• Title/Summary/Keyword: water absorption property

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Effects of Roasting Temperature on Phycochemical Properties of Job's tears (Coix lachryma jobi L. var ma-yeun) Powder and Extracts (볶음온도에 따른 율무 분말과 침출액의 이화학적 특성)

  • Chung Hun-Sik;Kim Jong-Kuk;Youn Kwang-Sup
    • Food Science and Preservation
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    • v.13 no.4
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    • pp.477-482
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    • 2006
  • This study was carried out to evaluate the effect of the masting temperature on the phycochemical properties of the roasted Job's tears. Raw seeds were roasted for 20 min at 150, 170, 190, 210 or $230^{\circ}C$, were milled and extracted with hot water. The L and a values of the powder were sharply decreased or increased at the masting temperature of above $190^{\circ}C$, respectively. The b value was maximum at $190^{\circ}C$. Water absorption capacity of the powder and browning index of the extract were proportionally increasing with increasing the masting temperature. The pH of the extracts was decreased at the masting temperature of above $190^{\circ}C$. Total sugar content of the extract tended to be decreased until $170^{\circ}C$ and then be increased from $190^{\circ}C$. Content of phenolic compound of the extract was increased at the masting temperature of above $210^{\circ}C$. At the sensory evaluation of the extract, aroma and taste of samples masted at $170^{\circ}C$ and above $190^{\circ}C$, respectively were higher than those masted at the others. Overall acceptability of the extract was highest at $190^{\circ}C$.

Characteristics of Cereals Prepared by Extrusion-Cooking and Freeze-drying (압출성형과 동결건조 곡류의 특성)

  • Tie, Jin;Park, Hee-Yong;Ryu, Gi-Hyung
    • Korean Journal of Food Science and Technology
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    • v.37 no.5
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    • pp.757-762
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    • 2005
  • Characteristics of cereals prepared by extrusion-cooking and freeze-drying were compared. Parameters used were water solubility index (WSI), water absorption index (WAI), paste viscosity, and sterilization. Variables for extrusion process were barrel temperature at die section (70, 90, and $110^{\circ}C$) and moisture content (25 and 30%). WAI and WSI of extruded cereals were higher, whereas trough, breakdown, and final viscosity were lower than those of raw and freeze-dried cereals. Plate counting revealed no microbes in extruded cereals, whereas microbe colony was observed in freeze-dried cereals. Extrusion-cooking at low temperature resulted in better sterilization of microbes than freeze-drying for preparation of instant cereal drinks.

Physical and Mechanical Properties of Magnesium Oxide Matrix depending on Addition Ratio of Magnesium Chloride (염화마그네슘 첨가율에 따른 산화마그네슘 경화체의 물리 및 역학적 특성)

  • Kim, Heon-Tae;Jung, Byeong-Yeol;Lee, Sang-Soo;Song, Ha-Young
    • Journal of the Korea Institute of Building Construction
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    • v.14 no.4
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    • pp.308-313
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    • 2014
  • Recently, for longevity of resident building, the main trend is that the change of the inside space organization of resident building from wall construction to rhamen construction, which resulted in increase in use of lightweight composite panel. Thus, in this study, authors analyzed the engineering property of oxide of magnesium depending on the magnesium chloride addition ratio. The results of this research is expected to contribute on providing a fundamental material for the surface materials of lightweight composite panel. As the result of the experiment, as fluidity increased, air content decreased and initial set and final set as the magnesium chloride addition ratio increase. In the aspect of flexural strength and compressive strength, the test specimen showed the highest strength at 40% of the magnesium chloride addition ratio. At 20% of the magnesium chloride addition ratio, the test specimen showed the lowest water absorption rate. As the magnesium chloride addition ratio increases, the expansibility tends to increase as well in the aspect of shrinkage strain. After observing microstructure, we can see hydration products in the form of needle. It appeared high flexural strength because the hydration products have mineral fibrous tissue shape, which also contribute to the cause of the expansibility.

Effect to Material Strength Recovery of Stepped Patch Repair with Epoxy based Particle Reinforced GFRP Composites under Hygrothermal Environment (에폭시 기지 입자 강화 GFRP를 사용한 계단형 패치 보수법이 고온 고습 환경하에서 재료의 물성 회복에 미치는 영향)

  • Jung, Kyung-Seok;Park, Soo-Jeong;Kim, Yun-Hae
    • Composites Research
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    • v.31 no.3
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    • pp.88-93
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    • 2018
  • In this study, damaged composite laminates were repaired by a stepped patch repair method using halloysite nanotube(HNT) and milled carbon(MC) reinforced composite materials with different amount of the particles. And the mechanical and structural effects of the particles on the interface between the damaged and repair surfaces were analyzed. At this time, after exposing them to a harsh environment of high temperature and humidity for a long time, the recovery rate of the material properties relative to the material forming the damaged plate was compared. As a result, at $70^{\circ}C$ high temperature distilled water, the hygroscopicity of the HNT/GFRP composites was significantly different from that of the MC/GFRP composites. Especially, 0.5, 1 wt. % HNT was added, the moisture absorption rate was the lowest and this was the factor that contributed to the mechanical strength increase. On the other hand, MC showed a high hygroscopic resistance only with a small amount, and the strength was different according to the action direction of the load, and the addition amount was also different.

