Made available in DSpace on 2014-10-09T12:54:39Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:07:58Z (GMT). No. of bitstreams: 0 / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Conselho Nacional de Desenvolvimento Científico e Tecnológico / This work aims to study the tribological behavior of two solid lubricant materials used in different conditions: nanoparticles as additives for lubrication fluids and self-lubricating sintered steels. The synthetic base oil with different concentrations and kinds of nanoparticles (MoS2 particles, MoS2 nanoflowers, carbon nanotubes+MoS2, silver nanoparticles) was extensively evaluated through tribological tests: ball on disk scuffing; ball on disk constant load (250 N, 20min. duration) and constant load (2N, 20min. duration) reciprocating linear sliding tests assessing friction coefficient. None of the nanoparticles affected the friction coefficient in a significant way. The nanoparticles were found to be an aggregated state. On the other hand, the effect of sintering temperatures (1100, 1150 and 1200 °C) and precursor content (0-5%) on the tribological behavior of self-lubricating sintered steels, produced by metal injection molding (MIM), was analyzed by using linear reciprocating sliding tests (constant load 7N, 60 min. duration). Solid lubrication effect was produced by in situ formation of graphite nodules due to the dissociation of precursor (SiC particles) during sintering. It was shown that presence of the graphite nodules significantly improved the friction coefficient and the wear rate of the alloys and that the sintering temperature little affected these parameters. Chemical analyses of the wear scars by scanning electron microscopy (SEM-EDX) and auger electron spectroscopy (AES) showed the presence of a tribolayer composed predominantly by carbon and oxygen. The graphite on the samples contributed to the formation of the tribolayer on the contact interface. It is suggested that during sliding graphite foils are removed from the in situ generated graphite nodules and remain at the interface thus contributing to the formation of the protective tribolayer. This tribolayer breaks up and forms during sliding and it is continuously replenished by graphite. Analyses of the wear scars showed the presence of plastic deformation traces on the samples and counter-bodies and the predominance of the wear mechanism by abrasion. Study of the influence of roughness surface showed that polishing the surfaces closed the graphite sources due to plastic deformation. This fact has resulted in a friction coefficient higher than 0.2, which means that, in this condition, this material does not act anymore as solid lubricant. / Este trabalho tem como objetivo estudar o comportamento tribológico de dois materiais lubrificantes sólidos usados em diferentes condições: nanopartículas como aditivos de lubrificantes fluidos e aços sinterizados autolubrificantes. O óleo sintético, com diferentes concentrações e tipos de nanopartículas (partículas MoS2, nanoflores de MoS2, nanotubos de carbono + MoS2, nanopartículas de prata), foi extensivamente avaliado por meio de testes tribológicos: pino sobre disco sob carga variável (scuffing) e constante (250N, durante 20 minutos) e deslizamento linear alternado (2N, durante 20 minutos). O coeficiente de atrito não apresentou alterações significativas com a presença das nanopartículas no óleo, sendo esse comportamento atribuído ao estado de aglomeração das mesmas. Por outro lado, o efeito da temperatura de sinterização (1100, 1150 e 1200 ° C) e do teor de precursor (0-5%) no comportamento tribológico dos aços sinterizados autolubrificantes, produzidos por moldagem de pós por injeção (MIM), foram analisados por meio de testes de deslizamento linear alternado sob carga constante (7N, durante 60 minutos). O efeito de lubrificação sólida foi produzido pela formação in situ de nódulos de grafita devido à dissociação do precursor (SiC) durante a sinterização. Foi mostrado que a presença de nódulos de grafita melhorou significativamente o coeficiente de atrito e a taxa de desgaste das ligas, e que a temperatura de sinterização pouco afetou estes parâmetros. As análises químicas das marcas de desgaste por microscopia eletrônica de varredura (SEM-EDX) e espectroscopia por elétron auger (AES) mostraram a presença de uma tribocamada composta predominantemente por carbono e oxigênio. Sugeriu-se que durante o deslizamento as folhas de grafita são removidas dos nódulos gerados in situ e permanecem na interface contribuindo assim para a formação da tribocamada protetora. Esta, por sua vez, rompe-se e forma-se durante o deslizamento sendo continuamente reabastecida pela grafita. As análises das marcas de desgaste das amostras e dos contra-corpos mostraram a presença de sulcos produzidos por deformações plásticas e a predominância do mecanismo de desgaste por abrasão. Estudos da influência da rugosidade superficial mostraram que as superfícies polidas apresentaram o fechamento das fontes de grafita devido à deformação plástica. Este fato deu origem a um coeficiente de atrito superior a 0.2, o que significa que, nestas condições, o material deixa de atuar como lubrificante sólido. / Doutor em Engenharia Mecânica

