• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.11a
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• pp.60-60
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• 2011

염색폐수의 정화에는 필연적으로 다량의 슬러지 폐기물이 발생한다. 염색폐수 슬러지는 그간 인근 공해 해상에 투기하는 해양 배출로 저렴하게 처리하였으나, 해양오염을 우려하는 국제협약(1972년 런던협약, 1996년 교토의정서)에 의하여 2008년 8월부터 배출기준이 강화되고 2012년 2월부터는 해양배출이 금지 될 예정이다. 염색폐수 슬러지의 해양 배출이 금지되면 대체 처리방법으로는 지정매립장을 통한 매립처리 방법이나 고온 소각시설에서의 소각처리 방법이 거론되고 있다. 그러나 매립처리는 슬러지 내 함유 수분으로 인한 침출수의 문제와 더불어 장기간 안정적으로 저렴하게 사용할 수 있는 대규모 처분장을 확보하기 어려운 실정이며 소각처리는 슬러지의 높은 함수율로 인해 소각 시보조 연료의 투입이 필연적으로 최근 원유가 급등 등 에너지 비용이 지속적으로 상승함을 고려할 때 소각처리비용 또한 상당한 고가가 될 것으로 예측된다. 이와 같이 슬러지 해양배출이 금지되면 섬유 염색업체들은 많은 환경비용 부담을 안을 것이다. 본 연구에서는 대규모 염색산업단지 공동폐수처리장에서 발생하는 염색폐수 슬러지의 효율적인 건조를 위해 산업단지 내의 열병합발전소에서 발생하는 보일러 폐열을 이용하였으며, 조건 특성 및 효율을 파악하기 위해 보일러 폐열의 특성을 고려하여 슬러지 두께 및 체류시간 등 건조공정 운영조건에 따른 변수별 연구를 수행하였다. 열병합발전소 보일러에서 배출되는 폐열은 온도가 $150^{\circ}C$ 정도로 기존의 슬러지 건조에서는 사용되는 $700^{\circ}C$에 비해서는 매우 저온이다. 하지만 보일러 배가스의 경우, 온도에 비해 많은 풍량을 가지고 있으므로 열량으로 환산시 충분히 가치가 있는 것으로 조사되었다. 염색폐수 슬러지의 경우, 함수율 70% 이내의 탈수 Cake 형태이므로 두께가 두꺼울수록 건조효율이 감소하였으며, 체류시간이 길어질수록 건조효율은 증가하나 20mm 이상에서는 건조효율이 급격히감소하였다. 이를 바탕으로 5톤/일 규모 슬러지 건조 Pilot Plant를 제작하여 운영하였는데, 염색폐수슬러지의 투입공정에서 슬러지와 열풍의 접촉면적을 넓혀 건조효율을 높이기 위하여 슬러지를 압출노즐을 이용하여 슬라이스 칩 형태로 제조하여 건조공정에 투입하였으며, 건조실 내에서도 건조효율의 상승을 위하여 내부열풍순환팬을 설치하여 운영하였다. Pilot 운영결과, 체류시간 52분에서 슬러지의 함수율은 70%에서 10%이하로 감소하였다.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.4
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• pp.333-338
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• 1985

In this experiment, the contents of free amino acids, and nucleotides and their related compounds of dried cod products were analysed by amino acid autoanalyzer and HPLC. Proline, histidine, lysine and alanine were dominant amino acids in raw extracts, having $65.4\%$ of total free amino acid contents, but the contents of aspartic acid, serine, isoleucine and phenylalanine were low, and methionine, tyrosine and arginine were detected in trace amount. In free amino acid composition of dried products, abundant amino acids were glycine, histidine, lysine, proline and alanine. Such amino acid as aspartic acid, methionine, tyrosine and phenylalanine were poor. In extracts of storage sample, most free amino acids were increased in both sun dried products and hot air dried products, and glycine, histidine, lysine, proline and alanine were abundant amino acid, such amino acid as methionine, tyrosine and phenylalanine were poor. In raw cod, inosine and IMP were dominant contents which 18.5, $10.0{\mu}mole/g$ on dry base, respectively, but the contents of ATP, ADP, hypoxanthine and AMP were detected less than $3.2{\mu}mole/g$. ATP and ADP were decreased while IMP, inosine and hypoxanthine were increased during drying and storage of cod.

