The Experts below are selected from a list of 285 Experts worldwide ranked by ideXlab platform

Ivar E. Reimanis - One of the best experts on this subject based on the ideXlab platform.

  • The formation of oriented Barium Carbonate from the decomposition of yttria-doped Barium zirconate films
    Scripta Materialia, 2020
    Co-Authors: D. Jennings, S. Ricote, J. Santiso, Ivar E. Reimanis
    Abstract:

    Abstract Yttria doped Barium zirconate (BZY) thin films show promise thanks to their high proton conductivities and their possibility for use in studying fundamental processes such as exsolution. This work demonstrates that highly oriented BZY thin (45 nm) films on (100) single crystal strontium titanate decompose into oriented Barium Carbonate rods and yttria stabilized zirconia when exposed to industrial grade Ar or pure CO2 at 800 °C. It is shown with transmission electron microscopy that the rods nucleate on the BZY surface. The causes and modes of decomposition in these thin films are discussed in detail.

Manuel Gaudon - One of the best experts on this subject based on the ideXlab platform.

  • thermochromic behavior 400 t c 1200 c of Barium Carbonate binary metal oxide mixtures
    Dyes and Pigments, 2011
    Co-Authors: E. Lataste, Alain Demourgues, J. Salmi, C. Naporea, Manuel Gaudon
    Abstract:

    Abstract Irreversible thermochromism over a wide temperature range has been observed from the decomposition of a mixture of a Barium Carbonate and a metal oxide. The control of the reaction temperature can be predicted from the calculation of the Madelung energy of the Barium/transition metal mixed oxide formed consecutively with the decarbonatation. Moreover, the Madelung energy of this formed mixed oxide may be predicted from bond valence considerations. This study offers a simple predictive approach to propose temperature indicators with significant optical contrast and a thermochromic temperature varying between 400 and 1200 °C.

  • Thermochromic behavior (400 < T °C < 1200 °C) of Barium Carbonate/binary metal oxide mixtures
    Dyes and Pigments, 2011
    Co-Authors: E. Lataste, Alain Demourgues, J. Salmi, C. Naporea, Manuel Gaudon
    Abstract:

    Abstract Irreversible thermochromism over a wide temperature range has been observed from the decomposition of a mixture of a Barium Carbonate and a metal oxide. The control of the reaction temperature can be predicted from the calculation of the Madelung energy of the Barium/transition metal mixed oxide formed consecutively with the decarbonatation. Moreover, the Madelung energy of this formed mixed oxide may be predicted from bond valence considerations. This study offers a simple predictive approach to propose temperature indicators with significant optical contrast and a thermochromic temperature varying between 400 and 1200 °C.

Ajay Kaushal - One of the best experts on this subject based on the ideXlab platform.

  • Is the ubiquitous presence of Barium Carbonate responsible for the poor aqueous processing ability of Barium titanate
    Journal of The European Ceramic Society, 2013
    Co-Authors: José M.f. Ferreira, Susana M. Olhero, Ajay Kaushal
    Abstract:

    Abstract The ubiquitous presence of Barium Carbonate (BaCO 3 – BC) as an impurity in Barium titanate (BaTiO 3 – BT) has been pointed out as the main reason for the well-known difficulties found by many investigators when attempting to process BT powders in aqueous media. Different and controversial arguments have been put forward to justify the observed aqueous processing difficulties of BT, but a satisfactory explanation is still to be found. With this aim, a systematic study was here undertaken to shed further light on the solid/liquid interactions occurring at the surface of BC and BT particles and their impact on the dispersion ability of both powders, separately and mixed in certain proportions. Long term colloidal stability and high solid loadings (60 vol.%) were obtained for BC, while colloidal instability and a lower maximum content of solids (50 vol.%) could be achieved for BT. This responds to the question risen in the title.

