Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2015-11-25T20:56:13Z No. of bitstreams: 1 TarcilaMariaPinheiroFrota_DISSERT.pdf: 2847806 bytes, checksum: 145d4638a1cda51760a6a1f51ae48737 (MD5) / Approved for entry into archive by Elisangela Moura (lilaalves@gmail.com) on 2015-11-25T22:37:39Z (GMT) No. of bitstreams: 1 TarcilaMariaPinheiroFrota_DISSERT.pdf: 2847806 bytes, checksum: 145d4638a1cda51760a6a1f51ae48737 (MD5) / Made available in DSpace on 2015-11-25T22:37:39Z (GMT). No. of bitstreams: 1 TarcilaMariaPinheiroFrota_DISSERT.pdf: 2847806 bytes, checksum: 145d4638a1cda51760a6a1f51ae48737 (MD5) Previous issue date: 2009-07-24 / Durante o processo de produ??o de petr?leo ? comum o aparecimento de g?s e ?gua associados. A produ??o pode ser comprometida pela precipita??o de sais inorg? nicos tanto no reservat?rio como no po?o produtor, atrav?s da forma??o de incrusta??o , e ? apontada como prov?vel causa ao dano da forma??o. Nas condi??es de alta temperatura e alta press?o (HTHP), a precipita??o de sais insol?veis pode ser favorecida. Os tipos de incrusta??es mais comuns em campos de petr?leo s?o o carbonato de c?lcio e os sulfatos de c?lcio, estr?ncio e b?rio. Atualmente, novos tipos de incrusta??o v?m despertando aten? ?o especia l como o sulfeto de zinco e de chumbo . Esta s precipita? ?es p ode m ocorrer nos poros da rocha - reservat?rio, na coluna de produ??o e nos equipamentos , provocando obstru??es e a conse qu ente perda da produ??o . Neste trabalho, estudou - se a influ ? ncia da profundidade, press?o e temperatura na composi??o das incrusta??es f ormadas, visando a otimiza??o de tratamentos de remo??o e seu comportamento ao longo da coluna. Foram selecionados 10 res?duos de uma coluna de produ??o (intervalo de 15,4 m a 4061,5 m), que apresentava problemas de corros?o/incrusta??o. Realiza ram - se ensa io s de dissolu??o em ?cidos org?nicos similares aos empregados em opera??es de remo??o desse tipo de incrusta??o. A composi??o majorit?ria foi definida e confirmada p elos testes de dissolu??o e por t?cnicas de Difratometria de Raios - X ( DRX ) , Espectrometria de Fluoresc?ncia de Raios - X ( EFRX ), Microscopia Eletr?nica de Varredura (MEV) . Foram observados res?duos com caracter?sticas distintas, em propor??es diferentes, mostrando uma tend?ncia de aumento e/ou diminui??o de massa com a profundidade. Os resultados obtidos indicam correla??es dos tipos de incrusta??es estudados com a profundidade e, consequentemente, com as condi??es termodin?micas de press?o e temperatura. / Water and gas is a common by - product of the oil production process. Production may be compromised by the precipitation of inorganic salts in both the reservoir and producing well, through scale formation. This precipitation is likely the cause of the formation damage. High temperatures and h igh pressures (HTHP) may favor the precipitation of insoluble salts. The most common types of scale in oil fields are calcium carbonate and calcium sulphate, strontium and barium sulphate. New types of scale formation have attracted special attention such as zinc sulphide and lead. This precipitation may occur in the pores of reservoir rocks, in the production string and in equipment, causing obstructions and consequent production losses. In this study, the influence of well depth on incrustation compositio n was investigated to design removal treatments and assess the behavior of these deposits along the string, through the analysis of pressure and temperature. Scale residues were recovered from the inside of the production string of an oil and gas well duri ng the string removal operation. A total of 10 samples from different depths (15.4 m to 4061.5 m) were obtained. Initially a dissolution test was conducted in weak acid, similar to that used in removal operations with this type of scale formation. Majority composition was defined and confirmed by dissolution tests using X - Ray Fluorescence Spectroscopy (XRF), X - Ray Diffraction (XRD) and Scanning Electron Microscope (SEM) techniques. Residues with distinct characteristics were observed in different proportion s, showing a tendency toward increased and/or decreased mass with depth. In the samples closest to the surface, typical sandstone residues were found, with calcium (45% Ca) as the metal of highest concentration. The obtained results indicate correlations o f the scale types studied with the depth and, consequently, with the thermodynamic conditions of pressure and temperature.