• Proceedings of the Korea Concrete Institute Conference
• /
• 1999.10a
• /
• pp.73-76
• /
• 1999

In recent, concrete material like specific cement and additives having many functions hsa been developed. In road pavement, ultra high early strength cement or organic material are used to open the road early, but there are many restrictions like workable time and special equipment. We aim to developed specific concrete which 1 day strength is over 300kgf/$\textrm{cm}^2$ to open the road within one day and workable time is maintained over 1 hour that can make the concrete ready mixed concrete. In this study, we are convinced if the ratio of hauyne clinker or its additive is increased early strength property is progressed and if the ratio of non hydrous gypsum is increased longtime strength is progressed. The concrete strength is 290-310 kgf/$\textrm{cm}^2$ at 1 day, 570-640 kgf/$\textrm{cm}^2$ at 28 day and the workable time is maintained over 30 minutes. As the results of this experiments We find out the possibility to developed the 1 day usable ready mixed concrete with high early strength.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.8 no.1
• /
• pp.40-46
• /
• 1988

This study was carried out to determine the effects of nitrogen (N) fertilization levels (0, 100 and 200kg/ha) and formaldehyde (0.4,0.8 and 1.2%: w/w CM) on the chemical composition, dry matter (DM) yield and in-vitro dry matter digestibility (IVDMD) of forage rape (Brassica napus Subsp. oleifera) silage. The results obtained are summarized as follows : 1. Forage rape was a catch crop which was highly digestible and low concentration in NDF, ADF, cellulose and lignin. 2. The concentration of the water soluble carbohydrate (WSC) and buffering capacity (PK) was 17.9% and 6.77g/100g, respectively, provided the WSC to PK ratio was 2.65. 3. DM content of silage decreased as the rate of N fertilization increased, but concentration of ammonia-N decreased. IVDMD was not affected by the rate of N fertilization. 4. By the addition of formaldehyde, the pH and IVDMD were increased, but the DM, lactic acid, total organic acid and ammonia-N content of rape silage were decreased, that was effective as a silage additive for forage rape.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.4 no.1
• /
• pp.61-67
• /
• 2011

Influence of hexamethyldisilazane(HMDS) in post processing technique by using n-butanol azeotropic distillation on the luminescence properties of YAG:Ce nanophosphor were studied. The organic solvent(n-butanol) azeotropic distillation which prevent powders from conglobation since lager molecules decrease the surface tension and more complete replace the residual water in the precipitate. HMDS that had larger molecules than that of n-butanol was added in azeotropic distillation. The phosphor synthesized from n-butanol azeotropic distillation exhibited lower agglomerate and better photoluminescence properties than that from HMDS added heterogeneous azeotropic distillation.

• Applied Biological Chemistry
• /
• v.48 no.3
• /
• pp.292-295
• /
• 2005

Synthesis of methyl 3-methyloctanoate, a perfume component isolated from African orchid Aerangis confusa (or Aerangis kirkii) was achieved starting from itaconic acid in 9 steps. Itaconic acid is one of the cheapest organic compounds which is the fermentation product of microorganism Asp. terreus. As the key intermediate, 2-methyl-1,4-butanediol 4-acetate was obtained through the enzymatic regioselective hydrolysis of 2-methyl-1,4-butanediol diacetate with lipase. After Grignard reaction and oxidation, 3-methyloctanoic acid was obtained and converted to the various corresponding scented esters with a variety of alkyl alcohols, and the resulting fragrancy esters are expected to be utilized as the aroma additive materials in cosmetics, drinks and foods.

• Analytical Science and Technology
• /
• v.12 no.6
• /
• pp.509-514
• /
• 1999

The systematic modification of titanium(IV) isopropoxide with acetic acid as a organic additive was done and identifided by FT-IR, $^1H$, $^{13}C$ NMR and UV-Vis spectroscopy. The structure was cbanged after hydrolysis-condensation reaction and drying process. The hydrolysis-condensation rates of modified Ti alkoxide with acetic acid were investigated by $^1H$ NMR spectroscopy. This modified Ti(IV) alkoxide was less reactive toward hydrolysis-condensation reaction than $Ti(OPr^i)_4$, which can be attributed to the stable ligand structure between Ti alkoxide and ligand. The structural change on obtained from gel powders with heat treatment was also observed by FT-IR spectroscopy.

