G. Apaydın

Elemental analysis of Akçaabat tobacco and its ash by EDXRF spectrometry

Abstract The concentration of eight different elements in tobacco of different region in Akcaabat (Trabzon/Turkey) was determined using energy dispersive X-ray fluorescence method. A radioisotope excited X-ray fluorescence analysis using the method of multiple standard addition is applied for the elemental analysis of tobacco and its ash. An annular 50 mCi 241 Am radioactive source and an annular 50 mCi 55 Fe radioactive source were used for excitation of characteristic K X-rays. An Si(Li) detector which has a 147 eV full width at half maximum for 5.9 keV photons was used for intensity measurements. A qualitative analysis of spectral peaks showed that the samples contained potassium, calcium, titanium, iron, copper, bromine, strontium and barium. Evaluation of these elements with their potential hazards for smokers is briefly discussed.

Chemical Effect on K Shell X-ray Fluorescence Parameters and Radiative Auger Ratios of Co, Ni, Cu, and Zn Complexes

The production cross-sections, intensity ratios, and radiative Auger intensity ratios of Co, Ni, Cu, and Zn elements in different complexes were measured. The chemical effects on the K shell fluorescence parameters and the radiative Auger intensity ratios of these elements were investigated and the changes in these parameters were interpreted according to the charge transfer process. The samples were excited by 59.5 keV γ-rays from a 241Am annular radioactive source. K X-rays emitted by samples were counted by an Ultra-LEGe detector with a resolution of 150 eV at 5.9 keV.

An LIII (2P3/2) subshell absorption jump ratio and jump factor for bismuth

In this paper, we report on measurement of the first experimental LIII (2P3/2) subshell absorption jump ratio and jump factor value which were derived from new mass attenuation coefficients measured at the upper and lower energy branches of the LIII absorption edge using an energy dispersive x-ray fluorescence (EDXRF) spectrometer for bismuth. The measurements of mass attenuation coefficients, at 36 energies from 10.010 to 17.478 keV, were done in a transmission geometry utilizing the Ki (i = α, α1,2, β, β1,2) and Li (i = α, β, β1,2, γ, γ1, l) x-rays from different secondary source targets excited by the 59.543 keV γ-photons from an 241Am annular source and detected by an ultra-LEGe solid-state detector with a resolution of 0.15 keV at 5.9 keV. The results have been compared with theoretical values.

Chemical effect on the K and L shell intensity ratios of Hf compounds

Chemical effects on the Ki/Kj (i=α2, β, β1, β2; j=α, α1, β1), Li/Lα (i=l, β, γ) and Li/Kj (i=l,α, β, γ; j=α1, α2) x-ray intensity ratios for  (Hf) compounds were investigated. The samples were excited by 123.6 keV γ-rays from a 57Co annular radioactive source. K and L x-rays emitted by samples were counted by an Ultra-LEGe detector with a resolution of 150 eV at 5.9 keV. We observed a chemical effect on the Li/La and Li/Kj x-ray intensity ratios for Hf compounds. However, for the Ki/Kj intensity ratios, dependence on the chemical state of Hf compounds is almost negligible. The experimental values have been compared with the theoretically calculated values of pure Hf.

Crystal structure, DFT and HF calculations and radical scavenging activities of (E)-4,6-dibromo-3-methoxy- 2-((3-methoxyphenylimino)methyl)phenol

In this study, (E)-4,6-dibromo-3-methoxy-2-[(3-methoxyphenylimino)methyl]phenol has been synthesized and characterized by using X-ray technique and FT-IR experimentally and using B3LYP/6-31G(d,p) and HF/6-31G(d,p) methods theoretically. The intermolecular and intramolecular interactions of the title compound have been determined according to X-ray results. The molecular geometry, vibrational frequencies of the title compound in the ground state have been calculated using the density functional B3LYP and HF method with the 6-31G(d,p) basis set and calculated bond parameters and vibrational frequencies values show good agreement with experimental values. Theoretical and experimental results show that tautomeric form of the structure is phenol-imine form. Besides HOMO-LUMO energy gap, molecular electrostatic potential map were performed at B3LYP/6-31G(d,p) level. It is worthy note of that, the free radical scavenging activities of the title compound were assessed using DPPH˙, DMPD˙(+), and ABTS˙(+) assays. The obtained results show that the title compound has effective DPPH˙ (SC50 2.61±0.09 μg/mL), DMPD˙(+) (SC50 2.82±0.14 μg/mL), and ABTS˙(+) (SC50 4.91±0.18 μg/mL) radical scavenging activities when compared with standard antioxidants (BHA, rutin, and trolox).

