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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Optimization of Configuration Management Processes

Kristensson, Johan January 2016 (has links)
Configuration management is a process for establishing and maintaining consistency of a product's performance, as well as functional and physical attributes with regards to requirements, design and operational information throughout its lifecycle. The way configuration management is implemented in a project has a huge impact on the project’s chance of success. Configuration management is, however, notoriously difficult to implement in a good way, i.e. in such a way that it increases performance and decrease the risk of projects. What works well in one field may be difficult to implement or will not work in another. The aim of this thesis is to present a process for optimizing configuration management processes, using a telecom company as a case study. The telecom company is undergoing a major overhaul of their customer relationship management system, and they have serious issues with quality of the software that is produced and meeting deadlines, and therefore wants to optimize its existing CM processes in order to help with these problems. Data collected in preparation for the optimization revealed that configuration management tools were not used properly, tasks that could be automated were done manually, and existing processes were not built on sound configuration management principles. The recommended optimization strategy would have been to fully implement a version handling tool, and change the processes to take better advantage of a properly implemented version handling tool. This was deemed too big a change though, so instead a series of smaller changes with less impact were implemented, with the aim of improving quality control to minimize the number of bugs that reached production. The majority of the changes had the purpose of replicating the most basic functions of a version handling tool, as well as automating manual tasks that were error prone. / Configuration management är en process för att etablera och bevara konsistensen hos en produkts prestanda, så väl som funktionella och fysiska attribut med avseende på krav, design och driftinformation genom dess livscykel. Hur konfigurationshantering implementeras i ett projekt har en avsevärd betydelse för huruvida projektet kommer att lyckas eller ej. Configuration management är dock ökänt för att vara svårt att implementera på ett bra sätt, d.v.s. så att det ökar prestandan och minskar risken i projekt. Det som fungerar bra inom en bransch kan vara svårt att implementera eller fungerar inte i en annan. Målet med denna studie är presentera en process for optimering av konfigurationshanteringsprocesser där ett telekomföretag använts som en fallstudie. Telekomföretaget genomgår en stor upprusting av sitt kund-system. Företaget har stora problem med kvalitén på den mjukvara de tar fram och att möta levaranstidpunkter, och vill därför förbättra sina processer för att komma till rätta med dessa problem. Data som samlades in inför optimeringen visar att CM-verktyg ej användes på korrekt vis, arbetsuppgifter som kunde automatiserats gjordes manuellt, och existerande processer byggde ej på best practices inom CM. De rekommenderade optimeringsstrategin var att implementera och använda ett versionhanteringssystem, och ändra processerna för att dra nytta av fördelarna med ett korrekt implementerat versionshanteringssystem. Detta ansågs dock vara en allt för stor förändring, så istället genomfördes ett antal mindre ändringar med mindre påverkan, med målet att förbättra kvalitetskontrollerna och minimera antalet fel som nådde produktion. Majoriteten av ändringarna hade syftet att replikera de mest grundläggande funktionaliteten hos ett versionhanteringsverktyg, så väl som att automatisera felbenägna manuella rutiner.
82

Förbättrad hantering av biobankssamtycke. : En kvalitativ studie om tidseffektiviserad handläggning av nej-talonger i en biobankverksamhet i Region Stockholm. / Improved handling of biobanking consent. : A qualitative study on time-efficient processing of biobanking consent at one biobank organization in the region of Stockholm.

