Дисертації з теми "Swimming"
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1
Thompson, Alicia R. "Synchronized Swimming." Scholar Commons, 2011. http://scholarcommons.usf.edu/etd/3381.
Анотація:
Most girls in Gopher Slough, Florida, worry about whether GSHS will win the next football game (they won't), when their boyfriends will take them muddin', and how many times they can sneak cigarettes behind the bleachers before they get thrown into in-school suspension.
Libby Hoyer is not most girls.
Instead, Libby is worried about her slipping grades, especially in Geometry, where she can barely keep her head up long enough to take the weekly quizzes. She's concerned about losing her friendship with her best (only) friend, Bobbi Jo, who's distracted with her own Aber-zombie boyfriend, and she's unsure of how to define her new relationship with Neil, a mysterious boy from her class who is not as carefree as he pretends to be. Libby is also troubled by the fact that she can't seem to remember her distant father, even though he only left five years ago.
Everyone else, it seems, is worried about Libby's sporadic eating habits. If she continues to refuse to eat or to purge anything she's forced to eat, she might disappear. But Libby isn't afraid of disappearing. She's afraid of being seen.
2
Nilsson, Linette. "Swimming Pool." Thesis, Konstfack, Textil, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:konstfack:diva-5827.
Анотація:
My project started with two words: Swimming Pool. They came to me through a song, Banshee Beat by Animal Collective (2005). To me, their music is mystical, abstract, unpredictable and also metaphorical. So I started to think about if a swimming pool could be something more than just an open container filled with water. After some thinking I came to the conclusion that it could be a metaphor for something calm, quiet and dreamy. However, I’m not sure but my aim is not to get to a specific answer through this project. I’ll turn the metaphor into a textile work that portrays what you see when you’re standing at the edge of the swimming pool; a distorted picture of a grid, the bottom of the pool. I’ll be working with dyeing, patchwork and quilting. The textile craft is important in this project because of how relaxed and calm I get by doing things with my hands. The questions I’m asking myself are how I can express the metaphor through my work? What if my interpretation is too wide? Is it possible for me to create a tactile and calm feeling without the physical touch?
3
Strange, Cecily. "The relationship of psycho-social factors to swimming competency and attendance at swimming programs among year seven students." University of Western Australia. School of Human Movement and Exercise Science, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0041.
Анотація:
Children in upper primary school who have not made progress along the Swimming and Water Safety Continuum may be at a greater risk in an aquatic environment because they have not developed the swimming competency, endurance and skills needed for survival in threatening aquatic situations. Three groups representing different socio-economic and geographical areas were selected to explore the relationships between psycho-social factors and the development of swimming ability among year seven students. Two groups from lower socio-economic areas were chosen. The first group was directly on the coast with easy access to the beach, while the second group was inland in the foothills of Perth. As higher socio-economic areas in Perth are generally not far from the coast only one group from a higher socio-economic coastal area was chosen. The participants were 540 year seven students, 282 of whom were males and 258 of whom were females. The primary variable of interest was the current swimming stage of year seven participants, and the differences between genders and/or locality groups. The primary research questions investigated differences between locality groups and/or genders for; a) perceived athletic competence and global self-worth, b) perceived swimming competency, confidence in deep water and importance placed on learning to swim well. c) perceived social support for sport and swimming activities and d) attendance at Interm, Vacswim and other swimming programs and aquatic venue experience. Relationships between swimming stage and the above variables were analysed. The secondary research questions investigated the most frequent reasons given by the students for not attending or discontinuing participation inVacswim, and whether there were differences between locality groups or genders. Findings indicated that the lower socio-economic groups had a significantly lower swimming stage and lower perceived self-worth than the higher socioeconomic group. Students from the lower socio-economic inland area had the lowest mean swimming stage as well as lower perceived social support for sport and swimming than either of the other two groups in the study. The two lower socioeconomic groups also attended less swimming instruction and placed less emphasis on the importance of learning to swim well than the higher socio-economic group. Despite these findings, the lower socio-economic groups did not view themselves as any less able in terms of athletic and swimming competence. However, as the two lower socio-economic groups have not progressed along the Swimming and Water Safety Continuum to the 'desirable standards' of the RLSSA (1999), these groups could be viewed as at-risk in an aquatic environment. At the same time, there was evidence that attendance at Interm along with attendance at another swimming program enabled participants to reach the 'desirable standards' of the RLSSA (1999). Girls generally had a higher swimming stage than boys in the lower socio-economic areas, attended year seven Interm and Vacswim more than boys, reported more social support for sport and swimming, and placed more emphasis on the importance of learning to swim well than boys. While many of these relationships between swimming stage and psycho-social factors have been intuitively accepted within the swimming teaching industry, we now have a better understanding of the strength and direction of these relationships.
4
Pachmann, Sydney. "Swimming in slime." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/1503.
Анотація:
The purpose of this thesis is to study the problem of a low Reynolds number
swimmer that is in very close proximity to a wall or solid boundary in a non-
Newtonian fluid. We assume that it moves by propagating waves down its length
in one direction, creating a thrust and therefore propelling it in the opposite
direction. We model the swimmer as an infinite, inextensible waving sheet.
We consider two main cases of this swimming sheet problem. In the first
case, the type of wave being propagated down the length of the swimmer is
specified. We compare the swimming speeds of viscoelastic shear thinning,
shear thickening and Newtonian fluids for a fixed propagating wave speed. We
then compare the swimming speeds of these same fluids for a fixed rate of work
per wavelength. In the latter situation, we find that a shear thinning fluid
always yields the fastest swimming speed regardless of the amplitude of the
propagating waves. We conclude that a shear thinning fluid is optimal for the
swimmer. Analytical results are obtained for various limiting cases. Next, we
consider the problem with a Bingham fluid. Yield surfaces and flow profiles are
obtained.
In the second case, the forcing along the length of the swimmer is specified,
but the shape of the swimmer is unknown. First, we solve this problem for a
Newtonian fluid. Large amplitude forcing yields a swimmer shape that has a
plateau region following by a large spike region. It is found that there exists
an optimal forcing that will yield a maximum swimming speed. Next, we solve
the problem for moderate forcing amplitudes for viscoelastic shear thickening
and shear thinning fluids. For a given forcing, it is found that a shear thinning
fluid yields the fastest swimming speed when compared to a shear thickening
fluid and a Newtonian fluid. The difference in swimming speeds decreases as
the bending stiffness of the swimmer increases.
5
Palmer, Soren G. "The Swimming Rabbit." University of Cincinnati / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1299005382.
6
Bartol, Ian K. "Distribution, swimming physiology, and swimming mechanics of brief squid Lolliguncula brevis." W&M ScholarWorks, 1999. https://scholarworks.wm.edu/etd/1539616562.
Анотація:
Squids are thought to have physiological and locomotive deficiencies that put them at a competitive disadvantage to fishes and exclude them from inshore, highly variable environments that are rich in nektonic fauna. However, brief squid Lolliguncula brevis may be a notable exception. Trawl surveys revealed that L. brevis, particularly juveniles <6 cm dorsal mantle length (DML), are abundant in the Chesapeake Bay, especially when salinity and water temperature are high, and tolerate a wide range of physical conditions relative to other cephalopods. L. brevis is also different from other cephalopods examined previously because its pattern of oxygen consumption as a function of velocity was found to be parabolic and thus similar to aerial flight, and its swimming costs were competitive with ecologically equivalent fishes. Power-speed curves derived from video footage of swimming squid and hydrodynamic force calculations also were parabolic in shape, with high costs both at low and high speeds because of power requirements for lift generation and overcoming drag, respectively. L. brevis employed various behaviors to increase swimming efficiency and compensate for negative buoyancy, such as swimming in various orientations (e.g., arms-first and tail-first), altering angles of attack of the mantle, arms, and funnel, and using fin activity. Fin motion, which could not be characterized exclusively as drag- or lift-based propulsion, was used over 50--95% of the sustained speed range and provided as much as 78% of the vertical and 55% of the horizontal thrust. Small squid (<3.0 cm DML) used different swimming strategies than larger squid possibly to maximize the benefits of toroidal induction, and aerobic efficiency curves indicated that squid 3--5 cm. DML are most efficient. Brief squid also may take advantage of unsteady phenomena, such as attached vortices, for added lift and thrust. Furthermore, an electromyographic study revealed that L. brevis uses different circular muscle layers for various speeds and like fish has muscular "gears", suggesting that there is specialization and efficient use of locomotive muscle in some cephalopods. Therefore, the presumption that squids are inescapably constrained by a second-rate propulsive system and physiological deficiencies is not applicable to L. brevis.
