• 공업화학
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• 제18권1호
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• pp.1-9
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• 2007

천연가스는 가솔린에 비하여 에너지 밀도가 매우 낮아 천연가스 차량의 경우 약 24.8 MPa로 압축된 압축천연가스(CNG)를 이용하기 때문에 고압을 얻기 위하여 다단계 압축이 요구될 뿐 아니라 안정성에 문제가 많다. 이런 이유로 비교적 낮은 압력에서 저장할 수 있는 흡착천연가스에 관심을 갖게 되었다. 천연가스의 저장에 용이한 매질을 개발하여 3.5 MPa에서 CNG와 에너지 밀도가 유사하고, 같은 용적의 가솔린에 비하여 1/4 수준의 운전거리를 확보하는 것이 현재의 목표이다. 본 총설에서는 흡착천연가스(ANG) 저장을 위한 탄소매질의 개발현황, 매질의 특성 및 실용화를 위하여 진행되고 있는 내용을 간략하게 소개하고 몇 가지 필요한 제언을 한다.

• 한국유기농업학회지
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• 제27권3호
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• pp.341-351
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• 2019

본 연구는 2018년 충북 괴산군 유기농업연구소에서 노지재배의 단점을 보완할 수 있는 수경재배 기술의 일환으로 명월초 유기 수경재배 시 천연배지 종류가 생육에 미치는 영향을 조사하여 최적의 천연배지를 선발하고자 수행하였다. 실험에 사용한 유기양액은 생육증 진용 유기농자재로 등록된 시판자재 34종을 성분 분석한 후 2종을 혼합하여 사용하였으며, pH 5.5~6.5, EC 0.5~1.0 ds/m로 5월 20일부터 1일 1회, 회 당 50 L씩 점적관수(Ø13 mm, Nam Kyung Co.)를 이용하여 처리하였다. 명월초 정식 후 5월~6월 중순까지 배지별 근권의 최저 온도는 코코피트가 포함된 배지의 최저온도가 다른 배지에 비해 높은 경향을 나타내었으며, 상대적으로 펄라이트가 포함된 배지의 최저온도가 다른 배지에 비해 낮은 경향을 나타내었다. 혼합배지를 제외한 단용 배지별 최저온도는 코코피트 배지가 가장 높게 나타났으며, 그 다음이 버미큘라이트 배지, 펄라이트 배지가 가장 낮게 나타났다. 명월초 정식 후 50일의 천연배지 조성에 따른 초기 생육특성(초장, 엽수, 엽장, 엽폭)은 버미큘라이트 배지에서 가장 우수하게 나타났다. 천연배지 조성별 명월초 수량은 버미큘라이트 배지와 코코피트 : 버미큘라이트 : 펄라이트(2:1:1) 혼합배지가 가장 우수하게 나타났다. 주요 항산화 성분인 총 폴리페놀의 함량은 버미큘라이트 배지에서 1.45 mg g^-1으로 가장 높게 나타났다. 따라서, 천연배지 조성에 따른 명월초 생육, 수량 및 총 폴리페놀 함량 등을 비교했을 때 버미큘라이트 단용 배지가 유기 수경재배 시 천연배지로 적합할 것으로 판단된다.

• 한국대기환경학회지
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• 제29권2호
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• pp.125-134
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• 2013

Various antimicrobial technologies have been developed to inactivate bioaerosols in indoor environments. In this study, air filter media were treated with a natural antibacterial agent of Sophora flavescens in order to inactivate the bacteria collected on the air filter. Three treatment methods were applied to manufacture the test antibacterial air filter media: electrospray, nebulization and dip-coating methods. In case of electrospray and nebulization processes, the size distribution of aerosolized natural antibacterial agent was measured using a scanning mobility particle sizer. Staphylococcus epidermidis bacteria were aerosolized to test inactivation of the filter media treated with a natural antibacterial agent. The pressure drop and the antibacterial efficiency of the filter media increased with increasing the mass loading of natural antibacterial agent in each treatment method. The antibacterial efficiency per loaded antibacterial agent mass by the electrospray method was the highest and the filter treated by the dip-coating method was the lowest among three treatment methods.

