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Morphodynamique des deltas de jusant et des flèches sableuses en domaine macrotidal : les embouchures de l'Orne et de la Dives / Ebb-tidal delta and sandspit morphodynamics in macrotidal environment : Orne and Dives inletsPellerin Le Bas, Xavier 18 December 2018 (has links)
L'objectif de ce mémoire est de comprendre le fonctionnement hydro-sédimentaire des embouchures tidales dominées par la marée et la construction d'une flèche sableuse à crochets perpendiculaires. Deux sites voisins ont été choisis : les embouchures de l'Orne et de la Dives sur la côte du Calvados (Normandie). L'utilisation de données d'agitation et topographiques, acquises selon plusieurs échelles spatio-temporelles, permet d'étudier la morphodynamique de ces deux embouchures.L'embouchure de l'Orne possède une évolution soumise à une forte pression anthropique causée par de nombreuses infrastructures portuaires. Elle est comparée à celle de l'embouchure de la Dives, où l'impact anthropique est plus limité. Il apparaît que ces deux embouchures partagent les mêmes mécanismes de transports sédimentaires, avec une composante transversale importante. Ce transport vers la côte est assuré par la migration de barres de swash sur les parties aval-dérive des deltas de jusant. Ces barres de swash possèdent des volumes et des vitesses de migration similaires, comprises entre 3.5 et 8.0 m/mois.Contrairement à la Dives, les côtes en amont et en aval-dérive de l'embouchure de l'Orne sont en accrétion. Si en amont, cette accrétion suit les nombreuses phases de construction du port de Caen-Ouistreham, en aval se développe depuis un peu plus d'un siècle une flèche sableuse à la morphologie atypique. En effet, cette flèche possède plusieurs crochons emboités, dont les extrémités - les crochets - sont perpendiculaires au corps à la flèche. Il est démontré que l'attachement des barres de swash à la côte est responsable de la formation d'un nouveau crochon. La diffraction des vagues au niveau de l'extrémité des barres de swash et des crochons, ainsi que les directions locales de l'agitation, expliquent la formation des crochets perpendiculaires à l'extrémité des crochons. / The aim of this thesis is to understand the mechanisms of sediment bypassing at tidal inlets in a macrotidal environment and the formation of a sandspit with perpendicular hooks. Two closed areas are studied, the Orne and Dives inlets on the coast of Normandy (France). Wave and topographic data, at several space-time scales, are used to study the inlet morphodynamics.The Orne inlet is affected by strong human impacts due to several port facilities whereas the Dives inlet knows a limited anthropogenic impact. The study of the two inlets allows to deduce the impact of the human activities in the sediment transport patterns. The Orne and Dives inlets share the same mechanisms of sediment transport. Both show a major cross-shore component of the transport, underlines by the swash bars migration over the ebb-tidal deltas. All swash bars have similar volumes and migration rates, between 3.5 and 8.0 m/month.The Orne inlet shows deposition on both sides. The accretion on the updrift coast follows the building stages of the harbour of Caen-Ouistreham. On the downdrift coast, the deposition creates the Merville spit, which has several interlocked ridges. A perpendicular hook is present on the distal part of each ridge. This work shows that the swash bar attachment at the shoreline shapes a new ridge. Wave diffraction around the distal part of the swash bars and ridges, and the local wave directions, explain the formation of perpendicular hooks.
