• 한국세라믹학회지
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• 제21권1호
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• pp.27-32
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• 1984

During the last decade there have been many studies on the new ceramics especially engineering ceramics. Sintered silicon carbide is one of the main materials in engineering ceramics. This study shows the effects of surface treatment and microstructure especially the abnormal grain growth on the strength of sintered SiC. Surface of sintered SiC and treated with 400, 800 and 1200 grit diamond wheel. Grain growth is introduced by increasing the sintering times at 205$0^{\circ}C$. The $\beta$longrightarrow$\alpha$ transformation occurs during the sintering of $\beta$-starting materials and is often accompanied by abnormal grain growth. The overall strength distribution are estimated using the Weibull statistics. The results show that the strength of sintered SiC is limited by extrinsic surface flaws in normal-sintered specimens. And it is sound that the finer the surface finishing and the grain size the higher the strength results. But the strength of abnormal sintering specimens is limited by the abnormally-grown large tabular grains. The Weibull modulus increases with the decreasing grain size and the decreasing grit size of grinding.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2008년도 International Symposium on Remote Sensing
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• pp.324-327
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• 2008

Microwave remote sensing has great potential, especially in monsoon Asia, since optical observations are often hampered by cloudy conditions. The radar backscattering characteristics of rice crop were investigated with a ground-based automatic scatterometer system. The system was installed inside a shelter in an experimental paddy field at the National Institute of Agricultural Science and Technology (NIAST) before transplanting. The rice cultivar was a kind of Japonica type, called Chuchung. The scatterometer system consists of X-band antennas, HP8720D vector network analyzer, RF cables, and a personal computer that controls frequency, polarization and data storage. This system automatically measures fully-polarimatric backscattering coefficients of rice crop every 10 minutes, accompanied by a digital camera that takes pictures in a fixed position with the same interval. The backscattering coefficients were calculated by applying a radar equation. Plant variables, such as leaf area index (LAI), biomass, plant height and weather conditions were measured periodically throughout the rice growth season. We have performed polarimetric decomposition of paddy data such as single, double and volume scattering to extract the scattering information effectively. We investigated the relationships between backscattering coefficients and the plant variables.

• 영어어문교육
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• 제9권1호
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• pp.205-225
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• 2003

This study attempts to survey the moral growth through prison motif. Malamud deals with the theme of suffering deeply. To learn love accompanied by suffering is the way to be moral and therefore suffering becomes Malamud's main concern. The hardship from suffering and love by trial leads Frank and Yakov to guest of selves. Through this their erotic impulses are changed into caritas. Malamud portrays Frank as a schlemiel. Like Malamud's other heroes he is also born to suffering, conditioned by it, and ultimately finds the meaning of his life in learning to deal with it. At last he carries the burden of supporting Helen and Ida. As a result, Frank becomes a social failure but a moral success as traditional American Adam. The prison motif is a rather strong function of setting symbolism in The Fixer. Yakov is imprisoned for a heinous crime that he did not commit. Yakov experiences hard physical and spiritual pains in prison for two and half years. His bitter suffering has matured him, changed him into a man with love, sacrifice and responsibility for others. At last he returns a true Jew and good man with perfect spirit.

• 한국미생물·생명공학회지
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• 제47권2호
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• pp.173-182
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• 2019

The use of double lumen catheters as a means of hemodialysis access is commonly accompanied with the use of gentamicin as an antibiotic lock. Other antibiotics and anticoagulants are often added to increase the efficacy of gentamicin in order to reduce catheter-related infection and to prevent biofilm formation. This review aimed to evaluate the following: 1) the use of gentamicin in eliminating catheter-related infection and reducing biofilm formation in hemodialysis catheters, 2) the efficacy of additional antibiotics in combination with gentamicin, and 3) the effect of additional anticoagulants to complement the efficacy of gentamicin as the main prophylactic antibiotic lock. We sorted through data from 242 PubMed and ScienceDirect studies, which were then short-listed to 33 studies. Next, they were grouped, extracted, and analyzed qualitatively to fulfil the objectives of this review. Consequently, the use of a gentamicin-lock solution was shown to reduce the incidence of bacteremia; however, it was not strong enough to inhibit the growth of infectious microbes and formation of biofilms. Several bacteria, such as Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, and Klebsiella pneumoniae, have been reported as infectious agents. Combination with other antibiotics also provided no effect in reducing bacterial growth and biofilm formation in catheters. Furthermore, the additional anticoagulants (trisodium citrate and EDTA) were reported to be effective in enhancing the efficacy of gentamicin in avoiding catheter-related infection, bacterial growth, and biofilm formation; thus, the use of gentamicin can be rationalized.

