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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.
11

[pt] ASPECTOS TÉCNICOS E REGULAMENTARES PARA REDUÇÃO DO NÍVEL DE PRESSÃO SONORA NO ENTORNO DE HELIPONTOS NA CIDADE DO RIO DE JANEIRO / [en] TECHNICAL AND REGULATORY ASPECTS TO REDUCE THE SOUND PRESSURE LEVEL AROUND HELIPADS IN THE CITY OF RIO DE JANEIRO

CARLA JORDAO CANELLA GOMES 26 October 2020 (has links)
[pt] O fenômeno da urbanização traz consigo o problema de mobilidade urbana nos grandes centros. A necessidade de vencer médias distâncias em um curto espaço de tempo resultou em um aumento na frota mundial de helicópteros. De acordo com os dados coletados na Agência Nacional de Aviação Civil (ANAC, 2019), a frota brasileira de helicópteros, com registro ativo, aumentou substancialmente nos últimos 40 anos, gerando grandes impactos na implantação de helipontos em áreas urbanas já consolidadas. Um desses impactos diz respeito à poluição sonora e consequentemente os efeitos decorrentes do ruído nas comunidades vizinhas aos locais de pouso e decolagem dessas aeronaves. O objetivo desta pesquisa consiste em discutir como compatibilizar os ruídos gerados com a implantação de helipontos em áreas urbanas já consolidadas por meio de modelagem de projeto baseada em marco teórico legal contemporâneo. A metodologia tem início com a revisão de literatura do planejamento urbano e ambiental, com vistas a acrescentar subsídios teóricos aos debates sobre a legislação que orienta e disciplina o licenciamento de helipontos em grandes metrópoles, análise dos pedidos de licenciamento ambiental e urbanístico, tendo como estudo de caso o licenciamento urbano e ambiental de helipontos no município do Rio de Janeiro e as evoluções tecnológicas para mitigação do ruído. / [en] The use of helicopter aircraft has increased dramatically in recent decades. Following countries like Japan, Australia, United Kingdom, France, Canada and the United States, Brazil has the seventh worldwide helicopter fleet. The city of São Paulo in 2005 was considered in the international ranking, as the second city in number of helicopters in operation (Alves, 2018). The survey of the number of helicopters in 2013 indicated 2076 registered helicopters, with 70 percent of the fleet concentrated in the states of São Paulo (723), Rio de Janeiro (467) and Minas Gerais (246). The Brazilian helicopter fleet has 1398 aircrafts with active registration in May 2018 (reference year: 2017), which corresponds to 14.79 percent of the total of this type of aircraft, which adds up to 9,452 helicopters. Of the total fleet of registered aircraft, the state of São Paulo has 33 percent of the fleet, followed by Rio de Janeiro with 20 percent and Minas Gerais with 11 percent. (ANAC, 2017) Despite the slight drop in the number of aircraft registered since 2016, the trend line continues to increase.Brazil has a large territorial area, occupying the fifth place in the world in countries in this category. Since 1927 the air transport sector has evolved with the economy. The 1994 economic stabilization plan leveraged the sector with significant growth in Brazilian tourism, generating an increase in employment and income, mainly after being chosen to host important sporting events on a global scale, such as the World Cup in 2014 and the 2016 Olympic Games, which significantly boosted the Brazilian air transport sector (Santos, 2015). All this increase in the aeronautical sector brought positive impacts to the economy, mainly in the area of tourism. However, it had a negative impact with regard to noise pollution in the communities surrounding these areas. Following the same path, the implementation of helipads has caused many disturbances to the neighborhood. Noise pollution from overflights, landings and takeoffs, in addition to the risk of accidents, brought up the issue of urban and environmental licensing of helipads. Noise pollution is anthropic pollution and is directly related to urbanization processes, which have been exacerbated with industrialization. In addition, it has a specificity, noise leaves no residue, environmental damage concerns the harm that causes health. It is noted that the concern with urban noise has been increasing in the same proportion as industrial development and population concentration. Consolidated urban areas find it difficult to reconcile activities and enterprises that have high noise levels with the permanence of the population around these areas. The emergence of new environmental technologies for noise reduction, especially in the airport sector and more specifically for helipads inserted in urban areas, as the case in the city of Rio de Janeiro, has mitigated the discomfort in the surrounding communities in the implementation of these projects, which encouraged research in this sector.
12

