• 한국초지학회:학술대회논문집
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• 한국초지조사료학회 2001년도 제25회 정기총회 프로그램 제39회 학술발표회 및 특별강연 초록(한국초지학회)
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• pp.94-94
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• 2001

• 한국환경과학회지
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• 제27권12호
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• pp.1169-1178
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• 2018

Two man-made carbon emissions, fossil fuel emissions and land use emissions, have been perturbing naturally occurring global carbon cycle. These emitted carbons will eventually be deposited into the atmosphere, the terrestrial biosphere, the soil, and the ocean. In this study, Simple Global Carbon Model (SGCM) was used to simulate global carbon cycle and to estimate global carbon budget. For the model input, fossil fuel emissions and land use emissions were taken from the literature. Unlike fossil fuel use, land use emissions were highly uncertain. Therefore land use emission inputs were adjusted within an uncertainty range suggested in the literature. Simulated atmospheric $CO_2$ concentrations were well fitted to observations with a standard error of 0.06 ppm. Moreover, simulated carbon budgets in the ocean and terrestrial biosphere were shown to be reasonable compared to the literature values, which have considerable uncertainties. Simulation results show that with increasing fossil fuel emissions, the ratios of carbon partitioning to the atmosphere and the terrestrial biosphere have increased from 42% and 24% in the year 1958 to 50% and 30% in the year 2016 respectively, while that to the ocean has decreased from 34% in the year 1958 to 20% in the year 2016. This finding indicates that if the current emission trend continues, the atmospheric carbon partitioning ratio might be continuously increasing and thereby the atmospheric $CO_2$ concentrations might be increasing much faster. Among the total emissions of 399 gigatons of carbon (GtC) from fossil fuel use and land use during the simulation period (between 1960 and 2016), 189 GtC were reallocated to the atmosphere (47%), 107 GtC to the terrestrial biosphere (27%), and 103GtC to the ocean (26%). The net terrestrial biospheric carbon accumulation (terrestrial biospheric allocations minus land use emissions) showed positive 46 GtC. In other words, the terrestrial biosphere has been accumulating carbon, although land use emission has been depleting carbon in the terrestrial biosphere.

• 대한기계학회논문집A
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• 제39권11호
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• pp.1131-1136
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• 2015

선박 디젤엔진용 실린더 라이너는 피스톤 링과 지속적인 왕복운동을 통해 마모가 발생한다. 마모는 디젤엔진의 성능을 저하시키고, 사용 수명을 단축시킨다. 본 논문은 선박 디젤엔진용 실린더 라이너의 GT 금속 및 기존 금속에 대하여 마모특성을 평가하였다. 마모시험은 상온, $175^{\circ}C$, $325^{\circ}C$의 온도조건과 10 N, 30 N, 50 N 의 하중조건에서 수행되었으며, 마모량, 비마마율 및 마찰계수를 평가하였다. 또한 각 조건에 대한 마모메커니즘을 분석하기 위해서 SEM 분석을 수행하였다. 두 금속 공히, 상온에서 연삭 및 응착마모가 진행되었고, 고온에서 부식마모가 발견되었다. GT 금속은 기존 금속 대비 모든 온도 범위에서 마모량 및 비마모율이 작고 마모특성이 더 우수하다.

• 한국자동차공학회논문집
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• 제21권6호
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• pp.64-71
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• 2013

In this study we designed a lean $NO_x$ trap (LNT) model with $GT-POWER^{TM}$ program and then the LNT model was compared to the bench flow reactor test results. This model consists of 9 kinetic reactions to represent the main steps of NO oxidation, $NO_x$ adsorption, $NO_x$ release and then its reduction. The comparison was performed on the operating conditions at the space velocity of 50,000 1/hr and 80,000 1/hr with the temperature range of $200^{\circ}C{\sim}500^{\circ}C$ with the even spaced temperature step of $50^{\circ}C$. The experimental results show that the $NO_x$ conversion efficiency was enhanced by the temperature up to $350^{\circ}C$ and then decayed at higher temperatures. The LNT model predicts the similar trend of the $NO_x$ conversion efficiency to the experimental results below $350^{\circ}C$, but overestimates above $350^{\circ}C$. This overestimation comes from the higher reduction efficiency which was obtained by the different reduction gas composition such as $C_3H_6$ in the model to replace $CH_4$, $C_2H_4$ in the bench test.

