• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집A
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• pp.274-279
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• 2001

Creep-fatigue crack growth behavior was experimentally measured particularly when a crack was located in the heat affected region of 1Cr-0.5Mo steel. Load hold times of the tests for trapezoidal fatigue waveshapes were varied among 0, 30, 300 and 3,600 seconds. Time-dependent crack growth rates were characterized by the $C_t$-parameter. It was found that the crack growth rates were the highest when the crack path was located along the fine-grained heat affected zone(FGHAZ). Cracks located in other heat affected regions had a tendency to change the crack path eventually to FGHAZ. Creep-fatigue crack growth law of the studied case is suggested in terms of $(da/dt)_{avg}$ vs. $(C_t)_{avg}$ for residual life assessment.

• Journal of Welding and Joining
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• 제16권4호
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• pp.83-91
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• 1998

Cracking problems which high temperature plant components suffer during long-term service, occur very often at welded locations. The crack occurs due to accumulated creep damage near fusion line or at heat affected zone (HAZ). However, most of the studies on creep crack growth behavior have been performed with matrix metal not wit welded metal due to the difficulty of interpreting the test results. In this study, creep crack growth rates were measured with C(T) specimens whose cracks were formed along the fusion line or HAZ. The measured crack growth rates were characterized by {TEX}$C_{t}${/TEX}-parameter derived for elastic-primary-secondary creeping material. Since contribution of primary creep was significant for the tested 1Cr-0.5Mo steel, its effect was carefully studied. Effects of crack tip plasticity and material aging were also discussed.

• Macromolecular Research
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• 제9권6호
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• pp.319-326
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• 2001

Fatigue crack growth (FCG) behavior of natural rubber/ethylene-propylene-diene rubber (NR/EPDM) blend vulcanizates under dynamic tearing condition was investigated by using a fracture mechanics approach. It appeared that variation of crack growth rate with blend compositions was dependent on the level of imposed tearing energy G. At low tearing energy region, the FCG rates of the blend were lower as the EPDM content was increased, while at high tearing energy region, the trend was reversed. Over the measured range of tearing energy G, all blend compositions showed the lower crack growth rates compared to the average of properties of component elastomers. When the blends were thermally aged, the fatigue resistance of the blends was deteriorated in proportion to the concentration of EPDM phase. Fatigue crack growth behavior of the blends was supposed to be associated with the inhomogeneities of the crosslink structure of the blends arising from cure incompatibility of the EPDM and NR when they are sulphur cured.

• 한국콘텐츠학회논문지
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• 제9권11호
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• pp.247-253
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• 2009

본 연구는 국소온열요법(Local Hyperthermia)에 사용되는 발열체(Thermo-rod)의 온도에 따른 세포성장률의 변화를 관찰하고자 한다. 연구에 사용된 발열체는 듀플렉스 스테인리스 강(Duplex Stainless Steel)을 이용하여 개발되었다. 세포성장률을 관찰하기 위하여 CPAE세포와 Osteoblast세포를 이용하였다. 각각의 세포를 well에 분주 후 3일, 6일, 9일, 12일, 15일 동안 배양만 한 군을 대조군으로 하고 well에 발열체를 식립 후 세포를 분주하여 3일 간격(3일, 6일, 9일, 12일, 15일)으로 하루 30분 유도가열을 실시하여 15일 간 배양한 군을 시험군으로 하였다. CPAE세포와 Osteoblast세포의 성장률을 관찰한 결과 두세포 모두 3일의 대조군과 시험군 모두 세포 성장률이 급격히 상승하다 6일의 대조군과 시험군 모두 급격히 감소하고 9일과 12일 그리고 15일의 대조군과 시험군의 성장률은 불규칙하게 감소하였다. 이러한 성장률 관찰 결과 두종의 세포 모두 약 $41^{\circ}C$의 온도를 가한 시험군과 온도를 가하지 않은 대조군의 차이가 없다. 따라서 CPAE세포와 Osteoblast세포는 발열체에 의한 온도(약 $41^{\circ}C$)에 영향이 없는 것으로 판단된다.