The takeoff of environmental technologies: a historical analysis of timing and affecting factors

Calabretta, Giulia 18 September 2009 (has links)
En les darreres dècades, l'impacte incontrolat de les activitats industrials sobre el medi ambient ha comportat l'aparició de preocupacions greus en relació amb el medi ambient. Encara que les empreses tenen moltes opcions per reduir l'impacte ambiental de les seves activitats mitjançant el disseny de productes i les tecnologies, la seva iniciativa sovint es veu sufocada pel fet que la introducció de productes ecològics al mercat tendeix a ser complicada, lenta i molt exigent. L'objectiu d'aquesta recerca és explicar els problemes de difusió de les ecotecnologies (green technologies) des de l'òptica del domini tecnològic. Segons aquesta literatura, "el canvi tecnològic pot caracteritzar-se realment com un procés evolutiu i sociocultural de variació, selecció i retenció" (Anderson i Tushman, 1990) mitjançant el qual sorgeix, finalment, una tecnologia dominant. Aquest procés de selecció pren forma a partir de les dinàmiques socials, polítiques i organitzatives que actuen tant a escala industrial com empresarial. Les ecotecnologies esdevenen innovacions disruptives per als sectors en què s'implementen; la seva acceptació definitiva està subordinada a la interacció constant de les capacitats de l'empresa, la bona voluntat dels directius, les normes de la institució i les dinàmiques competitives. Aquest estudi explora aquest estat d'ebullició en la difusió de les tecnologies netes (environmental technologies) amb l'anàlisi del temps d'eclosió necessari perquè un producte nou incorpori aquest tipus de tecnologies i la identificació d'un model sistemàtic en la interacció entre les forces evolutives. La part empírica consisteix en una anàlisi quantitativa de dades d'arxiu d'indústries caracteritzades per un gran impacte ambiental (automòbil, electrodomèstics, il·luminació). Amb l'objectiu d'estudiar l'eclosió de les tecnologies netes, s'han recollit i processat dades sobre les vendes i s'han ajustat amb la funció logística general. Els resultats demostren que existeix un model de difusió en forma de S, encara que el temps d'eclosió no es pot generalitzar. Per tal d'examinar el model temporal de la interacció entre les forces evolutives, s'han utilitzat tècniques d'anàlisi de supervivència i regressió per mínims quadrats generalitzats (GLS). A part d'això, els resultats suggereixen que el disseny de productes que incorporen tecnologies netes ha d'equilibrar sempre l'acompliment de l'atribut principal i del disruptiu. A més, és important per a l'eclosió de les ecotecnologies que hi hagi una regulació que hi doni suport, tot i que la seva efectivitat depèn del tipus d'eines reguladores. Finalment, el compromís dels alts directius també és un factor impulsor destacat a l'hora d'adoptar tecnologies netes, tot i que fins ara s'ha subestimat. / En las últimas décadas, el impacto incontrolado de las actividades industriales sobre el medioambiente ha comportado la aparición de fuertes preocupaciones en relación con el medio ambiente. Aunque las empresas tienen muchas opciones para reducir el impacte ambiental de sus actividades a través del diseño de productos y tecnologías, las suyas iniciativas se ven frecuentemente sofocadas por el hecho que la introducción de productos ecológicos al mercado suele ser complicada, lenta y muy exigente. El objetivo de esta investigación es explicar los problemas de difusión de las eco-tecnologías (green technologies) desde la perspectiva del dominio tecnológico. Según esta literatura, "el cambio tecnológico se puede caracterizar realmente como un proceso evolutivo y sociocultural de variación, selección y retención (Anderson y Tushman, 1990), a través del cual finalmente surge una tecnología dominante. Este proceso de selección prende forma a partir de las dinámicas sociales, políticas y organizativas que operan tanto a nivel industrial que empresarial. Siendo las eco-tecnologías innovaciones disruptivas para los sectores en que se implementan, la suya aceptación definitiva está subordinada a la interacción constante entre las capacidades de la empresa, la voluntad de los directivos, las normas institucionales y las dinámicas competitivas. Este estudio explora