• Analytical Science and Technology
• /
• v.33 no.4
• /
• pp.169-176
• /
• 2020

Separation of basic compounds using reverse phase chromatography on a silica-based stationary phase represents a major challenge, because of the interaction between the cationic sites of the basic compounds with the anionic silanols of the stationary phase. This study presents a simple, reliable, and organic solvent - free liquid chromatographic method for the determination of terbutaline and salbutamol, in which a room temperature ionic liquid (RTIL) is used as mobile phase additive. We investigated various mobile phase parameters affecting the retention of the two compounds, such as types and concentration of RTILs and, pH of the mobile phase were investigated. The developed method was validated according to International Conference on Harmonization (ICH) guidelines and successfully applied effectively to determine salbutamol sulfate in pharmaceutical preparations.

• Microbiology and Biotechnology Letters
• /
• v.48 no.3
• /
• pp.358-365
• /
• 2020

An organic solvent- and bleach-stable protease-producing strain was isolated from a polluted river water sample and identified as Aeromonas veronii OB3 on the basis of biochemical properties (API 20E) and 16S rRNA sequence analysis. The strain was found to hyper-produce alkaline protease when cultivated on fish waste powder-based medium (HVSP, 4080 U/ml). The biochemical properties and compatibility of OB3 with several detergents and additives were studied. Maximum activity was observed at pH 9.0 and 60℃. The crude protease displayed outstanding stability to the investigated surfactants and oxidants, such as Tween 80, Triton X-100, and H₂O₂, and almost 36% residual activity when incubated with 1% SDS. Remarkably, the enzyme demonstrated considerable compatibility with commercial detergents, retaining more than 100% of its activity with Ariel and Tide (1 h, 40℃). Moreover, washing performance of Tide significantly improved by the supplementation of small amounts of OB3 crude protease. These properties suggest the potential use of this alkaline protease as a bio-additive in the detergent industry and other biotechnological processes such as peptide synthesis.

• Korean Journal of Materials Research
• /
• v.30 no.4
• /
• pp.160-168
• /
• 2020

The current density in copper electroplating is directly related with the productivity; then, to increase the productivity, an increase in current density is required. This study is based on an analysis of changes in surface characteristics and mechanical properties by applying the addition of Alcian Blue (AB, C₅₆H₆₈Cl₄CuN₁₆S₄). The amount of Alcian Blue in the electrolytes is changed from 0 to 100 ppm. When Alcian Blue is added at 20 ppm, a seed layer is formed homogeneously on the surface at the initial stage of nucleation. However, crystals electroplated in electrolytes with more than 40 ppm of Alcian Blue are observed to have growth in the vertical direction on the surface and the shapes are like pyramids. This tendency of initial nucleation formation causes protrusions when the thickness of copper foil is 12 ㎛. Thereafter, a lot of extrusions are observed on the group of 100 ppm Alcian Blue. Tensile strength of groups with added Alcian Blue increased by more than 140% compare to no-addition group, but elongation is reduced. These results are due to the decrease of crystal size and changes of prior crystal growth plane from (111) and (200) to (220) due to Alcian Blue.

• Polymer(Korea)
• /
• v.36 no.3
• /
• pp.351-356
• /
• 2012

Acryl binder is a representative organic additive for the manufacture of the display electronic equipment. Acryl binder is usually synthesized by radical copolymerization. Glycidyl methacrylate (GMA), methyl methacrylate (MMA), and methacrylic acid (MAA) were used in this copolymerization of acryl binder. In this study the silane type mercaptane compound was used as a chain transfer agent (CTA) to enhance the adhesion property of the acrylic binder. The CTA used in this experiment was (3-mercaptopropyl) trimethoxysilane (MPTMS). Molecular weight of the copolymer, thickness of the coating, transmittance, and adhesion property were measured. The molecular weight was controlled and the adhesion property was improved by using this silane type chain transfer agent.

• Korean Journal of Materials Research
• /
• v.12 no.6
• /
• pp.499-507
• /
• 2002

The carbon nanotube emitters for field emission displays were fabricated by using screen printing techniques. The pastes for screen printing are composed of organic binders, carbon nanotubes (multiwalled or singlewalled), and some additive materials. The pastes were printed on Cr-coated/Ag-printed soda-lime glass substrates. From the I-V characteristics, the turn-on field of SWNT was lower than that of MWNT. The decrease in the mesh size of screen masks (i.e. increase in the opening size of the screen mesh) resulted in decreasing the turn-on field and increasing the electron emission current. When the carbon nanotubes were mixed with silver pastes, silver powders appeared to contribute to the vertically aligning of carbon nanotubes on a glass.