• 한국대기환경학회지
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• 제25권1호
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• pp.38-45
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• 2009

Since the seventies and the oil crisis, energy-saving measures have led to a reduction in the ventilation of room. The use of synthetic materials which emit various chemical substances had led to an increase in the concentration of indoor pollutants. "Sick building syndrome (SBS)" and "Sick house syndrome (SHS)" are worldwide problems. Also, the number of complaints about indoor air pollution caused by VOCs (Volatile organic compound) and HCHO (Formaldehyde) has increased. It is important that evaluating and understanding emission of indoor air pollutant from building materials. The object of this study was to evaluate emission test method for flooring such as wood based flooring, carpet tile, rubber tile, PVC sheet and tile, and to determine emission of TVOC and form-aldehyde. The quantity of TVOC and carbonyl compounds emission were sampled and measured by Tenax TA and gas chromatography/mass spectrometry (GC/MSD), 2,4-DNPH cartrige with ozone scrubber and high performance liquid from flooring. The TVOC concentration emitted from carpet tile was ($7.419\;mg/m^2 h$) the highest among 5 groups of test materials. In wood based flooring and PVC tile, the emitted concentration of toluene was high. And the dodecane emission was highest in carpet. The concentration of TVOC decreased by an increase in emission test period. After 7 days, the concentration of TVOC from floorings were about 50% below of the concentration at the first day. TVOC emission from wood based flooring, carpet tile, rubber tile, PVC sheet and tile were decreased in 28 days and remained steady after about 15 days. The concentration of formaldehyde emission from floorings showed extremely low.

• Korean Chemical Engineering Research
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• 제52권4호
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• pp.497-502
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• 2014

바이오매스 유래 타르 및 왁스 성분은 파클리탁셀의 분리정제에 많은 악영향을 미치기 때문에 반드시 제거되어야 한다. 흡착제 처리는 식물세포배양으로부터 유래된 타르 및 왁스 성분을 매우 간단하고 효과적으로 제거할 수 있는 방법이다. 본 연구에서는 전처리 단계에서 상용흡착제 실로퓨트를 이용한 흡착제 처리 공정에서 주요 공정 변수들(온도, 시간, 용매, 건조시료/실로퓨트 비율)을 최적화하였다. 최적의 흡착제 처리 온도, 시간, 용매, 건조시료/실로퓨트 비율은 각각 $30^{\circ}C$, 15분, 메틸렌 클로라이드, 1:1(w/w)이었다. 이러한 결과는 TGA와 HPLC 분석을 통한 유기물의 흡착 양상으로도 확인하였다. 흡착제 처리 단계에서 순도 증가는 미미하였으나 타르 및 왁스 성분의 제거로 인한 후속공정의 공정 가능성과 편리성에 상당히 영향을 미쳤다.

• 한국물환경학회지
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• 제23권5호
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• pp.705-711
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• 2007

Green quantum-dot nanocrystal (QD525) with anti-microcystin monoclonal antibody was applied for detection of microcystin, a monocyclic peptide hepatotoxin, extracted from the culture of Microcystis aeruginosa. The presence of microcystin in the cell lysate was verified by HPLC analysis with UV absorbance at 238 nm. Microcystis cell extract exhibited fluorescence emission spectra, which peak was around 460 nm because of their complex organic substances. When a spherical QD525 antibody conjugates (10~20 nm in diameter) were bound to the microcystins in the Microcystis cell lysate, the fluorescence intensity of the primary peak at 525 nm diminished while the secondary emission peak at 460 nm slightly increased intensities. It is due to energy transfer from the primary (major) to the secondary (minor) peak, resulting from physical deformation of QD525 and different environmental factors. On the other hand, other cell extracts did not show any fluorescence emission change. This study is very available for detecting and monitoring the microcystin because it is one step assay without washing step and portable spectrophotometer makes on-site measurement possible. For health risk assessment of the microcystin, the reliable and rapid system to detect and quantify microcystin is seriously required.

• 상하수도학회지
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• 제21권2호
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• pp.203-214
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• 2007

This study aimed at researching the process selection for two-stage and dual media filtration system, as a technology substituting the existing sand filter without expanding the site when retrofitting an old filter bed or designing a new one. In order to select the process for optimum complex filtration system, three running conditions have been tested. Test results demonstrated that Run 3 in which the 1st stage was filled with anthracite and coarse sand, and the 2nd stage was filled up with activated carbon and fine sand reduced the head loss and the load of turbidity substances. Also, Run 3 showed better performance in removing TOC, particle counts, THMFP and HAAFP, compared to other two conditions. 99 % of Cryptosporidium was removed. Bisphenol-A was rarely removed from the 1st stage of coarse sand and 2nd stage of fine sand, but 99 % of it was removed from the 2nd stage of activated carbon. In conclusion, when it is required to retrofit an old rapid filter bed or design a new one for the purpose of improving filtration performance, the following two-stage and dual media filtration system is suggested: the 1st stage of filter bed needs to be filled up with coarse sand to remove turbidity as the pretreatment for extending duration of filtering, the top part of 2nd stage needs to be filled up with granular activated caron to remove dissolved organic matters and others as the main process, and finally the bottom part of 2nd stage needs to be filled up with fine sand as the finishing process.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2018년도 추계학술대회
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• pp.21-21
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• 2018