Development of the Novel Cosmetics Impregnation Material and Study on Makeup W/O Emulsions using It (새로운 화장료 함침재의 개발과 이를 활용한 메이크업 유중수형 에멀전에 관한 연구)

  • Kang, Sungsoo;Kim, Hyeon Jeong;Oh, Se Woong;Park, Sang Wook;Kim, Kyung Seob
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.43 no.1
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    • pp.27-33
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    • 2017
  • Up to now, better convenience and portability were important factors in the development of the cosmetics and achieved by immersing low viscosity makeup water-in-oil (W/O) emulsion into the impregnation material. Conventionally, polyurethane sponges having porous network structures and hard textures have been dominantly used. It has an advantage of easy to manufacture because of its good impregnation property due to its structural characteristics. However, it releases emulsion too much at first use, and shows unexpected dramatic decline during the period of usage. In this study, we studied on makeup W/O emulsion with various features and developed the new foaming sponge, which showed excellent formability and proper absorption and discharge ability of cosmetic composition through the combination of natural rubber (NR) and styrene butadiene rubber (SBR). This impregnation material is characterized by the softness of elasticity like a rubber, high elongation and uniform output. We confirmed that this material can be used to develop makeup products using various oils depending on polarity and controlling the viscosity of the makeup W/O emulsion. Thus, it is concluded that these results provide valuable information in developing new cosmetics impregnation materials.

A study on the black core formation of artificial lightweight aggregates at various sintering atmospheres (인공경량골재의 소성조건이 블랙코어에 미치는 영향)

  • Kim, Yoo-Taek;Ryu, Yu-Gwang;Jang, Chang-Sub;Lee, Ki-Gang;Kang, Seung-Gu;Kim, Jung-Hwan
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.19 no.6
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    • pp.318-323
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    • 2009
  • The lightweight aggregates made of bottom ash (70 wt%) and dredged soil (30 wt%) were prepared to investigate the property differences at various sintering atmospheres. The green aggregates were sintered at $1150^{\circ}C$ and $1200^{\circ}C$ with oxidized, neutralized and reduced atmospheres. The aggregates sintered with oxidized atmosphere showed a clear border between shell and black core area. However, the aggregates sintered with a reduced atmosphere showed only black core area in the entire cross-section of the aggregates. The black core area of the aggregates sintered with a neutralized atmosphere increased with increasing $N_2$ gas flow rates. It was determined that the sintering atmosphere was similar to that of rotary kiln when the CO gas flow was 100 cc/min to make a reduced atmosphere in tube furnace. The water absorption rates of both aggregates from tube furnace with reduced atmosphere and rotary kiln were very similar to each other.

Remediation of the Diesel Contaminated Soils Using Thermally Enhanced Soil Vapor Extraction Process with Microwave Heating (마이크로웨이브 가열 토양증기추출 공정에 의한 경유 오염 토양처리)

  • 김종운;박갑성
    • Journal of Soil and Groundwater Environment
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    • v.9 no.1
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    • pp.39-46
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    • 2004
  • Removal efficiencies for diesel fuel and diesel hydrocarbons ($C_10$$C_22$) using microwave-enhanced SVE process were evaluated with dry and moist soil, respectively. Diesel removal rates of microwave-enhanced SVE process were 7 times for dry soil and 1580 times for moist soil as great as those of the SVE process without microwave heating. High dielectric property of water contents may accelerate the absorption of microwave energy into soil and thus vaporized the diesel fuel components drastically. The diesel removals were 67.7∼78.4% for $C_10$ and $C_12$, and 0∼18.5% for $C_14$$C_22$ for dry and moist soil with SVE process only. On the other hand, dry soil with microwave-enhanced SVE process showed 89.3∼99.4% removal for $C_10$ to and $C_12$ and 35.6∼67.0% for hydrocarbons over $C_14$. All hydrocarbons ($C_10$$C_22$) studied were significantly removed (93.6∼99.8%) for moist soil with microwave-enhanced SVE process.

