Дисертації з теми "Bark resin"

Extraction of mangrove bark with 4.0% aqueous sodium sulfite and 0.4% aqueous sodium carbonate at 100° and 2 hours gives 24-26% yields compared with extraction by water at 70° for 2 hours which gives 21%. The hot water extracts are more acidic (pH 3.6) than is the sulfite extract (pH 5.6); both are reasonably reactive toward formaldehyde (Stiasny number 70.6 using water and 85.4 using aqueous sulfite-carbonate). The ¹³C NMR spectra of R. mucronata shows this tannin to have phloroglucinolic A-rings with hydroxy groups at C-5 and C-7 and pyrogallolic B-rings with hydroxy groups at C-3', C-4', and C-5'. The interflavanoid linkages are C-4→C-8 and C-4→C-6. The ¹³C NMR spectra also indicate the presence of a considerable amount of carbohydrate which is shown to be mainly rhamnose, glucose, arabinose, and uronic acids. Sulfitation of R. mucronata bark reduces the total carbohydrate and the rhamnose extracted but increases the amount of arabinose and uronic acids. The bark storage period has significant effects on the pH and the reactivity of the aqueous tannin solution. Barks stored for <4 weeks produce higher extraction yields than those stored for > 6 weeks and contain significantly larger amount of reactive tannin and have shorter gel times. The reactivity of bark extracts towards formaldehyde can be controlled either by limiting the duration of bark storage to 4 weeks or by maintaining the aqueous tannin solution at pH <10.0. The aqueous tannin solution from R. mucronata exhibited properties such as viscosity, solubility and tackiness which were superior to those from the R. apiculata extract while the mixed R. mucronata-R. apiculata aqueous tannin solution had properties in between these. These barks could be used singly or together as a source of tannin without the bond strength of the resulting glued joints being significantly affected. The "honeymoon" bonding technique improved the bond strengths of joints made using sulfited tannin but is suitable only for tannin solutions containing > 4% aqueous sodium hydroxide. The viscosity of sulfited tannin adhesives is influenced by (a) the amount of aqueous sodium hydroxide added to the aqueous tannin solution, and (b) the lapse time, i.e. the period between the addition of sodium hydroxide to the aqueous tannin solution and the addition of phenol-resorcinol-formaldehyde (PRF) resin, hardener, and paraformaldehyde. The present study shows that with the addition of 5% w/w sodium hydroxide and at a curing temperature of 40° the sulfited tannin extracts from the bark of mangrove trees can replace about 50% w/w of the PRF resin in cold-setting wood adhesives with the production of bond strengths comparable to those produced by 100% PRF resin.

Les travaux de recherche présentés portent sur l'utilisation des produits de la liquéfaction des écorces d'épicéa dans le phénol pour la préservation du bois. Les produits de la liquéfaction permettent la synthèse d'une résine thermodurcissable de type phénolique. Les résines formulées sont imprégnées dans le bois suivi d'un durcissement in situ. Un prétraitement est mis au point dans le but d'enrichir la fraction phénolique des écorces. Ce prétraitement consiste à hydrolyser les polysaccharides principalement la cellulose et les hémicelluloses dans une solution acide. Ce prétraitement permet d'obtenir un taux de lignine dans les écorces de 60 %, et un taux de cellulose de 28 %. Un procédé de liquéfaction dans un système composé de phénol, d'eau et d'éthanol est optimisé dans le but d'obtenir des taux de liquéfaction supérieur à 85 %, et un taux d'écorces liquéfiées par rapport à la masse de phénol supérieur à 50 %. Les produits de la liquéfaction présentent l'avantage de polymériser sans ajout de formaldéhyde. La durabilité conférée au bois par les résines est bonne, surtout pour les résines phénol/formaldéhyde. Les résines sont peu lessivables. L'imprégnation du bois par les résines provoque un gonflement du bois ce qui améliore la stabilité dimensionnelle de ce dernier
This work focuses on the use of liquefaction products of spruce bark in phenol for the wood preservation. The liquefaction products allow the synthesis of phenolic thermosetting resins. The formulated resins were impregnated into the wood followed by in situ polymerization. A pretreatment was developed in order to increase the phenolic compounds in the spruce bark. This step is an acid hydrolysis of polysaccharides. This pretreatment allowed obtaining a Klason lignin content of 60 %, and a cellulose content of 28 %. A liquefaction process was developed in a mixture of solvent composed of phenol, ethanol, and water. The optimized experimental conditions allowed obtaining a liquefaction yield superior to 85 %, with liqui?ed bark/phenol ratio superior to 50 %. The lique?ed products had the advantage to polymerize without formaldehyde. The resins enhanced the wood durability especially for the phenol/formaldehyde resins. The leaching was low. The wood impregnation allowed a wood swelling, thereby the impregnated wood had a better dimensional stability

