A maior parte de toda a energia consumida no mundo provém do petróleo, carvão e gás natural (87% da matriz energética mundial). No entanto, essas fontes não renováveis possuem previsão de esgotamento em um futuro próximo. Além disso, são poluidores, afetando o meio ambiente, motivando a sociedade buscar fontes alternativas para mitigar esses problemas. O biodiesel, como alternativa de combustível, começou a ser estudado em 1937, e hoje mostra ser uma alternativa eficiente e não poluidora à utilização do diesel mineral. O estudo presente foi realizado com amostras de biodieseis obtidos utilizando catalisadores enzimáticos. Essa rota vem sendo investigada no país por diversos pesquisadores, e vem mostrando que o uso da enzima como catalisador minimiza os problemas relativos às etapas finais de purificação do biodiesel, pois reduz a ocorrência das reações indesejáveis de saponificação e permite uma simplificação e redução dos custos dos processos pela diminuição do número de operações associadas. Para ser um substituto, o biodiesel precisa se enquadrar em normas, no caso do Brasil, a resolução nº 42 da ANP (Agência Nacional de Petróleo, Gás Natural e Biocombustíveis) de 2004. Além disso, deve possuir qualidades que viabilize a sua substituição. Esse trabalho tem o objetivo de realizar o estudo térmico utilizando a Termogravimetria (TG) e a Calorimetria Exploratória Diferencial (DSC) dos biodieseis de babaçu, palma e sebo bovino obtidos pela rota enzimática e suas respectivas matérias-primas. Com os resultados da TG em atmosfera Inerte, foi possível analisar a volatilidade desses biodieseis, e também verificar o seu enquadramento no parâmetro de destilação da resolução nº 42 da ANP. A TG em atmosfera oxidativa possibilitou comparar esses biodieseis em relação às suas estabilidades termo-oxidativas. Também foram realizados o Estudo Cinético das curvas TG, visando o valor da energia de ativação das primeiras etapas de cada curva, utilizando o modelo matemático Ozawa. O estudo cinético das curvas TG em atmosfera de nitrogênio mostrou que a energia de ativação e a temperatura de inicio da degradação têm uma relação direta. / Most of all energy consumed worldwide comes from oil, coal and natural gas (87% of global energy production). However, these non-renewable resources are expected to exhaust in the near future. Moreover, they are polluters, affecting the environment, prompting the company to seek alternative sources to mitigate these problems. Biodiesel as alternative fuel, that began to be studied in 1937 and today has proved an efficient and non-polluting alternative to the use of mineral diesel. The present study was performed with babassu, palm and tallow biodiesel obtained using enzymatic catalysts. This route has been investigated by several researchers in the country, and has shown that the use of enzyme as catalyst minimizes the problems related to the final stages of purification of biodiesel, it reduces the occurrence of undesirable reactions of saponification and allows for simplification and cost reduction processes by reducing the number of associated operations. To be a substitute, biodiesel must fit in standards, in the case of Brazil, the resolution No. 42 of the ANP (National Agency of Petroleum, Natural Gas and Biofuels), 2004. Also this biofuel must posses qualities thet might allow the replacement. This work aims to realize the thermal studies using thermogravimetry (TG) and Differential Scanning Calorimetry (DSC) of babassu, palm and tallow biodiesel obtained by enzymatic route and also their raw materials. With the results of TG in an inert atmosphere, it was possible to analyze the volatility of biodieseis, and also check your guidelines on the parameter of the distillation of Resolution No. 42 of the Brazilian Petroleum Agency (ANP). The TG analysis of biodiesel in oxidative atmosphere turns possible to study their thermo-oxidative stabilities. Also, it was performed a kinetic study of the TG curves, seeking the value of activation energy of the first steps of each curve, using the mathematical model Ozawa. The kinetic study of the TG curves in nitrogen atmosphere showed that the activation energy and temperature of the beginning of degradation have a direct relationship.

