• 대한화학회지
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• 제20권5호
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• pp.380-390
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• 1976

전자 공여체로서 할로겐으로 치환되어 있는 아니솔 유도체들(아니솔, 4-클로로아니솔, 2,3-디클로로 아니솔, 2-플루오로-4-클로로아니솔, 2-브로모-4-클로로아니솔, 2-요도드-4-클로로아니솔, 2-브로모 4,6-디클로로아니솔, 2-요오드-4,6-디클로로 아니솔, 2-요오드-2,4,6-드리클로로아니솔)을 쓰고 전자를 받아들이는 화합물로서는 요오드 또는 염화 요오드를 사용하여 그 사이에 생성되는 전하이동 착물에 관하여서 사염화탄소 또는 헥산을 용매계로 하여 연구하여 보았다. 연구한 결과로서 착물의 생성량이 벤젠고리의 2-치환 할로겐 원자의 Van der Waals 반경에 따라서 영향을 받음이 확인 되었으며 더 나아가서 전자 공여 화합물 분자의 입체적 배치 환경에 의하여서도 역시 영향을 받고 있음을 알 수 있었다. 이와 같은 경향은 클로로포름과의 착물 생성에서도 핵자기 공명분석법으로 확인될 수 있었다. 분광 분석법으로 얻은 착물 생성에 관한 데이터를 제시하였으며 벤젠고리에 치환된 2-할로겐 원자의 입체구조와의 상호관계를 논의하였다.

• Bulletin of the Korean Chemical Society
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• 제26권1호
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• pp.115-118
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• 2005

The miniaturized NIR (Near-infrared) spectrometer has been utilized for the determination of water content (1-19% range) in ethanol that is the most popular organic solvent in pharmaceutical industries. It has many potential capabilities that can replace the conventional analyzers especially for the on-line measurement since it is compact, versatile and cost-effective. By using two dimensional (2D) correlation spectroscopy, it was preliminarily investigated to find any unforeseen spectral distortion among the spectra collected from the miniaturized spectrometer. The 2D study revealed that the spectral variation clearly followed the variation of water concentration without any spectral distortion or abnormality. PLS (Partial Least Squares) was employed to build the calibration model and the resulting prediction performance was acceptable and stable over several days. Even though the miniaturized NIR system was evaluated to fairly simple chemical matrix, the overall study demonstrates the sufficient feasibility for diverse practical and industrial applications.

• 한국생산제조학회지
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• 제23권6호
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• pp.533-538
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• 2014

We fabricated grooved mushroom structures with anisotropic wettability on silicon substrates using basic MEMS processes. The geometry of these grooved mushroom structures could be changed by controlling the additional IPA solution during Si etching by TMAH solution. To understand anisotropic wettability, contact angles (CAs) of hexadecane droplets were measured in the orthogonal and parallel directions to grooved lines. The CA measurement results displayed anisotropic wetting on the grooved mushroom structures. However, specimens with $80{\mu}m$ distance between top layers displayed isotropic and superoleophobic wetting. This study demonstrates that the thickness of the top layer is more critical than the width or height of the ridge when determining the wettability of organic solvent. Despite the wide distance between top layers ($80{\mu}m$), the specimen with a thin top layer (100 nm) showed highly anisotropic wetting and low CA due to the pinning of droplets at the edge of the top layer.

• 한국식품영양학회지
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• 제19권3호
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• pp.271-278
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• 2006

RPSO, SO, PNO의 3종 향미유에 대하여 로즈마리 유기 용매 추출물과 비교군으로 토코페롤을 각각 1,000ppm씩 동량으로 적용하여 60${\pm}$2$^{\circ}C$의 항온기에 저장하여 AV, POV 및 카르보닐 화합물 생성량의 변화 양상을 측정하였다. 이들 향미유의 AV, POV측정 과정에서는 고유의 색상으로 인하여 상대적으로 측정 오차가 크게 발생하였으며, 토코페롤은 AV, POV, 카르보닐 화합물 생성량 등 각종 측정 항목에서 항산화제로서의 역할보다는 오히려 산화 촉진제로 작용하는 것으로 밝혀졌다. 전체적으로 chloroform/MeOH 추출물 처리의 저장 안정성의 향상 효과가 가장 우수하였으며, 측정 항목 및 추출물별 저장 안점성의 향상 효과는 다음과 같았다. 즉, AV는 chloroform/ MeOH 추출물>ethyl alcohol 추출물>열수 추출물>ethyl acetate 추출물>acetone 추출물>무처리군>토코페롤 처리군이었으며, POV는 chloroform/MeOH 추출물>ethyl alcohol추출물${\geq}$ethyl acetate 추출물>acetone 추출물${\geq}$열수 추출물>무처리군>토코페롤 처리군이었고, 카르보닐 화합물 생성량은 chloroform/ MeOH 추출물>ethyl acetate추출물>ethyl alcohol 추출물>열수 추출물>acetone 추출물>무처리군>토코페롤 처리군의 순이었다.

