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Biossor??o utilizando alga marinha (sargassum sp.) aplicada em meio org?nicoMoreira, Albina da Silva 07 December 2007 (has links)
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Previous issue date: 2007-12-07 / In this work, biosorption process was used to remove heavy metals from used automotive lubricating oils by a bus fleet from Natal-RN-Brazil. This oil was characterized to determine the physical-chemistry properties. It was also characterized the used oil with the aim of determining and quantifying the heavy metal concentration. Fe and Cu were the metals existent in large concentration and these metals were choused to be studied in solubilization process. For the biosorption process was used the seaweed Sargassum sp for the study of influencing of the metals presents separately and with other metals. It was also studied the effect of the protonation treatment of alga with the objective to know the best efficiency of heavy metals removal. The study of the solubilization showed that the presence of more than a metal favors the solubilization of the metals presents in the oil and consequently, it favors the biosorption process, what becomes interesting the perspective application in the heavy metals removal in lubricating oils used, because the presence of more than a heavy metal favors the solubility of all metals present. It was observed that the iron and copper metals, which are present in large concentration, the protonated biosorbtent was more effective. In this study we used as biomass the marine alga Sargassum sp to study the influence of agitation velocity, temperature and initial biomass concentration on the removal of iron and copper from used lubricant oils. We performed an experimental design and a kinetic study. The experiments were carried out with samples of used lubricant oil and predetermined amounts of algae, allowing sufficient time for the mixture to obtain equilibrium under controlled conditions. The results showed that, under the conditions studied, the larger the amount of biomass present, the lower the adsorption capacity of the iron and of the copper, likely due to a decrease in interface contact area. The experimental design led us to conclude that a function can be obtained that shows the degree of influence of each one of the system variables / No presente trabalho escolheu-se o ?leo lubrificante automotivo usado de uma frota de ?nibus da cidade de Natal-RN-Brasil. Este ?leo foi caracterizado, indicando que os metais contidos em maior concentra??o s?o Ferro (Fe) e Cobre (Cu). Para o processo de biossor??o utilizou-se a alga marinha feof?cea Sargassum sp para se estudar a influ?ncia da presen?a de metal isoladamente e com outros metais. Estudou-se ainda o efeito do tratamento deprotona??o na alga visando a efici?ncia de remo??o de metais pesados. O estudo da solubiliza??o mostrou-se interessante para a aplica??o na remo??o de metais pesados em ?leos lubrificantes usados, j? que a presen?a de mais de um
metal pesado favorece a solubilidade de todos os metais presentes. Observou-se que, para os metais Fe e Cu, que est?o presentes no ?leo em maiores concentra??es, a utiliza??o do biossorvente protonado foi mais eficiente. Para estudar a influ?ncia da velocidade de agita??o, da temperatura, da quantidade de biomassa e da concentra??o inicial de biomassa na remo??o de Fe e Cu presentes em ?leos
lubrificantes usados utilizou-se a alga marinha Sargassum sp. protonada. Foi realizado um planejamento experimental e um estudo cin?tico. A partir dos resultados obtidos observou-se que nas condi??es estudadas, ? medida que a quantidade de biomassa aumenta, ? menor a capacidade de adsor??o do Fe e do Cu. Do planejamento experimental p?de-se concluir que ? poss?vel obter uma fun??o que mostre o n?vel de influ?ncia de cada uma das vari?veis do sistema. Sendo que para o Fe a vari?vel mais relevante foi a quantidade de biomassa e para o Cu foi a temperatura
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Circuito do livro escolar : elementos para a compreensão de seu funcionamento no contexto educacional amazonense 1852-1910 / The circuit of textbooks: elements to understand its functioning in the Amazonian school context, 1852-1910Correa, Carlos Humberto Alves 09 January 2006 (has links)
