• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 추계학술대회논문집
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• pp.156-159
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• 2004

Most formulations for a forming limit diagram (FLD) have been based on yield stress potentials defined in the stress field. Nevertheless, there are formulations where potentials defined in the stain-rate field are especially convenient to formulate the rigid plastic material. Based on a strain-rate potential proposed for materials exhibiting planar anisotropic, the formulations for the forming limit diagram has been developed applying M-K theory. As verification example, the formulation is applied for anisotropic AA5182-O sheet. The good verification results show that the formulation for the forming limit diagram has been successfully developed.

• 한국작물학회지
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• 제60권3호
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• pp.355-365
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• 2015

Environment-friendly growth enhancers for rice are being promoted to reverse the negative impact of intensive chemical-based and conventional rice farming on yield sustainability and environmental problems. Several rhizosphere microorganisms and pyroligneous acids (PA) had demonstrated beneficial influence on growth, yield and grain quality of rice. Since most of the previous study had evaluated the effect of PGPR and PA on paddy rice singly, the effect of combined application of these on the growth and yield of paddy rice and on some soil chemical properties were determined. A four factorial pot experiment was conducted to evaluate the effect of PGPR, PA in combination with fertilizers and on different soil types. There were 54 treatment combinations including the control with three replications under complete randomized design. Plant growth parameters were evaluated using standard procedures during tillering and heading stages. Rice yield and some soil chemical properties were determined at harvest. Results showed that inoculation of Bacillus licheniformis and Fusarium fujikuroi enhanced plant growth by increasing the plant height which could be ascribe to its ability to promote IAA and GA production in plants. Inoculation of Rhizobium phaseoli enhanced chlorophyll content indicative to its ability to improve the N nutrition. However, these plant growth benefits during the vegetative stage were override by the fertilizer application effect especially during the maturity stage and grain yield. High fertilization rates on coarse-textured soil without nutrient loss resulted to high available nutrients and consequently high yield. Wood vinegar application however improved nutrient availability in soil which could be beneficial for improving soil quality. Further evaluation is necessary to fully assess the potential benefits that could be derived from inoculation of these organisms and wood vinegar application in different soil environment especially under different field conditions.

• 대한기계학회논문집A
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• 제24권2호
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• pp.472-480
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• 2000

A macroscopic yield criterion for porous solids with pressure-sensitive matrices modeled by Coulomb's yield criterion was obtained by generalizing Gurson's yield criterion with consideration of the hydrostatic yield stresses for a spherical thick-walled shell and by fitting the finite element results of a voided cube. The macroscopic yield criterion is valid for negative mean normal stresses as well as for positive mean normal stresses. From the yield criterion, a plastic potential function for the porous solids was derived either for plastic normality flow or for plastic non-normality flow of pressure- sensitive matrices. In addition, the elastic relation, an evolution equation of the plastic flow stress of the matrices and an evolution equation of the void volume fraction were presented to complete a set of constitutive relations. The set of constitutive relations was implemented into a finite element code ABAQUS to analyze the material behavior of rubber-toughened epoxies. The cavitation and the deformation behavior were analyzed around a crack tip under three-point bending and around notch tips under four-point bending. In the numerical analyses, the cavitation of rubber particles was considered via a stress-controlled nucleation model. The numerical results indicate that a reasonable cavitation zone can be obtained with void nucleation controlled by the macroscopic mean normal stress, and a plastic zone is smaller around a notch tip under compression than under tension. These numerical results agree well with corresponding experimental results on the cavitation and plastic zones.

• 한국환경과학회지
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• 제24권1호
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• pp.17-23
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• 2015

This study was aimed to determine the effect of basal application of Effective Microorganisms (EM) on the grow and yield of cucumber. For treatments, the EM was applied to soil with fertilizer composed with $N-P_2O_5-K_2O$-manure (24.0-16.4-23.8-2,000kg) in the 1.0 strength (defined as EM+1S), 2/3 strength (defined as EM+2/3S), 1/2 strength (defined as EM+1/2S), without fertilizer (defined as EM), or only fertilizer in the 1.0 strength (defined as 1S). In result, there was no significant differences of organic substance content and pH with the EM treatment. While the EC (Electric conductivity) concentration was decreased, plant-available P (phosphorus) was markedly increased. Chlorophyll content was highest in the treatment of EM+standard application rate for both semi-forcing and retarding culture. In contrast, no significant difference was found in plant height and internode length under the fertilizer treatment. Weekly harvested number of cucumber was highest at the treatment of EM+standard application for the semi-forcing culture, while it was 3.6 at the EM+1/2 application for the retarding culture. Weekly yield was greatest at the EM+standard application treatment and decreased with the decrease of fertilizer application rate. In addition, weekly yield was significantly reduced in the treatment of EM. There was no significant difference in yields by production time with the fertilizer applications?. Yield was increased with temperature for the semi-forcing culture, while consistent pattern was maintained for the retarding culture.

