Resumo: Este trabalho desenvolve um sistema para gerar energia elétrica com caldeira e turbina, para ocupar um nicho de mercado em que os sistemas a vapor existentes não são economicamente viáveis. O sistema utiliza a turbina Tesla que é compatível para essa faixa e não possui pás, podendo operar com vapor saturado fornecido por uma pequena caldeira consumindo lenha. A micro-geração proposta pode levar energia a milhões de brasileiros no campo, onde se dispõe de algum tipo de biomassa. Apesar do baixo custo da turbina Tesla, por ser de simples construção e compacta, e de suas incontáveis possibilidades de aplicação, se desconhece, até então, aplicações comerciais massivas devido ao baixo torque obtido nos protótipos feitos desde 1910 e por essa razão foi modificada. Este trabalho inova ao desenvolver um protótipo da turbina Tesla modificado para fornecer maior torque e ao comparar à turbina Tesla original. Devido à inexistência de equações que descrevem a turbina Tesla, um modelo matemático que permite projetar a turbina Tesla foi desenvolvido e validado por resultados experimentais e de simulação. Testes comparativos com duas turbinas com as mesmas dimensões mostraram que a turbina Tesla modificada apresentou eficiência superior à turbina Tesla original. Desenvolveu-se, também, um protótipo do sistema para micro-geração utilizando a turbina Tesla modificada, caldeira e gerador elétrico. Os custos do sistema e da energia gerada foram comparados com os de outros meios de geração mostrando serem competitivos economicamente para essa faixa de operação. / Abstract: This work develops a system to generate electric power with boiler and turbine that aims to occupy the niche of the market for which steam systems are not economically viable. The system uses a Tesla turbine, which is compatible to the range of power. Also, it does not have blades, being able to operate with steam delivered by a small boiler fed with wood. The proposed micro-generation system can take energy to millions of Brazilians living in the country, where some type of biomass is available. In despite of the low cost of the Tesla turbine, because it is compact and simple to build, and despite of its uncountable possibilities of applications, massive commercial applications of the technology are not found due to the low torque of the prototypes built since 1910. For this reason, the Tesla turbine was modified. This work is original since it develops a modified Tesla turbine prototype to furnish a higher torque when compared to an original Tesla turbine. Due to the lack of equations that model a Tesla turbine, a mathematical model was developed to allow the design of the Tesla turbine; it was validated by means of experimental and simulating results. The comparative tests with two turbines, with same dimensions, showed that the modified Tesla turbine presents a higher efficiency than the original Tesla turbine. A micro-generation system, using the modified Tesla turbine, boiler and electric generator, was also developed. The costs of the system and of the generated energy were compared with other means of generation and showed to be commercially competitive for that range. / Orientador: João Andrade de Carvalho Junior / Coorientador: Heraldo da Silva Couto / Banca: Luiz Roberto Carrocci / Banca: Teófilo Miguel de Souza / Banca: Paulo César Razuk / Banca: Rogério José da Silva / Doutor

A packed condenser and the auxiliary equipment were designed, built and tested for the condensation of steam in direct contact with Aroclor 1242 and 1248, which are commercial heat transfer agents and are immiscible with water. The co-current flow of steam and liquid, through a four inch inside diameter column packed with three-eighth inch ceramic Raschig rings, was studied. The packing heights used in the condensation of steam were estimated from the liquid temperature profile in the column. The heights of the transfer units for condensation and the average volumetric overall heat transfer coefficients were calculated. The height of the transfer unit for condensation was found to be affected largely by the mean viscosity and the flow rate of the liquid. Two empirical equations have been developed to describe the results of this study. HCU = F ( μ ) (n) where n = 1. 10 for Aroclor 1242 and n = 1. 16 for Aroclor 1248 is mean viscosity of the Aroclor in centipoise. For Aroclor 1242, F= 0.0535 + 8.90 x l0⁻⁶ L when L ≤ 2290 and F =-0. 0737 + 6. 44 x 10⁻⁵ L when L > 2290. For Aroclor 1248, F = 0. 02765 + 1. 244 x 10⁻⁵ L. L is superficial mass velocity of the Aroclor in lb /hr. ft² / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

This doctoral thesis investigates the impact of the “maker movement” on education, exploring how making, tinkering, coding, and play contribute to the development of 21st-century skills such as creativity, problem-solving, and computational thinking. Grounded in the construc- tionist approach, it emphasizes the intrinsic value of the learning process and interdisciplinary connections across STEAM (Science, Technology, Engineering, Arts, and Mathematics) do- mains. Starting from a robust exploration of the literature and an empirical study into youth perceptions, this research outlines an expansive educational framework that transcends traditional STEAM boundaries. The thesis illustrates the transformative journey, highlighting the formation of communities of practice and the launch of innovative outreach initiatives. It argues against offering a singular conclusion, instead presenting an integrated approach that weaves together theoretical insights with practical outcomes. The work supports pedagogical principles and demonstrates the benefits of innovative educational activities, advocating for a model of cross-disciplinary contamination and inclusivity. By bridging the gap between various fields of research and between academia and the broader community, this dissertation suggests a paradigm capable of producing impactful educational advancements. It presents a journey through educational models and methodologies, the ex- pansion of university missions, and the measurement of the impact of university FabLabs, thus contributing significantly to both academic discourse and practical applications in educational settings.

