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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.
21

Surf scoter (Melanitta perspicillata) ecology on spring staging grounds and during the flightless period

O'Connor, Mark, 1983- January 2008 (has links)
No description available.
22

Options to reduce sediment build-up in a surf zone trench protected by an open-ended cofferdam

Muller, Jacobus Johannes 03 1900 (has links)
Thesis ((MEng)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: When constructing a submarine pipeline, construction teams must work in the hostile environment in the ocean known as the surf zone. The surf zone is the area along a shoreline stretching between the first evident point of wave breaking and the beach line. In order to ensure that the pipeline is shielded from the imposing forces within the surf zone, engineers use a burial technique which leaves the pipeline length in the surf zone buried underneath the active seabed once construction is finished. Thus a temporary surf zone trench is dredged and protected by an open-ended cofferdam built using iron sheet piles. As a result of the incoming wave climate and the surf zone currents created by this wave climate, sedimentation in and around the trench becomes problematic. In this study alternative geometric layouts for the open-ended cofferdam protecting the surf zone trench are investigated, attempting to minimize the sediment build-up in and around the trench. This was done by using both a 3D qualitative physical model conducted at the CSIR in Stellenbosch, and numerical model using MIKE developed by DHI. However, this study only considers sediment build-up and not structural integrity and constructability of the cofferdam designs. Combining the observations of both the physical- and numerical models, a conclusion was drawn that a structure built perpendicular to the shoreline with a 45oextended arm built from the upstream edge of the cofferdam wall, is the most effective. No dimensions are given as the cofferdam design will change depending on the site specific characteristics. Also an increase in structure length will result in the mouth of the structure being located outside the active sediment zone, which leads to a longer period of time before the pipeline pathway is compromised by sediment. / AFRIKAANSE OPSOMMING: Tydens die konstruksie van 'n onderwaterse pyplyn, moet konstruksie spanne in 'n gevaarlike gedeelte van die see werk naamlik die brandersone. Die brandersone kan gedefinieer word as die area tussen die eerste punt waar branders breek en die strandlyn. Om die pyplyn te beskerm teen die kragte wat branders op dit uitoefen, gebruik ingenieurs 'n installasietegniek waar hul die brandersone seksie van die pyplyn onder die aktiewe seebodem begrawe. Om die tegniek te bewerkstellig, grawe kontrakteurs 'n sloot deur die brandersone en beskerm dit met 'n tydelike struktuur bekend as 'n kofferdam. As gevolg van die inkomende branders en die strome wat deur die branders aangedryf word, kan die opbou van sediment in, en rondom die sloot in die brandersone problematies word. Hierdie studie ondersoek alternatiewe uitlegte vir die tydelike kofferdam struktuur met die oog daarop om die opbou van sediment in, en rondom die struktuur te verminder. Die doel was nagestreef deur gebruik te maak van beide 'n 3-dimensionele fisiese model, gebou en gebruik by die WNNR in Stellenbosch, en 'n numeriese model wat op MIKE, ontwikkel deur DHI gedoen was. Let wel die studie het slegs die sediment beweging in die nabye area van die tydelike kofferdam struktuur in ag geneem en nie die praktiese implimentering en strukturele integriteit van die struktuur nie. Deur die observasies van beide die fisiese- en numeriese modelering in ag te neem, is die volgende gevolgtrekkings gemaak. 'n Struktuur wat loodreg met die strandlyn gebou is en met 'n 45o arm wat na die stroom-op kant toe uitstrek, was die mees effektiewe een. Geen dimensies is deurgegee nie aangesien die ontwerp sal verskil afhangende van die spesifieke area waar die projek aangepak word. Daar is ook gesien dat indien die struktuur langer gemaak word, sal die kontrakteur langer tyd h^e voordat daar sediment probleme in die brander sone sloot ondervind sal word.
23

The generation of low-frequency water waves on beaches

Barnes, Timothy January 1996 (has links)
No description available.
24

Outside Things

Sorenson, Jacob 09 May 2011 (has links)
My thesis is a description of the issues encountered during the process of research and construction of the objects leading to, and consisting of, the work shown in Outside Things. The work is my attempt to gain personal insight into the complicated relationship between nature and culture. Through abstract furniture objects, floral patterns, and robots I explore the relationship between actual landscape and the constructed man-made bio-mimicry that convolutes the definition of Nature.
25

