• Journal of the Korean Chemical Society
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• v.44 no.3
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• pp.237-242
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• 2000

We have synthesized ester compounds from the soybean oil and some Polymer alcohol compounds and studied the physical properties of the synthesized esters. We have performed this experiment for the purpose of testing the physical properties by soybean oil ester compounds as a water-soluble metal working lubricant.In addition, we have studied siy, surface tension, viscosity for the synthesized ester compounds in aqueous solution state varying the mixing ratio of water.

• Analytical Science and Technology
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• v.9 no.1
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• pp.91-97
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• 1996

The extent of binding($K_B$) between chemical compound and humic acid was measured as an indicator of decrease in toxicity. From the experimental $K_B$ and estimated $K_B$ calculated from $K_{ow}$, no reduction of toxicity among test chemicals in aquatic systems were predicted except P,P'-DDT. The effect of humic acid on aquatic organisms is not expected to be significant for the compounds with $K_B{\leq}10^5$ or $K_{ow}{\leq}10^6$.

• The KSFM Journal of Fluid Machinery
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• v.2 no.2 s.3
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• pp.19-26
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• 1999

Thermal output in a nuclear power plant is verified with calorimetric heat balance on the secondary plant. The calorimetry involves the precise measurement of the feedwater flow rate. However, the correct indication of feedwater flow rate obtained by a pressure-difference measurement across a venturi can be affected by instrument errors, fouling or a poorly developed velocity profile. This can result in an inaccurate mass flow rate and consequently an inaccurate estimate of power. The purpose of this study is to develop verification methods with accuracy better than $0.5\%$ for high precision flow measurement to be used for measuring feedwater flow rate. This chemical tracer method is a testing process that uses tracers which can be applied to quantify losses in electrical output due to the incorrect measurements of feedwater flow rate. And this system has good response to the variation of the flow rate. Accuracy of better than 0.5 percent can be expected for feedwater flow measurement, providing that the system can be stabilized during the test. This methodology is applicable to other flow systems well.

• Restorative Dentistry and Endodontics
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• v.13 no.1
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• pp.131-137
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• 1988

The purpose of this study was to investigate the interfacial bond strength of repaired composite resins, Lite-Fil P and Bis-Fil II, under different interfacial conditions. The matured composite resin specimen were prepared as Table I and divided into 9 groups. All specimens were stored in distilled water at $37^{\circ}C$ for 24 hours before testing. The results were as follows; 1. The bond strength of the groups that bonding agent was applicated was greater than that of the groups that bonding agent was not applicated. 2. The bond strength of the saliva contaminated groups was the lowest. 3. The bond strength of the group that chemical cured composite resin bonded to chemical cured composite resin was greater than that of the other groups. 4. The bond strength of the no-treated group was greater than that of saliva contaminated group, and lesser than that of the bonding agent applicated groups.

• Analytical Science and Technology
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• v.5 no.1
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• pp.91-96
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• 1992

A simple and cheap AC voltammeter was manufactured in our lab. This instrument consists of a DC function generator and a lock-in amplifier. We tested this instrument in some chemical systems. Our data, CV voltammogram and AC voltammogram, obtained form using a Pt working electrode in 1M $H_2SO_4$ and a reversible system of $1{\times}10^{-3}M$ ${Fe(CN)_6}^{3-}$ proved our system works well. The quantitative result of iodine is also obtained.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.3
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• pp.2308-2313
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• 2015

In order to produce an optimal performance solid lubricant used in the refractory slates, various compositions of starch, graphite and water were evaluated by testing their viscosity, coefficient of friction and wear performance. At 15% starch content, the degree of viscosity increment rose in proportional to graphite content and the lowest coefficient of friction was observed when the graphite content was at 30 wt%. Our results demonstrate that, as the water content decrease, the ratio of solid content increases, which compromises the surface coating resulting in increase of coefficient of friction. The best wear test result was obtained when the starch content was at 15 wt% with graphite content at either 25 wt% or 30 wt%.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.443-446
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• 2009

In this study, a series of degradation test for structural adhesives was performed to investigate the possibility of replacement of the alternative adhesives to the conventional adhesives. Four types of the adhesives were exposed to combined environmental conditions over 1000 hours at an accelerated aging tester, which can simulate natural weather conditions such temperature, moisture and ultraviolet. Mechanical and chemical properties of the adhesives were evaluated through material testing system and FT/IR spectrometer. According to the results, the conventional adhesives can be replaced by the alternative adhesives because the alternative adhesives were more stable to environmental conditions rather than the conventional adhesives.

• Journal of Environmental Science International
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• v.21 no.2
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• pp.233-240
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• 2012

In this study, the alkiline water washing condition of mackerel(Scomber japonicus) dark meat was investigated to improve processing conditions of red muscle fish meat paste heating gel. Chemical alkaline water(CWM) and electrolytic alkiline water(EWM, pH 12) were used for washing the mackerel raw meat. Washed meats were minced with 2.5% salt and heated at $90^{\circ}C$/15 min to testing texture profile analysis. Moisture of CWM and EWM was increased with both washing times(p<0.05). Crude lipids and protiens were decreased with washing times. Lightness of chemical alkaline water washed mackerel heated paste gel(CWHPG) was higher than electrolytic alkaline water washed mackerel heated paste gel(EWHPG). Redness and yellowness were more decreased than control meats. Jelly strength of CWHPG and EWHPG was not increased more than 2 times wased meat and was increased with protein decrease. Texture profile analysis, max force1 of CWHPG and EWHPG was higher hardeness than the control meat except gel strains. From these results, it could be suggested that electric alkialine water washing is also effective in advance the red meat paste heating gel process of kamaboko industry.

• Korean Chemical Engineering Research
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• v.56 no.3
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• pp.343-348
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• 2018

Each of the two polycarbonates (PC) of different molecular weights was blended with acrylonitrile-butadiene-styrene (ABS) under high-shear rate processing to afford PC/ABS. Sizes of ABS dispersed phases and mechanical properties of PC/ABS blends were investigated and high-shear rate processing of PC/ABS was carried out by changing screw speed and processing time. Prepared specimens were examined by scanning electron microscope (SEM) to observe morphology changes. Sizes of ABS dispersed phases in PC/ABS blends were observed to decrease gradually as screw speeds increased. Tensile strengths and elongations of specimens were investigated by universal testing method (UTM) to study the influence of molecular weight of PC exerting on PC/ABS blends. As a result, PC1/ABS blends (PC1: higher molecular weight PC) exhibited more strengthened properties than PC2/ABS (PC2: lower molecular weight PC). The tensile strength of PC1/ABS showed an increasing tendency when the screw speed increased, and the elongation did not show a significant decrease, but increased slightly with increasing shear time at a constant screw speed of 1000 rpm.

• Journal of the Korean Chemical Society
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• v.28 no.4
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• pp.238-243
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• 1984

Three component $Ag_2S-PbS-PbMoO_4$ electrodes have been prepared and evaluated for sensitivity to molybdate. The 64.5 : 14.0 : 21.5(w/w%) composition is superior in terms of potentiometric response, stability, rapidity of response and reproducibility. Testing was done over the concentration range of $10^{-1}{\sim}10^{-5}M\;MoO_4^{2-}\;in\;0.1F\;NH_4Ac-NH_4OH$ buffer solution at pH 7.95 with constant ionic strength. $I^-,\;Cl^-,\;Br^-\;and\;CN^-$, etc. interfere.