15 research outputs found
Caracterização dos resíduos provenientes da geração de hidrogênio a partir de alumínio reciclável em meio básico e avaliação da potencial aplicação como substituto na indústria civil
No full textOrientador: Prof. Dr. José Viriato Coelho VargasCoorientador: Prof. Dr. Lauber de Souza Martins e Prof. Dr. Lúcio Cardozo-FilhoDissertação (mestrado) - Universidade Federal do Paraná, Setor de Tecnologia, Programa de Pós-Graduação em Engenharia e Ciência dos Materiais - PIPE. Defesa : Curitiba, 28/02/2025Inclui referênciasÁrea de concentração: Engenharia e Ciências dos MateriaisResumo: A transição para uma matriz energética sustentável é essencial para enfrentar desafios globais como mudanças climáticas, escassez de recursos naturais e segurança energética. Nesse contexto, a economia baseada no hidrogênio desponta como uma alternativa promissora, uma vez que esse elemento possui alto poder calorífico e pode ser produzido a partir de fontes renováveis. O uso de metais recicláveis, como o alumínio, oferece uma abordagem para processos sustentáveis de geração de hidrogênio. Neste estudo, analisou-se a geração de hidrogênio a partir de resíduos de latinha de alumínio, destinando-se o gás para a autonomia estendida de um veículo elétrico, enquanto o resíduo sólido foi avaliado quanto ao seu potencial na adição no âmbito da construção civil. Para a caracterização do resíduo, foram realizadas análises de Microscopia Eletrônica de Varredura (MEV) com Espectroscopia de Dispersão de Energia (EDS), Espectrometria de Emissão Óptica com Plasma Indutivamente Acoplado (ICP-OES) e Difração de Raios X (DRX), a fim de determinar sua composição química, estrutura cristalina e morfologia. Os resultados indicaram que, apesar da presença de impurezas metálicas como Cu, Mg e Fe nas latinhas recicladas, suas propriedades estruturais permanecem compatíveis com as do cavaco industrial, demonstrando que o processo de reciclagem não compromete significativamente a qualidade do material para o sistema de geração de H2 e consequentemente para a potencial destinação na indústria civil. Além disso, a análise DRX revelou a predominância de fases cristalinas, enquanto a presença de NaOH no meio reacional conferiu características básicas à estrutura do resíduo oriundo das latinhas. A fim de avaliar seu potencial na construção civil, foram conduzidos ensaios de resistência à compressão e módulo de elasticidade em diferentes formulações cimentícias com substituição da argamassa por 1% e 3% do resíduo. Os resultados demonstraram que a adição de 1% do resíduo foi a melhor alternativa, apresentando desempenho equivalente ao cimento padrão ao longo do tempo, sem comprometer as propriedades mecânicas. Em contrapartida, a formulação com 3% de adição, apesar de exibir boa resistência inicial, sofreu degradação aos 90 dias, sugerindo um limite de saturação do material na matriz cimentícia. Assim, o reaproveitamento do resíduo gerado na produção de hidrogênio demonstrou-se uma solução sustentável, promovendo a valorização de materiais reciclados e contribuindo para a redução dos impactos ambientaisAbstract: The transition to a sustainable energy matrix is essential to face global challenges such as climate change, scarcity of natural resources and energy security. In this context, the hydrogen-based economy emerges as a promising alternative, since this element has a high calorific value and can be produced from renewable sources. The use of recyclable metals, such as aluminum, offers an approach to sustainable hydrogen generation processes. In this study, the generation of hydrogen from aluminum can waste was analyzed, with the gas being used for the extended autonomy of an electric vehicle, while the solid waste was evaluated for its potential addition in the construction industry. To characterize the waste, Scanning Electron Microscopy (SEM) with Energy Dispersive Spectroscopy (EDS), Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) and X-ray Diffraction (XRD) analyses were performed in order to determine its chemical composition, crystal structure and morphology. The results indicated that, despite the presence of metallic impurities such as Cu, Mg and Fe in the recycled cans, their structural properties remain compatible with those of industrial chips, demonstrating that the recycling process does not significantly compromise the quality of the material for the H2 generation system and consequently for its potential use in the civil industry. Furthermore, the XRD analysis revealed the predominance of crystalline phases, while the presence of NaOH in the reaction medium conferred basic characteristics to the structure of the waste from the cans. In order to evaluate its potential in civil construction, compressive strength and modulus of elasticity tests were conducted on different cement formulations with mortar replacement by 1% and 3% of the waste. The results demonstrated that the addition of 1% of the waste was the best alternative, presenting performance equivalent to standard cement over time, without compromising the mechanical properties. In contrast, the formulation with 3% addition, despite exhibiting good initial strength, suffered degradation after 90 days, suggesting a saturation limit of the material in the cement matrix. Thus, the reuse of the waste generated in hydrogen production proved to be a sustainable solution, promoting the valorization of recycled materials and contributing to the reduction of environmental impact
Tradução dos contos Cacoethes scribendi e A razão por trás da razão, de Charles Bukowski
