• Korean Chemical Engineering Research
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• 제52권1호
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• pp.8-16
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• 2014

미세조류는 이산화탄소를 제거하고 산업적으로 유용한 다양한 이차 대사물질을 생산해 내는 광합성 미생물로 생물산업분야에서 주목 받고 있는 유용한 자원이다. 이러한 미세조류를 실내에서 효과적으로 배양하기 위해서는 무엇보다도 효율적인 광원이 필수적이다. 최근 발달하는 LED광원은 광원의 크기가 작고, 에너지 효율이 우수하며, 특정 파장만 조사할 수 있다는 점 등의 다른 인공광원과 차별되는 많은 장점을 가지고 있다. LED광원을 미세조류의 배양에 적용하는 연구는 최근에 와서야 점차 시도되고 있는 실정이며, 아직까지 실험실 규모의 실험과 대표적인 특정 종 위주의 결과들만 나오고 있어, LED광원을 미세조류의 산업적인 배양에 적용하기 위해서는 더 많은 세부적인 연구 결과가 요구된다. 하지만 LED 조명을 미세조류 배양 분야에 적용하는 것은 효과적인 접근으로 생각되며, BT(Bio Technology) 산업에 새로운 지평을 열 것으로 생각된다. 따라서 본고에서는 최근 연구되고 있는 LED광원을 이용한 미세조류의 배양 현황 및 그 가능성에 대해서 조사하고, 향후 나아갈 방향에 대해서 기술해 보았다.

• 한국광학회지
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• 제16권6호
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• pp.521-526
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• 2005

우리는 국내에서 처음으로 직경 300 mm인 광집속장치를 정렬 및 조립하였다. 이 장치는 주경, 부경 그리고 5개의 연결 거울로 구성된다. 이중에서 가장 중요한 부품인 주경은 각 구조물들과의 조립때마다 발생할 수 있는 변형을 정밀 측정하였다. 또한 사용되는 거울의 개수가 많기 때문에 광학정렬에는 체계적인 정렬 알고리즘을 도입하였다. 최종 조립결과 파면수차는 1.9 wave rms(wave =633 nm)로 예상치의 7배정도 큰 값이었다. 이것의 주원인은 조립 과정에서 발생한 연결 거울들의 변형인 것으로 확인되었다. 본 광집속장치를 정렬하면서 발생했던 문제점들에 대한 고찰은 향후 대형광학계를 만들 때 유용하게 사용될 수 있다.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2014년도 추계학술대회 및 정기총회
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• pp.19-19
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• 2014

Pleurotus ostreatus, P. eryngii, and Flammulina velutipes are major edible mushrooms that account for over 89% of total mushroom production in Korea. Recently, Agrocybe cylindracea, Hypsizygus marmoreus, and Hericium erinaceu are increasingly being cultivated in mushroom farms. In Korea, the production of edible mushrooms was estimated to be 614,224 ton in 2013. Generally, about 5 kg of mushroom substrate is needed to produce 1 kg of mushroom, and consequently about 25 million tons of spent mushroom substrate (SMS) is produced each year in Korea. Because this massive amount of SMC is unsuitable for reuse in mushroom production, it is either used as garden fertilizer or deposited in landfills, which pollutes the environment. It is reasonably assumed that SMS includes different secondary metabolites and extracellular enzymes produced from mycelia on substrate. Three major groups of enzymes such as cellulases, xylanases, and lignin degrading enzymes are involved in breaking down mushroom substrates. Cellulase and xylanase have been used as the industrial enzymes involving the saccharification of biomass to produce biofuel. In addition, lignin degrading enzymes such as laccases have been used to decolorize the industrial synthetic dyes and remove environmental pollutions such as phenolic compounds. Basidiomycetes produce a large number of biologically active compounds that show antibacterial, antifungal, antiviral, cytotoxic or hallucinogenic activities. However, most previous researches have focused on therapeutics and less on the control of plant diseases. SMS can be considered as an easily available source of active compounds to protect plants from fungal and bacterial infections, helping alleviate the waste disposal problem in the mushroom industry and creating an environmentally friendly method to reduce plant pathogens. We describe extraction of lignocellulytic enzymes and antimicrobial substance from SMSs of different edible mushrooms and their potential applications.