• Journal of the Korean Geotechnical Society
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• v.29 no.12
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• pp.25-34
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• 2013

This paper presents the results of a reduced-scale physical model investigation into the behavior of retaining walls subject to cycles of wetting and drying due to rainfall infiltration. Reduced-scale model walls equipped with a water spraying system that can simulate the wetting process were first constructed and a series of tests were conducted with due consideration of different rainfall intensities and backfill soil types. The results indicate that cycles of wetting and drying process have adverse effects on the wall behavior, increasing wall deformation as well as earth pressure acting on the wall, and that the first cycle of wetting and drying process has more pronounced effect on the wall performance than the ensuing cycles. It is also shown that the degree to which the wetting and drying cycles affect the wall behavior depends greatly on the backfill soil type, and that the larger the fine contents, the greater is the effect of cycles of wetting and drying on the wall behavior. Practical implications of the findings from this study are discussed in great detail.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.108-108
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• 2022

기후변화는 전 지구 수문순환과 수자원 분포에 커다란 영향을 준다. 하지만 지금까지 관측되어온 지구상의 건조도 변화에 있어서 기후의 자연변동성의 영향과 인간활동에 의한 온난화의 영향을 명시적으로 밝힌 연구는 존재하지 않는다. 본 연구에서는 데이터 구동형 모델과 물리 모델을 이용해 관측 기반의 전구 수자원 분포를 1902년부터 2014년까지 재구축함으로써 지구의 평균온도가 약 1도 상승해온 지난 세기에 걸쳐 건기의 수자원 분포가 어떻게 변해왔는지 보인다. 재구축된 전구 변화 패턴은 인간활동에 의한 온실가스 증가등을 고려한 기후 모델 시뮬레이션과 흡사함을 알 수 있었으며 기후의 자연변동성만을 고려한 기후 모델 시뮬레이션에서는 발견되지 않았다. 주로 북아시아, 북미, 유럽 등 중위도 온대지방에서 더욱더 건조한 건기가 뚜렷하게 나타났으며 이는 강수량의 감소보다는 증발산의 증가에 기인하는 것으로 나타난다. 이와 같은 건조도의 변화는 미래 있어서 또한 인류에 대한 커다란 위협으로 자리한다. 미래 기후에서의 가뭄의 변화에 대해 다양한 연구들이 존재하지만 대부분 높은 수준의 온난화 (예를들어 RCP-SSP 585)에서의 영향에 국한된다. 다시 말해 인류가 21세기 중반에 달성을 목표로 하는 탄소중립이 가뭄의 측면에서 어떤 영향을 주게 될지에 대한 연구는 아직 충분하지 않다고 할 수 있다. 본 연구에서는 약한 혹은 중간 수준의 기후변화 시나리오를 이용해 파리협약에서 목표로 하는 1.5℃와 2℃ 상승에 따라 전 지구의 건조도 분포가 어떻게 변하고 그 변화에 있어서 어떠한 수문기후학적 메커니즘이 작용하는지 밝힌다. 지중해 연안 지역에서는 건조도의 가속이 +1.5℃와 +2℃사이에 존재하였으나 동아시아에서는 +1.5℃와 +2℃ 모두에서 습윤해짐을 알 수 있었으며 이러한 지역적 불균일성은 기후변화 대응 노력에 있어서 과거 온실가스 배출에 대한 책임뿐만 아니라 다양한 부문에 걸친 미래의 잠재 적응 노력 또한 고려해야만 함을 시사한다. 본 연구는 제6차 Coupled Model Intercomparison Project의 Land Surface, Snow, Soil-moisture Model Intercomparison Project (CMIP6/LS3MIP)와 Half a degree Additional warming, Prognosis and Projected Impacts (HAPPI)의 다중 모델 앙상블 시뮬레이션 결과를 이용했다.

• Journal of Forest and Environmental Science
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• v.12 no.1
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• pp.1-12
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• 1996

This study was carried out to estimate drying schedule of Fagaceae four species grown in Kangwon-Do by oven-drying at $100^{\circ}C$ which aimed to elucidate the characteristics such as current moisture content, drying process, initial check, collapse and internal check during drying following each board thickness (1.5cm, 2.5cm, 3.5cm, 4.5cm). The results were as follows; Current moisture content of each board showed a rapid drying curve with the high initial moisture content of board. With the high initial moisture content, the incease of board thickness and the slowness of changing rate of moisture content, species took long to do drying. Also, the initial conditions of drying had to be mild condition with the increase of board thickness.