• 한국양식학회지
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• 제17권3호
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• pp.221-227
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• 2004

본 연구에서는 황복, T. obscurus의 초기발달동안 자치어의 성장과 생존에 미치는 먹이 종류와 염분별 영향을 조사하였다. 먹이별 실험에서는 Artemia공급 시기인 부화 25일의 자어를 이용해 Artemia (대조구)와 5가지의 먹이 (실지렁이, 물벼룩, 바지락육질, 배합사료, 곤쟁이)를 30일간 혼합 공급하여 실험구별 성장과 생존율을 비교하였다 염분별 실험에서는 일령 15일 자어(전장 5.8$\pm$0.4 mm: Stage I), 일령 36일 치어(전장 12.0$\pm$0.2 mm: Stage II) 및 일령 70일 치어(전장 44.5$\pm$0.7mm: Stage III)를 대상으로 4개의 염분 농도구(0, 10, 20 및 30 psu)를 설정하여 성장과 생존을 비교분석하였다. 먹이실험 결과, 성장도는 배합사료, 실지렁이, 물벼룩 공급구들이 비교적 양호하게 나타났으나, 생존율은 물벼룩 공급구가 가장 높게 나타났으며, 빠른 성장을 보였던 배합사료와 실지렁이 혼합 공급구는 오히려 낮은 생존율을 나타내었다. 염분별 실험에서는 Stage I 경우 성장에 있어 염분별 뚜렷한 차이를 찾아 볼 수 없었으나, 생존율은 10∼20 psu구에서 높게 나타났다. 또한 Stage II의 경우 성장과 생존 모두 10∼20 psu에서 양호하였으며, Stage III에서는 0∼30 psu의 모든 염분 조건에서 정상적인 성장과 생존을 나타내었다.

• 한국초지조사료학회지
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• 제11권1호
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• pp.6-11
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• 1991

Perennial ryegrass 유식물체의 가을철 생육과 1변초의 개처중 및 수량구성요소와의 관계를 검토하여 월동성을 나타낼 수 있는 형질을 션발하고 품종을 분류하고자 하였다. 1. 1 번초의 척체중은 유식물체의 개체당 경수와 유의힌 정상관을, 초세와는 유의한 부의 상관을 나타내었다. 2. 1번초의 개체중은 출수경중, 개체당경수, 영양경수, 출수경수, 1 경중 및 출수율과 유의한 정상관이 인정되었다. 3 .상대경수출현솔이 낮은 품종은 가을철에 분얼의 발생이 많으며 상대경수출현율이 높은품종은 봄철에 분얼의 발생이 많은 특성을 나다내었다. 4 .상대경수출현율당 개체중은 1번초의 개체중, 초장, 출수정중, 개체당 경수, 출수경수, 1 경중 및 출수율과 유의한 정상관을 나타내었다. 5 .상대경수출현율당 개체중에 의하여 2품종군으로 분류되었다 즉, 상대경수출현율당 개체중이 1.0 이 상의 품종에는 7 개 품종이, 1. 0 미만의 품종에는 9 개품종이 포함되었다. 6 상대경수출현율당 개체중에 의하여 분류된 품 종군에서는 수량구성요소의 차이가 인정되었다.7 .상대경수출현율당 개체중은 월동성을 나타내는 유효한 형질이라고 생각되었다.

• ALGAE
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• 제31권1호
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• pp.17-31
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• 2016

To explore the feeding ecology of the newly described heterotrophic dinoflagellate Aduncodinium glandula in the family Pfiesteriaceae, its feeding behavior and prey species were investigated. Additionally, the growth and ingestion rates of A. glandula on the mixotrophic dinoflagellates Heterocapsa triquetra and Akashiwo sanguinea, its optimal and suboptimal prey, respectively were measured. A. glandula fed on prey through a peduncle after anchoring to the prey using a tow filament. A. glandula ate all algal prey and perch blood cells tested and had the most diverse prey species in the family Pfiesteriaceae. Unlike for other pfiesteriacean species, H. triquetra and A. sanguinea support the positive growth of A. glandula. However, the cryptophytes Rhodomonas salina and Teleaulax sp. and the phototrophic dinoflagellate Amphidinium carterae did not support the positive growth of A. glandula. Thus, A. glandula may have a unique kind of prey and its optimal prey differs from that of the other pfiesteriacean dinoflagellates. With increasing mean prey concentration, the growth rates of A. glandula on H. triquetra and A. sanguinea increased rapidly and then slowed or became saturated. The maximum growth rates when feeding on H. triquetra and A. sanguinea were 1.004 and 0.567 d⁻¹, respectively. Further, the maximum ingestion rates of A. glandula on H. triquetra and A. sanguinea were 0.75 and 1.38 ng C predator⁻¹ d⁻¹, respectively. There is no other pfiesteriacean species having H. triquetra and A. sanguinea as optimal and suboptimal prey. Thus, A. glandula may be abundant during blooms dominated by these species not preferred by the other pfiesteriacean dinoflagellates.