Orientador: Lilian Lopes Martin da Silva / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Educação / Made available in DSpace on 2018-08-07T07:55:25Z (GMT). No. of bitstreams: 1
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Previous issue date: 2006 / Resumo: Este trabalho incide sobre a história dos livros escolares, tomando como objeto de análise o funcionamento do circuito organizado em torno deles ao longo da segunda metade do século XIX e na primeira década do século XX no contexto escolar amazonense. Nos últimos anos tem crescido o número de estudos que tomam a história do livro e das edições didáticas como objeto de investigação. O campo da história da educação tem sido especialmente fértil para o desenvolvimento dessa produção, uma vez que novos interesses e interrogações passaram a orientar o trabalho dos pesquisadores em relação a esse gênero de livro. É no interior desse contexto de produção que este trabalho se inscreve. Para o seu desenvolvimento priorizou-se o modelo de análise proposto por Robert Darnton (1990), ao examinar o circuito de comunicação percorrido pelos livros nas diferentes fases que marcam sua existência: produção, difusão e consumo. Operando com um conjunto diversificado de fontes, o trabalho evidenciou algumas facetas do circuito do livro escolar no Amazonas, colocando em cena aspectos até então pouco conhecidos, tais como: os sujeitos, as práticas e os dispositivos que estiveram envolvidos na dinâmica de funcionamento deste circuito / Abstract: This thesis deals about the history of textbooks taking as the object of analysis the functioning of the circuit that was organized around them on the second half of the 19th Century and the first decade of the 20th Century in the Amazonian school context. The number of studies that takes book history and didactic editions as objects of research has been increasing in Brazil. It is in the interior of that production context that this work is inserted. For the development our research, we have used Robert Darnton¿s model of analysis in regard to the communication circuit made by the books in the different phases of their existence: production, diffusion and consumption. Working with different sources, the thesis showed some faces of textbook circuit in the State of Amazonas zeroing on some aspects not very well known, such as: the subjects, the practices and devices that were involved in the dynamics of textbook circuit / Doutorado / Educação, Conhecimento, Linguagem e Arte / Doutor em Educação
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O uso do território na cidade de União dos Palmares – AL: o circuito inferior nas suas áreas central e periférica / The use the territory in the union of Palmares - AL city: the lower circuit in its centrla and peripheral areasSilva, Amistson Lopes da 31 August 2018 (has links)
This present search seek to understand the urban dynamics in the city of União dos Palmares - State of Alagoas, in the current period of Globalization, from the activities of lower circuit of the urban economy, especially the use about territory, synonymous with geographical space, by the agents of the small businesses that animate the popular economy of the city. Therefore, based on the theory of the two urban economy circuits in the underdeveloped countries, proposed by Milton Santos (2008c), an important theoretical and methodological way to understand urbanization, we selected the main plots of the built environment that the population uses to work. The city chosen here as a geographical situation (SILVEIRA, 1999) it has its genesis linked to the regional urbanization context, driven by the expulsion of workers from their lands, as well as by the floods that affected the Mundaú river basin in the last hundred years. With the implementation of several services over the last decades, including the public sector, the city has emerged like an important urban center in the mountainous region of Quilombos, but it was mainly from the 1970s that the expansion of large peripheral districts through invasions, donations by public authorities, by sales and by the housing reconstruction programs for the homeless. In this context is conformed in União dos Palmares city, a poor population, which seeks to survive