LRC devresi ile RF alan-çözelti etkileşiminde kayıp faktörleri ve hücre sabitleri

Bu tezin, veri tabanı üzerinden yayınlanma izni bulunmamaktadır.ÖZET Anahtar kelimeler : Kayıp faktörü(x")> Çözelti direnc(Rç), Eşdeğer iletkenlik(A), Çözelti sığası(Cç), Hücre sabiti(Ç) Elektrolitlerin (a) öziletkenlikleri, (A) eşdeğer iletkenlikleri ve (Rç) elektrolitik dirençleri, çözelti konsantrasyonu (y) 'ya bağlı olarak değişim göstermektedirler. Bu değişim elektrolitler için tanıtıcı araştırmalar yapılmasına olanak sağlamaktadır. Bu çalışmada elektrolitik çözeltilerin etkileşimi başka bir yol olan Radyo-Frekans elektromagnetik alanlar kullanılarak incelenmiştir. Bu uygulama için çeşitli yöntemler kullanılmaktadır. Rezonans yöntemi ve köprü yöntemleri bunların başında gelir. Rezonans yönteminde indüktif ve kapasitif hücre olmak üzere iki türlü hücre kullanılabilmektedir. Burada paralel LRC devresi ile rezonans yöntemi işleminde indüktif hücre tercih edilmiştir. Çözelti - alan etkileşiminde devrenin rezonans koşullarındaki değişimleri saptanarak incelenmiştir. Rezonans devresinin kalite faktörü Q ise çözeltilerin kayıp faktörleri % =Q~1 tanımlamasıyla saptanabilir. Kayıp faktörleri, çeşitli çözeltiler için devre parametrelerine ve frekansa bağlılıkları yönünden çok sayıda deneylerle incelenmişlerdir. Çalışma sonunda kayıp faktörlerinin devre parametreleriyle ilişkilerinden faydalanarak düzenlenen matematik bağıntılardan ve çözelti-alan etkileşimlerinden elde edilen verilerle çizilen grafiklerden, deney sisteminde kullanılan deneme bobinleri hücre sabitlerinin LRC devresinde çözelti-alan etkileşimi yönteminden yararlanarak hesaplanabileceği gösterilmiştir.Key words : Loss factor(x")> Solution resistance(Rç), Equivalent conductivity (A), Solution capacity (Cç), Cell Constant (Ç) The specific conduction (ct), equivalent conductivity (A) and electrolytical resistance (Rç) properties of electrolits vary with the consructions of the solutions. This variation allows us to identify electrolits. İn this study to analysis the interactions of electrolytical solutions more easily, Radiofrequiency fields used. For this approach different methodssuch us the resonance methods and the bridge methods are used, inductive or capacitive cells can be used, also. Here LRC circuit is used and solution field interaction is studied with determining the variations of resonance conditions of oscillation circuit, if the quality factor of the resonance circuit is Q, then the loss factor of the solutions can be evaluated with the definition %" = Q_1. This method is used in this work. %" loss factor of different solutions are examined for their dependence on circuit parameters and frequency in many experiments. The experimental results are seen to be suitable with Debye equations. This results supports the mathematical definitions of the solution interactions. As a results of this study by using the relation of circuit parameters and loss factors it is shown that for measuring cell used for experiment system the cell constant can be evaluated from the graphics by using this method. X

Palladyum ve aluminyum metallerinin ve alaşımlarının dinamik özelliklerinin moleküler-dinamik incelemesi

The dynamic properties of Palladium (Pd) and Aluminum (Al) metals and their alloys are investigated by means of Molecular Dynamics using the Quantum Sutton-Chen force field in five different concentrations. Calculations have been carried out for liquid structures. Although this study is done for liquid structures, basic solid state properties are also investigated to prove the validity of potential parameters. Results are compared with each other and with experimental, theoretical and simulated results. Liquid state transferability of Quantum Sutton-Chen parameters have been investigated and discussed. High temperature properties, which are not easy to work experimentally, are simulated and high temperature behavior of Pd-Al alloy is investigated.Ph.D. - Doctoral Progra

