In the last twenty years, chemists have devised numerous synthetic chemical systems in which self-replication operates, demonstrating that molecules can replicate themselves without the aid of enzymes and that self-replication is not a prerogative of nucleic acids only. However, the coupling of replication to other recognition-mediated events and its exploitation in the amplification of large supramolecular assemblies, such as mechanically interlocked molecules, have remained unexplored areas. Among mechanically interlocked molecules, rotaxanes represent particularly attractive targets because of their application as molecular switches. This thesis describes how the recognition-mediated synthesis of a rotaxane can be combined to the amplification of its structure by replication. Kinetic models for the integration of self-replication with the formation of a rotaxane are presented. The logical steps required to convert these models into molecular structures through consideration of the design criteria highlighted by the models are discussed and executed. The macrocyclic component is an essential part of a rotaxane. The synthesis of several novel macrocycles is presented. Their ability to bind guests in their cavities through hydrogen bonds was probed. The best macrocycle/guest pairs were integrated in the formation of rotaxanes. Further investigations on the stoppering reaction and on the various recognition processes involved in the system lead ultimately to the construction of self-replicating rotaxanes.

Para abordagem do controle não-linear geométrico, a síntese do controle e elaborada diretamente a partir da descrição do processo com a dinâmica não-linear em espaço de estados. O presente trabalho trata da aplicação dos principais conceitos e formalismos do controle não-linear geométrico para os processos multivariaveis típicos da engenharia química: o controle não-linear continuo da coluna de destilação e o controle não-linear discreto da unidade de craqueamento catalítico em leito fluidizado. A síntese e o projeto do controlador não-linear são enfocados separadamente. O projeto do controlador tem importância pratica para as aplicações industriais. O presente trabalho apresenta metodologias para a abordagem dos seguintes aspectos da aplicação multivariavel do controle geométrico não-linear: (a) como relaxar a sintonia do controlador interno de desacoplamento não-linear; (b) como definir o controlador externo como controle linear de alocação de pólos com coeficientes de hurwitz; (c) neste controlador externo, como incluir a ação integral com prevenção da saturação; e (d) como definir a dinâmica dossetpoints externos. / For the geometric nonlinear control approach, the controller synthesis is elaborated directly from the nonlinear dynamics state space description of the process. This work concerns the application of the main concepts and formalisms of the geometric nonlinear control theory to typical multivariable (MIMO) chemical engineering process as illustrative case studies: the continuous nonlinear control of the distillation column and the discrete nonlinear control of the fluid catalytic cracking unit. The synthesis and the project issues of the nonlinear controller are focused separately. The controller project has the practical importance for the industrial controller applications. This work applies the methodologies to approach the following issues for the MIMO applications of the geometric nonlinear control: (a) to detune the internal nonlinear decoupling controller; (b) to define the external controller as linear pole-placement controllers with Hurwitz coefficients; (c) to include the integral action with anti-reset windup on this external controllers and (d) to define the dynamics of the external setpoints.

Coupled Thermal-Hydrological-Mechanical-Chemical (THMC) processes that exist in the development of different geo-resources (e.g. deep geothermal and shale gas) affect the fracture response (i.e. aperture and permeability), which in turn influences the reservoir production. The main goal of this study was to experimentally evaluate the impact of THMC processes on the response of rock specimens relevant for deep geothermal and shale gas formations. The effects of THMC processes were investigated on: (i) success of the hydraulic fracturing/hydro-shearing mechanism during stimulation stage, and (ii) closure of the created network of fractures during production stage. The elastic, cyclic, creep, and failure characteristics of different intact reservoir rocks in both short- and long-term were investigated to evaluate their response in stimulation stage. In addition, a series of flow tests on fractured reservoir cores were conducted to evaluate how THMC processes affect fracture response subjected to different stress levels, temperatures, composition of injected fluid, and injection rate. Moreover, the sensitivity of ultrasonic signatures (i.e. velocity, amplitude, attenuation, and time-frequency content) to (i) microstructural changes in the intact rocks, and (ii) flow-induced alterations of aperture/permeability in the fractured rocks were investigated. Analysis of hydraulic data, chemical composition of the effluent, ultrasonic signatures, and X-Ray micro-CT and SEM images, provided invaluable information that facilitated interpretation of the effects of coupled THMC processes on fracture response.