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2015-11-27T13:08:55Z No. of bitstreams: 1 AseneteFrutuosoDaCosta_TESE.pdf: 4115238 bytes, checksum: 72a04780a21fa7344d83533cdbdd3d36 (MD5) / Approved for entry into archive by Elisangela Moura (lilaalves@gmail.com) on 2015-11-27T14:44:06Z (GMT) No. of bitstreams: 1 AseneteFrutuosoDaCosta_TESE.pdf: 4115238 bytes, checksum: 72a04780a21fa7344d83533cdbdd3d36 (MD5) / Made available in DSpace on 2015-11-27T14:44:06Z (GMT). No. of bitstreams: 1 AseneteFrutuosoDaCosta_TESE.pdf: 4115238 bytes, checksum: 72a04780a21fa7344d83533cdbdd3d36 (MD5) Previous issue date: 2014-08-18 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Dentre os principais pigmentos, os materiais cer?micos que possuem a estrutura espin?lio AB2O4 v?m se tornando objeto de grande interesse cient?fico e tecnol?gico devido ? capacidade em acomodar diferentes c?tions em sua estrutura, permitindo diferentes tipos dopagens e, consequentemente, a obten??o de diferentes cores. Estudos sobre pigmentos cer?micos, atualmente, v?m sendo direcionados para o desenvolvimento de pigmentos est?veis e obtidos a baixas temperaturas e com maior reprodutibilidade. O objetivo do seguinte estudo ? a utiliza??o de pigmentos inorg?nicos para aplica??es em revestimentos cer?micos, tentando compreender quais par?metros influenciam na colora??o do pigmento nos esmaltes cer?micos. Pigmentos a base de CoCr2O4, CoAl2O4, Co0,8Zn0,2Cr2O4 e Co0,8Zn0,2Al2O4Co/Cr, foram sintetizados por uma rota qu?mica usando gelatina como precursor org?nico. Tais pigmentos foram caracterizados por An?lise termogravim?trica, Difra??o de raios X (DRX), Espectroscopia na regi?o do Infravermelho, Microscopia eletr?nica de varredura (MEV) Espectroscopia na regi?o do UV-Vis?vel e Colorimetria. Os resultados confirmaram a viabilidade da rota de s?ntese utilizada; com rela??o aos p?s sintetizados, Os pigmentos mostraram-se cristalinos e as fases desejadas foram obtidas a partir de 500oC, com um aumento da cristalinidade, assim como o tamanho m?dio de cristalito. Os pigmentos possuem tonalidades que v?o do verde ao violeta de acordo com as dopagens e suas temperaturas de calcina??o. / Ceramic pigments that own mainly the spinel structure AB2O4 are becoming a matter of great scientific and technological interest due to the ability of accommodate different cations in its structure, allowing different dopings and thus obtaining different colors. Studies on ceramic pigments currently are being directed to the development of stable and pigments obtained at low temperatures and with greater reproducibility. This work aims at the use of inorganic pigments for applications in ceramic tiles, investigating the influence of doping and calcination temperature on the coloring pigments and ceramic glazes. the based pigments of CoCr2O4, CoAl2O4, Co0,8Zn0,2Cr2O4 and Co0,8Zn0,2Al2O4 were synthesized by a chemical route using commercial gelatin as organic precursor. The materials were characterized by thermogravimetric analysis (TG), X-ray diffraction (XRD), infrared spectroscopy (FTIR) spectroscopy scanning electron microscopy (SEM) in the UVVisible region and colorimetry. The results confirmed the feasibility of synthesis used, the route presented pigments crystal structures and the desired phases were obtained from 500 ?C with increased crystallinity and the crystallite size. The pigments have hues ranging from green to violet according to their doping and calcination temperatures.

Made available in DSpace on 2015-04-14T14:12:56Z (GMT). No. of bitstreams: 1 448144.pdf: 1972505 bytes, checksum: 11805093130d6e2ff21cd714a6c62441 (MD5) Previous issue date: 2012-08-30 / This paper reports an investigation aimed to understand how a Learning Unit, based in Education by Research can contribute to meaningful learning about inorganic compounds in high school. The study was conducted with a group of students enrolled in first grade high school students in a private school education in Porto Alegre, RS. The Learning Unit was developed in 2011. The research was developed based on a qualitative approach: a case study. The instruments of data collection were questionnaires, to identify initials knowledge and subsequent development of the Learning Unit and notes held by the teacher throughout the activities. For analysis and interpretation of data used the Discoursive Textual Analysis proposed by Moraes and Galiazzi (2007). From the analysis it was perceived as the activities allowed the identification of changes in the initial knowledge of the subjects highlighted the complexity of his views on the final explanations of the study. This work provided that the teaching strategies developed in the research enabled the expansion of knowledge. It was noted the relevance of the approach of different methodologies in the classroom to an embodiment of the process of teaching and learning. / Este trabalho relata uma investiga??o, cujo objetivo foi compreender de que modo uma Unidade de Aprendizagem, baseada no Educar pela Pesquisa, pode contribuir para a aprendizagem significativa do tema sobre compostos inorg?nicos no Ensino M?dio. A investiga??o foi realizada com uma turma de alunos matriculados na primeira s?rie do Ensino M?dio em uma escola da rede privada de ensino de Porto Alegre, RS. A Unidade de Aprendizagem foi desenvolvida no segundo trimestre de 2011. A pesquisa desenvolveu-se com base em uma abordagem qualitativa por meio de um estudo de caso. Os instrumentos de coleta de dados foram: question?rios, para