• Korean Journal of Food Science and Technology
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• v.45 no.6
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• pp.747-753
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• 2013

The physicochemical properties of sweet potato (SP) starches reclaimed from an SP-processing sludge without freezing (RC/NF) and with freezing (RC/FR) were investigated. Lab-isolated (LI) SP starch, as a control, were prepared from raw SP. RC/NF and RC/FR SP starches were recovered from SP-processing sludges by the repeated sieving and washing procedure. The total starch contents and amylopectin branch-chain distributions did not differ for three SP starches. Relative to LI and RC/NF SP starches (possessing similar physicochemical characteristics), the apparent amylose and phosphorus contents, swelling factor, and pasting viscosity were reduced for RC/FR SP starch. However, the freezing treatment altered X-ray diffraction pattern (at $5.5^{\circ}$, $11-12^{\circ}$, and $24^{\circ}$ $2{\theta}$) of RC/FR SP starch, which likely increased its gelatinization peak and completion temperatures. Its amorphous region in total diffractogram was reduced, resulting in the enhanced relative crystallinity. Overall results suggested SP starches recovered from an SP-processing sludge would have the potential to replace commercial SP starch products.

• Korean Journal of Food Science and Technology
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• v.52 no.4
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• pp.423-426
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• 2020

This study was performed to investigate how the addition of starch nanoparticles prior to whipping could affect the quality characteristics and stability of full-fat dairy cream. Starch nanoparticles were prepared by dry heating under mildly acidic conditions and added to dairy cream as amount of 1, 3, and 5% (w/w). The whipped cream's storage stability, viscosity, overrun, and droplet size were investigated in combination with various starch nanoparticle contents. The storage stability and apparent viscosity increased in parallel with the increasing starch nanoparticle content compared to the control. The mean size and homogeneity of the droplets in the whipped cream increased with higher starch nanoparticle addition levels. Even though the whipped cream overrun was reduced by the addition of starch nanoparticles, the 1% addition level exhibited a similar overrun value as the control.

• Korean journal of food and cookery science
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• v.23 no.3 s.99
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• pp.288-293
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• 2007

In this study, chunggukjang was made from soybeans and Bacillus natto. This chunggukjang was meant to be consumed as a margarine and butter substitute, to help lower trans-fatty acid (TFA) intake. A freeze-dried garlic product was used during fermentation to aid in removing the smell of the chunggukjang. Chunggukjang has a very low fluidity due to its high viscosity; therefore, we added 3%(w/w) soybean oil to improve the fluidity. We found that the TFA content of the garlic chunggukiang paste was no more than 0.02${\sim}$0.05%, which was low compared to the usual contents of margarine and butter. After 4 weeks of storage the TFA content was 0.03${\sim}$0.08%, and it remained within the limits of the permissible amount. The addition of soybean oil allowed this chunggukjang to be made with greater ease, and the freeze-dried garlic eliminated the negative inherent qualities of the chunggukjang. Therefore, this garlic chunggukjang paste could be considered reasonable for commercial production.

• Journal of the Korean Ceramic Society
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• v.34 no.1
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• pp.70-78
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• 1997

3Y-TZP/SUS316 Functionally Graded Material (FGM) was fabricated by slip casting method. Alumina mold was used to overcome problems of gypsum mold in slip casting process, and the optimal dispersion con-ditions of 3Y-TZP/SUS316 binary slurries was determined using electrokinetic sonic amplitude and a viscometer, and observing sedimentation behavior. The properties of the specimens casted by gypsum mold and alumina mold were compared in terms of changes in shrinkage rate, drying and sintering conditions, and microstructure. It was found that the specimens obtaine from the alumina mold showed a clean surface, easier thickness control of each layer, and higher productivity. Especially, no degradation was observed in the SUS316 prepared using alumina mold. Thus it is desirable to use porous alumina mold rather than gyp-sum mold for the slip casting of 3Y-TZP/SUS316-FGM.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.5
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• pp.519-524
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• 1992

purified rapeseed(Brassica napus var. Youngsan) protein was hydrolyzed by pronase. The hyrolysate protein was investigated for the some physicochemical and functional properties. UV and intrinsic fluorescence spectra of the hydrolysate showed the maximum absorption at 274nm and 360nm respectively. Intensity of yellow color decreased in the process of hydrolysis and the surface hydrophobicity decreased up to fourfold. The main bands of hydrolysate by sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE) were observed at 14,000 to 12,000 dalton molecular weight. Solubilities of hydrolyzed protein increased by 10~15% compared to those of unhydrolyzed protein at acidic pH. In the hydrolysate, while absorption of both water and oil, foam expansion and emulsion stability were increased, absolute viscosity, heat coagulation, calcium coagulation, foam stability and emulsion activity were decreased.