El alto grado de automatización adquirido en las plantas químicas durante las últimas décadas hace que las tareas de supervisión sean ahora más complejas y delicadas. Esta supervisión requiere de sistemas y herramientas sofisticadas que puedan sacar provecho de los módulos de adquisición de información instalados en planta. Así, el preciso seguimiento de las variables de proceso o la fácil operatividad de los procesos, gracias a los sistemas de control regulatorio actuales, son aspectos relevantes que deben ser contemplados a la hora de dar una respuesta global a las desviaciones del régimen normal de operación.Esta tesis presenta un enfoque global para la gestión de situaciones anormales en plantas químicas. En esta propuesta se contempla el flujo completo de información requerido para responder efectivamente a cualquier situación anormal que se pueda presentar. Mediante esta visión global, primeramente se identifican todos los módulos de planta involucrados en la gestión de fallos; luego se focalizan esfuerzos en mejorar las técnicas que estos módulos usan para su operación; por último, se aprovechan algunas de las sinergias descubiertas mediante esta visión global de la gestión de eventos anormales.De esta forma, el primer capítulo esetablece un primer acercamiento general a las motivaciones y ámbito de las tesis, describiendo rasgos fundamentales en la evolución de la industria química durante los últimos años y los requerimientos asociados al nuevo modelo de supervisión. El segundo capítulo resume las técnicas y aplicaciones actuales para reducir el riesgo de incidencias y accidentes en procesos químicos. Este resumen se centra principalmente en aquellas metodologías más empleadas en la literatura y aquellas con más aceptación en ambientes industriales. Una vez analizado el estado del arte en la supervisión de procesos, se propone un enfoque global de gestión de eventos anormales en el tercer capítulo, que presenta los eslabones de la cadena de gestión de eventos anormales, los cuales serán abordados en detalle en los capítulos restantes.De esta forma, el capítulo 4 se centra en la mejora de los sistemas de adquisición de datos y su posterior tratamiento mediante reconciliación con modelos del proceso. Los capítulos 5, 6, 7 y 8 se dedican al estudio de la parte central de cualquier sistema de respuesta a eventos anormales, el módulo de diagnóstico. El capítulo 5 formaliza el problema de diagnosis y estandariza los índices de evaluación de funcionamiento de los sistemas de diagnóstico. Los capítulo 6 y 7 preentan dos nuevos sistemas de diagnosis basados en el uso de datos históricos. El primero desarrollado en el capítulo 6, implementa un algoritmo de aprendizaje llamada "Máquinas de soporte vectorial" (SVM) adoptando un enfoque "MultiEtiqueta" que permite el diagnóstico eficaz de fallos simultáneos. El segundo sistema (capítulo 7) integra un módulo de detección basado en un modelo de Análisis de Componentes Principales y un módulo de diagnóstico basado en reglas "si-entonces". Como compendio de la diagnosis, el capítulo 8 estudia las fuerzas y debilidades de los sistemas de diagnóstico propuestos y propone una integración de módulos de diagnóstico complementarios que supera el rendimiento de cualquiera de los sistemas por separado.Los capítulos 9 y 10 están centrados en la toma efectiva de decisiones frente a desviaciones del régimen normal de operación. El capítulo 9 presenta una metodología novedosa de integración de conocimiento del proceso en línea y fuera de línea, que permite generar información sustancial de soporte al operador en la toma de decisiones. El capítulo 10 se centra también en la toma de decisiones, mostrando las sinergias generadas al integrar el sistema de diagnosis con otros módulos de planta. En este capítulo el sistema global de gestión de eventos anormales es complementado con un módulo de optimización en línea. De esta forma el nuevo soporte a la toma de decisiones frente a perturbaciones no sólo tiene en cuenta aspectos relacionados con la seguridad sino también con la economía de la planta. Además, la integración permite que la técnica de optimizaicón empleada sea más fiable en su aplicación.Todos los capítulos incluyen una primera parte teórica seguida de una segunda parte centrada en la validación académica e industrail. Aquellos temas que exceden el alcance de estas tesis, son comentados y propuestos como trabajo futuro en el capítulo 11. / The hight automation acquired in chemical industry during last decades has made supervision a delicate and complex task. Therefore, current plants supervision require of sophisticated systems and tools that can create profit from the information installed modules. Thus, the precise tracking of process variables or the high plant operability, achieved by the current regulatory control, are aspects that must be contemplated when the plant has to give a global response against deviations from normal operating regime. This thesis presents a global approach for the management of abnormal situations in chemical plants. In this proposal the complete flow of information required to respond to any nonstandard situation is considered. This global approach incorporates several key aspects: first, all the plant modules that are necessary in the faults management are presented; secondly, this thesis focuses on improving the techniques used in each of these modules so far. Lastly, synergies discovered by the proposed global approach are used to develop novel and promising solutions to address process safety and optimization difficulties.