Natural product substances have historically served as the most significant also be prepared by source of new leads for pharmaceutical development. They can chemical synthesis(both semisynthesis and total synthesis) and have played a important role in the field of organic chemistry by providing synthetic targets. Rcently, they have also been extended for commercial purpose to refer to medicinal products, health functional foods, dietary supplements and cosmetics from natural sources. A large number of currently prescribed drugs have been either directly derived from or inspired by natural products. However, with the advent of robotics, bioinformatics, high throughput screening(HTS), molecular biology-biotechnology, combinatorial chemistry, in silico(molecular modeling) and other methodologies, the pharmaceutical industry has largely moved away from plant derived natural products as a source for leads and prospective drug candidates. The strategy for natural prduct industry is now changing from drug approaches to health foods by identifying effective natural products as preparations. In Korea, a lot of development of natural product based drugs have been done, but very few on health functional foods. The concept of natural product based health foods is not active components as lead compounds but standardized extracts or preparation mixed with other medicinal plants. The representative material has been recently known to be a standardized ginseng extract "Ginsana G 115" developed by Swiss Pharmaton company. The purpose of this presentation is to underline how natural products research continues to make significant contributions in the domain of discovery and development of new health functional foods. It is proposed to present the development of high value added health food or health functional foods through scientific investigation on efficacy and standardization of new materials form natural products.

• 멤브레인
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• 제26권1호
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• pp.55-61
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• 2016

저압 침지식 멤브레인을 이용한 해수 담수화 전처리에 있어서 유기 파울링은 막간 압력 증가로 인한 화학 세정 횟수의 증가 및 에너지 소비 증가 등 멤브레인 운전시 문제점들을 야기한다. 조류대응 해수전처리에서 조류가 배출하는 extracellular polymeric substances의 대표물질인 sodium alginate를 이용하여 침지식 여과에서 파울링 현상을 관찰하였다. 공기 폭기가 적용되지 않은 경우 순수한 aglinate 파울링은 농도가 증가하면서 증가하였다. 그러나 공기 폭기를 적용해 준 경우 alginate 파울링 감소는 매우 효과적이었다. 공기 폭기가 없는 경우 칼슘 농도의 증가에 따라 alginate 파울링은 감소하였다. 동일 조건에서 공기 폭기 시 높은 alginate 파울링 감소효과를 나타내었으나 NaCl 농도를 증가시킨 경우 칼슘 농도의 증가에 따라 파울링 제어를 위한 공기 폭기 효과는 감소하였다. 해수와 유사한 높은 NaCl과 칼슘 농도에서 고농도 sodium alginate의 경우 공기 폭기량 증가를 통해 초기 파울링을 감소시킬 수 있었으나 시간의 경과에 따라 상대적으로 낮은 폭기량에서의 파울링 감소 효과와 큰 차이는 없었다.

• 한국수산과학회지
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• 제48권2호
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• pp.168-177
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• 2015

Shell waste from the butter clam Saxidomus purpuratus and littleneck clam Ruditapes philippinarum is a large by-product of shellfish aquaculture, and it is desirable to convert it into value-added products for industrial applications. In this study, calcium carbonate (CaC) polymorphs from butter clam (BCSP) and littleneck clam (LCSP) shell powders and commercial CaC were characterized using Fourier transmission infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results revealed that the optimal calcination conditions to eliminate organic substances and improve solubility for both BCSP and LCSP were $800^{\circ}C$ for 8 h in an electrical furnace. Calcination improved the white index of the butter clam (BCCP) and littleneck clam (LCCP) calcined powder compared with shell powders. The calcium content in BCCP (51.1%) was higher than that of LCCP (44.9%) or commercial calcium oxide (CaO, 44.7%). The XRD patterns of BCCP and LCCP were similar to that of CaO. Cubic-like crystals of CaC and irregular crystals of BCCP and LCCP were observed by SEM. The FT-IR and XRD analyses revealed the presence of calcite and aragonite in the BCSP and aragonite in the LCSP, whereas the CaC contained calcite. These results indicate that butter and littleneck clam shells are potential biomass resources for calcium carbonate and calcium oxide.

