The aim of the project was to investigate a green and sustainable replacement for boric acid in polyvinyl alcohol (PVA) adhesives for solid paperboard production. Boric acid acts as a cross-linker and tackifier in the adhesive but is classified as a harmful substance. Microfibrillated cellulose (MFC) was therefore investigated as a possible replacement for boric acid since it is produced from renewable and sustainable resources. In addition, it has hydroxyl groups available for interaction with the PVA, can be used to modulate the viscosity and can function under a variety of pH-values.  For the industrial process, there are three basic characteristics which must be met by the newly developed adhesive, which have to be the same as for the boric acid-containing reference. These three are the viscosity, the pH-value, and the dry content. Furthermore, it is important that the initial wet tack and the final adhesive strength are at least as high as the reference’s.  In this context, eight types of samples were investigated in total. Two were references, one prepared on industrial and the second on a laboratory scale according to a current industrial recipe. In the other six samples, the boric acid from the recipe was replaced by three different weight percentages of MFC of two different industrial grades. Both the dry content and the pH-value were not noticeably influenced by the addition of MFC. The viscosity however increased drastically with the increasing amount of MFC. The addition of MFC was enough to reach the three basic characteristics. In addition it was observed positive effects on a couple of other parameters that is beneficial for the glue.   A test method for evaluating the initial wet tack of the adhesive was developed. It was shown, that the tack of the adhesive containing MFC is 40 % lower than the one of the reference material. Therefore, five additives were tested in the formulation, in combination with MFC. The most promising result led to a comparable initial tack and final strength as the reference.

O método cromatográfico de troca iônica, em colunas de resina foi empregado no estudo do enriquecimento isotópico de 10B e H3 10BO3. Em dois sistemas cromatográficos de colunas (S1: seis colunas de acrílico de 1800 mm de comprimento e 70 mm de diâmetro interno; S2: seis colunas de acrílico de 1800 mm de comprimento e 30 mm de diâmetro interno) foi estudado a separação do isótopo 10B, no equilíbrio envolvendo ácido bórico em solução aquosa e íons borato adsorvidos em resina aniônica do tipo amônio quaternário (Dowex 1X8), 100 - 200 \"mesh\". Os sistemas de produção de H3 10BO3 foram avaliados individualmente e em processo cascata, com transferência de 10B entre os dois sistemas. As determinações de B no presente trabalho foram avaliadas por espectrometria de massas com plasma e espetrometria de massas por termoionização. No sistema S1 de colunas após 243 m (135 DBC) de deslocamento foi possível obter um enriquecimento médio, nos últimos 20 cm, de 40 % em átomos de 10B, correspondendo a 2830 mg de H3 10BO3. Essa massa foi transferida (interação) para o sistema S2 de colunas que apresentava, nos últimos 20 cm da banda, enriquecimento médio de 47,8 % em átomos de 10B e essa nova banda cromatográfica foi deslocada por 21,6 m, obtendo-se no último centímetro da banda (1 - 0 cm) da fração enriquecida 82 % em átomos de 10B. O fator de fracionamento (\'alfa\') e a altura equivalente de uma placa teórica dos isótopos estáveis de B (10B e 11B) foi determinado como sendo 1,0245 e 0,30 cm, respectivamente / The chromatographic method of ion exchange resin in columns was used to study the isotopic enrichment of 10B and H3 10BO3. In two column chromatographic systems (S1: six acrylic columns 1800 mm length and 70 mm diameter; S2: six acrylic columns 1800 mm length and 30 mm diameter) was studied 10B isotope separation in equilibrium involving aqueous boric acid and borate ions adsorbed on anionic resin of the quaternary ammonium type (Dowex 1X8) 100-200 \"mesh\". The production systems H3 10BO3 were evaluated individually and in cascade process with 10B transfer between both systems. The measurements of B in this study were evaluated by Inductively Coupled Plasma Mass Spectrometry and Thermal Ionization Mass Spectrometry. In the S1 columns system displacement after 243 m (135 DBC) was possible obtain an medium enrichment in the last 20 cm, of 40 % atoms 10B, corresponding to 2830 mg of H310BO3. This mass was transferred to the S2 column system which have introduced in the last 20 cm of the band medium enrichment of 47,8 atom% 10B and this new band chromatography was displaced 21,6 m, thus obtaining the last centimeter band (1-0 cm) from enriched fraction 82 % atoms 10B. The fractionation factor (\'alfa\') and the Height Equivalent of Theoretical Plate (HETP) of stable isotopes of B (10B and 11B) was determined like being 1,0245 and 0,30 cm, respectively

