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991.
Solubilization of graphene flakes through covalent modification with well‐defined azido‐terminated poly(ε‐caprolactone)
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Nabihah Abdullah Kazuya Hatano Daiki Ando Masataka Kubo Akira Koshio Fumio Kokai 《应用聚合物科学杂志》2015,132(9)
A well‐defined poly(ε‐caprolactone) (PCL) with terminal azido group was prepared. Grafting‐on reaction between the azido‐terminated PCL (N3? PCL) and ultrasonication‐assisted exfoliated graphene flakes (GF) was carried out to obtain PCL‐grafted‐GF (PCL‐g‐GF) which showed good dispersibility in a wide variety of organic solvents. Gel permeation chromatography, 1H NMR, IR, Raman, UV‐vis, and TEM measurements indicated that PCL macromolecules were covalently introduced on the surface of GF without disrupting the structure of GF. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41569. 相似文献
992.
Abdullah?Kurt Bekir?Yal?in Nihat?YilmazEmail author 《The International Journal of Advanced Manufacturing Technology》2015,81(1-4):315-327
Precision hard machining is an interesting topic in manufacturing die and mold, automobile parts, and scientific research. While the hard machining has benefit advantages such as short cutting cycle time, process flexibility, and low surface roughness, there are several disadvantages such as high tooling cost, need of rigid machine tool, high cutting stresses, and residual stresses. Especially, tool stresses should be understood and dealt with to achieve successful performance of finish hard turning with ceramic cutting tool. So, the influence of cutting parameters on cutting stresses during dry finish turning of hardened (52 HRC) AISI H13 hot work steel with ceramic tool is investigated in this paper. For this aim, a series finish turning tests were performed, and the cutting forces were measured in tests. After literature procedure about finite element model (FEM), FEM is established to predict cutting stresses in finish turning of hardened AISI H13 steel with Ceramic 650 grade insert. As shown, effect of the cutting parameters on cutting tool stresses in finish turning of AISI H13 steel is obtained. The suggested results are helpful for optimizing the cutting parameters and decreasing the tool failure in finish turning applications of hardened steel. 相似文献
993.
Gocer Abdullah Karamis M. Baki 《Protection of Metals and Physical Chemistry of Surfaces》2021,57(3):579-588
Protection of Metals and Physical Chemistry of Surfaces - Ceramic reinforcements are used in metal matrix composite materials to enhance the mechanical properties. Ceramic particles also improve... 相似文献
994.
Structure and Disorder in Squaraine–C60 Organic Solar Cells: A Theoretical Description of Molecular Packing and Electronic Coupling at the Donor–Acceptor Interface
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Yao‐Tsung Fu Demetrio A. da Silva Filho Gjergji Sini Abdullah M. Asiri Saadullah Gary Aziz Chad Risko Jean‐Luc Brédas 《Advanced functional materials》2014,24(24):3790-3798
Organic solar cells based on the combination of squaraine dyes (as electron donors) and fullerenes (as electron acceptors) have recently garnered much attention. Here, molecular dynamics simulations are carried out to investigate the evolution of a squaraine–C60 bilayer interface as a function of the orientation and order of the underlying squaraine layer. Electronic couplings between the main electronic states involved in exciton dissociation and charge (polaron pair) recombination are derived for donor–acceptor complexes extracted from the simulations. The results of the combined molecular‐dynamics?quantum‐mechanics approach provide insight into how the degree of molecular order and the dynamics at the interface impact the key processes involved in the photovoltaic effect. 相似文献
995.
Interfaces: Structure and Disorder in Squaraine–C60 Organic Solar Cells: A Theoretical Description of Molecular Packing and Electronic Coupling at the Donor–Acceptor Interface (Adv. Funct. Mater. 24/2014)
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996.
Ariffuddin Joret Mohammad Faiz Liew Abdullah Muhammad Suhaimi Sulong Asmarashid Ponniran Siti Zuraidah Zainudin 《中国电子科技》2014,(1):90-94
Moments have been used in all sorts of object classification systems based on image. There are lots of moments studied by many researchers in the area of object classification and one of the most preference moments is the Zernike moment. In this paper, the performance of object classification using the Zernike moment has been explored. The classifier based on neural networks has been used in this study. The results indicate the best performance in identifying the aggregate is at 91.4% with a ten orders of the Zernike moment. This encouraging result has shown that the Zernike moment is a suitable moment to be used as a feature of object classification systems. 相似文献
997.