• 한국해양학회지
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• 제29권3호
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• pp.248-257
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• 1994

심해저 망간단괴가 성장할 때 단괴 주변에서 작용하는 지화학적 과정들을 규명하 기 위하여 클라리온-클리퍼톤 균열대의 한국심해연구 (KODOS-89) 지역에서 채취한 망 간 단괴에 대하여 우라늄계열 비평형기법을 적용하여 성장속도가 추정되고 그 지화학 적 의미가 해석되었다. 과잉 230-Th 방사능과 이 값이 232-Th 에 대한 방사능비의 수 직적 분포로부터 추정된 두 망간단괴의 성장 속도는 백만년 당수 밀리미터 정도였다. 퇴적물과 접해 있는 단괴 아래쪽 부분의 성장속도는 해수와 접해있는 윗쪽 부분의 성 장속도보다 2∼3배 빠르다. 단괴의 바닥부분이 빠르게 성장하는 것은 속성작용에 의한 망간의 공급으로 인한 것으로 사료된다.

• 한국수산과학회지
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• 제44권1호
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• pp.58-63
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• 2011

This study investigated the effects of stocking density and feeding frequency (three and five times per week) on the growth of Pacific cod, Gadus macrocephalus. In the first experiment, experimental groups of fish (mean weight $167.8{\pm}41.4\;g$) were reared at three stocking densities (4, 8 and 12 kg/$m^3$) for 16 weeks. The total weight gain was 17.8, 17.1 and 35.4% at 4, 8 and 12 kg/$m^3$, respectively. The specific growth rates, survival rates and feeding efficiency increased with the density, but there were no significant differences (P>0.05). The daily feed intake decreased as the stocking density increased, whereas the condition factors increased with the stocking density (P<0.05). In the second experiment, groups of fish ($194.1{\pm}68.3\;g$) were fed either three or five times a week. The total wight gain was 14.4 and 18.5% for the fish fed three and five times per week, respectively. The specific growth rates of Pacific cod fed to satiation increased with the feeding frequency, although the difference was not significant (P>0.05). The survival rates, daily feed intake, feed efficiency, and condition factors of the Pacific cod were not significantly different (P>0.05). Based on these results, the optimum stocking density for juvenile cod is above 12 kg/$m^3$, and the best feeding frequency is three times a week, under the conditions used in this experiment.

• 유통과학연구
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• 제22권8호
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• pp.17-27
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• 2024

Economic growth is influenced by various factors, including support from the banking world in channeling funds ownedthrough bank credit which will be a stimulus from economic activities as a source of economic growth. Purpose: Thisstudy aims to analyze the determinants of bank lending in supporting regional economic growth in South Sulawesi Province. Research Design, Data, and Methodology: This study uses secondary data taken from banking data and analyzed using path analysis Data analysis is carried out using the help of SPSS statistical analysis tools. Results: Non-Performance Loan, Three Partied Fund, Inflation, Exchange Rate directly affect economic growth. For the analysis of the indirect effect of Non-performance loans and Three Partied Funds have an indirect effect on economic growth through lending while the Loan to deposit Ratio, Inflation and exchange rate do not indirectly affect economic growththrough lending. Credit disbursement has a positive and significant effect on economic growth Conclusion: Economicgrowth of a region is influenced by many factors and these factors are influences from the banking world, the results ofthis study show that economic growth is strongly influenced by bank support through lending to support the economy by considering other factors such as interest rates and currency exchange rates