O método cromatográfico de troca iônica, em colunas de resina foi empregado no estudo do enriquecimento isotópico de 10B e H3 10BO3. Em dois sistemas cromatográficos de colunas (S1: seis colunas de acrílico de 1800 mm de comprimento e 70 mm de diâmetro interno; S2: seis colunas de acrílico de 1800 mm de comprimento e 30 mm de diâmetro interno) foi estudado a separação do isótopo 10B, no equilíbrio envolvendo ácido bórico em solução aquosa e íons borato adsorvidos em resina aniônica do tipo amônio quaternário (Dowex 1X8), 100 - 200 \"mesh\". Os sistemas de produção de H3 10BO3 foram avaliados individualmente e em processo cascata, com transferência de 10B entre os dois sistemas. As determinações de B no presente trabalho foram avaliadas por espectrometria de massas com plasma e espetrometria de massas por termoionização. No sistema S1 de colunas após 243 m (135 DBC) de deslocamento foi possível obter um enriquecimento médio, nos últimos 20 cm, de 40 % em átomos de 10B, correspondendo a 2830 mg de H3 10BO3. Essa massa foi transferida (interação) para o sistema S2 de colunas que apresentava, nos últimos 20 cm da banda, enriquecimento médio de 47,8 % em átomos de 10B e essa nova banda cromatográfica foi deslocada por 21,6 m, obtendo-se no último centímetro da banda (1 - 0 cm) da fração enriquecida 82 % em átomos de 10B. O fator de fracionamento (\'alfa\') e a altura equivalente de uma placa teórica dos isótopos estáveis de B (10B e 11B) foi determinado como sendo 1,0245 e 0,30 cm, respectivamente / The chromatographic method of ion exchange resin in columns was used to study the isotopic enrichment of 10B and H3 10BO3. In two column chromatographic systems (S1: six acrylic columns 1800 mm length and 70 mm diameter; S2: six acrylic columns 1800 mm length and 30 mm diameter) was studied 10B isotope separation in equilibrium involving aqueous boric acid and borate ions adsorbed on anionic resin of the quaternary ammonium type (Dowex 1X8) 100-200 \"mesh\". The production systems H3 10BO3 were evaluated individually and in cascade process with 10B transfer between both systems. The measurements of B in this study were evaluated by Inductively Coupled Plasma Mass Spectrometry and Thermal Ionization Mass Spectrometry. In the S1 columns system displacement after 243 m (135 DBC) was possible obtain an medium enrichment in the last 20 cm, of 40 % atoms 10B, corresponding to 2830 mg of H310BO3. This mass was transferred to the S2 column system which have introduced in the last 20 cm of the band medium enrichment of 47,8 atom% 10B and this new band chromatography was displaced 21,6 m, thus obtaining the last centimeter band (1-0 cm) from enriched fraction 82 % atoms 10B. The fractionation factor (\'alfa\') and the Height Equivalent of Theoretical Plate (HETP) of stable isotopes of B (10B and 11B) was determined like being 1,0245 and 0,30 cm, respectively

One of the most important boron minerals, colemanite is reacted with sulfuric acid to produce boric acid. During this reaction, gypsum (calcium sulfate dihydrate) is formed as a byproduct. In this study, the boric acid production was handled both in a batch and four continuously stirred slurry reactors (4-CFSSR&rsquo / s) in series system. In this reaction system there are at least three phases, one liquid and two solid phases (colemanite and gypsum). In a batch reactor all the phases have the same operating time (residence time), whereas in a continuous reactor all the phases may have different residence time distributions. The residence time of both the reactant and the product solids are very important because they affect the dissolution conversion of colemanite and the growth of gypsum crystals. The main aim of this study was to investigate the dynamic behavior of continuous flow stirred slurry reactors. By obtaining the residence time distribution of the solid and liquid components, the non-idealities in the reactors can be found. The experiments performed in the continuous flow stirred slurry reactors showed that the reactors to be used during the boric acid production experiments approached an ideal CSTR in the range of the stirring rate (500-750 rpm) studied. The steady state performance of the continuous flow stirred slurry reactors (CFSSR&rsquo / s) in series was also studied. During the studies, two colemanites having the same origin but different compositions and particle sizes were used. The boric acid production reaction consists of two simultaneous reactions, dissolution of colemanite and crystallization of gypsum. The dissolution of colemanite and the gypsum formation was followed from the boric acid and calcium ion concentrations, respectively. The effect of initial CaO/ SO42- molar ratio (1.00, 1.37 and 2.17) on the boric acid and calcium ion concentrations were searched. Also, at these initial molar ratios the colemanite feed rate was varied (5, 7.5, 10 and 15 g/min) to change the residence time of the slurry. Purity of the boric acid solution was examined in terms of the selected impurities, which were the magnesium and sulfate ion concentrations. The concentrations of them were compared at the initial molar ratios of 1.00 and 1.37 with varying colemanite feed rates. It was seen that at high initial CaO/ SO42- molar ratios the sulfate and magnesium ion concentrations decreased but the calcium ion concentration increased. The gypsum crystals formed in the reaction are in the shape of thin needles. These crystals, mixed with the insolubles coming from the mineral, are removed from the boric acid slurry by filtration. Filtration of gypsum crystals has an important role in boric acid production reaction because it affects the efficiency, purity and crystallization of boric acid. These crystals must grow to an appropriate size in the reactor. The growth process of gypsum crystals should be synchronized with the dissolution reaction. The effect of solid hold-up (0.04&ndash / 0.09), defined as the volume of solid to the total volume, on the residence time of gypsum crystals was investigated and the change of the residence time (17-60 min) on the growth of the gypsum was searched. The residence time at each reactor was kept constant in each experiment as the volumes of the reactors were equal. The growth of gypsum was examined by a laser diffraction particle size analyzer and the volume weighted mean diameters of the gypsum crystals were obtained. The views of the crystals were taken under a light microscope. It was observed that the high residence time had a positive effect on the growth of gypsum crystals. The crystals had volume weighted mean diameters of even 240 &micro / m. The gypsum crystal growth model was obtained by using the second order crystallization reaction rate equation. The residence time of the continuous reactors are used together with the gypsum growth model to simulate the continuous boric acid reactors with macrofluid and microfluid models. The selected residence times (20-240 min) were modeled for different number of CSTR&rsquo / s (1-8) and the PFR. The simulated models were, then verified with the experimental data. The experimentally found calcium ion concentrations checked with the concentrations found from the microfluid model. It was also calculated that the experimental data fitted the microfluid model with a deviation of 4-7%.

Orientador: Prof. Dr. Daniel Zanetti de Florio / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Nanociências e Materiais Avançados, 2014. / Motores a combustão flexíveis foram desenvolvidos para diversificar a utilização de combustíveis para a indústria da mobilidade, com o intuito de trazer benefícios econômicos, ganho em sustentabilidade e redução do impacto ambiental. Tal diversificação tem proporcionado o desenvolvimento de linhas de pesquisa que aperfeiçoem essa utilização, através de incentivo fiscal do governo, bem como injeção de recursos da indústria nas universidades como, por exemplo, o programa Inovar Auto. Dentre os novos combustíveis está o etanol que devido às suas características físico-químicas, como a sua pressão de vapor traz vantagens como ganho de torque e potência e desvantagens como aumento de desgaste e corrosão dos componentes metálicos a ele expostos. As bronzinas são partes de base metálica que promovem a redução do contato metal-metal entre as principais peças de um motor como bloco, virabrequim e biela, além de permitirem uma melhor hidrodinâmica do óleo lubrificante, aumentando a vida útil do motor. Significativamente expostas ao ambiente etanol, óleo, gases e água, as mesmas são suscetíveis ao fenômeno de corrosão. Análise de corrosão por espectroscopia de impedância eletroquímica é um método conhecido na literatura e motivou a caracterização eletroquímica de componentes cíclicos metálicos de motores, através da obtenção de espectros de impedância para três diferentes recobrimentos em bronzinas, expostos sistematicamente a condicionamentos e envelhecimentos, variando-se temperatura, tempo de exposição em mistura óleo e etanol comuns. Dentre os três recobrimentos está uma proposta cerâmica a partir de óxido de boro depositado por uma técnica comum denominada slurry, apresentada na literatura aeroespacial com vantagens tribológicas. As medições foram feitas em solução aquosa de cloreto de sódio a 0,1 M, utlizando-se um eletrodo de referência de prata e cloreto de prata, um eletrodo de medição de platina como contra eletrodo e um eletrodo de trabalho com amostras de aço embutidas e recobertas com três diferentes superfícies; metálica (VW1), polimérica (P1) e cerâmica (C1), dispostos em uma célula ligada a um impedancímetro e a um potenciostato de marca Solartron. A intersecção do semicírculo do espectro com o eixo das abcissas ou parte real da impedância, Z¿ é conhecida como resistência de polarização Rp. Da literatura sabe-se que esta grandeza é proporcional ao inverso da corrente e taxa de corrosão da superfície do eletrodo de trabalho. A obtenção desta variável pode ser feita através de aproximações, com modelos de circuitos equivalentes RC, que calculam as resistências e capacitâncias destes circuitos. A partir do tratamento dos dados acima descritos, foi possível estabelecer três diferentes tendências de comportamento da taxa de corrosão ao longo do tempo de exposição ao meio etanol mais óleo, a saber: amostra de superfície metálica tipo VW1 apresentou corrosão dinâmica e controlada com taxa de corrosão decrescente ao longo do tempo; amostra polimérica tipo P1 apresentou também redução da taxa de corrosão por passivação ao longo do tempo após penetração da camada polimérica e; amostra cerâmica de óxido de boro tipo C1 apresentou maior redução da taxa de corrosão ao longo do envelhecimento em óleo e etanol. / Flex fuel combustion engines were developed to diversify the use of fuels for the mobility industry, in order to bring economic benefits gain in sustainability and environment impact reduction. Such diversification has permitted the research line development which optimizes this use through government incentive as well as fund injection in universities such as Inovar Auto program. Ethanol is among the new fuels, which due to its physical-chemical characteristics (vapor pressure) presents advantages as power and torque and disadvantages, as waste increase and corrosion of the exposed metal components. The bearings are parts made of metal that promote the metal-metal contact reduction among the main engine parts like cylinder block, cranckshaft and connecting rods. Besides, they allow better hydrodynamics of the lubrication oil increasing the