Identifying hazards is fundamental for ensuring the safe design and operation of a system in process plants and other facilities. Several techniques are available to identify hazardous situations, all of which require their rigorous, thorough, and systematic application by a multi-disciplinary team of experts. Success rests upon first identifying and subsequently analyzing possible scenarios that can cause accidents with different degrees of severity. While hazard identification may be the most important stage for risk management, it depends on subjectivity issues (e.g., human observation, good judgment and intuition, creativity, expertise, knowledge) which introduce bias. Without a structured identification system, hazards can be overlooked, thus entailing incomplete risk-evaluations and potential loss. The present Thesis is focused on developing both managerial and technical aspects intended to standardize one of the most used techniques for hazard identification; viz. HAZard & Operability (HAZOP) study. These criteria have been carefully implemented not only to ensure that most of the hazardous scenarios will be identified, but also that US OSHA PSM Rule, EPA RMP, and Seveso Directive requirements will be accomplished. Chapter I pioneers the main research topic; from introducing the process safety concept up to the evidence of more detailed information is required from related regulations. A review of regulations (i.e., US, Europe legislation) focused on Hazard Identification has been conducted, highlighting, there is an absence of specific criteria for performing techniques intended to identify what can go wrong. Chapter II introduces the risk management system required to analyze the risk from chemical process facilities, and justifies that hazard identification stage is the Process Safety foundation. Hereafter, an overview of the key Process Hazard Analyzes (PHA) has been conducted, and the specific HAZOP weaknesses and strengths have been highlighted to establish the first steps to focus on. Chapter III establishes the scope, the purpose and the specific objectives that the research covers. It answers the following questions on the spot: why the present research is performed, which elements are included, and what has been considered for acquiring the final conclusions of the manuscript. Chapter IV gathers HAZOP-related literature from books, guidelines, standards, major journals, and conference proceedings with the purpose of classifying the research conducted over the years and finally define the HAZOP state-of-the-art. Additionally, and according to the information collected, the current HAZOP limitations have been emphasized, and thus, the research needs that should be considered for the HAZOP improvement and advance. Chapter V analyzes the data collected while preparing, organizing, executing and writing HAZOPs in five petroleum-refining processes. A statistical analysis has been performed to extract guidance and conclusions to support the established criteria to conduct effectively HAZOP studies. Chapter VI establishes the whole set of actions that have to be taken into account for ensuring a wellplanned and executed HAZOP study. Both technical and management issues are addressed, criteria supported after considering the previous chapters of the manuscript. Chapter VI itself is the result of the present research, and could be used as a guideline not only for team leaders, but also for any related party interested on performing HAZOPs in continuous chemical processes. Chapter VII states the final conclusions of the research. The interested parties should be released about the hazard identification related-gaps present in current process safety regulations; which are the key limitations of the HAZOP study, and finally, which are the criteria to cover the research needs that have been found Annex I proposes the key tools (tables, figures and checklists "ready-to use'') to be used for conducting HAZOPs in continuous chemical processes. The information layout is structured according to the proposed HAZOP Management System. This information is intended to provide concise and structured documentation to be used as a reference book when conducting HAZOPs. Annex II is intended to overview the most relevant petroleum refining processes by highlighting key factors to take into account in the point of view of process safety and hazard identification, i.e. HAZOP. In this sense, key health and safety information of specific petroleum refining units is provided as a valuable guidance during brainstorming sessions. Annex III illustrates