A irrigação é uma das tecnologias cujo retorno econômico é mais facilmente percebido pelo usuário, apesar do seu alto custo de investimento inicial. Nos últimos anos, com o fim dos financiamentos subsidiados, o agricultor irrigante tem buscado alternativas tecnológicas que lhe permitam o retorno do investimento em prazos cada vez menores. As soluções encontradas vão desde o uso da agricultura intensiva com a semeadura de culturas em sucessão (cultivos anuais), ou de várias safras (perenes), como também a maximização do uso do equipamento de irrigação, que tem sido usado cada vez com maior freqüência para a aplicação de produtos químicos por meio da quimigação. Esse panorama tem gerado, em algumas situações, desequilíbrio no agroecossistema com várias conseqüências, entre as quais destacam-se a explosão de pragas e doenças e a compactação de solos. A quimigação, apresenta uma série de vantagens e desvantagens. Dentre as vantagens, destacam-se o seu baixo custo quando comparado a outros métodos, e o menor tráfego de máquina na área cultivada, o que também favorece o menor dano mecânico às culturas. Entre as limitações, destaca-se o fato de que nem todos os produtos podem ser utilizados, pois esses precisam apresentar determinadas características físico-químicas como baixa solubilidade em água e alta em solventes orgânicos. O presente trabalho visa gerar informações sobre o uso de óleos sem surfactantes para a dissolução de formulações comerciais de clorpirifós (concentrado emulsionável), e sua efetividade no controle da lagarta do cartucho (Spodoptera frugiperda) no milho quando comparado à formulação comercial sem mistura, aplicado por insetigação. Desse modo, espera-se viabilizar a quimigação foliar com possibilidade da redução de dose ou do número de aplicações além de propor uma metodologia para instalação de ensaios de quimigação a campo. Foram instalados durante os anos de 1996 e 1997, três ensaios em três safras distintas, todos com elevada pressão de infestação, em áreas comerciais, onde os tratamentos foram injetados diretamente na base do pivô por meio de uma bomba injetora-dosadora. As parcelas, em forma de cunha, tinham no mínimo 50 m no perímetro de modo a evitar contaminação entre os tratamentos, e uma área mínima de um hectare. Foram amostrados de quatro a seis pontos para cada parcela. Os resultados obtidos mostraram a viabilidade da técnica, uma vez que a metade da dose comercial dissolvida no óleo mostrou a mesma efetividade de controle que a dose comercial, o que sinaliza a possibilidade da redução da dose ou do número de aplicações minimizando os custos para o produtor com menor impacto ambiental, o que favorece o manejo integrado e a sustentabilidade da agricultura. As informações geradas viabilizam a quimigação como método de aplicação de baixo custo, e a metodologia sugerida comprovou-se eficiente para a instalação de ensaios a campo. / Irrigation is perceived by the farmers as the best payback technology, beside its initial investment cost. With the end of subsidized interests for agriculture in the last years, irrigated farmers are more and more looking for shorter paybacks of their investments. The alternatives presented are successive cropping (annual crops) or more that one harvest (perennial crops) per year, and to maximize the use of the irrigation equipment which is more frequently being used to apply chemical which is known as chemigation. This scenario generates in some situations an unbalance at the environment with several consequences like pest and diseases flare and soil compaction. Chemigation has advantages and limitations. Among the advantages is to be highlighted the lower application cost when compared to other methods, and less tracking in the area which reduce soil compaction and also crop losses due to crop damage. The main limitation is that not all products can be used in chemigation. They must attend some physical - chemical properties like low water solubility and high solubility in organic solvents. The present work has the intention to generate information about the feasibility of mixing commercial formulations (emulsifiable concentrate-EC) with oils and no addition of any surfactant and the effectiveness of this mixture in comparison to standard when insectigated to control fall armyworm (Spodoptera frugiperda) in corn. This way, it is expected to viabilize foliar chemigation, with the possibility of rate or applications number reduction, and also to propose a standardized methodology to install field trials. Three trials were installed during 1996 and 1997 in three different seasons, all of them with high infestation level, in commercial areas, where treatments were injected in the center of the pivots using an injection pump. The plots, in a wedge form, had a minimal lenght at the perimeter to avoid treatments contamination, which provided a minimal area of one hectare each plot. Sampling was done at four to six points for each plot. Data showed the viability of the techniques, since the half of commercial rate diluted in oil without surfactants had shown the same effectiveness that standard (full rate without oil). This sign up the possibility of a rate reduction or perhaps less applications, which will minimizes farmers’ costs with less environmental impact, being favorable to integrated pest management and agriculture sustainability. Generated information shows the workability of chemigation as a low cost application method, as well as the proposed methodology to install field trials had shown to be effective.

