• Journal of Biosystems Engineering
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• 제15권2호
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• pp.99-109
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• 1990

Rough rice is subjected to a series of static and dynamic forces during mechanical harvesting, handling and processing operations. The mechanical properties such as bioyield point, compressive strength, and deformations at the bioyield point and rupture point are important engineering data needed to develop processing machines and to determine reasonable operating conditions for these machines. The objectives of this study were to determine the mechanical properties of the rough rice kernel at loading rate of 0.664 mm/min and 1.673 mm/min and at various moisture contents, and to examine the effect of the moisture content and the loading rate on these mechanical properties. The follwing results were obtained from the study. 1. Bioyield point, rupture point, bioyield strength and ultimate strength of the rough rice kernel generally decreased in magnitude with an increase in moisture content. A little larger values of these mechanical properties were obtained at the higher loading rate. The rough rice variety and the loading rate affected significantly these mechanical properties at low moisture content, but not at the higher moisture levels. 2. Bioyield point of the sample grains varied from 20 to 80 N, and rupture point varied from 45 to 130N. Bioyield point for Japonica-type rough rice was a little higher than that for Indica-type rough rice, but there were little differnces in rupture point between two types of rough rice. 3. Bioyield strength and ultimate strength of the Japonica-type rough rice varied from 10 MPa. to 39 MPa., and from 13 MPa. to 45 MPa. respectively. Those of the Indica-type rough rice varied from 12 MPa. to 42 MPa., and from 15 MPa. to 53 MPa. respectively. 4. Deformations at bioyield point and rupture point ranged from 0.18 mm/min to 0.26 mm, and from 0.28 mm to 0.53 mm respectively. These deformations decreased with an increase in moisture content up to moisture content of approximately 17% (w.b.) and increased again thereafter. 5. Regression equations were developed to predict these mechanical properties for the rough rice kernel as a function of moisture content.

• Corrosion Science and Technology
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• 제6권1호
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• pp.12-17
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• 2007

Portland cement incorporating supplementary cementing material develops excellent mechanical properties and long term durability characteristics. India is a leading rice producing country and rice husk is considered as waste in the rice milling industries. In this present work, the rice husk ash (RHA) was added to concrete as cement replacement from 0 to 30%. Corrosion performance of reinforcing steel embedded in RHA blended concretes was studied using linear polarization, AC impedance and gravimetric methods. The corrosion rate of steel bars embedded in RHA concretes were compared with control concrete. The results clearly indicate that the corrosion rate of reinforcing steel embedded in concrete is significantly reduced with the incorporation of RHA. A good correlation among gravimetric method and electrochemical methods was observed. Electrochemical impedance study showed 98 percentage reduction in corrosion rate to the RHA blended concrete with 15% replacement than control concrete.

• 한국작물학회지
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• 제44권3호
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• pp.288-295
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• 1999

Nineteen japonica and Tongil-type rices were selected from seventy nine Korean and Japanese rice cultivars grown in 1989 based on the water uptake behavior of milled rice under the room temperature and boiling conditions. The selected rice cultivars were investigated for water absorbability and some physicochemical characteristics of milled rice, proper water amount for cooking and sensory evaluation of cooked rice. The relationships among the tested grain properties were also examined. The highest varietal variation of water uptake rate was observed at twenty minutes after soaking in water. The maximum water uptake of milled rices at room temperature occurred mostly at about eighty minutes after soaking in water. Newly harvested rices showed a significantly lower water uptake rate of milled rice at 20 minutes after soaking, a relatively higher maximum water absorption ratio under the room temperature, and the less water uptake and volume expansion of boiled rice compared with the one-year old rice samples. The water uptake rate and the maximum water absorption ratio showed significantly negative correlations with the K/Mg ratio and alkali digestion value(ADV) of milled rice. The rice materials showing the higher amount of hot water absorption exhibited the larger volume expansion of cooked rice. The harder rices with lower moisture content revealed the higher rate of water uptake at twenty minutes after soaking and the higher ratio of maximum water uptake under the room temperature condition. These water uptake characteristics were not associated with the protein and amylose contents of milled rice ansd the palatability of cooked rice. The water/rice ratio(in w/w basis) for optimum cooking was averaged to 1.52 in dry milled rices (12% wet basis) with varietal range from 1.45 to 1.61 and the expansion ratio of milled rice after proper boiling was averaged to 2.63(in v/v basis). The water amount needed for optimum cooking was the lowest in Cheongcheongbyeo (Tongil-type rice) and the highest in Jinbubyeo, and the amount could be estimated with about 70% fittness by the multiple regression formula based on some water uptake characteristics, ADV and amylose content of milled rice as the independent variables. Nineteen rice cultivars were classified into seven groups based on scatter diagram projected by principal component analysis using eight properties related to water uptake and gelatinization of milled rice.

