• Journal of Photoscience
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• v.8 no.1
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• pp.13-17
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• 2001

Cucumber leaves subjected to light chilling stress exhibit a preferential inactivation of photosystem(PS) I relative to PSII, resulting in the photoinhibition of photosynthesis. In light chilled cucumber leaves, Cu/Zn-Superoxide dismutase(SOD) is regarded as a primary target of the light chilling stress and its inactivation is closely related to the increased production of reactive oxygen species. In the present study, we further explored that inactivation of PSI in cucumber leaves is not a light chilling specific, but general to various oxidative stresses. Oxidative stress in cucumber leaves was induced by treatment of methylviologen(MV), a producer of reactive oxygen species in chloroplasts. MV treatment decreased the maximal photosynthetic O$_2$ evolution, resulting in the photoinhibition of photosynthesis. The photoinhibition of photosynthesis was attributable to the decline in PSI functionality determined in vivo by monitoring absorption changes around 820 nm. In addition, MV treatment inactivated both antioxidant enzymes Cu-Zn-superoxide dismutase and ascorbate peroxidase known sensitive to reactive oxygen species. From these results, we suggest that chloroplast antioxidant enzymes are the primary targets of photooxidative stress, followed by subsequent inactivation of PSI.

• The Microorganisms and Industry
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• v.26 no.1
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• pp.18-30
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• 2000

Three kinds of organic matter such as glucose, oxalic acid, and ethanol were added to the media(N-free or NO$\_$3/-riched) and their effects on the nitrogen fixation of Nostoc pruniforme were measured by manometric technique through the experiments in vivo. 1) The organic matters used in this experiments showed effective results as a role of substrate for the fixation of atmospheric nitrogen. 2) In the nitrogen-free medium treated with the both of flucose nad ethanol, the highest nitrogen uptakes were detected in the treated of low concentrations (glucose ; 0.1%, 0.5%, ethanol : 0.1%, 0.5%). On the contrary, the highest nitrogen uptakes in NO$\_$3/-riched medium were measured at the treated of high concentrations (glucose ; 2%, 1%, ethanol ; 1.5%, 1.0%). 3) The highest nitrogen uptakes in N-free medium treated with oxalic acid were measured at the concentration of 2% and 1%, respectively. In the medium of NO$\_$3/-riched, the nitrogen uptakes were in the opposite directions.

• Journal of Radiation Protection and Research
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• v.12 no.1
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• pp.26-33
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• 1987

An experimental study for an optimum etching of commercialized cellulose nitrate SSNTD, CA 80-15 and LR 115-1 for detecting alpha particles, was carried out. Alt-hough ordinary etching condition of the detectors has been recommended by the producer, a remarkable discrepancy in etching tine was found. The detectors were irradiated with a $0.1{\mu}Ci\;^{241}Am$ alpha source under a known geometrical arrangement. Analysis on the track size as functions of etching time and etchant concentration and comparative examination of theoretically predicted number of tracks per unit area with that recorded on the detectors were made, including a study on the variation of detection efficiency with the effective energy of the incident alpha particles.

• Journal of Veterinary Clinics
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• v.24 no.2
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• pp.142-149
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• 2007

The purpose of this study was to develop a computerized software program to help for reproductive management in dairy cows. The developed software program in the study is compatible with a window 95/98 or XP system. Data in the system were recorded, stored, and processed from two sources: 1) Data downloaded monthly from the database of the Korean Dairy Herd Improvement Association (milk yields, milk somatic cell counts, milk fat, protein, lactose and urea nitrogen content). 2) Data recorded by the farmer or veterinarians by the time (body condition score, heats, inseminations, veterinary diagnosis and treatments). These data indices after processing by computerized dairy management system were presented by numerical or graphical display. The presented data were obtained from three dairy farms with more than 50 milking cows. The presented reports of this program using milk fat, protein, urea nitrogen, and somatic cell counts enabled the dairy producer and veterinarians to monitor the protein-energy balance and feeding management practice, and for distribution of diseases (mastitis, metabolic and reproductive disorder) in individual cows. The presented analytical reports of this program also included herd average of reproductive indices such as day to first insemination, days open, and inseminations per conception. This software program will assist in analysis, interpretation and demonstrate the results of reproductive trials conducted in dairy herds.

