• 한국인쇄학회지
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• 제30권1호
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• pp.35-45
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• 2012

Polyacrylate dispersion(emulsion) as adhesive material was superior in quality such as preservation characteristics and reversibility. The tapes for repairing archival documents manufactured with four different types of formulation resulted in pH 7~8.8, soluble solid 50~52%, and viscosity 1,300~2,500 cps. Sample 4 of those was most excellent. Probably, sample 4 included inorganic materials such as MgO, silica gel, and zeolite. For selecting carrier of tape, tracing papers, were applied for manufacturing tapes and tested for adhesive strength and peel strength. Adhesive strength of tracing papers, was 3.1~3.8(N/10mm), 2.2~2.8(N/10mm), and 1.7-2.3(N/10mm), respectively. Peel strength was similar in all samples. To determine characteristic of conservation to the selected carriers, stability of deterioration was examined at conditions of $105^{\circ}C$ and $80^{\circ}C$ 65% for 7 days.

• 대한화학회지
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• 제52권2호
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• pp.155-163
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• 2008

유기-실리카 이용한 잔유 구리(II)의 양을 빠른 추출을 위한 간단하고 재현성을 가지는 방법과 불꽃원자 흡수분광법으로의 검출에 대해 연구하였다. 공통으로 존재하는 이온은 분리와 검출에 간섭받지 않았다. 예비농축인자는 100 ml시료 용량에 대해 100 (1 ml 추출용량) 이 였다.제안된 방법의 검출한계는 1.0 ng ml-1이다. 최적조건하에서 흡착제의 최고흡수용량은 5 mg 구리/g 흡착제 였다. 최적조건하에서 상대표준편차는 2.8% (n=10)을 얻었다. 다양한 양의 구리(II)이온은 스파이크한 자연수와 합성수를 시험 시료로 하여 정확도 등을 시험하였다.

• Applied Biological Chemistry
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• 제33권4호
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• pp.315-318
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• 1990

분쇄되지 않은 미량의 원제를 수화제로 제제하는데는 미분상 다공성 증량제의 물리성을 이용한 흡착법이 유호하다. 밀리그램 단위의 농약 원제를 휘발성 유기용매에 용해시킨 후 계면활성제 혼합물이 흡착되어 있는 미분상의 합성실리카에 흡수시키고 건조하여 11종의 10% 수화제를 제제하였다. 원료 상태의 합성실리카와 시료수화제의 입도분포를 측정하여 평균 입경의 변화를 관찰하였다. 이들 수화제중 pencycuron과 vinclozolin을 제외한 9종의 시료는 2시간후에도 80%이상의 현수율을 나타냈다. 제제중 유효성분량을 $30{\sim}50%$로 증가시켜도 4종의 시료중 3종에서 현수율의 변화가 거의 없었다. 또한 이들 수화제 시료는 현수성과 거의 무관하게 생리활성이 기존제품과 대등하게 나타나서 수화제로서 그 기능이 우수한 것으로 인정되었다.

• 한국식품위생안전성학회지
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• 제8권1호
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• pp.17-23
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• 1993

In an attempt to quantitate and qualitate residual antibiotics and antibacterial agents n meat simultaneously, we studied a gas chromatogrphy-mass spectrometry (GC/MS) analysis. For a simultaneous analysis of macrolide antibiotics such as erythromycin and tylosin in meat, the homogenization with MeOH, defatting with n-hexane, extraction with CHCl3, elution with CHCl3 : MeOH=2:1 from Sep-Pak silica cartridge, acid gydrolysis, back extraction with CHCl3, and quantitation by selected ion monitoring(SIM) mode after trimethylsilyl derivatization were performed. The recoveries of erythromycin and tylosin (CV,%) at 10 ppm fortification level were 90.59(4.89) and 45.91(0.20) , and the detection limits of those were 0.02 and 2.0 $\mu\textrm{g}$/g beef, respectively. From these results, the developed analytical method using GC/MS-SIM mode allows excellent detection and quantitation of residual macrolide antibiotics in meats, using complementary method with bio-assay.

• Bulletin of the Korean Chemical Society
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• 제28권12호
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• pp.2359-2362
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• 2007

MALDI-TOF-MS technique was applied to obtain structural and compositional information of synthetic polyamides, Nylon6 and Nylon66. Mass spectra of both the original and the hydrolyzed polyamide samples were analyzed using the self calibration method as well as the internal calibration method with the standard materials of known masses. The MALDI-TOF mass spectra of Nylon6 samples showed the presence of protonated, sodiated, and potassiated ions that were assigned to cyclic and NH2/COOH terminated linear oligomers. From the MALDI-TOF mass spectra of Nylon66 samples, the potassiated linear oligomers with three different end groups are identified as well as the cyclic oligomers, i.e., NH2/COOH terminated oligomers, NH2/NH2 terminated oligomers, and COOH/COOH terminated oligomers. Full characterization of the molecular species and end groups present in the polyamide samples has been achieved, and also the changes in mass spectral patterns after the hydrolysis of the samples are presented.