• Mycobiology
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• 제29권3호
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• pp.160-163
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• 2001

Sikhae is a Korean traditional beverage of saccharified rice. Its factory waste(SFW) is usually thrown away instead of being used. We developed a cheap substrate of SFW for use in liquid spawn that is known for its higher fruit body yields than grain spawn in sawdust cultivation. Mycelia of Lentinula edodes ASI 3046, which is regarded as the most suitable strain for sawdust cultivation, were cultured on six kinds of previous known media and SFW. As the seven kinds of media were applied, a Sikhae Factory Waste(SFW) was most excellent in growth. The dried mycelial weight in SFW was almost four times as much as that in the other media. In the flask culture, optimum culture conditions for the mycelial growth were obtained after 13 days of cultivation at media volume of 100 ml, 100 rpm, initial pH 4.5, and $25^{\circ}C$. The best mycelial growth was observed when $MgSO_4{\cdot}7H_2O$ and D-sucrose were added as a supplement in SFW. SWM must be a remarkable medium for L. edodes because of its simple preparation and low cost.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집B
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• pp.51-56
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• 2000

The Finite Element Solutions Is reported on solid-liquid phase change in porous media with natural convection including freezing. The model is based on volume averaged transport equations, while phase change is assumed to occur over a small temperature range. The FEM (Finite Element Method) algorithm used in this study is 3-step time-splitting method which requires much less execution time and computer storage the velocity-pressure integrated method and the penalty method. And the explicit Lax-Wendroff scheme is applied to nonlinear convective term in the energy equation. For natural convection including melting and solidification the numerical results show reasonable agreement with FDM (Finite Difference Method) results.

• 한국문헌정보학회지
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• 제22권
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• pp.143-177
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• 1992

The main purpose of the school library is to present the various kinds of instructional media for an effective instruction including not only books, but also audiovisual materials and equipments. But unfortunately our school libraries have only books for the students and faculties at this time. But hereafter school library should house the various kinds of audiovisual media as well as printed media for the promotion of scholarstic achivemint. With a view to promoting the teaching method, and at the same time improving the scholarstic achivement of the students, instructional media were used in the class. To verify the efficiency of the instructional media, transparencies were used in the social science class of the 1st grade in the middle school and the natural science class of the 1st grade in the high school. In consequence, the academic achievement of the experimental class in which instructional media were used is superior to that of controlled class in which the textbook was only used. In < Social Science I >, the mean difference between the experimental class and the controlled class is 4.199 marks. And the difference, 0.032 is verified as a significant value in concordance to the t-test. In < Natural Science I >, the mean difference of the experimental class over the controlled class is 6.333. And the difference, 0.034 is verified as a significant value in concordance to the t-test. As shown in the above experimental research, using various kinds of the instructional media is more efficient than using textbook only. As a result of the questionaire on using the instructional media, most of the students desire to use of them continually because the use of the instructional media induce the interest, promote the comprehension, and entice the development of better memories.

• 대한의생명과학회지
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• 제23권2호
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• pp.64-72
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• 2017

The formation of brown colonies due to phenol oxidase activity on classic agar media containing natural material extracts of Helianthus annuus or on medium containing L-3,4-dihydroxyphenylalanine has been used to identify Cryptococcus species complex. In this study, various natural materials were used to develop a modified medium and to identify five major serotypes of Cryptococcus species complex. Serotypes A, D, and A/D were pigmented on medium using Perilla frutescens var. japonica Hara (PerJ agar) after a three-day incubation. Serotypes B and C were pigmented on PerJ agar after four- and five-day incubations, respectively. Growth time and pigmentation of the five serotypes occurred more rapidly on PerJ agar than on the other media. In addition, colony morphology, size, and pigmentation were specific by serotype. In conclusion, PerJ agar should be used in clinic settings to identify Cryptococcus species complex and its serotypes rapidly.