in various ways in the central and peripheral areas. In order to understand the manifestation of urban poverty, we investigated the behavior of the lower central and residential circuit in the largest neighborhoods of the city: Center, Roberto Correia de Araújo, Nova Esperança housing and Newton Pereira Gonçalves housing. Thus, understanding these economic activities reveals how urban poverty manifests itself in places and demonstrates, especially, the political-institutional need that should be active from people to the economy, not the other way around. / A presente pesquisa busca compreender a dinâmica urbana de União dos Palmares – AL no período atual da Globalização a partir das atividades do circuito inferior da economia urbana, sobretudo o uso do território, sinônimo de espaço geográfico, pelos agentes dos pequenos negócios que animam a economia popular da cidade. Para tanto, com base na teoria dos dois circuitos da economia urbana nos países subdesenvolvidos, proposta por Milton Santos (2008c), importante caminho teórico e metodológico para se entender a urbanização, selecionamos as principais parcelas do meio ambiente construído que a população utiliza para desenvolver o trabalho. A cidade aqui escolhida como situação geográfica (SILVEIRA, 1999) da pesquisa tem sua gênese ligada ao contexto regional de urbanização, movida pela expulsão de trabalhadores de suas terras, bem como pelas enchentes que acometeram a bacia do Mundaú nos últimos cem anos. Com a implantação de diversos serviços ao longo das últimas décadas, inclusive do setor público, a cidade vem se destacando como um importante centro urbano na região Serrana dos Quilombos, mas foi principalmente a partir da década de 1970 que se iniciou de fato o processo de expansão de grandes bairros periféricos, por meio de invasões, doações por parte do poder público, pela venda e pelos programas de reconstrução de habitações para os desabrigados das enchentes. Nesse contexto é conformada na cidade de União dos Palmares, uma população pobre, que busca sobreviver de diversas formas nas áreas central e periférica. Para compreendermos a manifestação da pobreza urbana, investigamos o comportamento do circuito inferior central e residencial nos maiores bairros da cidade: Centro, Roberto Correia de Araújo, Nova Esperança e Newton Pereira Gonçalves. Destarte, a compreensão dessas atividades econômicas revela como a pobreza urbana se manifesta nos lugares e demonstra, sobretudo, a necessidade de uma ação político-institucional que parta dos sujeitos sociais, de suas demandas para a economia e não o contrário.
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Resíduos de poli (tereftalato de etileno) e de pneu na confecção de pisos flutuantes para o isolamento do ruído de impacto / Poly (ethylene-terephthalate) and tyre residues in floating floors for impact sound insulationCARVALHO, Maria Luiza de Ulhoa 21 August 2009 (has links)
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Previous issue date: 2009-08-21 / The demographic growth has created a gain in urban solid waste that deteriorates the citizen s
quality of life. High buildings represent the main way for accommodations in big cities for
these growing urban populations. However, impact sound insulation has shown itself quite
poor. In order to propose an alternative way of minimization to the two problems, residue
generation and impact noise, this study aimed to investigate the viability of using poly
(ethylene-terephthalate) - PET and rubber tire residues for impact sound insulation in floating
floors. Plates of 1 m² with thickness of 1.5 and 2.5 cm to 1:4 and 1:5 (ciment:residue) ratios
were molded for the acoustic experiments, as well as portable mortar slabs covered with high
and popular quality floor coverings. The main methods used were ISO 140-7 (1998) for
measuring the standardized impact sound pressure level, L nT, in one-third-octave bands and
ISO 717-2 (1996) to calculate the weighted standardized impact sound pressure level, L nT,w.
Both residues presented high sound insulation in relation to their references. It was observed
that the results for the PET specimen were superior to those of the rubber tires residue.
However, the results among the residues presented different tendencies as their ratio changed.
