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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.
101

Analýza komory diferenciálního čerpání EREM pomocí systému Cosmos FloWorks / Using Cosmos FloWorks for analysis of the ESEM differential chamber

Jašek, Michal January 2009 (has links)
The paper outlines fundamental issues of electron microscopy and models three selected shapes of the differential chamber using the SolidWorks system. The models are then analysed using Cosmos FloWorks with regard to vacuum pumping. The aim is to find a model with minimum pressure in the electron beam trajectory and hence the least dissipation.
102

Analýza rozložení tlaků v detektoru SE pomocí systému Cosmos FloWorks / Use of Cosmos FloWorks for analysis of the scintillation detector for EREM

Ambrož, Václav January 2009 (has links)
The paper briefly outlines high-pressure electron microscopy and then uses SolidWorks to model the scintillation detector, analysing pumping of gas in the EREM sample chamber at different pressure levels using Cosmos FloWorks. The results of the analysis are assessed with regard to minimising pressure in the trajectory of the primary electron beam in order to prevent dissipation of electrons on the gas molecules.
103

Automation av parametrisk CAD-modellering inom programmet Inventor

Hjoberg, Filip January 2021 (has links)
Companies today are constantly looking to improve the lead time of design and production processes through streamlining the process and looking for new solutions. CAD, computer-aided design, is something that has been very helpful for this. By reducing the use of 2D basis and instead having 3D models as the only main basis, the CAD process has seen improvements in the form of streamlining. The next step to improving the process even further is to automate modeling in order to reduce manual processing. The problem arises when a company has a finished product model and the customer requests different specific dimensions and/or functions. Then the CAD designer must then build the model from scratch even though the changes may be minimal. This is time-consuming and creates variation in how models are built among designers. Therefore, the purpose of this thesis is to find an automatic solution that reduces the manual work. A method that allows you to change dimensions or functions directly in the same CAD file. Question at issue: Is it possible to automate the CAD process when dimensions and/or functions need to be changed on a model, without having to remodel the model manually and therefore save time? This question was answered based on an assignment given by the company Roxtec Sweden AB. The product that the CAD model would represent and work with was the product type Module, which is a sealing solution for cables and pipes. The techniques and methods to achieve the goal of this project has been extracted from threads on the Autodesk community forum and YouTube videos. Reports from similar degree projects have been helpful for the layout and writing of the report. The practical work has consisted of creating two different dummies to test the found techniques and methods on, and then apply these to the product model, Module. The approach was to name and list all parameters from the CAD model, use iLogic Rules to control and monitor parameters, functions and components with programmable logic. Then apply iLogic Forms to create a user-friendly form where the user can control the parameters, functions and components of the CAD model. The main work included creating three different parts with named and listed parameters as well as rule-scripts with iLogic Rules. Then create an assembly that was a compilation of these parts. The parts parameters and rule-scripts were linked to the assembly. Additional parameters, rule-scripts and a form were created in the assembly to achieve a fully functional automated CAD model. The result was an automated and editable CAD file, representing Roxtec's product type, Module. With the CAD file, any user can easily select the desired dimensions and functions. This avoids the need to build the product model from scratch when new values are desired. In addition, each model gets built in the same way when using this solution. The automated solution was tested against a manual method. Results yielded a total time of 15 minutes using the manual method, whereas the automated solution only took a total of 40 seconds. The automated solution proved a 95.6% less time-consuming process. This method is best suited for repeated use on several work steps, where it shows a much higher efficiency-level. / Att ständigt effektivisera och hitta nyalösningar som förkortar ledtiden för designprocessen och produktionsprocessen är något som företag alltid strävar efter. CAD, datorstödd konstruktion, är något som har varit till stor hjälp för detta. Genom att minska användningenav 2D-underlag och istället ha 3D-modeller som det enda underlaget, har CAD-processen effektiviserats. Nästa steg för att spara ännu mera tid är att automatisera modelleringen för att minska den manuella bearbetningen. Problemet uppstår när ett företag har en färdig produktmodell, men kunden ber om andra specifika dimensioner och funktioner. Då måste CAD-konstruktören modellera modellen från grunden även fast ändringarna kan vara minimala. Detta är tidskrävande och det blir också en naturlig variation hur modellerna byggs upp bland konstruktörerna. Därför är syftet med detta examensarbete att komma fram till en automatisk lösning som minskar tiden att skapa en modell. En metod som gör det möjligt att ändra dimensioner eller funktioner direkt i samma CAD-fil. Frågeställning: Går det att automatisera CAD-processen när dimensioner och/eller funktioner behöver ändras på en modell utan att behöva modellera om modellen manuellt och genom detta spara tid? Frågeställningen besvarades utifrån ett uppdrag givet av företaget Roxtec Sweden AB. Produkten som CAD-modellen skulle representera och arbetas med var produkttypen modul, vilket är tätningslösningar för kablar och rör. Videoklipp från Youtube och trådar på Autodesk community forum har använts mest för att hitta möjliga tekniker och metoder för att uppnå målet med examensarbetet. Rapporter från liknanden examensarbeten har varit till hjälp för upplägget och skrivandet för den egna rapporten. Det praktiska arbetet har bestått av att skapa två olika dummys för att testa de funna teknikerna och metoderna för att sedan tillämpa dessa på produktmodellen, Modulen, som var huvudarbetet med examensarbetet. Tillvägagångsättet blev att namnge och lista samtliga parametrar iCAD-modellen. Använda sig av iLogic Rules för att skapa regler som styr och kontrollerar parametrar, funktioner och komponenter med programmerbar logik. Dels att tillämpa iLogic Forms för att skapa ett användarvänligt formulär där användaren kan styra parametrarna, funktionerna och komponenterna i CAD-modellen. Genomförandet av huvudarbetet omfattades av att skapa tre olika parts med namngivna och listade parametrar samt regler med iLogic Rules. Sedan skapa en assembly som var en sammanställning av dessa parts. Parternas parametrar och regler kopplades till assemblyn. Ytterligare parametrar, regler och ett formulär skapades i assemblyn för att uppnå en fullt fungerande automatiserad CAD-modell. Resultatet blev en automatiserad och redigeringsbar CAD-fil som representerar Roxtecs produkttyp, Modul. Med CAD-filen kan en användare enkelt välja önskade mått och funktioner. Genom detta undviks behovet av att modellera produktmodellen från grunden när nya värden önskas. Dessutom får varje modell samma uppbyggnadssätt vid användning av lösningen. Ett test utfördes genom att skapa en produktmodell med den automatiserade metoden och jämföra med den manuella metoden. Det resulterade att den nuvarande manuella tog 15 minuter och den nya automatiserade lösningen tog 40 sekunder, alltså 95,6% mindre tidskrävande. Metoden passar bäst vid upprepade arbetsmoment då vissa förberedelser krävs för att tillämpa metoden. När förberedelserna är gjorda och metoden är redo att användas, sparas mycket tid och arbetet blir mer effektivt med mindre manuell bearbetning.
104