Armus, Marija January 2023 (has links)
Enligt nuvarande biobankslag i Sverige ska handläggningen av patienternas biobankssamtycken ske omedelbart och utan onödig tidsfördröjning. Det är utifrån patientsäkerhetsperspektiv, viktigt att ha uppdaterade biobankssamtycken i laboratorieinformationssystemet eftersom korrekt uppdaterade samtycken är avgörande för leverans av säker vård. Tidigare behövde den berörda biobankverksamheten i genomsnitt 77 arbetsdagar för att handlägga en inkommen nej-talong, vilket var alldeles för lång tid. Det här förbättringsarbetet görs i syfte att tidseffektivisera processen för biobankssamtycke vid berörd biobankverksamhet i Region Stockholm. Nolans förbättringsmodell, Service Blueprint, 5 P´s analys och PDSA-hjulen användes som metod i det här förbättringsarbetet. Med hjälp av de införda förändringsidéerna under förbättringsarbetet minskades antalet handläggningsdagar för nej-talonger från 77 till 42 arbetsdagar på den berörda biobankverksamheten. Detta är en minskning med 35 arbetsdagar. Det här förbättringsarbetet resulterade i en mer tidseffektiviserad process för biobankssamtycke och en ny nationell rekommendation gällande antal handläggningsdagar för nej-talonger.  Studien av förbättringsarbetet syftade till att öka förståelsen om personalens erfarenheter av att genomföra förbättringsarbete med processen för biobankssamtycke. Studien genomfördes som en kvalitativ fallstudie med induktiv ansats. Kvalitativ datainsamling utfördes i form av åtta samtalsintervjuer. Studien visade att det fanns två viktiga faktorer som enligt berörd personal ledde till ökad teameffektivitet och tidseffektivisering av processen: systematisering av processen för biobankssamtycke och motivationsdrivande faktorer. Förändrat arbetssätt, ökade personalresurser och utvecklade kommunikationskanaler bidrog till skapandet av en systematisk process vilket underlättade genomförandet av förbättringsarbetet och tidseffektiviserade processen. Motivationsdrivande faktorer som påverkade teameffektivitet under förbättringsarbetets gång var gruppstöd, agilt arbetssätt och visuell utvärdering av förbättringsarbetet. / According to the current Biobanking Act in Sweden, processing of patients' biobanking consent must occur immediately without unnecessary time delay. From a patient safety perspective, it’s important to have updated consents in laboratory information systems because correctly updated consents are critical to the delivery of safe care. Previously, biobank organization where study was conducted needed an average of 77 working days to process an incoming biobanking consent, which was overly long. The aim of improvement work is to make the process for biobanking consent more time-efficient in one biobank organization in the Region of Stockholm. Nolan’s improvement model, Service Blueprint, 5 P's analysis and the PDSA-cycles were used as methods for this improvement work. With the help of five improvement interventions the number of processing days for biobanking consents was reduced from 77 to 42 working days which is a reduction of 35 days. This improvement work resulted in a more time-efficient process and a new recommendation regarding the number of processing days for biobanking consent.  The study of the improvement work aimed to increase the understanding of the staff's experiences regarding improvement work with the process for biobanking consent. The study was conducted as qualitative case study with an inductive approach. Qualitative data collection was carried out in the form of eight interviews. The study showed that the following factors led to increased team effectiveness and time efficiency of the process: systematization of the biobank consent process and motivational factors. Changed work methods, increased personnel resources, and developed communication channels contributed to the creation of the systematic process, which facilitated the implementation of the improvement work and made the process time efficient. Motivational factors that influenced team effectiveness under improvement work were group support, agile working methods and visual evaluation of improvement work.
83

Void Modeling in Resin Infusion

Brandley, Mark Wesley 01 June 2015 (has links) (PDF)
Resin infusion of composite parts has continually been reaching to achieve laminate quality equal to, or exceeding, the quality produced with prepreg in an autoclave. In order for this to occur, developers must understand the key process variables that go in to producing a laminate with minimal void content. The purpose of this research is to continue efforts in understanding 1) the effect of process conditions on the resultant void content, with a focus on resin infusion flow rate, 2) applying statistical metrics to the formation, location and size of voids formed, and 3) correlate these metrics with the local mechanical properties of the composite laminate. The variation in dispersion and formation of micro-voids and macro-voids varied greatly between the rates of flow the infusion occurred, especially in the non-crimp carbon fiber samples. Higher flow rates led to lower volumes of micro-voids in the beginning section of the carbon fiber laminates with macro-voids being introduced approximately half-way through infusion. This was determined to have occurred decreasing pressure gradient as the flow front moved away from the inlet. This variation in void content per location on the laminate was more evident in the carbon fiber samples than the fiberglass samples. Micro-voids follow void formation modeling especially when coupled with a pressure threshold model. Macro-void formation was also demonstrated to correlate strongly to void formation models when united with void mobility theories and pressure thresholds. There is a quick decrease in mechanical properties after the first 1-2% of voids signaling strength is mostly sensitive to the first 0-2% void content. A slight decrease in SBS was noticed in fiberglass laminates, A-F as v0 increased but not as drastically as represented in the NCF laminates, G and H. The lower clarity in the exponential trend could be due to the lack of samples with v0 greater than 0% but less than 1%. Strength is not well correlated to void content above 2% and could possibly be related to void morphololgy.
84