Made available in DSpace on 2014-10-09T12:54:39Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:07:58Z (GMT). No. of bitstreams: 0 / Os óleos lubrificantes automotivos durante o seu uso sofrem degradação parcial de compostos orgânicos e incorporam elementos inorgânicos indesejáveis. Estas substâncias tornam o óleo lubrificante usado classificado como perigoso e altamente tóxico. Assim, no que diz respeito à conservação ambiental, o consenso mundial é que a melhor solução para os óleos lubrificantes usados objetive no tratamento para a sua reutilização. Dentro deste contexto e visando o uso de uma tecnologia alternativa, neste trabalho foi proposto um estudo sobre a eficiência e a viabilidade técnica do processo de oxidação avançada (POA) por radiação gama para o tratamento de óleo lubrificante automotivo usado. Amostras de óleo lubrificante usado foram diluídas em concentrações variadas com peróxido de hidrogênio e água Milli-Q. Estas amostras foram submetida a um irradiador de Cobalto-60, tipo Gammacell, com as doses absorvidas de 100, 200 e 500 kGy. Os resultados das análises inorgânicas por fluorescência de raios X (WDXRF) mostraram que o tratamento proposto permite a remoção de elementos inorgânicos, principalmente enxofre, cálcio, ferro e níquel em níveis aceitáveis pela legislação ambiental para reuso destes óleos. Os resultados por cromatografia gasosa (CG/MS) mostraram que este tratamento, também, promove a degradação dos compostos orgânicos, formando principalmente, os compostos tridecano, 2-metil-naftaleno, trietilamina e uréia-tetrametil, os quais são de grande aplicação industrial. A análise multivariada, análise de Cluster (CA), confirmou que a aplicação POA é um tratamento promissor e viável para o reuso de óleo lubrificante usado. INORGANIC / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Demanding applications, as well as the push to eliminate the need for fossil-fuel based lubricants, create the need for the development of high-performance polymers. Polyphenylene Sulfide (PPS) is an example of a high-performance polymer and has a high service temperature, good dimensional stability, and excellent chemical resistance. However, it has a low impact strength and is very brittle in neat form. Another high-performance polymer, Polytetrafluoroethylene (PTFE), provides low friction in dry sliding conditions and can deposit polymer transfer films onto the counterface but exhibits high wear rates in neat form. To take advantage of the desirable characteristics of both polymers, PPS/PTFE-based composites were produced through the Injection Molding process. The individual disadvantages of these polymers were further improved by incorporating the following fillers: SCF, GO and CNT. The tribological performance under dry sliding conditions and two different loads were investigated as well as the microhardness and degree of crystallinity of the materials. The DSC results showed that the incorporation of reinforcements did not significantly alter the total degree of crystallinity in the material. PPS/PTFE and the composites have significantly lower specific wear rates and coefficient of friction values compared to neat PPS and PTFE. The composites have higher microhardness and friction coefficient values (60N and 100N) compared to PPS/PTFE. For both loads, composites SCFCNT, 5SCF and 10SCF had the lowest specific wear rates recorded where a synergistic effect between SCF and CNT has been observed. The filler loading content did not affect the friction performance of the composites in both loads. However, for composites with SCF as the only reinforcement, the increase in wt% content of SCF increased the specific wear rate at 60N and decreased the specific wear rate at 100N. SEM images of the pin surfaces show that the governing wear mechanisms in the polymer blend and composites are abrasive and adhesive wear. The reduction of the specific wear rate values is also accompanied by the improvement in the uniformity of the observed transfer film formation.