7
O'Malley, Stephen. "Bi-flagellate swimming dynamics." Thesis, University of Glasgow, 2011. http://theses.gla.ac.uk/2706/.
Анотація:
The propulsion of low Reynolds number swimmers has been widely studied, from the swimming sheet models of Taylor (1951), which were analogous to swimming spermatozoa, to more recent studies by Smith (2010) who coupled the boundary element method and method of regularised Stokeslets to look at cilia and flagella driven flow. While the majority of studies have investigated the propulsion and hydrodynamics of spermatozoa and bacteria, very little has been researched on bi-flagellate green algae. Employing an immersed boundary algorithm and a flexible beat pattern Fauci~(1993) constructed a model of a free-swimming algal cell. However, the two-dimensional representation tended to over-estimate the swimming speed of the cell. Jones~\etal~(1994) developed a three-dimensional model for an idealised bi-flagellate to study the gyrotactic behaviour of bottom-heavy swimmers. However, the un-realistic cell geometry and use of resistive force theory only offered order of magnitude accuracy. In this thesis we, investigate the hydrodynamics of swimming bi-flagellates via the application of the method of regularised Stokeslets, and obtain improved estimates for swimming speed and behaviour. Furthermore, we consider three-dimensional models for bi-flagellate cells with realistic cell geometries and flagellar beats. We investigate the behaviour of force- and torque-free swimmers with bottom-heavy spheroidal bodies and two flagella located at the anterior end of the cell body, which beat in a breast stroke motion. The cells exhibit gravitactic and gyrotactic behaviour, which result in cells swimming upwards on average in an ambient fluid and also towards regions of locally down-welling fluid, respectively. In order to compare how important the intricacies of the flagellar beat are to a cell's swimming dynamics we consider various beat patterns taken from experimental observations of the green alga \Rein~and idealised approaches from the literature. We present models for the bi-flagellate swimmers as mobility problems, which can be solved to obtain estimates for the instantaneous translational and angular velocities of the cell. The mobility problem is formulated by coupling the method of regularised Stokeslets with the conditions that there is no-slip on the surface of the body and flagella of the cell and that there exists a balance between external and fluid forces and torques. The method of regularised Stokeslets is an approach to computing Stokes flow, where the solutions of Stokes equations are desingularised. Furthermore, by modelling the cells as self-propelled spheroids we outline an approach to estimate the mean effective behaviour of cells in shear flows. We first investigate bi-flagellate swimming in a quiescent fluid to obtain estimates for the mean swimming speed of cells, and demonstrate that results for the three-dimensional model are consistent with estimates obtained from experimental observations. Moreover, we explore the various mechanisms that cells may use to re-orientate and conclude that gyrotactic and gravitactic re-orientation is due to a combination of shape and mass asymmetry, with each being equally important and complimentary. Next, we compare the flow fields generated by our simulations with some recent experimental observations of the velocity fields generated by free-swimming \rein, highlighting that simulations capture the same characteristics of the flow found in the experimental work. We also present our own experiments for \rein~and \Dunny~detailing the trajectories and instantaneous swimming speeds for free-swimming cells, and flow fields for trapped cells. Furthermore, we construct flagellar beats based upon experimental observations of \dunny~and \textit{D. bioculata}, which have different body shapes and flagellar beats than \chlamy. We then compare the estimates for swimming speed and re-orientation time with \rein, highlighting that, in general, \Dun~achieve greater swimming speeds, but take longer to re-orientate. The behaviour of cells in a shear flow is also investigated showing that for sufficiently large shear, vorticity dominates and cells simply tumble. Moreover, we obtain estimates for the effective cell eccentricity, which, contrary to previous hypotheses, shows that cells with realistic beat patterns swim as self-propelled spheres rather than self-propelled spheroids. We also present a technique for computing the effective eccentricity that reduces computational time and storage costs, as well as being applicable to unordered image data. Finally, we examine what effects interactions with boundaries, other cells, and obstacles have on a free-swimming cell. Here, we find that there are various factors which affect a cell's swimming speed, orientation and trajectory. The most important aspect is the distance between the interacting objects, but initial orientation and the flagella beat are also important. Free-swimming cells in an unbounded fluid typically behave as force-dipoles in the far field, and we find that for cell-to-cell and cell-to-obstacle interactions the far field behaviour is similar. However, swimming in the proximity of a boundary results in the flow field decaying faster. This implies that hydrodynamic interactions close to solid no-slip surfaces will be weaker than in an infinite fluid.
8
Johnson, Benjamin C. F. (Benjamin Cedar Fruehauf). "Bio-inspired swimming helix." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/77023.
Анотація:
Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2012.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 59-60).
This thesis investigated a bio-inspired swimming chain (BISH), inspired by Weelia cylindrica. After developing a model, it was used to investigate conditions under which helical motion would emerge. The properties of this chain as the number of nodes changes was also investigated, to see if the helical motion or other properties of its motion were emergent behaviors. Other modes of motion were also observed. Optimization of the angle of propulsion of each was performed, and other optimizations attempted, although practical difficulties prevented useful results. A ten node chain was constructed to empirically verify the helical mode of motion.
by Benjamin C. F. Johnson.
M.Eng.
9
Brumley, Douglas Richard. "Hydrodynamics of swimming microorganisms." Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608174.
10
Savory, Andrew. "Swimming patterns of zoospores." Thesis, University of Dundee, 2013. https://discovery.dundee.ac.uk/en/studentTheses/417e5e5d-bb27-4fc3-af1f-c96faae0faa6.
Анотація:
Phytophthora infestans is a highly destructive plant pathogen and the causal agent of the potato blight disease that devastated Ireland’s potato crops in the 19th century.Today, this disease is still a serious problem, with global crop losses and spending oncontrol measures estimated to exceed £3 billion annually. A key to the success of P. infestans is the dispersal of free-swimming zoospore cells from infected plant tissue into aqueous environments. These cells are specialised infection agents that have evolved an array of tactic responses in order to locate and infect new hosts. An interesting and poorly understood aspect of zoospore behaviour is the phenomenon of auto-aggregation. That is, large numbers of zoospores observed in vitro are seen to form complex, large-scale patterns in the absence of external signals or stimuli. Current competing hypotheses suggest that patterns are formed by one of two distinct, concentrative phenomena: chemotaxis and bioconvection. In this thesis we investigate the mechanics and implications of zoospore auto-aggregation behaviour using an interdisciplinary approach that combines continuum mathematical modelling with laboratory experimental work. We investigate the modelling of chemotactic and bioconvective processes and compare results with our experimental observations. Finally, we present a novel bioconvection-chemotaxis model and thus provide strong evidence to support the hypothesis that auto-aggregation in P. infestans zoospores results from a necessary combination of these processes.
11
Hill, Simon John. "Large amplitude fish swimming." Thesis, University of Leeds, 1998. http://etheses.whiterose.ac.uk/12760/.
