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41.
Mete Kaan Ekmekçi Mustafa İlhan Arzu Ege Mehmet Ayvacıklı 《Journal of fluorescence》2017,27(3):973-979
Undoped and different concentration Nd3+ doped SrNb2O6 powders with columbite structure were synthesized by molten salt process using a mixture of strontium nitrate and niobium (V) oxide and NaCl-KCl salt mixture as a flux under relatively low calcining temperature. X-ray diffraction analysis results indicated that SrNb2O6 phases found to be orthorhombic columbite single phase for undoped, 0.5 and 3 mol% Nd3+ doping concentrations. Phase composition of the powders was examined by SEM-EDS analyses. Radioluminescence properties of Nd3+ doped samples from UV to near-IR spectral region were studied. The emissions increased with the doping concentration of up to 3 mol%, and then decreased due to concentration quenching effect. There is a sharp emission peak around 880 nm associated with 4F5/2 → 4I9/2 transition in the Nd3+ ion between 300 and 1100 nm. The broad emission band intensity was observed from 400 to 650 nm where the peak intensities increased by increasing Nd3+ doping concentration. All the measurements were taken under the room temperature. 相似文献
42.
Electrodes based on oxidized polypyrrole films have potentiometric selectivity toward anions. When the films are overoxidized, however, electron-rich groups are introduced on to the polymer chains, reversing the selectivity of the electrodes from anionic to cationic. In this study, electrochemically overoxidized polypyrrole film electrodes were prepared, and the conditions for film formation that lead to near-Nernstian potentiometric response were investigated. It was found that the doping ion, overoxidation solution, and pH affect the response of these electrodes. Redox interference is significantly lower for the overoxidized polypyrrole films than for polypyrrole electrodes. 相似文献
43.
Arzu Sungur Sevim Akyüz J. Eric D. Davies 《Journal of inclusion phenomena and macrocyclic chemistry》1987,5(4):491-497
The infrared spectra of M(4,4-bipyridyl)Ni(CN)4 complexes (M=Ni or Cd) and their dioxane, benzene, toluene, aniline andN,N-dimethylaniline clathrates are reported. Additional information regarding the structure of the host lattice is obtained from the Raman spectra of the M=Cd complex. It is shown that the structure of the host lattice consists of infinite polymeric layers of {M-Ni(CN)4} analogous to those of Hofmann type clathrates that have tetragonal symmetry. Bidentate 4,4-bipyridyl molecules form bridges between the metal atoms {M} in the adjacent {M-Ni(CN)4} layers. It is found that the 4,4-bipyridyl molecules are centrosymmetric in this structure.Presented at the Fourth International Symposium on Inclusion Phenomena and the Third International Symposium on Cyclodextrins, Lancaster, U.K., 20–25 July 1986 相似文献
44.
Merve Dandan Doganci Hüseyin Balci Derya Davarcı Elif Şenkuytu Arzu Aysan Erdinc Doganci 《先进技术聚合物》2024,35(3):e6338
A series of poly(lactic acid) (PLA) films that including fully paraben substituted triazine derivatives having anti-bacterial properties have been prepared by utilizing the solvent-casting method. PLA as biodegradable polymer, poly(ethylene glycol) (PEG) as a plasticizing agent and s-triazine molecules (TA01, TA02, TA03, TA04, and TA05) behaving as an anti-bacterial component have been utilized in the experiments. The influence of TA compounds on the antibacterial performance of PLA/PEG films was investigated for the first time against Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus) bacteria via the contact active method. TA01-03-05 incorporated PLA/PEG films gave the best results against E.coli bacteria and log10 reductions of these films were 0.78, 0.64, and 0.65 respectively. The effect of TA compounds on the cell viability was investigated against cancer and non-cancerous cell lines using an MTS assay. The results showed that TA compounds had a positive effect on cell growth in non-cancerous cells, while they had a negative effect on cell growth in cancer cells. Furthermore, the addition of TA considerably increased the decomposition temperatures from 349° to 361° and char yield from 0.65 for PLA/PEG film to 2.3 for PLA/PEG/TA05. All of the films had good transparency and low opacity which was 7.2 for pure PLA used for control and the maximum opacity value was 11.2 observed for PLA/PEG/01. TA03 and TA04 caused a decrement of water vapor permission when compared to PLA/PEG films from 1439 to 749 and 664. It was also observed that pure PLA/PEG film lost weight rapidly over time during degradation tests. On the other hand, weight loss wasn't observed in PLA/PEG/TA films. This study focused on demonstrating the use of our new, flexible PLA/PEG derivatives in food and medical packaging. 相似文献
45.
