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Attempts have been made for the first time to produce a friction material with thermal sensitive modulus by the inclusion of combined plastic/rubber properties of thermoplastic elastomers (TPE) as viscoelastic polymeric materials into the formulation for the purpose of increasing the damping behavior. In order to evaluate the viscoelastic parameters such as loss factor (tan δ) and elastic modulus (E’) for the friction material, dynamic mechanical analyzer (DMA) was used. Styrene-butadiene-styrene (SBS), styrene-ethylene-butylene-styrene (SEBS) and nitrile rubber/polyvinyl chloride (NBR/PVC) blend systems were used as TPE materials. However, NBR/PVC and SEBS were found to be more effective in damping behavior. All the friction materials containing TPEs exhibited more damping behavior at a wide range of temperature compared with the reference sample.

Estudos tratando do processo de outsourcing em importantes setores industriais não-líderes ao redor do mundo, bem como propondo modelos práticos para a condução do processo de repasse de atividades de manufatura como um todo, e não somente no estágio de decisão, são difíceis de encontrar. Nesse contexto, este artigo procura apresentar um modelo prático para conduzir o processo de outsourcing na sua totalidade, dividindo-o em quatro estágios principais (motivação, decisão, implementação e gestão). O modelo foi aplicado com sucesso em um caso envolvendo duas companhias multinacionais operando no Brasil, em uma cadeia de suprimentos do setor de resinas fenólicas. Os resultados ressaltam, principalmente, a adequação do modelo proposto, no sentido de enfatizar os desafios em cada fase e as habilidades necessárias para enfrentá-los, bem como a importância da construção de parcerias baseadas na confiança e na integração por meio da tecnologia da informação.Studies related to the outsourcing process in several important non-leading industries worldwide and also regarding the existence of practical models and frameworks to guide the entire process and not only the decision-making stage are rare to find. In this context, this article presents a practical model to guide the whole outsourcing process, divided into four main stages (motivation, decision, implementation and management). It was successfully applied in a case involving two multinational companies operating in Brazil, in a supply chain of the phenolic resin industry. The results highlighted mainly the adequacy of the proposed model, as well as the importance of constructing a partnership based on trust and integration by information technology.

Polymeric materials are increasingly replacing metallic materials as a result of their properties. In this work a composite of phenolic resin and sugar cane pulp was developed. The sugar cane pulp has been previously alkalinised, dried, and milled and the particles had been classified in a range of grain sizes. Experimental assays were performed, varying the proportion of the resin and the reinforcement and the size of the cane pulp fibre, keeping the pressure and moulding temperature constant. These composites were characterised according to physical and chemical properties, through test bodies produced in moulds according to ASTM standards. The experiments performed showed that the use of sugar cane pulp as reinforcement in polymeric composites represents an option for reducing costs in industrial applications, thus suggesting a significant industrial applicability of the product.

Polymeric materials are increasingly replacing metallic materials as a result of their properties. In this work a composite of phenolic resin and sugar cane pulp was developed. The sugar cane pulp has been previously alkalinised, dried, and milled and the particles had been classified in a range of grain sizes. Experimental assays were performed, varying the proportion of the resin and the reinforcement and the size of the cane pulp fibre, keeping the pressure and moulding temperature constant. These composites were characterised according to physical and chemical properties, through test bodies produced in moulds according to ASTM standards. The experiments performed showed that the use of sugar cane pulp as reinforcement in polymeric composites represents an option for reducing costs in industrial applications, thus suggesting a significant industrial applicability of the product.

O objetivo deste trabalho foi avaliar a influência da estrutura do colchão e de diferentes concentrações de adesivo nas propriedades de chapas de partículas orientadas (strands), contendo 50% de partículas de Eucalyptus grandis e 50% de Pinus elliottii. Foram avaliados três tipos de estruturas. Em uma das estruturas as partículas foram distribuídas em camadas indistintas. Uma segunda estrutura foi constituída de 50% de partículas de eucalipto no miolo do colchão e 25% de pinus em cada face. A terceira estrutura foi formada por 50% de madeira de pinus no miolo e 25% de eucalipto nas faces. Cada uma dessas estruturas foi aglutinada com 4, 6 ou 8% de sólidos resinosos em relação ao peso seco das partículas de um adesivo fenólico com viscosidade de 350 cps, pH 12,15 e 47,63% de sólidos. Para os nove tratamentos foram feitas três repetições, totalizando 27 chapas. As chapas foram submetidas aos testes de flexão estática, ligação interna, arranque de parafuso, inchamento em espessura e absorção de água, obedecendo aos critérios da norma ASTM D 1037 – 91. De modo geral os painéis feitos com 8% de adesivo apresentaram melhores resultados que os demais. Para a maioria das propriedades mecânicas, inclusive para os painéis fabricados com 4% de resina, obtiveram-se resultados superiores àqueles estabelecidos pela Norma CSA O437-93. Contudo, nenhum tratamento produziu chapas com inchamento em espessura inferior ao valor máximo permitido por aquela norma. Não se verificou diferença estatística, ocasionada pela estrutura de colchão, entre todas as propriedades avaliadas. This work aimed to evaluate the influence of mat structure and different adhesive contents on the properties of oriented strand boards (OSB) made of 50% Eucalyptus grandis and 50% Pinus elliottii strands. Three types of structure were employed: the first consisted of indistinct layers, the second of boards made of 50% eucalypt strands in the core and 25% pine on each face, and the third structure containing eucalypt (25%) in each face, and core Pinus (50%). A total of 4%, 6% or 8% of phenolic resin, based on the oven-dry weight of the particles, was applied on all the structures. Resin total solids were equal to 47.63%, pH 12.15 and viscosity 350cps. A total of 27 boards, including three replications, were manufactured and tested for static bending (MOR and MOE), internal board, screw withdrawal, thickness swelling and water absorption, according to ASTM D 1037 – 91 procedures. In general, boards using 8% of resin obtained the best results. Most of the treatments, including the boards containing 4% adhesive, achieved mechanical resistances higher than those established under CSA-O437-93 standard. None of the treatments was sufficiently good for thickness swelling. Mat structure had no effect on board properties.