Process Intensification of Chemical Systems Towards a Sustainable Future

Zewei Chen (13161915) 27 July 2022 (has links)
<p>Cutting greenhouse gas emissions to as close to zero as possible, or ”net-zero”, may be the biggest sustainability goal to be achieved in the next 30 years. While chemical engineering evolved against the backdrop of an abundant supply of fossil resources for chemical production and energy, renewable energy resources such as solar and wind will find more usage in the future. This thesis work develops new concepts, methods and algorithms to identify and synthesize process schemes to address multiple aspects towards sustainable chemical and energy systems. Shale gas can serve as both energy resource and chemical feedstock for the transition period towards a sustainable economy, and has the potential to be a carbon source for the long term. The past two decades have seen increasing natural gas flaring and venting due to the lack of transforming or transportation infrastructure in emerging shale gas producing regions. To reduce carbon emission and wastage of shale resources, an innovative process hierarchy is identified for the valorization of natural gas liquids from shale gas at medium to small scale near the wellhead. This paradigm shift fundamentally changes the sequencing of various separation and reaction steps and results in dramatically simplified and intensified process flowsheets. The resulting processes could achieve over 20% lower capital with a higher recovery of products. Historically, heat energy is supplied to chemical plants by burning fossil resources. However, in future, with the emphasis on greenhouse gas reduction, renewable energy resources will find more usage. Renewable electricity from photovoltaic and wind has now become competitive with the electricity from fossil resources. Therefore, a major challenge for chemical engineering processes is how to use renewable electricity efficiently within a chemical plant and eliminate any carbon dioxide release from chemical plants. We introduce several decarbonization flowsheets for the process to first convert natural gas liquids (NGLs) to  mainly ethylene in an energy intensive dehydrogenation reactor and subsequent conversion of ethylene into value-added and easy-to-transport liquid fuels. </p> <p><br></p> <p>Molecular separations are needed across many types of industries, including oil and gas, food, pharmaceutical, and chemical industries. In a chemical plant, 40%–60% of energy and capital cost is tied to separation processes. For widespread use of membrane-based processes for high recovery and purity products from gaseous and liquid mixtures on an industrial scale, availability of models that allow the use of membrane cascades at their optimal operating modes is desirable towards sustainable separation systems. This will also enable proper comparison of membrane performance vis-a-vis other competing separation technologies. However, such a model for multicomponent fluid separation has been missing from the literature. We have developed an MINLP global optimization algorithm that guarantees the identification of minimum power consumption of multicomponent membrane cascades. The proposed optimization algorithm is implemented in GAMS and is demonstrated to have the capability to solve up to 4-component and 5-stage membrane cascades via BARON solver, which is significantly more advantageous than the state-of-the-art processes. The model is currently being further developed to include optimization of total cost including capital. Such a model holds the promise to be useful for the development in implementation of energy-efficient separation plants with least carbon footprint. This thesis work also addresses important topics in separation including dividing wall columns and water desalination. </p>
85

Propuesta de mejora del proceso de pilado de la empresa Agronegocios San Fabri SAC para incrementar su productividad