Анотація:
A fish swims by stimulating its muscles and causing its body to "wiggle", which in turn generates the thrust required for propulsion. The relationship between the forces generated by the fish muscles and the observed pattern of movement is governed by the mechanics of the internal structure ofthe fish, and the fluid mechanics of the surrounding water. The mathematical modell ing of how fish swim involves coupling the external "biofluiddynamics" to the body's internal solid mechanics. The best-known theory for the hydrodynamics of fish swimming is Lighthill's elongated body theory (Lighthill, 1975). In Lighthill's theory the curvature of the fish is assumed small and the effect on the fish of the vortex wake is neglected. Cheng et al. (1991) did not make these simplifications in developing their vortex lattice panel method, but the fish was assumed to be infinitely thin and its undulations of small amplitude. Lighthill's "recoil correction" is the addition of a solid-body motion to ensure that an imposed "swimming description" satisfies the conservation of momentum and angular momentum. A real fish is expected to minimize such sideways translation and rotation to avoid wasteful vortex shedding. Cheng and Blickhan (1994) found that the panel method model required a smaller recoil than did Lighthill's model. Our approach is to extend Cheng's model to large amplitude. Thus we include the effect of the wake on the fish, and the self-induced deformation of the wake itself. In studying the internal mechanics of the body we model the fish as an active bending beam. Using the equations of motion of cross-sectional slices of the body we can form a set of coupled differential equations for the bending moment distribution. At large amplitude the bending moment equations involve the tangential forces acting on the body (which may be neglected in the small amplitude version). Consequently we include the boundary layer along the fish in order to estimate the viscous drag directly. The panel method has been used successfully for the fluid mechanical calculations associated with large-amplitude fish swimming. We are able to use its results as input to calculate the bending moment distribution. The boundary layer calculations are based on a crude model; solutions to the large amplitude bending moment equations should also be considered in this light.
12
Lang, Melanie. "Swimming in the panopticon : an ethnographic study of good practice in competitive youth swimming." Thesis, Leeds Beckett University, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.496704.
Анотація:
Underpinned by a Foucauldian analysis, this research explores how key personnel at competitive youth swimming clubs at different levels of the elite-development ladder interpret and realise good practice. Adopting an ethnographic approach to three casestudy clubs in the North of England - an elite, a sub-elite and a 'low-level' club - it involves observations of thirteen coaches and one poolside helper, plus semistructured interviews with eleven coaches, one poolside helper and two Club Welfare Officers, who are charged with overseeing child welfare issues in their swimming clubs.
13
Bullock, Gillian. "Disinfection of swimming pool water." Thesis, Cranfield University, 2003. http://dspace.lib.cranfield.ac.uk/handle/1826/108.
Анотація:
Results from this study, which has investigated the impact of the treatment technologies of chlorination, ozonation and UV irradiation on pool water quality are reported. The aim of the study was to evaluate the effect of these technologies in an unbiased way using a unique protocol, and to calculate a mass balance across the pool system. Data refer to a protocol based on operation of a 2.2m (cubed) capacity pilot swimming pool, which allows the comparison of technologies applied with reference to the propensity to generate the chlorinated disinfection by-products (DBPs) of chloramines and trihalomethanes (THMs). The protocol makes use of a specially developed body fluid analogue (BFA), containing simulant endogenous organic matter, with a soiling analogue consisting of commercial humic acid (HA). Using this analogue, levels of organic carbon (OC) and chloramines similar to those recorded in real pools have been obtained, along with somewhat lower levels of THMs. Results revealed conventional chlorination leads to steady-state TOC and DBP levels following an equilibrium period of 200-600 hours, with concentration values which are dependent on BFA loading rate. Following equilibration nitrate is the only DBP accumulating in the pool water, accounting for between 4% and 28% of the ammoniacal nitrogen loaded into the pool depending upon the operating conditions (primarily the Cl:N ratio). Both UV irradiation and ozonation, the latter combined with downstream adsorption, provide a similar efficacy in reducing chloramine levels, with their effect on THM and nitrate formation being highly dependent on the pH level and chlorine dose rate. This study builds on previous experimentation by including a more rigorous analysis of ozone-GAC with respect to DBP formation, a unique analysis of UV irradiation and a more comprehensive mass balance calculation of C, Cl and N across the pool. The study has established that no accumulation of carbon takes place in the pool, contrary to postulations made in previous published studies, and that the balance between the chloramines and THM DBPs is significantly affected by the HA loading.
14
Whitmarsh, Blair Garnet. "Athletic pain in competitive swimming." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ29125.pdf.
15
Montenegro-Johnson, Thomas D. "Microscopic swimming in biological fluids." Thesis, University of Birmingham, 2013. http://etheses.bham.ac.uk//id/eprint/4220/.
Анотація:
Fluid interactions are ubiquitous in the natural world; all organisms must find strategies to generate, utilise or resist flow in order to be successful. A process fundamental to all life on earth is reproduction, which in many cases entails the swimming of sperm cells. Cell swimming arises from coupled interactions between physical and biological processes. We will focus on the effects of changing fluid rheology on microscopic swimmers, with a particular application to the study of internal mammalian fertilisation. To reach the egg, mammalian sperm must navigate the convoluted geometry of the female reproductive tract, actively bending their flagella in order to propel themselves through cervical mucus: a suspension of polymer chains that twist, tangle and align with flow, giving it complex properties. Whilst recent work has examined the effects of fluid viscoelasticity on sperm-like swimmers, relatively less attention has been given to the shear-thinning property. We develop a new finite element technique to simulate free swimmers with prescribed beat kinematics in shear-thinning fluids with nonlinear governing equations. This technique is then applied to three qualitatively different viscous swimmers in order to examine the different phenomena that arise from swimmer interactions with of shear-thinning fluid.
16
Knight, Graham Jay. "A reconstruction of eurypterid swimming." Thesis, University of Manchester, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.683929.
17
Ranucci, Jill. "Imagery Use in Synchronized Swimming." Diss., The University of Arizona, 2007. http://hdl.handle.net/10150/194423.
Анотація:
The purpose of this study was to examine the utilization of imagery and the impact of imagery use on collegiate synchronized swimmers. Swimmers (N=165) completed The Sport Imagery Questionnaire (Hall et al. 2005), reporting their frequency of imaging. Interviews were conducted (N=11) to further ascertain why and when synchronized swimmers use imagery and mechanisms they employ for more effective imaging experiences. Exploratory factor analyses indicated three of Hall et al's (2005) five subscales showed significant differences between skill level groups. Specifically, motivational specific functions of imagery data showed significant differences between elite swimmers and the other three groups (advanced, intermediate, and novice). Cognitive specific and motivational general-mastery functions of imagery data indicated significant differences between elite and novice swimmers, suggesting that novice swimmers are less likely to use these subscales of imagery compared to elite swimmers. Qualitative data provided evidence of elite swimmers having more sophisticated and developed applications of imaging skills. The results suggest the global implications of this study and how imagery improves synchronized swimming training programs. Key findings include: Each progressive skill level had better imaging skills and utilization than the lower levels Years experience, repetition, and training impact synchronized swimmers use of imagery The very nature of certain common synchronized swimming drills such as "think-throughs and land drill" elicit imaging training The sport of synchronized swimming is an excellent instrument to research imaging training techniques.
18
Ashraf, Intesaaf. "Interactions in Collective Fish Swimming." Thesis, Sorbonne Paris Cité, 2018. http://www.theses.fr/2018USPCC077/document.
