The conversion of ammonia to 2:4-dinitroaniline by reaction with 1-fluoro, 2:4-dinitrobenzene and the subsequent conversion of dinitroaniline to a diazo-dye with N-(1-naphthyl)ethylenediamine has been investigated as an analytical method for determining ammonia at the micromolar concentration level. Particular emphasis was placed upon the possibility of applying this method to the analysis of sea water. Dinitroaniline was formed under alkaline conditions (pH greater than 8) and required the presence of the fluoro-dinitrobenzene as a separate phase for initiation of the reaction. The conversion, which was light sensitive, was accelerated by increases in pH and temperature, but neither of these factors improved the final yield. The yield of dinitroaniline had a marked dependence on the amount of fluorodinitrobenzene; initially increasing with increasing fluorodinitro-benzene content, it then decreased with higher fluorodinitrobenzene concentrations suggesting further reaction between dinitroaniline and fluorodinitrobenzene. In both distilled and sea water, the maximum yield of dinitroaniline from solutions containing ammonia at the micromolar concentration level was found to be 55-58%. The absorbance of the diazo-dye in sea water of salinity 30.4% was only 42% of that observed in distilled water. Although sufficiently sensitive for application to sea water analysis, the precision of the conversion of dinitroaniline to the diazo-dye in sea water was poor compared to that achieved in distilled water. / Science, Faculty of / Chemistry, Department of / Graduate

Typescript (photocopy). / Digitized by Kansas Correctional Industries

The lack of availability of a single, complete paper on the analysis of a digital data acquisition system for in situ oceanographic measurements brought about the present work. In order to compile an accurate technical paper on such a complex system, it was necessary to design, construct, and calibrate a system for the in situ measurement of various physical and chemical properties of sea water. A unique digital encoding circuit was developed which utilizes the basic principles of null balance, resistance ratio bridge and potentiometer measurements. The circuit is a uniquely loaded binary ladder resistance network. Variation of the loading allows resistance ratio and potentiometric measurements to be made over different ranges with a constant high degree of resolution. The developed system has the capability of measuring any parameter which can be converted into a varying voltage, current, or resistance. The range over which the measurement can be made is adjustable; and the resolution equals ± 0.006% of the full range value. The resolution is constant over the full range, as a result of the analog-to- digital converter linearity characteristics. / Graduation date: 1968

A cruise of the R/V Yaquina off Oregon during June and July of 1968 provided data for a study of the relationships of hydrographic and chemical parameters to estimates of biological activity. The emphasis was on carbon and nitrogen reservoirs. Phytoplankton pigments, nitrogen and C/N ratio were used along with AOU and the nitrate content of the water to estimate the distribution of phytoplankton production. Sigma-t, AOU, and nitrate were used to define the hydrographic and chemical conditions. Upwelling was the major source of nitrate for the surface waters, and, consequently, phytoplankton production was most intense where upwelling was active. The Columbia River plume appeared to support a sizeable amount of phytoplankton production just south of the river mouth. Particulate nitrogen increased and particulate C/N ratio decreased as the water became more biologically productive. Chlorophyll, particulate nitrogen, and C/N ratio showed the effects of upwelling and the Columbia River plume on biological production. A subsurface negative AOU core was clearly defined in areal extent and intensity. Its occurrence was explained by inshore phytoplankton production, oxygen exchange with the atmosphere, and possible in situ phytoplankton production. / Graduation date: 1970

Phosphate, silicate and nitrate concentrations in the sea off the coast of Oregon were determined to study their seasonal distribution patterns. The water samples were collected monthly along the east-west hydrographic line off Newport, Oregon, from the shore to 165 miles (310 km) offshore. The samples were analyzed by both a Technicon Autoanalyzer® and by manual methods. Phosphate in January was greater than 0.5μM at the surface, increasing to a 3.3μM maximum at 1000m. A phosphate maximum occurred at 1000m throughout the year. With the onset of photosynthetic activity, there was a general decrease in surface concentrations. Concentrations decrease to less than 0.1μM in October with surface concentrations increasing in November and December, reaching a maximum in January. Silicate concentration was approximately 170μM at 2600m during the entire year. In January, surface silicate increased from less than 5μM offshore to 13μM nearshore; a weak silicate minimum was observed at a depth of 60m offshore and at 5m near the coast. In March nearshore surface concentrations were greater than 15μM due to increased coastal river runoff; the silicate concentrations of Oregon coastal rivers were 150-250μM. In July, a pronounced minimum occurred at 40-50m depth, where the concentration was less than 2μM. Summer surface concentrations were less than 2M offshore, increasing to 40μM nearshore as a result of coastal upwelling. Surface concentrations in October were generally less than 5FIM along the Newport hydrographic line with increased near shore concentrations due to river runoff. The nitrate maximum of 40-45μM existed at 1000- 1200m. In January surface concentrations ranged from 3μM offshore to 6μM nearshore. March values were lower, ranging from 11μM offshore to 5μM nearshore at NH-3 (6 km). In July patches of nitrate-free water were observed at 40-50m depth offshore, disappearing at 25 miles (46 km) off the coast, at station NH-25, as a result of the influence of upwelled and nitrate containing water. Late in October, nitrate concentrations were higher, 5-6μM, near the coast, and dropping to less than 0.1μM offshore. Patches of nitrate-free water were found from May to November. The existence of nitrate-free water near the surface indicated that the feature was formed by the photosynthetic activities of phytoplankton. The formation of the silicate minimum and oxygen maximum below or near the bottom of the Columbia River Plume during summer months indicated intense photosynthetic activity. Neither preformed phosphate nor preformed nitrate changed with depth below the layers of active photosynthetic processes. Preformed phosphate was generally 1.0-1.2μM below 200m with variation occurring in surface waters. For surface values, 1.2μM, the highest of the year, was observed in July in upwelled water; 0.4μM, the lowest, also occurred in July within the influence of the Columbia River Plume. The vertical distribution of preformed nitrate seemed to be random and may have reflected analytical techniques. The range was between 5 and 10μM with a maximum at 12μM. The 5μM values were found at approximately 200m with a maximum observed at 1000m deep. The highest surface values of preformed nitrate, 2.0-5.0μM, were observed in January and the lowest, 1.0-1.5μM, in July. March and October values were between the above extremes (1.1-2.0μM). / Graduation date: 1970

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Meteorology, 1979. / Microfiche copy available in Archives and Science. / Bibliography : leaves 37-39. / by Gerald J. Needell. / M.S.

