The Potassium Tantalum Niobate-Barium Titanate (KTN-BT) solid solution system ceramics with the composition 0.02K(Ta 0.5 Nb 0.5 )O 3 −0.98BaTiO 3 were prepared by a two-step sintering mechanism, for different sintering durations. Crystalline and microstructure analyses of the prepared samples were performed. Dielectric and piezoelectric properties were also investigated. Moreover, apparent piezoelectric constant d 33 was measured using the slope of strain vs. electric field curves for these ceramics. It was observed that the high values of density, electrical conductivity, relative dielectric permittivity (ε r = 3615.983), piezoelectric coefficient (d 33 = 315 pm/V) and remnant polarization (P r = 9.53 μC/cm 2 ) were obtained for ceramics prepared through a new variation of the conventional two-step sintering method. Finally, the relationship between sintering mechanism, microstructure and piezoelectricity was discussed for the 0.02K(Ta 0.5 Nb 0.5 )O 3 −0.98BaTiO 3 ceramics.

Sodium potassium niobate (NKN) powders were synthesized by the solid-state reaction method. The NKN ceramics for composition Na 0.92 K 0.08 NbO 3 (NKN) were then fabricated by a two-step sintering technique. The effects of the two-step sintering on the properties of the ceramics were investigated. The pure phase NKN was achieved for all sintering temperatures of 1100, 1150, 1200 and 1250 o C. The observed change in the microstructure indicates that the grain size increases with the increasing sintering temperatures. Also, the two-step sintering technique produced a higher value of K/(K+Na) weight-% ratio and peak dielectric constant for sintering temperatures 1100, 1150 and 1200 o C. However, further increasing of the sintering temperatures at 1250 o C, reduces the K/(K+Na) weight-% ratio and the peak dielectric constant (єc).

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Background: Some of the heavy metals are considered beneficial, if intake of them is within permissible trace amount and some other are highly toxic even in trace amount. So, heavy metals intake is one of the major concerns. Heavy metals enter into body via air, water, food, clothing and some of them gets accumulate in body organs this leads to many disorders and causes life threatening diseases including cancer. All of our food comes from plants directly or indirectly. Tea the highly consuming beverage after water comes from the leaves of plant/shrub Camellia Sinensis. Methods: Aim of the present work is to determine the elements present in Tea brew (Chai, boiling the Tea leaves in water) made from black Tea leaves of major brands available in local Indian market, more specifically heavy metals Cobalt (Co), Arsenic (As), Silver (Ag), Cadmium (Cd), Indium (In), mercury (Hg) and Lead (Pb). Total eleven samples were investigated with the instrument Perkin Elmer NexIon-300x Inductively Coupled Plasma Mass Spectrometer (ICP-MS). Result: Results have shown that Cobalt, Arsenic, Cadmium, Indium and Lead were present in all samples. Cobalt concentration varies from lowest 71.9 µg/kg to highest 214.3 µg/kg; Arsenic concentration varies from lowest 1.2 µg/kg to highest 53.7 µg/kg; Cadmium concentration varies from lowest 15.4 µg/kg to highest 75.03 µg/kg; Indium concentration varies from lowest 0.054 µg/kg to highest 0.70 µg/kg; Lead concentration varies from lowest 61.0 µg/kg to highest 2404.3 µg/kg. Mercury was present in two samples only in S9 and S11 with concentration 6.2 µg/kg and 1.4 µg/kg respectively; Out of eleven samples only seven samples have shown the presence of Silver its concentration varies from lowest 10.3 µg/kg to highest 193.0 µg/kg; Samples S2, S7, S8 and S10 were shown the absence of Silver and Mercury; Lead was found to be most abundant with concentration 2404.3 µg/kg and Indium was found to be least abundant with concentration 0.054 µg/kg.