: Biology, 87(2), 95-104. doi:10.1016/j.jphotobiol.2007.03.003Huong, S. P., Rocher, E., Fourneron, J.-D., Charles, L., Monnier, V., Bun, H., & Andrieu, V. (2008). Photoreactivity of the sunscreen butylmethoxydibenzoylmethane (DBM) under various experimental conditions. Journal of Photochemistry and Photobiology A: Chemistry, 196(1), 106-112. doi:10.1016/j.jphotochem.2007.11.023Mturi, G. J., & Martincigh, B. S. (2008). Photostability of the sunscreening agent 4-tert-butyl-4′-methoxydibenzoylmethane (avobenzone) in solvents of different polarity and proticity. Journal of Photochemistry and Photobiology A: Chemistry, 200(2-3), 410-420. doi:10.1016/j.jphotochem.2008.09.007Paris, C., Lhiaubet-Vallet, V., Jiménez, O., Trullas, C., & Miranda, M. Á. (2009). A Blocked Diketo Form of Avobenzone: Photostability, Photosensitizing Properties and Triplet Quenching by a Triazine-derived UVB-filter. Photochemistry and Photobiology, 85(1), 178-184. doi:10.1111/j.1751-1097.2008.00414.xYamaji, M., & Kida, M. (2013). Photothermal Tautomerization of a UV Sunscreen (4-tert-Butyl-4′-methoxydibenzoylmethane) in Acetonitrile Studied by Steady-State and Laser Flash Photolysis. The Journal of Physical Chemistry A, 117(9), 1946-1951. doi:10.1021/jp312774eOguchi-Fujiyama, N., Miyazawa, K., Kikuchi, A., & Yagi, M. (2012). Photophysical properties of dioctyl 4-methoxybenzylidenemalonate: UV-B absorber. Photochemical & Photobiological Sciences, 11(10), 1528. doi:10.1039/c2pp25101aYamaji, M., Paris, C., & Miranda, M. Á. (2010). Steady-state and laser flash photolysis studies on photochemical formation of 4-tert-butyl-4′-methoxydibenzoylmethane from its derivative via the Norrish Type II reaction in solution. Journal of Photochemistry and Photobiology A: Chemistry, 209(2-3), 153-157. doi:10.1016/j.jphotochem.2009.11.008Yamaji, M., Wakabayashi, S., Ueda, S., Shizuka, H., & Tobita, S. (2003). Laser photolysis studies of endoergonic triplet energy transfer in solution by observing the carbon–sulfur bond cleavage of triplet-sensitized naphthylmethyl phenyl sulfide. Chemical Physics Letters, 368(1-2), 41-48. doi:10.1016/s0009-2614(02)01816-xCogné-Laage, E., Allemand, J.-F., Ruel, O., Baudin, J.-B., Croquette, V., Blanchard-Desce, M., & Jullien, L. (2004). Diaroyl(methanato)boron Difluoride Compounds as Medium-Sensitive Two-Photon Fluorescent Probes. Chemistry - A European Journal, 10(6), 1445-1455. doi:10.1002/chem.200305321Košmrlj, J., Kočevar, M., & Polanc, S. (1996). A New Convenient Bromination with KBrO3/KBr/Dowex®. Synthetic Communications, 26(19), 3583-3592. doi:10.1080/00397919608003769Košmrlj, B., & Šket, B. (2007). Photocyclization of 2-Chloro-Substituted 1,3-Diarylpropan-1,3-diones to Flavones. Organic Letters, 9(20), 3993-3996. doi:10.1021/ol701654cFoerster, E. W., Grellmann, K. H., & Linschitz, H. (1973). Reaction patterns and kinetics of the photoconversion of N-methyldiphenylamine to N-methylcarbazole. Journal of the American Chemical Society, 95(10), 3108-3115. doi:10.1021/ja00791a004Hoshino, M., & Koizumi, M. (1972). Order of Quencher Participation in Photochemistry. I. Proton Transfer from the Excitedp-Hydroxybenzophenone in Mixed Solvents of Cyclohexane and Alcohols. Bulletin of the Chemical Society of Japan, 45(9), 2731-2736. doi:10.1246/bcsj.45.2731Yamaji, M., Aihara, Y., Itoh, T., Tobita, S., & Shizuka, H. (1994). Thermochemical Profiles on Hydrogen Atom Transfer from Triplet Naphthol and Proton-Induced Electron Transfer from Triplet Methoxynaphthalene to Benzophenone via Triplet Exciplexes Studied by Laser Flash Photolysis. The Journal of Physical Chemistry, 98(28), 7014-7021. doi:10.1021/j100079a021Okamoto, H., Takane, T., Gohda, S., Kubozono, Y., Sato, K., Yamaji, M., & Satake, K. (2014). Efficient Synthetic Photocyclization for Phenacenes Using a Continuous Flow Reactor. Chemistry Letters, 43(7), 994-996. doi:10.1246/cl.140182S. L. Murov , I.Carmichael and G. L.Hug, Handbook of Photochemistry, Second Edition, Revised and Expanded, Marcel Dekker, Inc., New York, 2nd edn, Revised and expanded edn., 1993Yamaji, M., Kojima, A., & Tobita, S. (2007). Stepwise Laser Photolysis Studies of β-Bond Cleavage in Highly Excited Triplet States of Biphenyl Derivatives Having C−O Bonds. The Journal of Physical Chemistry A, 111(5), 770-776. doi:10.1021/jp065782iYamaji, M. (2008). 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USE OF SUGARCANE BAGASSE AND CANDEIA WASTE FOR SOLID BIOFUELS PRODUCTION

