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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.
31

Surface tension driven water pumping : a bio inspired passive water pump

Fraser, Justin 03 1900 (has links)
Thesis (MEng)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: The purpose of this study is to construct and test a surface tension driven water pump. The surface tension driven water pump is a passive water pump which uses a similar mechanism to that of trees to pump water. This study was conducted at the Department of Mechanical and Mechatronic Engineering at the University of Stellenbosch. For the study an extensive literature survey was done encompassing aspects such as water properties, surface tension (basic principles, capillary forces, temperature and contaminant effects, wettability), bubble formation (nucleation theory and tensile strength of water) and, finally water and mineral transport in trees (plant structures and mechanisms, limiting factors, misconceptions and organic substance transport). Previous work by botanists who demonstrate the transpiration mechanism needed for water transport in trees was also considered. The study further required the development of a theoretical thermal-hydraulic model to simulate the pumping performance for the surface tension driven water pump. The developed water pump was also experimentally tested with particular focus on design improvement, pumping performance, pump behaviour, potential pumping head as well as water collection capability. The experimental data was statistically analysed by multi-linear regression. Both the experimental data and statically generated predictions were compared to the theoretical thermal-hydraulic model. The results show that a working surface tension driven pump was constructed. Evaporation rates of up to 400 mL/hr.m2 were obtained, with pumping head heights reaching up to 1.8 m and a maximum pump functional lifespan of 13 days. The results further suggest that there is a good correlation between the various statistical fits and the experimental data. The developed theoretical thermal-hydraulic model was also found to be in good agreement with the experimental results. A sensitivity analysis of the theoretical and statistical models showed that the statistical models fairs poorly under extrapolation. Additionally, the mechanistic causes of pump failure as well as the effect of heat and pumping head on water pumping performance were identified. Thereafter, the water collection efficiency was established to be 98% on average. Further testing revealed that the pumping performance of larger area or multiple grouped “leaves” are less accurately predicted with the theoretical model than a single “leaf”. In conclusion, the results provide some support that the surface tension driven pump may be used as a water transport system in an artificial photosynthesis project, if the functional lifespan of the pump can be greatly improved. It is recommended that a more rigid hydrophilic material be used in the “leaf” interface and that multiple narrower conduits be used instead of a single larger pipe. Additional future work may include the development of pit-like structures to prevent air spreading throughout the system as well as a simple mechanism for evaporative control. / AFRIKAANSE OPSOMMING: Die doel van hierdie ondersoek is om 'n oppervlakspanning-aangedrewe waterpomp te bou en te toets. Die oppervlakspanning-aangedrewe waterpomp is ‘n passiewe waterpomp wat gebruik maak van ‘n meganisme soortgelyke aan dié van bome om water te pomp. Hierdie ondersoek is by die Departement Meganiese en Megatroniese Ingenieurswese by die Universiteit van Stellenbosch uitgevoer. Vir die ondersoek is 'n uitgebreide literatuurstudie gedoen wat aspekte soos water eienskappe, oppervlakspanning (basiese beginsels, kapillêre kragte, die uitwerking van temperatuur, onsuiwerhede asook benatbaarheid), lugborrelvorming (kernvormingsteorie en die treksterkte van water) en uiteindelik water- en mineraalvervoer in bome (plantstrukture en -meganismes, beperkende faktore, wanpersepsies en die vervoer van organiese stowwe) insluit. Vorige navoring deur plantkundiges, wat die watervervoermeganismes in bome demonstreer, is ook in ag geneem. Die ondersoek het die ontwikkeling van 'n teoretiese termies-hidrouliese model ingesluit, wat gebruik is om die oppervlakspanning-aangedrewe waterpomp se werking te voorspel. Die waterpomp is ook eksperimenteel getoets met die fokus op ontwerpverbetering, pompwerkverrigting, pompwerking, potensiële pompopvoerdrukhoogte sowel as die waterversamelingsvermoë. Die eksperimentele data is statisties ontleed deur middel van meervoudige liniêre regressie. Beide die eksperimentele data en statisties-gegenereerde voorspellings is vergelyk met die teoretiese termies-hidrouliese-model. Die resultate toon dat 'n werkende oppervlakspanning-aangedrewe pomp gebou is. ‘n Verdampingstempo van tot 400 mL/hr.m2, pompopvoerdrukhoogte van tot 1.8m en 'n maksimum funksionele pompleeftyd van 13 dae is bereik. Die resultate dui verder daarop dat daar 'n goeie korrelasie tussen die verskillende statistiese lynpassings en die eksperimentele data is. Die teoretiese termies-hidrouliese-model wat ontwikkel is, toon 'n goeie ooreenkoms met die eksperimentele resultate. 'n Sensitiwiteitsanalise van die teoretiese en statistiese modelle het getoon dat die statistiese modelle swak voorspellings maak as geëkstrapoleerde data gebruik word. Verder is die meganismes wat pompweiering veroorsaak, die effek van hitte asook die effek van pompopvoerdrukhoogte op die pomp se werkverrigting geïdentifiseer. Daarna is die doeltreffendheid van waterversamelingsvermoë vir die waterpomp vasgestel op gemiddeld 98%. Verdere toetse het getoon dat die pompwerkverrigting van groter gegroepeerde "blare" minder akkuraat met die teoretiese model voorspel word as vir 'n enkele "blaar". Ten slotte: Die resultate toon dat die oppervlakspanning-aangedrewe waterpomp as 'n water vervoer stelsel gebruik kan word in 'n kunsmatige fotosinteseprojek, indien die funksionele leeftyd van die pomp verbeter kan word. Dit word aanbeveel dat 'n sterker hidrofiliese materiaal in die "blaar"-koppelvlak gebruik word en dat verskeie nouer leipype gebruik word in plaas van 'n enkele groter pyp. Bykomende toekomstige werk kan die ontwikkeling van put-agtige strukture insluit wat die verspeiding van lug deur die hele stelsel voorkom, sowel as 'n eenvoudige meganisme wat die verdampingstempo beheer.
32

