• Bulletin of the Korean Chemical Society
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• 제32권11호
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• pp.3963-3966
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• 2011

A series of pyranopyrazoles, was efficiently synthesized via one-pot, four component reaction of ethyl acetoacetate, hydrazine hydrate, aldehydes and malononitrile in the presence of catalytic amount silicotungstic acid under solvent free condition. NOE experiments confirmed that the product exist exclusively in the 2H form. The present protocol offers the advantages of clean reaction, short reaction time, high yield, easy purification and economic availability of the catalyst.

• Applied Biological Chemistry
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• 제40권4호
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• pp.267-270
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• 1997

쑥으로부터 Clostridium perfringens의 생육 저해 물질의 추출 조건을 조사하였다. 쑥의 유용성분을 최대한 추출하기 위하여 C. perfringens에 대한 생육 억제 정도를 기준으로 추출용매 농도, 추출온도 및 추출시간을 조사한 결과 100% ethanol, $40^{\circ}C$, 4시간 추출한 것이 C. perfringens의 생육 저해에 효과가 가장 좋았다.

• 한국염색가공학회지
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• 제10권2호
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• pp.18-28
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• 1998

in order to overcome disadvantage of the conventional two bath dyeing method of polyester/cotton blends, it had prompted significant effort to the development of the one bath dyeing method which can accomplish sayings in time, energy and water usage. Also, when dyeing polyester/cotton blends by the one bath dyeing method, the high salt concentrations needed for the reactive dye can cause particles of disperse dye, used for the polyester component, to aggregate. A supplementary problem that can occasionally be happened is the change of hue that occurs on dyed polyester in an alkaline dyebath. To improve dyeing property of polyester/cotton blends, cotton component was pretreated with epichlolohydrine-trimethylamine hydrochloride in aqueous solution of sodium hydroxide to produce a cationized cotton that can be dyed under neutral conditions with reactive dye in a non-electrolytic or il little electrolytic dyebath. The one bath dyeing method of polyester/cationized cotton blends with disperse dye/reactive dye mixture resulted in a satisfactory dyeing property and color yield in comparison with ordinary two bath dyeing method.

• 생약학회지
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• 제2권1호
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• pp.39-40
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• 1971

An alkaloidal component was extracted from the root of Aconitum koreanum R. $R_{AYMOND}$ of the commercial origin. Crude extract was obtained in ca. 2% yield out of dried root with ether-methanol (10:1). White amorphous compound was precipitated out from the HCl solution upon the addition of ammonia water, and crude base was obtained by extraction of its mother liquid with chloroform. This crude base was purified by the alumina-column chromatographic method. A pure alkaloidal component(500mg) was yielded from its crude base. Its pure base comes as needle crystals melting at $250{\sim}252^{\circ}C$ (decomp.), $[\alpha]^{20}_D$ D+9.82 (methanol) and Anal. calcd. for $C_{19}H_{27}O_{8}N$.

• 한국염색가공학회지
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• 제9권5호
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• pp.75-81
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• 1997

o-Aminobenzene sulfone-N-ethylanilide, the diazo component of C.I. Acid Red 57, is currently being diazotised by the use of nitrosylsulphuric acid because of its high molecular weight and weak basicity. However, this method has many problems such as complicated manufacturing process and discharge of large volume of strong acidic effluent. In this study, the possibility of replacing nitrosylsulphuric acid method by direct method, which is simpler and produces less effluent, has been checked and the optimum process condition was studied. The effect of HCl concentration, the amount of sodium nitrite and particle size of diazo component on diazotisation yield was investigated. The optimum pH condition for coupling reaction was also evaluated.

• Food Science and Biotechnology
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• 제18권5호
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• pp.1288-1292
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• 2009

Volatile flavor compounds were isolated from the flowers of Chrysanthemum indicum L. (gamguk) produced in Korea and China by the hydro distillation, and were analyzed by gas chromatography-mass spectrometry (GC/MS). The yield of oils from Korean and Chinese gamguk were 2.0 and 0.5%(v/w), respectively. Sixty-three volatile compounds of Korean gamguk representing 89.28% of the total peak area were tentatively identified, including 35 hydrocarbons, 12 alcohols, 6 ketones, 3 esters, 5 aldehydes, 1 oxide, and 1 miscellaneous component. Thirty-six volatile components of Chinese gamguk constituted 58.15% of the total volatile composition were tentatively characterized, consisting of 19 hydrocarbons, 7 alcohols, 2 ketones, 2 esters, 4 aldehydes, 1 oxide, and 1 miscellaneous component. The predominant components of Korean oil were ${\alpha}$-pinene, 1,8-cineol, and chrysanthenone. Whereas, camphor, ${\alpha}$-curcumene, and ${\beta}$-sesquiphellandrene were the main aroma compounds of Chinese gamguk.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제14권3호
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• pp.162-170
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• 2014

Appearance-based subspace models such as eigenfaces have been widely recognized as one of the most successful approaches to face recognition and tracking. The success of eigenfaces mainly has its origins in the benefits offered by principal component analysis (PCA), the representational power of the underlying generative process for high-dimensional noisy facial image data. The sparse extension of PCA (SPCA) has recently received significant attention in the research community. SPCA functions by imposing sparseness constraints on the eigenvectors, a technique that has been shown to yield more robust solutions in many applications. However, when SPCA is applied to facial images, the time and space complexity of PCA learning becomes a critical issue (e.g., real-time tracking). In this paper, we propose a very fast and scalable greedy forward selection algorithm for SPCA. Unlike a recent semidefinite program-relaxation method that suffers from complex optimization, our approach can process several thousands of data dimensions in reasonable time with little accuracy loss. The effectiveness of our proposed method was demonstrated on real-world face recognition and tracking datasets.

