• Title/Summary/Keyword: 입자직경

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Stabilization of Chopped Garlic Quality by the Addition of Natural Preservatives (천연보존제 첨가에 따른 다진 마늘의 품질 안정화)

  • 나영아;류영기
    • Journal of the East Asian Society of Dietary Life
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    • v.10 no.2
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    • pp.107-115
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    • 2000
  • Preservative effects of natural preservatives, citric acid and salt on chopped garlic were investigated. Bacterial multiplying and browning of chopped garlic were very effectively repressed by 0.5-1% citric acid. Salt had an effect on the repression of bacteria multiplying and browning of chopped garlic except for 1% NaCl. Synergistic effect between citric acid and NaCl was also very good for decreasing bacteria multiplying and maintaining Hunter color of chopped garlic. Compounded effect of the GF. citric acid. and ascorbic acid was somewhat proper in the sensory evaluation of chopped garlic. And the sensory evaluation score was the highest in chopping size 3mm(diameter) and viscosity 4500cp. of chopped garlic.

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Physico.chemical Properties of Inorganic Materials Currently Used as Root Medium Components for Crop Production in Korean Plant Factories (국내에서 식물공장용 배지 재료로 유통되는 무기물의 토양 물리화학적 특성)

  • Shin, Bo Kyoung;Son, Jung Eek;Choi, Jong Myung
    • Journal of Bio-Environment Control
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    • v.21 no.4
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    • pp.336-342
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    • 2012
  • Inorganic materials were commonly used as container media in domestic plant factories. Objective of this research was to secure the information in soil physical and chemical properties of inorganic materials such as vermiculites and perlites. To achieve this, 12 gold and silver vermiculites from China, Zimbabwe, and South Africa and 5 perlites from China were collected based on the marketing grades (MG) in particle sizes and analyzed for determination of their characteristics. The percentage of particles larger than $710{\mu}m$, in China perlite MG 3~5 mm, China silver vermiculites MG > 8 mm and MG 3~8 mm were 99.9%, 99.8%, and 99.7%, respectively, which were much higher than 28.4% in China gold vermiculite MG 0.3~1.0 mm, 14.0% in perlite MG < 1.0 mm, and 12.6% of Zimbabwe silver vermiculite MG < 1.0 mm. The container capacities of perlite MG < 1.0 mm and South Africa silver vermiculite MG 0.25~1.0 mm were 72.0% and 71.1%, respectively. The air space in China silver vermiculite MG 3~8 mm was 49.3% which was higher than other materials tested. However, the China gold and silver vermiculites MG 0.3~1 mm had 3.5% and 2.4% in air space indicating that possible problems could occur in soil aeration when they are used for container media. The percentage of easily available and buffering water of China gold vermiculite MG 0.3~1 mm and perlite MG < 1.0 mm were the highest among test materials. The ranges of pH and electrical conductivity were 6.36 to 10.7 and 0.032 to $0.393dS{\cdot}m^{-1}$ in vermiculites and 7.78 to 8.62 and 0.030 to $0.041dS{\cdot}m^{-1}$ in perlite, respectively. The cation exchange capacity of China silver vermiculite MG 0.3~1 mm were $14.7cmol{\cdot}kg^{-1}$ that was 10 times as high as $0.34cmol{\cdot}kg^{-1}$ in perlite MG 1~2.5 mm. The vermiculites had the higher contents of exchangeable cations such as Ca, K, and Na, than those of perlites.

Laboratory Tests for Trichloroethylene (TCE) and Toluene Remediation in Soil Using Soil Vapor Extraction (토양증기추출(Soil Vapor Extraction)을 이용한 토양 내 Trichloroethylene (TCE)과 Toluene정화 실험)

  • 이민희;강현민
    • Economic and Environmental Geology
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    • v.35 no.3
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    • pp.221-227
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    • 2002
  • Column experiments were performed to evaluate the removal efficiency of soil vapor extraction (SVE) iota TCE (trichloroethylene) and toluene in soil. Homogeneous Ottawa sands and real soils collected from contaminated area were used to investigate the effect of soil properties and SVE operation conditions on the removal efficiency. In column teats with two different sizes of Ottawa sand, the maximum effluent TCE concentration in a coarse sand column was 442 mg/L and 337 mg/L in a fine sand column. However, after 20 liter gas flushing, the effluent concentrations were very similar and more than 90% of initial TCE mass were removed from the column. For two real contaminated soil columns, the maximum effluent concentration decreased 50% compared with that in the homogeneous Ottawa coarse sand column, but 99% of initial TCE mass were extracted from the column within 40 liter air flushing, suggesting that SVE is very available to remove volatile NAPLs in the contaminated soil. To investigate the effect of contaminant existing time on the removal efficiency, an Ottawa sand column was left stable for one week after TCE was injected and the gas extraction was applied into the column. Its effluent concentration trend was very similar to those for other Ottawa sand columns except that the residual TCE after the air flushing showed relatively high. Column tests with different water contents were performed and results showed high removal efficiency even in a high water content sand column. Toluene as one of BTEX compounds was used in an Ottawa sand column and a real soil column. Removal trends were similar to those in TCE contaminated columns and more than 98% of initial toluene mass were removed with SVE in both column.

