• Journal of Welding and Joining
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• v.14 no.6
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• pp.93-100
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• 1996

Effect of a flux composition on weld metal toughness in submerged arc welding with 60kgf/$\textrm{mm}^2$ grade C-Mo type wires was investigated and interpreted in terms of weld metal microstructure and hardenability. Flux workability was also studied by characterizing a weld bead profile. Compared to other weld metals, .weld metal used alumina basic flux with nickel showed lowest oxygen content, highest hardenability and the most acicular ferrite. The highest impact toughness of that weld metal, however, was attributed to the tough matrix due to the nickel rather than to the larger amount of acicular ferrite. Manganese silicate flux had better workability than alumina basic flux, showing broader welding conditions resulting in a depth-to-width ratio of 0.5. The composition of oxides in the weld metal was dependent on the flux composition, showing MnO-SiO$_2$-TiO in manganese silicate flux and MnO-SiO$_2$-Al$_2$O$_3$-TiO in alumina basic flux. MnO-SiO$_2$composition in both oxides was similar to a tephroite.

• Journal of the Korean Society of Safety
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• v.8 no.2
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• pp.30-38
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• 1993

To increase fire proofing characteristics of protective coating based on soluble alkali silicate, silicate coatings were studied on thermal properties, IR spectroscopy, solubility and intumescence. Intumescence and solubility of the samples were dependent on the strength of cationic cross-links between polysilicate particles. The degree of intumescence and solubility decrease K-silicate > Na-silicate > Li-silicate in the order. Especially Si$_2$O$_{5}$ $^{-2}$ crystalline regions were found to exist in Potassium silicate sample. Mixture of two kinds of silicate, for example, Lithium silicate when added to sodium silicate or potassium silicate was find to significantly reduce efflorescence and increase water resistance. This appears to be a result of stronger crosslinking between polysilicate particles by the small lithium cation.

• Horticultural Science & Technology
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• v.30 no.3
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• pp.250-255
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• 2012

The effect of different source silicon ($CaSiO_3$, $K_2SiO_3$, and $NaSiO_3$) and their application methods (foliar application and subirrigation) on the growth of potted kalanchoe was investigated. Rooted terminal cuttings of Kalanchoe blossfeldiana 'Peperu' were transplanted into 10.5 cm plastic pots containing a commercial growing medium. Then, a nutrient solution, containing 0 or $50mg{\cdot}L^{-1}$ Si as $K_2SiO_3$, $Na_2SiO_3$, or $CaSiO_3$ and adjusted to EC 1.4-$1.6mS{\cdot}cm^{-1}$ and pH 6.0, was supplied through subirrigation along with the nutrient solution or by a foliar application. Plants were grown in a glasshouse under a mean temperature of $23^{\circ}C$ and RH of 70-80%. After 12 weeks of cultivation, plant growth characteristics and leaf tissue contents of P, K, Ca, Mg, Na, S, and Si were measured. Both subirrigational supply and foliar application of Si decreased the plant height and flower stem length. However, the plant condition in the foliar application resulted in disease-like soft rot on the leaf. Among three silicon sources tested, $CaSiO_3$ supplied through a subirrigation system increased shoot tissue contents of Si and chlorophyll as compared to the $Na_2SiO_3$ or $K_2SiO_3$ treatment. Shoot tissue contents of Ca, K, and Na increased when the plant was supplied with $CaSiO_3$, $K_2SiO_3$, and $Na_2SiO_3$, respectively. Subirrigational supply of $K_2SiO_3$ and $NaSiO_3$ decreased the shoot tissue contents of Ca and Mg, and K and Ca, respectively. Therefore, $CaSiO_3$ supplied through a subirrigation system could improve plant quality of kalanchoe 'Peperu' making compact potted plants.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.2
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• pp.370-376
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• 1998

The powder preparation of Zinc-Silicate phosphors compound was studied by hydrothermal reaction starting from the precursor which prepared by spray pyrolysis method. This process protect including of impuritied from crushing process and Mineralizing in hydrothermal reactions. Using spray pyrolysis precursor, ${\alpha}-Zn_2SiO_4$ powder was prepared by the hydrothermal reaction under $250^{\circ}C$.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.05a
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• pp.221-222
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• 2009

AZ31 마그네슘 합금에 AC 전류를 인가하여 MAO(micro-arc oxidation) process로 양극산화 할 때 알카리 전해액에 첨가되는 sodium silicate(Na2SiO3)의 농도에 따라 형성되는 양극 피막의 구조와 부식특성을 평가하였다. 전해질의 조성은 10g/1 KOH와 4g/1 KF 혼합 전해액에 sodium silicate를 (5, 10, 20, 40, 80)g/1로 달리하여 첨가한 후 $40mA/cm^2$의 전류밀도로 20분간 MAO 처리한 후 양극피막의 조직을 SEM, XRD, EPMA를 이용하여 분석하였고 동전위 분극시험으로 부식 거동을 평가하였으며 micro-vickers 경도계를 이용하여 단면의 경도를 측정하였다.