Cette thèse a été consacrée à la problématique de l’altération de substances organiques en contexte archéologique, avec pour objectifs de donner des clés analytiques et expérimentales pour étudier les processus mis en jeu, d’identifier de nouveaux outils moléculaires indicateurs des processus subis par les matériaux organiques archéologiques et d’interpréter l’impact de ces processus sur les signatures moléculaires de ces matériaux. Après la mise au point d’un protocole expérimental de vieillissement en laboratoire reproduisant les processus « naturels » de vieillissement de substances organiques archéologiques, nous avons déterminé que les réactions croisées entre ingrédients (esters d’acides gras, terpènes) conduit à la formation de composés oligo-/polymériques intéressants à étudier à l’aide de réactions de dégradation chimique. L’étude moléculaire de matériaux organiques archéologiques a aussi été abordée. Ainsi, de la résine de diptérocarpacées provenant de deux épaves asiatiques du XIIème siècle et du brai de bouleau utilisé pour réparer des céramiques néolithiques ont été identifiés. De nouveaux biomarqueurs triterpéniques d’altération issus de la dégradation anaérobie en milieu sédimentaire de triterpènes précurseurs (résine), et des biomarqueurs de traitement thermique intense (brai) ont été caractérisés
The present PhD thesis was devoted to the alteration processes affecting organic substances in an archaeological context, and aimed at providing analytical and experimental keys to investigate the nature of the alteration processes, to identify new molecular tools indicators of archaeological alteration processes and to interpret the impact of these processes on the molecular signatures of these organic materials. Following the development of a laboratory ageing experimental protocol able to reproduce “natural” alteration of archaeological organic substances, we could establish that cross reactions between ingredients (esters of fatty acids, terpenoids) result in the formation oligo/polymeric material worth to be investigated by means of chemical degradation reactions. Additionally, investigation of archaeological organic substances was carried out. Thus, dipterocarpaceae resins from two Asian shipwrecks from the XIInd Century and birch bark tar used to fix Neolithic ceramics have been identified. New triterpenoid biomarkers resulting from the sedimentary anaerobic degradation of parent triterpenoids (resins) and markers indicative of intense thermal treatment (tar) have been characterized