• 한국식품조리과학회지
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• 제4권1호
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• pp.47-52
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• 1988

녹차의 품종, 채엽시기, 가공방법별에 따라 13종류의 한국산 녹차시료를 조제하고 이들 시료의 이화학적 성질을 측정한 결과는 다음과 같다. 1. 수활, 회분, 가용성 고형분 및 조지방 함량은 대체적으로 품종, 차엽의 채취시기 및 가공방법의 상위에 따른 큰 차이점은 나타나지 않았지만 조단백질의 경우에서는 삽목 Yabukida 품종 1번 차의 볶음과 찐 것에서 각각 30.8%, 31.3%이던 것이 2, 3번차로 갈수록 점차 감소하여 4번차의 경우에서는 각각 18.8%, 16.0% 이었다. 이러한 경향은 다른 품종에서도 유사한 경향을 나타내었다. 품종별에 따른 변화도 크게 나타났다. 조섬유에서는 채엽시기에 따라 증가하는 경향을 나타내었다. 2. 표면색도는 볶음 차보다 찐 차가 보다 밝은 녹황색을 띄며 채엽시기가 늦을수록 밝은 황색을 나타내었다. 또한 클로로필함량은 찐 차의 경우가 볶은 차보다 높았고, 채엽시기에 따라 감소의 경향을 보였으나 삽목 Yabukida 4번 차의 경우에서는 증가하였다. 3. 탄닌의 함량은 볶음의 경우 채엽시기가 늦을수륵 증가하였지만 찐 차의 경우 그런 경향이 나타나지 않았으며 theaflavin과 thearubigin 함량은 평균하여 각각 0.07% 및 2.27%이었고 산화중합물비는 평균 0.22이었다. 4. Methylxanthine류에서는 caffeine이 주성분으로 94∼98%를 차지하였으며 볶음차의 caffeine 함량이 높았다. 베니호마래의 caffeine 함량은 다른 품종보다 낮았다. 5. 녹차의 환원당은 0.1% 내외로 거의 일정하였으며 유리당의 경우 삽목 Yabukida가 다른 품종에 비해서 sucrose 함량이 높게 나타났다. 6. 녹차중의 유기산은 succinic, malic, shikimic, citric, quinic, gallic, oxalic 및 malonic acid의 8종류이었으며 이중 quinic acid의 함량이 높았다. 삽목 Yabukida 품종에서는 채엽시기가 빠른 녹차에서는 malic acid 함량이 매우 낮은 반면 oxalic acid는 채엽시기가 늦을수록 감소하여 미량으로 검지되었다.

• 공업화학
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• 제31권3호
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• pp.277-283
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• 2020

본 연구는 건자재용 목재의 연기 유해성평가에 대하여 연기성능지수-II (SPI-II), 연기성장지수-II (SGI-II)를 중심으로 조사하였다. 시험편은 삼나무, 가문비나무, 나왕, 적송을 사용하였다. 연기 특성은 시험편 목재에 대하여 콘칼로리미터(ISO 5660-1) 장비를 이용하여 조사하였다. 연소반응 후 측정된 연기성능지수-II는 적송을 기준으로 1.31~2.15배 증가하였다. 연기성능지수-II에 의한 화재위험성은 가문비나무, 나왕, 삼나무, 적송의 순서로 증가하였다. 연기성장지수-II는 삼나무를 기준으로 1.18~2.55배 증가하였다. 연기성장지수-II에 의한 화재위험성은 삼나무, 가문비나무, 나왕, 적송의 순서로 높아졌다. CO 평균농도는 59~133 ppm이었으며 이 결과는 미국직업안전위생관리국(occupational safety and health administration, OSHA)의 허용기준(permissible exposure limits, PEL)인 50 ppm 보다 높게 나타났다. 결론적으로 적송과 같이 휘발성 유기물질을 다랑 함유한 목재는 연기성능지수-II가 낮고, 연기성장지수-II가 높으므로 화재로 인한 연기유해성이 높은 것으로 이해된다.

• 상하수도학회지
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• 제20권4호
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• pp.545-558
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• 2006

The current conditions of large water mains are evaluated by deteriorations and the causes of deterioration are investigated through visual assessments in the field, mechanical tests and analysis of chemical compositions in laboratory for each pipe material, unlined cast iron pipes (CIPs), ductile iron pipes (DCIPs) and steel pipes (SPs) Tubercles and scales from internal and external corrosion of unlined cast iron pipes were identified as the causes of functional performance limitations in large water mains. It is investigated that main causes of internal and external corrosion of water pipes are from lots of depositions of organic and inorganic substances on pipe surface, concentrated pitting, and uniform corrosion by local or global exfoliation or detachment of lining and coatings of DCIPs and SPs. Internal and external corrosion depths of CIPs were higher than those of DCIPs and SPs. Consequently, total corrosion rate summed internal and external corrosion rates of CIPs also were shown to be higher than those of DCIPs and SPs. The failure time from hole generation of CIPs by total corrosion rate was predicted to be taken sixteen years, and DCIPs and SPs were twenty-six years and one hundred and fifty three years. And longitudinal deflection of investigated water mains were not happened and mechanical strengths such as tensile strength, elongation, and hardness also were mostly suited to Korea Standards. It was thought that the weakness of tensile strength of one sample(S-11) was, however, due to higher carbon contents(%) in CIPs. Pipe deterioration score of S-46 was 55.2 and was preferentially assessed to be rehabilitated.