duration of a flex combustion engine. Exposed to the ethanol, oil, gases and water environment these bearings are prone to corrosion phenomenon. The corrosion analysis by impedance spectroscopy corrosion is a method known in the literature and has motivated the electrochemical characterization of metal cyclic components by obtaining impedance spectra for three different recovering in bearings. The third type of recovering was developed through bore oxide produced by slurry coating techniques, which was presented on a aerospacial research publication with tribologic gain. These are systematically exposed to conditionings and aging while varying temperature, exposure time and rotation of oil and ethanol common mixtures. The measurements were made on aquous solution of NaCl 0,1 M through a reference silver and silver cloride eletrode, a platine counter eletrode and the work eletrode with samples of the three different bearings surface, metallic (VW1), polymeric (P1) and ceramic (C1) all assembled in a eletrochemistry cell, switched to a potenciostat and an impedancimeter, both by Solartron. The intersection of the semicircle spectra with "X" axle or real part of the impedance Z¿ is known as polarization resistance Rp. From the bibliography review it is known that this resistance is proportional to the inverse of corrosion rate on the surface of the working electrodes. The obtention of this variable could be done through approximation of RC circuit models, which calculate the resistances and the capacitances. Through data treatment it was possible to establish three different tendencies of corrosion rate behavior during ethanol and oil exposure time: Metallic surface sample type VW1 presented dynamic controlled with descending corrosion rate during the aging processes. Polymeric recovery sample type P1 also presented reduction of corrosion rate after penetration of the polymeric recovering e less during the aging processes. Ceramic recovery sample type C1 presented major reduction of corrosion during the aging on oil plus ethanol.

À cause du renforcement des réglementations et de l'évolution de l'opinion publique, les tensioactifs issus de la biomasse sont de plus en plus étudiés. À l'heure actuelle, la diversité structurelle de ces composés reste faible et est bien loin de concurrencer les produits issus des ressources fossiles. Pour enrichir les structures disponibles, nous nous sommes intéressés aux composés furaniques, comme le 2,5-diformylfurane (DFF), synthétisés à partir des sucres. Dans cette optique, nous avons tout d'abord généralisé et optimisé une méthode de synthèse originale du DFF. Ce procédé permet de s'affranchir de l'usage des métaux de transition ou des liquides ioniques. Le système utilisé pour convertir des substrats complexes, comme les amidons, repose sur l'action combinée d'acide borique, de bromure de sodium et d'acide formique dans le diméthylsulfoxyde (DMSO). L'acide borique joue un rôle majeur dans ce système puisqu'il est impliqué dans les étapes de déconstruction de la biomasse, d'isomérisation des unités glucose en fructose et dans la formation du HMF. Le bromure de sodium dans le DMSO permet l'oxydation sélective en DFF alors que l'acide formique accélère cette étape. Dans ces conditions, nous avons été capables de produire du DFF à une échelle de plusieurs dizaines de grammes avec des rendements de l'ordre de 20 %. Après l'optimisation de la synthèse, nous avons également étudié le mécanisme d'oxydation impliqué dans cette transformation. La seconde partie de l'étude a été la transformation du DFF en composés tensioactifs. Au terme d'une synthèse de cinq étapes, nous avons obtenu des produits zwitterioniques originaux avec des rendements d'environ 50 %. Ces composés de type gemini issus de la transformation des sucres montrent de bonnes propriétés comme des concentrations micellaires critiques très faibles comparables aux autres tensioactifs gemini déjà étudiés. / Due to stricter reglementations and the development of public opinion, surfactants synthesized from biomass are becoming increasingly interesting. However, the structural diversity of these compounds is still too low to compete with the products synthesized from fossil resources. In order to increase the diversity of available structures, we focused on common furanic building blocks, such as 2,5-diformylfuran (DFF), which are synthesized form carbohydrates. Firstly, we optimized a new and innovative synthesis of DFF. This method allowed us to use neither transition metal catalysts nor ionic liquids. The system we used to convert complex substrates, such as starch, relies on boric acid, sodium bromide and formic acid in dimethylsulfoxide (DMSO). Boric acid plays a key role in this system. It is involved in the biomass deconstruction, glucose to fructose isomerization and HMF formation. Sodium bromide in DMSO promotes the oxidation to DFF and formic acid increases the rate of this step. By using this system, we were able to synthesized DFF from glucose at multigram scale with 20% yield. After optimization of the synthesis, we investigated the oxidation mechanism. The second part of this work was focused on the conversion of DFF into new gemini surfactants. At the end of a five steps transformation, zwitterionic products were obtained with 50% yield. These gemini type compounds shows interesting properties such as very low critical micellar concentration which are similar to these measured for already reported gemini surfactants.