The aim of this study was to prepare a topical water-in-oil type microemulsion containing metronidazole and to compare its effectiveness with a commercial gel product in the treatment of rosacea. A pseudo-ternary phase diagram (K(m)=2:1) was constructed using lecithin/butanol/isopropyl myristate/water. The microemulsion was chosen from the microemulsion region in the phase diagram. The formulation was a water-in-oil type microemulsion (droplet size: 11.6 nm, viscosity: 457.3 mPa·s, conductivity: 1.5 μs/cm, turbidity: 6.89 NTU) and the addition of the metronidazole did not alter the properties of the system. The release experiment showed that the release rate of metronidazole from the commercial gel product was higher than that of the microemulsion. Stability experiments showed that the metronidazole microemulsion remained stable for at least 6 months; none of the characteristic properties of the microemulsion had changed, the system retained its clarity and there was no sign that crystallization of metronidazole has occurred. Microemulsion was compared to a gel product in a randomized, double-blind, baseline-controlled, split-face clinical trial for the treatment of patients. After the 6-week treatment period there was a statistically significant difference in reduction of the main symptoms of rosacea. Of the patients treated with the microemulsion, 17% experienced complete relief from inflammatory lesions, and 50% from erythema. The microemulsion resulted in complete relief in 38% of the patients with telangiectasia while the commercial product did not provide any relief of telangiectasia symptoms. In conclusion, the microemulsion containing metronidazole was found to be more effective in reducing the symptoms of rosacea compared to the commercial gel product. 相似文献
46.
Heat pumps offer economical alternatives of recovering heat from different sources for use in various industrial, commercial
and residential applications. In this study, single-stage air-source vapor compression heat pump system has been optimized
using genetic algorithm (GA) and fuzzy logic (FL). The necessary thermodynamic properties for optimization were calculated
by FL. Thermodynamic properties obtained with FL were compared with actual results. Then, the optimum working conditions of
heat pump system were determined by the GA. 相似文献
47.
AbstractA new series of water-compatible proline catalysts (4–6) derived from calixarene bearing a hydrophobic nature have been synthesised. It was found that the compound 4 was a highly efficient organocatalyst for aldol reactions occurred in the water. Under optimised reaction conditions, high yields (up to 82%), good enantioselectivities (ee up to 81%) and high diastereoselectivities (dr up to 91:9) were obtained. 相似文献
48.
Rüstem Keçili Ayça Atılır Özcan Arzu Ersöz Deniz Hür Adil Denizli Rıdvan Say 《Journal of nanoparticle research》2011,13(5):2073-2079
The nanoparticle comprises a superparamagnetic iron oxide nanoparticle core conjugated with trimethoxylsilyl propylmethacrylate
(TMSPM) and methacryloylamido serine (MASE), methacryloylamido histidine (MAH), methacryloylamido glutamic acid (MAGA) monomers,
and p-nitrophenyl palmitate (p-NPP) which is a substrate of lipase as a template molecule, which enables the creation of lipase active region. The resulting
hybrid superparamagnetic nanotraps are magnetically separable, highly active, and stable under harsh conditions. In this study,
the advantages of high selectivity of molecular imprinting technique have used to get mimic lipase for the synthesis of methyl
jasmonate and methyl oleate. 相似文献
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