Sharif Digital Repository

The complexation between folic acid and the complexes of Cu(L)2 (L = Glycine, Alanine, Valine) were investigated using UV.Vis spectroscopy. The values of the equilibrium constant K and molar absorption coefficient Ɛ of the complexes were estimated in the aquation environment at various temperatures. The temperature dependence of the K can be used for the determination of the thermodynamic reaction quantities (∆G, ∆H, ∆S) for linear regression fits to the Van’t Hoff equation. The kinetic studies reveals that the stoichiometry of reaction were 1:1 for these systems. All reaction were endothermic and the values of the ∆H are positive. In all cases entropy increased and the values of the ∆S... 

In recent years, the Cognitive Radio Network has received significant attentions due to its high potential for better employment of the spectrum. One of the most important parts of this technology is the spectrum sensing that requires being fast and accurate. The conventional algorithms proposed so far encounter some fundamental challenges at low SNR regimes and in wideband sensing. On the other hand, the compressed sensing algorithms, which take advantages of the sparsity of the signal of interest and utilize measurements instead of the samples, can reduce the sampling rate and thus decrease the complexity associated with the wideband sensing. In this thesis, by exploiting the... 

Gamma-ray spectroscopy is the quantitative study of the energy spectra of gamma-ray sources. A gamma-ray spectrometer also determines the energies of the gamma-rays photons emitted by the source. A radioactive nucleus (radionuclide) commonly emits gamma rays in the energy range from a few keV to ~10 MeV, corresponding to the typical energy levels in nuclei with reasonably long lifetimes. Most radioactive sources produce gamma rays of various energies and intensities. When these emissions are collected and analyzed with a gamma-ray spectroscopy system, a gamma-ray energy spectrum can be produced. A detailed analysis of this spectrum is typically used to determine the identity and quantity of... 

A soft X-ray spectrometer based on Johann's method and an embedded curved crystal is designed and fabricated for Sharif University of Technology's Plasma Focus (SUT-PF) in this project. Focusing rays with the same wavelength at a point to increase the ray intensity is the reason of choosing the cylindrical curved crystal spectrometer since its performance is inspired to the Bragg's law.The optimal conditions for SUT-PF (pressure and voltage) is adjusted and examined by photodiode detector and the camera pinhole before spectroscopy experiments. The diameter of generated hot spots is measured as 80 microns in the optimal condition.The recorded spectral lines on the radiography film and the... 

The cyclometalated platinum(II) complex [Pt(Me)(bhq)(2-vpy)], 2, in which bhq = benzo{h}quinolone, 2-vpy = 2-vinylpyridine, has been prepared by reaction of the cyclometalated complex [Pt(Me) bhq)(SMe2)], 1 with one equiv 2-vinylpyridine. The similar complex [Pt(p-tolyl)(ppy)(2-vpy)], 3 in which ppy = 2-phenyl pyridine, has been prepared from reaction of the platinum(II) complex cis-[Pt(p-MeC6H4)2(SMe2)2] with one equiv 2-phenylpyridine and one equiv 2-vinylpyridine. Reaction of 2 with one equiv Br2 in acetone gave the cyclometalated platinum(IV) complex [Pt(bhq)Me(Br)(NC5H4CHCH2Br)], 4. The structure of the complexes 1-3 were determined using NMR Spectroscopy. The crystal structure of 3... 

Microfluidics is a novel technology that brought a revolution in the field of chemistry and biology. This technology allows precise control and manipulation of fluids and particles in sub-millimeter bio-compatible channels. This makes microfluidics a powerful tool to study and examine bio-particles and bio-processes. One of the most prominent areas in microfluidics is the integration of developed measurement tools and devices of the electrical engineering field, with microfluidic chips. The purpose of this thesis is to measure the electrical impedance spectrum of bio-particles with high precision and in a wide bandwidth. These valuable spectrums are useful in many applications such as... 

Efforts to identify, predict, and resolve problems linked to asphaltenes and flow assurance have resulted in the development of numerous laboratory and modelling techniques. However, there has been little research on the molecular structure of asphaltenes and how it relates to solubility, stability, aggregation, and deposition behavior. Not only was a thorough structural analysis of asphaltene extracted from three samples of light, medium, and heavy oil performed in this study, but medium oil asphaltene was also fractionated into three sub-fractions based on solubility, with minimum, medium, and maximum solubility, and each subfraction was subjected to a structural analysis. All asphaltene...