• Solar Energy
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• v.16 no.2
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• pp.3-6
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• 1996

태양광선을 전류로 직접 변화시키는 과정(Photo-voltamic)은 가장 근사하게 에너지를 얻어내는 방법중의 하나이다. 그러나, 이러한 태양전류가 미래 에너지의 원천으로서 가치를 갖게 하기 위해서는 새로 개발된 태양전지(Solar Cell)의 가격이 아주 저렴해야 한다. 스위스 대학교의 몇 개의 연구소는 이러한 태양에너지 개발에 대한 기술(Solar Technology)에 있어서 세계에서도 첨단적인 위치에 놓여있다. "고전적이고 재래식 재료가 새옷을 입고 나왔다"고 최근 스위스의 Neuenburg 대학의 Institute of Microtechnic(IMT)에서 개발한 Micromorphe Solar Cell을 두고 얘기하고 있다. 왜냐하면 이 새로 개발된 Solar Cell은 역시 재래에 늘 사용하던 Silicium을 부분적으로 이용하고 있기 때문이다. 그러나, 이 Solar Cell에서는 Silicium을 그냥 사용하지 않고 Thin Film형태로 변형해서 사용하고 있다. 이 Silicium Thin Film은 값이 저렴하면서도 효율적으로 태양전류를 태양광선에서 생산할 수 있게 하는 매우 기대가 큰 재료로 등장하고 있다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.3
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• pp.351-357
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• 1983

To study the relationships between soybean seed yield and meteorological elements, the investigation into the important agronomic characters of Bongeui cultivar and climatic factors such as precipitation, rainy days, and temperature from 1970 to 1981 was made. The results obtained were summarized as follows: 1) Coefficients of variabilities for pod-filling rate, seed yield, number of pods per plant, and seed weight were about 38%, 30%, 30%, and 5.5%, respectively. 2) Weather conditions mainly in July and August influenced soybean production. Particularly, high temperature played an important role in soybean yield reduction. 3) Correlation coefficients between maximum, minimum, or average temperature of July (and, in the case of August, maximum temperature only) and yield or seed weight, and between those of August and podfilling rate were significantly negative. 4) Regression equations between average temperature of July or maximum temperature of August and yield were Y=-42.46X +1200.86 and Y=-37.95X + 1210.42, respectively. 5) High temperature during the flowering stage affected soybean seed yield reduction significantly.

• Korea Petroleum Association Journal
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• no.3 s.181
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• pp.88-107
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• 1996

이 자료는 오는 3월말 특정석유제품수입잠정조치법 폐지를 앞두고 일본경제연구소가 마련한 연구자료중 발췌 전재한 것이다. <편집자 주>

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.1
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• pp.61-68
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• 2021

The application of renewable energies such as wind and solar has become an inevitable choice for many countries in order to achieve the reduction of greenhouse gases and healthy economic development. However, due to the intermittent characteristics of renewable energy, the issue with integrating a larger proportion of renewable energy into the grid becomes more prominent. A complex energy system, usually consists of two or more renewable energy sources used together to provide increased system efficiency as well as greater balance in energy supply. Compared with the power system, control and optimization of the complex energy system become more difficult in terms of modeling, operation, and planning. The main purpose of the complex energy system retrofit for samado island with microgrid system is to coordinate the operation with various distributed energy resources, energy storage systems, and power grids to ensure its reliability, while reducing the operating costs and achieving the optimal economic benefits. This paper suggests the improved complex energy system of samado island with optimal microgrid system. The results of test operation show about 12% lower SOC variation band of ESS, elimination of operation limit in PV and reduction of operation time in diesel generator.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.05a
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• pp.51-52
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• 2019

In the past, waves, which are the main external forces acting on marine and coastal structures, have been dealt with only in terms of safety. Recently, various studies have been conducted to define the characteristics of waves in a specific area in order to respond to the increasing demand for diversified marine activities such as ocean energy development and marine leisure sports. Although the characteristics of waves are specific to the site, the available spectrum model proposed in previous studies are limited. In this study, we analyzed the shape of the ocean wave spectrum by comparing it with the standard spectrum model.

