• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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• pp.179-184
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• 2000

The presens study was aimed to investigate the possibility of use of pozzolanic materials such as blast furnace slag, fly ash, paper sludge ash which are produced from industrial wastes, as construction materials. Experiments were undertaken to investigate the properties of concrete bricks and interlocking blocks made with these industrial by-products. As a result, it was found that the concrete bricks and interlocking blocks made with substitute materials have equivalent strength and quality to those of conventional concrete bricks and interlocking blocks made with only cement. Thus, it could be expected that recycling the industrial wastes can reduce manufacturing costs of the cement as well as prevent environmental pollution by the use of the by-products thrown out as wastes to make secondary products of the concrete.

• 품질경영학회지
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• 제22권4호
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• pp.28-39
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• 1994

This study is concerned with determination of an optimal target value in a filling process. Complete inspection procedures are widely used to improve outgoing quality of products. In many cases, however, it may be impossible or noneconomical to measure the quality characteristic, performance variable, directly. In such cases, it is a common practice to select an easily measurable variable which is highly correlated with the performance variable and perform screening products for the variable. This study proposes a model to determine the target value and the inspection rule based on the screening variable. This, study deals with the cases in which rejected products would be scrapped and sold at a reduced price in secondary markets.

• 산업경영시스템학회지
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• 제32권4호
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• pp.192-202
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• 2009

Disassembly of products at their end-of-life (EOL) is a prerequisite for recycling or remanufacturing, since most products should be disassembled before being recycled or remanufactured as secondary parts or materials. In disassembly sequence planning of EOL products, considered are the uncertainty issues, i.e., defective parts or joints in an incoming product, disassembly damage, and imprecise net profits and costs. The paper deals with the problem of determining the disassembly level and corresponding sequence, with the objective of maximizing the overall profit under uncertainties in disassembly cost and/or revenue. The solution is represented as the longest path on a directed acyclic graph where parameter (arc length) uncertainties are modeled in the form of intervals. And, a heuristic algorithm is developed to find a path with the minimum worst case regret, since the problem is NP-hard. Computational experiments are carried out to show the performance of the proposed algorithm compared with the mixed integer programming model and Conde's heuristic algorithm.

• 보존과학회지
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• 제1권1호
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• pp.3-11
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• 1992

Micromorphological changes in waterlogged archaeological woods excavated from Sweden and Germany were investigated. Especially bacterial attacks on those wood samples under near anaerobic conditions were examined by transmission electron microscopy(TEM). The major feature of micromorphological alterations in those wood samples was the preferential destruction of secondary wood cell wall. In contrast, the middle lamella was not extensively degraded. Three distinct degradation patterns by bacteria were observed : erosion, cavitation and tunnelling bacteria. Erosion and cavitation bacteria attacked primarily $S_2$ layer, whereas tunnelling bacteria made the tunnel-like degradation along the $S_1$ layer. Tunnelling bacteria, in some samples, were able to degrade tunnel in the lignin-rich areas, such as middle lamella, suggesting that these bacteria had the capacity to degrade the lignin. IR spectra indicate that hemicellulose and cellulose in the waterlogged woods were preferentially decomposed. Breakdown of the lignin, on the other hand, was much slower.

• 대한방사선기술학회지:방사선기술과학
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• 제43권2호
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• pp.123-128
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• 2020

Radiation Following the 2011 Fukushima nuclear accident in Japan, public interest and anxiety about radiation safety increased, and vague anxiety about commonly exposed living radiation was generated. The Atomic Energy Safety Commission has been conducting a survey of processed products that advertise "negative ions" and "far-infrared" emissions under the Living Radiation Safety Management Act. In this study, in-depth analysis was performed from a statistical point of view using the measurement data presented in the Nuclear Safety Committee's actual survey analysis report as secondary data. As a result, there was a statistically significant difference (p<0.005) between latex and civil affairs products. There were also statistically significant differences (p<0.05) in the results of testing whether there were significant differences in the annual exposure dose between groups after categorizing 71 civil products, including radon beds, into bed, bedding, and living and other categories. The correlation analysis results also confirm that, as is commonly known, the annual doses received from processed products are associated with radon derived from U-238 and Th-232.

• 한국식품위생안전성학회지
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• 제39권3호
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• pp.191-208
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• 2024

펩타이드형 독소인 마이크로시스틴(microcystins, MCs)과 노둘라린(nodularin, NOD)은 남조류라고도 알려진 시아노박테리아에 의해 생성되는 2차 대사산물로, 독소에 오염된 물, 토양 및 비료를 사용함으로써 농산물 내에 축적되고 이를 사람이 섭취함으로써 건강상 위해가 발생할 수 있다. 최근 MCs과 NOD의 농산물 내 오염에 대한 관심이 대두되며 국내외에서 여러 분석법을 기반으로 농산물 내 오염 수준을 조사하고 있다. 하지만 아직까지 수행된 연구가 많지 않으며, 특히 펩타이드형 독소 중 MCs의 분석 연구에 치중되어 있거나 오염 취약 지역에서 재배한 농산물이 주로 오염도 조사에 사용되는 등 연구에 한계가 있으므로 MCs과 NOD의 관리를 위해서는 보다 많은 체계적인 연구가 필요할 것으로 생각된다. 본 연구에서는 체계적인 모니터링 및 안전관리의 기반을 마련하기 위해 MCs 및 NOD의 이화학적 특성, 독성, 분석법, 오염사례 및 관리현황에 대해 기술하였다.

