In this study, Window-based computer program, named Synthesis Software, is developed for designing filters with equal-ripple or maximally flat passbands and general stopbands by using cascade synthesis technique in transformed frequency domain. Synthesis technique is applicable to lumped element and commensurate line distributed element filters with Lowpass, Highpass or Bandpass characteristics. Singly or Doubly terminated filters can be synthesized. friendly environment for typing in the parameters of the filter to be designed. This part uses Synthesis and Plot parts as modules. This software is based on the previous softwares developed in EEE Department of Middle East Technical University. All the previous softwares were gathered in the well-known software Filpro, which is in DOS environment, in Pascal. Thus, the new software is actually a conversion of Synthesis part of Filpro from DOS environment into Windows environment in the language C#, with some improvements in root finding algorithms for numerical conditioning. Synthesis Software is has three parts. The first and main part is the implementation of synthesis technique by using object oriented programming technique. In this way, synthesis technique implementation is isolated from other parts of Synthesis Software and it can be used by other filter design programs as a module. The second part of the program is responseplotting section. In this part Insertion Loss, Return Loss, Time Delay, Phase and Smith Chart responses are calculated and displayed. The last part is User Interface, which provides user

Weather radar imagery is important for several remote sensing applications including tracking of storm fronts and radar echo classification. In particular, tracking of precipitation events is useful for both forecasting and classification of rain/non-rain events since non-rain events usually appear to be static compared to rain events. Recent weather radar imaging-based forecasting approaches [3] consider that precipitation events can be modeled as a combination of localized functions using Radial Basis Function Neural Networks (RBFNNs). Tracking of rain events can be performed by tracking the parameters of these localized functions. The RBFNN-based techniques used in forecasting are not only computationally expensive, but also moderately effective in modeling small size precipitation events. In this thesis, an existing RBFNN technique [3] was implemented to verify its computational efficiency and forecasting effectiveness. The feasibility of modeling precipitation events using RBFNN effectively was evaluated, and several modifications to the existing technique have been proposed.

Laccase (benzenediol:oxygen oxidoreductase, EC 1.10.3.2), a multi-copper-containing oxidoreductase enzyme, is able to catalyze the oxidation of various low-molecular weight compounds, specifically, phenols and anilines. Due to their high stability, selectivity for phenolic substructures, and mild reaction conditions, laccases are attractive for fine chemical synthesis. In this study, new green domino syntheses were developed by conducting the reaction in an aqueous medium, an environmentally-friendly solvent, and using laccase as a biocatalyst. The first study presents a work on the synthesis of naphthoquinones in the aqueous medium. Herein, laccase was used to oxidize o- and p-benzenediols to generate o- and p-benzoquinones in situ. These quinones then underwent Diels-Alder and oxidation reactions to finally generate napthoquinone products. This reaction system can yield naphthoquinones in up to 80% yield. The next part of this thesis reports the cascade synthesis of benzofuran derivatives from the reaction of catechols and 1,3-dicarbonyl compounds via oxidation-Michael addition in the presence of laccase and Sc(OTf)3/SDS in an aqueous medium. Depending on the substrates, one-pot yields of benzofurans averaged 50-79%. From an environmental concern, this system still produced a hazardous waste from the transition metal catalyst. Therefore, the development of alternative methodologies to replace the lanthanide metal catalyst in this synthesis is a high priority to enhance the overall green chemistry aspect. As a consequence, lipase was used as a catalyst to replace Sc(OTf)3 for the synthesis of benzofuran derivatives. In addition, this catalytic system was also used to catalyze the reaction of anilines and catechol. In the last part of this thesis, laccase was applied to the modification of high-lignin softwood kraft pulp. This modification demonstrates the potential of laccase-facilitated grafting of amino acids to high lignin content pulps to improve their physical properties in paper products which resulted from the increase of carboxylic acid group of the fibers. In this study, a variety of amino acids were examined. Laccase-histidine treatment provided the best yield of acid groups on pulp fiber and was used in the preparation of handsheets for physical strength testing. Laccase-histidine-treated pulp showed an increase in the strength properties of the resulting paper.