• Transactions on Electrical and Electronic Materials
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• v.12 no.3
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• pp.127-130
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• 2011

We investigated the effects of $O_2$ annealing (i.e., temperature and time) on the characteristics of hafnium silicate ($HfSi_xO_y$) films deposited on a Si substrate by atomic layer deposition process (ALD). We found that the post deposition annealing under oxidizing ambient causes the oxidation of residual Hf metal components, resulting in the improvement of electrical characteristics (e.g., hysteresis window and leakage current are decreased). In addition, we observed the annealing temperature is more important than the annealing time for post deposition annealing. Based on these observations, we suggest that post deposition annealing under oxidizing ambient is necessary to improve the electrical characteristics of $HfSi_xO_y$ films deposited by ALD. However, the annealing temperature has to be carefully controlled to minimize the regrowth of interfacial oxide, which degrades the value of equivalent oxide thickness.

• Weed & Turfgrass Science
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• v.3 no.2
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• pp.137-142
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• 2014

This study was conducted to investigate the effect of silicate mixed with nitrogen fertilizer on improving the growth and reducing nitrogen input of zoysiagrass. Plant height, fresh and dry weight of shoots, roots, and stolons, the number of shoots and total of stolons length were increased with highest in silicate mixed with nitrogen 24 kg/10a than nitrogen 24 kg/10a, and it showed no significance in silicate mixed with nitrogen 18 kg/10a. Nitrogen use efficiency in mixed silicate fertilizer was increased by 25-30% than single nitrogen fertilization. Moreover, the contents of available $SiO_2$, and organic matters of silicate fertilization on soil was higher than not silicate fertilization on soil. The silicate enhanced the growth and density of zoysiagrass, while it was a crucial factor to affect the chemical property of the soil.

• Journal of the Korean Ceramic Society
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• v.34 no.5
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• pp.491-499
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• 1997

High flexible lightweight composites containing tobermorite as a main mineral is produced using various amorphous silicates, lime, cement and fibers. Here, Mechanical properties of the composites were studied by observing microstructures of hydrates and fibers. Amorphous silicates having better hydraulicity retarded the crystallization of tobermorite due to better formation of C-S-H gel in water bath curing, but, difficult conversion from C-S-H gel to tobermorite in hydrothermal reaction. In the low molar ratio of CaO/SiO2 (0.67), faster crystalization was observed dued to more impurities such as Al2O3 alkali, resulting in improving mechanical properties due to small crystal size and many contact points. It was identified that a lot of calcium silicate hydates formed at surface of pulps increase bonding strength and the crack-resistance of matrix in the composites, but decrease hardness and compressive strength. The choice of amorpous silicates having better hydraulicity, low CaO/SiO2 adding each fibers bellow about 5% in the raw mixs and lower molding pressure should be needed at improve mechanical properties of composites.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.2
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• pp.238-241
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• 1986

To clarify the effect of silicate application on the reduction of summer drought damage of orchardgrass, a pot experiment treated with 3 levels of available SiO$_2$ 100(control), 150, and 200 ppm was carried out in the phytotron, and field experiment in the medium textured hilly soils also was carried out. The plant height and weight of orchardgrass grown in the pots were increased with increasing of SiO$_2$ application, and the higher content of SiO$_2$ in plant became erect types of leaves with low ethylene evolution. With application of SiO$_2$ in the hilly soils, the reduction of summer drought phenomenon was recognized by the increasing 9% in yield with decreased ethylene evolution at summer drought stage but the nutritive values of the plant were not deteriorated.

• Bulletin of the Korean Chemical Society
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• v.18 no.2
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• pp.203-208
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• 1997

A series of MgO-SiO2 catalysts were prepared by coprecipitation from the mixed solution of magnesium chloride and sodium silicate. Some of the sample were modified with 1 N H2SO4 and used as modified catalysts. The addition of MgO to SiO2 caused the increase of acidity and the shift of O-H and Si-O stretching bands of the silanol group to a lower frequency in proportion to the MgO content. The acid structure of MgO-SiO2 agreed with that proposed by Tanabe et al.. Catalytic activity for 2-propanol dehydration increased in relation to the increase of acidity and band shift to a lower frequency.