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A Study on the Manufacturing Characteristics and Field Applicability of Engineering-scale Bentonite Buffer Block in a High-level Nuclear Waste Repository (고준위폐기물처분장 내 공학규모의 균질 완충재 블록 성형특성 및 현장적용성 분석)

  • Kim, Jin-Seop;Yoon, Seok;Cho, Won-Jin;Choi, Young-Chul;Kim, Geon-Young
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.16 no.1
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    • pp.123-136
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    • 2018
  • The objective of this study is to propose a new methodology to fabricate a reliable engineering-scale buffer block, which shows homogeneous and uniform distribution in buffer block density, for in-situ experiments. In this study, for the first time in Korea, floating die press and CIP (Cold Isostatic Press) are applied for the manufacture of an engineering-scale bentonite buffer. The optimized condition and field applicability are also evaluated with respect to the method of manufacturing the buffer blocks. It is found that the standard deviation of the densities obtained decreases noticeably and that the average dry density increases slightly. In addition, buffer size is reduced by about 5% at the same time. Through the test production, it is indicated that the stress release phenomenon decreases after the application of the CIP method, which leads to a reduction in crack generation on the surface of the buffer blocks over time. Therefore, it is confirmed that the production of homogeneous buffer blocks on industrial scale is possible using the method suggested in this study, and that the produced blocks also meet the design conditions for dry density of buffer blocks in the AKRS (Advanced Korea Reference Disposal System of HLW).

Synthesis and performance assessment of modified epoxy resins containing fatty acid (지방산 변성 에폭시수지 합성과 성능평가)

  • Lee, Dong-Chan;Kim, Jin-Wook;Choi, Joong-So
    • Journal of the Korean Applied Science and Technology
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    • v.33 no.4
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    • pp.634-646
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    • 2016
  • In this work, modified epoxy resins which were well melted in mild solvent were synthesized and solubility assessment was carried out for synthesized epoxy resins. Bisphenol-A type, phenol novolac type and ortho-cresol novolac type epoxy resins were used and fatty acid, dodecyl phenol (DP) and toluene diisocyanate (TDI) were added for synthesis of modified epoxy resins containing fatty acid (MEFA). Composition was epoxy resin/fatty acid = 1.0/0.5 and fatty acid/DP = 0.25/0.25 by equivalent weight and twelve MEFAs were synthesized according to epoxy resins. Viscosity and solubility were measured for twelve MEFAs. As a result, solubility of MEFA was excellent for mild solvent according to increasement of contents of benzene ring, glycidyl group and carbon number of alkyl group. And physical properties were measured for each coating of paints after preparing transparent paints of MEFA to melt well in mild solvent among twelve MEFAs. As a result, they showed an optimal performance on conditions of equivalent ratio of bisphenol-A type epoxy resin/fatty acid/DP/TDI; 1.0/0.25/0.25/0.5 and equivalent ratio of phenol novolac type epoxy resin/fatty acid/DP; 1.0/0.25/0.25 for drying time, adhesion, hardness, impact resistance and alkali resistance.

Growth and Production of Macrobenthic Fauna on a Macrotidal Flat, Inchon, Korea -II. Production of the Razor Clam, Solen (Solen) strictus (Bivalvia, Solenidae) from Chokchon Tidal Flat- (인천연안 간석지산 주요 저서생물의 성장과 생물생산 -II. 척전지역 간석지에 서식하는 맛조개, Solen (Solen) strictus의 생물생산-)

  • HONG Jae-Sang;PARK Heung-Sik
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.27 no.5
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    • pp.560-571
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    • 1994
  • A single station representative of the razor clam, Solen (Solen) strictus, on a macrotidal flat, Inchon, Korea was sampled at bimonthly intervals between May 1989 and July 1990 by using a can corer. Estimates of growth rate and annual production of this razor clam have been made using the techniques of cohort growth analysis. Growth rate and production were highest during the first year after spawning and recruitment. The annual production was $2.83g\;DWt/m^2/yr$, mean annual biomass $256.3\;g/w^20$, and a turnover time of 5.00 yea, giving an annual turnover rate (P/B) of $0.20\;yr^{-1}$. The total annual production in wet weight ($33.22g\;WWt/m^2/yr$) appeared to consist of water in live flesh($72.6\%$) and shell($18.9\%$), whereas the dry weight of the soft parts was $8.52\%$, the ash-free dry weight $5.4\%$, and the ash content $3.1\%$ of the total wet weight.