• 상하수도학회지
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• 제30권3호
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• pp.343-350
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• 2016

Membrane distillation (MD) is a novel separation process that have drawn attention as an affordable alternative to conventional desalination processes. However, membrane fouling and pore wetting are issues to be addressed prior to widespread application of MD. In this study, the influence of ultrasonic irradiation on fouling and wetting of MD membranes was investigated for better understanding of the MD process. Experiments were carried out using a direct contact membrane distillation apparatus Colloidal silica was used as a model foulants in a synthetic seawater (35,000 mg/L NaCl solution). A vibrator was directed attached to membrane module to generate ultrasonic waves from 25 kHz (the highest energy) to 75 kHz (the lowest energy). Flux and TDS for the distillate water were continuously monitored. Results suggested that ultrasonic irradiation is effective to retard flux decline due to fouling only in the early stage of the MD operation. Moreover, wetting occurred by a long-term application of ultrasonic rradiation at 75 kHz. These results suggest that the conditions for ultrasonic irradiation should be carefully optimized to maximize fouling control and minimize pore wetting.

• 공업화학
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• 제4권2호
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• pp.240-253
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• 1993

실리콘알콕사이드는 실리카섬유와 박막재료 및 각종 세라믹스의 합성원료로써 필수적인 물질이 되었으며, 최근에는 16MD램 이상의 초고도 전자제품의 VLSI용 박막 원료로 각광을 받게 되면서 그 중요성이 더한층 강조되고 있다. 따라서 본 본문에서는 실리콘알콕사이드의 각종 합성방법과 반응기구 및 응용분야 등을 요약 정리하고, 실리콘알콕사이드 합성에 관한 본 연구팀의 연구결과 및 문제점을 간략하게 소개하였다.

• 한국동물위생학회지
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• 제28권3호
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• pp.285-294
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• 2005

This study was conducted to investigate the extraction method for the determination of organochlorine, organophosphorus and synthetic pyrethroid pesticide residues in beef fat by gas chromatography-mass selective detector(GC-MSD). Twenty one pesticide residues in fat were determined using a simple and rapid procedure based on solid- phase extraction(SPE) clean-up cartridges with octadecyl $(C_{18})-bonded$ porous silica, florisil, $10\%$ deactivated florisil. a tandem $C_{18}$ and florisil and a tandem $C_{18}$ and $10\%$ deactivated florisil. Solvent-solvent extraction using acetonitrile was not satisfied to eliminate fat interference for pesticide residue analysis by GC-MSD, and the recoveries of the method in fat ranged from 16.2 to $57.3\%$ except DDT$(83.2\%)$. The recoveries of SPE methods using a tandem $C_{18}$ and Florisil was $59.6\~123.8\%$ except fenitrothion $(135.2\%)$. the SPE method was verified the satisfactory performance of pre-treatment for pesticide residues analysis in fat by GC-MSD. The efficiency of florisil deactivated with $10\%$ water has been not proved significantly on recoveries of pesticide residues in fat.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.1-1
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• 2011

We developed a new generalized synthetic procedure, called as "heat-up process," to produce uniform-sized nanocrystals of many transition metals and oxides without a size selection process. We were able to synthesize uniform magnetite nanocrystals as much as 1 kilogram-scale from the thermolysis of Fe-oleate complex. Clever combination of different nanoscale materials will lead to the development of multifunctional nano-biomedical platforms for simultaneous targeted delivery, fast diagnosis, and efficient therapy. In this presentation, I would like to present some of our group's recent results on the designed fabrication of multifunctional nanostructured materials based on uniform-sized magnetite nanoparticles and their medical applications. Uniform ultrasmall iron oxide nanoparticles of <3 nm were synthesized by thermal decomposition of iron-oleate complex in the presence of oleyl alcohol. These ultrasmall iron oxide nanoparticles exhibited good T1 contrast effect. In in vivo T1 weighted blood pool magnetic resonance imaging (MRI), iron oxide nanoparticles showed longer circulation time than commercial gadolinium complex, enabling high resolution imaging. We used 80 nm-sized ferrimagnetic iron oxide nanocrystals for T2 MRI contrast agent for tracking transplanted pancreatic islet cells and single-cell MR imaging. We reported on the fabrication of monodisperse magnetite nanoparticles immobilized with uniform pore-sized mesoporous silica spheres for simultaneous MRI, fluorescence imaging, and drug delivery. We synthesized hollow magnetite nanocapsules and used them for both the MRI contrast agent and magnetic guided drug delivery vehicle.

• 한국건축시공학회지
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• 제18권6호
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• pp.559-567
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• 2018

외단열 마감 공법에서 사용되는 바탕조정재는 화재가 발생하는 경우 얇은 마감과 폴리머의 연소로 인해 표면부가 급속하게 붕괴되어 화재에 취약한 소재이다. 본 연구에서는 열적 성능이 우수한 팽창 흑연을 사용할 경우 바탕조정재의 성능을 개선할 수 있을 것으로 기대하였다. 실험결과, 팽창흑연을 사용한 바탕조정재는 부착강도 저하 및 물흡수계수 등의 감소가 발생하는 문제점이 있으나 플라이애시와 실리카흄을 사용하여 물리적 성능이 향상되는 것으로 나타났다. 팽창흑연을 사용한 바탕조정재는 복합 단열 시험체 표면의 페놀폼은 화염에 의한 표면 뚫림이 나타나지 않아 열원의 투과를 감소시킬 수 있을 것으로 나타났다.