Thesis (Ph. D.)--University of Wisconsin--Madison, 1972. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliography.

In the past, sharks, skates and ray species have mainly occurred in incidental fisheries. Now they are increasingly being directly targeted due to the depleted status of traditionally targeted species. The life history characteristics of many elasmobranch species make them more sensitive to high rates of fishing mortality. The combination of these factors has resulted in the known local depletion of several elasmobranch species; including the barndoor skate, Raja laevis, of the Northwest Atlantic and the common skate, Raja batis, of Irish Sea. The longnose skate, Raja rhina, occurs commonly as incidental catch in trawl fisheries off the coast of California, Oregon and Washington. Commercial landings of skates, including R. rhina, have increased dramatically along the U.S. West coast. The objectives of this study have been to calculate accurate growth and maturity parameters for Raja rhina in order that the vulnerability of this species to fishing mortality can be assessed. The slow growth rates (k=0.04 to 0.06) and late ages-at-50% maturity (11 to 16 years with maximum ages between 15 and 22 years, depending on sex and region) which were calculated indicate that this species may be at great risk of depletion in the future. Survey biomass trends indicate that R. rhina populations have remained stable over the past twenty years. However, the possibility that biomass levels in the distant past were much higher than they are at present cannot be ruled out. It is recommended that the collection of fishery-dependent data for this species and other skate species begins immediately. This information, along with the results found in this are needed for a proper assessment for Raja rhina, so that the effects of current fishing pressures can be evaluated and regulated appropriately. / Graduation date: 2006

Thesis (M.A.)--Columbia University. / Bibliography: p. [169]-190.

Histochemical treatments specific for hyaluronic acid, chondroitin sulphate A/C, chondroitin sulphate B, and heparin, which are biological compounds classed as acid mucopolysaccharides, were applied to a series of Pacific great skate (Raja binoculata) embryos in order to characterize histochemically the acid mucopolysaccharides present in the embryos and to study the events leading to the situation of acid mucopolysaccharides localization in the adult. Embryonic stages examined ranged from early cleavage to immediate prehatching. A progression was observed from; 1. intracellular neutral polysaccharides in cleaving stages through, 2. a combination of extracellular neutral polysaccharides and weakly acidic acid mucopolysaccharides (hyaluronic acid) associated with cell processes in neurulating stages to, 3. extracellular strongly acidic sulphated acid mucopolysaccharides (chondroitin sulphates) in later stages, particularly in areas of cartilage development. In neurulating embryos hyaluronic acid appeared in considerable quantity between some adjacent tissue layers in a smooth layer form suggestive of some developmental significance for this compound. Hyaluronic acid also occurred in a similar form in lesser quantity in post neurulae (17-18 mm. embryos) in close association with developing gut and mesonephros. Results of histological tests in immediate prehatching embryos agreed with previously reported biochemical analyses of shark skins and cartilages i.e. chondroitin sulphate B occurred primarily in the skin and chondroitin sulphate A/c were a major component of the cartilage matrix. / Science, Faculty of / Zoology, Department of / Graduate

No description available.

Thesis (M.A.)--University of Michigan, 1980. / Typescript. Some parts are in Jawi. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (p. 132-133).

Thesis (M.A.)--University of Michigan, 1980. / Typescript. Some parts are in Jawi. Includes bibliographical references (p. 132-133). Also issued in print.

Industrial boilers that produce steam or electric power represent a large capital investment as well as a crucial facility for overall plant operations. In real applications, the operation of the superheater for producing high-pressure, high-temperature steam may result in problems frequently caused by ruptured superheater tubes. To make the boiler more efficient, less emission and less prone to tube rupture problems, it is important to understand the combustion and thermal flow behaviors inside the boiler. This study performs a detailed simulation of combustion and thermal flow behaviors inside an industrial boiler. The simulations are conducted using the commercial CFD package FLUENT. The 3-D Navier-Stokes equations and five species transport equations are solved with the eddy-breakup combustion model. Calculation of NOx is performed after obtaining a converged flow, thermal and combustion solution. The results provide insight into the detailed thermal-flow and combustion in the boiler and showing possible reasons for superheater rupture

xi, 246 leaves : ill. ; 25 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.1975) from the Dept. of English, University of Adelaide

There are many books on Yoga as it has become a fascinating subject of study for many scholars of Yoga. It is an interesting field of study for many scholars. There are many types of Yoga, however, in this thesis only Hatha-Yoga and Raja-Yoga will be considered in detail, Hatha-Yoga and Raja-Yoga will always remain interested in their attempts to give certain physical and mental characteristics to the physical body by certain types of physical exercises and to the mental structure by different types of mental exercises. These physical and mental exercises will develop the process of concentration of mind, the object of which when properly focused, will lead to the attainment of Self-Realization.