• Journal of the Korean Wood Science and Technology
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• v.29 no.1
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• pp.1-8
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• 2001

Red pine (Pinus densiflora), white pine (Pinus koraiensis), larch (Larix leptolepis) and Western hemlock (Tsuga heterophylla) lumber were vacuum-press dried under three drying schedules to investigate current moisture contents (MC), drying rates and drying time factors related to five lumber thicknesses of 3, 5, 7, 9 and 11cm. Current MC could be estimated by drying factors such as lumber thickness, initial Me and drying time. Average drying rate from 30% to 15% Me was the highest for Western hemlock below fiber satuartion point, red pine, white pine and larch in the order of their magnitude. Drying rate curvilinearly decreased as lumber thickness increased. Drying time factor curvilinearly increased as lumber thickness increased.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.1
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• pp.111-115
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• 2009

Carrots were dried using 30, 50, and 80% polyethylene glycol (PEG) or maltodextrin as a dehydrating agent, and the dried carrots were compared with the freeze dried and hot-air dried in terms of rehydration ratio, color, carotene content, and sensory evaluation. The amount of moisture loss during drying of carrots using PEG or maltodextrin increased with increasing concentration of dehydrating agent. Rehydration ratio as well as carotene content of the PEG-treated carrots were greater than those of freeze-dried or hot-air dried carrots. Regarding color and sensory evaluation of the dried carrots, the PEG-treated and maltodextrin-treated carrots were better than freeze-dried or hot-air dried carrots. These results suggest that drying of carrots using PEG or maltodextrin is a very efficient method because of its good rehydration capacity and minimal destruction of nutrients and cell structure.

• The Korean Journal of Food And Nutrition
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• v.16 no.4
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• pp.334-339
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• 2003

To increase the utilization of citron, citron juice that is by-product of citron tea was spray dried and freeze dried. Cyclodextrin(CD) was used as wall material to stabilize during drying. The physiochemical properties of citron juice were as follows: water content of 82.3%, pH of 2.45, and there were little different in two kinds of drying or CD added in different ratio. Citric acid, malic acid, succinic acid and lactic acid were detected in all of the samples. Spray and freeze-drying increased markedly yellowness compared to that of citron juice. Heat stability was reduced by both of two kinds of drying, and CD 15% was more decreased than CD 10%. Water uptake by freeze-drying was somewhat higher than that of spray-drying. When sensory properties of original citron juice was compared with those of spray and freeze dried, freeze drying with 10% of cyclodextrin was evaluated as superior to citron juice or other drying conditions.

• Food Engineering Progress
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• v.13 no.2
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• pp.105-109
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• 2009

The effects of drying methods on the physicochemical properties of Salicornia herbacea powder were investigated. Samples prepared by freeze drying showed a significantly higher L$^{*}$-value but lower a$^{*}$-value as compared with those prepared by hot-air drying and vacuum drying (p<0.05). Scanning electron micrograph revealed that freeze drying produced more orderly and denser samples than did vacuum and hot-air drying. Water solubility of the freeze-dried sample was significantly higher than those of the other methods while swelling ratio of the same sample was significantly lower than those of others (p<0.05). Freeze-dried Salicornia herbacea powder contained significantly higher amounts of total sugar and reducing sugar as compared to the other samples (p<0.05).

• Journal of Sericultural and Entomological Science
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• v.53 no.2
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• pp.101-109
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• 2015

To extend shelf life of mulberry fruits, usually expensive freeze drying of freezing process is required. In this study an economic to multipurpose agricultural products dryers with mulberry dryer and technique was developed to reduce postharvest processing cost. Fuel and electricity consumption for drying were lowest when drying temperature was $60^{\circ}C$. And various drying conditions (fuel 3 hrs, heat 1 hr, room temperature air velocity 51 hrs) of the developed dryer were analyzed to improve drying performance. Dried mulberry fruits had dark brown color and marketable high quality explain the semi-dried characteristics.