• Journal of The Korean Society of Grassland and Forage Science
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• v.25 no.1
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• pp.51-56
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• 2005

The dung beetle species living in grazing pasture in Korea and their life cycle such as characteristics of habitation and hibernation were investigated for five year. Eleven species belonging to five genera of dung beetles were found in the grazing pasture. They started to appear around the middle of April when grazing begins on pasture. Dung booties kept on laying eggs until the beginning of August and maintained their activity until the end of October. They passed the winter as a form of an imago twenty five to thirty centimeters under the ground. Loamy soil and sandy soil containing plenty of humus were prefered as a hibemaculum by them. Five genera of dung beetles. Aprodius spp, Onthophagus spp., Liatongus spp., Copris spp., Scarabaeus spp. were found and observed in s study. Three species of them like Scarabaeus affinis had more an twenty eight millimeter long body, and the body length of five species like Copris tripartitus were between ten and twenty millimeters. Three species of them like Apodius sublimbatus were had the body length of less than ten millimeters. The results of indoor experiments to study propagation power of dung beetle showed that the optimum temperature for propagation of Copris ochus and Copris tripartitus were between twenty and thirty degrees and the lowest temperature for living of dung beetle was eighteen degrees while e highest temperature being thirty five degrees. A light did not effect the propagation power of dung beetles.

• Journal of the Korean Society for Heat Treatment
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• v.6 no.4
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• pp.237-242
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• 1993

The fatigue behaviors of mechanically alloyed Al-4Mg alloys dispersed with either $Al_2O_3$ or $MgAl_2O_4$ oxide particles were investigated. This study maily concerned with the role of coherency of dispersed particles with the matrix on the fatigue behavior of the alloys. The $MgAl_2O_4$ which has a spinel structure with the lattice parameter of exactly the twice of Al showed the habit relation with the matrix. The mechanically alloyed Al-4Mg alloys showed stable stress responses with fatigue cycles from start to failure regadless of strain amplitudes and of existence of dispersoids. The Al-4Mg alloy dispersed with $MgAl_2O_4$ showed not only the better static mechanical properties but also the better low cycle fatigue resistance than that with $Al_2O_3$, i.e., much higher plastic strain energy dissipated to failure, at low strain amplitude. However, this alloy showed inferior fatigue resistance to that dispersed with $Al_2O_3$ or that without dispersion at high strain amplitude. These results imply that $MgAl_2O_4$ may promote lowering the stacking fault energy of the alloy inherited from the coherency with the matrix so that dislocations shuttle back and forth on the same slip plane without cross slipping to other planes during fatigue at low strain amplitude resulting in long fatigue life.

• Transactions of the Korean hydrogen and new energy society
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• v.22 no.1
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• pp.118-127
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• 2011

An IGCC was evaluated as one of the next generation technologies that would be able to substitute for coal-fired power plants. According to "The 4th Basic Plan of Long-term Electricity Supply & Demand" which is developed by the Electricity Business Acts, the first IGCC will be operated at 2015. Like other new and renewable energy such as solar PV, Fuel cell, The IGCC is considered as non-competitive generation technology because it is not maturity technology. Before the commercial operation of an IGCC in our electricity market, its economic feasibility under the Korean electricity market, which is cost-based trading system, is studied to find out institutional support system. The results of feasibility summarized that under the current electricity trading system, if the IGCC is considered like a conventional plant such as nuclear or coal-fired power plants, it will not be expected that its investment will be recouped within life-time. The reason is that the availability of an IGCC will plummet since 2016 when several nuclear and coal-fired power plants will be constructed additionally. To ensure the reasonable return on investment (NPV>0 IRR>Discount rate), the availability of IGCC should be higher than 77%. To do so, the current electricity trading system is amended that the IGCC generator must be considered as renewable generators to set up Price Setting Schedule and it should be considered as pick load generators, not Genco's coal fired-generators, in the Settlement Payment.