The kinetics of the polymerisation of resol-type phenolic resins has been modelled taking into account the phenol and formaldehyde equilibria. The kinetic parameters were obtained by adjusting the experimental evolution of phenol, formaldehyde and initial addition products during synthesis. The influence of the type and amount of catalyst, the initial pH, the initial formaldehyde-to-phenol molar ratio and the condensation temperature, on the kinetics rate constants was quantified. Fil: Riccardi, Carmen Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina Fil: Astarloa Aierbe, G.. Bakelite-Ibérica; España Fil: Echeverría, J. M.. Bakelite-Ibérica; España Fil: Mondragon, I.. Universidad del País Vasco; España

This work revealed electrical and mechanical properties of phenolic resin composites made from Gigantochloa apus carbon fiber, or bamboo carbon fiber reinforced polymer (BCFRP) composites. Bamboo fibers were carbonized at a temperature of 800°C, with a temperature rate of 4.2°C/minutes, held for 120 minutes. Carbon fibers were arranged in one direction. Phenolic resin weights were determined to be 5% to 10%. Higher carbon fiber contents indicated higher electrical conductivity of the composite. Increased carbon fiber content tends to increase the tensile strength of the composite, although this result was unstable. Mechanical instability was caused by cracks and cavities formed between the fiber and the phenolic resin. Cracks primarily occurred at the interface between bamboo carbon fibers and phenolic resin. This was most likely caused by the intrusion of air at the time the phenolic resin was cast. This air became trapped in between the fiber surfaces. Bamboo carbon fiber is fragile and easily broken in both longitudinal and transverse directions. When an air bubble bursts between carbon fibers, the carbon fiber braid breaks up, causing electrical resistance in composites. Not all carbon fibers in phenolic resin disconnect this way; most still form the strands that can conduct electricity. These breaks are the cause of the instability of the electrical conductivity properties of the composite.

Oil palm wood (OPW) is still difficult to utilize efficiently due to its low strength, non-durability, low dimensional stability, and poor machinability. This study was conducted to investigate semi-curing of OPW with low-molecular weight phenol formaldehyde (Lmw-PF) by a combination of oven and microwave heating. Four main processes in a modified compreg method were used, i.e. drying, impregnation, resin semi-curing heating, and hot-pressing densification. Heating type had a significant effect on the physical properties of treated OPW. The combination of the heating methods used a much shorter time compared to heating by oven only, where over 24 to 30 h were needed to dry the treated OPW.

O processo de cura envolve reações de múltiplos mecanismos e sua investigação pode ser feita por meio de várias técnicas. Este trabalho apresenta a comparação entre dois métodos que utilizam parâmetros reométricos para o cálculo da constante cinética de cura (k) relacionada com a cura da borracha nitrílica com a resina fenólica, tendo o policloropreno e o óxido de zinco como sistema ativador. Foi utilizado o planejamento de experimentos fatorial completo (2³ + ponto central) como base para a preparação das formulações e análise dos resultados. Os resultados obtidos identificaram a influência da temperatura, da quantidade de cada um dos componentes das formulações e da adequação dos métodos de avaliação para o processo de cura da borracha nitrílica pela resina fenólica.The cure process involves reactions with multiple mechanisms and its investigation can be followed by using different techniques. This work compares two methods in which rheometric parameters are used to calculate the cure rate constant (k), related to the cure of nitrile rubber with phenolic resin and having polychloroprene and zinc oxide as the activators. A complete factorial (2³ + central point) experimental design was used as base to prepare the formulations and to analyse the results. The results obtained identified the influence of the temperature, the amount of each component in the formulation and the suitability of the evaluation methods for the cure process of nitrile rubber with phenolic resin.

Neste trabalho, pré-polímeros do tipo fenólico ( resóis ) e lignina - fenol ( 40% w/w ) foram sintetizados e usados na preparação de matrizes em compósitos reforçados com diversas fibras vegetais : sisal, curaua e bagaço de cana-de açúcar, sendo as fibras previamente extraídas com cicloexano/etanol. Os compósitos reforçados com sisal apresentaram um aumento significativo na resistência ao impacto, quando comparados com a matriz termofixa. As fibras de curaua foram submetidas a um tratamento adicional com NaOH 10%, tendo os respectivos compósitos apresentado também resistência ao impacto superior ao da matriz fenólica não reforçada., enquanto que os compósitos reforçados com bagaço de cana de açúcar apresentaram pequena alteração nesta propriedade.In this work phenolics pre-polymer (resol type) and pre-polymer lignin-phenol (40% w/w sugar cane bagasse lignin) were synthesized. These pre-polymers were used to prepare matrice of several composites reinforced with bagasse fibers, sisal fibers and curaua fibers. The bagasse and sisal fibers were extracted with cyclohexane/ethanol. The improvement in impact strength was small for sugar cane bagasse reinforced composites and it was very significant for sisal reinforced composites. The curaua fibers were submitted to the same extration above mentioned and then treated with a 10% solution of NaOH. The composites containing treated curaua fibers also presented improvement in the impact strength.

After blending the triblock copolymer, poly(ethylene oxide-b-propylene oxide-b-ethylene oxide) (PEO-b-PPO-b-PEO) with novolac-type phenolic resin, Fourier transform infrared spectroscopy revealed that the ether groups of the PEO block were stronger hydrogen bond acceptors for the OH groups of phenolic resin than were the ether groups of the PPO block. Thermal curing with hexamethylenetetramine as the curing agent resulted in the triblock copolymer being incorporated into the phenolic resin, forming a nanostructure through a mechanism involving reaction-induced microphase separation. Mild pyrolysis conditions led to the removal of the PEO-b-PPO-b-PEO triblock copolymer and formation of mesoporous phenolic resin. This approach provided a variety of composition-dependent nanostructures, including disordered wormlike, body-centered-cubic spherical and disorder micelles. The regular mesoporous novolac-type phenolic resin was formed only at a phenolic content of 40–60 wt %, the result of an intriguing balance of hydrogen bonding interactions among the phenolic resin and the PEO and PPO segments of the triblock copolymer.

Influences of the amount of phenolic, curing temperature and curing time on the Mechanical Properties of phenolic/fiber composite were investigated by using two-level factorial design. The latter was used to determine the affects of those factors on mechanical properties. The purpose of this study was to investigate the affects of amount of phenolic, curing temperature and curing time of the composite to determine the best condition for mechanical properties according to MIL-I-24768 by the tensile strength is more than 103 MPa., {"references":["W. Smith and J. Hashemi, \"Foundations of materials science and \nengineering,\" 4th Ed. New York: McGraw-Hill, 2005.","M. L. Gregori, E. A. Barros, G. P. Filho, L. C. Pardini and S. F. Costa, \n\"Ablative and mechanical properties of quartz phenolic composites\", \nInstitute of Aeronautics and Space, Brazil.","M.H. Choi, B.H. Jeon, I.J. Chung, \"The effect of coupling agent on \nelectrical and mechanical properties of carbon fiber/phenolic resin \ncomposites\", Department of Chemical Engineering, Korea Advanced \nInstitute of Science and Technology, South Korea, July 1999.","W. D. callister, \"Materials science and engineering an introduction,\" 6th\nEd. New York: John Wiley & Sons, Inc, 2003.","S. Vineta and B. Gordana, \"Composite material based on an ablative \nphenolic resin and carbon fibers\", Faculty of Technology and \nMetallurgy, Sts. Cyril and Methodius University, February 2009.","J. Lu, \"Synthesis of phenolic resin amines and solid-state NMR of \nphenolic resin in NASA rocket motors\", department of chemistry, \nMississippi state, Mississippi, December 1998.","L. C. Dorwort, G. L. Gardiner and G. M. Mellema, \"Essentials of \nAdvanced composite fabrication & repair\", Newcastle: Aviation \nSupplies & Academics, Inc, 2009."]}

The adoption of bonded magnets in substitution of ferrites in small PM motors is an interesting challenge and represents a good opportunity for motor designers. The proposed analysis regards the production of bonded magnets based on rare earth powder mixed with different resins; the effect of the process parameters, in particular the pressure on the mold, is evaluated by means of measurements on the magnets, FEM simulations and experimental tests on prototypes. The opportunity to vary also the resin percentage is briefly proposed as a glance on future developments of the work.

