• 자원환경지질
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• 제37권4호
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• pp.383-389
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• 2004

지표 및 심토환경에서 물과 용액의 유동특성을 파악하는 것은 토양 및 지하수의 오염을 저감하고 방지하거나 기 오염 지역을 조사하고 정화하는데 있어서 필수적인 요소이다. 본 연구에서는 이 비형광, 비독성의 식용색소인 청색1호(Brilliant Blue FCF, $C_{37}H_{34}N_{2}Na_{2}O_{9}S_{3}$)를 염료 추적자로 이용하여 화강암에서 발달된 잔적토양에서의 침투 유형 및 그 특성을 조사하였다. 디지털 촬영된 수직 및 수평 착색영상은 지형정보 영상처리 프로그램인 ER Mapper, Version6.2를 이용하여 염료착색범위(dye coverage)로 전환되었다. 균질기반유동(homogeneous matrix flow)은 미약 입상 구조를 보이는 A 층위에서 발생하였으며, 상대적으로 세립조직인 A층위와 조립조직인 C층위의 경계에서는 선침투류(先浸透流, fingering)의 특징을 보여주었다. 모암인 화강암 조직의 기원인 거정질 광맥(pegmatitic vein)과 식물 뿌리는 C 층위에서 선택적 유동(preferential flow)을 유도하였음을 확인하였다.

• 한국가축번식학회지
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• 제26권4호
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• pp.329-338
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• 2002

This study was carried out to investigate the developmental rates of embryo reconstructed with different cell type and to estimate correlation of transcriptional level of octamer-binding transcription factor 4 (Oct4) and fibroblast growth factor 4 (FCF4) gene on peri-implantation stage embryos. Donor cells were transferred into perivitelline space of enucleated oocytes. The karyoplast-cytoplast couplets were accom- plished by cell to cell fusion and activated with ionomycin and 6-dimethylaminopurine. Reconstructed embryos were co-cultured with bovine oviduct epithelial cells in CR 1 aa medium. There is no difference in blastocyst formation rate following nuclear transfer UT) with fetal fibroblast cell (16/50; 32.0%), cumulus cell (16/49; 32.6%) and ear cell (17/52; 32.6%). The expression level of Oct4 and FCF4 in peri-implantation bovine embryo derived from in vitro fertilization (IVF) and NT were determined by reverse-transcription polymerase chain reaction (RT-PCR) technique. In peri-implantation of IVF result in a transient increased of FCF4 paralleled by an increased expression of Oct4. However, Oct4 gene was highly expressed in hatching blastocysts derived from NT compared to IVF. Also, FGF4 expression level in hatching blastocysts and outgrowth stage derived from NT was lower than that of IVF. In conclusion, it is suggested that the different transcription patterns observed in nuclear transfer embryos may lead to a lower rate of embryo development, implantation and pregnancy.

• ETRI Journal
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• 제38권4호
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• pp.634-644
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• 2016

Channel-based radio-frequency fingerprinting such as a channel impulse response (CIR), channel transfer function (CTF), and frequency coherence function (FCF) have been recently proposed to improve the accuracy at the physical layer; however, their empirical performance, advantages, and limitations have not been well reported. This paper provides a comprehensive empirical performance evaluation of RF location fingerprinting, focusing on a comparison of received-signal strength, CIR-, CTF-, and FCF-based fingerprinting using the weighted k-nearest neighbor pattern recognition technique. Frequency domain channel measurements in the IEEE 802.11 band taken on a university campus were used to evaluate the accuracy of the fingerprinting types and their robustness to human-induced motion perturbations of the channel. The localization performance was analyzed, and the results are described using the spatial and temporal radio propagation characteristics. In particular, we introduce the coherence region to explain the spatial properties and investigate the impact of the Doppler spread in time-varying channels on the time coherence of RF fingerprint structures.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2000년도 The 7th International Symposium
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• pp.96-113
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• 2000

Coleus forskohlii Briq. of the family Lamiaceae yields a valuable secondary metabolite known as forskolin which is a labdane diterpenoid. Coleus forskohlii is the only known source of this compound. Forskolin is used in medicine for the treatment of glaucoma, congestive cardiomyopathy and asthma. Morphogenic callus was induced from young leaves on MS medium augmented with NAA and BA. These calli, when subcultured on MS with KN alone gave rise to shoots. The regenerated shoot developed good root system on MS medium fortified with NAA. The fully grown plantlets were transferred to soil for acclimatization. Coleus plant is mainly infected by a fungi Lasiodiplodia theobromae which causes root of disease. The fungal culture filterate (FCF) of Lasiodiplodia theobromae, has been used in regeneration media to find the MIC and further to select resistant plants to the pathogen. In the present study 40% FCF in the medium showed maximum inhibition and is there fore considered as the MIC level of Coleus forskohlii. This data could prove to be useful for the future for selecting a resistant C,forskohlii plant against the root disease caused by L.theobromae.