AbstractThe use of agroforestry residues as an energy source acts as an alternative to conventional fossil fuels like petroleum and coal. The aim of this study was to evaluate the energy recovery of candeia sawdust and sugarcane bagasse wastes in the preparation of blends for the production of briquettes. Residues characterization took place by their size classification, proximate analysis and calorific value. Six treatments were applied: T1 (100% cane bagasse), T2 (90% cane bagasse + 10% candeia), T3 (75% cane bagasse + 25% candeia), T4 (50% cane bagasse + 50% candeia), T5 (25% cane bagasse + 75% candeia) and T6 (100% candeia sawdust). Briquettes were assessed by their density, dimensional stability and mechanical strength. It was observed that the higher the proportion of candeia sawdust in the treatment, the lower the volumetric expansion of the briquettes and the larger their mechanical strength. Results indicated that the mixture of sugarcane bagasse and candeia sawdust wastes in the blends was an efficient alternative to overcome the problems related to the high hygroscopicity and low durability of briquettes made using only sugarcane bagasse, thus allowing production of stable and resistant briquettes in all the studied treatments.Keywords: Biofuel; biomass; wastes; briquettes. ResumoAproveitamento de resíduos de bagaço de cana-de-açúcar e candeia para a produção de biocombustíveis sólidos. A utilização de resíduos agroflorestais como fonte de energia funciona como uma alternativa aos combustíveis fósseis convencionais como o petróleo e o carvão mineral. O objetivo deste trabalho foi avaliar o aproveitamento energético dos resíduos de serragem de candeia e bagaço de cana-de-açúcar na confecção de blendas para produção de briquetes. Os resíduos foram caracterizados a partir de sua classificação granulométrica, análise imediata e poder calorífico. Foram realizados seis tratamentos: T1 (100% bagaço de cana), T2 (90% bagaço de cana + 10% candeia), T3 (75% bagaço de cana + 25% candeia), T4 (50% bagaço de cana + 50% candeia), T5 (25% bagaço de cana + 75% candeia) e T6 (100% serragem de candeia). Os briquetes foram avaliados quanto a sua densidade, estabilidade dimensional e resistência mecânica. Observou-se que quanto maior a proporção de serragem de candeia nos tratamentos, menor foi a expansão volumétrica dos briquetes e maior foi a sua resistência mecânica. Os resultados indicaram que o uso das blendas foi uma alternativa eficiente para contornar os problemas relacionados à alta higroscopicidade e à baixa durabilidade dos briquetes confeccionados apenas com o bagaço de cana-de-açúcar, permitindo assim a obtenção de briquetes estáveis e resistentes para todos os tratamentos testados.Palavras-chave: Biocombustível; biomassa; resíduos; briquetes.AbstractThe use of agroforestry residues as an energy source acts as an alternative to conventional fossil fuels like petroleum and coal. The aim of this study was to evaluate the energy recovery of candeia sawdust and sugarcane bagasse wastes in the preparation of blends for the production of briquettes. Residues characterization took place by their size classification, proximate analysis and calorific value. Six treatments were applied: T1 (100% cane bagasse), T2 (90% cane bagasse + 10% candeia), T3 (75% cane bagasse + 25% candeia), T4 (50% cane bagasse + 50% candeia), T5 (25% cane bagasse + 75% candeia) and T6 (100% candeia sawdust). Briquettes were assessed by their density, dimensional stability and mechanical strength. It was observed that the higher the proportion of candeia sawdust in the treatment, the lower the volumetric expansion of the briquettes and the larger their mechanical strength. Results indicated that the mixture of sugarcane bagasse and candeia sawdust wastes in the blends was an efficient alternative to overcome the problems related to the high hygroscopicity and low durability of briquettes made using only sugarcane bagasse, thus allowing production of stable and resistant briquettes in all the studied treatments.Keywords: Biofuel; biomass; wastes; briquettes. ResumoAproveitamento de resíduos de bagaço de cana-de-açúcar e candeia para a produção de biocombustíveis sólidos. A utilização de resíduos agroflorestais como fonte de energia funciona como uma alternativa aos combustíveis fósseis convencionais como o petróleo e o carvão mineral. O objetivo deste trabalho foi avaliar o aproveitamento energético dos resíduos de serragem de candeia e bagaço de cana-de-açúcar na confecção de blendas para produção de briquetes. Os resíduos foram caracterizados a partir de sua classificação granulométrica, análise imediata e poder calorífico. Foram realizados seis tratamentos: T1 (100% bagaço de cana), T2 (90% bagaço de cana + 10% candeia), T3 (75% bagaço de cana + 25% candeia), T4 (50% bagaço de cana + 50% candeia), T5 (25% bagaço de cana + 75% candeia) e T6 (100% serragem de candeia). Os briquetes foram avaliados quanto a sua densidade, estabilidade dimensional e resistência mecânica. Observou-se que quanto maior a proporção de serragem de candeia nos tratamentos, menor foi a expansão volumétrica dos briquetes e maior foi a sua resistência mecânica. Os resultados indicaram que o uso das blendas foi uma alternativa eficiente para contornar os problemas relacionados à alta higroscopicidade e à baixa durabilidade dos briquetes confeccionados apenas com o bagaço de cana-de-açúcar, permitindo assim a obtenção de briquetes estáveis e resistentes para todos os tratamentos testados.Palavras-chave: Biocombustível; biomassa; resíduos; briquetes

