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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.
111

Simulation studies of the ion cooling processes of MALDI derived ions in fourier-transform mass spectrometry.

January 2006 (has links)
Ko Ka Lung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references. / Abstracts in English and Chinese. / Title page --- p.i / Abstract (English) --- p.ii / Abstract (Chinese) --- p.iii / Acknowledgement --- p.iv / Declaration --- p.v / Table of Content --- p.vi / List of Figure --- p.viii / Chapter 1. --- INTRODUCTION --- p.1 / Chapter 1.1 --- Matrix-assisted Laser Desorption / Ionization (MALDI) --- p.2 / Chapter 1.1.1 --- Evolution of Matrix-assisted laser desorption / ionization (MALDI) --- p.2 / Chapter 1.1.1.1 --- Lasers --- p.3 / Chapter 1.1.1.2 --- Matrices --- p.3 / Chapter 1.1.1.3 --- Sample preparation --- p.4 / Chapter 1.1.1.4 --- Desorption --- p.6 / Chapter 1.1.1.5 --- Ionization --- p.7 / Chapter 1.2 --- Fourier Transform Ion Cyclotron Resonance Mass Spectrometry with MALDI (FTICR-MS) --- p.9 / Chapter 1.2.1 --- History of Fourier Transform Ion Cyclotron Resonance Mass Spectrometry --- p.9 / Chapter 1.2.2 --- Basics of FTICR-MS --- p.11 / Chapter 1.2.3 --- FTICR couple with external ionization source --- p.15 / Chapter 1.2.4 --- Coupling of MALDI to FTICR --- p.16 / Chapter 1.3 --- Problems encountered on the coupling of MALDI to FTICR-MS --- p.17 / Chapter 1.4 --- Outline of present work --- p.19 / Chapter 2 --- SIMULATION METHOD --- p.20 / Chapter 2.1 --- Overview of the ion optics simulation --- p.21 / Chapter 2.2 --- History of SIMION Program --- p.22 / Chapter 2.3 --- Basics and theory of SIMION version 6.0 --- p.24 / Chapter 2.4 --- Simulation method --- p.26 / Chapter 2.4.1 --- Creating potential array --- p.27 / Chapter 2.4.2 --- User program --- p.29 / Chapter 2.4.3 --- Ion definition parameter --- p.31 / Chapter 2.4.4 --- Trajectories quality panel --- p.33 / Chapter 2.4.5 --- Data recording --- p.36 / Chapter 3 --- OPTIMIZATION OF RF-ONLY HEXAPOLE UNDER PULSE GAS CONDITION --- p.37 / Chapter 3.1 --- Introduction --- p.38 / Chapter 3.2 --- Simulation conditions --- p.39 / Chapter 3.3 --- Results and discussion --- p.40 / Chapter 3.3.1 --- rf-frequency (w) --- p.41 / Chapter 3.3.2 --- rf voltage (Vo-p) --- p.44 / Chapter 3.3.3 --- Pulse gas pressure(po) --- p.47 / Chapter 3.3.4 --- Trapping potential (VT) --- p.49 / Chapter 3.3.5 --- Effect of space charge --- p.53 / Chapter 3.4 --- Conclusions --- p.60 / Chapter 4 --- OPTIMIZATION OF DIFFERENT HEXAPOLE-BASED INTERFACES FOR PRE-TRAPPING COOLING --- p.61 / Chapter 4.1 --- Introduction --- p.62 / Chapter 4.2 --- Simulation conditions --- p.63 / Chapter 4.3 --- Results and discussion --- p.66 / Chapter 4.3.1 --- Static medium pressure interface --- p.66 / Chapter 4.3.1.1 --- Effect of pressure --- p.66 / Chapter 4.3.1.2 --- Effect of space charge --- p.70 / Chapter 4.3.2 --- Differential pressure model (Skimmer-based) --- p.73 / Chapter 4.3.2.1 --- Effect of pressure --- p.73 / Chapter 4.3.2.2 --- Effect of space charge --- p.76 / Chapter 4.3.3 --- A comparison of the optimal operating conditions for the three proposed interfaces --- p.81 / Chapter 4.3.4 --- Comparison of the theoretical results amd the experimental results --- p.83 / Chapter 4.4 --- Conclusion --- p.84 / Chapter 5 --- CONCLUSIONS --- p.85 / Chapter 5.1 --- Conclusions --- p.86 / REFERENCES --- p.R1 / APPENDIX --- p.A1
112