Este trabalho apresenta o desenvolvimento de novas instrumentações baseadas em efeitos fototérmicos para o estudo de interfaces sólido-líquido e líquido-gás, incluindo no último caso o efeito de surfactantes. O trabalho está dividido em capítulos, cada um enfocando o desenvolvimento e/ou aplicação de uma nova técnica. O Capítulo I apresenta uma introdução aos fenômenos fototérmicos e desecreve a construção de instrumentos clássicos de Lente Térmica (LT) nas configurações de simples e duplo feixe. Interfaces sólido-líquido foram estudadas nos capítulos II-IV usando variações da instrumentação clássica de LT. Um novo sinal fototérmico foi caracterizado, indicando a formação de uma lente térmica invertida na interface. Experimentos de varredura-z na configuração por reflexão foram usados para determinar a mudança no índice de refração da interface próximo ao ângulo crítico, e uma metodologia similar foi utilizada para a medida da difusividade térmica de amostras opacas. Nos capítulos V-VII, a deformação de superfícies líquidas foi estudada pelo efeito Marangoni induzido por laser e pela geração de ondas capilares. A transferência de calor pela interface líquido-gás foi monitorada por Deflexão Fototérmica Transversal. Em todos os casos, a influência de surfactantes foi estudada pela formação de uma monocamada na superfície dos líquidos. Observou-se que uma pequena quantidade de surfactante é capaz de cessar a movimentação de líquidos induzida por gradientes de tensão superficial e aumentar significativamente a transferência de calor pela interface. Os resultados indicam uma correlação entre as transições de fase das monocamadas e a atenuação da deformação superficial bem como o aumento na transferência de calor. Finalmente, o capítulo VIII apresenta uma coleção de trabalhos que derivaram dos estudos relacionados com as instrumentações desenvolvidas. / This work presents the development of new instrumentations based on photothermal phenomena to study solid-liquid and liquid-gas interfaces, including in the latter the effect of surfactants. The work is divided into chapters, each one focusing on the development and/or application of a new technique. Chapter I presents an introduction to photothermal phenomena and describes the construction of classical Thermal Lens (TL) instruments in the single and double-beam configurations. Solid-liquid interfaces were studied in chapters II-IV using variations of the classical TL instrumentation. A new photothermal signal was characterized, indicating the formation of an inverted thermal lens at the interface. Z-scan experiments in the reflection configuration were used to determine the change in the refractive index of an interface close to the critical angle, and a similar methodolody was used to measure the thermal diffusivity of opaque samples. In Chapters V-VII, the deformation of liquid surfaces was studied by laser-induced Marangoni effect and the generation of capillary waves. Heat transfer through the liquid-gas interface was monitored by Transverse Photothermal Deflection. In all cases, the influence of surfactants was studied by forming a monolayer on the surface of the liquids. It was observed that a tiny amount of surfactants was able to cease the motion of liquid induced by surface tension gradients and to increase significantly the heat transfer through the interface. The results indicate a correlation between phase transitions of the monolayers and the attenuation of the surface deformation as well as the increase in the heat transfer. Finally, chapter VIII is a collection of other works that derived from the studies related to the instrumentations developed.

