• Title/Summary/Keyword: Drying Time

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Preparation and Physical Properties of Two-Component Polyurethane Coatings Containing Alkyd Modified Polyesters (알키드 변성폴리에스테르를 함유하는 2성분계 폴리우레탄 도료의 제조와 도막물성)

  • Shin, Jae-Hyun;Kim, Sung-Gea;Ha, Kyung-Jin;Park, Hong-Soo
    • Applied Chemistry for Engineering
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    • v.8 no.6
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    • pp.907-913
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    • 1997
  • Alkyd modified polyester was synthesized by the polycondensation of 1,4-butanediol, trimethylolpropane, adipic acid, and the intermediate obtained by the esterification of 3,5,5-trimethylhexanoic acid(THA) and trimethylolpropane, where the contents of THA as a component of alkyd polyol in the intermediate were changed according to 10, 20, and 30wt%, respectively. Two-component polyurethane coatings were prepared by blending the synthesized alkyd modified polyester with Desmodur L-75 as a component of polyisocyanate. Various tests for coating properties with the prepared coatings show that high fineness of grind of $8^-$point, short drying time of 2~3 hours, and long pot-life of 18~23 hours were observed with the content of 3,5,5-trimethylhexanoic acid.

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Changes of Seed Quality of Chinese Milk Vetch(Astragalus sinicus L.) During Seed Developmental Stages

  • Na, Chae-Sun;Lee, Yong-Ho;Hong, Sun-Hee;Jang, Cheol-Seong;Kang, Byeung-Hoa;Lee, Jong-Ki;Kim, Tae-Ho;Kim, Wook
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.52 no.4
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    • pp.363-369
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    • 2007
  • The objective of this study was to investigate the variation of Chinese milk vetch(Astragalus sinicus L.; CMV) seed quality after flowering. We tagged individual open flowers of CMV at the day of maximum flowering(11 May) in Seoul, Korea. Seed samples were harvested serially at 15, 20, 25 and 30 days after flowering(DAF). To compare with dried seeds, non-dried seeds were tested immediately after harvest and the remaining seeds were placed at room temperature for 4 weeks. Seed length, 1000 seed weight, moisture content, germination rate(GR), mean germination time(MGT), germination speed(GS), germination performance index(GPI) and physical dormancy rate(PDR) were investigated. Seed length increased to 2.6 mm and 1000 seed weight reached up to 2.2 g until 25 DAF. Seed moisture content dramatically decreased from 20 to 25 DAF. Moisture content of non-dried seed(7.5%) was similar to that of dried seed(5.5%) at 25 DAF. The rate of seed viability reached up to 94% at 25 DAF. In case of dried seed, GR increased up to 39% at 25 DAF whereas GR of non-dried seed varied from 5 to 10%. GS and GPI of dried seed were significantly higher than those of non-dried seed since 25 DAF. PDR of dried seed has decreased since 20 DAF, whereas PDR of non-dried seed has increased. GR, GS and GPI increased as PDR decreased. Our results evidenced that PDR might be one of major factor in variation of seed quality, of which development was completed at 25 DAF.

The Dyeing Properties and Functionality of Water Lily(Nymphaea tetragona) Leaves Extract as a New Natural Dye Resource(2): Dyeing of Silk and Wool Fibers (새로운 천연염료로서 수련 잎 추출색소의 염색성과 기능성(2): 견·모섬유를 중심으로)

  • Yeo, Youngmi;Shin, Younsook
    • Textile Coloration and Finishing
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    • v.29 no.3
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    • pp.171-179
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    • 2017
  • This study was to investigate the practicality and functionality of water lily(Nymphaea tetragona) leaves as a natural dye resource while searching for various dyeing methods to utilize them. Effect of dyeing condition including methanol ratio of dyebath, dyeing temperature and time, mordanting method, etc were investigated. Colorants were prepared by extraction in methanol and followed drying process. When composing 30% of methanol in the dyebath, better dyeuptake and uniform dyeing were resulted. Pre-mordanting method gave better results in terms of dye uptake than post-mordanting method on the wool fabrics. Fe and Ti were effective for increasing the dye uptake on the silk fabrics. Depending on mordant type and mordanting method, the dyed fabrics got various color showing green, khaki, brownish yellow, dark brown, dark gray and so on. As for color fastness, the silk fabrics dyed with water lily extract showed relatively high rating in light fastness(3~4, 4~5 rating), washing fastness(4~5, 5 rating), and rubbing fastness(4, 4~5 rating). The silk and wool fabrics dyed with water lily leaves extract showed excellent antimicrobial activity over 98% of bacterial reduction rate against Staphylococcus aureus and Klebsiella pneumoniae. It was confirmed that water lily leaves can be used as a natural dye resource for dyeing wool and silk fabrics because its colorants showed excellent affinity and antimicrobial functionality as well as good colorfastness.