the complete set of data collected during the field work of the present research, and also analyzed in Chapter V of the manuscript. Additionally, it depicts a statistical summary of the key variables treated during the analysis. Finally, the Nomenclature, References, and Abbreviations & Acronyms used and cited during the manuscript have been listed. Additionally, a Glossary of key terms related to the Process Safety field has been illustrated. / La present Tesis doctoral té com a objectiu estandarditzar l'aplicació d'una de les tècniques més utilitzades a la industria de procés per a la identificació de perills; l'anomenat HAZard & OPerability (HAZOP) study, específicament a processos complexes, com per exemple, unitat de refineria del petroli.El capítol I defineix el concepte de Seguretat de Processos, i progressivament analitza les diferents regulacions relacionades amb la temàtica, detallant específicament les mancances i buits d'informació que actualment hi ha presents a la primera etapa de la gestió del risc en industries de procés: la identificació de perills.El capítol II defineix el sistema de gestió del risc tecnològic que aplica a les industries de procés, i es justifica que l'etapa d'identificació de perills és el pilar de tot el sistema. Finalment, es mencionen algunes de les tècniques d'identificació més utilitzades, els anomenats Process Hazard Analysis (PHA), i es detallen les seves mancances i fortaleses, característiques que han acabat definint la temàtica específica de la Tesis. Concretament, es dóna èmfasis a la tècnica anomenada HAZard & OPerability (HAZOP) study, objecte principal de la recerca.El capítol III defineix l'abast, el propòsit i els objectius específics de la recerca. La intenció d'aquest capítol és donar resposta a les següents qüestions: el perquè de la recerca, quins elements han estat inclosos i què s'ha considerat per tal d'assolir les conclusions de la Tesis.El capítol IV descriu l'estat de l'art de la literatura relacionada amb el HAZOP. Aquesta revisió no només permet classificar les diferents línies de recerca relacionades amb el HAZOP, sinó que també permet assolir un coneixement profund de les diferents particularitats de la pròpia tècnica. El capítol finalitza amb un conjunt de mancances tant de gestió com tècniques, així com les necessitats de recerca que poden millorar l'organització i execució dels HAZOPs.El capítol V analitza la informació que ha estat recopilada durant la fase experimental de la tesis. Les dades procedeixen de la participació en cinc estudis HAZOP aplicats a la industria de refineria del petroli.En aquest sentit, el capítol V desenvolupa una anàlisi estadística d'aquestes dades per extreure'n conclusions quant a la preparació, organització i execució dels HAZOPs.El capítol VI estableix el conjunt d'accions que s'ha de tenir en compte per tal d'assegurar que un estudi HAZOP estigui ben organitzat i executat (la metodologia). Es defineix un Sistema de Gestió del HAZOP, i a partir de les seves fases, es desenvolupa una metodologia que pretén donar suport a tots aquells punts febles que han estat identificats en els capítols anteriors. Aquesta metodologia té la intenció de donar suport i guia no només als líders del HAZOP, sinó també a qualsevol part interessada en aquesta temàtica.El capítol VII descriu les conclusions de la recerca. En primera instància s'enumeren les mancances quant a la definició de criteris a seguir de diferents regulacions que apliquen a la Seguretat de Processos.Seguidament, es mencionen les limitacions de la pròpia tècnica HAZOP, i finalment, es descriuen quins són els criteris establerts per donar solució a totes aquestes febleses que han estat identificades.L'Annex I és una recopilació de diferents criteris que han estat desenvolupats al llarg de l'escrit en forma de taules i figures. Aquestes han estat ordenades cronològicament d'acord amb les diferents fases que defineixen el Sistema de Gestió HAZOP. L'annex I es pot utilitzar com a una referència concisa i pràctica, preparada i pensada per ésser utilitzada directament a camp, amb la intenció de donar suport a les parts interessades en liderar estudis HAZOP.L'annex II recopila informació relacionada amb aspectes clau de seguretat i medi ambient en diferents unitats de refineria. Aquest informació és un suport per tal de motivar el "brainstorming" dels diferents membres que conformen l'equip HAZOP.L'Annex III recopila les dades de les diferents variables que han estat considerades a la fase experimental de la recerca, juntament amb un conjunt de figures que mostren la seva estadística bàsica.