Анотація:
Le banc de poisson est un exemple typique d’auto organisation de groupe. Ce système implique des interactions complexes d’individus dans un milieu fluide et fait l’objet de nombreuses recherches multidisciplinaire théoriques, numériques ou expérimentales.Plusieurs hypothèses ont déjà été formulées pour expliquer la formation de ces bancs: la fuite face à des prédateurs, l’optimisation dans la recherche de nutriments ou encore l’économie d’énergie. Dans la plupart des recherches, les travaux se concentrent sur ce que les poissons devraient faire pour optimiser une tâche plutôt que sur des observations directes. Cela conduit à des différences dans les conclusions issus du travail des physiciens théoriciens ou ingénieurs avec ce qui est observé dans la nature par les biologistes. Dans ce travail, nous apportons, basées sur des observations directes tetra Hemigrammus bleheri, de nouveaux éléments sur les interactions des poissons lors de la nage collective comme le phénomène de burst-and-coast ou la synchronisation des cinématiques entre plus proches voisins. Enfin, nous démontrons que les bancs de Hemigrammus bleheri privilégient la configuration en ligne plutôt que celle en diamant souvent mise en avant dans la littératureFish school is the classical example of self-emergent system of collective behavior in animal locomotion, which involves complex interactions between individuals and has drawn fascination of numerous multidisciplinary analytical, numerical and experimental researches. Various reasons have been cited for the formation of fish school such as evading predators, enhancing foraging success or advantage in terms of energy consumption. However, most of the works primary focus on what fish should do in a school instead of what fish really do, leading to discrepancies between the works of theoretical physicists and engineers and what is observed in the nature by biologists. This thesis is an attempt to bridge this gap. In this work, we investigate the swimming dynamics of the red nose tetra fish Hemigrammus bleheri in a controlled experiment. The tetra fish are observed to swim using a burst-and-coast strategy, which could be for the purpose of active flow sensing. We also address the case of red nose tetra fish Hemigrammus bleheri swimming in groups in a uniform flow, giving special attention to the basic interactions and cooperative swimming of a single pair of fish. We first bring evidence of synchronization of the two fish, where the swimming modes are dominated by "out of phase" and "in phase" configurations. At last, we challenge the question of energy benefit by discussing the channeling effect versus the vortex interaction hypothesis (Weihs, Nature 241:290-291, 1973) about diamond shape. We provide the experimental observation that fish prefer inline formation or phalanx formation over the diamond shape while swimming in a school
19
He, Pingguo. "Swimming performance of three species of marine fish and some aspects of swimming in fishing gears." Thesis, University of Aberdeen, 1986. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU004668.
Анотація:
This thesis examines the swimming performance of mackerel (Scomber scombrus L.), herring (Clupea harengus L.), and saithe (Pollachius virens (L.)), and relates it with the mechanical and the electrical properties and the volume of the red and the white swimming muscle. Analysis of kinematics of swimming from cine films and video recordings allows development of a mathematical model of swimming movements and examination of thrust and power output during swimming. This output can be scaled for the time of the tail beat cycle and the size of the fish. Swimming of mackerel at low speeds is related to the lift required in this negatively buoyant species in order to maintain a constant swimming depth. Longitudinal tilting of the mackerel body at low speeds is observed and related to the echo sounder target strength in fisheries surveys. Swimming performance of mackerel, herring and saithe at intermediate speeds is measured in terms of speed and endurance. The maximum sustained swimming speed for each species is related to the maximum cross-section area of the red muscle. Maximum burst swimming speed up to 18 body lengths per second is measured in a 30.5 cm long mackerel. This maximum speed is found to be limited by the minimum contraction time of the white muscle which is measured in 60 samples of 20 individual mackerel. Recordings of the electromyograms of swimming mackerel and measurements of muscle contraction time and muscle cross-section area lead to a new fish swimming model demonstrating how the thickest part of the red muscle is used when the maximum thrust is output from the caudal fin during one tail beat cycle. The swimming performance of marine fish near fishing gears, especially otter trawls is summarised by analysing video tapes recorded at sea and compared with the measured swimming performance in laboratory conditions. Some models of fish swimming behaviour near fishing gears are developed.
20
Klindt, Gary. "Hydrodynamics of flagellar swimming and synchronization." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2018. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-231897.
Анотація:
What is flagellar swimming? Cilia and flagella are whip-like cell appendages that can exhibit regular bending waves. This active process emerges from the non-equilibrium dynamics of molecular motors distributed along the length of cilia and flagella. Eukaryotic cells can possess many cilia and flagella that beat in a coordinated fashion, thus transporting fluids, as in mammalian airways or the ventricular system inside the brain. Many unicellular organisms posses just one or two flagella, rendering them microswimmers that are propelled through fluids by the flagellar beat including sperm cells and the biflagellate green alga Chlamydomonas.
Objectives. In this thesis in theoretical biological physics, we seek to understand the nonlinear dynamics of flagellar swimming and synchronization. We investigate the flow fields induced by beating flagella and how in turn external hydrodynamic flows change speed and shape of the flagellar beat. This flagellar load-response is a prerequisite for flagellar synchronization. We want to find the physical principals underlying stable synchronization of the two flagella of Chlamydomonas cells.
Results. First, we employed realistic hydrodynamic simulations of flagellar swimming based on experimentally measured beat patterns. For this, we developed analysis tools to extract flagellar shapes from high-speed videoscopy data. Flow-signatures of flagellated swimmers are analysed and their effect on a neighboring swimmer is compared to the effect of active noise of the flagellar beat. We were able to estimate a chemomechanical energy efficiency of the flagellar beat and determine its waveform compliance by comparing findings from experiments, in which a clamped Chlamydomonas is exposed to external flow, to predictions from an effective theory that we designed. These mechanical properties have interesting consequences for the synchronization dynamics of Chlamydomonas, which are revealed by computer simulations. We propose that direct elastic coupling between the two flagella of Chlamydomonas, as suggested by recent experiments, in combination with waveform compliance is crucial to facilitate in-phase synchronization of the two flagella of Chlamydomonas.
21
Chambers, Timothy. "Personal constructs on resilience in swimming." University of Western Australia. School of Sport Science, Exercise and Health, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0023.
Анотація:
[Truncated abstract] Resilience is a concept that originated from behavioural science; a branch of research aimed at explaining unexpected benign or malignant outcomes associated with human development. It is a psychological construct that encompasses both cognitive and behavioural responses to negative situations and appears to exist at both an individual and group level. As a concept, resilience receives considerable attention from researchers within developmental psychology fields, who primarily identify numerous risk and protective factors. Within sport, however, researchers have demonstrated a preference for the examination of more traditional concepts, such as coping strategies. Moreover, few investigations in either domain employ a cogent theoretical framework to guide the research. Therefore, the present research program utilises Personal Construct Psychology (PCP; Kelly, 1955) principles to direct the proposed research. PCP is a theory about theories that emphasised our underlying ambition to make sense of the world, the events people encounter and themselves. According to Kelly, PCP is guided by the fundamental postulate and 11 corollaries. The PCP research template employed by the current research program promotes the utilisation of multimethod designs (i.e., qualitative and quantitative investigations) in order to understand and facilitate the development of resilience in swimming. Three research investigations are proposed to examine resilience in swimming, and are structured according to PCP. Each investigation is outlined below. Study 1. An interview protocol based upon key elements of Kelly s (1955) psychotherapy retrospective interview protocol was employed to elicit an understanding of resilience in swimming. Fourteen interviews were scheduled with elite Australian swimmers and swimming coaches, utilising the interview schedule. ... Study 3. The aim of this study was to design, implement and evaluate a resilience intervention for youth swimmers. Utilising the data generated from the first study, a resilience enhancement program was designed and delivered to 16 developmental swimmers over a period of three months. Resilience was measured pre, during and post intervention, and three months after the intervention. Resilience was also measured on an age and ability matched control group (n = 20), at the same time points. Results revealed improvements in resilience for the experimental group following the completion of the resilience program. In summary, the present research program employed a PCP (Kelly, 1955) research template to guide the aforementioned studies of resilience. The data collected from the research investigations contributed considerable knowledge to the resilience concept, and the sport psychology field. The qualitative study was the first of its kind to examine the concept in swimming, revealing several elements and process pertaining to resilience that later formed the foundations for the resilience intervention. General conclusions propose that future research combine psychological measurement of resilience and more traditional sport psychology concepts, in addition to the development of a sport specific psychometric measure of resilience.
