• Journal of Energy Engineering
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• v.28 no.3
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• pp.65-79
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• 2019

The study attempted to estimate the optimal facility capacity by combining renewable energy sources that can be connected with gas CHP in industrial complexes. In particular, we reviewed industrial complexes subject to energy use plan from 2013 to 2016. Although the regional designation was excluded, Sejong industrial complex, which has a fuel usage of 38 thousand TOE annually and a high heat density of $92.6Gcal/km^2{\cdot}h$, was selected for research. And we analyzed the optimal operation model of CHP Hybrid System linking fuel cell and photovoltaic power generation using HOMER Pro, a renewable energy hybrid system economic analysis program. In addition, in order to improve the reliability of the research by analyzing not only the heat demand but also the heat demand patterns for the dominant sectors in the thermal energy, the main supply energy source of CHP, the economic benefits were added to compare the relative benefits. As a result, the total indirect heat demand of Sejong industrial complex under construction was 378,282 Gcal per year, of which paper industry accounted for 77.7%, which is 293,754 Gcal per year. For the entire industrial complex indirect heat demand, a single CHP has an optimal capacity of 30,000 kW. In this case, CHP shares 275,707 Gcal and 72.8% of heat production, while peak load boiler PLB shares 103,240 Gcal and 27.2%. In the CHP, fuel cell, and photovoltaic combinations, the optimum capacity is 30,000 kW, 5,000 kW, and 1,980 kW, respectively. At this time, CHP shared 275,940 Gcal, 72.8%, fuel cell 12,390 Gcal, 3.3%, and PLB 90,620 Gcal, 23.9%. The CHP capacity was not reduced because an uneconomical alternative was found that required excessive operation of the PLB for insufficient heat production resulting from the CHP capacity reduction. On the other hand, in terms of indirect heat demand for the paper industry, which is the dominant industry, the optimal capacity of CHP, fuel cell, and photovoltaic combination is 25,000 kW, 5,000 kW, and 2,000 kW. The heat production was analyzed to be CHP 225,053 Gcal, 76.5%, fuel cell 11,215 Gcal, 3.8%, PLB 58,012 Gcal, 19.7%. However, the economic analysis results of the current electricity market and gas market confirm that the return on investment is impossible. However, we confirmed that the CHP Hybrid System, which combines CHP, fuel cell, and solar power, can improve management conditions of about KRW 9.3 billion annually for a single CHP system.

• Korean Journal of Environmental Agriculture
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• v.19 no.3
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• pp.206-212
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• 2000

The effects of two phosphorus sources (fused phosphate and rock phosphate), applied at different rates, on growth, arbuscular-mycorrhizae(AM) formation in roots and nutrient contents of trifoliate orange grown in an uncultivated volcanic ash soil were investigated in a greenhouse. The seedlings were either inoculated with AM fungi or left uninnoculated. Growth of seedlings were best in the treatments of 156-272 mg P/kg with fused phosphate. Although the applied P in the rack phosphate treatments were nearly same or much higher comparing to the fused phosphate treatments, seedling growth were significantly less. Soil available P in the treatment of 272 mg P/kg of fused phosphate was maintained in the range of 3-5 mg/kg during the experiment, and the AM formation was about 60% in average. In the treatments of lower rates of fused phosphate application or of rock phosphate application, soil available P were lower than 3 mg P/kg and AM formations were less than 30%. Significant increases were found in seedling growth and nutrient absorption due to AM fungi inoculation, and the effects were much more significant in the treatments of higher AM formation. In most of citrus groves in Cheju island, soil available P is much higher than 200 mg P/kg, and average AM formation in citrus roots is less than 30%. Results obtained in this study show that the formation of AM can be increased at much lower level of available P than the present levels found in citrus groves.

• Journal of the Korea Organic Resources Recycling Association
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• v.18 no.1
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• pp.47-56
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• 2010

At present, 265 national food waste recycling facilities have been operated by public facilities 95 and private facilities 160. it has continuously installed a food waste treatment facility from 1997. The government set up and implemented guidelines and inspection standards for the installation and operation of the facilities. However, unclear detailed examination items, designs and process standards for the installation procedures of the facilities are causing problems due to the unskilled operation management system, decrease in efficiency and defects of a facility. This study conducted mail and site surveys on 95 public food waste recycling facilities that it suggest the ways to operate facilities which minimize problems. At the result of investigation, a pre-treatment facility was not installed 2 systems(2 inputting facilities) and hopper covers and food was overloaded. also the transportation amount was excessive. In case of a main treatment facility, the secondary environmental pollution was caused by inexperienced operation and the efficiency of the facility was reduced due to excessive input of food. also the operation management standards of the facilities were inappropriate. The odor and food waste leachate treatment facility is investigated as problems that are unskilled operation, lack of regular inspection and inappropriate capacity of the treatment facility. Based on the problems found through the investigation, it suggested some ways of efficient operation. this study might contribute to minimize mistakes and defects and improve the efficiency of install and operation course of food waste recycling facilities through finding.

