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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.
41

Studies on microporous materials

Murdoch, Morag Jessie January 2009 (has links)
Microporous titanosilicates and vanadosilicates were synthesised characterized and photoreactivity studies were carried out.  The titanosilicates synthesised were the titanosilicate pharmacosiderite and AM – 18 and the vanadosilicates were AM – 6, ETVS – 10, AM – 14 and VSH -13Na.  A variety of different techniques were used in the characterisation studies including different X-Ray methods, vibrational spectroscopy, electron microscopy, and solid state NMR spectroscopy.  The studies showed that the synthesised products were homogeneous and an insight into the structures of AM – 18 and AM – 14 was obtained. Raman spectroscopy was used to assess the levels of defects in large crystals of ETS – 10 and ETS – 4 by measuring the variation in the frequency of the Ti – O band and the width of this band.  A similar study was done on large crystals of AM – 6.  Raman spectroscopy showed that Ti – O stretching bands containing Ti(V) and Ti(IV) were present in AM – 18 structure.  The frequency of the vanadyl bands in AM – 14 indicated that it could contain vanadyl chains. Photoreactivity studies using EPR spectroscopy, on the potassium titanosilicate pharmacosiderite showed an O<sup>-</sup> species, after UV irradiation in the presence of oxygen.  When the partial pressure was reduced a superoxide and the anomalous ozonide species were observed.  On changing the cation to a proton form, a superoxide anion radical was observed but no other oxygen radicals were observed. Attempted oxidation and reduction studies on VSH – 13Na were unsuccessful and HRTEM and nitrogen adsorption studies showed that the one-dimensional channels were blocked. Oxidation and reduction studies on AM – 14 indicated that the vanadium sites were easily accessible to gas phase.
42

Carbon-13 NMR spectroscopy ; Thiols, thiolacetates, and lipoic acid derivatives ; Substituted biphenyls / Carbon-13 NMR spectroscopy

Byrne, Edmund Francis January 2011 (has links)
Typescript. / Digitized by Kansas Correctional Industries
43

Cobalt-59 NMR studies of cobalt complexes.

January 1994 (has links)
by Ho Kai Wing Kevin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1994. / Includes bibliographical references (leaves 94-98). / ABSTRACT --- p.iv / ACKNOWLEDGEMENTS --- p.vi / Chapter CHAPTER ONE: --- INTRODUCTION --- p.1 / Chapter 1.1 --- Basic Co-NMR Theory --- p.1 / Chapter 1.2 --- Method Employed --- p.5 / Chapter 1.2.1 --- Solvent Dependent Studies on Cobalt(III) complexes using 59Co NMR Spectroscopy --- p.5 / Chapter 1.2.2 --- Relationship between δiso and NQCC of Cobalt(III) Complexes in Solid --- p.7 / Chapter 1.3 --- Donor Acceptor Interactions --- p.8 / Chapter 1.4 --- Objectives of this Thesis --- p.10 / Chapter CHAPTER TWO: --- EXPERIMENTAL --- p.11 / Chapter 2.1 --- Synthesis --- p.11 / Chapter 2.2 --- NMR Measurements --- p.13 / Chapter 2.2.1 --- 59Co NMR Measurements --- p.13 / Chapter 2.2.2 --- 13c NMR Measurements (T1 Measurements) --- p.14 / Chapter 2.3 --- Viscosity Measurements --- p.15 / Chapter 2.4 --- UV-Vis Spectral Measurements --- p.15 / Chapter CHAPTER THREE --- 59Co NMR STUDY OF MAGNETIC COBALT(III) COMPLEXES --- p.16 / Chapter 3.1 --- Solvent-Dependent Studies of Cobalt(III) Complexes --- p.16 / Chapter 3.1.1 --- "Study of [Co(en)3]Cl3 and cis, trans-[Co(en)2(N3)2]NO3" --- p.17 / Chapter 3.1.2 --- Study of trans- [Co(en)2(NH3)2]Cl3 and trans- [Co(en)2(N02)2]NO3 --- p.29 / Chapter 3.1.3 --- "Study of trans- Na[Co(acac)2 (N02)2],trans- [Co(acac)2(N02)(NH3)] and trans-[Co(acac)2(NH3)2]I" --- p.36 / Chapter 3.1.4 --- Summary --- p.48 / Chapter 3.2 --- "Simultaneous Determination of CSA, ic, and NQCC of Cobalt(III) complexes in Different Solvents" --- p.49 / Chapter 3.2.1 --- Method --- p.49 / Chapter 3.2.2 --- "Study of trans- Na[Co(acac)2(N02)2],trans- [Co(acac)2(N02)(NH3)] and trans-[Co(acac)2(NH3)2]I and trans-[Co(acac)2(MeNH2)2]I" --- p.52 / Chapter 3.2.3 --- Study of trans- [Co(en)2(N〇2)2]N03 and trans- [Co(en)2(NCS)2]NCS --- p.58 / Chapter 3.2.4 --- Study of trans- [Co(en)2(NH3)2]Cl3 and trans- [Co(en)2(N3)2]NO3 --- p.63 / Chapter 3.2.5 --- Summary --- p.68 / Chapter 3.3 --- Resolution of the d-d Electronic Transition Energies in Cobalt Complexes and its Application to the Donor-Acceptor Interactionsin Cobalt Complexes - Application of Equation 3.3.1 --- p.70 / Chapter 3.3.1 --- Method --- p.70 / Chapter 3.3.2 --- "Study of trans- [Co(en)2(N02)2]N03,trans- [Co(en)2(NCS)2]NCS, trans- [Co(en)2(N3)2]N03 and trans- [Co(en)2(NH3)2]Cl3" --- p.72 / Chapter 3.3.3 --- "Study of trans- Na[Co(acac)2(NO2)2],trans- [Co(acac)2(N02)(NH3)] and trans-[Co(acac)2(NH3)2]I" --- p.86 / Chapter CHAPTER FOUR --- CONCLUSION AND FUTURE WORKS --- p.92 / REFERENCES --- p.94
44

