• Title/Summary/Keyword: 동결층

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Effect of Hydroxypropyl Cellulose Treatment for Surface Stabilization of Waterlogged Wood of Wan-do Shipwreck Impregnated with Polyethylene Glycol (폴리에틸렌글리콜(PEG) 함침처리한 완도선 목재의 표면 안정화를 위한 하이드록시프로필 셀룰로오스(HPC) 처리효과)

  • Kim, Eung Ho;Han, Gyu Seong
    • Journal of Conservation Science
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    • v.32 no.2
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    • pp.155-165
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    • 2016
  • This study aimed at verifying the effect of hydroxypropyl cellulose(HPC) treatment on polyethylene glycol(PEG)-treated waterlogged wood for surface stabilizing. This research investigated macroscopic and microscopic appearance, color change, weight change, and dimensional change. And effect of HPC was verified through variance analysis (ANOVA) and least significant difference test(LSD). HPC formed thin layer on the surface of wood specimen, and blocked the pore of tracheid and the gap between the crack. Specimens without deterioration showed no invisible change except HPC 1,000,000 treatment group. Whitening was appeared at the sound surface of HPC 1,000,000 treated wood. Specimens with deterioration showed a little color difference change by external moisture adsorption. Thin layer of HPC on the surface of wood specimen was maintained after the deterioration, and this HPC layer significantly suppressed the weight and dimensional change by moisture adsorption.

Analysis for Chloride Penetration in Concrete under Deicing Agent using Multi Layer Diffusion (다층구조확산을 고려한 제설제에 노출된 콘크리트의 염화물 해석)

  • Seo, Ji-Seok;Kwon, Seung-Jun
    • The Journal of the Korea Contents Association
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    • v.16 no.4
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    • pp.114-122
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    • 2016
  • Concrete is cost-benefit and high-durable construction material, however durability problem can be caused due to steel corrosion under chloride attack. Recently deicing salt has been widely spread in snowing season, which accelerates micro-cracks and scaling in surface concrete and the melted deicing salt causes corrosion in embedded steel. The previous governing equation of Fick's 2nd Law cannot evaluate the deteriorated surface concrete so that another technique is needed for the surface effect. This paper presents chloride penetration analysis technique for concrete subjected to deicing salt utilizing multi-layer diffusion model and time-dependent diffusion behavior. For the work, field investigation results of concrete pavement exposed deicing salt for 18 years are adopted. Through reverse analysis, deteriorated depth and increased diffusion coefficient in the depth are evaluated, which shows 12.5~15.0mm of deteriorated depth and increased diffusion coefficient by 2.0 times. The proposed technique can be effectively applied to concrete with two different diffusion coefficients considering enhanced or deteriorated surface conditions.

Electron Microscopical Property of Transglutaminase Added Milk (트랜스글루타미나제를 첨가한 우유의 전자현미경적 특성)

  • 문정한;홍윤호
    • Food Science of Animal Resources
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    • v.23 no.4
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    • pp.350-355
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    • 2003
  • Raw skim milk and colloidal calcium phosphate-free skim milk were treated with microbial transglutaminase (TGase), ultracentrifuged at varying rates and were observed to contain textural properties using a scanning electron microscope (SEM). Skim milk showed irregular signs of conformation at lower centrifugal rate, and associated regular (10,000 ${\times}$g) and thin with broad holes (20,000 ${\times}$g). The associated texture became thick and irregular (40,000 ${\times}$g), and fine particles were regularly associated (100,000 ${\times}$g). When skim milk was incubated for 1 hr with TGase, casein micelles aggregated and broadened as centrifugation rate increased. When skim milk was incubated for 8 hrs with TGase, casein micelles associated to large widened aggregates, and were associated regularly which then became irregular (100,000 ${\times}$g). When colloidal calcium phosphate-free skim milk incubated for 1 hr with TGase showed no sediment, the milk incubated for 8 hrs with TGase associated together, yielding broadened and regular layers as the centrifugation rate increased. It is assumed that such phenomena could be caused by protein crosslinking reaction with TGase and conformational change of casein molecules, as well as dependencies on reaction time, temperature and ultracentrifugation rate.