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / As concentrações na exaustão e os fatores de emissão dos hidrocarbonetos policíclicos aromáticos (HPA) prioritários de um veículo a diesel e as suas respectivas concentrações no diesel usado durante os ensaios de emissão veicular foram determinados com a finalidade de estimar a contribuição dos HPA provenientes do combustível nas emissões. Os produtos da combustão foram coletados diretamente nas emissões brutas do escapamento, utilizando um sistema de amostragem a volume constante sem diluição dos gases da exaustão. Os HPA associados ao MP foram amostrados de forma estratificada, utilizando um impactador em cascata MOUDI e filtros de fibra de vidro como substratos, e os HPA em fase gasosa foram amostrados usando cartuchos de amberlite XAD-2. A concentração dos HPA no óleo lubrificante do motor também foi monitorada ao longo do tempo até a sua troca após 12.000 km de uso. Após a extração e tratamento das amostras, a identificação e quantificação dos HPA foram realizadas, utilizando cromatografia de fase gasosa acoplada à espectrometria de massas (CG-EM) com injetor de grande volume de vaporização com a temperatura programável (PTV-LVI). Cinco variáveis do PTV-LVI foram otimizadas, utilizando planejamento de experimentos, o que permitiu obter limites de detecção menores do que 2,0 g L-1. Somente 7 dos 16 HPA prioritários foram identificados na exaustão: NAP, ACY, ACE, FLU, FEN, FLT e PYR. Os ensaios de emissão veicular foram realizados com o veículo em modo estacionário, sem aplicação de carga e com baixa velocidade de rotação do motor (1500 rpm), utilizando um diesel com menor teor de enxofre (10 mg kg-1) e com 5% v/v de biodiesel. Esses fatores possivelmente contribuíram para reduzir as emissões dos outros 9 HPA a valores abaixo dos limites de detecção do método desenvolvido. Aproximadamente 80% da massa dos HPA totais associados ao MP estavam presentes em partículas com tamanho entre 1,0 m e 56 nm, e aproximadamente 4,5% estavam presentes em partículas menores do que 56 nm. Partículas menores que 2,5 m são facilmente inaladas e depositadas no trato respiratório e na região alveolar, justificando a preocupação com relação às emissões de HPA associados a partículas provenientes da exaustão veicular de motores a diesel. Somente 5 dos 7 HPA identificados na exaustão foram detectados no diesel: NAP, ACY, FLU, FEN e PYR. A razão entre os fatores de emissão (g L-1diesel) dos HPA na exaustão e suas respectivas concentrações do diesel (g L-1) variaram de 0,01 0,02 a 0,05 0,029, dependendo do HPA. Esses valores indicam que pelo menos 95 a 99% dos HPA identificados no diesel foram destruídos e/ou transformados em outros compostos durante a combustão, e/ou foram retidos no reservatório do óleo lubrificante. Por outro lado, os HPA que tiveram maiores concentrações no diesel também apresentaram maiores fatores de emissão, o que sugere que os HPA provenientes do diesel possuem uma contribuição significativa para as emissões dos HPA totais. O perfil dos HPA prioritários no óleo lubrificante mostrou-se semelhante ao perfil dos HPA no diesel e nas emissões totais, onde o NAP, FEN e PYR foram os HPA majoritários / A diesel vehicle exhaust concentrations and emission factors of priorities polycyclic aromatic hydrocarbons (PAHs) and their respective concentrations in the diesel fuel used during the vehicle emissions testing were determined in order to estimate the fuel PAHs contribution to vehicle emissions. Combustion products are collected directly from the raw vehicle exhaust using a constant volume sampling system that does not employ exhaust products dilution. The particle-phase PAHs were sampled in stratified way using a Micro-orifice Uniforme Deposite Impactor (MOUDI) and glass fiber filter as substrates and the gas-phase PAHs were sampled using Amberlite XAD-2 cartridge. The PAHs concentrations in the engine lubricant oil were also monitored over time until its change after 12,000 km of use. After sample extractions and treatments, the PAHs identification and quantification were performed using gas chromatography coupled with mass spectrometry (GC-MS) and programmable temperature vaporization large volume injection (PTV-LVI). Five PTV parameters were optimized using statistical design experiments, which allowed to be obtained detection limits below 2.0 g L-1. Only 7 of 16 priority PAH were identified in exhaustion: NAP, ACY, ACE, FLU, FEN, FLT and PYR. The vehicle emission tests were carried out with the vehicle in stationary mode, without load, low engine speed (1500 rpm), using diesel fuel with lower sulfur (10 mg kg-1) and 5% v/v biodiesel. These factors may have contributed to reduce the other 9 PAH emissions to values below the detection limits