In this study, an ablation, mechanical and thermal properties of a rocket motor insulation from phenolic/ fiber matrix composites forming a laminate with different fiber between fiberglass and locally available synthetic fibers. The phenolic/ fiber matrix composites was mechanics and thermal properties by means of tensile strength, ablation, TGA and DSC. The design of thermal insulation involves several factors.Determined the mechanical properties according to MIL-I-24768: Density >1.3 g/cm3, Tensile strength >103 MPa and Ablation, {"references":["NASA space vehicle design criteria (Chemical propulsion) (1975). Solid\nrocket motor nozzles, National aeronautics and space administration,\nUnited state.","George P. Sutton and Oscar biblarz (2001). Rocket Propulsion Element,\n7th edition, John willey& sons, New York.","Practice no.PD-ED-1218 (2005). Application of ablative composites to\nnozzles for reusable solid rocket motors, Marshall space flight center,\nUnited state.","Guideline NO.GD-ED-2205 (2005). Design and manufacturing\nguideline for aerospace composites, Marshall space flight center. Page 8.","Natali, M., Kenny, J. and Torre, L. (2010). Phenolic matrix\nnanocomposites based on commercial grade resols: Synthesis and\ncharacterization, Composite Science and Technology,\nvol.70(2010),January 2010, pp.571-577.","Jiang, Y., Zhang, X., HE, J., Yu, L., and Yang, R. (2011). Effect of\npolyphenenylsisesquioxane on the ablative and flame-retardation\nproperties of ethylene propylene diene monomer (EPDM) composite,\nPolymer Degradation and Stability, vol.96(2011),January 2011, pp.949-\n954.","Lu, J. (1998). Synthesis of Phenolic Resin Amines and Solid-State NMR\nof Phenolic Resin in NASA Rocket Motors, Mississippi State\nUniversity.","Firouzmanesh MR., ArefAzar A., (2003). Study of thermal stability and\nablation behavior of carbon/epoxy-novolac composites, Journal of\nApplied Polymer Science, vol.88(2003), June 2003, pp. 2455-2461."]}

O objetivo deste estudo foi analisar a viabilidade técnica do uso de resíduo industrial composto de resina fenólica, lignocelulose, carbonato de cálcio, talco, mica e negro de fumo como carga para o polipropileno (PP). Compósitos de PP com 10, 15 e 20% em massa do resíduo foram processados em extrusora de rosca dupla e moldados por injeção. Os compósitos moldados foram caracterizados por microscopia eletrônica de varredura (MEV), análises térmicas (DSC e TGA), ensaios mecânicos (tração, flexão e impacto) e ensaio termo-mecânico (HDT). Os compósitos moldados apresentaram partículas do resíduo com tamanhos inferiores a 500 µm dispersas na matriz de polipropileno. As partículas do resíduo atuaram como agentes de nucleação da cristalização do PP. Os compósitos apresentaram maior resistência à degradação térmica, balanço de rigidez e resistência com aumento do módulo sob flexão e diminuição da resistência à tração, manutenção da resistência ao impacto sob entalhe, e aumento da temperatura de distorção ao calor (HDT). O desempenho dos compósitos demonstrou que o resíduo industrial de resina fenólica pode ser empregado como carga funcional para o PP. Além disso, os compósitos desenvolvidos representam uma alternativa para a reciclagem do resíduo industrial de resina fenólica. The aim of this study was to assess the technical feasibility of using industrial waste composed of phenolic resin, lignocellulose, calcium carbonate, talc, mica and carbon black as filler for polypropylene (PP). Composites of PP with 10, 15 and 20 wt% of the waste were processed in a twin-screw extruder followed by injection molding. Molded composites were characterized by scanning electron microscopy (SEM), thermal analyses (DSC and TGA), mechanical tests (tensile, flexural and impact) and thermo-mechanical test (HDT). The composites showed residue particles with sizes less than 500 µm dispersed in the PP matrix. The residue particles acted as nucleating agents for PP crystallization. The composites showed greater thermal degradation resistance as compared to PP. The composites showed a balance of stiffness and mechanical strength with increase of the flexural module and decrease of the tensile strength. The notched impact strength was not altered and the heat distortion temperature (HDT) of the composites was increased as compared to PP. The performance of the composites developed here showed that the industrial waste based on phenolic resin can be used as functional filler for PP. Furthermore, these composites are an alternative for the recycling of the phenolic resin industrial waste.

The ability to control the carbon nanotube (CNT) dispersion in polymers is considered the key to most applications of nanotube/polymer composites. The carbon nanotube dispersion into water with different surfactants, as well as its incorporation into phenolic resins, was investigated. Ultrasonication of liquid suspensions was used to prepare stable dispersions. In order to evaluate the best surfactant to be used, light scattering and UV-Visible spectroscopy were employed. The structure of CNT reinforced of phenolic resin was analyzed in function of the concentration and type of surfactant, sonication power and time. It was also evaluated the influence in the dispersion by using the glass temperature transition properties being obtained by dynamic mechanical analyses and impact energy. A capacidade de controlar a dispersão de nanotubos de carbono (CNT) em polímeros é considerada ponto chave para a maioria das aplicações de compósitos de nanotubo/polímero. A dispersão de nanotubos de carbono em água com diferentes surfactantes, assim como sua incorporação em resinas fenólicas, foi investigada. Ultrasonicação de suspenções líquidas foi usada para preparar dispersões estáveis. A fim de se avaliar o melhor surfactante a ser usado, espalhamento de luz e espectroscopia UV-Visível foram empregados. A estrutura de CNT reforçada de resina fenólica foi analisada em função da concentração e tipo de surfactante, potência e tempo de sonicação. A influência da dispersão pelo uso das propriedades de transição de temperatura vítrea também foi avaliada, sendo obtida por análise mecânica dinâmica e energia de impacto.