Avaliação fisiológica e biomecânica de surfistas recreacionais

Godoy, Daniel Fagundes January 2017 (has links)
Considerando as similaridades entre o nado crawl e a remada executada por surfistas, além da preparação física executada pelos mesmos em piscina, este trabalho objetivou avaliar surfistas recreacionais por meio da comparação, concordância e correlação das variáveis fisiológicas e biomecânicas obtidas a partir de testes nadando crawl e remando com prancha. Foram avaliados 14 surfistas (idade de 37,7 ± 4,7 anos) em duas situações: (i) teste em nado crawl, máximo, de 300 m e (ii) teste de remada, nas mesmas condições de intensidade e duração do teste de nado crawl. Os testes foram realizados na mesma piscina e nas mesmas condições de temperaturas e horário. Foram avaliados: consumo de oxigênio de pico (VO2pico) durante os testes, frequência cardíaca (Fcard), concentração sanguínea de lactato ([LA]), esforço percebido (EP) e cinemática em ambos os testes. Dentre os resultados: para teste de nado crawl e teste de remada respectivamente, destacam-se os resultados de VO2pico, Fcard, [LA], e EP: 38,5 ± 5,3 e 36,2 ± 5,3 ml.kg-1.min-1; 149,6 ± 17,4 e 162,2 ± 14,6 bpm; 10,4 ± 2,7 e 12,1 ± 2,7 mmol.l-1; e 16,1 ± 2,4 e 16,7 ± 1,4 pontos. As velocidades médias dos testes foram de, respectivamente, para teste de nado crawl e teste de remada: 0,91 ± 0,1 e 1,27 ± 0,1 m-s-1. De modo geral, os testes apresentaram resultados similares, com baixa concordância, alta correlação e de médios a grandes tamanhos de efeito entre nadar e remar. Considerando os resultados encontrados, o treinamento de surfistas, em piscina, não deveria ser apenas com natação. Conclui-se que os esforços e testes (nadar crawl e remar) não são plenamente intercambiáveis. / Considering the similarities between the front-crawl and the paddling movement, in addition to the physical preparation performed by surfers in swimming pool, this work aimed to compare, to test the agreement and to correlate surfers’ values of oxygen uptake obtained from swimming and paddling tests. A total of 14 surfers (age 37.7 ± 4.7 years) were evaluated in two situations: (i) a 300 m maximum front-crawl test (ii) a paddling test in the same conditions of intensity and duration of the swimming test. The tests were performed in the same pool and under the same conditions of temperatures and time of the day. Peak oxygen uptake (VO2peak) during the tests, heart rate (Fcard), blood lactate concentration ([LA]), perceived exertion (PE) and kinematics in both tests were assessed. Among the results, VO2peak, Fcard, [LA], and EP were, respectively for front-crawl and paddling test:: 38.5 ± 5.3 and 36.2 ± 5.3 ml.kg-1.min-1; 149.6 ± 17.4 and 162.2 ± 14.6 bpm; 10.4 ± 2.7 and 12.1 ± 2.7 mmol.l-1; and 16.1 ± 2.4 and 16.7 ± 1.4 points. The mean velocities of the tests were, respectively, for front-crawl test and paddling test: 0.91 ± 0.1 and 1.27 ± 0.1 m.s-1. In general, the tests presented similar results, with low agreement, high correlation, and medium to large effect sizes between swimming and paddling. Considering the results, the training of surfers, in swimming pool, should not be just with swimming. It is concluded that the efforts and tests (front-crawl and the paddling movement) are not fully interchangeable.
26

