Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2016-10-26T17:55:25Z No. of bitstreams: 1 2015 - Tha?s Gl?ucia Bueno Moreira.pdf: 292298 bytes, checksum: 71bdc650d433efc1801de110172240e0 (MD5) / Made available in DSpace on 2016-10-26T17:55:25Z (GMT). No. of bitstreams: 1 2015 - Tha?s Gl?ucia Bueno Moreira.pdf: 292298 bytes, checksum: 71bdc650d433efc1801de110172240e0 (MD5) Previous issue date: 2015-08-13 / CAPES / This study aimed evaluating changes in the Tifton 85 (Cynodon spp) hay chemical composition under different urea doses and treatment periods. The study was carried out at the Forage and Pastures Sector, Animal Nutrition and Pastures Department, Animal Science Institute in Universidade Federal Rural do Rio de Janeiro, Serop?dica-RJ, Brazil between August and September 2013. Completely randomized design with a factorial arrangement of five (45% N) (0, 1, 2, 3 and 4% based on dry matter) commercial urea doses distributed in a split-plot at two periods (30 and 45 days) for the bags opening, with five replications each was employed. The ammoniated material was stored in (1 kg hay / bag) plastic bags, sealed and after opening, samples were collected for bromathological analysis. No dose effect, time and dose x time interaction for dry matter, ether extract, neutral detergent fiber, acid detergent fiber, hemicellulose, cellulose, lignin, acid detergent insoluble nitrogen, mineral matter, total carbohydrates, B2 fractions and carbohydrates fraction (P> 0.05) were reported. The variables crude protein, neutral detergent insoluble nitrogen and non-fibrous carbohydrates were influenced by urea doses. The ammoniation of Tifton 85 hay with urea at 1; 2; 3: 4% doses on dry matter might promote increases in crude protein and non-fibrous carbohydrates. However, cell wall constituents of the forage might not be altered, as well. / Objetivou-se neste trabalho avaliar as altera??es na composi??o bromatol?gica do feno de Tifton 85 (Cynodon spp) submetido a diferentes doses de ureia e per?odos de tratamento. O trabalho foi conduzido no setor de Forragicultura e Pastagens do Departamento de Nutri??o Animal e Pastagens do Instituto de Zootecnia, da Universidade Federal Rural do Rio de Janeiro, no munic?pio de Serop?dica-RJ, entre os meses de agosto e setembro de 2013. O experimento foi conduzido segundo um delineamento experimental inteiramente casualizado, sendo os tratamentos constitu?dos por cinco doses de ureia pecu?ria (45% de N) (0; 1; 2; 3 e 4% com base da MS) distribu?dos em esquema de parcelas subdivididas, contendo dois per?odos (30 e 45 dias) para a abertura dos sacos, com cinco repeti??es cada. O material amonizado foi armazenado em sacos pl?sticos (1 kg feno/saco), lacrados e, ap?s a abertura, foram coletadas amostras para an?lises bromatol?gicas. N?o houve efeito de dose, tempo e intera??o dose x tempo para as vari?veis de mat?ria seca, extrato et?reo, fibra em detergente neutro, fibra em detergente ?cido, hemicelulose, celulose, lignina, nitrog?nio insol?vel em detergente ?cido, mat?ria mineral, carboidrato total, fra??es B2 e fra??o C de carboidratos (P>0,05). J? as vari?veis prote?na bruta, nitrog?nio insol?vel em detergente neutro e carboidrato n?o fibroso foram influenciados pelas doses de ureia. A amoniza??o de feno de tifton 85 com ureia nas doses 1; 2; 3 e 4% em base da MS promove incrementos nos teores de prote?na bruta e carboidrato n?o fibroso. Entretanto, n?o altera os constituintes da parede celular da forrageira.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-02-09T18:53:53Z No. of bitstreams: 1 2016 - Leonardo Fiusa de Morais.pdf: 1229717 bytes, checksum: 4c0be638ee0ef0a26e196c1343e1858b (MD5) / Made available in DSpace on 2017-02-09T18:53:53Z (GMT). No. of bitstreams: 1 2016 - Leonardo Fiusa de Morais.pdf: 1229717 bytes, checksum: 4c0be638ee0ef0a26e196c1343e1858b (MD5) Previous issue date: 2016-07-29 / CAPES / The aim of this study was to evaluate the effect of ammoniated with different doses of urea in two treatment periods, and 3 different sources of urease on the nutritional value of elephant grass harvested after flowering in two chapters. The first chapter assessed the nutrition value of hay application of 2, 4, 6 and 8% of urea in two treatment periods (30 and 45 days) and control (not hay ammoniated). The second chapter evaluated the legume soybean, pigeon peas and jack beans sedds as urease sources, with the addition of 1, 2, 3 and 4% in ammoniated hay with urea and the control treatment (ammoniated hay with 4% urea without urease sources). The Experimental design was completely randomized in organized in double factorial arrangement with additional treatment. Dry matter (DM), ash, ether extract (EE), neutral detergent fiber (NDF), neutral detergent fiber corrected for the ash and the protein (NDFap), acid detergent fiber (ADF), cellulose, lignin, total nitrogen (TN), acid detergent insoluble nitrogen (ADIN), neutral detergent insoluble nitrogen (NDIN), Non protein N (NPN), in vitro gas production(Parameters: Vf1, k1, Vf2, K2 e L) and Carbohydrates fractioning were analysed. In the first study, was applied urea different doses at treatment periods, there was a difference (p<0,05) between the control and combination of factorial treatments for DM, EE, NDF, ADF, lignina, cellulose, NDFap, A + B1 fraction, B2 fraction, C fraction, TN, NPN, ADIN, NDIN, k1, L, Vf2, k2. Linear effect from dose was observed to NDFap, ADIN and NDIN and increasing dose to A+B1 fraction, TN, NNP. A quadratic effect for to Vf2, with point absolute maximum of 5,2% urea, and effect treatment period to Vf2 e K2, with higher and lower Vf2 K2 for hay treated 45 days. There was interaction (p<0,01) between sources of urease and level for NDF, ADF and lignin. The addition of 3% soybean or jack bean as a source of urease, resulted in lower NDF, and were not statistically different (p> 0.05), while pork beans had the highest NDF. There was a difference (P<0,05) between the control and combination of factorial treatments for NDF, A + B1 fraction. There was no interaction (p> 0.05) between source application level of urease, but was no effect (p <0.01) of urease source for NPN and ADIN. There was interaction (p <0.05) between source application level of urease to Vf1, but there was no interaction (p> 0.05) for k1, L, Vf2 and k2. Ammoniation urea and adding urease sources is an efficient method for chemical treatment of the elephant grass hay harvested after flowering, mainly by increasing the solubility fiber, in addition to the increased supply of non-protein nitrogen to rumen microorganisms, which resulted in improvement in vitro gas production of the kinetic parameters. / Objetivou-se avaliar o efeito da amoniza??o com aplica??o de diferentes doses de ur?ia em dois per?odos tratamento, e 3 diferentes fontes de urease, sobre o valor nutritivo do feno de capim-elefante colhido ap?s o florescimento, em dois cap?tulos. O primeiro cap?tulo avaliou o valor nutritivo do feno com aplica??o de 2, 4, 6 e 8% de ureia com base na mat?ria seca, em dois per?odos de tratamento (30 e 45 dias) e o controle (feno n?o amonizado),e o segundo que avaliou o efeito da adi??o de gr?os mo?dos das leguminosas soja, feij?o guandu e feij?o de porco como fontes de urease, em niveis de 1, 2, 3 e 4% com base na mat?ria seca do feno amonizado com 4% de ureia, e o tratamento controle (feno amonizado com 4% de ureia sem adi??o de fonte de ur?ase). O Delineamento experimental foi inteiramente casualizado em esquema fatorial duplo com tratamento adicional com 4 repeti??es por tratamento para os dois estudos. Foram realizadas as an?lises de mat?ria seca (MS), cinzas, extrato et?reo (EE), fibra em detergente neutro (FDN), fibra em detergente neutro corrigido para cinzas e prote?nas (FDNcp), fibra em detergente acido (FDA), celulose, lignina, prote?na bruta (PB), nitrog?nio insol?vel no detergente ?cido (NIDA) e produ??o cumulativa de g?s in vitro (Par?metros: Vf1, k1, Vf2, K2 e L) e o fracionamento de carboidratos. No primeiro estudo, houve diferen?a entre controle e a combina??o de tratamentos fatoriais para MS, EE, FDN, FDA, Lignina, celulose, FDNcp, fra??o A + B1, fra??o B2, fra??o C, NT, NNP, NIDA, NIDN, K1, L, Vf2, K2, e efeito (p <0,05) linear decrescente de dose de ureia para FDNcp, NIDA e NIDN e crescente de dose para fra??o A+B1, NT, NNP, efeito quadr?tico crescente de dose de ureia para Vf2 com ponto m?ximo absoluto de 5,2% de ureia.houve efeito de per?odo de tratamento para Vf2 e K2, com maior Vf2 e menor K2 para o feno tratado durante 45 dias. Houve intera??o (p<0,01) entre fonte de ur?ase e n?vel de fonte de ur?ase para FDN, FDA e lignina, sendo que a adi??o de 3,0% de soja ou feij?o guandu como fonte de ur?ase, resultaram em menores valores de FDN. Houve diferen?a (P<0,05) entre o controle e a combina??o de tratamentos fatoriais para FDN e fra??o A + B1 , mas n?o houve diferen?a (p > 0,05) entre o controle e a combina??o de tratamentos fatoriais para mat?ria seca, cinzas e extrato et?reo, mas foi observado efeito (p < 0,01) de fonte de ur?ase para extrato et?reo. N?o houve intera??o (p>0,05) entre fonte de ur?ase de n?vel de aplica??o, mas houve efeito (p<0,01) de fonte de urease para NNP e NIDA. Houve intera??o (p<0,05) entre fonte de ur?ase de n?vel de aplica??o para Vf1, mas n?o houve intera??o (p>0,05) para k1, L, Vf2 e k2. A dose m?nima de 5,2% de ureia durante um per?odo de 45 dias, proporcionou melhoria valor nutricional do feno de capim elefante. A amoniza??o com ureia e adi??o de fontes de ur?ase ? um m?todo eficiente para tratamento qu?mico do feno de capim elefante colhido ap?s o florescimento, principalmente pelo aumento da solubilidade fibra, al?m da maior oferta de nitrog?nio n?o proteico aos microrganismos ruminais, que resultou em melhoria dos par?metros cin?ticos de produ??o de g?s in vitro.

