• 한국세라믹학회지
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• 제49권6호
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• pp.625-630
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• 2012

Highly porous silicon carbide (SiC) ceramics were fabricated from polysiloxane, SiC and carbon black fillers, AlN-$Y_2O_3$ additives, and poly (ether-co-octene) (PEOc) and expandable microsphere templates. Powder mixtures with a fixed PEOc content (30 wt%) and varying SiC filler contents from 0-21 wt% were compression-molded. During the pyrolysis process, the polysiloxane was converted to SiOC, the PEOc generated a considerable degree of interconnected porosity, and the expandable microspheres generated fine cells. The polysiloxane-derived SiOC and carbon black reacted and synthesized nano-sized SiC with a carbothermal reduction during a heat-treatment. Subsequent sintering of the compacts in a nitrogen atmosphere produced highly porous SiC ceramics with porosities ranging from 78 % to 82 % and a flexura lstrength of up to ~7 MPa.

• 한국세라믹학회지
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• 제49권4호
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• pp.325-327
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• 2012

Europium-doped $LaSi_3N_5$ phosphor was synthesized from LaSi/Si/$Si_3N_4/Eu_2O_3$ mixture by nitridation at $1390^{\circ}C$ and additional annealing at $1650^{\circ}C$ for 4 h. The phosphor shows emissions in the green light region with a maximum at 560 nm. With increasing europium content in the general formula $La_{1-z}Eu_zSi_3N_{5-z}O_{1.5z}$ from z = 0.01 to 0.06 there was a maximum emission for z = 0.04 followed by concentration quenching for the highest europium content (z = 0.06).

• Journal of Ecology and Environment
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• 제42권1호
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• pp.1-11
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• 2018

Background: In the study, the effects of elevated $CO_2$ and temperature on the nitrogen content, carbon content, and C:N ratio of seven rare and endangered species (Quercus gilva, Hibiscus hambo, Paliurus ramosissimus, Cicuta virosa, Bupleurum latissimum, Viola raddeana, and Iris dichotoma) were examined under control (ambient $CO_2$ + ambient temperature) and treatment (elevated $CO_2$ + elevated temperature) for 3 years (May 2008 and June 2011). Results: Elevated $CO_2$ concentration and temperature result in a decline in leaf nitrogen content for three woody species in May 2009 and June 2011, while four herb species showed different responses to each other. The nitrogen content of B. latissimum and I. dichotoma decreased under treatment in either 2009 and 2011. The leaf nitrogen content of C. virosa and V. raddeana was not significantly affected by elevated $CO_2$ and temperature in 2009, but that of C. virosa increased and that V. raddeana decreased under the treatment in 2011. In 2009, it was found that there was no difference in carbon content in the leaves of the six species except for that of P. ramosissimus. On the other hand, while there was no difference in carbon content in the leaves of Q. gilva in the control and treatment in 2011, carbon content in the leaves of the remaining six species increased due to the rise of $CO_2$ concentration and temperature. The C:N ratio in the leaf of C. virosa grown in the treatment was lower in both 2009 and 2011 than that in the control. The C:N ratio in the leaf of V. raddeana decreased by 16.4% from the previous year, but increased by 28.9% in 2011. For the other five species, C:N ratios increased both in 2009 and 2011. In 2009 and 2011, chlorophyll contents in the leaves of Q. gilva and H. hamabo were higher in the treatment than those in the control. In the case of P. ramosissimus, the ratio was higher in the treatment than that in the control in 2009, but in 2011, the result was the opposite. Among four herb species, the chlorophyll contents in the leaves of C. virosa, V. raddeana, and I. dichotoma did not show any difference between gradients in 2009, but decreased due to the rise of $CO_2$ concentration and temperature in 2011. Leaf nitrogen and carbon contents, C:N ratio, and chlorophyll contents in the leaves of seven rare and endangered species of plant were found to be influenced by the rise and duration of $CO_2$ concentration and temperature, species, and interaction among those factors. Conclusions: The findings above seem to show that long-term rise of $CO_2$ concentration, and temperature causes changes in physiological responses of rare and endangered species of plant and the responses may be species-specific. In particular, woody species seem to be more sensitive to the rise of $CO_2$ concentration and temperature than herb species.

