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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.
41

Μοντελοποίηση της διαδικασίας απορρόφησης και αποβολής αδρανών αερίων στο ανθρώπινο σώμα

Αρβανίτης, Νικόλαος 01 November 2010 (has links)
Ανάλυση των μοντέλων που περιγράφουν τη διαδικασία απορρόφησης και αποβολής αδρανών αερίων στο ανθρώπινο σώμα κατά τη διάρκεια μίας αυτόνομης κατάδυσης. / Analysis of the models that describe the procedure of absorption and expulsion of inert gases in the human body during scuba diving.
42

Citizen science data quality: Harnessing the power of recreational SCUBA divers for rockfish (Sebastes spp.) conservation

Gorgopa, Stefania M. 30 August 2018 (has links)
Monitoring rare or elusive species can be especially difficult in marine environments, resulting in poor data density. SCUBA-derived citizen science data has the potential to improve data density for conservation. However, citizen science data quality may be perceived to be of low quality relative to professional data due to a lack of ‘expertise’ and increased observer variability. We evaluated the quality of data collected by citizen science scuba divers for rockfish (Sebastes spp.) conservation around Southern Vancouver Island, Canada. An information-theoretic approach was taken in two separate analyses to address the overarching question: ‘what factors are important for SCUBA-derived citizen science data quality?’. The first analysis identified predictors of variability in precision between paired divers. We found that professional scientific divers did not exhibit greater data precision than recreational divers. Instead, precision variation was best explained by study site and divers’ species identification or recreational training. A second analysis identified what observer and environmental factors correlated with higher resolution identifications (i.e. identified to the species level rather than family or genus). We found divers provided higher resolution identifications on surveys when they had high species ID competency and diving experience. Favorable conditions (high visibility and earlier in the day) also increased taxonomic resolution on dive surveys. With our findings, we are closer to realizing the full potential of citizen science to increase our capacity to monitor rare and elusive species. / Graduate
43

“Decápodes Infralitorâneos dos Recifes Costeiros de Pernambuco, Nordeste do Brasil – Uma Abordagem Com Censo Visual Subaquático Noturno”

