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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.
11

Preparation of PZT thin films by pulsed laser deposition.

January 1992 (has links)
by Au Wing Shing. / Parallel title in Chinese characters. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1992. / Includes bibliographical references (leaves 56-58). / Acknowledgements --- p.i / Abstract --- p.ii / Table of Content --- p.iii / Chapter CHATPER 1 : --- INTRODUCTION --- p.1 / Chapter CHAPTER 2 : --- EXPERIMENTAL SET-UP / Chapter A. --- General Description --- p.4 / Chapter B. --- Vacuum System and Chamber --- p.6 / Chapter C. --- Target Rotation and Motor Connection --- p.7 / Chapter D. --- Substrate Heating and Temperature Control --- p.8 / Chapter E. --- Pressure and Flow Control --- p.9 / Chapter CHAPTER 3 : --- THICKNESS AND COMPOSITION DISTRIBUTIONS OF FILMS DEPOSITED AT ROOM TEMPERATURE / Chapter A. --- Experimental Details --- p.10 / Chapter B. --- Shape of the Plume --- p.12 / Chapter C. --- Effect of Laser Fluence --- p.15 / Chapter D. --- Investigation of the Pb Deficiency in the Deposited Film --- p.24 / Chapter E. --- Effect of Oxygen Pressure --- p.27 / Chapter CHAPTER 4 : --- TARGET MODIFICATION AND DEPOSITION RATE / Chapter A. --- Introduction --- p.34 / Chapter B. --- Experimental Details --- p.40 / Chapter C.i. --- Result 1 : Normal Incidence Case --- p.41 / Chapter ii. --- Result 2 : 45° Incidence Case --- p.42 / Chapter D. --- Discussion --- p.43 / Chapter CHAPTER 5 : --- HIGH TEMPERATURE GROWTH ON DIFFERRENT KINDS OF SUBSTRATES / Chapter A. --- Introduction --- p.45 / Chapter B. --- Experimental Details --- p.47 / Chapter C. --- High Temperature Growth / Chapter i. --- Films grown on MgO (100) --- p.49 / Chapter ii. --- Films grown on Spinel --- p.50 / Chapter iii. --- Films grown on c-plane Sapphire --- p.51 / Chapter D. --- Discussion --- p.52 / Chapter CHAPTER 6 : --- OVERALL CONCLUSION AND FURTHER WORKS --- p.54 / References --- p.56 / Appendix1 --- p.59 / Appendix2 --- p.61
12

Electrodeposition of PbS, PbSe and PbTe thin films /

Saloniemi, Heini. January 2000 (has links) (PDF)
Thesis (doctoral)--University of Helsinki, 2000. / Includes bibliographical references. Also available on the World Wide Web.
13

The preparation and spectroscopic studies of some cyclic urea adducts of triphenyl -tin and -lead halides /

Aitken, Clare T. (Clare Theresa) January 1983 (has links)
No description available.
14

Synthesis and photophysical properties of antimony and lead phthalocyanines /

Modibane, Kwena Desmond. January 2009 (has links)
Thesis (M.Sc. (Chemistry)) - Rhodes University, 2009.
15

Synthesis and photophysical properties of antimony and lead phthalocyanines / CHAPTER ONE:

Modibane, Kwena Desmond, Guest 27 February 2009 (has links)
This work hereby presents the synthesis, spectroscopic and photophysical properties of newly synthesized lead (PbPc) and antimony (SbPc) phthalocyanines. The complexes are either unsubstituted or substituted at the peripheral and non-peripheral positions with phenoxy, 4-t-butylphenoxy and 4-benzyloxyphenoxy groups. The photophysical properties of these complexes were studied in dimethylsulfoxide, dimethylformamide, toluene, tetrahydrofuran and chloroform as solvents. The fluorescence spectra for PbPc complexes were different to that of the excitation spectra due to demetallation upon excitation. On the other hand, the excitation spectra of oxidized antimony (Sb(V)Pc) derivatives were found to be similar to absorption spectra. High triplet quantum yields for PbPc and SbPc complexes ranging from 0.70 to 0.86, low triplet lifetimes (20–60 μs in DMSO, while they were <10 μs in the rest of the solvents) and low fluorescence quantum yields were observed and is attributed to the presence of heavy atoms (Pb and Sb ions). The nonlinear optical properties of PbPc complexes were studied in dimethylsulfoxide. The optical limiting threshold intensity (Ilim) for the PbPc derivatives were calculated and ranged from 2.1 to 6.8 W/cm2. The photodegradation studies of the PbPc and SbPc complexes synthesized showed that then are stable.
16