22
Berti, Leandro Antunes. "Modeling Mobility : Nanodevices swimming at nanoscale." Thesis, University of Sheffield, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.522504.
23
Ren, Xiaojing, and 任晓晶. "Modeling pattern formation of swimming E.coli." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B43704001.
24
Mukherjee, Aryesh. "Studies in Hydroelastodynamics: Singing and Swimming." Thesis, Harvard University, 2011. http://dissertations.umi.com/gsas.harvard:10242.
Анотація:
In this thesis we describe two instances of the nonlinear interaction between a fluid and an elastic solid to mimic or explain some phenomenon seen in nature. We focus on the phenomena of singing of small song birds and swimming of small fish. Song birds show a versatile range of tones and compositions that have highly complex spectral structure, while fish cut through water with amazing ease. The complexity of the Navier Stokes Equations that describe the fluid coupled with large deformation elasticity equations, makes analytic attempts intractable. Hence experiments were carried out with simple physical models to explain these observations. In the first case a cylindrical elastic tube (2.5cm long, 2.5mm diameter) was used to model the vocal organ, the syrinx, of a song bird. Muscle action was mimicked using a linear motor that implemented a squeezing action and the action of the lungs was modeled by a constant source of air flow. The combined fluid-elastic system behaved like a nonlinear dynamical system and produced sound under certain conditions of external parameters. Moreover the structure of the sound created depended sensitively on the control parameters, which in this case was dominated by the position of the linear motor. The motor was dynamically controlled to produce a range of songs from simple tonal ones of the Vireo to the complex chaotic songs of the Zebra Finch. In the second instance, a cantilever (5cm long, 1cm wide)suspended between and driven by magnetic coils arranged in an anti-Helmholtz configuration, was used to mimic the dynamics of the caudal fin of a small fish. Three different gaits were observed as a function of the control parameter, the drive frequency. One of these gaits maximized thrust and hydrodynamic efficiency, and velocities unto 6 body lengths per second were measured.Engineering and Applied Sciences
25
Davis, Gareth Michael. "Mathematical modelling of swimming pool chlorination." Thesis, University of Bristol, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.402341.
26
Bunker, Kristine (Kristine Alina). "Propeller based human powered swimming device." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/92601.
Анотація:
Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (page 31).
Currently the only human powered swimming device widely sold on the market are swim flippers. However, flippers are not efficient for the human body, and there is a potential to increase the speed while swimming with a device. This thesis is the planning, design, construction, and prototyping of a new human powered swimming device which increases human efficiency and speed in water. This device uses a squatting motion to drive counter rotating propellers up and down a threaded shaft creating the propulsion force to move the swimmer forward. The design of this device is primarily geared towards scuba divers and swimmers moving beneath the water surface. Through various tests we were able to prove that the design concept is valid, but alterations are still necessary to reach optimal speed. One such improvement would be enlarging the size of the propeller to increase the force generated with each leg thrust.
by Kristine Bunker.
S.B.
27
Wolfgang, Meldon J. (Meldon John) 1971. "Hydrodynamics of flexible-body swimming motions." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/9546.
Анотація:
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1999.Includes bibliographical references (p. 372-390).
The performance and agility of fish swimming motions have intrigued both biologists and fluid mechanicians for many years. Both have endeavored to understand the mechanics of fish swimming and to resolve the paradoxical observations surrounding the performance of fish, yet the unsteady hydrodynamics are not well-understood. In this thesis, the hydrodynamics of the fish-like swimming motions of a flexible body are examined through numerical simulation. Two- and three-dimensional boundary integral panel methods are developed which can model the steady straight-line swimming and unsteady maneuvering motions of a flexible-body of arbitrary thickness. Multiple, desingularized, infinitesimal wake sheet representation models the nonlinear dynamics of thin shear layer vorticity shed from an arbitrary number of predefined wake separation edges. The integrated performance quantities and the near-body unsteady flow features are corroborated through experimental comparisons. Employing this numeric scheme for a variety of fish forms, the unsteady flow dynamics are resolved in great detail and are found to be much more complex than that predicted by linear theory. In addition, fundamental mechanisms of near-body flow actuation, body-generated vorticity release, and wake vorticity control are found which allow the fish to generate thrust efficiently, to achieve outstanding performance, and to generate large, short-duration maneuvering forces. Specifically, the straight-line swimming motions of a flexible-body are studied through simulation of several fish geometries. Comparison to classical linear theory highlights the importance of the vortical dynamics in achieving performance and the complexity of the near-body flow patterns. The flow around the body is found to be highly longitudinal through systematic visualization of the body cross-sectional and waterline planes. A body-generated vortex ring structure, created through localized body undulations, actuates the smooth near-body longitudinal flow patterns around much of the fish body, resulting in strong vertical vorticity components bounding the wake thrust jet. Regions of high propulsive efficiency are identified for certain prescribed kinematics, and the performance is found to be strongly dependent on kinematic variation, recoil motions, and geometric modeling choices. Maneuvering hydrodynamics of fish swimming are studied through the simulation of a 60° "C" -turn of a Giant Dania. The formation and controlled release of body-generated vorticity through local contortions of the backbone is shown to affect the formation of a turning thrust jet for rapid maneuvering. The interaction body-generated free vorticity and regions of high fluid momentum with the sweeping motion of the tail fin is similarly shown to affect both the strength and direction of the turning jet. Through simulation of these straight-line swimming and unsteady maneuvering motions, fundamental mechanisms of vorticity control utilized by the fish are identified. Body-generated vorticity released by the body upstream is actuated by the motion of the oscillating tail fin, resulting in complex wake-wake-body interactions for varying kinematics. These interactions may enhance the performance by increasing thrust or increasing efficiency; similarly, large drag forces may be enhanced through constructive interaction of the wakes. Several novel vorticity control modes are elucidated for both straight-line steady swimming and unsteady maneuvering motions. Mechanisms of near-body flow actuation and vorticity control by the motions of swimming flexible-bodies and oscillating lifting surfaces may have tremendous potential for application to vehicle design and to unsteady maneuvering systems.
by Meldon John Wolfgang, IV.
Ph.D.
28
Shawkat, Salman, and Ragheed Hussain. "Concrete Cracks in Swimming Pool Basins." Thesis, KTH, Byggnadsteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-208349.
Анотація:
Majority of the swimming facilities in Sweden are facing some form of renovation or total substitution. The report analyses cracks in two different public bath facilities namely Eriksdalsbadet and Enskedehallen. The text also discusses different solution strategies for cracks in concrete. The aim with this thesis is to discuss how facility managers can extend the service life of these facilities by taking measures against the crack damages. Since renovation can be expensive, it is important to study cracks early on when they appear. This thesis also emphasizes on how important it is to add resources for preventing cracks, already during casting. Resources should also be added for maintaining the basins, managing repair methods for all types of cracking problems. This thesis is more of a generalized study for cracks in concrete, however it concludes with taking a more specific approach by discussing the problems in swimming basins. Causes of cracks, different types of cracks and evolution of cracks are studied and discussed with emphasis on the structural damages that can occur. With pictures taken and analyzed from the two facilities and a visitation with a experienced concrete investigator from CBI, this thesis concludes with a decision to immediately take repair actions against cracks that are shown in the report. The report discusses two perspectives, one where the authors of the thesis discusses solutions derived from information given in the report, and the other perspective is derived from guided inspection with consultant from CBI.Neris projektet
29
Clapham, Richard James. "Developing high performance linear Carangiform swimming." Thesis, University of Essex, 2015. http://repository.essex.ac.uk/16550/.