• Molecules and Cells
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• 제27권6호
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• pp.641-649
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• 2009

Pyrophosphate:fructose-6-phosphate 1-phosphotransferase (PFP) catalyzes the reversible interconversion of fructose-6-phosphate and fructose-1,6-bisphosphate, a key step in the regulation of the metabolic flux toward glycolysis or gluconeogenesis. To examine the role of PFP in plant growth, we have generated transgenic Arabidopsis plants that either overexpress or repress Arabidopsis PFP subunit genes. The overexpressing lines displayed increased PFP activity and slightly faster growth relative to wild type plants, although their photosynthetic activities and the levels of metabolites appeared not to have significantly changed. In contrast, the RNAi lines showed significantly retarded growth in parallel with the reduced PFP activity. Analysis of photosynthetic activity revealed that the growth retardation phenotype of the RNAi lines was accompanied by the reduced rates of $CO_2$ assimilation. Microarray analysis of our transgenic plants further revealed that the altered expression of $AtPFP{\beta}$ affects the expression of several genes involved in diverse physiological processes. Our current data thus suggest that PFP is important in carbohydrate metabolism and other cellular processes.

• 한국잡초학회지
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• 제17권2호
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• pp.207-213
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• 1997

단일식물인 수수의 개화에 지베렐린이 관여하는지를 조사하기 위하여 지베렐린 생합성 억제제인 ancymidol을 처리한후 내생 지베렐린의 함량과 개화 및 생육에 미치는 영향을 조사한 결과는 다음과 같다. 1. 지베렐린 생합성 억제제 ancymidol은 공시한 두 품종 모두의 생육을 억제함과 동시에 개화를 지연시켰다. 2. $GA_3$를 Ancymidol과 동시에 처리할 경우 생육억제와 개화지연이 모두 회복되어 지베렐린이 수수의 개화에 관여함을 보였다. 3. Ancymidol 10ppm은 수수의 모든 지베렐린 ($GA_{12}$, $GA_{53}$, $GA_{44}$, $GA_{19}$, $GA_{20}$, $GA_1$ 합성을 현저히 억제하였다.

• 한국결정성장학회지
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• 제8권2호
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• pp.240-248
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• 1998

화학기상증착 방법에 의한 다결정 다이아몬드 박막성장을 위한 공정가운데 가장 많이 사용되는 기법중의 하나가 바로 플라즈마에 의한 방법이다. 특히 플라즈마 화학기상증착(Plasma-Enhanced CVD)기술에 의한 다이아몬드 박막응용은 그 공정에 대한 세부 조정을 통하여 더욱 향상시킬 수 있다. 다이아몬드 박막증착의 경우 중요 변수들은 다이아몬드 필름이 증착되는 기판(substrate)의 온도, $CH_4/H_2$가스비율, 전체가스 압력 및 가스 excitation에너지 등이다. 분광 ellipsometry는 다이아몬드 필름 증착과 관련된 극단적인 환경에서도 물리적인 접촉이나 만들어지는 샘플의 손상없이도 필름자체의 여러 성질뿐만 아니라 기초 샘플의 온도까지도 결정할 수 있는 좋은 방법이다. 이러한 장점들을 이용하여 양질의 다이아몬드 박막을 성장시키기 위한 조건과 그에 따른 박막 특성을 얻기 위하여 분광 ellipsomerry의 사용과 해석이 소개된다. 그리고, 분광 ellipsometry를 이용, 플라즈마 화학기상증착 기술에 의하여 성장되는 다이아몬드 박막으로부터 나타나는 중요 변수들이 결정될 것이며 이러한 변수들은 필름의 두께, 필름에 포함되는 void 및 비다이아몬드의 체적비와, 그들의 시간에 따른 변화등을 포함한다. 그리고 샘플이 원하는 두께까지 성장된 후에 라만 분광기로 측정되어 다이아몬드 성분을 확인한다.