With the increase in production of biodiesel, a glut of glycerol has resulted in the world market. Glycerol, once a valuable chemical, has become a recalcitrant byproduct. It is also a potential renewable feedstock for hydrogen production. This study is focused on hydrogen production from glycerol steam reforming. During the initial stage, effect of process variables, such as system pressure (1-5 atm), temperature (327 – 727 oC), and water/glycerol molar ratio of (1:1-9:1) on hydrogen yield was investigated using a thermodynamic analysis. The equilibrium concentrations of different compounds were calculated by the method of Gibbs free energy minimization. The study revealed that the best conditions for producing hydrogen is at temperature > 627 oC, atmospheric pressure, and water/glycerol molar ratio (WGMR) 9:1. As a part of catalysts screening, 14 catalysts were prepared on monoliths and tested for their activity. Effects of those catalysts on hydrogen selectivity and glycerol conversion in temperatures ranging from 600-900 oC were discussed. Ni/Al2O3 and Rh/CeO2/Al2O3 were found to be the best performing catalysts based on hydrogen selectivity and glycerol conversion under the conditions investigated in this study. Also, the effect of WGMR, metal loading, and feed flow rate (FFR) were analyzed for the two best performing catalysts. Subsequently, effect of CeO2, MgO, and TiO2 supported Ni catalysts on hydrogen production from glycerol was studied. Effects of reaction temperature, FFR, and WGMR on hydrogen selectivity and glycerol conversion were also analyzed. Ni/CeO2 was found to be the best performing catalyst when compared to Ni/MgO and Ni/TiO2 under the experimental conditions investigated. The activation energy of glycerol reforming reaction was found to be 103 kJ/mol, and the reaction order with respect to glycerol was 0.23 over Ni/CeO2 catalysts based on the power law.

No description available.

Thesis. 1975. M.S.--Massachusetts Institute of Technology. Dept. of Mechanical Engineering. / Includes bibliographical references. / M.S.

Originally presented as a thesis (M.S.), M.I.T., Dept. of Civil Engineering, 1978, by Kenneth F. Najjar. / "COO-4114-8". Statement of responsibility on title page reads: Kenneth F. Najjar, John J. Shaw, E. Eric Adams, Gerhard H. Jirka and Donald R.F. Harleman. "January 1979." Bibliography: p. 182-187.

This report is a bachelor thesis at Karlstad University in collaboration with Invencon AB and Ranotor AB. The goal was to analyze a rotating valve leading water vapor through an inlet and five outlets. The quantifiable results that were addressed in this project are the mass flow through the outlets and the forces affecting the valve and its shaft (primarily radial forces). The tools used for this project are PTC Creo and ANSA for modelling and mesh as well as ANSYS-CFX and Matlab for computational help. The results show that the specified rotational speed of 4600 rpm doesn’t work for this model. The rotational speed was chosen because of an interest in this specific operating condition. A 3 mm radial gap between the rotating valve and the valve housing proved to cause a leakage in the form of pressure loss inside the valve. The boundary conditions that were laid out for this project are not valid for this operating condition. Since the difference in pressure is large (100 down to 1 bar) the flow is choked. A large difference in pressure also makes it important to adjust the total area of the outlets, since the pressure drop affects the density of the vapor. The forces on the rotating valve that were calculated (using ANSYS-CFX) create a foundation for choosing bearings for the valve. If the construction is modified, and/or the rotating valve will operate at a different rotational speed these forces will be subject to change. / Denna rapport är ett examensarbete på Karlstads Universitet i samband med Invencon AB och Ranotor AB. Målet var att analysera en roterande ventil som leder trycksatt vattenånga via ett inlopp och ut genom fem olika utlopp. De kvantifierbara resultaten som söktes var massflödet ut ur utloppen och krafterna som påverkar ventilen och axeln (främst radiellt). Verktyg som har använts för att analysera ventilen är PTC Creo och ANSA för modellering och mesh, samt ANSYS-CFX och Matlab för beräkningshjälp. Resultaten tyder på att det valda varvtalet, 4600 rpm, inte fungerar så bra. Varvtalet valdes pågrund av att man var intresserad av driftsfallet. Ett 3 mm radiellt avstånd mellan ventil ochventilhus visade sig även ge läckage i form av tryckfall inuti ventilen. Randvillkoren som är specificerade är inte giltiga vid detta driftsfall. Eftersom tryckförhållandet är så högt (100 till 1 bar) så är flödet chokat. Stor tryckskillnad gör det viktigt att anpassa arean på utloppen, då tryckfall påverkar densiteten. Krafterna på den roterande ventilen som beräknades (i ANSYS-CFX) är ett underlag vid val av lager för ventilen. Om konstruktionen modifieras, och/eller ventilen kommer att användas vid ett annat varvtal så kommer dessa krafter att ändras.

The master’s thesis deals with finding, measurement and evaluation of suitable physical parameters for quality analysis of saturated steam sterilization according to ČSN EN 285 + A2, which is the first step for the replacement of outdated processes of the analysis by modern automation systems. The other part of the project contains description of physical sterilization, saturated steam, methods and sensors for the monitoring of steam sterilization and the measurement and evaluation of these issues.

Diplomová práce se zabývá měřením, analýzou a následným nalezením vhodných fyzikálních parametrů pro analýzu kvality syté sterilizační páry. Tato práce si klade za cíl určit, kritické parametry systému vyvíječe páry pro provoz dle norem ČSN. Dílčí částí projektu je popis fyzikální sterilizace, syté páry, metod a senzorů pro kontrolu sterilizační páry.