Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
Browse
3 results
Search Results
Article Citation - WoS: 1Sol-Derived Hydroxyapatite Ddip-Coating of a Porous Ti6al4v Powder Compact(Al-Farabi Kazakh State National University, 2009) Altındiş, Mustafa; Güden, Mustafa; Ni, ChaoyingA sintered porous Ti6Al4V powder compact with a mean pore size of 63 µm and an average porosity of 37±1% was dip-coated at soaking times varying between 1- and 5-minute using a sol-derived calcium Hydrooxyapatite (HA) powder. The coated compacts were heat-treated at 840 °C. The coating thickness was found to increase with increasing soaking time, from 1.87 µm at 1-minute soaking to 9 µm at 5-minute soaking on the average. It was shown that at increasing soaking times, the originally open pores started to close, while at low soaking times the Ti6Al4V particles were partially coated. The coating layer was shown to be nano porous and the depth of coating was observed to be relatively shallow: only few particles near the compact surface were HA-coated.Article Citation - WoS: 85Citation - Scopus: 88Effect of Immobilization on Catalytic Characteristics of Saturated Pd-N Carbenes in Mizoroki-Heck Reactions(Elsevier Ltd., 2006) Aksın, Özge; Türkmen, Hayati; Artok, Levent; Çetinkaya, Bekir; Ni, Chaoying; Büyükgüngör, Orhan; Özkal, ErhanA saturated Pd-N-heterocyclic complex was immobilized on an amorphous silica. The complex itself is of very high thermal stability. However, TEM observations, hot filtration, reusability, and poisoning tests all revealed that the complex acted only as a precatalyst to highly active Pd species in Mizoroki-Heck reactions when immobilized. The complex appears more stable when used under homogeneous reaction conditions. The immobilized complex afforded high turnover numbers, 104-105. The higher turnover frequencies were realized at the lower Pd concentrations, which is a characteristic property of ligand-free Pd catalyzed reactions.Article Citation - WoS: 78Citation - Scopus: 83Synthesis, Characterization and Application of a Novel Sorbent, Glucamine-Modified Mcm-41, for the Removal/Preconcentration of Boron From Waters(Elsevier Ltd., 2005) Kaftan, Öznur; Açıkel, Müge; Eroğlu, Ahmet Emin; Shahwan, Talal; Artok, Levent; Ni, ChaoyingA novel sorbent was prepared by the functionalization of an inorganic support material, MCM-41, with N-methylglucamine for the uptake of boron from aqueous solutions prior to its determination by inductively coupled plasma optical emission spectrometry (ICP–OES). Characterization of the newly synthesized material was performed using BET, XRD, TEM, SEM and DRIFTS techniques, in addition to its C and N elemental content. Sorption behavior of the novel sorbent for boron was also investigated and found to obey Freundlich and Dubinin–Radushkevich (D–R) isotherm models. The maximum amount of B (as H3BO3) that can be sorbed by the sorbent was calculated from the D–R isotherm and was found to be 0.8 mmol B g−1 of sorbent. The applicability of the new sorbent for the removal/preconcentration of boron from aqueous samples was examined by batch method. It was found that the sorbent can take up 85% of boron in 5 min whereas quantitative sorption is obtained in 30 min. Any pH greater than 6 can be used for sorption. Desorption from the sorbent was carried out using 1.0 M HNO3. The sorption efficiency of the new sorbent was also compared to that of Amberlite IRA 743, a commercial resin with N-methylglucamine functional groups. Within the experimental conditions employed, the new sorbent was found to have higher sorption efficiency than the commercial resin. For method validation, spike recovery tests were performed at various concentration levels in different water types and were found to be between 83–95 and 75–92% for ultra pure water and geothermal water, respectively.