• 한국포장학회지
• /
• 제20권1호
• /
• pp.7-15
• /
• 2014

Agar-based composite films were prepared with variety of food processing and agricultural processing waste materials in order to screen natural lingo-cellulosic resources for the value-added utilization of the under-utilized materials. The effect of these waste materials (10 wt% based on agar) on mechanical properties, moisture content (MC), water vapor permeability (WVP), water absorption behavior of biocomposite films were investigated. Biocomposite films prepared with various fibers resulted in significant increase or decrease in color and percent transmittance. The MC, WVP, and surface hydrophobicity of biocomposite films increased significantly by incorporation of fibers, while the water uptake ratio and solubility of the film decreased. SEM images of biocomposite film showed better adhesion between the fiber and agar polymer. Among the tested cellulosic waste materials, rice wine waste, onion and garlic fibers were promising for the value-added utilization as a reinforcing material for the preparation of biocomposite food packaging films.

• Journal of Ginseng Research
• /
• 제16권1호
• /
• pp.24-30
• /
• 1992

Extracts of Panax ginseng root significantly induced tolerance of Fusarium oxysporum to heavy metal, mecury, as the fungal mycelial growth was less inhibited by mercury chloride on potato dextrose medium(PDA) amended with ginseng root than on the PDA with no ginseng amendment. The most favorable concentration of ginseng root powder in detoxification of mercury chloride was 1%. The induced tolerance of F. oxysporum to mercury chloride appeared to be rather due to absorption of ginseng components, and was not related to stimulation of mycelial growth of the fungus per so by ginseng treatment. Ginseng components responsible for inducing tolerance of the fungus to mercury were involved in the water fraction of the ginseng root extract, although the water fraction had no effect on enhancement of the mycelial growth on the medium without mercury chloride. The hexane fraction of ginseng root extract, by which the mycelial growth was stimulated, was not related to the inducement of the tolerance to mercury chloride. However, more tolerance to mercury chloride was noted in PDA with both the water and hexane fractions combined than with either of the two fractions. Six-year-old ginseng roots were more effective in detoxification of mercury chloride than 4-year-old ginsng roots, and American ginseng (P quinquifolium) had no or little effect on inducing tolerance of the fungus to mercury chloride. This method may be used to screen other natural materials for test in the detoxification of mercury chloride.

• 한국인쇄학회지
• /
• 제28권2호
• /
• pp.87-99
• /
• 2010

The ink which is left by sealed more than 6 months, it clogs head nozzle of machine due to precipitation and coagulation. In addition, if you stop printing about 3~4 hours in the middle of printing work, the head nozzles of printer could be naturally clogged. To prevent of this situation, worker should implement cleaning and checking head nozzle before hands. When the nozzle is clogged in the middle of work, running a head cleaning mode can clear the clogged nozzle. Yet, large amount of waste inks which are passed clogged nozzle will be remained after cleaning. It would be very nice that ink companies take the waste ink back by green marketing, but none of them are doing it currently. The purpose of this research is that making a black water-based recycle ink by waste inks which are left of nozzle clogging or passed expiration date. This recycle ink will improved working environment and reduce cost of disposing waste inks. Furthermore, it is very environment friendly and economical. It is called a recycle ink which is water-based black ink made by waste inks.

• Nuclear Engineering and Technology
• /
• 제53권12호
• /
• pp.4003-4013
• /
• 2021

During the long-term cooling (LTC) phase of a loss-of-coolant accident (LOCA) in a pressurized water reactor (PWR), water is supplied from the containment sump to the reactor coolant system (RCS) by the flooded sump water to the Reactor Vessel (RV) through the broken pipes. As part of the technical efforts for resolving GSI-191 [( Reid and Crytzer, May. 2007) 1, consideration is needed for the consequences of debris penetrating the sump screen and propagating downstream into the RV. Injection of debris (fiberglass) into the RV during the LTC recirculation phase needs special attention to assure that reactor core cooling is maintained. The point of concern is the potential for debris to adversely affect the reactor core flow paths or heat transfer [2]. However, all the experiments for proving the coolability of RV have been done with the assumption of the most of debris would be transferred to the RV and the bottom nozzle of the FAs. The purpose of the tests is to quantify the amount of the debris that would be accumulated at the lower plenum and the debris that passes through the FAs since non-conservatism of other researches assumptions that have been used in the past experimental or analytical programs.