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Effects of Metalized Al-2%Zn Layer on the Corrosion Behavior of Al 5083 Alloy (Al 5083 합금의 부식거동에 미치는 Al-2%Zn 용사 코팅층의 영향)

  • 김용철;김영근;이성민;고영태
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 1999.05a
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    • pp.2-2
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    • 1999
  • 금속재료의 표면 특성을 높이기 위해서 여러 표면처리 방법들이 사용되어져 오고 있다. 그 중 용사법에 의한 코팅방법이 최근의 현저한 기술적인 진보와 새로운 용사재료의 개발 등에 의해 여러 분야에 널리 응흉되고 있다. 일반적으로 이 용사법에 의한 코팅층은 다리, 선박 등의 대형 구조물에 대한 내식성 향상뿐만 아니라 자동차 및 항공기 부품, 핵 반응기 등의 코팅부에 널리 이용되고 였다. 특히 해수분위기에서 주로 사용되는 설비의 내식성을 향상시킬 목적으로 사용되 는 알루마늄 및 아연 합금의 용사 코팅층은 대부분의 경우 건조한 분위기보다는 수분이 많은 수용액 환경 하에서 사용되므로, 사용 환경 중에서 용사피막의 내식성을 조사하는 연구가 요구되고 있다. 사용되는 환경하에서의 침지시험에 의한 방법도 중요하지만, 가속화된 전기화학측정에 의한 방법 또한 이용된다. 열용사법에 의한 코팅층의 전기화학적 특성을 알아보기 위해서 3.5 % NaCI 수용액 내에서 AI 5 5083 모재와 Al-2%Zn 합금의 용사 코팅층 각각에 대한, 그리고 AI 5083 모재 위 AI-2%Zn 용사층이 코팅된 경우에 대한 분극거동과 침지시간에 따른 부식전위 및 분극저항성의 특성변화, 표면의 임피던스특성 변화 등을 측정하였다. 이 결과 모재에 대한 코팅층의 희생양극성올 판단할 수 있고, 모재/코팅 사스템의 분극거동은 혼성전위이론(mixed-potential theory)에 의해 결정되었다. 용사 코팅층이 박리되어 모재가 일부 드러난 경우를 모사한 시험편올 제작하고, 시험편 표면의 각 위치에 따라 부식전위 분포를 측정하였다. 그리고 측정 데이터를 기초로 표면의 상태변화를 모사하여 용사코팅에 의한 표면에서의 방식전위분포를 시율레이션하였다. 이와 같은 표면에서의 방식전위분포 해석을 통하여, 코팅층의 희생양극성에 의한 모재의 방식범위를 판단할 수 있다.의 비저 항을 갖는 철 박막에서도 99.9% 순도의 철을 타켓으로 하여 증착된 막은 일반 저탄소 강을 타켓으로 하여 증착된 막보다 훨씬 낮은 부식속도를 보였다.TEX>$He/O_2/Ar/N_2$의 gas를 사용 한 atmospheric pressure plasma cleaning 과 $Ar/O_2$의 gas를 사용한 ICP cleaning에서 이 차전자방출계수(SEEC)가 약 1.5~2.5배 증가된 것을 알 수 있었다. 저지능 등을 평가하여 각 실험결과를 비교분석하여 보았다. 수록 민감하여 304 의 IGSCC 와 매우 유사한 거동을 보인다. 본 강연에서는 304 와 600 의 고온 물에서 일어나는 IGSCC 민감도에 미치는 환경, 예민화처리, 합금원소의 영향을 고찰하고 이에 대한 최근의 연구 동향과 방식 방법을 다룬다.다.의 목적과 지식)보다 미학적 경험에 주는 영향이 큰 것으로 나타났으며, 모든 사람들에게 비슷한 미학적 경험을 발생시키는 것 이 밝혀졌다. 다시 말하면 모든 사람들은 그들의 문화적인 국적과 사회적 인 직업의 차이, 목적의 차이, 또한 환경의 의미의 차이에 상관없이 아름다 운 경관(High-beauty landscape)을 주거지나 나들이 장소로서 선호했으며, 아름답다고 평가했다. 반면에, 사람들이 갖고 있는 문화의 차이, 직업의 차 이, 목적의 차이, 그리고 환경의 의미의 차이에 따라 경관의 미학적 평가가 달라진 것으로 나타났다.corner$적 의도에 의한 경관구성의 일면을 확인할수 있지만 엄밀히 생각하여 보면 이러한 예의 경우도 최락의 총체적인 외형은 마찬가지로 $\ulcorner$순응$\lrcorner$의 범위를 벗어나지 않는다. 그렇기 때문에도 $\ulcorner$순응$\lrcorne