• 한국자원리싸이클링학회:학술대회논문집
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• 한국자원리싸이클링학회 2006년도 춘계임시총회 및 제27회 학술발표대회
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• pp.90-94
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• 2006

액정(LCD)과 반도체 제조공정에서 발생하는 인산, 질산, 초산, Al, Mo 등이 혼재하고 있는 인산계 혼산폐액을 액정제조공정에서 사용할 수 있는 고순도 에칭액으로 재활용하기 위해서 용매추출법, 진공 증발법, 확산투석법 및 이온교환법의 각각의 기술적 특성을 살린 혼합 처리공정을 이용하여 고순도 인산 회수 기술을 확립하고 상용화 시스템을 개발하고자 하였다. 시험 결과 진공증발에 의해 질산과 초산을 100% 제거할 수 있었고, TOP를 사용한 용매추출에서도 추출 4단, 탈거 6단, 상비 1/3으로 완벽하게 제거할 수 있었다. 이온교환의 전단계로 적용한 확산투석에서 Al 97%, Mo 75% 제거할 수 있었고 이온교환공정에서 Al 및 Mo를 각각 1ppm 이하로 정제할 수 있었다.

• Journal of the Korean Wood Science and Technology
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• 제45권3호
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• pp.268-277
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• 2017

본 연구는 리그노셀룰로오스의 주성분 용해에 우수하다고 알려진 이온성 액체인 1-ethyl-3-methylimidazolium acetate ([EMIM]Ac)와 셀룰로오스와 친화성이 있는 유기용매인 dimethylformamide (DMF)의 혼합용매를 이용하여 갯버들 목분을 처리한 후, 디스크밀 해섬에 의한 리그노셀룰로오스 나노섬유를 제조하고 그 특성을 평가하였다. 무처리샘플과 DMF 및 [EMIM]Ac가 10과 30% 포함된 혼합용매로 목분의 고형분량을 15%로 선정하였다. 전처리물의 X선 회절도로부터 모든 샘플이 셀룰로오스 I의 패턴을 나타냈으며, 상대결정화도는 [EMIM]Ac가 30% 포함된 혼합용매로 2시간 처리한 전처리물이 가장 낮았다. 무처리 및 DMF와 [EMIM]Ac가 10% 포함된 혼합용매로 처리한 전처리물의 평균결정크기는 약 3.2 nm였으며, [EMIM]Ac가 30%까지 포함되고 처리 시간이 경과할수록 다소 감소하는 경향을 나타내었다. 혼합용매의 사용을 통한 전처리물의 목재세포벽 구조의 완화로 해섬 효율이 향상되었으며, 전처리 시간 및 해섬 시간이 경과할수록 비표면적이 증가하는 경향을 나타내었다.

• Journal of Pharmaceutical Investigation
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• 제41권4호
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• pp.239-247
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• 2011

Simvastatin is an inhibitor of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, which catalyzes the conversion of HMG-CoA to mevalonate, an early and rate-limiting step in the biosynthesis of cholesterol. Simvastatin has good permeability, but it also has low solubility (BCS class II), which reduces its bioavailability. To overcome this problem, a solid dispersion is formed using a spray-dryer with polymeric material carrier to potentially enhance the dissolution rate and extend drug absorption. As carriers for solid dispersion, Gelucire$^{(R)}$44/14 and Gelucire$^{(R)}$ 50/13 are semisolid excipients that greatly improve the bioavailability of poorly-soluble drugs. To avoid any toxic effects of an organic solvent, we used aqueous medium to melt Tween$^{(R)}$ 80 and distilled water. The structural behaviors of the raw materials and the solid dispersion were analyzed by differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM). The DSC and PXRD data indicated that the crystalline structure of simvastatin was transformed to an amorphous structure through solid dispersion. Then, solid dispersion-based tablets containing 20 mg simvastatin were prepared with excipients. Dissolution tests were performed in distilled water and artificial intestinal fluid using the USP paddle II method. Compared with that of the commercial tablet (Zocor$^{(R)}$ 20 mg), the release of simvastatin from solid dispersion based-tablet was more efficient. Although the stability study is not complete, this solid dispersion system is expected to deliver poorly water-soluble drugs with enhanced bioavailability and less toxicity.

