• Journal of Environmental Science International
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• v.12 no.4
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• pp.503-510
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• 2003

How to plan the energy system is one of the keys f3r constructing the Environment -Friendly City. for this reason, a great number of surveys for utilizing unused energy have conducted by a planner. In regard to unused energy, the heat from incineration plants classify as a unused energy having high-exergy-energy. From this point of view, It is studied about the plant systems providing heat to district heating & cooling(D.H.C) and producing electric power. It is divided four system models as system I (10K [kgf/cm$^2$) vapor as outlet of boiler, supply far 10K vapor and return to 60$^{\circ}C$ as supply condition of district heating), system II (30 K vapor as outlet of boiler, supply for 5t vapor and return to 60f as supply condition of district heating), system 111 (30 K vapor as outlet of boiler, supply for 85$^{\circ}C$ hot water and return to 60$^{\circ}C$ as supply condition of district heating), system IV (30 K vapor as outlet of boiler, supply for 47$^{\circ}C$ hot water and return to 40t as supply condition of district heating). The results from the upper condition of four system, System II got a proper on economical benefits and system IV calculated as benefiting on energy saving effects, and suggest indifference curve as the total evaluation method of both economical benefits and energy saving.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.13 no.3
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• pp.16-22
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• 2017

It has become important for unutilized energy to be used for air conditioning of building. Economic evaluation on energy system by using treated sewage water as heat source, which is one of unutilized energy, was performed. The floor area of the subject building and the distance between heat source equipment and sewage treatment plant was assumed $30,000m^2$ and 200m. Absorption chiller-heater system was used for comparing to the energy efficient system, and payback period method was applied to carry out economic evaluation. Although the operating cost of this system is reduced compared to general heat source system, the ratio is not meaningful compared to the initial investment cost increase, and payback period was calculated to be about 36.1 years. However, when calculated based on the 2014 rate of electricity and city gas, it will be greatly reduced to 3.1 years. International commodity prices are constantly changing, and therefore national policy on the spread of unutilized energy should be maintained.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.2
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• pp.121-128
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• 2012

Improvement in the energy efficiency has been studied of the desiccant cooling system by applying a vapor compression type heat pump to modify the system into a hybrid system. The cycle simulation was performed and the results were compared between a reference desiccant cooling system composed of a desiccant rotor, a sensible rotor and a regenerative evaporative cooler, and a hybrid desiccant cooling system with the sensible rotor being replaced by a heat pump. Though the electric consumption increases as much as the compressor power consumption, the total cooling capacity increases and the thermal energy input decreases by the addition of the heat pump. Therefore, the total energy efficiency can be improved if the increase in the electric consumption can be compensated with the increase in the cooling capacity and the decrease in the thermal energy input. The results showed that the total energy efficiency is optimized at a certain heat pump capacity. When the heat from the CHP plant is used for the thermal energy input, the energy consumption of the hybrid system is reduced by 20~30% compared with the reference system when the heat pump shares 30~40% of the total cooling capacity.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.12
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• pp.1657-1662
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• 2004

The forage potential of mulberry (Morus alba) was evaluated under Malaysian conditions. The yield and nutrient composition of plant fractions of mulberry (whole plant, leaf and stem fractions) were determined at four harvest stages, namely, 3 (W3), 5 (W5), 7 (W7) and 9 (W9) weeks in a randomized block design. The study was conducted over a 9-month period to assess the persistence of the crop to repeated harvests. Fresh and dry matter (DM) yields of all plant fractions increased significantly (p<0.01) with increasing intervals between harvests, with highest DM yields at W9. The leaf to stem ratio declined significantly (p<0.01) from 5.2 (W3) to 0.9 (W9), indicating predominance of the stem fraction with advancing maturity. The nutritional composition of plant fractions was also significantly influenced (p<0.01) by advancing plant maturity at harvest. Crude protein (CP), ash and the metabolisable energy content of plant fractions declined significantly (p<0.01) from W3 to W9, while there was a corresponding significant increase (p<0.01) in the acid detergent fibre, neutral detergent fibre and acid detergent lignin. From this study it was concluded that the optimum stage to harvest the whole plant is 5 weeks, which is a compromise between yield, nutrient composition (CP and fibre components), and the annual number of cuts, with good crop persistence to repeated harvests. Fresh mulberry whole plant can provide a valuable supplemental source of nutrients to poor quality basal diets.

• Journal of Plant Biotechnology
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• v.32 no.3
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• pp.175-179
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• 2005

To develop a high efficiency plant regeneration system from in vitro cultures of strawberry, cv. Yeobong, petiole and leaf explants were cultured on MS basal medium containing a combination of 0.5 mg/L IBA and 3.2 mg/L kinetin or zeatin or benzyl amino purine (BAP) for 6 weeks, and leaf explants with dark pretreatment for a week ($T_1$), 2 weeks ($T_2$), and 4 weeks ($T_3$) were cultured on medium supplemented with 0.5 mg/L IBA and 3.2 mg/L zeatin under 16 hr photoperiod for 6 weeks. Shoot organogenesis was observed from the greenish calli containing minimal anthocyanin formed at proximal cutting edges of the leaf explant (57%) when cultured adaxial side on the medium, whereas was directly formed from a cutting edges of petiole explant (6.3%). Frequency of callus formation and shoot organogenesis at large size of leaf explant ($1.0{\sim}1.5\;cm^2$) was higher than small size ($0.5{\sim}1.0\;cm^2$), and dark pretreatment significantly improved the frequency of leaf explants that produced calli and shoots. The maximum frequency (87%) for shoot organogenesis was obtained from the leaf explants that transferred to a 16 hr photoperiod condition after the initial 4 weeks dark period. The improved frequency (87%) in comparision with control without dark pretreatment (27%). When the shoots were transferred to 1/2 MS basal medium, formed roots with 20 d of culture. The rooted plants were subsequently transferred to the pots and to the field.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.2
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• pp.151-158
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• 2011