• 한국식품조리과학회지
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• 제7권4호
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• pp.71-86
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• 1991

This study was attempted to enhance nutritional value of cooked rice by adding milk in cooking water. Cooked and soaked rice with five different levels of milk in cooking water (0%, A: 30%, B: 50%, C: 70%, D: 100%, E) was tested for rheological parameters, fine structural changes, sensory evaluation. 1. Water absorbance of raw rice in cooking water with varying amountes of milk, was tested at $5^{\circ}C$ and $15^{\circ}C$ for 2 hours. Water absorption ratio was decreased as milk content was increased and soaking temperature was low. Time for maximum water absorption of sample A was 40 min at 1$15^{\circ}C$ but for sample B to D, it was not reached until 120 min. 2. Electronmicroscopic observation revealed that starch granules of rice lost their regular forms by soaking for 90 minutes, but recovered most of initial regularity after 24 hours. Increase in milk content of soaking water decreased marginal sharpness of the starch granule, presumably due to reduced swelling of the granule. 3. Degree of gelatinization of cooked rice was highest in sample A and progressively decreased as milk content was increased. It was, however, increased in all samples when the cooking water to rice ratio was raised from 160% to 180%. During 4 hour storage, rates of retrogradation were not different between A and B samples, but those of C, D and E were about 2.5 times higher than A and B under the optimal condition of 170% cooking water to rice ratio. This was in the order reverse to hardness order of AC>A, D＞E at cooking water to rice ratios of 160% and 170%, above which A sample surpassed the rest of samples. 4. Sensory evaluation conducted by fifteen university students as panelists showed that there were more significant differences among five samples in flavour, texture than appearance and a notable preference for b and C over A, D and E.

• 정보처리학회논문지C
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• 제13C권2호
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• pp.155-160
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• 2006

오늘날 상용화된 DRM(Digital Rights Management) 제품들은 많이 있으나 DRM간 상호 호환성이 없는 상태이다. DRM간 호환성 결여로 인하여 사용자의 불편은 증대되고 디지털 콘텐츠의 유통은 제한된 범위로 제약을 받고 있다. 이러한 문제점을 해결하기 위하여 DRM의 호환성 지원을 위해 DRM 표준화에 대한 요구가 증대되고 있으나 지배적 위치의 DRM 표준이 마련되지 않아 호환성 문제를 해결하지 못하고 있는 상태이다. 이에 본 논문은 MP3 파일의 저작권보호를 위해 사용되는 상이한 DRM 시스템간 상호 호환을 위한 보완재적 DRM 기술로써 DRM 콘텐츠의 반출(EXport) 및 반입(IMport)을 통한 연동 방안(EXIM)을 제안한다. 제안하는 EXIM 방안은 상호 연동이 필요한 두 DRM 시스템이 자신의 구조를 공개하거나 변경하지 않고도 개방형 기술규격을 통해 DRM 콘텐츠를 상호 호환될 수 있도록 한다.

• 한국식품위생안전성학회지
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• 제6권2호
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• pp.83-87
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• 1991

육류중의 Tetracycline계 항상물질의 잔류량을 조사하기 위하여 시판 중인 쇠고기, 돼지고기. 닭고기 3종을 각각 3개시료씩 구입하여 Tetracycline(TC), Oxyteracycline(OTC) , Chlortetracycline(CTC) 의 잔류량을 분석하였으며, 아울러 잔류 항생물질의 조리가열에 의한 분해감소량을 조사한 결과는 다음과 같다. 1. 시판 육류중의 OTC 및 CTC 잔류량: OTC 잔류량은 닭고기의 경우 A 시료에서 흔적정도, B시료에서 불검출 , C시료에서는 0.09mg/kg이 검출되었다. 쇠고기 3개 시료에서는 C 시료에서만 돼지고기 A 및 B에서는 흔적정도로 검출되었다. CTC은 닭고기 A,C시료에서 0.14, 0.02mg/kg으로 각각 검출되었으며, 쇠고기와 돼지고기의 경우에는 쇠고기 B에서만 0.01mg/kg의 잔류량이 확인되었다. 2. TC 잔류량 : 쇠고기와 돼지고기의 Tc 분석에는 육류 자체에서 유래된 성분의 peak와 TC의 peak가 중복되어 잔류량의 판단을 방해하였으나, 닭고기의 경우에는 이러한 방해 성분이 없었으며, 3개중 A 시료에서만 0.01mg/kg의 잔류량이 검출되었다. 3. 가열방법별 항생물질의 분해정도 : 가장 고온가열인 굽기에서, 특히 TC 및 OTC의 분해가 많았다.. 4. 가열시간에 따른 분해정도 : 자불에서는 상당시간이 경과하여도 미량의 분해가 있었으나, 굽기에서는 시간경과에 따라 분해량의 현저한 증가를 보였다. 굽기와 같은 조리 효과를 가진 전자오븐 가열에서는 덜 분해되었다. 가열에 대한 각 항생물질의 내열성은 CTC>OTC>TC 의 순으로 나타났다.