• 한국환경농학회지
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• 제28권4호
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• pp.403-408
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• 2009

Dandelion (Taraxacum platycarpum) has been widely utilized for medicinal purposes. However, the dandelion seeds are relatively difficult to germinate under cultivation conditions, which hampers seedling propagation of dandelion plants and reduces the opportunity of usage of such a useful medicinal plant. Thus, in this study, in vitro conditions for the dandelion seed germination were optimized to enhance the germination rate. In seed washing steps, the sequential treatments with 20% of ethanol, 20% of NaOCl, and distilled water avoided microbial contamination with the highest in vitro germination rate (67.5%) from seeds sown in germination media. The media supplemented with 1.4 g/L of MS salts and 1% of sucrose significantly enhanced the germination rate compared to the media with 4.4 g/L of MS and 3% of sucrose. Sowing the seeds vertically in the optimized media supplement conditions, 1.4 g/L of MS salts and 1% of sucrose, gave the maximum in vitro germination rate (61%), which was almost three times higher than sowing seeds on a soil pot (23%). Our results indicate that the seed washing and sowing methods including germination medium supplements can be optimized to enhance in vitro seed germination of dandelion.

• 대한가정학회지
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• 제48권8호
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• pp.113-128
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• 2010

The purposes of this study were 1) to divide consumers into segments according to their consumption attitude and subjective knowledge about natural dyed products 2) to develop a profile for each segment with respect to the media types, the preferred media programs, the information sources, the lifestyle activities and the demographics. Data(n = 213) was collected using questionnaires via the internet. By cluster analysis of the consumers' attitude and their subjective knowledge about natural dyed products, four groups were identified 1) the loyal consumption group (20.1%), 2) the conditional/reluctant consumption group(36.6%), 3) the negative/reluctant consumption group(24.2%) and 4) the non purchasers(19.1%). Several characteristics of these four groups were then compared by ANOVA and chi-square statistics. The results indicated that the consumption attitude and subjective knowledge could be the criteria for segmenting the consumers and that the segmented groups had unique consumer characteristics. Implications of this study were discussed.

• Mycobiology
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• 제44권4호
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• pp.283-290
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• 2016

A double-stranded RNA (dsRNA) mycovirus was detected in malformed fruiting bodies of Pleurotus ostreatus strain ASI2792, one of bottle cultivated commercial strains of the edible oyster mushroom. The partial RNA-dependent RNA polymerase (RdRp) gene of the P. ostreatus ASI2792 mycovirus (PoV-ASI2792) was cloned, and a cDNA sequences alignment revealed that the sequence was identical to the RdRp gene of a known PoSV found in the P. ostreatus strain. To investigate the symptoms of PoV-ASI2792 infection by comparing the isogenic virus-free P. ostreatus strains with a virus-infected strain, isogenic virus-cured P. ostreatus strains were obtained by the mycelial fragmentation method for virus curing. The absence of virus was verified with gel electrophoresis after dsRNA-specific virus purification and Northern blot analysis using a partial RdRp cDNA of PoV-ASI2792. The growth rate and mycelial dry weight of virus-infected P. ostreatus strain with PoV-ASI2792 mycovirus were compared to those of three virus-free isogenic strains on 10 different media. The virus-cured strains showed distinctly higher mycelial growth rates and dry weights on all kinds of experimental culture media, with at least a 2.2-fold higher mycelial growth rate on mushroom complete media (MCM) and Hamada media, and a 2.7-fold higher mycelial dry weight on MCM and yeast-malt-glucose agar media than those of the virus-infected strain. These results suggest that the infection of PoV mycovirus has a deleterious effect on the vegetative growth of P. ostreatus.