Orientador: João Sinézio de Carvalho Campos
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química
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Resumo: É bem conhecida a necessidade de energia elétrica para o bem estar e desenvolvimento tecnológico da população em nosso planeta. Ao lado dos avanços científicos de novas tecnologias para geração, existem interesses na melhoria do transporte da energia. Dentre estes se encontram materiais para isolação elétrica de barras estatóricas, quer sejam para melhorar a isolação ou mesmo para reduzir custos. Assim, o presente trabalho visa apresentar resultados da aplicação de uma nova resina epóxi bisfenólica (DGEBF) (RN) à base de nanopartículas de sílica e comparar suas propriedades com a resina epóxi bisfenólica (DGEBA) (RE), atualmente utilizada para a isolação de hidrogeradores. Neste sentido, fabricaram-se protótipos de barras estatóricas, destinadas a hidrogeradores, sendo as resinas impregnadas em sistema VPI (Vácuo-Pressão-Impregnação) e avaliaram-se as propriedades físico-químicas pelas técnicas de viscosimetria, TGA, DSC, MEV e EDS. As propriedades elétricas foram avaliadas pelas técnicas de fator de dissipação (tan delta), descargas parciais, envelhecimento acelerado (VET) e tensão de ruptura. Dentre os resultados das propriedades físico-químicas pode-se comprovar um aumento inicial de três vezes o valor de viscosidade para resina RN em comparação com RE. Entretanto, não houve detrimento das características dielétricas em função da viscosidade, o que foi comprovado através dos resultados de tan delta e VET. Obteve-se um valor de Tg de 116°C e 145°C para RN e RE, respectivamente, o que limitaria a aplicação da resina em geradores por estar abaixo da temperatura de operação. Dentre os resultados dos testes elétricos para as resinas observou-se que: (i) o fator de dissipação e de envelhecimento são praticamente os mesmos para ambas as resinas; (ii) o valor de tip-up resultaram em 0,014 % para RE e 0,020 % para a resina RN, sendo que a norma EN 50209 exige que seja inferior a 0,25% e (iii) a estimativa do tempo de vida útil obtida foi de cerca de 40 anos para os dois tipos de resina, o que é aplicável para maioria dos enrolamentos em operação. Neste sentido sugere-se que a resina RN pode ser uma boa alternativa a resina RE, com um desempenho elétrico equivalente, desde que ajustadas suas condições de processamento e temperatura de aplicação
Abstract: It is well know the demand of electrical energy for the wellbeing and technological development of the population in our planet. Among the scientific development of new technologies for generation, are interests to optimize the energy transport. Among them are materials for electrical insulation of stator bars, whether for improving the insulation or even to reduce the costs. Therefore, the present work aim to present the results of the employment of a new bisphenolic epoxy resin (DGEBF) (RN) containing silica nanoparticles and compare its properties with the bisphenolic epoxy resin (DGEBA) (RE) currently used for the insulation of hydrogenerators. In this context, it was manufactured prototype stator bars, designed for hydrogenerators, being the resins impregnated through VPI (Vacuum-Pressure-Impregnation) system and their physicochemical properties evaluated with the technics of viscosimetry, TGA, DSC, MEV and EDS. The electrical properties were evaluated with the tests of dissipation factor (tan delta), partial discharges, voltage endurance test (VET) and breakdown. Among the results of the physicochemical properties it was possible to verify an initial increase of three times the value of viscosity for RN resin compared to RE. However there was no detriment of the dielectric characteristics depending on the viscosity, what was proven with the results of dissipation factor and VET. It was obtained a value of Tg of 116°C and 145°C for RN and RE respectively, what could limit its employment for hydrogenerators as being below the operational temperature. Among the results of electrical tests for the resins it was observed that: (i) the dissipation factor and VET are practically the same for both resins; (ii) the tip-up value resulted in 0,014% for RE and 0,020% for RN, being required lower than 0,25% according to the norm EN 50209 and (iii) the estimating lifecycle was approximately 40 years for both types of resin, what is applicable for most windings under operation. In this context it is suggested that the RN resin can be a good alternative for RE resin with an equivalent performance once the process conditions and employment temperature are adjusted
Mestrado
Ciencia e Tecnologia de Materiais
Mestre em Engenharia Química