No full textIn this paper we present two translation’s proposals to Portuguese of the short stories Cacoethes Scribendi and The Reason Behind Reason, from the book Absence of the Hero written by Charles Bukowski. In first place, we present Charles Bukowski as a poet and writer and his literary work published in Brazil. After that, some selected aspects about the translation process of the texts from Bukowski and a brief analysis from the two short stories translated are discussed. Bukowski provided autobiographical data for his productions, therefore by analyzing the two short stories from the book Absence of the Hero we also intended to trace the links between the character’s representation and the personality of the author. There are many elements ofhis own life disguised by fiction content that aims at creating a picaresque character to his novels. Besides discussing crucial aspects regarding the author and theautobiographical content of his writings, we explain the translation process of the two short stories that are still not published in Portuguese.No presente artigo são apresentadas duas propostas de tradução para o português dos contos Cacoethes Scribendi e The Reason Behind Reason, do livro Absence of the Hero, de Charles Bukowski. Primeiramente, busca-se se apresentar o poeta e escritor Charles Bukowski e situar temporalmente suas publicações traduzidas no Brasil. Procura-se discutir alguns aspectos particulares sobre a tradução das obras desse autor, bem como, trazer uma breve análise sobre os dois contos traduzidos. Por ser Bukowski um autor que, comprovadamente, trazia dados autobiográficos para as suas produções, ao analisar os dois contos do livro Absence of the Hero pretende-se também traçar essas ligações entre a representação do personagem que se espelha em traços da personalidade do autor. Bukowski colocou em seus romances elementos de sua vida encobertos por certo teor de ficção a fim de criar um personagem picaresco para o leitor, esses elementos são descritos ao longo de seus trabalhos. Além de trazer uma discussão sobre o autor e o teor autobiográfico de sua obra, são discutidos alguns caminhos tradutórios traçados para a tradução desses dois contos que ainda não possuem traduções publicadas em português
Editorial
No full textThe editorial of Thermal Engineering of this issue continues the discussion on scientific research needs in vital areas in which thermal engineering has important participation. The main goal is to motivate the readers, within their specialties, to identify possible subjects for their future research. The word "energy" has a historical origin that goes back to ancient Greek philosophy. Derived from the Greek word "energeia", which described the ability of a being or system to perform work or activity, the notion of energy was later incorporated into Latin as "energy" which was also used to describe the vital force that animates living beings. With the development of physics and engineering in the 19th century, the concept of energy was refined and acquired a more concise scientific meaning, linked to the ability to produce changes, or perform work in a physical system. Energy is recognized as the corner stone of several field of knowledge, considered a key concept for science, technology and economics. Energy is fundamental not only in the description and analysis of natural phenomena, but also in discussions related to energy resources, efficiency, sustainability and their impact in the global economy. Understanding and mastering the principles of energy generation is essential for the understanding natural processes, as the conception of strategies to advance the development of technologies and nations. Therefore, energy plays a decisive role in modern society, with significant implications in social and environmental sciences and in the quest for sustainable development. An economic study combined with thermodynamics principles is called thermoeconomic analysis. When taken into consideration, thermoeconomic analysis brings a new perspective for the decision making process when a current of new manufacturing process, product development, new energy generation strategies and its technologic applications are under scrutiny. Several well-known technology applications, from the thermodynamic point of view, have been seen with different lenses when they are studied considering thermoeconomic principles. Such analysis does not weaken previous conclusion but promote development. It does not only enhance the technology itself but also promotes scientific growth, since more scientific investigation must be performed to make a process not only highly efficient but also economic viable. The mission of Thermal Engineering is to document the scientific progress in areas related to thermal engineering (e.g., energy, oil and renewable fuels). We are confident that we will continue to receive articles’ submissions that contribute to the progress of science
ESTUDO COMPARATIVO DO CRESCIMENTO DE MICROALGAS Tetradesmus Obliquus EM DIFERENTES MEIOS DE CULTIVO
No full textMATHEMATICAL MODEL OF A FILTER FOR CO2 REMOVAL OF CONTINUOUS GAS SUPPLY FOR AN ALKALINE MEMBRANE FUEL CELL
No full textThe pursuit of new technologies capable of generating clean and sustainable energy has been growing over the years, not only for high-power generation systems but also to support the change from the world's dependence on internal combustion engines powered by fossil fuels. The Paris Agreement and the United Nations Sustainable Development Goal 2030 are examples of the international interested in switching their energy matrices to sustainable sources and reducing the use of fossil fuels. Fuel cells (FCs) have emerged as potential replacements for internal combustion engines and fossil fuel-powered generators. Due to their economic viability to continuously and safely generate electricity, FC’s are used in stationary energy generation systems and electric vehicles. Fuel cells are devices that convert chemical energy into electricity through a spontaneous redox reaction between two gases, hydrogen, and oxygen. The products of that reaction are the electric energy and water. There