Numerical methods for efficient blood flow simulations: application to coronary artery disease

Lucca, Alessia 06 December 2023 (has links)
The development of efficient mathematical models and numerical methods for the study of haemodynamics is becoming increasingly prominent in the analysis of pathological states of the cardiovascular system. Computational models contribute to medical diagnosis processes, reducing the need of classical invasive medical techniques, which are not risk-free for patients and generate high healthcare costs. The first part of this thesis focuses on the modeling and simulation of coronary blood flow, with emphasis on stable Coronary Artery Disease (CAD), a pathological condition that occurs when an abnormal narrowing builds inside coronary vessel walls. Our goal is to develop a CCTA-based Fractional Flow Reserve (FFR) model which incorporates clinical imaging and patient-specific characteristics to predict the haemodynamic behavior and properties of individuals, reducing the need for invasive measurements. A novel aspect of the proposed methodology is the inclusion of the pressure guidewire, used in clinical settings, and the assessment of its impact on local fluid dynamics and FFR predictions. Thereafter, the second part of this dissertation is devoted to the development of numerical methods for the simulation of incompressible flows with particular emphasis on the simulation of cardiovascular haemodynamics. A novel implicit hybrid finite volume/finite element methodology for the efficient simulation of blood flow is proposed and validated. The implicit discretization of the transport-diffusion equations making use of an inexact Newton-Krylov method with an SGS preconditioner yields to an efficient scheme avoiding the severe CFL condition arising in explicit or semi-implicit methods for blood flow dynamics. Besides, the Ducros flux function employed for the nonlinear convective terms leads to a provably kinetic energy stable scheme of the advection terms. In addition, a staggered semi-implicit method for the simulation of incompressible flows in one-dimensional elastic and viscoelastic vessels is proposed. The convective stage is treated explicitly in time, while the diffusive and pressure stage are handled implicitly to avoid strict bounds on the time steps. The one-dimensional methodology is then extended to networks of vessels by introducing a local three-dimensional representation of the junction.
105