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With the objective of testing the resistance and the biomechanical behavior of external fixators of low cost used in veterinary medicine, were created 6 prototypes la type manufactured from alternative materials, using as orthopedic implants, stainless steel screws 304 porous, and as stabilized bar the methacrylate resin or wood poles (Pinnus ellioti). The models of the fixators tested differ because they have 2, 3 or 4 implants per fractured segment. With the purpose of doing biomechanical evaluations that are closer to the real clinical situation, were selected 2 tubes of polyvinylchloride, commercially known as PVC, with 10 cm length, internal diameter of 1,27 cm and external diameter of 1,95, far 5 cm from each other, representing, this way, the bone bands and the focus of an unstable fracture. This kind of tube is like a long bone because it has an internal space that represents the medullar area and external walls that represent the two osseous cortical. To each external fixator model, were created 5 prototypes, which were submitted to mechanic tests to evaluate the axial compression strength. The device to evaluate the prototypes was the Instron model 4204, with a charge cell of 5 KN (Kilogram-Newton) and the speed of the axial compression was 2 cm/minute, according the rules ASTM D695-92. The values of rigidity, drainage point and maximum security charge were calculated, according to the methodology used by Willer et al., (1991) and by Falc?o (2004). The mechanical evaluation was done in the Instituto de Macromol?culas Elo?sa Mano in the Universidade Federal do Rio de Janeiro. We concluded that the models with the stabilized bar made of resin required a larger load than the models made of wood to suffer a plastic deformation. The model with 3 screws per segment of PVC tube and a resin stabilized bar showed to tolerate a higher weight than the others, before showing a plastic deformation, this way it s indicated to dogs that weight up to 26,5Kg with fractures in the thoracic limbs and for dogs that weight up to 44Kg that have fractures in the pelvic limbs.
Com objetivo de testar a resist?ncia e o comportamento biomec?nico de fixadores externos de baixo custo utilizados em medicina veterin?ria, foram criados 6 modelos de prot?tipos do tipo Ia confeccionados a partir de materiais alternativos, utilizando-se como implantes ortop?dicos parafusos de a?o inoxid?vel 304 porosos e totalmente rosqueados, e como barra estabilizadora a resina de metacrilato ou hastes de madeira (Pinnus ellioti). Os modelos dos fixadores testados ainda se diferenciam por apresentarem 2, 3 ou 4 implantes por segmento fraturado. Com a finalidade de realizar avalia??es biomec?nicas o mais pr?ximo poss?vel da situa??o cl?nica, optou-se pela escolha de 2 tubos de policloreto de vinila, comercialmente conhecido como PVC, apresentando 10 cm de comprimento, 1,27 cm de di?metro interno e 1,95 cm de di?metro externo, afastados 5 cm entre si, representando assim os fragmentos ?sseos e o foco de uma fratura inst?vel. Este tipo de tubo se assemelha a um osso longo por apresentar um espa?o interno que representa a ?rea medular enquanto que as paredes externas representam as duas corticais ?sseas. Para cada modelo de fixador externo foram criados 5 prot?tipos, submetidos a testes mec?nicos para avalia??o da for?a de compress?o axial. O aparelho para avalia??o dos prot?tipos foi o Instron modelo 4204, com c?lula de carga de 5 KN (Quilograma-Newton) e a velocidade da compress?o axial foi de 2 cm/minuto, seguindo as normas ASTM D695-91. Calculamos as cargas de rigidez, ponto de escoamento e carga de seguran?a m?xima. A avalia??o mec?nica foi realizada no Instituto de Macromol?culas Elo?sa Mano na Universidade Federal do Rio de Janeiro. Conclu?mos que os modelos com barra estabilizadora em resina necessitou de uma carga maior do que os modelos de madeira para sofrer deforma??o pl?stica. O modelo com 3 parafusos por segmento de tubo de PVC e barra estabilizadora de resina mostrou suportar maior peso que os demais, antes de apresentar uma deforma??o pl?stica, sendo indicado para c?es com peso corporal de at? 26,5 Kg portadores de fraturas nos membros tor?cicos e para c?es com peso de at? 44 Kg que apresentem fraturas nos membros p?lvicos.

Purpose: To investigate the effect of acrylic processing on push-out strength of Ti copings luted to Milled Ti frameworks using differing resin cements.

Materials and Methods: The experimental design consisted of three groups of 30 specimens each. Three different luting cements were utilized (One for each group), Panavia V5 Dual Cure Kuraray, Multilink Dual Cure Hybrid Ivoclar-Vivadent, and RelyX Unicem-2 self-adhesive 3M. The experimental model consists of trans-mucosal Titanium Coping, Abutment analog, Milled Ti hollow cylinder (9.0mm-OD) represents the milled Ti bar. The Abutment copings were luted to milled-Ti cylinders using the 3 dental cements and an alignment jig to assure repeatability used during cementation. Waxing then acrylic processed by two protocols (Fast and Conventional) for two groups (not the control) were completed. Processed specimens were finished, polished, and stored in distilled H₂O at 24 °C for 24 hours prior to testing. Push-out strengths were measured (N/mm²), with Instron 5565 mechanical testing system, crosshead speed 1 mm/min. Failure mode was evaluated by high-magnification light microscopy and SEM. Significance determined by ANOVA and Tukey’s post hoc test (p < 0.05).

Results: Two-way ANOVA shows no significant interaction (p = 0.45 > 0.05) between the two variables, processing technique and the cement. Only the cement is significantly different. So, the cement is not affected by the process and vise-versa. One-way ANOVA shows no significant differences in push-out strength within the same cement groups. However, it has found a difference among the groups (P < 0.0001). Tukey’s post hoc test found significant differences among the cements groups (p < 0.05).

Conclusion: Within the limitations of this in-vitro study, no differences in cement push-out strength were found between acrylic processing methods, but differed by cement type.