Giraldes, Bruno Welter 03 December 2012 (has links)
Submitted by Eduarda Figueiredo (eduarda.ffigueiredo@ufpe.br) on 2015-03-12T14:06:21Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Tese Bruno W. Giraldes 2012. Decápodes infralitorâneos dos recifes costeiros de Pernambuco, nordeste do Brasil – uma abordagem#8072.compressed.pdf: 9033191 bytes, checksum: 309c0c23f0af5e6c91611441cb570c94 (MD5) / Made available in DSpace on 2015-03-12T14:06:21Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Tese Bruno W. Giraldes 2012. Decápodes infralitorâneos dos recifes costeiros de Pernambuco, nordeste do Brasil – uma abordagem#8072.compressed.pdf: 9033191 bytes, checksum: 309c0c23f0af5e6c91611441cb570c94 (MD5) Previous issue date: 2012-12-03 / FACEPE / Esta tese é apresentada em forma de 5 capítulos e tem como objetivos: 1a) adaptar e testar técnica de censo visual subaquático para decápodes em ambientes recifais e montar guia de campo com espécies alvo; 1b) comparar a técnica de censo visual com a técnica tradicional de coleta de decápodes e apresentar uma sinopse taxonômica dos Decapoda de Porto de Galinhas; 2) registrar a presença do camarão barbouriídeo Janicea antiguesis (Chace, 1972) para Porto de Galinhas e Tamandaré em Pernambuco e para Guarapari no Espírito Santo, Brasil; 3) descrever a zonação dos decápodes infralitorâneos encontrados durante mergulho noturno no ecossistema recifal; 4) investigar a influencia da atividade turística sobre a comunidade dos decápodes infralitorâneos nos recifes; 5) analisar a influência do ciclo lunar sobre os decápodes infralitorâneos encontrados durante mergulho scuba noturno nos recifes costeiros. O CAPÍTULO I – descreve a técnica de censo visual subaquático com transecto faixa para ser realizada no período noturno com decápodes. Foram capturados 38 decápodes durante os mergulhos e foram escolhidas 28 espécies alvo para o guia de campo. Foram realizados 148 censos visuais noturno e comparados com os dados de bibliografia (43 decápodes coletados manualmente pela superfície). Foi montada a sinopse taxonômica com 70 decápodes para todo o recifes de Porto de Galinhas. Os resultados demonstram que cada técnica de coleta aborda um grupo específico de decápodes com diferentes valores de abundância e frequência e que a técnica de coleta com censo visual noturno é viável (principalmente para decápodes grandes de valor econômico) porém é complementar às técnicas tradicionais de coleta manual de superfície. O CAPÍTULO II – através do registro de exemplares de J. antiguensis para o Nordeste e Leste do Brasil, este trabalho estende consideravelmente para o Sul o limite de ocorrência desta espécie na costa brasileira. São apresentadas fotografias coloridas de J. antiguensis de varias localidades do Atlântico e seus padrões de coloração são comparados com o semelhante camarão Barboriidae do Indo-Oeste Pacifico Parhippolyte misticia (Clark, 1989). Múltiplas observações de pares de indivíduos ovígeros com embriões em diferentes estágios de desenvolvimento, sugere um hermafroditismo protândrico simultâneo em J. antiguensis. No CAPÍTULO III – referente a zonação dos decápodes, os resultados demonstram que as espécies estão distribuídas no ecossistema recifal em 3 habitats 1) o habitat “externo” recifal iluminado, (franja e parede); 2) o habitat recifal cavernoso “interno” e escuro, formado pelas cavernas, grutas e cavidades recifais; e 3) um habitat “circundante” de substrato móvel e fragmentos recifais que rodeiam a estrutura recifal. Dois fatores abióticos foram responsáveis por esta zonação, o tipo de substrato (recifal consolidado e fundo móvel); e a incidência luminosa no recife (externo iluminado e interno cavernoso). Os decápodes característicos de cada habitat apresentaram características e adaptações morfológicas em comum para a vida em cada habitat. Com relação ao hidrodinamismo e/ou a profundidade os decápodes se deslocam mais de um habitat ao outro com o aumento do hidrodinamismo/profundidade, e somente o habitat cavernoso não é afetado pelo alto hidrodinamismo. O CAPÍTULO IV – comparou Porto de Galinhas (alto turismo) e Tamandaré (baixo turismo) para determinar a influencia do turismo sobre os decápodes. Os resultados demonstram que as principais influências ocorrem no habitat fundo móvel e no habitat externo dos pontos rasos (fácil acesso humano) e principalmente sobre a comunidade de Brachyura e Anomura. Devido a falta de cobertura bêntica viva sobre o habitat externo causado pelo turismo (pisoteio), houve uma diminuição da diversidade de Brachyura associados as algas, esponjas e corais e v estimulou uma maior abundância de poucas espécies comedoras de macroalgas pisoteadas (disponíveis). Devido a tradicional coleta de conchas em pontos turísticos e a necessidade de conchas disponíveis para o crescimentos dos ermitões (Anomura), em Porto de Galinhas houve uma grande diminuição da abundância e diversidade de ermitões. Portanto o turismo afeta direta e indiretamente a comunidade de decápodes recifais. No CAPÍTULO V – foi determinada a influência do ciclo lunar sobre os decápodes, comparando (através de censos visuais noturnos) a distribuição das espécies nos recifes de Porto de Galinhas durante as luas Cheia, Minguante e Nova. Vários resultados sugerem que a ausência da luminosidade durante a lua nova, seja o principal fator a influenciar na distribuição dos decápodes crípticos de hábito noturno (principalmente os cavernosos). A maré de quadratura também influenciou na distribuição dos decápodes e estimulou algumas espécies a saírem mais de seus esconderijos neste período semilunar. Portanto, as fases da lua influenciam diretamente na composição e distribuição dos decápodes nos recifes estudados e podem estar revelando uma sincronicidade reprodutiva ou um comportamento alimentar (forrageamento) sincronizado padrão para os decápodes recifais no nordeste do Brasil.
44

Sounding silent space: a narrative exploration of scuba diving as a therapeutic wilderness adventure bridging deaf and hearing experience