While the impact sound insulation of the rubber tires samples decreased with the increase of
residue, PET samples presented more insulation with residue increase. Another observed
factor was that the high quality floor covering presented a significant superior impact sound
isolation compared to the popular floor covering. Considering all results, it is possible to
conclude that the use of the studied residues in floating floors contributes to impact sound
insulation / O crescimento demográfico mundial tem criado um aumento na geração de resíduos sólidos
urbanos e deteriorado a qualidade de vida dos cidadãos. As edificações altas se apresentam
como a principal forma de acomodação da crescente população nas cidades, no entanto, o
conforto sonoro em relação ao ruído de impacto tem se mostrado precário. Com o intuito de
propor uma alternativa de minimizar ambos os problemas, a geração de resíduos e o ruído de
impacto, a presente pesquisa teve como principal objetivo estudar a viabilidade de uso dos
resíduos de poli (tereftalato de etileno) - PET e do pneu inservível na confecção de pisos
flutuantes no isolamento do ruído de impacto. Placas de 1 m² com traço 1:4 e 1:5
(cimento:resíduo) nas espessuras de 1,5 e 2,5 cm foram moldadas para realizar os ensaios
acústicos, assim como placas de argamassa armada revestida com cerâmica popular e de alto
padrão. As principais metodologias utilizadas foram a ISO 140-7 (1998) para obter o nível de
pressão sonora de impacto padronizada por bandas de terças de oitavas, L nT, e a ISO 717-2
para ponderar o valor único do nível de pressão sonora de impacto padronizado e ponderado,
L nT,w. Ambos resíduos apresentaram isolamento superior em relação às respectivas
referências. Observou-se que o isolamento do ruído de impacto das amostras com PET foi
superior às com pneu. No entanto, os resultados entre os resíduos apresentaram tendências
diferentes com a mudança do traço. Enquanto que o isolamento das amostras do pneu decaiu
com o acréscimo do resíduo, as amostras com PET tiveram um ganho maior com o aumento
do resíduo. Outro fator observado foi que o contrapiso com cerâmica de alto padrão
apresentou um efeito significativo do isolamento em relação à cerâmica popular. Em vista de
todos os resultados pode se concluir que é viável a utilização dos resíduos estudados na
confecção de pisos flutuantes para o isolamento do ruído de impacto
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Geografia da fome: a expressão dramática da desigualdade sócio-espacial brasileira / Geography of hunger: the dramatic expression of Brazilian socio-spatial inequalitiesMaria Leidiana Mendes de Oliveira 03 December 2013 (has links)
Este trabalho tem como objetivo discutir a fome numa perspectiva geográfica. A importância do tema se deve ao fato de que a alimentação é fundamental para a manutenção da vida; portanto, essencial à existência. Assim, inferimos a fome como um processo constituído ao longo da nossa história, no caso específico do Brasil, o reflexo vigente de uma formação desigual. Refletir sobre a formação territorial de nosso país, ajuda-nos a apreender a formação sócioespacial brasileira. Essa discussão nos auxilia também a entender como a fome se revela no território usado brasileiro. A Geografia exibe os usos desiguais do território, com a extensão do meio técnico-científico-informacional que chega para alguns e continua a excluir muitos. Acontecimento este que amplia a perversidade decorrente, nesta contemporaneidade, do alijamento da maioria da população do meio referido anteriormente. Discutir a fome geograficamente é discutir também o uso do território não apenas pela produção, mas pelas possibilidades que todos devem ter de produzir alimentos, inclusive discutir a sua distribuição para aqueles que ainda passam fome. O território usado, portanto, se transforma numa poderosa categoria de análise social, importante argumento para a apreensão da fome como processo político, e não como fenômeno. / This paper aims to discuss hunger in a geographical perspective. The topic is important due to the fact that food is essential for the maintenance of life, so, essential to existence. Thus, we infer the hunger as a process consisting throughout our history, in the specific case of Brazil, the reflection effect of unequal formation. Reflecting on the territorial formation of our country, helps us to grasp the Brazilian socio-spatial formation. This discussion also helps us to understand how hunger is revealed in Brazilian territory. Geography displays the unequal uses of the territory, with the extension of the technicalscientific- informational arriving for some and continuing to exclude many. This event extends the resulting perversity, this contemporary, the jettisoning of the majority of the middle mentioned above. To discuss hunger geographically also means to discuss the use of the territory not only for production, but the possibilities that everyone should have to produce food, including discussing their distribution to those who are still hungry. Therefore, the territory which is used becomes a powerful category of social analysis, an important argument for the seizure of hunger as a political process, and not as a phenomenon.
