As part of the sustainable management of the Port of Saint John there is a critical need to maintain sufficient under keel clearance for the various container and cruise ship traffic in and out of the harbour. Because of high and variable sedimentation rates, annual maintenance dredging is necessary and causes economic concerns for the Port. Therefore to better predict future dredging volumes and hence improve the budgeting process for the Port of Saint John, the estuarine circulation of the harbour has been analysed to better quantify the relative importance of the offshore sediments that contribute to the high dredging volumes in the Saint John harbour. The Port of Saint John lies at the mouth of the Saint John River on the north side of the macrotidal Bay of Fundy. Because of this, the harbour sedimentation is influenced by two major sources of siltation: the Saint John River and the Bay of Fundy. The sediment flux from the river is strongly modulated by the seasonal variations in river discharge. In the Bay of Fundy, there is significant resuspension of offshore marine sediments. To better understand this complex interaction between the fresh water flow and the tidal inflow of salt water, high density oceanographic surveys have been conducted at four different river discharge periods. In order to quantitatively analyse the mixing of the fresh and salt water in the harbour channels, high density ADCP currents and CTD measurements were acquired along main longitudinal axis of the Main Harbour channel and Courtenay Bay over four tidal cycles. By imaging the 200kHz acoustic volume backscatter within the water column, the appearance of interfacial waves at the pycnocline can be examined. The optical backscatter sensor provided observations used to estimate suspended sediment concentrations. A cross-sectional analysis of the flow at a location 700m south and seaward of the Rodney bay terminal in the Main Channel revealed that regardless of the river discharge rate, the interfacial waves are best developed on the rising tide. However, during the Spring freshet the interfacial waves are also developed at high tide, low tide and falling tide. Examination of the timing and location of the interfacial waves are important because they influence the nature of sediment transport in the Main Harbour Channel. During high river discharge periods, the sediment concentration and volume flux estimates indicate that the river is the main source of sediments. For the low river discharge periods, the observations suggest that the possible source of suspended sediments observed in the lower saline layer are either from outside of the harbour or bottom sediments being resuspended on the rising tide.

No description available.

Condition monitoring of machines and structures is commonly utilized in order to prevent failures before they can occur. For these reasons, data such as temperature, vibrations or displacements are collected and analysed. Sensors collect this information, which is sent to a base station to be examined. Wired sensors have been used since the appearance of condition monitoring maintenance; however, wireless sensors are becoming more popular in this area. The use of wired sensors can be very expensive, due to the cost related to the installation and maintenance of the wiring between the sensors and the base station. In wind turbines, wired sensor networks are starting to be substituted by wireless sensor networks. However, for tidal turbines, such as those developed by Delta Stream, this is still a challenge. The use of batteries to supply energy to sensors is not an optimal solution for turbines that are located in remote areas. Batteries have a limited life and their replacement is costly and complicated. Thus, alternative sources of energy have to be found. The environment found in a tidal turbine provides several sources of profitable energy, such as vibration and temperature differences which can be used to supply energy by means of energy harvesters. The aim of this project is to demonstrate the operation of self-powered short-range wireless sensor nodes for a potential use in a Delta Stream nacelle of tidal turbine. This project focuses on the wireless communication inside the nacelle (where most of the sensors are located) using a land protocol (Zigbee), and the energy harvesting using waste heat by means of thermoelectric devices. In order to prove the operation of the whole system (thermoelectric generator and sensor node), a power management circuit was also constructed and tested.

No description available.

Shippagan Gully is a highly dynamic tidal inlet located on the Gulf of St-Lawrence near Le Goulet, New Brunswick. This tidal inlet is highly unusual due to the fact that the inlet has two open boundaries with phase lagged tidal cycles that drives flow through the inlet. Over the past few decades, the shipping activities through the inlet have been threatened due to the narrowing of the navigation channel caused by deposited sediment on the east side of the channel. Many engineering projects have been undertaken at Shippagan Gully in order to try and mitigate the deposition problem. However, these attempts have either been unsuccessful or the engineered structures have deteriorated over the years. This study uses the CMS-Flow and CMS-Wave numerical models to provide guidance concerning the response of the inlet to various potential interventions aimed at improving navigation safety.