este estado de ebullición en la difusión de las tecnologías ecológicas (environmental technologies) por medio de un análisis de las etapas necesarias para el arranque de un nuevo producto que incorpora este tipo de tecnologías, y por medio de la identificación de un modelo sistemático en la interacción entre las fuerzas evolutivas. La parte empírica consiste en una análisis cuantitativa de los datos de archivo de industrias caracterizadas por un gran impacte medioambiental (automóvil, electrodomésticos, iluminación). Con el objetivo de estudiar el arranque de las tecnologías ecológicas, se han recogido y procesado datos sobre las ventas y se han ajustado con la función logística generalizada. Los resultados demuestran la existencia de un modelo de difusión en forma de S, aunque que el tiempo de arranque no se puede generalizar. Para examinar el modelo temporal de la interacción entre las fuerzas evolutivas, se han utilizado técnicas de análisis de sobrevivencia y regresión por mínimos cuadrados generalizados. Los resultados sugieren que el diseño de productos que incorporan tecnologías ecológicas debería siempre equilibrar el rendimiento del atributo tradicional y del atributo disruptivo. Además, es importante para el arranque de las eco-tecnologías que haya una regulación que dé suporte, aunque su efectividad depende del tipo de herramientas reguladores. Finalmente, el compromiso de los altos directivos también es un factor impulsor destacado a la hora de adoptar tecnologías ecológicas, aunque hasta hora su importancia se ha subestimado. / In the last decades the uncontrolled impact of industrial activities on the natural environment has created critical ecological concerns. Although companies have many options to reduce the environmental impact of their activities through product design and technologies, their initiative is often stifled from the evidence that market entrances of green products tend to be difficult, slow and highly requiring. The aim of this research is to explain the diffusion problems of green technologies through the lens of technological dominance. According to this literature "technological change can be fruitfully characterized as a socio-cultural evolutionary process of variation, selection and retention" (Anderson and Tushman, 1990) through which a dominant technology finally emerges. This process of selection is shaped by social, political, and organizational dynamics acting both at industry and firm level. Being green technologies disruptive innovations in each industry in which they are implemented, their full acceptance is subordinated to the repeated interaction of firm capabilities, managerial willingness, institutional rules and competitive dynamics. The present study investigates this era of ferment in the diffusion of environmental technologies through the analysis of the time to takeoff needed by a new product incorporating environmental technologies, and through the identification of systematic patterns in the interaction among evolutionary forces. The empirical part consists of a quantitative analysis of archival data in industries characterized by a high environmental impact (automobile, appliances, lighting). In order to investigate the take-off of environmental technologies data on sales have been collected, plotted, and fitted with the generalized logistic function. The results provide evidence of a S-shaped pattern of diffusion, although no generalization is possible on the time to takeoff. In order to examine the temporal pattern of interaction among evolutionary forces, survival analysis techniques and GLS regression have been used. Among the rest, the results suggest that the design of products incorporating environmental technologies should always balance the performance of the disruptive attribute and the mainstream attribute. Additionally, supporting regulation is important for accelerating the takeoff of environmental technologies, although its effectiveness depends on the type of regulatory tools. Finally top management commitment emerges as an underestimated central driver of the adoption of environmental technologies.
13

APPLICATIONS OF MICROHEATER/RESISTANCE TEMPERATURE DETECTOR AND ELECTRICAL/OPTICAL CHARACTERIZATION OF METALLIC NANOWIRES WITH GRAPHENE HYBRID NETWORKS

