Thesis (M.S. in Physical Oceanography)--Naval Postgraduate School, December 2003. / Thesis advisor(s): Thomas H.C. Herbers, Edward B. Thornton. Includes bibliographical references (p. 71-73). Also available online.

No description available.

No description available.

No description available.

Thesis (Ph. D.)--University of Texas at Austin, 2005. / Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Texas at Austin, 2005. / Vita. Includes bibliographical references (leaves 181-200). Also available in an electronic version.

Thesis (Dissertação de Mestrado)--Universidade de São Paulo, 1978. / Includes translation of abstract in English. Includes bibliographical references (p. 97-102).

Thesis (M.S.)--University of New Hampshire, 1983. / Typescript. Includes bibliographical references (leaves 41-42).

Coastal States have laid claim, progressively, to the sea areas adjoining them found until recent times these claims have been, ostensibly, to ensure the security of the State and the right to harvest the potential of the sea. It is obvious that foreign vessels, close to the coast of a State, could constitute a threat and in the past, as the dangers of improved weaponry became apparent, some coastal States felt the need to extend their territory still further seawards. However, the most significant claims to extended sovereignty have been in recent times, as a result of the efforts of coastal States to control the newly discovered potential of the seabed, and in particular, the continental shelf. As technology improves, the possibility of exploiting sea-bed resources will extend further and further seawards to the point where, in time, it will be possible to harvest and mine all of the seabed, regardless of depth. It should be noted that some States have extended their claims to a limit that the international community will not accept. An example oftJ,;s is the 200 nautical mile(nm) territorial waters claims of Argentina in 1966 and Brazil in 1970. Argentina has subsequently adjusted its claim to conform with the articles of the Law of the Sea Convention of 1982 LOSC. (1) Vast changes in the type and quantity of potentially hazardous substances, that are being transported by sea, such as crude oil, nuclear waste, chemicals, etc, have also brought with them an ever-increasing threat of pollution. To prevent the destruction of their resources, coastal States are also taking more stringent measures in the seas surrounding them. To illustrate this threat, during the period 1950 to 1975, the dead-weight tonnages of crude-oil tankers increased from an average of 30 000 to 500 000 tonnes and the draughts (depths) of these vessels increased from 10 metres to about 30 metres when loaded. This marked increase in size and draught of vessels could mean that the information on navigational hazards is inadequate for their safe passage. This has increased both the possibility of accidents and the gravity of the consequences of such accidents, thus making it urgent for coastal States to control their seaward territories and zones. It is the intention to consider all aspects of international law and marine-geological factors that could affect continental shelf claims of the Republic of South Africa (RSA). To be able to do this satisfactorily it is necessary to consider international treaties, conventions, judgements in international disputes and the practice of States that could be regarded as customary law. As some of the criteria used in international law to claim continental shelf depend on the geological configuration of the continental shelf of a coastal State it is necessary to consider geological concepts in general and the history of the shelf of the RSA in particular. It is anticipated that in some areas insufficient data will be available to finalise a claim and it is the intention also, therefore, to identify these areas and the data required for a comprehensive and internationally acceptable claim to be made. The deep-sea bed is being explored for possible exploitation, but the ownership of deep-sea resources was not satisfactorily regulated in international customary law. LOSC, adopted in J 982, has not been ratified by the major and most powerful coastal States. This is in spite of attending States to the Conference endeavouring at great length to resolve the problems. This is most likely due to the Articles in the Convention dealing with exploration and exploitation of the deep-sea bed. Of the resources found on the continental shelf, as defined in LOSC, extensive oil and gas reserves phosphorites, manganese nodules and diamonds make up more than 90% of the value of the total. Some of the lesser important resources include sand and gravel, titanium, tin, chromium, and zirconium. Pools of brine contain concentrations of lead, zinc, gold and silver and it must be accepted that advancing technology will eventually make these resources economically viable propositions. Continental shelf claims beyond any exclusive economic or fishing zones include sedentary species such as oysters, clams, lobsters and ~rabs, which could in some areas such as the Pacific Ocean become an important consideration for exploitation. The requirements for acceptable international standards of delineation of the continental shelf have not evolved through international customary Jaw, because there has been little if any reason for a coastal State to give serious thought to the exploitation of the land under the sea until the middle of the 20th century. The Convention on the Continental Shelf adopted in Geneva in 1958 was the first real effort, on an international scale, to draw up Convention rules capable of resolving the overlapping claims of States. (This convention is usually known as CSC, but to avoid confusion, it will be referred to as CSC58). This convention did not clarify the complexities of continental shelf or margin claims and the problem was further considered during the drafting of LOSC. In spite of the fact that major coastal States have not ratified this Convention most have, nevertheless, laid claim to areas of the continental shelf and to the exploration of the potential of the resources of the deep-sea bed. The criteria laid down in LOSC to delineate continental shelf claims include limits that could be determined ' from bathymetric records, from seismic reflection or refraction profiles of the margin and also from the ratio of sediment thickness to the distance of that sediment position to the foot of the slope.