• Natural Product Sciences
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• 제20권1호
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• pp.29-32
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• 2014

In the present study, we examined the chemoprotective effects of different rice bran, which are produced by fermentation or not, on doxorubicin induced rat model, and detected the change of components of rice bran. Rats receiving fermented rice bran of 100 mg/kg by oral plus doxorubicin 10 mg/kg had greater weight gain as +24% than that observed with doxorubicin alone. In case of the treatment of non-fermented rice bran of 100 mg/kg by oral with doxorubicin of 10 mg/kg, fermented rice bran showed a -1.3% decrease in body weight. 100 mg/kg fermented rice bran decreased the incidence to 30%, and non-fermented rice bran decreased the incidence to 50%. In lethality, the rate of death of doxorubicin was 60%. 100 mg/kg fermented rice bran decreased to 10% in death rate and non-fermented rice bran to 30%. In gross gastrointestinal pathology, doxorubicin showed the gross gastrointestinal mucosal pathology in 70% of treated rats, fermented rice bran decreased to 40% and non-fermented rice bran to 50%. In the change of constituent, xylose concentration of fermented rice bran was detected to 59.33 mg/g while its concentration of non-fermented rice bran was 11.12 mg/g.

• 한국작물학회지
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• 제44권2호
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• pp.102-105
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• 1999

Mineralization of organic N is an important factor in determining the appropriate rate of organic matter application to paddy fields. A kinetic analysis was conducted for nitrogen mineralization of rice, barley, Chinese milk Ovetch (Astragalus sinicus L.; MV) and narrow leaf vetch straw in paddy soil. Nitrogen immobilization occurred rapidly and its rate increased in straw with high C/N ratio. The amount of nitrogen mineralization was rapid in the first year of rice-vetch cropping system. The rate constant (K) depended on the C/N ratio of organic matter. Mineralization of straw increased at high temperature. The amount of available N increment resulted in fast mineralization of straw, especially in rice and barley straw. Chinese milk vetch had the greatest mineralization rate at all temperatures and fertilization levels followed by narrow-leaf vetch. However, rice and barley straws with high C/N ratio immobilized the soil N at the initial incubation duration. Chinese milk vetch or narrow leaf vetch was not effectively mineralized in mixed treatments with rice or barley straw. The mineralization rate of organic matter was mostly affected by the C/N ratio of straw and temperature of incubation. Organic matter with low C/N ratio should be recommended to avoid the immobilization of soil N and the increasing mineralization rate of straw.

