Master of Science / Department of Biological & Agricultural Engineering / Donghai Wang / Camelina sativa (L). Crantz that belongs to Brassicaceae family has been grown as a dicotyledonous oilseed crop in the cold places like America and Canada. Camelina seeds are widely used for the extraction of oil and protein. Recently, research found that camelina gum is an excellent candidate for food and industrial uses as thickener or stabilizer. The objectives of this research were 1) to increase camelina gum isolation efficiency using spray drying technology, and 2) to develop an innovative method to remove gum from seed bran to increase protein and oil extraction efficiency and quality. The camelina gums isolated using ethanol precipitation and spray drying method from the whole camelina seeds were compared. Effects of spray drying temperature on yield, gum morphology, and gum rheological and thermal properties were studied. The representative sample dried at 165°C was chosen to study the effects of concentration, temperature, pH and additives (NaCl, CaCl₂, sucrose, and ethanol) on viscosity and viscoelastic properties of the isolated gum. The gum showed a shear thinning behavior when shear rate increased gradually, higher concentrations of additives only slightly affect the rheological properties. Results showed that spray drying is an effective method in terms of saving time and energy, and provided positive rheology benefits on camelina gum isolation. Pre-removal of gum from camelina seeds can increase protein and oil yield and their quality. Decortication can separate 10-17% of the total camelina seed as bran. A wind tunnel was used to separate lighter bran particles from heavier endosperm and unbroken seeds. Camelina gum isolation from the separated seed bran using the traditional ethanol precipitation method was optimized using response surface methodology where the simultaneous effect of the three independent variables (seed bran to water ratio, isolation temperature, and isolation time) were investigated for gum yield, purity, and optimum rheological properties. Three independent quadratic modules were developed and the original data fitted the models fitted (R² = 0.995, 0.877, and 0.804). The optimal isolation conditions were seed bran to water ratio of 1:39, isolation temperature of 35 ºC, and isolation time of 1.5 h and 0.839 desirability was obtained by the rigorous statistics analysis. The protein yield and quality extracted from decorticated endosperm were improved significantly compared with that extracted from whole seeds meal without decortication. In addition, the degumming step can be eliminated before protein and oil extraction that increase protein and oil extraction efficiency.

Submitted by Deyse Queiroz (deysequeirozz@hotmail.com) on 2018-06-11T14:17:04Z No. of bitstreams: 1 ACÁCIO FIGUEIREDO NETO - TESE PPGEA 2012..pdf: 36488715 bytes, checksum: f4cbebe212c4e906fda1a7703532628e (MD5) / Made available in DSpace on 2018-06-11T14:17:04Z (GMT). No. of bitstreams: 1 ACÁCIO FIGUEIREDO NETO - TESE PPGEA 2012..pdf: 36488715 bytes, checksum: f4cbebe212c4e906fda1a7703532628e (MD5) Previous issue date: 2012 / A cultura da abóbora é de uma maneira geral um bom negócio para vários produtores que se situam no semiárido, principalmente na região do Vale do São Francisco. A abóbora 'Jacarezinho' é uma das hortaliças de grande importância no Nordeste do Brasil, destacando-se pelo seu valor comercial. A qualidade fisiológica das sementes é de vital importância para que se obtenha sucesso em uma lavoura e as sementes de abóbora não fogem dessa realidade. O conhecimento da maturidade dos frutos e sementes, durante o processo de maturação é de interesse dos produtores, uma vez que auxilia no controle de qualidade. Com isso, objetivou-se neste trabalho avaliar a cinética da maturação dos frutos e a qualidade das sementes da abóbora 'Jacarezinho' sob