<p>Cellulosans tillgänglighet och reaktivitet är nyckelparametrar vid framställning av regenererad cellulosa och cellulosaderivat. Det är välkänt att på grund av cellulosans kristallina struktur är tillgängligheten begränsad för lösningsmedel och olika reagens. Till exempel kan en inhomogen substitution av hydroxylgrupperna i cellulosakedjan resultera i cellulosaderivat av sämre kvalitet. Baserat på detta har en del av arbetet i denna studie fokuserat på att förbättra cellulosans tillgänglighet och reaktivitet genom att studera effekten av olika enzymatiska behandlingar med monokomponent endoglukanaser. Resultaten visar att närvaron av en cellulosabindande domän fyller en viktig funktion för att öka cellulosans reaktivitet, men strukturen för den katalytiska domänen visade sig ha den största inverkan på cellulosans tillgänglighet. I kompletterande studier har även effekten av en mekanisk förbehandling i kombination med enzymatisk behandling utvärderats. Kombinationen av förbehandlingarna resulterade i en positiv effekt, cellulosans reaktivitet kunde ökas i större omfattning.</p><p>I dag används huvudsakligen dissolvingmassor som råvara vid framställning av cellulosaregenerat och cellulosaderivat. Kraven för dessa s.k. specialmassor är högt cellulosainnehåll samt lågt hemicellulosa- respektive lignininnehåll. På grund av dessa specifika krav är produktionskostnaderna för dessa massor högre än konventionella sulfatmassor. Den andra delen av studien har därför fokuserat på möjligheten att använda dessa sulfatmassor som dissolvingmassa. Det har visats att kombinationen av enzymatiska behandlingar med monokomponent endoglukanas och xylanas följt av ett alkaliskt steg kan resultera i massor där kraven uppfylls med avseende på cellulosans reaktivitet, och cellulosa- respektive hemicellulosainnehåll.</p> / <p>The accessibility and reactivity of cellulose are key parameters on the manufacturing of cellulose derivatives and regenerated cellulose. It is well known that, due to the crystalline structure of cellulose, the accessibility of solvents and reagents is limited. For instance, an inhomogeneous substitution of the hydroxyl groups of the cellulose chain might lead to the production of derivatives of low quality. As a consequence, part of this work has focused on improving the accessibility and reactivity on cellulose by studying the effect of different monocomponent endoglucanases. It has been demonstrated that the presence of the cellulose-binding domain plays an important role on the enhancement of cellulose reactivity; however, the structure of the catalytic domain has been showed to have the highest influence on this parameter. Furthermore, the influence of mechanical treatment prior to enzymatic treatment has been examined. The combination of pretreatments showed a positive effect enhancing to a larger extent the cellulose reactivity.</p><p>Currently, dissolving-grade pulps are commonly used for the production of cellulose derivatives and regenerated cellulose. The requirements for these so-called “special pulps” are a high cellulose content and a low hemicelluloses and lignin content. As a result of these specific demands, the production costs of these pulps are higher than those of common kraft pulps. The second part of this work, therefore, has been focused on the study on the viability of converting kraft pulps into dissolving pulps. It has been demonstrated that the combination of enzymatic treatments using a monocomponent endoglucanase and a xylanase together with the addition of an alkaline step could fulfil the requirements of a commercial dissolving pulp in terms of cellulose reactivity and cellulose and hemicellulose content.</p>