Glyoxal, which can be obtained from biomass (as by lipids oxidation), is non-toxic and non-volatile. It was used as a substitute of formaldehyde, which does not have these properties, in the synthesis of a novolac-type phenolic resin, using oxalic acid as a catalyst, which can also be obtained from renewable sources. The glyoxal-phenol resin was used in the preparation of composites reinforced with microcrystalline cellulose (MCC 30, 50, and 70% w/w). Scanning electron microscopy (SEM) images of the fractured surfaces showed that the composites presented a good reinforcement/matrix interface. This can be attributed to the high surface area of the MCC and also to the presence of polar groups (hydroxyl) in both cellulose and matrix, which allowed the formation of hydrogen bonds, leading to a good adhesion between the components present at the interface. Dynamic mechanical thermoanalysis (DMTA) showed that all of the obtained composites have high storage modulus at room temperature. Moreover, the composite reinforced with 30% of MCC showed the lowest water absorption, almost the same as that of the phenolic thermoset, which is used in industrial applications. The results showed that composites with good properties can be prepared using high proportions of materials obtained from biomass., Glioxal pode ser obtido a partir de biomassa (como da oxidação de lipídeos) e não é tóxico ou volátil, tendo sido por isso utilizado no presente trabalho como substituto de formaldeído na preparação de resina fenólica do tipo novolaca, sendo usado como catalisador o ácido oxálico, que também pode ser obtido de fontes renováveis. A resina glioxal-fenol foi utilizada na preparação de compósitos reforçados com celulose microcristalina (CM, 30, 50 e 70% em massa), uma celulose com elevada área superficial. As imagens de microscopia eletrônica de varredura (MEV) das superfícies fraturadas demonstraram que os compósitos apresentaram boa interface reforço/matriz, consequência da elevada área superficial da CM e presença de grupos polares (hidroxilas) tanto na matriz como na celulose, o que permitiu a formação de ligações hidrogênio, favorecendo a compatibilidade entre ambas. A análise térmica dinâmico-mecânica (DMTA) demonstrou que todos os compósitos apresentaram elevado módulo de armazenamento à temperatura ambiente. Além disso, o compósito reforçado com 30% de CM apresentou baixa absorção de água, comparável à do termorrígido fenólico, que é utilizado em escala industrial. Os resultados demonstraram que compósitos com boas propriedades podem ser preparados usando elevada proporção de materiais obtidos de biomassa.

Glioxal pode ser obtido a partir de biomassa (como da oxidação de lipídeos) e não é tóxico ou volátil, tendo sido por isso utilizado no presente trabalho como substituto de formaldeído na preparação de resina fenólica do tipo novolaca, sendo usado como catalisador o ácido oxálico, que também pode ser obtido de fontes renováveis. A resina glioxal-fenol foi utilizada na preparação de compósitos reforçados com celulose microcristalina (CM, 30, 50 e 70% em massa), uma celulose com elevada área superficial. As imagens de microscopia eletrônica de varredura (MEV) das superfícies fraturadas demonstraram que os compósitos apresentaram boa interface reforço/matriz, consequência da elevada área superficial da CM e presença de grupos polares (hidroxilas) tanto na matriz como na celulose, o que permitiu a formação de ligações hidrogênio, favorecendo a compatibilidade entre ambas. A análise térmica dinâmico-mecânica (DMTA) demonstrou que todos os compósitos apresentaram elevado módulo de armazenamento à temperatura ambiente. Além disso, o compósito reforçado com 30% de CM apresentou baixa absorção de água, comparável à do termorrígido fenólico, que é utilizado em escala industrial. Os resultados demonstraram que compósitos com boas propriedades podem ser preparados usando elevada proporção de materiais obtidos de biomassa. Glyoxal, which can be obtained from biomass (as by lipids oxidation), is non-toxic and non-volatile. It was used as a substitute of formaldehyde, which does not have these properties, in the synthesis of a novolac-type phenolic resin, using oxalic acid as a catalyst, which can also be obtained from renewable sources. The glyoxal-phenol resin was used in the preparation of composites reinforced with microcrystalline cellulose (MCC 30, 50, and 70% w/w). Scanning electron microscopy (SEM) images of the fractured surfaces showed that the composites presented a good reinforcement/matrix interface. This can be attributed to the high surface area of the MCC and also to the presence of polar groups (hydroxyl) in both cellulose and matrix, which allowed the formation of hydrogen bonds, leading to a good adhesion between the components present at the interface. Dynamic mechanical thermoanalysis (DMTA) showed that all of the obtained composites have high storage modulus at room temperature. Moreover, the composite reinforced with 30% of MCC showed the lowest water absorption, almost the same as that of the phenolic thermoset, which is used in industrial applications. The results showed that composites with good properties can be prepared using high proportions of materials obtained from biomass.

Plywood manufactured from thin veneer sheets of different species is one of the most traditional structural composite panels. The objective of this study was to produce experimental plywood panels using a temperature of 100 °C, which is 10 to 30% lower than typical press temperature of plywood manufacture. It was determined that shear strength characteristics of the samples were not adversely influenced as function of reduced press temperature. This process can be considered as a promising way to save substantial amounts of energy during pressing processes, which results in a major reduction in overall production costs.

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2009, Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2009, Karbon fiber takviyeli polimerik matrisli kompozitler düşük yoğunluk, yüksek mukavemet ve sıcaklık altında mükemmel ablatif davranışları gibi özelliklerinden dolayı yüksek sıcaklık uygulamalarında tercih edilen mühendislik malzemeleridir. Bu çalışmada, karbon fiber esaslı polimerik matrisli kompozitlerin yüksek sıcaklık altında ısıl davranışları ve mekanik özellikleri incelenmiştir. Yapılan deneysel çalışmalarda takviye elemanı olarak karbon fiber, polimerik matris olarak da fenolik reçine kullanılmıştır. Kompozit parçanın üretilmesi, spreyleme prosesi ile gerçekleştirilmiştir. Kısa fiberli kompozit malzemelerin elastisite modülü ve termal iletkenlik özelliklerin modellenmesi için Cox ve Halphin-Tsai tasarımlarından yararlanılmıştır. Yük ve vakum altında üretilen numunelere dinamik ve statik ısı akısı testleri, termogravimetrik analiz, kayma dayanımı ve ısıl iletkenlik testleri uygulanmıştır. Elde edilen veriler incelendiğinde vakum altında üretilen numuneler en iyi sonucu vermektedir. Bu sonuçlar ağırlık kaybı % 14, kupon arkası sıcaklık 75 °C, ısıl iletkenliği 0,7 W/ m °C, ilk bozunma sıcaklığı 190 °C, 900 °C’deki ağırlık kaybı % 11 ve kayma dayanımı 8 MPa olarak belirlenmiştir., Carbon fiber reinforced polymeric matrix composites are engineering materials which are preferred for high temperature applications because of their low density, high strength and excellent ablative properties. In this study, the temperature on the back of coupon, weight loss, first decomposition temperature and shear strength of carbon fiber reinforced polymeric matrix composites were investigated. In experimental studies, carbon fiber and phenolic resin were used as reinforcement and matrix. Laminated composite was produced by spray-up process. Cox and Halpin-Tsai modeling studies were used for Young’s modulus and thermal conductivity prediction of short-fiber reinforced composites. Composites produced in load and vacuum were tested dynamic and static heat flux, thermogravimetric analysis, shear strength and thermal conductivity. Based on the experimental data, composites produced in vacuum showed the best results, including weight loss of 14 %, the temperature on the back of coupon of 75 °C, thermal conductivity of 0.7 W/ m °C, first decomposition temperature of 190 °C, weight loss at 900 °C of 11 %, shear strength of 8 MPa, Yüksek Lisans, M.Sc.

