• Journal of Bio-Environment Control
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• v.6 no.2
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• pp.103-109
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• 1997

This experiment was conducted to investigate the effects of root zone warming on rhizosphere temperature of Oriental melon (Cucumis melo L. var. Makuwa) in winter season. Root zone was warmed by hot water flowing through pipe set at 35cm depth from the ridge. Treatments of minimum soil temperature at 20cm depth were 17, 21, $25^{\circ}C$, and non-warmed from Jan. 18 to Apr. 18. The results are summarized as follows. 1. The cumulative soil temperature for 1 month after planting oriental melon was 441, 558, 648, and 735$^{\circ}C$ at control, 17, 21, and $25^{\circ}C$ plot, respectively. 2. As soil temperature was higher, air temperature in tunnel was higher. The lowest temperature in control plot at night was 9.5$^{\circ}C$, 11.$0^{\circ}C$ in 17$^{\circ}C$ plot, 13.5$^{\circ}C$ in 21$^{\circ}C$ plot, and 16.5$^{\circ}C$ in $25^{\circ}C$ plot, respectively. 3. The xylem exudate amount of control plot for 24 hours just after basal stem abscission was 8.1$m\ell$. It was 1.2 times higher in 17$^{\circ}C$ plot, 1.3 times higher in 21 $^{\circ}C$ plot, and 4.8 times higher in $25^{\circ}C$ plot than in control plot at 30 days after planting. The xylem exudate amount at 67 days after planting of control plot was 10.4$m\ell$, those of 17, 21, $25^{\circ}C$ plots were 1.1, 3.2, and 3.3 times as compared to control plot. 4, Early growth in leaf length, stem diameter, leaf number and leaf area for 30 days after planting were better in higher temperature plots than in control plot. Particularly, the increase of leaf area was striking in higher temperature plots. Leaf area of control plot was 279.5$\textrm{cm}^2$ for 30 days after planting, 153.4% in 17$^{\circ}C$ plot, 745.6% in 21$^{\circ}C$ plot and 879.4% in $25^{\circ}C$ plot were increased as compared to in control plot.

• Journal of Energy Engineering
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• v.18 no.4
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• pp.221-229
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• 2009

This study develops the optimized operation program which enables effective and economic operation between individual and connected branch offices by analyzing the current status and influential indicators of district heating companies' capital branch offices. Accordingly, the study examines the efficiency of optimized operation program. In doing so, this study has diagnosed and analyzed various factors, such as boilers, pumps, and relevant tags (temperature, pressure, fuel amount) through investigation of individual branch offices, and finally succeeded in developing wide-ranging data base by factor covering one-year time period. Additionally, after running the optimized operation program, different branch offices, optimum preference has turned out "incinerator receiving heat from KEPCO>CHP >PLBs>PLBw." Meantime, except the connected offices, there has been no big difference between actual and optimum operation program in branch offices. Meanwhile, the integrated optimum operation program has made it possible the most optimal result only via the connecting supply and demand heat without changing received Heat from KEPCO which is the same as total productive heat. The result has showed that the reduction percentage per day is 2.45~6.80%, and the reduction cost per day is 22,727~60,077 thousand won given the randomly selected sample days. In particular, winter time shows the highest demand with the largest reduction cost whereas summer time illustrates the lowest demand with the smallest reduction cost. Given this result, reduction cost per year compared to actual heat production cost for one year theoretically would be 84 hundred million won. Also, the economic effect showed that the reduction cost percentage per year is more than 2.74% on heat production cost per year for all capital branch offices.