of the method developed. Approximately 80% of the PAHs total mass associated with the particulate matter were present in particle size between 1.0 m and 56 nm and approximately 4.5% were present in particles smaller than 56 nm. Particles smaller than 2.5 m are easily inhaled and deposited in the respiratory tract and in the alveolar region, justifying the concern about PAHs emissions associated with particles from vehicle exhaust diesel engine. Only 5 of the 7 PAHs identified in exhaust were detected in diesel fuel: NAP, ACY, FLU, PHE and PYR. The ratio between the PAHs emission factors in exhaust (g L-1 diesel) and their respective concentrations in diesel fuel (g L-1) ranged from 0.01 0.02 a 0.05 0.029, depending on the PAH. These values indicate that al least 95 to 99% of the PAH identified in diesel fuel were destroyed and/or converted into other compounds during the combustion, and/or been retained in lubricant oil reservoir. On the other hand, PAHs that had higher concentration in diesel also had higher exhaust emission factors, which suggests that the PAH from diesel have a mean contribution to total PAHs emissions. The PAH priority profile in lubricant oil was similar to PAH profile in diesel and in vehicle exhaust, where the NAP, FEN and PYR were the majorities PAHs

Submitted by Silvana Teresinha Dornelles Studzinski (sstudzinski) on 2017-02-08T14:57:22Z No. of bitstreams: 1 Ilana Freitas Freire de Carvalho Cairo Flores_.pdf: 1493935 bytes, checksum: 9c28f8d3ccd4c6f5e5d0ec03d527cc98 (MD5) / Made available in DSpace on 2017-02-08T14:57:22Z (GMT). No. of bitstreams: 1 Ilana Freitas Freire de Carvalho Cairo Flores_.pdf: 1493935 bytes, checksum: 9c28f8d3ccd4c6f5e5d0ec03d527cc98 (MD5) Previous issue date: 2016-07-28 / Nenhuma / A promulgação da Política Nacional de Resíduos Sólidos – PNRS realinhou o cenário do saneamento básico brasileiro, com atribuições atreladas a todos os envolvidos no ciclo de vida do produto. Como instrumento de planejamento para esta política, destacam-se os planos de resíduos sólidos, obrigatórios inclusive para captação de recurso federal. Salienta-se que a PNRS determina que os sistemas de logística reversa devem ser executados pela cadeia produtiva dos materiais, porém compete aos gestores públicos, a fiscalização e monitoramento dos mesmos. Assim, este estudo buscou analisar a implementação, por todos os envolvidos na cadeia, das rotinas de logística reversa das embalagens plásticas de óleos lubrificantes na Bacia Hidrográfica do Rio dos Sinos. Para alcançar o objetivo proposto, a pesquisa foi subdividida em etapas. Inicialmente, as metas estipuladas no Acordo Setorial foram analisadas de modo comparativo com as metas propostas nos planos inerentes a PNRS, sendo eles: plano nacional, estadual do Rio Grande do Sul, Regional e 26 planos municipais. A seguir, como a ênfase desta pesquisa permeou o estudo da responsabilidade compartilhada no sistema de logística reversa de embalagens plásticas de óleos lubrificantes (SLREPOL), foi possível conhecer o comportamento dos diversos atores envolvidos neste sistema. Por fim, a efetividade da responsabilidade compartilhada foi avaliada a partir da reflexão sobre o comportamento dos diversos atores envolvidos no sistema de logística reversa e o papel estipulado na legislação vigente. Os diversos atores foram estudados utilizando-se das técnicas de entrevistas com gestor público estadual da FEPAM e do MMA, representante da empresa de coleta das embalagens plásticas; visitas técnicas à Central de Triagem e empresa recicladora; envio por email de 26 questionários aos municípios do Pró-Sinos (com 39% de retorno); e, aplicação de 143 formulários em pontos geradores de embalagens. Os municípios foram divididos em grupos de acordo com o impacto, devido à quantidade de pontos geradores de embalagens (PGE). Foi possível concluir que não ocorre diálogo entre Estado e Municípios, quanto à temática logística reversa de embalagens plásticas de óleos lubrificantes. A fiscalização e monitoramento do sistema são pontuais e esporádicos, e ainda não ocorrem em todo o comércio varejista de óleos lubrificantes. Após 15 anos, o SLREPOL ainda não é obrigatório em todos os estabelecimentos geradores de embalagens plásticas de óleos lubrificantes na área estudada. / The enactment of the National Solid Waste Policy - PNRS realigned the scene of Brazil's basic sanitation, with responsibilities linked to everyone involved in the product life cycle. As a planning tool for policy, we highlight the plans of solid waste, including mandatory for federal fund raising. Please note that the PNRS determines that the reverse logistics systems must be performed by the supply