Antioxidant Activity of Various Fractions Extracted from Mustard Leaf (Brassica juncea) and Their Kimchi (청갓과 청갓김치의 용매별 추출물의 항산화성)

  • Kim, Jae-I;Park, Jae-Sue;Kim, Woo-Seong;Woo, Kang-Lyung;Jeon, Jung-Tae;Min, Byung-Tae;Cheigh, Hong-Sik
    • Journal of Life Science
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    • v.14 no.2
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    • pp.286-290
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    • 2004
  • The antioxidant activities of the various fractions extracted from mustard leaf (Brassica juncea) and mustard leaf kimchi were determined by the radical scavenging effect on 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical. The fractions from dried mustard leaf, and fermented mustard leaf kimchi for 0 day and fermented mustard leaf kimchi for 5 days at 15$^{\circ}C$ were screened for the scavenging effects by using DPPH assay. The fractions prepared by the systematic extraction procedure with the solvents such as hexane, C $H_2$Cl$_2$, EtOAc, BuOH and $H_2O$ were used for the determination of free radical scavenging effects. The antioxidant activity of EtOAc and n-BuOH soluble fraction from mustard leaf and mustard leaf kimchi for 0 day had stronger than the others. During fermentation at 15$^{\circ}C$ for 5 days, the antioxidant activity was changed. C $H_2$Cl$_2$ and EtOAc soluble fraction showed more potent radical scavenger effects than the others. The difference or results were to the various supplements and fermentation process.

Analisys on Freezing Characteristics of Pavement Layer Using the Feild Pavement Model test (현장 모형 도로 축소 실험을 이용한 포장구성층의 동결 특성 분석)

  • Shin, Eun-Chul;Ryu, Byung-Hyun;Moon, Yong-Soo;Park, Jeong-Jun
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.03a
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    • pp.1164-1171
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    • 2010
  • Korea is considered to be a seasonal frozen soil area that is thawed in the spring, and most of the area is frozen in winter as to the characteristic of geography. In the current design codes for anti-freezing layer, the thickness of anti freezing layer is calculated by freezing depth against the temperature condition. Therefore, they have a tendency of over-design and uniform thickness without the considerations of thermal stability, bearing capacity and frost susceptibility of materials. So, it is essential for studying the appropriateness and bearing capacity besides the seasonal and mechanical properties of pavement materials to take a appropriate and reasonable design of the road structure. In this research, the evaluation of frost susceptibility on subgrade, ant-freezing layer, sub base was conducted by means of the mechanical property test and laboratory field road model downed scale experiment. The temperature, heaving amount, heaving pressure and unfrozen water contents of soil samples, the subgrade, anti-freezing layer, sub base soils of highway construction site, were measured to determine the frost susceptibility.

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Morphological Changes in the Skin of Hairless Mouse Fed Various Kimchi Diet (김치종류별 식이가 Hairless Mouse 피부의 형태학적 변화에 미치는 영향)

  • Ryu, Bog-Mi;Ryu, Seung-Hee;Yang, Young-Churl;Lee, Yu-Soon;Jeon, Young-Soo;Moon, Gap-Soon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.33 no.9
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    • pp.1469-1475
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    • 2004
  • Skin is the most frequently exposed tissues to oxidative stress from exogenous and endogenous sources. Dietary antioxidants, which suppress oxidative stress including reactive oxygen metabolites, play an important role in protecting skin from deleterious reactive oxygen species. Kimchi containing lots of antioxidative compounds shows anti-aging effect on skin. Therefore the morphologic changes on the skin of hairless mice fed diets containing Korean cabbage, mustard leaf, and buchu kimchi for 16 weeks were determined. Although epidermal thickness was decreased with age, kimchi prevented this thinning of epidermis compared to control group. In kimchi groups, the staining area of cytokeratin was smaller and stratum corneum was thinner than control group. It suggests that various kinds of kimchi diets prevent the increase of keratinization in epidermis with aging. Type Ⅳ collagen, a major structural protein of basement membrane supporting matrices, existed greater amount in kimchi groups than control group, especially in mustard leaf kimchi group. Rough endoplasmic reticulum (RER) of fibroblast was well developed in dermis of Korean cabbage and mustard leaf kimchi groups, which means collagen synthesis at dermis increased in those kimchi groups. This morphological changes of skin suggest that kimchi consumption can retard skin aging due to the presence of antioxidant and anti-aging compounds, especially some components of mustard leaf kimchi may largely affect on the skin rejuvenescence.