• Journal of Bio-Environment Control
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• v.6 no.2
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• pp.110-116
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• 1997

This experiment was conducted to investigate the effects of root zone warming on fruit yield of oriental melon (Cucumis melo L. var. Makuwa) in winter season. Root zone was warmed by hot water flowing through pipe set at 35cm depth from the ridge. Treatments of minimum soil temperature at 20cm depth were 17, 21, $25^{\circ}C$ and non-warming from Jan. 18 to Apr. 18. The results are summarized as follows. 1. The blooming of female flower was faster 1 days in 17$^{\circ}C$ plot, 6 days in 21$^{\circ}C$ plot, and 7 days in $25^{\circ}C$ plot than in control plot and the days from blooming to harvesting were shorter 5 days in 17$^{\circ}C$ plot, 11 days in 21$^{\circ}C$ plot, and 12 days in $25^{\circ}C$ plot than in control plot. 2. Mean fruit weight was the highest in 21$^{\circ}C$ plot, followed $25^{\circ}C$, 17$^{\circ}C$ and control plots, respectively, and flesh thickness was the highest in $25^{\circ}C$ plot, followed by 21, 17$^{\circ}C$ and control plots, respectively. 3. Early and middle-phase yield was the highest in $25^{\circ}C$ plot, followed by 21$^{\circ}C$, 17$^{\circ}C$ and control plots but late yield was the highest in 17$^{\circ}C$ plot, followed by control, 21, and $25^{\circ}C$ plots. Total yield per 10a was higher 33% in 17$^{\circ}C$ plot, 49% in 21$^{\circ}C$ plot, and 37a in $25^{\circ}C$ plots than in control plot, harvested 1, 490kg per 10a. 4. Total yield was highest in 21$^{\circ}C$ plot, followed by $25^{\circ}C$, 17$^{\circ}C$, and control plots. Malformed and fermented fruit rates were the highest in control, followed by 17, 25, and 21$^{\circ}C$ plots and marketable fruit rate was 21, 25, 17$^{\circ}C$, and control plot in order.

• Journal of Bio-Environment Control
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• v.27 no.3
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• pp.253-259
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• 2018

This study set out to select a system to realize an optimal environment for strawberry cultivation greenhouses based on data about the growth and development of strawberry and its environment and to provide basic data for the research of its improved productivity. For these purposes, the investigator conducted a field survey with greenhouses for strawberry cultivation in western Gyeongnam. The findings show that farmers in their fifties and sixties accounted for the biggest part in the age groups of strawberry farmers. While those who were under 50 were accounted for approximately 67.5%, those who were 60 or older accounted for 32.5%. As for cultivation experiences, the majority of the farmers had ten years of cultivation experiences or less with some having 30 years of cultivation experiences or more. All the farmers built an arch type single span greenhouse. Those who used nutrient solutions were about 75.0%, being more than those who used soil. All of the farmers that used a nutrient solution adopted an elevated hydroponic system. The single span greenhouses were in the range of 7.5~8.5m, 1.3~1.8m and 2.5~3.5m for width, eaves, and ridge height, respectively, regardless of survey areas. The rafters interval was about 0.7~0.8m. In elevated hydroponic cultivation, the width, height, and interval of the beds were about 0.25m, 1.2m and 1.0m, respectively. As for the strawberry varieties, the domestic ones accounted for approximately 97.5% with Seolhyang being the most favorite one at about 65.0%. As for the internal environment factors of greenhouses, 38 farmers measured only temperature and relatively humidity. As for hydroponics, the farmers used a hydroponics control system. Except for the farmers that introduced a smart farm system for temperature and humidity control, approximately 85.0% controlled temperature and humidity only with a control panel for side windows and ventilation fans. As for heating and heat insulation, all of the farmers were using water curtains with many farmers using an oil or electric boiler, radiating lamp or non-woven fabric, as well, when necessary.

• 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.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.975-984
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• 2018

