• Korean Journal Plant Pathology
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• v.11 no.2
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• pp.120-131
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• 1995

이 연구는 우리나라의 유용 자원식물에 발생하는 진균성 미기록 병해에 대한 두 번째 보고이다. 10가지 병해에 대한 각각의 병징, 병 발생환경, 병원균, 그리고 몇 가지 병리학적 소견을 기록하였다. 동자꽃 갈색 무늬병은 장마철부터 발생하여 심한 잎마름을 일으켰으며, 병원균은 Septoria lychnidis로 동정되었다. 산박하 모무늬병은 장마철에 심하게 발생하고 작은 모무늬가 합쳐져 잎의 한쪽이 검게 고사하였는데, 병원균은 Septoria plectranthi로 동정되었다. 좀명아주 갈색 무늬병은 여름부터 가을까지 흔히 발생하여 조기낙엽을 일으켰으며, 병원균은 Cercospora dubia로 동정되었다. 나팔꽃 점무늬병은 장마철부터 가을까지 흔히 발생하여 관상가치를 떨어뜨렸는데, 병원균은 Cercospora ipomoeae로 동정되었다. 돌콩 점무늬병은 장마철부터 가을까지 계속 발생하여 생육을 크게 저해하였는데, 병원균은 Pseudocercospora ligustri로 동정되었다. 박주가리 뒷면곰팡이병은 여름부터 가을까지 흔히 발생하여 조기낙엽과 황화를 일으켰는데, 병원균은 Passalora miurae로 동정되었다. 고려엉겅퀴 흰가루병은 여름부터 발생하여 묵나물의 수향과 품질에 피해를 주었는데, 병원균은 Sphaerotheca fusca로 동정되었다. 왜당나귀흰가루병은 국지적으로 발생하여 생육을 저해하고 어린 묘는 고사시켰는데, 병원균은 Erysiphe heraclei로 동정되었다. 가래나무 점무늬병은 장마철에서 가을까지 발생하여 잎마름을 유발하였는데, 병원균은 Sphaerulina juglandis로 동정되었다.

• 한국산학경영학회:학술대회논문집
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• 2006.06a
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• pp.147-170
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• 2006

Landfill gas is a mixture of methane and carbon dioxide produced by the bacterial decomposition of organic wastes, and it is considered to produce bad smells and pollute the environment. Economic trials and the developments of landfill gas, as an alternative energy resource, become known at the recent years, Resource development of landfill gas, which is managed by Korea up to now, is for the most part generation using gas engine. Medium BTU and High BTU are considered for the power generation as well. Most income of generation using gas engine is selling charge through a power plant. Expecting to manage the power plant for up to 10 years, the analysis based on revenue and expenditure shows when the unit price is 65.2 Won and the operating rate reaches 90%, it is possible to be into the black in 2012 without considering additional financial expense, It was also analyzed that the profit at a unit price of 85 Won under the anticipated rising unit price by the operating rate of 71% is larger than at the operating rate of 90% under limited unit price of 65.2 Won. It means to manage the power plant at a unit price of 65.2 Won and the operating rate must be higher than 90% for economic logicality. If we assume that the operating rate is 90% and it increases the unit price, the unit price must be higher than 85 Won for the management of a power plant. Analysis of changing a unit price, however, might be expected to have a gradual rise of prices. If there is no price rising and additional income related to CDM(Clean Development Mechanism) and emission trading upon Kyoto protocol, the management of a power plant using gas engine will get financial difficulties because of many operating expenses. However, since landfill gas is considered as a worthy energy resource for the guarantee of sustainable development and for the equity between recent generation and future generation, the development of it must be accomplished by the government's additional supporting and efforts under the interest of all stakeholder who are involved.

• Environmental and Resource Economics Review
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• v.16 no.4
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• pp.763-779
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• 2007

The combined heat-and-power (CHP) plant is recently suggested as an effective resolution in response to recent rising oil prices and the Kyoto Protocol. This research provides a model for economic appraisal to evaluate CHP investment. Real option model is developed to incorporate a case where the investment is irreversible and underlying revenue is stochastic. The analysis shows that power plant capacity more than 40 Gcal makes CHP investment profitable while the results may vary 10 modest level with respect to investment cost, heat sales price and discount rate.

• Applied Chemistry for Engineering
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• v.27 no.2
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• pp.171-178
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• 2016

Extensive efforts from all over the world have been made to solve energy problems, such as high oil prices, global warning due to the depletion of oil. Among them, biofuel has been drawing attention as a clean energy, which can replace fossil fuels. However, conventional biofuels were often converted from eatable biomass such as sugar cane, corn and soy which should be replaced with uneatable biomass. In this study, a techno-economical evaluation of the gasification of biomass waste with mixed alcohol synthesis process was performed. Considering available domestic biomass wastes, a 2000 ton/day conversion plant were assumed to produce 533000 L/day ethanol. Also, financial data from previous studies were evaluated and used and economical sensitivities with various operation conditions were established. Economic analysis were conducted by the payback period and internal rate of return (IRR) and net present value (NPV). Sensitivity analyses of raw material costs, initial investment, the major process cost, ethanol price changes and operating costs were all performed.

