• 대한화학회지
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• 제52권1호
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• pp.52-56
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• 2008

제법을 위한 쉽고 효과적인 이 방법은 solvent-free하에서 H3PMo12O40 촉매를 사용해서 개선되었다. 이 방법의 큰 이점은 조작의 간편성, 더 작은 촉매량, 선택성, 온화한 반응조건,짧은 반응 시간 그리고 높은 수율이다. 재생된 촉매는 어떤 정제도 없이 다시 사용되어질 수 있다.

• Bulletin of the Korean Chemical Society
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• 제31권10호
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• pp.2823-2829
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• 2010

We investigated the solvent effects on the relative free energies of binding of $Na^+$ and $Li^+$ ions to 12-crown-4 and ${\Delta}log\;K_s$ (the difference of stability constant of binding) by a Monte Carlo simulation of statistical perturbation theory (SPT) in several solvents. Comparing the relative free energies of binding of $Na^+$ and $Li^+$ ions to 12-crown-4, in $CH_3OH$ of this study with experimental works, there is a good agreement among the studies. We have reported the quantitative free energy polarity (of solvent) relationships (QFPR) of the relationship between the relative free energies and solvent polarity studied on the solvent effects on the relative free energies of binding of $Na^+$ and $Li^+$ ions to 12-crown-4.

• Bulletin of the Korean Chemical Society
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• 제32권12호
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• pp.4167-4170
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• 2011

An inexpensive and efficient catalyst system has been developed for the N-arylation of phenylurea including a variety of aryl halides. This simple protocol uses $Cu_2O$ as the catalyst, microwave assisted, solvent- and ligand-free, $K_3PO_4{\cdot}H_2O$ as the base.

• Bulletin of the Korean Chemical Society
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• 제34권10호
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• pp.2963-2967
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• 2013

This paper describes a simple and efficient method involving domino Knovenegal/$6{\pi}$ electrocyclization for the preparation of a variety of 2H-pyrans using microwave irradiation under solvent- and catalyst-free conditions. This method offers the advantages of a green approach, high yields, and short reaction times. Sixteen compounds (9a-p) were obtained in good to excellent yields using the procedure.

• Bulletin of the Korean Chemical Society
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• 제30권5호
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• pp.1127-1130
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• 2009

The effects of different dihydroxybenzoic acid (DHB) isomers, when used as matrix materials in matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS), were investigated in analyses of polyethylene glycol (PEG) polymers. PEG polymers ranging from 400 to 8,000 Da were prepared in different DHB isomer matrices using solvent-based and solvent-free methods. PEG samples were detected only in matrices of 2,3-DHB, 2,5-DHB, and 2,6-DHB while the most intense peaks were observed using 2,6-DHB in both solvent-free and solvent-based preparations.

• Bulletin of the Korean Chemical Society
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• 제26권9호
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• pp.1331-1332
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• 2005

• Bulletin of the Korean Chemical Society
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• 제23권11호
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• pp.1579-1584
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• 2002

Since surfactant or emulsifiers remained on the nanoparticle surface significantly affect the physicochemical properties, the biodegradation rate, the biodistribution, and the biocompatibility of nanoparticles, surfactant-free nanoparticles should be good candidate. surfactant-free PLGA nanoparticles were successfully prepared by both the dialysis method and the solvent diffusion method. The PLGA nanoparticles prepared using the solvent diffusion method has a smaller particle size than the dialysis method. The solvent diffusion method was better for a higher loading efficiency than the dialysis method but the nanoparticle yield was lower. Testosterone (TST) release from the PLGA nanoparticles was dependent on the particle size rather than the drug contents. Testosterone release from the PLGA nanoparticles prepared by the solvent diffusion method using acetone was faster than those prepared by the dialysis method. TST release from the PLGA nanoparticles prepared by the solvent diffusion method using acetone and the dialysis method using dimethylformamide (DMF) was completed for 4 days while the PLGA nanoparticles prepared by the dialysis method using acetone showed approximately 80% TST release after 4 days. Since the PLGA nanoparticle degradation ratio was below 20% within 5 days at all samples while TST release completed within 4 days, TST release was dependent on the diffusion mechanism rather than degradation.

• 대한화학회지
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• 제54권6호
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• pp.723-726
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• 2010

마이크로 반응을 이용하여 $NaHSO_4/SiO_2$을 촉매로 하는 solvent-free 합성을 통하여 $\beta$-enaminone 과 2-methylquinolin-4(1H)-one 및 그 유도체를 합성하는 효율적인 방법을 개발하였다. 반응 시간이 짧고, 수율이 좋았으며, 마이크로웨이브를 사용하지 않는 반응보다는 높은 선택성, 간단성, 무용매 반응 및 친환경적인 반응이다.

• 한국기계가공학회지
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• 제10권2호
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• pp.67-72
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• 2011

Solvent-free paint is sprayed from higher-pressure conditions, because the viscosity is large. The hydraulic actuator which can be operated under higher-pressure condition is required to spray solvent-free paints in painting process for the environmental protection. The purpose of this paper is to develop the hydraulic actuator under higher-pressure conditions for solvent-free paint spraying system. The hydraulic actuator consists of inner spool, outer spool and ball. The analysis of a structural stability was conducted by using ANSYS V11 under the design condition of upward and downward movement of spool. As a result, the maximum von-Mises stress applied on spool under 4mm displacement showed a value of 106MPa which was greater than the allowable stress of the spool with a value of 250MPa and a value of safety factor 3. This result suggested that the spool system be unstable under the design condition so that it was necessary for the spool system to be reinforced to secure the structural stability.

• Bulletin of the Korean Chemical Society
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• 제32권5호
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• pp.1575-1578
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• 2011

Antimony trichloride (SbCl3) was demonstrated to be an effective catalyst for the cyanosilylation of a wide variety of carbonyl compounds under solvent-free conditions. The reactions proceeded smoothly at room temperature to afford the corresponding cyanosilylethers in good to excellent yields.