chain of materials, but it is for the public managers, supervision and monitoring of the same. This study sought to examine the implementation by all involved in the chain of reverse logistics routines of plastic packaging of lubricating oils in the basin of the Rio dos Sinos. To achieve the proposed objective, the research was divided into stages. Initially, the goals stipulated in the Sectoral Agreement were analyzed comparative way with the goals proposed in the plans inherent in PNRS, namely: national, state of Rio Grande do Sul, regional and 26 municipal plans. Next, as the emphasis of this research permeated the study of shared responsibility in the reverse logistics system of plastic packaging of lubricating oils (SLREPOL), it was possible to know the behavior of the various actors involved in this system. Finally, the effectiveness of shared responsibility was evaluated from the behavior of the reflection of the various actors involved in the reverse logistics system and the role stipulated by law. The various actors were studied using the techniques of interviews with state public manager FEPAM and the MMA, representative collection company of plastic packaging; technical visits to the Screening Center and recycling company; e-mailing questionnaires to 26 municipalities of the Pro-bells (39% return); and application of 143 forms in packs of generating points. The municipalities were divided into groups according to the impact due to the amount of packaging generator points (PGE). It was possible to conclude that there is dialogue between the state and municipalities, as the theme reverse logistics plastic packaging of lubricating oils. The inspection and monitoring system are occasional and sporadic and does not occur throughout the retail sale of lubricating oils. After 15 years, the SLREPOL is not binding in the generating facilities of plastic packaging of lubricating oils in the study area.

Submitted by Rosina Valeria Lanzellotti Mattiussi Teixeira (rosina.teixeira@unisantos.br) on 2017-12-15T11:51:10Z No. of bitstreams: 1 Rafael de Moura Campos.pdf: 942118 bytes, checksum: 8c503d67f06f1991c956c4e67107c613 (MD5) / Made available in DSpace on 2017-12-15T11:51:15Z (GMT). No. of bitstreams: 1 Rafael de Moura Campos.pdf: 942118 bytes, checksum: 8c503d67f06f1991c956c4e67107c613 (MD5) Previous issue date: 2017-10-26 / This dissertation proposes to analyze the reverse logistics of used or contaminated lubricating oil within the scope of the national solid waste policy, against the background of the economic analysis of the law regarding the efficiency of legislation relevant to the achievement and effectiveness of logistics lubricant oil used or contaminated. Beginning with the conceptualization of economic analysis of law, a free translation of the law and economics movement, which aims to study legal events under certain economic principles, notably that of efficiency, according to the economists of the movement. Beginning with some mandatory definitions in the field of environmental law, through sustainable development, the national solid waste policy and the polluter pays and protector-receiver principles, through the practical example in which the reverse logistics of the used lubricating oil itself or already occurred even before the validity of the national solid waste policy, and as a result of the mandatory reverse logistics of that waste. The aforementioned case analysis shows, supported by an executive interview of the company that provided the example paradigm, evidence in a practical way that the economic efficiency, which can be equated with the financial viability, of a given transaction can transcend the legal determination. The research will be based on indirect documentation. There will be documentary and bibliographic research, including Internet research. In the work the hypothetical-deductive method will be used with the construction of conjectures based on the hypotheses, that is, they can be confirmed or not in the final considerations. / Esta dissertação propõe-se a analisar a logística reversa do óleo lubrificante usado ou contaminado no âmbito da política nacional de resíduos sólidos, tendo como pano de fundo a análise econômica do direito no que tange à eficiência da legislação pertinente para a consecução e eficácia da logística reversa do óleo lubrificante usado ou contaminado. Começando pela conceituação da análise econômica do direito, tradução livre do movimento ¿law and economics¿, que visa estudar os eventos jurídicos sob a égide de determinados princípios econômicos, notadamente o da eficiência segundo assim entendimento pelos economistas do movimento. Iniciando