Orientadores: Edvaldo Sabadini, Rosângela Barros Zanoni Lopes Moreno / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-25T12:17:08Z (GMT). No. of bitstreams: 1 Rodrigues_RobertaKamei_D.pdf: 3168201 bytes, checksum: 311be9e2895bc6d972563662136638fa (MD5) Previous issue date: 2013 / Resumo: O presente trabalho descreve o potencial das micelas gigantes como aditivos para facilitar operações de gravel-pack. O objetivo da operação de completação gravel-pack é obtenção de um filtro de areia ou cerâmica (gravel) capaz de conter areia da formação durante a produção de um poço de petróleo. As micelas gigantes podem ser utilizadas na fase de preenchimento do gravel-pack, com a finalidade de produzir um sistema capaz de reduzir as perdas de carga geradas pelo fluxo turbulento do fluido (por redução de atrito hidrodinâmico), melhorar a homogeneidade da distribuição de areia na dispersão e, consequentemente, viabilizar a operação em cenários de janela operacional estreita. O fênomeno de redução de atrito hidrodinâmico está relacionado com a menor energia requerida para o escoamento de líquidos em regime turbulento, quando certas macromoléculas estão dissolvidas. Estudos indicam que a redução de atrito hidrodinâmico pode estar diretamente relacionada à flexibilidade e ao tamanho de macromoléculas, que podem interagir com os vórtices e evitar a dissipação da energia. Soluções de alguns surfactantes, em determinadas condições, podem formar micelas alongadas (gigantes). O sistema resultante possui algumas características de soluções poliméricas, sendo capaz de produzir o mesmo efeito, sem, no entanto, sofrer degradação mecânica devido ao bombeamento ou cisalhamento prolongado. Foram desenvolvidos estudos fundamentais a partir de medidas reológicas, calorimétricas e de espalhamento dinâmico de luz para investigar a estabilidade térmica e mecânica de micelas gigantes formadas por surfactantes catiônicos e ânions aromáticos. Em seguida, foram avaliadas as melhores composições, nas quais se obtiveram significativos níveis de redução de atrito hidrodinâmico em condições de temperaturas de fundo de poço, em soluções de alta salinidade e usando-se micelas gigantes formadas por surfactantes comerciais. Os resultados desses estudos fundamentais foram utilizados para avaliar o desempenho das micelas gigantes em circuitos de escoamento. Também foi verificado o efeito da presença das micelas gigantes no arraste do grão de areia, em condições próximas às das operações de gravel-pack / Abstract: This thesis describes the potential of wormlike micelles as additives to improve gravel-pack operations. The aim of the completion operation of grave-pack is to create a sand or ceramic filter able to contain the sand formation during the gravel-pack operation in order to produce a system capable of reducing friction losses on a fluid in turbulent flow (by drag reduction), to improve the homogeneity of the distribution of sand dispersion and thus facilitate the operation in case of narrow window scenarios. The phenomenon of drag reduction is related to the lower energy required for liquid transports in turbulent flow when certain macromolecules are dissolved. Studies indicate that drag reduction can be directly related to the flexibility and size of the macromolecules, which can interact with the vortices and prevent dissipation of energy. Solutions of some surfactants, under certain conditions, can form long micelles (wormlike micelles). The resulting system has some characteristics of polymer solutions, being able to produce the same effect, however without suffering degradation due to pumping or high shear. Fundamental studies were conducted using rheological, calorimetric and dynamic light scattering measurements in order to investigate the thermal and mechanical stability of wormlike micelles formed by cationic surfactants and aromatic anions. Then, the best compositions were evaluated, which were obtained significant levels of drag reduction under bottom hole temperature, in solutions of high salinity and using wormlike micelles formed by commercial surfactants. The results of these fundamental studies were used to evaluate the performance of wormlike micelles in flow loops. We also checked the effect of the presence / Doutorado / Físico-Química / Doutora em Ciências