  • Is the ubiquitous presence of Barium Carbonate responsible for the poor aqueous processing ability of Barium titanate?
    Journal of the European Ceramic Society, 2013
    Co-Authors: José M.f. Ferreira, Susana M. Olhero, Ajay Kaushal
    Abstract:

    The ubiquitous presence of Barium Carbonate (BaCO3 - BC) as an impurity in Barium titanate (BaTiO3 - BT) has been pointed out as the main reason for the well-known difficulties found by many investigators when attempting to process BT powders in aqueous media. Different and controversial arguments have been put forward to justify the observed aqueous processing difficulties of BT, but a satisfactory explanation is still to be found. With this aim, a systematic study was here undertaken to shed further light on the solid/liquid interactions occurring at the surface of BC and BT particles and their impact on the dispersion ability of both powders, separately and mixed in certain proportions. Long term colloidal stability and high solid loadings (60 vol.%) were obtained for BC, while colloidal instability and a lower maximum content of solids (50 vol.%) could be achieved for BT. This responds to the question risen in the title. (C) 2013 Elsevier Ltd, All rights reserved

Eric Fouquet - One of the best experts on this subject based on the ideXlab platform.

Pao-chi Chen - One of the best experts on this subject based on the ideXlab platform.

  • Crystallization kinetics of Barium Carbonate crystals in a lab-scale bubble-column scrubber
    Journal of the Taiwan Institute of Chemical Engineers, 2014
    Co-Authors: Pao-chi Chen, Welly Shi, Vanessa Chen
    Abstract:

    Abstract The crystallization kinetics of Barium Carbonate crystals in the absorption of CO2 gas and reactive crystallization with Barium chloride solution within pH range 12–13 was explored in a continuous lab-scale bubble-column scrubber under a constant pH environment. In considering the agglomeration of crystals, a population balance model with well mixed scrubber was proposed to determine the crystallization kinetic data by simultaneously including nucleation rate, agglomeration kernel and growth rate, using the first three moments. Investigation parameters focused on the pH of the solution, liquid concentration, liquid flow rate, gas concentration and gas flow rate. The effect of these parameters on the crystallization kinetics was explored. Herein, liquid concentration and liquid flow rate were found to be the dominant factors significantly influencing both nucleation rate and agglomeration kernel, while the pH of the solution had a moderate influence. Correlation expressions of the kinetic data were also discovered and analyzed further. Evidence indicated that particle size was limited by the nucleation rate, agglomeration kernel and mean residence time.

  • Removal of carbon dioxide by reactive crystallization in a scrubber—kinetics of Barium Carbonate crystals
    Journal of Crystal Growth, 2001
    Co-Authors: Pao-chi Chen, K.l. Kou, H.k. Tai, S.l. Jin, C.l. Lye, C.y. Lin
    Abstract:

    Abstract A bubble column scrubber was utilized to remove simulated CO 2 waste gas under a constant pH value. Using Barium chloride solution as an absorbent reacting with CO 2 -gas in the scrubber under an alkaline solution condition, precipitates of Barium Carbonate were formed during the operation. Measured crystal size distributions at a given time were used to calculate the growth rate of Barium Carbonate crystals, which is proportional to a 1.49 order of relative supersaturation. This demonstrates that both mass transfer and surface integration are important to the crystal growth of Barium Carbonate. The classical nucleation theory can be used to describe the nucleation rate of Barium Carbonate. In addition, the agglomeration kernel is proportional to a 2.86 order of relative supersaturation.

  • Nucleation and morphology of Barium Carbonate crystals in a semi-batch crystallizer
    Journal of Crystal Growth, 2001
    Co-Authors: Pao-chi Chen, G.y Cheng, M.h Kou, P.y Shia, P.o Chung
    Abstract:

    Abstract A double-jet feed, semi-batch crystallization system was used to explore the nucleation kinetics, growth kinetics and morphology of Barium Carbonate crystals under a constant pH value. The nucleation rate and the growth rate can be determined successfully by the initial rate method. The results showed that heterogeneous nucleation is dominant in the primary nucleation mechanism, and the effect of specific power input on the nucleation rate is obvious. The results also showed that the pH and initial concentration of the solution play an important role on the morphology of Barium Carbonate crystals. The crystal forms are floc, candy-like, olivary with end dendrite, olivary-like and needle-like, depending on the operating conditions. At high to moderate concentrations the floc precipitates are the major products in the pH range of 9.0–10.0. At moderate to low concentrations the candy-like and olivary with end dendrite crystals become the major products. At low concentrations and low pH values the crystal forms are olivary-like and needle-like precipitates. However, the results showed that the crystal forms of Barium Carbonate are concerned with the nucleation rates. On the other hand, the investigations showed that the well-sharp crystal forms follow the surface-integration growth mechanism and the dendrite crystals obey the diffusion growth mechanism.