Ett problem vid byggandet av nya kärnkraftverk för elproduktion är de stora investeringskostnaderna samt den långa tiden det att få tillstånd för en reaktor och bygga den. Nyligen färdigställdes den tredje reaktorn vid Olkiluoto I Finland, den tog 18 år att färdigställa exklusive tiden att få tillstånd för reaktorn. Små modulära kärnkraftsreaktorer, SMR är mindre reaktorer med en lägre elektrisk effekt har föreslagits vara en lösning på problemet. Det behövs inte lika stora investeringar för att uppföra en reaktor och de ska också gå snabbare att bygga. Det finns flera fördelar med SMR, de kommer att tillverkas i fabriker vilket minskar konstruktionstiden. Samma reaktormodell behöver bara ett tillstånd för licensering medan stora reaktorer som byggs idag behöver ett nytt för varje reaktor. Det är dessutom billigare att serieproducera reaktorer då kostnaden går ned för varje producerad reaktor. De flesta reaktorer idag använder lättvatten som en moderator och för att kyla ned reaktorn, reaktorerna kallas för lätt vatten reaktorer, LWR. Det finns två vanliga designer, en där vatten kokas inuti reaktorn och driver sedan en turbin, reaktorn kallas för kokvattenreaktor, BWR. Den andra vanliga reaktordesignen är tryckvattenreaktorn, PWR där det är ett högre tryck som gör att vattnet inte kokar i reaktorn, i stället kokar det varma vattnet från reaktorn vatten i en sekundär vattenloop i en ånggenerator. Det är ångan i sekundär loopen som sedan driver turbinen. Det finns även flera reaktorkoncept som inte använder lättvatten. De SMR koncept som är närmast att påbörja konstruktion är alla LWR eftersom det är där den största erfarenheten från tidigare reaktordesigner finns. Genom att undersöka sju SMR koncept, sex PWR och en BWR är bilden att många är väldigt lika reaktorerna som finns idag, däremot så har många tagit bort komplicerade system och infört passiva säkerhetssystem som bland annat naturlig cirkulation för att få en passiv kylning. Materialen som används är också material som tidigare har används. En av de föreslagna förenklingarna är borttagandet av en löst neutronabsorbent i PWR reaktorer, i stället ska kontroll stavar och neutron gift i bränslet användas i en större grad. Den vanligaste neutronabsorbenten som används i lösning är borsyra eftersom bor har ett högt neutrontvärsnitt. Användandet av borsyra i reaktorn leder till lägre pH vilket ökar korrosionen, borsyran påverkar även radiolysen av vatten. I det här arbetet har hastighetskonstanten för reaktionen mellan borsyra och hydroxylradikalen som bildas genom radiolys av vatten undersökts. I experimenten användes coumarin-3-karboxylsyra som en radikalinfångare för att studera reaktionshastigheten genom tävlingskinetik. Den hydroxylerade produkten som bildas har detekterats genom fluorescens. Hastighetskonstanten mättes till 1.25 ∙ 106 M-1 s-1 vilket är högre än tidigare litteraturvärden. Skillnaden kan delvis förklaras genom närvaron av motbasen till borsyra, borat samt trimeren tetraborat som bildas vid höga koncentrationer av borsyra. / One problem with building new nuclear reactors for electricity production is the large investment costs and the long time needed for permissions and construction. Most recently is the Olkiluoto nuclear power plant in Finland where a third reactor was built, it took 18 years to finalize the reactor, and this is not including the time of handling the licencing application. Small modular nuclear reactors, SMR which is a smaller reactor with a reduced effect has been proposed to reduce the cost of investment and the time it takes from license application to finalized reactor. The SMR reactors have many advantages. It will be fabricated in factories reducing the time of construction, since reactor units are the same, the same reactor design only needs one licencing for all reactors. Compared to large reactors built today, where every single reactor needs a new licencing. Smaller reactors lead to shorter construction times and lower investment. It is also less expensive to produce reactors in series where the cost per unit decreases for every unit produced. Most reactors in operation today use light water as a moderator and coolant and are called light water reactors, LWR. Two designs are common, one where the water is boiled in the reactor and goes directly to the turbine, this reactor is called a boiling water reactor, BWR. The other common reactor is a pressurized water reactor, PWR where a higher pressure does not allow the water to boil. Instead, it is heated and boils water in a steam generator that then turns the turbine blades. There are other reactor concepts which do not use light water as a moderator and coolant, The SMR concepts that are the closest to construction are all LWR because it is where most experience from previous reactor designs is. By investigating