Villafuerte Meza, Anne del Milagro January 2024 (has links)
En el marco de esta investigación, se realizó un análisis del proceso de pilado de arroz ejecutado por la empresa SAN FABRI SAC, con el objetivo de incrementar su productividad. Este estudio comprendió una evaluación detallada de la situación actual de la empresa, abarcando la identificación de indicadores relacionados con la producción, productividad, eficiencia y capacidad. La productividad total se estableció en 0,4 sacos de arroz pilado/soles. Asimismo, se procedió a identificar las actividades del proceso mediante un cursograma analítico, revelando que la etapa de secado, realizada artesanalmente con una duración de 2880 minutos y una eficiencia del 56,20%, era el principal factor limitante. De igual manera, se detectó que la falta de mantenimiento preventivo generó 53 fallos en 2022, con un total de 513 horas de tiempo de parada. Conociendoxlasxcausas, se propuso la implementación de una secadora industrial y un plan de mantenimiento preventivo, logrando un aumento del 65% en la productividad global, un incremento del 22,54% en la eficiencia del proceso y una disminución del 69,57% en la capacidad ociosa. Por último, gracias a un análisis de costobeneficio, reveló que la empresa obtiene una ganancia de S/.0,68 por cada sol invertido. / In this research, an analysis of the rice piling process carried out by the company SAN FABRI SAC was carried out, with the aim of increasing its productivity. This study included a detailed evaluation of the current situation of the company, covering the identification of indicators related to production, productivity, efficiency and capacity. Total productivity was established at 0.4 bags of piled rice/soles. The process activities were identified using an analytical course, revealing that the drying stage, carried out by hand with a duration of 2880 minutes and an efficiency of 56.20%, was the main limiting factor. In addition, it was detected that the lack of preventive maintenance generated 53 failures in 2022, with 513 hours of downtime. In response, the implementation of an industrial dryer and a preventive maintenance plan was proposed, achieving a 65% increase in global productivity, a 22.54% increase in process efficiency and a 69.57% decrease in idle capacity. Finally, thanks to a cost-benefit analysis, it revealed a profit of S/. 0.68 for each sol invested.
86

Processing of toughened cyanate ester matrix composites

Rau, Anand V. 06 June 2008 (has links)
This investigation explored the feasibility of recently developed toughened cyanate ester networks as candidate materials for high performance composite matrix applications. The resin investigated was a Bisphenol-A cyanate ester toughened with hydroxy functionalized phenolphthalein based amorphous poly(arylene ether sulfone). The thermoplastic modified toughened networks exhibited improvement in the fracture toughness over the base cyanate ester networks without significant reductions in mechanical properties or glass transition temperature. Void free, unidirectional carbon fiber prepreg was successfully manufactured with the toughened cyanate resin using a solventless hot-melt technique. The resin mass fraction of the prepregs was between 31 and 35%. The carbon fiber, toughened cyanate ester prepreg was fabricated into composite panels for mechanical and physical testing. The cure cycle used to manufacture the composite laminates was developed with the aid of a process simulation model developed by Loos and Springer. In order to accurately simulate the resin curing and flow processes, the cure reaction kinetics and melt viscosity was characterized as a function of temperature and degree of cure and input into the simulation model. The model generated cure cycle was used in the manufacture 8-ply unidirectional and 16-ply quasi-isotropic composite laminates. The manufactured laminates were well consolidated to the specified fiber volume fraction between 59 and 60%. Photomicrographs showed that the laminates are void free, the fiber and resin distribution is uniform and fiber wet-out is very good. Mechanical tests were performed to measure the impact damage resistance and shear properties of the toughened cyanate ester resin composites. The results show improvements in impact damage resistance compared with the commonly used hot-melt epoxy resin composites. The influence of processing on performance was observed from the results of shear tests. Carbon fabric composite panels were manufactured by liquid molding processes (resin transfer molding and resin film infusion), with a series of four toughened cyanate ester resins generated by varying the concentration and the molecular weight of the toughener. The panels were subjected to physical, damage tolerance, and fracture toughness tests. The results of physical testing indicate consistently uniform quality, and the void content was found to be less than 2%. The toughened cyanate ester composites exhibited significantly improved impact damage resistance and tolerance compared with hot-melt epoxy systems. Marked increase in the mode II fracture toughness were observed with an increase in the concentration and the molecular weight of the toughener. / Ph. D.
87