a identifica??o dos conhecimentos pr?vios e posteriores ao desenvolvimento da Unidade de Aprendizagem e registros realizados pela pesquisadora ao longo das atividades. Para a an?lise e interpreta??o dos dados coletados antes, durante e ap?s o desenvolvimento da Unidade de Aprendizagem, foi utilizada a metodologia da An?lise Textual Discursiva proposta por Moraes e Galiazzi (2007). A partir da an?lise percebeu-se como as atividades desenvolvidas possibilitaram a identifica??o de mudan?as no saber inicial dos sujeitos, destacadas pela complexifica??o de suas concep??es nas descri??es finais do estudo. Este trabalho proporcionou que as estrat?gias pedag?gicas desenvolvidas na investiga??o possibilitassem a amplia??o do conhecimento. Constatou-se a relev?ncia da abordagem de metodologias diferenciadas em sala de aula para uma concretiza??o no processo de ensino-aprendizagem. Destacam-se como conclus?es, a import?ncia da abordagem de temas relevantes, da considera??o de informa??es a respeito dos conhecimentos iniciais e interesses dos alunos e da intera??o professor-aluno no desenvolvimento da pesquisa.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-11-22T20:18:43Z No. of bitstreams: 1 MariaDeFatimaDantasESilva_TESE.pdf: 4790020 bytes, checksum: 76003788c17fef9645769d5d4a851b01 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-11-23T00:20:06Z (GMT) No. of bitstreams: 1 MariaDeFatimaDantasESilva_TESE.pdf: 4790020 bytes, checksum: 76003788c17fef9645769d5d4a851b01 (MD5) / Made available in DSpace on 2017-11-23T00:20:06Z (GMT). No. of bitstreams: 1 MariaDeFatimaDantasESilva_TESE.pdf: 4790020 bytes, checksum: 76003788c17fef9645769d5d4a851b01 (MD5) Previous issue date: 2017-09-01 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Assim como a maioria dos setores industriais, o setor cer?mico tamb?m sentiu a necessidade de desenvolvimento. Desta forma, a ind?stria cer?mica vem buscando cada vez mais novos pigmentos para a produ??o de pisos e revestimentos, visando atender a demanda de cer?micas para decora??o de ambientes, tanto dom?sticos quanto comerciais. Al?m disso, h? um grande interesse em desenvolver novos materiais que estejam de acordo com a preserva??o ambiental e que tamb?m sejam relativamente de baixo custo. O xisto retortado (XR) ? um rejeito proveniente da ind?stria do xisto que, armazenado de forma inadequada, pode causar danos ? sa?de e ao meio ambiente.O objetivo deste estudo ? avaliar a viabilidade desse material, xisto retortado puro e xisto retortado impregnado com metais, na obten??o de pigmentos que colorem, de forma est?vel, diversas matrizes cer?micas; tentando compreender quais par?metros influenciam na pigmenta??o dos esmaltes. Os pigmentos a base de XR foram preparados impregnando os metais por via ?mida e calcinados a 700 e 900?C. Em seguida foram caracterizados por Fluoresc?ncia de Raio X (FRX) An?lise termogravim?trica (Tg), Difra??o de raios X (DRX), Espectroscopia na regi?o do Infravermelho (FTIR), Microscopia eletr?nica de varredura (MEV/EED), Espectroscopia na regi?o do UV-Vis?vel e Colorimetria. Os resultados confirmam a viabilidade do uso do xisto como pigmento cer?mico al?m de ser obtido por um m?todo simples, o pigmento ? de baixo custo e reduz o impacto ambiental causado por esse rejeito. Os pigmentos possuem tonalidades marrom claro, vermelha e tons de cinza de acordo com a impregna??o e suas temperaturas de calcina??o, que se tornaram mais escuras em maior temperatura. / Like most of the industries sectors, the ceramic sector also felt the need of developing. In this way, the ceramic industry has been seeking to create more and more pigments for the production of floors and coatings, aiming to meet the demand of ceramics for the decoration of domestic and commercial environments. In addition to that, there is a great interest in developing new materials that are in accordance with the environmental preservation that are also relatively low-cost. Retorted shale (RS) is a waste from the shale industry that may harm health and the environment if improperly stored. The aim of this study is to evaluate the viability of the materials, pure RS and metal-impregnated RS, to obtain pigments that are stable in several ceramic matrices, as well as to try to understand which parameters influence the pigmentation of the enamels. The RS-based pigments were prepared by wet impregnating of the metals and calcined at 700 and 900?C. After that, the materials were characterized by X-ray Fluorescence (XRF), Thermogravimetric analysis (Tg), X-ray diffraction (XRD), Fourier-Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM /EDS), UV-Visible Spectroscopy and Colorimetry. The results confirm the feasibility of using RS as a ceramic pigment obtained by a simple method, low-cost and that reduces the environmental impacts caused by such waste. The pigments are light brown, red and shades of gray, according to the impregnation and calcination temperatures, which get darker at higher temperatures.