Evaluation of CAD Design for Manufacturability

Akula, Durga Venkata Sai Naidu, Srinivasan, Chinmay January 2023 (has links)
In today’s rapidly evolving product development landscape, the efficiency and effectiveness of making a product heavily depend on the seamless integration of design and manufacturing processes. The progression of a design concept from development to manufacturing is often impeded by deviations arising during the manufacturing process and the subsequent repercussions they entail. While minor changes made during the initial stages of design have limited consequences, the necessity for significant manufacturing modifications later in the development cycle incurs substantial time and financial costs. To mitigate these challenges, it becomes critical to prioritize manufacturing validation as an integral component of the design evaluation process in all through its evolution, rather than as an afterthought once the design has been finalized. However, this endeavor is not without its complexities, given the intricate nature of designs.  This thesis delves into the critical aspect of design validation for manufacturing, collaborating closely with the NXPS department of Scania to address their specific challenges due to manufacturing in EATS development. The prevailing method currently employed for evaluating the manufacturability of CAD designs heavily relies on supplier feedback or experiential knowledge garnered over years of experience as a mechanical engineer. While undoubtedly valuable, this approach often fails to keep pace with planned development cycles, resulting in frequent deviations. Moreover, beyond mere assessment, a thorough comprehension of manufacturing processes is essential for validating various functions of a design, ensuring alignment with real-world expected capabilities of the product. Thus, the central focus of this thesis lies in devising a method to address these shortcomings and contribute to optimizing the transition from design to manufacturing.  Given the dynamic nature of manufacturing processes, this thesis centre’s its attention on sheet metal manufacturing, a primary process in manufacturing EATS. Through the utilization of real-world case studies, a two-step methodology is developed, intending to seamlessly integrate with the current SDD approach in EATS development. The initial step involves the utilization of Autoform for analyzing design manufacturability, while the subsequent step capitalizes on this knowledge to enhance structural analysis, thereby enabling more realistic stress assessments. By concentrating on sheet metal manufacturing and implementing a comprehensive two-step approach, this thesis proposes a tangible solution to comprehend the challenges associated with manufacturing deviations, thereby aiding decision-making processes in selecting more feasible and manufacturable design alternatives. / Autoform, CAD, CAE, CATIA V5, DataMapping, Manufacturability, Optimization, Parametric CAD models, Sheet Metal Manufacturing, Simulation Driven Design
106

Handikappsanpassad cykelpedal

Nielsen, Mikael, Norrman, Maida January 2017 (has links)
Detta är ett examensarbete på 7,5hp för CAD-Tekniker programmet på Högskolan I Halmstad. Gruppen har fått som uppdrag att ta fram en prototyplösning för en handikapsanpassad cykelpedal till en privatperson i Halmstad. Användaren kan inte böja sitt knä helt och kan inte använda en normal cykelpedal för höger ben. / This is a thesis report of 7,5hp for the CAD-Technician program at Halmstad Univeristy. The group was tasked with developing a prototype for a bicycle crank for an individual in Halmstad. The user has a bad knee, unable to bend it fully and is unable to use a normal crank for the right leg.
107

Modelando o futuro: a evolução do uso de tecnologias digitais no desenvolvimento de projetos de arquitetura / Shapping the future: the evolution of digital technology design in architecture