Applying bio-mimicry to design an eco-efficient supply chain model for the South African Post Office

26 March 2015 (has links)
M.Tech. (Industrial Engineering) / Please refer to full text to view abstract
33

New dynamic pallet for Volvo Trucks based in biomimicry : New support modular and adaptable to different geometries, based in the structures of the radiolarian microorganisms and honeycomb

Paredes Almaraz, Israel January 2019 (has links)
The logistics department at the Powertrain plant of Volvo Trucks seeks to improve the efficiency within their processes. A new concept solution to the supports (pallets) that hold and carry different types of engine parts during the transportation between the sequencing area and the final assembly line called “The new dynamic pallet based on biomimicry” was presented. The concept solves the issues of the constant modifications in the pallets lead by the changes in the design of the engine parts. The main objectives of the project is the creation of a dynamic pallet, dynamic in this case translates into a modular, flexible to different geometries and scalable system, also the design solution should be inspired by nature (biomimicry) to boost a new sustainable design approach related to the values of Volvo brand. This project required iterative research regarding the principles of biomimicry and systems found in nature. Biomimicry literally means ‘the imitation of life’ but, it is better defined as a design approach to innovation which takes inspiration from systems of nature. It is provided by Volvo as the core of the project, if the result is good then there will be a push to develop new projects following this strategy seeking sustainable solutions to solve human problems. In addition, prototyping concepts from a generation of ideas to testing results were conducted to evaluate the concepts generated. The resulting concept proposal is a whole new system but preserves the functional aspects necessary to integrate the new pallet in the current logistics performance.
34