ALVES, Ana paula Melo. Vermiculitas tratadas quimicamente na obten??o de s?lidos microporosos como precursores para h?bridos inorg?nico-org?nicos com aplica??es adsortivas. 2009. 124 f. Tese (Doutorado em Quimica) - Centro de Ci?ncias Exatas e da Natureza, Universidade Federal da Para?ba, Jo?o Pessoa, PB, 2009. / Submitted by Sonia Leite (sonia@geologia.ufrn.br) on 2010-09-27T16:18:21Z No. of bitstreams: 2 2000Tese_AnaPaulaMAlves.pdf: 2643720 bytes, checksum: 1e6e5bae6c1a2fb7113b073819b6445a (MD5) license_rdf: 19710 bytes, checksum: aa65da15f424ff71c620a992a187295c (MD5) / Rejected by clediane guedes(clediane@bczm.ufrn.br), reason: ALVES dever? est? em mai?sculo on 2010-09-27T18:01:29Z (GMT) / Submitted by Sonia Leite (sonia@geologia.ufrn.br) on 2010-09-27T18:28:33Z No. of bitstreams: 2 2000Tese_AnaPaulaMAlves.pdf: 2643720 bytes, checksum: 1e6e5bae6c1a2fb7113b073819b6445a (MD5) license_rdf: 19710 bytes, checksum: aa65da15f424ff71c620a992a187295c (MD5) / Approved for entry into archive by clediane guedes(clediane@bczm.ufrn.br) on 2010-09-30T12:05:26Z (GMT) No. of bitstreams: 2 2000Tese_AnaPaulaMAlves.pdf: 2643720 bytes, checksum: 1e6e5bae6c1a2fb7113b073819b6445a (MD5) license_rdf: 19710 bytes, checksum: aa65da15f424ff71c620a992a187295c (MD5) / Made available in DSpace on 2010-09-30T12:05:26Z (GMT). No. of bitstreams: 2 2000Tese_AnaPaulaMAlves.pdf: 2643720 bytes, checksum: 1e6e5bae6c1a2fb7113b073819b6445a (MD5) license_rdf: 19710 bytes, checksum: aa65da15f424ff71c620a992a187295c (MD5) / A lixivia??o seletiva de argilominerais ? um m?todo importante na prepara??o de silicatos porosos constituindo-se em uma rota simples, efetiva e de baixo custo. Neste estudo a vermiculita foi submetida a tratamento ?cido com acido n?trico nas concentra??es 1, 2, 3 e 4 mol dm-3, originando os s?lidos precursores denominados VacX (x=1 a 4), respectivamente. As matrizes ativadas e a vermiculita reagiram covalentemente com os organosilanos aminopropil-, propiletilenodiamino-,propildietilenotriamino- e glicid?xipropiltrimetoxissilano (GPTS) atrav?s dos grupos metoxilas do silano e as hidroxilas da superf?cie das matrizes. O h?brido Vac3G, derivado da silaniza??o do Vac3 com GPTS, sofreu rea??es subseq?entes com as diaminas etil, propil, butildiamina e 2-aminopiridina, possibilitando a entrada de novos centros b?sicos. Os diversos s?lidos foram caracterizados por an?lise qu?mica, espectroscopia na regi?o do IV, DRX, RMN 29Si e 27Al, MEV, volume de poro e ?rea superficial. A lixivia??o da vermiculita s?dica originou s?lidos porosos reestruturados com elevadas ?reas superficiais cujos valores foram 133, 334, 673 e 575 m2 g-1 para os s?lidos Vac1, Vac2, Vac3 e Vac4,respectivamente. Independentemente do s?lido, observou-se que ? medida que a lixivia??o se torna mais acentuada, houve um aumento na reatividade das matrizes ativadas em rela??o ? vermiculita original, sendo a matriz Vac3 a mais reativa diante das rea??es aqui propostas. Todos os s?lidos modificados apresentaram altos teores de grupos org?nicos incorporados. A s?rie de vermiculitas modificadas com o grupo aminopropil foi utilizada para a adsor??o de c?tions divalentes de cobre e n?quel em solu??o aquosa, mostrando maior afinidade para os ?ons de Ni2+(aq) do que para Cu2+(aq) como ilustrado pelos valores Nf de 2,97 e 1,23 mmol g-1, respectivamente. Os s?lidos porosos argilosos derivados de tratamento ?cido da vermiculita s?o substratos potenciais para imobiliza??o de silanos apresentando importantes aplica??es como adosrventes para esp?cies poluentes como metais pesados. ABSTRACT: The selective leaching of clay minerals is an important method in the preparation of porous silicates presenting as a simple, effective and low cost route. In this study, vermiculite was submitted to acid treatment at concentrations 1, 2, 3, and 4 mol dm-3, resulting the precursor solids named as VacX (x=1 a 4), respectively. The lixiviated matrices and vermiculite reacted covalently with the organosilanes aminepropyl-, propyletilenediamine-, ropyldietilenetriamine- and glycidoxypropyltrimethoxisilane (GPTS). The hybrid Vac3G, derived from silanization reaction between Vac3 and GPTS, was submitted to subsequent reactions with ethyl, propyl, butyldiamines and 2- aminepiridine resulting in the entrance of new basic centres. The products were characterized by chemical analysis, infrared spectroscopy, X-ray diffraction, 29Si and 27Al NMR in solid state, SEM, and pore volume and surface area determination. The lixiviation of sodic vermiculite originated the restructured porous solids with high superficial area showing the values133, 334, 673 e 575 m2 g-1 for VacX where X = 1,2,3,4, respectively. These solids and sodic vermiculite reacted covalently with each organosilane through methoxyl groups of silane and the hydroxyl surface of matrices. Independently of solid, it was observed that the lixiviation favored the reactivity of activated matrices compared with sodic vermiculite, showing the Vac3 as more reactive comparing with others solids. All modified solids presented high nitrogen content showing the values of 6,31 %. The set of modified vermiculites containing aminepropyl group was applied as adsorbent for divalent cations as copper and nickel in aqueous solution. These solid showed highest affinity for Ni2+ than Cu2+ ions as illustrated by Nf values of 2,97 and 1,23 mmol g-1, respectively. Clay porous solids obtained of leaching treatment of vermiculite are potential substrates for grafting of silanes showing important applications as adsorbents for contaminant species as heavy metals