A zona costeira de Pernambuco compreende uma faixa de 187 km de extensão e abrange 21 municípios. Apresenta o maior aglomerado populacional do Estado, onde está concentrada aproximadamente 44 % da população. Pesca intensiva e poluição ambiental, aliadas a uma mudança de clima global conduzirão a um colapso de todos os pescados em 2048. Esses impactos ambientais alteram a concentração ou distribuição de nitrogênio, fósforo e silício (biolimitantes da produção primária) e interferem em seus ciclos biogeoquímicos. A aplicação de modelos numéricos a zonas costeiras pode indicar uma previsão melhor dos fluxos de nutrientes associados com suas transferências e conseqüência geoquímica. O objetivo deste trabalho foi estimar concentrações dos principais nutrientes dissolvidos: nitrogênio, fósforo e silício através de modelagem matemática. Na metodologia foram utilizados dados do Programa REVIZEE, coletados pelo Departamento de Oceanografia (UFPE) no verão pernambucano de 1997. As estimativas das concentrações dos nutrientes nitrogênio, fósforo e silício da costa marinha no estado de Pernambuco geram informações que dão suporte à atividades futuras de pesca artesanal. O apoio científico serve de suporte para o aumento da demanda pesqueira que é de produção econômica para a região, considerando ser a mesma uma zona costeira / The coastal zone of Pernambuco comprises a range of 187 km and covers 21 cities. It presents the greatest agglomeration of the state, which concentrates approximately 44% of the population. Overfishing and pollution environment, coupled with global climate change will lead to a collapse of all fish in 2048. These environmental impacts change the concentration or the distribution of nitrogen, phosphorus and silicon (limiting production primary). It also interferes in their biogeochemical cycles. The application of numerical models in coastal areas may indicate a better estimate of nutrient fluxes associated with their transfer and geochemistry consequence. The objective of this study was to estimate concentrations of the major nutrients:nitrogen, phosphorus and silicon through mathematical modeling. In the methodology it was used the data Program REVIZEE, collected by the Department of Oceanography (UFPE) in the summer of 1997. The estimates of concentrations of nitrogen, phosphorus and silicon from the sea coast in the state of Pernambuco generated information to support the future activities of fishing. The scientific support for the increased demand of fishing is related to the economic production of the coastal area region

Made available in DSpace on 2017-06-01T18:20:29Z (GMT). No. of bitstreams: 1 dissertacao_luiz_queiroz.pdf: 1547317 bytes, checksum: 857e36c6f9b83aa7f85250f7a37ba4ec (MD5) Previous issue date: 2010-06-17 / The coastal zone of Pernambuco comprises a range of 187 km and covers 21 cities. It presents the greatest agglomeration of the state, which concentrates approximately 44% of the population. Overfishing and pollution environment, coupled with global climate change will lead to a collapse of all fish in 2048. These environmental impacts change the concentration or the distribution of nitrogen, phosphorus and silicon (limiting production primary). It also interferes in their biogeochemical cycles. The application of numerical models in coastal areas may indicate a better estimate of nutrient fluxes associated with their transfer and geochemistry consequence. The objective of this study was to estimate concentrations of the major nutrients:nitrogen, phosphorus and silicon through mathematical modeling. In the methodology it was used the data Program REVIZEE, collected by the Department of Oceanography (UFPE) in the summer of 1997. The estimates of concentrations of nitrogen, phosphorus and silicon from the sea coast in the state of Pernambuco generated information to support the future activities of fishing. The scientific support for the increased demand of fishing is related to the economic production of the coastal area region / A zona costeira de Pernambuco compreende uma faixa de 187 km de extensão e abrange 21 municípios. Apresenta o maior aglomerado populacional do Estado, onde está concentrada aproximadamente 44 % da população. Pesca intensiva e poluição ambiental, aliadas a uma mudança de clima global conduzirão a um colapso de todos os pescados em 2048. Esses impactos ambientais alteram a concentração ou distribuição de nitrogênio, fósforo e silício (biolimitantes da produção primária) e interferem em seus ciclos biogeoquímicos. A aplicação de modelos numéricos a zonas costeiras pode indicar uma previsão melhor dos fluxos de nutrientes associados com suas transferências e conseqüência geoquímica. O objetivo deste trabalho foi estimar concentrações dos principais nutrientes dissolvidos: nitrogênio, fósforo e silício através de modelagem matemática. Na metodologia foram utilizados dados do Programa REVIZEE, coletados pelo Departamento de Oceanografia (UFPE) no verão pernambucano de 1997. As estimativas das concentrações dos nutrientes nitrogênio, fósforo e silício da costa marinha no estado de Pernambuco geram informações que dão suporte à atividades futuras de pesca artesanal. O apoio científico serve de suporte para o aumento da demanda pesqueira que é de produção econômica para a região, considerando ser a mesma uma zona costeira