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2009, Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2009, Bu çalışmada karbon fenolik esaslı kompozit ısı kalkanı üretimi gerçekleştirilmiş, üretilen kompozitlerin mekanik özellikleri ve yüksek sıcaklık altındaki ısıl davranışları incelenmiştir. Karbon fenolik kompozitler, yüksek sıcaklık altında mükemmel ablatif davranışa, düşük yoğunluğa ve yüksek mukavemete sahip, gelişmiş mühendislik malzemeleridir. Bu özellikler karbon fenolik kompozitleri uzay aracı ısı kalkanları uygulamalarında tercih edilen bir malzeme yapmıştır. Deneysel çalışmalarda karbon fenolik kompozitlerin üretimi sıcak laminasyon prosesiyle gerçekleştirilmiştir. Pekiştirici olarak karbon dokumalar, matris olarak ise fenolik reçine kullanılmıştır. Farklı yönlenmelerde karbon dokumalar, farklı reçine-çözücü oranları ve farklı jelleştirme yöntemleri kullanılmış ve bu değişkenlerin malzemenin ısıl ve mekanik özelliklerine olan etkisi incelenmiştir. Isıl ve mekanik özeliklerin belirlenmesi için yapılan karakterizasyon çalışmalarında, üretilen numunelere çekme ve basma dayanımı testi, statik ısı akısı testi, dinamik ısı akısı testi ve ısıl iletkenlik testleri uygulanmıştır. Uygulanan testler sonucunda mekanik ve ısıl özelliklerin, malzemenin içerdiği reçine oranından önemli derecede etkilendiği, reçine oranının ise, reçine-çözücü konsantrasyonu ve jelleştirme koşulları ile kontrol edilebildiği görülmüştür., In this study, phenolic impregnated carbon ablators are manufactured, mechanical and thermal behaviours of produced composites are observed. Carbon phenolic composites are advanced engineering materials which have high strength, low density and excellent ablative properties. Therefore these composites are preferred for spacecraft heat shield applications. In the experimental, carbon phenolic composites are produced by hot lamination process. Carbon fabrics are used as reinforcements and phenolic resin is used as a matrix. Different carbon vowen types, resin-solvent ratios and gelation methods are used and effects of these variables are inspected by mechanical and thermal characterizations. Characterizations of samples involve; tensile strength test, compression test, static and dynamic heat flux test and thermal conductivity tests. As a result, thermal and mechanical properties of the composites are seen highly dependent to the resin ratio in the material. And the resin ratio can be controlled by resin-solvent ratio used and gelation conditions applied., Yüksek Lisans, M.Sc.

A aplicação de PRF no reforço de estruturas de concreto pode requerer a utilização de elevadas temperaturas para minimizar o tempo de cura dos adesivos. A possibilidade de substituição dos adesivos tradicionais utilizados na colagem de laminados de PRF por Filmes Termo- Ativados (FTA), que apresentam temperaturas de transição vítrea (Tg) mais elevadas que a dos adesivos tradicionais, vem estimulando o desenvolvimento de estudos acerca da sua viabilidade de aplicação. Para o presente estudo, testes em vigas de concreto entalhadas, reforçadas com laminados de PRFC, foram realizados no EMPA (Swiss Federal Laboratories for Material Testing and Research), analisando o comportamento de dois FTA, baseados em resinas termofixas fenólica e epoxídica. Visando verificar a redistribuição de tensões nos elementos estudados, um modelo computacional foi implementado. Os resultados da análise do comportamento da interface concreto-laminado demonstram que os modelos numéricos são ferramentas eficazes para complementar e explicar os dados obtidos experimentalmente. The application of FRP for post-strengthening of concrete structures induces the use of elevated temperatures to minimize the curing time of the adhesive. The replacement of traditional adhesives by Heat-Activated Films (HAF), with higher glass transition temperatures (Tg), is na interesting prospect, and has been motivating studies regarding the viability of applying termo-activated adhesives. For this study, notched beams post-strengthened with CFRP bonded with two types of heat-activated films (epoxy and phenolic based) and one classical adhesive were tested in bending at EMPA (Swiss Federal Laboratories for Material Testing and Research). To verify the stress redistribution on the notched beams, a computational model, which divides the structure in solid elements, was implemented. The analysis of the behavior of the concrete-laminate interface demonstrates that numerical models are an efficient tool to supplement and explain experimental data.

Usually used in the aerospace field as thermal protection, the phenolic resin/carbon fiber (C/R) composite undergoes a strong thermochemical degradation during its use, the knowledge of which is necessary in order to predict the overall behavior of the material. The main motivation for the study undertaken here lies in the need to identify and characterize the link between pre-pyrolytic drying and microstructural transformation of the C/R ablation material in order to model this phenomenon. The assumptions made during the experimental study to establish the cracking scenario are justified by scientific calculations. The work carried out constitutes a significant advance in the understanding of the development of cracking in the prepyrolysis phase and the influence of this on the structural evolution of the C/R composite during thermochemical degradation. Indeed, if the literature provides a significant number of studies for the pyrolysis phase, very few results and analyses are available for the dewatering phase, which remained before this work incompletely understood., Habituellement utilisé dans le domaine de l'aérospatial en tant que protection thermique, le composite résine phénolique/fibre de carbone (C/R) subit une forte dégradation thermochimique au cours de son utilisation, dont la connaissance est nécessaire afin de prévoir le comportement global du matériau. La motivation principale de l'étude entreprise ici réside dans la nécessité d'identifier et de caractériser le lien entre le séchage pré-pyrolytique et la transformation microstructurale du matériau d'ablation C/R afin de modéliser ce phénomène. Les hypothèses prises au cours de l'étude expérimentale afin d'établir le scénario de fissuration sont justifiées par des calculs scientifiques. Le travail réalisé constitue une avancée significative dans la compréhension du développement de la fissuration en phase de prépyrolyse et l'influence de celle-ci sur l'évolution structurale du composite C/R lors de la dégradation thermochimique. En effet, si la littérature fournit un nombre conséquent d'études pour la phase de pyrolyse, bien peu de résultats et d'analyses sont disponibles pour la phase d'assèchement, qui restait avant ce travail incomplètement comprise.