The preparation and spectroscopic studies of some cyclic urea adducts of triphenyl -tin and -lead halides /

Aitken, Clare T. (Clare Theresa) January 1983 (has links)
No description available.
17

Bismuth based thin film superconductors

Guldeste, Ayhan January 1994 (has links)
This thesis describes investigations performed into the growth and characterisation of Bi-based (Bi<sub>2</sub>Sr<sub>2</sub>Ca<sub>n-1</sub>Cu<sub>n</sub>O<sub>2n + 4 + x</sub>, n=2, 3) ceramic superconducting material in the form of thin films, about 0.5μm thick, grown on single crystal MgO, LaAIO<sub>3</sub> and SrTiO<sub>3</sub> substrates by r.f. magnetron sputtering. The effect of oxygen content on the Pb doped Bi-2223 (n=3) phase was also studied by changing the cooling process and by annealing in different partial pressures of oxygen at ambient pressure. The films produced have been assessed by considering their initial composition where it is found that Bi/Sr ratios can be between 0.9<Bi/Sr<1 for the Bi-2212 (n=2) phase, while for the Bi-2223 phase the Bi-content should be below 1.9 or lower than the Sr-content, for the films not to peel off the substrate during high temperature annealing. T<sub>c- zero</sub> of around 80K is achievable for (Ca + Sr)/Bi ratios between 1.4 and 1.65 while T<sub>c- onset</sub> remains above 90K for Bi-2212 films. However, the best superconducting properties can be obtained for a (Ca + Sr)/Bi ratio which is quite close the nominal composition. The use of a heavily Pb doped target is an effective way of Pb doping Bi-2223 thin films. A Bi-content of 1.4<Bi<1.8 in as deposited films may provide almost single phase Bi-2223 thin films with Tc values running from 105.5K to 109.5K and Jc>10,sup>4</sup>A/cm<sup>2</sup> at 77K. The effect of the initial Pb content and annealing conditions on the formation of the Bi-2223 phase was investigated. It was found that high Pb content (0.9<Pb/Bi<1.5) lowers the formation temperature appreciably and increases the range of sintering temperature (to at least 10K). The Bi-2223 phase starts to form at 835°C from the initial phases (Bi-2212, CuO and Ca<sub>2</sub>PbO<sub>4</sub>) formed below 835°C and its fraction increases with increasing sintering temperature up to 862°C, while the fraction of initial phases decreases. An annealing duration of 30 min. has provided highly oriented films with c-axis perpendicular to the substrate surface and sharp superconducting transition (<5K). Although Pb/Bi ratio is not critical in the range studied, when it is above 1.3 slow heating and cooling is necessary to prevent retention of excess Ca<sub>2</sub>PbO<sub>4</sub> in the film after sintering. On LaAIO<sub>3</sub> and SrTiO<sub>3</sub> perovskite substrates, T<sub>c</sub> is at least 5K lower than in the case of MgO. Nevertheless, LaAIO<sub>3</sub> can provide good microstructure with a critical current density, of 5x10<sup>4</sup>A/cm<sup>2</sup> at 77K. The direction and the range of variation of T<sub>c</sub> in Bi-2223 films with oxidising process can be related to both the film composition (especially Bi and Pb content) and initial oxygen content. The variation range of T<sub>c</sub> with oxidising is controlled by the Pb content. However, the maximum variation is around 4K at ambient pressure. Radiation response measurements were carried out on films patterned into a 150μm wide, and 1 cm long meander-type structure using standard photolithography and wet chemical etching in EDTA. The results showed that the optical response using a continuous wave (cw) He-Ne laser is bolometric, while the microwave response using a 34.5 GHz Gunn diode microwave generator contains a non bolometric component. Such polycrystalline Bi-based high T<sub>c</sub> thin films may have interesting applications as sensitive microwave detectors, but they are not particularly good for microwave applications because of their high surface resistance, Rs, at microwave frequencies.
18

The properties of lead titanate thin films produced by chemical vapour deposition.

