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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.
31

Enzymatic synthesis of complex carbohydrates : approaches to the enzymatic synthesis and chemical modification of oligosaccharides

Kriek, Marco January 2000 (has links)
No description available.
32

A synthesis of tetrahydropyrethrolone and the chemistry of ethyl diazopyruvate /

Greenberg, Richard Scot, January 1983 (has links)
Thesis (Ph. D.)--University of California, San Diego, 1983. / Vita. Includes bibliographical references (leaves 101-107).
33

A synthesis of tetrahydropyrethrolone and the chemistry of ethyl diazopyruvate

Greenberg, Richard Scot, January 1983 (has links)
Thesis (Ph. D.)--University of California, San Diego, 1983. / Vita. Includes bibliographical references (leaves 101-107).
34

1.Treatment of 2-Ethyl Hexanol in an air stream by a pilot-scale Biotrickling Filters. 2.Treatment of gaseous VOC emissions from a resin manufacturing plant by a full-scale Biotrickling Filters.

Chen, Liang-Chi 05 July 2000 (has links)
The subject of this thesis is divided into two parts: (1) Treatment of 2-ethyl hexanol (2-EH) in an air stream by a pilot-scale biotrickling filter, and (2) Treatment of gaseous VOC emissions from a resin manufacturing plant by a full-scale biotrickling filter. Treatment of 2-Ethyl Hexanol in An Air Stream by A Pilot-Scale Biotrickling Filter 2-Ethyl Hexanol (2-EH) may release from the thermal breakdown of di-isooctyl phthalate (DOP), a commonly-used plasticizer, in the curing stage when manufacturing PVC synthetic leather and gloves. This paper reports the results of studies using a biotrickling filter (BTF) with blast-furnace slag packings (sizes = 2-4 cm and specific surface area = 120 m2/m3) for treatment of 2-EH in an air stream. The experimental setup consisted of a set of two-stage-in-series biotrickling filters. Each stage of the biotrickling filter was constructed from a 19.5-cm x 200-cm (ID x H) acrylic column packed with slags of 125 cm in height. The operation started with the conditions of recirculation liquid pH = 8.0 and rate (VL) = 8.83 m3/m2.h, a steady nutrient (ammonia nitrogen and phosphate phosphorus) addition, and without a special microbial seeding. Results indicate that, yellowish-brown biofilms on the surface of packing slags could be observed in one week and well developed in two weeks after the start-up operation. The effects of volumetric 2-EH loading (L) and superficial gas velocity (U0) on the 2-EH elimination capacity (K) and the removal efficiency (K/L) were tested. Long-term experimental results show that, in the conditions of influent 2-EH concentration C0 = 250 mg/m3, U0 = 162 m3/m2.h, and gas empty-bed-retention time EBRT = 55 s, K/L could be correlated by the equation K/L = 71.9/(72.4+L) with a correlation coefficient (R) of 0.9988. The 2-EH elimination rate was mass-transfer controlled when L<16 g/m3.h and reaction-controlled when L>16 g/m3.h. Results also indicate that nutrient addition and liquid recirculation were important for the normal operation of the BTF in eliminating the influent 2-EH. Treatment of Gaseous VOC Emissions from A Resin-Manufacturing Plant by A Full-Scale Biotrickling Filter A resin and chemical company located in Tainan County, Taiwan engages in the manufacture of PU (poly urethane), PVAC (poly vinyl acetate), PS (poly styrene), and PMMA (poly methyl methacrylate) resins from various chemical stocks. Gaseous volatile organic compounds (VOCs) emitted from the reactors include toluene, methyl ethyl ketone (MEK), acetone, vinyl chloride, styrene, butyl acetate, 2-ethyl hydroxyl acetate, and methyl methacrylate. These VOCs should be properly eliminated before discharging the reactor vents to the atmosphere. This paper reports the performance results of using a biotrickling filter (BTF) with wood packings (sizes = 2-12 cm and specific surface area = 97 m2/m3) for treating the reactor vents with a total flowrate of 80 m3/min at 20-30¢J. The BTF was constructed from a 7.0 m x 6.0 m (ID x H) SUS 304 column with wood packings of 4.0 m in height. The operation started with the conditions of recirculation liquid pH = 7.0-8.0 and rate (VL) = 1.56 m3/m2.h, a steady nutrient (urea and phosphate phosphorus) addition, and without a special microbial seeding. Results indicate that, yellowish-brown biofilms on the surface of packings could be observed in one week and well developed in two weeks after the start-up operation. Long-term operation results show that, in the conditions of influent VOC concentration C0 = 200-10000 ppm (expressed in terms of methane), U0 = 125 m3/m2.h, and gas empty-bed-retention time EBRT = 115 s, K/L could be correlated by the equation K/L = 345/(467+L) with a correlation coefficient (R) of 0.9913. The VOC elimination rate was mass-transfer limited when L<45 g/m3.h, with the mass of VOCs expressed as that of methane. Results also indicate that the liquid recirculation might be interrupted for a hour without influencing the performance. Toluene was the most difficult one to eliminate among the VOCs in the gas stream.
35

