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61.
In order to develop a new and cost effective formed coke production process which does not require higher temperature carbonization stage, coke breeze was briquetted with resol binders and the change in the tensile strength of the briquettes with the amount and the type of the alkaline metal hydroxides, alkaline earth metal oxides, their carbonates and amine catalysts were studied. It was recognized that carbonates of alkaline or alkaline earth metals have a modifying effect on the properties of resol binders which results in briquettes of higher tensile strength than the resol produced with hydroxide or oxides of these metals. The average tensile strength of the briquettes was found to be much higher with the sodium carbonates catalyzed resol used as binder comparing with sodium hydroxide catalyzed resoles. The former was 45.40 MPa while the latter was 33.72 MPa. Although triethanolamine catalyzed resol, resulted in the briquettes of the highest tensile strength (53.43 MPa), among the catalyst studied in this work, due to flammability caused by triethanolamine, it was found unsuitable for this purpose. 相似文献
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63.
Berksoy-Yavuz Ayse Kaya Mustafa Yunus Avcı Tubanur Cakırbas Gizem Menşur Ebru 《Journal of Materials Science: Materials in Electronics》2022,33(5):2336-2349
Journal of Materials Science: Materials in Electronics - The effect of crystallographic texture on the properties of 0.94(Na0.5Bi0.5TiO3)–0.06BaTiO3 (0.94NBT–0.06BT) ceramics were... 相似文献
64.
Experience with continuous venovenous hemodiafiltration in four newborns: A case series and review of the literature
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Ali Ulas Tugcu Asli Kantar Aslihan Abbasoglu Ayse Ecevit Aylin Tarcan Esra Baskn 《Hemodialysis international. International Symposium on Home Hemodialysis》2015,19(4):E59-E62
When conventional methods for treating complicated problems such as acute and chronic renal failure or metabolic diseases fail, the therapy of choice is peritoneal dialysis (PD) in neonatal period. However, in cases that involve technical difficulties, such as bulky lesions in the abdomen or complications from previous abdominal surgeries, it is not always possible to place a peritoneal catheter. In such situations, continuous venovenous hemodiafiltration (CVVHDF) can be effective. This case series presents our experience in 2013 with the administration of CVVHDF to four patients in our neonatal intensive care unit who could not undergo PD for various reasons. 相似文献
65.
This investigation is based on the production of lightweight, heat-insulating, water-resistant or water-repellent materials from lightweight aggregates, such as pumice and/or expanded perlite, without using cement or plaster as a binder. The results of this investigation reveal that a H3PO4- or NH4NO3-hardened molasses binder with the addition of 2.5% borax could be an alternative binder for the production of lightweight, heat-insulating materials with moderate tensile strength. When these bricks were exposed to temperatures up to 825 °C, they did not lose their strength but, rather gained strength. Therefore, molasses binder could be an alternative to cement or plaster binder for construction and building materials with specific properties. 相似文献
66.
Tamara V. Basova Irina V. Jushina Ayse G. Gürek Devrim Atilla Vefa Ahsen 《Dyes and Pigments》2009,80(1):67-72
The synthesis, liquid crystalline behavior and self-organizing properties of Cu(II)Pc bearing monoazacrown ether moieties that contain long alkyloxyphenyl N-pivotal groups are described. The Cu(II) phthalocyanine derivative has a hexagonal, columnar structure; optical absorption and vibrational spectroscopy revealed a predominantly co-facial interaction between the chromophores and their orientation parallel to a NaCl surface. It is proposed that such homeotropic alignment is attributable to the ability of the pendant monoazacrown ether groups to coordinate the Na+ ions within the NaCl surface. 相似文献
67.
Ayse Kalemtas Gulsum Topates Hüseyin Özcoban Hasan Mandal Ferhat Kara Rolf Janssen 《Journal of the European Ceramic Society》2013,33(9):1507-1515
In this study, porous β-Si3N4 ceramics containing limited amount of Sm2O3 and CaO as sintering aids were produced by addition of potato starch (10 and 20 vol.%) and partial sintering. Two different Si3N4 powders, α- and β-, were used as starting materials. Scanning electron microscopy investigations revealed that development of elongated β-Si3N4 grains were much more pronounced when α-Si3N4 starting powder was used. Even though porosity values of the compositions prepared by using α-Si3N4 (~57.0–58.4%) is significantly higher than the samples produced by β-Si3N4 (42.6%), no significant change was observed for the bending strength, fracture toughness and Weibull modulus. This indicates that microstructural features have a significant contribution to the mechanical properties of the porous materials in terms of bending strength and fracture toughness. 相似文献
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69.
?mer D?nmez Fahrettin Sarcan Ayse Erol Mustafa Gunes Mehmet ?etin Arikan Janne Puustinen Mircea Guina 《Nanoscale research letters》2014,9(1):141
We report the observation of thermal annealing- and nitrogen-induced effects on electronic transport properties of as-grown and annealed n- and p-type modulation-doped Ga1 - xInxNyAs1 - y (x = 0.32, y = 0, 0.009, and 0.012) strained quantum well (QW) structures using magnetotransport measurements. Strong and well-resolved Shubnikov de Haas (SdH) oscillations are observed at magnetic fields as low as 3 T and persist to temperatures as high as 20 K, which are used to determine effective mass, 2D carrier density, and Fermi energy. The analysis of temperature dependence of SdH oscillations revealed that the electron mass enhances with increasing nitrogen content. Furthermore, even the current theory of dilute nitrides does not predict a change in hole effective mass; nitrogen dependency of hole effective mass is found and attributed to both strain- and confinement-induced effects on the valence band. Both electron and hole effective masses are changed after thermal annealing process. Although all samples were doped with the same density, the presence of nitrogen in n-type material gives rise to an enhancement in the 2D electron density compared to the 2D hole density as a result of enhanced effective mass due to the effect of nitrogen on conduction band. Our results reveal that effective mass and 2D carrier density can be tailored by nitrogen composition and thermal annealing-induced effects.
PACS
72.00.00; 72.15.Gd; 72.80.Ey 相似文献70.
The free‐radical‐initiated copolymerization of 2‐(4‐acetylphenoxy)‐2‐oxoethyl‐2‐methylacrylate (AOEMA) and 2‐(4‐benzoylphenoxy)‐2‐oxoethyl‐2‐methylacrylate (BOEMA) with 2‐[(4‐fluorophenyoxy]‐2‐oxoethyl‐2‐methylacrylate (FPEMA) were carried out in 1,4‐dioxane solution at 65°C using 2,2′‐azobisisobutyronitrile as an initiator with different monomer‐to‐monomer ratios in the feed. The monomers and copolymers were characterized by FTIR and 1H‐ and 13C‐NMR spectral studies. 1H‐NMR analysis was used to determine the molar fractions of AOEMA, BOEMA, and FPEMA in the copolymers. The reactivity ratios of the monomers were determined by the application of Fineman‐Ross and Kelen‐Tudos methods. The analysis of reactivity ratios revealed that BOEMA and AOEMA are less reactive than FPEMA, and copolymers formed are statistically in nature. The molecular weights (M w and M n) and polydispersity index of the polymers were determined using gel permeation chromatography. Thermogravimetric analysis of the polymers reveals that the thermal stability of the copolymers increases with an increase in the mole fraction of FPEMA in the copolymers. Glass transition temperatures of the copolymers were found to decrease with an increase in the mole fraction of FPEMA in the copolymers. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献