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151.
Turgay Korkut Zeynep Itır Umaç Bünyamin Aygün Abdulhalik Karabulut Sinan Yapıcı Remzi Şahin 《International Journal of Polymer Analysis and Characterization》2013,18(6):423-429
The neutron equivalent dose rates (µSv/h) of gypsum, steel-reinforced rubber waste tire, and gypsum-waste tire rubber sandwich composite samples were investigated. Prepared samples were irradiated with 241Am-Be neutrons and transmission values were obtained using dose equivalent rates measured with a BF3 neutron detector. Results were compared to those of concrete, and as a result of neutron shielding, the performance of gypsum, waste tire, and waste tire (steel-reinforced rubber) embedded gypsum samples was higher than that of concrete. This information may be useful for shielding design of nuclear application areas. 相似文献
152.
Nizam M. El-Ashgar Issa M. El-Nahhal Mohamed M. Chehimi Florence Babonneau Jacques Livage 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3):392-402
Abstract Polysiloxane-immobilized monoamine, diamine, and triamine ligand systems of the general formula P-(CH2)3-X [where P represents a polysiloxane three-dimension silica like network, and X represents monoamine(-NH2), diamine (-NH(CH2)2NH2), or triamine (-NH(CH2)2NH(CH2)2NH2) functional ligand groups] were prepared by hydrolytic polycondensation of the tetraethylorthosilicate (TEOS) and the appropriate amine silane coupling agent (RO)3Si-(CH2)3X in the presence of cetyltrimethylammonium bromide (CTAB) as surfactant using the sol-gel method. The polysiloxane-immobilized amine ligand systems exhibit a higher potential for divalent metal ions (Cu2+, Ni2+, Co2+) when CTAB was used as surfactant than those of the corresponding polysiloxane ligand systems prepared without CTAB. X-ray Photoelectron Spectroscopy (XPS) analyses show a significant change in the surface composition as resulting from the incorporation of CTAB, which can be related to the increase in the uptake of metal ions. 相似文献
153.
Synthesis and Structural Characterization of a Binuclear Mixed‐Ligand (Salicylate and N,N‐diethylnicotinamide) Nickel(II) Complex,Its Magnetic Properties. [Ni2(µ‐Sal)4(Dena)2]H2O 下载免费PDF全文
The title complex of [Ni2(µ‐Sal)4(Dena)2]H2O, [( µ‐tetrakissalicylato‐κ‐O,O)(bis‐N,N‐diethylnicotinamide‐κ‐N)(binickel(II))]hydrate, C48H52Ni2N4O16, has been synthesized and explained as structural using some elemental analysis, FT‐IR spectra, UV‐Vis reflectance, magnetic measurements, thermal analysis and x‐ray diffraction methods. The analysis results showed that the unit cell of complex includes two molecules NiII cation, four molecules salicylates as bridge and two molecules N,N‐diethylnicotinamide ligands, also there is one molecule hydrated aqua. The compound crystallizes in the monoclinic space group P21/c with the following unit‐cell parameters: a =13.6776(6) Å, b =10.5238(3) Å, c =21.8165(9), α=90.00°, β=126.546(3)°, γ=90.00º and Z=2. The compound [Ni2(µ‐Sal)4(Dena)2]H2O is a typical paddle‐wheel complex structure. Two NiII ions are bridged by four salicylate ligands (O2, O2i, O3, O3i, O5, O5i, O6 and O6i) using a µ‐COO? coordination mode [symmetry code: (i) 1‐x, 1‐y, 1‐z]. Each NiII also coordinates to one nitrogen atom (N1 and N1i) from one N,N‐diethylnicotinamide ligand molecule in the axial position. The complex has strong paramagnetic properties. 相似文献
154.
Korkut S Saville DA Aksay IA 《Langmuir : the ACS journal of surfaces and colloids》2008,24(21):12196-12201
A "stable" electrohydrodynamic jet is used to print arrays of colloidal suspensions on hydrophobic surfaces. Printed lines break up into sessile drops, and capillary forces guide the self-assembly of colloidal particles during the evaporation of the liquid, resulting in arrays of colloidal single particles or particle clusters depending on the concentration of the suspensions. The clusters differ from those formed in the absence of a substrate when the number of particles is larger than three. Multiple structures are found for the same number of particles. 相似文献
155.
Gamma irradiation was used to form interpenetrating polymer networks structure (IPNs) hydrogels based on different ratios of acrylic acid monomer (AAc) and polyethyleneimine (PEI). The property-behavior was characterized by IR spectroscopy, gel content, thermogravimetric analysis (TGA) and swelling in water at room temperature and different pH values. The AAc/PEI hydrogels were used as a carrier for atorvastatin drug, in which the uptake-release character was studied. The results showed that the gel content of AAc/PEI hydrogels decreased greatly with increasing the ratio of PEI in the initial feeding solution. The AAc/PEI hydrogels displayed pH-sensitive character. The drug uptake-release study indicated that AAc/PEI hydrogels possessed controlled release behavior and that the release process depends on pH. In this respect, the release of atorvastatin drug was significant in acidic medium. 相似文献
156.
Korkut A??kal?n 《Journal of Thermal Analysis and Calorimetry》2012,109(1):227-235
Pyrolytic characteristics and kinetics of pistachio shell were studied using a thermogravimetric analyzer in 50?C800?°C temperature range under nitrogen atmosphere at 2, 10, and 15?°C?min?1 heating rates. Pyrolysis process was accomplished at four distinct stages which can mainly be attributed to removal of water, decomposition of hemicellulose, decomposition of cellulose, and decomposition of lignin, respectively. The activation energies, pre-exponential factors, and reaction orders of active pyrolysis stages were calculated by Arrhenius, Coats?CRedfern, and Horowitz?CMetzger model-fitting methods, while activation energies were additionaly determined by Flynn?CWall?COzawa model-free method. Average activation energies of the second and third stages calculated from model-fitting methods were in the range of 121?C187 and 320?C353?kJ?mol?1, respectively. The FWO method yielded a compatible result (153?kJ?mol?1) for the second stage but a lower result (187?kJ?mol?1) for the third stage. The existence of kinetic compensation effect was evident. 相似文献