• Toxicological Research
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• 제14권3호
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• pp.365-370
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• 1998

To evaluate the renal toxicity of the antitumor agent, p-{N,N,-Bis(2-chloroethyl)amino}-4-phenyl acetyl-amino-2,6-piperidinedione(CK-15), rats were treated with CK-15 (acute: 50mg/kg. i.p., single and subacute: 5mg/kg, i.p., daily for 7 days). The changes in the body weight, water consumption, kidney weights and urine volume after and during the treatment were observed. The concentrations of urinary creatinine and portein, the activities of N-acetyl-${\beta}$-D-glucosaminidase (NAG), alanine aminopeptidase (AAP), ${\gamma}$-glutamyl transpeptidase (${\gamma}$-GT) and lactate dehydrogenase (LDH) in 24hr urine were also determined. The body weight, water consumption, and urine volume were decreased after the acute and subacute administration. However the weights of kidney were not changed after the treatments. The excretion of creatinine was significantly decreased 1 day after acute administration but, returned to the control value. In subactute administration, the excretion of creatinine was gradually decreased. However, the protein excretion did not changed in both treatment. Those indicate that CK-15 might decrease the metabolic rate of muscle. THe urinary activities of NAG, AAP, ${\gamma}$-GT, and LDH were significantly affected bythe drug treatment. The urinary activities of NAG, AAP and ${\gamma}$-GT were significantly increased 1 day after the acute administration and then returned to the control value. However, the urinary activities of LDH were not changed in acute treatment. In subacute treatment, although the urinary activities of NAG were not changed, those of AAP and ${\gamma}$-GT were significantly increased 2.3 times at 3 days during the subacute administration. Also the urinary activities of LDH were significantly increased at 7 day after the administration. These results indicate that the high and subacute administration might induce a damage in the kidney cells. Furthermore the present results suggest that the toxic effects of CK-15 might be due to the accumulation of the metabolites.

• 한국환경과학회지
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• 제11권9호
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• pp.971-977
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• 2002

The isolated strain, Rhodococcus sp. EL-GT was able to degrade high phenol concentrations up to 10 mM within 24 hours in the medium consisting of 5.3 mM $KH_2PO_4$. 95 mM $Na_2HPO_4$, 18mM $NH_4NO_3$, 1 mM $MgSO_4{\cdot}7H_2O$,\;50{\mu}M CaCl_2$,\;0.5 {\mu}M FeCl_3$, initial pH 8.0, temperature $30^{\circ}C$ in rotary shaker at 200 rpm. This strain was good cell growth and phenol degradation in the alkaline pH range range, and the highest in the pH range of 7 to 9. The microorganism was able to grow at the various chlorinated phenols, benzene, toluene, and bunker-C oil. As Rhodococcus sp. EL-GT was good capable of attachment on the acryl media, it would be used as microorganism to consist of biofilm in wastewater treatment.

• Restorative Dentistry and Endodontics
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• 제29권4호
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• pp.378-385
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• 2004

The purpose of this study was to compare the effects of preparation with GT files and profiles .04 in shaping of root canals and reconstruct the three-dimensional root canal system using micro computed tomography 40 canals of the extracted human mandibular molars were used, and randomly distributed into two experimental groups. In group 1. canals were prepared by GT files. In group 2, Profiles .04. were used. Apical preparation size was #30. For each tooth pre and post operative cross-sectional images were obtained by the micro CT at 50 micron intervals. Pre and post operative cross-sectional images of 1, 2, 3, 5, and 8mm from the apex were compared. For each section. canal area and centering ratio were determined. For each tooth pre- and post-operative root canal volume from the furcation to the apex of the roots was calculated by three-dimensional image software. Following results were obtained: 1. At 8mm from the apex, area of dentin removed by GT rotary file was significantly larger than that by Profile .04. And at the other levels there was not a significant difference. 2. There was a trend for GT rotary file to remain more centered in the canals than Profile .04 at all levels. But at 3mm level. there was a statistically significant difference. 3. In root canal volume increments after instrumentation, there was no significant difference between two groups.

• Restorative Dentistry and Endodontics
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• 제36권4호
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• pp.300-305
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• 2011