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Universidade Estadual Paulista (UNESP)
Nesta pesquisa estudou-se o aproveitamento dos resíduos de compósitos a base de resina poliéster insaturado e fibra de vidro provenientes dos processos de transformação: Moldagem por contato manual Hand lay-up, moldagem por projeção simultânea Spray-up e moldagem por injeção de resina Resin Transfer Moulding - RTM. As rebarbas de compósitos, oriundas das empresas transformadoras, são descartadas como lixo em aterros industriais ou clandestinos e levam décadas para se degradarem, poluindo, desta forma, o meio ambiente. A utilização destes resíduos pode conduzir ao desenvolvimento de uma nova tecnologia competitiva e sustentável. Este trabalho propõe a moagem e micronização das rebarbas de compósitos dando origem a um pó fino, contendo resina mais vidro, e substituição da carga mineral (calcita - CaCO3), tradicionalmente utilizada no processo RTM, por este pó, denominado pó de rebarba de compósito a base de resina poliéster e fibra de vidro. Confeccionaram-se placas de ensaios variando o tipo de carga, entre calcita e pó de rebarba, e a porcentagem em peso da carga na mistura com a resina. Em corpos-de-prova retirados das placas foram realizados ensaios de resistência à tração, resistência à flexão, resistência ao impacto e dureza. Complementarmente, foram realizados ensaios de densidade aparente das cargas, viscosidade da mistura, contração linear, exame microscópico e ensaio prático operacional, contribuindo para avaliar a proposta apresentada. Os resultados obtidos mostraram, que em alguns casos, ocorreram variações de propriedades. Em contrapartida expressaram-se fatores limitantes como por exemplo a viscosidade da mistura contendo pó de rebarba. Entretanto, pode-se afirmar que, tanto tecnicamente quanto operacionalmente, é possível a substituição do pó de calcita pelo pó de rebarba de compósito no processo de moldagem por injeção...
In this research the exploitation of the residues of composites was studied the resin polyester not saturated and fiber glass proceeding from the transformation processes: Molding for manual contact Hand lay-up, molding for simultaneous projection Spray-up and molding for resin injection Resin Transfer Moulding - RTM. The barbs of composites, deriving of the transforming companies, they are discarded as garbage in appropriate or clandestine places and take decades to be degraded, contaminating, of this form, the environment. The use it of these residues can lead to the development of a new competitive and sustainable technology. This work considers the milling and particle's formation of the barbs of composites giving origin to a fine dust, contend resin more glass, e substitution of the mineral load (calcite - CaCO3) traditionally used in process RTM for this dust, called dust of composite barb the resin base polyester and fiber glass. Plates of assays had been confectioned varying the type of load, between calcite and dust of barb, e the percentage in weight of the load in the mixture with the resin. In body-of-test removed of the plates assays of tensile strenght had been carried through, resistance to the flexion, resistance to the impact and hardness. Complementarily, assays of apparent density of loads had been carried through, viscosity of the mixture, linear contraction, microscopical examination and operational practical assay, contributing to evaluate the proposal presented. The gotten results had shown, that in some cases, had occurred variations of properties. On the other hand limitantes factors had been expressed as for example the viscosity of the mixture contends barb dust...(Complete abstract click electronic access below)

Hur kan en bok med bilder på fallande bomber, stridsvagnar och en döende hund i en flickas armar vara en barnbok? Hur berättar man egentligen om krig, död och sorg för ett barn? Vad om skiljer barn- och ungdomslitteratur från annan litteratur har länge diskuterats och studerats. Ännu har forskare inte funnit någon definition som alla kan komma överens om, förutom det faktum att den är skriven för en tilltänkt målgrupp.  Syftet med uppsatsen är att undersöka hur Ilon Wikland och Rose Lagercrantz berättelse Den långa, långa resan och dess sorgliga motiv adapterats genom att studera verkets ikonotext, den helhet som uppstår vid läsningen av en ”text” konstituerad av både text och bild. Hur texten och bilderna tar hänsyn till dess tilltänkta läsare.