• The Plant Pathology Journal
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• v.35 no.3
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• pp.200-207
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• 2019

Fusarium head blight (FHB) is a devastating wheat disease with a significant economic impact. Fhb1 is the most important large effect and stable QTL for FHB resistance. A pore-forming toxin-like (PFT) gene was recently identified as an underlying gene for Fhb1 resistance. In this study, we developed and validated a PFT-based Kompetitive allele specific PCR (KASP) marker for Fhb1. The KASP marker, PFT_KASP, was used to screen 298 diverse wheat breeding lines and cultivars. The KASP clustering results were compared with gelbased gene specific markers and the widely used linked STS marker, UMN10. Eight disagreements were found between PFT_KASP and UMN10 assays among the tested lines. Based on the genotyping and sequencing of genes in the Fhb1 region, these genotypes were found to be common with a previously characterized susceptible haplotype. Therefore, our results indicate that PFT_KASP is a perfect diagnostic marker for Fhb1 and would be a valuable tool for introgression and pyramiding of FHB resistance in wheat cultivars.

• The Plant Pathology Journal
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• v.35 no.5
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• pp.417-424
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• 2019

Melanose, caused by Diaporthe citri, is one of severe diseases in citrus, a major economic resource in Jeju island. To reduce the usage amount of organic synthetic fungicide, bio-sulfur was tested as an alternative chemical to control citrus melanose in the present study. Direct antifungal activity of bio-sulfur against D. citri was determined through in vitro experiment using artificial nutrient media. Disease severity of melanose on bio-sulfur pretreated citrus leaves was lower than that on untreated ones. To illustrate the mechanism of disease suppression by bio-sulfur, infection structures were observed with a fluorescent microscope and a scanning electron microscope. In fluorescent microscopic observation, most conidia rarely germinated. In addition, hyphal growth on leaves pretreated with bio-sulfur was inhibited compared to that on untreated ones. In scanning electron microscope images of bio-sulfur pretreated leaves, surfaces of most conidia were shrunk while hyphae were morphologically changed and frequently branched. Such microscopic observations were also found for leaves pretreated with a commercial fungicide Dithianon. These results suggest that bio-sulfur may be used to control citrus melanose as an environment friendly alternative to organic synthetic fungicides

• Environmental and Resource Economics Review
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• v.12 no.2
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• pp.217-244
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• 2003

As energy industry is undergoing a rapid structural changes, economic feasibility analysis based on the conventional discounted cash flow (DCF) method has limitations to incorporate management's flexibilities. We present a real options pricing method (ROPM) which can be applied to an energy sector as an alternative. In order to examine the usefulness of ROPM, this study compares the result of DCF method applied to the investment of cogeneration power plant with that based on the ROPM incorporating the value of real of options inherent in the project. The simulation results show that the value of investment opportunities improves using ROPM compared to that with the conventional DCF methods. Therefore, a specific project which appears to be unprofitable from the conventional point of view could be, actually, an economically feasible one based on ROPM method, when properly incorporating the management's flexibilities inherent in the project.

• Journal of the Korea Organic Resources Recycling Association
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• v.24 no.4
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• pp.11-20
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• 2016

Depletion of natural resources and reduction of greenhouse gas emissions are an important issue which we have to solve. The recycling of waste has emerged as a global concern. In Korea, the development of cost-effective treatment and recycling technologies also need to be improved. In this study, we compared and analyzed the cost per unit of treatment and recycling of organic waste, and presented an effective recycling scheme. We investigated the current status of treatment and costs for six types of organic wastes from 80 workplaces, including organic wastewater treatment sludge, processed organic sludge, and plant residues. In addition, environmental costs for greenhouse gas reduction were calculated. It's an economic way that organic waste is composted and used as cement additives. In particular, the economic analysis was done by realistic results of the survey target companies. In conclusion, in order for reliable processing and recycling of organic wastes, wastewater treatment sludge and sewage sludge need to be classified based on hazard characteristics. Finally, technical difficulties need to be further resolved such as odors, leachate, and debris on recycling organic wastes.

• Journal of Climate Change Research
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• v.3 no.4
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• pp.271-280
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• 2012

The study aims to analyze economic viability of Integrated Gasification Combined Cycle, an innovative technology to utilize clean coal effectively and efficiently in the era of energy crisis. The study is conducted to evaluate business value of 300 MW IGCC demonstration plant technology development based on binomial option, in consideration of uncertainty of fuel price. Binomial option is one of the real option valuation methods, which is ideally suited to irreversible decision making under uncertainty. With this analysis, it shows that investment value is higher compared with economic evaluation based on discounted cash flow, since this method can measure quantity. As a result, this study is proved to be economically feasible, which have a positive impact on the next generation of IGCC and the connection with Carbon Capture and Storage.

• The Plant Pathology Journal
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• v.28 no.2
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• pp.137-148
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• 2012

During investigating of shiitake mushroom competitors, 289 isolates of Trichoderma spp. were collected from shiitake mushroom farms in different districts and the Forest Mushroom Research Center of Korea, among which 29 representative strains were selected. Based on the DNA sequences of the rpb2 and tef1 genes and the ITS rDNA, and their morphological characteristics, they were identified as T. atroviride, T. citrinoviride, T. harzianum, T. longibrachiatum, and two undescribed species, Trichoderma spp. 1 and 2, which are considered to be the candidate of new species. Competition tests between Lentinula edodes (Sanjo302) and the Trichoderma species indicated that the six species of Trichoderma were significantly different from each other in terms of their ability to invade the mycelial blocks of shiitake. In both of dual cultures on potato dextrose agar and sawdust media, Trichoderma spp. 1 and 2 strongly invaded the mycelial blocks of shiitake. Our results suggest that the two Trichoderma species may cause potentially serious economic losses in shiitake cultivation of Korea.