Investigations of Ancient Terra-cotta Sarcophagi, Excavated in Enez (Ainos) Turkey, by Instrumental Neutron Activation Analysis

Ten terra-cotta sarcophagi, together with a terra-cotta aryballos (perfume jar), excavated in Su Terazisi necropolis of Enez-Turkey (Ancient Ainos), were investigated by Instrumental Neutron Activation Analysis (INAA), to determine the concentration of thirty two chemical elements: Na, K, Ca, Fe, Sc, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Br, Rb, Sr, Sb, Cs, Ba, La, Ce, Nd, Sm, Eu, Tb, Dy, Yb, Lu, Hf, Ta, Th and U. The dataset was submitted to multivariate statistical analysis. The classification was done by cluster analysis. The results demonstrated the occurrence of two different groups of terra-cotta samples. Group I contains nine sarcophagi and terra-cotta aryballos whereas group II contains only one sample (E09-ST5-M26). High correlations between La and Ce (r2 = 0.92), and U and Th (r2 = 0.91) indicated that local clay was used for manufacturing the terra-cotta sarcophagi and aryballos but probably the claybed used for E09-ST5-M26 was different from that of others

Cerebrospinal fluid flow dynamics in patients with multiple sclerosis: a phase contrast magnetic resonance study

Cerebrospinal fluid (CSF) flow dynamics, which supposedly have a strong relationship with chronic cerebrospinal venous insufficiency (CCSVI), might be expected to be affected in multiple sclerosis (MS) patients. In this study, CSF flow at the level of the cerebral aqueduct was evaluated quantitatively by phase contrast magnetic resonance imaging (PC-MRI) to determine whether CSF flow dynamics are affected in MS patients. We studied 40 MS patients and 40 healthy controls using PC-MRI. We found significantly higher caudocranial(p=0.010) and craniocaudal CSF flow volumes(p=0.015) and stroke volume (p=0.010) in the MS patients compared with the controls. These findings may support the venous occlusion theory, but may also be explained by atrophy-dependent ventricular dilatation independent of the venous theory in MS patients

The effects of conformation and intermolecular hydrogen bonding on the structural and vibrational spectral data of naproxen molecule

The structural and vibrational properties of naproxen, an inhibitor of cyclooxygenase (COX) enzyme, were investigated by molecular modeling and experimental IR and Raman spectroscopic techniques. Possible conformers of the molecule were searched via a molecular dynamics simulation carried out with MM2 force field. The total energies, equilibrium geometries, force fields, IR and Raman spectral data of the found stable conformers were determined by means of geometry optimization and harmonic frequency calculations carried out using the B3LYP method and Pople-style basis sets of different size. The stability order obtained for the lowest-energy conformers was confirmed by high-accuracy thermochemistry calculations performed with G3MP2B3 composite method. Some electronic structure parameters of naproxen and the anharmonicity characters of its vibrational modes were determined by means of natural population analysis (NPA) and anharmonic frequency calculations at B3LYP/6-31++G(d,p) and B3LYP/6-311++G(d,p) levels of theory. A part of these calculations carried out for free naproxen molecule were repeated also for its energetically most favored dimer forms. Two different scaling procedures ((1) "SQM-FF methodology" and (2) "Dual scale factors") were independently applied to the obtained harmonic vibrational spectral data to fit them to the corresponding experimental data. In the light of the obtained calculation results, which confirm the remarkable effects of conformation and intermolecular hydrogen bonding on the structural and vibrational spectral data, in particular, on those associated with the functional groups in the propanoic acid chain, a reliable assignment of the fundamental bands observed in the experimental IR and Raman spectra of the molecule was achieved. (C) 2013 Elsevier B.V. All rights reserved

A vibrational spectroscopic investigation on benzocaine molecule

The stable conformers of free benzocaine molecule in electronic ground state were searched by means of successive single point energy calculations carried out at B3LYP/3-21G level of theory. The obtained calculation results have indicated that the molecule has three different stable conformers (one trans and two gauche) at room temperature. The resultant equilibrium geometrical parameters of these stable conformers were determined through the geometry optimizations performed at B3LYP/6-31G(d), B3LYP/6-3l++G(d,p), B3LYP/aug-cc-pvTZ and MP2/6-31++G(d,p) levels of theory, separately. The vibrational normal modes of each conformer and associated wavenumbers, IR intensities and Raman activities were calculated in the harmonic oscillator approach at B3LYP/6-31G(d), B3LYP/6-3l++G(d,p), B3LYP/aug-cc-pvTZ levels of theory. In the fitting of the calculated harmonic wavenumbers to the experimental ones, two different scaling procedures, called "Scaled Quantum Mechanics Force Field (SQM FF) methodology" and "scaling wavenumbers with dual scale factors", were proceeded independently. Both procedures have yielded results in very good agreement with the experiment and thus proved the necessity of proceeding an efficient scaling procedure over the calculated harmonic wavenumbers for performing a correct vibrational spectroscopic analysis on the basis of B3LYP calculations. In the light of the obtained scaled theoretical spectral data, a successful assignment of the fundamental bands observed in the recorded IR and Raman spectra of the free molecule was achieved. (C) 2008 Elsevier B.V. All tights reserved

A theoretical vibrational spectroscopic investigation on free Ethyl 2- and 3-aminobenzoate molecules

