• 한국토양비료학회지
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• 제46권5호
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• pp.313-321
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• 2013

The Average daily PET (Potential evapotranspiration), evaluated based on the last 30 years meteorological data and the lysimeter experiment carried out by RDA during 11 years, of 9 regions in Korea for the tomato cultivated in greenhouse, was $3.41mm\;day^{-1}$. Two kinds of water saving irrigation standard (WSIS), deficit irrigation standard (DIS) and partial root-zone drying irrigation standard (PRDIS) that include the irrigation interval and the amount of irrigation water according to the region, soil texture and growing stage, were established. According to the DIS and PRDIS, the cultivator can save water up to 29.2% and 53.7%, respectively, for tomato cultivation in greenhouse compared to the full irrigation standard (FIS) which established in 1999. WSIS can be used easily by the cultivator without complicate procedures such as soil sampling and measurement of soil water status by expensive sensors. But the cultivator should care about irrigation method such as PRDI (partial root-zone drying irrigation) without yield decrease.

• 한국약용작물학회지
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• 제19권5호
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• pp.341-346
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• 2011

The objective of this study was to evaluate antioxidant activities of Rehmannia glutinosa (Raw Jihwang) by traditional method. The total phenol content of Rehmannia radix Preparata (the final cycle of Jihwang) was increased to 205%, compared with Rehmannia glutinosa. Antioxidant activities, determined by ferric-reducing antioxidant potential (FRAP), 2,2'-azinobis(3 ethybenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity, 1,1-diphenyl-2-picrydrazyl (DPPH) and hydroxyl radical scavenging activities, increased remarkably as the number of steaming-drying cycles increased. Especially, FRAP value increased 285%. Also, $IC_{50}$ values for DPPH and hydroxyl radical scavenging activities of the final 9th-cycling product, decreased 48.4% and 76%, respectively, compared with those of Rehmannia glutinosa. Our result was suggested that antioxidant activities of Rehmannia radix Preparata improve according to the increasing number of steaming-drying cycles.

• 콘크리트학회지
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• 제5권1호
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• pp.157-164
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• 1993

콘크리트내의 물의 흐름의 양과 방향을 결정하는 수리에너지의 분포는 그양의 변화에 따라 콘크리트의 수축과 팽창을 지배하는 응력의 일종이다. 따라서 이 수리에너지와 건조수축 변형율 사이에는 직접적인 연관관계가 있다. 본 논문에서는 건조수축과 수리에너지 사이의 이론적인 관계를 논리적으로 유도하여 두 개의 변수사이의 상관관계를 밝히는 이론식을 유도하였다. 본 논문에서는 세 개의 건조수축 작동구조(메카니즘)중 평상적인 상대습도하에서, 즉 50%이상에서, 작용하는 작동구조만을 고려하였다. 열전 쌍 싸이크로미터를 콘크리트 슬라브에 매설하여 수리에너지를 측정하고 동시에 건조수축량을 측정하여 두 측정값사이의 상관관계를 밝힘으로서 유도된 이론을 증명하고자 하였다. 측정결과는 본 이론의 타당성을 증명하는 동시에 본 이론이 실제 구조물의 건조수축량의 측정에 이용될수 있는 방법도 동시에 보여 주었다.

• 한국세라믹학회지
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• 제30권9호
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• pp.775-783
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• 1993

TiO2-SiO2 system anti-reflective(AR) film was prepared to decrease reflectance on the glass surface. The experiments were carried out as fellow, 1) preparation & hydrolysis of TiO2-SiO2 system sols. 2) glass dipping, and 3) drying & heat treatment. We investigated the refractive index and thickness of film with viscosity, zeta-potential of sol, sol concentration, withdrawal speed, drying and heat treatment condition. As a result, we prepared good qualitative Quarter-Half-Quarter type anti-reflective film that had minimum, 0.02% and average reflectance, 0.087% in the visible region.

• 전기화학회지
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• 제10권3호
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• pp.175-178
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• 2007

Pure iron, Fe-0.4, and 1.2 wt.%Cu alloys were examined by conducting the electrochemical techniques in the weakly alkaline solution, pH9, controlled by $Ca(OH)_2$, solution added with 0.02M NaCl. The $R_P$ measured from ac impedance, selected 10 kHz and 10mHz, in weakly alkaline solutions containing chloride ions indicated that the addition of copper up to 1.2wt.% into the pure iron significantly improved the pitting resistance of iron. In contrast to alloy, the pure iron showed the rapid pitting occurrences in drying period. During the drying period, the corrosion potential of pure iron was shifted to less noble value, pitting initiation.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.898-905
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• 2006

In the present paper, for a quantitative assessment of early-age cracking in an RC wall, an improved analytical model is proposed. First of all, a three-dimensional finite element model for the analysis of stresses due to hydration heat and differential drying shrinkage is introduced. A discrete steel element derived using the equivalent nodal force concept is used to simulate reinforcing steels, embedded in a concrete matrix. In advance, to quantitatively calculate the cracking potential, an analytical model that can estimate the post-cracking behavior in an RC tension member is proposed Subsequent comparisons. of analytical results with test results verify that the combined use of both the finite element model for the stress analysis as well as the analytical model for the estimation of the post-cracking behavior in an RC tension member make it possible to accurately predict the cracking ,behavior of RC walls.