Orientador: Rosângela Barros Zanoni Lopes Moreno / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica e Instituto de Geociências / Made available in DSpace on 2018-08-23T09:28:13Z (GMT). No. of bitstreams: 1 BonillaSanabria_FabianCamilo_M.pdf: 7814055 bytes, checksum: 6037ae62c4e94a0903183711290b83a9 (MD5) Previous issue date: 2013 / Resumo: Os surfactantes são utilizados para diferentes propósitos na indústria do petróleo. As formulações de recuperação avançada utilizando surfactantes são aplicadas visando incrementar o fator de recuperação em reservatórios de óleo, tanto na etapa de recuperação secundária como na etapa terciária. Através de poços injetores, os volumes requeridos de uma solução aquosa com uma concentração definida de surfactante são introduzidos no reservatório para induzir à geração de um novo banco de óleo móvel por meio da diminuição da tensão interfacial água-óleo. Tensões interfaciais ultra baixas são obtidas e, consequentemente, o número capilar e a recuperação de óleo são incrementados. A eficiência do processo de deslocamento é influenciada por várias características das soluções de surfactantes, incluindo o comportamento de fases, a tensão interfacial, a concentração de eletrólitos em solução (salinidade) e a adsorção à superfície sólida da rocha. Assim sendo, um projeto de injeção de surfactantes deve ser planejado adequadamente para a obtenção do melhor cenário para a implementação da técnica. Este trabalho mostra um processo metodológico para identificar e avaliar formulações de surfactantes a serem aplicadas como método de recuperação química. Três surfactantes aniônicos e dois surfactantes não-iônicos foram selecionados da literatura para a análise experimental: Dodecil Sulfato de Sódio (SDS), Dodecil Sulfato de Amônio (ADS), Lauriléter Sulfato de Sódio (SLES), Monolaurato de sorbitano (SPAN-20) e o Polisorbato-20 (TWEEN-20). Álcool isopropílico foi utilizado como cosurfactante e poliacrilamida parcialmente hidrolisada (HPAM) foi empregada na solução polimérica usada para deslocar o banco de óleo formado e corroborar com a avaliação das formulações de surfactante. Inicialmente, utilizando-se tensiometria ótica, foram feitas medições de tensão superficial das soluções de surfactante para identificar a Concentração Micelar Crítica (CMC) característica de cada surfactante. A partir dos resultados de tensão interfacial obtidos e seguindo-se com o processo metodológico, foram selecionadas as formulações a serem analisadas nos Testes de Comportamento de Fases. Estes testes foram conduzidos com diferentes formulações de surfactante e uma mistura de óleo de campo e querosene. As soluções aquosas e o óleo foram colocados em pipetas de 5 ml para a análise do comportamento das formulações de surfactante em uma dada faixa de salinidade. Entre as formulações analisadas, algumas foram selecionadas para a avaliação da recuperação avançada de óleo através de testes de deslocamento. Estes testes foram conduzidos em amostras de arenito de alta permeabilidade provenientes da formação Botucatu. Uma vez que nesses arenitos, o fenômeno de histerese pode ser negligenciado, é possível conduzir um processo de injeção de água convencional (embebição) seguido de um processo de injeção de óleo (drenagem) visando restaurar as saturações dos fluidos no meio poroso próximas daquelas obtidas no processo da saturação inicial. Finalmente, a eficiência do método de recuperação melhorada é determinada injetando-se um banco de uma formulação de surfactante de tamanho definido. O banco de surfactante é deslocado ao longo do meio poroso utilizando soluções poliméricas e/ou água. Os resultados sugerem que os surfactantes podem ser utilizados com os requerimentos técnicos para a aplicação como método de recuperação avançada em reservatórios de arenitos / Abstract: Surfactants have been used for many purposes in petroleum industry. EOR surfactants formulations are applied for increasing the recovery factor in oil reservoirs as both secondary and tertiary techniques. By injector wells, required volumes are introduced into the reservoir with surfactant formulations for developing a new stabilized oil bank via ultralow interfacial tension between oil and water phases. Ultralow Interfacial tensions are obtained and, consequently, capillary number and oil recovery are increased. There are several surfactants characteristics involved with the efficiency of the process including phase behavior, IFT (Interfacial Tension), electrolyte concentration and rock solid adsorption. Therefore, it's necessary to design properly the project to obtain the best scenario for implementing the technique. This research work shows an applied methodological process for screening, designing and testing surfactant formulations on reservoir sandstones. Three commercial anionic surfactants and two commercial non-ionic surfactants were selected from literature for experimental analysis: Sodium dodecyl sulfate (SDS), Ammonium dodecyl sulfate, Sodium laureth sulfate (SLES), Sorbitan Monolaurate (SPAN-20) and Polysorbate-20 (TWEEN-20). Isopropyl