• 대한기계학회논문집A
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• 제23권7호
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• pp.1120-1128
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• 1999

An elastic-viscoplastic finite element analysis is performed to investigate detailed growth behavior of creep cracks and the numerical results are compared with experimental results. In Cr-Mo steel stress fields obtained from the crack growth method by mesh translation were compared with both cases that the secondary creep rate is only used as creep material property and the primary creep rate is included. Analytical stress fields, Riedel-Rice(RR) field, Hart-Hui-Riedel(HR) field and Prime(named in here) field, and the results obtained by numerical method were evaluated in details. Time vs. stress at crack tip was showed and crack tip stress fields were plotted. These results were compared with analytical stress fields. There is no difference of stress distribution at remote region between the case of 1st creep rate+2nd creep rate and the case of 2nd creep rate only. In case of slow velocity of crack growth, the effect of 1st creep rate is larger than the one of fast crack growth rate. Stress fields at crack tip region we, in order, Prime field, HR field and RR field from crack tip.

• 한국환경복원기술학회지
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• 제4권4호
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• pp.25-35
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• 2001

This study aims to find out the growth characteristics of riparian plants on the artificial floating islands (AFI). Three types of experiments were performed. The vegetation growth were compared by the plant-supporting materials; natural cotton mat, coir mat on the AFI or in the water, and natural soil at the waterfront. Major findings are; 1. The survival rate of riparian plants was 100% on both coir-mat and cotton-matislands, which implies that we may substitute cheaper cotton for expensive coir-mat. 2. Both natural cotton mat and coir mat were good for the growth of plants. Especially, the natural cotton mat was good for Sparganium stoloniferum and Miscanthus sacchariflorus, and the coir mat was good for Typha latifolia. 3. The growth rate of stem and root showed difference between the stem-removed plants and stem-remaining plants. As a whole, the growth rate of stem-removed plants was bigger than the one of stem-remaining plants. 4. The growth rate of plants showed difference between those grown on the AFI and those grown in the water. The growth rate of plant on the AFI was bigger than the one in the water. 5. The growth rate of plants on the AFI was bigger than the one on the natural soil at the waterfront.

• 미생물학회지
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• 제25권4호
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• pp.353-359
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• 1987

균 성장속도가 tylosin 생합성에 미치는 영향을 조사하기 위하여, 여러 성장속도로 배양한 균체내에서 oxaloacetate 대사에 관여하는 효소들의 활성을 살펴보았다. 그 결과, 비 tylosin 생합성 속도($q_{p}$ )는 성장속도 $0.013h^{-1}$까지는 성장속도와 함께 증가하지만, 더 높은 성장속도에선 감소됨을 알 수 있었다. Citrate synthase, aspartate aminotransferase와 PEP carboxylase의 활성 및 합성은 $0.013h^{-1}$ 보다 낮은 성장속도에선 매우 낮게 나타났으며, 반면 methylmaionyl-CoA carboxyltransferase의 활성 및 합성은 tylosin 생합성과 마찬가지로 높은 성장속도에선 감소되었다. 따라서 tylosin 생합성은 균 성장속도에 의해 조절됨을 명백히 알 수 있었다.

• 현장농수산연구지
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• 제19권1호
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• pp.129-137
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• 2017

This study was conducted to investigate of growth performances and net assimilation rate(NAR) of Allium microdictyon Prokh. distributed inland and Allium ochotense Prokh. originated Ulleung-do. The Allium microdictyon on the growth of 1-2 years showed the largest relative growth rate, and showed high relative growth from three to four years. Allium ochotense on the growth from one year to three years showed high relative growth rate. The T/R rate of Allium ochotense of 2~5years was in the range of 0.4~0.5. However, The T/R rate of Allium microdictyon was increased as increasing with age. This implies that Allium microdictyon was consumed more energy on growing subterranean part. The LWR of 1~3years old Allium ochotense. was showed more smaller than 4~5years old. It seems that the growth characteristics of Allium ochotense 1-3 years after sowing the leaf growth consume more energy than Allium microdictyon. Net assimilation rate(NAR) of Allium ochotense for 1-3 years after sowing was higher than that of Allium microdictyon. In this time, the material of Allium ochotense has a higher production efficiency can be seen indirectly.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.367-369
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• 2001

Recombinant lipase gene (pYEGA ${\alpha}$ -lip) originated from Bacillus stearothermophillus Ll was overexpressed in Saccharomyces cerevisiae. The lipase gene expression level was compared by controlling a constant specifjc growth rates( ${\mu}$ = 0.03, 0.05, 0.07 and $0.1h^{-1}$. Cell g개wth was successfully controlled at the desired rates by feeding rate of glucose and the formation of by-product or accumulation of the glucose was not observed. Above the growth rate of $0.1h^{-1}$. the desired growth rate could not be achieved caused accumulation of by-products(ethanol). The lipase production increased as the specific growth rate decreased. The specific production rate at the lowest specific growth rater(${\mu}$ =0.03) was above 2- folds than the others.

