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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Estudo da estabilidade do biodiesel de crambe e soja / Stability study of crambe and soybean biodiesel

Wazilewski, Willian Tenfen 27 February 2012 (has links)
Made available in DSpace on 2017-07-10T15:14:46Z (GMT). No. of bitstreams: 1 Willian Wazilewski.pdf: 3585508 bytes, checksum: 5c100553aa68a7f4273707361803185a (MD5) Previous issue date: 2012-02-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Biodiesel quality is critical to the successful commercialization of this fuel, so the product must meet some worldwide established parameters to guarantee their full environment roll functionality. Within these parameters there is the kinematic viscosity which may be affected due the degradation of the biofuel, such degradation occurs due atmospheric disturbances which all forms of organic matter are exposed to, and this degradation is accentuated when exposed to high temperatures or in contact with a catalyst matter. As a result of this, a factor that relates the degrees of resistance of a product to different oxidizing agents were created called as oxidation stability. This work aimed to study the oxidative stability of biodiesel produced from vegetable oil of soy and crambe. For this study the techniques of infrared spectroscopy, refractive index at 40 ° C and kinematic viscosity at 40 ° C were used to monitor the level of oxidation of the biodiesel. Viscometric studies revealed that biodiesel of crambe is more stable than soybean when they were exposed to thermal stress in an incubator at 130 ° C, with the addition of 5 and 10% of crambe biodiesel it reduces the viscosimetric change about 43,9% compared to pure soybean biodiesel. Looking at the index of refraction were found that the variation, in the case of pure soybean biodiesel, was about 0.0042 and its blends were 0.0028, 0.0025 and 0.0022 for 5, 10 and 20% of crambe biodiesel, respectively, compared to pure soybean biodiesel would be a stabilization of 33.3, 41.4 and 47.6% for the blends with 5, 10 and 20% of crambe biodiesel, respectively. By infrared spectroscopy it is clear that there was a formation of carbonyl grouping more intense in the soybean biodiesel compared to crambe biodiesel subjected to thermal stress for the same period. / A qualidade do biodiesel é de suma importância para o sucesso da comercialização deste combustível, sendo assim, o produto deve atender a parâmetros estabelecidos mundialmente, para que seja garantida sua total funcionalidade ambiental. Dentro destes parâmetros tem-se a viscosidade cinemática a qual pode ser afetada em virtude da degradação do biocombustível. Tal degradação ocorre devido às intempéries atmosféricas a qual estão expostos todas as formas de matéria orgânica, sendo esta degradação acentuada quando da exposição a temperaturas elevadas ou em contato com agentes catalisadores. Em virtude disto denominou-se a estabilidade à oxidação como sendo um fator que relaciona o grau de resistência do produto aos diferentes agentes oxidantes. O presente trabalho teve como objetivo o estudo da estabilidade oxidativa do biodiesel produzido a partir do óleo vegetal de crambe e soja. Utilizou-se para este estudo as técnicas de espectroscopia no infravermelho, índice de refração a 40ºC e viscosidade cinemática a 40ºC para acompanhar o nível de oxidação dos biodieseis. Os estudos viscosimétricos revelaram que o biodiesel de crambe é mais estável que o de soja quando da exposição destes ao stress térmico em estufa a 130ºC, sendo que a adição de 5 e 10% de biodiesel de crambe reduz a alteração viscosimétrica em cerca de 43,9% em relação ao biodiesel de soja puro. Observando o índice de refração constatou-se que a alteração deste, no caso do biodiesel de soja, foi de 0,0042 e para suas blendas foram 0,0028, 0,0025 e 0,0022 para 5, 10 e 20% de biodiesel de crambe, respectivamente. Em relação ao biodiesel de soja seria uma estabilização de 33,3, 41,4 e 47,6%, para as blendas com 5, 10 e 20 % de biodiesel de crambe, respectivamente. Pela espectroscopia no infravermelho percebe-se que houve uma formação de grupamento carbonila mais intensa no biodiesel de soja quando comparado com o biodiesel de crambe submetido ao stress térmico pelo mesmo período de tempo.
2

Stanovení viskozity pro různé typy splaškových vod / Determination of the viscosity of various types of wastewater

Glombová, Pavla January 2015 (has links)
The aim of this diploma thesis is a description of viscosity as a physical characteristic of liquids, next a description of projecting different types of sewer systems (pressure sewer system, vacuum sewer system and gravity sewer system). There was a range of density and viscosity of wastewater experimentally determined. These values were compared with ordinary values used in practice. The practical part of this work consists of sampling wastewater from different types of sewer systems and various localities. Chemical-biological analysis was realized on those samples with defined density, then dynamic viscosity was measured by the rotary viscometer for various temperatures. Measured data are evaluated. Finally, a calculation related to the design of sewers was made.

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