Evaluation of Mixed Probiotic Starter Cultures Isolated from Kimchi on Physicochemical and Functional Properties, and Volatile Compounds of Fermented Hams

  • Kim, Young Joo;Park, Sung Yong;Lee, Hong Chul;Yoo, Seung Seok;Oh, Sejong;Kim, Kwang Hyun;Chin, Koo Bok
    • Food Science of Animal Resources
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    • v.36 no.1
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    • pp.122-130
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    • 2016
  • The objective of this study was to investigate the effects of mixed starter cultures isolated from kimchi on physicochemical properties, functionality and flavors of fermented ham. Physicochemical properties, microbial counts, shear force, cholesterol contents and volatile compounds of fermented ham were investigated during processing (curing and ripening time). Curing process for 7 d increased saltiness, however, decreased hunter color values (L, a, and b values). Ripening process for 21 d increased most parameters, such as saltiness, color values, weight loss, shear force and cholesterol content due to the drying process. The mixed starter culture had higher lactic acid bacteria than the commercial one. While eight volatile compounds were identified from fermented hams during curing process, total fiftyeight volatile compounds were identified from fermented hams during ripening process. The main volatile compounds were alcohols, esters and furans. However, no differences in volatile compounds were observed between two batches. Fermented hams (batch B) manufactured with probiotic starter culture (LPP) had higher sensory score in texture, color and overall acceptability than counterparts (batch A), while the opposite trend was observed in flavor. Therefore, mixed probiotic starter culture isolated from kimchi might be used as a starter culture to be able to replace with commercial starter culture (LK-30 plus) for the manufacture of fermented ham.

Synthesis of Hyaluronic Acid Scaffold for Tissue Engineering and Evaluation of Its Drug Release Behaviors (히아루론산을 이용한 조직공학용 Scaffold의 제조와 약물 방출 거동에 관한 연구)

  • Nam, Hye-Sung;Kim, Ji-Heng;An, Jeong-Ho;Chung, Dong-June
    • Polymer(Korea)
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    • v.25 no.4
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    • pp.476-485
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    • 2001
  • In this study, we tried to design and synthesize using natural polymers (hyaluronic acid and sodium alginate) and also to make some kinds of scaffolds as sponge type for reducing the burst effect of loaded drug from them. Photo-dimerizable group was incorporated to hyaluronic acid and degradable hydrogel was prepared by the UV radiation of the polymer. The pore size and its distribution of scaffold were controlled by changing microsphere production conditions such as solution concentration and spraying pressure. It was found that drug release behavior from synthesized scaffolds was affected by hybridization of two naturally originated polymers (cinnamoylated tetrabutylammonium hyaluronate: CHT and cinnamolylated sodium alginate: CSA) and the obtained scaffolds were degraded in fairly long time (about 2 months) under in vitro environment. Therefore, we expect that obtained scaffolds can be applicable for the tissue regeneration scaffolds in the fields of orthopaedic surgery.

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Studies on the Production and Optimal Drying Condition of Curcuma longa L. (울금(Curcuma longa L.)의 생산 및 최적 건조조건에 관한 연구)

  • Kim, Yongsik;Choi, Seongkyu;Yun, Kyeong Won;Seo, Youngnam;Seo, Kyoungsun
    • Korean Journal of Plant Resources
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    • v.26 no.4
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    • pp.450-456
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    • 2013
  • We investigated the optimal cultivation system and dry processing method of rhizomes from Curcuma longa L. in Suncheon, the southern area of Korea. The experimental results are summarized as followings. Curcma longa rhizomes were transplanted on Apr. 30th, May 10th, and May 20th. The plant height, stem diameter, number of leaves and yield were highest in transplanted on May 10th. The fresh rhizome weight of Curcma longa was the heaviest in November 20 and the optimal dry temperature was $40^{\circ}C$. In sensory evaluations, there were significant differences among the Curcuma longa pills in terms of flavor, color, color and texture and overall acceptability, and honey added groups received significantly higher scores than the other groups.

A STUDY ON OXIDATION TREATMENT OF URANIUM METAL CHIP UNDER CONTROLLING ATMOSPHERE FOR SAFE STORAGE

  • Kim, Chang-Kyu;Ji, Chul-Goo;Bae, Sang-Oh;Woo, Yoon-Myeoung;Kim, Jong-Goo;Ha, Yeong-Keong
    • Nuclear Engineering and Technology
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    • v.43 no.4
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    • pp.391-398
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    • 2011
  • The U metal chips generated in developing nuclear fuel and a gamma radioisotope shield have been stored under immersion of water in KAERI. When the water of the storing vessels vaporizes or drains due to unexpected leaking, the U metal chips are able to open to air. A new oxidation treatment process was raised for a long time safe storage with concepts of drying under vacuum, evaporating the containing water and organic material with elevating temperature, and oxidizing the uranium metal chips at an appropriate high temperature under conditions of controlling the feeding rate of oxygen gas. In order to optimize the oxidation process the uranium metal chips were completely dried at higher temperature than $300^{\circ}C$ and tested for oxidation at various temperatures, which are $300^{\circ}C$, $400^{\circ}C$, and $500^{\circ}C$. When the oxidation temperature was $400^{\circ}C$, the oxidized sample for 7 hours showed a temperature rise of $60^{\circ}C$ in the self-ignition test. But the oxidized sample for 14 hours revealed a slight temperature rise of $7^{\circ}C$ representing a stable behavior in the self-ignition test. When the temperature was $500^{\circ}C$, the shorter oxidation for 7 hours appeared to be enough because the self-ignition test represented no temperature rise. By using several chemical analyses such as carbon content determination, X-ray deflection (XRD), Infrared spectra (IR) and Thermal gravimetric analysis (TGA) on the oxidation treated samples, the results of self-ignition test of new oxidation treatment process for U metal chip were interpreted and supported.