Submitted by Boris Flegr (boris@uerj.br) on 2021-01-07T19:00:27Z No. of bitstreams: 1 dissertacao jose luiz.pdf: 1386934 bytes, checksum: 4b92d08cec027e97d889c51231214371 (MD5) Made available in DSpace on 2021-01-07T19:00:27Z (GMT). No. of bitstreams: 1 dissertacao jose luiz.pdf: 1386934 bytes, checksum: 4b92d08cec027e97d889c51231214371 (MD5) Previous issue date: 2008-06-26 In this Thesis Dissertation, acrylonitrile-butadiene rubber (NBR) compositions were vulcanized using phenolic resin and sulfur as vulcanization agents with different proportions of phenolic resin and only one proportion of sulfur. The activator system was composed of polycloroprene and zinc oxide to phenolic resin compositions, while stearic acid and zinc oxide to sulfur composition. The materials were vulcanized in a temperature of 190ºC. The influence of the components content on rheometric, physico-mechanical and rheological properties of the materials was evaluated. In order to assist in the interpretation of the to physico-mechanical and rheometric properties results, a statistical planning of variant analysis was used to observe a possible influence of the variables and also their possible associations into the evaluated properties. The results showed that the nitrile rubber become more stiffness with the presence of phenolic resin. It was also observed the occurrence of post-vulcanization on the compositions vulcanized with phenolic resin. The rheological results showed homogeneity of the samples submitted to a strain sweep test, with a linear plateau until 10% of strain. Neste trabalho de Dissertação de Tese, composições do copolímero de butadieno-acrilonitrila (NBR) foram vulcanizadas utilizando como agentes de vulcanização, a resina fenólica e o enxofre, com diferentes proporções de resina fenólica e uma única proporção de enxofre. O sistema ativador foi composto por policloropreno e óxido de zinco para as composições com resina fenólica, enquanto que por ácido esteárico e óxido de zinco para a composição com enxofre. Os materiais foram vulcanizados em uma temperatura de 190ºC. Foi avaliada a influência da variação dos componentes das composições sobre as propriedades reométricas, físico-mecânicas e reológicas dos materiais. Para auxiliar na interpretação dos resultados obtidos para as propriedades reométricas e físico-mecânicas, foi utilizado um planejamento estatístico de análise de variância para verificar a possibilidade da influência das variáveis e suas possíveis combinações nas propriedades avaliadas. Para as composições vulcanizadas com resina fenólica, os resultados mostraram que a composição de borracha nitrílica se tornou mais rígida com a presença da resina. Também foi observada a ocorrência de pós-cura nas composições vulcanizadas com resina fenólica. Os ensaios reológicos revelaram uma homogeneidade nas amostras submetidas aos testes de varredura de deformação, com desvio de linearidade a partir de 10% de deformação.

It is known that generalist herbivores may circumvent intoxication by ingesting small quantities from a mixture of plant secondary metabolites. However a single chemical, a highly toxic one or the most abundant in the mixture could cause toxicity. Survivorship and toxicity in Rockland male mice were measured to determine if the toxic effects of the phenolic resin of creosote bush (Larrea divaricata Cav.) is due to its major constituent, the nordihydroguaiaretic acid (NDGA) or to the total concentration of phenolic compounds in this resin. This objective was accomplished by exposing mice to voluntary feeding on resin-treated rat chow and by oral gavaging of mice with the following doses and compounds: Resin-100 mg (n = 7), NDGA-15 mg (n = 8), and NDGA-100 mg (n = 10) and Control (n = 6). Our hypothesis was that NDGA is responsible for the toxicity of Larrea divaricata's phenolic resin. Voluntary resin intake by mice had a pronounced toxic effect, producing body mass loss and significant reduction of food intake. Mice gavaged with Resin-100 mg, NDGA-100 mg, and NDGA-15 mg showed a significant reduction in survival probability compared to mice under Control conditions. Animáis exposed to NDGA-15 mg had a higher survivorship compared to the NDGA-100 mg animáis, and equivalent survivorship to the Resin-100 mg (containing 15 mg of NDGA) animáis. No significant differences in detoxification, measured as glucuronic acid conjugates in urine, were detected among gavage treatments. Therefore, given that just 15 mg of NDGA were enough to produce the same effect as the whole resin, we suggest that NDGA is the main constituent of Larrea divaricata's resin responsible for the toxic effect of the phenolic resin of this plant.

Los herbívoros generalistas pueden evitar la intoxicación ingiriendo pequeñas cantidades de una mezcla de metabolitos secundarios de plantas. Sin embargo, un solo compuesto, uno altamente tóxico o el más abundante en la mezcla es el que podría causar la intoxicación. La sobrevida y la toxicidad en ratones Rockland machos fueron evaluadas para determinar si los efectos tóxicos de la resina fenólica de jarilla (Larrea divaricata Cav.) se debe a su compuesto mayoritario, el ácido nordihidroguaiarético (ANDG) o a la concentración total de compuestos fenólicos en esta resina. Este objetivo fue logrado mediante la exposición de ratones a la alimentación voluntaria de alimento para rata tratado con resina y mediante el gavage oral de ratones con las siguientes dosis y compuestos: Resina-100 mg (n = 7), ANDG-15 mg (n = 8), ANDG-100 mg (n = 10) y Control (n = 6). Nuestra hipótesis fue que los efectos tóxicos de Larrea divaricata son atribuibles al ANDG solamente. La ingesta voluntaria de resina por ratones tuvo un efecto tóxico pronunciado, evidenciado en una pérdida en masa corporal y una reducción significativa de la ingesta de alimento. Ratones expuestos a gavage con Resina-100 mg, ANDG-100 mg y ANDG-15 mg mostraron una reducción significativa de la sobrevida comparada con ratones bajo las condiciones Control. Animales expuestos a ANDG-15 mg tuvieron una mayor sobrevida comparado con animales expuestos a ANDG-100 mg y una sobrevida equivalente a los animales expuestos a Resina-100 mg (que contiene a su vez 15 mg de ANDG). No se detectaron diferencias significativas en la detoxificación medida como conjugados de ácido glucurónico en orina entre los tratamientos de gavage. Dado que 15 mg de ANDG fueron suficientes para producir el mismo efecto que la resina total, sugerimos que el ANDG es el constituyente principal de la resina de Larrea divaricata responsable del efecto tóxico de esta planta. It is known that generalist herbivores may circumvent intoxication by ingesting small quantities from a mixture of plant secondary metabolites. However a single chemical, a highly toxic one or the most abundant in the mixture could cause toxicity. Survivorship and toxicity in Rockland male mice were measured to determine if the toxic effects of the phenolic resin of creosote bush (Larrea divaricata Cav.) is due to its major constituent, the nordihydroguaiaretic acid (NDGA) or to the total concentration of phenolic compounds in this resin. This objective was accomplished by exposing mice to voluntary feeding on resin-treated rat chow and by oral gavaging of mice with the following doses and compounds: Resin-100 mg (n = 7), NDGA-15 mg (n = 8), and NDGA-100 mg (n = 10) and Control (n = 6). Our hypothesis was that NDGA is responsible for the toxicity of Larrea divaricata's phenolic resin. Voluntary resin intake by mice had a pronounced toxic effect, producing body mass loss and significant reduction of food intake. Mice gavaged with Resin-100 mg, NDGA-100 mg, and NDGA-15 mg showed a significant reduction in survival probability compared to mice under Control conditions. Animáis exposed to NDGA-15 mg had a higher survivorship compared to the NDGA-100 mg animáis, and equivalent survivorship to the Resin-100 mg (containing 15 mg of NDGA) animáis. No significant differences in detoxification, measured as glucuronic acid conjugates in urine, were detected among gavage treatments. Therefore, given that just 15 mg of NDGA were enough to produce the same effect as the whole resin, we suggest that NDGA is the main constituent of Larrea divaricata's resin responsible for the toxic effect of the phenolic resin of this plant. Fil: Ríos, Juan Manuel. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Grupo de Investigación en Ecología de Comunidades del Desierto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; Argentina Fil: Mangione, Antonio Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina Fil: Gianello, Jose Carlos. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Departamento de Química. Area de Química Orgánica; Argentina