• Journal of Soil and Groundwater Environment
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• v.27 no.6
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• pp.37-46
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• 2022

As the amount of livestock wastewater increases, ammonia contamination in surface water and groundwater is also increasing, and its treatment is urgently needed. In this study, indigenous soil bacteria was utilized for ammonia removal in artificial wastewater and associated removal mechanisms and efficiencies were evaluated. Two batch reactors were configurated to contain natural soil and artificial wastewater at 1:10 mass ratio, and incubated for 84 and 168 hours, respectively. The results showed that ammonia was completely removed within 48 and 72 hours in the first and second reactors, respectively. There were no significant changes in ammonia concentrations in the control groups without soil. Nitrate was formed in the reactors, indicating that the main removal mechanism of ammonia was nitrification by nitrifying bacteria. Nitrate was further converted to nitrogen gas by denitrification in the anaerobic environment, which was caused by consumption of oxygen during the nitrification process.

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.4
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• pp.437-445
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• 2022

This paper presents an experimental study on the main management factors of the condenser contamination such as fouling and corrosion for the R-134a turbo-chiller to save energy, reduce corrosion rates, and reduce maintenance costs through the application of condenser non-cleaning water treatment chemical. The series of experiment is conducted using combining oxidative microbial sterilizers, non-oxidizing microbial sterilizers, and anti-corrosion agents. The leaving temperature difference and corrosion rates for three different combination of chemicals are collected and analyzed. The experimental results show that the cost reduction (4,066,000 Won/year) of the disinfectant (FT-830) can be achieved by adding the oxidative disinfectant (NaOCl) and the non-oxidizing disinfectant (NX-1116). The LTD value is maintained at 1.9℃, and the corrosion rates of copper and carbon steel specimens are 0.07 mpy and 1.61 mpy, respectively.

• Research in Plant Disease
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• v.28 no.4
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• pp.204-208
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• 2022

Hydrogen peroxide is an eco-friendly oxidizing agent, which has exhibited a broad spectrum of antimicrobial activity without adverse environmental impact. This study was conducted to investigate the antifungal effect of hydrogen peroxide treatment against Cylindrocarpon destructans, and consequently to evaluate its control efficacy against root rot disease of 2-year-old ginseng plants. Hydrogen peroxide treatment strongly inhibited the viability of C. destructans conidia in vitro. The hydrogen peroxide at a concentration of 300 mg/l significantly reduced disease infection of the ginseng root when treated to spore suspension (10⁷ conidia/ml). Spraying with 300 mg/l of hydrogen peroxide reduced the root rot disease of the ginseng sprouts by 15% compared to the untreated control at 14 days after the inoculation. However, 300 mg/l of hydrogen peroxide delayed the emergence of ginseng plants during sprouting under aeroponic conditions. Further works need to be done to provide an acceptable control efficacy of hydrogen peroxide against the disease and its good safety to ginseng plants.

• 해운
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• s.81
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• pp.11-16
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• 2011

2011년 1분기에는 예기치 못한 일본 대지진과 중동사태 등으로 세계경제는 큰 타격을 입었으며 그로 인해 신재생 에너지 개발과 에너지 효율적인 경제구조 확립, 부품 소재 산업의 경쟁력 강화와 공급처 다변화의 중요성이 대두되었다. 이에 따라 한국 경제는 그 전략을 점진적으로 세워야 한다는 지적이 나왔다. 그러므로 우리는 이 시점에서 세계경제를 분석하고 한국 경제의 중장기적인 계획을 세워 보아야 할 필요가 있다. 다음은 삼성경제연구소에서 발표한 "2011년 세계경제 및 한국경제 전망"의 주요 내용을 정리 요약한 것이다.

• Korean Journal of Poultry Science
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• v.50 no.3
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• pp.119-124
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• 2023

This study was conducted to investigate the effect of dietary levels of the metabolic energy (ME) on performance, egg quality, and hatchability of Woorimatdag breeder hens during late laying period. A total of eighty Woorimatdag breeder hens were individually housed in cages from 48 to 64 weeks of age. The hens were assigned to two groups with different dietary ME levels: 2,500 kcal/kg and 2,700 kcal/kg. Each group consisted of four replicates of ten birds. The results indicated that the dietary ME levels did not have a significant effect on the body weight and feed intake of the breeder hens. The egg production was significantly (P<0.05) higher in breeder hens fed 2,500 kcal/kg ME than in those fed 2,700 kcal/kg ME from 48 to 52 weeks of age. However, the egg production was shown to be similar values in both groups from 52 to 64 weeks of age. No significant differences were observed between groups with respect to egg weight, eggshell thickness, and eggshell strength of breeder's eggs. There was no difference in the fertility and hatchability between dietary groups. In conclusion, 2,500 kcal/kg of dietary ME could be considered to meet Woorimatdag breeder hens requirement sufficiently during late laying period.