Einfluss von Impuls und Energie auf die Kontrolle und Optimierung der Fallgewichtsverdichtung

Knut, Alexander 25 June 2024 (has links)
Die vorliegende Arbeit beschäftigt sich mit der Prozessführung der Fallgewichtsverdichtung. Konkret wird der Einfluss der eingetragenen kinetischen Energie und des Impulses auf die Kinematik des Fallgewichts und die Reaktion des Bodens untersucht. Die aktuell etablierte Dimensionierung der Fallgewichtsverdichtung erfolgt einzig auf Basis der potentiellen Energie des Fallgewichts. Mindestens eine weitere unabhängige Steuergröße fehlt, um den Prozess zu optimieren. Die Arbeit analysiert hierzu den Einfluss des Impulses mit 1-g-Modellversuchen. Die Beschleunigung des Fallgewichts zeigt zwei charakteristische Bereiche: (1) eine starke Überhöhung, kurz nach dem Einschlag und (2) ein Plateau, welches länger anhält und dann abrupt endet. Die Überhöhung der Beschleunigung ist direkt proportional zur quadratischen Einschlaggeschwindigkeit und ergibt sich aus der Impulsfortpflanzung im Boden. Dies mobilisiert eine zusätzliche Masse im Boden, die gemeinsam mit dem Fallgewicht mit gleicher Geschwindigkeit in den Boden eindringt. Diese Phase wird dominiert durch den Unelastischen Stoß zwischen Fallgewicht und Boden. In der zweiten Phase erfolgt ein reibungsbehafteter Lastabtrag, der mit der Änderung der Kratertiefe korreliert. Mit dem Wissen um diese Mechanismen wird ein Optimierungsparameter vorgeschlagen, Mit dem gezeigt wird, dass durch Reduktion der Einschlaggeschwindigkeit bei gleichbleibendem Impuls die Fallgewichtsverdichtung effizienter ausgeführt werden kann. Ferner wird demonstriert, dass die Kratertiefenentwicklung mit fortschreitender Ausführung progressiv oder degressiv verlaufen kann. Zusammenfassend zeigt die Arbeit, dass der Einsatz schwerer Fallmassen, die aus geringer Höhe fallen effizienter ist, als der Einsatz leichter Fallmassen, welche aus großer Höhe fallen. Der Grund dafür liegt in der nachteiligen Mobilisierung der zusätzlichen Bodenmasse, welche proportional zur quadratischen Einschlaggeschwindigkeit zunimmt und das Eindringen des Fallgewichts durch seine zusätzliche axiale Trägheit hemmt.
88

