No description available.

This paper presents an introduction to the theory of ideals in a ring with emphasis on ideals in a commutative ring with identity.

The effect of varying substituents on structure and energies of bisketenes was studied using ab initio methods. Effect of substituents on ring closing reaction of bisketenes to the corresponding cyclobutenediones was also studied using ab initio methods. One or two of the following substituents were used to study the effect of varying substituents: BH2, CH3, NH2, OH, F, AlH2, SiH3, PH2, SH, Cl. Studies were done at the Hartree-Fock (HF), Møller-Plesset (MP2), and Density Functional Theory (B3LYP) levels of theory using the 6-31G* basis set.

Thesis advisor: David Burgess / The contractile ring is pictured, analyzed, and even named under the basic assumption that the geometry of the structure begins and ends circularly and the ring is a single homogenous structure acting uniformly. However, under physiological conditions cell-to-cell adhesions force cells and therefore initial contractile rings into highly irregular and noncircular shapes. To investigate this basic assumption of contractile ring geometry, contractile ring shape of dividing sea urchin embryos was analyzed under three conditions: in seawater where cell-to-cell adhesion is strong, calcium free seawater where cell-to-cell adhesion is minimized, and in microfabricated chambers to artificially manipulate the initial contractile ring shape. We found that contractile ring geometry evolves over time to become circular even when it begins as an irregular shape due to cell-to-cell adhesions or artificial manipulation. By analyzing velocities of specific regions of the contractile ring, it became apparent that there is always a pattern of rounding regions of lowest circularity before overall ring contraction. This pattern suggests that the contractile ring is capable of producing varying forces in a coordinated manner. Therefore the contractile ring can not only be noncircular, but can also possess regions with different molecular and biophysical properties. / Thesis (MS) — Boston College, 2016. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Biology.

A thesis presented in the University of the Witwatersrand for the degree of Doctor of Philosophy / AC 2018

by Fung Wing-chuen. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1994. / Includes bibliographical references (leaves 57-59). / Abstract --- p.i / Acknowledgments --- p.ii / Biography --- p.iii / Abbreviation --- p.v-vi / Chapter 1. --- Introduction / Chapter 1.1 --- Natural O-heterocycles --- p.1 / Chapter 1.2 --- Methods for the construction of O-heterocycles --- p.5 / Chapter 1.3 --- Intramolecular nitrone cycloaddition in the construction of O-heterocycles --- p.9 / Chapter 2. --- Results and discussion / Chapter 2.1 --- Introduction --- p.12 / Chapter 2.2 --- Synthesis of 68，77，84 Via INC --- p.13 / Chapter 2.3 --- Acyclic INC of nitrones --- p.16 / Chapter 2.4 --- "Studies on 7-, 8-membered rings formation" --- p.24 / Chapter 3. --- Conclusions --- p.29 / Chapter 4. --- Experimental --- p.34 / Chapter 5. --- References --- p.57 / Chapter 6. --- List of spectra --- p.60 / Chapter 7. --- Appendices --- p.72

by Man-Wai Woo. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 77-81). / Abstracts in English and Chinese. / ABSTRACT --- p.i / ACKNOWLEDGMENT --- p.iii / CONTENTS --- p.iv / LIST OF FIGURES --- p.vi / LIST OF TABLES --- p.ix / ABBREVIATIONS --- p.x / Chapter 1. --- INTRODUCTION / Chapter 1.1 --- General Background of Phthalocyanines --- p.1 / Chapter 1.2 --- Previous Examples of Phthalocyanine-containing Polymers --- p.5 / Chapter 1.2.1 --- Poly(phthalocyanines) Linked Via Peripheral Substituents --- p.5 / Chapter 1.2.2 --- Poly(phthalocyanines) Linked Via Axial Ligation --- p.7 / Chapter 1.2.3 --- Poly(phthalocyanines) Attached Laterally to a Polymer Backbone --- p.11 / Chapter 1.3 --- Ring Opening Metathesis Polymerization (ROMP) --- p.15 / Chapter 1.4 --- ROMP of Norbornene Substituted Porphyrazine --- p.18 / Chapter 2. --- RESULTS AND DISCUSSION / Chapter 2.1 --- Phthalocyanines Substituted with Four Poly(norbornene)s --- p.20 / Chapter 2.1.1 --- Preparation of Tetra(norbornene) Phthalocyanines --- p.20 / Chapter 2.1.2 --- Polymerization of Tetra(norbornene) Phthalocyanines --- p.30 / Chapter 2.1.3 --- Characterization of Polymers --- p.39 / Chapter 2.1.4 --- Photophysical Properties of the Polymers --- p.43 / Chapter 2.2 --- Phthalocyanines Substituted with One Poly(norbornene) --- p.49 / Chapter 2.2.1 --- Preparation and Polymerization of Mono(norbornene) Phthalocyanines --- p.49 / Chapter 2.2.2 --- Characterization of the Polymers 41 - 44 --- p.56 / Chapter 2.2.3 --- Fluorescence Quenching of 40 Polymers 41 -44 --- p.61 / Chapter 2.2.4 --- Preparation of Water-soluble Poly(7-oxanorbornene) --- p.63 / Chapter 2.3 --- Conclusion --- p.65 / Chapter 3 --- EXPERIMENTAL SECTION --- p.66 / Chapter 3.1 --- General Methods --- p.66 / Chapter 3.2 --- Photophysical Measurements --- p.67 / Chapter 3.3 --- Synthesis of Phthalocyanines with Four Poly(norbornene) Substituents --- p.68 / Chapter 3.4 --- Synthesis of Phthalocyanines with One Poly(norbornene) Substituent --- p.74 / Chapter 4. --- REFERENCES --- p.77

No description available.

Dielectric permittivity measurements provide important input to engineering and scientific disciplines due to the effects of permittivity on the interactions between electromagnetic energy and materials. A novel ring resonator design is presented for the measurement of permittivity of low dielectric constant foams. A review of dielectric material properties and currently available measurement methods is included. Measurements of expanded polystyrene are reported and compared with results from the literature; good agreement between measurements and published results is shown.

by Yong-li Zhong. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (p. 234-246). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web.