Ward, Edmund Herbert 14 November 2008 (has links)
M.A. / The study presents a narrative exploration of the potential offered by SCUBA (Self Contained Underwater Breathing Apparatus) diving as a therapeutic wilderness adventure context bridging Deaf and hearing experiences. It is structured as an emerging narrative in three parts. Part I explores the philosophical and theoretical literature with a view to providing an overview of the epistemological frameworks against which the study is presented and which could result in a sense of tension between modern/post modern discourses within the reader/author. Part II reviews the current literature pertaining to: Deafness and Deaf/hearing relations, contrasting the medical-pathological perspective of Deafness with a socio-cultural model and examining perceptions regarding the development of a Deaf cultural identity, the articulation of meaning and culturally affirmative proposals with regard to the integration of Deaf and hearing experiences; adventure, wilderness programmes and practices as agents of therapeutic change with particular reference to the Deaf and other disabled communities; and the potential application of SCUBA diving and the underwater environment as metaphorically different agents of therapeutic change and particularly as they relate to Deaf/hearing relations. Part III attempts to provide a multi-levelled dialogical space for the voices of Deaf and hearing participants in the study to emerge and reflect on their lived experiences of their participation in a SCUBA diver course and its potential impact on lived experiences and personal narratives and metaphors. The study is written as a post modern text and explores Bakhtin’s (1973) theories of dialogism as a basis for presenting a polyphonic text.
45

From gas and dust to protostars: addressing the initial stages of star formation using observations of nearby molecular clouds

Mairs, Steve 11 December 2017 (has links)
Though there has been a considerable amount of work investigating the early stages of low-mass star formation in recent years, the general theory is only broadly understood and several open questions remain. Specifically, the dominant physical mechanisms which connect large-scale molecular cloud structures, intermediate-scale filamentary gas flows, and small-scale collapsing prestellar envelopes in the interstellar medium are poorly constrained. Even for an individual forming protostar, the evolution of the mass accretion rate from the envelope onto the central object is debated with little observational evidence to help guide the theoretical framework. In addition, with the development of new technology such as the continuum imaging instrument in operation at the James Clerk Maxwell Telescope (JCMT), the Submillimetre Common User Bolometer Array 2 (SCUBA-2), the best practices for data reduction and image calibration for ground-based, submillimetre wavelength observations are still being investigated. In this dissertation, I address facets of these open questions in five main projects with an overarching focus on the flow of material from the largest to the smallest scales in a molecular cloud. By performing synthetic observations of a numerical simulation of a turbulent molecular cloud, I investigate the nature of prestellar envelopes and find evidence of larger mass reservoirs that form filamentary structures and feed cluster formation. Then, after robustly investigating and suggesting improvements for ground-based, submillimetre data reduction techniques, I continue to probe the connection between larger and smaller scales by characterising structure fragmentation in the Southern Orion A Molecular Cloud from the perspective of 850 m continuum data. Finally, I follow star forming material to even smaller scales by exploring the evolution of the mass accretion rate onto individual protostars. This examination has required designing and implementing unprecedented spatial alignment and flux calibration techniques at 850 m. Using these newly calibrated images, I am able to identify several candidate sources that show evidence for submillimetre variability, suggesting changes in protostellar accretion rates over several year timescales. / Graduate
46

The hearing abilities and middle ear functioning of the recreational scuba diver

Pieterse, Izabelle 11 September 2007 (has links)
Scuba diving as a recreational activity has increased in popularity over the past few years. It is believed that repeated exposure to the hyperbaric environment may have a long term effect on the auditory system. The research literature has given a lot of attention to acute injury but is very limited relating to the long term implications of scuba diving. Previous research studies did not perform a full audiometric test battery. A comprehensive audiological assessment is critical to determine in which part of the ear a pathology may occur during recreational diving. This study endeavoured to assess and describe the hearing abilities and middle ear functioning of the recreational scuba diver and investigate the possibility that diving, on a recreational level, may have an influence on the auditory system. In order to achieve the aims of this study, a descriptive, correlation research design was selected. The results of the current study indicate that scuba diving on a recreational level does not have a significant effect on the hearing and middle ear functioning of the individual, with the exclusion of static compliance. It appears that the inevitable compression and decompression that the middle ears are exposed to during scuba diving might have a more permanent effect on the elasticity of the tympanic membrane. Finally this study aims to increase the awareness of possible risks concerning the auditory system relating to scuba diving and in so doing, attribute to the prevention, diagnosing and intervention of diving related ear injuries. / Dissertation (M (Communication Pathology))--University of Pretoria, 2007. / Speech-Language Pathology and Audiology / M (Communication Pathology) / unrestricted
47

Rozdíl spotřeby dýchaného média mezi muži a ženami při jednotné zátěži v přístrojovém potápění / Differences in inhalation between men and famales during the identic scuba diving output