Sguizzardi, Silvio 13 May 2011 (has links)
A pesquisa aborda processos criativos e produtivos da arquitetura contemporânea, a partir da história do desenvolvimento tecnológico da computação gráfica e sua influência sobre a atividade profissional do arquiteto. Baseada na análise projetual, de forma a explicitar a problemática colocada, toma como estudos de caso três projetos desenvolvidos em diferentes momentos dessa evolução: a Casa da Ópera de Sidney, na Austrália; o pavilhão H2Oexpo na ilha de Neeltje Jans, Holanda; e, o Museu Mercedes-Benz em Stuttgart, Alemanha. Através de uma análise crítica, procuramos entender as relações do uso de computadores no desenvolvimento e construção destes projetos. Para cada caso, foram analisadas as técnicas empregadas, os benefícios conquistados e inovações proporcionadas, bem como, as dificuldades, limitações e os desafios enfrentados, desde o início do desenvolvimento do projeto, ao término da execução da edificação. A leitura integral e objetiva do objeto baseia-se em acervo documental, material bibliográfico e no discurso e posicionamento de profissionais envolvidos, visando à compreensão da riqueza e diversidade do tema. O trabalho pretende dar uma contribuição ao entendimento desta relação, colaborando também para o estudos de questões projetuais ligadas as novas mídias, como forma de estabelecer uma base de conhecimento para a reflexão a respeito do uso de ferramentas da computação gráfica no universo arquitetônico. / With the history of the graphic computation technological development and its influence on the architect\'s professional activity as the starting point, the present research addresses the creative and productive processes of contemporary architecture. Based on the project analysis as a way of explaining the problem being presented, three projects developed at different times along this evolution are presented as case studies: the Sydney Opera House, Australia; the H2Oexpo Pavilion in the island of Neeltje Jans, Netherlands; the Mercedes-Benz Museum in Stuttgart, Germany. By using a critical analysis we try to understand the relations in the use of computers in the development and building of these projects. The analysis of each case included the techniques that were used, the benefits obtained and innovations provided, as well as the difficulties, limitations and challenges that were faced from the very beginning of the project development until the building was constructed. In order to better understand the wealth and diversity of the theme, the collection of documents, bibliography and statements and positioning of the professionals involved were used to obtain a full and objective reading of the object. The present work was designed to bring a contribution to understand this relation, cooperating with the study of project issues related to the new media, as a way to establish a knowledge foundation to reflect on the use of graphic computation tools in the architectural universe.
108

Automated process of morphing a CAD geometry based on a measured point cloud

Augustsson, Rasmus January 2019 (has links)
As part of the quality process and to assure that the product meets all geometric requirements, the produced part is measured and compared to the nominal geometry definition. If the part deviates outside given tolerances, there is a need to understand the effect on aero performance and mechanical function. Hence, a new analysis model must be created that reflects the produced shape and form of the product. The current procedure for measuring the part is to use white light scanning equipment to analyze the deviation with the scanning software GOM™. The analysis model is then created using Space claim™ and is meshed and analyzed using Ansys™ software. The objective with this thesis is to investigate the capabilities within Siemens NX™ to automate the procedure as there is a need to be more efficient and reduce lead-time.The Design Research Method is used to develop the automated procedure. This is a systematic method that identifies the task, presents possible solutions to that task and then evaluates those solutions. That workflow is repeated until a satisfying solution is found.It is found that it is possible to create an automated procedure in Siemens NX. This automated procedure requires no user interaction while running, so the lead-time is drastically reduced. The automated procedure morphs the nominal geometry to create a new surface with better resemblance to the scanned geometry. About 90% of the original surface area is outside a tolerance of 0.1mm, after the automated procedure the new surface has about 90% of the surface area inside a tolerance of 0.1mm.The limiting factor for the procedure is the skill of the developer and not the capability of the software. Therefore it is thought that the procedure could be improved to create a surface completely inside the specified tolerance, given that a more skilled developer refines the procedure.
109

Desenvolvimento e validação de método analí­tico indicativo de estabilidade por CLAE-DAD-CAD para besilato de anlodipino e seus produtos de degradação / Development and validation of analytical method indicative of stability by HPLC-DAD-CAD for amlodipine besylate and its degradation products