alcohol (2-propanol) was also used as co-surfactant for testing the surfactant formulations. Initially, it was performed surface tensions measurements to identify the critical micellar concentration (CMC) characteristic of each surfactant, using a pendant drop tensiometer. After determining interfacial tensions (IFT), some of the tested formulations were selected for conducting phase behavior tests with field oil and kerosene mixture. Phase behavior tests were conducted by adding brine solutions and crude oil in 5 ml pipettes to analyze the performance of the chemical formulations over a range of salinities. Again, some selected surfactant formulations were tested for enhanced oil recovery using coreflood tests in high permeability Botucatu Formation samples. Since hysteresis phenomena are not significant on these sandstone cores, it's possible to perform a waterflooding followed by another drainage process for returning the porous media saturations close to the initial values. Subsequently, Enhanced Oil recovery is determined by injecting a slug of the surfactant formulation followed by brine, in a new imbibition process. The results suggest that surfactants can be used according technical requirements for their application in sandstones reservoirs as enhanced oil recovery technique / Mestrado / Reservatórios e Gestão / Mestre em Ciências e Engenharia de Petróleo

A review of the chemistry of poly(lactic acid) was carried out with a focus on techniques and applications of PLA polymer and copolymers with reference to some of the work that has been accomplished over the last 20 years or so. A review of the characterisation techniques used to analyse PLA polymers and copolymers was also carried out giving reference to the equipment and methods used herein. An investigation into the potential of PLA as the hydrophilic portion of a polymeric surfactant was carried out. To develop PLA based surfactants, the ring opening polymerisation of lactide was carried out in a melt in the presence of a long chain alcohol (C₇ to C₂₀) or diol (C₄ & C₆) to produce AB or ABA type polymers that follow the traditional surfactant template. Stannous octanoate and 4-dimethylaminopyridine were typically used as catalysts due to their high activity and relative cheapness. PLA only shows good hydrophilicity with up to 12 lactic acid units in the chain. Above this the electrostatic interactions between polymer chains reduced water solubility. It was also noted that D,L-lactide produced more water soluble polymers (syndiotactic) than the enantiomerically pure L-lactide (isotactic polymer chains). An investigation of the hydrophobic properties of PLA was carried out to evaluate their usefulness for other biodegradable surfactant applications. To this end an investigation of sugars as the hydrophilic portion of the molecule was carried out. Due to problems with solubilising sugars, they were deemed unsuitable for use as initiatiors within the scope of this research. Choline chloride was then investigated as a potential hydrophilic initiator and indeed has produced some of the most water soluble of PLA polymers. Choline chloride presented several challenges as an initiator, its high melting point resulted in polar solvents such as t-butanol being employed. Alternatively, more success was achieved by preparation of a choline chloride eutectic mixture prior to the polymerisation. It was discovered that a choline chloride/urea eutectic mixture was capable of self initiation, thus required no further addition of catalyst, this result shows a potential step forward in PLA green chemistry. A final investigation into producing surface-active PLA in a one-pot process that required only a hydroxycarboxylate initiator was carried out. The production of PLA sodium or potassium salts was carried out in a melt polymerisation and the results show some promise. Initiators that have been employed include a range of a, b and g-hydroxycarboxylic acids. These work through tautomerisation to the alkoxide, which then initiates a living type polymerisation of lactide to produce surface-active polymers. As well as the synthesis of these polymers some analysis of the physical and aqueous properties of these materials was carried out. PLA sodium salts were shown to have reasonable surfactant ability (~45 mNm⁻¹) and low CMC values of around 5x10⁻⁹ mol cm⁻³. They were also shown to have some properties as emulsifiers, and in some cases showed non-Newtonian fluid behaviour such as shear-thinning (thixotropy) and shear-thickening (dilatant). The thermal characteristics of the polymers such as T[subscript]g and stability were assessed as well as their ability to retain water.

