排序方式: 共有142条查询结果,搜索用时 15 毫秒
91.
Mithat Celebi Zafer Omer Ozdemir Emre Eroglu Melda Altikatoglu Ibrahim Guney 《光谱学与光谱分析》2015,(2):340-345
Synthetic dyes are very important for textile dyeing,paper printing,color photography and petroleum products.Traditional methods of dye removal include biodegradation,precipitation,adsorption,chemical degradation,photo degradation,and chemical coagulation.Dye decolorization with enzymatic reaction is an important issue for several research field(chemistry,environment)In this study,minimum decolorization time of Remazol Brilliant Blue R dye with Horseradish peroxidase enzyme was calculated using with mathematical equation depending on experimental data.Dye decolorization was determined by monitoring the absorbance decrease at the specific maximum wavelength for dye.All experiments were carried out with different initial dye concentrations of Remazol Brilliant Blue R at 25 ℃ constant temperature for 30 minutes.The development of the least squares estimators for a nonlinear model brings about complications not encountered in the case of the linear model.Decolorization times for completely removal of dye were calculated according to equation.It was shown that mathematical equation was conformed exponential curve for dye degradation. 相似文献
92.
Isa. Degirmenci Tugba Furuncuoglu Ozaltın Ozlem Karahan Veronique Van Speybroeck Michel. Waroquier Viktorya Aviyente 《Journal of polymer science. Part A, Polymer chemistry》2013,51(9):2024-2034
In this study, the relative rate of polymerization of acrylic acid (AA) versus methacrylic acid (MAA) and the effect of water on the polymerization kinetics are investigated within a combined static and molecular dynamics set of computational tools. Experimentally the relative rate of propagation of AA versus MAA is around 35 in bulk and 31 in water. Classical Molecular Dynamics calculations have been carried out to determine the location of the solvent molecules in the proximity of the dimeric poly(AA) and poly(MAA) units. A combined implicit/explicit solvent model was used for the evaluation of the kinetics of the dimeric polymer chains. We show that the rate acceleration of both polymers in water is mainly due to entropic rather than electrostatic effects and is in agreement with experimental findings. Moreover the slower propagation rate of MAA versus AA is ascribed to additional steric effects present in MAA due to the methyl group at the α position of the monomer. Among the functionals used, the M06‐2X/6‐311+G(3df,2p)//B3LYP/6‐31+G(d) methodology reproduces the experimental rate constants quantitatively the best. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013 相似文献
93.
Mustafa Sahin Hatice Korkmaz Nuriye Kocak Ozlem Sahin Serdar Karakurt 《高分子科学杂志,A辑:纯化学与应用化学》2017,54(5):288-300
The metal complexes of Zn(II), Ni(II), Cu(II) and Pb(II) with asymmetrical Schiff bases were synthesized. The asymmetrical Schiff base was obtained through the condensation of 1,2-phenylenediamine, 4-methyl-1,2-phenylenediamine, 2-hydroxy-1-napthaldehyde and biphenyl-4-carbaldehyde. The new Schiff base ligands (L1' and L2') and their metal complexes were characterized by TG/DTG, FT-IR, 1H-NMR, UV–Vis, ESR, powder XRD, elemental analysis, magnetic moment and fluorescence studies. The powder XRD studies indicate that Co(II) and Cu(II) complexes are amorphous, while Ni(II) and Zn(II) complexes are crystalline. The anticarcinogenic effects of L1' and L2' were also investigated against colon (SW-620) and cervical cancer (HeLa) cell lines and compound L2' was found to possess the highest anticarcinogenic potential, with 16.7 µM and 27.5 µM of IC50 values for HeLa and SW620 cells, respectively. 相似文献
94.
Mithat Celebi Mehmet Arif Kaya Melda Altikatoglu Huseyin Yildirim 《Applied biochemistry and biotechnology》2013,171(3):716-730
In this study, covalent immobilization of the horseradish peroxidase (HRP) onto various polysulfone supports was investigated. For this purpose, different polysulfones were methacrylated with methacryloyl chloride, and then, nonwoven fabric samples were coated by using solutions of these methacrylated polysulfones. Finally, support materials were immersed into aquatic solution of HRP enzyme for covalent immobilization. Structural analysis of enzyme immobilization onto various polysulfones was confirmed with Fourier transform infrared spectroscopy, atomic force microscopy, and proton nuclear magnetic resonance spectroscopy. Decolorization of textile diazo (Acid Black 1) and anthraquinone (Reactive Blue 19) dyes was investigated by UV–visible spectrophotometer. Covalently immobilized enzyme has been used seven times in freshly prepared dye solutions through 63 days. Dye decolorization performance of the immobilized systems was observed that still remained high (70 %) after reusing three times. Enzyme activities of immobilized systems were determined and compared to free enzyme activity at different conditions (pH, temperature, thermal stability, storage stability). Enzyme activities of immobilized systems and free enzyme were also investigated at the different temperatures and effects of temperature and thermal resistance for different incubation time at 50 °C. In addition, storage activity of free and immobilized enzymes was determined at 4 °C at different incubation days. 相似文献
95.
