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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.

Examination of the relationship of river water to occurrences of bottom water with reduced oxygen concentrations in the northern Gulf of Mexico

Belabbassi, Leila 25 April 2007 (has links)
Six years of comprehensive data sets collected over the northern continental shelf and upper slope of the Gulf of Mexico during the LATEX-A and NEGOM-COH programs showed that low-oxygen waters (<2.4 mL·L-1) are found only in spring and summer and only in water depths between 10 and 60 m. Four regions in the northern Gulf show considerable differences in the occurrence of low-oxygen waters. Lowoxygen waters are observed almost exclusively in regions subject to large riverine influences: the Louisiana and Mississippi-Alabama shelves. Hypoxic waters (oxygen concentrations <1.4 mL·L-1) are found only over the Louisiana shelf. No low-oxygen water is found over the Florida shelf which has minimum riverine influence. Lowoxygen water is found at only one station on the Texas shelf; this is during spring when the volume of low-salinity water is at maximum. The distributions of low-salinity water influenced the different distributions of low-oxygen and hypoxic waters in the four regions. Low-oxygen occurrences are clearly related to vertical stratification. Lowoxygen occurred only in stable water columns with maximum Brunt-Väisälä frequency (Nmax) greater than 40 cycles·h-1. When Nmax exceeded 100 cycles·h-1 in summer over the Louisiana shelf, oxygen concentrations dropped below 1.4 mL·L-1, and the bottom waters became hypoxic. Salinity is more important than temperature in controlling vertical stratification. Locations where temperature influence was larger were found in summer in water depth greater than 20 m over the Louisiana shelf, along the near shore areas of the Mississippi-Alabama shelf west of 87ºW, and in the inner shelf waters of the Texas shelf. The extent of oxygen removal at the bottom of these stable water columns is reflected in the amount of remineralized silicate. Silicate concentrations are highest closest to the Mississippi River Delta and decrease east and west of the Delta. EOF analyses show that more than 65% of the oxygen variance is explained by the first mode. The amplitude functions of the first EOF modes of bottom oxygen, water column Brunt- Väisälä maxima, and bottom silicate are well correlated, indicating that much of the variance in bottom oxygen is explained by water column stratification and bottom remineralization.

The physical limnology and dissolved oxygen regimes of small eutrophic lakes

Ruiz, Zoë January 1999 (has links)
No description available.

Stable boundary layer flow over hills and valleys

Holden, John Joseph January 1998 (has links)
No description available.

Stratified Neighborhoods, Stratified Schools: Intradistrict Transfer and Racial and Socioeconomic Stratification

Larsen, Elisabeth Stuart 21 April 2009 (has links)
Intra-district transfer policies allow students to attend any school within a district and thus may have unique consequences for stratification within a district. If parents make choices based on common academic interests, this policy can create racial and socioeconomic integration across the schools in a district. However, socially motivated choices may lead to the creation of increasingly stratified zones. This study examines one urban school district with an intra-district transfer policy to examine if the schools in the district become more racially and economically stratified under the choice policy and if the level of stratification at family's zoned schools is correlated with participation in choice. Results show that families zoned to schools mirroring the district's diverse composition are more likely to participate in choice, suggesting that more factors than simple academically-based motivations guide choice behavior. Exploration of the levels of stratification in schools with and without the choice policy suggests that the overall trend is to maintain the level of stratification present in the residential areas. Although most changes under the choice policy are small in magnitude, the changes that do occur push the district towards increased stratification.

Willow Pond Village family, marriage, and social stratification in a Yangzi Delta farming community /

Murphy, Eugene Thomas. January 1994 (has links) (PDF)
Thesis (Ph.D.)--Columbia University, 1994. / Sponsor: Myron L. Cohen. Includes bibliographical references.

The Claremont Foodshed: A Historical Analysis

Comet, Allie 01 January 2009 (has links)
On the southeast corner of the Pomona College campus a small community farm and lush oasis is nestled in the suburban jungle of Claremont, California. ‘The Farm’ is a two-acre food forest that produces a wide variety of annual vegetable crops, fruits, and perennial herbs and berries in a landscape otherwise covered largely in asphalt and lawn.From my experiences on the Farm and in the classroom studying environmental analysis , I have developed a great interest in sustainable food and farming. The failures of the modern food system, destructive to the natural environment and inadequate in providing the world’s population with sufficient food or nutrition, posed against a great variety of emerging alternatives, has led me to study and engage in local, grassroots efforts to create new (and remember old) ways of feeding ourselves. In this project, I focus on the development of the Claremont area and the role that food and agriculture have played in its history. Additionally, I discuss the current situation and the local food system alternatives that are emerging.

Standardised measures in stroke rehabilitation and their application to stroke research

Kalra, Lalit January 1994 (has links)
No description available.

Évolution de la polarisation au Canada : 1973-2003 /

Goyette, Marc-André. January 2007 (has links) (PDF)
Thèse (M.A.)--Université Laval, 2007. / Bibliogr.: f. [62]-63. Publié aussi en version électronique dans la Collection Mémoires et thèses électroniques.

Sociological theory and social stratification outline of a nonfunctionalist theory of stratifiction /

Buckley, Walter Frederick, January 1900 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1958. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Structural change and inequality skill premia, firm selection and political consequences /

Morrow, John Miles. January 2010 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 2010. / Digitized and made available by the University of Wisconsin Digital Collections Center as part of Minds@UW. WU Includes bibliographical references (p. 86-94).

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