Orientador: João Sinézio de Carvalho Campos / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-19T08:39:45Z (GMT). No. of bitstreams: 1 Bento_RonaldoEuzebio_M.pdf: 1080016 bytes, checksum: c783e50a51346a7d89eb82f52976eb49 (MD5) Previous issue date: 2011 / Resumo: Esse trabalho concentra os estudos na investigação das propriedades de resistência a tração e alongamento do compósito de Politetrafluoretileno (PTFE) com 60% de bronze após a substituição do tipo de PTFE utilizado na formulação desse compósito. Atualmente esse compósito utiliza PTFE convencional na formulação e o objetivo é alterar para PTFE modificado. A motivação para essa alteração deveu-se ao fato que o PTFE convencional apresenta disponibilidade limitada dificultando o desenvolvimento dos segmentos que utilizam os compósitos de PTFE com 60% de bronze. A escolha do PTFE modificado para a substituição do PTFE convencional na formulação do compósito de PTFE com 60% de bronze deveu-se ao fato que polímero puro de PTFE modificado apresenta propriedades mecânicas e químicas superiores ao polímero puro de PTFE convencional, além de não apresentar limitações de disponibilidade, possibilitando a continuidade do crescimento dos segmentos industriais. A escolha do compósito de PTFE com 60% de bronze deveu-se ao fato que essa formulação é a mais empregada no segmento automobilístico para a fabricação de anéis para amortecedores e retentores. Após a substituição da resina de PTFE, os resultados demonstraram que o compósito de PTFE modificado com 60% de bronze apresentou propriedades inferiores ao compósito fabricado com PTFE convencional. A queda dessas propriedades pode estar relacionada com possíveis micros fissuras na estrutura do compósito em virtude de ar preso durante o processo de fabricação / Abstract: This work focuses on research studies of the properties of tensile strength and elongation of the composite of Polytetrafluoroethylene (PTFE) with 60% bronze after replacing the type of PTFE used in the formulation of this compound. Currently, this composite uses conventional PTFE in the formulation and the objective is to change to modified PTFE. The motivation for this change was due to the fact that the conventional PTFE has limited availability hindering the development of the segments that use the PTFE composite with 60% bronze. The choice of PTFE modified PTFE to replace the conventional formulation of the composite with 60% PTFE bronze was due to the fact that pure polymer modified PTFE has superior mechanical and chemical properties of the pure polymer PTFE conventional, and not present availability limitations, enabling the continued growth of industries. The choice of the composite with 60% PTFE bronze due to the fact that this formulation is the most used in the automotive sector for the manufacture of rings and seals for shock absorbers / Mestrado / Ciencia e Tecnologia de Materiais / Mestre em Engenharia Química

Orientador: Marco Aurelio Cremasco / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-21T16:19:52Z (GMT). No. of bitstreams: 1 Oliveira_CarlosEduardoLimade_M.pdf: 2139178 bytes, checksum: a60210b4b807de0c845fa8804f6ebb27 (MD5) Previous issue date: 2012 / Resumo: As espécies vegetais Lippia gracilis, popularmente conhecida como "alecrim-da-chapada" ou "alecrim-de-tabuleiro", são arbustos caducifólios, ramificados, com caule quebradiço, de até 2 m de altura...Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital / Abstract: The plant species Lippia gracilis, popularly known as "alecrim-da-chapada" or "alecrim-de-tabuleiro", are deciduous shrubs, branched, with brittle stems, up to 2 m tall. Belong to the family Verbenaceae and are widely distributed in America and Africa, mainly in tropical countries. ...Note: The complete abstract is available with the full electronic document / Mestrado / Engenharia de Processos / Mestre em Engenharia Química