Made available in DSpace on 2014-12-17T14:06:51Z (GMT). No. of bitstreams: 1 TharsiaCCC.pdf: 1127571 bytes, checksum: caf0ffeeb86abc73d08cddd51d5f1c0b (MD5) Previous issue date: 2009-03-16 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Natural nanoclays are of great interest particularly for the production of polymer-based nanocomposites. In this work, kaolinite clays from two natural deposits in the State of the Rio Grande do Norte and Paraiba were purified with thermal treatment and chemical treatments, and characterized. Front to the gotten data, had been proposals methodologies for elimination or reduction of coarse particle texts, oxide of iron and organic substance. These methodologies had consisted of the combination of operations with thermal treatments, carried through in electric oven, and acid chemical attacks with and hydrogen peroxide. The Analyzers Thermogravimetric was used to examine the thermal stability of the nanoclays. The analysis indicated weight losses at temperatures under 110 ?C and over the temperature range of 350 to 550 ?C. Based on the thermal analysis data, the samples were submitted to a thermal treatment at 500 ?C, for 8 h, to remove organic components. The X-ray diffraction patterns indicated that thermal treatment under 500 ?C affect the basic structure of kaolinite. The BET surface area measurements ranged from 32 to 38 m2/g for clay samples with thermal treatment and from 36 to 53 m2/g for chemically treated samples. Thus, although the thermal treatment increased the surface area, through the removal of organic components, the effect was not significant and chemical treatment is more efficient, not affect the basic structure of kaolinite, to improve particle dispersion. SEM analysis confirms that the clay is agglomerated forming micron-size particles / As nanoargilas naturais s?o de grande interesse tecnol?gico, particularmente para a obten??o de nanocomp?sitos com matriz polim?rica. Neste trabalho, foram estudadas duas argilas caulin?ticas provenientes de dep?sitos naturais localizados nos estados do Rio Grande do Norte e da Para?ba. Estas argilas foram caracterizadas f?sica e quimicamente. Frente aos dados obtidos, foram propostos metodologias para elimina??o ou redu??o dos teores de part?culas grosseiras, de ?xido de ferro e de mat?ria org?nica. Estas metodologias consistiram na combina??o de tratamentos t?rmicos, realizadas em forno el?trico, e ataques qu?micos com ?cidos e per?xido de hidrog?nio. Com a an?lise termogravim?trica verificou-se a estabilidade t?rmica das amostras, que indicou perdas de massa na temperatura de 110 ?C e numa faixa de temperatura de 350?C a 550?C. Baseado nesses dados, as amostras foram submetidas a um tratamento t?rmico de 500?C por 8 horas para a remo??o dos componentes org?nicos. Os difratogramas de raios-X indicaram que o tratamento t?rmico alterou a sua estrutura b?sica. As medidas da ?rea da superficial (BET) variaram de 32 a 38 m2/g para amostras da argila com tratamento t?rmico e 36 a 53 m2/g para amostras tratadas quimicamente. Verificouse que o tratamento t?rmico promove um aumento significativo na ?rea de superf?cie. No entanto, seu efeito ? superado pelos tratamentos qu?micos que, adicionalmente, preservam a estrutura b?sica da caulinita e melhoram a dispers?o de part?culas, conforme evidenciado por microscopia eletr?nica de varredura

Submitted by MARA LUCIA DIAS RIBEIRO null (mara_frutal@hotmail.com) on 2016-04-20T19:56:09Z No. of bitstreams: 1 Dissertação.pdf: 1035693 bytes, checksum: 3b76521d5124be58245e79d2b5e7bec8 (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-04-25T17:10:59Z (GMT) No. of bitstreams: 1 ribeiro_mld_me_jabo.pdf: 1035693 bytes, checksum: 3b76521d5124be58245e79d2b5e7bec8 (MD5) / Made available in DSpace on 2016-04-25T17:10:59Z (GMT). No. of bitstreams: 1 ribeiro_mld_me_jabo.pdf: 1035693 bytes, checksum: 3b76521d5124be58245e79d2b5e7bec8 (MD5) Previous issue date: 2016-03-08 / A cachaça é a aguardente produzida a partir da destilação do fermentado de caldo de cana. Diversos fatores afetam negativamente a qualidade deste destilado, dentre esses o processo produtivo, e a levedura utilizada na fermentação. Avaliou- se o desempenho de dois tipos de fermento (selecionado e natural) e o prévio tratamento físico-químico do caldo de cana e sua influência na qualidade do destilado final. O experimento foi realizado na safra 2014/2015, utilizando-se a variedade de cana-de-açúcar SP83-2847, obtida da Fazenda Santa Clara, localizada à 21º14’05’’S e 48º17’09’’W. O delineamento experimental foi realizado em blocos casualizados com 9 repetições, sendo 3 ciclos com 3 repetições cada. O tratamento primário principal, foi constituído por 2 mostos (clarificado e não clarificado); e o secundário os dois tipos de leveduras (Natural e CA-11). Avaliou-se a qualidade da cana e no mosto determinou-se: Brix, Compostos Fenólicos Totais (CFT), Açúcares Redutores Totais (ART) e Acidez Total. Ao longo do processo fermentativo avaliou-se a Viabilidade das Células e Brotos e o Índice de Brotamentos. No vinho determinou-se o Brix, Açúcares Redutores Residuais Totais (ARRT), pH, Acidez Total, Teor Alcoólico, Glicerol