Doosan Back (6872132) 16 December 2020 (has links)
<div>A microheater and resistance temperature detector (RTD) are designed and fabricated for various applications. First, a hierarchical manifold microchannel heatsink with an integrated microheater and RTDs is demonstrated. Microfluidic cooling within the embedded heat sink improves heat dissipation, with two-phase operation offering the potential for dissipation of very high heat fluxes while maintaining moderate chip temperatures. To enable multi-chip stacking and other heterogeneous packaging approaches, it is important to densely integrate all fluid flow paths into the device. Therefore, the details of heatsink layouts and fabrication processes are introduced. Characterization of two-phase cooling as well as reliability of the microheater/RTDs are discussed. In addition, another application of microheater for mining particle detection using interdigitated capacitive sensor. While current personal monitoring devices are optimized for monitoring microscale particles, a higher resolution technique is required to detect sub-micron and nanoscale particulate matters (PM) due to smaller volume and mass of the particles. The detection capability of the capacitive sensor for sub-micron and nanoparticles are presented, and an incorporated microheater improved stable capacitive sensor reading under air flow and various humidity. </div><div>This paper also introduces the characterization of nanomaterials such as metallic nanowires (NWs) and single layer graphene. First, the copper nanowire (CuNW)/graphene hybrid networks for transparent conductors (TC) is investigated. Though indium tin oxide (ITO) has been widely used, demands for the next generation of TC is increasing due to a limited supply of indium. Thus, the optical and electrical properties of CuNW/graphene hybrid network are compared with other transparent conductive materials including ITO. Secondly, silver nanowire (AgNW) growth technique using electrodeposition is introduced. A vertically aligned branched AgNW arrays is made using a porous anodic alumina template and the optical properties of the structure are discussed.</div><div><br></div>
14

Community small scale wind farms for New Zealand: a comparative study of Austrian development, with consideration for New Zealand’s future wind energy development

Thomson, Grant January 2008 (has links)
In New Zealand, the development of wind energy is occurring predominantly at a large scale level with very little opportunity for local people to become involved, either financially or conceptually. These conditions are creating situations of conflict between communities and wind energy developers – and are limiting the potential of the New Zealand wind energy industry. The inception of community ownership in small scale wind farms, developed in Europe in the late 20th Century, has helped to make a vital connection between wind energy and end users. Arguably, community wind farms are able to alleviate public concerns of wind energy’s impact on landscapes, amongst a wide range of other advantages. In Austria, community wind farms have offered significant development opportunities to local people, ushered in distributed generation, and all the while increasing the amount of renewable energy in the electricity mix. This thesis investigates whether community small scale wind (SSW) farms, such as those developed in Austria, are a viable and feasible option for the New Zealand context. The approach of this thesis examines the history of the Austrian wind industry and explores several community wind farm developments. In addition, interviews with stakeholders from Austria and New Zealand were conducted to develop an understanding of impressions and processes in developing community wind energy (CWE) in the New Zealand context. From this research an assessment of the transfer of the Austrian framework to the New Zealand situation is offered, with analysis of the differences between the wind energy industries in the two countries. Furthermore, future strategies are suggested for CWE development in New Zealand with recommendations for an integrated governmental approach. This research determines that the feasibility for the transfer of the Austrian framework development of ‘grassroots’ community wind farms in the next 10 years is relatively unlikely without greater support assistance from the New Zealand Government. This is principally due to the restricted economic viability of community wind farms and also significant regulatory and policy limitations. In the mid to long term, the New Zealand government should take an integrated approach to assist the development of community wind farms which includes: a collaborative government planning approach on the issue; detailed assessment of the introduction of feed-in tariff mechanisms and controlled activity status (RMA) for community wind farms; and development of limited liability company law for community energy companies. In the short term, however, the most feasible option available for the formation of community wind farms lies in quasi community developments with corporate partnerships.

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