Investigating Assembly Process Automation : A Case Study in Consumer Electronics

Mertzanopoulos, Aristotelis January 2024 (has links)
This thesis addresses the automation of the Pin Header Assembly (PHA) process in sensor manufacturing at Senseair AB. The manual assembly of pin headers presents significant challenges and inefficiencies, necessitating automation to enhance production capabilities and reduce costs. A detailed analysis of the time and cost associated with the manual assembly and a proposed automation solution was conducted on the assembly line of the S11 product series. Data were collected from the actual shop floor by measuring operation times for manual tasks and from a simulated automation cell to compare the two solutions in terms of cost, cycle time, and throughput. The investigation identified that automating the PHA process could significantly improve product consistency and increase throughput, addressing the inefficiencies and error rates of the current manual method. The automation of this process is essential for meeting higher volume demands and improving production scalability. Following this analysis, a collaborative robot (UR5) was evaluated for automating the PHA process. The evaluation involved simulating the automation scenario with the robot, including programming it to perform PHA operations and testing two alternative grippers to determine the most effective design. The main results indicate that automating the PHA process will significantly reduce unit costs and increase potential throughput. This automation is not only feasible but also represents a beneficial investment, providing both direct and indirect benefits to the production process. Overall, the automation of the PHA process is a strategic step towards optimizing production, reducing costs, and improving product quality. / Sure, here is the text with the missing spaces added: Denna avhandling handlar om automatiseringen av Pin Header Assembly (PHA)-processen vid sensortillverkning hos Senseair AB. Den manuella monteringen av stifthuvuden innebär betydande utmaningar och ineffektivitet, vilket kräver automatisering för att förbättra produktionskapaciteten och minska kostnaderna. En detaljerad analys av tiden och kostnaden förknippad med den manuella monteringen och en föreslagen automationslösning genomfördes på löpande bandet i produktserien S11. Data samlades in från själva verkstadsgolvet genom att mäta drifttider för manuella uppgifter och från en simulerad automationscell för att jämföra de två lösningarna vad gäller kostnad, cykeltid och genomströmning. Undersökningen identifierade att automatisering av PHA-processen avsevärt kan förbättra produktens konsistens och öka genomströmningen, och åtgärda ineffektiviteten och felfrekvensen i den nuvarande manuella metoden. Automatiseringen av denna process är avgörande för att möta högre volymkrav och förbättra produktionsskalbarheten. Efter denna analys utvärderades en kollaborativ robot (UR5) för att automatisera PHA-processen. Utvärderingen innefattade simulering av automatiseringsscenariot med roboten, inklusive programmering av den för att utföra PHA-operationer och testning av två alternativa gripdon för att bestämma den mest effektiva designen. Huvudresultaten indikerar att automatisering av PHA-processen avsevärt kommer att minska enhetskostnaderna och öka den potentiella genomströmningen. Denna automatisering är inte bara genomförbar utan representerar också en fördelaktig investering som ger både direkta och indirekta fördelar för produktionsprocessen. Sammantaget är automatiseringen av PHA-processen ett strategiskt steg mot att optimera produktionen, minska kostnaderna och förbättra produktkvaliteten.
89

Método de clasificación ABC para optimizar la gestión de los inventarios en la empresa acabados Marcelino E.I.R.L en Chiclayo 2022

Yajahuanca Cuzque, Maria Elva January 2024 (has links)
La presente investigación tiene como título “método de clasificación ABC para optimizar la gestión de los inventarios en la empresa acabados Marcelino E.I.R.L en Chiclayo 2021, teniendo como principal objetivo aplicar el método de clasificación ABC para la mejora de la gestión de inventarios en la empresa Acabados Marcelino E.I.R.L. Así mismo la investigación esta abordada desde el enfoque tipo mixta (cuantitativa y cualitativa). A la vez se aplicó una entrevista al encargado del almacén para poder conocer la gestión de los inventarios de empresa e identificar cuáles son las deficiencias para el orden del almacén y poder desarrollar el método ABC. Por lo cual se obtuvo los resultados que la empresa no cuenta con un método para controlar sus inventarios, no conocen la rotación de sus productos, todas las revisiones lo hacen bajo un sistema de facturación y no conocen el stock real ni que productos están por agotarse ocasionado pérdidas de ventas puntuales y costos por almacenaje innecesarios. Finalmente se concluye que la metodología ABC optimizara la gestión de la empresa en relación a sus inventarios dado que contara con un detalle más exacto sobre qué y que cantidad pedir en cada reposición de productos, dentro la categorización ABC. / The title of this research is “ABC classification method to optimize inventory management in the Marcelino E.I.R.L. finishing company in Chiclayo 2021, with the main objective of applying the ABC classification method to improve inventory management in the Finishing company. Marcelino E.I.R.L. Likewise, the research is approached from a mixed approach (quantitative and qualitative). At the same time, an interview was carried out with the warehouse manager in order to learn about the management of company inventories and identify the deficiencies in the order of the warehouse and to be able to develop the ABC method. Therefore, the results were obtained that the company does not have a method to control its inventories, they do not know the rotation of their products, all reviews are done under a billing system and they do not know the real stock or which products are about to run out. caused specific sales losses and unnecessary storage costs. Finally, it is concluded that the ABC methodology will optimize the company's management in relation to its inventories given that it will have more exact detail about what and what quantity to order in each product replacement, within the ABC categorization.
90

Otimização de um processo industrial de produção de isopreno via redes neurais. / Optimization of an industrial process for isoprene production using neural networks.