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Barotropní oceánický slapový model / Barotropní oceánický slapový modelEinšpigel, David January 2012 (has links)
Title: Barotropic ocean tide model Author: David Einšpigel Department: Department of Geophysics Supervisor: prof. RNDr. Zdeněk Martinec, DrSc., Department of Geophysics Abstract: The main aim of this thesis is developing of a numerical model of an oceanic circulation forced by the lunisolar tidal potential. The circulation is described by the shallow water equations which are derived from the fundamental balance laws assuming that the ratio of the vertical and horizontal dimension of the investigated problem is small, which leads to the formulation of the 2- D task. Furthermore, programs for solving the shallow water equations were written. Their functionality is demonstrated on several examples. The programs include an ephemeridal tidal modul which computes the complete lunisolar tidal potential. Keywords: oceanic flow, shallow water equations, lunisolar tidal potential
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Vybrané gravitační jevy ve vesmíru a jejich přiblížení středoškolákům / Selected gravitational effects in the UniverseFranc, Tomáš January 2014 (has links)
Title: Selected gravitational effects in the Universe Author: Mgr. Tomáš Franc Department: Astronomical Institute of Charles University Supervisor: doc. RNDr. Marek Wolf, CSc., Astronomical Institute of Charles University Abstract: In this Thesis we have given an overview of tidal phenomena with their explanations and also explained the gravitational assist with examples of its use. We have created many pictures and 17 animations for better understanding of these topics. This part of the Thesis is focused on high school students and their teachers, it can be used by teachers for their inspiration for lessons, or students and more generally people interested in these topics can read this part as a study text. The main part of the Thesis is the result of research conducted on 13 high schools in the Czech Republic. 800 students took part in the research; its purpose was to find out students' knowledge of tidal phenomena and the gravitational assist. The research was carried out in the form of questionnaires. Keywords: gravity, tidal phenomena, gravitational assist, pedagogical research
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An enhanced and validated performance and cavitation prediction model for horizontal axis tidal turbinesKaufmann, Nicholas, Carolus, Thomas, Starzmann, Ralf 02 December 2019 (has links)
Tidal energy represents a promising resource for the future energy mix. For harnessing tidal currents free stream horizontal axis turbines have been investigated for some years. The acting physics is very similar to the one of horizontal axis wind turbines, with the additional phenomenon of cavitation, which causes performance reduction, flow induced noise and severe damages to the turbine blade and downstream structures.
The paper presents an enhanced semi-analytical model that allows the prediction of the performance characteristics including cavitation inception of horizontal axis tidal turbines. A central component is the well-known blade element momentum theory which is refined by various submodels for hydrofoil section lift and drag as a function Reynolds number and angle of attack, turbine thrust coefficient, blade hub and tip losses and cavitation. Moreover, the model is validated by comparison with comprehensive experimental data from two different turbines.
Predicted power and thrust coefficient characteristics were found to agree well with the experimental results for a wide operational range and different inflow velocities. Discrepancies were observed only at low tip speed ratios where major parts of the blades operate under stall conditions. The predicted critical cavitation number is somewhat larger than the measured, i.e. the prediction is conservative. As an overall conclusion the semi-analytical model developed seems to be so fast, accurate and robust that it can be integrated in a future workflow for optimizing tidal turbines.
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Spatial and Temporal Distributions of Larval Clupeid Fishes in a Tidal Freshwater Marsh ComplexAnderson, Philip Reid 01 January 2019 (has links)
Tidal freshwater wetlands provide valuable ecosystem services such as nutrient cycling, coastal flood control, and reproductive habitat for early life stages of economically and ecologically important fishes. The nutrient rich environments that tidal freshwater wetlands occur in support high levels of primary productivity of phytoplankton and vegetation that provide essential reproductive habitat for anadromous clupeid fishes (Alosa spp., Brevoortia tyrannus) in Chesapeake Bay tributaries. Seasonal retention of clupeid eggs and larvae within tidal freshwater habitats may enhance early growth, survival, and year class strength. The primary goal of the present study was to characterize the relative importance of tidal freshwater wetlands to the early life history stages of anadromous, migratory, and resident clupeid fishes in the lower James River. From 2014-2018, conical tow nets were used to collect ichthyoplankton samples from representative locations within the tidal freshwater marsh-creek complex of Curles Neck Creek, Virginia during the period of February through May. Boat electrofishing was used to sample juvenile target clupeids within the marsh-creek complex during March through November 2014-2018. A strong positive correlation between larval and juvenile Blueback Herring and Atlantic Menhaden, supported the hypothesis of seasonal in-system retention. This was the first published study to describe spatial and temporal patterns of occurrence of clupeid fishes with varying life history strategies in a tidal freshwater marsh and highlighted the importance of tidal freshwater marshes as nursery habitat.