Experimental (UV, NMR, IR and Raman) and theoretical spectroscopic properties of 2-chloro-6-methylaniline

In this work, the experimental and theoretical UV, NMR and vibrational spectra of 2-chloro-6-methylaniline (2-Cl-6-MA, C7H8NCl) were studied. The ultraviolet absorption spectra of compound that dissolved in ethanol were examined in the range of 200-400 nm. The 1H, 13C and DEPT NMR spectra of the compound were recorded. FT-IR and FT-Raman spectra of 2-Cl-6-MA in the liquid phase were recorded in the region 4000-400 cm-1 and 3500-50 cm-1, respectively. The structural and spectroscopic data of the molecule in the ground state were calculated using density functional theory (DFT) employing B3LYP exchange correlation and the 6-311++G(d,p) basis set. The vibrational frequencies were calculated and scaled values were compared with experimental FT-IR and FT-Raman spectra. The observed and calculated frequencies were found to be in good agreement. The complete assignments were performed on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method. Isotropic chemical shifts were calculated using the gauge-invariant atomic orbital (GIAO) method. Comparison of the calculated NMR chemical shifts and absorption wavelengths with the experimental values revealed that DFT method produces good results.https://doi.org/10.1080/0026897090282157

FT-IR, FT-Raman, NMR spectra, and molecular structure investigation of 2,3-dibromo-N-methylmaleimide: A combined experimental and theoretical study

In the present work, the experimental and theoretical vibrational spectra and chemical shifts of 2,3-dibromo-N-methylmaleimide (2,3DBrNMM, C(5)H(3)NO(2)Br(2)) were studied. FT-IR and FT-Raman spectra of 2,3DBrNMM in the solid phase were recorded in the region 4000-4400 cm(-1) and 3500-3550 cm(-1), respectively. The structural and spectroscopic data of the molecule in the ground state were calculated by using Hartree-Fock and density functional method (B3LYP) with the 6-31G(d), 6-31G(d,p), 6-31G(d,p), 6-31+G(d,p), 6-31++G(d), 6-311G(d,p). 6-311+G(d,p) and 6-311++G(d,p) basis sets. The scaled values have been compared with experimental FT-IR and FT-Raman spectra. The observed and calculated frequencies are found to be in good agreement. The complete assignments were performed on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method. (13)C NMR, (1)H NMR and DEPT spectra were recorded. (13)C NMR and (1)H NMR chemical shifts were calculated by using HF and B3LYP methods with 6-311++G(d,p) basis sets. The optimized geometric parameters (bond lengths and bond angles) were given corresponding experimental values of maleimide and 3-benzoylmethyl-2-chloro-N-methylmaleimide molecules. (C) 2008 Published by Elsevier B.V

A comparative study of selected disperse azo dye derivatives based on spectroscopic (FT-IR, NMR and UV-Vis) and nonlinear optical behaviors

In the present work, a combined experimental and quantum chemical study on ground state equilibrium structure, spectroscopic and nonlinear optical properties of selected disperse azo dye molecules are reported. The vibrational transitions were identified based on the recorded FT-IR spectra in the range of 4000-400 cm(-1) for solid state, simulated IR spectra and total energy distribution (TED) of vibrational modes. The chemical shifts were determined from the results of observed H-1 and C-13 NMR spectra in chloroform and dimethylsulfoxide solution. The DFT/gauge-invariant atomic orbital (CIAO) methodology was applied to predict the magnetic properties. Electronic properties were carried out by UV-Vis spectroscopy and TD-DFT/CIS approach. The nonlinear optical (NLO) features were addressed theoretically. A detailed description of spectroscopic and NLO behaviors of studied disperse azo dyes was reported with the help of comparison of experimental measurements and theoretical calculations. (C) 2013 Elsevier B.V. All rights reserved

FT-IR, UV-vis, H-1 and C-13 NMR spectra and the equilibrium structure of organic dye molecule disperse red 1 acrylate: A combined experimental and theoretical analysis