Microbiological Safety of Infant Formula and Baby Food (조제분유와 이유식의 미생물학적 안전성)

  • Lee, Seung-Bae;Choe, Jae-Won;Choe, Seok-Ho
    • Journal of Dairy Science and Biotechnology
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    • v.23 no.1
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    • pp.65-71
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    • 2005
  • Powered infant formula and baby food contaminated with Enterobacter sakazakii were reported to cause infection among infants and to be associated with sporadic cases and outbreaks of sepsis, menigitis, cerebritis, and necrotizing enterocolitis. Salmonella contamination of infant formula has also been responsible for multiple outbreaks. Other species of Enterobacteriaceae in powdered infant formula may be causative agents, about which there has been no report. Other pathogenic bacteria have been isolated from powdered infant formula but they were not associated with outbreaks among infant. While Enterobacter sakazakii caused disease in all age groups, premature infants under 28 days old and with birth weight are most sensitive to its infection. Even if low contamination level of the bacteria in powdered infant formula and baby food may not cause infection, the possibility to multiplicate during preparation and storage of reconstituted formula may increase. The etiological factors and pathogenecity of S. sakazakii have not been elucidated. There were wide variability in phenotype and genotype between its strains. S. sakazakii has been isolated from factory facility and surroundings more frequently than Salmonella and thus factory environment should be the source for post-processing contamination of the formula with S. sakazakii. Considering current technology to manufacture power infant formula and baby food it is impossible to sterilize powdered formula but the frequency of outbreak hazard by S. sakazakii can be reduced by pasteurizing the formula base before drying and shortening storage time of the reconstituted formula.

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The Components of Cultivated Poria cocos (인공재배 복령(茯笭)의 성분조성)

  • 최옥법;조덕봉;김동필
    • The Korean Journal of Food And Nutrition
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    • v.9 no.4
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    • pp.438-440
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    • 1996
  • The various components of cultivated Poria cocos were studied to obtain basic data. The contents of moisture, ash, lipid, protein & fiber were estimated as 58%, 1.8%, 0.9%, 0.6% & 0.35 and the mineral contents of water extracts from poria cocos were Zn 0.63mg%, Cu 0.18mg%, Fe 1.56mg%, Mn 1.62mg%, Mg 5.28mg%, Ca 12.59mg%, Na 10.12mg% and K 52.39mg%. Among them, K, Ca and Na were abundant. Proximate components of Poria cocos were varied according to cultivated place & methods, harvest time and drying condition. Free sugars determined from Poria cocos water extracts were glucose whose contents were 1.16mg%, but sucrose, maltose and fructose were not detected. Amino acids compositions of Poria cocos were detected as free amino acids 9 kinds, constitunent amino acid 13 kinds and their contents were 1247.17mg%, 174.44mg%, Major amino acids were Phe, Iso, Leu, Tyr and His.

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Evaluation of Fermented Sausages Manufactured with Reduced-fat and Functional Starter Cultures on Physicochemical, Functional and Flavor Characteristics

  • Kim, Young Joo;Park, Sung Yong;Lee, Hong Cheol;Yoo, Seung Seok;Oh, Se Jong;Kim, Hyeong Sang;Chin, Koo Bok
    • Food Science of Animal Resources
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    • v.34 no.3
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    • pp.346-354
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    • 2014
  • Fermented foods with probiotics having functional properties may provide beneficial effects on health. These effects are varied, depending on the type of lactic acid bacteria (LAB). Different probiotic LAB might have different functional properties. Thus, this study was performed to evaluate the quality of fermented sausages manufactured with functional starter cultures (Lactobacillus plantarum 115 and 167, and Pediococcus damnosus L12) and different fat levels, and to determine the optimum condition for the manufacture of these products. Medium-fat (~15%) fermented sausages reduced the drying time and cholesterol contents, as compared to regular-fat counterparts. In proximate analysis, the contents of moisture and protein of regular-fat products were lower than medium-fat with reduced fat content. The regular-fat products also had a lighter color and less redness, due to reduced fat content. Approximately 35 volatile compounds were identified in functional fermented sausages, and hexanal, trans-caryophyllene, and tetradecanal were the major volatile compounds. Selected mixed starter culture showed the potential possibility of replacing the commercial starter culture (LK30 plus) in flavor profiles. However, medium-fat fermented sausage containing selected mixed starter culture tended to be less acceptable than their high-fat counterparts, due to excess dry ring developed in the surface. These results indicate that the use of combinations of L. plantarum 115 and 167, and P. damnosus L12 as a starter culture, will prove useful for manufacturing the fermented sausage.