e Eficiência Fermentativa. A composição das cachaças (Acroleína, Acidez volátil, Acetaldeído, Carbamato de etila, Ésteres, Metanol, Alcoóis superiores (propílico, isobutílico, isoamílico)) foi determinada por cromatografia. Analisou-se ainda Condutividade Elétrica, Turbidez e pH. A utilização da levedura selecionada CA-11 e o prévio tratamento do caldo possibilitou a obtenção de destilados de melhor qualidade e com composição química dentro dos limites estabelecidos pela legislação brasileira. / Cachaça is the spirit produced from the distillation of fermented sugarcane juice. Several factors affect negatively the productive chain, among them the juice treatment and the yeast used into the fermentative process. We evaluated the performance of two different yeast (selected and natural) as well the previous physical-chemical treatment of sugarcane juice and ita influence in the final spirit. The periment was carried out through 2014-2015 season, using the SP83-2847 sugar cane variety which was obtained at Santa Clara Farm, located at 21º14’05’’S e 48º17’09’’W . The experimental statistic design used was the randomized blocks with three cycles and three replications each. The main primary factor had two types of musts (clarified and non-clarified) and the secondary two types of yeast (Natural and CA-11). We evaluated the sugarcane and must and we determined: Brix, Total Phenolic Compounds (CFT), Total Reducing Sugars (ART) and Total Acidity. Along the fermentative process we evaluated the Cells and Sprouts Viability and the Sprouting Index. At the wine we determined the Brix, Total Reducing Residual Sugars (ARRT). pH, Total Acidity, Alcohol By Volume, Glycerol, and Fermentative Efficiency. The cachaça composition (Acrolein, Volatile Acidity, Acetaldehyde, Ethyl Carbamate, Total Esters, Methanol, Superior Alcohols (propilic, isobutilic, isoamilic)) was determined through gas chromatography. Yet, we determined the Electric conductivity, Turbidity and pH. Using the selected yeast CA-11, together to the previous treatment of the juice, we could obtain spirits with higher quality and with a chemical composition fitting the Brazilian Legislation parameters.

Master of Science / Grain Science and Industry / Cassandra K. Jones / Feed mill biosecurity is a growing concern for the feed industries, especially since the entry of Porcine Epidemic Diarrhea Virus (PEDV) to the United States. Porcine Epidemic Diarrhea Virus (PEDV) is primarily transmitted by fecal-oral contamination. However, research has confirmed swine feed and ingredients as potential vectors of transmission, so strategies are needed to mitigate PEDV in feed. The objective of the first experiment was to evaluate the effectiveness of various chemical additives to prevent or mitigate PEDV in swine feed and ingredients that had been contaminated post-processing. Time, formaldehyde, medium chain fatty acids, essential oils, and organic acids all enhance the degradation of PEDV RNA in swine feed and ingredients, but their effectiveness varies within matrix. Notably, the medium chain fatty acids were equally as successful at mitigating PEDV as a commercially-available formaldehyde product. Salmonella is also another potential feed safety hazard in animal feed ingredients. Thermal mitigation of Salmonella in ingredients and feed manufacturing is effective, but it does not eliminate the potential for cross contamination. Therefore, the objective of the second experiment was to evaluate the effectiveness of chemicals to mitigate Salmonella cross-contamination in rendered proteins over time. Both chemical treatment and time reduced Salmonella concentrations, but their effectiveness was again matrix dependent. Chemical treatment with medium chain fatty acids or a commercial formaldehyde product was most effective at mitigating Salmonella in rendered protein meals. The final experiment was conducted to evaluate the effectiveness of a dry granular acid, sodium bisulfate (SBS; Jones-Hamilton, Co., Waldridge, OH), to mitigate contamination of Salmonella in poultry feed. A surrogate organism, Enterococcus faecium, was utilized for this research in order to evaluate the effectiveness of SBS. Thermal processing, SBS concentration, and time all impacted biological pathogen levels in poultry diets, and including a dry granular acid may be an effective method to reduce pathogen risk. However, the most significant reduction of Enterococcus faecium was due to thermal mitigation. Notably, pelleting reduced Enterococcus faecium by 2-3 logs on day 0. In summary, both thermal processing and chemical inclusion can be used to reduce the risk of microbial pathogens in feed.