• 한국물환경학회지
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• 제22권1호
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• pp.51-58
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• 2006

The effluent limitations for individual industry based on the best available technology economically achievable (BAT) have been required to achieve effective regulation. BAT assessment criteria that are suitable for the circumstances of Korean industry were developed in the previous study. The criteria were applied to determine the BAT for leather tanning and finishing industry. For the evaluation BAT, a subcategorization for the industry considering wastewater characteristics, source equipments, raw material and so on should be suggested. Three subcategories: A) Unharing, Chrome Tan, Retan-Wet Finish, B) Chrome Tan, Retan-Wet Finish, and C) Furskins were proposed in this study. Wastewater discharged from the each category contains high concentration of COD, chrome, nitrogen and sulfide. In particular, the concentration of nitrogen from the subcategory A is significantly greater. Twenty sites were surveyed and wastewater qualities were analyzed. Therefore, six different technologies were applied to the subcategory A for the end-of-pipe treatment technology, and a technology was used in the subcategory B and C, respectively. The technology candidates were evaluated in terms of environmental impacts, economically achievability, treatment performance and economical reasonability. As the result, the technology options for each subcategories: A) primary chemical precipitation + modified Ludzack-Ettinger process (MLE) + secondary chemical precipitation, B) chemical precipitation + typical activated-sludge process + Fenton oxidation, C) chemical precipitation + typical activated-sludge process + batch Fenton oxidation or batch activated carbon treatment were selected as the BAT, respectively.

• 한국약용작물학회지
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• 제23권5호
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• pp.385-394
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• 2015

Background : Dibenzocyclooctadiene lignans are secondary metabolites present abundantly in the fruits belonging to the genus Schisandra. According to previous studies, Schisandra lignans exhibit anti-inflammatory, anti-cancer and anti-diabetic properties, as well as an inhibitory effect on platelet aggregation. Therefore, establishing the Korean "Omija" (Schisandra chinensis) as a lignan-rich source, in addition to identifying and quantifying the lignans, is extremely valuable. Methods and Results : Dibenzocyclooctadiene lignans were analyzed with liquid chromatography using diode array detection/mass spectrometry, from methanol extracts subsequently identified by a constructed chemical library of 50 lignans. A total of 27 components of lignan including gomisin S were identified, of which schisandrin, gomisin A, gomisin N, deoxyschisandrin, ${\gamma}$-schisandrin, and schisandrin C were identified as the major components in the Korean Omija, Schisandra chinensis. These compounds were divided into two groups, S-biphenyl and R-biphenyl based on the configurations of the stereoisomers structures with contents of 661.7 and 1350.1mg per 100 g dry weight, respectively. The total lignan content averaged 2011.4mg per 100 g dry weight, of which schisandrin and gomisin N comprised the majority (771.8 and 420.5mg per 100 g dry weight respectively). Conclusions : Lignans which are present in high quantities in the ripe fruit of Schisandra chinensis are important functional compounds that play a major role in the prevention and treatment of human diseases.

• 가족자원경영과 정책
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• 제17권2호
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• pp.93-119
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• 2013

The actual time fathers spend in childcare has not increased much in spite of recent attention paid to nurturing their children and changes in the fathers' role. In this study, parenting time is measured by time spent in childcare, shared housework, and shared leisure. In this way, this study seeks to analyze trends in fathers' time spent with children and the factors that influence fathers' participation in parenting. The data source for this study was the 2009 Korean Time Use Survey. The main results of this research are as follows: First, when measuring childcare time as a primary activity, fathers' time spent in parenting averaged 17 minutes on weekdays and 32 minutes on Sundays. This extended to 44 minutes on weekdays and 166 minutes on Sundays when including the secondary childcare time and the shared time with their children while doing housework or leisure. Second, fathers' probability of participating in childcare was higher for fathers who had shorter working hours, younger children, higher spouse average monthly income, and a college or higher education level. The variable that influenced fathers' participation in shared housework on weekdays was working hours. On Sundays, the variables were working hours, age of the youngest child, and the type of occupation. Fathers' participation in shared leisure was influenced by father's working hours, number of children, age of the youngest child, and type of occupation on weekdays. On Sundays, it was influenced by working hours and the age of the youngest child.

• The Korean Journal of Physiology and Pharmacology
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• 제13권5호
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• pp.373-378
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• 2009

Cerebellar Purkinje cells (PCs) play a crucial role in motor functions and their progressive degeneration is closely associated with spinocerebellar ataxias. Although immunohistochemical (IHC) analysis can provide a valuable tool for understanding the pathophysiology of PC disorders, the method validation of IHC analysis with cerebellar tissue specimens is unclear. Here we present an optimized and validated IHC method using antibodies to calbindin D28k, a specific PC marker in the cerebellum. To achieve the desired sensitivity, specificity, and reproducibility, we modified IHC analysis procedures for cerebellar tissues. We found that the sensitivity of staining varies depending on the commercial source of primary antibody. In addition, we showed that a biotin-free signal amplification method using a horseradish peroxidase polymer-conjugated secondary antibody increases both the sensitivity and specificity of ICH analysis. Furthermore, we demonstrated that dye filtration using a $0.22\;{\mu}m$ filter eliminates or minimizes nonspecific staining while preserving the analytical sensitivity. These results suggest that our protocol can be adapted for future investigations aiming to understand the pathophysiology of cerebellar PC disorders and to evaluate the efficacy of therapeutic strategies for treating' these diseases.