• Korean journal of applied entomology
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• v.41 no.4
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• pp.255-261
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• 2002

Tomato russet mite, Aculops lycopersici Massee (Acari. Eriophyidae) was recorded in Korea and their SEM observations, distribution, host range, development on different temperature, and chemical control method were studied. Tomato russet mite is a microscopic animal (134.9 $\mu\textrm{m}$) with 2 pairs of legs which had 4 rays of feathered craw. Infected leaf turn reddish brown, stem loss hair, become shiny or surface cross-cracked, and shoot wilted or shrunk. Surface of fruit around fruit stalk appeared rusted or cross-cracked. It was found in glass greenhouse at Buyeo and Yuseong in Chungnam Province, Pyeongchang in Gangwon Province, and Chilgok and Guryongpo in Gyeongbuk Province. Convolvulus, black nightshade, chinese lanternplant, eggp1ant, morning glory, petunia, potato, pepper, tobacco and tomato were confirmed as a host plant in inoculation test. It could develop at temperature around $15-30^{\circ}C$, it took 6-11 days from eggs to adult, higher temperature shorten its life cycle. Female lived longer than male and it lived as long as 12 days at 25-28"C. Among acaricides tested, fenazaquin and cypermethrin were most effective.tive.

• Animal cells and systems
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• v.16 no.6
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• pp.469-478
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• 2012

Sex hormones have long been considered to play an important role in bone turnover rate, periodontal diseases, and wound healing. We have studied the effect of porcine testis steroid extract (PTSE), an extract of porcine testes, which holds a good ratio of 19-nortestosterone (nandrolone), testosterone, androstenedione, $17{\beta}$-estradiol, and estrone, on the healing rate of a standardized full-thickness linear wound on the back of the rat. Skin punch or carbon dioxide ($CO_2$) laser methods were used to create the deep skin injury in two groups of animals. The animals were treated with the PTSE cream, control cream and Vaseline (control) to find out the effect in re-epithelialization, contraction, and formation of granulation and scar tissues. Histological examination after 21 days showed 100, 87.4, and 80.5% recovery of epidermis, dermis, and hypodermis, respectively in the PTSE-treated animals. Similarly, on the 15th day of treatment, complete healing of intact skin was observed in the PTSE cream-treated animals among the laser radiation group. Even though the beginning of re-epithelialization phase and completion of serum crust formation was also observed in the base cream- and Vaseline-treated animals respectively, the complete healing cycle was observed only in the PTSE-treated group. The white blood cell count in the PTSE-treated group showed that PTSE cream is nontoxic to animals.

• Journal of the Korean Society for Railway
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• v.11 no.3
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• pp.334-341
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• 2008

Ballast track needs maintenance works because it is supported by the compressible trackbed and subgrade layers. Maintenance works are essential to secure riding comfort and extend the life cycle of it. The necessities of maintenance works are determined from track irregularities measured by EM120. Track irregularities is the results of the track deformation. Therefore, it is natural to evaluate the cause of it. This paper focuses on the points the track irregularities come from the trackbed and the subgrade. Nondestructive techniques, such as Ground Penetrating Radar (GPR) and Portable Falling Weight Deflectometer (PFWD) are applied to evaluate the trackbed conditions, ballast layer thickness and vertical track stiffness, in the test section 500m long of Gyungbu line. The trackbed investigation results are compared with the track irregularities measured by EM120 and maintenance works. Conclusively, it was found that some maintenance works were unnecessary on the test section.

• The Transactions of the Korean Institute of Power Electronics
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• v.23 no.2
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• pp.77-85
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• 2018

Renewable energy has been increasingly used and widely acclaimed as one of the solutions to rampant environmental problems. Among numerous kinds of renewable sources, the penetration rate of the PV system is relatively higher than that of others due to ease of installation. However, one disadvantage of the PV system is its dependence on weather condition. The PV system is especially critical when it is used for standalone systems because it cannot operate when the power generated from a PV module is not enough. Therefore, PV systems are often used with an energy storage system, such as batteries, to store backup energy when the weather condition is insufficient to supply power to the system. Blackout time can be reduced by increasing the size of the energy storage system, but it is a trade-off with system cost. In this work, optimal sizing of a standalone PV system is proposed to supply power to the system without blackout. The sizing of PV modules and batteries is performed by a simulation based on actual irradiation data collected during the past five years. The Life cycle costing of each system is evaluated to determine an optimal set of PV modules and batteries among several different combinations. The standalone PV system designed by the proposed method can supply power to the system with no interruption as long as the weather condition is similar to those of the past five years.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.1 no.1
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• pp.19-33
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• 1997