Fast pyrolysis bio-oil has unfavorable properties that restrict its use in many applications. Among the main issues are high acidity, instability, and water and oxygen content, which give rise to corrosiveness, polymerization during storage, and a low heating value. Esterification and azeotropic water removal can improve all of these properties. A 500 g of Quercus mongollica which grounded 0.8~1.4 mm was processed into bio-oil via fast pyrolysis for 2 seconds at $550^{\circ}C$. The esterification consists of treating pyrolysis oil with a high boiling alcohol like n-butanol at $70^{\circ}C$ under reduced pressure (100 hPa). All products are analyzed for water mass fraction, viscosity, higher heating value, pH, FT-IR and GC/MS. The water mass fraction can be reduced by 91.4 % (from 31.5 % to below 2.7 %), the viscosity by 65.8 % (from 36.5 to 12.5 cP) and the higher heating value can be increased by 96.8 % (from 3,918 to 7,712 kcal/kg), the pH by 1.3 (from 2.7 to 4.0). FT-IR and GC/MS analysis indicated that labile acids, aldehydes, ketones and lower alcohols were transformed to stable target products. Using this approach, the water content of the pyrolysis oil is reduced significantly. These improvements should allow the utilization of upgraded pyrolysis liquids in standard boilers and as fuel in CHP (Combined heat and power) plants.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.985-994
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• 2018

Bio-heavy oil for power generation is a product made by mixing animal fat, vegetable oil and fatty acid methyl ester or its residues and is being used as steam heavy fuel(B-C) for power generation in Korea. However, if the fuel supply system of the fuel pump, the flow pump, the injector, etc., which is transferred to the boiler of the generator due to the composition of the raw material of the bio-heavy oi, causes abrasive wear, it can cause serious damage. Therefore, this study evaluates the fuel characteristics and lubricity properties of various raw materials of bio-heavy oil for power generation, and suggests fuel composition of biofuel for power generation to reduce frictional wear of generator. The average value of lubricity (HFRR abrasion) for bio-heavy oil feedstocks for power generation is $137{\mu}m$, and it varies from $60{\mu}m$ to $214{\mu}m$ depending on the raw materials. The order of lubricity is Oleo pitch> BD pitch> CNSL> Animal fat> RBDPO> PAO> Dark oil> Food waste oil. The average lubricity for the five bio-heavy oil samples is $151{\mu}m$ and the distribution is $101{\mu}m$ to $185{\mu}m$. The order of lubricity is Fuel 1> Fuel 3> Fuel 4> Fuel 2> Fuel 5. Bio-heavy oil samples (average $151{\mu}m$) show lower lubricity than heavy oil C ($128{\mu}m$). It is believed that bio-heavy oil for power generation is composed of fatty acid material, which is lower in paraffin and aromatics content than heavy oil(B-C) and has a low viscosity and high acid value, resulting in inhibition of the formation of lubricating film by acidic component. Therefore, in order to reduce friction and abrasion, it is expected to increase the lubrication of fuel when it contains more than 60% Oleo pitch and BD pitch as raw materials of bio-heavy oil for power generation.

• Journal of the Korean Society of Urban Environment
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• v.18 no.4
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• pp.485-494
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• 2018

This study aims to identify the characteristics of oxidation and chemical composition of PM in winter season, 2017 at Incheon area. The mean concentration of air pollutants were $46{\pm}22{\mu}g/m^3-PM_{10}$, $29{\pm}18{\mu}g/m^3/-PM_{2.5}$, $5{\pm}3ppb-SO_2$, $0.56{\pm}0.24ppm-CO$, $21{\pm}13ppb-O_3$ and $28{\pm}17ppb-NO_2$, respectively. The dominant ion of the $PM_{1.0}$ chemical component were organic with $3.2{\mu}g/m^3$ and nitrate with $1.9{\mu}g/m^3$. The day and night variation of the $PM_{1.0}$ chemical components was higher in nighttime than those of daytime. The averaged nitrate oxidation rate (SOR) was 0.06 and sulfate oxidation rate was 0.11 during the field campaign. In the high mass loading period, nitrate oxidation rate (NOR) was up to 0.6 and also the nitrate in $PM_{1.0}$ was increased. The averaged ratio of $NO_x/SO_2$ was 8.7 and nitrate/sulfate was 3.1, respectively. In this results, the nitrate component in $PM_{1.0}$ was influenced by NOx from the stationary source as power plant and the mobile source around the measurement site.

