• Korean Chemical Engineering Research
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• 제53권6호
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• pp.682-689
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• 2015

A two-step process was investigated for pretreatment and fractionation of rice straw. The two-step fractionation process involves first, soaking rice straw in aqueous ammonia (SAA) in a batch reactor to recover lignin-rich hydrolysate. This is followed by a second-step treatment in a fixed-bed flow-through column reactor to recover xylo-oligomer-rich hydrolysate. The remaining glucan-rich solid cake is then subjected to an enzymatic process. In the first variant, SAA treatment in the first step dissolves lignin at moderate temperature (60 and $80^{\circ}C$), while in the second step, hot-water treatment is used for xylan removal at higher temperatures ($150{\sim}210^{\circ}C$). Under optimal conditions ($190^{\circ}C$ reaction temperature, 30 min reaction time, 5.0 ml/min flow rate, and 2.3 MPa reaction pressure), the SAA-hot-water fractionation removed 79.2% of the lignin and 63.4% of the xylan. In the second variant, SAA was followed by treatment with dilute sulfuric acid. With this process, optimal treatment conditions for effective fractionation of xylo-oligomer were found to be $80^{\circ}C$, 12 h reaction time, solid-to-liquid ratio of 1:12 in the first step; and 5.0 ml $H_2SO_4/min$, $170^{\circ}C$, and 2.3 MPa in the second step. After this two-step fractionation process, 85.4% lignin removal and 78.9% xylan removal (26.8% xylan recovery) were achieved. Use of the optimized second variant of the two-step fractionation process (SAA and $H_2SO_4$) resulted in enhanced enzymatic digestibility of the treated solid (99% glucan digestibility) with 15 FPU (filter paper unit) of CTec2 (cellulase)/g-glucan of enzyme loading, which was higher than 92% in the two-step fractionation process (SAA and hot-water).

• 유기물자원화
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• 제25권1호
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• pp.57-65
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• 2017

저급탄을 충전한 칼럼실험에서 미생물과 영양물질을 공급한 상태에서 미생물에 의한 메탄가스 발생을 유도하기 위하여 볏짚을 추가로 공급하여 장기간 바이오 가스 발생 특성을 관찰하였다. 충전한 석탄 대비 볏짚의 무게비가 0.04 이하에서는 유의미한 가스의 발생이 없었으며, 0.08에서는 약 90일간 바이오 가스가 발생되었으나, 최적 조건에서의 vial 실험 결과와 비교하면 투입한 볏짚 무게당 바이오 가스의 발생량이 5 % 수준에 불과하였다. 따라서 원위치에서 석탄을 채굴하지 않은 상태에서 바이오 가스를 생산하기 위해서는 볏짚 : 석탄의 비율이 1:3 이상의 조건에서 분해액의 COD 농도가 2000 mg/L 이상이 되도록 운전하는 반응조를 지상 혹은 지중에 설치할 필요가 있다. 또한 석탄과 볏짚을 충전한 칼럼실험 후의 지중수는 볏짚만을 투입한 vial 내 용액과 함께 파이로시퀀싱 방법으로 미생물 군집 분석을 실시하여 두 시료 간의 우점하는 미생물 종을 비교하였다. Bacteria의 균일도와 다양성 측면에서 석탄 충전탑이 보다 다양한 종분포를 이루고 있으며, 이는 결과적으로 메탄 생성에는 불리한 미생물 분포임을 나타낸다.

• Applied Biological Chemistry
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• 제37권2호
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• pp.94-99
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• 1994

일반계(13품종)와 통일계(12품종) 현미의 겨층구조와 수분 흡수 속도를 조사하고 각 특성들간의 유의성을 분석하였다. 일반계 현미의 길이는 통일계보다 유의적으로 짧았으나, 폭과 무게는 유의적인 차이가 없었다. 호분층과 과피의 두께는 일반계와 통일계 모두 등부가 배부보다 두꺼웠으며, 호분층 수는 일반계가 통일계보다 많았으나 배부 또는 등부의 호분층과 과피의 두께는 일반계와 통일계 사이에 유의적인 차이가 없었다. $60^{\circ}C$ 에서의 수분 흡수 속도는 일반계가 폭이 컸으나 통일계와 유의성은 없었으며, 겨층의 구조와는 상관을 보이지 않았다.