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Återhämtning Efter Stroke : En Litteraturstudie Om Sjuksköterskans ErfarenheterBenjamen Toma, Georget, Khudaverdiyev, Ghassan January 2022 (has links)
ABSTRACT Background: Every year, 30,000 people in Sweden suffer from stroke. The disease leads to disability and patients with stroke are in need of recovery process. Previous research highlighted patients 'and relatives' experiences after stroke. The accumulated knowledge clarifies which nursing measures nurses use to support patients' recovery process. Purpose: to describe the nurse's experience in supporting the patient's recovery after a stroke. Method: Systematic literature study with descriptive synthesis. Results: It emerged that seeing the patient as unique was significant, and to have a functioning recovery process, patients must be given sufficient time and be well informed. Showing honesty also resulted in nurses being able to build trust with patients and relatives. The nurses' support in the form of guidance and individually adapted information as well as physical, emotional, social support was important for patients. A positive communication between patients and nurses contributed to a good care relationship that resulted in success in the recovery process, thus relatives were a resource for patients' recovery process. Conclusion: Patients suffering from stroke may suffer and experience pain after the life change. Patients can also experience well-being in their health, this by having a well-functioning recovery process. Nurses with their unique role and professional knowledge can support the recovery process.
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FYSISK VÅRDMILJÖ - FRÄMJANDE ELLER HÄMMANDE FÖR PERSONENS ÅTERHÄMTNING? : En kvalitativ intervjustudie utifrån en psykiatrisk slutenvårdskontextDavidsson, Karin, Nygren, Susanne January 2021 (has links)
Bakgrund: Fysisk vårdmiljö på psykiatriska slutenvårdsavdelningar erfars positivt och negativt. Dock undersöks sällan huruvida miljön erfars främja eller hämma återhämtning. Syfte: Beskriva hur personer som vårdas inom psykiatrisk slutenvård erfar den fysiska vårdmiljöns betydelse för återhämtning. Metod: Semistrukturerade intervjuer med tio deltagare som nyligen varit inlagda på psykiatrisk slutenvårdsvårdsavdelning. Kvalitativ innehållsanalys med induktiv ansats användes. Resultat: Det erfars främjande för återhämtningen att få uppleva ljus när det känns mörkt, att uppleva avdelningens miljö inbjudande, att få hjälp att komma till ro samt att få känna liv med hjälp av växter i den fysiska vårdmiljön. Det erfars hämmande för återhämtningen att känna sig begränsad av att dela rum med andra, att inte få möjlighet till en god sömn, att känna frustration när inget stimulerar samt att uppleva miljön som fängelselik. Slutsatser: Det är inte stora renoveringar eller interiör som är centralt i resultatet. Snarare handlar det om tanke bakom utformningen, som kan främja gemenskap, social interaktion och valmöjligheter. Utformningen kan skapa trygghet och underlätta återhämtningsprocessen. Sjuksköterskan behöver tänka steget längre och väga in den fysiska vårdmiljön som betydelsefull för återhämtningen och med de medel som finns skapa en återhämtningsfrämjande miljö för varje enskild person. / Background: Physical care environment in psychiaric wards experienced positively and negatively. However, it is rarely investigated whether the environment is experienced to promote or inhibit recovery. Purpose: Describe how people who are cared for in psychiatric inpatient care experience the importance of the physical care environment for recovery. Method: Semi-structured interviews with ten participants who have recently been admitted to a psychiatric inpatient ward. Qualitative content analysis with an inductive approach was used. Results: It is experienced to promote recovery to experience light when it feels dark, to experience the ward's environment inviting, to get help to calm down and to feel life with the help of plants in the physical care environment. It is experienced as inhibiting the recovery to feel limited by sharing a room with others, not to have the opportunity for a good sleep, to feel frustration when nothing stimulates and to experience the environment as prison-like. Conclusion: It is not major renovations or interiors that are central to the result. Rather, it is about thought behind the design, which can promote community, social interaction and choices. The design can create security and facilitate the recovery process. The nurse needs to think one step further and consider the physical care environment as important for recovery and with the means available to create a recovery-promoting environment for each individual person.
