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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

Solvent extraction of B- monothiodiketones and their metal chelates.

Leban, Marzio Amletto January 1970 (has links)
No description available.
12

Photochemical degradation of sediment organic matter : effect on Zn-65 release

Lenaers, William Michael 30 August 1971 (has links)
Columbia River sediment was irradiated with ultraviolet light to determine if organic material could be removed without altering the sorptive properties of the hydrous oxides of iron and manganese. A laboratory preparation of Zn-65 spiked hydrous ferric oxide was subjected to ultraviolet irradiation in order to assess the photochemical effect upon Zn-65 release. The photochemically induced release of Mn-54 present on the Columbia River sediment was used to assess the effect on the hydrous oxides of manganese. The ultraviolet irradiation proved effective in removing up to 68% of the sedimentary organic material in 17 hours without causing release of Zn-65 or Sc-46. While the ultraviolet irradiation had no effect upon Zn-65 release from laboratory preparations of hydrous ferric oxides and Zn-65 spiked montmorillonite, a significant release of Mn-54 resulted from the photolysis treatment. The removal of Mn-54 was not accompanied by the release of sorbed Zn-65 or Sc-46 (nuclides expected to be sorbed by hydrous oxides), nor did there appear to be any permanent change in the nature of the Mn-54 on the sediment. Although it is possible that the hydrous oxides of manganese are affected by the ultraviolet treatment, it is likely that another species, such as the carbonate, is the species involved. Photo-oxidation appears to provide a method of obtaining sediments with substantially reduced organic content without affecting the sorptive properties of hydrous oxides or clay minerals. This result should allow the use of uptake studies to determine the importance of organic material in trace metal sorption by sediments. / Graduation date: 1972
13

Techniques of solvent extraction of organic material from natural waters

Cronin, John Thomas, 1935- 12 May 1967 (has links)
Manual and automatic solvent extraction techniques were used to concentrate organic material from natural waters. Field and laboratory extractions were compared to determine the most probable method and best solvents for efficient concentration of organic material from estuarine and sea waters. The large scale extraction processes utilizing extractors made from 55 gallon drums were operated both by manually moving perforated metal discs through the water and solvent for mixing and by bubbling air through the aqueous-solvent mixture. Resulting samples proved large enough for the detection of short-chain fatty acids (carbon length 1 through 10). Identification of organic constituents was by gas chromatography-mass spectroscopy. Other portions of these samples were separated by column chromatography with subsequent analysis by infrared, visible, ultraviolet, and mass spectroscopy. The proximity of the Hanford Atomic Product Operations to the collecting area caused some of the organics to be labeled with trace amounts of radionuclides. A counter-current pulse column extractor was used at sea aboard the Research Vessel YAQUINA. The organic solvent, hexone, used in this extraction was distilled before and after the extraction with various fractions of solvent being kept for control. The extraction was carried out under varying chemical and physical conditions. The hexone was back-extracted into hydrochloric acid, sodium bicarbonate, or sodium hydroxide before analysis by flame-ionization gas chromatography and mass spectroscopy. Other portions of the product hexone were analyzed for total solid matter recovered and carbon, hydrogen, and nitrogen content. Small intermediate scale extractions were carried out in the laboratory using several solvents. Resulting organic material was analyzed by tandem gas chromatography-mass spectroscopy. Where possible, organic derivatives were prepared to aid in the identification of the recovered organic material. The advantages and disadvantages of large scale extractions and small laboratory procedures were discussed. / Graduation date: 1967
14

A kinetic study of enargite dissolution in ammoniacal solutions

Gajam, Soliman Younes January 1981 (has links)
No description available.
15

Application of potential-PH diagrams to the extraction of transition metals from ferromanganese nodules

Dyke, James Tiner January 1979 (has links)
No description available.
16

The use of automated continuous analysis in the determination of solvent extraction equilibrium constants

Frazier, Willow Marie, 1946- January 1972 (has links)
No description available.
17

Substituted 8-quinolinols as metal extractants

Tsao, Fu-Pao, 1942- January 1975 (has links)
No description available.
18

A kinetic study of the adsorption of cobalt species from ammonia-ammonium carbonate solution by a chelating cation exchange resin

DeCorse, Gretchen Layton Graef January 1978 (has links)
No description available.
19

The extraction of oil and protein from cottonseed by a water-grinding and centrifuging process

Cheng, Fa-wu 08 1900 (has links)
No description available.
20

Efficiency of ethanol extraction from aqueous mixtures

Tawfik, Wahid Yosry 12 1900 (has links)
No description available.

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