Proposta de modelo de operação sustentável à luz da biomimética

Royer, Maykel 26 July 2013 (has links)
Submitted by Maicon Juliano Schmidt (maicons) on 2015-06-25T14:20:01Z No. of bitstreams: 1 Maykel Royer.pdf: 4010666 bytes, checksum: 7b0dd893cb6c6141941f42c2ff2c19aa (MD5) / Made available in DSpace on 2015-06-25T14:20:01Z (GMT). No. of bitstreams: 1 Maykel Royer.pdf: 4010666 bytes, checksum: 7b0dd893cb6c6141941f42c2ff2c19aa (MD5) Previous issue date: 2013-01-31 / Nenhuma / A forma como se produz tem sido discutida ultimamente. Mais do que benefícios de um dos atuais modelos de alta produtividade, o que está em pauta são os efeitos gerados. A degradação do meio ambiente tem alertado a todos quanto à necessidade de criação de modelos de operação sustentáveis, que primeiramente são vistos como amenizadores de efeitos ambientais, mas também são aplicados a aspectos sociais e econômicos. Entretanto, uma nova ciência denominada Biomimética busca inspiração na natureza para resolver problemas criados pelo homem e, com certo nível de aderência avaliada por especialistas, é convergente aos modelos de operação sustentáveis. O estudo faz uso dos sistemas maduros tipo III, que têm como meta organizarem-se numa comunidade diversificada e integrada com objetivos comuns, tais como: manter a sua existência num único lugar, aproveitar ao máximo o que têm à disposição e conservar-se ao longo do tempo, de tal maneira que estes princípios da biomimética possam melhorar os atuais modelos de operação sustentáveis onde os especialistas apontaram oportunidades. Diante disso, a proposta de um modelo de operação sustentável com características biomiméticas é o objetivo desta pesquisa. / The way we produce has been discussed lately. More than benefits generated from the actual high productivity models, what is at issue are the effects. The environmental degradation has alerted everyone about the need to create a sustainable operation model, which are primarily seem like reducers of environment effects but also applied to social and economic aspects. However, a new science called Biomimicry search for nature inspiration to solve problems created by humans and, which a certain adherence evaluated by experts, is convergent to sustainable operation models. The research uses mature systems type III, which aim to organize themselves in a diverse community and integrated with common goals, such as maintaining their existence in one place, make the most of what they have available and save themselves over time. So these biomimicry’s principles can improve current models of sustainable operation where experts pointed out opportunities. Therefore, the proposal of a model for sustainable operation with biomimetic characteristics is the goal of this research.
35