• 약학회지
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• 제33권5호
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• pp.308-311
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• 1989

Binding parameters of some edible dyes with bovine serum albumin were determined at pH 7.4 buffer solution. The edible dyes used were fast green, brilliant blue FCF, indigo carmine and allura red AC, and the final concentrations of each dyes were $3{\sim}9{\times}10^{-6}M$, $6{\times}10^{-6}M$, $3{\times}10^{-5}M$ and $3{\times}10^{-5}M$, respectively. The final concentrations of bovine serum albumin were $1{\sim}7{\times}10^{-5}M$. The values of binding free energy between edible dye and protein were ranged from -6,024 to -6,800 cal/mole.

• The Journal of Asian Finance, Economics and Business
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• 제8권8호
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• pp.137-148
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• 2021

The study investigates the existence of an optimal level of cash and the firm characteristics influencing the decision to hold cash, and the adjusting speed of the cash holdings to the target level. It highlights the heterogeneity of cash adjustment speed in the Vietnam market. The research employs the 417 samples of Vietnamese non - financial listed firms in the period of 2010 to 2019. The study uses the Pool OLS model, Fixed effect model (FEM), Random effect model (REM), and GMM model. According to the research findings, there is an optimal amount of cash at which the firm's value is maximized in Vietnamese listed firms, and the majority of the firms in the sample retain cash over the target level. Furthermore, the study demonstrates that firms actively modify their cash holdings to the optimal level with an adjustment speed of less than one owing to adjustment cost constraints. This speed varies between groupings of enterprises with different characteristics, underlining the heterogeneity of the adjustment speed even more. Small deviation firms adjust more rapidly than large deviation firms. Large free cash flow (FCF) firms adjust more readily than small FCF firms, and fiscal deficit firms modify more rapidly than firms with a financial surplus.

• Geomechanics and Engineering
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• 제34권2호
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• pp.125-138
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• 2023

To improve the understanding of infiltration characteristic of modified slurry and the support efficiency of filter cake in silty sand strata, the slurry infiltration (SI) and filter cake formation (FCF) were investigated in a laboratory apparatus. The water discharge and the excess pore pressure at different depths of silty sand strata were measured during SI. The relationship between permeability coefficient/thickness ratio of filter cake (k_c/ΔL) and effective slurry pressure conversion rate of filter cake (η) were analyzed. Moreover, the SI and FCF process as well as the modification mechanism of CMC (carboxymethyl cellulose) were clarified. The experimental results indicate the formation of only external filter cake in the silty sand strata. The slurry particles obtain thicker water membrane after being modified by CMC, which blocks partial water path in filter cake and decreases the water discharge significantly. The silty sand excavated from tunnel face also contributes to the water discharge reduction. The k_c of the external filter cake ranges from 3.83×10^-8 cm/s to 7.44×10^-8 cm/s. The η of the external filter cake is over 96%, which decreases with increasing k_c/ΔL. A silty sand content within 10% is suggested during construction to ensure the uniformity of the filter cake.

• Asian-Australasian Journal of Animal Sciences
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• 제22권10호
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• pp.1366-1376
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• 2009