com algumas definições obrigatórias na seara do direito ambiental, passando pelo desenvolvimento sustentável, a política nacional de resíduos sólidos e os princípios do poluidor-pagador e de protetor-recebedor, através do exemplo prático em que a logística reversa do próprio óleo lubrificante usado ou contaminado já ocorria mesmo antes da vigência da política nacional de resíduos sólidos, e por consequência da obrigatoriedade da logística reversa daquele refugo. A mencionada análise de caso mostra, lastreada por entrevista de executivo da companhia que forneceu o exemplo paradigma, evidência de forma prática que a eficiência econômica, que pode ser equiparada com a viabilidade financeira, de determinada operação pode transcender a determinação legal. A pesquisa se baseará na documentação indireta. Haverá pesquisa documental e bibliográfica, incluindo também a pesquisa na Internet. No trabalho se empregará o método hipotético-dedutivo com a construção de conjecturas baseada nas hipóteses, ou seja, podem ser confirmadas ou não nas considerações finais.

L’objectif de ce travail est d’utiliser les nanoparticules (NPs) de nanosondes fluorescentes de température en particulier dans les films lubrifiants. Le développement de ces nanosondes nécessite la détermination de leurs sensibilités thermiques afin de pouvoir sélectionner les NPs les plus prometteuses. Pour atteindre cet objectif, nous avons présenté deux méthodes d’élaboration utilisées pour la synthèse des nanostructures à base de SiC-3C, la méthode d’anodisation électrochimique et la méthode d’attaque chimique. Dans le premier cas, les analyses FTIR,RAMAN et MET des NPs finales ont montré que la nature chimique de ces NPs est majoritairement formée de carbone graphitique. L’étude détaillée de la photoluminescence de ces NPs a montré que le processus d’émission dépend de la chimie de surface des NPs, du milieu de dispersion et de sa viscosité, de la concentration des suspensions et de la température du milieu. Pour la deuxième famille de NP de SiC, les analyses cohérentes MET, DLS et PL ont montrées une taille moyenne de 1.8 nm de diamètre avec une dispersion de ±0.5nm. Le rendement quantique externe de ces NPs est de l’ordre de 4%. Les NPs dispersées dans l’éthanol, n’ont pas montré une dépendance à la température exploitable pour notre application. Par contre, les NPs de SiC produites par cette voie, étant donné la distribution en taille resserrée et le rendement quantique « honorable » pour un matériau à gap indirect, sont prometteuses pour des applications comme luminophores en particulier pour la biologie grâce à la non toxicité du SiC. Dans le cas des NPs de Si, nous avons également étudié deux types différents de NPs. Il s’agit de : (i) NPs obtenues par anodisation électrochimique et fonctionnalisées par des groupements alkyls (décène, 1-octadécène). Nous avons mis en évidence pour la première fois une très importante variation de l’énergie d’émission dEg/dT avec la température de type red-shift entre 300 et 400K. Les mesures de(T) conduisent à une sensibilité thermique de 0.75%/°C tout à fait intéressante par rapport aux NPs II-VI. De plus il a été montré que la durée de vie mesurée n’est pas fonction de la concentration. (ii) NPs obtenue par voie humide et fonctionnalisées par le n-butyl. Pour ce type de NPs nous avons mis pour la première fois en évidence un comportement de type blue-shift pour dEg/dT de l’ordre de -0.75 meV/K dans le squalane. Pour ces NPs, la sensibilité thermique pour la durée de vie de 0.2%°C est inférieure à celle des NPs de type (i) mais largement supérieure à celle des NPs de CdSe de 4 nm (0.08%/°C). La quantification de cette la sensibilité à la température par la position du pic d’émission dEg/dT et de la durée de vie nous permet d’envisager la conception de nanosondes de température basée sur les NPs de Si avec comme recommandations l’utilisation de NPs obtenues par anodisation électrochimique et de la durée de vie comme indicateur des variations en température. / The goal of this study is the use of Si and SiC nanoparticles (NPs) as fluorescent temperature nanoprobes particularly in lubricating films. The development of these nanoprobes requires the determination of their thermal sensitivity in order to select the best prospects NPs. To achieve this goal, we presented two preparation methods used for the synthesis of 3C-SiC based nanostructures : (i) anodic etching method and (ii) chemical etching method. In the first case, the FTIR, Raman and TEM analysis of final NPs showed that the chemical nature of these NPs is formed predominantly of graphitic carbon. The detailed photoluminescence study of these NPs showed that