Forty nine accessions of the Sorghum bicolor (L) Moench collected from different agronomical zone of Gangwondo province, Korea were characterized morphologically on field trial. Plant length, stem diameter, tiller number, ear type, ear length, ear width, leaves length, leaves width and leaf color differed significantly in the cultivated accessions. Out of forty nine test accessions, six accessions (12.2%) showed comparatively taller height, measuring more than 300 cm, while, other ten test accessions (20.4%) were measured from 200~300 cm. There were no significant differences in the diameter of stem in the collected test accessions (2~3 cm). Of the total test accession, seven accessions showed leaf length of over 70 cm, and twenty two test accession revealed leaf length between 60-70 cm. Forty nine of the collected test accessions showed narrow and short leaves with white mid vain. These results provided additional information for the breeding programs and conservation of Sorghum bicolor as a bio-energy crop.

• Korean Journal of Soil Science and Fertilizer
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• v.7 no.2
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• pp.113-118
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• 1974

A study was carried out to investigate the effect of application time of fertilizer nitrogen on its rate of uptake and its distribution in rice plant. The rate of applied fertilizer was 100kg/ha, as a single application at transplanting time and four equal split applications of 25kg/ha was applied at transplanting time, 3 weeks after transplanting, 1 week before the primodial initiation stage of growth and at the flag leaf stage of growth, respectively. The ammonium sulfate was labelled with N-15, as 1% atom excess for single application and 4.4% atom excess for split applications. The results are sumarized as follows: 1. The effect of split application of nitrogen on yield was observed. The yield of brown rice of the single application at transplanting time was 3.1 ton/ha and the split application was 3.4 ton/ha. However, without nitrogen the yield was reduced to 1.9 ton/ha. 2. The number of grains per panicle and 1000 grains weight were increased as split application of nitrogen, but for the number of panicles per hill and maturing rate, the single application of nitrogen revealed favorable results. 3. The rate of uptake of applied fertilizer nitrogen showed a tendency that the efficiency of fertilizer nitrogen increased by top dressing. The rate of uptake of applied nitrogen as basal application, first top dressing, second top dressing and third top dressing was 28%, 33% 51% and 63%, respectively. 4. After shooting stage of the growth, nitrogen in straws transfered to grains. The nitrogen applied at flag leaf stage was absorbed by root and easily accumulated in grains rather than straw.

• Journal of Energy Engineering
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• v.26 no.4
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• pp.100-106
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• 2017

The materials of SUS304 and SS400 are adopted for prediction of workpiece temperature variation according to ambient temperature in a reheating furnace. Five thermocouples were installed in a depth direction inside the material, and the ambient temperature was raised to 1200 Celsius degrees. As a result, the material average temperature reached more than 1150 Celsius degrees, and the surface and inside of workpiece locally showed a temperature difference of more than 10K. In order to verify the experimental results, numerical analysis was conducted by applying a thermal model, and the error of numerical simulation compared with the experimental results was within the range of 15K at the average outlet temperature. Also, the error was relatively higher in the SS400 material, which has a larger specific heat change than the SUS304 material. In conclusion, the workpiece temperature in the reheating furnace can be achieved through the atmospheric temperature control, and it is experimentally proved that the material temperature change according to the atmospheric temperature can be estimated within about 3% error range at the outlet position using a thermal model.

• Plant Journal
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• v.10 no.2
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• pp.28-37
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• 2014

Recently, it is considered that environment and energy are critical issues all over the world. In power generation sector in Korea, almost power stations are constructed and operated as cogeneration plants in conformity with this trend. KDHC(Korea District Heating Corporation) goes one step further adopting renewable energy technology like heat pump using wasted heat for energy-saving and environment improvement. This study investigates the performance characteristics by the location of waste heat recovery heat pumps of 5 Gcal/h capacity in 150 MW-class Gwang-gyo cogeneration plant using commercial software 'THERMOFLEX'. Prior to analysis, the simulations are performed with actual operation data, and then the validation of simulations is verified by checking the error within 2%. After verification, the simulations are carried out with 3 locations and the effect on electrical power output and heat output is analyzed. As a result, overall efficiency of cogeneration plant is the highest in the case of heat pump located before DH(District Heating) Heater because of the largest increase of heat output despite of decrease of electrical power output.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2002.11a
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• pp.9-15
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• 2002

PDM(Product Data Management)은 제품정보 및 개발 프로세스를 관리하는데 많은 이점이 있는 도구로써 인식되어 왔으며, 제품 설계, 제작, 건설, 유지, 보수하는데 필요한 많은 양의 데이터 및 정보를 효율적으로 관리할 수 있다. PDM은 일반적으로 EDM(engineering data management), DM(document management), PIM(product information management), TDM(technical data management), TIM(technical information management) 등으로 알려진 기술의 보다 더 일반화된 개념이다.(중략)