O estilo de vida da Tribo do Surf e a cultura de consumo que a envolve

Segabinazzi, Rodrigo Costa January 2011 (has links)
O consumo, especialmente em sociedades capitalistas, não está ligado apenas ao valor funcional dos produtos, mas também aos símbolos que eles representam. (MCCRACKEN 1986; 2003; FEATHERSTONE 1995). Nessas sociedades, as posses tem influência na construção da identidade do indivíduo, que busca produtos para se associar a grupos ou a sub – grupos no seu cotidiano.(BELK 1988; SCHOUTEN e MCLAEXANDER 1995; COVA 1999;2010; MAFESSOLI 2006). Sub – culturas de consumo, comunidades de marca e tribos tem se tornado grupos cada vez mais observados tanto pela academia de Marketing como pelas marcas. Alguns desses grupos já foram investigados principalmente nos EUA (SCHOUTEN e MCALEXANDER 1995 ; KOZINETS 1997; 2001). Estudos como os de Irwin (1973), indicam a possibilidade de uma organização semelhante representada pela figura do surfista. No Brasil, o mercado do surf, emprega mais de 140.000 pessoas e movimenta bilhões de reais anualmente (ZUCO ET AL, 2002). Com essa perspectiva em mente, o presente estudo teve como objetivo investigar a existência de uma sub – cultura de consumo relacionada ao Surf no Brasil. A pesquisa buscou entender também a relação das posses tanto para o Surfista como para o simpatizante, que é o grande consumidor desse mercado (FORNECK 2008), e a relação das empresas do setor com esses indivíduos. Para esse fim foi seguida uma abordagem qualitativa multi métodos, com a utilização e integração das técnicas de Videografia, observação não participante, entrevistas em profundidade e elicitação visual. Além de entrevistas com Surfistas, simpatizantes e produtores de Marketing (empresas) foram realizadas observações a lojas de Surf e a um torneio comemorativo do esporte. Os resultados apontam a existência de uma tribo, representada na figura do Surfista. Essa tribo se integra por um estilo de vida comum, baseado em ideais como o amor ao esporte, a comunhão com a natureza, estilo de vida saudável e uma linguagem própria. Os resultados também apontam que o simpatizante está inserido em uma grande cultura de consumo, em que o mesmo busca roupas e acessórios para ser identificado dentro da sociedade. É aparente também a ação das marcas de Surf na apropriação de alguns dos ideais e do estilo de vida do surfista para vender um cenário ideal e um novo estilo de vida ao simpatizante. / The consumption, especially in the capitalist societies, isn´t connected only to the functional value of products. But also to the symbols that they represent (MCCRACKEN 1988;2003; FEATHERSTONE 1995). In These societies, possessions have influence on the individual´s identity construction, Who search for products to associate himself to groups or sub groups in his every day life. (BELK 1988; SCHOUTEN e MCLAEXANDER 1995; COVA 1999;2010; MAFESSOLI 2006). Subcultures of consumption, brand communities and tribes have gained more attention from the Marketing academy and Brands. Some of these groups have already been researched especially in the US (SCHOUTEN e MCALEXANDER 1995 ; KOZINETS 1997 ; 2001). Studies like the one performed by Irwin (1973), indicates a similar organization on the figure of the Surfer. In Brazil, the Surf market is responsible for more than 140.000 jobs and generates billions in the local currency annually. (ZUCO ET AL, 2002). With this perspective in mind, the current study had the objective to investigate the existence of a subculture of consumption related to the Surf in Brazil. The research aimed to understand also the role of possessions to the Surfer and the Sympathizer, the biggest responsible for the purchases on this market (FORNECK, 2008), and the relation of the companies of this sector with these individuals. To achieve this goal, it was followed a multi – methods approach with the integration of the techniques like Videography, In dept interviews, non participant observations and Photo Elicitation Technique. The results points to the existence of a tribe, represented on the figure of the Surfer. This tribes integrates itself by a common life style based in ideals like love to the sport, communion with nature, an healthy life Style and an own language. The results also shows that the sympathizer is insert in an large culture of consumption, where he buys clothes and accessories to be an part of the society. It is also apparent the role of the Surf brands on the appropriation of some the ideals and life style of the surfer to sell an new an ideal scenario and life style to the sympathizer.
27

An Ethnographic Exploration of Gender Experiences of a New Zealand Surf Culture

Corner, Sarah Britt January 2008 (has links)
This thesis is an ethnographic exploration of gender experiences in a New Zealand surf culture. I employed the methods of participant observation, semi-structured interviews and focus groups to accumulate in-depth and descriptive qualitative data from the men and women who surf in the community of Raglan. I was especially interested in the rules surrounding the act of lining up - a systematic etiquette used to queue for waves. I inquired about surfers' struggles when lining up to deepen my understanding of the cultural behaviour of surfing and to help reveal implicit rules underpinning surf etiquette. As a female surfer, I was especially interested to understand the gender-relations between men and women in the waters in which I participated in. I discovered that subtle rules pertain to different groups of surfers and group emerged based on 'other' surfer characteristics. Although gender surfaced as a characteristic way of sorting surfers into groups, gender did not stand out more critical than others revealed throughout the research process. What was evident throughout the research was that men and women experience more commonalities in their surfing experiences than differences. Therefore, this research shows how the waves become a contested spaces for surfers and how surf culture serves as a site for resistance to gendered identities in contemporary Western society.
28