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참깨의 수세 후 탈수 정도에 따른 참깨 볶음 조건과 참기름 품질 영향 비교

  • 모승영;이우진;은종방
    • Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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    • 2003.10a
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    • pp.153-153
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    • 2003
  • 우리나라와 일본에서 특유의 향미로 인해 오래 전부턴 조미식품으로 애용되었던 참기름은 최근 토코페롤과 세사몰류 항산화 성분의 인체 기능성으로 인해 유지시장에 서 더욱 증가일로에 있다. 지금까지 좋은 향미와 품질을 지닌 참기름을 얻기 위해 참깨의 roasting조건에 대한 많은 연구가 이루어져 왔으나, 가공 전처리인 이물질 제거를 위한 수세 작업 및 탈수 작업에 관한 연구는 아직까지 없었다. 따라서, 본 연구에서는 이물질을 제거하는 수세 작업을 한 후 수분의 제거 정도 즉, 참깨가 roasting 과정으로 들어가기 직전의 수분 함량이 참기름의 제조와 품질에 미치는 영향을 알아보고자 하였다. 시료 350g을 수세 후 24 hr, 48 hr, 120 hr 실온에서 송풍 건조를 시켜 참깨 자체의 수분 함량을 각각 17.14%, 11.78%, 6.08%로 조절하여 착유하였다. 수분함량이 다른 세 군 시료를 각기 24$0^{\circ}C$, 26$0^{\circ}C$, 28$0^{\circ}C$에서 20분간 roasting하여 착유된 참기름에 대해 이화학적 품질 특성을 알기 위해 seed와 oil의 색도, 산가, 과산화물가, TBA가, 점도와 굴절률을 측정하였다. 또한, sample single test(5점 척도)를 이용한 관능검사를 행하여 benny, nutty, burnt flavor 및 전체적 만족도와 향의 강도 항목을 조사한 후 상관분석을 실시하였다. roasted sesame seed와 oil에 대해 색도를 측정하고 분산 분석을 실시한 결과, 참깨의 색도 중 L*가 R-suare=1로서 전체 자료가 모형을 잘 설명해줌을 의미하는데, 고수분 시료일수록 whiteness가 높게 나왔고(60이상), 고온일수록 미미한 감소가 나타났다. 이것은 수분함량이 시료의 건화속도에 요인자로 작용함을 말해준다. oil의 L*도 마찬가지 경향을 보이나 고수분 시료구의 경우(40 이상), 타 시료구(20이하)에 비해 백색도가 높은 것을 볼 수 있어 볶음에 더 많은 시간을 투자해야 함을 보여주었다. 그러나 a*와b*는 시료구간 뚜렷한 차이는 보이지 않았다. 참기름에 대하여 화학적 품질 평가로 산가는 수분함량 시료구별로 1.204, 3.28, 1.862가 측정되었고, 과산화물가는 0.493, 0.169, 0.315가 기록되었고, TBA가 또한 13.45, 10.27, 11.73로서 시료의 수분 함량과 상관없이 초기 산패 경향은 거의 없는 것으로 나타났다. 참기름의 물리적 품질요소로서 점도는 평균 85.57 cS, 굴절률은 평균 1.471로서 시험구간 이화학적 차이는 없는 것으로 드러났다. 관능검사결과의 상관분석에서는 beany와 burnt flavor간에 -0.9975(p<0.05)의 음상관을, nutty flavor와 전체favor간에 0.99662의 양상관(p$\leq$0.05)을 보였고, burnt와 향의 strength, 전체 favor와 nutty flavor간에도 상관성이 높았다. strength와 nutty 항목간에도 0.982의 높은 상관을 보였으나 전체 favor와 burnt 항목간에는 높은 음상관(-0.9862)을 보였다. 고수분 함량의 시료는 28$0^{\circ}C$의 고온 처리시 외에는 향미가 좋지 못한 것으로 나타났고, 수분량이 적은 실험구는 고온일수록 향과 고소함은 강해지나 수분 보유량이 적어 타 실험구에 비해 탄내가 많이 발생하였다. 향미 만족도는 중간 수분량, 26$0^{\circ}C$ 볶음 처리구가 가장 컸다. 결론적으로 수분함량을 10~12%로 조절한 시료로 26$0^{\circ}C$~28$0^{\circ}C$에서 20분 이내로 roasting할 때가 좋은 참기름을 얻을 수 있을 것으로 사료된다.

