• Applied Chemistry for Engineering
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• v.4 no.3
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• pp.530-536
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• 1993

Acidic degreasing agent(ADA) was prepared by blending n-octanoic acid, MJU-100A, Tetronix T-701, POE(6)-2-ethylhexyl ether, Newpol PE-68, sorbitol, and phosphoric acid. The physical properties of ADA tested with aluminum specimen showed the following results; when 3wt% ADA-5 was performed at $70^{\circ}C$, the degreasing rate was 98% which is comparitively good, and the percentage of etching was 0.277% which was found to be less than that of commercialized product. When 20wt% of ADA-5 was added at $65^{\circ}C$, the percentage of derusting was 93% and the good defoaming effect proved by following low foaming power tests respectively : Ross and Miles, and Ross and Clark methods.

• Korean Journal of Food Science and Technology
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• v.20 no.6
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• pp.762-768
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• 1988

The lipolytic enzyme of milk from hormone treated and non treated cows was isolated and purified, It was shown that the crude lipase extract from the milk before and after a hormone treatment of the cows was different in color, foaming properties, yield and specific activity. Final purification of the lipase system was achieved by affinity chromatography on Heparin-Sepharose CL-6B. The lipase bound by Heparin-Sepharose was then characterised. The pH-optimum of the purified enzyme was 8.5 for butteroil emulsion as a substrate and the optimum temperature was $30^{\circ}C$ respectively. The molecular weight. determined by SDS-polyacrylamidegel electrophoresis, was about 70,000. The activity increased by 10% hen 0.01% bovine serum albumin was added to the substrate. The results indicate the enzymes obtained by affinity chromatography from milk before and after hormone treatment had the similar characteristics. The second lipolytic active component that was not bound by Heparin-Sepharose must be the cause of spontaneous rancidity.

• Korean Journal of Materials Research
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• v.26 no.8
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• pp.449-453
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• 2016

$HA(hydroxyapatite)/{\beta}-TCP$ (tricalcium phosphate) biomaterial (BCP; biphasic calcium phosphate) is widely used as bone cement or scaffolds material due to its superior biocompatibility. Furthermore, $NH_4HCO_3$ as a space holder (SH) has been used to evaluate feasibility assessment of porous structured BCP as bone scaffolds. In this study, using a spark plasma sintering (SPS) process at 393K and 1373K under 20MPa load, porous $HA/{\beta}-TCP$ biomaterials were successfully fabricated using $HA/{\beta}-TCP$ powders with 10~30 wt% SH, TiH2 as a foaming agent, and MgO powder as a binder. The effect of SH content on the pore size and distribution of the BCP biomaterial was observed by scanning electron microscopy (SEM) and a microfocus X-ray computer tomography system (SMX-225CT). The microstructure observations revealed that the volume fraction of the pores increased with increasing SH content and that rough pores were successfully fabricated by adding SH. Accordingly, the cell viabilities of BCP biomaterials were improved with increasing SH content. And, good biological properties were shown after assessment using Hanks balanced salt solution (HBSS).

• Journal of the Society of Cosmetic Scientists of Korea
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• v.38 no.1
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• pp.1-13
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• 2012

In this review, the use of air bubbles in the pharmaceutical and cosmetic formulations was discussed. The foam bubbles show different characteristics depending on the foaming agents and foam generating devices. The foam bubbles are generated in the form of dispersion of gas bubbles in a solvent. The assessment of stability and rheological properties of bubbles are the starting point for the formulation to be used. Pharmaceutical and cosmetic uses of bubbles are substantially growing, and the foam formulations of drugs can be used for rectal, vaginal, and dermal symptoms. The foam formulation is used in hair mousse, makeup foundation, and sunscreen cosmetics in basic cosmetics. Recently, a lot of studies and patents have been filed in stabilization of active ingredients and delivery of the active ingredient in terms of foam formulations. In the future, foam formulations are expected to be used as novel cosmeceutical formulations.

• Journal of the Korean Recycled Construction Resources Institute
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• v.1 no.3
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• pp.219-224
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• 2013

In this study, the inorganic insulating material was fabricated with quartzite, ordinary portland cement(OPC), lime and anhydrous gypsum. After characteristic analysis of slurry, the optimum mixing ratio was derived with different $CaO/SiO_2$ mole ratio. Based on derived mixing ratio, the inorganic insulating material was fabricated at different water content and hydrothermal synthesis conditions. Specific gravity was $0.26g/cm^3$, compressive strength was 0.4 MPa, and thermal conductivity was 0.064 W/mK. This properties were enhanced performance of conventional ALC (Autoclaved Lightweight Concrete). And it can replace organic insulation with harmless inorganic insulation through continues research and development.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.10
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• pp.865-871
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• 2016