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Towards more circular economy and sustainable consumption : The practice of second hand clothing consumption in Sweden.Mahmoud, Abdelrahman January 2018 (has links)
The rapid increase in clothing consumption over the last decades has meant a significant burden on the environment. Some examples of this are the high consumption of natural resources and land, increasing amounts of carbon emissions, excessive use of toxic chemicals, polluting air, land and water and increasing amounts of waste. The average clothing consumption in Europe is far higher than the world average, especially in Nordic countries including Sweden. Adopting and encouraging more circular economies is a part of the European commission‘s strategy to achieve sustainable consumption of resources and protection for environment. The purpose of this Research is to study the possibilities of improving the practice of second hand clothes consumption in Sweden and make it more effective towards the goal of sustainable consumption and circular economies. In order to achieve this goal, it is necessary to understand the challenges and find abilities for improvement in the value chain of used clothes in Sweden, with focus on the reverse logistics system of used clothes (collection and sorting processes) as well as the market of second hand clothes. In order to achieve the purpose of the study, the conceptual framework has been formulated upon studying relevant literature and results of previous studies. Value chains of three charity organizations have been studied and empirical data have been collected through semi-structured interviews with participants from these three organizations. The empirical findings have been interpreted in relation to the conceptual framework and the results of previous studies, in order to answer the research questions. The results of the study showed potential for improvement and development in the reverse logistics system (collections and sorting processes) of used clothes, as well as in the Swedish market of second hand clothes. However, benefiting of this potential requires collaboration between all stakeholders in the value chain of used clothes, including individuals (either in a position of donors or consumers), interested businesses (nonprofit or commercial organizations), government, municipalities, politicians and finally the private sector in clothing industry.
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Play therapy: an overview and marketing planMcNeil Sallman, Cyndi January 1900 (has links)
Master of Science / Department of Family Studies and Human Services / Anthony Jurich / Play is essential to child development because it contributes to the cognitive, physical, social, and emotional well-being of children and youth. The integration of play and play therapy techniques with child and family therapy offers a creative, age appropriate way to provide mental health treatment. This report offers an overview of play therapy, the therapeutic value of play, the historical background, theory, techniques, materials, and settings. Further, it provides the reader with many therapeutic modalities in which to implement play in family therapy. Because play therapy is a specialized field, this report also provides the reader with information on how to use this to create a marketing niche. This report was written with the Masters’ or Doctoral student in mind, as well as practicing therapists; with hopes to provide them a creative avenue in which to enhance their current therapeutic modalities.
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Automatisk kontroll av status för switch-portar / Automatic control of switchport statusDan, Östergren January 2020 (has links)
I stora nätverksmiljöer kan det idag vara svårt att få en komplett sammanställning av hur många switch-portar som är i bruk. Den lösning som vanligtvis används är manuell inloggning till aktuell switch för kontroll, ett moment med tidsåtgång och som ofta utförs vid enstaka tillfällen. Information riskerar därför att upptäckas för sent med en åtgärd som blir reaktiv. Metoder för att tillgängliggöra informationen på ett sådant sätt att den till stor del kan bli proaktiv kan istället möjliggöra åtgärder i tid men även tillhandahålla aktuell information mer lättillgängligt och i slutändan spara både tid och utgifter för ett företag. Arbetet inriktar sig på framtagandet av en lösning med specifika krav med en inriktning för att förenkla nuvarande moment; att på ett enkelt sätt kunna ta del av dagsaktuell information om status för switch-portar, att kunna få en övergripande bild av fördelningen av switch-portar för en anläggning och möjlighet för notifiering vid gränsöverskridelser. Inledande görs en undersökning av aktuella lösningar som finns att tillgå inom området idag, där flera visar sig ha brister men även saknar nödvändiga funktioner. Då de lösningar som finns tillgängliga idag inte stämmer överens med kraven finns en motivering till framtagandet av en lösning med egna funktioner. Den lösning som tas fram utvecklas med separata funktioner för att inhämta information, tolka, presentera och notifiera information för administratör. För att garantera en stabil lösning med kontinuerlig drift installerades en server i en extern datahall där en linuxdistribution användes. Två olika protokoll för inhämtning av information jämförs