• 한국식품과학회지
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• 제10권2호
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• pp.194-202
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• 1978

In order to evaluate the utility of the anthocyanin pigments in Ganges Amaranth as an edible pigment, this study was designed to isolate and identify the anthocyanins. The anthocyanins present in leaves of Ganges Amaranth were extracted with 0.1% HCl in methanol. The extracted pigments were purified by organic solvent treatment and Amberlite CG-400 Type cation exchanger, and then separated into individual pigments by paper chromatography with n-butanol-formic acid-water(100:25:60, v/v) as a solvent system. The separated pigments were identified by their Rf values, sugar moieties, complete hydrolysis and spectral characteristics in the visible and ultraviolet regions. The amounts of individual anthocyanins were also determined. The results obtained from these experiments were as follows. 1. Chromatograms of the Ganges Amaranth extract developed with BFW yielded three anthocyanin bands. The two of the anothocyanin bands were tentatively identified as malvidin-3-glucoside(acylated with caffeic acid) in band 1 and peonidin-3-glucoside (acylated with caffeic acid) in band 2. But the anthocyanin in band 3 was not identified due to extremly low concentration. 2. The amount of total anthocyanins was 101.57 mg/100g fresh weight of leaves in which 82.15 mg of malvidin-3-glucoside (acylated with caffeic acid) and 27.20 mg of peonidin-3-glucoside(acylated with caffeic acid) were contained per 100g fresh weight. Maividin-3-glucoside acylated with the acid was, therefore, the most abundant pigment in the Ganges Amaranth.

• Journal of the Korean Wood Science and Technology
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• 제16권4호
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• pp.70-78
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• 1988

To separate and utilize the main components of hardwood (Quercus mongolica) by organosov pulping (ester pulping), chips were cooked at various conditions such as; the solvent ratio (acetic acid: ethylacetate: water, 50:25:25; 33:33:34; 25:50:25), maximum temperature (165, 170, $175^{\circ}C$), and cooking times (2, 2.5, 3 hr). The pulps were bleached by the sequences of CEDED, C/DEDED, PEDED. Lignin, sugars, and acetic acid were separated from black liquor and washing liquors. 1. The selective delignification at optimal pulp yield (43-45%) was obtained by cooking at acetic acid: ethylace tate: water ratio of 33:34:34 for 3 hr at $170^{\circ}C$. But in this case, kappa no. of the pulp was not reduced under 60 points. 2. Kappa no. of the pulp could be dropped by an acetone wash to remove reprecipitated lignin a t cooked pulp. 3. The unbleached pulps had a brightness of 45-50%, whereas the bleached pulps gave at 88-93% brightness. Tensile, burst, and tear strengths of the bleached pulps were lower than those of kraft pulp, especially in tear strength. The pulps which were bleached with CEDED sequence were higher in strengths than another bleaching sequences. 4. Lignin of 90-95%(lignin base on wood)was separated from black liquor and washing liquors, while the purified sugars and recovery of acetic acid were a low. An organic phase composed of acetic acid, ethylacetate, and water was separated to a two-phase system by proper adjustment of the solvent ratios.

• 한국염색가공학회지
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• 제28권3호
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• pp.125-133
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• 2016

In this study, efforts were made to enhance the mechanical properties of the poly(vinyl alcohol) (PVA) fibers of medium molecular weight(number-average degree of polymerization=1735) varying the ratio in $DMSO/H_2O$ mixed solvent and spinning/drawing conditions. The gel fibers prepared from pure DMSO were opaquely frozen in the coagulating bath of $-20^{\circ}C$. However, transparent gel fibers were formed without freezing for the mixture to contain water less than 80wt%. As the amount of water in the mixture increased the residual solvent in the coagulated gel fibers decreased ranging from 85 to 42wt%. The complex viscosity increased with increasing PVA concentration in 80/20 $DMSO/H_2O$ exhibiting remarkable shear thinning at 18wt%. In the Cole-Cole plot, the 18wt% PVA solutions gave a deviated curve from 12 and 15wt% ones. Thus the optimum PVA concentration for the spinning processing of medium MW PVA solutions in 80/20 $DMSO/H_2O$ was determined to 18wt% with rheological concept. Low degree of drawing during hot drawing process in the dry state was available for high bath draft in the coagulation bath. The most improved mechanical properties were observed by applying the highest possible draw ratio attained by reducing bath draft over multi-step drawing process. In the given bath draft, linear relationship was observed between both tensile strength and modulus and draw ratio showing the inflection points at the draw ratio of 19.5 and 18.0 for tensile strength and modulus, respectively.