the emission process depends on the surface chemistry of the NPs, the dispersion medium and its viscosity, the suspension concentration and temperature of the environment.. In the second case, coherent TEM, DLS and PL analyzes showed an average size of 1.8 nm in diameter with a dispersion of ±0.5 nm. The external quantum efficiency of these NPs is 4%. NPs dispersed in ethanol, did not show an exploitable fluorescence dependence on temperature for our application. On the other hand, 3C-SiC NPs produced by this way, given the narrow size distribution and the reasonably high quantum yield for an indirect bandgap material, are promising for applications such as luminophores in particular in the biology field thanks to nontoxicity of SiC. In the case of Si we studied also two different types of NPs. (i) NPs obtained by anodic etching and functionalized by alkyl groups (decene, octadecene). We have demonstrated for the first time an important red-shift in the emission energy dEg/dT with temperature from 300 to 400K. The PL lifetime measurement(T) lead to a thermal sensitivity of 0.75% /°C very interesting compared to II-VI NPs. Furthermore it has been shown that t is not depending on the concentration. (ii) NPs obtained by wet-chemical process and functionalized with n-butyl. For this type of NPs we have identified for the first time a blue-shift behavior of dEg dT in the order of -0.75 meV/K in squalane. The thermal sensitivity for the PL lifetime of these NPs is 0.2%/°C, which is lower than that of NPs obtained by anodic etching method, but much greater than that of CdSe NPs with 4 nm of diameter (0.08%/°C). Quantification of the temperature sensitivity by the position of emission peak dEg/dT and the PL lifetime dτ/dT allows us to consider the realization of temperature nanoprobes based on Si NPs with recommendations to use Si NPs obtained by anodic etching method and PL lifetime as an indicator of temperature changes.

Målet med detta arbete är att undersöka smörjsystemet på två utsatta leder på en Boomer E2C. Förfrågan om examensarbetet kommer från Atlas Copco Rock Drills AB i Örebro som också tillverkar maskinen. Atlas Copco Rock Drills AB har idag ett fettsmörjningssystem som upprätthåller funktionerna på lederna. Uppgiften är att sammanfatta och utvärdera dagens system samt att finna nya lösningsförslag som skulle kunna ersätta eller delvis ersätta systemet. Information har hämtats från dokumentation, ritningar och samtal med konstruktörer på företaget. Efter att alla förutsättningarna för lederna specificerats så har lösningsförslag sökts. Genom att träffa lagerleverantörer och söka artiklar så har idéer formats. Brainstorming har använts för att kunna se nya lösningar. Undersökningen har visat att det finns problem med dagens lösning vad gäller slanghaverier och driftstopp i fält. Atlas Copco AB uttrycker även att kunskapen och dokumentationen angående systemet är otillräckligt. Efter artikelsökning så kan konstateras att forskningen och kunskapen på området med tungt belastade, oscillerande och fettsmörjda leder är liten. Dimensionering sker ofta med hjälp av erfarenhet och med tankesättet ”det har fungerat förut”. När lösningsförslagen har jämförts så har detta gjorts genom att använda metoden AHP (Analytic Hierachy Process). Med denna metod så jämför man kriterierna från kravspecifikationen med lösningsförslag så att man matematiskt kan räkna fram ett vinnande lösningsförslag. Resultatet visar att en smörjfri lösning skulle teoretiskt vara att föredra. Denna skulle tillverkas av en modern polymer och kompletteras med en inre tätning och ett yttre skydd. Atlas Copco rekommenderas att testa de olika förslagen för att komma fram till vilken som är bäst lämpad för applikationen. / The goal of this work is to investigate the lubrication system on two exposed joints on a Boomer E2C. The request for the thesis comes from Atlas Copco Rock Drills AB, Örebro, which also manufactures the machine. Today Atlas Copco Rock Drills AB has a grease lubrication system that secures the function of the joints. The task is to summarize and evaluate the current systems and to find new solutions that would be able to replace or partially replace the current system. Information was gathered from documents, construction drawings and conversations with engineers at the company. Solutions and ideas have been formed by meeting stock suppliers and searching for articles. Brainstorming has been used in order to find new solutions. The investigation has shown that there are problems with the current solution in terms of hose failures and downtime in the field. Atlas Copco AB also expresses that there is a lack of documentation and