Orientador: Alcides Lopes Leão
Banca: Adriano Wagner Ballarin
Banca: José Augusto Marcondes Agnelli
Resumo: Nesta pesquisa estudou-se o aproveitamento dos resíduos de compósitos a base de resina poliéster insaturado e fibra de vidro provenientes dos processos de transformação: Moldagem por contato manual "Hand lay-up", moldagem por projeção simultânea "Spray-up" e moldagem por injeção de resina "Resin Transfer Moulding - RTM". As rebarbas de compósitos, oriundas das empresas transformadoras, são descartadas como lixo em aterros industriais ou clandestinos e levam décadas para se degradarem, poluindo, desta forma, o meio ambiente. A utilização destes resíduos pode conduzir ao desenvolvimento de uma nova tecnologia competitiva e sustentável. Este trabalho propõe a moagem e micronização das rebarbas de compósitos dando origem a um pó fino, contendo resina mais vidro, e substituição da carga mineral (calcita - CaCO3), tradicionalmente utilizada no processo RTM, por este pó, denominado pó de rebarba de compósito a base de resina poliéster e fibra de vidro. Confeccionaram-se placas de ensaios variando o tipo de carga, entre calcita e pó de rebarba, e a porcentagem em peso da carga na mistura com a resina. Em corpos-de-prova retirados das placas foram realizados ensaios de resistência à tração, resistência à flexão, resistência ao impacto e dureza. Complementarmente, foram realizados ensaios de densidade aparente das cargas, viscosidade da mistura, contração linear, exame microscópico e ensaio prático operacional, contribuindo para avaliar a proposta apresentada. Os resultados obtidos mostraram, que em alguns casos, ocorreram variações de propriedades. Em contrapartida expressaram-se fatores limitantes como por exemplo a viscosidade da mistura contendo pó de rebarba. Entretanto, pode-se afirmar que, tanto tecnicamente quanto operacionalmente, é possível a substituição do pó de calcita pelo pó de rebarba de compósito no processo de moldagem por injeção...(Resumo completo, clicar acesso eletrônico abaixo)
Abstract: In this research the exploitation of the residues of composites was studied the resin polyester not saturated and fiber glass proceeding from the transformation processes: Molding for manual contact "Hand lay-up", molding for simultaneous projection "Spray-up" and molding for resin injection "Resin Transfer Moulding - RTM". The barbs of composites, deriving of the transforming companies, they are discarded as garbage in appropriate or clandestine places and take decades to be degraded, contaminating, of this form, the environment. The use it of these residues can lead to the development of a new competitive and sustainable technology. This work considers the milling and particle's formation of the barbs of composites giving origin to a fine dust, contend resin more glass, e substitution of the mineral load (calcite - CaCO3) traditionally used in process RTM for this dust, called dust of composite barb the resin base polyester and fiber glass. Plates of assays had been confectioned varying the type of load, between calcite and dust of barb, e the percentage in weight of the load in the mixture with the resin. In body-of-test removed of the plates assays of tensile strenght had been carried through, resistance to the flexion, resistance to the impact and hardness. Complementarily, assays of apparent density of loads had been carried through, viscosity of the mixture, linear contraction, microscopical examination and operational practical assay, contributing to evaluate the proposal presented. The gotten results had shown, that in some cases, had occurred variations of properties. On the other hand limitantes factors had been expressed as for example the viscosity of the mixture contends barb dust...(Complete abstract click electronic access below)
Mestre