O prazer estético e as flores: dispositivos cognitivos e semiótica evolutiva

Kajimoto, Cláudio 18 October 2012 (has links)
Made available in DSpace on 2016-04-26T18:12:33Z (GMT). No. of bitstreams: 1 Claudio Kajimoto.pdf: 2033019 bytes, checksum: 665cc2dca23d77d16eb6666a9f2bdb44 (MD5) Previous issue date: 2012-10-18 / This paper discusses the relationship between the field of Communication and Design, from concepts of biosemiotics and research on aesthetic experience. Studies of communication among living beings, as in Ethology, Biosemiotics and Biomimetics (Bispo, 2004 and Vieira, 2007; also Benyus, 1997) suggest that aesthetic experience, as conceived by the human Umwelt (Kull, 2001), is an adaptive strategy that living systems use in order to survive. This hypothesis is consistent with the proposal that the concept of communication, as well as aesthetic experience, has an objective root. In this context, the latter implies an efficient form of objective organization. Communication among living systems allows their communicative interaction to mold such systems, making them fitted to survive through the production of morphogenesis, among other aspects. As a case study we chose as object the mechanism of communication between flowers and insects, showing how this leads to the evolution and adaptation of such systems (Souza, 1994). If flowers are the reproductive organs of plants, evolutionarily designed to assist in reproduction through the seduction of pollinator insects, why do humans also feel attracted to them, even though we are endowed with a perception and an Umwelt differentiated from those of birds, insects and other animals? We claim that the aesthetic experience with flowers operates in the observer a biological response to the activation of certain cognitive devices we acquire throughout our evolutionary history, and the feeling of pleasure experienced would be associated with the systems of gratification and reward in the brain, pointing to objective qualities of the flower. Thus, we propose the existence of a semiotics capable of organizing natural processes, and a complex system of communication that permeates all living things. In the end, when we unfold the aesthetic strategy of the flowers, we also discover a new way to create and handle design in all its forms and manifestations / Esta dissertação discute a relação existente entre o domínio da Comunicação e do Design, a partir de conceitos da biossemiótica e de pesquisas sobre a experiência estética. Estudos sobre a comunicação entre seres vivos, como na Etologia, Biossemiótica e Biomimética (ver Bispo, 2004 e Vieira, 2007; ver ainda Benyus, 1997) sugerem que a experiência estética, como concebida pela Umwelt humana (Kull, 2001), é uma estratégia adaptativa que os sistemas vivos utilizam na busca de sua permanência. Esta hipótese é coerente com a proposta de que o conceito de Comunicação, assim como a experiência estética, possui uma raiz objetiva. Neste contexto essa última implica uma forma de organização objetiva eficiente. A comunicação entre sistemas vivos permite que a interação comunicacional entre os mesmos modele tais sistemas tornando‐os aptos a sobrevivência, por meio da produção de morfogênese, entre outros aspectos. Como estudo de caso, escolhemos como objeto o mecanismo de comunicação entre flores e insetos, mostrando como isto leva à evolução e adaptação de tais sistemas (Souza, 1994). Sendo as flores os órgãos reprodutivos das plantas, criadas evolutivamente para auxiliar na reprodução por meio da sedução dos insetos polinizadores, porque nós, seres humanos, também nos sentimos atraídos por elas, mesmo dotados de uma percepção e Umwelt diferenciados daqueles dos pássaros, insetos e outros animais? Alegamos que a experiência estética com flores opera no observador uma resposta biológica ao disparo de certos dispositivos cognitivos que adquirimos ao longo de nossa história evolutiva, e a sensação de prazer experimentada estaria associada a sistemas de gratificação e recompensa no cérebro, apontando para qualidades objetivas da flor. Desta forma, estamos propondo a existência de uma semiótica capaz de organizar os processos naturais, além de um complexo sistema de comunicação que permeia todos os seres vivos. No fim, ao desvendarmos a estratégia estética das flores, descobrimos também uma nova forma de criar e lidar com o design em todas as suas formas e manifestações
36

Symbiotic design practice : designing with-in nature

Sanchez Ruano, David January 2016 (has links)
Human culture has recognized the damage being caused to our environment and is in the process of transitioning toward sustainable systems. Design disciplines and environmental studies are engaging in alternative ways to support a sustainable world and, to a large extent, on resolving the disconnection between humans and nature. The conceptualization of <i>Symbiotic Design</i> proposed in this research, facilitates theoretical-practical reflections and recognizes that learning through closer association with the natural world can trigger innate responses and enhance human creativity. Designers need to have an understanding of these concepts to allow them to design in an ecologically conscious way. Using biophilia, biomimicry and resilience thinking as core eco-techniques, the research develops a series of teaching/learning practices that aim to enhance the embodiment of design with-in nature. This <i>Symbiotic Design</i> Practice process was developed, tested and evaluated across a sample of undergraduate and postgraduate design students. Text, visuals and workshop activities evolved through a method of action-based cycles. In essence, the research proposes a new eco-pedagogical strategy that facilitates nature-based experiences and behavior change toward an ecologically conscious design culture.
37

