Předmětem tohoto studia bylo prozkoumat reologické chování vodných roztoků vysokomolekulárního hyaluronanu. Byl studován vliv zvyšující se koncentrace biopolymeru v roztoku, která se pohybovala v rozmezí od 1 do 3 hmotnostních procent, a také vliv vzrůstající iontové síly rozpouštědla, způsobené přídavkem chloridu sodného, na viskoelasticitu a stabilitu těchto roztoků. Pro obsáhlejší popis viskoelasických vlastností roztoků byla použita, vedle běžných oscilačních měření, také metoda ceepových testů, ze které bylo možno určit důležité veličity, jako je procentuální poměr viskozní a elastické složky vzorku, rovnovážná poddajnost, viskozita při nulovém smykovém napětí a retardační čas. Ty byly následně porovnávány s výstupy z jiných typů měření, jako jsou právě oscilační a tokové křivky, nebo nesly dopňující informace důležité pro detailnější popis viskoelastických vlastností těchto roztoků. Ke studiu stability vzorků během namáhání pak byla použita metoda peak-hold, která ukázala na velmi dobou mechanickou i časovou odolnost roztoků hyaluronanu a naznačila hranice, za kterými už dochází k trvalému poškození struktury a degradaci řetězců hyaluronanu a je s němi proto potřeba při manipulaci s roztoky tohoto biopolymeru pro jejich další použití v aplikacích počítat.

Submitted by Neusa Fagundes (neusa.fagundes@unioeste.br) on 2018-02-23T12:23:38Z No. of bitstreams: 2 Wagner_Aguiar2017.pdf: 18143581 bytes, checksum: 12b22329f78b4696bdd0b54a4a35409c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-02-23T12:23:38Z (GMT). No. of bitstreams: 2 Wagner_Aguiar2017.pdf: 18143581 bytes, checksum: 12b22329f78b4696bdd0b54a4a35409c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-11-08 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Changes in soil use and occupation in watersheds affect the hydrological cycle, which may potentialize or delay the surface runoff of rainwater, as well as the impacts brought about by such process. This work aimed to understand the variation of the surface runoff of two main soil occupation conditions in the basin that drains the high valley of the Marrecas river, upstream of the urban perimeter of Francisco Beltrão-PR. The first condition evaluated the implications of the changes in the criteria for the delimitation of permanent preservation areas (PPAs) established by the new Forest Code (Law 12.651/2012), in detriment of the old standard (Law 4.771/1965), comparing them with the current use of the soil in the basin, in the process of flood mitigation. The second condition studied the temporal distribution generation potentials of surface runoff and the flood risks due to the seasonal dynamics of agricultural land use for each month of the year. The effects of surface runoff were verified by means of HEC-HMS simulated flow peaks, submitted to seven probabilities of precipitation occurrences. The changes in the Forest Code indicated a reduction of PPAs from 44.5 to 13.7%, resulting in a 22.1% increase in average flow peaks. Seasonal use of agricultural land temporarily delimited the months of April and March as the highest potential runoff generators, as well as the lowest in January and August, allowing the establishment of increase rates in the Marrecas river flow peaks due to the occupation of the soil in the contributing basin, ranging from 0.78 to 1.64 m3s-1 for each km2 of exposed soil, depending on the probability of precipitation. It is concluded that the institution of the new Forest Code, compared to the old one, reduced in 69.2% the recoverable PPAs, minimizing the legal possibilities of flood mitigation to the urban perimeter of Francisco Beltrão, as well as the seasonal use and agricultural occupation of the soil established a strong correlation between the increase in the flow peaks and the occupation by exposed soil. / As alterações no uso e na ocupação do solo na bacia hidrográfica afetam o ciclo hidrológico, podendo potencializar ou retardar o escoamento superficial das águas pluviais, bem como os impactos inerentes a este processo. Este trabalho objetivou a compreensão da variação do escoamento superficial de duas condições principais de ocupação do solo na bacia que drena o alto vale do rio Marrecas, à montante do perímetro urbano de Francisco Beltrão-PR. A primeira condição avaliou as implicações nos picos de vazão das alterações nos critérios de delimitação das áreas de preservação permanente (APPs) instituídas pelo novo Código Florestal (Lei 12.651/2012), em detrimento das regras da antiga norma (Lei 4.771/1965) e as comparou, ainda, com o atual uso do solo na bacia, no processo de mitigação das inundações. A segunda condição estudou a distribuição temporal dos potenciais de geração de escoamento superficial e dos riscos de inundação decorrentes da dinâmica sazonal do uso do solo agrícola para cada mês do ano. Os efeitos do escoamento superficial foram verificados por meio de picos de vazão simulados pelo