Two fuzzy controllers are presented. A fuzzy controller with intermediate variable designed for cascade control purposes is presented as the FCIV controller. An intermediate variable and a new set of fuzzy logic rules are added to a conventional Fuzzy Logic Controller (FLC) to build the Fuzzy Controller with Intermediate Variable (FCIV). The new controller was tested in the control of a nonlinear chemical process, and its performance was compared to several other controllers. The FCIV shows the best control performance regarding stability and robustness. The new controller also has an acceptable performance when noise is added to the sensor signal. An optimization program has been used to determine the optimum tuning parameters for all controllers to control a chemical process. This program allows obtaining the tuning parameters for a minimum IAE (Integral absolute of the error). The second controller presented uses fuzzy logic to improve the performance of the convention al internal model controller (IMC). This controller is called FAIMCr (Fuzzy Adaptive Internal Model Controller). Twofuzzy modules plus a filter tuning equation are added to the conventional IMC to achieve the objective. The first fuzzy module, the IMCFAM, determines the process parameters changes. The second fuzzy module, the IMCFF, provides stability to the control system, and a tuning equation is developed for the filter time constant based on the process parameters. The results show the FAIMCr providing a robust response and overcoming stability problems. Adding noise to the sensor signal does not affect the performance of the FAIMC.The contributions presented in this work include:The development of a fuzzy controller with intermediate variable for cascade control purposes. An adaptive model controller which uses fuzzy logic to predict the process parameters changes for the IMC controller. An IMC filter tuning equation to update the filter time constant based in the process paramete rs values. A variable fuzzy filter for the internal model controller (IMC) useful to provide stability to the control system.

A purificação do biodiesel originado do processo de produção por transesterificação de óleos e gorduras requer a remoção de resíduos de glicerina. Como metodologia de cálculos correlações que dão origem a diagramas de dimensionamento foram transformados em modelos matemáticos envolvendo importantes números adimensionais. Apresenta-se uma estratégia de separação da glicerina dispersa no biodiesel utilizando um hidrociclone otimizado da família Rietema. Foram simuladas e analisadas as condições de separação da mistura biodiesel-glicerina, etapa integrante do processo de produção desse biocombustível por transesterificação de óleos e gorduras, em condições operacionais otimizadas e não otimizadas. A estratégia de otimização foi o uso de correlações econômicas e geométricas, as quais levaram à obtenção de um custo mínimo. Uma das etapas mais importante do processo de produção de biodiesel é a de sua purificação. Um hidrociclone do tipo convencional foi proposto para a referida etapa. A estratégia usada para elaboração da função objetivo foi composta de três termos: custo de aquisição, custo de operação e o custo associado a não coleta do biodiesel, todas como função do diâmetro do equipamento. Como programas de cálculos para dimensionamento e otimização foram utilizadas a planilha eletrônica Excel e sua ferramenta solver. Os resultados mostraram que a estratégia e otimização forneceram valores de dimensionamento muito próximos dos de condição não otimizadas, demonstrando que a mesma pode ser utilizada como reforço, numa época em que os critérios econômicos são importantes justificativas de investimentos nas melhorias dos processos produtivos / The purification of biodiesel of the production process by transesterification of oils and fats require the removal of glycerin waste. It