• Journal of the Korean Ceramic Society
• /
• v.52 no.5
• /
• pp.350-355
• /
• 2015

To develop ceramic composite anodes of solid oxide fuel cells without metal catalysts, a small amount of barium carbonate was added to an $(La_{0.8}Sr_{0.2})(Cr_{0.5}Mn_{0.5})O_3(LSCM)$ - YSZ ceramic composite anode and its catalytic effects on the electrode performance were investigated. A barium precursor solution with citric acid was used to synthesize the barium carbonate during ignition, while a barium precursor solution without citric acid was used to create hydrated barium hydroxide. The addition of barium carbonate to the ceramic composite anode caused stable fuel cell performance at 1073 K; this performance was higher than that of a fuel cell with $CeO_2$ catalyst; however, the addition of hydrated barium hydroxide to the ceramic composite anode caused poor stability of the fuel cell performance.

• Journal of the korean society of oceanography
• /
• v.35 no.2
• /
• pp.98-108
• /
• 2000

A geochemical study on a hemipelagic core sediment taken from the northwest Pacific Ocean (eastern edge of the Shikoku Basin) was conducted to use of excess barium (Ba(ex)) for evaluate the paleoceano-graphic changes. Also, the excursion of sedimentary Ba(ex) was compared with those of biogenic opal, carbonate and organic carbon content in the sediment during the last glacial and interglacial periods. The calculated Ba(ex) derived from the major and minor element shows a distinctive glacial-interglacial variations, and the mass accumulation rate (MAR) of Ba(ex) shows coincident variations with the MARs of biogenic fractions. Especially, strong positive correlation (r$^2$=0.85) between the MAR of Ba(ex) and the MAR of biogenic carbonate is recognized. Based on the strong positive correlation(r$^2$=0.85) between the MAR of Ba(ex) and the MAR of carbonate content, we estimated the degree of carbonate dissolution rate during the glacial and interglacial periods. Assuming the proportional variation and the refractory nature of barium exist between two factors, the variation of index Ca/Ba ratio in sediment indicates the degree of carbonate dissolution. Sedimentary Ca/Ba ratios index clearly show a striking fluctuation between the glacial and interglacial periods with higher positive correlation during glacial and lower correlation during interglacial. This fact indicates enhanced carbonate dissolution during interglacial period. Thus, the sedimentary Ca/Ba ratio in sedimentary records can be used as one of the useful tools for estimation of the relative degree of carbonate dissolution. The excursion of Ba(ex) and the sedimentary Ca/Ba ratio follows the typical pacific carbonate dissolution type(enhanced dissolution during interglacial and reduced dissolution during glacial time) as suggested by previous work (e.g., Wu et al., 1990). Variation in sedimentary Ca/Ba ratio thus strongly supports that glacial-interglacial fluctuation in carbonate dissolution has been prevailed in the northwest Pacific Ocean.

• Proceedings of the KIEE Conference
• /
• 1989.07a
• /
• pp.299-301
• /
• 1989

This study presents a method of preparing $YBa_2Cu_3O_{7-x}$ ceramic and chlorine doping in it for the purpose of Jc enhancement us ins sol-gel process.Tetramethylammonium-hydroxide and pottasium carbonate solution were added to the aqueous solution of Yttrium nitrate, Barium chloride and Copper nitrate for pH control as well as forming hydroxy-carbonate precipitation. Instead of Barium nitrate, Barium chloride was used for doping chloride impurities in the specimen. The resulted materal showed good high Tc-superconductivity after calcination. Tc and Jc value are 92 K and 120.8 $A/cm^2$ respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2003.07b
• /
• pp.714-718
• /
• 2003

Usually for the commercial preparation of barium titanate films or ceramics the reaction atmosphere must be preferably in air. However, normally air is not used because it contains carbon dioxide, which can easily react with barium to form the undesired product barium carbonate, leading to unwanted second-phase formation in the (mal stages of the process. In the present work a series of perovskite barium titanate films was prepared by the sol-gel method, using a metal alkoxide solutions in the electrophoretic deposition (EPD). The influence of several process parameters, like sintering temperature of sol preparation before EPD and heat-treatment temperature and non-oxidized atmosphere, on the film properties is described.

• Applied Microscopy
• /
• v.1 no.1
• /
• pp.43-48
• /
• 1969

X-ray diffraction intensity of barium ferrite sintered at $1280^{\circ}C$ as first sintering, varing mole ratio of barium carbonate and iron (III) oxide was checked. The results corresponed to of that magnetic coercivity in previous peport. The microstructure and sintering condition were observed-by means of two step replica method without etching by electron microscope.