Two different research projects were investigated for this thesis, which has consequently been presented in two parts. PART 1 An attempt has been made to improve the high temperature performance of phenol-formaldehyde thermosets by modification of their structure with inorganic phosphate groups. Transesterification of tri-phenyl phosphate with resorcinol has given a resorcinol phosphate resin, which cured with hexamethylenetetramine. A pilot scale batch of this resin has been made and used in high temperature stability studies. Post-cured resorcinol phosphate resin-chrysotile asbestos (30: 70) moulded bars retained 59.5% of their flexural strength after ageing at 523K for 1000 hr in air. Similar phenol-formaldehyde composite bars aged under identical conditions retained only 5.3% of their initial flexural strength. The utility of the resorcinol phosphate resin composite as a commercial product is limited, since the bars had a much lower initial flexural strength (30.85 MNm-2) than the phenol-formaldehyde resin composite bars (108.5 MNm-2). Thermogravimetry and isothermal heating studies have indicated that the degradation of resorcinol phosphate resin was greatly accelerated by chrysotile asbestos, which may catalyse a bond re-organisation process that has been tentatively proposed as a mechanism for the fragmentation of the resin. PART 2 Recently an ionomer dental cement (ASPA), prepared from aqueous poly(acrylic acid) and an ion-leachable aluminosilicate glass, has been developed. The system has been extended by studying other aqueous polymers. The factors influencing the gelation and the properties of the set cements have been examined. Poly(carboxylic acids) with hydrophobic, or no pendant substituents were found to be the most satisfactory polymers for preparing water stable cements. To study the influence of the nature of the cation and polymer structure on the gelation and water stability of ionomer cements, a wide range of metal oxide-polyacid products have been studied. The formation of water stable cements depended markedly on the type of oxide and polyacid employed and appeared to involve factors such as the co-ordination geometry and radius of the cation and the nature of the cation-polyanion bonding in the matrix. A comparison between the water stabilities of ASPA cement and poly(acrylic acid)-CaO, Al2O3, or Al(OH)3 cements has shown that the chemistry of ASPA cement is more complex than has been hitherto reported. Stability constants have been determined for Ca 2+ and Cd 2+ with poly(acrylic acid) and ethyl ethylene-maleic acid copolymer by a potentiometric titration method developed by Gregor and modified by Mandel and Leyte. The stability constants obtained in 1.0M NaNO3 at 298.2 ± 0.2K were: for poly(acrylic acid), with Cat2+, log b1 Ca2+ PAA ~ -3.35 with Cd2+, log Bav Cd2+ PAA = -2.30 for ethylene-maleic acid copolymer, with Cat2+, log b1 CA2+ EMA ~ -4.05 with Cd2+, log Bav Cd2+ EMA = -1.95 The log b1 values probably had little precise meaning, although to a first approximation, log b1 Ca2+ PAA > log b1 Ca2+ EMA The determined stability constants have been used with limited success in predicting the water stabilities of the corresponding metal oxide-polyacid cements.

Submitted by Haroudo Xavier Filho (haroudo.xavierfo@ufpe.br) on 2016-04-14T17:04:05Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação_Taynara_Lins.pdf: 2092995 bytes, checksum: 279f65308ce3391337c22f33dbbe9243 (MD5) / Made available in DSpace on 2016-04-14T17:04:05Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação_Taynara_Lins.pdf: 2092995 bytes, checksum: 279f65308ce3391337c22f33dbbe9243 (MD5) Previous issue date: 2015-02-25 / CNPq / Este estudo teve como finalidade desenvolver metodologias analíticas para os estudos de caracterização do estado sólido do fármaco atorvastatina cálcica e, também, das suas dispersões sólidas pelas correlação das técnicas difratometria de Raios X (DRX), espectroscopia de infravermelho (FTIR) e analise térmica (DSC e TG). A atorvastatina cálcica (ATC) é um agente redutor de lipídios sintético, que já tem muitos polimorfos relatados na literatura. No estudo de caracterização no estado sólido do fármaco, foram obtidos cristais da ATC com solventes de graus de polaridade diferentes e foi observado que os solventes clorofórmio, etanol e metanol levaram a formação de uma estrutura cristalina mais amorfa, e essa alteração estrutural foi perceptível no FTIR com alteração na banda do estiramento da hidroxila e pelos dados de DSC como diminuição da entalpia e desaparecimento do pico de fusão. Enquanto que, solventes éter e acetato de etila não levaram a mudança no habito cristalino quando comparado com o fármaco antes do processo de recristalização. As dispersões sólidas foram feitas com 5 surfactantes diferentes (carbopol®, hidroxipropil metil celulose (HPMC), lauril sulfato sódio, polietileno glicol (PEG) 6000 e carbopol-ultrez® 20) e pela correlação do dados DRX, FTIR e DSC foi visto que a dispersão com carbopol-utlrez foi a que apresentou grande interação com mudanças nas banda de absorção e desaparecimento do pico de fusão. Ao avaliarmos a estabilidade das dispersões por termogravimetria, observou-se