• Journal of Microbiology and Biotechnology
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• 제24권2호
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• pp.168-176
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• 2014

The morphology of filamentous fungi closely correlates with the productivity in submerged culture. Using itaconic acid (IA) production by Aspergillus terreus as a research model, the quantitative relationship between the growth form of A. terreus and IA production was investigated. IA fermentation was scaled up from shake flasks to a 7 L stirred tank bioreactor based on the quantitative relationship. Our results demonstrated the following: (1) Three morphologies of A. terreus were formed by changing the inoculum level and shape of the flask. (2) Investigation of the effects of the three morphologies on broth rheology and IA production revealed the higher yield of IA on dry cell weight (DCW, IA/DCW) and yield of glucose on DCW (consumed glucose/DCW) were achieved during clump growth of A. terreus. (3) By varying the $KH_2PO_4$ concentration and culture temperature, the relationships between clump diameter and IA production were established, demonstrating that the yield of IA on DCW ($R^2$ = 0.9809) and yield of glucose on DCW ($R^2$ = 0.9421) were closely correlated with clump diameter. The optimum clump diameter range for higher IA production was 0.40-0.50 mm. (4) When the clump diameter was controlled at 0.45 mm by manipulating the mechanical stress in a 7 L fermentor, the yield of IA on DCW and yield of glucose on DCW were increased by 25.1% and 16.3%, respectively. The results presented in this study provide a potential approach for further enhancement of metabolite production by filamentous fungi.

• 한국응용곤충학회지
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• 제22권1호
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• pp.7-14
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• 1983

2년간에 걸쳐 조사한 대두의 수량감소는 갈색무늬병을 접종한 경우 농약 살포구에 비해 $15.7-16.4\%$ 감소 차였으며 자연감염의 경우에는 $8.2-9.2\%$의 감소를 나타냈다. 갈색무늬병의 감염은 초장, 주당절수(株當節數), 주당분지수(分枝數)에는 큰 영향이 없었으나 주당협수(狹數)와 종실중(種實重)에는 현저한 감소 현상을 보였다. 대두의 수량감소율을 갈색무늬병의 이병율과 정(正)의 상관을 보였으며 그 상관도는 Van der Plank's infection rate (0.156) 보다는 병 진전국선면적(AUBC) 과의 상관도가 높았다$(r=0.388^*)$. 병진전곡선 면적으로 표시된 갈색무늬병의 감염율과 대두수량 감소율과의 관계는 y=4.38+0.5X $(r=0.686^{**},\;df=25)$으로 나타났다.

• 한국토양비료학회지
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• 제19권1호
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• pp.14-20
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• 1986

무우, 배추, 고추 등(等)의 채소작물(作物)에 대(對)한 관수효과(灌水效果)를 구명(究明)하기 위(爲)하여 1979년(年)부터 1983년(年)까지 본량(本良) 사양토(砂壤土)에서 무관수(無灌水), 관수점(灌水點) -3.0bar, -1.0bar, -0.5bar, -0.2bar로 하였을때 토양수분(土壤水分)의 변화양상(變化樣相)과 이에따른 작물(作物)의 양(養) 수분(水分) 흡수(吸收), 증발산량(蒸發散量)과 물이용효율(利用效率) 및 생육양상(生育樣相)과 수량(收量) 등(等)을 조사(調査)한 결과(結果)는 다음과 같다. 1. 무관수시(無灌水時) 동일(同一)한 기상조건하(氣象條件下)에서 배추, 무우, 고추의 순(順)으로 한발(旱魃)을 받는 정도(程度)가 심(甚)하였다. 2. 토양수분함량(土壤水分含量)이 많을수록 봄채소에 있어 토양온도(土壤溫度)의 지나친 상승을 억제시켜 주었다. 3. 관수(灌水)에 의(依)해 토양수분(土壤水分)potential이 높을수록 엽수분함량(葉水分含量) 및 무기양분(無機養分)의 흡수량(吸收量)이 증가(增加)하였다. 4. 토양수분(土壤水分)potential이 높을수록 물소모량(消耗量)은 증가(增加)하였으며, 물소모량(消耗量)이 어느 정도(程度)까지 증가(增加)할수록 물이용효율(利用效率)도 증가(增加)하였으나 그 이상(以上)에서는 감소(減少)하는 경향이었다. 5. 토양수분(土壤水分)potential이 20~30cm 깊이에서 -1.7bar 이하(以下)로 유지될 때 봄배추의 생장량(生長量) 증가(增加)는 거의 없었다. 6. 작물별(作物別) 최대수량(最犬收量)을 나타낸 관수점(灌水點)은 배추 -0.2bar, 무우 -0.5bar, 고추 -0.2~0.5bar 이었으며, 관수(灌水)에 의(依)한 증수효과(增收效果)는 봄배추에서 가장 컸었다. 7. 적정관수(適正灌水) (-0.2~-0.5bar)에 의(依)해 증수(增收)는 물론 품질향상(品質向上)의 효과(效果)가 컸었다.