seven SMR reactor concepts, six PWR and one BWR, it was concluded that they are similar to reactors operating today, but with some simplification and passive safety systems like natural circulation for many of them. The materials that will be used are also materials that have previously been used. One of the simplifications for several of the reactor concepts is the removal of a soluble neutron absorber in PWR reactors and instead, the use of control rods and burnable neutron poison to a larger extent. The soluble neutron absorber is usually boric acid which has a high neutron cross-section. The use of boric acid will reduce the pH in the reactor which increases corrosion, and it also affects the radiolysis of water. This work has investigated the rate constant for the reaction of boric acid with hydroxyl radicals formed in the radiolysis of water. In the experiments, coumarin-3-carboxylic acid was used as a probe to study the reaction rate using competition kinetics. The hydroxylated product formed has been detected using fluorescence. The rate constant measured was 1.25 ∙ 106 M-1 s-1 which is higher than previous literature values. Some of the discrepancies could be explained by the presence of the counter base, borate and the tetraborate that is formed at high concentrations.

Em experimentos agronômicos são comuns ensaios planejados para estudar determinadas culturas por meio de múltiplas mensurações realizadas na mesma unidade amostral ao longo do tempo, espaço, profundidade entre outros. Essa forma com que as mensurações são coletadas geram conjuntos de dados que são chamados de dados longitudinais. Nesse contexto, é de extrema importância a utilização de metodologias estatísticas que sejam capazes de identificar possíveis padrões de variação e correlação entre as mensurações. A possibilidade de inclusão de efeitos aleatórios e de modelagem das estruturas de covariâncias tornou a metodologia de modelos lineares mistos uma das ferramentas mais apropriadas para a realização desse tipo de análise. Entretanto, apesar de todo o desenvolvimento teórico e computacional, a utilização dessa metodologia em delineamentos mais complexos envolvendo dados longitudinais e tratamentos adicionais, como os utilizados na área de forragicultura, ainda é passível de estudos. Este trabalho envolveu o uso do diagrama de Hasse e da estratégia top-down na construção de modelos lineares mistos no estudo de cortes sucessivos de forragem provenientes de um experimento de adubação com boro em alfafa (Medicago sativa L.) realizado no campo experimental da Embrapa Pecuária Sudeste. Primeiramente, considerou-se uma abordagem qualitativa para todos os fatores de estudo e devido à complexidade do delineamento experimental optou-se pela construção do diagrama de Hasse. A incorporação de efeitos aleatórios e seleção de estruturas de covariâncias para os resíduos foram realizadas com base no teste da razão de verossimilhanças calculado a partir de parâmetros estimados pelo método da máxima verossimilhança restrita e nos critérios de informação de Akaike (AIC), Akaike corrigido (AICc) e bayesiano (BIC). Os efeitos fixos foram testados por meio do teste Wald-F e, devido aos efeitos significativos das fontes de variação associadas ao fator longitudinal, desenvolveu-se um estudo de regressão. A construção do diagrama de Hasse foi fundamental para a compreensão e visualização simbólica do relacionamento de todos os fatores presentes no estudo, permitindo a decomposição das fontes de variação e de seus graus de liberdade, garantindo que todos os testes fossem realizados corretamente. A inclusão de efeito aleatório associado à unidade experimental foi essencial para a modelagem do comportamento de cada unidade e a estrutura de componentes de variância com heterogeneidade, incorporada aos resíduos, foi capaz de modelar eficientemente a heterogeneidade de variâncias presente nos diferentes cortes da cultura da alfafa. A verificação do ajuste foi realizada por meio de gráficos de diagnósticos de resíduos. O estudo de regressão permitiu avaliar a produtividade de matéria seca da parte aérea da planta (kg ha-1) de cortes consecutivos da cultura da alfafa, envolvendo a comparação de adubações com diferentes fontes e doses de boro. Os melhores resultados de produtividade foram observados para a combinação da fonte ulexita com as doses 3, 6 e 9 kg ha-1 de boro. / Assays aimed at studying some crops through multiple measurements performed in the same sample unit along time, space, depth etc. have been frequently adopted in agronomical experiments. This type of measurement originates a dataset named longitudinal data, in which the use of statistical procedures capable of identifying possible standards of variation and correlation among measurements has great importance. The possibility of including random