Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-02-22T21:55:15Z No. of bitstreams: 1 ErineiaDaSilvaSantos_DISSERT.pdf: 3035882 bytes, checksum: 42818d7e895e041fcfb6ca927e2d4834 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-02-24T00:26:37Z (GMT) No. of bitstreams: 1 ErineiaDaSilvaSantos_DISSERT.pdf: 3035882 bytes, checksum: 42818d7e895e041fcfb6ca927e2d4834 (MD5) / Made available in DSpace on 2016-02-24T00:26:37Z (GMT). No. of bitstreams: 1 ErineiaDaSilvaSantos_DISSERT.pdf: 3035882 bytes, checksum: 42818d7e895e041fcfb6ca927e2d4834 (MD5) Previous issue date: 2014-08-08 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Os fluidos de corte s?o lubrificantes usados no processo de usinagem nas ind?strias metalmec?nica por apresentarem v?rios benef?cios que variam de acordo com o tipo de opera??o executada. Estes fluidos s?o largamente utilizados como refrigeradores, como lubrificantes para melhorar o acabamento de superf?cies met?licas, reduzir o desgaste de ferramentas e proteg?-las contra a corros?o. Considerando as legisla??es vigentes e a demanda por produtos e processos considerados ?verdes?. Assim os ?leos vegetais representam uma solu??o para esses problemas, pois os ?leos vegetais aparecem como uma excelente alternativa para substitui??o do ?leos minerais. Deste modo, este trabalho teve como objetivo obter um fluido de corte emulsion?vel a base de ?leo vegetal epoxidado, para uma melhor lubrifica??o e refrigera??o no processo de usinagem, que n?o seja t?xico ao meio ambiente. O ?leo vegetal foi modificado quimicamente atrav?s da rea??o de epoxida??o com ?cido f?rmico. Foram determinadas as principais propriedades f?sico-qu?micas, tais como: densidade, acidez, ?ndice de iodo, ?ndice de oxirano, viscosidade, estabilidade t?rmica, al?m de caracteriza??es atrav?s de infravermelho e Resson?ncia Magn?tica Nuclear. O ?leo sintetizado foi utilizado para a formula??o das emuls?es O/A com diferentes concentra??es de ?leo epoxidado (10%, 20% e 25%) e com diferentes concentra??es de tensoativo (1%, 2,5% e 5%), e realizados estudos sobre a sua estabilidade. O desempenho tribol?gico das emuls?es O/A foi analisado pelo trib?metro HFRR (High Frequency Reciprocating Rig), que consiste num ensaio de desgaste do tipo esfera-plano. Os resultados mostraram que o biolubrificante pode ser sintetizado por rea??o de epoxida??o, os espectros, demonstraram que n?o houve 100% de convers?o das insatura??es em an?is ep?xi. Em rela??o ? avalia??o tribol?gica observa-se que o percentual de ?leo presente na emuls?o influenciou diretamente na forma??o de filme e coeficiente de atrito para maiores concentra??es o processo de forma??o de filme ? mais lento e inst?vel, bem como os valores de coeficiente de atrito. Maiores concentra??es de tensoativos n?o melhoraram o desempenho tribol?gico das emuls?es. O melhor desempenho para o processo de usinagem ? a emuls?o desenvolvida com 10% e 5% de tensoativo, a sua escara de desgaste em m?dia foi de WSD = 202?m. / The cutting fluids are lubricants used in machining processes, because they present many benefits for different processes. They have many functions, such as lubrication, cooling, improvement in surface finishing, besides they decreases the tool wear and protect it against corrosion. Therefore due to new environment laws and demand to green products, new cutting fluids must be development. These shall be biodegradable, non-toxic, safety for environment and operator healthy. Thus, vegetable oils are a good option to solve this problem, replacing the mineral oils. In this context, this work aimed to develop an emulsion cutting fluid from epoxidized vegetable oil, promoting better lubrication and cooling in machining processes, besides being environment friendly. The methodology was divided in five steps: first one was the biolubricant synthesis by epoxidation reaction. Following this, the biolubricant was characterized in terms of density, acidity, iodo index, oxirane index, viscosity, thermal stability and chemical composition. The third step was to develop an emulsion O/A with different oil concentration (10, 20 and 25%) and surfactant concentration (1, 2.5 and 5%). Also, emulsion stability was studied. The emulsion tribological performance were carried out in HFRR (High Frequency Reciprocating Rig), it consists in ball-disc contact. Results showed that the vegetable based lubricant may be synthesized by epoxidationreaction, the spectra showed that there was 100% conversion of the epoxy rings unsaturations. In regard the tribological assessment is observed that the percentage of oil present in the emulsion directly influenced the film formation and coefficient of friction for higher concentrations the film formation process is slow and unstable, and the coefficient of friction. The high concentrations of surfactants have not improved the emulsions tribological performance. The best performance in friction reduction was observed to emulsion with 10% of oil and 5% of surfactant, its average wear scar was 202 ?m.