As pesquisas com resinagem de árvores de espécies de pinus têm mostrado o efeito de fatores que afetam a produção e a qualidade da resina, relacionado com as espécies, variabilidade genética, taxa de crescimento, idade, manejo florestal, etc. As práticas de extração da goma-resina, a concentração, freqüência da aplicação de estimulantes químicos, época de abertura dos painéis, etc., têm sido, da mesma forma, analisadas. No entanto, há necessidade do desenvolvimento de pesquisas direcionadas ao estudo da formação e da estrutura do lenho e dos canais de resina das árvores de pinus. Pelo exposto, o presente trabalho teve como objetivos a caracterização da estrutura anatômica do lenho, dos anéis de crescimento e dos canais de resina, através de metodologias de histologia e de densitometria de raios X, de amostras de árvores de Pinus caribaea var. hondurensis resinadas e não resinadas, de três classes de diâmetro. Árvores de pinus, de plantação florestal instalada em 1969, na Estação Ecológica Experimental de Itirapina, do Instituto Florestal do Estado de São Paulo, foram mensuradas e estratificadas em três classes de diâmetro do tronco. As árvores de pinus têm sido resinadas desde 2004, com a abertura de dois painéis simultâneos e opostos. Sessenta amostras do lenho das árvores de pinus foram extraídas do tronco das árvores através de método não destrutivo e, em laboratório, (i) analisada e descrita a estrutura anatômica macro e microscópica do lenho; (ii) caracterizados os anéis de crescimento e determinada a densidade aparente do lenho por densitometria de raios X; (iii) caracterizados e descritos os canais de resina axiais e radiais e sua interconexão. Os resultados das análises evidenciaram que (i) a estrutura anatômica macro e microscópica do lenho e dos anéis de crescimento é característica da espécie; (ii) os anéis de crescimento falsos ocorrem nos lenhos inicial e tardio dos anéis de crescimento anuais devido as variações climáticas; (iii) a análise dos anéis de crescimento demonstrou que as árvores têm 38 anos, comprovada pela data de plantio; (iv) o comprimento e a espessura da parede das traqueídes não diferiram nas três classes de diâmetro do tronco; (v) a largura e o diâmetro do lume das traqueídes mostraram diferenças significativas, com maiores valores na classe de maior diâmetro do tronco; (vi) a densitometria de raios X possibilitou a demarcação dos limites dos anéis de crescimento e a determinação da freqüência dos canais de resina axiais; (vii) a densidade aparente média do lenho mostrou diferença significativa entre as árvores da classe de diâmetro alta em relação as das classes média-baixa; (viii) os canais de resina axiais localizam-se em maior freqüência no lenho tardio e apresentaram maior diâmetro de menor classe de diâmetro; (ix) as características do lenho e dos canais de resina nas faces testemunha e resinada não mostraram diferenças significativas.
The research on resin tapping trees with pine species have shown the effect of factors that affect the production and quality of resin, related with the species, genetic variability, growth rate, age, forest management, etc.. The gum-resin extraction practices, the concentration, frequency of application of chemical stimulants, the time of year that panels are opening, etc., have been in the same manner, discussed. However, there is need for further research directed to study the formation and structure of the wood and resin canals from the pine trees. Therefore, this work aimed to characterize the anatomical structure of wood, the tree rings and resin canals, through methodology of histology and X-ray densitometry, of resin tapped and not resin tapped Pinus caribaea var. hondurensis trees samples, of three diameter classes. Pine trees, in forest plantation established in 1969, in the Ecological Experimental Station of Itirapina, from the Forestry Institute of São Paulo State, were measured and stratified into three classes of diameter of the trunk. The pine trees have been resin tapped since 2004, with the opening of two simultaneous and opposing panels. Sixty samples of pine wood trees were extracted from the tree trunk through a non-destructive method, and in the laboratory, (i) examined and described the macro- and microscopic anatomical structure of wood, (ii) characterized the tree rings and determined the wood apparent density by X-ray densitometry, (iii) characterized and described the ducts for axial and radial resin and its inter-connection. The test results showed that (i) the macro- and microscopic anatomical structure of wood and the tree rings are characteristic of the species, (ii) the false tree rings occur in the early wood and latewood of the tree rings due to climate change (iii) the analysis of tree rings showed that 38 years have proven the date of planting of the trees, (iv) the length and thickness of tracheids wall did not differ in the three diameter classes of the trunk, (v) the tracheids lumen width and diameter showed significant differences, with higher values in the larger diameter class trunk, (vi) the Xray densitometry allowed the demarcation of the tree rings limits and determination of the axial resin canals frequency (vii) the wood apparent density average was significantly different between the trees in high class diameter from the medium-low, (viii) the axial resin canals can be found more frequently in the latewood and had larger diameter in the lowest diameter class, (ix) the wood and resin canals characteristics from the resin tapped and no resin tapped faces did not show significant differences.