Effect of sulfur (S) on utilization efficiency of fresh cassava foliage and cassava hay in dairy cows was evaluated using thirty-two $1^{st}-2^{nd}$ lactation Holstein-Friesian crossbred dairy cows. The experimental treatment was a 2${\times}$2 factorial arrangement in a randomized complete block design (RCBD) using two roughages (rice straw+fresh cassava foliage (FCF) and rice straw+cassava hay (CH)) and two elemental sulfur (S) levels (0.15 and 0.4% S of dry matter (DM)), respectively. Four dietary treatments (FCF+0.15, FCF+0.4, CH+0.15 and CH+0.4) were offered ad libitum in the form of a total mixed ration (TMR) with concentrate to roughage (chopped rice straw+chopped cassava foliage) ratio at 60:40. Fresh cassava foliage or cassava hay resulted in similar dry mater intake, rumen ecology parameters, total tract digestibility, blood chemistry, milk production and composition. However, HCN intake, blood and milk thiocyanate concentration were significantly higher (p<0.01) in cows fed fresh cassava foliage with no sign of potential toxicity. Dry matter intake, body weight changes, molar percentage of propionate in rumen, neutral detergent fiber (NDF) digestibility and nitrogen (N) retention of cows tended to be increased while DM digestibility (65.6, 72.7, 68.6 and 72.1% of total DM intake for the respective treatments), rumen bacteria population (1.4, 1.7, 1.6 and $1.7{\times}10^{11}$ cell/ml for respective treatments), fungal zoospore population (0.4, 0.6, 0.4 and $0.5{\times}10^{6}$ cell/ml for respective treatments), urinary allantoin (25.3, 28.0, 26.3 and 27.6 g/d for respective treatments), microbial N yield (136.0, 154.6, 142.8 and 151.3 g N/d for respective treatments) and milk protein content (3.4, 3.5, 3.2 and 3.5% for respective treatments) were significantly (p<0.05) higher in cows fed on supplemented sulfur at 0.4% of DM in comparison with 0.15% S-supplemented diets. Based on these results, it is concluded that cassava foliage could be used as a portion of roughage for dairy cows and supplementation of S would be nutritionally beneficial.

• 한국식품위생안전성학회지
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• 제26권1호
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• pp.57-63
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• 2011

다양한 식품첨가물의 사용과 소비가 증가하고 있으며, 최근 어린이기호식품을 통한 타르색소 등 첨가물의 섭취량이 늘어가고 있다. 본 연구는 시중 유통중인 학교 주변 어린이기호식품을 대상으로 식용색소 황색 제 4호(Y4), 황색 제5호(Y5), 청색 제1호(B1), 청색 제2호(B2), 적색 제2호(R2), 적색 제3호(R3), 적색 제40호(R40), 적색 제102호(R102), 녹색 제3호(03)등 국내 허용된 타르색소 9종에 대한 실태조사를 실시하고 모니터링 분석을 통하여 노출량, 위해성 평가를 수행하였다. 그 결과, 어린이기호식품 82종(과자류 3종, 캔디류 71종, 초콜릿 4종, 음료류 4종)을 통한 타르색소의 섭취수준이 매우 낮고 상위섭취군(95th percentile)에서도 일일섭취허용량(ADI)의 0~3.56%에 불과하였다. 결론적으로 어린이기호식품 섭취에 따른 어린이의 타르색소에 대한 위해성 수준은 매우 낮은 것으로 판단되며, 타르색소 9종 각각의 일일추정섭취량(EDI)이 평균적으로 FAO/WHO에서 권장하는 양보다 낮아 안전한 수준으로 평가되었다. 그러나 어린이기호식품에 사용되는 식품첨가물은 보편적으로 몇 가지 첨가물이 복합적으로 사용되고 있어 어린이의 식품첨가물 섭취에 대한 지속적인 모니터링과 그에 따른 적절한 관리가 필요할 것이다.

• 분석과학
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• 제13권3호
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• pp.378-384
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• 2000

8종 합성착색료의 동시정성 정량법을 확립하기 위하여 고속액체크로마토그래프(HPLC)를 이용한 분석법에 관한 연구를 수행하였다. 식품에 첨가된 타르색소는 물 또는 에탄올의 혼합액으로 추출하여 진한염산으로 0.5% 염산농도가 되도록 조정하여 시료액으로 하였다. 이를 Sep-pak $C_{18}$으로 정제한 후 HPLC를 이용하여 254nm 및 각 색소별 최대흡수파장에서 정성 정량분석을 실시하였다. 식품별 회수율은 각각 청량음료 81.2-98.0%, 사탕 80.6-96.1%, 껌 79.8-96.3%, 과자 76.5-91.7%, 아이스크림 79.9-93.8%, 젤리 78.6-94.7% 이었다. 색소별 검출한계는 식용색소 청색제1호(B1) 청색제2호(B2), 녹색제3호(G3)는 $0.05{\mu}g/g$, 식용색소 황색제4호(Y4), 황색제5호(Y5), 적색제2호(R2), 적색제3호(R3), 적색제40호(R40)는 $0.10{\mu}g/g$이었다.