presents a strategy for separation of glycerin dispersed in biodiesel using an optimized hydrocyclone of the Rietema family. As calculation methodology correlations that lead to the sizing diagrams were converted into mathematical models involving significant dimensionless numbers. It presents a strategy for separation of glycerin dispersed in biodiesel using an optimized hydrocyclone of the Rietema family. They had been simulated and analyzed the conditions of separation of the mixture biodiesel-glycerin, integrant stage of the process of production of this biofuel of separation of oils and fats, in optimized and not optimized operational conditions. The optimization strategy was the use of economic and geometric correlations, which had led to the attainment of a minimum cost. One of the stages most important of the process of production of biodiesel is of its purification. One hidrociclone of the conventional type was considered for the related stage. The used strategy for elaboration of the objective function was composed of three terms: cost of acquisition, cost of operation and the associated cost does not collect of biodiesel, all as function of the diameter of the equipment. As programs of calculations for sizing and optimization the electronic spread sheet Excel and its tool had been used to solve. The results had shown that the strategy and optimization had supplied values of not optimized sizing very next to the ones of condition, demonstrating that the same one can be used as reinforcement, at a time where the economic criteria are important justifications of investments in the improvements of the productive processes

Para abordagem do controle não-linear geométrico, a síntese do controle e elaborada diretamente a partir da descrição do processo com a dinâmica não-linear em espaço de estados. O presente trabalho trata da aplicação dos principais conceitos e formalismos do controle não-linear geométrico para os processos multivariaveis típicos da engenharia química: o controle não-linear continuo da coluna de destilação e o controle não-linear discreto da unidade de craqueamento catalítico em leito fluidizado. A síntese e o projeto do controlador não-linear são enfocados separadamente. O projeto do controlador tem importância pratica para as aplicações industriais. O presente trabalho apresenta metodologias para a abordagem dos seguintes aspectos da aplicação multivariavel do controle geométrico não-linear: (a) como relaxar a sintonia do controlador interno de desacoplamento não-linear; (b) como definir o controlador externo como controle linear de alocação de pólos com coeficientes de hurwitz; (c) neste controlador externo, como incluir a ação integral com prevenção da saturação; e (d) como definir a dinâmica dossetpoints externos. / For the geometric nonlinear control approach, the controller synthesis is elaborated directly from the nonlinear dynamics state space description of the process. This work concerns the application of the main concepts and formalisms of the geometric nonlinear control theory to typical multivariable (MIMO) chemical engineering process as illustrative case studies: the continuous nonlinear control of the distillation column and the discrete nonlinear control of the fluid catalytic cracking unit. The synthesis and the project issues of the nonlinear controller are focused separately. The controller project has the practical importance for the industrial controller applications. This work applies the methodologies to approach the following issues for the MIMO applications of the geometric nonlinear control: (a) to detune the internal nonlinear decoupling controller; (b) to define the external controller as linear pole-placement controllers with Hurwitz coefficients; (c) to include the integral action with anti-reset windup on this external controllers and (d) to define the dynamics of the external setpoints.

