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71.
Ahmet Örnek 《Journal of the American Ceramic Society》2017,100(12):5668-5680
Excellent core‐shell morphology and nanoscale high‐voltage LiNiPO4@C cathode materials have been synthesized by a low‐level and long‐time microwave and solvothermal synthesis methodology. The effects of the changing physicochemical parameters on the crystal‐quality and electrochemical properties of the products have been evaluated in relation to the cycling stability. X‐ray diffraction analysis shows that it is possible to synthesize phase‐pure LiNiPO4 material when the reaction parameters are carefully elaborated. High‐resolution transmission electron microscopy analysis reveals a core‐shell morphology with a coating thickness of 6‐8 nm for 30 minutes at 180°C solvothermal temperature and time‐spread microwave energy. This mentioned cathode material exhibits the best electrochemical properties, achieving a discharge capacity of 157 mAh·g?1 at a 0.l C current rate, and shows a remarkable 81% capacity retention at the end of the 80th cycle. 相似文献
72.
A general dynamic model for a cross-flow dryer is developed from fundamental balance equations. Six dimensionless groups that govern the process are defined and the resulting dimensionless equations are solved with the method of lines, using the Advanced Continuous Simulation Language software package ACSL (1986). The mesh influence on the numerical solution is investigated, and the assumption of quasi-steady state for the air is discussed. Application of the model to rice-drying experiments shows good agreement, and the results underline the potential of the model and the numerical solution strategy in obtaining critical physical insight towards the operation of cross-flow rice dryers. 相似文献
73.
Nilgün Kzlcan Belks Ustamehmetolu Nesrin
z A. Sezai Sara Ahmet Akar 《应用聚合物科学杂志》2003,89(11):2896-2901
Soluble and processable conductive copolymers of silicone tegomers and pyrrole were developed. This was easily accomplished by the oxidative polymerization of pyrrole monomer by Ce(IV) salt in the presence of silicone tegomers with hydroxyl chain ends. The resulting copolymers were soluble in dimethylformamide. The products were characterized by Fourier transform infrared, 1H‐NMR, and four‐point probe conductivity, and their surface properties were investigated with contact‐angle measurements. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2896–2901, 2003 相似文献
74.
Mehmet Uysal Ramazan Karslioğlu Ahmet Alp Hatem Akbulut 《Ceramics International》2013,39(5):5485-5493
Core–shell nanostructured Ni-coated Al2O3 composite powders were synthesised by using the electroless plating method. The influence of the chemical components and powder concentration in the Ni coating was investigated by scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction techniques. The results show that the concentration of the plating components plays an important role in the formation of core–shell Al2O3/Ni composite powders. The nickel content in the composite powders could be effectively controlled by adjusting the nickel chloride content and the concentration of NaH2PO2·H2O in the plating solution. The nanostructure of the crystalline Ni coatings was observed to be very attractive for achieving good bonding between ceramic particles and matrices for composite production. 相似文献
75.
H. Erdem Çamurlu Ahmet Gençer Burcu Becer Şükrü Özdoğan 《Ceramics International》2013,39(8):8589-8595
Effect of potassium carbonate addition on the carbothermic formation of hexagonal boron nitride (hBN) was investigated by keeping the K2CO3 added B2O3+C mixtures in nitrogen atmosphere at 1400 °C for 40–160 min. K2CO3 amount was varied in the range of 10–60 wt% of the B2O3+C mixture. Products were subjected to XRD and quantitative analyses, SEM and TEM observations, and particle size measurement. Amount of hBN increased considerably with K2CO3 addition; also particle size and crystallinity improved. Catalytic role of K2CO3 was suggested as forming a potassium borate melt in which hBN particles form, in addition to carbothermic formation reaction. Effect of K2CO3 on increasing the hBN amount decreased when it was used over 40%. This was attributed to the rapid evaporation of the formed potassium borate liquid. 相似文献
76.
avdar kr Deniz Emre Turan Neslihan Ta Ahmet Tolga ztrk zgr Koralay Haluk 《Glass and Ceramics》2022,79(1):75-81
Glass and Ceramics - The crystallisation kinetics and effects of doping on Bi2Sr2CaCu2Oδ (BSCCO) glass ceramic system with 0.0%, 0.1%, 0.3% and 0.5% PbSe were investigated in this study.... 相似文献
77.
