Refracting properties of lyotropic nematic calamitic mesophase under magnetic field

The present study found the time-dependent extraordinary refractive index and birefringence of lyotropic nematic calamitic mesophase for different temperatures during its orientation under magnetic field. Based on the experimental results, the average angle between the mesophase directors and magnetic field was calculated to estimate the orientation dynamics of the mesophase during the director rotation from planar to homeotropic orientations. On the other hand, the textural properties were investigated during the orientation. The ordinary and extraordinary refractive indices were also measured depending on temperature to obtain the orientational order parameter of the mesophase. Using the macroscopic refractive index results, the microscopic polarizability was studied as well.     

1H-NMR spectra of some ditriazolyls and ditriazolyalkanes

Summary The proton magnetic resonance spectra of 12 azoles were measured in neutral and acidic solvents. The protonation shifts observed by comparison of the spectra inDMSO-d ₆ andTFA were attributed to an amidinium type resonance of the resulting cations. The synthesis and characterization of the azoles are also discussed.

---

¹H-NMR-Spektren einiger Ditriazolyle und Ditriazolylalkane

Zusammenfassung Es wurden die¹H-NMR-Spektren von 12 Azol-Verbindungen in neutralem (DMSO-d ₆) und azidischem (TFA) Lösungsmittel gemessen und die chemischen Verschiebungswerte verglichen. Der Unterschied beider Werte beruht höchstwahrscheinlich auf einer Amidinium-Typ Resonanz der im azidischen Bereich entstandenen Kationen. Im Rahmen dieser Arbeit wurden 12 Azol-Verbindungen synthetisiert und beschrieben.

     

Investigation of spherical oil agglomeration properties of celestite

In this study, concentration of celestite particles was investigated by using oil agglomeration. For this purpose, effects of operating parameters were investigated, and zeta potential measurements and Fourier transform infrared spectrophotometry (FTIR) analyses have also been carried out. In the experiments, effects of operating parameters such as pH, stirring speed, amount of Na oleate as a anionic type collector and kerosene as a bridging liquid, solid ratio, agglomeration time, collector stirring time, conditioning time, and amount of EDTA were investigated to obtain optimum conditions. Zeta potential measurements were carried out for various pH values and amounts of Na oleate. FTIR analyses were investigated to determine the adsorption type of Na oleate on celestite surface. By evaluation of the experimental results, optimum oil agglomeration conditions of celestite were determined as follows: pH 7, stirring speed 1500 rpm, amount of kerosene 100 l/t, amount of Na oleate 10 kg/t, solid ratio 5 wt%, conditioning time 5 min, collector stirring time 1 min, agglomeration time 5 min, and amount of EDTA 1.0 kg/t. In the optimum conditions, celestite was concentrated with recovery of 89.47 wt%.     

Laser Induced Lowest Triplet State Properties of Dibenzothiophene in Solution

Laser induced triplet state lifetimes are measured in the presence of air and for oxygen, air, argon saturated, and vacuum degassed solution of dibenzothiophene in solution at room temperature by triplet decay, including the prompt and p-type delayed fluorescence. The results are discussed and compared to those of molecules with the same symmetry.     

15N allocation into wheat grains (Triticum aestivum L.) influenced by sowing rate and water supply at flowering under a Mediterranean climate

This study examined the effects of a reduced wheat sowing rate (250 vs. 500 grains m^–2) on grain yield, uptake of ¹⁵N into grains, and the incorporation into gluten and non-gluten proteins of wheat under field conditions in the Aegean region. A single ¹⁵N application was applied at stem elongation, at flowering, or at both developmental stages. Each ¹⁵N treatment included either additional water supply, or no additional water supply at flowering. Sowing rate (either 250 or 500 grains m^–2) had no impact on grain yield. Grain yield increased with additional water supply, but at the expense of protein quality, because of a decrease in the protein content of gluten. The ¹⁵N content of the gluten and non-gluten proteins at grain maturity was not different among cultivars. ¹⁵N applied at both stem elongation and flowering was found in comparable amounts in grains and protein fractions, irrespective of sowing rate.     

A multiple exp-function method for the three model equations of shallow water waves

Nonlinear Dynamics - In this study, we consider three model equations of shallow water waves. Shallow water equations model the propagation of strongly nonlinear waves up to breaking and run-up in...     

A study on the relationship between critical surface tension of wetting and oil agglomeration recovery of calcite

In this study, it was investigated that the relationship between the critical surface tension of wetting of calcite and agglomeration recovery depending on pH and amount of collector (Na oleate). For this purpose, effects of pH and the amount of collector on the agglomeration recovery were investigated and, also, zeta potential measurements and Fourier transform infrared spectrophotometer (FTIR) analyses have been carried out to determine the adsorption type of Na oleate on calcite surface. In this paper, the decisive rules could not put down as evidence of agglomeration success with the critical surface tension of wetting value as in the flotation, because there are different liquids as water and oil (bridging liquid) in the agglomeration system.     

Hexa(1-vinylimidazole)Co(II) perchlorate

A new cobalt(II) complex of 1-vinylimidazole (vinim) has been synthesized as the perchlorate salt and structurally characterized. The molecular structure of the complex exhibits six coordination in which the geomety is a distorted octahedron. The vinylimidazole ring is coordinated through the imidazole nitrogen, as expected from earlier spectroscopic studies of related adducts. The space group is P2₁/n, with a = 8.512(2), b = 13.857(2), c = 16.146(2) Å, = 96.30(1)°, V = 989.31 ų, and Z = 2.     

Spectroscopic and structural properties of N-(acetamide) morpholinium bromide

A new crystal of N-(acetamide) morpholinium (NAM) bromide has been prepared in methanol at room temperature and characterized by single crystal X-ray analysis, elemental analysis, GS-MS, FTIR, NMR((1)H,(13)C, DEPTH and HETCOR). The N-(acetamide) morpholinium crystallizes in the orthorhombic crystal system, Pnma with unit cell a=12.798(9) ?, b=7.222(5) ?, c=9.244(5) ?, β=90.00, V=854.4(9) ?(3), Z=4. The X-ray structure determination revealed that there are strong inner and intermolecular hydrogen bonds in the crystal.     

Comparisons of an external magnetic field effect and chemical effect on X-ray <Emphasis Type="Italic">Kβ</Emphasis>/<Emphasis Type="Italic">Kα</Emphasis> intensity ratio and line-shape of some Chromium compounds

The effect of chemical composition and external magnetic field on the Kβ/Kα intensity ratio and line-shape of some chromium compounds have been investigated using the energy dispersive X-ray fluorescence analysis. The measurements were done using the 22.69 keV photon energy and energy dispersive Si(Li) semiconductor detector. The samples are located in the external magnetic field of intensities 0.6 T and 1.2 T. The experimental results obtained for B = 0 are compared with other experimental and theoretical values. The results have shown that the X-ray Kβ/Kα intensity ratios, chemical shifts, asymmetry indices and full widths at half maximum (FWHM) values can change when irradiation is conducted in a magnetic field.