effects and modeling of covariance structures makes the methodology of mixed linear models one of the most appropriate tools to perform this type of analysis. However, despite of all theoretical and computational development, the use of such methodology in more complex designs involving longitudinal data and additional treatments, such as those used in forage crops, still needs to be studied. The present work covered the use of the Hasse diagram and the top-down strategy in the building of mixed linear models for the study of successive cuts from an experiment involving boron fertilization in alfalfa (Medicago sativa L.) carried out in the field area of Embrapa Southeast Livestock. First, we considered a qualitative approach for all study factors and we chose the Hasse diagram building due to the model complexity. The inclusion of random effects and selection of covariance structures for residues were performed based on the likelihood ratio test, calculated based on parameters estimated through the restricted maximum likelihood method, the Akaike\'s Information Criterion (AIC), the Akaike\'s information criterion corrected (AICc) and the Bayesian Information Criterion (BIC). The fixed effects were analyzed through the Wald-F test and we performed a regression study due to the significant effects of the variation sources associated with the longitudinal factor. The Hasse diagram building was essential for understanding and symbolic displaying regarding the relation among all factors present in the study, thus allowing variation sources and their degrees of freedom to be decomposed, assuring that all tests were correctly performed. The inclusion of random effect associated with the sample unit was essential for modeling the behavior of each unity. Furthermore, the structure of variance components with heterogeneity, added to the residues, was capable of modeling efficiently the heterogeneity of variances present in the different cuts of alfalfa plants. The fit was checked by residual diagnostic plots. The regression study allowed us to evaluate the productivity of shoot dry matter (kg ha-1) related to successive cuts of alfalfa plants, involving the comparison of fertilization with different boron sources and doses. We observed the best productivity in the combination of the source ulexite with the doses 3, 6 and 9 kg ha-1 boron.

This thesis aims at developing a method of chemical aftertreatment for reduction of free formaldehyde release of a tetrakis (hydroxymethyl) phosphonium chloride (THPC) urea precondensate, ammonia cured durable flame retardant finished cotton fabric, by preventing the formation of free formaldehyde. Formaldehyde is toxic and carcinogenic. According to the worldwide standards, acceptable limit of free formaldehyde release, for the fabrics that have skin contact, is only 75 ppm (measured by water extraction method). In this research, a cotton fabric flame retardant finished in an industrial plant in Pakistan is used. Fabric is finished by the application of THPC urea precondensate and ammonia cured, oxidized and washed. After finishing, it is not aftertreated with sodium metabisulfite that is a commonly used aftertreatment method for the reduction of free formaldehyde release. Aftertreatment with sodium metabisulfite has various problems that include large number of hot washings and there is an increase in the formaldehyde release during fabric storage. If the fabric has 75 ppm of free formaldehyde, there is often an increase in free formaldehyde release during fabric storage. There is a very limited research on the aftertreatment methods and few reports of application of these aftertreatments on flame retardant fabrics have been published. In this research, two methods of aftertreatments are developed to reduce the free formaldehyde contents to 75 ppm or less. One is the aftertreatment with a combination of resorcinol 1% and diethylene glycol 4%. The other is the combination of resorcinol 1% and boric acid 6%. For both these aftertreatments, ammonium acetate 0.5% is used as a catalyst. Fabric is padded with the solution and then dried at 130̊ C for 8 minutes. After drying, fabric is rinsed with water at 40̊ C. The aftertreatment methods developed in this research have shown a long term effect in keeping the formaldehyde release below 75 ppm during fabric storage that is not available with other conventional aftertreatment methods. These aftertreatment methods have no adverse effect on the flame retardancy of the THPC ammonia cured finished fabric and the fabric is soft as compared to the original flame retardant finished fabric and to the fabric after treated with existing methods. These new developed methods have industrial application because there is no use of any solvent and there is no use of any special equipment for the aftertreatment.