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2018-03-20T17:21:12Z No. of bitstreams: 1 MarinalvaFerreiraTrajano_TESE.pdf: 6319363 bytes, checksum: 1a264d4d3fb0025a7862072124e8405a (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2018-03-22T12:58:55Z (GMT) No. of bitstreams: 1 MarinalvaFerreiraTrajano_TESE.pdf: 6319363 bytes, checksum: 1a264d4d3fb0025a7862072124e8405a (MD5) / Made available in DSpace on 2018-03-22T12:58:55Z (GMT). No. of bitstreams: 1 MarinalvaFerreiraTrajano_TESE.pdf: 6319363 bytes, checksum: 1a264d4d3fb0025a7862072124e8405a (MD5) Previous issue date: 2017-09-29 / O Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Engrenagens e outros conjuntos mec?nicos s?o muito importantes para a convers?o da energia e?lica em energia el?trica em turbinas e?licas, mas a sua durabilidade e efici?ncia s?o severamente prejudicadas por algumas quest?es tribol?gicas como corros?o, desgaste, deforma??o e fragmenta??o. Os lubrificantes utilizados para reduzir esse desgaste e deforma??o s?o de fontes n?o renov?veis podendo n?o ser vi?veis ambientalmente. Assim, surgem novas tecnologias que visam o desenvolvimento de produtos de fontes renov?veis substituindo o ?leo mineral e aditivo de extrema press?o. A este respeito, ?leos vegetais e novos aditivos inorg?nicos est?o sendo pesquisados como uma alternativa adequada para substituir os lubrificantes utilizados atualmente em engrenagens de turbinas e?licas. O objetivo desse trabalho foi sintetizar nanopart?culas est?veis inorg?nicas em ?leos vegetais por sputtering, desenvolvendo lubrificantes mais adaptados ao meio ambiente com aditivos mais eficientes. A metodologia aplicada est? divida em 5 etapas: 1- prepara??o do biolubrificante (?leo de girassol epoxidado); 2- caracteriza??o f?sico-quimica dos lubrificantes; 3- deposi??o das nanopart?culas por sputtering; 4- caracteriza??o da dispers?o e 5 avalia??o tribol?gica. Nas deposi??es foram utilizados tr?s n?veis de corrente de descarga e taxa de deposi??o (30 mA- 0,8 ?/s, 40 mA- 1,3 ?/s e 50 mA- 1,51 ?/s), tr?s diferentes concentra??es, em peso, de nanopart?culas (0,05%, 0,1% e 0,3%) e com alvo Cu para se obter nanopart?culas de cobre. As nanopart?culas formadas foram caracterizadas em fun??o do tamanho de part?cula pela t?cnica de SAXS e por MEV. A dispers?o das nanopart?culas foi analisada por Uv-Vis?vel, Polidispersividade, Potencial Zeta e SAXS. Para avaliar o desempenho tribol?gico foi utilizado o trib?metro HFRR. Os resultados mostraram que os biolubrificantes com melhoram o desempenho tribol?gico melhorando o desgaste e reduzindo atrito em superf?cies met?licas. Al?m disso, este m?todo de preparo do nanobiolubrificante eliminou o problema de dispers?o verificado por outras t?cnicas de dispers?o. / Gears and other mechanical assemblies are very important for the conversion of wind energy into electrical energy in wind turbines, but their durability and efficiency are severely hampered by some tribological issues such as corrosion, wear, deformation and fragmentation. The lubricants used to reduce this wear and deformation is from non-renewable sources and may not be environmentally viable. Thus, new technologies appear that aim at the development of renewable products replacing mineral oil and extreme pressure additive. In this regard, vegetable oils and new inorganic additives are being researched as a suitable alternative to replace the lubricants currently used in wind turbine gears. The objective of this work is to synthesize inorganic nanoparticles in vegetable oils by sputtering to obtain stable colloidal nanoparticles (NPs), developing lubricants more adapted to the environment with more efficient additives, with a better level of tribological performance. The applied methodology is divided in 5 steps: 1- preparation of the biolubrificante (epoxidized sunflower oil); 2- physico-chemical characterization of the lubricants; 3- deposition of the nanoparticles by sputtering; 4 - characterization of the dispersion and 5 tribological evaluations. In the depositions three discharge current levels (30 mA- 0.8 ? / s, 40 mA- 1.3 ? / s and 50 mA- 1.51 ? / s) and three deposition rates were used to obtain three different concentrations by weight of nanoparticles (0,05%, 0,1 % and 0,3%) and with Cu target to obtain copper nanoparticles. The nanoparticle formed was characterized as a function of the particle size by the SAXS technique and a sample by SEM. The dispersion of the nanoparticles was analyzed by Uv-Visible, Polydispersivity, Zeta Potential and SAXS. To evaluate the tribological performance was used the HFRR trbometer. The results showed that the biolubrificants with additives had good performace, improved wear and reduced friction on metal surfaces. In addition, this method of preparing the nanobiolubrifier eliminated the dispersion problem ascertained by other dispersion techniques.