A Study on the Development Lightweight Aggregate using Recycled-Paint for Reduction in Freezing Ground (단열골재 개발을 통한 동토방지 기술개발에 관한 연구)

  • Moon, Jong-Wook;Back, Min-Ho
    • Journal of the Korean Society of Hazard Mitigation
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    • v.10 no.4
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    • pp.47-54
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    • 2010
  • This study is progressed function ratio, it's trued taste by an experiment to present data for human work light weight aggregate development that use clink ash progressed liquid limit, small success limit, wear loss in quantity, sand equivalent, sieve cutting examination. 80:20's match of function rain examination is 1.4, and that use rubble aggregate as recyeled-panit lightweight aggregate's capacity ratio increases by 1.0 increase of function rain many. Also, examination multiplied delicate flavor gradually according to increase of the mixing rate, and absorption coefficient increased. This is judged by phenomenon that appear by special quality upper recycled-panit of polystyrene bid and porosity's increase between lightweight aggregate. It is case that use aggregate of wear loss in quantity is 13.5 in sand equivalent and a wear loss in quantity experiment and although case that mix 20% increases by 14.4, this phenomenon by weak tissue of lightweight aggergate be judged. When it's as a these experiment, the statue prevention floor of a street improvement specifications is prescribing so that satisfy by sand equivalent 20, CBR 10. This is showed result that this satisfies in quality standard all in match experiment ago that see.

Preparation of Laver Powder and Its Characteristics (김분말의 제조와 특성)

  • Lee, Hyang-Hee;Lee, Jang-Wook;Rhim, Jong-Whan;Jung, Soon-Teck;Park, Yang-Kyun;Ham, Kyung-Sik;Kim, In-Chul;Kang, Seong-Gook
    • Korean Journal of Food Science and Technology
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    • v.31 no.5
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    • pp.1283-1288
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    • 1999
  • Effect of drying methods, such as natural solar drying, hot air drying$(at\;60^{\circ}C\;and\;105^{\circ}C)$, vacuum drying and freeze drying methods, on the quality of laver were investigated to develop optimum processing conditions for preparation of laver powder. Appreciable amount of laver pigments such as chlorophyll, carotenoid and phycobilin were lost during washing and drying process. Their loss was affected significantly by the method of drying. Among the methods tested, high temperature air drying was the worst in retaining laver pigment, while freeze drying was the best. Loss of vitamin C which was in the range of 75-99% was also affected by the method of drying. Isotherms for laver powder shelved sigmoidal shape and monomolecular layer moisture content of both laver powder(Porphyra dentata and Porphyra tenera) determined by the BET equation was 6.30%(dry basis). Laver powders prepared with Porphyra dentata and classified with 50-, 80- and 100- mesh sieves showed monomodal size distribution with the high frequency at 110-120, 100-110 and $80\;{\mu}m$, respectively, which indicated that size or laver powder was homogeneous.

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Worries and Reality Regarding Porous Asphalt Pavements: Structural Integrity, Flood Mitigation and Non-Point Pollution Reduction (투수성 아스팔트 포장에 대한 우려와 실제: 구조적 적합성, 홍수 완화 그리고 비점오염 저감)

  • Yoo, Inkyoon;Lee, Suhyung;Han, Daeseok;Lee, Sanghyuk
    • Ecology and Resilient Infrastructure
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    • v.3 no.4
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    • pp.272-278
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    • 2016
  • Porous pavements are recommended as a Low-Impact Development (LID) method which is a strategy to develop a water cycle as close to a natural state as possible, and to solve the urban impervious surface problems. Porous pavements can yield a solution if it provides a more permeable surface with extra space to contain extra water from building roofs. But there are few applications in Korea because of a lack of recognition and experience. Highway engineers are mainly concerned about the infiltration of water into pavement structures. They worry about the weakening of the asphalt mixture and subgrade, and freezing during the winter season due to the infiltration of water. Meanwhile, hydrological experts doubt the effects of the amount of water to control during the flooding season, and environmental experts prefer a non-point pollution treatment system established beside highway. In this study, from reviewing the history and the body of literature about porous pavements, conclusions regarding the most advanced technologies were made. First, traditional thickness designs can be used for porous pavement, no extra distresses was found by weakening and freezing during the winter season. Second, hydrological design can be made by controlling the thickness of the pavement and the outlet of water. Third, the treatment efficiency of non-point pollution of porous pavements is not worse than any other method. Importantly, it's a more eco-friendly solution because of its lower requirement for de-icing agents.