• 한국수자원학회논문집
• /
• 제49권9호
• /
• pp.741-748
• /
• 2016

개착식 하상여과에 대해서 실험실 규모의 모형을 구축하고 중사, 왕사, 화산석, 자갈에 대한 단일 여재를 구성하였다. 실험을 통해 투수계수 및 하상 여과에 대한 취수량을 추정하고, 지하수 유동 모델링인 Visual MODFLOW를 통해 탁도 변화에 따라 수정된 투수계수를 적용하고 미치는 영향을 분석하였다. 각 여재마다 22개의 수정 투수계수 시나리오가 적용되었다. 전체 모델링에서 최소 오차는 화산석(2~5 mm)을 여재로 한 경우 상부에서부터 3개 지층에 대해서 20% 감소된 투수계수를 적용한 시나리오다. 이는 화산석의 특성상 탁도를 유발하는 황토가 여재에 흡착되어 상부에서 3번째 지층까지 영향을 미치는 것으로 추정되었다. 또한 입자의 크기가 작은 중사의 경우 5% 감소된 투수계수를 상부에서 두 번째 지층까지 적용한 시나리오에서도 작은 오차 값을 나타냈다.

• Journal of Pharmaceutical Investigation
• /
• 제32권3호
• /
• pp.191-197
• /
• 2002

Polymer based physical mixtures or solid dispersions containing solubilizing compositions[OA, tween80 and SLS] were prepared using a spray-dryer. Lovastatin(LOS), simvastatin(SIMS), aceclofenac(AFC) and cisapride(CSP) were selected as poorly water-soluble drugs. Dextrin, poly(vinylalcohol) (PVA), poly(vinylpyrrolidone)(PVP) and polyethylene glycol(PEG) were chosen as solubilizing carriers for solid dispersions. The solid dispersions containing solubilizing compositions without drug were prepared without using organic solvents or tedious changes of formulation compositions. This system could be used to quickly screen the dissolution profiles of poorly water-soluble drugs by simply mixing with drugs thereafter. In case of solid dispersion containing drug, organic solvent systems could be used to solubilize model drugs. The dissolution rates of the drugs were higher when mixed with drug and solid dispersions containing solubilizing compositions. However, solid dispersions of LOS, AFC, and CSP simultaneously containing drug and solubilizing compositions in organic solvent systems were more useful than physical mixtures of drug and solid dispersions without drug except SIMS. Based on solubilizing capability of polymer based physical mixtures in gelatin hard capsules, optimal solid dispersion system of poorly water-soluble drugs could be formulated. However, it should be noted that dissolution rate of poorly water-soluble drugs were highly dependent on drug properties, solubilizing compositions and polymeric carriers.

• 한국환경과학회지
• /
• 제17권8호
• /
• pp.899-905
• /
• 2008

Quality test for activated carbon(AC) filter used for drinking water purifier is now an obligatory test and the standard material for valid purifying amount in water purifier performance test has been changed from residual chlorine to chloroform according to the notice of Ministry of Environment in 2006. Therefore, this study aimed to compare the ingredients of AC filters by confirming chloroform removal rate of AC filter and conducting 4 adsorption tests (Iodine, methylene blue decolorization, phenol value, ADS value) for AC filters provided by manufacturers. With water pressure of $1kgf/cm^2$, 1,500 liters of prepared inflow went through to check chloroform removal rate. As a result, product with removal rate of below 60% from all products. On the other hand, 4 adsorption tests were conducted for filters in the market and filters from manufacturers. None of the products satisfied all 4 tests. In particular, they showed great shortage to the standard in phenol value and ADS value test. However, manufacturers' filter showed much better performance than filters in the market. Also, the result of valid purifying amount test for each of five products of appropriate product and inappropriate product based on filter quality test showed average 4,440 liters for appropriate product and average 2,620 liters for inappropriate product. According to the result, it is shown that the filter with good adsorption also had good chloroform removal efficiency and adsorption efficiency. Therefore, it is expected that customers can screen good quality product through obligatory conduct of filter quality test. However, it is considered that complementation in system is required for future inspection.

• 생태와환경
• /
• 제47권3호
• /
• pp.214-218
• /
• 2014

본 연구노트는 K-water가 고안하여 개발한 녹조수상 콤바인 장치에 대하여 소개하고자 하였다. 녹조제거장치는 본체와 부력재, 이송호퍼, 스크린 컨베이어, 슬러지 제거기 및 수거물질 분리대 등 총 5개 모듈로 구성되어 있다. 그리고 스컴성 녹조현상 이하일 때 녹조제거제를 전처리할 수 있는 살포기가 별도로 장착되어 있다. 전반적으로 본 장치의 모듈 시스템은 매우 간단하다. 2014년 5월부터 7월까지 낙동강 및 대청호 현장에서 테스트 운영한 결과, 1일 처리할 수 있는 수표면적은 $500,000m^2day^{-1}$에 해당하였다. 그리고 장치 적용 전후 처리효율은 90%를 상회하였고, 수처리량은 수질 상태에 따라 차이가 있지만 $500,000m^3day^{-1}$은 가능하였다. 또한 장치의 운영기간은 3월~11월(9개월) 동안으로써 기존 계획보다 연장될 수 있었다. 본 장치 및 기술을 통해 상수원과 공공수역의 녹조현상 및 사회문제로 확대된 파급 영향을 해결하는 데 기여할 수 있는 신기술로서 활용되기를 기대한다.