Sammanfattning Vid psykisk ohälsa är ångest ett centralt fenomen, uppskattningsvis drabbas ca 25% avbefolkningen någon gång under livet av ett ångestsyndrom. Förekomst av obehandladångestsjukdom innebär såväl ett personligt lidande och ett hot mot den allmänna folkhälsan ochsamhällsekonomin. Behandling av ångestsjukdomar består av farmakologiska och psykologiskametoder. Sjuksköterskan utgör en central roll i omvårdnaden av människor med ångestsjukdom.Relationen mellan vårdare och patienten utgör en betydelsefull del i vårdandet, och är enförutsättning för en fungerande vårdprocess. Denna projektplan utgår ifrån Tidalmodellen somomvårdnadsteoretisk referensram där vårdrelationen och patientens egna inneboende resurser ärcentrala. Syftet med studien är att undersöka patienters upplevelse av stöd i ångesthantering inompsykiatrisk slutenvård. Kommande studie kommer genomföras med fenomenografisk ansats medindividuella, inspelade, semi-strukturerade djupintervjuer som datainsamlingsmetod.Fenomenografisk ansats lämpar sig väl till vårt syfte att utforska individers upplevelse av stöd ochäven till Tidalmodellen vars fokus är på individens upplevelser, berättelser och inneboenderesurser. I enlighet med fenomenografins ansats kommer vi att i studien använda oss av ettstrategiskt urval där skillnader eftersträvas för att få så stor variation av uppfattningar som möjligt.Dataanalys kommer även den att ske i enlighet med den fenomenografiska ansatsen. Nyckelord: Ångest, Vårdrelation, Stöd, Tidalmodellen.

Graduate

In the quest to reduce the release of carbon dioxide to limit the effects of global climate change, tidal-in-stream energy is being investigated as one of many possible sustainable means of generating electricity. In this scheme, turbines are placed in a tidal flow and kinetic energy is extracted. With the goal of producing maximum power, there is an ideal amount of resistance these turbines should provide; too little resistance will not a develop a sufficient pressure differential, while too much resistance will choke the flow. Tidal flow in a strait is driven by the difference in sea-level along the channel and is impeded by friction; the interplay between the driving and resistive forces determines the flow rate and thus the extractible power. The use of kinetic energy flux, previously employed as a metric for extractible power, is found to be unreliable as it does not account for the increased resistance the turbines provide in retarding the flow. The limits on extraction from a channel are dependant on the relationship between head loss and velocity. If head loss increases with the square of the velocity, a maximum of 38% of the total fluid power may be extracted; this maximum decreases to 25\% if head loss increases linearly with velocity. Using these values, the estimated power potential of BC's Inside Passage is 477MW, 13% of previous assessments. If a flow has the ability to divert through a parallel channel around the installed turbines, there are further limits on production. The magnitude of this diversion is a function of the relative resistance of impeded and diversion channels. As power extraction increases, the flow will slow from its natural rate. This reduction in velocity precipitously decreases the power density the flow, requiring additional turbine area per unit of power. As such, the infrastructure costs per watt may rise five to eight times as additional turbines are installed. This places significant economic limitations on utility-scale tidal energy production.

Tidal power is a clean renewable energy. Furthermore, electricity is acknowledged as a key need for development. However, until recently, due to high capital costs and extensive environmental concerns, few tidal power plants are operative around the world. These problems are now being mitigated by the application of appropriate, modern practices and technologies. In particular the use of small scale technologies, innovative financing and the involvement of local communities creates the potential for tidal power to be a tool in coastal development. This thesis examines the appropriateness of tidal power in the rural coastal community of Bangladesh, where electricity demand is a major development problem. Coastal Bangladesh is highly vulnerable to natural disasters, especially from cyclones, tidal surges and the effects of global warming on sea-level rise. Consequently, most of this coastal area has been protected by embankments and sluice gates, which can accommodate the normal tidal head rise and fall. The potential of tidal power to use this infrastructure, together with its associated problems and mitigation measures, have been analysed by comparing existing and potential tidal power technologies around the world, including a proposed Kimberley tidal power project in Western Australia. The research has identified that a significant amount of power could be produced from the tidal range of coastal Bangladesh by using the simple low-cost technology of tidal wheels in the tidal embankment sluice gates. The electricity produced could be utilised by various coastal interests, such as agriculture, shrimp aquaculture and other resource producing activities. However, the real benefits of this technology are that it can be applied in a way that simultaneously enables the development of local infrastructure and the improvement in living conditions of the local people by creating income generation and employment opportunities in these coastal communities. The thesis puts forward a community based co-management model as a means of effectively integrating tidal power in coastal area management in Bangladesh.

Thesis (Ph. D.)--University of Hawaii at Manoa, 2003. / Includes bibliographical references (leaves 65-68).