med praktiska tester, inloggning via SSH, samt SNMP-poll, där den valda lösningen bygger på SSH som metod på grund av säkerhetsaspekter, men där SNMP visar mer kompatibilitet mellan tillverkare och modeller av hårdvara. Vidare beskrivs tillvägagångssätt hos de funktioner som utvecklats för tolkning av inhämtad information samt de svårigheter som uppstått i samband med detta, för undvikandet av feltolkningar. Olika alternativ för presentation av information till administratör jämförs, där den valda lösningen blev åtkomst via webbsida, detta på grund av det grundläggande stöd oberoende av plattform. Något som exempelvis en applikation inte kan ge i samma omfattning. Bland de olika notifieringsmetoder som undersöktes föll valet även i detta fall på en plattformsoberoende metod, där notifiering via e-post ansågs både enkel att implementera och med ett brett stöd hos klienter. Varningar vid förangivna kriterier av antal lediga switch-portar kunde därmed tas emot av administratör. Samtliga funktioner fungerade vid utförandet som planerat och lösningen används av kunden. Det finns några förslag på förbättringsåtgärder där SNMP istället med fördel kan användas med bredare stöd hos andra tillverkare och modeller, samt även skyddsfunktioner vid tolkning av information. / In large network environments today, it can be difficult to get a complete summary of how many switchports are in use. The solution that is usually used is manual login to the current switch for control, a step with time consumption and which is often performed on occasion. Information therefore risks being discovered too late with a measure that becomes reactive. Methods for making the information available in such a way that it can largely become proactive can instead enable timely action but also provide up-to-date information more easily accessible and ultimately save both time and expenses for a company. The work focuses on the development of a solution with specific requirements with a focus on simplifying current steps; to be able to easily access up-to-date information on the status of switchports, to be able to get an overall picture of the distribution of switchports for a facility and the possibility of notification in the event of border crossings. Initially, an investigation is made of current solutions that are available in the area today, where several turn out to have shortcomings but also lack the necessary functions. As the solutions available today do not comply with the requirements, there is a motivation for developing a solution with its own functions. The solution that is put together is developed with separate functions for collecting information, interpreting, presenting and notifying information to the administrator. To ensure a stable solution with continuous operation, a server was installed in an external datacenter where a Linux distribution was used. Two different protocols for obtaining information are compared with practical tests, login via SSH, and SNMP-poll, where the chosen solution is based on SSH as a method due to security reasons, but where SNMP shows more compatibility between manufacturers and models of hardware. Furthermore, the procedures of the functions that have been developed for the interpretation of collected information and the difficulties that have arisen in connection with this, for the avoidance of misinterpretations are described. Different options for presenting information to the administrator are compared, where the chosen solution was accessed via a website, this is due to the basic support regardless of platform. Something that, for example, an application cannot provide to the same extent. Among the various notification methods examined, the choice also fell in this case on a platform-independent method, where notification via e-mail was considered both easy to implement and with broad support among clients. Warnings for the specified criteria of the number of available switchports could thus be received by the administrator. All functions worked during the execution as planned and the solution is used by the customer. There are some suggestions for improvement measures where SNMP can instead be used to advantage with broader support from other manufacturers and models, as well as protection functions when interpreting information.
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Estudio del comportamiento y de la influencia en el desgaste de los aceites lubricantes de baja viscosidad en MCIAMiró Mezquita, Guillermo 10 March 2017 (has links)
The current socio-economic and environmental context worldwide, with different actors and needs, requires continued progress towards energy efficiency and environmental improvements in order to create a sustainable future, and this implies a scientific and technologic effort to achieve the proposed goals.
Transport by propulsive systems based on reciprocating internal combustion engines (ICE) is one of the major agents affecting future environmental sustainability. Included in the wide research done in this area, one of the options considered is the use of low viscosity oils (LVO) as an option for increasing ICE efficiency. This technology presents a modest contribution to the efficiency target, but the excellent cost-effectiveness ratio and ease of application to current and future vehicle parc are two reasons that has driven towards research into the use of these oils.