• 한국미생물·생명공학회지
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• 제26권3호
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• pp.264-268
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• 1998

덱스트란수크라제는 Sucrose를 이용하여 덱스트란의 합성을 촉진하는데 sucrose이외에 다른 탄수화물이 효소 반응기 중에 존재하는 경우에는 Sucrose의 glucose를 이 탄수화물에 전달하는 반응을 촉진하여 새로운 구조의 산물을 생산한다. Leuconostoc mesenteroides B-742CB로 부터 얻은 덱스트란수크라제를 이용하여 플루란을 변형하고 그 조건을 최적화 하고자 했다. 수용성 변형 플루란은 이론적 수율의 57%(<$\pm$5)를 얻었다. 플루란 변형의 최적 조건으로는 pH 5.2, 28$^{\circ}C$ 에서 기질 0.37%(w/v)와 반응한 효소의 농도와 Sucrose농도가 각각 0.1 U/$m\ell$과 48mM일 때였다. 변형 플루란을 pullulanase, endodextranase로 처리하여 변형 전의 플루란과가수분해 상태를 비교 분석한 결과 변형전의 산물에 비해 이들 가수 분해 효소에 대해 더 저항성을 보였다. 변형 플루란을 methylation과 산가수분해 후 TLC한 결과 sucrose의 glucose가 플루란 glucose의 C3, C4, C6 위치의 free-OH group에 수식된 새로운 구조의 변형 플루란임을 확인하였다.

• 한국분말재료학회지
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• 제16권6호
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• pp.396-402
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• 2009

Tantalum nitrides ($Ta_3N_5$) have been developed to substitute the Cd based pigments for non-toxic red pigment. Various doping elements were doped to reduce the amount of high price Tantalum element used and preserve the red color tonality. Doping elements were added in the synthesizing process of precursor of amorphous tantalum oxides and then Tantalum nitrides doped with various elements were obtained by ammonolysis process. The average particle size of final nitrides with secondary phases was larger than the nitride without the secondary phases. Also secondary phases reduced the red color tonality of final products. On the other hand, final nitrides without secondary phase had orthorhombic crystal system and presented good red color. In other words, in the case of nitrides without secondary phases, doping elements made a solid solution of tantalum nitride. In this context, doping process controlled the ionic state of nitrides and the amount of oxygen/nitrogen in final nitrides affected the color tonality.

• The Plant Pathology Journal
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• 제26권1호
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• pp.57-62
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• 2010

Low-molecular-weight secondary metabolites from plants play an important role in reproductive processes and in the defense against environmental stresses or pathogens. In the present study, we isolated various volatiles and phenolic compounds from white Rosa rugosa flowers, and evaluated the pharmaceutical activities of these natural products in addition to their ability to increase survival in response to environmental stress and pathogen invasion. The DPPH and hydroxyl radical-mediated oxidation assay revealed that the white rose flower extract (WRFE) strongly scavenged free radicals in a dose dependent manner. Moreover, WRFE inhibited the growth of E. coli and fatally attacked those cells at higher concentration (>0.5 mg/mL). FITC-conjugated Annexin V stain provided further evidence that WRFE had strong antimicrobial activity, which may have resulted from a cooperative synergism between volatiles (e.g. 1-butanol, dodecyl acrylate and cyclododecane) and phenolic compounds (e.g. gallic acid) retained in WRFE. In conclusion, secondary metabolites from white rose flower hold promise as a potential natural source for antimicrobial and non-chemical based antioxidant agents.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2018년도 추계학술대회
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• pp.23-23
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• 2018

Taiwan, formerly known as Formosa, located on tropical and subtropical climate zones with abundant biological resources. According to the latest version of the Flora of Taiwan, there are 4339 species of vascular plants including 1054 endemic species. First, Taiwania (Taiwania cryptomerioides), named after its native island of Taiwan, have been isolated more than 500 secondary metabolites, including lignans, terpenoids, steroids, and flavonoids. Several of the metabolites are reported to have antibacterial, antifungal, antimite, antitermite and antitumor activities. In order to investigate plant secondary metabolic diversity toward industrial applications, we established deep transcriptome resources for non-model plants and fungi to produce terpenoid metabolites of economic importance. Second, many plants of Lauraceae have been utilized in folk medicine for their exciting bioactivities. The twigs and leaves from 27 tree species of Lauraceae grown in Taiwan were performed to evaluate potential bioactivity. The leaves of Cinnamomum osmophloeum are traditionally used in folk medicines, and many biological activities have been identified, such as antibacterial, antifungal, antitermite, antidiabetic, antihyperuricemia, antiinflammatory, and antioxidant activities. However, C. osmophloeum has nine chemotypes with various secondary metabolite profiles. In order to efficiently produce active compounds, we established the genetic markers to identify the chemotype plants. Finally, Cinnamomum kanehirae is the host of the medicinal mushroom Antrodia cinnamomea. Several in vivo and in vitro studies indicated that A. cinnamomea possesses a diverse range of biological activities. Because of the potential pharmacological application, we established the transformation system to enhance the triterpenoid contents production.