MICROLEAKAGE OF THE EXPERIMENTAL COMPOSITE RESIN WITH THREE COMPONENT PHOTOINITIATOR SYSTEMS (3종 광중합개시제를 함유한 실험용 복합레진의 미세누출도)

  • Kim, Ji-Hoon;Shin, Dong-Hoon
    • Restorative Dentistry and Endodontics
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    • v.34 no.4
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    • pp.333-339
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    • 2009
  • This study was done to determine if there is any difference in microleakage between experimental composite resins, in which various proportions of three component photoinitiators (Camphoroquinone, OPPI, Amine) were included. Four kinds of experimental composite resin were made by mixing 3.2% silanated barium glass (78 wt.%, average size; 1 ${\mu}m$) with each monomer system including variously proportioned photoinitiator systems used for photoinitiating BisGMA/BisEMA/TEGDMA monomer blend (37.5:37.5:25 wt.%). The weight percentage of each component were as follows (in sequence Camphoroquinone, OPPI, Amine): Group A - 0.5%, 0%, 1% / Group B - 2%, 0.2%, 2% / Group C - 0.2%, 1%, 0.2% / Group D - 1%, 1%, 2%. Each composite resin was used as a filling material for round class V cavities (diameter: 2/3 of mesiodistal width; depth: 1.5 mm) made on extracted human premolars and they were polymerized using curing light unit (XL 2500, 3M ESPE) for 40 s with an intensity of 600 mW/$cm^2$. Teeth were thermocycled fivehundred times between $50^{\circ}C$and $550^{\circ}C$for 30s at each temperature. Electrical conductivity (${\mu}A$) was recorded two times (just after thermocycling and after three-month storage in saline solution) by electrochemical method. Microleakage scores of each group according to evaluation time were as follows [Group: at first record / at second record; unit (${\mu}A$)]: A: 3.80 (0.69) / 13.22 (4.48), B: 3.42 (1.33) / 18.84 (5.53), C: 4.18 (2.55) / 28.08 (7.75), D: 4.12 (1.86) / 7.41 (3.41). Just after thermocycling, there was no difference in microleakage between groups, however, group C showed the largest score after three-month storage. Although there seems to be no difference in microleakage between groups just after thermocycling, composite resin with highly concentrated initiation system or classical design (Camphoroquinone and Amine system) would be more desirable for minimizing microleakage after three-month storage.

Effect of surface sealant on surface roughness of dental composite with different surface roughness (서로 다른 거칠기의 복합레진에 표면 강화제 도포시 표면 거칠기의 변화)

  • Dong-Ah Shin;Seon-Ju Jin;Kkot-Byeol Bae;In-Nam Hwang
    • Journal of Dental Rehabilitation and Applied Science
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    • v.39 no.4
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    • pp.195-203
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    • 2023
  • Purpose: This study aimed to evaluate the influence of surface sealants on the surface roughness of composite resins. Materials and Methods: The study used microfilled composite resin (Metafil CX, Sun Medical Co.) and hybrid composite resin (AeliteTM LS posterior, Bisco). Sixty specimens (8 mm in diameter and 4 mm in height) of each composite resin type were prepared and divided into 3 groups. Each specimen was ground with 600, 1000, and 2000-grit sandpaper. The Surface roughness (Ra) values were measured using a surface roughness tester (SJ-301, Mytutoyo) before and after surface sealant application. Surface sealants, BisCoverTM LV (Bisco), Optiguard® (Kerr), and Seal-n-ShineTM (Pulpdent), were applied to the specimens, as instructed and observed by scanning electron microscope (JSM-7500, JEOL) and atomic force microscope (MultiMode IV, Veeco Instruments). Results: Specimens ground with 600-grit sandpaper coated with surface sealants exhibited significantly lower Ra values than the untreated group (P < 0.05). Specimens ground with 1000 and 2000-grit sandpaper showed statistically no difference. There was no significant difference in surface roughness among BisCoverTM LV, Optiguard®, and Seal-n-ShineTM. SEM and AFM revealed remarkably decreased microdefects on the surfaces of composite resins after surface sealant application. Conclusion: Surface sealants can influence surface roughness when applied on the rough surface of composite resins but not on highly polished composite resins.