연구목적: 본 연구의 목적은 원형의 치근단 삭제를 제공하는 능력에 관한 수 종의 Ni-Ti 회전 기구들을 평가하는 것이다. 연구 재료 및 방법: 실험은 50개의 단근치를 선택하여 백악상아질 경계에서 절단하였고, 근관의 치관부 1/3은 Gates Glidden bur (#2, #3, #4)를 이용하여 확대하였다. 시편들은 각 군당 10개씩 5개의 실험군들로 나누었다. 1군은 GT file, Profile .04, Quantec #9, #10을 사용했고, 2군은 1군과 유사하나 Quantec 파일 대신 Lightspeed를 사용했고, 3군은 Orifice shaper, Profile .06 종류들, Lightspeed를 사용했고, 4군은 3군과 유사하나 Lightspeed 대신 Quantec #9, #10를 사용했고, 5군은 근관 확대를 위해 GT file, Profile .04를 사용했다. 모든 치아 시편들은 치근첨으로부터 1 mm, 3 mm, 5 mm에서 절단하여 현미경하에서 관찰했다. 결과: 본 연구의 결과 실험군 2, 3군(Lightspeed file군)이 실험군 1, 4군(Quantec), 실험군 5군(GT file, profile .04종류들)에 비하여 치근단 1 mm에서 더 원형에 가까운 치근단 삭제를 보였다(p < 0.05). 치근단 3, 5 mm들에서는 각 군들 사이에서 통계학적 유의차가 없었다. 치근단 5 mm 시편들에서는 대부분의 시편들이 완전한 원형을 나타내었으며 불규칙한 모양은 관찰되지 않았다. 결론: 치근단 1 mm 시편에서 Lightspeed를 사용한 경우에서 다른 Quantec, GT와 Profile .04 종류들을 사용한 것보다 더 원형의 삭제를 얻었고, 근관장에서 최초의 Lightspeed에 맞는 크기보다 ISO 크기보다 3단계 크기 확대로는 모든 치근단 1 mm에서 원형의 삭제를 얻었을 수 없었고 단지 35%에서만 원형의 삭제를 얻을 수 있었다는 것이다. 따라서 ISO 크기보다 3단계 크기 확대가 원형 삭제를 얻기에는 불충분하며 좀 더 큰 크기로 확대하는 것이 필요함을 알 수 있으나 치아에 따라 치근단 부위 치질의 양이 다를 수 있으므로 일률적으로 적용하기에는 무리가 있을 수 있다.

• 한국식품과학회지
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• 제41권1호
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• pp.100-105
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• 2009

양념 돈육의 저장성 증진 및 기능성 보강용 돈육 양념소스 소재를 개발하기 위해 산사, 차조기, 현초, 하수오의 생리활성을 검토하였다. Gram positive 5균주와 Gram negative 5균주에 대한 항균활성을 검정한 결과 산사와 현초가 가장 넓은 항균 spectrum을 보였다. 열처리 온도가 높을수록 추출물의 항균 활성은 다소 감소하였으나 열처리 후에도 잔존하였다. 0.1% 산사, 차조기, 현초, 하수오 에탄올 추출물의 총 폴리페놀 함량은 각각 66.24 mg/g, 28.97 mg/g, 96.51 mg/g, 그리고 13.33 mg/g를 나타내어 현초가 가장 높았다. 현초의 DPPH 라디칼 소거능은 0.1, 0.5, 1.0%에서 각각 56.79, 92.24, 97.56%를 보였으며, 산사, 차조기, 현초, 하수오 추출물 중 DPPH 라디칼 소거능은 현초 추출물이 가장 높았으며 산사, 차조기, 하수오 순이었다. 추출물의 아질산염 소거능은 0.1% 농도에서 산사, 차조기, 현초 추출물은 각각 19.66, 1.66, 3.86%를 나타내어 산사가 가장 높았다. 각 추출물의 지방 산패 억제도는 산사 89.99%, 차조기 88.57%, 현초 99.71% 그리고 하수오는 43.21%로 현초가 가장 높았다. 추출물을 $121^{\circ}C$에서 15분 동안 열처리한 후 DPPH 라디칼 소거능은 산사는 감소하였으며, 차조기와 현초는 증가하였다. 산사, 차조기의 아질산염 소거활성은 열 처리 후에 다소 감소하기는 하였으나, 잔존하는 것으로 보였다. 열처리 후 지방 산패 억제도는 산사를 제외한 차조기, 현초에서는 다소 감소하였으나, 열처리 후에도 50${\sim}$99.8% 범위의 높은 활성을 보였다.

• 생물환경조절학회지
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• 제15권3호
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• pp.239-243
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• 2006

폐펄라이트와 폐유리를 가공하여 입상화한 cellular glass foam(CGF)을 각각 입상암면과 피트모스를 혼합한 배지에서 매트저면관수한 $Viola{\times}wittrockiana$ 'Majestic GT Scarlet Shadow'를 재배하여 개화와 생육을 조사하였다. 엽수, 분지수, 지상부 생체중과 건물중, 엽면적과 총엽록소 함량은 폐펄라이트+입상암면+피트모스 (25:50:25, v/v/v) 혼합배지에서 가장 좋았으며, 초장과 최대근장은 CGF+피트모스(25:75, v/v) 혼합배지에서 가장 좋았다. 대조구인 폐펄라이트+피트모스(25:75, v/v) 혼합배지와 비교하여 CGF+피트모스(25:75, v/v)에서의 초장, 엽수, 근장, 총엽록소 함량, 지상부와 지하부의 생체중과 건물중이 더 켰다. 그러나 폐펄라이트+입상암면(25:75, v/v) 혼합배지와 비교하여 CGF+입상암면(25:75, v/v)에서의 생육은 매우 저조하였다.