Made available in DSpace on 2016-12-08T17:19:17Z (GMT). No. of bitstreams: 1 1 - Introducao.pdf: 683948 bytes, checksum: 323bfbfe06d963d7bfbecaaf890583ab (MD5) Previous issue date: 2012-05-14 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The aim of this work was the development of polyester matrix and taquara-lixa (Merostachys sp.) sticks or fibers composites and mechanical characterization by means of flexural tests for the composites and tension tests for taquara. First, it was determined the average mass distribution from a group of taquara sticks with 150 mm length, taquara medium moisture content and tension tests. Billets measuring 150 x 50 x 50 mm were prepared and were characterized by flexural tests. After the observation of the delamination effect in the composites, due to the poor interaction between matrix and fiber, a study of a chemical treatment of the sticks with sodium hydroxide was performed, for the partial removal of lignin and hemicellulose and to allow the stick s fibers to reorganize and reduce its hydrophilicity. Taquara specimens were made and suffered chemical treatment, varying the type of washing for each group, and flexural tests were performed to verify its mechanical properties. In another experiment, the average mass of a stick with 280 mm length was determined and the composites were made in a mold with 280 x 60 x 50 mm dimensions. To check the effect of the chosen treatment and the compression force during the confection of the composites, it was produced composites with dried taquara sticks and without compression, chemically treated sticks and without compression, dried sticks and with compression, chemically treated sticks and with compression and chemically treated taquara pieces that have its fibers separated by a rolling machine, and with compression. Specimens were extracted from the composites and flexural tests were performed to determine the maximum flexural stress, 1st rupture flexural stress, maximum displacement, 1st rupture displacement and flexural modulus. It was observed that both chemical treatment and the compression force had influence on composites mechanical properties, raising its flexural stress and elasticity modulus and reducing its displacement during flexural tests. / Este trabalho teve por objetivo o desenvolvimento de compósitos de matriz de resina poliéster e gravetos ou fibras de taquara-lixa (Merostachys sp.) e a caracterização mecânica por ensaios de flexão dos compósitos e por ensaios de tração da taquara. Inicialmente, foi realizada a determinação da massa média de um lote de gravetos de taquara de 150 mm de comprimento, o seu teor de umidade médio e a realização de ensaios de tração da taquara. Os compósitos confeccionados foram feitos em um molde de 150 x 50 x 50 mm e caracterizados por ensaios de flexão. Após a observação do efeito de delaminação nos compósitos, devido a fraca interação entre a matriz e a taquara, foi realizado um estudo de tratamento químico dos gravetos com hidróxido de sódio, para realizar a remoção parcial da lignina e hemicelulose e permitir que as fibras do graveto se reorganizassem e reduzissem a sua hidrofilicidade. Corpos de prova de taquara foram confeccionados e sofreram tratamento químico, variando o tipo de enxágüe em cada lote, e os mesmos foram ensaiados na máquina de flexão para verificar as suas propriedades mecânicas. Em outro experimento, foi determinada a massa média de um lote de gravetos de taquara de 280 mm de comprimento e os compósitos foram produzidos em um molde de dimensões de 280 x 60 x 50 mm. Para verificar o efeito do tratamento escolhido e da força de compressão durante a confecção dos compósitos, foram produzidos compósitos com gravetos in natura e sem compressão, gravetos tratados e sem compressão, gravetos in natura e sem compressão, gravetos tratados e com compressão, e pedaços de taquara tratados quimicamente e que tiveram as fibras separadas com o auxílio de uma calandra e com compressão. Os corpos de prova foram extraídos dos compósitos e foram realizados ensaios de flexão para a determinação da tensão máxima de flexão, tensão de flexão na 1ª delaminação, o deslocamento máximo e o deslocamento sofrido no momento da 1ª delaminação e o módulo de elasticidade em flexão. Foi observado que tanto o tratamento químico quanto a força de compressão exerceram influência nas propriedades mecânicas dos compósitos, aumentando sua tensão de flexão e seu módulo de elasticidade e reduzindo o deslocamento durante o ensaio de flexão.