Bio-inspired Design of a Turbine Stage

Paht Juangphanich (7275371) 30 October 2019 (has links)
<div>This dissertation presents a strategy that incorporates nature and bio-inspired shapes to redesign turbine airfoils and stator-rotor rim seal cavity.</div><div><br></div><div>The first objective consists of the development of tools to optimize the turbine velocity triangles and then the 3D shape using 75 parameters. Design trends that minimize loss in the stator and rotor were discussed. The second objective expands on the first by incorporating wavy structures at the leading and trailing edges as well as the suction side mimicking design features of seal whiskers and tubercles of a whale. The airfoils were optimized to maximize the efficiency of a highly loaded high-pressure turbine at positive incidence.</div><div><br></div><div>The last objective addressed the design of the cavity to reduce cooling massflow and protect the turbine platform. A novel strategy was proposed to assess and optimize the shape of the cavity. In an attempt to simply the problem and identify the main physical phenomena, a slice of the flow was examined by considering a purely a 2D case in the relative frame of reference. This simplification enabled the cavity to be optimized in 2D using a geometry inspired by the meandering of rivers. The optimization produced designs that reduce the heat flux in the rear rotor platform and are less sensitive towards variations in gap and cavity total pressure. The methodology was demonstrated in 3D rotating cavity and later in a full turbine stage configuration. The strategy and design tools developed in this dissertation seek to provide understanding of the effects of bio-inspired shapes on turbine blades and lay the foundation for future experimental research into cavity flows.<br></div>
38

Ecological Coexistence: A Nature Retreat and Education Center on Rattlesnake Key, Terra Ceia, Florida

Peterika, Richard F 21 November 2008 (has links)
Applied ecology has been used to design communities around the world; however suburban neighborhoods in west central Florida do not usually utilize existing or potential ecological function as a modeling parameter or success measure. Since the end of the great depression, developments in the Tampa Bay Area have displaced many wetland and upland natural communities. Private ownership and development of sensitive natural lands have restricted their use and hampered the functional longevity of important ecological systems in this area. These displaced areas have historically functioned as habitat for many types of animal life, have passively conveyed nutrient loads, and have facilitated the succession of organisms. They have also been used as recreational opportunities for local residents and visitors, children and adults. Applied ecological design usually occurs at a community or master plan scale, or separately at a singular building level, but rarely both simultaneously. This design proposal was the investigation and formation of an ecocentric architectural design methodology for coastal environments; from master plan to conceptual building design. The scope was the synthesis of a recreational tourism facility with the existing ecological communities of Rattlesnake Key, a barrier island in northwest Manatee County, Florida. The program included an ecological education center, where visitors could learn about their relationship with the ecological communities present on the island, and a group of cabins, where inhabitants could interact with each other and the surrounding natural communities intimately. Master planning strategies were outlined using extensive ecological mapping overlays, in-field observation, and feasibility analysis. Building forms, means of construction, and structural systems were created by integrating biomimicry methods, habitat restoration techniques, and sustainable practices into a programmed, built environment. The results of the investigation were a series of physical models and graphic representations of spaces that manifest the sensitive relationship between human inhabitance and ecological function; where both processes coexist and support the longevity and persistence of one another through habitat creation. By analyzing the existing ecological functions present on a site, a designer could propose a typology that strengthens the relationship between man and his environment; where development is no longer displacement.
39

Biomimicry For Sustainability: An Educational Project In Sustainable Product Design

Bakirlioglu, Yekta 01 September 2012 (has links) (PDF)
The notion of sustainability has become an extensive area of research ever since the term emerged in the late 1980s, due to the negative effects of unsustainable production and consumption patterns on environmental stewardship, social equity and economic development. There have been various approaches developed for product design and education within the context sustainability. Biomimicry is one of those approaches, and its implications for product design education have recently started to be explored. In this study, an educational tool - Biomimicry Sketch Analysis (BSA) - was developed and integrated into the idea-generation phase of an educational design project at the undergraduate level in the Department of Industrial Design at the Middle East Technical University (METU). This integration is analyzed throughout the graduate thesis study, to understand and explore the implications of the biomimicry approach for sustainability in product design education. The educational tool within this approach was found as influential among the third year industrial design students for the idea-generation phase, yet the results of this study included both pros and cons for the incorporation of the BSA exercise.
40

Flexible piezoelectric composites and concepts for bio-inspired dynamic bending-twisting actuation

Samur, Algan 10 April 2013 (has links)
No description available.

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