Investigation of Coster-Kronig Transition Probabilities (L1 ! L2, L1 ! L3, and L2 ! L3) for Hf and Hf Compounds

In this study, the L 1 →L 2 , L 1 →L 3 , and L 2 →L 3 Coster–Kronig (CK) transition probabilities ( f 12 , f 13 , and f 23 ) for Hf compounds were investigated. The samples were excited by 59.5 keV γ-rays from a 241 Am annular radiative source. L X-rays emitted by samples were counted by an Ultra-LEGe detector with a resolution of 150 eV at 5.9 keV. In addition, it was observed a chemical effect on the CK transition probabilities for Hf compounds. The semi-empirical values of f 12 , f 13 , and f 23 CK transition probabilities have been compared with the semi-empirical, theoretical and experimental data for pure Hf, respectively.

Molecular structure, quantum mechanical calculation and radical scavenging activities of (E)-4,6-dibromo-2-((3,5-dimethylphenylimino) methyl)-3-methoxyphenol and (E)-4,6-dibromo-2- ((2,6-dimethylphenylimino)methyl)-3-methoxyphenol compounds

In this study, (E)-4,6-dibromo-2-[(3,5-dimethylphenylimino)methyl]-3-methoxyphenol and (E)-4,6-dibromo-2-[(2,6-dimethylphenylimino)methyl]-3-methoxyphenol compounds have been synthesized and characterized by using X-ray crystallographic method, FT-IR and Density functional method. The molecular geometry, vibrational frequencies of the title compounds in the ground state have been calculated by using B3LYP with the 6-31G(d,p) basis set. The tautomeric form of the compounds has been demonstrated by using single crystal X-ray method, FT-IR spectrometer and DFT method. In addition, HOMO-LUMO energy gap, molecular electrostatic potential map and NBO analysis of the compounds are performed at B3LYP/6-31G(d,p) level. It may be remarked that the free radical scavenging activities of the title compounds were assessed using DPPH, DMPD+, and ABTS+ assays. The obtained results show that especially compound 2 has effective DPPH (SC50 1.52±0.14 μg/mL), DMPD+ (SC50 1.22±0.21 μg/mL), and ABTS+ (SC50 3.32±0.17 μg/mL) scavenging activities compared with standards (BHA, rutin, and trolox).

Investigation by XRF and XRD of Zn and Fe in Fex Zn1−x thin films

FexZn1?x alloys were electrochemically deposited on aluminum substrates from a sulfate bath. The K?/K? x-ray intensity ratios of Zn and Fe in FexZn1?x thin films have been experimentally studied. The energy dispersive x-ray fluorescence (EDXRF) technique was used to measure K x-ray photons. Samples were excited by using 59.5?keV photons emitted by a 50 mCi 241Am radioactive source. The emitted K x-rays were detected by an Ultra-LEGe detector having a resolution of 150?eV at 5.9?keV. In addition, the effect of bath composition on the phase structure was investigated by x-ray diffraction (XRD) analysis. The composition of the thin films was analyzed by atomic absorption spectrometry analysis. Iron content was shown to strongly affect the structure of Zn?Fe alloys. It was found that the K-shell x-ray intensity ratio changed in FexZn1?x thin films for different values of x. The reason for this change may be that the electronegativity of iron is higher than that of zinc and that electron transfer from zinc to the outermost orbital of iron occurs. In conclusion, in FexZn1?x thin films, intensity ratio increases with increasing concentration of Zn but decreases with increasing concentration of Fe.

Calculation of K Shell Intensity Ratios and Line Widths of Ti and some of its compounds by means of 5,96 keV energy

K shell intensity ratios and Line Widths of pure Ti and some of its compounds have been determined experimentally using an Ultra-LEGe detector with resolution 140 eV at 5.9 keV. The samples were excited 5.96 keV photons emitted from a 55Fe radioisotope source with 50 mCi activity. The experimental values of the K shell intensity ratios have been compared with the experimental and theoretical values available in the literature for pure Ti and line widths have been only compared with a theoretical value for pure Ti.

Studies on mass attenuation coefficients, effective atomic numbers and electron densities for CoCuAg alloy thin film

The mass attenuation coefficients for the elements Co, Cu and Ag and a thin film of CoCuAg alloy were measured in the energy range 4.029–38.729 keV. Effective atomic numbers and electron densities were calculated by using these coefficients. The energies were obtained by using secondary targets that were irradiated with gamma-ray photons of 241Am. The x-rays were counted by using a Canberra Ultra-LEGe detector with a resolution of 150 eV at 5.9 keV. The results were compared with theoretical calculated values and fairly good agreement was found between them within an average experimental error. The mass attenuation coefficients, effective atomic numbers and electron densities were plotted versus photon energy.