The high oxidants, which occur the daily maximum concentrations in the afternoon, are transported into the other region via long range transport mechanisms or trapped within the shallow mixing boundary layer and then removed physically (deposition, transport by mountain wind, etc.) and chemically (reaction with local sources). Therefore, modeling formation of photochemical oxidants requires a complex description of both chemical and meteorological processes. In this study, as a part of air quality studies, we reviewed various aspects of photochemical modeling on the basis of currently available literature. The result of the review shows that the model is based on a set of coupled continuity equations describing advection, diffusion, transport, deposition, chemistry, emission. Also photochemical oxidant models require a large amount of input data concerned with all aspects of the ozone life cycle. First, emission inventories of hydrocarbon and nitrogen oxides, with appropriate spatial and temporal resolution. Second, chemical and photochemical data allowing the quantitative description of the formation of ozone and other photochemically-generated secondary pollutants. Third, dry deposition mechanisms particularly for ozone, PAN and hydrogen peroxide to account for their removal by absorption on the ground, crops, natural vegetation, man-made and water surfaces. Finally, meteorological data describing the transport of primary pollutants away from their sources and of secondary pollutants towards the sensitive receptors where environmental damage may occur. In order to improve our present study, shortcomings and limitation of existing models are pointed out and verification process through observation is emphasized.

• KIEAE Journal
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• v.14 no.5
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• pp.103-109
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• 2014

Apartment housing should require the systematic maintenance to provide the decent living condition during its life. Each household should participate the maintenance activities and pay for the repair. Therefore, the required cost for repair would be needed to plan in the repair schedule because each household could not pay the much repair money at a time. After apartment constructed, a long term repair plan would be prepared in repair time, repair scope and a required cost. A few studies are said that the repair cost depends on the building deterioration, elapsed year and management factors. The above factors are not be certain to affect the repair management while it may be important to prepare the required money and the repair time. In this paper, it aimed at analyzing the correlation between the repair management and the management factors, especially total area, number of household. This would educe the unit cost per number of household and management area in the individual boiler and elevator with full change and full repair. The unit cost per number of household and area for full change are about 199,000 won/household and $1,954won/m^2$ in the individual boiler respectively. The unit cost of the elevator for full change is 94,000 won/household and $5,429won/m^2$ respectively. Second, this study shows that the elapsed year after construction would not be related the repair unit cost.

• Transactions of the Korean hydrogen and new energy society
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• v.26 no.5
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• pp.416-422
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• 2015

Lithium Ion capacitor (LIC) is a new storage device which combines high power density and high energy density compared to conventional supercapacitors. LIC is capable of storing approximately 5.10 times more energy than conventional EDLCs and also have the benefits of high power and long cycle-life. In this study, LICs are assembled with activated carbon (AC) cathode and pre-doped graphite anode. Cathode material of natural graphite and artificial graphite kinds of MAGE-E3 was selected as the experiment proceeds. Super-P as a conductive agent and PTFE was used as binder, with the graphite: conductive agent: binder of 85: 10: 5 ratio of the negative electrode was prepared. Lithium doping condition of current density of $2mA/cm^2$ to $1mA/cm^2$, and was conducted by varying the doping. Results Analysis of Inductively Coupled Plasma Spectrometer (ICP) was used and a $1mA/cm^2$ current density, $2mA/cm^2$, when more than 1.5% of lithium ions was confirmed that contained. In addition, lithium ion doping to 0.005 V at 10, 20 and $30^{\circ}C$ temperature varying the voltage variation was confirmed, $20^{\circ}C$ cell from the low internal resistance of $4.9{\Omega}$ was confirmed.