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An Edible Alginate Microcapsulation of Entomopathogenic Nematode, Steinernema carpocapsae (알지닌캡슐을 이용한 곤충병원선충(Steinernema carpocapsae)의 섭식유도형 제제화 기술)

  • 김용균;이승화;유용만;한상찬
    • Korean journal of applied entomology
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    • v.42 no.2
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    • pp.145-152
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    • 2003
  • Field application of the entomopathogenic nematode, Steinernema carpncapsae, is limited by its susceptibility to UV irradiation and desiccation especially at leaf spray control. This study was conducted to develop the control technique using alginate biocapsulation of the nematodes against the beet armyworm, Spodoprera exigua and the tobacco cutworm, Sp. litura that are normally infesting hosts above ground level. The alginate capsules including infective juveniles gave significant feeding toxicities to the larvae of the two lepidopteran species. The lethality followed a typical sigmoid dose-mortality pattern with increase of the nematode densities embedded in the capsules. Moisture content in the capsule was critical to the survival of the infective juveniles. More than 80% nematodes could survive above 10% moisture content remained in the capsule. Remaining moisture content within the capsule was dependent on relative humidity, ambient temperature, and capsule size, but not on citric acid reaction time during capsule formation. More than 80% of infective juveniles in the alginate capsules could survive in distilled water at 15$^{\circ}C$ for 60 days. When these nematode capsules containing welsh onion extract as another phagostimulant were applied on the 3rd instar larvae of Sp. exigua infesting peanut plants, they resulted in about 90% control efficacy. These results indicate that the alginate capsulation can be used for leaf-spray agent of the entomopathogenic nematodes as well as for improved storage purpose.

System Development for Analysis and Compensation of Column Shortening of Reinforced Concrete Tell Buildings (철근콘크리트 고층건물 기둥의 부등축소량 해석 및 보정을 위한 시스템 개발)

  • 김선영;김진근;김원중
    • Journal of the Korea Concrete Institute
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    • v.14 no.3
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    • pp.291-298
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    • 2002
  • Recently, construction of reinforced concrete tall buildings is widely increased according to the improvement of material quality and design technology. Therefore, differential shortenings of columns due to elastic, creep, and shrinkage have been an important issue. But it has been neglected to predict the Inelastic behavior of RC structures even though those deformations make a serious problem on the partition wall, external cladding, duct, etc. In this paper, analysis system for prediction and compensation of the differential column shortenings considering time-dependent deformations and construction sequence is developed using the objected-oriented technique. Developed analysis system considers the construction sequence, especially time-dependent deformation in early days, and is composed of input module, database module, database store module, analysis module, and analysis result generation module. Graphic user interface(GUI) is supported for user's convenience. After performing the analysis, the output results like deflections and member forces according to the time can be observed in the generation module using the graphic diagram, table, and chart supported by the integrated environment.

