Methods in Mathematica for Solving Ordinary Differential Equations

An overview of the solution methods for ordinary differential equations in the Mathematica function DSolve is presented.Comment: 13 page

Computation of conservation laws for nonlinear lattices

An algorithm to compute polynomial conserved densities of polynomial nonlinear lattices is presented. The algorithm is implemented in Mathematica and can be used as an automated integrability test. With the code diffdens.m, conserved densities are obtained for several well-known lattice equations. For systems with parameters, the code allows one to determine the conditions on these parameters so that a sequence of conservation laws exist.Comment: To appear in Physica D, 17 pages, Latex, uses the style files elsart.sty and elsart12.st

Computation of conserved densities for systems of nonlinear differential-difference equations

A new method for the computation of conserved densities of nonlinear differential-difference equations is applied to Toda lattices and discretizations of the Korteweg-de Vries and nonlinear Schrodinger equations. The algorithm, which can be implemented in computer algebra languages such as Mathematica, can be used as an indicator of integrability.Comment: submitted to Phys. Lett A, 10 pages, late

Subgap absorption spectroscopy in microcrystalline silicon thin films

Thesis (Master)--Izmir Institute of Technology, Physics, Izmir, 2004Includes bibliographical references (leaves: 79-82)Text in English; Abstract: Turkish and Englishxii, 93 leavesIntrinsic hydrogenated microcrystalline silicon thin films prepared by VHF-PECVD and HW-CVD methods under different deposition conditions have been investigated using steady state photoconductivity method (SSPC), photothermal deflection spectroscopy (PDS) and dual beam photoconductivity (DBP) method, and transmission spectroscopy. Absorption spectra of the investigated thin films were measured in a wide energy region using PDS and DBP. A procedure, for the firs time, was used to calculate fringe free absolute absorption coefficient of thin films from DBP yield spectrum and simultaneously measured transmission signal. The results were found to be in agreement with those of PDS above the bandgap energy. However, there are differences between below the bandgap energy in the spectra of both methods. The differences are discussed to be consistent with the underlying physics of these methods. For some of investigated thin films there are remaining fringes in the .(h.) spectra measured using both methods. This is a strong indication of inhomogeneity present in the films in growth direction. DBP measurements were also performed for ac monochromatic light incident from substrate side in order to investigate the effect of inhomogeneous microstructure of the material on the absorption spectrum. It is found that some films have remaining fringes on their spectra for back ac measurements both for VHF-PECVD and HW-CVD grown thin films, whereas there is no remaining fringes observed for front ac measurements or vice versa. These findings are discussed to be an indication of inhomogeneity in growth direction which is already reported from TEM and Raman study. Sub-bandgap absorption coefficients .(0.8 eV) were correlated with the silane concentration, which is main parameter to change the microstructure of these films. It is found that the thin films that deposited in the transition region, where a transition from a fully amorphous growth to full microcrystalline growth occurs, have smaller absorption coefficients indicating that the thin films deposited at transition region have less defect density. However, thin films deposited at the highly crystalline region have the highest defect density due to etching effect of H during the deposition. These results are also consistent with reported ESR studies

Copolymer Synthesis with Redox Polymerization and Free Radical Polymerization Systems

In this study, block copolymer synthesis was evaluated by combining the redox polymerization technique and different polymerization techniques. By combining such different polymerization techniques, block copolymer synthesis has recently become an important part of polymer synthesis and polymer technology. The block/graft copolymers synthesized by combining such different techniques contribute greatly to macromolecular engineering. In today’s polymer synthesis, copolymer synthesis is of great interest in polymer technologies especially by using controlled radical polymerization and different polymerization techniques together. The success achieved in copolymer synthesis by using different polymerization techniques such as ATRP-ROP, RAFT-ROP, and ATRP-RAFT on the same step or different steps was achieved by combining redox polymerization with moderate polymerization conditions and controlled radical polymerization techniques as well