유기농 이유식 제품 제조 기술 현황과 소비 전망

  • Sin, Hyeon-Ho
    • 한국유가공학회:학술대회논문집
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    • 2006.06a
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    • pp.29-45
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    • 2006
  • 최근에 들어 웰빙(well-being)과 함께 로하스(LOHAS: Lifestyle of Health and Sustainability)란 개념이 급속도로 확산되고 있으며, 이를 만족하는 식품으로 친환경 농산물과 유기 가공 식품이 대두되고 있다. 여러 마케팅 조사에서도 친환경 농산물과 유기 가공 식품의 소비자 선호도는 상당히 높게 나타난다. 이러한 다양한 소비자의 요구에 맞춰 우리의 2세에게 더욱 안전하고 좋은 품질의 이유식을 제공하고 나아가 한계에 이른 '지구와 환경을 해치지 않는 지속가능 한 소비'를 유도하고자 업체들은 유기농 이유식을 개발하고 있다. 유기농 소비자 10명 가운데 7명은 최근의 웰빙 붐 때문에 유기농에 관심을 가지게 됐으며, 가격이 다소 비싸더라도 가족의 건강을 위해 친환경 농산물을 구입하는 것으로 나타났으며, 국내외를 막론하고 친환경 농산물과 유피 가공 식품의 시장 동향을 살펴보면 지속적으로 증가하고 있으나, 아직까지 일반 제품에 비해 미미한 수준이며, 국내는 인증 제도가 없으나, 유기 가공 식품표시기준에 따라 표시되고 있다. 일반적으로 이유식이라 함은 식품공전에서 영 ${\cdot}$ 유아용 곡류 조제식만을 말하지만 넓게 축산물의 조제유류, 영아용 조제식, 성장기용 조제식, 기타 영 ${\cdot}$ 유아식을 포함할 수 있으며, 유기농 이유식 제조 현황을 살펴보면 동결, 분무, 드럼 등의 건조와 퍼핑이나 Extruder를 통한 알파화로 원료를 가공하여 은 살균, 멸균, 균질, 혼합, 건조, 냉각, 포장 등의 다양한 공정으로 이루어진 분무건조나 유동층이나 연속식 과립기를 사용하여 분말이나 입자형 이유식을 생산하며, 동결 건조를 하여 열수를 가해 죽 상태로 먹을 수 있도록 한 제품, 데워서 떠 먹일 수 있도록 병조림이나 레토르트 유동식 제품, 바로 마실 수 있는 쥬스류, 두유류, 과자 등으로 생산하고 있다. 주된 메이저4사는 일동후디스, 남양유업, 매일유업, 파스퇴르유업으로 다양한 제품들을 생산하고 있으며, 두유를 위주로 한 정식품, 연세우유와 종근당건강, 다양한 다국적 기업들의 제품이 수입되고 있는 실정이다. 이유식 시장도 96년 하반기부터 정체를 보이는 상태다. 2002년도 이유식 시장은 약 1,300억원 규모로 업체들의 고가 신제품과 유기농 이유식 출시로 판매 금액은 소폭 상승하였으나 판매 수량은 큰 변동이 없다. 저출산에 따른 양육비 집중과 유기농 제품에 대한 저변이 크게 확산돼 베이비 웰빙은 어느 정도 예견된 일이거니와 이미 미국 등 선진국에선 유아에 그치지 않고 아동까지 유기농과 고급 원료를 사용한 고가의 웰빙 제품이 봇물을 이루고 있는 상황이어서 유아식 시장은 어느 때보다 경쟁이 치열할 것이며, 국내 식품 업체들이 너도나도 유기농 제품과 매장사업에 뛰어들고 있다. 유기 가공 식품의 지속적인 발전을 위해서 (1) 국내산/수입산 공통으로 인증 제도가 도입되고 원료 농산물뿐만 아니라, 모든 공정이나 공장에 대한 종합적 관리와 동일한 인증 표시가 이루어져야 한다. (2) 정부 부처의 이기를 타파할 수 있는 법정부적 기구나 대책이 필요하다. (3) 유기 가공 식품을 취급하는 업계에서는 기존 3%의 비의도적 혼입치의 고려나 상한선 재설정을 요구하고 진정한 유기 가공 식품으로 공정 경쟁한다. (4) 활발한 인증심사원의 교육과 배출로 인증이나 심사기관의 민간 이양을 적극 장려하고 국가관 상호 신뢰를 구축한다. (5) 각 소비자 단체나 소비자는 환경을 살리고 생명체의 공생이라는 관점에서 최선의 길이 유기농 제품임을 인식하고 소비하여 우리의 다음 세대에게서 빌려온 소중한 환경을 물려준다.

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