Noise Signatures Analysis of Nearshore Breaking Wave

Wu, Jian-Yi 23 August 2010 (has links)
¡@The ocean ambient noise of coast is mainly influenced by sea waves, boats or ships, or human¡¦s coast activities. Among them, most of the ambient noise is from the breaking wave noise caused by wind, and its frequency range is quite wide (0.5~50 kHz). The breaking wave noise mechanism of surf zone is very complex, and has a variety of signal features. In this research, the location is at the Sizih Bay near Kaohsiung Harbor. Hydrophone was used to collect the noise and the wave motion process of surf zone was recorded simultaneously with a digital video camera. It was shown from the experiment results, as the wave evolved in the surf zone, it would eventually become unstable and collapsed, so a large amount of air would be trapped in water and forming bubble clouds. The oscillating bubble cloud from breaking wave would generate high frequency sound. The results also indicated that when breaking wave reached the location hydrophone, a wide band pulse sound was generated with a level as high as 120 dB. In the analysis of each frequency (1k, 2k, 3k, 4k, 5k Hz), due to the oscillating effects air bubbles after breaking wave, the noise level at 2~5k Hz were higher as compared to that without breaking wave passing the hydrophone. The last result was also validated by the time integral of the noise energy through out the wave evolution. In addition to the process of breaking waves and residual air bubbles under breaking waves contributing to the breaking wave source, for example discussed in the study breaking wave¡¦s period and breaking wave height, the results from these two studies found, when the longer the breaking wave period , the breaking wave SPL will be bigger with the longer the breaking wave period. And in the breaking wave height, when the breaking wave height much higher, breaking wave SPL will be much bigger too. And learned from these two conclusions , breaking wave periods and height will make the breaking waves source level caused by changes.
29

The effect of wave grouping on shoaling and breaking processes

Shand, Thomas Duncan, Civil & Environmental Engineering, Faculty of Engineering, UNSW January 2009 (has links)
Determining the largest breaking wave height which can occur in water of finite depth is a fundamental reference quantity for the design of coastal structures. Current design guidelines are based on investigations which predominantly used monochromatic waves, thereby neglecting group effects which are inherent to the free propagation of waves in deep water. The Coastal Engineering Manual (CEM) states that wave grouping and its consequences is of significant concern, with breakwater armour damage being generally attributed to higher waves associated with wave groups. However, the CEM also acknowledges that there is little guidance and few formulae for use in practical engineering. This thesis describes a laboratory-based investigation into the effect of wave groupiness on wave shoaling, breaking and surf zone processes. New optical-based techniques for data abstraction, developed within this study, have allowed examination of the interaction between deep water intra-wave group processes and shallow water shoaling processes. The applicability of existing methods for predicting breaking wave height and position is evaluated, along with the implications of groupiness on engineering design in the nearshore. The effect of wave groupiness on overtopping and hazard on emerged rock platforms is similarly assessed. Wave group testing has revealed that the spatial phasing of intra-group processes during shoaling can result in considerably different shoaling and breaking regimes. Under certain regimes, wave breaking occurred further shoreward and in a more plunging manner than under other regimes. Within the mid to inner surf zone, waves were also observed to propagate into shallower water before breaking than is predicted by existing design guidelines. This could result in under-prediction of wave height by up to 100%. Expressions are developed for the prediction of maximum wave heights and surface elevation on plane slopes. These expressions implicitly include non-linear group effects and group-induced water-level variations within the surf zone, and are found to provide conservative upper envelopes for the range of data observed within the current testing regimes. Predictive schemes are similarly developed for overtopping hazard on emerged rock platforms based on critical wave and water-level conditions. Variations in maximum overtopping flow values due to intra-wave group processes of up to +/-35% were found. These group effects were found to reduce by up to 30% the threshold wave conditions before the initiation of hazard.
30

Closing motor vehicle beach access in the Mid-Atlantic implications for social welfare /

Magee, Laura E. January 2008 (has links)
Thesis (M.S.)--University of Delaware, 2008. / Principal faculty advisor: George R. Parsons, College of Marine & Earth Studies. Includes bibliographical references.

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