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-01-03T18:22:01Z No. of bitstreams: 1 AntonioCesarNobreDeAbrantes_DISSERT.pdf: 2550671 bytes, checksum: cb02cd1401011998407d1b88ed485674 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-01-04T20:35:17Z (GMT) No. of bitstreams: 1 AntonioCesarNobreDeAbrantes_DISSERT.pdf: 2550671 bytes, checksum: cb02cd1401011998407d1b88ed485674 (MD5) / Made available in DSpace on 2017-01-04T20:35:17Z (GMT). No. of bitstreams: 1 AntonioCesarNobreDeAbrantes_DISSERT.pdf: 2550671 bytes, checksum: cb02cd1401011998407d1b88ed485674 (MD5) Previous issue date: 2016-06-30 / As emuls?es s?o formula??es empregadas em diferentes segmentos da ind?stria, principalmente na ?rea aliment?cia, terap?uticas, cosm?ticas. Os ?leos de Linum usitatissimum e Sesamun indicum apresentam propriedades anti-inflamat?rias, em raz?o da presen?a de ?cidos graxos essenciais, podendo ter aplica??o na prepara??o de medicamentos pelo potencial farmacol?gico. O objetivo desse trabalho foi usar as propriedades farmacol?gicas do Punica granatum, como ativo, em sistema emulsionado, para aplica??o fitoter?pica. As emuls?es foram obtidas a partir de diagrama tern?rio utilizando a ?gua destilada como fase aquosa e a lecitina de Glycine max como tensoativo. Na prepara??o dos dois diagramas, na fase oleosa, utilizou-se os ?leos de Linum usitatissimum e Sesamun indicum. Nos diagramas obtidos, na regi?o de emuls?o do tipo O/A, foram escolhidos seis sistemas (tr?s em cada diagrama) por apresentar maior estabilidade. Os conservantes adicionados aos sistemas foram metilparabeno (Nipargin) e propilparabeno (Nipazol) e o estabilizador de emuls?es, hidrocol?ide Xanthan Gum (goma xantana). Da casca do vegetal Punica granatum foi obtido extrato aquoso, e em seguida liofilizado. Foram definidos tr?s percentuais (0,3%, 0,5% e 1,0%) de extrato liofilizado em cada sistema. Essas formula??es foram caracterizadas atrav?s das t?cnicas de medida pH, viscosidade, condutividade, estabilidade acelerada e estabilidade t?rmica. Antes de adicionar o bioativo foi empregada a espectrofotometria no Ultravioleta para quantificar o bioativo presente no p? da casca da rom?. A formula??es com a adi??o do extrato tiveram seus valores de pH diminu?dos e viscosidade aumentada quanto maior foi o percentual do extrato no meio. Isso se deve por que o extrato apresenta fen?is de car?ter ?cido e a quantidade maior de extrato no meio precisa de mais mol?culas para hidratar esse extrato, tornando o meio com menos ?gua livre. / Emulsions are formulations used in different industry segments, mainly in the food, pharmaceutical, cosmetic industry. The Linum usitatissimum and Sesamun indicum oils have anti-inflammatory properties, due to the presence of essential fatty acids and they can be applied in the preparation of drugs for the pharmacological potential. The aim of this study was to use the dried extract of Punica granatum to incorporate in the macro emulsified system, as active one, for herbal application. The emulsions were obtained from ternary diagram using distilled water as aqueous phase and Glycine max lecithin as surfactant. In preparing the two diagrams in the oil phase, the Linum usitatissimum and Sesamun indicum oils were used. In the diagrams obtained in the region of emulsion type O / A, they were selected six systems (three in the diagram) due to presenting greater stability. Preservatives added to systems were methylparaben (Nipagin?) and propylparaben (Nipazol?) and stabilizer of emulsions, hydrocolloid xanthan gum (xanthan gum). From peel Punica granatum plant, was obtained the aqueous extract, and then lyophilized. They have been defined three percentage (0.3%, 0.5% and 1.0%) of lyophilized extract in each system. These formulations were characterized by measuring pH techniques, viscosity, conductivity, accelerated stability and thermal stability. Before adding the bioactive was used the spectrophotometry in the ultravioleta and infrared to quantify the bioactive present in the pomegranate peel powder, and was also applied to the optical microscopy technique to determine the droplet size. The formulations with the addition of the dry extract of Punica granatum had their pH values decreased and viscosity increased as higher was the percentage of the extract in the medium. This happens because the extract has phenols of acid character and the largest amount of extract in the middle needs more molecules to hydrate this formulation, making the middle less free water.