• 한국작물학회지
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• 제42권5호
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• pp.522-527
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• 1997

담수직파와 건답직파의 절충형 직파양식인 벼 요철골 담수직파방법에서 적정 파종량을 구명하고자 영남농업시험장 영덕출장소에서 1994년과 1995년 2년가 파종량 3, 4, 5, 6, 7kg/10a으로 실시한 시험결과를 요약하면 다음과 같다. 1. $m^2$당 입모수는 97~161개로 파종량이 증가할수록 입모수가 많았으나 파종량 3kg /10a에서도 요철골 담수직파재배시 안전 입모수 확보는 가능하였다. 2. 도복관연형질중 분얼결당 생중, 간벽두께 중심고비율 등은 파종량간에 큰 차이가 없었다. 파종량이 많을수록 좌절중이 떨어져 도복지수가 컸고, 포장도복은 파종량 5kg /10a이상에서 1~3정도 발생하였다. 3. 출수기는 10a당 파종량 5~7kg이 3~4kg보다 1일이 빨랐다. 4. 수량 구성요소는 파종량이 증가할수록 수수는 많았으나 등숙비율은 떨어졌고 수당 입수 및 천립중은 파종량간에 뚜렷한 차이가 없었다. 5. 건물중은 파종량 증가에 따라 증가했으나 수확지수는 떨어졌고, 2개년 평균 쌀 수량은 518~552kg /10a당 파종량 5kg /10a에서 가장 높았다. 6. 2차 회귀곡선식으로 추정한 최고수량을 나타낸 파종량은 4.3~4.8kg /10a이었고 이때 $m^2$당 입모수는 126~135개였다.

• Journal of Plant Biotechnology
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• 제33권2호
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• pp.133-137
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• 2006

Evaluation of physiological performance of trehalose-producing transgenic rice line was conducted to investigate drought tolerance at early growth stage. Under artificially induced drought condition of 8% polyethylene glycol 6000, this transgenic rice line had leaf photosynthetic rate of 11.08 uml CO$_2$ $m^{-2}s^{-1}$, leaf transpiration rate of 8.38 mmol $H_2O$ $m^{-2}s^{-1}$ and leaf water potential of -1.12 MPa after 96 hours of treatment. Nakdongbyeo, the parent of this tyansgenic rice line, had photosynthetic rate of 15.42 $\mu$mol CO$_2$ $m^{-2}s^{-1}$, leaf transpiration rate of 8,04 mmol $H_2O$ $m^{-2}s^{-1}$ and leaf water potential of -0.88 MPa. The other variety used in this experiment for comparison, IR 72, showed higher values than both tyansgenic rice line and variety Nakdonbyeo on all three parameters; leaf photosynthetic rate of 20.61 $\mu$mol CO$_2$ $m^{-2}s^{-1}$, leaf transpiration rate of 12.88 mmol $H_2O$ $m^{-2}s^{-1}$, and leaf water potential of -0.82 MPa. So this transgenic rice line did not show superior performance in leaf transpiration rate, leaf photosynthetic rate and leaf water potential compared to variety Nakdongbyeo. This result along with visual observation on leaf rolling and drying during the experimental period indicated poor physiological performance of this transgenic rice line. Further studies on metabolic status of stress-induced trehalose, along with study on physiological response of this transgenic rice line during drought stress would shed more light on overall physiological performance of this transgenic rice line.

• Journal of Biosystems Engineering
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• 제37권3호
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• pp.184-191
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• 2012

Purpose: This study was conducted to investigate the storage and quality characteristics of brown rice under the low temperature warehouse conditions using ambient cold air in the winter. Methods: This new technique maintains rough rice warehouse temperature below $15^{\circ}C$ without cooling operation until the end of May. Four hundred tons of rough rice were stored in the low temperature grain warehouse, and were aerated from the top to the bottom using ambient cold air in February. The quality of rough rice was evaluated from February through October. Results: The results were as followings. Moisture contents of rough rice in the low temperature storage had decreased less than the ordinary temperature storage. Cracked rate of brown rice in the ordinary temperature storage and low temperature storage increased by 4~10.8% and 1.6~7.2%, respectively. The germination rate of rough rice under the ordinary and the low temperature warehouse decreased by 15.0~25.0% and 1.7~8.0%, respectively. The acid value of brown rice under the ordinary and the low temperature warehouse increased by 3.67~6.72 KOH mg/100g and 3.08~4.08 KOH mg/100g, respectively. Conclusions: The result indicates that low temperature storage using ambient winter air showed better maintaining germination of rice, less change of physiological activities and cracked kernel, and better maintaining of rice quality, comparing the ordinary temperature storage.