Demirkiran O Topcu G Hussain J Ahmad VU Choudhary MI 《Magnetic resonance in chemistry : MRC》2011,49(10):673-677
Two new unusual monoterpene glycosides, (Z)-3,6-dimethyl-3-(β-D-O-glucosylmethylene)cyclohept-4-ene-1-one (1) and 3,6-dimethyl-3-(β-D-O-glucosylmethylene)cycloheptanone (2) have been isolated along with five known compounds, 3-hydroxy-4-methoxybenzoic acid, 6,7-dihydroxycoumarin, luteolin, apigenin 5-O-αl-L-rhamnoside, and pinocembrin-7-O-rutinoside from ethyl acetate extract of Euphorbia decipiens. The structures of the isolated compounds were elucidated by extensive 1D- and 2D-NMR, and mass spectroscopic analyses. 相似文献
96.
Dr. Ozlem Sel Dr. Thierry Azais Dr. Manuel Maréchal Dr. Gérard Gébel Prof. Christel Laberty‐Robert Prof. Clément Sanchez 《化学:亚洲杂志》2011,6(11):2992-3000
Hybrid organic–inorganic approaches are used for the synthesis of bifunctional proton exchange membrane fuel cell (PEMFC) membranes owing to their ability to combine the properties of a functionalized inorganic network and an organic thermostable polymer. We report the synthesis of both sulfonic and phosphonic acid functionalized mesostructured silica networks into a poly(vinylidenefluoride‐co‐hexafluoropropylene) (poly(VDF‐co‐HFP) copolymer. These membranes, containing different amounts of phosphonic acid and sulfonic acid groups, have been characterized using FTIR and NMR spectroscopy, SA‐XRD, SAXS, and electrochemical techniques. The proton conductivity of the bifunctional hybrid membranes depends strongly on hydration, increasing by two orders of magnitude over the relative humidity (RH) range of 20 to 100 %, up to a maximum of 0.031 S cm−1 at 60 °C and 100 % RH. This value is interesting as only half of the membrane conducts protons. This approach allows the synthesis of a porous SiO2 network with two different functions, having SO3H and PO3H2 embedded in a thermostable polymer matrix. 相似文献
97.
Sevgi Kolayli Ozlem Tarhan Meryem Kara Rezzan Aliyazicioglu Murat Kucuk 《Chemistry of Natural Compounds》2011,47(3):347-351
The fatty acid profiles of frequently consumed oils and crops cultivated in Turkey were investigated in regard to omega fatty
acids. Analyses were carried out on commercially sold oils, sunflower, olive, and fish oils, and oils extracted from fatty
seeds of hazelnut, walnut, olive, sunflower, poppy, sesame, and pumpkin, and butter produced in Turkey. Hazelnut and olive
oils were found to be rich in omega-9 (oleic acid 18:1), walnut, poppy seed, sesame, and pumpkin seed were rich in omega-6
(linoleic acid 18:2), and butter was rich in short chain fatty acids and omega-9. Fish oil, from mackerel, was the richest
in omega-3 fatty acids and fatty acid diversity. There were some alterations between commercially sold oils and oils extracted
from seeds in regard to fatty acid percentages and variety. 相似文献
98.
In this paper, we introduce a parallelized version of a novel, non-iterative domain decomposition algorithm, called Characteristic Basis Finite Element Method (CBFEM-MPI), for efficient solution of large-scale electromagnetic scattering problems, by utilizing a set of specially defined characteristic basis functions (CBFs). This approach is based on the decomposition of the computational domain into a number of non-overlapping subdomains wherein the CBFs are generated by employing a novel procedure, which differs from all those that have been used in the past. Clearly, the CBFs are obtained by calculating the fields radiated by a finite number of dipole-type sources, which are placed hypothetically along the boundary of the conducting object. The major advantages of the proposed technique are twofold: (i) it provides a substantial reduction in the matrix size, and thus, makes use of direct solvers efficiently and (ii) it enables the utilization of parallel processing techniques that considerably decrease the overall computation time. We illustrate the application of the proposed approach via several 3D electromagnetic scattering problems. 相似文献
99.
Niyazi Bicak Mesut Ozlem 《Journal of polymer science. Part A, Polymer chemistry》2003,41(21):3457-3462
Trace amounts of labile chlorines present in poly(vinyl chloride) (PVC) were found to act as initiation sites for the preparation of graft copolymers of PVC by copper‐mediated atom transfer radical polymerization (ATRP). High grafting yields were attained during the graft copolymerizations of n‐butyl acrylate (161.8%) and 2‐ethyl hexyl acrylate (51.2%) in 7.5 h. In both cases, the grafting proceeded with first‐order kinetics with respect to the monomer concentrations, this being typical for ATRP. Gel permeation chromatography traces of the resulting products did not exhibit additional peaks attributable to the formation of free homopolymers. The presented procedure offers an efficient means of preparing self‐plasticized PVC structures. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3457–3462, 2003 相似文献
100.
An experimental study of the use of an S-transform to evaluate the phase distribution from a two-dimensional fringe pattern by introducing the carrier frequencies in two spatial directions, x and y, is presented. The phase distribution is extracted from the optical fringe pattern by using an S-transform gradient and S-transform phase methods. The experimental result for the Fourier transform profilometry algorithm is compared with the results of the S-transform analysis. 相似文献