Les matériaux d’oxyde de silice et de titane sont présents dans de nombreux domaines (chimie, environnemental, médical, pharmaceutique, etc.). Le principal problème de ces matériaux concerne les forts coûts financier et environnemental de leur synthèse. Dans ce travail de recherche, l’objectif fut de résoudre cette problématique. Ainsi, une nouvelle synthèse d’oxyde de silice a été élaborée. Ces nanostructures ont été analysées par les méthodes de caractérisation classique en sciences des matériaux (Adsorption volumétrique N2, Analyse Thermogravimétrique (ATG), …). Les propriétés viscoélastiques des milieux réactionnels ont été déterminées par micro-rhéologie. Une stratégie d’élimination de certaines familles de surfactant non ioniques (poloxamères et polyéthoxydes) utilisées comme template dans les synthèses de matériaux mésoporeux à base de silice (SBA-n, MSU-X, …) a été également mise en œuvre. Cette procédure a permis à la fois de récupérer les surfactants et d’obtenir des matériaux aux propriétés physicochimiques remarquables, identifiées par les mêmes méthodes d’instrumentation. Après fonctionnalisation de leur surface, les matériaux lavés semblent plus efficaces en termes d’adsorption de composés organiques que leurs homologues calcinés. Etendu aux oxydes de titane, tout aussi efficace pour éliminer les composés tensio-actifs, le procédé de lavage semble produire à partir d’un pourcentage de TiO2 (> 70 %) des matériaux hautement réactifs en photocatalyse et au pouvoir antibactérien assez élevé. / Silica and titanium oxides are present in many fields (chemistry, environmental, medical, pharmaceutical, etc…). The main problem of these materials concerns the synthesis financial and environmental costs. In this work, the aim was to solve this problem. A new greener silica oxide nanoparticles synthesis was prepared. These nanomaterials have been analyzed by the conventional characterization methods in material sciences (N2 volumetric adsorption, Thermogravitometric Analysis (TGA),...). The viscoelastic properties of the reaction media were determined by micro-rheology. A strategy for the elimination of non-ionic surfactant families (poloxamers and polyethylene oxide) ) used as template in the synthesis of mesoporous materials based on silica (SBA-n, MSU-X, ....) was also implemented. This procedure allowed to recover the surfactants and to obtain materials with remarkable physicochemical properties identified by the same methods instrumentation. After functionalization of the surface, the washed materials appear to be more efficient in terms of adsorption of organic compounds as their calcined counterparts. Extended to titanium oxide, the washing process seems to produce from a percentage of TiO2 (> 70%) highly reactive materials in photocatalysis and with a high antibacterial power.

Abstract Deficiency of pulmonary surfactant is the main cause of respiratory distress syndrome (RDS) in premature newborn infants, which is often complicated by chronic lung disease (CLD). Preterm birth is often associated with intra-amniotic infection (IUI), which is characterized by increased proinflammatory cytokines, such as interleukin-1 (IL-1) and tumor necrosis factor-α (TNF-α), in the amniotic fluid. In very preterm birth due to IUI, the incidence of RDS is decreased, while the incidence of CLD is increased. Maternal glucocorticoids are used in imminent preterm birth to prevent RDS. This study was designed to clarify the contrasting association of these perinatal pulmonary diseases with IUI and the pathogenesis of these lung diseases using an in vitro rabbit model. IL-1 increased the expression of surfactant protein (SP)-A and SP-B in very immature lung. Contrariwise, in transitional and mature fetal lung as well as in newborn lung, IL-1 additively with TNF-α decreased the expression of SP-B and SP-C. Bacterial lipopolysaccharide (LPS) decreased SP-A, -B and -C mRNAs in mature fetal and newborn lung, but had no effect on SP expression in immature lung. Interferon-γ (IFN-γ) had no effect on SP expression at any gestational age, but it modified the effects of the other cytokines. Dexamethasone (Dx) and IL-1 in combination additively increased SP-A and SP-B mRNAs in immature lung. Dx abolished the inhibitory effect of IL-1 on SP-B and SP-C in mature lung. Dx and IL-1 together tended to stabilize SP mRNAs. The present findings provide additional evidence of the role of