modelo HEC-HMS, submetidos a sete probabilidades de ocorrências de precipitações. As alterações no Código Florestal indicaram a redução de APPs de 44,5 para 13,7%, tendo como consequência o aumento médio nos picos de vazão em 22,1%. A utilização sazonal do solo agrícola delimitou temporalmente os meses de abril e março como os maiores potenciais geradores de escoamento superficial, bem como os menores, janeiro e agosto, permitindo o estabelecimento de taxas de aumento nos picos de vazão do rio Marrecas em função da ocupação do solo na bacia contribuinte, que variaram de 0,78 a 1,64 m3 s-1 para cada km2 de solo exposto, dependendo da probabilidade de precipitação. Conclui-se que a instituição do novo Código Florestal comparado ao antigo reduziu em 69,2% as APPs passíveis de recuperação, minimizando as possibilidades legais de mitigação das inundações ao perímetro urbano de Francisco Beltrão, bem como o uso e a ocupação sazonal do solo agrícola estabeleceram forte correlação entre o acréscimo nos picos de vazão e a ocupação por solo exposto.

<p>Hydraulic systems have many applications in the construction, transportation, and manufacturing sectors. Recent design trends involve systems with higher working pressures and more compact systems, which are advantageous because of power density increase. However, these trends imply higher forces and larger vibration amplitudes while having lesser mass and damping, leading to higher noise levels. Meanwhile, hydraulic machinery started prospecting new applications with tighter noise regulations, a trend which was also pushed by the electrification tendency in several fields of transportation and agriculture. One method to attain noise mitigation is passive-noise canceling techniques have the advantage of not introducing energy to the system. This approach arranges pressure ripple waves in a destructive pattern by projecting a hydraulic circuit's geometry, configuration, and features.</p> <p> </p> <p>This dissertation aims to predict fluid-borne noise sources and investigate passive noise-canceling solutions for multiple operations conditions targeting to impact many hydraulic systems and a broad range of operating conditions. Primarily a coupled system model strategy that includes a one-dimensional line finite element model is developed. The line model predicts pressure wave generation and propagation. The model features versatility since parameters like line diameter and material can be discretized node by node. Simulations are compared to measured data in a realistic novel hydraulic hybrid transmission for validation. </p> <p> </p> <p>Subsequently, an extensive numerical investigation is performed by setting fixed parameters along the hydraulic lines' length and comparing several isolated geometric properties in simulation. The developed line model is also used to study the influence of line features such as diameter and extent of the conduit. Cost-effective and simple passive solution solutions such as Quincke tubes (parallel lines), expansion chambers, and closed branches are selected and investigated on simulation. Four target pressure ripples are chosen as indicators for summarizing passive line elements behavior. The frequency-domain behavior of the pressure ripple peaks regarding the line's length is identified and isolated in simulation at the 50-5000Hz frequency spectrum. An experiment test rig is designed to implement these solutions and the experiments show three developed passive elements as practical and effective solutions for reducing fluid borne noise sources. The selected designs yielded noise source attenuation over most of the frequency spectrum measured with piezoelectric pressure variation sensors and accelerometers in different positions in the hydraulic circuit. Sound pressure measurements detected reductions over 3dB in the best cases. </p> <p> </p> <p>Also, a passive interference approach based on the principle of secondary source flow ripple cancellation was conceptualized, modeled, and implemented in a tandem axial-piston unit. The strategy consists of setting the phase between the two synchronous units to accomplish destructive interference in targeted unit harmonics. Two indexing strategies are investigated first analytically and then on simulation. One of the indexing strategies was implemented in a pre-existent commercial axial-piston tandem unit. Experiment results confirmed effectiveness for the first and third unit’s harmonics, where reductions over 15dB on pressure ripple were measured.</p> <p> </p> <p>Finally, a fluid-structure interaction based on the poison coupling principle is developed using the method of characteristics. Transfer functions of the pipeline accelerations versus the pressure ripples on lines calculated on simulation and later obtained experimentally to highlight ta critical vibration band from 2000Hz to 3000Hz with high acceleration response.</p> <p> </p><br>