Анотація:
This thesis examines the linear swimming motion of Carangiform fish, and investigates how to improve the swimming performance of robotic fish within the fields of kinematic modeling and mechanical engineering, in a successful attempt to replicate the high performance of real fish. Intensive research was conducted in order to study the Carangiform swimming motion, where observational studies of the common carp were undertaken. Firstly, a full-body length Carangiform swimming motion is proposed to coordinate the anterior, mid-body and posterior displacements in an attempt to reduce the large kinematic errors in the existing free swimming robotic fish. It optimizes the forces around the centre of mass and initiates the starting moment of added mass upstream therefore increasing performance, in terms of swimming speed. The introduced pattern is experimentally tested against the traditional approach (of posterior confined body motion). A first generation robotic fish is devised with a novel mechanical drive system operating in the two swimming patterns. It is shown conclusively that by coordinating the full-body length of the Carangiform swimming motion a significant increase in linear swimming speed is gained over the traditional posterior confined wave form and reduces the large kinematic errors seen in existing free swimming robotic fish (Achieving the cruising speeds of real fish). Based on the experimental results of the first generation, a further three robotic fish are developed: (A) iSplash-OPTIMIZE: it becomes clear that further tuning of the kinematic parameters may provide a greater performance increase in the distance travelled per tail beat. (B) iSplash-II: it shows that combining the critical aspects of the mechanical drive system of iSplash-I with higher frequencies and higher productive forces can significantly increase maximum velocity. This prototype is able to outperform real Carangiform fish in terms of average maximum velocity (measured in body lengths/ second) and endurance, the duration that top speed is maintained. (C) iSplash-MICRO: it verifies that the mechanical drive system could be reduced in scale to improve navigational exploration, whilst retaining high-speed swimming performance. A small robotic fish is detailed with an equivalent maximum velocity (BL/s) to real fish.
30
Ren, Xiaojing. "Modeling pattern formation of swimming E.coli." Click to view the E-thesis via HKUTO, 2010. http://sunzi.lib.hku.hk/hkuto/record/B43704001.
31
Parker, Alison Claire. "An urban historical perspective : swimming a recreational and competitive pursuit 1840 to 1914." Thesis, University of Stirling, 2003. http://hdl.handle.net/1893/3518.
Анотація:
Over the last three decades or more, there has been a considerable interest in the socio-historical analysis of sport. While a number of historians have examined the development of the major team games and commercial sports in the context of the changing nature of Victorian and Edwardian society, very few have considered the development of individual and more recreational sports, or located the transformation of sport to the process of urbanization. This thesis examines the relationship between growing urbanization and the transformation of swimming from a recreative activity, into an urban recreation and 'modern' competitive sport. Swimming as a recreation and as a competitive sport, developed as a reaction to and consequence of, both the positive and negative features of urbanization. The hypotheses that the greater the urbanization, the more developed and 'modern' sport became, will be supported with evidence from the sport of swimming.
32
Beltz, John D. "Physiological response to interval training." Virtual Press, 1987. http://liblink.bsu.edu/uhtbin/catkey/486191.
Анотація:
The purpose of this study was to examine the effect of swimming distance and rest interval on the intensity of swimming (relative to VO2 max) and the contributions of the three energy systems (aerobic, anaerobic, and alactic) during these interval sets. Nine male college swimmers performed fourteen different interval training sets. Distances were 25, 50, 100, or 200 yards with rest intervals of 10 seconds, 1, and 3 minutes. During these sets only the distance to be swum and the rest interval for the set was given. No qualitative information from the coach was provided. These interval sets were performed by the swimmers with the influence from timers being kept minimal. Oxygen cost during the swim was determined from the velocity of the swim based on a linear regression for swimming velocity and oxygen uptake for each swimmer. The same interval sets were completed with pace controled where venous blood samples were obtained 1, 3, 5, and 7 minutes after the completion of each training set. 81ood samples were analyzed for lactate accumulation, blood pH, p0.,, pCO2, and hemoglobin. From these values bicarbonate, base excess, and blood oxygen saturation were calculated using equations developed by Siggard-Anderson. The results of this study do indicate that there is a predictable relationship between swimming distance and rest interval on swimming intensity (relative to VO., max). There was a curvilinear L relationship between swimming intensity (relative to VO max) and rest interval for 50, 100, and 200 yard interval sets. The correlation at these distances were r-0.96, 0.93, and 0.94 respectively. There was a linear relationship between intensity and the distance swum for the 10 second, 1, and 3 minute rest intervals. The correlation for these rest intervals were r= 0.99, 0.99, and 1.00 respectively. There was an increase in the relative contribution of aerobic energy as the distance of the swim increased for all three rest intervals. At a given swiming distance there was a greater contribution of non-aerobic energy as the rest interval increased. Contrary to continuous swimming, greater swimming velocity does not directly correspond to greater contributions of anaerobic energy during intermittent swimming. The distance and rest interval during intermittent training greatly effect the relative contributions of the three energy systems. The intensity of the swim and the relative contributions of each energy system should be considered when planning specific training regimens.
33
Lindley, Steven L. "Kinematic analysis of freestyle and backstroke flip-turns in competitive swimming." Virtual Press, 2001. http://liblink.bsu.edu/uhtbin/catkey/1221279.
Анотація:
The primary purpose of this study was to gain a better understanding of the turn interval and the factors that influence turn performance. A secondary purpose was to investigate the relationship between turn time, the components that influence turn time, and performance in competitive swimming. Fifty-eight swimmers (24 female, 34 male) from four NCAA Division I schools were videotaped in the 100 and 200 yd freestyle and backstroke events during three collegiate competitions. The freestyle was shown to be significantly different from the backstroke in race time, turn time, and time during the in phase of the turn for both genders in the 100 and 200 yard events. Significant positive correlations were found between turn time and race time across both genders and all four events. Inspecting the velocity curves of the turns allowed the key outphase variables to be defined. Turn time is an important determinant of race time in collegiate swimming. Using the dolphin kick technique during a turn causes large fluctuations in velocity during the active glide phase of the turn.School of Physical Education
34
Slawson, Sian. "A novel monitoring system for the training of elite swimmers." Thesis, Loughborough University, 2010. https://dspace.lboro.ac.uk/2134/6292.
Анотація:
Swimming performance is primarily judged on the overall time taken for a swimmer to complete a specified distance performing a stroke that complies with current regulations defined by the Fédération Internationale de Natation (FINA), the International governing body of swimming. There are three contributing factors to this overall time; the start, free swimming and turns. The contribution of each of these factors is event dependent; for example, in a 50m event there are no turns, however, the start can be a significant contributor. To improve overall performance each of these components should be optimised in terms of skill and execution. This thesis details the research undertaken towards improving performance-related feedback in swimming. The research included collaboration with British Swimming, the national governing body for swimming in the U.K., to drive the requirements and direction of research. An evaluation of current methods of swimming analysis identified a capability gap in real-time, quantitative feedback. A number of components were developed to produce an integrated system for comprehensive swim performance analysis in all phases of the swim, i.e. starts, free swimming and turns. These components were developed to satisfy two types of stakeholder requirements. Firstly, the measurement requirements, i.e. what does the end user want to measure? Secondly, the process requirements, i.e. how would these measurements be achieved? The components developed in this research worked towards new technologies to facilitate a wider range of measurement parameters using automated methods as well as the application of technologies to facilitate the automation of current techniques. The development of the system is presented in detail and the application of these technologies is presented in case studies for starts, free swimming and turns. It was found that developed components were able to provide useful data indicating levels of performance in all aspects of swimming, i.e. starts, free swimming and turns. For the starts, an integrated solution of vision, force plate technology and a wireless iii node enabled greater insight into overall performance and quantitative measurements of performance to be captured. Force profiles could easily identify differences in swimmer ability or changes in technique. The analysis of free swimming was predominantly supported by the wireless sensor technology, whereby signal analysis was capable of automatically determining factors such as lap times variations within strokes. The turning phase was also characterised in acceleration space, allowing the phases of the turn to be individually assessed and their contribution to total turn time established. Each of the component technologies were not used in isolation but were supported by other synchronous data capture. In all cases a vision component was used to increase understanding of data outputs and provide a medium that coaches and athletes were comfortable with interpreting. The integrated, component based system has been developed and tested to prove its ability to produce useful, quantitative feedback information for swimmers. The individual components were found to be capable of providing greater insight into swimming performance, that has not been previously possible using the current state of the art techniques. Future work should look towards the fine-tuning of the prototype system into a useable solution for end users. This relies on the refinement of components and the development of an appropriate user interface to enable ease of data collection, analysis, presentation and interpretation.