Efficient STFT analysis over limited frequency regions

Paneras, Demetrios E January 1992 (has links)
Thesis (M.S.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / We address the problem of efficiently computing, over narrow frequency bands, the short-time Fourier transform (STFT) and approximations to the STFT. This problem is important for the design of signal understanding systems that have to efficiently carry out STFT reprocessing of signals in order to examine detailed features of signal components that have already been located within narrow frequency bands. In the computation of the exact STFT we use an "overlap pruning" approach (Covell et al. 1992) for exploiting the commonality of computations between successive slices of the STFT with unity decimation interval. We have also extended this approach to the STFT with non-unity decimation intervals and combined it with a frequency pruning method (Sreenivas et al. 1980) to provide additional computational savings. In the computation of approximations to the STFT we use an algorithm (Khan et al. 1988) for efficiently computing Taylor series approximations over narrow frequency bands. Through examples involving real data we demonstrate the feasibility of using the approximated STFT to obtain more accurate estimates of the center frequency of spectral peaks, and to resolve multiple peaks that have been smeared due to the use of short window lengths. The efficiency of all the algorithms we have investigated is less than 0(N log N) multiplications per STFT slice and can be as small as O(N) multiplications per STFT slice in certain cases. Consequently, all the algorithms compare favourably with the standard FFT implementation of the STFT which requires O(N log N) multiplications per slice. All the algorithms considered in this thesis were implemented in software and tested on synthetic and real sound signals. / 2031-01-01
113

Application of library search techniques of FTIR fingerprint for the identification of traditional Chinese herbal medicine.

January 2003 (has links)
Lo, Yu Ching. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 79-82). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abbreviations --- p.ii / Abstract --- p.iii / Table of Contents --- p.v / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Basic Theory of FTIR --- p.1 / Chapter 1.1.1 --- Infrared Spectroscopy --- p.1 / Chapter 1.1.2 --- Dispersive Infrared Spectrometer --- p.2 / Chapter 1.1.3 --- Fourier Transform Infrared Spectrometer (FTIR) --- p.3 / Chapter 1.1.4 --- Advantages of FTIR --- p.5 / Chapter 1.1.4.1 --- Multiplex advantage --- p.5 / Chapter 1.1.4.2 --- Throughput advantage --- p.5 / Chapter 1.2 --- Traditional Chinese Medicine (TCM) --- p.6 / Chapter 1.3 --- Identification of Traditional Chinese Herbal Medicine --- p.8 / Chapter 1.3.1 --- Traditional method for the identification of TCM --- p.8 / Chapter 1.3.2 --- Instrumental method for the identification of TCM --- p.9 / Chapter 1.3.2.1 --- Identification of TCM using fingerprint method --- p.9 / Chapter 1.3.3 --- Identification of TCM using FTIR fingerprint method --- p.10 / Chapter 1.4 --- Objective --- p.11 / Chapter Chapter 2 --- Experimental / Chapter 2.1 --- Outline of the Method --- p.12 / Chapter 2.2 --- Reagents and Glassware --- p.13 / Chapter 2.3 --- Instrumentation --- p.13 / Chapter 2.4 --- Library Search Program --- p.13 / Chapter 2.5 --- Samples --- p.14 / Chapter 2.6 --- Sample Pretreatment --- p.16 / Chapter 2.7 --- Extraction of Ingredients --- p.16 / Chapter 2.8 --- Preparation of KBr Pellet --- p.17 / Chapter 2.9 --- IR Spectrum Measurement --- p.17 / Chapter 2.10 --- Data Processing --- p.18 / Chapter 2.11 --- IR Databases --- p.18 / Chapter 2.12 --- Reproducibility of Extraction --- p.29 / Chapter Chapter 3 --- Application of Library Search Techniques - Results and Disscussion / Chapter 3.1 --- Introduction --- p.31 / Chapter 3.2 --- Euclidean Search Method --- p.32 / Chapter 3.2.1 --- Similarly score of reference spectra --- p.32 / Chapter 3.2.2 --- Similarity score of known sample spectra --- p.37 / Chapter 3.3 --- Soft Independent Modeling of Class Analogy (SIMCA) --- p.45 / Chapter 3.3.1 --- Verification Diagnostic Report of the Reference flowers --- p.47 / Chapter 3.3.2 --- Classification of Flowers --- p.51 / Chapter 3.4 --- Performance Limitation --- p.75 / Chapter 3.4.1 --- Euclidean Search Method --- p.75 / Chapter 3.4.2 --- SIMCA --- p.75 / Chapter 3.5 --- Conclusion --- p.77 / References --- p.79
114

Generation and fragmentation of protein radical ions in a fourier-transform ion cyclotron resonance mass spectrometer. / CUHK electronic theses & dissertations collection

