Authors:Shin-Tae Bae, Hyunho Shin, Sangwook Lee, Dong Wook Kim, Hyun Suk Jung, and Kug Sun Hong
TiO 2 , Ta 2 O 5 shows photocatalytic activity under UV light irradiation [ 4 , 5 ]; furthermore, nitrogen-doped Ta 2 O 5 decomposes gaseous iso-propanol under Vis light irradiation [ 6 ], as in the case of N-doped TiO 2 . As the degree of nitrogen
Authors:Yu Huimei, Qi Lingjun, Zhang Qinghong, Jiang Danyu, and Lu Changwei
Thermal analysis (TA) is a technology with a history of more than 100 years. It has been used to measure the physical and chemical transformation of samples as a function of temperature in the scanning mode or as a
Authors:Hyun-Gyu Kang, Hyunho Shin, and Gihong Kim
(TiO 2−x N x ) was reported to be successful as a visible-light-sensitive photocatalyst [ 1 ].
Nitrogen-doped Ta 2 O 5 also demonstrates photocatalytic activity to decompose organic compounds under visible-light irradiations [ 2 , 3 ]. It is
Authors:L. Avaldi, L. Confalonieri, M. Milazzo, and E. Paltrinieri
X-ray fluorescence energy dispersive analysis is applied for the determination of Ta and W in sintering compounds. The combination of selective excitation and very simple mathematical procedures permits the determination of the concentrations of the two adjacent elements /Ta and W/ even when the sample contains only few per cent of Ta. Other possible applications are shown.
TA-MS provides chemical and thermal response information. In order for this information to be meaningful sampling must be
performed with minimum dead volume and without cold spots. Dead volume leads to response lag and peak broadening. Cold spots
result in sample condensation, leading to inaccurate data and potentially inlet blockage. This paper describes a hot zone
inlet system and 'in-situ' probe both of which provide fast response, zero dead volume sampling directly to the MS. The paper
also discusses data interpretation methodologies and introduces 'soft ionisation' as a means of providing simplified analysis
of complex mixtures.
Authors:B. Zatolokin, I. Konstantinov, and N. Krasnov
The influence of activation of Ta by secondary neutrons on the results of proton activation instrumental analysis of W in
Ta is described. It is shown that the detection limit of W in Ta using 11 MeV protons cannot be lower than 3 ppm.
Authors:Zuzana Netriová, M. Boča, V. Danielik, and Eva Mikšíková
The phase diagrams of the binary system Ta2O5-K2TaF7 and the ternary system KF-Ta2O5-K2TaF7 were determined using the thermal analysis method. The system Ta2O5-K2TaF7 was measured up to 25 mol% of Ta2O5. Eutectic point is estimated to be at
=0.14 and t=601°C. Crystallization of K2TaF7, K2Ta2O3F6 and a new phase was identified. The new phase shows isomorphism with K3Nb2F11O. In the ternary system four nonvariant equilibria points at 3 mol% of Ta2O5, 72 mol% of KF and 25 mol% of K2TaF7 at 715(1)°C; 6 mol% of Ta2O5, 44 mol% of KF and 50 mol% of K2TaF7 at 603(2)°C; 1 mol% of Ta2O5, 22 mol% of KF and 77 mol% of K2TaF7 at 704(1)°C and 8 mol% of Ta2O5, 8 mol% of KF and 84 mol% of K2TaF7 at 580(1)°C were proposed. Crystallization fields of KF, K2TaF7, K3TaF8, K3TaOF6, K4Ta2OF12 and K2Ta2O3F6 were considered.
Authors:M. Boča, V. Danielik, Z. Ivanová, E. Mikšíková, and B. Kubíková
The phase diagrams of the systems KF-K2TaF7 and KF-Ta2O5 were determined using the thermal analysis method. The phase diagrams were described by suitable thermodynamic model. In
the system KF-K2TaF7 eutectic points at xKF=0.716 and t=725.4°C and at xKF=0.214 and t=712.2°C has been calculated. It was suggested that K2TaF7 melts incongruently at around 743°C forming two immiscible liquids. The system KF-Ta2O5 have been measured up to 8 mol% of Ta2O5. The eutectic point was estimated to be at xKF∼0.9 and t∼816°C. The formation of KTaO3 and K3TaO2F4 compounds has been observed in the solidified samples.
The method of the separation of182Ta from urine and stool by precipitating as tantalum phosphate was elaborated. The conditions of Ta phosphate precipitation
as well as coprecipitation of45Ca,106Ru,144Ce,147Pm,152Eu,60Co,90Sr,90Y,95 Zr,95Nb and U were studied. The results show that tantalum can be separated from all macrocomponents of the mineralized biological
material and from the great number of radionuclides which can be present in the sample.