35
Kroll, Stephan. "Extended life of swimming pools through LCC." Thesis, KTH, Byggvetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-96505.
Анотація:
Swimming pools constructed with reinforced concrete require a high level of expertise within both, its planning and execution. To build waterproof concrete shells, extensive concrete technology knowledge, detailed planning of joint formation and high quality safety measures are needed. This thesis evaluates concrete technology features for swimming pool construction in Germany and Sweden. In particular, guidelines by DafStb, DIN and DgfdB provide the planner with detailed advice and specifics about swimming pools. It also gives an overview about the actual condition of swimming pools in Sweden that reached an age of at least 30 years and shows structural consequences of mistakes in planning and construction of swimming pools. The aspect of financial consequences is also analyzed. With the support of the software “Legep”, the methodology of LCC was used to estimate costs in the future. Additionally, a proposal of post tensioned concrete as a more sustainable technology for watertight concrete basins is shown and under equal aspects analyzed and compared.
36
Peng, Zhiwei. "Inertialess swimming and propulsion of slender bodies." Thesis, University of British Columbia, 2016. http://hdl.handle.net/2429/57718.
Анотація:
In this thesis, two problems relevant to the biological locomotion in inertialess environments are studied, one is the characteristics of undulatory locomotion in granular media, the other is the optimal flexibility of a driven microfilament in a viscous fluid. Undulatory locomotion is ubiquitous in nature and observed in different media, from the swimming of flagellated microorganisms in biological fluids, to the slithering of snakes on land, or the locomotion of sandfish lizards in sand. Despite the similarity in the undulating pattern, the swimming characteristics depend on the rheological properties of different media. Analysis of locomotion in granular materials is relatively less developed compared with fluids partially due to a lack of validated force models but recently a resistive force theory in granular media has been proposed and shown useful in studying the locomotion of a sand-swimming lizard. In this work, we employ the proposed model to investigate the swimming characteristics of a slender filament, of both finite and infinite length, undulating in a granular medium and compare the results with swimming in viscous fluids. In particular, we characterize the effects of drifting and pitching in terms of propulsion speed and efficiency for a finite sinusoidal swimmer. We also find that, similar to Lighthill's results using resistive force theory in viscous fluids, the sawtooth swimmer is the optimal waveform for propulsion speed at a given power consumption in granular media. Though it is understood that flexibility can improve the propulsive performance of a filament in a viscous fluid, the flexibility distribution that generates optimal propulsion remains largely unexplored. In this work, we employ the resistive force theory combined with the Euler-Bernoulli beam model to examine the optimal flexibility of a boundary driven filament in the small oscillation amplitude limit. We show that the optimality qualitatively depends on the boundary actuation. For large amplitude actuation, our numerics show that complex asymmetry in the waveforms emerge. The results complement our understanding of inertialess locomotion and provide insights into the effective design of locomotive systems in various environments.Applied Science, Faculty of
Mechanical Engineering, Department of
Graduate
37
Bottom, Richard Glenn II. "On the hydrodynamics of ray-like swimming." Thesis, State University of New York at Buffalo, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=1561510.
Анотація:
Discovering the key-features of how aquatic swimmers such as stingrays propel themselves in nature can inspire the next generation of underwater vehicles with improved maneuverability and decreased noise signatures. To discover the key-features of stingrays swimming, fluid-structure interaction simulations of a self-propelled virtual stingray, modeled closely after the freshwater stingray, Potamotrygon orbignyi, are performed. The first closed-form kinematics description of the stingray's body motion was developed from three-dimensional experimental measurements of undulatory body motion of the fresh water stingray, Potamotrygon orbignyi, which is prescribed in our simulations. The self-propelled simulations produce a high-resolution view of the three-dimensional flow field and quantifiable forces created from the stingray's swimming unobtainable by other experimental means. A leading edge vortex (LEV) was discovered to be present on the pectoral disc of the stingray, which drastically affects the hydrodynamic forces and the pressure distribution on its disc. The LEV was found to stays attached to the stingray's body until its swimming cycle reverses direction at which time the vortex detaches to travels along with the stingray's swimming undulations, creating pressure differentials across the surfaces of the stingray which promotes thrust. At the time instance of highest thrust generation during its swimming cycle, three separate vortices present on the stingrays body, all of which were formed on the leading edge, are creating a pressure distribution promoting thrust. This finding can inspire new propulsive fins that generate LEV instead of mitigating separation.
38
Hawthorne, Colin. "Energy conservation in swimming pools and supermarkets." Thesis, University of Ulster, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359655.
39
Michel, Anna Pauline Miranda 1976. "Experimental flow characterization of anguilliform swimming motion." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/91368.
40
Locsei, Janos Tobias. "Individual and collective behaviour of swimming microorganisms." Thesis, University of Cambridge, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.612404.
41
Porter, Nicola J. "Muscarinic actions in Xenopus laevis tadpole swimming." Thesis, University of St Andrews, 2013. http://hdl.handle.net/10023/4286.
Анотація:
Muscarinic acetylcholine receptors (mAChRs) mediate effects of acetylcholine (ACh) in many systems, including those involved in locomotion. In the stage 37/38 Xenopus laevis tadpole, a well-understood model system of vertebrate locomotion, mAChRs have been found to be located on motor neurons with evidence suggesting that mAChRs are involved in swimming behaviour. The current study aimed to further investigate the role of mAChR-mediated cholinergic transmission by employing extracellular and whole-cell patch clamp recordings to examine the effects of mAChR activation on the properties of different types of neurons in the Xenopus laevis tadpole swimming circuit. It was found that mAChR activation can increase the threshold for initiating swimming by skin stimulation and can lead to the generation of spontaneous motor output in the absence of physical stimuli. These effects were found to be a result of direct inhibition of dorsolateral sensory interneurons of the mechanosensory pathway, direct inhibition of glycinergic inhibitory interneurons in the CPG and a decrease in CPG neuron firing reliability during swimming. The data presented here comprise the first whole-cell patch-clamp investigation into mAChR-mediated cholinergic transmission in the Xenopus laevis tadpole swimming circuit and provide novel evidence that mAChRs modulate the properties of mechanosensory pathway and CPG neurons in this model system of vertebrate locomotion.
42
Tasevska, Tamara. "Intimate Spaces in Francois Ozons Swimming Pool." Miami University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=miami1408096845.
43
Holbrook, Robert Iain. "Fish swimming and navigation in three-dimensions." Thesis, University of Oxford, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.669975.
44
Samson, Ophir. "Low Reynolds number swimming in complex environments." Thesis, Imperial College London, 2010. http://hdl.handle.net/10044/1/5723.