que todas elas tinham menor estabilidade que a ATC. Esses resultados apontam para a utilidade de técnicas de análise térmica como uma ferramenta de triagem relevante para a caracterização do estado sólido durante o desenvolvimento de formulação. Através da análise multivariada foi possível estabelecer a correlação entre a técnicas estudadas mostrando a relevância da utilização destas na avaliação dos parâmetros de controle qualidade de processos e produtos farmacêuticos. / This study aimed to develop analytical methods for the characterization studies of solid state drug atorvastatin calcium and also their solid dispersions by the correlation of techniques: X-ray diffraction (XRD), infrared spectroscopy (FTIR) and thermal analysis (DSC and TG). The atorvastatin calcium (ATC) is a reducing agent synthetic lipids, which already has many polymorphs reported in the literature. In the characterization studies in the solid state of the drug, ATC crystals were obtained with different degrees of polarity solvent and it was observed that the solvents chloroform, ethanol and methanol led to formation of a more amorphous crystal structure, and this structural change was noticeable in FTIR with changes in the band of the hydroxyl stretch and by the DSC data as decreased enthalpy and disappearance of the melting peak. While, ether and ethyl acetate solvents did not lead to change in the crystal habit when compared with the drug before the recrystallization process. Solid dispersions were made with 5 different surfactants (Carbopol®, hydroxypropyl methyl cellulose (HPMC), sodium lauryl sulfate, polyethylene glycol (PEG) 6000 and carbopol-ultrez® 20) and by the correlation data of XRD, FTIR and DSC was seen that the dispersion with carbopol-utlrez showed the great interaction with changes in absorption band and disappearance of the melting peak. In evaluating the stability of the dispersions by thermogravimetric analysis, it was observed that all of them had lower stability than ATC. These results point to the utility of thermal analysis techniques as an important screening tool for the characterization of the solid state during the development of formulation. Through multivariate analysis was possible to establish the correlation between the techniques studied shows the importance of using these in the evaluation of the quality control parameters of process and pharmaceuticals.

Submitted by Haroudo Xavier Filho (haroudo.xavierfo@ufpe.br) on 2016-04-14T18:12:12Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação_Waleska Vianna.pdf: 2762250 bytes, checksum: 49ac43d4d17ee59b86aa1081a15fb0ff (MD5) / Made available in DSpace on 2016-04-14T18:12:12Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação_Waleska Vianna.pdf: 2762250 bytes, checksum: 49ac43d4d17ee59b86aa1081a15fb0ff (MD5) Previous issue date: 2015-02-25 / CAPES / O besilato de anlodipino é um antagonista dos canais de cálcio, utilizado como um anti-hipertensivo e anti-isquêmico, sendo utilizado como uma mistura racêmica dos enantiômeros S e R, dos quais o S-anlodipino é o que apresenta maior atividade como bloqueador de cálcio. Por tanto, o objetivo desse estudo foi caracterizar as formas cristalinas do besilato de anlodipino e correlacionar os parâmetros térmicos e analíticos das dispersões sólidas do besilato de anlodipino obtidas por liofilização. Os ângulos vistos no DRX demonstraram a presença de uma estrutura cristalina anidra, para o AMB. Os deslocamentos nos comprimentos de onda no espectro de infravermelho (FTIR) do cristal do AMBACt corroboraram com os resultados do DRX que apresentou mudança no tamanho dos cristalitos, além disso a curva de DSC apresentou dois picos endotérmicos diferentemente do fármaco, com apenas um processo endotérmico e grau de pureza de 96%. A energia cinética de ativação (Ea = 121,6 KJ mol-1 ±1,2), o fator de frequência (A = 27,87 ± 4,1 min-1), e a ordem de reação (n = 0) da etapa principal da decomposição térmica do AMB foram realizadas de acordo com o Modelo de Ozawa. No estudo das dispersões sólidas, os dados do DRX para o AMBHPMC apresentou amorfização e essa alteração no arranjo cristalino também foi evidenciada nos resultados encontrados no FTIR, com deslocamentos nas bandas de intensidade, supressão e aparecimento de novas bandas. Além disso, o método termoanalítico mostrou supressão e deslocamento dos picos de fusões das dispersões sólidas, e perda de massa diferente do fármaco. Portanto, juntas, as técnicas colaboraram para a caracterização das formas cristalinas, e nos estudos