This study reports the characterization of disperse red 1 acrylate compound by spectral techniques and quantum chemical calculations. The spectroscopic properties were analyzed by FT-IR. UV-vis, H-1 NMR and C-13 NMR techniques. FT-IR spectrum in solid state was recorded in the region 4000-400 cm(-1). The UV-vis absorption spectrum of the compound that dissolved in methanol was recorded in the range of 200-800 nm. The H-1 and C-13 NMR spectra were recorded in CDCl3 solution. The structural and spectroscopic data of the molecule in the ground state were calculated using density functional theory (DFT) employing B3LYP exchange correlation and the 6-311++G(d,p) basis set. The vibrational wavenumbers were calculated and scaled values were compared with experimental FT-IR spectrum. A satisfactory consistency between the experimental and theoretical spectra was obtained and it shows that the hybrid DFT method is very useful in predicting accurate vibrational structure, especially for high-frequency region. The complete assignments were performed on the basis of the experimental results and total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method. Isotropic chemical shifts were calculated using the gauge-invariant atomic orbital (GIAO) method. A study on the electronic properties were performed by timedependent DFT (TD-DFT) and CIS(D) approach. To investigate non linear optical properties, the electric dipole moment mu, polarizability alpha, anisotropy of polarizability Delta alpha and molecular first hyperpolarizability beta were computed. The linear polarizabilities and first hyperpolarizabilities of the studied molecule indicate that the compound can be a good candidate of nonlinear optical materials. (C) 2011 Elsevier B.V. All rights reserved

Theoretical investigation on the molecular structure, Infrared, Raman and NMR spectra of para-halogen benzenesulfonamides, 4-X-C6H4SO2NH2 (X = Cl, Br or F)

In the present study, the structural properties of para-halogen benzenesulfonamides, 4-XC6H4SO2NH2 (4-chlorobenzenesulfonamicle (I). 4-bromobenzenesulfonamide (II) and 4-fluorobenzenesulfonamide (III)) have been studied extensively utilizing ab initio Hartree-Fock (HF) and density functional theory (DFT) employing B3LYP exchange correlation. The vibrational frequencies were calculated and scaled values were compared with experimental values. The complete assignments were performed on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method. The effects of the halogen substituent on the characteristic benzenesulfonamides bands in the spectra are discussed. The H-1 and C-13 nuclear magnetic resonance (NMR) chemical shifts of the molecules were calculated using the Gauge-Invariant Atomic Orbital (GIAO) method. Finally, geometric parameters, vibrational bands and chemical shifts were compared with available experimental data of the molecules. The fully optimized geometries of the molecules were found to be consistent with the X-ray crystal structures. The observed and calculated frequencies and chemical shifts were found to be in very good agreement. (c) 2009 Published by Elsevier B.V

Magnetic metal nanoparticles coated polyacrylonitrile textiles as microwave absorber

Polyacrylonitrile (PAN) textiles with 2 mm thickness are coated with magnetic nanoparticles in coating baths with Ni, Co and their alloys via an electroless metal deposition method. The crystal structure, morphology and magnetic nature of composites are investigated by X-ray Powder diffraction, Scanning Electron Microscopy, and dc magnetization measurement techniques. The frequency dependent microwave absorption measurements have been carried out in the frequency range of 12.4-18 GHz (X and P bands). Diamagnetic and ferromagnetic properties are also investigated. Finally, the microwave absorption of composites is found strongly dependent on the coating time. One absorption peak is observed between 14.3 and 15.8 GHz with an efficient absorption bandwidth of 3.3-4.1 GHz (under -20 dB reflection loss limit). The Reflection loss (RL) can be achieved between -30 and -50 dB. It was found that the RL is decreasing and absorption bandwidth is decreasing with increasing coating time. While absorption peak moves to lower frequencies in Ni coated PAN textile, it goes higher frequencies in Co coated ones. The Ni-Co alloy coated composites have fluctuating curve of absorption frequency with respect to coating time. These results encourage further development of magnetic nanoparticle coated textile absorbers for broadband applications. Crown Copyright (c) 2012 Published by Elsevier B.V. All rights reserved