• ALGAE
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• 제31권2호
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• pp.175-187
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• 2016

This study evaluated the effects of γ-aminobutyric acid (GABA)-enriched fermented sea tangle (GFST), as a functional food, on brain derived neurotrophic factor (BDNF)-related muscle growth and lipolysis, in a sarcopenic obesity high-risk group. Twenty-one middle-aged women (53-63 y) participated in this randomized, double-blind, placebo controlled study. Participants ingested either 1,000 mg of GFST (n = 10) or a sucrose placebo (CON) (n = 11) everyday, for 8 weeks. Subjects were asked to abstain from any regular exercise. Fasting venous blood samples, body composition and muscular strength were measured before and after supplementation period. Collectively, we demonstrated that GFST significantly decreased total fat mass and triglyceride in body composition, as well as significantly increasing serum BDNF (p < 0.001), angiotensin converting enzyme (p < 0.001), human growth hormone and insulin-like growth factor-1 levels (p < 0.05 and p < 0.05, respectively) accompanied by increased total lean mass (p < 0.01). Furthermore, the reported improvements in total work, knee extension and flexion at 60° s⁻¹ (p < 0.05), and peak torque normalized to body weight of knee flexion at 60° s⁻¹ (p < 0.05), support an ergogenic effect of GABA associated with increased growth factor levels. The use of GFST, as a functional food ingredient, to elicit anti-obesity effects and stimulate the release of muscle-related growth factors with increasing serum BDNF levels may provide a protective intervention for age-related degeneration such as sarcopenic obesity.

• Asian-Australasian Journal of Animal Sciences
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• 제17권5호
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• pp.655-658
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• 2004

Heat stress is known to affect physiological systems in goats. This study investigated changes in nutrient digestibility, behavior and growth hormone secretion among goats in a hot environment (H; 35${\pm}$ 1.2$^{\circ}C$, [RH] 80${\pm}$7.2%, 13 d), and in a thermoneutral environment (T; 20${\pm}$0.6$^{\circ}C$, [RH] 80${\pm}$3.4%, 20 d), and accompanied by the same restricted diet as provided in the hot environment. The following results were obtained: rectal temperature and water intake were higher in the H treatment than in the T treatment or TR treatment, while hay consumption was lower. CP, NDF and ADF digestibility was highest in H treatment. Time spent eating in the H treatment was also the highest, followed in order by T treatment and TR treatment. Ruminating time was lower in H treatment than in T treatment or TR treatment, and reposing time was highest in the TR treatment. Growth hormone concentrations in T increased 4.5 h after feeding. In H, growth hormone concentrations increased 0.5 h after feeding. However, growth hormone concentrations were not changed following TR feeding. In conclusion, heat exposure in goats decreased feed intake, but increased digestibility. However, when goats in a thermoneutral environment received the same restricted feeding as they received in the hot environment, digestibility increased. Between the H treatment and TR treatment, the changes in digestibility were accomplished by coordinate changes in hormone secretion in order to maintain body homeostasis. To maintain energy balance under a hot temperature or a restricted feeding condition, goats may control their metabolism by changing growth hormone release.

• 한국작물학회지
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• 제47권4호
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• pp.286-291
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• 2002

Seedling establishment of soybean [Glycine max (L.) Merr.] is a critical factor in production system and cultural practices. The objective of this study was to identify the components of soybean seedling developments encompassing planting dates and cultivars that respond to emergence, early growth stage and dry matter accumulation. Three soybean cultivars, Hwangkeumkong, Shinpaldalkong 2, and Pungsannamulkong, were planted at Baegsan silty loam soil. Planting date was May 13, June 3, and June 24 in 2001. Sprinkler irrigation was accompanied with 30mm after seeding for three planting dates. Soybean seedlings were sampled at the growth stages from VE to V5. Days to emergence of soybean seedlings were taken 8 at May 13 and 5 at June 24 plantings. Emergence percentage was over 90 at three planting dates. May 13 planting took 33 days and June 24 planting was 25 days for reaching V5 growth stage. Cotyledon number was decreased after V2. Significant cultivar difference was found in cotyledon dry weight until V2 which differed in seed dry weights at the planting times. Leaf and total dry weights of soybean seedlings were not differed from V1 to V3 among planting dates and cultivars. Leaf water contents were generally ranged 78 to 85%. Branch was appeared from V4. Leaf/stem ratio among cultivars was similar at five growth stages and gradually increased from 2.1 at V1 to 2.8 at V5. The results based on this experiment indicated that seedling establishment of soybean was continued from VE to V3 growth stages affecting mainly by planting date and soil moisture.