• 한국환경과학회지
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• 제33권5호
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• pp.333-343
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• 2024

This study aimed to investigate whether inhaling the aroma of essential oils could alleviate physiological stress responses and mimic the effects of forest therapy in urban settings. Briefly, 31 participants underwent stress index assessments for two days and inhaled the selected plant essential oils. The effects of this treatment on physiological responses were determined through electroencephalogram (EEG) and heart rate variability (HRV) measurements taken before and after inhaling the aroma of essential oils, extracting results for low frequency (LF) and high frequency (HF) components of HRV, as well as 𝜃 and 𝛼 brainwave activities. The results indicated that lavender oil did not yield significant differences, whereas pine, chamomile, and cypress oils exhibited significant differences in effects. Overall, stress relief was associated with enhanced 𝜃 and 𝛼 brainwave activities, a decrease in the LF component and an increase in the HF component of HRV. Among the essential oils studied, pine oil was the most effective. These findings underscore the potential of plant essential oils in replicating the therapeutic benefits of forest therapy, even in urban environments. Further investigations into their utilization are warranted to better understand and harness their therapeutic potential.

• 한국환경농학회지
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• 제29권1호
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• pp.1-6
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• 2010

Organic farming system in rice paddy is rapidly expanding in Korea. This study was to find out optimum japonica rice cultivars for organic farming. A field research was conducted to evaluate the characteristics of japonica rice cultivars under no-tillage paddy at Doo-ryangmyeon, Sacheon, Gyeongsangnam-do, Korea. The experimental soil was Juggog series (silty clay loam: 56.0% silt, 31.2% clay and 12.8% sand). In experiment, ten lines of Japanese rice cultivars were tested under no-tillage amended with rye (NTR) and no-tillage without cover crop treatment (NTNT). In addition, two Korean japonica rice cultivars as check cultivars were used in this study. The grain yield in NTR was significantly higher in 6.13 Mg $ha^{-1}$ for Kinuhikari, 5.30 Mg $ha^{-1}$ for Komekogane, 5.25 Mg $ha^{-1}$ for Kosihikari, 5.22 Mg $ha^{-1}$ for Mazizbare and 5.12 Mg $ha^{-1}$ for Akitakomachi compared to two Korean rice cultivars (4.57 Mg $ha^{-1}$ for Hwayoungbyeo and 4.00 Mg $ha^{-1}$ for Ilmibyeo) in that order. While, grain yield in NTNT was significantly higher in 4.90 Mg $ha^{-1}$ for Akitakomachi 3.81 Mg $ha^{-1}$ for Hinohikari, 3.74 Mg $ha^{-1}$ for Umezkusi, 3.67 Mg $ha^{-1}$ for Kosihikari and 3.54 Mg $ha^{-1}$ for Dondokuri compared to 3.02 Mg $ha^{-1}$ for Ilmibyeo and 2.36 Mg $ha^{-1}$ for Hwayoungbyeo, respectively. The number of panicle per $m^2$ and grain number per panicle were indispensible for increasing the yield of rice. These results were able to find out optimum japonica rice cultivar Akitakomachi for organic farming in no-tillage paddy.

• Bulletin of the Korean Chemical Society
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• 제31권5호
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• pp.1143-1148
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• 2010

We investigated the separation of nitrogen heterocyclic compound (NHC) contained in a model coal tar fraction comprising four kinds of NHC [indole (In), quinoline (Q), iso-quinoline (iQ), quinaldine (Qu)], three kinds of bicyclic aromatic compound (BAC) [1-methylnaphthalene (1MN), 2-methylnaphthalene (2MN), dimethylnaphthalene (DMN) mixture with ten structural isomers (DMNs; regarded as one component)], biphenyl (Bp) and phenyl ether (Pe) by liquid membrane permeation (LMP). A batch-stirred tank was used as the permeation unit. An aqueous solution of saponin and n-hexane were used as the liquid membrane and the outer oil phase, respectively. Yield and selectivity of individual NHC was much larger than that of BAC, Bp and Pe. Increasing the initial mass fraction of the saponin to the membrane solution ($C_{sap,0}$) and the initial volume fraction of O/W emulsion to total liquid in a stirred tank (${\phi}_{OW,0}$) resulted in deteriorating the yield of individual NHC, but increasing the stirring speed (N) resulted in improving the yield of each NHC. With increasing $C_{sap,0}$, the selectivity of each NHC based on DMNs increased. Increasing ${\phi}_{OW,0}$ and N resulted in decreasing the selectivity of individual NHC based on DMNs. At an experimental condition fixed, the sequence of the yield and selectivity in reference to DMNs for each NHC was Q > Qu = iQ > In. Furthermore, we compared LPM method with methanol extraction method in view of the separation efficiency (yield, selectivity) of NHC.