• 동아시아식생활학회지
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• 제16권1호
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• pp.99-106
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• 2006

New application of rice was carried out by coating the rice with the mixture solution of ginseng and chungkukjang water extract The physicochemical characteristics of the coated rice were investigated. Moisture content of uncoated (15.26%) and coated rice$(15.57\sim15.66%)$ was not different significantly. The contents of crude protein, crude fat, and crude ash of the coated rice were higher as much as $4.28\sim11.82%\;8.47\sim47.46%$, and $11.54\sim42.31%$ than those of control, respectively. As total free amino acids in coated rice were increased by augmenting the amount of the extract, total free amino acids according to rate was increased to $3.1\sim7.8$ times. The major amino acids in the coated rice was alanine$(19.56\sim39.88\;mg%)$, leucine$(5.14\sim17.66\;mg%)$, and proline$(9.98\sim16.82\;mg%)$. Of those amino acids, alanine and $\gamma-aminobutyric$ acid in only coated rice were detected to the level of $19.56\sim39.88\;mg%$ and $7.78\sim12.36\;mg%$ respectively. The calcium amount of coated rice was increased to 15% to 20%. As increasing the coating rate, hardness, cohesiveness, chewiness, and brittleness of coated rice were decreased, but springiness was increased. Before cooking, the color of coated rice appeared yellow and after cooking turned to the light yellow. The color intensity was increased feasibly as increasing the coating rate. The sensory characteristic of rice coated manufactured by adding 15% of the extract was best and found to be similar to that of the control.

• 한국작물학회지
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• 제18권
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• pp.1-27
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• 1975