• 한국식품조리과학회지
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• 제20권1호
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• pp.49-56
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• 2004

Neuti-dduk is a steamed rice cake made of nonglutious rice How, with Neuti leaves powder, sugar, and water. The objective of study was designed to seek the best recipe to make Neuti-dduk The procedure was as follows Neuti-dduk containing different ratios of the above mentioned ingredients, such as Neuti leaves powder (4, 8, and 12g), sugar and water. The most desirable recipe was determined after sensory examinations and mechanical tests to measure the texture, moisture content and colorimeter. The results of the sensory evaluation showed the Neuti-dduk containing 8g Neuti leaves powder, 20g sugar 20 and 45$m\ell$ water had the highest scores in overall acceptability, color and flavor preference. In the textural analysis the hardness, adhesiveness and cohesiveness of the Neuti-dduk decreased on the addition of increasing amounts of Neuti leaves powder. The moisture content of Neuti-dduk with 4g Neuti leaves powder was higher than that with 12g. The L- and a-values of Neuti-dduk were increased by decreasing the amount of Neuti leaves powder. The overall quality of the sensory examination of Neuti-dduk in relation to the amount of Neuti leaves powder had positive correlation with the moistness, but negative correlations with the L-value andmoisture content. (Eds note: would these 2 highlighted features not be related; if so, why does one have a positive and the other a negative correlation\ulcorner) From the results of these tests, the most desirable recipe for the Neuti-dduk was 8g of Neuti leaves powder, 20g of sugar, 45$m\ell$ of water and2g of salt, for every 200g of rice powder. The moisture content of this recipe was 42.18％.

• 한국식품조리과학회지
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• 제30권3호
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• pp.307-316
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• 2014

This study was carried out in order to investigate the quality characteristics of baguette with different amounts of yeast and fermented rice bran sourdough(Control: Yeast 30 g + Fermented rice bran sourdough 0 g, A sample: Yeast 20 g + Fermented rice bran sourdough 150 g, B sample: Yeast 10 g + Fermented rice bran sourdough 300 g, C sample: Yeast 0 g + Fermented rice bran sourdough 450 g). The pH of fermented rice bran sourdough by fermentation time was decreased as the fermentation time was longer. The pH of baguette dough was decreased as the fermented rice bran sourdough increased; the volume was the highest in control at the 1st fermentation, and in the B sample at the 2nd fermentation. The weight of baguette was the highest in the C sample, and the volume and specific volume were the highest in the B sample. The microstructure of the cross section analysis indicated that the air cell of baguette crumb was large and regular in the B sample. The moisture content and water binding capacity were the highest in the B sample, although significantly different. The L value was decreased as there was an increasing addition ratio of fermented rice bran sourdough; further, the a and b values were decreased with an increase in baguette volume. Hardness, gumminess and chewiness were decreased as volume and specific volume were increased; yet, springiness was increased. According to the result of the sensory evaluation, the flavor, taste, appearance and texture were the highest in the B sample.

• Computers and Concrete
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• 제10권6호
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• pp.631-647
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• 2012

This paper focuses on the application of Fuller's ideal gradation curve to theoretically design blended ratio of all solid materials of high performance concrete (HPC), with the aid of error function, and then to study the effect of rice husk ash (RHA) on the performance of HPC. The residual RHA, generated when burning rice husk pellets at temperatures varying from 600 to $800^{\circ}C$, was collected at steam boilers in Vietnam. The properties of fresh and hardened concrete are reviewed. It is possible to obtain the RHA concrete with comparable or better properties than those of the specimen without RHA with lower cement consumption. High flowing concrete designed by the proposed method was obtained without bleeding or segregation. The application of the proposed method for HPC can save over 50% of the consumption of cement and limit the use of water. Its strength efficiency of cement in HPC is 1.4-1.9 times higher than that of the traditional method. Local standards of durability were satisfied at the age of 91 days both by concrete resistivity and ultrasonic pulse velocity.

• 한국식품영양학회지
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• 제12권4호
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• pp.409-414
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• 1999

In order to investigate the changes of rice qualities during 4 years storage of paddy stored in ware-house of normal temperature condition. Temperature in warehouse was changed more than 3$0^{\circ}C$ under the influence of average temperature outside of a warehouse. Water content of paddy was not increased over 15% But as average temperature in warehouse was gone up 18$^{\circ}C$ from June to September every years it was supposed that these periods were to be deterioration of rice quality. On investigation of change in paddy it was supposed that these periods were to be deterioration of rice quality. On investigation of change in paddy components during the long term storage, reducing, sugar, amylose, crude protein were increased 0.24%, 19.23%, 7.02% at enterance time to 0.5%, 20.31% 7.46% 4 years later respectively. Max viscosity final visocity and set back value by amylograph were increased 449B,U 610B.U, 161B.U to 493B.U, 715B,U 222B.U but breakdown was decreased 125B.U to 76B.U with the increase of storage period. Gel consistency of rice stored was decreased 44.7mm at enterance time to 39,9mm 4years later. Fatty acid was increased remarkably 4.5KOHmg/100g to 24.4KOHmg/100g. Germination ratio and germ activity of paddy during long-term storage were decreased 97%, 100% to 0%, 0.4% respectively, With the increase of storage period contaminated paddy by molds increased and its by bacteria decreas-ed.