The low viscosity oils base their contribution to improving energy efficiency by reducing mechanical losses associated with viscous friction in hydrodynamic regime. This in turn reduces energy consumption to operate the system, and it is associated with a reduction of pollutant emissions for the same performance.
The hypotheses of application of LVO are well founded, but there are a number of uncertainties surrounding the application of low viscosity oils in MCIA today. On one hand, it is possible to expect a modification of the ICE tribological performance, as well as changes in lubricant performance which ultimately could lead to a reduction in the period of useful life, an early lubrication failure or other consequences difficult to predict. Also, a reduction in viscosity may increase wear production, so there is also an interest in the remote diagnosis of lubricated system status.
In this Thesis a concise review of the state-of-the-art has been done applied to ICE tribology and lubricating oils, with special interest in the low viscosity oils development. Then, a series of different studies have been performed to deepen the understanding of oil performance and its influence on ICE wear, supported by a set of physico-chemical analytical techniques applied to diagnose the state of the lubricating oil.
The different results obtained show that the application of low viscosity oils in ICE is a viable alternative, since the results obtained in the various tests validate the different hypotheses done, and it opens a line of research possibilities around future enhancements and technology development. / La situación actual a nivel mundial, enmarcada en un contexto socioeconómico y medioambiental complejo, con diferentes actores y necesidades presentes, requiere un avance continuo hacia la eficiencia energética y las mejoras medioambientales de cara a poder crear un futuro sostenible, así como de un esfuerzo científico y tecnológico para poder alcanzar los objetivos propuestos.
El transporte mediante sistemas propulsivos basados en motores de combustión interna alternativos (MCIA) es uno de los grandes agentes que afectan a la sostenibilidad medioambiental futura. Dentro de la profunda investigación que se realiza en éste ámbito, una de las opciones estudiadas es la del uso de aceites de baja viscosidad (LVO) como opción para el aumento de la eficiencia de los MCIA. Esta tecnología presenta una aportación modesta al objetivo de eficiencia energética, pero la excelente relación coste-beneficio y la facilidad de aplicación al parque automovilístico actual y futuro son dos razones que han impulsado a la industria hacia la investigación en el uso de estos aceites.
Los aceites de baja viscosidad basan su aportación a la mejora de la eficiencia energética en la reducción de las pérdidas mecánicas asociadas a la fricción viscosa en régimen hidrodinámico. Así, se consigue reducir el consumo de energía utilizado para hacer funcionar el sistema, y lleva asociada una reducción de las emisiones contaminantes para el mismo desempeño.
La hipótesis de aplicación de los aceites de baja viscosidad están bien fundamentadas, pero existen una serie de incertidumbres alrededor de la aplicación de los aceites de baja viscosidad en MCIA a día de hoy. Por un lado, es posible esperar una modificación del comportamiento tribológico en el propio MCIA, así como una variación del propio comportamiento del lubricante que en último lugar podría provocar una reducción del período de vida útil del mismo, un fallo temprano de lubricación u otras consecuencias difíciles de prever. Además, la bajada de viscosidad puede aumentar el fenómeno de desgaste, por lo que existe también un interés en la cuantificación y diagnóstico de manera continua y remota del estado del sistema lubricado.
Así, en esta Tesis se ha realizado un conciso trabajo de revisión del estado del arte de la tribología aplicada a MCIA y de los aceites lubricantes, poniendo especial interés en el desarrollo de la idea de los aceites de baja viscosidad. A continuación, y con el apoyo de un conjunto de técnicas analíticas físico-químicas aplicadas a diagnosticar el estado del aceite lubricante, se han planteado una serie de estudios desde diferentes ámbitos para poder profundizar en el conocimiento del comportamiento del aceite y de su influencia en el desgaste en MCIA.