[pt] Atualmente existe grande empatia da sociedade por produtos de origem renovável, devido à crescente conscientização da finitude dos recursos naturais. Um resíduo muito comum da agroindústria e gerado em grande escala, sendo majoritariamente descartado em lixões, é a casca de coco. Com o intuito de dar um aproveitamento a este resíduo, o presente trabalho experimentou diferentes metodologias para se isolar a nano celulose proveniente da fibra de coco e caracterizou os produtos das diferentes etapas do seu processo de extração. A metodologia que obteve os melhores resultados consistiu em deslignificar exaustivamente com NaOH até o licor remanescente não apresentar mais a coloração escura, lignina. Em seguida, foi realizado um tratamento com H2O2 e NaOH por duas vezes e a hidrólise com ácido sulfúrico. As etapas posteriores objetivaram a remoção do ácido através de seguidos ciclos de centrifugação com a remoção do sobrenadante acompanhado de diálise até que o meio externo atingisse pH neutro. A dispersão final da nano celulose em meio aquoso foi feita através do ultrassom. As caracterizações da celulose hidrolisada e dos produtos das etapas realizadas até o isolamento da mesma foram feitas por: análise térmica gravimétrica; por difração de raios X e por microscopia eletrônica de varredura. Ao final foram determinadas as estabilidades térmicas das nano celuloses obtidas, os seus respectivos índices de cristalinidade e o tamanho do cristal obtido e os efeitos dos diferentes tratamentos experimentados. A lignina teve sua estrutura química atestada por FTIR, a partir do efluente gerado durante o isolamento da nano celulose, o licor negro. / [en] Nowadays there is great empathy from society for products from renewable resources, due to growing awareness of the finiteness of natural resources. A very common residue of agribusiness and generated on a large scale, being largely discarded in landfills, is coconut shell. With the objective of giving a benefit to this residue, this work tried different methods to isolate the nanocellulose derived from coconut fiber and characterized the products of the different stages of the extraction process. The methodology, which achieved the best results, was the one which did the mercerization with NaOH until the remaining liquor does not look like a black liquor anymore. After that, the bleaching was made twice with H2O2 and NaOH and the hydrolysis was carried with sulfuric acid. Subsequent steps aimed to remove the acid from the fibers. The centrifugation was made and supernatant was removed, followed by dialysis until the external medium reached neutral pH. The final dispersion of nanocellulose in aqueous medium was performed using ultrasound. The characterizations of hydrolyzed cellulose and the products of the process steps was performed by TGA analysis; by X-ray diffraction and scanning electron microscopy. The thermal stabilities were determined from the obtained nanocellulose, their respective indices of crystallinity and crystal size achieved and the effects of the different treatments tested. The chemical structure of the generated effluent from the isolation of the nanocellulose black liquor was attested by FTIR.

Cellulosans tillgänglighet och reaktivitet är nyckelparametrar vid framställning av regenererad cellulosa och cellulosaderivat. Det är välkänt att på grund av cellulosans kristallina struktur är tillgängligheten begränsad för lösningsmedel och olika reagens. Till exempel kan en inhomogen substitution av hydroxylgrupperna i cellulosakedjan resultera i cellulosaderivat av sämre kvalitet. Baserat på detta har en del av arbetet i denna studie fokuserat på att förbättra cellulosans tillgänglighet och reaktivitet genom att studera effekten av olika enzymatiska behandlingar med monokomponent endoglukanaser. Resultaten visar att närvaron av en cellulosabindande domän fyller en viktig funktion för att öka cellulosans reaktivitet, men strukturen för den katalytiska domänen visade sig ha den största inverkan på cellulosans tillgänglighet. I kompletterande studier har även effekten av en mekanisk förbehandling i kombination med enzymatisk behandling utvärderats. Kombinationen av förbehandlingarna resulterade i en positiv effekt, cellulosans reaktivitet kunde ökas i större omfattning. I dag används huvudsakligen dissolvingmassor som råvara vid framställning av cellulosaregenerat och cellulosaderivat. Kraven för dessa s.k. specialmassor är högt cellulosainnehåll samt lågt hemicellulosa- respektive lignininnehåll. På grund av dessa specifika krav är produktionskostnaderna för dessa massor högre än konventionella sulfatmassor. Den andra delen av studien har därför fokuserat på möjligheten att använda dessa sulfatmassor som dissolvingmassa. Det har visats att kombinationen av enzymatiska behandlingar med monokomponent endoglukanas och xylanas följt av ett alkaliskt steg kan resultera i massor där kraven uppfylls med avseende på cellulosans reaktivitet, och cellulosa- respektive hemicellulosainnehåll. / The accessibility