knowledge regarding the lubrication system. After the various article searches it became clear that research and knowledge in the area with heavy duty, oscillating and grease lubricated joints is insufficient. The design is often done with the help of experience and with the mindset "it has worked before." When the solutions and ideas have been compared, this has been done by using AHP (Analytic Hierarchy Process). This method compares the criteria that must be fulfilled by the solutions and then calculates the best one. The results show that a lubrication-free solution would theoretically be preferable. This would be produced by a modern polymer and supplemented with an inner seal and an outer protection. Atlas Copco is recommended to test the various proposals to be able to decide which the best solution for the application is.

Submitted in partial fulfillment of the academic requirements for the Masters degree in Technology, Chemistry department, Durban University of Technology, Durban, South Africa, 2015. / The focus of most lubricating grease testing has been based on performance and appearance rather than determining the concentration of chemical components. The primary reason being lubricating grease is a difficult matrix to work with from the perspective of the analytical laboratory. The purpose of this study was to develop a simple, reproducible method for elemental determination in lubricating grease and to apply the developed method to work out a flushing procedure for the filling lines in a grease manufacturing plant. The first part of the experimental work focused on developing a suitable and efficient sample preparation technique. Three techniques were explored: direct dilution, microwave assisted acid digestion and emulsification. Direct dilution involved shear mixing the lubricating grease with metal free base oil and diluting it with an organic solvent. Use of these solvents caused plasma destabilization or even plasma extinction and their use posed health risks for laboratory personnel. Microwave digestion involved mineralising the lubricating grease using an optimised microwave assisted acid digestion procedure. In the third sample preparation technique, microemulsions were formed by mixing the lubricating grease with a relatively small volume of a strong mineral acid mixture followed by the surfactant (triton X-100) at room temperature and pressure (RTP). This approach does not require the destruction of the organic matter or the use of large amounts of organic solvents. For all three techniques the sample was subsequently analysed for Al, B, Ba, Ca, Li, Na, S, Mo and Zn. All analysis was performed using an Optima ICP-OES with previously optimised parameters. The direct dilution method gave the most inconsistent results with relative standard deviation (RSD) as high as 56% for calcium, 79% for boron and 66% for lithium. Microwave digestion and emulsification gave comparable results, with the calibration curves of oil emulsions not differing significantly from aqueous ones. For microwave assisted acid digestion the limits of detection ranged from 0.028 mg/L for sodium to 0.255 mg/L for boron. Correlation coefficient values (r2) of all the elements were greater than 0.99. Likewise the limits of detection for emulsification ranged from 0.03 mg/L for aluminium to 0.37 mg/L for sulphur. The correlation coefficients for all the elements were greater than 0.99 and this indicates that the calibration curves were sufficient for analysing the digested grease samples. Five quality assurance samples were analysed using both methods and in addition a t-test performed at the 99.9% confidence level and 4 degrees of freedom showed that the two sample preparation techniques gave similar results. Emulsification has several advantages over microwave digestion technique and superior analytical performance over direct sample dilution using solvents, and hence was chosen as the method of choice for routine analysis of lubricating grease. The second part of the experimental work focused on developing a flushing procedure for filling lines in a lubricating grease plant. A flushing procedure is essential in order to minimise waste, which will in turn minimise production costs and avoids incurring disposal costs. In this series of experiments, the microwave digestion sample preparation technique was utilised for the subsequent determination of the flushing mass required in between product changes. The flushing procedure was implemented and monitored by the use of statistical quality control tools for a specified period of time, and as indicated by Shewart Control charts, the process was in statistical control.