Em experimentos agronômicos são comuns ensaios planejados para estudar determinadas culturas por meio de múltiplas mensurações realizadas na mesma unidade amostral ao longo do tempo, espaço, profundidade entre outros. Essa forma com que as mensurações são coletadas geram conjuntos de dados que são chamados de dados longitudinais. Nesse contexto, é de extrema importância a utilização de metodologias estatísticas que sejam capazes de identificar possíveis padrões de variação e correlação entre as mensurações. A possibilidade de inclusão de efeitos aleatórios e de modelagem das estruturas de covariâncias tornou a metodologia de modelos lineares mistos uma das ferramentas mais apropriadas para a realização desse tipo de análise. Entretanto, apesar de todo o desenvolvimento teórico e computacional, a utilização dessa metodologia em delineamentos mais complexos envolvendo dados longitudinais e tratamentos adicionais, como os utilizados na área de forragicultura, ainda é passível de estudos. Este trabalho envolveu o uso do diagrama de Hasse e da estratégia top-down na construção de modelos lineares mistos no estudo de cortes sucessivos de forragem provenientes de um experimento de adubação com boro em alfafa (Medicago sativa L.) realizado no campo experimental da Embrapa Pecuária Sudeste. Primeiramente, considerou-se uma abordagem qualitativa para todos os fatores de estudo e devido à complexidade do delineamento experimental optou-se pela construção do diagrama de Hasse. A incorporação de efeitos aleatórios e seleção de estruturas de covariâncias para os resíduos foram realizadas com base no teste da razão de verossimilhanças calculado a partir de parâmetros estimados pelo método da máxima verossimilhança restrita e nos critérios de informação de Akaike (AIC), Akaike corrigido (AICc) e bayesiano (BIC). Os efeitos fixos foram testados por meio do teste Wald-F e, devido aos efeitos significativos das fontes de variação associadas ao fator longitudinal, desenvolveu-se um estudo de regressão. A construção do diagrama de Hasse foi fundamental para a compreensão e visualização simbólica do relacionamento de todos os fatores presentes no estudo, permitindo a decomposição das fontes de variação e de seus graus de liberdade, garantindo que todos os testes fossem realizados corretamente. A inclusão de efeito aleatório associado à unidade experimental foi essencial para a modelagem do comportamento de cada unidade e a estrutura de componentes de variância com heterogeneidade, incorporada aos resíduos, foi capaz de modelar eficientemente a heterogeneidade de variâncias presente nos diferentes cortes da cultura da alfafa. A verificação do ajuste foi realizada por meio de gráficos de diagnósticos de resíduos. O estudo de regressão permitiu avaliar a produtividade de matéria seca da parte aérea da planta (kg ha-1) de cortes consecutivos da cultura da alfafa, envolvendo a comparação de adubações com diferentes fontes e doses de boro. Os melhores resultados de produtividade foram observados para a combinação da fonte ulexita com as doses 3, 6 e 9 kg ha-1 de boro. / Assays aimed at studying some crops through multiple measurements performed in the same sample unit along time, space, depth etc. have been frequently adopted in agronomical experiments. This type of measurement originates a dataset named longitudinal data, in which the use of statistical procedures capable of identifying possible standards of variation and correlation among measurements has great importance. The possibility of including random effects and modeling of covariance structures makes the methodology of mixed linear models one of the most appropriate tools to perform this type of analysis. However, despite of all theoretical and computational development, the use of such methodology in more complex designs involving longitudinal data and additional treatments, such as those used in forage crops, still needs to be studied. The present work covered the use of the Hasse diagram and the top-down strategy in the building of mixed linear models for the study of successive cuts from an experiment involving boron fertilization in alfalfa (Medicago sativa L.) carried out in the field area of Embrapa Southeast Livestock. First, we considered a qualitative approach for all study factors and we chose the Hasse diagram building due to the model complexity. The inclusion of random effects and selection of covariance structures for residues were performed based on the likelihood ratio test, calculated based on parameters estimated through the restricted maximum likelihood method, the Akaike\'s Information Criterion (AIC), the Akaike\'s information criterion corrected (AICc) and the Bayesian Information Criterion (BIC). The fixed effects were analyzed through the Wald-F test and we performed a regression study due to the significant effects of the variation sources associated with the longitudinal factor. The Hasse diagram building was essential for understanding and symbolic displaying regarding the relation among all factors present in the study, thus allowing variation sources and their degrees of freedom to be decomposed, assuring that all tests were correctly performed. The inclusion of random effect associated with the sample unit was essential for modeling the behavior of each unity. Furthermore, the structure of variance components with heterogeneity, added to the residues, was capable of modeling efficiently the heterogeneity of variances present in the different cuts of alfalfa plants. The fit was checked by residual diagnostic plots. The regression study allowed us to evaluate the productivity of shoot dry matter (kg ha-1) related to successive cuts of alfalfa plants, involving the comparison of fertilization with different boron sources and doses. We observed the best productivity in the combination of the source ulexite with the doses 3, 6 and 9 kg ha-1 boron.