Les lymphoproliférations survenant après transplantation sont une situation rare mais préoccupante car mettant en jeu la survie des patients. Ces hémopathies ont des caractéristiques épidémiologiques et physio-pathologiques qui les distinguent des lymphomes du sujet immunocompétent. Nous nous sommes intéressé à l’analyse des facteurs de risque associés aux lymphomes post-greffe et à la recherche de facteurs pronostiques de survie des patients par l’analyse détaillée des registres américain et français de patients transplantés rénaux. Le Registre Français des lymphomes survenant après transplantation rénale a permis de recenser tous les cas de syndromes lymphoprolifératifs se développant chez des patients adultes survenant entre le 1er janvier 1998 et le 31 décembre 2007. Tous les centres français de Transplantation rénale ont participé. Nous avons recensé 500 cas de lymphomes sur une période de 10 ans. Les différentes analyses de cette base de données ont donné lieu à la publication d’une analyse intermédiaire sur les 230 premiers cas, à une publication consacrée à l’incidence et aux facteurs de risque de développement des lymphomes surla cohorte complète et à une publication concernant les facteurs pronostiques de décès des patients porteurs d’une lymphoprolifération avec établissement d’un score de risque spécifique de cette population. D’autre part, cette base de données unique au monde représente un support intéressant pour le développement de travaux de recherche: étude de l’origine des cellules tumorales, étude des facteurs de susceptibilité pharmacogénétique au développement des lymphoprolifération post-greffe, étude des microRNA de l’EBV dans les lymphomes post-greffe
Post transplant lymphoproliferative disorders (PTLD) are a rare but serious complication occurring after kidney transplantation. Features of PTLD are specific and different of those of immunocompetent patients. We studied incidence, risk factors for development of PTLD and prognostic factors of patients with PTLD using two databases: American and French. The French Registry of PTLD enrolled all adult patients with PTLD occurring between the 1st January 1998 and the 31st December 2007 from all transplant centers in France. Five hundred patients were included in the Registry. This enables us to analyse first the incidence and risk factors of PTLD and second the risk factors of kidney recipients’ survival. We constructed a new prognostic score specific of transplant patients. Finally, the French Registry gave us the opportunity to support others research projects: determination of the origin of tumoral cells, analysis of pharmacogenetic factors associated with the risk of developing PTLD, study of EBV microRNA in lymphoproliferations

Phenol formaldehyde (PF) resol resins have long been used widely as wood adhesives due to their excellent bonding performance, water resistance and durability. With the growing concern for fossil fuel depletion and climate change, there is a strong interest in exploring renewable biomass materials as substitutes for petroleum-based feedstock. Bark, rich in phenolic compounds, has demonstrated potential to partially substitute phenol in synthesizing bio-based PF resins. In this study, acid-catalyzed phenol liquefaction and alkaline extraction were used to convert mountain pine beetle (MPB; Dendroctonus ponderosae) infested lodgepole pine (Pinus contorta) barks to phenol substitutes, liquefied bark and bark extractives. Two types of bio-based phenol formaldehyde (PF) resol resins, namely liquefied bark-PF resin and bark extractive-PF resins, were then synthesized and characterized. It was found that acid-catalyzed phenol liquefaction and alkaline extraction were effective conversion methods to obtain phenol substitute with the maximum yield of 85% and 68%, respectively. The bio-based PF resol resins had higher molecular weights, higher polydispersity indices, shorter gel times, and faster curing rates than the lab synthesized control PF resin without the bark components. Based on the lap-shear tests, the bio-based PF resol resins exhibited comparable wet and dry bonding strength to lab PF resin and commercial PF resin. The post-curing thermal stability of the bio-based PF resins was similar to the lab control PF resin. The liquid-state 13C nuclear magnetic resonance (NMR) study revealed significant influences on the resin structures by the inclusion of the bark components. Methylene ether bridges, which were absent in the lab PF resin, were found in the bio-based PF resins. The bark components favored the formation of para-ortho methylene linkages in the bio-based bark extractive-PF resins. The liquefied bark-PF resin showed a higher ratio of para-para/ortho-para methylene link (-CH2-), a higher unsubstituted/substituted hydrogen (-H/-CH2OH) ratio and a higher methylol/methylene (-CH2OH/-CH2-) ratio than the bark extractive-PF resin. Both tannin components of bark alkaline extractives and phenolated barks contributed to the acceleration of the curing rate of the bio-based resins. This research demonstrated the promise of the bio-based PF resins containing either bark alkaline extractives or liquefied barks as environmentally friendly alternatives to PF adhesives derived solely from fossil fuel based phenol and proposed a novel higher value-added application of the largely available barks from the mountain pine beetle-infested lodgepole pine trees.