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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Numerical Computation of Water Tranquility in a Harbor

Chen, San-xue 26 February 2004 (has links)
Harbor construction is the most important basic development in fishery. To sustain harbor tranquility and prevent entrance from siltation are essential for maintaining normal operations of a harbor. Although the number of fishing harbors in Taiwan is said to be as many as the car parks on the land, there are numerous reports of poor tranquility that required urgent public attention. Supported by recent development in science and technology, research advances in numerical modeling have produced accurate results from a range of numerical schemes. Comparing to the conventional hydraulic models that require long executive time and large budget, numerical modeling on computer is a most effective alternative. In this study, the wave analysis system¡ÐCATWAVES developed by Professor Shigeaki Tsutsui at University of the Ryukyu in Okinawa, Japan is adopted to simulate the wave motions around a fishing harbor, in order to evaluate the tranquility of a harbor basin. CATWAVES calculates the transformation of surface gravity waves in the ocean using a mild-sloped equation of elliptic type. A finite-element scheme is used effectively to handle arbitrary bottom bathymetry and irregular boundary. This report first provides an outlines of the CATWAVES system, followed by verification of wave height distribution for two classic cases, being waves passing a semi-infinite breakwater in constant depth and waves propagating over a submerged circular shoal on a sloping beach, respectively. The CATWAVES system is then applied to assess the harbor tranquility at two prototype fishing harbors in Taiwan. The first case is to verify the results of several improvement options tested in hydraulic models elsewhere to improve the tranquility at Badoutz, a class one fishing harbor in northeastern Taiwan. The second case is to provide a better alternative plan of breakwater extension at Mito, a class three harbor in the southwestern part of Taiwan, where excessive wave heights have been experienced by local fishermen. It is believed that Tsutsui¡¦s CATWAVES system has made a great breakthrough in handling irregular bottom bathymetry and arbitrary outline of harbor plan. From the two prototype cases examined in this study, this system is found to be highly adaptive for calculating wave motions around any fishing harbor in Taiwan.
12

none

Chen, Ding-Ding 21 August 2001 (has links)
The principal objectives of this research are to investigate seasonal and spatial variabilities of species composition and numerical abundance of the copepods in relation to environment factors in the Kaohsiung Harbor and it¡¦s adjacent coastal waters, and compared the carbon ¡B nitrogen and hydrogen contents of the animal. In all, 61 species of copepods belonging to 16 families were identified from the samples collected at six stations in the Kaohsiung Harbor. The mean numerical abundance of copepods was 5.3 ¡Ó4.8 ¡Ñ10 5 inds/100m 3 . The dominant and frequent species were Parvocalanus crassirostris, Oithona dissimilis, Oithona brevicornis, Acrocalanus spp. and immature copepods (copepodite and nauplius), amounting to 91% of the total copepods catch. Among them, P. crassirostris was the most abundant and frequent species (contributed to 30% of the total catch). The numerical abundance of copepods exhibited seasonal and tidal variations, with higher abundance in spring and winter and during the high tide. The species composition of the copepods in the harbor was different from that of the local coastal water, with higher abundance and species number in the latter. From the monthly collections at a fixed station north of Kaohsiung Harbor, 42 species of copepods were identified and the mean abundance of copepods was 3.3 ¡Ó3.6 ¡Ñ10 5 inds/100m 3 . The most dominant and frequent copepods was Parvocalanus. crassirostris, O. dissimilis, O. brevicornis, Acrocalanus spp., Euterpina acutifrons and immature copepods, contributing to 92% of the total numerical abundance of copepods. The abundance of copepods exhibited significant seasonal change at this station, with higher abundance in winter and summer and lower in spring. The carbon content and dry weight of copepod were not significantly different between harbor and coastal water, but copepod¡¦s carbon content showed significant difference among body sizes. Copepod dry weight was significantly different among body sizes, but not seasons.
13

Prey selection in Gulf of Maine harbor seals (Phoca vitulina) in relation to fish abundance and fish mercury concentrations /

Kopec, Audrey Dianne, January 2009 (has links)
Thesis (Ph.D.) in Biological Sciences--University of Maine, 2009. / Includes vita. Includes bibliographical references (leaves 136-165).
14

Study of the cranial sinus nematode, Stenurus minor (Metastrongyloidea), in the harbour porpoise, Phocoena phocoena