• 한국식품영양과학회지
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• 제13권1호
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• pp.117-126
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• 1984

Aflatoxins are toxic and carcinogenic secondary metabolites which are produced by trains of A. flavus and A. parasiticus during their growth on foods and feedstuffs. Aflatoxins are a group of closely related heterocyclic compounds of which $B_1$, $B_2$, and $G_2$ are the major members. Aflatoxins are synthesized via a polyketide pathway in which the general steps are acetate, an-thraquinones, xanthone and aflatoxins. Aflatoxin formation is favored by high moisture or high $a_w$(0.95${\sim}$0.99). The limiting $a_w$ for aflatoxin production on agricultural commodities is 0.83. Optimum temperature for aflatoxin production by the molds is $25{\sim}30^{\circ}C$ and the incubation time for the maximum production of the toxin is 7${\sim}$15 days. The limiting temperatures for aflatoxin production are ${\leq}7.5^{\circ}C\;and\;\geq40^{\circ}C$. Cycling temperatures may or may not stimulate aflatoxin production depending on the amplitude of cycling, substrate and strains of molds. Aflatoxin pro-ducing molds are aerobic organisms and thus have a requirement for oxygen. A decreasing $O_2$ concentration and/or increasing concentrations of $CO_2$ or $N_2$ depress the mold growth and aflatoxin formation. A. flavus grows competitively or associatively in the presence of other microorganisms and occasionally loses the competition with other microorganisms. Some lactic acid bacteria have been shown to reduce growth and aflatoxin production by A. parasiticus. Carbon source is the most important nutritional factors affecting aflatoxin formation by the molds. Sucrose, fructose and glucose are the most favorable carbon sources. Food substrates of plant derived products which have high carbohydrate content such as agricultural commodities and their products are most vulnerable to contamination by aflatoxins.

• 한국전자파학회논문지
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• 제25권2호
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• pp.208-216
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• 2014

달 탐사 미션 수행을 위한 지상국은 달 궤도선과 착륙선의 상태 정보 및 관측한 센서 데이터를 수신할 수 있어야 한다. 이러한 지상 시스템 개발 초기 단계에서는 정확한 링크 파라미터에 의한 링크 분석을 통해 지상 안테나의 크기 및 시스템 잡음 성능이 도출되어야 한다. 한편, 지상 안테나가 달 궤도선과 착륙선과 통신을 할 경우에 달을 지향하게 되고, 이 때 달은 자체 밝기에 의해 안테나의 수신 성능을 열화 시키는 잡음으로써 동작한다. 본 논문에서는 안테나가 달을 지향할 때 발생되는 수신 성능 열화에 대한 분석 결과를 제시한다. 결과 검증을 위해 달에 의한 안테나 잡음 온도를 우선 계산 한 후에 이를 본 논문에서 제안하는 시험 방식의 결과와 비교하였고, 그 결과는 허용 오차 수준에서 일치함을 확인하였다. 이는 달에 의한 안테나 잡음 온도의 계산 방식이 정당함을 검증한 것이므로 이 방식을 통하여 다양한 주파수와 안테나의 크기에 따른 달 탐사 지상 안테나의 수신 열화 분석을 수행할 수 있었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 추계학술대회 논문집 전기물성,응용부문
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• pp.202-203
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• 2006

In the AC PDP, the MgO film is used as electrode protective film. This film must provide excellent ion bombardment protection, high secondary electron emission, and should be high transparent to visible radiation. In this study, we investigated the relations between the crystal orientation and e-beam evaporation process parameters. The crystal orientation of the MgO layer depends on the conditions of deposition. The parameters are the thickness of the MgO film $1000{\AA}-6500{\AA}$, the deposition rate $200{\AA}/min{\sim}440{\AA}/min$, the temperature $150^{\circ}C{\sim}250^{\circ}C$, and the distance between crucible and substrate 11cm ${\sim}$ 14cm. The temperature of substrate and evaporation rate of source material, or deposition rate of the film, are definitely related to the crystal orientation of the MgO thin film. The crystal orientation can be changed by the distance between the target(MgO tablet) and the substrate. However, the crystal orientation is not much affected by the thickness of MgO thin film.