It is known that generalist herbivores may circumvent intoxication by ingesting small quantities from a mixture of plant secondary metabolites. However a single chemical, a highly toxic one or the most abundant in the mixture could cause toxicity. Survivorship and toxicity in Rockland male mice were measured to determine if the toxic effects of the phenolic resin of creosote bush (Larrea divaricata Cav.) is due to its major constituent, the nordihydroguaiaretic acid (NDGA) or to the total concentration of phenolic compounds in this resin. This objective was accomplished by exposing mice to voluntary feeding on resin-treated rat chow and by oral gavaging of mice with the following doses and compounds: Resin-100 mg (n = 7), NDGA-15 mg (n = 8), and NDGA-100 mg (n = 10) and Control (n = 6). Our hypothesis was that NDGA is responsible for the toxicity of Larrea divaricata's phenolic resin. Voluntary resin intake by mice had a pronounced toxic effect, producing body mass loss and significant reduction of food intake. Mice gavaged with Resin-100 mg, NDGA-100 mg, and NDGA-15 mg showed a significant reduction in survival probability compared to mice under Control conditions. Animáis exposed to NDGA-15 mg had a higher survivorship compared to the NDGA-100 mg animáis, and equivalent survivorship to the Resin-100 mg (containing 15 mg of NDGA) animáis. No significant differences in detoxification, measured as glucuronic acid conjugates in urine, were detected among gavage treatments. Therefore, given that just 15 mg of NDGA were enough to produce the same effect as the whole resin, we suggest that NDGA is the main constituent of Larrea divaricata's resin responsible for the toxic effect of the phenolic resin of this plant. Los herbívoros generalistas pueden evitar la intoxicación ingiriendo pequeñas cantidades de una mezcla de metabolitos secundarios de plantas. Sin embargo, un solo compuesto, uno altamente tóxico o el más abundante en la mezcla es el que podría causar la intoxicación. La sobrevida y la toxicidad en ratones Rockland machos fueron evaluadas para determinar si los efectos tóxicos de la resina fenólica de jarilla (Larrea divaricata Cav.) se debe a su compuesto mayoritario, el ácido nordihidroguaiarético (ANDG) o a la concentración total de compuestos fenólicos en esta resina. Este objetivo fue logrado mediante la exposición de ratones a la alimentación voluntaria de alimento para rata tratado con resina y mediante el gavage oral de ratones con las siguientes dosis y compuestos: Resina-100 mg (n = 7), ANDG-15 mg (n = 8), ANDG-100 mg (n = 10) y Control (n = 6). Nuestra hipótesis fue que los efectos tóxicos de Larrea divaricata son atribuibles al ANDG solamente. La ingesta voluntaria de resina por ratones tuvo un efecto tóxico pronunciado, evidenciado en una pérdida en masa corporal y una reducción significativa de la ingesta de alimento. Ratones expuestos a gavage con Resina-100 mg, ANDG-100 mg y ANDG-15 mg mostraron una reducción significativa de la sobrevida comparada con ratones bajo las condiciones Control. Animales expuestos a ANDG-15 mg tuvieron una mayor sobrevida comparado con animales expuestos a ANDG-100 mg y una sobrevida equivalente a los animales expuestos a Resina-100 mg (que contiene a su vez 15 mg de ANDG). No se detectaron diferencias significativas en la detoxificación medida como conjugados de ácido glucurónico en orina entre los tratamientos de gavage. Dado que 15 mg de ANDG fueron suficientes para producir el mismo efecto que la resina total, sugerimos que el ANDG es el constituyente principal de la resina de Larrea divaricata responsable del efecto tóxico de esta planta.

Asbestos possesses properties that are ideally suitable for use as a friction material in automotive and a number of other applications. Animal and human studies carried out since the early 1900s have established that asbestos is carcinogenic and that exposure to especially asbestos dust causes a large number of diseases. Realizing the health hazards posed by asbestos, many countries started phasing out asbestos from all asbestos-containing products since the 1980s. Some of them imposed a total ban in the 1990s on the use of asbestos-containing friction products. This situation forced many manufacturers to look for alternatives to asbestos. But the efforts have only been partly successful. The search is, therefore, still on to find suitable substitutes for asbestos. Though steel wool, Kevlar, glass, and a number of other mineral fibers have been tried out on an experimental basis over the last two decades, glass and Kevlar fibers, in particular, have shown promise as potential substitutes for asbestos. These days, therefore, studies on polymer-based friction materials reinforced with glass, Kevlar, and ceramic fibers are being pursued with much fervor. However, conflicting views are prevailing even today as to the suitability of asbestos-free composites for automotive applications and freedom from the concomitant health risks posed by them. In the present work, therefore, phenolic resin matrix samples reinforced with different amounts of glass and Kevlar fibers were produced and characterized for their mechanical, physical, friction, and wear properties to assess their suitability for light passenger car applications. The study establishes that composites based on glass and Kevlar fibers show good mechanical, physical, friction, and wear characteristics, enhancing thereby their suitability for automotive applications. The property improvements achieved are correlated to the composition, microstructure, and the changes taking place on the surface of the friction composites.

