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K. K. Sahu

Bio: K. K. Sahu is an academic researcher from Utkal University. The author has contributed to research in topics: Thermal decomposition & Artificial intelligence. The author has an hindex of 3, co-authored 10 publications receiving 19 citations.

Papers
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Journal ArticleDOI
TL;DR: In this article, the catalytic activity of rare earth oxides (REOs) on the isothermal decomposition of calcium oxalate has been studied within the temperature range 693-733 K.

6 citations

Journal ArticleDOI
TL;DR: In this paper, the catalytic activity of rare earth oxides (REO) was studied at 723 K and α−t plots for pure salt as well as mixtures indicate that the process follows: initial gas evolution, a short acceleratory and a long decay stages.
Abstract: Catalytic activity of rare earth oxides (REO); La2O3, Sm2O3, Gd2O3 and Ce2O3 on the isothermal decomposition of barium oxalate has been studied at 723 K. The α−t plots for pure salt as well as mixtures indicate that the process follows: initial gas evolution, a short acceleratory and a long decay stages. The results of the kinetic analysis show that Prout-Tompkins relationship and two-dimensional phase boundary reaction give best fit of the data for both pure salt as well as mixtures. The rate constants of acceleratory and decay periods are enhanced remarkably by adding REO admixtures and their catalytical activity is in the order La2O3>Sm2O3>Gd2O3 >Ce2O3. The plausible mechanism of decomposition and the role of admixture there on has been discussed in the light of electron transfer process.

5 citations

Journal ArticleDOI
TL;DR: In this article, the effect of γ-irradiation on the thermal decomposition of barium oxalate hemihydrate has been studied at 723K by a gas evolution method.
Abstract: The effect of γ-irradiation (1.0–4.0 MGy) on the thermal decomposition of barium oxalate hemihydrate has been studied at 723K by a gas evolution method. Decomposition isotherms of unirradiated and irradiated crystals are characterized by (i) rapid initial gas evolution, (ii) acceleratory and (iii) decay stages. Irradiation enhances the rate of decomposition without altering the mechanism of the process, the effect being higher at higher irradiation doses. The analysis of the data reveal that the two-dimensional phase boundary reaction model gives the best fit to the results.

3 citations

Journal ArticleDOI
TL;DR: In this paper, the catalytic effect of Dy2O3 on the isothermal decomposition of sodium bromate has been investigated at 6130 K and the results show that DyO3, being a p-type semiconductor, accelerates the decomposition by favoring the electron transfer reaction involved in the process.
Abstract: The catalytic effect of Dy2O3 on the isothermal decomposition of sodium bromate has been investigated at 6130 K The data are analyzed in the light of various topochemical models Dy2O3, being a p-type semiconductor, accelerates the decomposition of bromate by favoring the electron transfer reaction involved in the process The plausible mechanism of the catalytic activity on the decomposition process is discussed

2 citations

Journal ArticleDOI
TL;DR: In this paper, the effects of radiation dose in the range of 0.5-2.0 MGy of 60Co γ-rays on the isothermal decomposition of sodium bromate at 633.0 K were investigated.
Abstract: Influence of radiation dose in the range of 0.5–2.0 MGy of60Co γ-rays on the isothermal decomposition of sodium bromate at 633.0 K shows that irradiation increases the initial gas evolution {ie37-1}, shortens the induction period (I), enhances the rate of reaction in the accelerating and decay stages. The data fit well the Prout-Tompkins relationship, indicating that nucleation occurs in a chain branching manner during the process. The fraction decomposed, α, increases with increasing radiation dose.

1 citations


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Journal ArticleDOI
TL;DR: In this article, mixed manganites exhibiting very large specific surface areas were synthesized by thermal decomposition of mixed oxalates in an oxygen-containing atmosphere, and a close control of the reaction kinetics was found to be necessary in order to prepare reproducible materials due to the high exothermic character of the oxalate decomposition, otherwise local increases of temperature led to a fast uncontainable growth of the crystallites.
Abstract: Mixed manganites exhibiting very large specific surface areas were synthesized by thermal decomposition of mixed oxalates in an oxygen-containing atmosphere. A close control of the reaction kinetics was found to be necessary in order to prepare reproducible materials due to the high exothermic character of the oxalate decomposition, otherwise local increases of temperature led to a fast uncontainable growth of the crystallites. The effects of the powder bed thickness, thermal conditions and partial pressure of oxygen were also investigated and it was shown that the fixed-bed processing method was not suitable for the reproducible synthesis of large amounts of material.