Rosenkranzová, Michaela January 2016 (has links)
Name: : The difference of consumption of a medium being inhaled between a man and a woman at the same level of endurance in scuba diving. Goals: The primary goal of this work, is to determine if and how is the amount of the inhaled medium depending on the gender of the divers. Compare the consumption between men and women while being faced with the same amount of stress, meaning during a united profile of a dive, try to maximize the decrease of the influence of stress factors. Confirm or deny the hypothesis that men show higher values of the inhaled medium. Methods: The theoretical part of this paper, was created based on the research of the appropriate literature. To obtain all the data, there was used the method of experiments, the results were then analyzed, compared and than statistically evaluated using the Students T- test. Probandi (n=10+10) took part in a 30 minute long and 20 meters deep dive in Bořená hora, during which their consumption of the inhaled medium was recorded every 5 seconds using a special underwater computer with a probe. Results: It was found out that men, during the same dive, consume more air than women because of their higher body weight. Key words: scuba diving, air, sex, respirator, minute ventilation
48

Ouvindo o silêncio: a construção identitária por meio da prática do mergulho scuba como consumo hedônico

Gomes, Maurício de Brito January 2008 (has links)
Made available in DSpace on 2009-11-18T19:01:38Z (GMT). No. of bitstreams: 1 mbgomes.pdf: 1916342 bytes, checksum: d3e274b572fe37fd42cf2d47606bb34f (MD5) Previous issue date: 2008 / This work aims to explore the context and emotions related to the experience of scuba diving as hedonic consumption, as well as to understand in which conditions the benefit arising from the regular practice of this activity impact the identity construction of the practitioner. Through in-depth interviews, data were collected from scuba divers living in the city of Rio de Janeiro, during the months of January and February of 2008. In order to obtain the expected objectives, the chosen methodology of research was qualitative, with priority of the subject and the subjectivity, using an interpretative approach for the data analysis. The research results confirm some benefits of high-risk sports practice such as flow, self-evolution and communitas. Two additional benefits are presented: the condition of alterity of the ¿underwater world¿, which attributes extraordinany meaning to scuba diving and impacts identity construction, and the scuba ¿buddy¿ practice, that helps to build-up an overall sense of trust to the other. The work is concluded with some managerial recommendations aiming the development of scuba diving industry and related tourism. These above mentioned suggestions include a new industry positioning, integrated marketing communications with specific references to alterity and flow, market segmentation, the creation of gathering spaces and a gradation scale among practitioners. / Este trabalho tem como objetivo explorar o contexto e as emoções relacionadas à experiência do mergulho scuba como atividade hedônica e as condições em que os benefícios oriundos de seu consumo habitual impactam a construção de identidade do praticante. Por meio de entrevistas em profundidade, foram coletados dados junto a mergulhadores scuba residentes na cidade do Rio de Janeiro, durante os meses de janeiro e fevereiro de 2008. Para atingir os objetivos propostos, o método de pesquisa adotado foi qualitativo, com priorização do sujeito e da subjetividade, utilizando-se uma forma interpretativa para análise de dados. Os resultados confirmaram alguns benefícios da prática de esportes de alto risco já pesquisados academicamente como o fluxo, communitas e evolução pessoal. Apresentam-se dois benefícios adicionais: a condição de alteridade do mundo submarino, que atribui significância extraordinária a essa atividade esportiva e impacta a construção identitária dos envolvidos, e a prática de dupla de mergulho, que desenvolve uma confiança generalizada no próximo e serve como referência na definição do indivíduo. Conclui-se o trabalho, fazendo-se recomendações gerenciais com o intuito de beneficiar e desenvolver a indústria e o turismo relacionado a esse esporte. Essas sugestões incluem um novo posicionamento da indústria, comunicação integrada de marketing com menções específicas à alteridade e à experiência de fluxo, segmentação de mercado, criação de espaços de convivência para praticantes e por último, a criação de uma gradação relativa aos diversos níveis de mergulhadores.
49

Etude de la variation de la capacité de diffusion pulmonaire du monoxyde de carbone (DLCO) sur les riques d'accident de décompression / Study of the decreases of diffusing lung capacity of carbon monoxide on decompression sickness risks