Анотація:
The study of swimming micro-organisms has been of interest not just to biologists, but also to fluid dynamicists for over a century. As they are rarely in isolation, much interest has been focused on the study of the swimmers’ interaction with their environment. By virtue of the typically small sizes of these organisms and their swimming protocols, the characteristic Reynolds number of the motion of the fluid around them is small. Hence they reside in a Stokes flow regime where viscous forces dominate inertial effects and where far-field interactions (e.g. with nearby walls) can have a significant effect on the swimmer’s dynamical evolution. This thesis provides a detailed investigation of idealised models of low Reynolds number swimmers in a variety of wall-bounded fluid domains. Our approach employs a combination of analytical and numerical techniques. A simple two-dimensional point singularity is used to model a swimmer. We first study its dynamics when placed in the half-plane above an infinite no-slip wall and find it to be in qualitative agreement with numerical and experimental studies. The success of the model in this case encourages its use to study the swimmer’s dynamics in more complicated domains. Specifically, we next explore the dynamics of the same swimmer above an infinite straight wall with a single gap, or orifice. Using techniques of complex analysis and conformal mapping theory, a dynamical system governing the swimmer’s motion is explicitly derived. This analysis is then extended to the case in which the swimmer evolves near an infinite straight wall with two gaps. We are also interested in how the presence of background flows can affect the swimmer’s dynamics in these confined geometries. We therefore employ the same techniques of complex analysis and conformal mappings to find analytical expressions for pressure-driven flows near a wall with either one or two gaps. We then extend this to find new solutions for the shear flows and stagnation point flows in the same geometry. The effect of a background shear flow on the swimmer’s dynamics is then explored. Finally, while there have been a number of studies of Stokes flows within domains which are simply connected, the doubly connected analogues are rather rare. By building upon the analytical techniques presented in this thesis, we present numerical solutions to such problems, including that of theWeis-Fogh mechanism in the low Reynolds number regime.
45
Hall, Betty Lou. "Rating of perceived exertion of four swimming strokes at a constant intensity /." View online, 1989. http://repository.eiu.edu/theses/docs/32211998880350.pdf.
46
Quinlan, Paul. "The design and monitoring of periodised modular training programmes in swimming." Thesis, Federation University Australia, 2000. http://researchonline.federation.edu.au/vital/access/HandleResolver/1959.17/164997.
Анотація:
"This study sets out to investigate the current scientific basis of training in swimming, from the novice to elite levels and provide formats to monitor training in line with current science and technology, and to provide the practitioner on the pool deck with a tool that will assist him or her in the planning process, through the use of a computer software package".Master of Applied Science
47
Vitelli, Carol A. "Comparison of heart rate to lactate as related to performance of competitive male swimmers." Virtual Press, 1986. http://liblink.bsu.edu/uhtbin/catkey/445247.
Анотація:
Twelve competitive male swimmers were studied for a comparison of lactate/velocity profiles to heart rate/velocity profiles during a season of swim training. Lactate concentration (mM) and post-exercise heart rate (sum of three) after a 200-yard submaximal swim (approximately 90% of maximal attainable velocity) and a maximal swim were determined three times during the season: at the beginning (T1), after two months of training (T2) and after four months of training (T3). Both profiles demonstrated a significant rightward shift at T2 and a smaller, further shift at T3. Both lactate and heart rate significantly decreased at an absolute and relative exercise intensity in response to training. It is concluded that either parameter can be useful in monitoring training progress and for determining optimal training intensities. Because of the expense and difficulty of blood lactate measurements, heart rate/ velocity profiles can provide a practical and non-invasive alternative to blood lactate testing.
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Stamm, Andy. "Velocity and Arm Symmetry in Freestyle Swimming using Accelerometry: Data Collection, Analysis and Feature Extraction." Thesis, Griffith University, 2013. http://hdl.handle.net/10072/365340.
Анотація:
This research quantified the velocity during the swimming phase and investigated the arm symmetry using a single triaxial accelerometer in freestyle swimming. This included the data collection, analysis and feature extraction of parameters of interest.
A main question related to the collection of acceleration data from several athletes in the discipline of swimming under training conditions. This involved developing and testing of suitable sensor technology for tracking the movement of the swimmer. Furthermore, after the first data was collected, more elementary questions evolved: Which data is of interest to athletes and coaches and therefore should be collected? What does the acceleration data mean? How should this data be interpreted? These questions involve human movement studies, especially related to biomechanical & physiological sports science. It also includes digital signal processing of the data. This analysis was performed on a desktop computer after the data were collected from the inertial sensor. This thesis therefore addresses two issues, the data collection and the data analysis used to extract information of interest to athletes and coaches.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Griffith School of Engineering
Science, Environment, Engineering and Technology
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Cock, Steven. "The sportization of swimming : a sociological examination of the development of swimming as a modern competitive sport, c.1595-1908." Thesis, University of Chester, 2012. http://hdl.handle.net/10034/336563.
Анотація:
Modern competitive swimming is a highly structured, organized, codified and regulated sport. This has not always been the case. The aim of this thesis has been to examine the long-term development of competitive forms of swimming throughout the periods between the late sixteenth and early twentieth centuries. Despite some recent historical analyses, the emergence of swimming as a modern competitive sport is an under-researched topic. There are no sociological analyses relating to the development of competitive swimming and significant gaps within much historical research. This thesis has been conducted from a sociological perspective in order to test the relative adequacy of Norbert Elias’s concept of sportization. Figurational sociologists have often examined the concept of sportization in relation to the development of contact sports such as boxing and rugby. Some authors have sought to criticize figurational sociologists for over-emphasizing issues relating to the increasing control of violence when examining the development of such activities. In this manner, there is scope to contribute to existing empirical and theoretical knowledge by testing the relative adequacy of the concept of sportization in relation to the long-term development of the predominantly non-contact sport of competitive swimming. To this end, data have been examined from a range of documentary sources. Various swimming-based texts, treatises, periodicals and magazines were examined at the British Library and Colindale Newspaper Library in London. The original minute books of the Amateur Swimming Association and its predecessor bodies have also been analyzed. In addition, a range of digitized source material has been examined from several electronic databases. It has been argued that the development of modern competitive swimming was an unplanned and unintended outcome resulting from the complex interweaving of wider social processes in England throughout the periods between the Middle-Ages and the early twentieth century. The earliest reported swimming contests took place in the eighteenth and early nineteenth centuries in the form of a cash wager between two or more individuals. These events were less structured and regulated than modern forms of competitive swimming. Betting upon the outcome of such events was deemed to be an appropriate means to experience heightened levels of tension-excitement within the context of an emerging society in which people were increasingly expected to demonstrate greater self-control over their behaviour and emotions. More organized forms of competitive swimming gradually emerged during the nineteenth and early twentieth centuries. The emergence of an increasingly complex network of clubs, societies and associations at local, county, district and national levels facilitated such developments and contributed to the emergence of standardized rules and regulations within the emerging sport of swimming. Such developments have been explained in relation to ongoing processes of state-formation, pacification, lengthening chains of interdependence and a gradual lowering in the threshold of repugnance within England in the period between the Middle-Ages and the early twentieth century. In this manner, it has been argued that the concept of sportization is an appropriate theoretical framework for explaining the long-term development of the modern non-contact sport of competitive swimming.
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Tuncdemir, Safakcan. "Design Of Mini Swimming Robot Using Piezoelectric Actuator." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12605682/index.pdf.
Анотація:
This thesis deals with the design, fabrication and analysis of a novel actuator for a fish-like swimming mini robot. The developed actuator is tested on a mini boat. The
actuator relies on a novel piezoelectric ultrasonic motor, developed according to the design requirements of actuator for fish-like swimming mini robots. Developed motor is within the dimensions of 25x6x6 mm in a simple mechanical structure with simple driving circuitry compared to its predecessor. Bidirectional rotation of the motor is transformed to a flapping tail motion for underwater locomotion in a simple mechatronic structure. The simplicity in the motor and actuator enables
further development on the miniaturization, improvement on the performances as well as easy and low cost manufacturing. The developed actuator is a candidate to
be used in mini swimming robot with fish- like locomotion.