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-02-17T18:51:45Z No. of bitstreams: 1 TaisaCristineDeMouraDantas_TESE.pdf: 4130731 bytes, checksum: 1cb82be7c6c1b80529423696ce7dcfef (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-02-17T21:16:26Z (GMT) No. of bitstreams: 1 TaisaCristineDeMouraDantas_TESE.pdf: 4130731 bytes, checksum: 1cb82be7c6c1b80529423696ce7dcfef (MD5) / Made available in DSpace on 2017-02-17T21:16:26Z (GMT). No. of bitstreams: 1 TaisaCristineDeMouraDantas_TESE.pdf: 4130731 bytes, checksum: 1cb82be7c6c1b80529423696ce7dcfef (MD5) Previous issue date: 2016-07-26 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / A necessidade de encontrar novas tecnologias para a minimiza??o da emiss?o crescente de gases poluentes no planeta se torna cada vez mais urgente. Dos processos estudados atualmente a t?cnica de adsor??o utilizando materiais mesoporosos v?m tendo bastante enfoque. A fam?lia do SBA est? dentro desses materiais, onde pode ser destacado o SBA-15 e SBA-16 como estruturas com propriedades texturais interessantes. O presente trabalho realizou a s?ntese destes materiais de acordo com a metodologia descrita na literatura. Ap?s estas etapas, as estruturas de sil?cio foram funcionalizados atrav?s das t?cnicas de impregna??o com um pol?mero Polietilenimina ramificada com etilendiamina (PEI) em meio metan?lico, onde a rea??o das aminas com a estrutura de sil?cio apresenta car?ter i?nico; e a funcionaliza??o por enxerto com organossilanos, empregando o N-[(3-trimetoxissilil)propil] dietilenotriamina (DT-NNN), onde a estrutura ? formada de um grupo de sil?cio e tr?s aminas. A rea??o dessa mol?cula com a superf?cie de sil?cio ? realizada atrav?s de uma liga??o covalente. Tamb?m houve a funcionaliza??o do SBA-16 utilizando a dupla funcionaliza??o combinando as duas t?cnicas para obter uma maior porcentagem aminas. A parte foi proposta a reciclagem do material de sil?cio SBA-15, onde ap?s a funcionaliza??o, foram tratados termicamente a uma temperatura de 550 ?C para a elimina??o dos grupos org?nicos. A cada etapa de funcionaliza??o foi executada na estrutura uma nova etapa de funcionaliza??o, onde estas foram repetidas por 6 vezes. Os materiais foram caracterizados por t?cnicas f?sico-qu?micas no intuito de verificar a forma??o da estrutura e sua organiza??o. O processo de adsor??o de CO2 puro para o material SBA-16 funcionalizado foi executado em um equipamento volum?trico sob press?o de 1 bar a 45 ?C, onde a amostra E-SBA16-10PEI e CC-SBA16-50PEI exibiram quantidades de adsor??o de 47 mg CO2/g ads e 108 mg CO2/g ads, respectivamente. Os ensaios de adsor??o para o SBA-15 foram realizados tamb?m a 1 bar e 45 ?C, e menos quantidades de CO2 adsorvidos foram reportadas para as amostras com DT e isto pode ser relacionada a perda da efici?ncia das aminas. Esse comportamento n?o foi observado nas amostras impregnadas com PEI. / The need to find new technologies to minimize the increasing emission of greenhouse gases on the planet becomes increasingly urgent. Currently processes studied the adsorption technique using mesoporous materials are having enough focus. The family of the SBA is within these materials, which can be highlighted the SBA-15 and SBA-16 as structures with interesting textural properties. In the present work was carried out the synthesis of these materials according to the methodology described in the literature. After these steps, the silicon structures were functionalized by means of impregnation techniques with a branched polyethylenimine polymer etilendiamina (PEI) in the methanolic medium, where the reaction of amines with the silicon structure has ionic character; and graft functionalization with organosilanes, where we used the N [(3-trimetoxissilil) propyl] diethylenetriamine (DT- NNN) where the structure is formed from a group of silicon and three amines. The reaction of this molecule with the silicon surface is performed through a covalent bond. There was also the functionalization of SBA-16 using double functionalization combining the two techniques to get higher percentage amines. The part was proposed recycling of SBA-15 silicon material, which after functionalization, were heat-treated at a temperature of 550 ?C for the removal of organic groups. Each functionalization step was performed a new structure functionalization step, where they were repeated 6 times. The materials were characterized by physico-chemical techniques in order to verify the formation of structure and organization. The process of pure CO2 adsorption on functionalized SBA-16 materials, was performed on a volumetric equipment under 1 bar pressure at 45 ?C where the sample E-SBA16-10PEI and CC-SBA16-50PEI showing adsorption amounts of 47 mg CO2/g ads and 108 mg CO2/g ads, respectively. Adsorption tests for SBA-15 were also performed at 1 bar and 45 ? C, less amounts of CO2 absorbed were reported out for samples with DT and this is related to loss of efficiency of amines. This behavior was not observed in the samples impregnated with PEI.

