The research project investigated the effects of CoO additive on dielectric ferroelectric physical and mechanical properties of modified Bi0.5(Na0.81K0.19)0.5TiO3 ceramics were investigated. The samples were synthesized by solid state reaction technique where powders were calcined at 850 °C for 4 h and ceramics were sintered at 1050 °C for 4 h which difference heating rate controlled i.e. 100 300 and 600 °C/h for. The ceramics of BNKT/x wt.% CoO was added CoO by various x=0.00 0.10 0.20 0.30 0.60 and 0.90. Phase formation was determined by X-ray diffraction technique (XRD). The X-ray diffraction analysis of the ceramics suggests that all samples exhibited a perovskite structure. The dielectric properties under room temperature and various temperatures were also determined. Dielectric measurement data showed that the additive and heating rate controlled influenced dielectric constant and dielectric loss. Furthermore the hysteresis loop behaviors slightly changed with increasing the CoO contents.

This paper presents a quadrature sinusoidal oscillator providing sinusoidal signal which differs in phase. The features of the proposed circuit can be electronically controlled. The proposed circuit consists of 4 operational transconductance amplifiers(OTAs) and 2 grounded capacitors which is able to control the oscillation frequency(OF) and condition of oscillation(CO). To confirm the performance and theory of proposed circuit is verified by PSPICE simulations and the experimental results can be achieved by using the commercial parts(LM13700s). The power consumption is about 33.3mW at supply voltages

Dyes contaminated in wastewater that negatively affecting the environment and human health. The objectives of this study to prepare activated carbon from Salacca zalacca (Sumalee) seeds activated by 36 mmol/g KOH dye solution and activated carbon ratio 20:32 ml/g for dye removal. The influents of dye removal from wastewater by Salacca zalacca (Sumalee) seeds activated carbon were investigated as initial dye concentration activated carbon and dye solution ratio and contraction time. The moisture content the iodine number the methylene blue index and the functional groups by FTIR technique of the Salacca zalacca (Sumalee) activated carbon were characterized and the kinetics adsorption were also analyzed. The results showed that the activated carbon was the microporous material the highest dye removal from wastewater was 7.50 ± 0.25 mg/g the equilibrium time was 150 min with the activated carbon to dye solution ratio of 1:500 g/ml for 200 mg/l initial concentration. The kinetics of the adsorption process can be described by a pseudo-second order model (R2 = 0.9999). When increasing the initial concentration of dyes the adsorption efficiency was increased. The amount of activated carbon increased resulting in lower adsorption efficiency and the equilibrium time was longer