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Developing Warning and Disaster Response Capacity in the Tourism Sector in Coastal Washington, USAJohnston, David, Becker, Julia, Gregg, Chris, Houghton, Bruce, Paton, Douglas, Leonard, Graham, Garside, Ruth 01 January 2007 (has links)
Purpose - There has been a considerable effort over the last decade to increase awareness of the tsunami risk in coastal Washington, USA. However, contemporary research on warning systems spawned by the recent Indian Ocean tsunami tragedy highlights the need for development of an effective tsunami warning system for both residents and transient populations, including visitors and tourists. This study sets out evaluate staff training for emergencies, emergency management exercises (including drills and evacuation), and hazard signage within motels and hotels in Ocean Shores, Washington, USA. Design/methodology/approach - Data were collected from interviews with reception staff and managers at 18 hotels, motels, and other accommodation establishments. Findings - Levels of staff training and preparedness for tsunami and other hazards were found to be generally very low, although examples of "best practice" were found at a select few establishments. Larger hotels already had orientation or general training programmes set up which had the potential to incorporate future tsunami and hazard training, while smaller "owner-operator" businesses did not. Research limitations/implications - Suggestions on how to improve preparedness are discussed, including undertaking training needs analyses and conducting workshops, simulations and employee training to empower both businesses and employees. Originality/value - This case study provides an insight into the challenges faced by emergency managers and the tourism sector in improving the effectiveness of warning systems in areas with high transient populations.
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Degradation of Deepwater Horizon Oil Buried in a Florida Beach Influenced by Tidal PumpingHuettel, Markus, Overholt, Will A., Kostka, Joel E., Hagan, Christopher, Kaba, John, Wells, Wm Brian, Dudley, Stacia 01 January 2018 (has links)
After Deepwater Horizon oil reached the Florida coast, oil was buried in Pensacola Beach (PB) sands to ~ 70 cm depth, resulting in Total Petroleum Hydrocarbon (TPH) concentrations up to ~ 2 kg per meter of beach. This study followed the decomposition of the buried oil and the factors influencing its degradation. The abundance of bacteria in oiled sand increased by 2 orders of magnitude within one week after oil burial, while diversity decreased by ~ 50%. Half-lives of aliphatic and aromatic hydrocarbons reached 25 and 22 days, respectively. Aerobic microbial oil decomposition, promoted by tidal pumping, and human cleaning activities effectively removed oil from the beach. After one year, concentrations of GC-amenable hydrocarbons at PB were similar to those in the uncontaminated reference beach at St. George Island/FL, and microbial populations that disappeared after the oil contamination had reestablished. Yet, oxihydrocarbons can be found at PB to the present day.
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Small September semidiurnal tidal amplitudes over Collm in 2002Jacobi, Christoph, Kürschner, Dierk 11 January 2017 (has links)
The mesopause region monthly mean winds and semidiurnal tidal amplitudes and phases over Central Europe in the height range between 85-105 km have been measured at Collm Observatory continuously since September 1982. The regular annual cycle of the semidiurnal tidal amplitudes show in all cases maximum values during late August and September. In contrast to that, in autumn 2002 no enhancement of the tidal amplitudes was measured, while the autumn tidal phase transition occurred unusually early. The unexpected behaviour of the semidiurnal tides seems to be connected with a very early autumn transition of the zonal prevailing winds. This suggests that in 2002 the zonal mean winds influence the tidal propagation in a different way than usual. / Die monatlich gemittelten Grundwinde und halbtägigen Gezeiten werden am Collm seit September 1982 im Höhenbereich zwischen 85-105 km gemessen. Der normale Jahresgang der halbtägigen Gezeiten zeigt maximale Amplituden im Winter und vor allem im Spätsommer/Herbst. Dieses Maximum ist im Jahre 2002 nicht zu verzeichnen. Dies ist begleitet von einer ungewöhnlich frühen Phasenänderung von der Sommer- zur Winterposition. Das Verhalten der Gezeiten scheint mit einer sehr frühen Änderung des zonalen Grundwindes vom Sommer- zum Winterregime verbunden zu sein, so dass die Anomalie der mittleren Zirkulation für die Gezeitenanomalie verantwortlich zu sein scheint.
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