Structural studies on hydrated lanthanide oxalates by ESR spectroscopy.

January 1980 (has links)
by Wong Lai-ping, Gloria. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1980. / Bibliography: leaves 136-140.
45

Cation solvation kinetics in mixed solvent systems by PMR.

January 1978 (has links)
Fung Wai-man. / Thesis (M.Phil.)--Chinese University of Hong Kong. / Includes bibliographies.
46

Nematic phase NMR investigation of naphthyridines

Lee, Yuen-ping. January 1974 (has links)
No description available.
47

Applications of irreducible spherical tensor operators to NMR and NQR spectroscopy

Krishnan, Mangala Sunder January 1987 (has links)
No description available.
48

Validation of quantitative nuclear magnetic resonance (QNMR) spectroscopy as a primary ratio analytical method for assessing the purity of organic compounds: a metrological approach.

Al-Deen, Tareq, Chemistry, Faculty of Science, UNSW January 2002 (has links)
No description available.
49

Application of high-resolution NMR spectroscopy in metabolic studies of the eye

Risa, Øystein January 2004 (has links)
<p>High-resolution NMR spectroscopy has, during the last two decades, had an increasing impact in biological and biochemical research. Rapid advances have led to improvements in sensitivity and dispersion of the spectra and have allowed more detailed assignment and monitoring of endogenous biochemical molecules. One of the latest implementations has been a technique known as high-resolution magic angle spinning (HR-MAS) NMR spectroscopy which has made it possible to obtain high-resolution proton spectra of intact tissue and cells. Simultaneous detection of a large number of metabolites by NMR spectroscopy has been successfully applied to investigate disordered metabolism for a numerous of diseases and toxic processes.</p><p>The objectives in the present work have been to evaluate different <sup>1</sup>H NMR spectroscopy protocols as analytical tools in eye research, and further use these protocols to extract and interpret information on metabolic changes in the eye induced by external pathological stimuli. Special focus has been paid to changes in the lens and the development of cataracts.</p><p>The <sup>1</sup>H NMR spectra of intact lenses and eye tissue extracts in present thesis showed an extensive picture of NMR detectable metabolites. In addition to the detailed analysis of extracts from cornea, lens and aqueous humour, this work has created a basis for implementation and interpretation of HR-MAS <sup>1</sup>H NMR spectroscopy on intact lens tissue. Several significant changes in the metabolic content in cornea, aqueous humour, and lens after alkali-burns to the eye were detected and showed how careful <sup>1</sup>H NMR spectroscopy analysis of tissue extracts provided new information (quantitative and qualitative) on the metabolic reaction pattern in the anterior eye segment in relation to eye alkali-burn injuries.</p><p>HR-MAS studies on lenses exposed <i>in vivo </i>to different ultraviolet-B doses did not reveal any dose-response relationship for the metabolic changes. However, significant concentration changes for most of the observed metabolites seven days post exposure demonstrated that closeto- threshold UVB radiation had great impact on the metabolites in the lens. Further time dependency studies of metabolic changes in rat lens after UVB radiation showed that significant changes in metabolite concentrations were subsequent to lens opacity development. Long-term steroid treatment (36 days) seemed to have greater impact on the metabolic changes compared to the UVB-induced changes 24 hours after UVB radiation. Even though no obvious cataract was detected after the combined treatment of steroids and UVB radiation, significant changes were observed for several metabolites.</p> / Paper III is reprinted with kind permission from Elsevier, sciencedirect.com
50

High-temperature, high-pressure NMR probe for superconducting magnets

Mullen, Corina P. 13 December 1996 (has links)
A high-temperature, high-pressure autoclave has been adapted for use with a high-field nuclear magnetic resonance spectrometer. The autoclave has an internal pressure range of atmospheric pressure to 1.5 kbar and a temperature range of 273 K to 1900 K. The autoclave is usable in a high field (8 T) magnet with a room temperature, 76.4 mm bore. The autoclave was tested using assorted nuclear species with resonant frequencies ranging from 57 to 70 MHz at pressures ranging from atmospheric pressure to 1220 bar and temperatures ranging from 273 K to 448 K. Previously, the autoclave was used in conjunction with an iron magnet at temperatures to 1900 K and pressures to 1.5 kbar. / Graduation date: 1997

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