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11.
Optimization and characterization of electrospun chitosan/poly(vinyl alcohol) nanofibers as a phenol adsorbent via response surface methodology
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Aliyeh Yousefi Abdolmaleki Hamid Zilouei Saied Nouri Khorasani Amir Abdolmaleki 《先进技术聚合物》2017,28(12):1872-1878
Fabrication and characterization of chitosan/poly(vinyl alcohol) electrospun nanofibers for adsorption of phenol from water were investigated. The effects of voltage (15–30 kV), solution injection flow rate (0.5–1.5 ml/hr), distance of needle and collector (10–20 cm) and chitosan/poly(vinyl alcohol) ratio (25/75, 50/50, 75/25) were studied to obtain the optimum electrospinning conditions for the maximum adsorption capacity of phenol. Central composite design (CCD) was used to investigate and optimize the processing factors for production of chitosan/poly(vinyl alcohol) nanofibers from aqueous solutions. The nanofibers were characterized using scanning electron microscopy and Fourier transform infrared spectroscopy (FTIR). Uniform beadless nanofibers with the minimum diameters of 3–11 nm were obtained at chitosan/poly(vinyl alcohol) ratio of 50/50, voltage of 22.5 kV, distance of 15 cm and injection flow rate of 1.99 ml hr?1. Fourier transform infrared spectrum of chitosan/poly(vinyl alcohol) exhibited the existence of relevant functional groups of both poly(vinyl alcohol) and chitosan in the blends. Results of CCD show that among all processing factors, rate of electrospinning will highly affect the nanofiber adsorption. The response surface quadratic order model presented correlation coefficient explaining 69.5% of the variability in the adsorption. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
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New aromatic poly(amide-imide)s with high inherent viscosities were prepared by direct polycondensation reaction of diimide-diacid (I) and aromatic diamines using triphenyl phosphite in N-methyl-2-pyrrolidone (NMP)/pyridine solution containing dissolved CaCl2. The bis(3-trimellitimidophenyl) phenyl phosphine oxide (I) was readily obtained by the condensation reaction of bis(3-aminophenyl) phenyl phosphine oxide (BAPPO) with trimellitic anhydride. The resulting poly(amide-imide)s showed high thermostability. Their decomposition temperatures at 10% weight loss in nitrogen atmosphere were above 532 °C and the anaerobic char yield at 800 °C ranged from 56% to 74%. Almost all the poly(amide-imide)s showed high glass transition temperature above 233 °C by differential scanning calorimetry (DSC) measurements. These polymers were readily soluble in various organic solvents and by their casting into transparent, tough and flexible films can be easily achieved. 相似文献
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[reaction: see text] Large shape-persistent conjugated macrocycles with tunable pore diameters in the nanometer regime were prepared by a simple, one-pot procedure. These new self-assembled macrocycles contain rings of 48-66 covalently bonded atoms and can bind multiple metal ions, forming soluble luminescent complexes. 相似文献
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Bioeffects of magnetic field exposure have been motivated accomplishing various studies. However, no consensus or guideline is available for experimental designs relating exposure conditions as yet. In the present work, in order to analyze and predict the melatonin excretion patterns in the rat exposed to extremely low frequency magnetic fields (ELF-MF), linear discriminate analysis (LDA) and support vector machines (SVMs) were utilized. Subsequently, performances of LDA and SVMs were compared through resubstitution and jackknife tests on a database containing 33 experiments. Predictor variables were more effective parameters including frequency, polarization, exposure duration and strength of magnetic fields. Also, five performance measures including accuracy, sensitivity, specificity, matthew's correlation coefficient (MCC) and normalized percentage better than random (S) were used to evaluate the performance of models. The LDA as a conventional model obtained poor prediction performance. On the other hand, SVMs as a more powerful model, which has not been introduced in predicting melatonin excretion patterns in the rat exposed to ELF-MF, showed 0.38 value of MCC through jackknife test that confirms the higher reliability of the SVMs. 相似文献
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Amir Sabet Sarvestani Parviz Abdolmaleki Seyed Javad Mowla Faezeh Ghanati Emran Heshmati Zeinab Tavasoli Azadeh Manoochehri Jahromi 《Micron (Oxford, England : 1993)》2010,41(2):101-104
In order to evaluate the influence of static magnetic fields (SMF) on the progression of cell cycle as a monitor of presumptive genotoxicity of these fields, the effects of a 15 mT SMF on cell cycle progression in rat bone marrow stem cells (BMSC) were examined. The cells were divided into two groups. One group encountered SMF alone for 5 h continuously but the other group exposed with X ray before treatment with SMF. The population of cells did not show any significant difference in the first group but the second group that was exposed with acute radiation before encountering SMF showed a significant increase in the number of cells in G2/M phase. So SMF has intensified the effects of X ray, where SMF alone, did not had any detectable influence on cell cycle.These findings suggest that magnetic fields (MF) play their role by increasing the effects of genotoxic agents and because of the greater concentration of free radicals in the presence of radical pair producers, this effect is better detectable. 相似文献
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Fully conjugated Schiff base macrocycle has been prepared through a simple and mild condition,a one-pot cyclization procedure of four-component without using a template.The condensation reaction of related bis(hydroxybenzaldehyde) with phenylenediamines to prepare a conjugated[2 + 2]Schiff base macrocycle has been investigated and fluorescent[2 + 2]Schiff base macrocycles with N2O2 binding pockets has been prepared and characterized by elemental analysis,1H NMR,IR,fluorescent,UV-visible and MALDI mass spectroscopies. 相似文献
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Baghery Karim Abdolmaleki Behzad Khazaei Shahram Aref Mohammad Reza 《Wireless Networks》2019,25(3):1235-1252
Wireless Networks - Due to their impressive advantages, Radio Frequency IDentification (RFID) systems are ubiquitously found in various novel applications. These applications are usually in need of... 相似文献
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Bromand Nourozi Arash Boochani Ahmad Abdolmaleki Elmira Sartpi Pezhman Darabi Sirvan Naderi 《理论物理通讯》2018,69(1):101-106
The electronic and optical properties of 2D Cu_2Si and Cu_2Si:Ti are investigated based on the density functional theory(DFT) using the FP-LAPW method and GGA approximation. The 2D Cu_2Si has metallic and non magnetic properties, whereas adding Ti impurity to its structure changes the electronic behavior to the half-metallic with 3.256μB magnetic moment. The optical transition is not occurred in the infrared and visible area for the 2D Cu_2Si in x-direction and by adding Ti atom, the real part of dielectric function in the x-direction, Re(ε(ω))_x is reached to a Dirac peak at this energy range. Moreover, the absorption gap tends to zero in x-direction of the 2D Cu_2Si:Ti. 相似文献
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The proton structure functions at small x region in the holographic QCD are determined. In this study, the complicated nonperturbative interaction between the virtual photon and the target nucleon is described via the Pomeron swap, which corresponds to the reggeized graviton swap in the AdS space. We will show that the proton structure functions determined are consistent with the experimental data measured at HERA. 相似文献