CONTENIDO Artículos ADRIANA PADILLA, JUDITH PETIT, DELFINA PADILLA y LUCY QUINTERO Especies usadas como combustible en la comunidad de Villanueva, Lara-Venezuela ERIC BARRIOS, OSVALDO ENCINAS, WILVER CONTRERAS y ADOLFO RIVERA Evaluación del efecto de las sales CCA sobre la línea de cola en probetas hechas con pino caribe utilizando resina fenol-formaldehido e isocianato ERMIN ESCALA, EDWARD THOMSON y WILVER CONTRERAS Evaluación del estado actual del método de diseño por estados límites (LSD) para estructuras de maderas (Capítulo 1) WILLIAMS J. LEÓN y NARCISANA ESPINOZA DE PERNÍA Estudio anatómico del leño de ocho especies del género Aniba, Aublet (Lauraceae) WILLIAMS J. LEÓN y NARCISANA ESPINOZA DE PERNÍA Estudio anatómico del leño de siete especies del género Beilschmiedia Nees (Lauraceae) ALEX BARRIOS Distribución espacial del factor LS (RUSLE) usando procedimientos SIG compatibles con IDRISI. Aplicación en una microcuenca andina ALEX BARRIOS y ESNEIRA QUIÑONEZ Evaluación de la erosión utilizando el modelo (R) USLE, con apoyo de SIG. Aplicación en una microcuenca de Los Andes venezolanos JOSÉ RAFAEL LOZADA y ERNESTO ARENDS Impacto de diferentes intensidades de aprovechamiento forestal sobre la masa remanente, en la Estación Experimental Caparo JOSÉ RAFAEL LOZADA y ERNESTO ARENDS Clasificación ecológica de especies arbóreas, con fines de aprovechamiento forestal, en la Estación Experimental Caparo ARMANDO BRICEÑO VERGARA y WILSON RAMÍREZ Diagnóstico de insectos Coleóptera asociados a las plantaciones de plátano en el sur del Lago de Maracaibo-Venezuela LUIS CEDEÑO y CHRYSTIAN CARRERO Cylindrocladium pteridis causando manchas foliares en eucaliptos de Portuguesa-Venezuela ROSAIMA GARCÍA Especies y sub-especies de Erwinia, causantes de pudrición blanda y pierna negra en la papa cultivada, en el estado Mérida-Venezuela Nota XUEJUAN FAN, ALFREDO MAGGIORANI y SAMIR GUDIÑO Uso de nemátodos entomopatógenos como una alternativa en el control de polilla (Tecia solanivora), importante plaga de la papa (Solanum tuberosum). Mérida-Venezuela Tesis ELSA ROCIO LÓPEZ SÁNCHEZ Aplicación de las metodologías USLA e IRE a través de una SIG para estimar la erosión hídrica en la cuenca del río Anaime, departamento del Tolima-Colombia OSMAR BARRIOS TORO Productividad de cercas vivas de teca Tectona grandis L.F. como actividad agroforestal de fincas localizadas en la región desafectada de la Reserva Forestal de Ticoporo, Barinas-Venezuela ANDRÉS FORTI Escorrentía y erosión bajo diferentes grados de cobertura y sistemas de siembra en suelos de ladera JOEL MEJÍA Un modelo suelo-paisaje para la evaluación automatizada de tierras con fines conservacionistas en cuencas altas. Caso: microcuenca del río Zarzales, estado Mérida-Venezuela CONTENTS Articles ADRIANA PADILLA, JUDITH PETIT, DELFINA PADILLA and LUCY QUINTERO Raw materials used as woodfuel in the Villanueva community, Lara-Venezuela ERIC BARRIOS, OSVALDO ENCINAS, WILVER CONTRERAS and ADOLFO RIVERA Evaluation of the effect of salts CCA on the glueline of caribe pine samples joined with resin fenol-formaldehyde and isocyanate ERMIN ESCALA, EDWARD THOMSON and WILVER CONTRERAS Evaluation of the present state of the limit states desing method (LSD) for timber structures (Chapter 1) WILLIAMS J. LEÓN and NARCISANA ESPINOZA DE PERNÍA Wood anatomy of eigth species of Aniba Aublet (Lauraceae) WILLIAMS J. LEÓN and NARCISANA ESPINOZA DE PERNÍA Wood anatomy of seven species of Beilschmiedia Nees (Lauraceae) ALEX BARRIOS Spatial distribution of LS (RUSLE) factor using GIS procedures compatible with IDRISI. Application to one Andean watershed ALEX BARRIOS and ESNEIRA QUIÑONEZ Assessment erosion using (R) USLE model with GIS tools. Application to one small watershed of venezuelan Andes JOSÉ RAFAEL LOZADA and ERNESTO ARENDS Environmental impact of different intensities of logging on residual stand, in the Caparo Experimental Station JOSÉ RAFAEL LOZADA and ERNESTO ARENDS Ecological classification of tree species, with logging purpose, in the Caparo Experimental Station ARMANDO BRICEÑO VERGARA and WILSON RAMÍREZ Diagnostic of Coleoptera associated to plantain plantations in south of Maracaibo Lake-Venezuela LUIS CEDEÑO and CHRYSTIAN CARRERO Cylindrocladium pteridis ausing Eucaliptus leaf spots in Portuguesa state Venezuela ROSAIMA GARCÍA Species and sub-species of Erwinia, causal a of soft rot and black leg the potato cultivated, in the Mérida state Venezuela Note XUEJUAN FAN, ALFREDO MAGGIORANI and SAMIR GUDIÑO Use of entomophathogenic nematodes as an alternative control of Tecia solanivora, an important pest of potato (Solanum tuberosum) Thesis ELSA ROCIO LÓPEZ SÁNCHEZ Application of USLE e IRE throught a GIS to stimatic hidric erosion in the Anaime river basin, department of Tolima-Colombia OSMAR BARRIOS TORO Productivity of teck Tectona grandis living fences as an agroforest farm activity at Ticoporo Forest Reservation, Barinas-Venezuela ANDRÉS FORTI Runoff and erosion under different cover and crop system in slope soils JOEL MEJÍA A model soil-landscape relationships to land automatic evaluation with conservation purpose high watershed: Zarzales river watershed, Mérida-Venezuela ericbarrios@latinmail.com wilver_c@hotmail.com, wilconmi@doctor.upv.es; wilmercontrerasmiranda@yahoo.es oencinas@ula.ve semestral Nivel analítico

Estudos tratando do processo de outsourcing em importantes setores industriais não-líderes ao redor do mundo, bem como propondo modelos práticos para a condução do processo de repasse de atividades de manufatura como um todo, e não somente no estágio de decisão, são difíceis de encontrar. Nesse contexto, este artigo procura apresentar um modelo prático para conduzir o processo de outsourcing na sua totalidade, dividindo-o em quatro estágios principais (motivação, decisão, implementação e gestão). O modelo foi aplicado com sucesso em um caso envolvendo duas companhias multinacionais operando no Brasil, em uma cadeia de suprimentos do setor de resinas fenólicas. Os resultados ressaltam, principalmente, a adequação do modelo proposto, no sentido de enfatizar os desafios em cada fase e as habilidades necessárias para enfrentá-los, bem como a importância da construção de parcerias baseadas na confiança e na integração por meio da tecnologia da informação. Studies related to the outsourcing process in several important non-leading industries worldwide and also regarding the existence of practical models and frameworks to guide the entire process and not only the decision-making stage are rare to find. In this context, this article presents a practical model to guide the whole outsourcing process, divided into four main stages (motivation, decision, implementation and management). It was successfully applied in a case involving two multinational companies operating in Brazil, in a supply chain of the phenolic resin industry. The results highlighted mainly the adequacy of the proposed model, as well as the importance of constructing a partnership based on trust and integration by information technology.

2-hydroxy-5-tert-butyl benzylalcohol and 2,6-bis(hydroxymethyl)-4-tert-butylphenol were identified as contact allergens in a phenolic resin used as a tackifier in the ink of a marking pen, which, after being used directly on the skin, caused an acute contact dermatitis on the hand of a 13-year-old boy. The patient also reacted to 4-tert-butylphenol-formaldehyde resin (BPF resin) 1% pet. included in the European standard series.