O objetivo do presente trabalho foi estudar, por meio da técnica de titulação colorimétrica e análise da microdureza dentinária, o shelf life da solução de quitosana 0,2% armazenada em frascos de vidro e plástico. Trinta caninos superiores humanos tiveram as coroas desprezadas e a porção cervical das raízes seccionada, obtendo-se 3 cortes. O segundo e terceiro cortes foram divididos ao meio e incluídos em resina acrílica resultando em 4 corpos de prova por dente. A solução de quitosana 0,2% (pH 3,2) foi preparada e distribuída em 3 frascos iguais de vidro (v1, v2 e v3) e em 3 de plástico (p1, p2 e p3) para realização dos testes em triplicata. Os testes de microdureza e colorimetria foram realizados durante seis meses nos períodos de 0, 7, 15, 30, 45, 60, 90, 120, 150 e 180 dias após o aviamento da solução. Para a mensuração da microdureza Knoop utilizou-se carga de 10 gramas por 15 segundos. O corpo de prova recebeu 50 &mu;L da solução teste por 5 minutos e, após lavagem e secagem foi levado para mensuração. A análise foi realizada com as soluções v1, p1, EDTA 17% e água destilada (controle); v2, p2, EDTA 17% e controle; v3, p3, EDTA 17% e controle, para cada tempo proposto. Foram realizadas 3 endentações com espaço de 200 &mu;m. As mensurações foram anotadas e arquivadas em um banco de dados. Para o teste da colorimetria utilizou-se uma solução padrão de carbonato de cálcio 0,3%, na qual gotejava-se por meio de micropipeta a solução de quitosana com volume pré determinado. A alteração da coloração da solução de carbonato, do violeta para azul, indicava quelação dos íons cálcio, detectada por meio de espectrofotometro Ultravioleta Visivel. O aparelho emitia um valor da absorbância para cada análise da coloração, expressa por meio de gráfico (comprimento de onda/absorbância). Empregou-se Análise de Variância (one-Way ANOVA) (&alpha; = 0,05) para comparar a microdureza entre as soluções, os diferentes tempos para cada solução, bem como a interação microdureza/tempo para cada solução. Houve semelhança entre as soluções testadas no que se refere ao tempo de estudo (p=0,113), bem como em relação à interação microdureza/tempo (p=0,329). As soluções testadas apresentaram, individualmente, o mesmo efeito sobre a microdureza da dentina, desde o tempo zero até os 180 dias. Quando comparadas entre si foram diferentes (p<0,0001). O teste de Tukey evidenciou que a quitosana (v1, v2, v3, p1, p2 e p3) e EDTA reduziram a microdureza de forma semelhante entre si (p>0,05) e diferente do controle (p<0,001). Os gráficos da análise colorimétrica mostraram que tanto a quitosana em vidro como a em plástico apresentaram valores médios de absorbância no mesmo comprimento de onda (234nm) para todos os tempos, enquanto que para a solução padrão de carbonato de cálcio o comprimento de onde foi de 206nm. Concluiu-se que independentemente da forma de armazenamento a quitosana apresenta propriedade quelante por um período mínimo de 6 meses. / The aim of this study was evaluate, through the colorimetric titration method and analysis of the dentine microhardness, the shelf life of the solution of chitosan 0,2% stored in flasks of glass and plastic. Thirty human superior canines had their crown discarded and the cervical portion of the root sectioned, obtaining 3 sections. The second and the third sections were divided in half and included in acrylic resin resulting in 4 specimens per tooth. The chitosan solution 0,2% (pH 3,2) was prepared and distributed in 3 flasks of glass (v1, v2, v3) and in 3 of plastic (p1, p2, p3) to perform the test in triplicate. The tests of microhardness and colorimetry were performed during 6 months in the period of 0, 7, 15, 30, 45, 60, 90, 120, 150 and 180 days after the preparation of the solution. For the measurement of microhardness Knoop, it was used a load of 10 grams for 15 seconds. The test object received 50 &mu;L of the test solution for 5 minutes and after washing and drying, it was taken out for measurement. The analysis was performed with the solutions v1, p1, EDTA 17% and distilled water (control); v2, p2, EDTA 17% and control; v3, p3, EDTA 17% and control, for each proposed time. Three indentations were performed with a 200&mu;m space. Measurements were noted and filed in a database. For the colorimetric test, a standard solution of calcium carbonate 0.3% was used and a predetermined volume of chitosan solution was inserted to it by using a micropipette. The color changes observed in the carbonate solution, from violet to blue, indicated the chelation of calcium Ions, detected through visible ultraviolet absorbance spectrophotometry. The instrument generated a specific value of absorbance for each coloring solution analyzed, expressed through the graphic (wavelength/absorbance). Variation of analysis was used (One-Way ANOVA) (&alpha;= 0,05) to compare the microhardness among the solutions, the different time for each solution, as well as the interaction microhardness/time for each solution. The time of study was similar among the tested solutions (p=0,113), as well as the interaction between microhardness/time (p=0,329). The tested solutions showed, individually, the same effect over the dentine microhardness, from time zero until 180 days. When compared among each other the results were different (p<0,0001). The Tukey test demonstrated that chitosan (v1, v2, v3, p1, p2 and p3) and EDTA reduced the microhardness in a similar pattern among them (p>0,05) and different from the control (p<0,001). The graphics of the colorimetric analysis showed that either chitosan in glass or plastic presented medium values of absorbance in the same wave length (234nm) for all the different times, meanwhile the standard solution of calcium carbonate wavelength was 206 nm. It was concluded that independently of storing methods, the chitosan presents chelating property for a minimum period of six months.