In recent years, traditional scaffold fabrication techniques such as gas foaming, salt leaching, sponge replica, and freeze casting in tissue engineering have significantly limited sufficient mechanical property and cell interaction effect due to only random pores. Fused deposition modeling is the most apposite technology for fabricating the 3D scaffolds using the polymeric materials in tissue engineering application. In this study, 3D slurry mould was fabricated with a blended biphasic calcium phosphate (BCP)/Silica/Alginic acid sodium salt slurry in PCL mould and heated for two hours at $100^{\circ}C$ to harden the blended slurry. 3D dual-pore BCP/Silica scaffold, composed of macro pores interconnected with micro pores, was successfully fabricated by sintering at furnace of $1100^{\circ}C$. Surface morphology and 3D shape of dual-pore BCP/Silica scaffold from scanning electron microscopy were observed. Also, the mechanical properties of 3D BCP/Silica scaffold, according to blending ratio of alginic acid sodium salt, were evaluated through compression test.

• Applied Chemistry for Engineering
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• v.5 no.2
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• pp.247-254
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• 1994

Nonionic surfactants, diglycerol N-acyl glutamates were prepared through the esterification of N-acryl glutamic acids and glycidol in the presence of quarternary ammonium salts. Their cmc evaluated by the surface tension method was $0.15{\sim}0.75mol/{\ell}$, and the surface tension of aqueous solution was decreased to 28~35dyne/cm. L-DGLG with acyl group of carbon number of 12 showed good foaming power and emulsifying power, and the emulsifying power in toluene was stronger than in soybean oil. Dispersion effect of L-DGPG and L-DGSG with acyl group of carbon number of 16 and 18 in carbon black and ferric oxide were higher than L-DGLG. All of them showed good biodegradability at $20^{\circ}C$.

• Elastomers and Composites
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• v.35 no.2
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• pp.106-114
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• 2000

The foam of ethylene vinyl acetate (EVA)/styrene-vinyl isoprene-styrene triblock copolymer(SVIS) blend was prepared to improve the shock-absorption and compression set characteristics at room temperature. The effects of blowing agent and blend ratio of EVA/SVIS on expansion ratio, cell structure and mechanical properties of the foam were investigated. As the SVIS content increased, the viscosity of blends was increased but the crosslinking rate was slow down, the expansion ratio was decreased. and the specific gravity was increased. At room temperature, the resilience was not affected by increasing the amount of blowing agent. The value of tan ${\delta}$ was increased by increasing the amount of SVIS. As a result, the value of compression set was decreased. This is due to the increased values of specific gravity and crosslinking density of the EVA/SVIS foam.

• Korean Journal of Materials Research
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• v.24 no.2
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• pp.111-115
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• 2014

Titanium and its alloys are useful for implant materials. In this study, porous Ti-Nb-Zr biomaterials were successfully synthesized by powder metallurgy using a $NH_4HCO_3$ as space holder and $TiH_2$ as foaming agent. Consolidation of powder was accomplished by spark plasma sintering process(SPS) at $850^{\circ}C$ under 30 MPa condition. The effect of high energy milling time on pore size and distribution in Ti-Nb-Zr alloys with space holder($NH_4HCO_3$) was investigated by optical microscope(OM), scanning electron microscope(SEM) & energy dispersive spectroscopy(EDS) and X-ray diffraction(XRD). Microstructure observation revealed that, a lot of pores were uniformly distributed in the Ti-Nb-Zr alloys as size of about $30-100{\mu}m$ using mixed powder and milled powders. In addition, the pore ratio was found to be about 5-20% by image analysis, using an image analyzer(Image Pro Plus). Furthermore, the physical properties of specimens were improved with increasing milling time as results of hardness, relative density, compressive strength and Young's modulus. Particularly Young's modulus of the sintered alloy using 4h milled powder reached 52 GPa which is similar to bone elastic modulus.

• Korean journal of food and cookery science
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• v.6 no.3 s.12
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• pp.9-15
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• 1990

Peanut prptein isolate was tested for the purpose of finding out the effect of pH, Sodium Chloride concentration and heat treatment on the solubility, surface hydrophobicity, foam expansion and foam stability. The solubility of peanut protein isolate was affected by pH and showed the lowest value at pH 4.5. When the peanut protein isolate was heated, the solubility decreased at pH 3 and pH 7 but at pH 9 solubility increased. At all pH range, solubility decreased as NaCl was added. The surface hydrophobicity of peanut protein isolate showed the highest value at pH 1.5. Generally, at acidic pH range the surface hydrophobicity was high, but at alkaline region, the surface hydrophobicity increased as the temperature increased. And when NaCl was added, the surface hydrophobicity was also increased. Foam expansion of peanut protein isolate was no significant difference among the values about pH. When the peanut protein was heated and NaCl was added, foam expansion was increased at pH 7. Foam stability was significantly low at pH 4.5 and foam stability was increased at acidic pH region below pH 4.5. At pH 7 and pH 9, heat treatment above $60^{\circ}C$ increased foam stability. When NaCl was added, foam stability was significantly increased at pH 3 and pH 7.