• Korean Journal of Food Science and Technology
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• v.27 no.4
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• pp.439-444
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• 1995

Preparative conditions and characteristics of six-vegetable and fruit juice were studied for the effects of mixing ratio, heat treatment and addition of sugar, salt and organic acid. The vegetables and fruit used were carrot(Ct), cabbage(Cg), pear(Pr), cucumber(Cr), celery(Cy) and dongchimi(Di). From the sensory results of mixing ratio of three of binary mixtures of Cg-Pr(1:3):Ct-Di(1:4):Cr-Cy(3:1), two ratios of 5.0:2.5:2.5(V-6A) and 6.0:2.0:2.0(V-6B) were suggested optimal for six-vegetable and fruit juice. Addition of 2% sucrose and 0.3% NaCl improved the preference significantly. The pH 4.0 for V-6A and pH 3.5 for V-6B were more prefered when pH was adjusted by citric acid. Heating the juice at $100^{\circ}C$ for 100 minutes slightly decreased pH and increased the acidity. Total solids and viscosity were also decreased by heating. All of those changes were more significant in V-6B than V-6A, probably due to lower pH. Heating the juice resulted in a slight decrease in L value and an increase in a and b values. Heating at $100^{\circ}C$ caused an increase in moldy flavor and a decrease in fresh vegetable flavor while heating at $80^{\circ}C$ for 20 minutes changed them little.

• Elastomers and Composites
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• v.33 no.5
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• pp.345-354
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• 1998

Rheological properties of polyamide-modified poly(vinyl choride) (PVC)-sol sealants were investigated. PVC-sol was prepared by plasticization with dioctyl phthalate(DOP). Two kinds of polyamide rosins having different amino values and thus different viscosities were compared. The effects of the polyamide types and contents on the viscosities, thixotropic indices, and specific gravities of the PVC-sol were discussed. It was found that viscosities of the PVC-sol sealants were significantly affected by the types of the added polyamide resins, and the thixotropic index of the polyamide-modified PVC-sol sealant was observed to be dependent on the contents(not on the types of the polyamides). The viscosity behaviors of the polyamide-modified PVC-sol sealants aged at $45^{\circ}C$ and the effect of the addition of $CaCO_3$ were also discussed.

• Polymer(Korea)
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• v.38 no.3
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• pp.286-292
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• 2014

The rheology of highly concentrated polymer bonded explosive (PBX) simulant was studied. An energy material, polyethylene plastomer (Exact$^{TM}$) having similar properties to poly(BAMO-AMMO) was selected as a binder. Dechlorane with similar properties to RDX (Research Department eXplosive) was chosen as a filler. Mixing behavior in a batch melt mixer was investigated. During mixing a large amount of heat of viscous dissipation was generated and a continuous decrease in torque was observed when the filler content was above 70 v%. It was believed due to wall slip phenomena. From the SEM images, the fillers were well dispersed and the effect of mixing condition affected slightly on the dispersion. Owing to distinct shear thinning behavior of the suspensions, measuring viscosity of highly filled suspensions was possible in a high shear rate capillary rheometer though it was impossible even in a low shear rate plateplate rheometer.

• Composites Research
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• v.33 no.3
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• pp.147-152
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• 2020

In this study, void behavior of composite laminate by local internal pressure gradient due to structural geometry and surface film application condition was experimentally evaluated through fabrication of spar/skin integrated structure specimens. Viscosity comparison and thermal analysis for both carbon fiber prepreg and surface film were conducted and cure characteristic and rate difference were analyzed. 2 types of spar/skin integrated structural specimens were prepared based on different application condition of surface film. Subsequently, those specimens were evaluated through visual surface inspection, non-destructive and destructive inspection. In a specimen #1 with full application of surface film, low pressurized area of composite laminate created by pressure gradient of structural geometry had voids. It exhibited that voids could not be evacuated and were locked in cured laminate by the influence of pre-cured surface film with relatively faster cure rate. In a specimen #2 without surface film, it revealed that all internal voids disappeared in the cured laminate. Therefore, it is verified that surface film acts as barrier film preventing void movement and evacuation during autoclave cure.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1475-1486
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• 2008

Bentonite-based grouting has been popularly used to seal a borehole installed for a closed-loop vertical ground heat exchanger in a geothermal heat pump system (GHP) because its high swelling potential. However, if the bentonite-based grouting is conducted in coastal areas, the salinity of groundwater changes in the mineral fabric of bentontie. In order words, an increase of cation concentration in groundwater leads to a reduction in the diffuse double-layer thickness in the bentonite mineral structure, and thus the volume of bentointe-based grouts will decrease proportional to the salinity of groundwater. In this paper, the effect of salinity (i.e., NaCl 0.5M, 0.25M, and 0.1M) on the change of swelling potential for bentonite-based grouts has been quantitatively evaluated for seven bentonite grouts from different product sources. In addition, in case of using addictives such as a silica sand to increase the thermal conductivity of bentonite-based grouts, the possibility of particle segregation has been studied considering the viscosity of grouts and salinity of groundwater.

