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Filtering by: Creator Welter%2C Stephen C. Remove constraint Creator: Welter%2C Stephen C. Degree Field Chemistry Remove constraint Degree Field: Chemistry

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  • Diffusion of n-alkanes in polydimethylsilicones

    Creator:
    Millen, William George
    Abstract:
    Diffusion of short chain n-alkanes was found to be faster in the polydimethylsilicone elastomer SE-30 than in the polydimethylsilicone oil SF-96-2000. The opposite was true for the longer chain n-alkanes suggesting that choice of stationary phase for gas chromatography would depend on the chain length of sample components. The dependence...
    Resource Type:
    Masters Thesis
    Full Text:
    PrivacyAbstract approved: Stephen J. Hawkes Diffusion of short chain n-alkanes was found to be faster in the

  • Solute-solvent interactions in gas chromatography

    Creator:
    Chan, Edwin Ming Yeung
    Resource Type:
    Masters Thesis
    Full Text:
    Privacy Dean of Graduate School Date thesis is presented /(4:e-C-77L- -6 Typed by Clover Redfern for

  • Synthesis and oligomerization of y,4-Diamino-2-oxo-1(2H)-pyrimidinepentanoic acid

    Creator:
    Nelson, Jeffrey Stephen
    Abstract:
    Described herein is the synthesis of an uncharged stereoregular oligonucleotide analog consisting of cytosine bases linked at specific intervals to a polyamide backbone derived from (L)-glutamic acid. Preparation of this analog entailed borane reduction of (L)- pyroglutamic acid to give optically pure lactam alcohol 9. Tosylation and alkylation with cytosine...
    Resource Type:
    Masters Thesis
    Full Text:
    to C-terminal hydrazide monomer 33, which served as a temporarily masked acid terminus, and which

  • The diffusion coefficient of propane in helium

    Creator:
    Tang, Fa-tai
    Abstract:
    A specially designed gas chromatograph with both TCD and FID has been tested for the measurement of the diffusion coefficients of methane and propane in helium. Knox's arrested elution technique(⁴) was used and yielded a value of 0.6431 cm²/sec averaged with the value obtained by Yang and Hawkes(⁷). Values of...
    Resource Type:
    Masters Thesis
    Full Text:
    : Redacted for Privacy Dr. Stephen J. Hawkes A specially designed gas chromatograph with both TCD and FID

  • Part I: Synthetic Studies toward C10-functionalized Lycopodium Alkaloids. Part II: Exploration of the Pummerer Cyclization and Its Application to the Total Syntheses of the Abietane Diterpenoids

    Creator:
    Li, Xin
    Abstract:
    This dissertation is separated into two parts according to the two major distinct research projects. In Part I, the full account of synthetic studies toward C10-functionalized lycopodium alkaloids is described. In Part II, the detailed discussion on the exploration of the Pummerer cyclization methodology and its application to the total...
    Resource Type:
    Dissertation
    Full Text:
    of multiple abietane diterpenoids (ent-triptobenzene T, vitexifolin C, hinokiol, 4-epi

  • Classification of stationary liquids in gas chromatography by infrared spectrophotometry

    Creator:
    De Briceno, Maria Betania Orduz
    Abstract:
    A classification of stationary liquids by infrared spectroscopy to evaluate the polarity was made using the solvent effect technique. The infrared C-Cl absorption frequency shift was measured for solutions of 1-chlorohexane dissolved in each stationary phase. These frequency shifts were correlated to the relative retention times of 1-octene/n-octane, trans-2-octene/n-octane and...
    Resource Type:
    Masters Thesis
    Full Text:
    to evaluate the polarity was made using the solvent effect technique. The infrared C-Cl absorption

  • Chiral synthesis of monic acid C

    Creator:
    Theramongkol, Parinya
    Abstract:
    Bromoalkoxylation of dihydropyran with bromine and 1-borneol, followed by dehydrobromination and epoxidation, afforded trans-2-1- bornyloxy-3,4-epoxytetrahydropyran as a major product. This was treated with sodium phenylselenide to give a 1:1 mixture of (2R,3R,4R)- 2-1-bornyloxy-3-hydroxy-4-phenylselenotetrahydropyran and its (2S,3S, 4S) diastereomer. Elimination of the selenoxide, derived from oxidation of the former with hydrogen...
    Resource Type:
    Dissertation
    Full Text:
    Chiral synthesis of monic acid C AN ABSTRACT OF THE

  • Diffusion in silicone polymers

    Creator:
    Kong, Ming J.
    Abstract:
    The study of diffusion coefficients of n-alkanes and other organic compounds in silicones is undertaken by gas-liquid chromatography. About 0. 3% of stationary phase is coated on glass bead support so that the only significant source of peak spreading is due to slow liquid phase mass transfer. Diffusion coefficients are...
    Resource Type:
    Masters Thesis
    Full Text:
    ) (date) Title: DIFFUSION IN SILICONE POLYMERS Abstract approved: Redacted for privacy Stephen J

  • The obstructive factor in gas chromatography

    Creator:
    Thumneum, Pornpan
    Abstract:
    The study of the obstructive factor by Hawkes (11) showed a relation between the obstructive factor and velocity using a continuous method. Later, Bowers and Hawkes (12) developed a similar method with some improvements in the apparatus and found out that the obstructive factor was not flow dependent. This study...
    Resource Type:
    Masters Thesis
    Full Text:
    : Redacted for Privacy J (Dr. Stephen J. Hawkes) The study of the obstructive factor by Hawkes (11) showed

  • Classification of stationary phases in gas chromatography

    Creator:
    Chong, Elee Elizabeth
    Abstract:
    Ultraviolet spectroscopy and dispersive solubility parameters correlated to the ratios of retention times have proven valuable in classification of gas chromatography stationary phases by the donor-acceptor properties. Iodine was directly dissolved into stationary phases and the absorption frequency shift of complexes was correlated with the carbon tetrachloride/chloroform retention ratio on...
    Resource Type:
    Masters Thesis
    Full Text:
    Redacted for Privacy Abstract approved: Stephen J. Hawkes Ultraviolet spectroscopy and dispersive