the transcription factors nuclear factor-κB (NF-κB) and C/CAAT enhancer-binding protein δ (C/EBPδ) in the upregulation of SP-A by IL-1 in immature lung. Proinflammatory cytokines profoundly influence the expression of surfactant proteins in a manner that is strictly dependent on the length of gestation. The present findings help to explain the differences in the incidence of RDS and CLD in preterm births caused by IUI, and they may clarify further the role of surfactant in the pathogenesesis of lung diseases in neonatal infants. / Tiivistelmä Keuhkosurfaktantin puute aiheuttaa ennenaikaisesti syntyville keskosille vastasyntyneen hengitysvaikeusoireyhtymää eli RDS-tautia (Respiratory Distress Syndrome). Toinen keskosilla esiintyvä keuhkosairaus on krooninen keuhkosairaus eli CLD (Chronic Lung Disease). Glukokortikoideja käytetään hoitona ennenaikaisen synnytyksen uhatessa, koska niiden tiedetään vähentävän RDS-taudin riskiä. Kohdunsisäinen infektio on huomattava ennenaikaisen synnytyksen aiheuttaja. Infektiossa tulehduksen välittäjäaineet, kuten sytokiinit interleukiini-1 (IL-1) ja tuumorinekroositekijä alfa (TNF-α) lisääntyvät lapsivedessä. Infektiosta aiheutunut ennenaikainen synnytys vähentää RDS-taudin ilmaantumista pienille keskosille ja toisaalta lisää kroonisen keuhkosairauden riskiä. Tutkimuksen oli tavoitteena selvittää, miksi RDS ja CLD ilmaantuvat eriävästi infektion vuoksi ennenaikaisesti syntyneille vauvoille. Viljelemällä eri-ikäisten kanin sikiöiden sekä vastasyntyneiden kanin poikasten keuhkon kappaleita tutkittiin tulehduksen välittäjäaineiden sekä anti-inflammatorisen glukokortikoidin (deksametasonin) vaikutusta surfaktantin toiminnalle tarpeellisten surfaktanttiproteiinien (SP) ilmentymiseen. IL-1 lisäsi SP-A:n ja SP-B:n ilmentymistä erittäin epäkypsässä kanin sikiön keuhkossa. Toisaalta IL-1 ja TNF-α vähensivät SP-B:n ja SP-C:n ilmentymistä kypsemmässä sikiön sekä vastasyntyneen kanin keuhkossa. Interferoni-gamma (IFN-γ) ei vaikuttanut surfaktanttiproteiinien ilmentymiseen missään gestaatioiässä, mutta se muunsi muiden sytokiinien surfaktanttivaikutusta. Gram-negatiivisten bakteerien soluseinän tuote, lipopolysakkaridi (LPS) vähensi SP-A:n, SP-B:n ja SP-C:n ilmentymistä kypsässä kanin sikiön ja vastasyntyneen kanin keuhkossa. IL-1:llä ja deksametasonilla oli positiivinen yhteisvaikutus surfaktanttiproteiinien ilmentymiseen. Tämän surfaktanttiproteiineja lisäävän vaikutuksen mekanismiksi havaittiin pääasiallisesti lisääntynyt mRNA:n stabiliteetti. Lisäksi tutkimus antaa lisätietoa kahden transkriptiofaktorin, NF-κB:n (nuclear factor kappa B) ja C/EBPγ:n (C/CAAT enhancer binding protein delta), osuudesta IL-1:n aiheuttamassa SP-A:n ilmentymisen lisääntymisessä. Sytokiinien vaikutukset surfaktanttiproteiinien ilmentymiseen ovat riippuvaisia gestaatioiästä. Tutkimuksen löydökset auttavat ymmärtämään RDS:n ja CLD:n vastakohtaista esiintymismäärää keskosilla, joiden ennenaikainen synnytys on aiheutunut kohdunsisäisestä tulehduksesta. Edelleen tutkimus selittää glukokortikoidien positiivista vaikutusta hengitysvajaukseen johtavassa keuhkotulehduksessa.

This study investigates electrochemical oxidation of m-cresol on boron-doped diamond electrode using direct current voltammetry (DCV), differential pulse voltametry (DPV) and cyclic voltammetry (CV). In aqueous media in pH range 2.0 - 12.0 m-cresol provides one oxidation peak. The electrode reaction is diffusion-controled. Because of electrode passivation two types of pretreatment were applied for reactivation of electrode surface., i.e. alumina polishing and anodic activation using potential of +2400 mV. Peak heights and potentials are strongly dipending on the type of pretreatment for DCV and DPV - the difference in peak potentials can reach 430 mV. Using optimal conditions for alumina polishing in 0.01 μmol·L-1 NaOH the linear dynamic range is 1.0 - 75 μmol·L-1 for DCV and 0.75 - 75 μmol·L-1 for DPV. And for anodic activation in BR buffer pH 2.0 the linear dynamic range is 0.75 - 75 μmol·L-1 for DCV and DPV. The influence of boron-doping level was investigated using a semiconductive and mettalic-type BDD film. For the latter the sensitivity in DP voltammetry is two times higer and for both types the linear dynamic range is ca 1 - 25 μmol·L-1 . The voltammetric response of m-cresol was further investigated in the presence of cationic surfactants. In the presence of CTAB and CPB the peak current...