Alves, Rita Maria de Brito 02 July 2003 (has links)
Este trabalho descreve a aplicação de redes neurais \"feed-forward\" com três camadas em diferentes áreas da Engenharia Química. O objetivo principal do projeto é a modelagem, simulação e posterior otimização do processo de produção de isopreno empregando técnicas de redes neurais em substituição as equações de modelagem fenomenológica. A planta industrial testada é a unidade de produção de isopreno da BRASKEM (antiga COPENE). O sistema consiste essencialmente de um reator de dimerização e uma série de colunas de destilação. Uma vez que redes neurais são capazes de aprender eficientemente o processo a partir de informações extraídas diretamente de dados da planta, para este trabalho o modelo de rede neural gerado foi construído a partir de dados históricos operacionais coletados a cada 15 minutos durante o período de 1 ano. Em uma primeira etapa é realizada a análise dos dados operacionais de modo a detectar e eliminar erros grosseiros e sistemáticos. Em seguida, a modelagem e simulação do processo são realizadas. O modelo de redes neurais gerado é, então, empregado na otimização qualitativa/quantitativa do processo, construindo um \"grid\" de busca detalhado da região de interesse, através um mapeamento completo da função objetivo no espaço das variáveis de decisão. A segunda etapa diz respeito à predição de azeótropos, visando um melhor entendimento do comportamento do sistema da seção de extração de isopreno. Nas duas etapas, a grande vantagem em utilizar modelos de redes neurais, além de ajustar dados, é a capacidade que estes apresentam em representar eficientemente sistemas multivariáveis, complexos e não lineares, aprendendo o sistema, sem o conhecimento das leis físicas e químicas que o regem. Comparações entre a predição dos modelos propostos e os dados experimentais foram executadas e resultados muito bons foram conseguidos do ponto de vista industrial. ) Esta metodologia fornece informações interessantes e de maior compreensão para a análise dos engenheiros de processo do que os procedimentos convencionais correspondentes. Além disso, este trabalho mostra que a metodologia de redes neurais é promissora para varias aplicações indústrias, tais como análise de dados, modelagem, simulação e otimização de processos, bem como predição de propriedades termodinâmicas. / This work describes the application of a three-layer feed-forward neural network (NN) in different areas of chemical engineering. The main objective of this study is to model, simulate and optimize a real industrial plant, using NN by replacing phenomenological models. The industrial process studied is the isoprene production unit from BRASKEM. The chemical process consists basically of a dimerization reactor and a separation column train. Since NNs are able to extract information from plant data in an efficient manner, for this work, the neural network model was built directly from historical plant data, which were collected every 15 minutes during a period of one year. These data were carefully analyzed in order to identify and eliminate gross error data and non-steady state operation data. The modeling using NN was carried out by parts in order to get information on intermediate streams. Then, the global model was built, by interconnecting each individual model, and used to simulate and optimize the process. The optimization procedure carries on a detailed grid search of the region of interest, by a full mapping of the objective function on the space of decision variables. The second stage of this work deals with the azeotropic prediction using also the neural network approach. The objective of this step was to obtain a better understanding of the system behavior in the isoprene extraction section. Since all the cases studied are non-linear, complex andmultivariable systems, NN approach appears as a technique of interest due to its capability of learning the system without knowledge of the physical and chemical laws that govern it. Comparisons between the model\'s prediction and the experimental data were performed and reasonable results were achieved from an industrial point of view. ) Using neural network approach provides more comprehensive information for an engineer\'s analysis than the conventional procedure. This work shows that the use of NN methodology is promising for several industrial applications, such as data analysis, modeling, simulation and optimization process, as well as thermodynamics properties prediction. However, success in obtaining a reliable and robust NN depends strongly on the choice of the variables involved, as well as the quality of available data set and the domain used for training purposes.

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