Loddé, Brice 18 December 2018 (has links)
L’exposition hyperbare induit des risques sanitaires, en particulier d’accidents de décompression (ADD), dont la probabilité dépend de multiples facteurs, tant externes qu’individuels. Parmi ceux-ci, l’altération de la barrière alvéolo-capillaire est peu ou pas étudiée. Nous avons donc cherché à identifier les effets d’une altération pulmonaire caractérisée par une diminution de la capacité de diffusion alvéolo-capillaire du monoxyde de carbone (DLCO) sur le risque d’ADD. Après un bilan d’aptitude préalable, chaque volontaire a été évalué avant et après la plongée.15 plongeurs professionnels civils répartis en 2 groupes en fonction de leur DLCO, normale (Contrôle) ou diminuée (DLCO), ont réalisé une plongée standardisée à 20 mètres pendant 40 minutes dans le bassin d’eau de mer d’IFREMER. Nous avons mesuré le score de bulles intravasculaires (VGE), la réponse microcirculatoire par débitmétrie laser doppler et les concentrations de différents paramètres biologiques en particulier l’aldostéronémie. Même en l’absence de survenue d’ADD, tous les plongeurs produisent des VGE. Le groupe DLCO est caractérisé par un pic de VGE plus tardif (60 minutes vs 30 minutes) et une tendance à des scores plus importants (Grade IV : 17% vs 11%). Par ailleurs, l’hypoaldostéronémie n’est observée que dans le groupe contrôle (-30.4±24.6%), pas dans le groupe DLCO (+14.8±34.7%). En dehors d’une diminution du risque thrombotique chez tous les plongeurs, les autres paramètres mesurés sont inchangés. Ces résultats évoquent une augmentation du risque d’ADD devant être confirmée par d’autres études. / Hyperbaric exposure leads to a risk of decompression sickness (DCS). The likelihood of DCS depends on multiple factors, external as well as individual. Among them, the alteration of the blood-air barrier has been poorly studied.Therefore, we measured the effect of pulmonary impairment characterized by a decreased diffusing lung capacity of carbon monoxide (DLCO) on the risk of DCS.15 professional divers were splited into 2 groups according to their DLCO, normal (control) or decreased (DLCO), and enrolled after an initial full “fit-to-dive” clinical check-up. They made a standardized 20 meters/40 minutes SCUBA dive in a sea water pool (IFREMER) Vascular Gas Emboli (VGE) score, micro-circulatory response, inflammatory biomarkers, thrombotic factors, and aldosteron rate were measured pre- and post-dive. Although no DCS occurred, all the divers showed VGE after diving. Compared to the control group, we observed in the DLCO group an increased latency to the VGE peak (60 vs 30 minutes) and a tendency for higher VGE scores (Grade IV: 17% vs 11%). A significant decrease (-30.4±24.6%) of aldosteron rate was observed in control and not in the DLCO group (+14.8±34.7%). Most of the biological parameters and microvascular response remained unchanged while all divers had a lowered post-dive thrombotic risk.These results imply that divers with a decreased DLCO might be exposed to an increased DCS risk.Further studies are required to confirm the implication and significance of pulmonary impairment in DCS.
50

En Djupdykning i Kommunikationsstrategi : om konsten att locka folk till svenska dykvatten

Björklund, Anna January 2008 (has links)
<p><strong>Purpose/Aim:</strong> To create a communication strategy for PADI Nordic with the intention of getting Swedish divers, who have been certified abroad, to Swedish dive centers.</p><p><strong>Material/Method: </strong>The study is based on a number of personal interviews conducted with a) divers who are active in Sweden, b) divers who are not active in Sweden and c) representatives from PADI and PADI affiliated dive centers.</p><p><strong>Main results: </strong>The main reason that people who have been certified abroad do not dive in Sweden is that they regard it as being too complicated, too cold, too expensive and with nothing interesting to see. These might partly be misconceptions that can be corrected through a communication strategic effort. The best way to change this perception is by two different forms of communication. One will go from PADI Nordic straight to the divers through an email. This will have the purpose of getting their attention, making diving sound interesting and raise their awareness in preparation for the other part of the process. The other part is communication from PADI affiliated dive centres directed towards the divers. This will be in the form of more traditional marketing, and will have the purpose of making diving in Sweden sound easy, uncomplicated and price worthy. Hopefully this will bring people in to the dive centres, and in the ideal case they will in time also bring their friends along – by becoming the first link in a two step flow of communication.</p><p> </p>

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