Madsen, Lynnette D. Weatherly, G.C. Emesh, I. Unknown Date (has links)
Thesis (Ph.D.)--McMaster University (Canada), 1994. / Source: Dissertation Abstracts International, Volume: 56-08, Section: B, page: 4527. Adviser: G. C. Weatherly.
19

Stabilization of Different Lead Compounds in Portland Cement

Zhao, Baoshu (Baoshu Eric) 08 1900 (has links)
This research investigated the chemistries and mechanisms involved in lead-cement systems through the study of a larger number of lead compounds.
20

An investigation into gene regulation involved in human gamma-globin gene reactivation induced by a lead compound.

January 2006 (has links)
Chan Kai Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 109-119). / Abstracts in English and Chinese. / Title --- p.i / Thesis committee --- p.ii / Statement --- p.iii / Acknowledgement --- p.iv / Abbreviations --- p.v / Abstract (English) --- p.vii / Abstract (Chinese) --- p.ix / Table of contents --- p.xi / List of Figures --- p.xvi / Chapter Chapter 1: --- General Introduction --- p.1 / Chapter 1.1 --- Human Hemoglobin --- p.1 / Chapter 1.2 --- Hemoglobinopathies --- p.4 / Chapter 1.3 --- Hereditary Persistence of Fetal Hemoglobin (HPFH) and β - Thalassemias --- p.6 / Chapter 1.4 --- Globin Genes Switching --- p.7 / Chapter 1.5 --- Pharmaceutical Agents for γ-Globin Gene Reactivation --- p.9 / Chapter 1.6 --- Discovery of LC978: A Novel Fetal Hemoglobin Inducing Agent --- p.10 / Chapter 1.7 --- Aim of Study --- p.11 / Chapter Chapter 2: --- Specific Induction of Gamma Globin Gene Transcription in K562 Leukemia Cell Line by Lead Compound LC978 --- p.12 / Chapter 2.1 --- K562 Cell Line as a Model for Gamma Globin Gene Induction Studies --- p.12 / Chapter 2.2 --- LC978-Induced Fetal Hemoglobin Expression in K562 Cell Line --- p.12 / Chapter 2.3 --- Materials --- p.14 / Chapter 2.3.1 --- "Chemicals, Kits and Reagents" --- p.14 / Chapter 2.3.2 --- Buffers and Solutions --- p.15 / Chapter 2.3.3 --- Cell Line --- p.16 / Chapter 2.3.4 --- Instruments and Equipments --- p.16 / Chapter 2.3.5 --- Enzymes --- p.16 / Chapter 2.3.6 --- Nucleic Acids --- p.17 / Chapter 2.3.7 --- Oligo Primers --- p.17 / Chapter 2.4 --- Methods --- p.17 / Chapter 2.4.1 --- In vitro Bioassay for Total Hemoglobin Production --- p.17 / Chapter (a) --- Preparation of Treatment Cell Culture Plates --- p.17 / Chapter (b) --- Treatment of K562 Cells by LC978 --- p.18 / Chapter (c) --- Signal Development --- p.18 / Chapter 2.4.2 --- Detection of Fetal Hemoglobin Production by HbF Sandwich ELISA --- p.18 / Chapter (a) --- Treatment of K562 Cells by LC978 --- p.18 / Chapter (b) --- Preparation of Capture Antibody-Coated and BSA-Blocked ELISA Plate --- p.19 / Chapter (c) --- Preparation of K562 Cell Lysates --- p.19 / Chapter (d) --- Antigen Capture and Signal Development --- p.19 / Chapter 2.4.3 --- Detection of Gamma Globin mRNA Level by Real-time RT-PCR --- p.20 / Chapter (a) --- Treatment of K562 Cells by LC978 --- p.20 / Chapter (b) --- Preparation of K562 Cell Lysate in Guanidium Thiocyanate (GT) Solution --- p.20 / Chapter (c) --- Isolation of Total RNA from LC978-treated K562 Cells --- p.21 / Chapter (d) --- cDNA Synthesis from mRNA by Reverse Transcriptase (RT) --- p.22 / Chapter (e) --- Real-Time Quantitative Polymerase Chain Reaction (PCR) --- p.23 / Chapter 2.5 --- Results --- p.24 / Chapter (a) --- In vitro Bioassay for Total Hemoglobin Production --- p.24 / Chapter (b) --- Fetal Hemoglobin