• Journal of the Korean Ceramic Society
• /
• v.16 no.1
• /
• pp.31-37
• /
• 1979

The middle point of composition within the system $MgO-Al_2O_3-SiO_2$ has been studied for applicability as ceramics dielectrics. A Kyul Sung Tale of high purity, magnesia clinker of Sam-wha chemical company, C.P. aluminium oxide, calcium carbonate, red lead, barium carbonate which was made into frit were used the raw materials. A number of steatite ceramics were prepared under carefully controlled condition and the water absorption, linear shrinkage, power factor, dielectric constant and dielectric loss were measured at elevated temperature. When we used magnesia clinker as flux, the quantity of this flux was 0.05mole, sintering temperature was continued for 2 hrs. at 1, 27$0^{\circ}C$. From this conditions, we could get the data whose power factor was 0.142%, water absorption was zero, linear shrinkage was 8.76%, dielectric constant was 5.63, dielectric loss was 0.00799. When we used red lead as flux, the quantity of this flux was 0.033mole and 0.066mole, sintering temperature was continued for 2hrs. at 1, 26$0^{\circ}C$. From this conditions, we could get the data whose water absorption was zero, linear shrinkage was 8.03%, and 8.48%, power factor was 0.136% and 0.062%, dielectric loss was 0.0072 and 0.0037. When we used barium carbonate made into frit as flux, the quantity of this flux was 0.02mole, sintering temperature was continued for 2hrs. at 1, 27$0^{\circ}C$. From this conditions, we could get the data whose water absoption was zero, linear shrinkage was 8.44%, power factor was 0.138%, dielectric constant was 5.69, dielectric loss was 0.0074.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.07a
• /
• pp.620-623
• /
• 2001

The peculiarities of using Self-propagating High-temperature Synthesis (SHS) and solid state phase synthesis for production of high temperature superconductor materials are discussed. Oxide superconductors with general formula $ReBa_2$$Cu_3$$O_{7-x}$ (Re= Y, Yb, Sm, Nd) have been made with using barium oxide initial powder instead of traditional barium carbonate. X-ray powder diffraction showed a single phase orthorhombic perovskite structure was produced in all reactions. Phenomena observed during the grinding of the reactant mixture are presented. Mechano-chemical activation - as a pretreatment of the reactant mixture - strongly influences the kinetic parameters, the reaction mechanism, and the composition and structure of the final product.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.15 no.3
• /
• pp.275-280
• /
• 2002

The peculiarities of using Self-propagating High-temperature Synthesis (SHS) and solid-stave chase synthesis for production of high temperature superconductor materials were discussed. Oxide superconductors with general formula of $ReBa_2Cu_3O_{7-x}$ (Re=Y, Sm) haute been made by using barium oxide initial powder instead of traditional barium carbonate. Phenomena observed during the grinding of the reactants mixture are presented. Mechano-chemical activation - as a pre-treatment of the reactants mixture - strongly influences the kinetic parameters, the reaction mechanism, and the composition and structure of the final product.

• Polymer(Korea)
• /
• v.38 no.1
• /
• pp.103-107
• /
• 2014

Poly(acrylonitrile-butadiene-styrene) (ABS) composite sheets containing titanium dioxide ($TiO_2$), barium sulfate ($BaSO_4$), calcium carbonate ($CaCO_3$) were prepared by using a co-rotating twin screw extruder, and the reflectance and flexural modulus of the composite sheets were measured. The fillers were well dispersed in ABS matrix. The reflectance of composite sheet was increased with increasing $TiO_2$ and $BaSO_4$ content. Sheet having $TiO_2$ 20 wt% composition, with 5~20 wt% $BaSO_4$ resulted in more than 95% of reflectance. The flexural modulus of composite sheet was increased from 1864 MPa for $ABS/TiO_2/BaSO_4$ 85/10/5 (w/w/w) to 3134 MPa for $ABS/TiO_2/BaSO_4$ 55/20/25 (w/w/w).

• Journal of Environmental Science International
• /
• v.18 no.5
• /
• pp.509-515
• /
• 2009

The aim of this study is investigated greenhouse gas emissions of glass industry, and when calculates greenhouse gas emission, using formula(Tier 3) advising in IPCC(Intergovernmental Panel on Climate Change) and using self designed formula(Tier 3+) authors of this study. Studied to propose calculation formula that can compare these two calculation results and apply to domestic. Formula of Tier 3 calculated to theoretical composition of carbonate material, And Formula of Tier 3+ calculated on the basis of chemical substance formation table that get from glass manufacture company(The S company). As a result, Dolomite, Soda ash, Limestone, Industrial Barium carbonate is calculated value of Tier 3+ lower than value of Tier 3, And Industrial Potassium carbonate, Industrial Strontium carbonate was calculated value of Tier 3 lower than value of Tier 3. This study finding, formula of Tier 3+ has higher confidence than formula of Tier 3 when consider revision about purity of injection raw material. And hereafter, When calculate greenhouse gas emissions about nonmetallic mineral industry, use of Tier 3+ is considered that should be encouraged.