• 콘크리트학회논문집
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• 제12권1호
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• pp.113-125
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• 2000

The purpose of this study was to examine the durability characteristics of controlled low strength material(flowable fill) with high volume fly ash content. Flowable fill refer to self-compacted, cementitious material used primarily as a backfill in lieu of compacted fill. The two primary advantages of flowable fill over traditional methods are its ease of placement and the elimination of settlement. Therefore, in difficult compaction areas or areas where settlement is a concern, flowable fill should be considered. The fly ash used in this study met the requirements of KS L 5405 and ASTM C 618 for Class F material. The mix proportions used for flowable fill are selected to obtain low-strength materials in the 10 to 15kgf/$\textrm{cm}^2$ range. The optimized flowable fill was consisted of 60kg f/$\textrm{m}^3$ cement content, 280kgf/$\textrm{m}^3$ fly ash content, 1400kgf/$\textrm{m}^3$ sand content, and 320kgf/$\textrm{m}^3$ water content. Subsequently, durability tests including permeability, warm water immersion, repeated wetting & drying, freezing & thawing for high volume fly ash-flowable fill are conducted. The results indicated that flowable fill has acceptable durability characteristics.

• 한국식품과학회지
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• 제32권5호
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• pp.1058-1067
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• 2000

In this study, eel, puffer and snake head fish, which are widely taken and highly valued for processing into baked fish, soup or fish juice were studied by classifying them into wild fish and cultured fish, and evaluated in terms of taste. The samples were gathered in the area including Kimhae, Samchonpo and Haman in Kyungsangnam-do, Kangsu-Gu in Pusan and Bukcheju-Gun in Cheju-do. Proximate compositions, the content of nucleotides and their related compounds, total and free amino acids, organic acids and fatty acids of the fishes were analysed. Generally, as for the compositions, wild fish had a higher crude fat content and a lower moisture content as compared with cultured fish, while there was no great difference between them in terms of crude protein and ash contents. Nucleotides and their related compounds including ATP, ADP, AMP, IMP, HxR, Hx were detected, and the amounts of which were nearly the same with respect to the growth conditions. IMP content was high in all of the samples, while ATP content was extremely low. Total 17 amino acids were detected from the samples, and most of the samples had high contents of glutamic acid, aspartic acid, lysine, leucine, glycine, alanine and arginine, and low contents of cystein, isoleucine and methionine. As for the other amino acids, generally same level of contents were detected for each samples. In cases of eel and snake head fish, the wild fish had higher total amino acid contents in comparison with cultured fish. And the result to the contrary was obtained for the case of puffer. Sample fishes had nearly the same compose distribution of free amino acid though the contents of which were a little different according to the samples. Each sample had high contents of taurine, hydroxyproline, glutamic acid, glycine, cystathionine, ${\beta}-aminoisobutyric$ acid and lysine. Total organic acid contents of cultured fish was higher than that of wild fish. All fishes commonly had high contents of lactic acid, iso-valeric acid, oxalic acid and fumaric acid. High levels of $C_{16:0},\;C_{16:1},\;C_{18:1(cis)},\;C_{18:3},\;and\;C_{22:6}$ were shown in all of the samples and ${\omega}-3$ polyunsaturated fatty acid content of cultured fish was higher than that of wild fish, and as for the essential fatty acid, wild fish has higher content in comparison with cultured fish.

• 한국식품영양과학회지
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• 제43권5호
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• pp.741-748
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• 2014

본 연구는 인진쑥의 광범위한 약리작용과 다양한 생리활성을 이용한 식품소재로서의 개발을 위하여 반응표면분석법에 의한 인진쑥 유효성분의 에탄올 추출특성을 모니터링 하여 최적의 추출조건을 예측하였다. 에탄올을 이용한 추출공정에서 중요변수로 추출온도($X_1$; 60, 70, 80, 90 및 $100^{\circ}C$), 추출시간($X_2$; 1, 2, 3, 4 및 5 hr) 및 에탄올 농도($X_3$; 0, 20, 40, 60 및 80%)를 각각 독립변수로 설정하였고 추출물의 품질특성 즉 가용성 고형분 함량($Y_1$), chlorogenic acid($Y_2$) 및 coumaric acid($Y_3$) 등을 종속변수로 하여 반응표면 회귀분석을 실시하였다. 고형분 함량에 대한 예측된 최적조건은 추출온도 $87.65^{\circ}C$, 추출시간 3.19시간, 에탄올 농도 42.40%이었고 chlorogenic acid는 추출온도 $84.30^{\circ}C$, 추출시간 3.14시간, 에탄올 농도 47.85%이었으며 coumaric acid는 추출온도 $83.45^{\circ}C$, 추출시간 3.40시간 및 에탄올 농도 45.39%로 나타났다. 각 변수에 대한 회귀식을 도출하여 인진쑥 추출물의 각 유효성분들에 대한 최적 추출조건을 superimposing 한 결과, 추출온도 $85{\sim}90^{\circ}C$, 추출시간 3~4시간 및 에탄올 농도 40~50%로 예측되었다. 이때 각 성분의 함량은 가용성 고형분 함량 1.09%, chlorogenic acid 25.66 mg%, coumaric acid 20.25 mg%이었다.

• Asian-Australasian Journal of Animal Sciences
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• 제2권3호
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• pp.441-443
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• 1989