Warm-season turfgrass species adaptation, drought resistance and response to trinexapac-ethyl application under a Mediterranean environment /

Severmutlu, Songul. January 2009 (has links)
Thesis (Ph.D.)--University of Nebraska-Lincoln, 2009. / Title from title screen (site viewed October 13, 2009). PDF text: xiii, 173 p. : col. ill. ; 6 Mb. UMI publication number: AAT 3355630. Includes bibliographical references. Also available in microfilm and microfiche formats.
36

The isolation and synthesis of compounds from the South African Hyacinthaceae

Waller, Catherine January 2012 (has links)
No description available.
37

A spectral and photochemical study of ethyl iodide

Ginsburg, Eli, January 1900 (has links)
Thesis (Ph. D.)--New York University, 1934. / Vita. Bibliography: p. 50-51.
38

I. The Claisen ester condensation with ethyl thiolacetate II. The action of sulphur on n-heptane and n-butane ...

Baker, Ralph Baylies, January 1929 (has links)
Thesis (Ph. D.)--Johns Hopkins University, 1928. / Biography.
39

Phase equilibrium studies in the binary system, methyl ethyl ketone-water

Siegelman, Irwin. January 1959 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1959. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 97-99).
40

Potential adulterating capabilities of commercial zinc products on preliminary immunoassay screenings for the detection of ethyl glucuronide (ETG)

Ledoux, Daniel Arthur 09 March 2017 (has links)
Alcohol has been consumed over many centuries, but its connection to criminal activity and accidental fatalities has become a prominent concern in more recent centuries(1). Scientists have developed numerous testing methods to detect alcohol consumption. Numerous studies have recently suggested that zinc has the potential to interfere with the results of these testing methods for drugs of abuse such as enzyme-linked immunosorbent assay (ELISA) and enzyme multiplied immunoassay technique (EMIT) (2, 3). False negatives have been reported from urine testing of drugs such as cocaine, methamphetamine, opiates, and cannabinoids. Nevertheless, minimal research has been conducted concerning zinc’s effect on the adulteration of alcohol metabolite testing. Ethyl glucuronide (EtG) is a promising ethanol metabolite for the confirmation of alcohol consumption. Previous research conducted by Shanna Cawley, a graduate from the Boston University School of Medicine’s Biomedical Forensic Sciences program, has found that zinc sulfate is ineffective at producing conclusive false negative results using two immunochromatographic assay brands in synthetic urine solutions(4). This study uses five different immunoassay brands, five different zinc sources, and two distinct matrices to determine the effectiveness of commercial zinc products as adulterants in drugs of abuse testing. Zinc and EtG solutions were produced at concentrations of 15mg/mL and 750ng/mL, respectively. A positive control, negative control, and two to three experimental trials were conducted for each immunoassay brand and each zinc source resulting in a total of 165 tests. Approximately sixty experimental trials in synthetic urine were invalidated or positive for the presence of EtG (81%) in zinc adulterated EtG solutions. Immunoassay kits produced false positive results when testing human urine from subjects who abstained from alcohol consumption Therefore, preliminary immunoassay screenings for the presence of EtG are not a reliable method for confirming alcohol consumption. Previously researched methods, ELISA and EMIT, and confirmatory methods such as gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) are currently the most robust and reliable techniques for EtG detection in urine.

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