• Asian-Australasian Journal of Animal Sciences
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• 제21권7호
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• pp.995-1002
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• 2008

Kura clover (Trifolium ambiguum M. Bieb.) is a rhizomatous perennial legume that has potential as a forage crop in the North-Central USA because of its excellent persistence under environmental extremes. Little information is available about defoliation effects on productivity of mixtures of kura clover with grasses typically grown in this region. Two field trials were conducted to evaluate the effects of defoliation management on yield and species composition of binary mixtures of 'Rhizo' kura clover with 'Comet' orchardgrass (Dactylis glomerata L.), 'Badger' smooth bromegrass (Bromus inermis Leyss.), 'Park' Kentucky bluegrass (Poa pratensis L.), and solo-seeded kura clover near Arlington, WI. Three harvest schedules (three, four, or five times annually) and two cutting heights (4 or 10 cm) were imposed. Infrequent defoliation and lower cutting height produced significantly greater total forage yield, 6.6, 5.8, and 5.2 Mg/ha in 3-, 4-, and 5-harvest systems, respectively; and 6.5 and 5.2 Mg/ha for the 4- and 10-cm cutting height, respectively. Averaged over 3 yr and two environments, mixtures had higher forage productions than solo kura clover (6.3, 5.7, and 6.0 Mg/ha for the Kentucky bluegrass, orchardgrass, and smooth bromegrass mixtures, respectively; compared to 5.2 Mg/ha for solo kura clover). The proportion of kura clover in mixtures increased from yr 1 to yr 2 and was constant from yr 2 to yr 3 (34, 58, and 57%, respectively). We conclude that kura clover has excellent potential as a long-term component of grass-legume mixtures regardless of the cutting height, harvest frequency or grass species, even though the proportion of kura clover in harvested forage was significantly greater with less frequent harvest and shorter cutting height of all mixtures.

• Natural Product Sciences
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• 제23권2호
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• pp.75-83
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• 2017

The optimization and microwave assisted extraction of stem bark of Terminalia arjuna, quantitative estimation of the marker compounds arjunic acid and arjunolic acid using HPTLC and the evaluation of free radical scavenging activity has been performed in this study. The central composite design was used for optimization and the values of parameters for optimized batch of microwave assisted extraction were 1000 W (Power), 3 minutes (Time) and 1/120 (Solid/solvent ratio). The solvent system to carry out the HPTLC was toluene: acetic acid: ethyl acetate (5: 5: 0.5) and quantitative estimation was done using standard equations obtained from the marker compounds. The in-vitro free radical scavenging activity was performed spectrophotometrically using ascorbic acid as standard. The value of estimated percentage yield of arjunic acid and arjunolic acid was 1.42% and 1.52% which upon experimentation was obtained as 1.38% and 1.51% respectively. The DPPH assay of the different batches of microwave assisted extraction and marker compounds taken suggested that the marker compounds arjunic acid and the arjunolic acid were responsible for the free radical scavenging activity as the batch having the maximum percentage yield of the marker compounds showed best free radical scavenging effect as compared to standard ascorbic acid. The $IC_{50}$ value of the optimized batch was found to be 24.72 while that of the standard ascorbic acid was 29.83. Hence, the yield of arjunic acid and arjunolic acid has direct correlation with the free radical scavenging activity of stem bark extract of Terminalia arjuna and have potential to serve as active lead compounds for free radical scavenging activity.

• 생물환경조절학회지
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• 제11권3호
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• pp.133-138
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• 2002

본 실험은 가지과 작물의 염 스트레스에 대한 생장 특성 및 생리적 반응을 구명하기 위하여 수행되었다. 생육단계에 따라 NaCl을 농도별로 처리한 결과는 다음과 같았다. 초장, 생체중 등 생육은 유묘기 및 영양 생장기 모두 NaCl 농도가 높을수록 모든 작물에서 억제되었다 특히 토마토 및 가지에서는 NaCl 40mM 이상에서, 그리고 고추에서는 20mM 이상에서 작물의 생육이 크게 억제되었다. 수량은 토마토 및 가지에 서는 NaCl 20 mM 이상에서, 그리고 고추에서는 10 mM 이상에서 감소하였다. 이러한 수량감소는 낮은 농도에서는 착과수의 감소에, 그리고 농도가 높을수록 착과수의 감소와 더불어 평균과중의 감소의 영향이 컸다. 광합성 속도는 NaCl 농도가 높을수록 감소하는 경향이었으며. 고추가 가장 낮았고, 토마토, 가지 순으로 낮았다. 잎의 수분포텐셜과 기공 전도도도 광합성과 같은 경향을 나타냈다. 경엽의 무기 양분 함량에서는 질소, 인산, 칼슘, 마그네슘 및 칼륨 함량은 NaCl 농도가 증가할수록 감소하였으나 Na 및 Cl 함량은 증가하였다.