Faulkner, Jacqueline January 1995 (has links)
Seventy-eight harbour porpoises, Phocoena phocoena, (33 females, 45 males) were obtained from the summer (June-September) cod fishery incidental-by-catch in the Gulf of St. Lawrence, and examined for the presence of cranial sinus nematodes. This is the first quantitative and in-depth study of the distribution of Stenurus minor (Kuhn, 1829) Baylis and Daubney, 1925 in the cranium of by-caught harbour porpoises. Stenurus minor was present in the cranial sinuses of all adult porpoises ($>$1yr, n = 66, x = 2362, range 87-8920) and absent in all young-of-the-year ($<$1yr, n = 12). Only fifth-stage worms were observed and these were equally distributed between the right and left side ot the skull (mean intensity = 1158 and 1213 in the left and right side, respectively). Female S. minor were predominant (1:1.8 sex ratio). Mean intensity of S. minor was similar among all infected porpoises, suggesting an annual loss and recruitment of this parasite. Parasite load had no apparent effect on porpoise body condition (measured as % blubber weight of carcass). No gross lesions associated with the presence of numerous S. minor in the cranial sinuses, were observed. There was an inverse relationship between the intensity of S. minor and mean worm-length, suggestive of a "crowding effect". Mean worm-length in lightly infected porpoises was 17.8 $ pm$ 0.2 mm and 16.1 $ pm$ 0.2 mm in heavily infected animals. Possible life-cycles and modes of transmission are examined in light of our findings. The absence of S. minor in porpoises less than 1 year old suggests heteroxenous transmission of this parasite, via an intermediate host in the food chain. Transmammary and or transplacental transmission is unlikely.
15

Striving for a sustainable urban waterfront for Victoria Harbour, Hong Kong /

Lam, Fan-yau, Karen. January 2005 (has links)
Thesis (M. Sc.)--University of Hong Kong, 2005.
16

Physical and behavioral development of nursing harbor seal (Phoca vitulina) pups in Maine

Skinner, John P. January 2006 (has links) (PDF)
No description available.
17

A study of ship size and turnaround time in the port of Vancouver

Studer, Keith Ronald January 1969 (has links)
Ships of all types spend a large part of their lives in port and this idle time adds considerably to the fixed cost of providing shipping service. Technological progress has empowered the construction of larger, faster and more economical vessels, but organisational and cargo handling innovations in the ports have not kept pace; in many instances the line-haul savings achieved by larger vessels are negated by excessive idle time in port, during which many costs continue unabated. The extent to which ship size affects loading time is thus a measure of the extent to which economies of scale can be implemented in the shipping industry; it is also important when making a rational selection of an optimal ship size. This study concentrates on the loading of grain ships in the port of Vancouver; the operations of the port are examined and the constituent factors of turnaround time delineated. Some of the possible causes of delay are investigated. The costs associated with unproductive ship time are then estimated and it is shown that many of the developments in the shipping industry are placing increased emphasis on a fast turnaround, the latter is often difficult to achieve because of disorganisation and conflicting interests in the port. The loading records of a sample of 1,305 grain ships are then examined with a view to determining the degree of size dependency inherent in the loading time and loading rate attained. It is concluded that there is an appreciable positive correlation between ship size and loading rate and that the portion of the variation explained by linear regression analysis is not inconsiderable. Combining these dependencies of ship size and loading rate with the dependency of ship size and cost estimated previously, the general form of the relationship between ship size and total loading time cost per ton is obtained. It is found that for those types of grain for which the results are most conclusive, the cost per ton falls up to large ship sizes. Having regard to the present loading procedures for grain in Vancouver some possible improvements are suggested, namely the provision of increased loading capacity and the aggregation of specific grades of grain around the harbour. A rough estimate of the possible benefits associated with these course of action is made. The potential benefits would seem to be considerable, but a high degree of co-operation and co-ordination between the various port interests would be required to attain them. / Business, Sauder School of / Graduate
18

Spatial structuring of port-linked flows; The Port of Vancouver, Canada, 1965.

Robinson, Ross January 1968 (has links)
This study first postulates the existence of an "operational" port, a nodal organization of port functions, defined in terms of inter-port shipping linkages of foreign trade shipping in Southwestern British Columbia. A number of variables for each foreign trade vessel is programmed into a series of port by port adjacency matrices. The set of ports (nodes) and ship movements (linkages) is regarded as a planar graph and real values assigned to both linkages and nodes. Through matrix analysis and network theoretic concepts, the connectivity and orientations of ports within the area are defined. The analysis reveals not only the dominance of the port of Vancouver but also the high degree of dependence of a number of adjacent ports upon it. Second, the relationship of the nodal status of a port to its location in a system of ports and to its operational role as a node between discrete transportation networks is demonstrated by an examination of the movement patterns of export lumber and general cargo imports through the port of Vancouver. Lumber movement patterns to shipping points, derived from computer analyses, reveal the significance of innovatory shipping technologies, together with other necessary conditions, as the basis of explanation of nodal status and network structuring. The movements of general cargo imports are examined in a series of data matrices computationally derived from Shipping Manifest data. Each matrix preserves the relationship between foreland origin; and hinterland destination and the analysis clearly demonstrates the correlation of hinterland limits with the foreland origin of flows. Third, the relationships between the principles of nodal structuring and the concept of port hierarchy in spatial theory are explored. The adequacy of an alternative concept of port hierarchy derived from an analysis of the network of shipping linkages between ports is postulated and a descriptive model of port network development in British Columbia is formulated. / Arts, Faculty of / Geography, Department of / Graduate
19

Study of the cranial sinus nematode, Stenurus minor (Metastrongyloidea), in the harbour porpoise, Phocoena phocoena

Faulkner, Jacqueline January 1995 (has links)
No description available.
20

Harbor seals in Hood Canal : predators and prey /

London, Josh M. January 2006 (has links)
Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (leaves 71-77).

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