Sintering temperature dependence of optimized microstructure formation of BaFe12O19 using sol–gel method

In an attempt to obtain the best possible properties of barium hexaferrite (BaFe12O19), the sol–gel synthesis method was chosen and, the optimum sintering conditions were established. The effects of the sintering temperature on the structural, morphological and magnetic properties of hexaferrite were studied. X-ray analysis indicates that the sintered samples (1,000–1,150 °C) remained in the hexagonal structure. From this analysis, no secondary phases are identified. The effect of sintering temperature on the grain growth of BaFeBaFe12O19 is confirmed by the microstructure using HR-SEM and is in good agreement with the XRD analysis based on the peak intensity of the (107) plane. The samples sintered at 1,150 °C showed the densities as ~93 % of theoretical density. Sintering temperature affected the grains in compact samples. The results show that homogeneous and dense BaFeBaFe12O19 ceramics obtained at a lower sintering temperature of 1,150 °C which is lower than the normally reported sintering temperature of ≥1,200 °C. The thermal treatment can markedly affect the grains in compact samples

E-learning User Interface Acceptance Based on Analysis of User's Style, USAbility and User Benefits

E-learning does not function properly if the system is not in accordance with user needs. This study aims to establish an evaluation model for e-learning user interface according to user acceptance. The model is designed based on three categories: user learning style, USAbility and user benefits. Results of measurements of the three categories will determine the level of user acceptance of the e-learning interface. The data were taken using a questionnaire which was distributed to 125 ELS students from various countries. Then processed using SEM and Lisrel v8.80. This paper presents experimental set up for the general research and some results for technology acceptance theories

Influence of Microstructural Effect on Microvickers Hardness Properties of SiO2-Na2O-CaO (SNC) Waste Based Glass-ceramic

There are a lot of waste materials consist of silicate based such as coal combustion ash, slag from steel production, fly ash, mud, as well as glass cullet or mixtures to produce glass-ceramics. This research work using clam shell (CS) ash and soda-lime-silica (SLS) waste glass powder for fabricating novel SiO2-Na2O-CaO (SNC) glass-ceramic. The samples were composed of SLS (50%), Na2CO3 (30%), and CS (20%) in weight percentage via conventional melt-quenching technique and solid-state sintering technique. The samples were investigated via X-Ray Diffractometer (XRD), Field emission microscope (FESEM), and microvickers hardness tester. The samples were sintered at 550-950 °C to investigate the influence of microstructural effect on microvickers hardness properties at applied force 0.5 and 1.0 kgf. The optimal Vickers hardness properties at sintering temperature 850 °C due to high crystallization of SiO2 phase from the residual glass and CaO content enhanced the viscosity flow, high compactness of particles arrangement and densification of sample

Influence of Microstructural Effect on Microvickers Hardness Propertiesof SiO2-Na2O-CaO (SNC) Waste Based Glass-ceramic

There are a lot of waste materials consist of silicate based such as coal combustion ash, slag from steel production, fly ash, mud, as well as glass cullet or mixtures to produce glass-ceramics. This research work using clam shell (CS) ash and soda-lime-silica (SLS) waste glass powder for fabricating novel SiO2-Na2O-CaO (SNC) glass-ceramic. The samples were composed of SLS (50%), Na2CO3 (30%), and CS (20%) in weight percentage via conventional melt-quenching technique and solid-state sintering technique. The samples were investigated via X-Ray Diffractometer (XRD), Field emission microscope (FESEM), and microvickers hardness tester. The samples were sintered at 550-950 °C to investigate the influence of microstructural effect on microvickers hardness properties at applied force 0.5 and 1.0 kgf. The optimal Vickers hardness properties at sintering temperature 850 °C due to high crystallization of SiO2 phase from the residual glass and CaO content enhanced the viscosity flow, high compactness of particles arrangement and densification of sample