The possible stable conformers of free Ethyl 2- and 3-aminobenzoate molecules were searched via subsequent single point energy calculations carried out at semi-empirical PM3 theory level. The final equilibrium geometrical parameters for the obtained stable conformers were defined by performing geometry optimizations with B3LYP hybrid DFT method and basis sets of different size and type. The harmonic vibrational normal modes of the two molecules and their corresponding wavenumbers and IR intensities were calculated at the obtained equilibrium geometries using the same method and basis sets used in the geometry optimizations. In the light of these calculated spectral data, a successful assignment for the fundamental bands in the IR spectra of the two molecules was given. In order to fit the calculated harmonic wavenumbers to the experimentally observed ones, two different scaling procedures, called "scaling wavenumbers in Scaled Quantum Mechanics Force Field (SQM FF) methodology" and "scaling wavenumbers with dual empirical scale factors", were proceeded independently. (C) 2006 Elsevier B.V. All rights reserved

A theoretical vibrational spectroscopic study with density functional theory and force field refinement calculation methods on free 4-aminopyrimidine molecule

A detailed investigation of the geometric structure, force field, electro-optical parameters, relative IR intensities and harmonic vibrational wavenumbers of free 4-aminopyrimidine molecule (4APM) in the electronically ground state has been carried out by using both the DFT-B3LYP (with 6-31 + +G(d,p) double and 6-311 + +G(d,p) triple basis sets) and force field refinement calculation methods. The vibrational wavenumbers calculated with DFT method were scaled by using two different methods: (1) scaling with dual scaling factors, (2) deriving the scaling factors from the graph of observed versus calculated wavenumbers. In the case of force field refinement method, the force constants of the pyrimidine were slightly refined so as to fit the calculated wavenumbers to the experimental ones. In order to define the contributions of the internal coordinates of the molecule on its each normal vibrational mode, P.E.D. calculations were performed. In wavenumber and PED calculations, both methods have yield results in agreement with the experimental assignment and also with each other, particularly for ring vibrations. The relative IR intensities calculated by the force field refinement method are considerably in good agreement with experimental ones, however, the results of the IR intensities, obtained from the DFT method are found to be significantly different from the experimental values. (c) 2004 Elsevier B.V. All rights reserved

A comparative vibrational spectroscopic investigation of free mn-12S(2)O(2) and fn-12S(2)O(2) dithiacrown ethers based on DFT calculations

A successful assignment for the fundamental bands observed in the experimental IR spectra of mn-12S(2)O(2) and fn-12S(2)O(2) dithiacrown ethers was achieved by the aid of the density functional theory (DFT) based quantum mechanical calculations carried out at the 133LYP/6-31G(d) and B3LYP/6-31 + G(d) level of theory. Two different scaling approaches, '(i) scaled quantum mechanics force field (SQM FF) methodology', and (ii) the 'scaling frequencies with dual empirical scale factors', were used in order to fit the calculated harmonic frequencies to the experimental ones. Potential energy distribution (PED) calculations were carried out to define the internal coordinate contributions to each normal mode and to define the corresponding normal modes of the molecules. The effects of the conformational differences onto the IR active normal modes of the two isomeric molecules and their corresponding experimental frequencies were discussed in the light of the calculated spectral data. (c) 2005 Elsevier B.V. All rights reserved

An experimental and theoretical vibrational spectroscopic study on niflumic acid, a non-steroidal anti-inflammatory drug

The theoretically possible stable conformers of niflumic acid (NFA) molecule in electronic ground state were investigated by means of potential energy surface scan and thermochemistry calculations carried out at room temperature using DFT-B3LYP method and different Pople-style basis sets. The data obtained from these calculations confirmed that the two planar conformers in which the carboxyl and fluoromethyl functional groups are located either in "trans" or in "cis" position to each other are the most favorable ones in energy among all the stable conformers of the free molecule. This conclusion was also confirmed by the energy values obtained from the higher-accuracy thermochemistry calculations carried out using G3MP2B3 composite method. For both conformers and also for their most favorable dimer forms in energy, the equilibrium geometry, force field and vibrational spectral data were calculated first at B3LYP/6-31G(d) and then at B3LYP/6-311++G(d,p) levels of theory. On the basis of these theoretical data, the effects of the conformation and dimerization on the corresponding experimental data of NFA molecule were discussed in detail. The overestimations of the calculated harmonic wavenumbers were corrected by the aid of two different empirical scaling procedures referred to as "scaled quantum mechanical force field (SQM FF) methodology" and "dual scale factors". In the light of the improved theoretical data obtained in these two approaches applied independently from each other, a successful assignment of the fundamental bands observed in the room-temperature IR and Raman spectra of the molecule was given. (C) 2010 Elsevier B.V. All rights reserved

Investigations of historical textiles from the Imperial Pavilion (Hunkar Kasri) of the new mosque Eminonu-Istanbul (Turkey) by multiple analytical techniques

This article presents some approaches for chemical and physical characterization of materials applied to a specific category of cultural material, historical textiles. The investigation and characterization of historical objects by non-destructive methods are important since they are important sources of reference for cultural studies. In this study, two historic textiles (the original one and its repaired part), obtained from the ceiling decorations of Imperial Pavilion (Hunkar Kasri) of the New Mosque Eminonu-Istanbul (Turkey) were analyzed using Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR), Energy Dispersive X-ray Fluorescence (EDXRF) and Scanning Electron Microscopy (SEM) techniques, for the purpose of material identification. The results showed that the investigated samples were linen fabric. EDXRF results revealed that in the original part of the textile, metallic gold was used for gilding. No gold gilding was observed in the repaired part of the textile. In the paint layers of the original part of the textile, both lead white {2PbCO(3)center dot Pb(OH)(2)}, and gypsum {CaSO4 center dot 2H(2)O} were used as white pigment, but in the repaired part, the white pigment was mainly gypsum, and contained only a small amount of the lead white. The FTIR analysis was successfully used in quantifying the degradation of historic textiles in terms of the crystalline structure of cellulosic fibers. (C) 2016 Elsevier Masson SAS. All rights reserved