diferentes épocas de colheita, e relacioná-los com as transformações físicas e fisiológicas que ocorreram simultaneamente durante o amadurecimento e o armazenamento nas condições do semiárido nordestino. O trabalho foi conduzido em uma área experimental de horticultura irrigada pertencente ao Departamento de Agronomia da Universidade Estadual da Bahia, no Laboratório de Sementes da Embrapa Seimárido em Petrolina - PE e no Laboratório de Ensaios de Materiais da Engenharia Mecânica da Universidade Federal do Vale do São Francisco em Juazeiro - BA. Em uma determinada área foi cultivado sementes de abóbora da variedade 'Jacarezinho' para seus frutos serem colhidos em épocas determinadas no período de dezembro de 2010 a março de 2011. Após a colheita, os frutos passaram pelas análises com ensaios de compressão com posterior extração das sementes, para determinação do teor de água e a realização dos testes de germinação e vigor. As sementes atingiram a maturidade fisiológica no tempo de 50 a 60 dias após antese configurando o tempo da colheita dos frutos para produção de sementes. Para as análises da pesquisa sobre comportamento mecânico dos frutos o resultado mostra que com o aumento do tempo de maturação ocorre o aumento da rigidez dos frutos com consequente aumento da carga máxima para atingir maiores deformações. E o tempo mais aconselhável para colheita e transporte foi entre 30 a 40 dias após antese para comercialização dos frutos. E por fim, com o armazenamento das sementes foi verificado que os maiores valores de germinação foram obtidas acondicionadas em embalagem de plástico para os doze meses e papel para os três meses de armazenamento desta cucurbitácea. / The pumpkin crop is generally a good deal for many producers who are located in the semiarid, mainly in the region of the San Francisco. The pumpkin 'Jacarezinho' is one o f the vegetables of great importance in northeastem Brazil, especially for its commercial value. It is known that the physiological seed quality is of vital importance in order to obtain success in a farming and pumpkin seeds do not escape this reality. Knowledge o f the maturity o f fruits and seeds during the maturation process is of interest to producers because it helps in quality control. Thus the objectives of this study: to evaluate the kinetics of fruit maturation and quality of seeds Pumpkin 'Jacarezinho' under different harvest times, and relate them to physical and physiological changes that occur simultaneously during the ripening and storage conditions of the semiarid northeast. The study was conducted in an experimental area of irrigated horticultura from the Department of Agronomy, State University of Bahia, in the Seed Laboratory of "Embrapa" semiarid in Petrolina - PE and Materials Testing Laboratory of Mechanical Engineering, Federal University o f the San Francisco in Juazeiro - BA. In a given area was grown pumpkin seeds variety 'Jacarezinho' for its fruits being harvested at certain times during the period December 2010 to March 2011. After harvesting, the fruits passed through the analysis of compression tests with subsequent extraction of the seeds, to determine the moisture content and the tests of germination and vigor. Seeds reached physiological maturity at the time of 50 to 60 days after anthesis by setting the time of fruit harvest for seed production. For the analysis of research on mechanical behavior of the fruit the result shows that with increasing aging time is increased stiffness of the fruit with a consequent increase o f the maximum load to achieve greater deformation. And the longer advisable to harvest and transport was between 30 to 40 days after anthesis to fruit commercialization. And finally, with the seed storage was found that the highest germination values were obtained in plastic packaging for the twelve months and paper for the three months storage of cucurbit.