Made available in DSpace on 2014-12-17T14:06:56Z (GMT). No. of bitstreams: 1 AseneteFC_DISSERT.pdf: 1219908 bytes, checksum: bebef255f66d82cd8504a8398fd23379 (MD5) Previous issue date: 2010-12-10 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Inorganic pigment comprises a host lattice, which is part of the chromophore component (usually a transition metal cation) and possible components modifiers, which stabilize, add or restate the properties pigments. Among the materials with spinel, ferrites, and the chromite stand out, because they have broad technological importance in the area of materials, applicability, pigments, catalytic hydrogenation, thin film, ceramic tiles, among others. The present work, pigments containing CuFe2O4, CuCr2O4,e CuFeCrO4, were synthesized by a method that makes use of gelatin as organic precursor using their application to ceramic pigments. The pigments were characterized by X-ray diffraction (XRD), Infrared spectroscopy, scanning electron microscopy (SEM) spectroscopy in the UV-visible and Colorimetry. The results confirmed the feasibility of the synthetic route used, with respect to powders synthesized, there is the formation of spinel phase from 500?C, with an increase in crystallinity and the formation of other phases. The pigments were shown to be crystalline and the desired phases were obtained. The copper chromite have hues ranging from green to black according to the calcination temperature, while the copper chromite doped with iron had brownish. The ferrites showed copper color and darker brown to black, which may indicate an interesting factor because of the importance of black pigment / Pigmento inorg?nico ? formado por uma rede hospedeira, na qual se integra o componente crom?foro (normalmente um c?tion de metal de transi??o) e os poss?veis componentes modificadores, que estabilizam, conferem ou reafirmam as propriedades pigmentantes. Dentre os pigmentos, as estruturas tipo espin?lio se destacam por possuir ampla import?ncia tecnol?gica na ?rea de materiais, com aplica??o em pigmentos, cat?lise de hidrogena??o, filmes finos, revestimentos cer?micos, dentre outros. No presente trabalho, pigmentos contendo CuFe2O4, CuCr2O4,e CuFeCrO4 foram sintetizados por uma nova rota qu?mica usando gelatina como precursor org?nico visando sua aplica??o para pigmentos cer?micos. Os pigmentos foram caracterizados por difra??o de raios X (DRX), espectroscopia na regi?o do Infravermelho, Microscopia eletr?nica de varredura (MEV) espectroscopia na regi?o do UV-Vis?vel e Colorimetria. Os resultados confirmaram a viabilidade da rota de s?ntese utilizada; Com rela??o aos p?s-sintetizados, observase a forma??o da fase espin?lio a partir de 500oC, com um aumento da cristalinidade, bem como a forma??o de outras fases. Os pigmentos se mostraram cristalinos e as fases desejadas foram obtidas. As cromitas de cobre possuem tonalidades que v?o do verde ao preto, de acordo com a temperatura de calcina??o, enquanto que as cromitas de cobre dopadas com ferro obtiveram colora??o marrom. As ferritas de cobre apresentaram cores bem mais escuras, do marrom ao preto, o que ? uma caracter?stica interessante devido ? grande import?ncia dos pigmentos pretos na ind?stria cer?mica

Made available in DSpace on 2014-12-17T14:07:05Z (GMT). No. of bitstreams: 1 YaraFG_DISSERT.pdf: 4146827 bytes, checksum: 3586f66a1b391a184d1b6034e91b85c0 (MD5) Previous issue date: 2012-12-20 / In the ceramics industry are becoming more predominantly inorganic nature pigments. Studies in this area allow you to develop pigments with more advanced properties and qualities to be used in the industrial context. Studies on synthesis and characterization of cobalt aluminate has been widely researched, cobalt aluminate behavior at different temperatures of calcinations, highlighting especially the temperatures of 700, 800 and 900? C that served as a basis in the development of this study, using the method of polymerization of complex (CPM), economic, and this method applied in ceramic pigment synthesis. The procedure was developed from a fractional factorial design 2 (5-2) in order to optimize the process of realization of the cobalt aluminate (CoAl2O4), having as response surfaces the batch analysis data of Uv-vis spectroscopy conducted from the statistic software 7.0, for this were chosen five factors as input variables: citric acid (stoichiometric manner), puff or pyrolysis time (h), temperature (? C), and calcinations (? C/min), at levels determined for this study. By applying statistics in the process of obtaining the CoAl2O4 is possible the study of these factors and which may have greater influence in getting the synthesis. The pigments characterized TG/DSC analyses, and x-ray diffraction (XRD) and scanning electron microscope (SEM/EDS) in order to establish the structural and morphological aspects of pigment CoAl2O4, among the factors studied it were found to statically with increasing calcinations temperature 700?