Orientador: José Roberto Nunhez / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-22T21:36:55Z (GMT). No. of bitstreams: 1 TorresGaravito_AnaMilena_M.pdf: 2300264 bytes, checksum: 43e45d59aa30ab0f64716f86095c8a43 (MD5) Previous issue date: 2013 / Resumo: Frequentemente os processos de agitação e misturas tão fundamentais são negligenciados na indústria como um todo petroquímico, farmacêutica, química, de alimentos, etc. No entanto, existem sistemas em que o desempenho desses processos depende fortemente do grau de homogeneidade conseguido durante a mistura. Quando o processo de mistura não está devidamente projetado e controlado, obtêm-se misturas com flutuações significativas nas suas características físicas e/o químicas, que no geral são indesejáveis e que suscitam perdas de lotes inteiros de produtos, aumentando o custo e o impacto ambiental do processo de produção. O custo final da energia utilizada no processo de agitação e mistura depende de vários fatores, sendo um deles o impelidor empregado. Para analisar um processo são considerados fatores de interesse como: melhor agitação, menor tempo de mistura e menor potência consumida. Este trabalho de pesquisa teve como objetivo a determinação experimental do número de potência em função do número de Reynolds nos regimes turbulento e laminar para impelidores de proximidade tipo âncora (reta e tubular) com e sem raspadores e para um impelidor do tipo helicoidal, usando como fluido pseudoplástico de alta viscosidade a carboximetilcelulose (CMC) diluída em água. Desta forma, foi possível selecionar a configuração que apresentava o menor consumo de potência. Para isto foi utilizado o protótipo em escala piloto desenvolvido pelo grupo de pesquisa do laboratório de Fluidodinâmica Computacional (LCDF) da Faculdade de Engenharia Química da Unicamp / Abstract: Frequently, agitation and mixing processes, so fundamental ones, are neglected in the industry sector in general, such as petrochemical, pharmaceutical, chemical and food processing industries. However, there are systems in which the performance of the process depends strongly on the degree of homogeneity achieved during the mixing process. When the mixing process is not properly projected and controlled, mixtures with significant fluctuations regarding their physical and/or chemical characteristics are obtained, and been that usually undesirable, it may cause the loss of entire product batches, increasing the production cost and the environmental impact of the production process. The final cost of the energy used in the agitation process depends on several factors, being one of them the type of impeller used. In order to analyze any process, factors of interest such as better agitation, least mixing time and least power consumption are considered. This research aim is to experimentally determine the power number as a function of Reynolds number in turbulent and laminar regimes for anchor-type impellers (straight and tubular) with and without scrapers and for a helical-type impeller, using as a high viscosity pseudoplastic fluid the carboximethyl cellulose diluted in water. For this purpose, it was used a pilot plant scale prototype, developed by the research group of the Computational Fluid Dynamic Laboratory (LCFD) of the Chemical Engineering College at Unicamp / Mestrado / Desenvolvimento de Processos Químicos / Mestra em Engenharia Química

Studiens syfte är att skildra hur förskollärare ser på sin roll i att stötta barnens språkutveckling i samband med lärandet om kemiska processer. Undersökningarna genomfördes med hjälp av pedagoger som arbetade på förskolor i fem kommuner i Mellansverige. I studien har en kvalitativ och en kvantitativ metod använts i form av enkäter och intervjuer. Enkäternas del i studien var att få en bred förståelse inom vilka kemiska processer som genomförs i förskolan. Intervjuerna genomfördes för att fördjupa studien inom de områden som framkom från enkäterna. Detta för att sedan ha möjligheten att diskutera och analysera resultatet kopplat till studiens frågeställningar och syfte. Resultaten åskådliggör att pedagogerna anser att de har en viktig roll i kemiska processer och har stor betydelse för utvecklingen av barnens vokabulär. Genom att vara aktiv som pedagog i en kemiaktivitet stimuleras barns språkutveckling då pedagogen kan tillföra fler begrepp vid den kemiska processen. Pedagogerna var också eniga om att aktiva och närvarande pedagoger stimulerar språkutvecklingen hos barnen i alla aktiviteter i förskoleverksamheten. I studien uppenbarades även att pedagogerna tycker att det är viktigt att benämna det som sker med rätt begrepp i aktiviteterna, redan med de allra yngsta barnen. / The purpose of the study is to describe how preschool teachers view their role of supporting children in their language development, in connection with learning of chemical processes. The study was conducted with the help of educators who worked at preschools in five municipalities in Central Sweden. In the study, a qualitative and a quantitative method was used in the form of questionnaires and interviews. The questionnaires part in the study was to gain a broad understanding of which chemical processes are carried out in preschool. The interviews were conducted to deepen the study in these areas that emerged from the questionnaires. This is to then have the opportunity to discuss and analyze the results linked to the study's questions and purpose. The results illustrate that educators believe that they have an important role in chemical processes and are of great importance for the development of children's vocabulary. By being active as an educator in a chemistry activity, children's language development is stimulated as the educator can add more concepts to the chemical process. The educators also agreed that active and present educators stimulate the language development of the children in all activities in the preschool activities. The study also revealed that the educators think it is important to name what happens with the right concept in the activities, already with the very young children.