• 열처리공학회지
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• 제16권6호
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• pp.315-319
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• 2003

Effect of nitriding on fatigue crack initiation and growth rate has been studied in Ni-Cr-Mo steel. Specimens were nitrided at $860^{\circ}C$ for 15 hr. The fatigue limit of nitrided specimens were superior to those ofannea1ed($860^{\circ}C$, 15 hr) specimens. Based on detailed observations of slip band and micro crack initiation, it is concluded that the excellent fatigue limit of nitrided specimens is attributed to improved slip initiation resistance by nitriding. The characteristic of fatigue crack growth rate of nitrided specimens was investigated by comparing with those of annealed specimens. It was found that the crack growth rate was markedly decreased and the threshold stress intensity factor range was improved by nitriding. It is concluded that the excellent fatigue limit of nitrided specimens is also attributed to improved fatigue crack growth rate and threshold stress intensity factor range by nitriding.

• 산업기술연구
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• 제23권A호
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• pp.3-7
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• 2003

Effect of nitriding on fatigue crack initiation and growth rate has been studied on SNCM. Specimens were nitrided for 15 hr at $860^{\circ}C$. The fatigue limit of nitrided specimens was superior to that of annealed($860^{\circ}C$, 15 hr) specimens. Based on detailed observations of slip band and micro crack initiation, it is concluded that the excellent fatigue limit of nitrided specimens is attributed to improved slip initiation resistance by nitriding. The characteristic of fatigue crack growth rate of nitrided specimens was investigated and compared with those of annealed specimens. It was found that by nitriding the crack growth rate was markedly decreased and the threshold stress intensity factor range was improved. It is concluded that the excellent fatigue limit of nitrided specimens is also attributed to improved fatigue crack growth rate and threshold stress intensity factor range by nitriding.

• The Journal of Asian Finance, Economics and Business
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• 제8권5호
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• pp.595-605
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• 2021

The objectives of this research are to see if the phenomena of "demand following" and "supply leading" exist in the business cycle, as well as to look at how liquidity and output react to changes in credit risk, investment-saving gap, inflation, exchange rate, and growth rate of real national output. Employing quarterly data of Maluku and North Maluku (2008-2019), this study utilizes VAR/VECM for inferential analysis. This research found three important findings. First, liquidity and output growth influenced each other in the long run. Second, the determinants of output growth for Maluku are liquidity, investment-saving gap, and inflation, while the determinants of liquidity are output-growth, the gap of investment-saving, and inflation. Third, the determinants of output growth for North Maluku are liquidity, credit risk, investment-saving gap, inflation, exchange rate, and the national output-growth, while the determinants of liquidity are output-growth, credit risk, investment-saving gap, inflation, exchange rate, and national output-growth. The findings of this study supported the hypothesis of demand following and supply leading theory in the Maluku and North Maluku business cycles. This study concludes that economic development would improve if supported by liquidity adequacy through increased deposit growth.

• 한국패류학회지
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• 제32권2호
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• pp.103-109
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• 2016

본 연구는 3년산 북방전복의 해상가두리의 먹이공급비율에 따른 성장 및 생존율을 조사하여, 미역과 다시마등의 천연먹이의 적정 공급율을 제안하여 북방전복 성패의 생산성 향상을 유도하고자 실시하였다. 먹이공급율은 실험전복 어체중량을 기준으로 일간공급율 (daily feeding rate, DFR) 5, 10, 15, 20% (5 DFR, 10 DFR, 15 DFR, 20 DFR) 를 설정하여, 해상가두리에서 2반복으로 13개월간 실시하였다. 해상가두리에서 사육한 전복 (최초 수용 시 평균각장 $73.77{\pm}11.27mm$) 성장에서 각장과 각폭의 성장율 (growth rate, GR), 일간성장율 (daily growth rate, DGR) 및 특수생장율 (specific growth rate, SGR) 과 체중의 증중률 (weight gain, WG), 일간증중률 (daily weight gain, DWG) 및 특수증중률 (specific weight gain, SWG), 그리고 생존율에서 5 DFR이 유의적으로 높았다 (P < 0.05). 생존율은 모든 실험구가 유의적 차이가 없었으며, 30%이하로 나타났다. 따라서 3년산 북방전복을 해상가두리에서 사육 시 미역, 다시마 등의 생먹이의 일간 공급율은 어체중량의 5-10%에서 공급되는 것이 성장에 유리하지만, 생존율을 향상 시킬 수 있는 다각적 검토가 필요하다.

• 한국생산제조학회지
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• 제8권1호
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• pp.119-125
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• 1999

The distribution of fatigue crack growth rate is subjected to the measuring interval and calculated method of growth rate. In this paper, in order to establish the method of determining the distribution of fatigue crack growth rate, which ignores those influences, a series of fatigue crack growth experiments and measuring intervals of crack length calculated reasonable are presented. The main conclusions obtained are summarized as follows: 1) As a result of the ΔP constant test and ΔK constant test, it is thought that an approximate measuring interval of 0.3~0.7mm is reasonable, which allows for few errors and is little subjected to the calculated method of crack growth rate. 2) After generally comparing the error estimation by using the experimental data of CCT specimen with the error rating of the CT specimens, it is possible that the fatigue test has few errors within the measuring interval, ξ(Δa/W)=0.0067~0.017, regardless of the dimension of specimen geometry.