January 2010 (has links)
During the course of the systematic study, it was also discovered that doubly-protonated diarginated peptides containing multiple glutamic acid residues (E) (n>4) could suppress the backbone fragmentation of [M+2H]+· . Together with the results obtained from conformational searches, it was hypothesized that the interactions between carboxylic oxygens of E side chains and backbone amide hydrogens could stabilize the radical intermediate and thereby inhibiting the usual N-Calpha cleavages and H · loss from [M+2H]+·. / In order to ascertain the impacts of the structural features of polypeptide and oligosaccharide ions on the dissociation of these biomolecules under typical collision induced dissociation (CID) and electron capture dissociation (ECD) conditions, the dissociation patterns of even-electron precursor ions generated by protonation ([M+nH]n+)/metalation ([Metal+M]n+), odd-electron hydrogen-deficient precursor ions (M+·) generated by SORI-CID of [Cu(Tpy)M]2+ and odd-electron hydrogen-surplus precursor ions ([M+2H]+·) generated by ECD of [M+2H] 2+ were examined. It was found that backbone cleavages, with the generation of b/y and c/z ions, were dominant in the dissociation of [M+H]+ and [M+2H]+· respectively. Whilst in the dissociation of M+·, side chain loss reactions were the major fragments generated. For post translational modification (PTM)-containing peptides, the labile PTM groups were found to cleave preferentially in the dissociation of M+· and [M+H]+, but were found to be retained in the intact peptides and peptide fragments in the dissociation of [M+2H]+·. It is hypothesized that the different dissociation pathways is attributed to the different nature of radicals. Further to these, it was found that in the dissociation of oligosaccharides, similar cleavage patterns (glycosidic and cross-ring cleavages) were obtained regardless of the nature of the precursor ions (i.e. whether odd- or even-electron) and the ion activation conditions. / Chan, Wai Yi. / Adviser: T.W. Dominic Chan. / Source: Dissertation Abstracts International, Volume: 73-02, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 145-152). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
115

Fourier transform ion cyclotron resonance studies of dendrimers and metal porphyrin-phthalocyanine sandwich complexes.

January 1996 (has links)
by Lim Che Lau. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1996. / Includes bibliographical references (leaves 79-84). / Title Page --- p.i / Table of Contents --- p.ii / List of Tables --- p.iv / List of Figures --- p.v / List of Schemes --- p.vii / Acknowledgments --- p.viii / Abstract --- p.ix / Chapter CHAPTER 1: --- INTRODUCTION / Chapter 1.1. --- Historical Background --- p.1 / Chapter 1.2. --- FTICR with External Ion Source --- p.2 / Chapter 1.3. --- High Mass Analysis in FTICR --- p.4 / Chapter 1.4. --- Outline of Present Work --- p.7 / Chapter CHAPTER 2: --- INSTRUMENTATION AND EXPERIMENTAL / Chapter 2.1. --- Instrumentation --- p.8 / Chapter 2.1.1 --- Ion Source --- p.10 / Chapter 2.1.1.1. --- Liquid Secondary Ion Mass Spectrometry --- p.11 / Chapter 2.1.1.2. --- Electrospray Ionization --- p.12 / Chapter 2.1.2. --- Electrostatic Ion Focusing System --- p.15 / Chapter 2.1.3. --- ICR Analyzer Cell and Magnet --- p.18 / Chapter 2.1.4. --- Data Acquisition and Handling System --- p.22 / Chapter 2.2. --- Experimental --- p.22 / Chapter 2.2.1. --- Liquid Secondary Ion Mass Spectrometry --- p.22 / Chapter 2.2.2. --- Electrospray Ionization --- p.23 / Chapter 2.2.3. --- Nozzle-Skimmer Dissociation --- p.24 / Chapter 2.2.4. --- Sustained Off-Resonance Irradiation Collision- Induced Dissociation --- p.24 / Chapter 2.2.5. --- Data Acquisition and Processing --- p.27 / Chapter 2.2.6. --- Mass Calibration --- p.27 / Chapter CHAPTER 3: --- STRUCTURAL CHARACTERIZATION OF TERPYRIDINE-BASED POLYETHER DENDRIMERS AND THEIR IRON(II) METALLOCOMPLEXES BY LIQUID SECONDARY ION MASS SPECTROMETRY AND ELECTROSPRAY IONIZATION MASS SPECTROMETRY / Chapter 3.1. --- Introduction --- p.28 / Chapter 3.2. --- Sample Preparation --- p.29 / Chapter 3.3. --- Results and Discussion --- p.30 / Chapter 3.3.1. --- Liquid Secondary Ion Mass Spectrometry Studies --- p.30 / Chapter 3.3.1.1. --- Dendrimers --- p.30 / Chapter 3.3.1.2. --- Metallodendrimers --- p.41 / Chapter 3.3.2. --- Electrospray Ionization Mass Spectrometry Studies --- p.47 / Chapter 3.4. --- Conclusions --- p.53 / Chapter CHAPTER 4: --- STUDIES OF LANTHANIDE(III) PORPHYRIN- PHTHALOCYANINE HETEROLEPTIC SANDWICH COMPLEXES USING ELECTROSPRAY IONIZATION / Chapter 4.1. --- Introduction --- p.54 / Chapter 4.2. --- Results and Discussion --- p.55 / Chapter 4.2.1. --- Molecular Weight Determination --- p.57 / Chapter 4.2.2. --- Structural Elucidation --- p.65 / Chapter 4.2.3. --- Charge-Transfer Processes --- p.72 / Chapter 4.3. --- Conclusions --- p.76 / Chapter CHAPTER 5: --- CONCLUSIONS --- p.77 / References --- p.79
116