and reactivity of cellulose are key parameters on the manufacturing of cellulose derivatives and regenerated cellulose. It is well known that, due to the crystalline structure of cellulose, the accessibility of solvents and reagents is limited. For instance, an inhomogeneous substitution of the hydroxyl groups of the cellulose chain might lead to the production of derivatives of low quality. As a consequence, part of this work has focused on improving the accessibility and reactivity on cellulose by studying the effect of different monocomponent endoglucanases. It has been demonstrated that the presence of the cellulose-binding domain plays an important role on the enhancement of cellulose reactivity; however, the structure of the catalytic domain has been showed to have the highest influence on this parameter. Furthermore, the influence of mechanical treatment prior to enzymatic treatment has been examined. The combination of pretreatments showed a positive effect enhancing to a larger extent the cellulose reactivity. Currently, dissolving-grade pulps are commonly used for the production of cellulose derivatives and regenerated cellulose. The requirements for these so-called “special pulps” are a high cellulose content and a low hemicelluloses and lignin content. As a result of these specific demands, the production costs of these pulps are higher than those of common kraft pulps. The second part of this work, therefore, has been focused on the study on the viability of converting kraft pulps into dissolving pulps. It has been demonstrated that the combination of enzymatic treatments using a monocomponent endoglucanase and a xylanase together with the addition of an alkaline step could fulfil the requirements of a commercial dissolving pulp in terms of cellulose reactivity and cellulose and hemicellulose content. / QC 20101117

O alisamento químico é o método mais empregado para melhorar a penteabilidade e a estilização de cabelos afro-étnicos. O cabelo é composto basicamente de três partes: cutícula, córtex e medula. O principal constituinte é uma proteína, a queratina. O tratamento com agente alcalino, redutor e/ou oxidante, provoca modificações nessa estrutura, ocasionando danos que podem ocorrer na camada superficial (cutícula) ou em toda a fibra, atingindo inclusive o córtex e modificando as propriedades físico-químicas do cabelo, pois o torna mais quebradiço, frágil, sem brilho, áspero e com mais dificuldade para ser penteado e desembaraçado. O emprego de agentes condicionadores auxilia na melhora dos atributos físicos e sensoriais do cabelo tornando-o mais resistente e facilitando o manuseio. Neste estudo foi preparado um creme-base alisante com tioglicolato de amônio acrescido de agentes condicionadores pré-escolhidos e adicionados no momento do uso. A formulação-base foi submetida ao estudo de estabilidade física por dois meses. Foram realizados testes de: quantificação da perda de proteína equivalente em albumina, empregando-se o método de Lowry modificado por Peterson; penteabilidade e tração de ruptura. Os resultados indicaram que a adição de óleo de jojoba e de silicones, como Lauril PEG/PPG18/18 meticona e Ciclopentasiloxano (e) PEG-12 polímero de dimeticone reticulado, melhoram os atributos físico-químicos e sensoriais das mechas de cabelo afro-étnico, sendo indicado como agentes condicionadores que poderão ser acrescidos à formulação do creme-base alisante. / Chemical hair relaxing is the most common used method to improve combability and styling on afro-ethnic hair. The hair is basically composed of three parts: cuticle, cortex and medulla. The main basic element is a protein, the keratin. The treatment with an alkaline reducing agent and/or an oxidant agent causes modifications in this structure, and related damages that can occur in the superficial layer (cuticle) through ali the fiber, reaching the cortex and modifying the physical-chemical properties of the hair. In that case, the hair becomes more fragile, it has no shine, gets rough and it is very difficulty to comb and to detangle it. Conditioning agents can improve the physical and sensorial attributes of the hair, thus allowing it to become more resistant and making it easier to take care of. In this study a hair straightener cream-base with ammonium thioglycolate was prepared and the selected conditioning agents added at the moment of the use. The straightener cream-base was submitted to the physical stability study for two months. The tests had been carried through: quantification of protein loss of albumine equivalent, using the Lowry method modified by Peterson; the combability and rupture traction. The results have indicated that the addition of Jojoba oil and silicones as Lauryl PEG/PPG-18/18 methicone; and Cyclopentasiloxane (and) PEG-12 dimethicone crosspolymer, improve the physical-chemical and sensorial attributes of the afro-ethnic hair tresses, being indicated as conditioning agents that could be added in a hair straighteners cream formulation to help its care.