• 한국광학회지
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• 제3권3호
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• pp.148-154
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• 1992

홀로 그래피 은염 감광 물질에 위상형 회절격차를 기록하여 71%가 넘는 회절 효율을 얻었다. 화학적 처리가 끝난 후 전자 주사 현미경을 통해 Agfa 8E75 감광유제의 부풀은 모습을 밝혔다. 비경화 정착액, 중크롬산 표백액과 알코올에 의한 급속 전조가 강한 변조효과를 가져와 회절 효율이 20% 이상 증가하였다. Kogelnik 결합과 이론의 중요한 특성 파라미터들에 대해 검토하였으며, 두께 변화에 따른 새로운 파라미터 값을 컴퓨터 시뮬레이션을 통해 제시하였다. 결론적으로 감광유제의 정밀한 두께 제어가 고회절 효율을 얻기 위한 잠재적인 원천으로 작용함을 보였다.

• 대한의생명과학회지
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• 제25권2호
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• pp.170-176
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• 2019

The objective of this study was to evaluate the characteristics of the mixtures of choline alphoscerate (alpha-glycerylphosphorylcholine, alpha-GPC), in the liquid form, and sucrose ester, which formed a solid composite. The choline alphoscerate solid composites were prepared using different ratios of sucrose ester, and different preparation methods, such as air drying and rotary evaporation, were compared for their preparation efficacy. We examined the characteristics of the solid composites by using scanning electron microscopy (SEM), angle of repose, and moisture content. The ideal mixing ratio of choline alphoscerate and sucrose ester was determined as 1:3 and air drying was found to be more suitable for the preparation of solid composites than rotary evaporation. SEM measurements of the degree of dispersion and the size of particles indicated that a high-temperature air method was more suitable. These results demonstrated the successful preparation of choline alphoscerate solid composites that have potential for industrial use.

• 한국식품저장유통학회지
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• 제23권2호
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• pp.246-251
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• 2016

건조 방법을 달리하여 건조한 산사과 추출물의 항산화활성 및 생리활성의 특성을 비교하였다. 건조 산사과의 추출 수율은 동결건조 추출물이(61.70%) 열풍건조 추추물(53.50%) 보다 높은 값을 나타내었으며, 총 폴리페놀과 플라보노이드 함량에서도 동결건조 산사과 추출물이 열풍건조 추출물에 비하여 높은 값을 보였다. 항산화 활성 또한 동결 건조 산사과 추출물에서 열풍 건조 산사과 추출물보다 높은 활성을 나타내었고, 특히 DPPH 라디칼 소거능에서 동결건조 산사과 추출물이 열풍건조 산사과 추출물 보다 3배 넘는 활성을 나타내었다. ${\alpha}-Glucosidase$ inhibitory ability에서는 동결건조 산사과가 열풍건조 산사과, 양성대조군인 acarbose보다 높은 활성을 나타내었으며, HMG-CoA reductase 저해활성에서는 동결, 열풍 산사과 추출물이 전체적으로 높은 저해 활성을 나타내어 콜레스테롤 개선효과에 대한 가능성을 나타내었다. 이러한 결과를 종합해 볼 때 동결건조 방법을 이용하는 것이 산사과의 건조효율 증대와 품질손상을 억제 할 수 있는 건조 방법으로 판단된다.

• 한국관개배수논문집
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• 제17권2호
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• pp.82-94
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• 2010

Recently, biomass application for energy is getting more interests from many countries since biomass is widely available over the nation wide, whereas fossil fuels are produced in several limited regions. Recognizing the importance, government is promoting renewable energy use in Korea. The locational characteristics of the existing biomass potential directly can be used to decide scale of power plant for local agricultural facility. Although there are a few studies on feasible biomass potential in local areas, it is expected that both government and commercial sectors recognize the potential of biomass energy and the importance of reducing greenhouse gases. When planning biomass energy systems, biomass price is determined by the costs of collection, transportation, chipping, drying if required. In this paper investigates the economic and spatial characteristic of biomass location by land use map. However typical area of each categories in local region is not correct to agricultural census data. Therefore we concerned about how to calculate feasible biomass potential which it can be describing total amount of plant scale, and to match both of data. Even though its spatial distribution, in rural area in Korea, to expand biomass energy programs in the area, government serve to find areas of higher biomass production with suitable locations for plants to convert to bio-energy in order to increase the usage of renewable energy.