La vitesse à laquelle le monde actuel fonctionne a des répercutions directes sur tout ce qui nous entoure et, en premier plan, sur le marché de la construction dont les cirières sont de plus en plus exigeants tels que les courts délais de construction, la complexité des formes, etc. L’utilisation des bétons fluides dont les propriétés rhéologiques sont bien maîtrisées est une clé pour satisfaire à ces critères, d’autant plus qu’on se trouve au seuil d’une nouvelle ère dans le monde de la construction incluant l’impression 3D des bétons. Cependant, une sélection adéquate des ajouts minéraux (AM) et des adjuvants chimiques (superplastifiants, SP et agents de viscosité, AV) qui entrent dans la conception des bétons fluides s’avère un problème crucial. Un programme expérimental très étendu est mené pour mettre la lumière sur l’effet de huit différents AM dans des systèmes binaires et ternaires ainsi que l’effet de leurs interactions avec les adjuvants chimiques (SP et AV) sur les propriétés des mortiers de bétons équivalents (MBE). Deux classes de bétons fluides sont visées dans cette étude comprenant les bétons autoplaçants (BAP) pour la construction des bâtiments et les bétons semi-fluides (BSF) pour les infrastructures de transport. Une attention particulière est portée sur les propriétés rhéologiques, sans pour autant négliger la chaleur d’hydratation ainsi que les propriétés mécaniques. Les résultats ont montré qu’il est difficile de faire une généralisation sur l’influence des AM sur les propriétés des MBE. Les propriétés physiques des AM telles que la finesse, la forme ou encore la granulométrie des particules sont des facteurs qui jouent un rôle important dans la rhéologie des bétons fluides. Cependant, l’influence de ces facteurs peut être masquée par l’interaction physique et chimique qui peut avoir lieu entre les poudres et les adjuvants chimiques utilisés (type de SP en présence de ou sans AV compatibles). La morphologie des particules des AM a un effet direct sur la viscosité plastique des MBE. Une forme angulaire et irrégulière (facteur de Ferret autour de 0,4), contribue à augmenter la viscosité plastique des MBE et une forme sphérique (facteur de Ferret proche de 1) contribue à diminuer leur viscosité plastique. Par ailleurs, les résultats de l’analyse statistique ont montré que l’influence des AM en combinaison ternaire (une poudre à faible réactivité avec une poudre à réactivité élevée), en présence d’un rapport eau/poudres (E/P) relativement élevé (0,45), sur la majorité des réponses n’est que la somme des effets individuels de ces poudres. Par contre, un effet d’interaction entre les poudres pour certaines réponses a commencé légèrement à prendre place lorsque le rapport E/P est diminué à 0,41. Cependant, dans le développement des résistances à la compression à 28 et 91 jours, les poudres à réactivité élevée comme la fumée de silice ou le métakaolin avaient généralement une contribution positive plus importante que celle des poudres à faible réactivité. Les résultats de l’hydratation des MBE ternaires, suivie par la calorimétrie isotherme, n’ont pas montré l’effet synergétique escompté de la combinaison d’une poudre à faible réactivité avec une autre à réactivité élevée dû à l’augmentation de la demande en SP en présence de cette dernière. Une optimisation multiparamétrique a permis de sélectionner des ciments ternaires servis au développement des bétons écologiques présentant les meilleures performances. Finalement, l’utilité de la méthode des MBE dans la prédiction de l’effet des AM sur les bétons a été discutée. / Abstract : The speed with which the world operates today has direct repercussions on everything around us and, in the foreground, on the construction market, where the criteria are more and more demanding such as short construction times, complexity of forms, etc. The use of fluid concretes where rheological properties are well controlled is a key to satisfy these criteria, especially since we are on the threshold of a new era in the construction world including the 3D concrete printing. However, an adequate selection of mineral additives (MA) and chemical admixtures (superplasticizers, SP and viscosity agents, VA) that are used in the design of fluid concretes is a crucial problem. A very extensive experimental program is conducted to shed light on the effect of eight different MA in binary and ternary systems as well as the effect of their interactions with the chemical admixtures (SP and VA) on the properties of concrete equivalent mortars (CEM). Two classes of fluid concretes are investigated in this study, including self-consolidating concrete (SCC) for building constructions and semi-flowable concrete (SFC) for transportation infrastructures. Particular attention is paid to the rheological properties, without neglecting the heat of hydration as well as the mechanical properties. The results showed that it is difficult to generalize on the influence of MA on the properties of CEM. The physical properties of MAs such as fineness, shape or particle size distribution