Sandwich ELISA --- p.24 / Chapter (c) --- LC978-Induced Gamma Globin mRNA Accumulation --- p.25 / Chapter 2.6 --- Discussion --- p.31 / Chapter Chapter 3: --- Construction of Promoter-Reporter Plasmid Constructs --- p.33 / Chapter 3.1 --- The Human Gamma Globin Gene Promoter --- p.33 / Chapter 3.2 --- SEAP as a Reporter Gene for Promoter Deletion Study --- p.34 / Chapter 3.3 --- Materials --- p.35 / Chapter 3.3.1 --- "Chemicals, Kits and Reagents" --- p.35 / Chapter 3.3.2 --- Buffers and Solutions --- p.35 / Chapter 3.3.3 --- Bacterial Strain --- p.36 / Chapter 3.3.4 --- Cell Line --- p.36 / Chapter 3.3.5 --- Enzymes --- p.37 / Chapter 3.3.6 --- Nucleic Acids --- p.37 / Chapter 3.3.7 --- Oligo Primers --- p.37 / Chapter 3.4 --- Methods --- p.38 / Chapter 3.4.1 --- Molecular Cloning of A-Gamma Globin Gene Promoter and 3' Enhancer into pBlueScript II SK (-) --- p.38 / Chapter (a) --- Design and Synthesis of Oligo Primers --- p.38 / Chapter (b) --- Isolation of Genomic DNA from K562 Cells --- p.39 / Chapter (c) --- PCR Amplification of Gamma Globin Gene Promoter and 3' Enhancer --- p.40 / Chapter (d) --- Ligation of PCR Fragments into EcoR V-cut pBlueScript II SK (-) --- p.41 / Chapter (e) --- Preparation of E coli DH5a Competent Cells --- p.43 / Chapter (f) --- Heat-Shock Transformation of E. coli DH5a Competent Cells --- p.44 / Chapter (g) --- PCR Screening and Plasmid Purification of Putative pBlu2SKM-γAP and pBlu2SKM-γAE --- p.44 / Chapter (h) --- Isolation of Putative pBlu2SKM-γAP and pBlu2SKM-γAE Plasmid DNA --- p.45 / Chapter (j) --- Nucleotide Sequencing of Putative pBlu2SKM-yAP and pBlu2SKM-γAE --- p.47 / Chapter (j) --- Graphical Summary of Section 3.6.1 Sub-cloning Procedures --- p.49 / Chapter 3.4.2 --- Molecular Cloning of A-Gamma Globin Gene Promoter and 3' Enhancer into pSEAP2-Enhancer --- p.51 / Chapter (a) --- Sub-cloning of Promoter Fragment into pSEAP2-Enhancer --- p.51 / Chapter (b) --- Sub-cloning of 3' Enhancer Fragment into p 1224γAP-SEAP2 --- p.52 / Chapter (c) --- Graphical Summary of Section 3.6.2 Sub-cloning Procedures --- p.54 / Chapter 3.4.3 --- Construction of p 1224γAP-SEAP2-γAE Promoter Deletions Constructs --- p.56 / Chapter (a) --- Restriction Digestion at 5' End of A-Gamma Promoter Deletions --- p.56 / Chapter (b) --- Restriction Digestion at 3' Ends of A-Gamma Promoter Deletions --- p.56 / Chapter (c) --- Blunting 5'-overhangs and Self-Ligation of Linearized Plasmid Constructs --- p.57 / Chapter (d) --- Graphical Summary of Section 3.6.3 5,Deletions Procedures --- p.58 / Chapter 3.5 --- Results --- p.59 / Chapter (a) --- Nucleotide Sequence Confirmed by Cycle Sequencing --- p.60 / Chapter (b) --- "Resulting Plasmid Constructs p 1224γAP-SEAP2-yAE, p754yAP-SEAP2-yAE and p205yAP-SEAP2-γAE" --- p.64 / Chapter 3.6 --- Discussion --- p.67 / Chapter Chapter 4: --- Mapping of LC978-Responsive Elements on Human A-Gamma Globin Gene Promoter --- p.69 / Chapter 4.1 --- Introduction --- p.69 / Chapter 4.2 --- pSV-β-Galactosidase as a Transfection Normalization Standard --- p.69 / Chapter 4.3 --- pSV-β-Galactosidase as a Transfection Normalization Standard --- p.70 / Chapter 4.4 --- Materials --- p.72 / Chapter 4.4.1 --- "Chemicals, Kits and Reagents" --- p.72 / Chapter 4.4.2 --- Buffers and Solutions --- p.73 / Chapter 4.4.3 --- Cell Line --- p.74 / Chapter 4.4.4 --- Nucleic Acids --- p.74 / Chapter 4.4.5 --- Instruments and Equipments --- p.74 / Chapter 4.5 --- Methods --- p.74 / Chapter 4.5.1 --- Determination of Optimal Dose of Transfection Reagent for --- p.74 / Chapter (a) --- Sterilization of Plasmid DNA for Transfection --- p.74 / Chapter (b) --- Transient Transfection of K562 Cells by pEGFP-N 1 --- p.75 / Chapter (c) --- Examination of EGFP Expression Level --- p.76 / Chapter 4.5.2 --- β-Galactosidase as Normalization Standard for K562 Transfections --- p.76 / Chapter (a) --- Transient Transfection of K562 Cells by pSV-β-Gal --- p.76 / Chapter (b) --- Determination of β-Galactosidase Expression Level --- p.76 / Chapter 4.5.3 --- Mapping of LC978-Responsive Elements on Human Gamma Globin Gene Promoter --- p.77 / Chapter (a) --- Co-Transfection of K562 Cells by p1224/754/205γAP-SEAP2 -γAE and pSV-β-Gal --- p.77 / Chapter (b) --- Treatment of Co-Transfected K562 Cells by LC978 --- p.77 / Chapter (c) --- Determination of β-Galactosidase Expression Level --- p.78 / Chapter (d) --- Determination of Secreted Alkaline Phosphatase (SEAP) Expression Level --- p.78 / Chapter (e) --- Determination of Fetal Hemoglobin Expression Level --- p.79 / Chapter 4.5.4 --- Mapping of Hydroxyurea-Responsive Elements on Human Gammm Globin Gene Promoter --- p.80 / Chapter (a) --- Determination of Optimal Biological Dose (OBD) of Hydroxyurea --- p.80 / Chapter (b) --- Co-Transfection of K562 Cells and Subsequent Treatment by Hydroxyurea --- p.80 / Chapter (c) --- "Assay for β-Galactosidase (β-Gal), Secreted Alkaline Phosphatase (SEAP) and Fetal Hemoglobin (HbF) Expression Level" --- p.81 / Chapter 4.5.5 --- Sodium Butyrate-Induced SEAP Expression --- p.81 / Chapter (a) --- Determination of Optimal Biological Dose (OB(d) of Sodium Butyrate --- p.81 / Chapter (b) --- Co-Transfection of K562 Cells and Treatment by Sodium Butyrate --- p.82 / Chapter (c) --- "Assay for p-Galactosidase (β-Gal), Secreted Alkaline Phosphatase (SEAP) and Fetal Hemoglobin (HbF) Expression Level" --- p.83 / Chapter 4.5.6 --- Data Analysis --- p.83 / Chapter (a) --- "Data Processing, Normalization and Graphing" --- p.83 / Chapter (b) --- Statistical Analysis --- p.83 / Chapter 4.6 --- Results --- p.84 / Chapter 4.6.1 --- Optimal Dose of Transfection Reagent for K562 --- p.84 / Chapter 4.6.2 --- β-Galactosidase as Normalization Standard for K562 Transfections --- p.84 / Chapter 4.6.3 --- LC978 Induction on Co-Transfected K562 Cells --- p.84 / Chapter 4.6.4 --- Hydroxyurea Induction on Co-Transfected K562 Cells --- p.85 / Chapter 4.6.5 --- Sodium Butyrate Induction on Co-Transfected K562 Cells --- p.86 / Chapter 4.7 --- Discussion --- p.98 / Chapter 4.7.1 --- Theme Question to be Answered --- p.98 / Chapter 4.7.2 --- Optimal Dose of DMRIE-C Transfection Reagent on K562 Cell Line --- p.98 / Chapter 4.7.3 --- pSV-β-gal as an Internal Normalization Control --- p.99 / Chapter 4.7.4 --- Responsive Element Mapping --- p.99 / Chapter (a) --- LC978-Induced Response --- p.100 / Chapter (b) --- Hydroxyurea-Induced Response --- p.100 / Chapter (c) --- Sodium Butyrate-Induced Response --- p.101 / Chapter 4.7.5 --- LCR-Dependent Gamma Globin Gene Reactivation --- p.101 / Chapter 4.7.6 --- Induction of Gamma Globin by Histone Deacetylase Inhibitor --- p.104 / Chapter 4.7.7 --- Basal SEAP Expression Levels of the Promoter-Reporter Constructs --- p.105 / Chapter 4.7.8 --- Summary --- p.105 / Chapter Chapter 5: --- General Discussion --- p.106 / References Cited --- p.109

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