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Sequential Solvent Extraction Of Argonne Premium Coal Samples, Wanping Mai

Masters Theses

Five coals from the Argonne Premium Coal Sample program, ranging in rank from sub-bituminous to low volatile bituminous, before and following artificial weathering, were exhaustively extracted with solvents in the sequence: toluene, tetrahydrofuran, N,N-dimethyl-formamide, and pyridine.

Sequential solvent extraction reveals more insight into the coal structure than single solvent extraction because fractions are isolated on the basis of both molecular size and polarity. The recovered extracts and residue from the extraction are monitored by FT-IR spectroscopy, elemental analysis, phenol content, solvent swelling, and Gel Permeation Chromatography analysis (GPC). The extraction results show that for fresh coals, the total extract yields …

Electrochemical Studies Of Iron, Cobalt, And Nickel Complexes Of Bidentate Phosphine Thioether Ligands, Robert L. Turner

Masters Theses

The electrochemical behavior of a series of cationic complexes, [Ni(S-P)₂]²⁺, [Fe(S-P)₂(CH₃CN)_2.5]²⁺ and [Co(S-P)₂CH₃CN]²⁺, where S-P= (C₆H₅)₂PCH₂CH₂SCH₂CH₃, has been examined in acetonitrile on mercury and platinum electrodes. The nickel compound was reduced in two reversible diffusion controlled, one-electron transfers. Addition of PPh₃ (Ph=C₆H₅) and S-P caused a positive potential shift in the nickel(I) to nickel(0) wave. An EC mechanism was postulated to account for this …

Isolation And Partial Characterization Of Serogroup Specific Antigens From Bradyrhizobium Japonicum 61a123, Miguel Eduardo Carrion

Masters Theses

Serogroup specific antigens of Bradyrhizobium japonicum 61A123 were isolated using an immunochemical assay. Bacterial antigens were isolated by phenol-water extraction. These antigens were detected by inhibition of an enzyme linked immunosorbant assay (ELISA). Low pressure chromatography and digestion with proteinase K served to purify the antigens. Chemical composition was determined by gas chromatography (GC), mass spectrometry (MS), and colorimetric assays. The antigens were also characterized by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis, and immunological properties determined by ELISA. These antigens were shown to be lipopolysaccharides (LPSs) containing fucose, a 2-amino-2,6-dideoxy hexose (unidentified), glucose and mannose as the major sugars, along …

The Structure Of O-Antigen From Lipopolysaccharide Of Rhizobium Leguminosarum 128c53 And Its Nod-Fix-Mutant, Tong-Bin Chen

Masters Theses

The LPS of R. leguminosarum 128C53 sm^r rif^r (a streptomycin and rifampicin resistant strain of wild type 128C53) and its mutant ANU54 (nod^-, fix^-) were isolated from the bacterial pellet by hot phenol/water extraction followed by gel filtration chromatography. The O-antigen was isolated by mild-acid hydrolysis of the LPS and purified by gel filtration chromatography using a Sephadex G-50 or G-25. The following results were the same for both the parent and mutant. The composition and linkage of the O-antigen were determined by gas chromatography (GC), GC-mass spectrometry, ¹H and ¹³C nuclear …