The oxidation and carbonization stages of viscose rayon fibers were performed in the presence of 3 % phosphoric acid and 4 % boric acid (PA–BA) impregnation. The results showed that PA–BA impregnation enhanced thermal stability and prevented the evolution of volatile by-products. During the oxidation stage carried out at 250 °C, the cellulose II crystalline structure was totally lost due to the decrystallization process. Carbonization was carried out in a pure nitrogen atmosphere at temperatures ranging from 600 to 1000 °C. The results obtained from the fiber thickness, linear density, carbon fiber yield, elemental analysis, volume density, X-ray diffraction, infrared (IR) and Raman spectroscopy, tensile testing, and electrical conductivity measurements showed that the carbonization temperature had a significant effect on the structure and properties of the resulting carbon fibers. Carbon fibers obtained from the oxidized viscose rayon fibers showed physical and chemical transformations with increasing carbonization temperature and were characterized by a reduction in fiber thickness and linear density values due to the removal of non-carbon elements together with increases in the carbon content, carbon to hydrogen ratio (C/H), volume density, tensile strength, tensile modulus, and electrical conductivity values. X-ray diffraction analysis showed that the interplanar d-spacing (d 002) decreased, and that the apparent crystallite thickness (L c) and the apparent crystallite width (L a) increased with increasing temperature. IR spectroscopy in agreement with the elemental analysis showed the total loss of OH, CH, C=O, CH2, C–O, and C–O–C groups arising from the completion of dehydration and dehydrogenation reactions indicating total elimination of the cellulose structure and the formation of amorphous carbon during high temperature treatment. 相似文献
998.
Abdullah Konak 《工程优选》2014,46(1):130-145
This article presents a network design problem with relays considering the two-edge network connectivity. The problem arises in telecommunications and logistic networks where a constraint is imposed on the distance that a commodity can travel on a route without being processed by a relay, and the survivability of the network is critical in case of a component failure. The network design problem involves selecting two-edge disjoint paths between source and destination node pairs and determining the location of relays to minimize the network design cost. The formulated problem is solved by a hybrid approach of a genetic algorithm (GA) and a Lagrangian heuristic such that the GA searches for two-edge disjoint paths for each commodity, and the Lagrangian heuristic is used to determine relays on these paths. The performance of the proposed hybrid approach is compared to the previous approaches from the literature, with promising results. 相似文献
999.
The effect of micro‐ and nanometer‐sized boron particles on boron‐potassium nitrate (BPN) ignition composition was investigated in this paper. As a starting point, thermochemical calculations were made to determine the most promising ignition compositions. Both stoichiometric and fuel‐rich formulations of BPN were produced to observe the performance variation due to boron content. Particle morphology of boron particles and the surface structure of the ignition compositions were investigated by SEM. The influence of micro‐ and nanometer‐sized boron particles on the calorific value, sensitivity properties, and pressure buildup of compositions were investigated. Sensitivity tests showed that all compositions were safe enough for handling. It was seen that although nanometer‐sized boron particles enhanced calorific value and pressurization rate, they did not have a contribution on the maximum pressure level. The maximum adiabatic flame temperature was attained by the stoichiometric composition, but in practice, the stoichiometric composition resulted in much lower performance than the fuel rich composition. Possible reasons for these behaviors of the compositions were discussed in the paper. 相似文献
1000.
Anish Khan Aftab A.P. Khan Abdullah M. Asiri Khalid A. Alamry 《Polymer Composites》2015,36(2):221-228
Graphene oxides decorated with Sn(II) (Sn‐GO) were prepared via a redox reaction between graphene oxide (GO) and SnCl2. GO was reacted Sn2+ leading to a homogeneous distribution of Sn on GO. An electrochemical sensor based on the electrocatalytic activity of functionalized graphene oxide for sensitive detection of paracetamol is presented. The electrochemical behaviors of paracetamol on grapheme modified carbon fiber electrodes were investigated by DC potential amperometry. The results showed that the Sn‐GO‐modified electrode exhibited excellent electrocatalytic activity to paracetamol. A redox process of paracetamol at the modified electrode was obtained. Such electrocatalytic behavior of graphene oxide is attributed to its unique physical and chemical properties, e.g., subtle electronic characteristics, attractive π–π interaction, and strong adsorptive capability. This electrochemical sensor shows an excellent performance for detecting paracetamol with a detection limit of 8 µM, a response time of 27 s, and a satisfied recovery. The sensor shows great promise for simple, sensitive, and quantitative detection and screening of paracetamol. We have investigated the composite properties of the self‐assembled electrodes for biological compounds analysis and showed that the Sn‐GO composite biosensor can achieve great sensitivity without significant bio material. The sensor shows great promise for simple, sensitive, and quantitative detection and screening of paracetamol. POLYM. COMPOS., 36:221–228, 2015. © 2014 Society of Plastics Engineers 相似文献