Fabrication of Mono-Dispersed Ultrafine BaTiO$_3$ Powder Using Microwave (마이크로파를 이용한 초미세 균일 분산 BaTiO$_3$ 분말 제조)

  • 김현상;최광진;이상균;김영대;심상준;우경자;김경림;조영상
    • Journal of the Korean Ceramic Society
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    • v.36 no.4
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    • pp.343-353
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    • 1999
  • Microwave(2.45 GHz) was used as energy source in hydrothermal reaction to fabricate ultrafine BaTiO3 powder. Using microwave of 700 W, crytal BaTiO3 began to fom after 5 min in microwave-autoclave sys-tem. The crystallinity was not noticeably increased with increasing longer reaction time than 10 min. On the other hand in microwave-reflux system crytal BaTiO3 began to form after 15min and the crystallinity was not noticeably increased with increasing longer reaction time than 1hr,. In either case particle size dis-tribution was considerably uniform due to the effect of homogeneous heating by microwave. In addition mi-crowave heating gave an extremely small degree of particle agglomeration compared to electric heating. Av-erage sizes of as-synthesized powders were 30-60nm. Ba/Ti ratio in sol played an important role in det-ermining the particle size. It seems that excess barium forms different phases such as Ba(OH)2 which makes thin layer on the surface of BaTiO3 powder. This thin layer would inhibit the agglomeration of Ba-TiO3 powders and keep the small grain size. In microwave-autoclave system tetragonal-BaTiO3 was formed directly by the reaction of only 15 min. In the case of microwave-reflux system tetragonal-BaTiO3 was formed by driyng over 25$0^{\circ}C$.

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Rheological Changes of Dough and Breadmaking Qualities of Wheat Flour with Additions of Soy Flour (대두혼합식빵 제조시 대두첨가량에 따른 반죽과 식빵의 물성 변화)

  • 김인호;하상철;이인구
    • Food Science and Preservation
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    • v.9 no.4
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    • pp.418-424
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    • 2002
  • This study was undertaken to develop the optimum baking formular and process in making the improved soy-wheat composite breads furtified with soy flour, which has been known for a source of biologically active phytochemicals and for more vegetable proteins as well. The effects of the addition of soy flour on a rheological properties of dough, on the sensory characteristics of breads, and on the possibilities of commercialization of these functional breads were investigated. As the added amount of soy flour increased, water absorption, development time and the weakness value of dough were increased, but dough stability were decreased in the farinograph. In the extensograph, the more soy flour was added, the less the extensibility and the resistance to extention were shown. As the amount of soy flour increased, gelatinazation point was increased in the amylograph, but the maxium viscosity was decreased. As the added amount of soy flour was increased, b value(yellowness) was obviously increased, L value(lightness) was slightly decreased. However, a value(redness) was not nearly changed in the color of cut loaves. In sensory evaluation, the more soy flour was added, the less the external, the internal characteristics and the eating qualities were shown. Accorting to the addition of soy flour, the toughness and the brittleness tended to be increased proportionally. The dough of 10% soy-wheat composite flour(SF10) was the most favorable on the baking performance.

Antioxidant and antimicrobial activities of black Doraji (Platycodon grandiflorum) (흑도라지의 항산화 및 항균 활성)

  • Lee, Soo-Jin;Bang, Woo-Suk;Hong, Ju-Yeon;Kwon, O-Jun;Shin, Seung-Ryeul;Yoon, Kyung-Young
    • Food Science and Preservation
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    • v.20 no.4
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    • pp.510-517
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    • 2013
  • This study was conducted to investigate the antioxidant and antimicrobial activities of the hot-water and methanol extracts of raw and black Doraji to increase its utilization. In order to prepare the black Doraji, it was steamed for 15 days at a temperature of $60^{\circ}C$ and then it was dried at a temperature of $30^{\circ}C$ for 3 hr. The methanol extract from the black Doraji (BM) contained the highest levels of total polyphenols among the extracts, and the total polyphenol content of the extract from a black Doraji was higher than that of the extract from a raw Doraji. The total flavonoid contents of the hot-water extract from a black Doraji (BW) was the highest (7.94 mgQE/g) among the samples. The DPPH and ABTS radical scavenging activities increased according to the increase in the concentrations of the Doraji extracts. The BM has the highest radical scavenging activity among the extracts. Each extract showed a slight difference in the antibacterial activity according to the tested strains. The Black Doraji showed a higher antimicrobial activity compared to the raw Doraji. The hot-water extracts demonstrated higher activities than the methanol extracts, and the BW revealed the strongest activity. In this study, the black Doraji showed more effect of the antioxidant and anti-microbial activities than the raw Doraji. These results will provide fundamental data for improving the sitological value and the black Doraji can be used as a valuable resource for the development of nutraceutical foods.