• Journal of the Korea Organic Resources Recycling Association
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• v.28 no.3
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• pp.37-44
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• 2020

The Project supporting organic fertilizer started in 1999 as a national policy. In farmhouse, over application of mixed organic compound fertilizer(OC) caused salt accumulation in plastic film house soil. To replace inorganic fertilizer with OC fertilizer, this study was investigated the effect of OC application on yield and soil chemical properties for lettuce cultivation in plastic film house. The OC fertilizer was applied at 50(OC50+N50), 100(OC100), and 150(OC150) % level of the basal amount of nitrogen fertilizer in soil testing recommendation. And these were compared to NPK(nitrogen, phosphat, and potash fertilizer) and PK treatment. The yield of lettuce in OC100 was similar to that of NPK treatment. In OC 50, 100 and 150 treatments, pH had a tendency to increase than that of NPK treatment. Nitrate nitrogen(NO₃-N) and electrical conductivity(EC) were similar to NPK treatment. These showed that nutrients from OC fertilizer were less likely to accumulate in soil than NPK. Also, use efficiency of nitrogen in OC100 treatment were similar to NPK treatment. These results suggest that OC application as the basal dressing at the 100% level could be best to prevent a nutrient accumulation of soil and to increase the yield and commercial quality for lettuce.

• Applied Biological Chemistry
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• v.41 no.6
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• pp.457-464
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• 1998

For investigating the effect of amount of applied fertilizer with pig and chicken manures in the field, the number of soil bacteria were counted on the full strength conventional nutrient broth (NB) medium and its 100-fold dilution (DNB) medium. From the control soil samples without organic amendments, the number of bacteria on DNB medium was 5 to 10 times higher than that on NB medium. However, population density on NB medium was higher than on DNB medium from the treated soil with 60 and 120 Mg/㏊ for 3 years. Most of isolates from DNB plates did not grow on the NB plates. There were only grown on the 100-fold dilution medium, so it was called as DNB organisms. The DNB organisms were occupied as dominant group over 60% fo isolates in control soil. However, their occupation rates were rapidly decreased in the treatment soil with pig and chicken manures above 60 and 120 Mg per ha. These DNB organisms (oligotrophs) were significantly low population desities in the treatment soil with organic materials.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.3 no.1 s.4
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• pp.53-65
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• 2004

A series of accidents, which are non-recurrent and non-anticipated, are called incidents. These incidents make standard traffic flows interrupt, which result in the decrease of road capacity and a number of social and economic costs, such as the traffic congestion and air pollution. In order to prevent the hazard of incidents, domestic and foreign traffic management center are likely to opt auto-sense system with algorithms of auto-incident sense. However, it is evaluated that the algorithms have a low function with frequent wrong alarms, even if they accurately ry to speculate the incidents. In the case of bottleneck which has lack of road capacity, compared with other roads, due to inefficient road structured over-capacity of the demand of on-off ramp, the incidents regularly take place. Nonetheless, it can be more difficult to speculate the auto-incidents sense owing to similar incidents, such as the queue of in-out flows of cars and the change of road line. Throughout this research, the function of the model has improved excluding near road line in the module of the incidents which is based on the auto-incidents algorithms during the sense of the congestion of ramp areas.

• Korean Journal of Environmental Agriculture
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• v.24 no.4
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• pp.358-363
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• 2005

A large amount of oyster-shell waste has been illegally disposed at oyster farm sites along the southern coast of Korea, which already created serious environmental problems. Therefore, the study was undertaken to increase the consumption of oyster shell meal as a soil amendment. The effects of oyster shell meal on dynamics of heavy metals and uptake of heavy metals by spring Chinese cabbage were evaluated in silt loam soil (in Gyeongsang National University, Jinju, Gyeongnam-do, Korea), where 0, 4, 8, 12 and 16 Mg $ha^{-1}$ oyster-shell meal fertilizer were added. Lime treatment (2 Mg $ha^{-1}$) was selected as a control. In the results of this study, cabbage yields were increased by increasing levels of oyster-shell meal fertilizer. With increasing levels of oyster-shell meal fertilizer, total heavy metals concentrations were not significant among treatments. However, 0.1N HCl extractable heavy metals concentration was significantly reduced due to increasing of soil pH. A lot of portion (ca. $80{\sim}90%$) heavy metals fraction of all fractions was residual phase in soil after harvesting. The contents of Cu, Mo, Zn in cabbage were slightly increased by increasing levels of oyster shell meal fertilizer. However, there were no toxic symptoms of heavy metals during cultivation. Conclusively, it was estimated that oyster shell fertilizer could be a good amendment to increase productivity of crop and reduce uptake of heavy metals by crop and mobility of heavy metals in soil.