are factors that play an important role in the rheology of fluid concretes. However, the influence of these factors can be masked by the physical and chemical interaction that may occur between the powders and the chemical admixtures used (type of SP in the presence or not of a compatible VA). The particle morphology of MA has a direct effect on the plastic viscosity of CEM. An angular and irregular shape (Ferret factor around 0.4) contributes to increase the plastic viscosity of CEM and a spherical shape (Ferret factor close to 1) contributes to decrease their plastic viscosity. Moreover, the results of the statistical analysis showed that the influence of MA in ternary combination (low-reactivity powder with high-reactivity powder), in the presence of a relatively high water-to-powder ratio (W/P) of 0.45, on the majority of responses is only the sum of the individual effects of these powders. On the other hand, an interaction effect between the powders for some responses began slightly when the W/P was decreased to 0.41. However, in developing 28- and 91-day compressive strengths, high-reactivity powders such as silica fume or metakaolin generally had positive contribution higher than low-reactivity powders. Results of ternary CEM hydration followed by isothermal calorimetry did not show the expected synergistic effect of combining a low-reactivity powder with another with high reactivity due to increased demand in SP in the presence of the latter. A multiparametric optimization allowed selection of ternary cements used to develop ecological concretes with the best performance. Finally, the use of the CEM method in prediction of the effect of AM on concrete was discussed.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-10-31T17:20:21Z No. of bitstreams: 1 2016 - Elisa Vila Nova de Noronha.pdf: 4419781 bytes, checksum: 0804df588af66f56621082802458f769 (MD5) / Made available in DSpace on 2017-10-31T17:20:21Z (GMT). No. of bitstreams: 1 2016 - Elisa Vila Nova de Noronha.pdf: 4419781 bytes, checksum: 0804df588af66f56621082802458f769 (MD5) Previous issue date: 2016-12-21 / For the drilling process to succeed, it is necessary the use of a drilling fluid. The measurement of rheological properties from these fluids becomes important in order to allow good hydraulic gusher maintenance and management. If these measures are taken in an on- line order that will mean agility in decision-making about the maintenance of the properties of the fluid and it will result in savings of thousands of dollars during the drilling of a well. It is in this context that this current report, developed in the UFRRJ laboratory of fluid flow, aims to evaluate the performance of a modified and calibrated process viscometer, making it a unique equipment for conducting real-time measures of apparent viscosity and thixotropy curve. The process viscometer chosen has the geometry of coaxial cylinders being, thus similar to the current workbench equipment used in drilling rigs. The modified viscometer performance was confronted with the rheometer benchtop Haake Rheostress 1. Different compositions of fluids, containing assorted concentrations of viscosifier polymers and suspension solid have been tested. The results indicated that there was an agreement on the results towards a considered error permissible for a viscometer process. The online viscometer brings a pioneering real-time measuring capacity and plotting of rheological behavior curves towards the current technology used in drilling operation. / Para que o processo de perfura??o seja bem-sucedido, ? necess?rio o uso de um fluido de perfura??o. A medi??o das propriedades reol?gicas destes fluidos torna-se importante para permitir uma boa manuten??o e gest?o hidr?ulica do po?o. Se estas medidas forem realizadas de forma online isso significar? agilidade na tomada de decis?o sobre a manuten??o das propriedades do fluido e acarretar? na economia de milhares de d?lares durante a perfura??o de um po?o. ? neste contexto que o presente trabalho, desenvolvido no Laborat?rio de Escoamento de Fluidos da UFRRJ, tem como objetivo avaliar o desempenho de um viscos?metro de processo modificado e calibrado, tornando-o em um equipamento exclusivo, para realizar medidas em tempo real de curva de viscosidade aparente e tixotropia. O viscos?metro de processo escolhido tem a mesma geometria de cilindros coaxiais sendo desta forma semelhante ao atual equipamento de bancada utilizado nas sondas de perfura??o. O desempenho do viscos?metro modificado foi confrontado com o re?metro de bancada Haake Rheostress 1. Foram testadas diferentes composi??es de fluidos contendo concentra??es variadas de pol?meros viscosificantes e s?lidos em suspens?o. Os resultados obtidos indicaram que houve concord?ncia nos resultados diante de um erro considerado admiss?vel para um viscos?metro de processo. Acredita-se que o viscos?metro online avaliado traz uma capacidade pioneira de medi??o em tempo real e plotagem de curvas de comportamento reol?gico diante da atual tecnologia utilizada na ?rea petroqu?mica.