are two types of low-temperature fuel cells mainly used, the Proton-Exchange Membrane Fuel Cell (PEMFC) and the Alkaline Membrane Fuel Cell (AMFC). They differ in the chemical reactions that take place in the electrodes and in the membrane, that can be either acid or alkaline. The membrane allows the ions (cations or anions) from one side of the FC to reach the other side completing the overall chemical reaction. PEMFC is most commonly used due to its versatility, as it can be applied in stationary and mobile systems. However, the AMFC has superior efficiency and similarity in membrane manufacturing, although its use is restricted when is present in the air supply. When the coming in with the air supply reacts with the KOH present in the membrane, it forms potassium carbonates () in the membrane, which impairs the efficiency of the AMFC. The present study proposes a mathematical model of the capture through a filter composed of a container with KOH solution placed between the air supply and the fuel cell. The goal is to quantify the capture of carbon dioxide the efficiency of the filter through mass balance, inhibiting and allowing only the passage of air without the presence of substances that contaminate the alkaline membrane. We also consider the need of filter replacement or replenishment, ensuring a constant pure air flow to the AMFC. The control of passage to the alkaline membrane would provide increased reliability in the use of fuel cell technology and result in higher efficiency
MODELAGEM TERMODINÂMICA DA REAÇÃO QUÍMICA DE PRODUÇÃO DE HIDROGÊNIO A PARTIR DE ALUMÍNIO RECICLADO
No full textDEVELOPMENT OF A METHODOLOGY FOR UTILIZING INFRARED IMAGING TO ANALYZE THERMAL RESPONSE AND DIAGNOSE BREAST CANCER
No full textBreast cancer is among the diseases that kill the most women in Brazil and worldwide. The lethality of the disease is related to its stage, that is, to the degree of the disease's involvement in the individual. Early diagnosis is, therefore, of utmost importance to increase the chances of cure and patients' survival. The thermography exam, a safe method free of radiation exposure and physical contact, is capable of detecting the first metabolic alterations caused by a tumor. However, it provides only metabolic information and not anatomical information about the tumor, besides being strongly influenced by environmental factors (humidity, radiation, room temperature) and patient factors (age, breast shape and size). The objective of the work is, therefore, to develop a standardized method of using thermography through infrared imaging for the diagnosis of breast cancer. The method aims to provide anatomical information about the tumor, based on metabolic information from infrared imaging. For this purpose, breast imaging exams will be transformed into 3D STL models and subsequently smoothed and discretized using a uniform cubic mesh. The Method of Volume Elements divides the domain to be studied into control volumes, with each element of the mesh corresponding to a volume element of the breast. Using physical laws and empirical and theoretical correlations for mass, heat, and fluid flow, each volume element can be represented by a system of ordinary differential equations, which indicate the heat exchange and blood flow in each unit. In this way, the internal and surface temperature distributions of the breast as functions of time, space, and known initial and boundary conditions can be calculated. By comparing the obtained surface temperature of the breast and the actual infrared image temperature distribution of the breast, it will be possible to simulate the internal temperature distribution of the breast and obtain a precise estimate of the tumor location. This approach could make thermography more independent of complementary exams, as well as enable accurate early-stage cancer diagnosis and tumor depth prediction
INNOVATIVE ENERGY SOLUTION: SUSTAINABLE ENERGY GENERATION VIA FORESTRY WASTE INCINERATION IN RANKINE CYCLE POWER PLANT
No full textThe use of organic solid waste for energy generation has become a promising and sustainable solution to address environmental issues, particularly those related to fossil fuel consumption. Producing energy from forest biomass offers a viable and eco-friendly alternative, aiming to reduce greenhouse gas (GHG) emissions. A key factor for the sustainable production and supply of bioenergy is the abundant availability of suitable raw materials. Among these, forestry pruning waste stands out as a significant resource, often poorly managed and improperly disposed of. An environmentally responsible way to utilize these residues is through incineration, using the resulting hot gases from combustion for energy generation. The primary goal of this study was to quantify the energy generation potential from the forestry pruning waste of UFPR. To achieve this, the organic waste from UFPR was chemically characterized through Proximate Analysis, along with determining the higher heating value and moisture content. A mathematical model was developed to quantify the generation of electrical energy, simulating the steady-state operation of the incineration system. Additionally, a mathematical model of the Rankine cycle plant was created to predict the necessary thermal exchange areas in the plant. The analyses of the collected samples showed heterogeneity, with low ash content at 0.76% and moisture content ranging from 10.67% to 16.80%, but an average high higher heating value of 19.39 MJ.kg-1. The mathematical model predicted that these residues could be sustainably used for electricity generation, with a power output of 54.28 kW. The chemical analysis results led to optimization in the thermal exchange areas of the Rankine cycle plant, facilitating the efficient utilization of hot gases produced from the incineration of these forestry residues