• 한국작물학회지
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• 제40권4호
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• pp.473-480
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• 1995

냉수처리답에서 적고현상, 간장, 수장 그리고 수수 등 각 형질에 대하여 내냉성이 강한 품종과 약한 품종을 교배하고, 그 후대에 대하여 각 형질의 유전분석을 실시하였던 바, 그 결과를 요약하면 다음과 같다. 1. 적고현상에 대하여 강한 품종과 약한 품종의 교배조합에서 강한 개체와 약한 개체의 F$_2$의 분리비가 7개 조합 중 4개 조합에서 저항성 쪽이 우성으로 3 : 1의 단성잡종분리비를 나타냈다. 2. F$_1$세대와 F$_2$집단에서 간장과 수장은 긴 쪽이 우성이고, 단축이 적게 되는 쪽으로 초우성 또는 불완전우성을 나타냈고, 수수는 많은 쪽이 우성이고, 냉수처리하에서 수수가 오히려 많아지는 쪽으로 초우성을 나타냈다. 3. 냉수답에서 간장, 수장 및 수수의 유전력은 형질 및 교배조합에 따라 다소 차이는 있으나 대체로 높았으며, 자연답보다는 냉수처리답에서 유전력이 높게 나타났다. 4. 각 형질의 잡종강세정도는 간장에서 매우 높았으며, 수장과 수수에서는 대체로 낮게 나타났다. 특히 인디카 /통일형품종의 교배조합에서, 자연답보다는 냉수처리답에서 잡종강세가 높게 나타났다.

• 한국토양비료학회지
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• 제4권1호
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• pp.1-11
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• 1971

1. 규산시용(珪酸施用)으로 수도(水稻)의 출수(出穗)가 수경(水耕)과 추낙답(秋落畓)에서 공(共)히 약(約) 일주일(一週日)이 빨렀고 수도(水稻)의 엽(葉)은 현저히 직립(直立)되였다. 2. 규산시용(珪酸施用)으로 수도(水稻)의 규산함량(珪酸含量)이 증가(增加)하며 추낙답(秋落畓)에서는 규산(珪酸)을 박비(迫肥)보다 기비(基肥)로 시용(施用)하는 것이 수도(水稻)의 규산함량(珪酸含量)을 증가(增加)시켰다. 규산시용(珪酸施用)으로 다른 양분(養分)의 함량(含量)은 감소(減少)되는 경향(傾向)이며 특(特)히 추락도(秋落稻)의 Fe 함량(含量)은 현저히 감소(減少)되었다. 3. 수도(水稻)의 규산함량(珪酸含量)과 엽도열병(葉稻熱病), 호마엽고병(胡麻葉枯病), 응애 및 멸구의 저항성(抵抗性)과는 부(負)의 상관(相關)이 있다. 4. 수도(水稻)에 대(對)한 규산(珪酸)의 증수효과(增收效果)는 수경(水耕)에서는 거의 없으나 추낙답(秋落畓)에서는 현저하다. 추낙답(秋落畓)에 대(對)한 규산(珪酸)의 증수효과(增收效果)는 pot 재배(栽培)보다 포장(圃場)에서 더 현저하다. 규산시용(珪酸施用)으로 추낙도(秋落稻)의 수당입수(穗當粒數)와 등숙률(登熟率)이 높아지고 규산(珪酸)의 비효(肥效)는 질소(窒素)와 가리(加里)의 균형시비(均衡施肥)로 증가(增加)한다. 5. 따라서 규산(珪酸)은 수도(水稻)에 대(對)한 필수원소(必須元素)라기보다 추낙답(秋落畓)과 같이 가급태규산함량(可給態珪酸含量)이 적은 토양(土壤)에서는 수도(水稻)의 건전생육(健全生育)을 위(爲)하여 농경학적(農耕學的) 의미(意味)에서 규산(珪酸)의 공급(供給)이 필요(必要)하다고 생각(生覺)된다.

• 한국농공학회논문집
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• 제61권3호
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• pp.15-22
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• 2019

In order to preserve water environment, Total Maximum Daily Load(TMDL) is used to manage the total amount of pollutant from various sources, and the annual average load of source is calculated by the unit load method. Determination of the unit load requires reliable data accumulation and analysis based on a reasonable estimation method. In this study, we propose a revised unit load estimation method by analyzing the unit load calculation procedure of National Institute of Environment Research(NIER) method. Both methods were tested using observed runoff ratio and water quality data of rice paddy fields. The estimated values with the respective NIER and revised NIER methods were highly correlated each other. However, the Event Mean Concentration(EMC) and the runoff ratio considered in the NIER method appeared to be influenced by rainfall classes, and the difference in unit load increases as the runoff and EMC increase. The error can be further increased when the EMC and runoff ratio are changed according to changes in rainfall patterns by climate change and change of agricultural activities. Therefore, it is recommended to calculate unit load by applying the revised NIER method reflecting the non point pollution runoff characteristics for different rainfall classes.