de compatibilidade fármaco-excipiente através avaliação das interações físico-químicas nas dispersões sólidas. / The amlodipine besylate is a calcium channel antagonist used as antihypertensive and anti- ischemic , and used as a racemic mixture of R and S enantiomers , of which the S- amlodipine is what is more active as blockers calcium. Therefore, the aim of this study was to characterize the crystalline forms of amlodipine besylate and correlate the thermal and analytical parameters of solid dispersions of amlodipine besylate obtained by lyophilization. The angles viewed XRD showed the presence of an anhydrous crystalline structure for the AMB. The shifts in wavelengths in the infrared spectrum (FTIR) of the AMBACt crystal corroborate with the results of the XRD which showed change in the size of the crystallites, furthermore the DSC curve showed two endothermic peaks unlike the drug with only one process endothermic and purity of 96%. The activation kinetic energy (Ea = 121.6 kJ mol-1 ± 1.2), the frequency factor (A = 27.87 ± 4.1 min-1) and the reaction order (n = 0) of the main stage of AMB thermal decomposition were performed according to the Ozawa model. In the study of of the solid dispersions, the XRD data for AMBHPMC which showed amorphization and this change in the crystalline arrangement was also evidenced in the results found in the FTIR, with shifts in intensity bands, suppression and appearance of new bands. Also, the thermal method proved suppression and displacement of the melting peaks of the solid dispersions and loss of mass different than drug. Porting together the characterization techniques contributed to the evaluation of crystalline forms, and of the physicochemical interactions in solid dispersions.

This thesis deals with the system of titanium and hydrogen. Interstitial hydrogen alloys and hydrides are subject to intensive investigation, both theoretical and experimental. It has been proved, that absorbed hydrogen lowers the formation energy of defects in metals, and thus works as the so called 'defactant'. Surfactants on the surfaces of liquids lower the surface tension; defactants in solids lower the formation energy of defects. It has also been proved, that titanium absorbs hydrogen readily, when exposed to high temperature, or high pressure (fugacity); while different loading conditions lead to different features of the final sample. Beside ordinary coarse grained titanium, ultra-fine grained titanium shall be studied in present work, due to its high content of defects. Positron Annihilation Life-time Spectroscopy, a non-destructive technique sensitive on open-volume defects, shall be of prime importance in our investigation. We shall further use the X-ray diffraction, Micro-hardness measurements and Differential Scanning Calorimetry together with Thermogravimetry. Lastly, we shall strongly benefit from using existing computational tools like the Vienna ab-initio Simulation Package, or Pos330; a program for positron life--times calculations.

Rostlinné oleje se používají v mnoha odvětvích chemického průmyslu. V průběhu zpracování konkrétního produktu, ve kterém jsou rostlinné oleje použity, dochází často ke zvyšování teploty. Vyšší teplota urychluje průběh auto-oxidace což negativně ovlivňuje stabilitu olejů nebo výrobků z nich připravených. Mezidruhové mísení olejů je poměrně častým jevem jak při samotné výrobě tak i ve finálním výrobku. Cílem této práce bylo stanovit termo-oxidační stabilitu šesti čistých rostlinných olejů a jejich binárních směsí. První část práce zkoumá oleje a připravené směsi pomocí metody diferenciální kompenzační kalorimetrie. Tato metoda umožnila pochopení vztahů mezi termo-oxidačním chováním olejů a jejich směsmi pomocí stanovení teplot degradace. Přímá souvislost mezi obsahem mastných kyselin a stabilitou byla prokázána pouze zčásti, stejně tak jako původní předpoklad, že přídavek stabilnějšího olej zvýší stabilitu oleje méně stabilního. V několika případech docházelo dokonce ke snížení stability pod teplotu degradace obou čistých olejů. Ve druhé části byl zjišťován mechanismus pro-oxidační fáze vedoucí k degradaci olejů pomocí termogravimetrie, která ukázala přírůstek hmotnosti ve vzorcích oleje způsobeného absorpcí kyslíku a tvorbou peroxidů předcházející degradaci. V tomto případě již bylo možné pozorovat jistou souvislost mezi obsahem mastných kyselin a vzrůstem hmotnosti, pouze však jen pro čisté oleje. Ani v tomto případě nebyla prokázána aditivita vlastností způsobujících stabilitu směsí rostlinných olejů.