Ichinose, Livia dos Santos 26 April 2018 (has links)
O presente estudo foi realizado com o objetivo de se desenvolver e validar uma metodologia analítica indicativa de estabilidade para separação e quantificação de anlodipino e seus produtos de degradação no medicamento besilato de anlodipino 5 mg por comprimido. Para tanto, realizou-se um estudo de degradação forçada, como forma de identificar os principais produtos de degradação, que podem vir a formar num estudo de estabilidade, bem como estabelecer possíveis rotas de degradação. Foi utilizada a técnica instrumental de separação, cromatografia a líquido (CL), com dois tipos de detectores: arranjo de diodos (DAD) e corona CAD (Detector de aerossol carregado), coluna cromatográfica Zorbax SB-Phenyl 1,8µm 4,6 x 50 mm Agilent® e fase móvel constituída por tampão pH3,0, metanol e acetonitrila sob condições de gradiente (75% de tampão pH 3,0, 15% de metanol e 10% de acetonitrila; no tempo de 10 minutos tem-se 20% de tampão pH3,0, 60% de metanol e 20% de acetonitrila; no tempo de 13 minutos tem-se 75% de tampão pH3,0, 15% de metanol e 10% de acetonitrila; e no tempo de 15 minutos tem-se 75% de tampão pH3,0, 15% de metanol e 10% de acetonitrila); fluxo de 1,0mL/min até 10 minutos; de 10,1 a 13 minutos tem-se fluxo de 0,5 mL/min; e de 13,1 a 15 minutos volta ao fluxo de 1,0 mL/min; e detecção em 238 nm. O método apresentou-se linear, preciso, exato, robusto e seletivo, e proporcionou resultados confiáveis, sem interferência de degradantes e impurezas. / This study was conducted in order to develop an analytical methodology indicative of stability for separation and quantification of the antihypertensive amlodipine and its degradation products in the drug amlodipine besylate 5 mg per tablet. For this development was performed a forced degradation study, in order to identify the main degradation products that may form in a stability study, as well as establish possible degradation routes. It was used the instrumental separation technique, liquid chromatography (LC) with two types of detectors: diode array (DAD) and corona CAD (Charged Aerosol Detector), chromatographic column Zorbax SB-Phenyl 4.6 x 50 mm 1,8µm Agilent® and mobile phase of buffer pH3,0, methanol and acetonitrile under gradient conditions (75% buffer pH3,0, 15% methanol and 10% acetonitrile; 10 minutes has 20% buffer pH3,0, 60% methanol and 20% acetonitrile; 13 minutes has become 75% of buffer pH3,0, 15% methanol and 10% acetonitrile; and 15 minutes has become 75% of buffer pH3,0, 15% methanol and 10% acetonitrile); flow 1.0 mL/ min up to 10 minutes; a flow 0,5 mL/min is obtained from 10,1 to 13 minutes; and from 13,1 minutes the flows returns to 1,0 mL/min; and detection in 238 nm. The method is linear, precise, accurate, robust and selective, and provided reliable results without interference from degradation products and impurities.
110

A utilização de computadores no projeto do edifício: conceitos e perspectivas. / Use of computers in building design: concepts and perspectives.

Cardoso, Francisco Ferreira 12 September 1986 (has links)
O computador vem ocupando atualmente um papel de crescente destaque na vida do homem moderno. Nesse contexto, também a área de projeto e, mais particularmente, a do projeto de edifícios, encontram nele uma ferramenta de inestimável valor. Seu atual nível de utilização nesse setor, no entanto, não tem se aproveitado de todo o potencial oferecido. Um dos motivos que justificam tal fato está no desconhecimento, por parte dos projetistas, das reais possibilidades de emprego dos computadores na área do projeto de edifícios. Nesse sentido, o objetivo dessa Dissertação é contribuir para a organização dos conceitos necessários a tais empregos, bem como montar um painel sobre as perspectivas de utilização dessa poderosa ferramenta na área. / The computer is playing an increasing role in the life of the modern man. With this point of view the design and more specifically the building design can make the computer a valuable tool. However, despite the potential of this equipment, it has not been yet properly used. This happens because the designers do not know the actual possibilities of the use of computers for the building designs. This Dissertation aims to organize the concepts related with this possibilities and also to bring out the prospective uses of this power full tool in this area.

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