Study of fluorescent properties of zinc phthalocyanine and derivatives using fourier transform spectroscopy.

January 2008 (has links)
Han, Fangyuan. / Thesis submitted in: November 2007. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 68-72). / Abstracts in English and Chinese. / Title Page --- p.I / Thesis Committee --- p.II / Acknowledgements --- p.III / Abstract --- p.IV / 摘要 --- p.V / Table of Contents --- p.1 / List of Figures --- p.4 / List of Tables --- p.6 / Chapter Chapter 1 --- Introduction --- p.7 / Chapter Chapter 2 --- Fourier Transform Spectroscopy --- p.10 / Chapter A. --- The Michelson Interferometer and the Interferogram --- p.10 / Chapter B. --- The Link between the Interferogram and the Spectrum: the Fourier Transform --- p.12 / Chapter C. --- "Resolution, Apodization and Spectral Folding" --- p.13 / Chapter D. --- Advantages and Disadvantages of FTIR Spectroscopy --- p.17 / Chapter E. --- Time-resolved FTIR Spectroscopy --- p.18 / Chapter (1) --- Time-resolved Rapid Scan Scheme --- p.18 / Chapter (2) --- Step-scan Scheme --- p.19 / Chapter F. --- Several Considerations in Step-scan Time-resolved Spectroscopy / Chapter Chapter 3 --- Molecular Fluorescence --- p.24 / Chapter A. --- Transitions Between Electronic States --- p.24 / Chapter B. --- Absorption and Vibrational Relaxation --- p.26 / Chapter C. --- Internal Conversion and Fluorescence --- p.26 / Chapter D. --- Intersystem Crossing and Phosphorescence --- p.27 / Chapter E. --- Fluorescence Lifetime and Quantum Yield --- p.29 / Chapter Chapter 4 --- Fourier Transform Spectroscopy of Zinc Phthalocyanine and Derivatives --- p.32 / Chapter A. --- Introduction --- p.32 / Chapter B. --- Apparatus --- p.35 / Chapter (1) --- VERTEX 70 FTIR Spectrometer --- p.35 / Chapter (2) --- Excitation Source --- p.38 / Chapter (3) --- Detectors and the Transient recorder --- p.38 / Chapter (4) --- Samples and Sample Cells --- p.39 / Chapter C. --- Experimental Setup --- p.40 / Chapter (1) --- Absorption Experiments --- p.40 / Chapter (2) --- Emission Experiments --- p.42 / Chapter D. --- Results and Discussion --- p.45 / Chapter (1) --- Absorption and Fluorescence Spectra --- p.45 / Chapter (2) --- Fluorescence Lifetimes and Quantum Yields --- p.51 / Chapter (3) --- Time-resolved Fluorescence Spectra --- p.54 / Chapter E. --- Some Experimental Details --- p.60 / Chapter (1) --- Choice of Windows for Regular Tests of the Instrument Performance --- p.60 / Chapter (2) --- Configurations of the Transient Recorder in OPUS --- p.61 / Chapter (3) --- Configurations of Detectors in OPUS --- p.61 / Chapter (4) --- The Standard Method of Extracting Time Slices --- p.62 / Chapter (5) --- Parameters that Easily Cause Problems --- p.63 / Chapter (6) --- Elimination of Background Noises --- p.64 / Chapter Chapter 5 --- Concluding Remarks --- p.66 / Reference --- p.68
117

Quantitative analysis of sugars in confectionery products by Fourier transform infrared spectroscopy : development of analytical methodology using a mid-infrared fiber optic probe and investigation of the effects of sugar-water interactions in model systems

Dimitri-Hakim, Aline. January 2000 (has links)
No description available.
118

Analysis of edible oils by Fourier transform near-infrared spectroscopy

Li, Hui, 1970- January 2000 (has links)
No description available.
119

Isolation and characterization of a high gelling protein from soybean

Abdolgader, Ramadan E. January 2000 (has links)
No description available.
120

Application of high-pressure homogenization for the proximate analysis of meat and meat products by Fourier transform infrared (FTIR) spectroscopy

Dion, Bruno J. January 2000 (has links)
No description available.

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