Mechanické vlasnosti intermetalika na bázi titan hliník Ti-46Al-7Nb-0.7Cr-0.1Si-0.2Ni jsou konstatní do teploty 700 °C. Nad touto teplotou slitina oxiduje. Cílem této práce bylo zlepšit oxidační vlastnosti pomocí kovové multivrstvy na bázi yttrium hlinik. Pro depozici vrstev byla použita metoda PVD. Na vzorky byly naneseny vrstvy čistého ytria nebo kombinace yttrium, hliník. Vzorky byly následně žíhány v inertní atmosféře na 700°C a 900°C nebo nebyly. Kvalita nanesených vrstev byla zkoumána pomocí scratch testu a EDS analýzi. Dále byly vzorky izotermicky oxidovány na 900°C po dobu 100 hodin. Na vzorcích byly po oxidaci prováděny měření pevnosti v tříbodovém obybu a měření hmotnosti. Chemické složení oxidické vrstvy bylo vyhodnoceno pomocí EDS. Žádná z vrstev s nebo bez žíhání neprokázaly zlepšení oxidických vlastností. Vyšší teplota žíhání prokýzala zlepšení mechanických vlastnotí vrstvy, ale zhoršení materiálu.

The aim of this thesis was the experimental evaluation of thermogravimetry (TG) to assess the status of organic matter supply in agricultural soils. TG is an innovative analytical method for recording thermal mass losses (TML) during heating of soil samples from room temperature to 950 °C. The determination of TML in 10 °C temperature increments (TG indicators) is a central method of TG data evaluation. There is a very close correlation between selected temperature ranges and classically determined soil properties (organic carbon, total nitrogen and clay content). The regression parameters of these relationships can be used to estimate soil properties and to assess the quality of SOM.:List of Tables VI List of Figures VII List of Abbreviations VIII Summary 10 Zusammenfassung 13 Chapter One – Synthesis: Thermogravimetry – a promising technique to assess the status of organic matter supply in agricultural soils 16 1 Introduction 16 1.1 Soils and agriculture 16 1.2 The Importance of soil organic matter (SOM) 17 1.3 Current challenges in the assessment of SOM as an indicator of soil quality 18 1.4 Main objectives 20 2 Methodological Approach 22 2.1 General approach 22 2.2 Experimental areas and soil description 22 2.3 Application of thermogravimetric analysis (TG) 28 2.4 Experimental design 29 2.4.1 SOC content determination using TML (chapter two and chapter five) 29 2.4.2 Detectability of thermal stabilities of organic amendments in soil samples using TML (chapter two) 30 2.4.3 Comparison between biological and thermal stability of SOM (chapter two and chapter three) 30 2.4.4 Linking thermogravimetric data with soil properties, thermal stability of SOM and SOC fractions (chapter four and chapter five) 31 3 Results and Discussion 32 3.1 Thermogravimetric-based fingerprint predictions of soil properties and soil organic matter stability (chapter two and chapter three) 32 3.2 Linking thermogravimetric indicators with functional SOC fractions to assess SOM quality (chapter four and chapter five) 35 4. Research needs and perspectives 37 5. Conclusion 40 References 40 Chapter Two: Contribution of organic amendments to soil organic matter detected by thermogravimetry 51 Chapter Three: Detectability of degradable organic matter in agricultural soils by thermogravimetry 52 Chapter Four: Linking soil organic matter thermal stability with contents of clay, bound water, organic carbon and nitrogen 53 Chapter Five: Linking thermogravimetric data with soil organic carbon fractions 54 Appendix 55 List of publications 55 Acknowledgments 56