• Polymer(Korea)
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• v.38 no.2
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• pp.199-204
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• 2014

To prepare acrylic pressure sensitive adhesives (PSAs), quaternary copolymer syrups were photopolymerized from 2-ethylhexyl acrylate and 2-hydroxyethyl acrylate as default constituents and isobornyl acrylate and tetrahydrofurfuryl acrylate (THFA) as variable constituents. After polymerization, 1,6-hexanediol diacrylate and photoinitiator were added and then crosslinked by UV-irradiation to prepare the PSAs. The characteristics of the syrup such as viscosity, molecular weight, and solid content were investigated. As increasing THFA contents, the relationship between molecular weight and solid content of the syrup was reciprocal. Also, the relationship between peel strength and surface energy of the PSAs showed the same tendency. All the PSA samples showed high transmittance (more than 92%), low haze (less than 1.0%) and low color-difference (less than 1.0).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.3
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• pp.1247-1252
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• 2014

In the present study, sedimentation and shear stress of MR fluid are investigated to physical characteristics of MR fluid along temperature conditions. MR fluid is a suspension of micrometer-sized magnetic particles in a base liquid. Therefore, dispersion of MR fluid is important in the case of the design and optimization of the system using MR fluid. Due to sedimentation characteristics of MR fluid by magnetic particles, the sedimentation and shear stress of commercial MR fluid are investigated at $25^{\circ}C$ and $80^{\circ}C$ temperatures by using a forced convection oven and a viscometer. From experimental results, the sedimentation and shear stress are more affected by the temperatures of $80^{\circ}C$ than $25^{\circ}C$ and the mixing time of 5min than 10min. Shear stress by the applied current increases the shape of a quadratic equation and are lower 6-18% at $80^{\circ}C$ than $25^{\circ}C$.

• Journal of the Korean Society for Marine Environment & Energy
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• v.6 no.3
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• pp.37-44
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• 2003

To know the penetration behavior of spilled oil into sandy beach sediment is very important, because the penetration depth of the stranded oil into the sediments is one of the most significant information to know effect of spilled oil on biological communities and to set up cleaning method. The purpose of this study is to clarify the effects of wave and/or tidal action on penetration of spilled oil into the sediments and to clarify main factor in oil penetration using sandy beach model. Specific conclusions derived from this study are as follows. Spilled fuel oil C penetrated into the sediments only by falling tidal fluctuation and not by wave action on sandy beach environment, and the first tide is most important for the penetration of stranded oil. Over 80% of bulk fraction in penetrated fuel oil C was concentrated to the top 2 cm sediment-layer. Moreover, the penetration of stranded oil into the sandy beach sediments was strongly correlated with the oil viscosity affected by temperature.

• Tunnel and Underground Space
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• v.23 no.6
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• pp.470-479
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• 2013

Hydraulic fracturing is used as a method for promoting the fluid flow in the rock and, in the energy field such as geothermal development and the development of sales gas, many studies has been actively conducted. In many cases, hydraulic fracturing is not performed in isotropic rock and especially in the case of sedimentary rocks, hydraulic fracturing is conducted in the transverse isotropic rock. The direction of the crack growth on hydraulic fracturing does not necessarily coincides with the direction of maximum principal stress in the transverse isotropic rock. Therefore, in this study, bonded particle model with hydro-mechanical coupling analysis was adopted for analyzing the characteristics of hydraulic fracturing in transverse isotropic rock. In addition, experiments of hydraulic fracturing were conducted in laboratory-scale to verify the validity of numerical analysis. In this study, the crack growth and crack patterns showed significant differences depending on the viscosity of injection fluid, the angle of bedding plane and the influence of anisotropy. In the case of transverse isotropic model, the shear crack growth due to hydraulic fracturing appeared prominently.

• Weed & Turfgrass Science
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• v.3 no.1
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• pp.6-12
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• 2014

The survey of weed occurrence was conducted to identify problem weed species in the paddy field. The 320 sites of the 13 regions in Gyeongbuk Province were investigated from June to July, 2013. In the whole region, 51 weed species were identified including 34 annuals and 17 perennials. The highest importance value of annual weed and perennial was dominant 88.4 and 48.7%, in Gumi region, respectively. The most dominant weed species in paddy fields of Gyeongbuk Province were Monochoria vaginalis var. plantaginea (10.80%), followed by Lemna paucicostata (10.74%), Bidens tripartite (8.77%), Echinochloa oryzoides (7.17%), and Scirpus juncoides (6.20%). The similarity of paddy weeds in 13 regions observed through TWINSPAN analysis was distinguished by Ludwigia prostrata, Scirpus juncoides, Lindernia dubia, Polygonum aviculare, and Alopecurus aequalis var. amurensis. The weed species, Ludwigia prostrata, was divided into the four regions, Gyeongju, Gumi(direct seeding cultivation), Youngcheon and Euiseong and ten regions, Gumi, Bonghwa, Sanju, Goryung, Youngdeog, Pohang, Sanju, Andong, Yecheon, and Cheongdo.