Sensory and Quality Evaluation of Aseptic-Packaged Cooked Rice by Cultivar (벼 품종에 따른 무균포장밥의 식미특성 및 품질 변이)

  • Chun, A-Reum;Song, Jin;Kim, Kee-Jong;Kim, Jae-Hyun;Son, Jong-Rok;Oh, Ye-Jin
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.52 no.4
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    • pp.439-446
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    • 2007
  • We carried out this experiment on the purpose to investigate the quality properties of aseptic-packaged cooked rice by cultivars in 2006. Brown rice was milled for white rice to 89.6% weight of it. Based on cluster analysis of acceptance of sensory evaluation, eleven rice cultivars of 29 cultivars had superior palatability. Whiteness(r=0.42, p<5%), lightness(r=0.39, p<5%), Toyo value(r=0.35, p<10%), and moisture content(r=0.33, p<10%) of milled rice were correlated positively with acceptability. Protein content(r=-0.40, p<5%), expansion rate(r=-0.68, p<1%) and water absorption rate(r=-0.42, p<5%) of milled rice, and yellowness(r=-0.45, p<5%) of aseptic-packaged cooked rice were negatively correlated. In sensory evaluation, correlation coefficients of taste and texture with acceptability were higher than those of appearance and flavor. During storage, hardness and cohesiveness of aseptic-packaged cooked rice before reheating were increased and decreased, but those after reheating had no difference based on storage period and cultivar. On the contrary, whiteness of reheated aseptic-packaged cooked rice with no distinct differences before reheating was decreased during storage. There were no significant differences of texture property, color characteristics and moisture contents by cultivar during storage.

Physicochemical Properties of Crosslinked Potato Starch (가교결합 감자 전분의 이화학적 특성)

  • Kim, Hyang-Sook;Lee, Young-Eun
    • Korean Journal of Food Science and Technology
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    • v.28 no.3
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    • pp.573-579
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    • 1996
  • Crosslinked potato starches (XP), from 2,400 to 1,900 anhydroglucose units per crosslinked (AGU/CL), were prepared by reacting with epichlorohydrin. Some of the physicochemical properties of the XPs were then compared with those of native potato and cowpea starches. Crosslinking decreased moisture, protein and ash contents but had no effect on phosphorus content. Water binding capacities of the XPs increased as the degree of crosslinking increased, and that of the XP with 2,100 AGU/CL approached the value of cowpea starch. The absorption maxima of the starch-iodine complex shifted from 594 to 580 nm. Granule size increased slightly and surface appearance of the granule became rough when crosslinked. Both native and crosslinked potato starches showed B type X-ray diffraction pattern, and the relative crystallinity was not affected by crosslinking. Gelatinization temperature and the heat of gelatinization, measured by differential scanning calorimeter (DSC), did not change within the range of crosslinking tested. From X-ray and DSC data, it was concluded that the crosslinking ocurred in the amorphous region of the starch granule.

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A Quality Comparison of Traditional Korean Papers: Mixtures of Bast-Fiber with Straw pulp(Rice straw paper) in Different Composition Ratio (고정(藁精) 혼합비율에 따른 한지의 물성 비교)

  • Jung, Sun-Young
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.39 no.1 s.119
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    • pp.48-55
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    • 2007
  • The aim of this article is to review the general property of the famous traditional Korean paper, "rice straw paper"(Bast-Fiber mixed with straw pulp), and to compare the paper qualities varying with the composition ratio of straw pulp, in order to revive the traditional paper in modem Korea. The experiment was carried out by making first the two different mixture papers, i. e., one is the paper of 50% bast fiber mixed with 50% straw pulp, and the other is the paper of 75% bast fiber with 25% oats straw pulp, and finally the 100% bast fiber paper was made for the purpose of comparison. The qualitative properties of these three kinds of paper with the different mixing ratio of the straw pulp were evaluated, and the findings of the experiment can be summarized as follow: 1. As to the quality aspects of the paper strength like tensile strength, breaking length, elongation, and tear strength, the test proved the 100% bast fiber paper as best, and the 50% mixed paper as the next good one. 2. In aspect of the printing adaptability such as density, opacity, brightness, whiteness, lab colors, air permeability, and roughness, the 50% mixed paper proved to be the best, due to the short cells in the straw pulp. 3. As to the air permeability, the larger ratio of straw pulp was found to be the lesser, and 75% bast fiber with 25% straw pulp mixture paper and the 100% bast fiber one were found 1/5 degree efficient. 4. In terms of the water absorption degree, 100% bast fiber paper was the fastest, but in case of mixture paper, 50% mixed one was a little faster up to the point of 1cm, while the two kinds of mixed ones appear to be almost similar to each other beyond the point. 5. The straw pulp mixed paper, especially the 50% mixed one was evaluated as the highest by the calligraphers who had experienced using the papers in terms of movement and feeling of the caligraphy and painting. In addition, although the 25% mixed paper is judged to be good for book printing because of the strength, the 50% mixed paper can be thought to be more desirable for painting and calligraphy. In conclusion, we will be able to make the quality paper with durability, by mixing the straw pulp with the bast fiber in proper ratio, following the tradition of Korean paper making.