• Journal of Korean Society of Forest Science
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• v.41 no.1
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• pp.7-18
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• 1979

Almonds are one of the oldest sources of food and oil for man as used the ice cream, candy, roast, salting, chocolate, breads, backed, cookies, and flavoring ect. So, we wish to plant Almond in our country at the most parts of mountains. In this purpose we must be find out of both root stock of more compatibility and new techniques of grafting was rather simples as compared with the many steps of machinary involved today. This investigation has been carried out to reveral compatibility and practical controls of environment effectives involved in the occurence of each difference combination results in interspecific grafting of Almonds on the root stock of Prunus mandshurica and Prunus persica as materials during the 9 months period from March to November in 1978. With these selected scions were 4 varieties of Almond employing as the Hal1's hardy, Nonpareil, and Thompson grafted in the polyethylene green house with almost identical provision made for effective controls of automatical supplying to heating and mistsprayers as the $22{\sim}25^{\circ}C$ of temperature and 70~90% humidity. Following results have been obtained. Those environmental controls were more effective and practical to grafting unions and success by means veneer-grafting at the green house. 1. Hall's hardy Almond grafted on the root stock of Prunus persica was more compatibility than Prunus mandshurica. 2. The survival percentages as follows of the 95.33% of Hall's hardy/Prunus persica and 92.66% of Hall's hardy/Prunus mandshurica. And those were no significant between root stock of both species. 3. The 3 varieties of sweet Almond grafted on the root stock of P. mandshurica. And those were no significant between root stock of both species. 4. And the survival percentages as fellows. Thompson 92.66%, Nonpareil 90.66% and Kapareil 89.33% those grafted on the root stock of Prunus persica. 5. And then the survival percentage of interspecific grafts on the root Prunus mandshurica as follows of the materials of Thompson 89.66%, Nonpareil 87%, Kapareil 85%. 6. The analysis of variance were no significant among the interactions between 3 varieties Almond and 2 species of root stock plants. 7. And the growth of interspecific grafts of the high 161cm, diameter 12.3mm and length of roots 21.5cm growth as the Hall's hardy Almond grafted on the root stock of Prunus persica. 8. The root stock plants of Prunus mandshurica more effected to 6~8 days early developed leafing of scions and dark green colour than the Prunus persica. 9. The identical provision of automatic systems was more effective to graft unions and grafting process. 10. The veneer-grafting method at the green house was more effective and practical method for the mass production of Almond grafts.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.9
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• pp.1447-1456
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• 2014

The purpose of this study was to compare perception of school foodservice facilities and utilities in dietitians and school nutrition teachers in the Gyeongnam area between schools that improved foodservice facilities and utilities versus those who did not. From July 23 to Aug 31, 2012, 391 questionnaires were distributed, and 289 questionnaires were obtained. A total of 275 questionnaires were used for the final analysis, excluding improper ones. The results of this study were as follows. First, among 275 schools, 90 schools (32.7%) improved school foodservice facilities and utilities while 175 schools (67.3%) did not. Second, schools with improved facilities had a more well-equipped receiving room (P<0.01), preparation room (P<0.001), dishwashing room (P<0.001), storage room for supplies (P<0.001), rest-room for school foodservice employees (P<0.05), locker room (P<0.01), shower room (P<0.001), laundry room (P<0.001), boiler room (P<0.05), and room for serving cart (P<0.05) than schools with no improvement. Third, total perception score of school foodservice facilities area from schools with improved facilities (1.71) was significantly higher than that (1.60) of school without improvement (P<0.001). Fourth, total satisfaction (3.32) of school foodservice facilities and utilities in school with improved facilities was significantly higher than that (2.62) of schools without improvement (P<0.01). Fifth, schools with improved facilities had a better equipped of floor (P<0.05), entrance (P<0.001), drain (P<0.001), water supply (P<0.01), lighting (P<0.001), hand washing (P<0.001), foodservice management room (P<0.001), locker room (P<0.001), rest-room and shower room (P<0.001), and preparation room (P<0.001) than schools without improvement. However, there was no significant difference in terms of walls and ceilings, windows, ventilation, and storage. In conclusion, school foodservice facilities and utilities improvement should conducted as soon as possible.