실험 I. 질소의 시비량을 달리 하였을 때 출수기에 있어 실비의 효과 및 전엽처리에 따른출수후의 각엽위별 엽신이 등숙 및 수량에 미치는 영향을 알고저 포장시험을 한바 그 결과는 다음과 같다. 1. 질소시비에 따른 1주평균 수수 및 1수당 경화수는 질소의 시비량이 많을수록 증대되었으나 등숙율, 제현비율 및 현미천립중은 질소시비량이 많을수록 저하되었다. 2. 출수기 실비시비에 따른 등숙률 및 현미천립중은 표준구보다 질소시비량이 많을수록 증대되었으며 정조중은 통계적인 유의차는 인정할 수 없으나 수치적으로 증대되었다. 3 전엽처리에 따른 등숙율, 정조중, 현미천립중 및 제현비율은 전엽의 정도가 클수록 현저히 저하되었다. 4. 엽위별 존치엽수의 조합에 따른 등숙율, 정조중현미천립중 및 제현비율은 엽신 1매를 존치하였을 때는 $L_1(지엽)>L_2>L_3>L_4$순으로 저하되었으며, 엽신 2매를 존치하였을 때는 상위엽과 조합될수록 증대되었다. 그리고 엽신 3매를 존치하였을 때도 같은 경향을 보였다. 5. 전엽처리에 따라 엽위별 엽신수가 감소될 경우에는 존치엽면적이 넓고 엽신건물중과 엽신질소함량이 증대될 때에 등숙률, 정조중, 현미천립중 및 제현비율이 증대되었다. 6. 시비량의 증대는 존치엽수와 관계없이 등숙률 및 현미천립중을 저하시켰으나, 실비의 시용은 이와는 반대의 결과를 보였다. 정조수량은 기비 및 추비량의 증대에 따라 증대되는 경향을 보였으며 실비의 효과는 존치엽수가 적을 경우에는 많을 경우보다 저하되었다. 7. 엽신이 차지하는 등숙률 및 현미수량에 대한 생산효과는 50% 이상이었으며 천립중은 10%에 불과하였다. 질소의 시비량의 증가에 따라 등숙율 및 천립중에 대한 엽신의 영향은 증대되었다. 기비량의 증가에 따라 현미중에 대한 엽신의 영향은 증대되었으나 수전기의 추비량이 증가될수록 그 영향은 저하되었다. 8. 엽위별 엽신이 등숙율, 현미중 및 천립중에 미치는 생육효과는 $L_1(지엽)>L_2>L_3>L_4$순이었으며 질소의 시비량이 많을수록 $L_1$과 $L_2$의 생산효과가 증대되는 경향을 보였다. 시험 II. 질소의 시비시기를 달리 하였을 때 전엽처리에 따른 출수후 엽위별 엽신이 등숙 및 수량에 미치는 영향을 알고저 포장시험을 한바 그 결과는 다음과 같다. 1. 1주당 평균 수수는 기비로부터 출수전 22일까지 시비된구와 분시된구에 있어서 증대되었으며 경화수는 출수전 36일부터 15일까지 시비된구가 증대되었다. 등숙율은 기비구로부터 출수전 15일까지는 무비구보다 저하되었으며 출수전 8일 이후에 시비된 구는 증대되었다. 가장 저하된 구는 출수전 29일구였다. 정조수량은 출수전 29일부터 22일 시비구가 가장 증대되었다. 현미천립중은 출수전 22일부터 8일까지의 시비된구가 다소 높았다. 2. 전엽처리에 따른 등숙율, 정조중, 현미천립중 및 정현비율은 전엽의 정도가 클수록 모두 현저히 저하되었으며 처리간에 고도의 유의차를 보였다. 3. 엽위별 존치엽수와 그의 조합에 따른 등숙율 정조중, 현미천립중 및 제현비율은 엽신 1매가 존치되었을 때는 $L_1(지엽)>L_2>L_3>L_4$순으로서 상위엽이 존치될수록 증대되었다. 엽신 2매시는 상위엽과 조합되었을 때 등숙율, 정조중 및 제현비율이 증대되었으며 현미천립중의 증대에는 지엽이 가장 크게 작용한 것 같았다. 엽신 3매를 존치하였을 때도 상위엽과 조합된 것일수록 증대되었다. 4. 전엽처리에 따라 엽위별 엽신수가 감소될 경우 엽면적 엽신건물중 및 엽신질소함량과 등숙율 및 정조중간에는 정의 상관을 보였으나 현미천립중간에는 시비시기에 따라 일정한 경향을 보이지 않았다. 5. 시비시기가 출수기에 가까울수록 전엽에 의한 등숙율 및 천립중은 저하되었으며 존치엽수가 적어질수록 그 경향은 증대되었다. 출수기 이후의 추비는 존치엽수의 증대에 따라 등숙율 및 천립중을 증대시키며 존치엽수가 적을 경우에는 출수기에 가까운 시기에 시비가 정조수량을 증대시켰다. 6. 시비시기에 따른 각기관별 생산효과는 등숙율에 있어서는 시비시기가 늦어질수록 엽신의 생산효과가 크며 무비구에 있어서는 엽신과 간의 생산효과가 동일하였다. 현미수량에 대한 생산효과는 시비시기에 구애됨이 없이 간의 생산효과는 50%이상을 찾 하였으며 무비구에 있어서는 그 경향이 더욱 증대되었다. 현미천립중은 간에 의하여 지배되며 엽신의 영향은 근소하였다. 7. 엽위별 엽신이 등숙율, 정조중 및 현미천립중에 미치는 생산효과는 시비시기가 늦어짐에 따라 상위엽일수록 생산효과가 증대되는 경향을 보였다. 전생육기간을 통하여 분시된구는 등숙율 및 정조수량에 있어서는 지엽과 2위엽이 거의 같은 정도였으나 현미천립중에 있어서는 지엽이 전엽의 생산량의 60%이상을 차지하였다.