• 한국해양학회지:바다
• /
• 제19권1호
• /
• pp.88-98
• /
• 2014

미세플라스틱의 분포, 거동, 생태계 영향 등은 해양생태계 보전을 위한 중요한 연구관심사가 되고 있다. 그러나 국내외적으로 통일된 조사 및 정성 정량 분석법이 제시되어 있지 않아 자료들의 비교에 한계가 있다. 본 연구는 해수에 잔류하는 미세플라스틱에 대한 국내외 조사방법들을 고찰하고, 불확실성을 증가시킬 수 있는 과정들에 대해 재현성여부를 평가하여 적용가능한 조사 및 정성 정량 분석법을 확립하였다. 또, 확립된 방법을 적용해 인천경기연안 해수에 잔류하는 미세플라스틱의 분포특성에 대한 사전조사 결과를 제시하였다. 해수는 표면해수층(surface microlayer; SML)과 해수층(subsurface water; SSW)로 나누어 SML층은 2 mm mesh screen를 이용해서 채취하였고 SSW층은 동물플랑크톤채집용 trawl net(mesh size=$330{\mu}m$)과 식물플랑크톤채집용 hand net(mesh size=$20{\mu}m$)을 이용해서 채취하였다. 채취된 양에 기초해 계산된 SML층은 대략 $100{\mu}m$로써 SML층을 잘 반영하는 것으로 판단된다. 미세플라스틱의 우점적인 크기는 < $300{\mu}m$으로 관측되어 SSW층에 대한 채취는 trawl-net보다는 hand-net이 더 적절한 것으로 판단된다. 적외선 분광분석(IR)을 통해 플라스틱 여부와 polymer성분을 결정하였는데, SML에 대해서는 IR분석결과에 기초해 계수한 농도와 육안계수법에 기초한 농도가 잘 일치하였으나 SSW에 대해서는 그렇지 못해서 기존 연구들의 육안계수에 의한 결과 값들이 불확실할 수 있음이 관측되었다. 본 연구에서 확립된 방법을 적용해서 사전조사한 결과 인천경기연안 지역 해수 중 잔류하는 미세플라스틱 농도는 낙동강 하구연안에서 관측된 값과 유사한 범위에 있었다. 본 연구에서 확립된 분석방법은 미세플라스틱에 대한 향후 연구를 위해 중요한 기초자료로 활용되리라 사료된다.

• 대한바이러스학회지
• /
• 제27권1호
• /
• pp.87-95
• /
• 1997

Methanol and/or boiling water extraction of 201 natural products and subsequent MTT assay using MT-4 cell line was carried out to screen the anti-HIV-1 activity. Among 97 methanol extracts, 7 extracts from Chrysanthemi Indicium Flos, Magnoliae Cortex, Machili Cortex, Reynoutriae Rhizoma, Lithospermi Radix, Agastachis Herba, and Chaenomelis Fructus showed anti-HIV-1 activity and their SI value were 2.25 to 5.77. In addition, among 119 boiling water extracts, 10 extracts from Lonicerae Caulis et Foloium, Elsholtziae Herba, Leonuri Herba, Portulacae Herba, Schizonepetae Herba, Curcumae Rhizoma, Amomi Cardamomi Fructus, Cirsii Radix et Herba, Carpesii Herba, and Siegesbeckiae Herba showed anti-HIV-1 activity and their SI value were 1.30 to 7.64. Methanol extracts of above seven natural products were fractionated and the anti-HIV-1 activity of each fraction was examined. Extraction was carried out with hexane, chloroform, butanol, and water to trace active anti-HIV-1 componets. As a result, the water fraction of Magnoliae Cortex, Machili Cortex, Reynoutriae Rhizoma, Agastachis Herba, Chaenomelis Fructus and the butanol fraction of Chrysanthemi Indicium Flos, Reynoutriae Rhizoma showed anti-HIV-1 activity and their SI value were 1.40 to 8.02. We could reach a conclusion that studies to trace the anti-HIV-1 active component of each natural products in further fractionation and to identify its structure by Infrared spectroscopy, NMR spectroscopy and gel permeation chromatography were needed.