Los diferentes resultados obtenidos señalan que la aplicación de los aceites de baja viscosidad en MCIA es una alternativa viable y exitosa, ya que los resultados obtenidos en los diferentes ensayos realizados validan el comportamiento de esta opción, y abre una línea de posibilidades de investigación alrededor de futuras mejoras y de desarrollo de la tecnología. / La situació actual a nivell mundial, emmarcada en un context socioeconòmic i mediambiental complex, amb diferents actors i necessitats presents, requereix d'un avanç continu cap a l'eficiència energètica i les millores mediambientals de cara a poder crear un futur sostenible, així com d'un esforç científic i tecnològic per poder assolir els objectius proposats.
El transport mitjançant sistemes propulsius basats en motors de combustió interna alternatius (MCIA) és un dels grans agents que afecten la sostenibilitat mediambiental futura. Dins de la profunda investigació que es realitza en aquest àmbit, una de les opcions estudiades és la de l'ús d'olis de baixa viscositat (LVO) com a opció per a l'augment de l'eficiència dels MCIA. Aquesta tecnologia presenta una aportació modesta a l'objectiu d'eficiència energètica, però l'excel¿lent relació cost-benefici i la facilitat d'aplicació al parc automobilístic actual i futur són dues raons que han impulsat a la indústria cap a la investigació en l'ús d'aquestos olis.
Els olis de baixa viscositat basen la seva aportació a la millora de l'eficiència energètica en la reducció de les pèrdues mecàniques associades a la fricció viscosa en règim hidrodinàmic. Així, s'aconsegueix reduir el consum d'energia utilitzat per fer funcionar el sistema, i porta associada una reducció de les emissions contaminants per a l'obtenció del mateix resultat.
Les hipòtesis d'aplicació dels olis de baixa viscositat estan ben fonamentades, però hi ha una sèrie d'incerteses al voltant de l'aplicació dels olis de baixa viscositat en MCIA a dia de hui. D'una banda, és possible esperar una modificació del comportament tribològic en el propi MCIA, així com una variació del propi comportament del lubricant que en últim lloc podria provocar una reducció del període de vida útil d'aquest, una fallada de lubricació primerenca o altres conseqüències difícils de preveure. A més, la baixada de viscositat pot augmentar el fenomen de desgast, pel que existeix també un interès en la quantificació i diagnòstic de manera contínua i remota de l'estat del sistema lubricat.
Així, en aquesta Tesi s'ha realitzat un concís treball de revisió de l'estat de l'art de la tribologia aplicada a MCIA i dels olis lubricants, posant especial interès en el desenvolupament de la idea dels olis de baixa viscositat. A continuació, i amb el suport d'un conjunt de tècniques analítiques fisico-químiques aplicades a diagnosticar l'estat de l'oli lubricant, s'han plantejat una sèrie d'estudis des de diferents àmbits per poder aprofundir en el coneixement del comportament de l'oli i de la seva influència en el desgast en MCIA.
Els diferents resultats obtinguts assenyalen que l'aplicació dels olis de baixa viscositat en MCIA és una alternativa viable, ja que els resultats obtinguts en els diferents assajos realitzats validen el comportament d'aquesta opció, i obre una línia de possibilitats d'investigació al voltant de futures millores i de desenvolupament de la tecnologia. / Miró Mezquita, G. (2017). Estudio del comportamiento y de la influencia en el desgaste de los aceites lubricantes de baja viscosidad en MCIA [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/78615 / TESIS
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Polyfunkční dům / Mixed-use BuildingFicza, Silvia January 2018 (has links)
The aim of the master thesis is to process the project doucmentation for a mixed-used building in the cadastre unit of Brno-Líšeň. The object is designed as a building with a basement and four above-ground floors. The building has a regular floor plan with partial basement and flat roof and comprises 12 housing units. On the ground floor there is a mixed-used zone. The building has a wall structural system. It is designed with filigree floor slabs. The vertical structural system is mainly made from sand-lime blocks, while the rest is made from permanent formwork. The roof is designed as flat - single and green. The structure is based on strip foundations.
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