• Korean Journal of Environmental Agriculture
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• v.25 no.4
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• pp.339-345
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• 2006

Accumulation of nitrate in green vegetables is undesirable due to potential risks to human health. Lettuce was cultivated in pots under greenhouse conditions with compost applications of 2,000 and 4,000 kg/10a, and the growth and nitrate accumulation of lettuce were compared with those found in the lettuce cultivated with chemical fertilizers of recommended levels. Content of $NH_4-N$ in the soils of compost applications were much lower than those found in the soil of chemical fertilizer application. Two weeks after lettuce transplant $NH_4-N$ was not found in the soils of compost applications, and in the soils of chemical fertilizers application $NH_4-N$ was not found three weeks after lettuce transplant. One week after lettuce transplant content of $NO_3-N$ was much higher in the soils of compost applications, and the contents were rapidly decreased. While, the content of $NO_3-N$ in the soil of chemical fertilizers application was rapidly increased due to the nitrification of $NH_4$ released from the applied urea. At the time of harvest contents of $NO_3-N$ in the soils of compost applications were less than 1.4 mg/kg, but in the soil of chemical fertilizers application the content of $NO_3-N$ was 54.2 mg/kg. Contents of $NH_4$ in lettuce were about 20 mg/kg FW and were not much different among the treatments. However, contents of $NO_3$ in lettuce were significantly different between the treatments of chemical fertilizer and compost. There were significant differences in fresh and dry weights, and growth of lettuce in the compost treatment of 4,000 kg/10a was highest among the treatments. These results indicate that the cultivation with compost only as N source can produce higher yield of lettuce and significantly reduce nitrate accumulation as compared to the conventional cultivation with chemical fertilizers.

• Journal of Navigation and Port Research
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• v.28 no.3
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• pp.269-276
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• 2004

The reclaimed land has peculiar characteristic of nature environment unlike midtown or inland and also, in comparison with inland, has bad weather condition, such as low temperature, strong wind, excessive sunshine, and moisture involved in a salt. Therefore the case of developing water front needs understanding characteristic of weather environment mused by reclamation in detail and proper development and organized maintenance. If development which doesn't investigate topographic and climate characteristic sufficiently is drove ahead, a rise of expense for energy and maintenance is going to be mused by deteriorating weather environmental, occurring a flaw of facility and calculating inaccurate capacity of facility. We looked into the weather state and drew up the standard weather data of the newport area in Busan which is reclaiming and developing now. In this research at the base qf the standard weather data, we calculate the dynamic peak loads for commerce, business and residence and then we utilize the results of the load calculation as basic information to determine facility capacity in the rear city of the newport area.

• Clinical and Experimental Pediatrics
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• v.52 no.1
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• pp.111-118
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• 2009

Puopose : Exposure to dietary phytoestrogens such as genistein during early childhood is a growing public health concern. We examined the effect of early exposure to genistein on sexual maturation in immature rats. Methods : Weaning (3wk-old) Sprague-Dawley female rats were assigned to three groups (n=6 for each): fed by high dose of genistein (100 mg/kg/d), low dose of genistein (10 mg/kg/d) and control group. First vaginal opening (VO) day was observed. Structural alterations in the ovary and uterus were assessed by histologically. Expression of genes of $ER{\alpha}$, $ER{\beta}$, and progesterone receptor (PR) in the ovary and uterus were investigated by RT-PCR. Results : High genistein group had earlier VO than control and low genistein group. Graafian follicles and corpora lutea were observed from the ovary of genistein-treated groups, while primary, secondary follicles and small atretic follicles were observed in the control group. Hypertrophy of luminal and glandular uterine epithelia were found in the genistein-treated groups while poor development of gland and fewer myometrial cell layers were evident in control group. In ovary, the transcriptional activities of $ER{\alpha}$ and $ER{\beta}$ were higher in high genistein group than in controls. In uterus, the transcriptional activities of $ER{\alpha}$, $ER{\beta}$ and PR were higher in low genistein group than in controls. Conclusion : Acute exposure to genistein during the prepubertal period could activate the reproductive endocrine system resulting in the early onset of puberty in female rats. Further clinical investigation on the effect of genistein on the sexual maturation in children is warranted.