Harvester and Forwarder machines efficiency and operational performance in forest harvesting

The knowledge on productive capacity and variable elements that affect machines efficiency is essential for optimizing operations in forest harvesting. This study aimed to evaluate Harvester and Forwarder machines efficiency and operational performance, for forest exploitation, in the south of the Bahia State, Brazil. Data concerning the number of programmed and effective working hours, as well as reasons for machine downtime, were collected from historical archives, from October 2010 to September 2011. Based on these data, the total working hours, operational efficiency, and mechanical availability were calculated. Harvester machines showed an average of total working hours of 480 hours and 18 minutes, being 75.6% (363.2 hours) of effective work and 24.4% (117.1 hours) of downtime. Forwarder machines showed an average of total working hours of 481 hours and 36 minutes, being 84.7% (407.9 hours) of effective work and 15.3% (73.7 hours) of downtime. The average operational efficiency was of 73.2%, for the Harvester, and 82.2%, for the Forwarder, and technical downtimes, such as displacements and corrective and preventive maintenances, comprised the main reason for explaining those values. The machines operational performance showed to be adequate, according to time distribution, with 76% and 85% of effective working time, respectively for the Harvester and Forwarder, and an average of 89% for mechanical availability, for both machines, which showed satisfactory operational efficiency (above 70%)

Efeito da radiação solar na dinâmica de uma floresta

The flux of energy irradiated by the sun is essential to the earth’s life. The sun is the source of energy for photosynthesis and it is very important to regulate the vegetable’s life. The present paper is about the solar radiation influence on the dynamics of the forest. Thus, first it was made a brief explanation about the species, classification in ecological groups.The objective was to learn about the solar radiation influence on the inside of forest at differents stages and at the clearing formation. In order to understand the radiation effect starting on the seed germination until the structuring and flora composition of forest

USE OF CASTOR OIL PLANT PIE FOR SOLID BIOFUEL PRODUCTION

The objective of this study was the characterization, analysis and compaction of residues from castor oil plant pie extraction to verify its potential as solid biofuel. The chemical analysis, the mechanical test and the gross calorific value had satisfactory results. With the extraction of residual oil of the material there was a decrease on the high heating value. The produced briquettes presented good longitudinal expansion as well as mechanical strenght, however the presence of residual oil had influence on their strenght. In conclusion, the castor oil plant pie possesses  energetic characteristics suitable for solid biofuel production, in addition it contributes with the reduction of industrial waste amount