Made available in DSpace on 2014-12-17T15:42:03Z (GMT). No. of bitstreams: 1 ClaudiaASM.pdf: 1242411 bytes, checksum: c3160a204092117e2180c02e3fd1b0bc (MD5) Previous issue date: 2008-11-12 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Cutting fluids are lubricants used in metal-mechanical industries. Their complex composition varies according to the type of operation carried out, also depending on the metals under treatment or investigation. Due to the high amount of mineral oil produced in Northeastern Brazil, we have detected the need to better use this class of material. In this work, two novel formulations have been tested, both based on naphthenic mineral oil and additives, such as: an emulsifying agent (A), an anticorrosion agent (B), a biocide (C) and an antifoam agent (D). Each formulation was prepared by mixing the additives in the mineral oil at a 700-rpm stirring velocity for 10 min, at 25?C, employing a 24 factorial planning. The formulations were characterized by means of density, total acid number (TAN), viscosity, flash point and anticorrosion activity. In a subsequent study, oil-in-water emulsions were prepared from these novel formulations. The emulsions were analyzed in terms of stability, corrosion degree, percentage of foam formation, conductivity, accelerated stability and particle size. The samples were appropriately labeled, and, in special, two of them were selected for featuring emulsion properties which were closer to those of the standards chosen as references (commercial cutting oils). Investigations were undertaken on the ability of NaCl and CaCl2 to destabilize the emulsions, at concentrations of 2%, 5% and 10%, at an 800-rpm stirring velocity for 5 min and temperatures of 25?, 40?, 50? and 60?C. The recovered oils were chemically altered by reincorporating the same additives used in the original formulations, followed by preparation of emulsions with the same concentrations as those of the initial ones. The purpose was to assess the possibility of reusing the recovered oil. The effluents generated during the emulsion destabilization step were characterized via turbidity index, contents of oil and grease, pH, and contents of anions and cations, observing compliance with the parameters established by the current environmental legislation (Brazil s CONAMA 357/05 resolution). It could be concluded that the formulations presented excellent physicochemical properties as compared to commercial cutting fluids, showing that the quality of the newly-prepared fluids is superior to that of the formulations available in the market, enabling technically and environmentally-safe applications / Fluidos de corte s?o lubrificantes usados nas ind?strias metal-mec?nicas. Possuem composi??es complexas que variam de acordo com o tipo de opera??o executada e com os metais a serem trabalhados. Levando-se em conta a grande quantidade de ?leo mineral produzido na regi?o nordeste, verificou-se a necessidade de melhor aproveit?-los. Neste trabalho desenvolveram-se duas formula??es usando-se como base ?leo mineral naft?nico e aditivos, tais como: emulsificante (A), anticorrosivo (B), biocida (C) e antiespumante (D). Cada formula??o foi preparada com a mistura dos aditivos ao ?leo mineral, sob agita??o de 700 rpm por 10 min, a 25?C, utilizando-se um planejamento fatorial 24. As formula??es foram caracterizadas atrav?s da densidade, ?ndice de acidez, viscosidade, ponto de fulgor e corros?o. Em seguida foram preparadas emuls?es O/A obtidas a partir das novas formula??es. Destas emuls?es estudou-se a estabilidade, grau de corros?o, percentual de espuma formado, condutividade, estabilidade acelerada e tamanho de part?culas. Escolheram-se as amostras F8 e F16 por apresentarem as propriedades das emuls?es mais pr?ximas dos padr?es escolhidos como refer?ncia (fluidos de corte comerciais). Realizou-se o estudo da quebra das emuls?es utilizando o NaCl e o CaCl2 , nas concentra??es de 2%, 5% e 10%, com agita??o durante 5 min, ? velocidade de 800 rpm, nas temperaturas de 25?, 40?, 50? e 60?C. Os ?leos recuperados foram readitivados com os mesmos aditivos utilizados nas formula??es iniciais. Em seguida, prepararam-se emuls?es nas mesmas concentra??es das emuls?es iniciais com o intuito de verificar se o ?leo recuperado poderia ser reutilizado. Os efluentes gerados durante a quebra das emuls?es foram caracterizados atrav?s da turbidez, teor de ?leos e graxas, pH, ?nions e c?tions, verificando-se enquadramento dos par?metros avaliados na legisla??o ambiental em vigor (Resolu??o CONAMA 357/05). As formula??es apresentaram ?timas propriedades f?sico-qu?micas quando comparadas com os fluidos de corte comerciais, mostrando, dessa forma, que os fluidos obtidos s?o de qualidade superior aos encontrados no mercado e podem ser utilizados com seguran?a t?cnica e ambiental