Coatings for exterior wood have two basic functions. One isto give an aesthetically acceptable surface appearance andcolour. The other is to provide protection against wooddegradation by microbiological or physical attack. Theseprotective properties, often called the barrier properties,play an important role in the selection of proper material forsupreme durability. The assessment of these barrier propertiesis of great importance. Within the CEN Technical Committee 139,Working Group 2, Coatings for exterior wood test methods andperformance specifications have been established. Forassessment of water protection efficiency a standard testprocedure, EN 927-5, has been launched. The present work hasfocused on its applicability in assessing water protectionefficiency in relation to the degradation of coatings duringexposure. Assessments according to EN 927-5 is shown to givesignificant differences in water absorption values fordifferent types of coatings on wood. The proposed performancespecifications in ENV 927 - 2 for the water absorption valuesfor coatings to be used in different constructions seem to beset at acceptable levels. It has been shown that there is agood correlation between the level of water absorption andpractical experience of the performance of paints inScandinavia. However, it has also been shown that thecombination of a standard procedure for water absorptionmeasurement and an artificial weathering procedure gives moreinformation regarding expected durability and longtermperformance than a single measurement of water absorption onfresh, unweathered coated wood. A combination of waterabsorption measurement and artificial weathering could become auseful tool in product development as well as in benchmarking.Together with statistical tools, such as reliability-basedservice life prediction methodologies for predicting theservice life of coating systems a reduction in testing timesmay be achieved. Surface-active substances in coatings have a negative effecton the coatings ability to prevent water ingress, which mostprobably is due to the hydrophilic character of thesesubstances. The presence of these substances, which are commonin waterborne coatings, alters the moisture sorptioncharacteristics of wood. Considering that these substancesoccur in waterborne coatings, may be mobilised during and afterfilm formation and accumulate at the coating/substrateinterface, there is a great probability that these substanceschange the moisture sorption characteristics of the woodsubstrate in an unfavourable way and create unexpected dynamicmoisture conditions at the coating/wood interface. Computerized tomography has been found to be a valuable,non-destructive tool for visualising the spatial moisturedistribution of water and moisture in coated wood panels. Themethod is suitable for recurrent testing of a specimen exposedto a series of processes of wetting, drying. This thesis showsthat high moisture contents occur locally at and around cracks.In these areas there is an increased risk of internal tensionand stress resulting in crack initiation and propagation andthat high moisture contents may occur in the first fewmillimetres under waterborne coatings despite intact coatingfilms. Even with good barrier properties of the coating,moisture may accumulate by water-vapour absorption in air gapsbehind the cladding thus causing favourable conditions formicrobiological colonization. The work that has been carried out regarding assessment ofthe water protection efficiency shows promising resultsregarding the possibility to use reliability-based service lifeprediction methodology for the assessment. The aim of futurework will be to establish more reliable techniques andprotocols for assessing service life expectancy and durability,especially for waterborne coatings with special focus ontendencies to early failure and robustness of the coatingsystems. Keywords:Coatings, surfactants, water absorption value,EN 927, paint, additives, moisture dynamics, absorption,desorption, artificial weathering, artificial exposure,computerized tomography, MRI. / <p>NR 20140805</p>

The presented diploma thesis deals with the study of interactions between humic acids as the main component of soil organic matter with a model organic pollutant presented by cationic surfactant Septonex (which was expected to interact positively with humic acids due to its charge) through unconventional combination of dialysis and diffusion techniques realized in diffusion cells together with isothermal titration calorimetry capable of elucidating the nature of ongoing reactions from a thermodynamic point of view. The experiments were performed with a humic acid isolated by standard isolation procedure from Leonardite (1S104H) purchased from the International Society for Humic Substances, with humic acids isolated from lignite as well as modal chernozem. The aim of the submited diploma thesis is to assess the influence of carboxyl functional groups in the structure of humic acids to interactions with Septonex. For this reason, said samples of humic acids have been modified by selective methylation of their carboxyl functional groups, which can no longer participate in interactions with ionic substances. Results from diffusion cells and isothermal titration calorimetry confirmed the assumption that Septonex interacted with all types of unmodified humic acids more than with their methylated derivatives. Despite the available literature, it was surprising that the differences in the interaction of humic acids with Septonex were not diametrically different when comparing unmodified humic acids with their methylated derivatives. The extent of these interactions was assessed through the apparent equilibrium constant Kapp determined in the diffusion (dialysis) experiments and from the course of enthalpy curves from isothermal titration calorimetry. After the experiments and their evaluation, it can be concluded that humic acids and Septonex in their interactions, due to their structures, probably apply not only electrostatic interactions, especially through available carboxyl functional groups of humic acids and positively charged hydrophilic parts of Septonex molecules, but also a significant role have a hydrophobic effect, hydrogen bonds and Van der Waals forces.