• Resources Recycling
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• v.33 no.1
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• pp.3-14
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• 2024

Owing to technological advancements and energy-saving policies, the demand for LED is increasing, leading to rapid industry expansion. Consequently, efficient recycling of accumulated LED waste has become a growing social concern, and current recycling status of LED waste resources and future directions were reviewed. Currently, waste LED recycling is focused on Ga recovery. Therefore, the development of integrated recycling technologies such as pre-treatment and concentration/recovery of high valued materials is necessary. In this study, we investigated the status and recycling technologies of waste LED and presented prospects.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.10
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• pp.704-710
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• 2014

Biomass is considered an alternative energy which can solve an greenhouse gas problem like $CO_2$ which is a major contributor to global warming. The biomass can be converted to various energy sources through thermochemical conversion. In this study, a continuous gasifier was engineered for a wood biomass gasification. The biomass was used a waste wood. The experiments of $CO_2$ gasification were achieved as the gasification temperature, moisture content and input $CO_2$ concentration. The results showed that the yield of producer gas increased with an increasing the gasification temperature. The amount of the light tar increased due to the decomposition of gravimetric tar by the thermal cracking, and the char was confirmed pore development through the SEM analysis. The CO concentration was increased with an increased input $CO_2$ concentration from Boudouard reaction. Through the parametric screening studies, the hydrogen and carbon monoxide concentration were 32.91% and 48.33% at the optimal conditions of this test rig.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.5
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• pp.95-108
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• 2011

Smart Grids are intelligent next generating Electric Power System (EPS) that provide environment-friendliness, high-efficiency, and high-trustworthiness by integrating information and communication technology with electric power technology. Smart grids help to supply power more efficiently and safely than past systems by bilaterally exchanging information between the user and power producer. In addition, it alleviates environmental problems by using renewable energy resources. However, smart grids have many cyber security risks because of the bilateral service, the increase of small and medium-sized energy resources, and the installation of multi-sensors or control devices. These cyber risks can cause critical problems within a national grid through even small errors. Therefore, in order to reduce these risks, it is necessary to establish a cyber security strategy and apply it from the developmental stage to the implementation stage. This thesis analyzes and recommends security strategy in order to resolve the security risks. By applying cyber security strategy to a smart grid, it will provide a stepping-stone to creating a safe and dependable smart grid.

• Microbiology and Biotechnology Letters
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• v.32 no.1
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• pp.52-59
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• 2004

When both fructose and galactose were added to a production medium as carbon sources, the productivity of PAFS (Psedomonas Antifungal Substance) biosynthesized by Pseudomonas aeruginosa was observed to be reduced significantly due to the well-known phenomenon of catabolite repression. In order to overcome this phenomenon by use of fermentation bioprocess, fed-batch cultivation method was examined. In addition, a high producer mutant strain, AP-20 obtained by a rational screening method was tested for its productivity of PAFS in both batch and fed-batch fermentation processes. Notably fed-batch operation showed approximately 4 fold higher PAFS productivity than traditional batch operation process. It was appeared that galactose was utilized principally for the cell growth of Pseudomonas aeruginosa whereas large portion of fructose was used for the biosynthesis of PAFS. Furthermore it was observed that composition and feeding rate of production media should be optimized even in the fed-batch fermentation bioprocess. As an example, very slow feeding of carbon sources gave rather negative effect on the production of PAFS due to significant limitation of carbon and energy sources available for the producer microorganism.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.582-583
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• 2021

As the production of new and renewable energy such as solar and wind power has diversified, microgrid systems that can simultaneously produce and consume have been introduced. . In general, a decrease in electricity prices through solar power is expected in summer, so producer protection is required. In this paper, we propose a transparent and safe gift power transaction system between users using blockchain in a microgrid environment. A futures is simply a contract in which the buyer is obligated to buy electricity or the seller is obliged to sell electricity at a fixed price and a predetermined futures price. This system proposes a futures trading algorithm that searches for futures prices and concludes power transactions with automated operations without user intervention by using a smart contract, a reliable executable code within the blockchain network. If a power producer thinks that the price during the peak production period (Hajj) is likely to decrease during production planning, it sells futures first in the futures market and buys back futures during the peak production period (Haj) to make a profit in the spot market. losses can be compensated. In addition, if there is a risk that the price of electricity will rise when a sales contract is concluded, a broker can compensate for a loss in the spot market by first buying futures in the futures market and liquidating futures when the sales contract is fulfilled.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.584-585
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• 2021

As the production of new and renewable energy such as solar and wind power has diversified, microgrid systems that can simultaneously produce and consume have been introduced. In general, a decrease in electricity prices through solar power is expected in summer, so producer protection is required. In this paper, we propose a transparent and safe gift power transaction system between users using blockchain in a microgrid environment. A futures is simply a contract in which the buyer is obligated to buy electricity or the seller is obliged to sell electricity at a fixed price and a predetermined futures price. This system proposes a futures trading algorithm that searches for futures prices and concludes power transactions with automated operations without user intervention by using a smart contract, a reliable executable code within the blockchain network. If a power producer thinks that the price during the peak production period is likely to decrease during production planning, it sells futures first in the futures market and buys back futures during the peak production period to make a profit in the spot market. losses can be compensated. In addition, if there is a risk that the price of electricity will rise when a sales contract is concluded, a broker can compensate for a loss in the spot market by first buying futures in the futures market and liquidating futures when the sales contract is fulfilled.