Burcu Selen alayan Ahmet K. Avc Z. lsen
nsan A. Erhan Aksoylu 《Applied Catalysis A: General》2005,280(2):181-188
Indirect partial oxidation (IPOX) of propane was studied over bimetallic 0.2 wt.% Pt–15 wt.% Ni/δ-Al2O3 catalyst in the 623–743 K temperature range. The unreduced and reduced forms of the catalyst were characterized by ESEM–EDAX and X-ray diffraction (XRD). In the IPOX tests, the effects of steam to carbon ratio (S/C), carbon to oxygen ratio (C/O2) and residence time (W/F (gcat h/mol HC)) on the hydrogen production activity, selectivity and product distribution were studied in detail. The effect of temperature program applied (increasing from 623 to 743 K, ITP; decreasing from 743 to 623 K, DTP) during reaction was also tested. The results showed that the Pt–Ni bimetallic system has superior performance characteristics compared to the monometallic catalysts reported in literature. The reason is thought to be the utilization of the catalyst particles as micro heat exchangers during IPOX; the heat generated by Pt sites during exothermic total oxidation (TOX) being readily transferred through the catalyst particles acting as micro heat exchangers to the Ni sites, which promote endothermic steam reforming (SR). The optimal conditions were found as S/C = 3, C/O2 = 2.70 and W/F = 0.51 gcat h/mol HC for IPOX of propane on the basis of high hydrogen productivity and selectivity between 623 and 748 K for the experimental conditions tested. The thermo-neutral points obtained showed the sustainability of reaction in terms of energy. 相似文献
78.
Adsorption of Remazol Red B on activated carbon prepared from olive stone and commercial activated carbon from aqueous solutions was compared. Different activating agent (ZnCl2) amounts and adsorbent particle size were studied to optimize adsorbent surface area. The adsorptive property of commercial activated carbon and activated carbon prepared from olive stone were investigated in terms of adsorbent dose, temperature, equilibrium time and pH. Then the obtained results were compared for all parameters, According to the results, the equilibrium time, optimum pH, adsorbent dosage were found 60 min, pH < 3–4 and 1.0 g/50 ml respectively. Lower adsorption capacity for RRB on activated carbon prepared from olive stone was found. The kinetic data for both adsorbents supports pseudo-second order model (r2 > 0.99) and intra-particle model (r2 > 0.95) but the first order kinetic model did not adequately fit to the experimental values (r2 < 0.76). The equilibrium adsorption data were interpreted using Langmuir and Freundlich models. The adsorption of Remazol Red B was better represented by the Langmuir equation. In addition, the thermodynamic parameters, standard free energy (ΔG°), standard enthalpy (ΔH°), standard entropy (ΔS°) of the adsorption process were calculated for both adsorbents. To reveal the adsorptive characteristics of the produced active carbon, surface area measurements were carried out and structural analysis was performed using SEM-EDS. 相似文献
79.
Conducting polymers containing polyether pseudocages (P I , P II , P III ) have been synthesized via chemical oxidation of 1,5‐bis(1,1‐pyrrole)‐3‐oxabutane (M I ), 1,8‐bis(1,1‐pyrrole)‐3,6‐dioxahexane (M II ), and 1,11‐bis(1,1‐pyrrole)‐3,6,9‐trioxaundecane (M III ) using anhydrous FeCl3 in CHCl3. Because as obtained polymer resins did not give any response toward any cations, they were reduced (undoped) using chemical reducing agents. Tetrabutylammonium hydroxide was found to be more effective in undoping to obtain more reproducible and reusable polymer resins. The undoped polymer resins were tried in the extraction of rare earth metal ions from the aqueous medium. Among them, only P III resin removes La(III), Eu(III) and Yb(III) and can be employed for the preconcentration of these metal ions. For batch extraction of La(III), Eu(III) and Yb(III) at neutral pH values, percent recoveries of 98.0 ± 1.0, 90.7 ± 1.4, 87.3 ± 4.0, respectively, has been obtained. The sorption capacity is found as 1.3 mg of La(III) per gram of P III resin. The P III resin could be reused at least five times without significant change in its sorption capacity. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
80.
The synthesis, characterization and voltammetric and spectroelectrochemical properties of newly synthesized lead phthalocyanines bearing tetra-(1,1-(dicarbpenthoxy)-2-(4-biphenyl)-ethyl), tetra-(1,1-(dicarbpenthoxy)-2-(1-naphthyl)-ethyl and tetra-((1,1,2-(tricarbopentoxyethyl)) substituents have been presented in this work for the first time. The characterization of the complexes was made by elemental analysis, 1H NMR, FT-IR, UV-vis and Maldi-TOF. The solution redox properties and spectroelectrochemical investigation of the complexes are studied using various electrochemical techniques in DCM on a platinum electrode. Cyclic voltammetry and differential pulse voltammetry studies show that the complexes give three one-electron ligand-based reductions and two one-electron oxidation couples having diffusion-controlled mass transfer character. Assignments of the redox couples were confirmed by spectroelectrochemical measurements. Spectroelectrochemical studies reveal that all complexes are demetallized during the spectroelectrochemical measurement under the applied potentials at the first reduction and oxidation potentials of the complexes. Different ring substituents of the complexes affect the easy demetallization processes of the complexes. 相似文献