• Korean Chemical Engineering Research
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• v.45 no.4
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• pp.356-363
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• 2007

The stability of paste solutions for electroluminescence display(ELD) device was found to be greatly affected by kind and dosage of a stabilizer used. The stabilizer Disperbyk-180 showed the best stability performance against phosphor paste solutions among the stabilizers used during this study. The phosphor paste solutions remained stable over 90 days with a wide range of added amounts of Disperbyk-180. Based on the above results, screen printing test was performed. The addition of Disperbyk-180 into phosphor and dielectric paste solutions produced improved qualities such as no phase separation, no bubble generation and no significant viscosity change during printing process. Especially for the phosphor paste solution, both uniformity and brightness were significantly improved and the excellent adhesion onto the ITO film was found. The ELD device fabricated using the above same paste solutions showed brightness of $57.6cd/m^2$ at 100V and 400 Hz. The half lifetime of ELD device was measured as 1,250 hours and almost the same value observed with imported commercial paste solutions.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2006.09a
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• pp.39-54
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• 2006

An experimental study on the hydro-cracking of recycling oil obtained from refused plastics was performed for up-grading of its fuel characteristics. Major experimental parameters were reaction temperature ($300^{\circ}C{\sim}700^{\circ}C$) and presence of catalysts (Al-Si, activated carbon, zeolite). The effect of the experimental parameters on the liquid product characteristics such as flash point, kinetic viscosity, and solid content was investigated. The hydro-cracking reactions of the recycling oil at $300^{\circ}C{\sim}400^{\circ}C$ improved the oil characteristics of the liquid products. Activated carbon was revealed as a stable and active catalyst in the hydro-cracking reaction at a temperature range investigated.

• Membrane and Water Treatment
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• v.6 no.3
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• pp.205-224
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• 2015

A novel hydrophilic poly (vinylidene fluoride)/poly (p-phenylene terephthalamide) (PVDF/PPTA) blend membrane was prepared by in situ polycondensation of p-phenylene diamine (PPD) and terephthaloyl chloride (TPC) in PVDF solution with subsequent nonsolvent induced phase separation (NIPS) process. For comparison, conventional solution blend membrane was prepared directly by adding PVDF powder into PPTA polycondensation solution. Blend membranes were characterized by means of viscometry, X-ray photoelectron spectroscopy (XPS), Field Emission Scanning Electron Microscopy (FESEM). The effects of different blending methods on membrane performance including water contact angle (WCA), mechanical strength, anti-fouling and anti-compression properties were investigated and compared. Stronger interactions between PVDF and PPTA in in situ blend membranes were verified by viscosity and XPS analysis. The incorporation of PPTA accelerated the demixing rate and caused the formation of a more porous structure in blend membranes. In situ blend membranes exhibited better hydrophilicity and higher tensile strength. The optimal values of WCA and tensile strength were $65^{\circ}$ and 34.1 MPa, which were reduced by 26.1% and increased by 26.3% compared with pure PVDF membrane. Additionally, antifouling properties of in situ blend membranes were greatly improved than pure PVDF membrane with an increasing of flux recovery ratio by 25%. Excellent anti-compression properties were obtained in in situ blend membranes with a stable pore morphology. The correlations among membrane formation mechanism, structure and performance were also discussed.

• The Journal of Natural Sciences
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• v.4
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• pp.69-83
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• 1991

To determine optimum ethanol concentration and clarification time in ethanol clarification of red ginseng extract(RG-Ext), physical properties, crude saponin recovery of clarified RG-Ext. and stability of red ginseng drink prepared from clarified RG-Ext. were investigated. Color intensity, redness(a value), viscosity and yield of clarified RG-Ext. were decreased in proportion to the increase of ethanol concentration and clarification time, but transmittance, brightness(L value) and yellowness (b value) were decreased. Crude saponin recovery of clarified RG-Ext. were not change significantly by the increase of ethanol concentration. Red ginseng drink prepared from 50-90% ethanol clarified RG-Ext. were stable without precipitation until six months at the storage of $0-5^\circC$ and $40^\circC$.

• Journal of the East Asian Society of Dietary Life
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• v.13 no.2
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• pp.130-135
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• 2003

The Characteristics of dough and the quality of baguette with 1~5% pigmented rice(PR) were investigated. The pH of dough with PR were lower(pH 4.93~5.06) than that of the control(pH 5.13). The viscosity of dough with PR(498~575 BU) measured by the amylograph were lower than that of the control(600 BU). The volume of the baguette with PR(1~3%) was higher than that of the control. Color $L^{*}$ value of baguette crumb with PR decreased from 60.65 to 50.44~60.36 and color $a^{*}$ value increased from -2.13 to 0.28~3.30 as the concentration of PR increased. The hardness of the baguette decreased from 375.51$\times$10$^4$dyne/c $m^2$to 273.95~256.83$\times$10$^4$dyne/c $m^2$as the concentration of PR increased. The overall acceptability score of baguette was the highest with 3% PR.R.R.