12 citations

Journal ArticleDOI
TL;DR: In this article, the thermal decomposition of Ln2(C2O4)3 · 9H2O concentrate (Ln = La, Ce, Pr, Nd) was studied by X-ray diffraction, thermogravimetry, and chemical analysis.
Abstract: Thermal decomposition of Ln2(C2O4)3 · 9H2O concentrate (Ln = La, Ce, Pr, Nd) in the presence of CaC2O4 · H2O was studied by X-ray diffraction, thermogravimetry, and chemical analysis. Annealing at temperatures above 374°C in the absence of calcium oxalate gives rise to the solid solution of CeO2-based rare-earth oxides. Calcite CaCO3 is formed in the presence of calcium oxalate at annealing temperatures above 442°C, which impedes the formation of lanthanide oxide solid solution and favors crystallization of oxides as individual La2O3, CeO2, Pr6O11, and Nd2O3 phases. An increase in temperature above 736°C is accompanied by decomposition of calcium carbonate to give rise to an individual CaO phase and an individual phase of CeO2-based lanthanide oxide solid solution.

9 citations

Journal ArticleDOI
TL;DR: In this article, the authors applied the simultaneous rising temperature (DTA-TG) technique and the gas evolution method for studying the thermal decomposition of unirradiated and irradiated MgC2O4 and mgC 2O4 + TiO2 mixtures and obtained the best fit for the Avrami-Erofeev mechanism (n=2) suggesting that both the nucleation and growth processes occur at the reactant product interface in a two dimensional chain branching manner.
Abstract: The simultaneous rising temperature (DTA-TG) technique and the gas evolution method are adopted for studying the thermal decomposition of unirradiated and irradiated MgC2O4 and MgC2O4 + TiO2 mixtures. The data are applied to theories of different solid state reaction models and the best fit is obtained for the Avrami-Erofeev mechanism (n=2) suggesting that both the nucleation and growth processes occur at the reactant product interface in a two dimensional chain branching manner. Low irradiation doses decrease the rate of reaction remarkably whereas the reverse phenomenon takes place at higher doses. The n-type semiconducting oxide, TiO2 (5-40 mol%) enhances the rate of decomposition which increases with increasing concentration of the catalyst. The influence of n -irradiation is explained in the light of defects, dislocations and electron-hole (e−, h+) pairs generated in the lattice, whereas the influence of TiO2 is understood on the basis of electron transfer process involved in the reaction.

6 citations

Journal ArticleDOI
H Nayak1, D. Bhatta1
TL;DR: In this paper, the effect of γ-irradiation (4.0 MGy ) and the presence of Dy 2 O 3 (10 MGy) on the decomposition of anhydrous barium oxalate was investigated by the rising temperature technique.

5 citations

Journal ArticleDOI
N. Routra1, D. Bhatta1
TL;DR: In this paper, the effects of γ-irradiation on the thermal decomposition of BaC2O4+CuO, 10 mol%) mixture has been studied between the temperature range 678-718 K. Analysis of the kinetic data in the light of theories of various kinetic models are found to be well fitted to Prout-Tompkins, Avrami-Erofeyev and contracting square mechanisms.
Abstract: Influence of γ-irradiation, 0.1–0.75 MGy on the thermal decomposition of (BaC2O4+CuO, 10 mol%) mixture has been studied between the temperature range 678-718 K. It is evident from ‘α-f’ plots that decomposition of both unirradiated and irradiated mixtures follows: (i) initial gas evolution (initial puff of gas), (ii) acceleratory and (iii) decay periods. Irradiation promotes the initial gas evolution (α1), decreases the fractional decomposition (α), the effect being higher at lower doses, without altering the nature of the isotherms. But these effects increase with increasing radiation dose. Analysis of the kinetic data in the light of theories of various kinetic models are found to be well fitted to Prout-Tompkins, Avrami-Erofeyev and contracting square mechanisms. It is found that irradiation diminishes the rate of reaction of both the periods and decreases the energy of activation of the acceleratory stage without affecting the same in the decay period. Plausible mechanism of decomposition and the effect of γ-irradiation thereon has been discussed in detail.

5 citations