Investigation of tRNA-derived small RNAs in drosophila melangaster

Thesis (Master)--Izmir Institute of Technology, Molecular Biology and Genetics, Izmir, 2011Includes bibliographical references (leaves: 35-39)Text in English; Abstract: Turkish and Englishxi, 39 leavesTypes of small RNAs considered as crucial players of regulation of gene expression increase gradually in number. Improvements in cloning and sequencing strategies and technologies resulted in identification of tRNA derived small RNAs which are highly expressed in the cell just like other small RNAs such as microRNAs, endosiRNA, and Piwi interacting RNAs. Depending on stress and changing physiological conditions, tRFs are originated from different positions, in different frequency and different tRNAs. However, their functions and the complexes they interact with remain largely unknown. In this thesis study, one of the aims is to characterize tRNA derived small RNAs expressed during embryonic development in Drosophila melanogaster by in-vitro and invivo experiments. This study also aimed to demonstrate the differences between embryonic tRFs and stress induced tRNA derived small RNAs. Lastly, it was aimed to obtain some clues about their biogenesis, mechanism and functions. It was shown that the tRFs expressed in 1-hour and 8-h Drosophila embryos are different from stress induced tRNA derived small RNAs in terms of both position and length. The other important result is that embryonic tRFs are associated with complexes in mRNP and 60S fractions and they are expressed temporally and selectively during Drosophila embryogenesis

A novel drug carrier system using clinoptilolite for ginkgo biloba leaf extract

Thesis(Master)--Izmir Institute of Technology, Chemical Engineering, Izmir, 2004Includes bibliographical references (leaves: 78)Text in English; Abstract: Turkish and Englishxiv, 96 leavesThe use of natural and synthetic zeolites for pharmacological applications in possible encapsulation and/or adsorption of different ions and molecules in their open frame-work, and the subsequent release has emerged as a promising field during last years. In this study, the possible use of clinoptilolite-rich mineral as a novel drug carrierfor the active constituents present in Ginkgo biloba leaf extract solutions was investigated.In the first place, the extraction conditions for the compounds of interest (terpene lactones and flavonoid aglycones) within the leaf material were optimized. The extraction processes were performed with 80% ethanol aqueous solution due to its being non-toxic in nature and widely-used solvent for the preservation of the antioxidant activity possessed by the extract. For the quantification of the extracted species, HighPerformance Liquid Chromatography (HPLC) analysis was conducted. The quantification of terpene lactones was achieved with Evaporative Light Scattering Detection (ELSD), whereas flavonoid glycosides were quantified by Ultraviolet (UV) detection after being converted to their aglycone forms via acidic hydrolysis.In the adsorption studies, clinoptilolite having a particle size in the range 25- 106um was experimented. The flavonoid aglycone constituents were found to be selectively adsorbed on the clinoptilolite surface, whereas terpene lactones were determined to be adsorbed on the clinoptilolite surface in negligible amount. Therefore, the study concentrated on the adsorption of flavonoid constituents on the surface of the zeolitic material.Finally, the antioxidant activity determinations of the extract solutions were performed by the Trolox Equivalent Antioxidant Capacity (TEAC) assay. The antioxidant activity measurements performed for the Ginkgo leaf extract and commercial tablet extract solutions both showed decreasing antioxidant activities via adsorption. The decrease in antioxidant activity was related to the adsorption of phenolic constituents on the clinoptilolite surface

Algorithmic Integrability Tests for Nonlinear Differential and Lattice Equations

Three symbolic algorithms for testing the integrability of polynomial systems of partial differential and differential-difference equations are presented. The first algorithm is the well-known Painlev\'e test, which is applicable to polynomial systems of ordinary and partial differential equations. The second and third algorithms allow one to explicitly compute polynomial conserved densities and higher-order symmetries of nonlinear evolution and lattice equations. The first algorithm is implemented in the symbolic syntax of both Macsyma and Mathematica. The second and third algorithms are available in Mathematica. The codes can be used for computer-aided integrability testing of nonlinear differential and lattice equations as they occur in various branches of the sciences and engineering. Applied to systems with parameters, the codes can determine the conditions on the parameters so that the systems pass the Painlev\'e test, or admit a sequence of conserved densities or higher-order symmetries.Comment: Submitted to: Computer Physics Communications, Latex, uses the style files elsart.sty and elsart12.st

Kartpostallarda erkek kıyafetleri "Sokak ve zümre kıyafetleri"

Taha Toros Arşivi, Dosya No: 136-Kartpostallarİstanbul Kalkınma Ajansı (TR10/14/YEN/0033) İstanbul Development Agency (TR10/14/YEN/0033