< 800 <900 ?C, the bands of Uv-vis decrease with increasing intensity of absorbance and that with increasing time of puff or pyrolysis (h) there is an increase in bands of Uv-vis proportionally, the generated model set for the conditions proposed in this study because the coefficient of determination can explain about 99.9% of the variance (R?), response surfaces generated were satisfactory, so it s possible applicability in the ceramics industry of pigments / Na ind?stria cer?mica utilizam-se cada vez mais pigmentos de natureza predominantemente inorg?nica. Os estudos nessa ?rea permitem desenvolver pigmentos com qualidades e propriedades mais avan?adas para serem empregados em ?mbito industrial. Estudos de s?ntese e caracteriza??o do aluminato de cobalto t?m sido amplamente pesquisados, o comportamento do aluminato de cobalto em diferentes temperaturas de calcina??es, destacando principalmente as temperaturas de 700, 800 e 900?C utilizando o m?todo de polimeriza??o de complexos (MPC), m?todo este, econ?mico e aplicado em s?ntese de pigmentos cer?micos. O procedimento foi desenvolvido a partir de um planejamento fatorial fracionado 2(5-2) com o objetivo de otimizar o processo de realiza??o do aluminato de cobalto (CoAl2O4), tendo como superf?cies de respostas os dados da an?lise de espectroscopia do Uv-vis realizados a partir do software statistic 7.0, para isso, foram escolhidos cinco fatores como vari?veis de entrada: concentra??es de ?cido c?trico (de maneira estequiom?trica), tempo de puff ou pir?lise (h), temperatura (?C), tempo e taxas de calcina??es(?C/min), em patamares determinados para este estudo. Atrav?s da aplica??o estat?stica no processo de obten??o do CoAl2O4 foi poss?vel estudar entre estes fatores quais possam ter maior influ?ncia na obten??o da s?ntese. Os p?s-precursores foram caracterizados pelas an?lises termogravim?tricas TG/DSC, e os p?s-calcinados (pigmentantes) foram analisados pela difra??o de raios- x (DRX) e microscopia eletr?nica de varredura com energia dispersiva (MEV/EDS) a fim de comprovar os aspectos estruturais e morfol?gicos do CoAl2O4, entre os fatores estudados estaticamente verificou-se que com o aumento da temperatura de calcina??o 700<800<900?C, as bandas do Uv-vis diminuem com o aumento da intensidade da absorb?ncia e que com o aumento do tempo de puff ou pir?lise (h) h? um aumento das bandas do Uv-vis proporcionalmente, o modelo gerado ajustou-se para as condi??es propostas neste estudo, pois o coeficiente de determina??o consegue explicar cerca de 99,9%, da vari?ncia (R?), as superf?cies de respostas geradas foram satisfat?rias, sendo assim sua poss?vel aplicabilidade na ind?stria cer?mica de pigmentos

Made available in DSpace on 2014-12-17T15:42:27Z (GMT). No. of bitstreams: 1 WashingtonCMG_TESE.pdf: 1906631 bytes, checksum: 6b7dc12db13ffeb89c11288d55cea5a8 (MD5) Previous issue date: 2013-09-09 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In this work, the structures of LaCoO3, La0,8Ba0,2CoO3 and La0,8Ca0,2CoO3 perovskites were characterized as a function of temperature (LaCoO3 structure being analyzed only at room temperature). The characterization of these materials were made by X-Ray Absorption Spectroscopy (XAS), in the cobalt K-edge, taking into account the correlated Einstein model X-ray absorption fine structure (EXAFS). The first part of the absorption spectrum corresponded the X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS). These materials were prepared by the combustion method. The combustion products were calcinated at 900 0C, for 6 hours in air. Noted that the sample LaCoO3 at room temperature and samples doped with Calcium and Barium in the temperature range of 50 K to 298 K showed greater distortion to monoclinic symmetry with space group I2/a. However, the sample doped with barium at the temperatures 50 K, 220 K, and 260 K showed a slight distortion to rhombohedral symmetry with space group R-3c. The La0,8Ca0, 2CoO3 structure was few sensitive to temperature variation, showing a higher local distortion in the octahedron and a higher local thermal disorder. These interpretations were in agreement with the information electronic structural on the XANES region and geometric in the EXAFS region / Neste trabalho foram investigados estruturas de perovskitas LaCoO3, La0,8Ba0,2CoO3 e La0,8Ca0,2CoO3 em fun??o de temperatura, sendo que a estrutura LaCoO3 foi analisada apenas em temperatura ambiente. As caracteriza??es destes materiais foram realizadas pela espectroscopia de absor??o de raios X (XAS) na borda K do cobalto levando em considera??o modelo de Einstein correlacionado na estrutura fina de absor??o (EXAFS). A primeira parte do espectro de absor??o de raios X corresponde absor??o de raios X pr?xima ? borda de absor??o (XANES) e a outra estende ? espectroscopia da estrutura fina de absor??o (EXAFS). Estes materiais foram preparados pelo m?todo de combust?o. Os produtos obtidos da combust?o foram tratados termicamente por 9000C por 6 horas nesses materiais. Observou que a amostra LaCoO3 em temperatura ambiente e as amostras dopadas com C?lcio e B?rio na faixa de temperatura entre 50 K a 298 K apresentaram uma maior distor??o com simetria monocl?nica com grupo espacial I2/a. No entanto, a amostra dopada com B?rio nas temperaturas 50 K, 220 K e 260 K mostrou uma leve distor??o com simetria rombo?drica com grupo espacial R-3c. A estrutura La0,8Ca0,2CoO3 foi pouco sens?vel com a varia??o de temperatura, apresentando uma maior distor??o local no octaedro e uma maior desordem t?rmica local. Estas interpreta??es est?o de acordo com as informa??es estruturais eletr?nica na regi?o XANES e geom?trica na regi?o EXAFS